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1

Using cavitation to measure statistics of low-pressure events in large-Reynolds-number turbulence  

E-Print Network [OSTI]

Using cavitation to measure statistics of low-pressure events in large-Reynolds-number turbulence A is studied using cavitation. The flow is seeded with microscopic gas bubbles and the hydrostatic pressure is reduced until large negative pressure fluctuations trigger cavitation. Cavitation is detected via light

La Porta, Arthur

2

Carderock Large Cavitation Tunnel | 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 Center Home Page on Office of InspectorConcentrating SolarElectricEnergyCTBarreis aCallahan DivideCannonCirculating Water Channel Jump

3

Prediction of Small-Scale Cavitation in a High Speed Flow Over an Open Cavity Using Large Eddy  

E-Print Network [OSTI]

Prediction of Small-Scale Cavitation in a High Speed Flow Over an Open Cavity Using Large Eddy- gether with the cavitation models predict that inception occurs near the trailing edge similar in cavitation. 1 INTRODUCTION The problem of cavitation has been widely studied owing to its influence

Apte, Sourabh V.

4

Implicit Large Eddy Simulation of Cavitation in Micro Channel Flows  

E-Print Network [OSTI]

We present a numerical method for Large Eddy Simulations (LES) of compressible two-phase flows. The method is validated for the flow in a micro channel with a step-like restriction. This setup is representative for typical cavitating multi-phase flows in fuel injectors and follows an experimental study of Iben et al., 2010. While a diesel-like test fuel was used in the experiment, we solve the compressible Navier-Stokes equations with a barotropic equation of state for water and vapor and a simple phase-change model based on equilibrium assumptions. Our LES resolve all wave dynamics in the compressible fluid and the turbulence production in shear layers.

Hickel, S; Schmidt, S J

2014-01-01T23:59:59.000Z

5

Large-eddy simulation of turbulent cavitating flow in a micro channel  

SciTech Connect (OSTI)

Large-eddy simulations (LES) of cavitating flow of a Diesel-fuel-like fluid in a generic throttle geometry are presented. Two-phase regions are modeled by a parameter-free thermodynamic equilibrium mixture model, and compressibility of the liquid and the liquid-vapor mixture is taken into account. The Adaptive Local Deconvolution Method (ALDM), adapted for cavitating flows, is employed for discretizing the convective terms of the Navier-Stokes equations for the homogeneous mixture. ALDM is a finite-volume-based implicit LES approach that merges physically motivated turbulence modeling and numerical discretization. Validation of the numerical method is performed for a cavitating turbulent mixing layer. Comparisons with experimental data of the throttle flow at two different operating conditions are presented. The LES with the employed cavitation modeling predicts relevant flow and cavitation features accurately within the uncertainty range of the experiment. The turbulence structure of the flow is further analyzed with an emphasis on the interaction between cavitation and coherent motion, and on the statistically averaged-flow evolution.

Egerer, Christian P., E-mail: christian.egerer@aer.mw.tum.de; Hickel, Stefan; Schmidt, Steffen J.; Adams, Nikolaus A. [Institute of Aerodynamics and Fluid Mechanics, Technische Universität München, Boltzmannstr. 15, 85748 Garching bei München (Germany)

2014-08-15T23:59:59.000Z

6

Penn Large Water Tunnel | 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 Center Home5b9fcbce19 No revision hasInformation Earth'sOklahoma/GeothermalOrange County isParadise,Large Water Tunnel Overseeing

7

Quantum Cavitation  

E-Print Network [OSTI]

We consider the theoretical setting of a superfluid like 3He in a rotating container, which is set between the two layers of a type-II superconductor. We describe the superfluid vortices as a 2-dimensional Ising-like model on a triangular lattice in presence of local magnetic fields. The interaction term of the superfluid vortices with the Abrikosov vortices of the superconductor appears then as a symmetry breaking term in the free energy. Such a term gives a higher probability of quantum tunnelling across the potential barrier for bubbles nucleation, thus favouring quantum cavitation.

Paola Zizzi; Eliano Pessa; Fabio Cardone

2010-06-05T23:59:59.000Z

8

Vacuum gaps with small tunnel currents at large electric field...  

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

with small tunnel currents at large electric field and its potential applications for energy storage, charge storage and power supplies. Friday, May 27, 2011 - 4:00pm SSRL...

9

Experimental and analytical study of rotating cavitation  

SciTech Connect (OSTI)

This paper describes experimental and analytical results of rotating cavitation. There are four major sections in this paper. The first section presents the main characteristics of rotating cavitation which was found in the inducer test using a water tunnel. The second section describes the rotating cavitation which occurred in the development test of an LE-7 liquid oxygen pump for the H-II rocket. Also described in this section is how the rotating cavitation was suppressed. The rotating cavitation was the cause of both super synchronous shaft vibration and an unstable head coefficient curve. The third section presents how the theory of rotating cavitation was developed. The final section shows the measured cavitation compliance and mass flow gain factor of the LE-7 pump inducer for comparison of the experimental and analytical results of the rotating cavitation of the LE-7 pump inducer. Almost all the information presented in this paper has already been reported by Kamijo et al. (1977, 1980, 1993, 1993) and by Shimura (1993). In the present paper, the authors attempt to combine and give a clear overview of the experimental and analytical results described in the previous papers to systematically show their experience and findings on rotating cavitation.

Kamijo, Kenjiro; Shimura, Takashi; Tsujimoto, Yoshinobu [National Aerospace Lab., Miyagi (Japan). Kakuda Research Center

1994-12-31T23:59:59.000Z

10

Shear viscosity, cavitation and hydrodynamics at LHC  

E-Print Network [OSTI]

We study evolution of quark-gluon matter in the ultrarelativistic heavy-ion collisions within the frame work of relativistic second-order viscous hydrodynamics. In particular, by using the various prescriptions of a temperature-dependent shear viscosity to the entropy ratio, we show that the hydrodynamic description of the relativistic fluid become invalid due to the phenomenon of cavitation. For most of the initial conditions relevant for LHC, the cavitation sets in very early during the evolution of the hydrodynamics in time $\\lesssim 2 $fm/c. The cavitation in this case is entirely driven by the large values of shear viscosity. Moreover we also demonstrate that the conformal term used in equations of the relativistic dissipative hydrodynamic can influence the cavitation time.

Jitesh R. Bhatt; Hiranmaya Mishra; V. Sreekanth

2011-09-28T23:59:59.000Z

11

A large volume 2000 MPA air source for the radiatively driven hypersonic wind tunnel  

SciTech Connect (OSTI)

An ultra-high pressure air source for a hypersonic wind tunnel for fluid dynamics and combustion physics and chemistry research and development must provide a 10 kg/s pure air flow for more than 1 s at a specific enthalpy of more than 3000 kJ/kg. The nominal operating pressure and temperature condition for the air source is 2000 MPa and 900 K. A radial array of variable radial support intensifiers connected to an axial manifold provides an arbitrarily large total high pressure volume. This configuration also provides solutions to cross bore stress concentrations and the decrease in material strength with temperature. [hypersonic, high pressure, air, wind tunnel, ground testing

Constantino, M

1999-07-14T23:59:59.000Z

12

Cavitation induced by explosion in an ideal fluid model Christophe Josserand*  

E-Print Network [OSTI]

Cavitation induced by explosion in an ideal fluid model Christophe Josserand* The James Franck a cavitation bubble for large enough energy. This gives a consistent view for rebound bubbles in superfluid.55.Bx, 67.55.Fa, 64.70.Fx I. INTRODUCTION Cavitation is a physical process involving such aspects

13

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

14

OPTIC CAVITATION W. Lauterborn  

E-Print Network [OSTI]

, especially ship pro- pellers, turbines, pumps and hydrofoils. This type of cavitation is called hydraulic up to a million frames per second. In a series of experiments bubble oscillations in the bulk

Paris-Sud XI, Université de

15

Cavitation guide for control valves  

SciTech Connect (OSTI)

This guide teaches the basic fundamentals of cavitation to provide the reader with an understanding of what causes cavitation, when it occurs, and the potential problems cavitation can cause to a valve and piping system. The document provides guidelines for understanding how to reduce the cavitation and/or select control valves for a cavitating system. The guide provides a method for predicting the cavitation intensity of control valves, and how the effect of cavitation on a system will vary with valve type, valve function, valve size, operating pressure, duration of operation and details of the piping installation. The guide defines six cavitation limits identifying cavitation intensities ranging from inception to the maximum intensity possible. The intensity of the cavitation at each limit Is described, including a brief discussion of how each level of cavitation influences the valve and system. Examples are included to demonstrate how to apply the method, including making both size and pressure scale effects corrections. Methods of controlling cavitation are discussed providing information on various techniques which can be used to design a new system or modify an existing one so it can operate at a desired level of cavitation.

Tullis, J.P. [Tullis Engineering Consultants, Logan, UT (United States)

1993-04-01T23:59:59.000Z

16

To appear in the International Journal of Fracture Cavitation in Rubber: An Elastic Instability or a Fracture Phenomenon?  

E-Print Network [OSTI]

To appear in the International Journal of Fracture Cavitation in Rubber: An Elastic Instability that cavitation in rubber -- that is, the sudden growth of inherent defects in rubber into large enclosed cavities incomplete. Essentially, this is because the local stretches around the defects at which cavitation initiates

Lopez-Pamies, Oscar

17

Acoustic cavitation and its chemical consequences  

E-Print Network [OSTI]

Acoustic cavitation and its chemical consequences By Kenneth S. Suslick, Yuri Didenko, Ming M. Fang Acoustic cavitation is responsible for both sonochemistry and sonoluminescence. Bubble collapse in liquids, sonochemistry and sonoluminescence derive principally from acoustic cavitation: the formation, growth

Suslick, Kenneth S.

18

Large-scale fabrication of BN tunnel barriers for graphene spintronics  

SciTech Connect (OSTI)

We have fabricated graphene spin-valve devices utilizing scalable materials made from chemical vapor deposition (CVD). Both the spin-transporting graphene and the tunnel barrier material are CVD-grown. The tunnel barrier is realized by Hexagonal boron nitride, used either as a monolayer or bilayer and placed over the graphene. Spin transport experiments were performed using ferromagnetic contacts deposited onto the barrier. We find that spin injection is still greatly suppressed in devices with a monolayer tunneling barrier due to resistance mismatch. This is, however, not the case for devices with bilayer barriers. For those devices, a spin relaxation time of ?260 ps intrinsic to the CVD graphene material is deduced. This time scale is comparable to those reported for exfoliated graphene, suggesting that this CVD approach is promising for spintronic applications which require scalable materials.

Fu, Wangyang; Makk, Péter; Maurand, Romain; Bräuninger, Matthias; Schönenberger, Christian [Department of Physics, University of Basel, Basel (Switzerland)

2014-08-21T23:59:59.000Z

19

CAV2001 Fourth International Symposium on Cavitation Cavitation and the state of stress  

E-Print Network [OSTI]

CAV2001 Fourth International Symposium on Cavitation Cavitation and the state of stress/2001/paper/Cavitation/cavupdate.tex ca Abstract The problem of the inception of cavitation is formulated in terms of a comparison of the breaking strength or cavitation threshold at each point

Joseph, Daniel D.

20

Cavitation-resistant inducer  

DOE Patents [OSTI]

An improvement in an inducer for a pump wherein the inducer includes a hub, a plurality of radially extending substantially helical blades and a wall member extending about and encompassing an outer periphery of the blades. The improvement comprises forming adjacent pairs of blades and the hub to provide a substantially rectangular cross-sectional flow area which cross-sectional flow area decreases from the inlet end of the inducer to a discharge end of the inducer, resulting in increased inducer efficiency improved suction performance, reduced susceptibility to cavitation, reduced susceptibility to hub separation and reduced fabrication costs.

Dunn, Charlton (Calabasas, CA); Subbaraman, Maria R. (Canoga Park, CA)

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Cavitation-resistant inducer  

DOE Patents [OSTI]

An improvement in an inducer for a pump is disclosed wherein the inducer includes a hub, a plurality of radially extending substantially helical blades and a wall member extending about and encompassing an outer periphery of the blades. The improvement comprises forming adjacent pairs of blades and the hub to provide a substantially rectangular cross-sectional flow area which cross-sectional flow area decreases from the inlet end of the inducer to a discharge end of the inducer, resulting in increased inducer efficiency improved suction performance, reduced susceptibility to cavitation, reduced susceptibility to hub separation and reduced fabrication costs. 11 figs.

Dunn, C.; Subbaraman, M.R.

1989-06-13T23:59:59.000Z

22

Cavitation-controlled ultrasonic agitator  

SciTech Connect (OSTI)

High-intensity ultrasound generally produces nonlinear acoustic cavitation and streaming in liquids. The ultrasonic energy required to cause cavitation and streaming in a liquid depends on the physical properties of the liquid, e.g., surface tension, viscosity, and entrained gases. Both cavitation and streaming generate acoustic noise whose signatures may be used to distinguish the stage of agitation and thus allow the process to be controlled. An ultrasonic agitator has been designed for application in a confined area with a high-temperature, high-pressure, and corrosive environment. Control of this agitator is based on the detection of noise levels and subharmonics produced during cavitation and streaming. Noise signatures of agitation in different liquids and in liquids with particles have been determined, and discussed. 6 refs., 6 figs.

Sheen, S.H.; Lawrence, W.P.; Raptis, A.C.

1989-10-01T23:59:59.000Z

23

Cavitation Fatigue. Embolism and Refilling Cycles Can Weaken the Cavitation Resistance of Xylem1  

E-Print Network [OSTI]

Cavitation Fatigue. Embolism and Refilling Cycles Can Weaken the Cavitation Resistance of Xylem1Culloh Department of Biology, University of Utah, Salt Lake City, Utah 84112 Although cavitation and refilling cycles could be common in plants, it is unknown whether these cycles weaken the cavitation resistance

Stiller, Volker

24

Cavitation in elastomeric solids: II--Onset-of-cavitation surfaces for Neo-Hookean materials  

E-Print Network [OSTI]

Cavitation in elastomeric solids: II--Onset-of-cavitation surfaces for Neo-Hookean materials Oscar a fairly general theory of cavitation in elastomeric solids based on the sudden growth of pre-existing defects. In this article, the theory is used to determine onset-of-cavitation surfaces for Neo

Lopez-Pamies, Oscar

25

Cavitation in elastomeric solids: II--Onset-of-cavitation surfaces for Neo-Hookean materials  

E-Print Network [OSTI]

Cavitation in elastomeric solids: II--Onset-of-cavitation surfaces for Neo-Hookean materials Oscar of cavitation in elastomeric solids based on the sudden growth of pre-existing defects. In this article, the theory is used to determine onset-of-cavitation surfaces for Neo-Hookean solids where the defects

Nakamura, Toshio

26

EXPERIMENTS AND MODELLING OF CAVITATING FLOWS IN VENTURI: ATTACHED SHEET CAVITATION  

E-Print Network [OSTI]

1 EXPERIMENTS AND MODELLING OF CAVITATING FLOWS IN VENTURI: ATTACHED SHEET CAVITATION S. Barre* , J and numerical studies were carried out to analyse cavitating flows and to describe the two- phase flow structures of attached sheet cavitation in Venturi geometries. New double optical probe measurements were

Paris-Sud XI, Université de

27

Spatial control of cavitation in therapeutic ultrasound  

E-Print Network [OSTI]

Inertial cavitation has been implicated as the primary mechanism for a host of emerging applications. In all these applications, the main concern is to induce cavitation in perfectly controlled locations in the field; this ...

Gauthier, Thomas P., 1980-

2005-01-01T23:59:59.000Z

28

Quasiconformal Hyperelasticity Cavitation is not Allowed  

E-Print Network [OSTI]

Quasiconformal Hyperelasticity when Cavitation is not Allowed Tadeusz Iwaniec Jani Onninen Abstract that the lower bound at (3) prevents all sorts of cavitation from growing to higher dimensions. For instance

Kovalev, Leonid

29

ULTRASONIC CAVITATION IN FREON AT ROOM TEMPERATURE  

E-Print Network [OSTI]

ULTRASONIC CAVITATION IN FREON AT ROOM TEMPERATURE FR´ED´ERIC CAUPIN AND VINCENT FOURMOND on ultrasonic cavitation in freon (1,1,2-trichloro 1,2,2-trifluoro ethane). We use a high intensity 1 MHz observe the nucleation of bubbles. We describe the three different methods we use to detect cavitation

Caupin, Frédéric

30

Compressible fluid model for hydrodynamic lubrication cavitation  

E-Print Network [OSTI]

Compressible fluid model for hydrodynamic lubrication cavitation G. Bayada L. Chupin I.C.J. UMR.chupin@math.univ-bpclermont.fr Keywords: cavitation, compressible Reynolds equation Date: april 2013 Summary In this paper, it is shown how vaporous cavitation in lubricant films can be modelled in a physically justified manner through

Sart, Remi

31

Membrane disruption by optically controlled microbubble cavitation  

E-Print Network [OSTI]

LETTERS Membrane disruption by optically controlled microbubble cavitation PAUL PRENTICE1 , ALFRED October 2005; doi:10.1038/nphys148 I n fluids, pressure-driven cavitation bubbles have a nonlinear underpinning phenomena such as sonoluminescence1 and plasma formation2 . If cavitation occurs near a rigid

Loss, Daniel

32

Design and calibration of a scanning tunneling microscope for large machined surfaces  

SciTech Connect (OSTI)

During the last year the large sample STM has been designed, built and used for the observation of several different samples. Calibration of the scanner for prope dimensional interpretation of surface features has been a chief concern, as well as corrections for non-linear effects such as hysteresis during scans. Several procedures used in calibration and correction of piezoelectric scanners used in the laboratorys STMs are described.

Grigg, D.A.; Russell, P.E.; Dow, T.A.

1988-12-01T23:59:59.000Z

33

Investigation of noninertial cavitation produced by an ultrasonic horn  

E-Print Network [OSTI]

Investigation of noninertial cavitation produced by an ultrasonic horn Peter R. Birkin,a) Douglas G; accepted 22 September 2011) This paper reports on noninertial cavitation that occurs beyond the zone close to the horn tip to which the inertial cavitation is confined. The noninertial cavitation is characterized

Sóbester, András

34

Cavitation in an Orifice Flow , W. A. Sirignano  

E-Print Network [OSTI]

Cavitation in an Orifice Flow S. Dabiri , W. A. Sirignano Department of Mechanical and Aerospace the potential locations for cavitation induced by total stress on the flow of a liquid through an orifice. The total-stress criterion for cavitation is applied to find the regions where cavitation is likely to occur

Joseph, Daniel D.

35

Carderock 2-ft Variable Pressure Cavitation Water Tunnel | Open Energy  

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 Center Home Page on Office of InspectorConcentrating SolarElectricEnergyCTBarreis aCallahan DivideCannon (Various)LimitedInformation

36

Carderock 3-ft Variable Pressure Cavitation Water Tunnel | Open Energy  

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 Center Home Page on Office of InspectorConcentrating SolarElectricEnergyCTBarreis aCallahan DivideCannon

37

Mechanical Damage from Cavitation in High Intensity Focused Ultrasound Accelerated Thrombolysis  

E-Print Network [OSTI]

3.3 Cavitation Model . . . . . . . . . . . . . . . . . . . .Field Characterization / Passive Cavitation Detection 2.3Method for Estimation of Cavitation Damage for an Embedded

Weiss, Hope

2012-01-01T23:59:59.000Z

38

Generation of laser-induced cavitation bubbles with a digital hologram  

E-Print Network [OSTI]

C. D. Ohl, “Controlled cavitation-cell interaction: trans-R. Dijkink and C. D. Ohl, “Cavitation based micropump,” Labobservations of laser- induced cavitation bubbles in water,”

Quinto-Su, P. A; Venugopalan, V.; Ohl, C.-D.

2008-01-01T23:59:59.000Z

39

A body force model for cavitating inducers in rocket engine turbopumps  

E-Print Network [OSTI]

Modern rocket engine turbopumps utilize cavitating inducers to meet mass and volume requirements. Rotating cavitation and higher order cavitation instabilities have frequently been observed during inducer testing and ...

Sorensen, William Alarik

2014-01-01T23:59:59.000Z

40

Cavitation-Induced Fusion: Proof of Concept  

E-Print Network [OSTI]

Cavitation-induced fusion (also known as bubble fusion or sonofusion) has been a topic of much debate and controversy and is generally (albeit incorrectly) perceived as unworkable. In this paper we present the theoretical foundations of cavitation-induced fusion and summarize the experimental results of the research conducted in the past 20 years. Based on the systematic study of all available data we conclude that the cavitation-induced fusion is feasible, doable, and can be used for commercial power generation. We present the results of our own research and disclose a commercial reactor prototype.

Max I. Fomitchev-Zamilov

2012-09-09T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Frequency dependence of mass flow gain factor and cavitation compliance of cavitating inducers  

SciTech Connect (OSTI)

Unsteady cavitation characteristics are analyzed based on a closed cavity model in which the length of the cavity is allowed to oscillate. It is shown that the present model blends smoothly into quasisteady calculations in the low frequency limit, unlike fixed cavity length models. Effects of incidence angle and cavitation number on cavitation compliance and mass flow gain factor are shown as functions of reduce frequency. The cavity volume is evaluated by three methods and the results were used to confirm the accuracy and adequacy of the numerical calculation. By comparison with experimental data on inducers, it was shown that the present model can simulate the characteristics of unsteady cavitation qualitatively.

Otsuka, S.; Tsujimoto, Yoshinobu [Osaka Univ. (Japan); Kamijo, Kenjiro [National Aerospace Lab., Kakuda, Miyagi (Japan). Kakuda Research Center; Furuya, O. [AMP Technologies, Osaka (Japan)

1994-12-31T23:59:59.000Z

42

Channel tunnel  

ScienceCinema (OSTI)

Jacques Lemley, américain et "chief executif" parle du projet de l'Eurotunnel - tunnel sous la manche

None

2011-04-25T23:59:59.000Z

43

Cavitation Thermometry Using Molecular and Continuum Sonoluminescence Lawrence S. Bernstein* and Mitchell R. Zakin  

E-Print Network [OSTI]

Cavitation Thermometry Using Molecular and Continuum Sonoluminescence Lawrence S. Bernstein (SB) sonoluminescence (SL) is explored as a probe of bubble temperature during cavitational collapse discrete intervals along the cavitational collapse time line, thus yielding different cavitation

Suslick, Kenneth S.

44

Using Passive Cavitation Detection to Observe Postexcitation Response of Ultrasound Contrast  

E-Print Network [OSTI]

Using Passive Cavitation Detection to Observe Postexcitation Response of Ultrasound Contrast Agents, FR Email: daking3@illinois.edu Abstract-- Passive cavitation detection was used to improve. Keywords - microbubbles; postexcitation; passive cavitation detection; inertial cavitation; flow rate I

Illinois at Urbana-Champaign, University of

45

Evaporation-induced cavitation in nanofluidic channels  

E-Print Network [OSTI]

Cavitation, known as the formation of vapor bubbles when liquids are under tension, is of great interest both in condensed matter science as well as in diverse applications such as botany, hydraulic engineering, and medicine. ...

Karnik, Rohit N.

46

Wind effects on large-scale buildings and structures : field measurements, wind tunnel tests and numerical prediction.  

E-Print Network [OSTI]

??Modern large-scale buildings and structures, such as super tall buildings and large roof structures, are usually constructed with innovative structural systems and high strength materials;… (more)

Fu, Jiyang (???)

2007-01-01T23:59:59.000Z

47

Pre-breakdown cavitation development in the dielectric fluid in the inhomogeneous, pulsed electric fields  

E-Print Network [OSTI]

We consider the development of pre-breakdown cavitation nanopores appearing in the dielectric fluid under the influence of the electrostrictive stresses in the inhomogeneous pulsed electric field. It is shown that three characteristic regions can be distinguished near the needle electrode. In the first region, where the electric field gradient is greatest, the cavitation nanopores, occurring during the voltage nanosecond pulse, may grow to the size at which an electron accelerated by the field inside the pores can acquire enough energy for excitation and ionization of the liquid on the opposite pore wall, i.e., the breakdown conditions are satisfied. In the second region, the negative pressure caused by the electrostriction is large enough for the cavitation initiation (which can be registered by optical methods), but, during the voltage pulse, the pores do not reach the size at which the potential difference across their borders becomes sufficient for ionization or excitation of water molecules. And, in the third, the development of cavitation is impossible, due to an insufficient level of the negative pressure: in this area, the spontaneously occurring micropores do not grow and collapse under the influence of surface tension forces. This paper discusses the expansion dynamics of the cavitation pores and their most probable shape.

Mikhail N. Shneider; Mikhail Pekker

2014-12-01T23:59:59.000Z

48

Ultrafast scanning tunneling microscopy  

SciTech Connect (OSTI)

I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

Botkin, D.A. [California Univ., Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)

1995-09-01T23:59:59.000Z

49

Numerical study of expansion tube problems: toward the simulation of cavitation  

E-Print Network [OSTI]

.11.019 #12;diminution of the speed of sound in the mixture), large density ratio be- tween the liquid-phase flow models. This method makes no attempt to track the liquid and vapour interface. As most two for inviscid high-speed cavitating applications and two-phase Riemann problems [2, 3, 4, 5]. For thermal- 2 hal

Paris-Sud XI, Université de

50

Cavitation level-acoustic intensity hysteresis: experimental and numerical characterization  

E-Print Network [OSTI]

Cavitation level-acoustic intensity hysteresis: experimental and numerical characterization P such as sonoporation, inertial cavitation is commonly considered as the main candidate inducing membrane poration. Thus, characterizing inertial cavitation, as related to bubble size distribution and medium history, is of great

Boyer, Edmond

51

Extreme conditions during multibubble cavitation: Sonoluminescence as a spectroscopic probe  

E-Print Network [OSTI]

Extreme conditions during multibubble cavitation: Sonoluminescence as a spectroscopic probe Kenneth Cavitation MBSL Plasma a b s t r a c t We review recent work on the use of sonoluminescence (SL) to probe spectroscopically the conditions created during cavitation, both in clouds of collapsing bubbles (multibubble

Suslick, Kenneth S.

52

Hot Spot Conditions during Cavitation in Water Yuri T. Didenko,  

E-Print Network [OSTI]

Hot Spot Conditions during Cavitation in Water Yuri T. Didenko, William B. McNamara III-13 the effective hot spot temperature during aqueous cavitation remains unresolved. Given the importance of aqueous cavitation (sonography and bioeffects of ultrasound, sonochemical remediation of aqueous pollutants

Suslick, Kenneth S.

53

Energy Minimising Properties of the Radial Cavitation Solution in  

E-Print Network [OSTI]

Energy Minimising Properties of the Radial Cavitation Solution in Incompressible Nonlinear in the deformed body. This result has implications for the study of cavitation in certain polymers. Mathematics, radial minimizer, cavitation. 1 #12;2 J. Sivaloganathan and S. J. Spector 1 Introduction. Let B Rn

Sivaloganathan, J.

54

Heterogeneous cavitation in liquid helium 4 near a glass plate  

E-Print Network [OSTI]

Heterogeneous cavitation in liquid helium 4 near a glass plate X. Chavanne, S. Balibar and F wave to study cavitation, i.e. the nucleation of bubbles, in liquid helium 4 near a clean glass plate and threshold pressures in the range 0 to -3 bar, significantly less negative than for homogeneous cavitation

Caupin, Frédéric

55

POLYCONVEX ENERGIES AND CAVITATION P. CELADA S. PERROTTA  

E-Print Network [OSTI]

POLYCONVEX ENERGIES AND CAVITATION P. CELADA ­ S. PERROTTA Dedicated to Arrigo Cellina on his to mention a few other references. We mention also [4] for a description of cavitation in the language of currents and we refr to [5] for a survey of theoretical and experimental results about cavitation. Among

Celada, Pietro

56

NUMERICAL INVESTIGATION OF CAVITATION IN MULTI-DIMENSIONAL COMPRESSIBLE FLOWS  

E-Print Network [OSTI]

NUMERICAL INVESTIGATION OF CAVITATION IN MULTI-DIMENSIONAL COMPRESSIBLE FLOWS KRISTEN J. DEVAULT, cavitation, pseudospectral AMS subject classifications. 35Q30, 65M70, 76N99 1. Introduction. A long to first make a careful numerical study of the simplest possible scenario where one could expect cavitation

57

Breakthrough Technologies In Vivo Observation of Cavitation and Embolism Repair  

E-Print Network [OSTI]

Breakthrough Technologies In Vivo Observation of Cavitation and Embolism Repair Using Magnetic that approximately 10 vessels had cavitated during this time. Leaf water potentials decreased from 1.25 to 2.1 MPa cavitation. Refilling of xylem vessels occurred as soon as the lights were switched off, with the majority

Holbrook, N. Michele

58

Double Passive Cavitation Detection of OptisonTM Shell Rupture  

E-Print Network [OSTI]

Double Passive Cavitation Detection of OptisonTM Shell Rupture Azzdine Y. Ammi1 , Robin O). The experimental setup is based on a passive cavitation detection system described in previous work. However by ultrasonic capsule destruction [3,4]. In previous work using a passive cavitation detection (PCD) system [5

Illinois at Urbana-Champaign, University of

59

On Cavitation, Configurational Forces and Implications for Fracture in  

E-Print Network [OSTI]

On Cavitation, Configurational Forces and Implications for Fracture in a Nonlinearly Elastic tensile stress can induce cavitation, that is, the appearance of voids that were not previously evident con- sequence of this viewpoint is that cavitation may then take place at a point

Sivaloganathan, J.

60

Numerical Simulation of Unsteady Three-Dimensional Sheet Cavitation  

E-Print Network [OSTI]

Numerical Simulation of Unsteady Three-Dimensional Sheet Cavitation A.H. Koop #12;Numerical Simulation of Unsteady Three-Dimensional Sheet Cavitation A.H. Koop Thesis University of Twente, Enschede, the Netherlands #12;NUMERICAL SIMULATION OF UNSTEADY THREE-DIMENSIONAL SHEET CAVITATION PROEFSCHRIFT ter

Twente, Universiteit

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Controlled cavitation in microfluidics Severine Le Gac,2  

E-Print Network [OSTI]

Controlled cavitation in microfluidics Ed Zwaan,1 S´everine Le Gac,2 Kinko Tsuji,3 and Claus-Hahn-Strasse 6-10, D-47269 Duisburg, Germany. (Dated: February 20, 2007) We report on cavitation in confined microscopic environments which are commonly called microfluidic or lab-on-a-chip systems. The cavitation

Ohl, Claus-Dieter

62

d Original Contribution IDENTIFYING THE INERTIAL CAVITATION THRESHOLD AND SKULL  

E-Print Network [OSTI]

d Original Contribution IDENTIFYING THE INERTIAL CAVITATION THRESHOLD AND SKULL EFFECTS IN AVESSEL unknown. To investigate the pressure threshold for inertial cavitation of pre- formed microbubbles during sonication, passive cavitation detection in conjunction with B-mode imaging was used. A cerebral vessel

Konofagou, Elisa E.

63

WATER TRANSPORT IN VESSELLESS ANGIOSPERMS: CONDUCTING EFFICIENCY AND CAVITATION SAFETY  

E-Print Network [OSTI]

WATER TRANSPORT IN VESSELLESS ANGIOSPERMS: CONDUCTING EFFICIENCY AND CAVITATION SAFETY U. G. Hacke. Second, vesselless wood ought to be exceptionally safe from cavitation if the small cumulative area woods averaged a cavitation pressure of Ã?3:4 6 0:3 MPa, which is low for their wet habitats

Hacke, Uwe

64

Measurements of Cavitation Dose, Echogenicity, and Temperature during Ultrasound Ablation  

E-Print Network [OSTI]

Measurements of Cavitation Dose, Echogenicity, and Temperature during Ultrasound Ablation T traces from the array, time-domain signals received by a 1 MHz, unfocused passive cavitation detector signals received by the array. Cavitation dose was quantified from the spectra of signals measured

Mast, T. Douglas

65

Role of Cavitation in Bulk Ultrasound Ablation: A Histologic Study  

E-Print Network [OSTI]

Role of Cavitation in Bulk Ultrasound Ablation: A Histologic Study Chandra Priya Karunakaran, Mark of Cincinnati, Cincinnati, Ohio Abstract. The role of cavitation in bulk ultrasound ablation has been evaluated-ablate probe at 31 W/cm2 for 20 minutes under normal and elevated ambient pressures. A 1 MHz passive cavitation

Mast, T. Douglas

66

Cavitation in holographic sQGP  

E-Print Network [OSTI]

We study the possibility of cavitation in the nonconformal N=2^* SU(N) theory which is a mass deformation of N=4 SU(N) Yang-Mills theory. The second order transport coefficients are known from the numerical work using AdS/CFT by Buchel and collaborators. Using these and the approach of Rajagopal and Tripuraneni, we investigate the flow equations in a 1+1 dimensional boost invariant set up. We find that the string theory model does not exhibit cavitation before phase transition is reached. We give a semi-analytic explanation of this finding.

Aleksandra Klimek; Louis Leblond; Aninda Sinha

2011-04-05T23:59:59.000Z

67

A theoretical analysis of rotating cavitation in inducers  

SciTech Connect (OSTI)

Rotating cavitation was analyzed using an actuator disk method. Quasi-steady pressure performance of the impeller, mass flow gain factor, and cavitation compliance of the cavity were taken into account. Three types of destabilizing modes were predicted: rotation cavitation propagating faster than the rotational speed of the impeller, rotating cavitation propagating in the direction opposite that of the impeller, and rotating stall propagating slower than the rotational speed of the impeller. It was shown that both types of rotating cavitation were caused by the positive mass flow gain factor, while the rotating stall was caused by the positive slope of the pressure performance. Stability and propagation velocity maps are presented for the two types of rotating cavitation in the mass flow gain factor-cavitation compliance place. The correlation between theoretical results and experimental observations is discussed.

Tsujimoto, Y.; Kamijo, K. (National Aerospace Lab., Miyagi, (Japan)); Yoshida, Y. (Osaka Univ., Toyonaka, (Japan). Engineering Science)

1993-03-01T23:59:59.000Z

68

Bulk Viscosity and Cavitation in Boost-Invariant Hydrodynamic Expansion  

E-Print Network [OSTI]

We solve second order relativistic hydrodynamics equations for a boost-invariant 1+1-dimensional expanding fluid with an equation of state taken from lattice calculations of the thermodynamics of strongly coupled quark-gluon plasma. We investigate the dependence of the energy density as a function of proper time on the values of the shear viscosity, the bulk viscosity, and second order coefficients, confirming that large changes in the values of the latter have negligible effects. Varying the shear viscosity between zero and a few times s/(4 pi), with s the entropy density, has significant effects, as expected based on other studies. Introducing a nonzero bulk viscosity also has significant effects. In fact, if the bulk viscosity peaks near the crossover temperature Tc to the degree indicated by recent lattice calculations in QCD without quarks, it can make the fluid cavitate -- falling apart into droplets. It is interesting to see a hydrodynamic calculation predicting its own breakdown, via cavitation, at the temperatures where hadronization is thought to occur in ultrarelativistic heavy ion collisions.

Krishna Rajagopal; Nilesh Tripuraneni

2010-02-16T23:59:59.000Z

69

A novel way of detecting transient cavitation near a solid surface during megasonic cleaning using electrochemical impedance spectroscopy  

E-Print Network [OSTI]

A novel way of detecting transient cavitation near a solid surface during megasonic cleaning using Keywords: Megasonic cleaning Transient cavitation Acoustic streaming Microelectrode Electrochemical to transient cavitation. Development of a method to monitor transient cavitation events in solutions irradiated

Deymier, Pierre

70

Characterization of transient cavitation in gas sparged solutions exposed to megasonic field using cyclic voltammetry  

E-Print Network [OSTI]

Characterization of transient cavitation in gas sparged solutions exposed to megasonic field using 2011 Keywords: Megasonic energy Transient cavitation Acoustic streaming Dissolved gases Microelectrode been a significant interest in understanding the phenomena of cavitation and acoustic streaming, which

Deymier, Pierre

71

Electrochemical investigations of stable cavitation from bubbles generated during reduction of water  

E-Print Network [OSTI]

Electrochemical investigations of stable cavitation from bubbles generated during reduction April 2014 Keywords: Megasonic cleaning Stable cavitation Microstreaming Hydrogen bubbles Water on wafers without affect- ing the transient cavitation responsible for feature damage. Ã? 2014 Elsevier B

Deymier, Pierre

72

On the construction and properties of weak solutions describing dynamic cavitation  

E-Print Network [OSTI]

On the construction and properties of weak solutions describing dynamic cavitation (In: Journal associated with dynamically cavitating solutions coincides with the critical stretching in the bifurcation with contents. Keywords: Cavitation, Shock wave, Polyconvex elasticity Mathematics Subject Classification: 35L67

Miroshnikov, Alexey

73

Predictors of cavitation in glassy polymers under tensile strain: a coarse grained molecular dynamics  

E-Print Network [OSTI]

Predictors of cavitation in glassy polymers under tensile strain: a coarse grained molecular the cavity position before the cavitation occurs. Even if the localization of a cavity is not directly: Cavitation, Plasticity, Computational modeling, Molecular dynamics simulation, Mechanical properties. 1

Paris-Sud XI, Université de

74

Creation of cavitation activity in a microfluidic device through acoustically driven capillary waves  

E-Print Network [OSTI]

Creation of cavitation activity in a microfluidic device through acoustically driven capillary acoustic cavitation generated by ultrasonic vibrations in polydimethylsiloxane (PDMS) based microfluidic in the microfluidic channels. Also, it is observed that nuclei leading to intense inertial cavitation are generated

Ohl, Claus-Dieter

75

A NEW CAVITATION MODEL IN LUBRICATION: THE CASE OF TWOZONE CAVITATION GUSTAVO C. BUSCAGLIA, IONEL CIUPERCA, ERIC DALISSIER, AND MOHAMMED JAI  

E-Print Network [OSTI]

A NEW CAVITATION MODEL IN LUBRICATION: THE CASE OF TWO­ZONE CAVITATION GUSTAVO C. BUSCAGLIA, IONEL of cavitation in lubricated devices is proposed, such that the translation velocity V for the saturation field of course the cavitation boundary leaves the domain or disappears. A few preliminary numerical examples

Buscaglia, Gustavo C.

76

E-Print Network 3.0 - acoustic cavitation bubble Sample Search...  

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

Collection: Physics 62 Acoustic saturation in bubbly cavitating flow adjacent to an oscillating wall T. Colonius,a) Summary: Acoustic saturation in bubbly cavitating flow...

77

Cavitation effects on the confinement/deconfinement transition  

E-Print Network [OSTI]

Cavitation is a process where the viscous terms in a relativistic fluid result in reducing the effective pressure, thus facilitating the nucleation of bubbles of a stable phase. The effect is particularly pronounced in the vicinity of a (weak) first-order phase transition. We use the holographic correspondence to study cavitation in a strongly coupled planar cascading gauge theory plasma close to the confinement/deconfinement phase transition. While in this particular model the shift of the deconfinement temperature due to cavitation does not exceed 5%, we speculate that cavitation might be important near the QCD critical point.

Alex Buchel; Xian O. Camanho; Jose D. Edelstein

2014-05-23T23:59:59.000Z

78

Rapid Tunneling and Percolation in the Landscape  

E-Print Network [OSTI]

Motivated by the possibility of a string landscape, we reexamine tunneling of a scalar field across single/multiple barriers. Recent investigations have suggested modifications to the usual picture of false vacuum decay that lead to efficient and rapid tunneling in the landscape when certain conditions are met. This can be due to stringy effects (e.g. tunneling via the DBI action), or by effects arising due to the presence of multiple vacua (e.g. resonance tunneling). In this paper we discuss both DBI tunneling and resonance tunneling. We provide a QFT treatment of resonance tunneling using the Schr\\"odinger functional approach. We also show how DBI tunneling for supercritical barriers can naturally lead to conditions suitable for resonance tunneling. We argue using basic ideas from percolation theory that tunneling can be rapid in a landscape where a typical vacuum has multiple decay channels and discuss various cosmological implications. This rapidity vacuum decay can happen even if there are no resonance/DBI tunneling enhancements, solely due to the presence of a large number of decay channels. Finally, we consider various ways of circumventing a recent no-go theorem for resonance tunneling in quantum field theory.

Sash Sarangi; Gary Shiu; Benjamin Shlaer

2007-12-21T23:59:59.000Z

79

Vol. 22, No. 3, Aug. 1, 2002 Scientists measure energy dissipation in a single cavitating bubble  

E-Print Network [OSTI]

. Cavitation also is responsible for submarine propeller noise, for erosion of turbines, and for the noise

Suslick, Kenneth S.

80

EUROMECH Young Scientist Prize Paper "Cavitation in rubber: The role of elasticity"  

E-Print Network [OSTI]

EUROMECH Young Scientist Prize Paper "Cavitation in rubber: The role of elasticity" AUTHOR won suddenly "appear" in the interior of rubber. This phenomenon has come to be popularly known as cavitation and describe cavitation in rubber, Gent and Lindley [2] proposed to consider the initiation of cavitation

Lopez-Pamies, Oscar

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Cavitation in normal liquid helium 3 F. Caupin, P. Roche, S. Marchand and S. Balibar  

E-Print Network [OSTI]

Cavitation in normal liquid helium 3 F. Caupin, P. Roche, S. Marchand and S. Balibar Laboratoire de 24 rue Lhomond 75231 Paris Cedex 05, France We have studied cavitation, i.e. bubble nucleation, cavitation is found to be stochastic, with a cavitation probability 0.5 at a given value of the sound

Caupin, Frédéric

82

Proceedings of the 8th International Symposium on Cavitation CAV2012 -Abstract No. 153  

E-Print Network [OSTI]

Proceedings of the 8th International Symposium on Cavitation CAV2012 - Abstract No. 153 August 14-16, 2012, Singapore TOWARDS NUMERICAL SIMULATION OF CAVITATING FLOWS IN COMPLEX GEOMETRIES Aswin for benchmark problems and applied to a cavitating flow over a circular cylinder. INTRODUCTION Cavitation occurs

Mahesh, Krishnan

83

Conservative one-dimensional finite volume discretization of a new cavitation model for pistonring lubrication  

E-Print Network [OSTI]

Conservative one-dimensional finite volume discretization of a new cavitation model for piston Cavitation Elrod­Adams model Piston­rings a b s t r a c t This paper presents a conservative numerical implementation of a new cavitation model that is well suited for lubrication problems with cavitated regions

Buscaglia, Gustavo C.

84

Response to ``Comment on `Ultrasound-induced lung hemorrhage is not caused by inertial cavitation'''  

E-Print Network [OSTI]

Response to ``Comment on `Ultrasound-induced lung hemorrhage is not caused by inertial cavitation cavitation nuclei in lung versus other tissues such that overpressure does not affect the inertial cavitation this question, let us first be clear as to what we believe would and would not constitute inertial cavitation

Illinois at Urbana-Champaign, University of

85

TEXTURE-INDUCED CAVITATION BUBBLES AND FRICTION REDUCTION IN THE ELROD-ADAMS MODEL  

E-Print Network [OSTI]

TEXTURE-INDUCED CAVITATION BUBBLES AND FRICTION REDUCTION IN THE ELROD-ADAMS MODEL Hugo M. Checoa, Friction reduction, Cavitation, Numerical simulation. Symbol Description a, b the pad occupies the region of textures µ dynamic viscosity cavitation boundary 0 cavitated region + pressurized region 1 INTRODUCTION

Buscaglia, Gustavo C.

86

Preprint version -March 7, 2006 REITERATED HOMOGENIZATION OF A CAVITATION PROBLEM  

E-Print Network [OSTI]

Preprint version - March 7, 2006 REITERATED HOMOGENIZATION OF A CAVITATION PROBLEM IN THIN FILMS theory: cavitation phenomena and roughness of the surfaces in relative motion: cavitation is defined to describe the behavior of a viscous cavitated flow in the lubrication framework. However, in practical

Paris-Sud XI, Université de

87

Cavitation in an orifice flow S. Dabiri and W. A. Sirignano  

E-Print Network [OSTI]

Cavitation in an orifice flow S. Dabiri and W. A. Sirignano Department of Mechanical and Aerospace locations for cavitation induced by total stress on the flow of a liquid through an orifice of an atomizer. The total-stress criterion for cavitation is applied to find the regions where cavitation is likely to occur

Joseph, Daniel D.

88

Cavitation-induced ignition of cryogenic hydrogen-oxygen fluids V. V. Osipov,1,a  

E-Print Network [OSTI]

Cavitation-induced ignition of cryogenic hydrogen-oxygen fluids V. V. Osipov,1,a C. B. Muratov,2 E-ignite in the process of their sudden mixing. Here, we propose a cavitation-induced self-ignition mechanism that may a cavitation-induced self- ignition mechanism of cryogenic H2/Ox fluids. Cavitation is the formation

Muratov, Cyrill

89

A unified electrostatic and cavitation model for first-principles molecular dynamics in solution  

E-Print Network [OSTI]

The electrostatic continuum solvent model developed by Fattebert and Gygi is combined with a first-principles formulation of the cavitation energy based on a natural quantum-mechanical definition for the surface of a solute. Despite its simplicity, the cavitation contribution calculated by this approach is found to be in remarkable agreement with that obtained by more complex algorithms relying on a large set of parameters. Our model allows for very efficient Car-Parrinello simulations of finite or extended systems in solution, and demonstrates a level of accuracy as good as that of established quantum-chemistry continuum solvent methods. We apply this approach to the study of tetracyanoethylene dimers in dichloromethane, providing valuable structural and dynamical insights on the dimerization phenomenon.

Damian A. Scherlis; Jean-Luc Fattebert; Francois Gygi; Matteo Cococcioni; Nicola Marzari

2005-10-06T23:59:59.000Z

90

Flatback airfoil wind tunnel experiment.  

SciTech Connect (OSTI)

A computational fluid dynamics study of thick wind turbine section shapes in the test section of the UC Davis wind tunnel at a chord Reynolds number of one million is presented. The goals of this study are to validate standard wind tunnel wall corrections for high solid blockage conditions and to reaffirm the favorable effect of a blunt trailing edge or flatback on the performance characteristics of a representative thick airfoil shape prior to building the wind tunnel models and conducting the experiment. The numerical simulations prove the standard wind tunnel corrections to be largely valid for the proposed test of 40% maximum thickness to chord ratio airfoils at a solid blockage ratio of 10%. Comparison of the computed lift characteristics of a sharp trailing edge baseline airfoil and derived flatback airfoils reaffirms the earlier observed trend of reduced sensitivity to surface contamination with increasing trailing edge thickness.

Mayda, Edward A. (University of California, Davis, CA); van Dam, C.P. (University of California, Davis, CA); Chao, David D. (University of California, Davis, CA); Berg, Dale E.

2008-04-01T23:59:59.000Z

91

Notes 06. Liquid cavitation in fluid film bearings  

E-Print Network [OSTI]

[s] U ?R. Journal surface speed [m/s] V dh/dt. Squeeze film velocity [m/s] X= ?R, y, z Coordinate system on plane of bearing ? ()/ cav ?? . Density ratio ? P ? ? ? ? . Liquid bulk-modulus [N/m 2 ] ? Liquid density [kg/m 3 ] cav... ? Density at Pcav [kg/m 3 ] ? Fluid absolute viscosity [N.s/m 2 ] ? Journal angular speed (rad/s) Subscripts * Inception of the cavitation zone a Ambient value cav Cavitation NOTES 6. CAVITATION IN LIQUID FILM BEARINGS. Dr. Luis San Andr?s ? 2009...

San Andres, Luis

2009-01-01T23:59:59.000Z

92

On acoustic cavitation of slightly subcritical bubbles Anthony Harkin  

E-Print Network [OSTI]

On acoustic cavitation of slightly subcritical bubbles Anthony Harkin Department of Mathematics, such as submicron air bubbles in water, where the natural oscilla- tion frequencies are high. In contrast, when

Kaper, Tasso J.

93

ACOUSTIC CAVITATION ASSESSMENT OF THE REVERSIBILITY AND PERMEABILITY OF THE ULTRASOUND-INDUCED BLOOD-BRAIN BARRIER OPENING  

E-Print Network [OSTI]

ACOUSTIC CAVITATION ASSESSMENT OF THE REVERSIBILITY AND PERMEABILITY cavitation can be potentially used to assess the reversibility and permeability of the induced BBB opening. Method: This study links the microbubble dynamics, represented by the cavitation dose, as monitored

Konofagou, Elisa E.

94

Reproducible cavitation activity in water-particle suspensions Bram M. Borkent, Manish Arora, and Claus-Dieter Ohla  

E-Print Network [OSTI]

Reproducible cavitation activity in water-particle suspensions Bram M. Borkent, Manish Arora January 2007 The study of cavitation inception in liquids rarely yields reproducible data, unless special technique is demonstrated which allows repeatable measurements of cavitation activity in liquid

Ohl, Claus-Dieter

95

Summary Xylem vulnerability to cavitation is a promising criterion for identifying trees with high drought tolerance, but  

E-Print Network [OSTI]

Summary Xylem vulnerability to cavitation is a promising criterion for identifying trees with high drought tolerance, but traditional techniques for measuring cavitation resistance are unsuitablefor throughput screening of cavitation resistance in five poplar (Populus spp.) andfour willow (Salix spp

Mencuccini, Maurizio

96

Comparison and Validation of Compressible Flow Simulations of Laser-Induced Cavitation  

E-Print Network [OSTI]

Comparison and Validation of Compressible Flow Simulations of Laser-Induced Cavitation Bubbles)). The validation is performed for the case of laser-induced cavitation bubbles collapsing in an infinite medium

97

Journal of Fluids and Structures 20 (2005) 753762 Fluidstructure interaction and transient cavitation tests in a  

E-Print Network [OSTI]

­structure interaction (FSI); Vaporous cavitation; Column separation 1. Introduction Pressure variations in a water-hammer

Tijsseling, A.S.

98

A nonlinear calculation of rotating cavitation in inducers  

SciTech Connect (OSTI)

In the previous linear analysis (Tsujimoto et al., 1993) it was found that there can be a backward rotating cavitation as well as a forward mode which rotates faster than impeller. Although some shaft vibration has been observed which might be caused by the backward mode, experimental evidence has been obtained only for the forward mode. The ultimate goal of the present study is to answer the question which mode of the cavitation instabilities -- cavitation surge and the two modes of rotating cavitation -- occurs in a given system and operating condition, and to find out analytical method to determine their amplitude. A time marching non-linear 2-D flow analysis was carried out for this purpose. It was found that the increase of cavitation compliance at lower inlet pressure can be a factor which limits the amplitude. The mode selectivity is mainly dependent on the stability limit obtained by a linear analysis for which the phase delay of cavity has a most important effect.

Tsujimoto, Y.; Watanabe, S.; Yoshida, Y. [Osaka Univ., Osaka (Japan); Kamijo, K. [Kakuda Research Center (Japan). Rocket Propulsion Division

1994-12-31T23:59:59.000Z

99

Quantum tunneling in the adiabatic Dicke model  

SciTech Connect (OSTI)

The Dicke model describes N two-level atoms interacting with a single-mode bosonic field and exhibits a second-order phase transition from the normal to the superradiant phase. The energy levels are not degenerate in the normal phase but have degeneracy in the superradiant phase, where quantum tunneling occurs. By means of the Born-Oppenheimer approximation and the instanton method in quantum field theory, the tunneling splitting, inversely proportional to the tunneling rate for the adiabatic Dicke model, in the superradiant phase can be evaluated explicitly. It is shown that the tunneling splitting vanishes as exp(-N) for large N, whereas for small N it disappears as {radical}(N)/exp(N). The dependence of the tunneling splitting on the relevant parameters, especially on the atom-field coupling strength, is also discussed.

Chen Gang [Department of Physics, Shaoxing College of Arts and Sciences, Shaoxing 312000 (China); Institute of Theoretical Physics, Shanxi University, Taiyuan 030006 (China); Chen Zidong [Department of Physics, Shaoxing College of Arts and Sciences, Shaoxing 312000 (China); Liang Jiuqing [Institute of Theoretical Physics, Shanxi University, Taiyuan 030006 (China)

2007-10-15T23:59:59.000Z

100

Proceedings of the 8th International Symposium on Cavitation CAV2012 -Abstract No. 198  

E-Print Network [OSTI]

Proceedings of the 8th International Symposium on Cavitation CAV2012 - Abstract No. 198 August 14-PHASE FLOW WITH CAVITATION Keh-Ming Shyue Department of Mathematics National Taiwan University Taipei, Taiwan for the efficient numerical simulation of compressible two-phase flow with cavitation. The algorithm uses a five

Shyue, Keh-Ming

Note: This page contains sample records for the topic "large cavitation tunnel" 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.


101

Modeling for non isothermal cavitation using four-equation Eric Goncalv`es  

E-Print Network [OSTI]

Modeling for non isothermal cavitation using four-equation models Eric Goncalv`es LEGI-fluid solver has been developed to investigate the behaviour of cavitation models including thermodynamic between phases are studied. Numerical simulations are firstly performed on rarefaction cavitating problems

Paris-Sud XI, Université de

102

Ultrasound-induced lung hemorrhage is not caused by inertial cavitation  

E-Print Network [OSTI]

Ultrasound-induced lung hemorrhage is not caused by inertial cavitation William D. O'Brien, Jr to an inertial cavitation mechanism. The purpose of this article is to report the results of two experiments that directly contradict the hypothesis that ultrasound-induced lung hemorrhage is caused by inertial cavitation

Illinois at Urbana-Champaign, University of

103

ON THE DrFF,US~VE CAVITATION OF ISOLATED GRAIN BOUNDARY FACETS TN  

E-Print Network [OSTI]

ON THE DrFF,US~VE CAVITATION OF ISOLATED GRAIN BOUNDARY FACETS TN CREEPING POLYCRYSTALS J. R. RICE-Following concepts introduced by B. F. Dyson (Metal Sci.349 19761,the dilTusive cavitation of grain facets is considered in circumstances for which the cavitated fasts are well separated from one another. In this case

104

Controlled Multibubble Surface Cavitation Nicolas Bremond,* Manish Arora, Claus-Dieter Ohl, and Detlef Lohse  

E-Print Network [OSTI]

Controlled Multibubble Surface Cavitation Nicolas Bremond,* Manish Arora, Claus-Dieter Ohl been notorious because of its irreproducibility. Here controlled multibubble surface cavitation of the cavitation events where the inner bubbles in the two- dimensional cluster are shielded by the outer ones

Ohl, Claus-Dieter

105

Capacitive effect of cavitation in xylem conduits: results from a dynamic model  

E-Print Network [OSTI]

Capacitive effect of cavitation in xylem conduits: results from a dynamic model TEEMU HÃ?LTTÃ?1. A dynamic model is presented that models xylem water potential, xylem sap flow and cavitation, taking; xylem transport. INTRODUCTION Xylem embolism formation by cavitation causes a decrease in plant

Mencuccini, Maurizio

106

Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation  

E-Print Network [OSTI]

Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions)" #12;Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions, cavitation, fluid flow load, CFD. Abstract: The evaluation of fluid forces on the stem is important for wear

Paris-Sud XI, Université de

107

Proceedings of the 8th International Symposium on Cavitation CAV2012 -Abstract No. #240  

E-Print Network [OSTI]

Proceedings of the 8th International Symposium on Cavitation CAV2012 - Abstract No. #240 August 14-16, 2012, Singapore STUDY OF PASSIVE CONTROL STUDY OF THE CAVITATION INSTABILITY ON A VENTURI PROFILE Am SUMMARY As a source of vibrations, noise, erosion and structure dam- ages, cavitation is a major handicap

Paris-Sud XI, Université de

108

APPLICATION OF BUTTERFLY VALVES FOR FREE DISCHARGE, MINIMUM PRESSURE DROP, AND FOR CHOKING CAVITATION  

E-Print Network [OSTI]

CAVITATION Butterfly valves are commonly used as control valves in applications where the pressure drops and the use of a butterfly valve for flashing or choking cavitation service. Free discharge typically produces high pipe velocities at moderate pressure drops, and choking cavitation typically produces high

Rahmeyer, William J.

109

Graphite-to-diamond transformation induced by ultrasound cavitation A.Kh. Khachatryan a,c  

E-Print Network [OSTI]

Graphite-to-diamond transformation induced by ultrasound cavitation A.Kh. Khachatryan a,c , S microcrystals have been synthesized using ultrasonic cavitation of a suspension of hexagonal graphite in various. © 2008 Elsevier B.V. All rights reserved. Keywords: Ultrasound cavitation; Microcrystalline diamond 1

Bristol, University of

110

Cavitation and the state of stress in a flowing liquid Daniel D. Joseph  

E-Print Network [OSTI]

Cavitation and the state of stress in a flowing liquid Daniel D. Joseph University of Minnesota The problem of the inception of cavitation is formulated in terms of a compar- ison of the breaking strength or cavitation threshold at each point of a liquid sam- ple with the principal stresses there. A criterion

Joseph, Daniel D.

111

Prevention of tissue damage by water jet during cavitation Daniel Palanker,a)  

E-Print Network [OSTI]

Prevention of tissue damage by water jet during cavitation Daniel Palanker,a) Alexander Vankov Cavitation bubbles accompany explosive vaporization of water following pulsed energy deposition in liquid can produce tissue damage at a distance exceeding the radius of the cavitation bubble by a factor of 4

Palanker, Daniel

112

Vulnerability of Xylem Vessels to Cavitation in Sugar Maple. Scaling from Individual Vessels to  

E-Print Network [OSTI]

Vulnerability of Xylem Vessels to Cavitation in Sugar Maple. Scaling from Individual Vessels 02318 (M.A.Z., N.M.H.) The relation between xylem vessel age and vulnerability to cavitation of sugar-related changes in vulnerability to the overall resistance to cavitation, we combined data on the pressure

Melcher, Peter

113

Birth and Growth of Cavitation Bubbles within Water under Tension Confined in a Simple Synthetic Tree  

E-Print Network [OSTI]

Birth and Growth of Cavitation Bubbles within Water under Tension Confined in a Simple Synthetic. Cavitation can spontaneously occur, nucleating a bubble. We investigate the dynamics of spontaneous or triggered cavitation inside water filled microcavities of a hydrogel. Results show that a stable bubble

Ohl, Claus-Dieter

114

Denoual, C., and Diani, J.M., 2002, ``Cavitation in Compressible Visco-Plastic Materials",  

E-Print Network [OSTI]

Denoual, C., and Diani, J.M., 2002, ``Cavitation in Compressible Visco-Plastic Materials", Shock-498. CAVITATION IN COMPRESSIBLE VISCO­PLASTIC MATERIALS C. Denoual and J. M. Diani D´epartement de Physique Th materials in hydrostatic tension is a cavitation instabil- ity ¡£¢¥¤ , i.e., nucleation and coalescence

Paris-Sud XI, Université de

115

ImageGuided Ex vivo Liver Ablation by Unfocused Ultrasound using Passive Cavitation Detection  

E-Print Network [OSTI]

Image­Guided Ex vivo Liver Ablation by Unfocused Ultrasound using Passive Cavitation Detection echogenicity from image brightness. Passively detected acoustic emissions are used to quantify cavitation and cavitation. The latter two quantities can potentially be monitored noninvasively and used as a surrogate

Mast, T. Douglas

116

Cavitation pressure in water Eric Herbert, Sbastien Balibar, and Frdric Caupin  

E-Print Network [OSTI]

Cavitation pressure in water Eric Herbert, Sébastien Balibar, and Frédéric Caupin Laboratoire de investigate the limiting mechanical tension negative pressure that liquid water can sustain before cavitation experiments on cavitation, we describe our method which consists in focusing a high amplitude sound wave

Caupin, Frédéric

117

Megasonic cleaning of wafers in electrolyte solutions: Possible role of electro-acoustic and cavitation effects  

E-Print Network [OSTI]

-acoustic and cavitation effects M. Keswani a , S. Raghavan a,*, P. Deymier a , S. Verhaverbeke b a Materials Science Keywords: Wafer Cleaning Electrolyte Megasonic Electro-acoustic Cavitation Pressure amplitude a b s t r a c Waals adhesion forces. The effect of ionic strength on cavitation has been investigated through

Deymier, Pierre

118

Plasma Line Emission during Single-Bubble Cavitation David J. Flannigan and Kenneth S. Suslick*  

E-Print Network [OSTI]

Plasma Line Emission during Single-Bubble Cavitation David J. Flannigan and Kenneth S. Suslick-bubble cavitation in sulfuric acid are reported. The excited states responsible for these emission lines range 8.3 e the plasma generated during cavitation is comprised of highly energetic particles. DOI: 10.1103/Phys

Suslick, Kenneth S.

119

Xylem cavitation caused by drought and freezing stress in four co-occurring Juniperus species  

E-Print Network [OSTI]

Xylem cavitation caused by drought and freezing stress in four co-occurring Juniperus species: 10.1111/j.1399-3054.2006.00644.x Previous studies indicate that conifers are vulnerable to cavitation cavitation, along with wood density, conduit reinforcement, trac- heid diameter, and hydraulic conductivity

Jackson, Robert B.

120

In vivo transcranial cavitation threshold detection during ultrasound-induced bloodbrain barrier opening in mice  

E-Print Network [OSTI]

In vivo transcranial cavitation threshold detection during ultrasound-induced blood­brain barrier cavitation threshold detection during ultrasound-induced blood­brain barrier opening in mice Yao-Sheng Tung1 cavitation response associated with blood­brain barrier (BBB) opening as induced by transcranial focused

Konofagou, Elisa E.

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Chemistry Induced by Hydrodynamic Cavitation Kenneth S. Suslick,* Millan M. Mdleleni, and  

E-Print Network [OSTI]

Chemistry Induced by Hydrodynamic Cavitation Kenneth S. Suslick,* Millan M. Mdleleni, and Jeffrey T, Urbana, Illinois 61801 ReceiVed July 1, 1997 Cavitation (the formation, growth, and implosive collapse the chemical effects of acoustic cavitation (i.e., sonochemistry and sonoluminescence) have been extensively

Suslick, Kenneth S.

122

Modeling for isothermal cavitation with a four-equation model Eric Goncalv`es  

E-Print Network [OSTI]

Modeling for isothermal cavitation with a four-equation model Eric Goncalv`es , Boris Charri-dimensional inviscid cavitating tube problems. This mass transfer term appears explicitly as a source term of a void realistic cavitating flows. Numerical results are given for various inviscid cases (underwater explosion

Paris-Sud XI, Université de

123

Effect of Nuclei Concentration on Cavitation Cluster Dynamics C.D. Ohl, and D. Lohse  

E-Print Network [OSTI]

Effect of Nuclei Concentration on Cavitation Cluster Dynamics M. Arora, C.D. Ohl, and D. Lohse, The Netherlands. (Dated: July 2, 2007) 1 #12;Abstract Cavitation cluster dynamics after the passage of a single pressure wave is studied for different concentrations of artificial cavitation nuclei (30 to 3·105 nuclei

Ohl, Claus-Dieter

124

Simulating Cavitation and Hydraulic Flip Inside Hydroentangling Nozzles H. VAHEDI TAFRESHI AND B. POURDEYHIMI  

E-Print Network [OSTI]

Simulating Cavitation and Hydraulic Flip Inside Hydroentangling Nozzles H. VAHEDI TAFRESHI AND B at high pressures. Recent studies have shown that cavitation severely affects the integrity of high-state simulation, which shows the inception and time-evolution of a cavitation cloud inside a hydroentan- gling

Tafreshi, Hooman Vahedi

125

Quantum Cavitation: a comparison between superfluid helium-4 and normal liquid helium-3  

E-Print Network [OSTI]

Quantum Cavitation: a comparison between superfluid helium-4 and normal liquid helium-3 S. Balibar Department of Physics, Brown University, Providence RI 02912, USA Cavitation has now been studied cases and discuss the existence of a crossover from quantum cavitation, where bubbles are nucleated

Caupin, Frédéric

126

Hydrodynamic cavitation and boiling in refrigerant (R-123) flow inside microchannels  

E-Print Network [OSTI]

Hydrodynamic cavitation and boiling in refrigerant (R-123) flow inside microchannels Brandon cavitation has on heat transfer. The fluid medium is refrigerant R-123 flowing through 227 lm hydraulic diameter microchannels. The cavitation is instigated by the inlet orifice. Adiabatic tests were con- ducted

Peles, Yoav

127

Cavitation Inception on Microparticles: A Self-Propelled Particle Accelerator Manish Arora,1  

E-Print Network [OSTI]

Cavitation Inception on Microparticles: A Self-Propelled Particle Accelerator Manish Arora,1 Claus) Corrugated, hydrophilic particles with diameters between 30 and 150 m are found to cause cavitation inception of the particle and the displaced liquid. The analysis suggests that all particles which cause cavitation

Ohl, Claus-Dieter

128

Cavitation pressure in water Eric Herbert, Sebastien Balibar and Frederic Caupin  

E-Print Network [OSTI]

Cavitation pressure in water Eric Herbert, S´ebastien Balibar and Fr´ed´eric Caupin Laboratoire de mechanical tension (negative pressure) that liquid water can sustain before cavitation occurs of a postulated anomaly of its equation of state. After a brief review of previous experiments on cavitation, we

Balibar, Sébastien

129

Luminescence from acoustic-driven laser-induced cavitation bubbles Claus-Dieter Ohl*  

E-Print Network [OSTI]

Luminescence from acoustic-driven laser-induced cavitation bubbles Claus-Dieter Ohl* Drittes and on the cavitation luminescence of a transient laser-induced bubble is investigated experimentally. The variation.60.Mq, 47.55.Bx, 47.55.Dz A vast concentration of energy occurs during the collapse of a cavitation

Ohl, Claus-Dieter

130

SYMPOSIUM PAPER Simulation of the effects of cavitation and anatomy in the shock  

E-Print Network [OSTI]

SYMPOSIUM PAPER Simulation of the effects of cavitation and anatomy in the shock path of model types of tissue encountered along the shock path, and by the presence of cavitation bubbles that attempt to characterize the mechanisms by which collapsing cavitation models erode stones, and by which

Dabiri, John O.

131

ccsd-00095604,version1-18Sep2006 Understanding crack versus cavitation in pressure-sensitive  

E-Print Network [OSTI]

ccsd-00095604,version1-18Sep2006 Understanding crack versus cavitation in pressure show that in addition to cavitation, interfacial cracks are encountered in a probe-tack traction test mechanisms in usual adhesives. The most common one is cavitation, as evidenced by the first tests

Paris-Sud XI, Université de

132

Comment on ``Ultrasound-induced lung hemorrhage is not caused by inertial cavitation''  

E-Print Network [OSTI]

Comment on ``Ultrasound-induced lung hemorrhage is not caused by inertial cavitation'' [J. Acoust­1297 2000 that ultrasound-induced lung hemorrhage is not caused by inertial cavitation. An argument is provided that illustrates how cavitation inception conditions in the lungs of animals are not altered

Illinois at Urbana-Champaign, University of

133

Drought experience and cavitation resistance in six shrubs from the Great Basin, Utah  

E-Print Network [OSTI]

Drought experience and cavitation resistance in six shrubs from the Great Basin, Utah Uwe G. Hacke capability of the xylem. This is due to drought-induced cavitation. We used the centrifuge method to measure the vulnerability of root and stem xylem to cavitation in six native shrub species. The shrubs fall into three

Hacke, Uwe

134

Molecular and atomic emission during single-bubble cavitation in concentrated sulfuric acid  

E-Print Network [OSTI]

Molecular and atomic emission during single- bubble cavitation in concentrated sulfuric acid David during cavitation. Single-bubble sonoluminescence (SBSL) from sulfuric acid (H2SO4) is much brighter than occurring during single- bubble cavitation. In fact, SBSL spectra from organic liquids8,9 have been

Suslick, Kenneth S.

135

PAPER www.rsc.org/loc | Lab on a Chip Laser-induced cavitation based micropump  

E-Print Network [OSTI]

PAPER www.rsc.org/loc | Lab on a Chip Laser-induced cavitation based micropump Rory Dijkinka as versatile and robust pumping techniques. Here, we present a cavitation based technique, which is able cavitation event is created by focusing a laser pulse in a conventional PDMS microfluidic chip close

Ohl, Claus-Dieter

136

A creep model for austenitic stainless steels incorporating cavitation and wedge cracking  

E-Print Network [OSTI]

A creep model for austenitic stainless steels incorporating cavitation and wedge cracking S Mahesh evolution in the form of cavitation and wedge- cracking on grain boundary facets is considered. Both: Austenitic stainless steel, creep, grain boundary sliding, cavitation, wedge- cracking. Submitted to

Mahesh, Sivasambu

137

American Journal of Botany 87(9): 12871299. 2000. VULNERABILITY TO XYLEM CAVITATION AND THE  

E-Print Network [OSTI]

1287 American Journal of Botany 87(9): 1287­1299. 2000. VULNERABILITY TO XYLEM CAVITATION to evaluate how the limitation of xylem pressure ( x) by cavitation corresponded with plant distribution along xylem, which shows the decrease in hydraulic conductance from cavitation as a function of x and the crit

Pockman, William T.

138

New Insights into the Mechanisms of Water-Stress-Induced Cavitation in Conifers  

E-Print Network [OSTI]

New Insights into the Mechanisms of Water-Stress-Induced Cavitation in Conifers Herve´ Cochard of Edinburgh, Edinburgh EH9 3JN, United Kingdom (M.M.) Cavitation resistance is a key parameter to understand at a pressure sufficient to aspirate pit tori and well above the pressure for cavitation induction we failed

Mencuccini, Maurizio

139

Cavitation and the state of stress in a flowing liquid Daniel D. Joseph  

E-Print Network [OSTI]

Cavitation and the state of stress in a flowing liquid Daniel D. Joseph University of Minnesota The problem of the inception of cavitation is formulated in terms of a compar­ ison of the breaking strength or cavitation threshold at each point of a liquid sam­ ple with the principal stresses there. A criterion

Joseph, Daniel D.

140

Cavitation within a dropletCavitation within a droplet G. L. Heijnen1,2, P. A. Quinto-Su2, X. Zhao2, C. D. Ohl1,2  

E-Print Network [OSTI]

Cavitation within a dropletCavitation within a droplet G. L. Heijnen1,2, P. A. Quinto-Su2, X. Zhao2 University, Singapore. A cavitation bubble expanding and collapsing inside a liquid droplet creates two high jets taken 400µs after the cavitation bubble has been created. The central jet is surrounded

Ohl, Claus-Dieter

Note: This page contains sample records for the topic "large cavitation tunnel" 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

A nonlinear calculation of rotating cavitation in inducers  

SciTech Connect (OSTI)

In the previous linear analysis (Tsujimoto et al., 1993) it was found that there can be a backward rotating cavitation as well as a forward mode which rotates faster than impeller. Although some shaft vibration has been observed, which might be caused by the backward mode, experimental evidence has been obtained only for the forward mode. The purpose of the present study is to find out the factors which determine the amplitude of each mode of rotating cavitation by taking into account several nonlinearities. A time marching nonlinear 2-D flow analysis was carried out for this purpose. It was found that the increase of cavitation compliance at lower inlet pressure can be a factor which limits the amplitude. The mode selectivity is mainly dependent on the stability limit obtained by a linear analysis for which the phase delay of cavity has a most important effect.

Tsujimoto, Y. [Osaka Univ., Toyonaka, Osaka (Japan). Dept. of Mechanical Engineering]|[National Aerospace Lab., Kakuda, Miyagi (Japan); Watanabe, S.; Yoshida, Y. [Osaka Univ., Toyonaka, Osaka (Japan); Kamijo, K. [National Aerospace Lab., Kakuda, Miyagi (Japan)

1996-09-01T23:59:59.000Z

142

Cavitation rheology for soft materials Jessica A. Zimberlin, Naomi Sanabria-DeLong, Gregory N. Tew and Alfred J. Crosby*  

E-Print Network [OSTI]

Cavitation rheology for soft materials Jessica A. Zimberlin, Naomi Sanabria-DeLong, Gregory N. Tew the modulus local to the site of cavitation, heterogeneities within a material can easily be probed systems. 2. Experimental 2.1 Cavitation rheology technique (CRT) Cavitation rheology involves quantifying

Tew, Gregory N.

143

Cavitation in a metallic liquid: Homogeneous nucleation and growth of nanovoids  

SciTech Connect (OSTI)

Large-scale molecular dynamics (MD) simulations are performed to investigate homogeneous nucleation and growth of nanovoids during cavitation in liquid Cu. We characterize in detail the atomistic cavitation processes by following the temporal evolution of cavities or voids, analyze the nucleation behavior with the mean first-passage time (MFPT) and survival probability (SP) methods, and discuss the results against classical nucleation theory (CNT), the Tolman equation for surface energy, independent calculation of surface tension via integrating the stress profiles, the Johnson-Mehl-Avrami (JMA) growth law, and the power law for nucleus size distributions. Cavitation in this representative metallic liquid is a high energy barrier Poisson processes, and the steady-state nucleation rates obtained from statistical runs with the MFPT and SP methods are in agreement. The MFPT method also yields the critical nucleus size and the Zeldovich factor. Fitting with the Tolman's equation to the MD simulations yields the surface energy of a planar interface (?0.9 J m{sup ?2}) and the Tolman length (0.4–0.5 Å), and those values are in accord with those from integrating the stress profiles of a planar interface. Independent CNT predictions of the nucleation rate (10{sup 33?34} s{sup ?1} m{sup ?3}) and critical size (3–4 Å in radius) are in agreement with the MFPT and SP results. The JMA law can reasonably describe the nucleation and growth process. The size distribution of subcritical nuclei appears to follow a power law with an exponent decreasing with increasing tension owing to coupled nucleation and growth, and that of the supercritical nuclei becomes flattened during further stress relaxation due to void coalescence.

Cai, Y. [Department of Modern Mechanics, CAS Key Laboratory of Materials Behavior and Design, University of Science and Technology of China, Hefei, Anhui 230027 (China); The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610207 (China); Wu, H. A., E-mail: wuha@ustc.edu.cn [Department of Modern Mechanics, CAS Key Laboratory of Materials Behavior and Design, University of Science and Technology of China, Hefei, Anhui 230027 (China); Luo, S. N., E-mail: sluo@pims.ac.cn [The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610207 (China)

2014-06-07T23:59:59.000Z

144

Effect of austempering temperature on cavitation behaviour of unalloyed ADI material  

SciTech Connect (OSTI)

This paper provides an in-depth study and description of cavitation damage and microstructural changes in two types of unalloyed austempered ductile iron (ADI). ADI materials used were austempered at 300 and 400 °C having ausferrite microstructure with 16 and 31.4% of retained austenite, respectively. Metallographic examination was carried out to study the morphology of their cavitation-damaged surfaces. Cavitation damage was initiated at graphite nodules as well as in the interface between a graphite nodule and an ausferrite matrix. Furthermore, microcracking and ferrite/retained austenite morphology were proved to be of great importance for cavitation resistance. Mass loss rate revealed that ADI austempered at 400 °C has a higher cavitation resistance in water than ADI austempered at 300 °C. A higher amount of retained austenite in ADI austempered at 400 °C played an important role in increasing cavitation resistance. The good cavitation behaviour of ADI austempered at 400 °C was due to the matrix hardening by stress assisted phase transformation of retained austenite into martensite (SATRAM) phenomenon, as shown by X-ray diffraction analysis. - Highlights: • Cavitation rate of two ADI materials was tested. • ADI material with a lower hardness has had a lower cavitation rate. • The main reason is microstructural transformations during cavitation. • SATRAM phenomenon increases cavitation resistance.

Dojcinovic, Marina [University of Belgrade, Faculty of Technology and Metallurgy, Karnegijeva 4, Belgrade (Serbia); Eric, Olivera [Innovation Centre, Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, Belgrade (Serbia); Rajnovic, Dragan; Sidjanin, Leposava [Department of Production Engineering, Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovi?a 6, Novi Sad (Serbia); Balos, Sebastian, E-mail: sebab@uns.ac.rs [Department of Production Engineering, Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovi?a 6, Novi Sad (Serbia)

2013-08-15T23:59:59.000Z

145

Large  

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 MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample6, 2011 CERN 73-11Large area avalanche photodiode

146

Compressible Effects Modelling in Turbulent Cavitating Jean Decaix  

E-Print Network [OSTI]

Nomenclature c speed of sound Cp, Cv thermal capacities E total energy Corresponding author. Email address area because of the drastic diminution of the speed of sound. The detailed mechanisms cavitation number total stress tensor specific dissipation ()L liquid value ()V vapour value ()v viscous

Paris-Sud XI, Université de

147

The Tunneling Transform  

E-Print Network [OSTI]

We supplement the Lorentz transform $L(v)$ with a new "Tunneling" transform $T(v)$. Application of this new transform to elementary quantum mechanics offers a novel, intuitive insight into the nature of quantum tunneling; in particular, the so called "Klein Paradox" is discussed.

Robert Hipple

2014-11-10T23:59:59.000Z

148

Dynamique d'une bulle cylindrique de cavitation : tude analytique et validation de la mthode  

E-Print Network [OSTI]

Dynamique d'une bulle cylindrique de cavitation : étude analytique et validation de la méthode. Introduction La présente étude a pour objectif dans un premier temps d'étudier analytiquement la cavitation permettra par la suite d'étudier la cavitation numériquement. La méthode numérique Lagrangienne SPH est

149

Onset of cavitation in the quark-gluon plasma  

E-Print Network [OSTI]

We study the onset of bubble formation (cavitation) in the quark-gluon plasma as a result of the reduction of the effective pressure from bulk-viscous corrections. By calculating velocity gradients in typical models for quark-gluon plasma evolution in heavy-ion collisions, we obtain results for the critical bulk viscosity above which cavitation occurs. Since present experimental data for heavy-ion collisions seems inconsistent with the presence of bubbles above the phase transition temperature of QCD, our results may be interpreted as an upper limit of the bulk viscosity in nature. Our results indicate that bubble formation is consistent with the expectation of hadronisation in low-temperature QCD.

Mathis Habich; Paul Romatschke

2014-07-11T23:59:59.000Z

150

acoustic cavitation of slightly subcritical bubbles of Mathematics, Boston University, Boston, Massachusetts 02215  

E-Print Network [OSTI]

On acoustic cavitation of slightly subcritical bubbles Anthony ¡ Harkin Department in liquids when surface tension is the dominant effect, such as submicron air bubbles in water, where

Harkin, Anthony

151

Comment on "Nuclear Emissions During Self-Nucleated Acoustic Cavitation"  

E-Print Network [OSTI]

In a recent Letter to PRL, Taleyarkhan and coauthors claim to observe DD fusion produced by acoustic cavitation. Among other evidence, they provide a proton recoil spectrum that they interpret as arising from 2.45 MeV DD fusion neutrons. My analysis concludes the spectrum is inconsistent with 2.45 MeV neutrons, cosmic background, or a PuBe source, but it is consistent with a Cf-252 source.

B. Naranjo

2006-09-12T23:59:59.000Z

152

Measurements and computations of second-mode instability waves in three hypersonic wind tunnels.  

SciTech Connect (OSTI)

High-frequency pressure-fluctuation measurements were made in AEDC Tunnel 9 at Mach 10 and the NASA Langley 15-Inch Mach 6 and 31-Inch Mach 10 tunnels. Measurements were made on a 7{sup o}-half-angle cone model. Pitot measurements of freestream pressure fluctuations were also made in Tunnel 9 and the Langley Mach-6 tunnel. For the first time, second-mode waves were measured in all of these tunnels, using 1-MHz-response pressure sensors. In Tunnel 9, second-mode waves could be seen in power spectra computed from records as short as 80 {micro}s. The second-mode wave amplitudes were observed to saturate and then begin to decrease in the Langley tunnels, indicating wave breakdown. Breakdown was estimated to occur near N {approx} 5 in the Langley Mach-10 tunnel. The unit-Reynolds-number variations in the data from Tunnel 9 were too large to see the same processes.

Lewis, Daniel R. (Aerospace Testing Alliance, Silver Spring, MD); Alba, Christopher R. (Air Force Research Laboratory, Wright-Patterson AFB, OH); Rufer, Shann J. (NASA Langley Research Center, Hampton, VA); Beresh, Steven Jay; Casper, Katya M.; Berridge, Dennis C. (Purdue University, West Lafayette, IN); Schneider, Steven P. (Purdue University, West Lafayette, IN)

2010-06-01T23:59:59.000Z

153

Summary We tested the hypothesis that greater cavitation resistance correlates with less total inter-vessel pit area per ves-  

E-Print Network [OSTI]

Summary We tested the hypothesis that greater cavitation resistance correlates with less total cavitation safety and transport efficiency. Fourteen species of diverse growth form (vine, ring- and diffuse species total). Two types of vulnerability-to-cavitation curves were found. Ring-porous trees and vines

Hacke, Uwe

154

Passive cavitation imaging with ultrasound arrays Vasant A. Salgaonkar, Saurabh Datta, Christy K. Holland, and T. Douglas Masta  

E-Print Network [OSTI]

Passive cavitation imaging with ultrasound arrays Vasant A. Salgaonkar, Saurabh Datta, Christy K September 2009 A method is presented for passive imaging of cavitational acoustic emissions using, stable and inertial cavitation was passively imaged in saline solution sonicated at 520 kHz. Bubble

Mast, T. Douglas

155

Ecological differentiation in xylem cavitation resistance is associated with stem and leaf structural traitspce_2231 137..148  

E-Print Network [OSTI]

Ecological differentiation in xylem cavitation resistance is associated with stem and leaf ABSTRACT Cavitation resistance is a critical determinant of drought tolerance in tropical tree species how vulnerability to cavitation (P50) related to dry season leaf water poten- tials and stem and leaf

Sack, Lawren

156

A finite element approach to study cavitation instabilities in non-linear elastic solids under general loading conditions  

E-Print Network [OSTI]

A finite element approach to study cavitation instabilities in non-linear elastic solids under a b s t r a c t This paper proposes an effective numerical method to study cavitation instabilities a single infinitesimal defect at its center. The occurrence of cavitation is identified as the event when

Lopez-Pamies, Oscar

157

JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 15, NO. 5, OCTOBER 2006 1319 Development of Cavitation in Refrigerant (R-123)  

E-Print Network [OSTI]

of Cavitation in Refrigerant (R-123) Flow Inside Rudimentary Microfluidic Systems Chandan Mishra and Yoav Peles Abstract--The existence of hydrodynamic cavitation in the flow of refrigerant (R-123) through micro-Venturis has been viewed in the form of a bubbly cavitating regime. Flow visualization discloses inchoate

Peles, Yoav

158

REVIEW OF SCIENTIFIC INSTRUMENTS 82, 034904 (2011) Fiber optic probe hydrophone for the study of acoustic cavitation in water  

E-Print Network [OSTI]

of acoustic cavitation in water Arnaud Arvengas, Kristina Davitt, and Frédéric Caupina) Laboratoire de. Accord- ing to nucleation theory, increasing the ultrasound frequency increases the cavitation threshold in liquids. We are able to resolve the fractional change in the pressure threshold for cavitation in water

Davitt, Kristina

159

Feasibility of noninvasive cavitation-guided blood-brain barrier opening using focused ultrasound and microbubbles in nonhuman  

E-Print Network [OSTI]

Feasibility of noninvasive cavitation-guided blood-brain barrier opening using focused ultrasound://apl.aip.org/about/rights_and_permissions #12;Feasibility of noninvasive cavitation-guided blood-brain barrier opening using focused ultrasound 2011; published online 20 April 2011 In vivo transcranial and noninvasive cavitation detection

Konofagou, Elisa E.

160

Cavitation in flow through a micro-orifice inside a silicon microchannel Chandan Mishra and Yoav Pelesa)  

E-Print Network [OSTI]

Cavitation in flow through a micro-orifice inside a silicon microchannel Chandan Mishra and Yoav) Hydrodynamic cavitation in flows through a micro-orifice entrenched in a microchannel has been detected. The flow of de-ionized water through the micro-orifice reveals the presence of multifarious cavitating flow

Peles, Yoav

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Cavitation inception following shock wave passage Department of Applied Physics, TU Twente, Postbus 217, 7500 AE Enschede, The Netherlands  

E-Print Network [OSTI]

Cavitation inception following shock wave passage C. D. Ohl Department of Applied Physics, TU; published 5 September 2002 Cavitation bubble nucleation following the passage of an extracorporeal shock of the bubble center; however, considerable disagreement between a simple cavitation inception theory

Ohl, Claus-Dieter

162

Resonance et contr^ole en cavite ouverte Jer^ome Hoepffner  

E-Print Network [OSTI]

R´esonance et contr^ole en cavit´e ouverte J´er^ome Hoepffner KTH, Sweden Avec Espen °Akervik, Uwe) From Rowley et al, JFM 2002 Self sustained cycle: perturbation growth pressure wave new perturbation localised and where are they sensitive ? #12;Optimal transient energy growth from initial conditions System

Hoepffner, Jérôme

163

A CAVITATION TRACKING METHOD FOR ELASTIC-PLASTIC FLOW IN SOLIDS  

E-Print Network [OSTI]

A CAVITATION TRACKING METHOD FOR ELASTIC-PLASTIC FLOW IN SOLIDS Keh-Ming Shyue Department tracking approach for the numerical simulation of one-dimensional elastic- plastic flow in solids, and the von Mises condition for the elastic-plastic phase change. To characterize the cavitation

Shyue, Keh-Ming

164

Cavitation and two-phase flow characteristics of SRPR (Savannah River Plant Reactor) pump. Final report  

SciTech Connect (OSTI)

The possible head degradation of the SRPR pumps may be attributable to two independent phenomena, one due to the inception of cavitation and the other due to the two-phase flow phenomena. The head degradation due to the appearance of cavitation on the pump blade is hardly likely in the conventional pressurized water reactor (PWR) since the coolant circulating line is highly pressurized so that the cavitation is difficult to occur even at LOCA (loss of coolant accident) conditions. On the other hand, the suction pressure of SRPR pump is order-of-magnitude smaller than that of PWR so that the cavitation phenomena, may prevail, should LOCA occur, depending on the extent of LOCA condition. In this study, therefore, both cavitation phenomena and two-phase flow phenomena were investigated for the SRPR pump by using various analytical tools and the numerical results are presented herein.

Not Available

1991-07-01T23:59:59.000Z

165

Cavitation erosion of silver plated coating at different temperatures and pressures  

SciTech Connect (OSTI)

Cavitation often occurs in inducer pumps used for space rockets. Silver plated coating on the inducer liner faces the damage of cavitation. Therefore, it is important to study about the cavitation erosion resistance for silver plated coating at several operating conditions in the inducer pumps. In this study, the cavitation erosion tests were carried for silver plated coating in deionized water and ethanol at several liquid temperatures (273K–400K) and pressures (0.10MPa–0.48MPa). The mass loss rate is evaluated in terms of thermodynamic parameter ? proposed by Brennen [9], suppression pressure p–p{sub v} (p{sub v}: saturated vapor pressure) and acoustic impedance ?c (?: density and c: sound speed). Cavitation bubble behaviors depending on the thermodynamic effect and the liquid type were observed by high speed video camera. The mass loss rate is formulated by thermodynamic parameter ?, suppression pressure p–p{sub v} and acoustic impedance ?c.

Hattori, Shuji; Motoi, Yoshihiro [Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fuku-shi, Fukui 910-8507 (Japan); Kikuta, Kengo; Tomaru, Hiroshi [IHI Corperation, TOYOSU IHI BUILDING, 1-1, Toyosu 3-chome, Koto-ku, Tokyo 1358710 (Japan)

2014-04-11T23:59:59.000Z

166

Penn Small Water Tunnel | 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 Center Home5b9fcbce19 No revision hasInformation Earth'sOklahoma/GeothermalOrange County isParadise,Large Water TunnelWater Tunnel

167

Prediction of the reversibility of the ultrasound-induced blood-brain barrier opening using passive cavitation detection with magnetic resonance imaging  

E-Print Network [OSTI]

cavitation detection with magnetic resonance imaging validation Tao Sun1 , Gesthimani Samiotaki1 and Elisa E (diameters: 1-2, 4-5, or 6-8 m). A 10-MHz passive cavitation detector was used to acquire cavitation signals that the stable cavitation dose increased with the number of days required for closing while it reached a plateau

Konofagou, Elisa E.

168

Method of forming cavitated objects of controlled dimension  

DOE Patents [OSTI]

A method of controllably varying the dimensions of cavitated objects such as hollow spherical shells wherein a precursor shell is heated to a temperature above the shell softening temperature in an ambient atmosphere wherein the ratio of gases which are permeable through the shell wall at that temperature to gases which are impermeable through the shell wall is substantially greater than the corresponding ratio for gases contained within the precursor shell. As the shell expands, the partial pressures of permeable gases internally and externally of the shell approach and achieve equilibrium, so that the final shell size depends solely upon the difference in impermeable gas partial pressures and shell surface tension.

Anderson, Paul R. (Toledo, OH); Miller, Wayne J. (Ann Arbor, MI)

1982-01-01T23:59:59.000Z

169

Method of forming cavitated objects of controlled dimension  

DOE Patents [OSTI]

A method is disclosed of controllably varying the dimensions of cavitated objects such as hollow spherical shells wherein a precursor shell is heated to a temperature above the shell softening temperature in an ambient atmosphere wherein the ratio of gases which are permeable through the shell wall at that temperature to gases which are impermeable through the shell wall is substantially greater than the corresponding ratio for gases contained within the precursor shell. As the shell expands, the partial pressures of permeable gases internally and externally of the shell approach and achieve equilibrium, so that the final shell size depends solely upon the difference in impermeable gas partial pressures and shell surface tension.

Anderson, P.R.; Miller, W.J.

1981-02-11T23:59:59.000Z

170

Risk analysis for tunneling projects  

E-Print Network [OSTI]

Tunnel construction is increasing world wide. Although the majority of tunnel construction projects have been completed safely, there have been several incidents that have resulted in delays, cost overruns, and sometimes ...

Sousa. Rita L

2010-01-01T23:59:59.000Z

171

Lamellar thickness and stretching temperature dependency of cavitation in semicrystalline polymers  

E-Print Network [OSTI]

Polybutene-1 (PB-1), a typical semicrystalline polymer, in its stable form I shows a peculiar temperature dependent strain-whitening behavior when being stretched at different temperatures where the extent of strain-whitening weakens with the increasing of stretching temperature reaching a minima value followed by an increase at higher stretching temperatures. Correspondingly, a stronger strain-hardening phenomenon was observed at higher stretching temperatures. The strain-whitening phenomenon in semicrystalline polymers has its origin of cavitation process during stretching. In this work, the effect of crystalline lamellar thickness and stretching temperature on the cavitation process in PB-1 has been investigated by means of combined synchrotron ultrasmall-angle and wide-angle X-ray scattering techniques. It was found that, with respect to the cavitation process, three modes of cavitation during the stretching process can be identified, namely no cavitation for sample with the thinnest lamellae where only shear yielding occurred, cavitation with reorientation for the samples stretched at lower temperatures and samples with thicker lamellae, and cavitation without reorientation for samples with thinner lamellae stretched at higher temperatures. The mode cavitation with reorientation occurs before yield point where the plate-like cavities start to be generated within the lamellar stacks with normal perpendicular to the stretching direction due to the blocky substructure of the crystalline lamellae and reorient gradually to the stretching direction after strain-hardening. The mode of cavitation without reorientation appears after yield point where ellipsoidal shaped cavities are generated in those lamellae stacks with normal parallel to the stretching direction followed by an improvement of their orientation at larger strains.

Yaotao Wang; Zhiyong Jiang; Lianlian Fu; Ying Lu; Yongfeng Men

2014-05-13T23:59:59.000Z

172

On the dynamics and acoustics of cloud cavitation on an oscillating hydrofoil  

SciTech Connect (OSTI)

Observations have been made of the growth and collapse of surface and cloud cavitation on a finite aspect ratio hydrofoil oscillating in pitch. The cavitation was recorded using both still and high-speed motion picture photography, and the variations with cavitation number and reduced frequency of oscillation were investigated. The noise generated by the cavity collapse was also measured and analyzed. The acoustic signals associated with individual cavity collapse events have been synchronized with the motion pictures, providing insights into the correspondence between the flow structures involved in the cavity collapse process and the sound generated by them.

McKenney, E.A.; Brennen, C.E. [California Inst. of Tech., Pasadena, CA (United States). Dept. of Mechanical Engineering

1994-12-31T23:59:59.000Z

173

Cavitation controlled acoustic probe for fabric spot cleaning and moisture monitoring  

DOE Patents [OSTI]

A method and apparatus are provided for monitoring a fabric. An acoustic probe generates acoustic waves relative to the fabric. An acoustic sensor, such as an accelerometer is coupled to the acoustic probe for generating a signal representative of cavitation activity in the fabric. The generated cavitation activity representative signal is processed to indicate moisture content of the fabric. A feature of the invention is a feedback control signal is generated responsive to the generated cavitation activity representative signal. The feedback control signal can be used to control the energy level of the generated acoustic waves and to control the application of a cleaning solution to the fabric.

Sheen, Shuh-Haw (Naperville, IL); Chien, Hual-Te (Naperville, IL); Raptis, Apostolos C. (Downers Grove, IL)

1997-01-01T23:59:59.000Z

174

Investigation of aluminum surface cleaning using cavitating fluid flow  

SciTech Connect (OSTI)

This paper investigates efficiency of specially designed atomizer used to spray water and cavitate microbubbles in water flow. Surface cleaning system was used to clean machined (grinded) aluminum surface from abrasive particles. It is established that cleaning efficiency depends on diameter of the diffuser, water pressure and distance between nozzle and metal surface. It is obtained that the best cleaning efficiency (100%) is achieved at pressure 36 bar, when diameter of diffuser is 0.4 mm and distance between nozzle and surface is 1 mm. It is also established that satisfactory cleaning efficiency (80%) is achieved not only when atomizer is placed closer to metal surface, but also at larger (120 mm) distances.

Ralys, Aurimas; Striška, Vytautas; Mokšin, Vadim [Vilnius Gediminas Technical University, Faculty of Mechanics, Department of Machine Engineering, J. Basanavi?iaus str.28, 03224, Vilnius (Lithuania)

2013-12-16T23:59:59.000Z

175

Cavitation from bulk viscosity in neutron stars and quark stars  

E-Print Network [OSTI]

The bulk viscosity in quark matter is sufficiently high to reduce the effective pressure below the corresponding vapor pressure during density perturbations in neutron stars and strange stars. This leads to mechanical instability where the quark matter breaks apart into fragments comparable to cavitation scenarios discussed for ultra-relativistic heavy-ion collisions. Similar phenomena may take place in kaon-condensed stellar cores. Possible applications to compact star phenomenology include a new mechanism for damping oscillations and instabilities, triggering of phase transitions, changes in gravitational wave signatures of binary star inspiral, and astrophysical formation of strangelets. At a more fundamental level it points to the possible inadequacy of a hydrodynamical treatment of these processes in compact stars.

Jes Madsen

2009-09-30T23:59:59.000Z

176

Effect of cavitation on the properties of coal-tar pitch as studied by gas-liquid chromatography  

SciTech Connect (OSTI)

The applicability of the cavitation-wave effect to coal-tar pitch processing is considered. The results of the GLC analysis of the test material before and after rotor-pulsation cavitation treatment are given. The organic matter of coal-tar pitch was found to degrade upon cavitation; as a result of this, the yields of light and medium fractions considerably increased. 5 refs., 2 figs., 4 tabs.

M.I. Baikenov; T.B. Omarbekov; S.K. Amerkhanova (and others) [Buketov State University, Karaganda (Kazakhstan)

2008-02-15T23:59:59.000Z

177

HYPOTHSES SUR L'ORIGINE DES BRUITS DU COEUR ET DES ACCIDENTS DE DCOMPRESSION EN PLONGE : LA CAVITATION.  

E-Print Network [OSTI]

CAVITATION. HYPOTH�SE SUR L'ORIGINE DE LA FERMETURE DES VALVES CARDIAQUES : LE PH�NOM�NE DE VENTOUSE. Dr. R'un phénomène de cavitation à l'origine des bruits de Korotkoff. Encouragés par l'aphorisme de MacDonald comme quoi le phénomène de cavitation est plus fréquent qu'on peut le penser dans le système cardio

178

LA CAVITATION A L'ORIGINE DES BRUITS DU COEUR ET DES ACCIDENTS DE DCOMPRESSION EN PLONGE.  

E-Print Network [OSTI]

1 LA CAVITATION A L'ORIGINE DES BRUITS DU COEUR ET DES ACCIDENTS DE D�COMPRESSION EN PLONG�E. R'un phénomène de cavitation à l'origine des bruits de Korotkoff. Encouragés par l'aphorisme de MacDonald comme quoi le phénomène de cavitation est plus fréquent qu'on peut le penser dans le système cardio

179

Extracting a Whisper from the DIN: A Bayesian-Inductive Approach to Learning an Anticipatory Model of Cavitation  

SciTech Connect (OSTI)

For several reasons, Bayesian parameter estimation is superior to other methods for inductively learning a model for an anticipatory system. Since it exploits prior knowledge, the analysis begins from a more advantageous starting point than other methods. Also, since "nuisance parameters" can be removed from the Bayesian analysis, the description of the model need not be as complete as is necessary for such methods as matched filtering. In the limit of perfectly random noise and a perfect description of the model, the signal-to-noise ratio improves as the square root of the number of samples in the data. Even with the imperfections of real-world data, Bayesian methods approach this ideal limit of performance more closely than other methods. These capabilities provide a strategy for addressing a major unsolved problem in pump operation: the identification of precursors of cavitation. Cavitation causes immediate degradation of pump performance and ultimate destruction of the pump. However, the most efficient point to operate a pump is just below the threshold of cavitation. It might be hoped that a straightforward method to minimize pump cavitation damage would be to simply adjust the operating point until the inception of cavitation is detected and then to slightly readjust the operating point to let the cavitation vanish. However, due to the continuously evolving state of the fluid moving through the pump, the threshold of cavitation tends to wander. What is needed is to anticipate cavitation, and this requires the detection and identification of precursor features that occur just before cavitation starts.

Kercel, S.W.

1999-11-07T23:59:59.000Z

180

Relativistic tunneling and accelerated transmission  

E-Print Network [OSTI]

We obtain the solutions for the tunneling zone of a one-dimensional electrostatic potential in the relativistic (Dirac to Klein-Gordon) wave equation regime when the incoming wave packet exhibits the possibility of being almost totally transmitted through the potential barrier. The conditions for the occurrence of accelerated and, eventually, superluminal tunneling transmission probabilities are all quantified and the problematic superluminal interpretation originated from the study based on non-relativistic dynamics of tunneling is overcome. The treatment of the problem suggests revealing insights into condensed-matter experiments using electrostatic barriers in single- and bi-layer graphene, for which the accelerated tunneling effect deserves a more careful investigation.

Alex E. Bernardini

2007-06-26T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Computational design and analysis of flatback airfoil wind tunnel experiment.  

SciTech Connect (OSTI)

A computational fluid dynamics study of thick wind turbine section shapes in the test section of the UC Davis wind tunnel at a chord Reynolds number of one million is presented. The goals of this study are to validate standard wind tunnel wall corrections for high solid blockage conditions and to reaffirm the favorable effect of a blunt trailing edge or flatback on the performance characteristics of a representative thick airfoil shape prior to building the wind tunnel models and conducting the experiment. The numerical simulations prove the standard wind tunnel corrections to be largely valid for the proposed test of 40% maximum thickness to chord ratio airfoils at a solid blockage ratio of 10%. Comparison of the computed lift characteristics of a sharp trailing edge baseline airfoil and derived flatback airfoils reaffirms the earlier observed trend of reduced sensitivity to surface contamination with increasing trailing edge thickness.

Mayda, Edward A. (University of California, Davis, CA); van Dam, C.P. (University of California, Davis, CA); Chao, David D. (University of California, Davis, CA); Berg, Dale E.

2008-03-01T23:59:59.000Z

182

DNS and LES of two-phase flows with cavitation  

E-Print Network [OSTI]

We report on recent progress in the physical and numerical modeling of compressible two-phase flows that involve phase transition between the liquid and gaseous state of the fluid. The high-speed dynamics of cavitation bubbles is studied in well-resolved simulations (DNS) with a sharp-interface numerical model on a micro scale. The underlying assumption of the employed evaporation/condensation model is that phase change occurs in thermal non-equilibrium and that the associated timescale is larger than that of the wave dynamics. Results for the collapse of a spherical vapor bubble close to a solid wall are discussed for three different bubble-wall configurations. The major challenge for such numerical investigations is to accurately reproduce the dynamics of the interface between liquid and vapor during the entire collapse process, including the high-speed dynamics of the late stages, where compressibility of both phases plays a decisive role. Direct interface resolving simulations are intractable for real wor...

Hickel, Stefan

2014-01-01T23:59:59.000Z

183

Roles of cavitation/column separation due to earthquake-induced hydraulic transients  

SciTech Connect (OSTI)

The roles of cavitation/column separation due to earthquake-induced hydraulic transients in pipe flow were investigated experimentally and theoretically. It is known that when the system pressure during a hydraulic transient reaches the saturation pressure of the liquid, cavitation/column separation occurs. When the cavities collapse or when the separated liquid columns rejoin, very high pressures are produced. The experiment employed a pipe mounted between a constant-pressure tank and a piston-type excitation device. The resulting pressure variation at the piston was recorded continually. Comparison of pressure response for various test runs indicated that the peak pressures at/near resonance frequency were not affected significantly by the excitation velocity amplitude in cases of cavitation/column separation. These results were confirmed by comparison with theoretical analysis. A numerical method to simulate column separation/cavitation was developed. In order to eliminate numerical oscillation, the flux-correction method was introduced. Results obtained suggest that the cavitation/column separation due to earthquake-induced hydraulic transients is an important damage mechanism.

Hwang, Y.D.

1986-01-01T23:59:59.000Z

184

To cite this document: Duplaa, Sbastien and Coutier-Delgosha, Olivier and Dazin, Antoine and Bois, Grard and Caignaert, Guy and Roussette, Olivier Cavitation inception  

E-Print Network [OSTI]

, Gérard and Caignaert, Guy and Roussette, Olivier Cavitation inception in fast startup. (2008) In-Hawaii : United States (2008)" #12;1 CAVITATION INCEPTION IN FAST STARTUP S. Duplaa1 , O. Coutier-Delgosha1 , A in partial flow vaporization, i.e. cavitation. An existing experimental test rig has been updated in the LML

Boyer, Edmond

185

Real-time prediction of the reversibility of the ultrasound-induced blood-brain barrier opening using passive cavitation detection with MRI validation  

E-Print Network [OSTI]

using passive cavitation detection with MRI validation Tao Sun1 , Gesthimani Samiotaki1 and Elisa E, represented by the cavitation dose, as monitored during BBB opening to the reversibility of BBB opening). A single-element, pulse-echo ultrasound transducer served as a passive cavitation detector was used

Konofagou, Elisa E.

186

Cavitation in elastomeric solids: I--A defect-growth theory Oscar Lopez-Pamies a,, Martin I. Idiart b,c  

E-Print Network [OSTI]

Cavitation in elastomeric solids: I--A defect-growth theory Oscar Lopez-Pamies a,�, Marti´n I. The occurrence of such instabilities, commonly referred to as cavitation, can be attributed to the growth of pre-existing defects into finite sizes. This paper introduces a new theory to study the phenomenon of cavitation

Nakamura, Toshio

187

Combination of thermal and cavitation effects to generate deep lesions with an endocavitary applicator using a plane transducer: Ex vivo studies.  

E-Print Network [OSTI]

1 Combination of thermal and cavitation effects to generate deep lesions with an endocavitary@lyon.inserm.fr Running title : Combination of thermal and cavitation effects inserm-00189856,version1-22Nov2007 Author.ultrasmedbio.2003.09.005 #12;2 Combination of thermal and cavitation effects to generate deep lesions

Paris-Sud XI, Université de

188

Mathematical model of cavitation during resin lm infusion process I. Sevostianov a,*, V.E. Verijenko b  

E-Print Network [OSTI]

Mathematical model of cavitation during resin ®lm infusion process I. Sevostianov a,*, V ®lm infusion (RFI) process. An analytical model is developed to describe the cavitation conditions formation; Resin ®lm infusion 1. Introduction The resin ®lm infusion (RFI) method of producing composite

Sevostianov, Igor

189

The effect of tungsten and molybdenum additions on the cavitation corrosion behavior of duplex stainless steel (DSS) in seawater  

SciTech Connect (OSTI)

Cavitation corrosion studies were conducted on two duplex stainless steel (DSS) specimens of which one was containing tungsten and more molybdenum than the other. Experiments were conducted in seawater using an ultrasonically-induced cavitation facilities. The rate of mass-loss, free corrosion potential, and microscopic examinations were compared for the two alloys in the presence and absence of cavitation. There was negligible mass loss for the two alloys under stagnant conditions. However, some differences were observed between the two alloys with respect to mass-loss, corrosion potential and morphology of attacked areas. The alloy containing tungsten and mover molybdenum experienced more loss in weight regardless of their more noble corrosion potential during cavitation. This difference in behavior was explained in terms of the effect of the alloying elements on the microstructure of the alloys and their susceptibility to absorb the impact energy of cavitation.

Al-Hashem, A.; Abdullah, A.; Shalaby, H.M. [Kuwait Inst. for Scientific Research, Safat (Kuwait). Materials Application Dept.

1998-12-31T23:59:59.000Z

190

Measurement of the thorium-228 activity in solutions cavitated by ultrasonic sound  

E-Print Network [OSTI]

We show that cavitation of a solution of thorium-228 in water does not induce its transformation at a faster rate than the natural radioactive decay. We measured the activity of a thorium-228 solution in water before, and after, it was subjected to a cavitation at 44 kHz and $250 $W for 90 minutes in order to observe any change in the thorium half-life. The results were compared to the original activity of the sample and we observed no change. Our results and conclusions conflict with those in a recent paper by F. Cardone et. al. [Phys. Lett. A 373 (2009) 1956-1958].

R. Ford; M. Gerbier-Violleau; E. Vazquez-Jauregui

2009-11-10T23:59:59.000Z

191

Drying by Cavitation and Poroelastic Relaxations in Porous Media with Macroscopic Pores Connected by Nanoscale Throats  

E-Print Network [OSTI]

We investigate the drying dynamics of porous media with two pore diameters separated by several orders of magnitude. Nanometer-sized pores at the edge of our samples prevent air entry, while drying proceeds by heterogeneous nucleation of vapor bubbles (cavitation) in the liquid in micrometer-sized voids within the sample. We show that the dynamics of cavitation and drying are set by the interplay of the deterministic poroelastic mass transport in the porous medium and the stochastic nucleation process. Spatio-temporal patterns emerge in this unusual reaction-diffusion system, with temporal oscillations in the drying rate and variable roughness of the drying front.

Olivier Vincent; David A. Sessoms; Erik J. Huber; Jules Guioth; Abraham D. Stroock

2014-09-30T23:59:59.000Z

192

Electron acceleration in cavitated laser produced ion channels  

SciTech Connect (OSTI)

This paper is concerned with the channeling of a relativistic laser pulse in an underdense plasma and with the subsequent generation of fast electrons in the cavitated ion channel. The laser pulse has a duration of several hundreds of femtoseconds and its power P{sub L} exceeds the critical power for laser channeling P{sub ch}, with P{sub ch}?1.1P{sub c}, P{sub c} denoting the critical power for relativistic self-focusing. The laser pulse is focused in a plasma of electron density n{sub 0} such that the ratio n{sub 0}/n{sub c} lies in the interval [10{sup ?3},10{sup ?1}], n{sub c} denoting the critical density. The laser-plasma interaction under such conditions is investigated by means of three dimensional Particle-In-Cell (PIC) simulations. It is observed that the steep laser front gives rise to the excitation of a surface wave which propagates along the sharp radial boundaries of the electron free channel created by the laser pulse. The mechanism responsible for the generation of relativistic electrons observed in the PIC simulations is also analyzed by means of a test particles code. The fast electrons are found to be generated by the combination of a surface wave and of the betatron resonance. The maximum electron energy observed in the simulations is scaled as a function of P{sub L}/P{sub c}; it reaches 350–600 MeV for P{sub L}/P{sub c} = 70–140.

Naseri, N. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada) [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Tech-X Corporation, Boulder, Colorado 80303 (United States); Pesme, D. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada) [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Centre de Physique Théorique, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Rozmus, W. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada)] [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada)

2013-10-15T23:59:59.000Z

193

Tunneling progress on the Yucca Mountain Project  

SciTech Connect (OSTI)

The current status of tunneling progress on the Yucca Mountain Project (YMP) is presented in this paper. The Exploratory Studies Facility (ESF), a key part of the YMP, has been long in development and construction is ongoing. This is a progress report on the tunneling aspects of the ESF as of January 1, 1996. For purposes of discussion in this summary, the tunneling has progressed in four general phases. The paper describes: tunneling in jointed rock under low stress; tunneling through the Bow Ridge Fault and soft rock; tunneling through the Imbricate Fault Zone; and Tunneling into the candidate repository formation.

Hansmire, W.H. [Parsons Brinckerhoff, Las Vegas, NV (United States); Munzer, R.J. [Kiewit Construction Co., Las Vegas, NV (United States)

1996-06-01T23:59:59.000Z

194

H-CANYON AIR EXHAUST TUNNEL INSPECTION VEHICLE DEVELOPMENT  

SciTech Connect (OSTI)

The H-Canyon at Savannah River Site is a large concrete structure designed for chemical separation processes of radioactive material. The facility requires a large ventilation system to maintain negative pressure in process areas for radioactive contamination control and personnel protection. The ventilation exhaust is directed through a concrete tunnel under the facility which is approximately five feet wide and 8 feet tall that leads to a sand filter and stack. Acidic vapors in the exhaust have had a degrading effect on the surface of the concrete tunnels. Some areas have been inspected; however, the condition of other areas is unknown. Experience from historical inspections with remote controlled vehicles will be discussed along with the current challenge of inspecting levels below available access points. The area of interest in the exhaust tunnel must be accessed through a 14 X 14 inch concrete plug in the floor of the hot gang valve corridor. The purpose for the inspection is to determine the condition of the inside of the air tunnel and establish if there are any structural concerns. Various landmarks, pipe hangers and exposed rebar are used as reference points for the structural engineers when evaluating the current integrity of the air tunnel.

Minichan, R.; Fogle, R.; Marzolf, A.

2011-05-24T23:59:59.000Z

195

Localization of gauge fields and monopole tunnelling  

SciTech Connect (OSTI)

We study the dynamical localization of a massless gauge field on a lower-dimensional surface (2-brane). In flat space, the necessary and sufficient condition for this phenomenon is the existence of confinement in the bulk. The resulting configuration is equivalent to a dual Josephson junction. This duality leads to an interesting puzzle, as it implies that a localized massless theory, even in the Abelian case, must become confining at exponentially large distances. Through the use of topological arguments we clarify the physics behind this large-distance confinement and identify the instantons of the brane world-volume theory that are responsible for its appearance. We show that they correspond to the (condensed) bulk magnetic charges (monopoles), that occasionally tunnel through the brane and induce weak confinement of the brane theory. We consider the possible generalization of this effect to higher dimensions and discuss phenomenological bounds on the confinement of electric charges at exponentially large distances within our Universe.

Dvali, G. [CERN, Theory Division, CH-1211 Geneva 23 (Switzerland); Center for Cosmology and Particle Physics, Department of Physics, New York University, New York, New York 10003 (United States); Nielsen, H. B. [CERN, Theory Division, CH-1211 Geneva 23 (Switzerland); Niels Bohr Institute, Copenhagen DK 2100 (Denmark); Tetradis, N. [Department of Physics, University of Athens, Zographou 157 84, Athens (Greece)

2008-04-15T23:59:59.000Z

196

FLUID-STRUCTURE INTERACTION AND TRANSIENT CAVITATION TESTS IN A T-PIECE PIPE  

E-Print Network [OSTI]

FLUID-STRUCTURE INTERACTION AND TRANSIENT CAVITATION TESTS IN A T-PIECE PIPE ARRIS S TIJSSELING. The model is a closed, water-filled, T-shaped, laboratory pipe system, where the T- junction and the three, the cavity can occupy the entire pipe cross-section, thereby separating adjacent regions of fully-liquid flow

Eindhoven, Technische Universiteit

197

Supplementary Methods for "Comment on 'Nuclear Emissions During Self-Nucleated Acoustic Cavitation'"  

E-Print Network [OSTI]

Neutron simulation methods and statistical fitting methods for "Comment on 'Nuclear Emissions During Self-Nucleated Acoustic Cavitation'" are presented. The fit that underlies the Comment's background-subtracted "Cf-252" curve is shown. Also included are numerically sampled distributions of the goodness-of-fit variable for the four candidate neutron sources and a sketch of the assumed geometry.

B. Naranjo

2006-09-11T23:59:59.000Z

198

1 Copyright 1999 by ASME MULTI-PHASE CFD ANALYSIS OF NATURAL AND VENTILATED CAVITATION  

E-Print Network [OSTI]

volume fraction transport/generation for liquid, condensable vapor and non-con- densable gas fields between condensable vapor and non-condensable gas, a requirement of our current applica- tion. By solving1 Copyright © 1999 by ASME MULTI-PHASE CFD ANALYSIS OF NATURAL AND VENTILATED CAVITATION ABOUT

Kunz, Robert Francis

199

Acoustically driven cavitation cluster collapse in planar geometry Ivan van der Kroon,1  

E-Print Network [OSTI]

the dynamics of arrays of transient cavitation bubbles exposed to a sound field in a planar geometry. Single with a digital hologram and focusing it into a thin gap of liquid. The liquid is driven with an oscillating with high-speed photography with a two-dimensional Rayleigh model. For multibubble configura- tions we

Ohl, Claus-Dieter

200

Propeller design optimization for tunnel bow thrusters in the bollard pull condition  

E-Print Network [OSTI]

Tunnel bow thrusters are often used by large ships to provide low-speed lateral maneuverability when docking. Required to provide high thrust while essentially at a standstill, the design point for these thrusters is the ...

Wilkins, James R., IV

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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

HYPOTHSES SUR L'ORIGINE DES BRUITS DU COEUR ET DES ACCIDENTS DE DCOMPRESSION EN PLONGE : LA CAVITATION.  

E-Print Network [OSTI]

CAVITATION. HYPOTH�SE SUR L'ORIGINE DE LA FERMETURE DES VALVES CARDIAQUES : LE RETARD � LA FERMETURE DES un travail antérieur, l'hypothèse d'un phénomène de cavitation à l'origine des bruits de Korotkoff. Encouragés par l'aphorisme de MacDonald comme quoi le phénomène de cavitation est plus fréquent qu'on peut le

Paris-Sud XI, Université de

202

Hybrid Inflation Exit through Tunneling  

E-Print Network [OSTI]

For hybrid inflationary potentials, we derive the tunneling rate from field configurations along the flat direction towards the waterfall regime. This process competes with the classically rolling evolution of the scalar fields and needs to be strongly subdominant for phenomenologically viable models. Tunneling may exclude models with a mass scale below 10^12 GeV, but can be suppressed by small values of the coupling constants. We find that tunneling is negligible for those models, which do not require fine tuning in order to cancel radiative corrections, in particular for GUT-scale SUSY inflation. In contrast, electroweak scale hybrid inflation is not viable, unless the inflaton-waterfall field coupling is smaller than approximately 10^-11.

Bjorn Garbrecht; Thomas Konstandin

2006-10-24T23:59:59.000Z

203

Report Tunneling Cost Reduction Study prepared for Fermilab  

SciTech Connect (OSTI)

Fermi National Accelerator Laboratories has a need to review the costs of constructing the very long tunnels which would be required for housing the equipment for the proposed Very Large Hadron Collider (VLHC) project. Current tunneling costs are high, and the identification of potential means of significantly reducing them, and thereby helping to keep overall project costs within an acceptable budget, has assumed great importance. Fermilab has contracted with The Robbins Company to provide an up-to-date appraisal of tunneling technology, and to review the potential for substantially improving currently the state-of-practice performance and construction costs in particular. The Robbins Company was chosen for this task because of its long and successful experience in hard rock mechanical tunnel boring. In the past 40 years, Robbins has manufactured over 250 tunneling machines, the vast majority for hard rock applications. In addition to also supplying back-up equipment, Robbins has recently established a division dedicated to the manufacture of continuous conveying equipment for the efficient support of tunneling operations. The study extends beyond the tunnel boring machine (TBM) itself, and into the critical area of the logistics of the support of the machine as it advances, including manpower. It is restricted to proven methods using conventional technology, and its potential for incremental but meaningful improvement, rather than examining exotic and undeveloped means of rock excavation that have been proposed from time to time by the technical community. This is the first phase of what is expected to be a number of studies in increasing depth of technical detail, and as such has been restricted to the issues connected with the initial 34 kilometer circumference booster tunnel, and not the proposed 500 kilometer circumference tunnel housing the VLHC itself. The booster tunnel is entirely sited within low to medium strength limestone and dolomite formations, typical of the Chicago area. The rock is generally competent with widely spaced jointing, and slowdown of the operation for the installation of rock support is expected to be minimal. The tunneling system will have to be equipped with the necessary equipment for an efficient response to poor rock conditions however. Because the ground conditions are expected to be very favorable, a state-of-the-art TBM should have no difficulty in excavating at a high penetration rate of 10 meters per hour or more in rock of the average of the range of strengths stated to exist. Disc cutter changes will be few as the rock has very low abrasivity. However, experience has shown that overall tunneling rates are a relatively low percentage of the machine's penetration rate capability. Therefore the main focus of improvement is guaranteeing that the support systems, including mucking and advance of the utilities do not impede the operation. Improved mechanization of the support systems, along with automation where practicable to reduce manpower, is seen as the best means of raising the overall speed of the operation, and reducing its cost. The first phase of the study is mainly involved with establishing the baseline for current performance, and in identifying areas of improvement. It contains information on existing machine design concepts and provides data on many aspects of the mechanical tunneling process, including costs and labor requirements. While it contains suggestions for technical improvements of the various system, the time limitations of this phase have not permitted any detailed concept development. This should be a major part of the next phase.

Not Available

1999-07-16T23:59:59.000Z

204

Influence of Heat Treatment on Mercury Cavitation Resistance of Surface Hardened 316LN Stainless Steel  

SciTech Connect (OSTI)

The cavitation-erosion resistance of carburized 316LN stainless steel was significantly degraded but not destroyed by heat treatment in the temperature range 500-800 C. The heat treatments caused rejection of some carbon from the carburized layer into an amorphous film that formed on each specimen surface. Further, the heat treatments encouraged carbide precipitation and reduced hardness within the carburized layer, but the overall change did not reduce surface hardness fully to the level of untreated material. Heat treatments as short as 10 min at 650 C substantially reduced cavitation-erosion resistance in mercury, while heat treatments at 500 and 800 C were found to be somewhat less detrimental. Overall, the results suggest that modest thermal excursions perhaps the result of a weld made at some distance to the carburized material or a brief stress relief treatment will not render the hardened layer completely ineffective but should be avoided to the greatest extent possible.

Pawel, Steven J [ORNL; Hsu, Julia [Massachusetts Institute of Technology (MIT)

2010-11-01T23:59:59.000Z

205

Cavitation nanopore in the dielectric fluid in the inhomogeneous, pulsed electric fields  

E-Print Network [OSTI]

This paper discusses the nanopores emerging and developing in a liquid dielectric under the action of the ponderomotive electrostrictive forces in a nonuniform electric field. It is shown that the gradient of the electric field in the vicinity of the rupture (cavitation nanopore) substantially increases and determines whether the rupture grows or collapses. The cavitation rupture in the liquid (nanopore) tends to stretch along the lines of the original field. The mechanism of the breakdown associated with the generation of secondary ruptures in the vicinity of the poles of the nanopore is proposed. The estimations of the extension time for nanopore in water and oil (polar and nonpolar liquids, respectively) are presented. A new mechanism of nano- and subnanosecond breakdown in the insulating (transformer) oil that can be realized in the vicinity of water microdroplets in modern nanosecond high-voltage devices is considered

M. Pekker; M. N. Shneider

2014-12-19T23:59:59.000Z

206

The resistance to cavitation erosion of CrMnN stainless steels  

SciTech Connect (OSTI)

The resistance to cavitation erosion (CE) was measured using a magnetostrictive device and a rotating disk device for some CrMnN stainless steels (Chinese patent ZL 90 1 02197.0). The microstructural changes in the surface layer before and after CE were analyzed by use of Mossbauer spectra. Results show that the resistance to CE of duplex austenitic-martensitic CrMnN stainless steels is much better than that of ZG0Cr13Ni4-6Mo and ZG0Cr16Ni5Mo steel, which are in common use for hydraulic turbine runners. The metastable austenite and its changes in the process of CE are the key factors why the CrMnN stainless steels have excellent resistance to cavitation erosion.

Fu, W.T. [Yanshan Univ., Qinhuangdao (China). Dept. of Materials Engineering] [Yanshan Univ., Qinhuangdao (China). Dept. of Materials Engineering; [Harbin Inst. of Tech. (China); Jing, T.F.; Zheng, Y.Z. [Yanshan Univ., Qinhuangdao (China). Dept. of Materials Engineering] [Yanshan Univ., Qinhuangdao (China). Dept. of Materials Engineering; Yang, Y.B. [Yanshan Univ., Qinhuangdao (China). Dept. of Materials Engineering] [Yanshan Univ., Qinhuangdao (China). Dept. of Materials Engineering; [Bohai Aluminum Industries Co., Ltd., Qinhuangdao (China); Yao, M. [Harbin Inst. of Tech. (China)] [Harbin Inst. of Tech. (China)

1998-12-01T23:59:59.000Z

207

Effect of temperature and strain rate on cavitation in a superplastic duplex stainless steel  

SciTech Connect (OSTI)

The effect of temperature and strain rate on cavitation during superplastic deformation of a duplex stainless steel has been studied at 1,223 K and 1,253 K for initial strain rates ranging from 2 {times} 10{sup {minus}4} s{sup {minus}1} to 2 {times} 10{sup {minus}3} s{sup {minus}1}. The cavitation was analyzed quantitatively for a specifically developed image processing technique that allows an accurate determination of the volume fraction and size distribution of the voids. The results show that increasing temperature and/or decreasing strain rate cause a more homogeneous deformation of the specimen characterized by a uniform size and distribution of the cavities. The increase of the strain rate results in an increase in cavity volume fraction related to more cavity nucleation and interlinkage. This reflects the lack of accommodation process during the mechanism of grain boundary sliding.

Pulino-Sagradi, D.; Nazar, A.M.M.; Ammann, J.J.; Medrano, R.E. [State Univ. of Campinas, Sao Paulo (Brazil). Dept. of Materials Engineering] [State Univ. of Campinas, Sao Paulo (Brazil). Dept. of Materials Engineering

1997-11-01T23:59:59.000Z

208

Cavitation nanopore in the dielectric fluid in the inhomogeneous, pulsed electric fields  

E-Print Network [OSTI]

This paper discusses the nanopores emerging and developing in a liquid dielectric under the action of the ponderomotive electrostrictive forces in a nonuniform electric field. It is shown that the gradient of the electric field in the vicinity of the rupture (cavitation nanopore) substantially increases and determines whether the rupture grows or collapses. The cavitation rupture in the liquid (nanopore) tends to stretch along the lines of the original field. The mechanism of the breakdown associated with the generation of secondary ruptures in the vicinity of the poles of the nanopore is proposed. The estimations of the extension time for nanopore in water and oil (polar and nonpolar liquids, respectively) are presented. A new mechanism of nano- and subnanosecond breakdown in the insulating (transformer) oil that can be realized in the vicinity of water microdroplets in modern nanosecond high-voltage devices is considered

Pekker, M

2014-01-01T23:59:59.000Z

209

Large Plastic Deformation in High-Capacity Lithium-Ion Batteries Caused by Charge and Discharge  

E-Print Network [OSTI]

Large Plastic Deformation in High-Capacity Lithium-Ion Batteries Caused by Charge and Discharge, Massachusetts 02138 Evidence has accumulated recently that a high-capacity elec- trode of a lithium-ion battery in the particle is high, possibly leading to fracture and cavitation. I. Introduction LITHIUM-ION batteries

Suo, Zhigang

210

Direct Observation of Tunneling and Nonlinear Self-Trapping in a Single Bosonic Josephson Junction  

SciTech Connect (OSTI)

We report on the first realization of a single bosonic Josephson junction, implemented by two weakly linked Bose-Einstein condensates in a double-well potential. In order to fully investigate the nonlinear tunneling dynamics we measure the density distribution in situ and deduce the evolution of the relative phase between the two condensates from interference fringes. Our results verify the predicted nonlinear generalization of tunneling oscillations in superconducting and superfluid Josephson junctions. Additionally, we confirm a novel nonlinear effect known as macroscopic quantum self-trapping, which leads to the inhibition of large amplitude tunneling oscillations.

Albiez, Michael; Gati, Rudolf; Foelling, Jonas; Hunsmann, Stefan; Oberthaler, Markus K. [Kirchhoff-Institut fuer Physik, Universitaet Heidelberg, Im Neuenheimer Feld 227, D-69120 Heidelberg (Germany); Cristiani, Matteo [CNR-INFM, Dipartimento di Fisica E. Fermi, Universita di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa (Italy)

2005-07-01T23:59:59.000Z

211

Heat Transfer in Underground Rail Tunnels  

E-Print Network [OSTI]

The transfer of heat between the air and surrounding soil in underground tunnels ins investigated, as part of the analysis of environmental conditions in underground rail systems. Using standard turbulent modelling assumptions, flow profiles are obtained in both open tunnels and in the annulus between a tunnel wall and a moving train, from which the heat transfer coefficient between the air and tunnel wall is computed. The radial conduction of heat through the surrounding soil resulting from changes in the temperature of air in the tunnel are determined. An impulse change and an oscillating tunnel air temperature are considered separately. The correlations between fluctuations in heat transfer coefficient and air temperature are found to increase the mean soil temperature. Finally, a model for the coupled evolution of the air and surrounding soil temperature along a tunnel of finite length is given.

Sadokierski, Stefan

2007-01-01T23:59:59.000Z

212

VOLUME 84, NUMBER 4 P H Y S I C A L R E V I E W L E T T E R S 24 JANUARY 2000 Effect of Noble Gases on Sonoluminescence Temperatures during Multibubble Cavitation  

E-Print Network [OSTI]

on Sonoluminescence Temperatures during Multibubble Cavitation Yuri T. Didenko, William B. McNamara III, and Kenneth S atoms serves as an internal thermome- ter of cavitation. The intensity and temperature occur during acoustic cavitation [1,2]. This highly nonlinear bubble motion is accompanied

Suslick, Kenneth S.

213

A mixture-energy-consistent six-equation two-phase numerical model for fluids with interfaces, cavitation and evaporation waves  

E-Print Network [OSTI]

and nuclear power plants technologies. Cavitating fluids are multiphase mixtures that often involve complex dedicated in the past decades to the simulation of cavitating flows and liquid-vapor flows with phase change fronts, when heat and mass transfer processes are included in the physical description through thermal

Pelanti, Marica

214

Competition between cotunneling, Kondo effect, and direct tunneling in discontinuous high-anisotropy magnetic tunnel junctions  

E-Print Network [OSTI]

The transition between Kondo and Coulomb blockade effects in discontinuous double magnetic tunnel junctions is explored as a function of the size of the CoPt magnetic clusters embedded between AlO[subscript x] tunnel ...

Ciudad, David

215

High Tunnels: A First Years Experience Ron Goldy, MSUE and  

E-Print Network [OSTI]

). This is a report on our experience. Tunnel Construction The tunnel consists of pipe, hardware, wire, plastic in tunnel plants went a foot or more over the stake and had more lateral growth. `Mt. Spring' total fruit

216

Superconducting Tunnel Junctions as Direct Detectors for Submillimeter Astronomy  

E-Print Network [OSTI]

Superconducting Tunnel Junctions as Direct Detectors for Submillimeter Astronomy A Dissertation 2008 by John Daniel Teufel. All rights reserved. #12;Abstract Superconducting Tunnel Junctions on the of performance of superconducting tunnel junctions (STJ) as direct detectors for submillimeter radiation. Over

217

Feasibility study of tuned-resonator, pulsating cavitating water jet for deep-hole drilling  

SciTech Connect (OSTI)

This study presents the advantages of pulsing a submerged jet to increase its erosion capability (particularly as caused by cavitation) in augmenting deep-hole drill bits. Various methods of accomplishing the pulsation are presented and discussed. The most attractive systems uncovered are acoustic oscillators which passively accomplish pulsations in the flow at frequencies corresponding to a Strouhal number in the range of 0.2 to 1.0. Such passive oscillators are assessed to be feasible candidates for development into practical deep hole drill bit systems and a long range plan for this research and development is presented and discussed.

Johnson, V.E. Jr.; Lindenmuth, W.T.; Conn, A.F.; Frederick, G.S.

1981-08-01T23:59:59.000Z

218

Enhancement of tunnel magnetoresistance in magnetic tunnel junction by a superlattice barrier  

SciTech Connect (OSTI)

Tunnel magnetoresistance of magnetic tunnel junction improved by a superlattice barrier composed of alternate layers of a nonmagnetic metal and an insulator is proposed. The forbidden band of the superlattice is used to predict the low transmission range in the superlattice barrier. By forbidding electron transport in the anti-parallel configuration, the tunnel magnetoresistance is enhanced in the superlattice junction. The results show that the tunnel magnetoresistance ratio for a superlattice magnetic tunnel junction is greater than that for traditional single or double barrier junctions.

Chen, C. H.; Hsueh, W. J., E-mail: hsuehwj@ntu.edu.tw [Nanomagnetism Group, Department of Engineering Science and Ocean Engineering, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 10660, Taiwan (China)

2014-01-27T23:59:59.000Z

219

A New Interpretation of the Scanning Tunneling Microscope Image...  

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

of Graphite. A New Interpretation of the Scanning Tunneling Microscope Image of Graphite. Abstract: In this work, highly-resolved scanning tunneling microscopy images of graphite...

220

The Tunnel Vision Syndrome: Massively Delaying Progress  

E-Print Network [OSTI]

The Tunnel Vision Syndrome: Massively Delaying Progress Reiner Hartenstein, Professor, IEEE fellow facet as the complete answer are far from solving the problem. What is the reason of these slow-down- stream-based computing was delayed for decades by the tunnel vision syndrome. The History of Systolic

Hartenstein, Reiner

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221

Tunneling characteristics in chemical vapor deposited graphene–hexagonal boron nitride–graphene junctions  

SciTech Connect (OSTI)

Large area chemical vapor deposited graphene and hexagonal boron nitride was used to fabricate graphene–hexagonal boron nitride–graphene symmetric field effect transistors. Gate control of the tunneling characteristics is observed similar to previously reported results for exfoliated graphene–hexagonal boron nitride–graphene devices. Density-of-states features are observed in the tunneling characteristics of the devices, although without large resonant peaks that would arise from lateral momentum conservation. The lack of distinct resonant behavior is attributed to disorder in the devices, and a possible source of the disorder is discussed.

Roy, T.; Hesabi, Z. R.; Joiner, C. A.; Vogel, E. M. [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332 (United States); Liu, L.; Gu, G. [Department of Electrical Engineering and Computer Science, University of Tennessee, 1520 Middle Drive, Knoxville, Tennessee 37996 (United States); Barrera, S. de la; Feenstra, R. M. [Department of Physics, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213 (United States); Chakrabarti, B. [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332 (United States); Department of Materials Science and Engineering, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080 (United States)

2014-03-24T23:59:59.000Z

222

Title: Combined passive detection and ultrafast active imaging of cavitation events induced by short pulses of high intensity  

E-Print Network [OSTI]

1 Title: Combined passive detection and ultrafast active imaging of cavitation events induced by short pulses of high intensity ultrasound Authors: Jérôme GATEAU, Jean-François AUBRY, Mathieu PERNOT / INSERM, U979 / Université Denis Diderot, Paris VII Key words: single nucleation events, ultrafast active

Boyer, Edmond

223

A 233 km tunnel for lepton and hadron colliders  

SciTech Connect (OSTI)

A decade ago, a cost analysis was conducted to bore a 233 km circumference Very Large Hadron Collider (VLHC) tunnel passing through Fermilab. Here we outline implementations of e{sup +}e{sup -}, pp-bar , and {mu}{sup +}{mu}{sup -} collider rings in this tunnel using recent technological innovations. The 240 and 500 GeV e{sup +}e{sup -} colliders employ Crab Waist Crossings, ultra low emittance damped bunches, short vertical IP focal lengths, superconducting RF, and low coercivity, grain oriented silicon steel/concrete dipoles. Some details are also provided for a high luminosity 240 GeV e{sup +}e{sup -} collider and 1.75 TeV muon accelerator in a Fermilab site filler tunnel. The 40 TeV pp-bar collider uses the high intensity Fermilab p-bar source, exploits high cross sections for pp-bar production of high mass states, and uses 2 Tesla ultra low carbon steel/YBCO superconducting magnets run with liquid neon. The 35 TeV muon ring ramps the 2 Tesla superconducting magnets at 9 Hz every 0.4 seconds, uses 250 GV of superconducting RF to accelerate muons from 1.75 to 17.5 TeV in 63 orbits with 71% survival, and mitigates neutrino radiation with phase shifting, roller coaster motion in a FODO lattice.

Summers, D. J.; Cremaldi, L. M.; Datta, A.; Duraisamy, M.; Luo, T.; Lyons, G. T. [Dept. of Physics and Astronomy, University of Mississippi-Oxford, University, MS 38677 (United States)

2012-12-21T23:59:59.000Z

224

Field dynamics and tunneling in a flux landscape  

E-Print Network [OSTI]

We investigate field dynamics and tunneling between metastable minima in a landscape of Type IIB flux compactifications, utilizing monodromies of the complex structure moduli space to continuously connect flux vacua. After describing the generic features of a flux-induced potential for the complex structure and Type IIB axio-dilaton, we specialize to the Mirror Quintic Calabi--Yau to obtain an example landscape. Studying the cosmological dynamics of the complex structure moduli, we find that the potential generically does not support slow-roll inflation and that in general the landscape separates neatly into basins of attraction of the various minima. We then discuss tunneling, with the inclusion of gravitational effects, in many-dimensional field spaces. A set of constraints on the form of the Euclidean paths through field space are presented, and then applied to construct approximate instantons mediating the transition between de Sitter vacua in the flux landscape. We find that these instantons are generically thick-wall and that the tunneling rate is suppressed in the large-volume limit. We also consider examples where supersymmetry is not broken by fluxes, in which case near-BPS thin-wall bubbles can be constructed. We calculate the bubble wall tension, finding that it scales like a D- or NS-brane bubble, and comment on the implications of this correspondence. Finally, we present a brief discussion of eternal inflation in the flux-landscape.

Matthew C Johnson; Magdalena Larfors

2008-11-06T23:59:59.000Z

225

A comparative investigation of laminar separation bubbles at low Reynolds numbers in wind tunnels and free flight environments  

E-Print Network [OSTI]

in the Notre Dame wind tunnel. The airfoil support structure was designed so that it could be used as a free-standing test bed in large wind tunnels and mounted atop the research aircraft. The primary criteria in its design were 1) simplicity... the results of the airfoil study as well as the results of per- 18 forming this kind of study in a free-flight environment. Chapter V draws conclusions from the comparisons between free-flight and wind- tunnel data. Also listed are recommendations...

Blohowiak, James Russell

1988-01-01T23:59:59.000Z

226

Giant tunneling magnetoresistance in silicene  

SciTech Connect (OSTI)

We have theoretically studied ballistic electron transport in silicene under the manipulation of a pair of ferromagnetic gate. Transport properties like transmission and conductance have been calculated by the standard transfer matrix method for parallel and antiparallel magnetization configurations. It is demonstrated here that, due to the stray field-induced wave-vector filtering effect, remarkable difference in configuration-dependent transport gives rise to a giant tunneling magnetoresistance. In combination with the peculiar buckled structure of silicene and its electric tunable energy gap, the receiving magnetoresistance can be efficiently modulated by the externally-tunable stray field, electrostatic potential, and staggered sublattice potential, providing some flexible strategies to construct silicene-based nanoelectronic device.

Wang, Yu, E-mail: ywang@semi.ac.cn [Department of Physics, Faculty of Science, Kunming University of Science and Technology, Kunming, 650500 Yunnan (China); Lou, Yiyi [Yiyuan Student Community, Center of Student Community Education and Management, Kunming University of Science and Technology, Kunming, 650500 Yunnan (China)

2013-11-14T23:59:59.000Z

227

Quantitative tunneling spectroscopy of nanocrystals  

SciTech Connect (OSTI)

The proposed goals of this collaborative work were to systematically characterize the electronic structure and dynamics of 3-dimensional metal and semiconducting nanocrystals using scanning tunneling microscopy/spectroscopy (STM/STS) and ballistic electron emission spectroscopy (BEES). This report describes progress in the spectroscopic work and in the development of methods for creating and characterizing gold nanocrystals. During the grant period, substantial effort also was devoted to the development of epitaxial graphene (EG), a very promising materials system with outstanding potential for nanometer-scale ballistic and coherent devices ("graphene" refers to one atomic layer of graphitic, sp2 -bonded carbon atoms [or more loosely, few layers]). Funding from this DOE grant was critical for the initial development of epitaxial graphene for nanoelectronics

First, Phillip N; Whetten, Robert L; Schaaff, T Gregory

2007-05-25T23:59:59.000Z

228

Preliminary studies of tunnel interface response modeling using test data from underground storage facilities.  

SciTech Connect (OSTI)

In attempting to detect and map out underground facilities, whether they be large-scale hardened deeply-buried targets (HDBT's) or small-scale tunnels for clandestine border or perimeter crossing, seismic imaging using reflections from the tunnel interface has been seen as one of the better ways to both detect and delineate tunnels from the surface. The large seismic impedance contrast at the tunnel/rock boundary should provide a strong, distinguishable seismic response, but in practice, such strong indicators are often lacking. One explanation for the lack of a good seismic reflection at such a strong contrast boundary is that the damage caused by the tunneling itself creates a zone of altered seismic properties that significantly changes the nature of this boundary. This report examines existing geomechanical data that define the extent of an excavation damage zone around underground tunnels, and the potential impact on rock properties such as P-wave and S-wave velocities. The data presented from this report are associated with sites used for the development of underground repositories for the disposal of radioactive waste; these sites have been excavated in volcanic tuff (Yucca Mountain) and granite (HRL in Sweden, URL in Canada). Using the data from Yucca Mountain, a numerical simulation effort was undertaken to evaluate the effects of the damage zone on seismic responses. Calculations were performed using the parallelized version of the time-domain finitedifference seismic wave propagation code developed in the Geophysics Department at Sandia National Laboratories. From these numerical simulations, the damage zone does not have a significant effect upon the tunnel response, either for a purely elastic case or an anelastic case. However, what was discovered is that the largest responses are not true reflections, but rather reradiated Stoneley waves generated as the air/earth interface of the tunnel. Because of this, data processed in the usual way may not correctly image the tunnel. This report represents a preliminary step in the development of a methodology to convert numerical predictions of rock properties to an estimation of the extent of rock damage around an underground facility and its corresponding seismic velocity, and the corresponding application to design a testing methodology for tunnel detection.

Sobolik, Steven Ronald; Bartel, Lewis Clark

2010-11-01T23:59:59.000Z

229

Photon tunnelling microscopy of polyethylene single crystals  

E-Print Network [OSTI]

Photon tunnelling microscopy of polyethylene single crystals Mohan Srinivasarao* and Richard S:photon tunnellingmicroscopy;single crystals; polyethylene) INTRODUCTION The study of morphology of polymers is an area

Srinivasarao, Mohan

230

Macroscopic quantum tunneling in Josephson junctions -  

E-Print Network [OSTI]

Macroscopic quantum tunneling in Josephson junctions - a method to characterise a well-shielded low Theory 5 1. The classical theory of Josephson junctions . . . . . . . . . . . . . . . . . 9 1-Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. Josephson junction dynamics . . . . . . . . . . . . . . . . . . . . . . . . 15 2.1 The basics

Gross, Rudolf

231

Screening and Tunneling at Metal-Surfaces  

E-Print Network [OSTI]

way as to satisfy continuity and charge neutrality re- quirements, and to agree with the correct work function for tungsten. Although this procedure has advantages in calculating tunneling currents (see Sec. IV), a treatment which is not fully...

KENNER, VE; Allen, Roland E.; SASLOW, WM.

1973-01-01T23:59:59.000Z

232

Tunneling characteristics in chemical vapor deposited graphene hexagonal boron nitride graphene junctions  

E-Print Network [OSTI]

1 Tunneling characteristics in chemical vapor deposited graphene ­ hexagonal boron nitride ­ graphene junctions T. Roy1 , L. Liu2 , S. de la Barrera,3 B. Chakrabarti1,4 , Z. R. Hesabi1 , C. A. Joiner1 Abstract: Large area chemical vapor deposited graphene and hexagonal boron nitride was used to fabricate

Feenstra, Randall

233

Molecular engineering of oligomerization and metabolite channeling through a molecular tunnel of carbamoyl phosphate synthetase  

E-Print Network [OSTI]

-23, and Gly-575 from the large subunit of CPS were substituted by mutagenesis with bulkier amino acids in an attempt to obstruct and/or hinder the passage of the unstable intermediate through the carbamate tunnel. The kinetic data are consistent...

Kim, Jungwook

2004-09-30T23:59:59.000Z

234

Le LHC, un tunnel cosmique  

ScienceCinema (OSTI)

Et si la lumière au bout du tunnel du LHC était cosmique ? En d?autres termes, qu?est-ce que le LHC peut nous apporter dans la connaissance de l?Univers ? Car la montée en énergie des accélérateurs de particules nous permet de mieux appréhender l?univers primordial, chaud et dense. Mais dans quel sens dit-on que le LHC reproduit des conditions proches du Big bang ? Quelles informations nous apporte-t-il sur le contenu de l?Univers ? La matière noire est-elle détectable au LHC ? L?énergie noire ? Pourquoi l?antimatière accumulée au CERN est-elle si rare dans l?Univers ? Et si le CERN a bâti sa réputation sur l?exploration des forces faibles et fortes qui opèrent au sein des atomes et de leurs noyaux, est-ce que le LHC peut nous apporter des informations sur la force gravitationnelle qui gouverne l?évolution cosmique ? Depuis une trentaine d?années, notre compréhension de l?univers dans ses plus grandes dimensions et l?appréhension de son comportement aux plus petites distances sont intimement liées : en quoi le LHC va-t-il tester expérimentalement cette vision unifiée ? Tout public, entrée libre / Réservations au +41 (0)22 767 76 76

None

2011-10-06T23:59:59.000Z

235

Mercury-Mercury Tunneling Junctions. 1. Electron Tunneling Across Symmetric and Asymmetric Alkanethiolate Bilayers  

E-Print Network [OSTI]

Mercury-Mercury Tunneling Junctions. 1. Electron Tunneling Across Symmetric and Asymmetric by bringing in contact two small (3 Ã? 10-3 cm2) mercury drop electrodes in a 5-20% (v/v) hexadecane solution incorporating alkanethiolate-type monolayer films. The results reported below convince us that the mercury

Majda, Marcin

236

Giant amplification of tunnel magnetoresistance in a molecular junction: Molecular spin-valve transistor  

SciTech Connect (OSTI)

Amplification of tunnel magnetoresistance by gate field in a molecular junction is the most important requirement for the development of a molecular spin valve transistor. Herein, we predict a giant amplification of tunnel magnetoresistance in a single molecular spin valve junction, which consists of Ru-bis-terpyridine molecule as a spacer between two ferromagnetic nickel contacts. Based on the first-principles quantum transport approach, we show that a modest change in the gate field that is experimentally accessible can lead to a substantial amplification (320%) of tunnel magnetoresistance. The origin of such large amplification is attributed to the spin dependent modification of orbitals at the molecule-lead interface and the resultant Stark effect induced shift in channel position with respect to the Fermi energy.

Dhungana, Kamal B.; Pati, Ranjit, E-mail: patir@mtu.edu [Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States)

2014-04-21T23:59:59.000Z

237

Antenna-coupled Photon Emission from hexagonal Boron Nitride Tunnel Junctions  

E-Print Network [OSTI]

The ultrafast conversion of electrical to optical signals at the nanoscale is of fundamental interest for data processing, telecommunication and optical interconnects. However, the modulation bandwidths of semiconductor LEDs are limited by the spontaneous recombination rate of electron-hole pairs and the footprint of electrically-driven ultrafast lasers is too large for practical on-chip integration. A metal-insulator-metal (MIM) tunnel junction approaches the ultimate size limit of electronic devices and its operating speed is fundamentally limited only by the tunneling time. Here we study the conversion of electron energy - localized in vertical gold-h-BN-gold tunnel junctions - into free space photons, mediated by resonant slot antennas. Optical antennas efficiently bridge the size-mismatch between nanoscale volumes and far-field radiation and strongly enhance the electron-photon conversion efficiency. We achieve polarized, directional and resonantly enhanced light emission from inelastic electron tunnelin...

Parzefall, Markus; Jain, Achint; Watanabe, Kenji; Taniguchi, Takashi; Novotny, Lukas

2015-01-01T23:59:59.000Z

238

Fission gas bubble nucleated cavitational swelling of the alpha-uranium phase of irradiated U-Pu-Zr fuel  

SciTech Connect (OSTI)

Cavitational swelling has been identified as a potential swelling mechanism for the alpha uranium phase of irradiated U-Pu-Zr metal fuels for the Integral Fast Reactor being developed at Argonne National Laboratory. The trends of U-Pu-Zr swelling data prior to fuel cladding contact can be interpreted in terms of unrestrained cavitational driven swelling. It is theorized that the swelling mechanisms at work in the alpha uranium phase can be modeled by single vacancy and single interstitial kinetics with intergranular gas bubbles providing the void nuclei, avoiding the use of complicated defect interaction terms required for the calculation of void nucleation. The focus of the kinetics of fission gas evolution as it relates to cavitational swelling is prior to the formation of a significant amount of interconnected porosity and is on the development of small intergranular gas bubbles which can act as void nuclei. Calculations for the evolution of intergranular fission gas bubbles show that they provide critical cavity sizes (i.e., the size above which the cavity will grow by bias-driven vacancy flux) consistent with the observed incubation dose for the onset of rapid swelling and gas release.

Rest, J.

1992-04-01T23:59:59.000Z

239

Method of fabricating a solar cell with a tunnel dielectric layer  

DOE Patents [OSTI]

Methods of fabricating solar cells with tunnel dielectric layers are described. Solar cells with tunnel dielectric layers are also described.

Dennis, Tim; Harrington, Scott; Manning, Jane; Smith, David; Waldhauer, Ann

2012-12-18T23:59:59.000Z

240

Method of fabricating a solar cell with a tunnel dielectric layer  

DOE Patents [OSTI]

Methods of fabricating solar cells with tunnel dielectric layers are described. Solar cells with tunnel dielectric layers are also described.

Dennis, Tim; Harrington, Scott; Manning, Jane; Smith, David D; Waldhauer, Ann

2014-04-29T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Chiral tunneling in single and bilayer graphene  

E-Print Network [OSTI]

We review chiral (Klein) tunneling in single-layer and bilayer graphene and present its semiclassical theory, including the Berry phase and the Maslov index. Peculiarities of the chiral tunneling are naturally explained in terms of classical phase space. In a one-dimensional geometry we reduced the original Dirac equation, describing the dynamics of charge carriers in the single layer graphene, to an effective Schr\\"odinger equation with a complex potential. This allowed us to study tunneling in details and obtain analytic formulas. Our predictions are compared with numerical results. We have also demonstrated that, for the case of asymmetric n-p-n junction in single layer graphene, there is total transmission for normal incidence only, side resonances are suppressed.

T. Tudorovskiy; K. J. A. Reijnders; M. I. Katsnelson

2011-06-15T23:59:59.000Z

242

Conifolds and Tunneling in the String Landscape  

E-Print Network [OSTI]

We investigate flux vacua on a variety of one-parameter Calabi-Yau compactifications, and find many examples that are connected through continuous monodromy transformations. For these, we undertake a detailed analysis of the tunneling dynamics and find that tunneling trajectories typically graze the conifold point---particular 3-cycles are forced to contract during such vacuum transitions. Physically, these transitions arise from the competing effects of minimizing the energy for brane nucleation (facilitating a change in flux), versus the energy cost associated with dynamical changes in the periods of certain Calabi-Yau 3-cycles. We find that tunneling only occurs when warping due to back-reaction from the flux through the shrinking cycle is properly taken into account.

Pontus Ahlqvist; Brian R. Greene; David Kagan; Eugene A. Lim; Saswat Sarangi; I-Sheng Yang

2011-01-17T23:59:59.000Z

243

EECBG Success Story: Topeka's "Green Light Tunnel" Saves Fuel...  

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

Topeka's "Green Light Tunnel" Saves Fuel and Time EECBG Success Story: Topeka's "Green Light Tunnel" Saves Fuel and Time April 22, 2011 - 1:50pm Addthis Topeka, Kansas has...

244

Quantum tunneling, quantum computing, and high temperature superconductivity  

E-Print Network [OSTI]

observed with scanning tunneling microscope (STM) in high temperature superconductors. The integrated tunneling intensities on all predominant sites have been estimated. The results can be used to test the predictions of any tight-binding model calculation...

Wang, Qian

2005-02-17T23:59:59.000Z

245

Electron tunneling studies of Mn12-Acetate  

E-Print Network [OSTI]

]. . . . . . . . . . . . . . . . 24 10 Frame for rotating the tunneling wires in the PLD chamber during deposition. The two black posts are brass that were wrapped with shrink tubing so that the wires can be attached to them and still be insulated from one another. The two white... copper posts that are made from 0.010” diameter bare copper wires. The tunneling wires are first wrapped around the copper posts and then fixed in position with PbSn solder. Although silver print and silver epoxy have also been used to connect the wires...

Ma, Lianxi

2008-10-10T23:59:59.000Z

246

Fabrication of magnetic tunnel junctions with epitaxial and textured ferromagnetic layers  

DOE Patents [OSTI]

This invention relates to magnetic tunnel junctions and methods for making the magnetic tunnel junctions. The magnetic tunnel junctions include a tunnel barrier oxide layer sandwiched between two ferromagnetic layers both of which are epitaxial or textured with respect to the underlying substrate upon which the magnetic tunnel junctions are grown. The magnetic tunnel junctions provide improved magnetic properties, sharper interfaces and few defects.

Chang, Y. Austin (Middleton, WI); Yang, Jianhua Joshua (Madison, WI)

2008-11-11T23:59:59.000Z

247

Optical realization of two-boson tunneling dynamics  

E-Print Network [OSTI]

An optical realization of the tunneling dynamics of two interacting bosons in a double-well potential, based on light transport in a four-core microstructured fiber, is proposed. The optical setting enables to visualize in a purely classical system the entire crossover from Rabi oscillations to correlated pair tunneling and to tunneling of a fragmented pair in the fermionization limit.

Stefano Longhi

2011-11-15T23:59:59.000Z

248

NACA0015 Measurements in LM Wind Tunnel and Turbulence  

E-Print Network [OSTI]

NACA0015 Measurements in LM Wind Tunnel and Turbulence Generated Noise Franck Bertagnolio Risø, Denmark November 2008 #12;Author: Franck Bertagnolio Title: NACA0015 Measurements in LM Wind Tunnel on its surface and measured in the wind tunnel at LM Glasfiber at various inflow speeds, angles of attack

249

Josephson inplane and tunneling currents in bilayer quantum Hall system  

SciTech Connect (OSTI)

A Bose-Einstein condensation is formed by composite bosons in the quantum Hall state. A composite boson carries the fundamental charge (–e). We investigate Josephson tunneling of such charges in the bilayer quantum Hall system at the total filling ? = 1. We show the existence of the critical current for the tunneling current to be coherent and dissipationless in tunneling experiments with various geometries.

Ezawa, Z. F. [Nishina Center, RIKEN, Saitama 351-0198 (Japan); Tsitsishvili, G. [Georgia Department of Physics, Tbilisi State University, Tbilisi 0179 (Georgia); Sawada, A. [Research Center for Low Temperature and Materials Sciences, Kyoto University, Kyoto 606-8501 (Japan)

2013-12-04T23:59:59.000Z

250

Effect of temperature and pH on cavitation erosion of super duplex stainless steel  

SciTech Connect (OSTI)

Cavitation erosion characteristics of super duplex stainless steel (S32760) and austenitic stainless steel (S30400) in 3.5% NaCl solution with controlled temperature and pH value in the range of 10 to 70 C and pH 3 to 11 have been studied by means of a 20kHz ultrasonic vibrator at a peak to peak amplitude of 50 {micro}m. The erosion resistance of other stainless steels including S31803 and S31603 was also investigated for comparison purpose. Plots of cumulative erosion mass loss per unit area versus temperature for S32760 and S30400 indicate that the degree of erosion initially increases as the temperature increases from 10 C to 50 C and passes through a maximum at about 50 C and then decreases with further increase in temperature to 70 C. Results of cumulative erosion versus pH indicate that the degree of erosion of S32760 is more sensitive to pH value than that of S30400 at 23 C.

Kwok, C.T.; Man, H.C.; Leung, L.K. [Hong Kong Polytechnic Univ., Kowloon (Hong Kong)

1996-10-01T23:59:59.000Z

251

Understanding crack versus cavitation in pressure-sensitive adhesives: the role of kinetics  

E-Print Network [OSTI]

We perform traction experiments on viscous liquids highly confined between parallel plates, a geometry known as the probe-tack test in the adhesion community. Direct observation during the experiment coupled to force measurement shows the existence of several mechanisms for releasing the stress. Bubble nucleation and instantaneous growth had been observed in a previous work. Upon increasing further the traction velocity or the viscosity, the bubble growth is progressively delayed. At high velocities, cracks at the interface between the plate and the liquid appear before the bubbles have grown to their full size. Bubbles and cracks are thus observed concomitantly. At even higher velocities, cracks develop fully so early that the bubbles are not even visible. We present a theoretical model that describes these regimes, using a Maxwell fluid as a model for the actual fluid, a highly viscous silicon oil. We present the resulting phase diagramme for the different force peak regimes. The predictions are compatible with the data. Our results show that in addition to cavitation, interfacial cracks are encountered in a probe-tack traction test with viscoelastic, \\emph{liquid} materials and not solely with viscoelastic solids like adhesives.

Jérémie Teisseire; F. Nallet; P. Fabre; Cyprien Gay

2006-09-18T23:59:59.000Z

252

RESULTS FROM CAVITATION DAMAGE EXPERIMENTS WITH MERCURY SPALLATION TARGETS AT THE LANSCE WNR IN 2008  

SciTech Connect (OSTI)

Damage assessment from proton beam induced cavitation experiments on mercury spallation targets done at the LANSCE WNR facility has been completed. The experiments investigated two key questions for the Spallation Neutron Source target, namely, how damage is affected by flow velocity in the SNS coolant channel geometry, and how damage scales with proton beam intensity at a given constant charge per pulse. With regard to the former question, prior in-beam experiments indicated that the coolant channel geometry with stagnant mercury was especially vulnerable to damage which might warrant a design change. Yet other results indicated a reduction in damage with the introduction of flow. Using more prototypic to the SNS, the 2008 experiment damage results show the channel is less vulnerable than the bulk mercury side of the vessel wall. They also show no benefit from increasing channel flow velocity beyond nominal SNS speeds. The second question probed a consensus belief that damage scales with beam intensity (protons per unit area) by a power law dependence with exponent of around 4. Results from a 2005 experiment did not support this power law dependence but some observations were inconsistent and unexplained. These latest results show weaker damage dependence.

Riemer, Bernie [ORNL] [ORNL; Abdou, Ashraf A [ORNL] [ORNL; Felde, David K [ORNL] [ORNL; Sangrey, Robert L [ORNL] [ORNL; Wendel, Mark W [ORNL] [ORNL

2010-01-01T23:59:59.000Z

253

Quantum Tunneling Enabled Self-Assembly of Hydrogen Atoms on Cu(111)  

SciTech Connect (OSTI)

Atomic and molecular self-assembly are key phenomena that underpin many important technologies. Typically, thermally enabled diffusion allows a system to sample many areas of configurational space, and ordered assemblies evolve that optimize interactions between species. Herein we describe a system in which the diffusion is quantum tunneling in nature and report the self-assembly of H atoms on a Cu(111) surface into complex arrays based on local clustering followed by larger scale islanding of these clusters. By scanning tunneling microscope tip-induced scrambling of H atom assemblies, we are able to watch the atomic scale details of H atom self-assembly in real time. The ordered arrangements we observe are complex and very different from those formed by H on other metals that occur in much simpler geometries. We contrast the diffusion and assembly of H with D, which has a much slower tunneling rate and is not able to form the large islands observed with H over equivalent time scales. Using density functional theory, we examine the interaction of H atoms on Cu(111) by calculating the differential binding energy as a function of H coverage. At the temperature of the experiments (5 K), H(D) diffusion by quantum tunneling dominates. The quantum-tunneling-enabled H and D diffusion is studied using a semiclassically corrected transition state theory coupled with density functional theory. This system constitutes the first example of quantum-tunneling-enabled self-assembly, while simultaneously demonstrating the complex ordering of H on Cu(111), a catalytically relevant surface.

Jewell, April D.; Peng, Guowen; Mattera, Michael F.; Lewis, Emily A.; Murphy, Colin J.; Kyriakou, Georgios; Mavrikakis, Manos; Sykes, E. Charles H.

2012-11-27T23:59:59.000Z

254

Inelastic Tunneling Spectroscopy in Unconventional Superconductors  

E-Print Network [OSTI]

Inelastic Tunneling Spectroscopy in Unconventional Superconductors Molecular Vibration and Single Superconductors ­ p.1/13 #12;Old Results R.C. Jaklevic and J. Lambe, Phys. Rev. Lett. 17, 1139-1140 (1966 in Unconventional Superconductors ­ p.2/13 #12;STM observation of local inelastic mode B.C. Stipe, M.A Rezaei, and W

255

A Note on Real Tunneling Geometries  

E-Print Network [OSTI]

In the Hartle-Hawking ``no boundary'' approach to quantum cosmology, a real tunneling geometry is a configuration that represents a transition from a compact Riemannian spacetime to a Lorentzian universe. I complete an earlier proof that in three spacetime dimensions, such a transition is ``probable,'' in the sense that the required Riemannian geometry yields a genuine maximum of the semiclassical wave function.

S. Carlip

2005-08-17T23:59:59.000Z

256

On the Superluminal Quantum Tunneling and "Causality Violation"  

E-Print Network [OSTI]

This is an analysis of some aspects of an old but still controversial topic, superluminal quantum tunneling. Some features of quantum tunneling described in literature, such as definition of the tunneling time and a frequency range of a signal, are discussed. The argument is presented that claim of superluminal signaling allegedly observed in frustrated internal reflection experiment was based on the wrong interpretation of the tunneling process. A thought experiment similar to that in the Tolman paradox is discussed. It shows that a new factor, attenuation, comes in the interplay between tunneled signals and macroscopic causality.

Moses Fayngold

2014-12-22T23:59:59.000Z

257

Superconductive tunnel junction integrated circuit  

SciTech Connect (OSTI)

Josephson Junction integrated circuits of the current injection type and magnetically controlled type utilize a superconductive layer that forms both Josephson Junction electrode for the Josephson Junction devices on the integrated circuit as well as a ground plane for the integrated circuit. Large area Josephson Junctions are utilized for effecting contact to lower superconductive layers and islands are formed in superconductive layers to provide isolation between the groundplane function and the Josephson Junction electrode function as well as to effect crossovers. A superconductor-barrier-superconductor trilayer patterned by local anodization is also utilized with additional layers formed thereover. Methods of manufacturing the embodiments of the invention are disclosed.

Jillie, D.W. Jr.; Smith, L.N.

1984-02-07T23:59:59.000Z

258

Scanning tunneling microscope assembly, reactor, and system  

DOE Patents [OSTI]

An embodiment of a scanning tunneling microscope (STM) reactor includes a pressure vessel, an STM assembly, and three spring coupling objects. The pressure vessel includes a sealable port, an interior, and an exterior. An embodiment of an STM system includes a vacuum chamber, an STM reactor, and three springs. The three springs couple the STM reactor to the vacuum chamber and are operable to suspend the scanning tunneling microscope reactor within the interior of the vacuum chamber during operation of the STM reactor. An embodiment of an STM assembly includes a coarse displacement arrangement, a piezoelectric fine displacement scanning tube coupled to the coarse displacement arrangement, and a receiver. The piezoelectric fine displacement scanning tube is coupled to the coarse displacement arrangement. The receiver is coupled to the piezoelectric scanning tube and is operable to receive a tip holder, and the tip holder is operable to receive a tip.

Tao, Feng; Salmeron, Miquel; Somorjai, Gabor A

2014-11-18T23:59:59.000Z

259

Direct observation of electron emission from the grain boundaries of chemical vapour deposition diamond films by tunneling atomic force microscopy  

E-Print Network [OSTI]

.1063/1.3475506 Direct observation of electron emission site on boron-doped polycrystalline diamond thin films using or energy harvesting devices. Electron emission studies usually use doped polycrystalline diamond films observation of the emission sites over a large area of polycrystalline diamond using tunneling atomic force

Bristol, University of

260

Graphene on Ru(0001) Moire Corrugation Studied by Scanning Tunneling Microscopy on Au/Graphene/Ru(0001) Heterostructures  

E-Print Network [OSTI]

Graphene on Ru(0001) Moire Corrugation Studied by Scanning Tunneling Microscopy on Au/Graphene on graphene/Ru(0001) were used to study the corrugation of the moire structure of graphene/Ru(0001 for the graphene/Ru(0001) moire is of structural nature rather than electronic. STM showed a large value

Ciobanu, Cristian

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Time Evolution of Tunneling in Thermal Medium -- Environment-driven Excited Tunneling --  

E-Print Network [OSTI]

Time evolution of tunneling phenomena proceeding in thermal medium is studied using a standard model of environment interaction. A semiclassical probability formula for the particle motion in a metastable state of one dimensional system put in thermal medium is combined with the formula of quantum penetration factor through a potential barrier, to derive the tunneling rate in medium. Effect of environment, its influence on time evolution in particular, is clarified in a real-time formalism. A nonlinear resonance effect is shown to enhance the tunneling rate at finite times of order $2/\\eta $, with $\\eta $ the friction coefficient. In the linear approximation this effect has relevance to the parametric resonance. This effect enhances the possibility of early termination of the cosmological phase transition much prior to the typical Hubble time.

Sh. Matsumoto; M. Yoshimura

2003-07-18T23:59:59.000Z

262

Ferroelectric tunneling element and memory applications which utilize the tunneling element  

DOE Patents [OSTI]

A tunneling element includes a thin film layer of ferroelectric material and a pair of dissimilar electrically-conductive layers disposed on opposite sides of the ferroelectric layer. Because of the dissimilarity in composition or construction between the electrically-conductive layers, the electron transport behavior of the electrically-conductive layers is polarization dependent when the tunneling element is below the Curie temperature of the layer of ferroelectric material. The element can be used as a basis of compact 1R type non-volatile random access memory (RAM). The advantages include extremely simple architecture, ultimate scalability and fast access times generic for all ferroelectric memories.

Kalinin, Sergei V. (Knoxville, TN) [Knoxville, TN; Christen, Hans M. (Knoxville, TN) [Knoxville, TN; Baddorf, Arthur P. (Knoxville, TN) [Knoxville, TN; Meunier, Vincent (Knoxville, TN) [Knoxville, TN; Lee, Ho Nyung (Oak Ridge, TN) [Oak Ridge, TN

2010-07-20T23:59:59.000Z

263

Cavitation in trees and the hydraulic sufficiency of woody Department of Botany, University of Vermont, Burlington, VT 05405, and Northeastern Forest Ex-  

E-Print Network [OSTI]

Cavitation in trees and the hydraulic sufficiency of woody stems M. Tyree Department of Botany cycle of water stress leading to loss of hydraulic conductance and further dynamic stress (see Fig. 1 of hydraulic conductance in the stem. A loss of conductance means that sap will have to overcome a larger

Paris-Sud XI, Université de

264

Cavitation as a complementary tool for automotive aerodynamics J.F. Beaudoin, O. Cadot, J.L. Aider, K. Gosse, P. Paranthoen, B. Hamelin,  

E-Print Network [OSTI]

Cavitation as a complementary tool for automotive aerodynamics J.F. Beaudoin, O. Cadot, J.L. Aider consists in reducing the aerodynamic drag of the vehicles. As a matter of fact, aerodynamic forces play and Sovran 1993; Hucho 1998). Since the pioneering work of Morel (1978) and Ahmed (1983) about aerodynamics

Wesfreid, José Eduardo

265

Low frequency noise measurements of resonant tunnel diodes  

E-Print Network [OSTI]

-n junctions, and tunnel diodes 9] ~ Techniques for obtaining information such as energy levels, lifetimes, and concentrations of these conduction mechanisms have been determined for Schottky barriers, p-n junctions, and tunnel diodes. Some...LOW FREQUENCY NOISE MEASUREMENTS OF RESONANT TUNNEL DIODES A Thesis by SAMUEL SIMON VILLAREAL Submitted to the Office of Graduate Studies of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE...

Villareal, Samuel Simon

2012-06-07T23:59:59.000Z

266

Tunneling spectroscopy of superconducting MoN and NbTiN grown by atomic layer deposition  

SciTech Connect (OSTI)

A tunneling spectroscopy study is presented of superconducting MoN and Nb{sub 0.8}Ti{sub 0.2}N thin films grown by atomic layer deposition (ALD). The films exhibited a superconducting gap of 2?meV and 2.4?meV, respectively, with a corresponding critical temperature of 11.5?K and 13.4?K, among the highest reported T{sub c} values achieved by the ALD technique. Tunnel junctions were obtained using a mechanical contact method with a Au tip. While the native oxides of these films provided poor tunnel barriers, high quality tunnel junctions with low zero bias conductance (below ?10%) were obtained using an artificial tunnel barrier of Al{sub 2}O{sub 3} on the film's surface grown ex situ by ALD. We find a large critical current density on the order of 4?×?10{sup 6}?A/cm{sup 2} at T?=?0.8T{sub c} for a 60?nm MoN film and demonstrate conformal coating capabilities of ALD onto high aspect ratio geometries. These results suggest that the ALD technique offers significant promise for thin film superconducting device applications.

Groll, Nickolas R., E-mail: ngroll@anl.gov; Klug, Jeffrey A.; Claus, Helmut; Pellin, Michael J.; Proslier, Thomas, E-mail: proslier@anl.gov [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Cao, Chaoyue; Becker, Nicholas G.; Zasadzinski, John F. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Altin, Serdar [Fen Edebiyat Fakultesi, Fizik Bolumu, Inonu Universitesi, 44280 Malatya (Turkey)

2014-03-03T23:59:59.000Z

267

Design and Commissioning of a Wind Tunnel for Integrated Physical...  

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

Physical and Chemical Measurements of PM Dispersing Plume of Heavy Duty Diesel Truck Design and Commissioning of a Wind Tunnel for Integrated Physical and Chemical Measurements...

268

Calculation of tunneling rates across a barrier with continuous potential  

E-Print Network [OSTI]

Here, approximate, but accurate expressions for calculation of wavefunctions and tunneling rates are obtained using the method of uniform asymptotic expansion.

Sina Khorasani

2011-04-10T23:59:59.000Z

269

The impact of disorder on charge transport in three dimensional quantum dot resonant tunneling structures  

SciTech Connect (OSTI)

Efficient iso-entropic energy filtering of electronic waves can be realized through nanostructures with three dimensional confinement, such as quantum dot resonant tunneling structures. Large-area deployment of such structures is useful for energy selective contacts but such configuration is susceptible to structural disorders. In this work, the transport properties of quantum-dot-based wide-area resonant tunneling structures, subject to realistic disorder mechanisms, are studied. Positional variations of the quantum dots are shown to reduce the resonant transmission peaks while size variations in the device are shown to reduce as well as broaden the peaks. Increased quantum dot size distribution also results in a peak shift to lower energy which is attributed to large dots dominating transmission. A decrease in barrier thickness reduces the relative peak height while the overall transmission increases dramatically due to lower “series resistance.” While any shift away from ideality can be intuitively expected to reduce the resonance peak, quantification allows better understanding of the tolerances required for fabricating structures based on resonant tunneling phenomena/.

Puthen-Veettil, B., E-mail: b.puthen-veettil@unsw.edu.au; Patterson, R.; König, D.; Conibeer, G.; Green, M. A. [Australian Centre for Advanced Photovoltaics, UNSW, Sydney 2052 (Australia)

2014-10-28T23:59:59.000Z

270

DEVELOPMENT AND APPLICATION OF A FAST-RUNNING TOOL TO CHARACTERIZE SHOCK DAMAGE WITHIN TUNNEL STRUCTURES  

SciTech Connect (OSTI)

Successful but time-intensive use of high-fidelity computational capabilities for shock loading events and resultant effects on and within enclosed structures, e.g., tunnels, has led to an interest in developing more expedient methods of analysis. While several tools are currently available for the general study of the failure of structures under dynamic shock loads at a distance, presented are a pair of statistics- and physics-based tools that can be used to differentiate different types of damage (e.g., breach versus yield) as well as quantify the amount of damage within tunnels for loads close-in and with standoff. Use of such faster running tools allows for scoping and planning of more detailed model and test analysis and provides a way to address parametric sensitivity over a large multivariate space.

Glascoe, L; Morris, J; Glenn, L; Krnjajic, M

2009-03-31T23:59:59.000Z

271

delta-biased Josephson tunnel junctions  

SciTech Connect (OSTI)

The behavior of a long Josephson tunnel junction drastically depends on the distribution of the dc bias current. We investigate the case in which the bias current is fed in the central point of a one-dimensional junction. Such junction configuration has been recently used to detect the persistent currents circulating in a superconducting loop. Analytical and numerical results indicate that the presence of fractional vortices leads to remarkable differences from the conventional case of uniformly distributed dc bias current. The theoretical findings are supported by detailed measurements on a number of delta-biased samples having different electrical and geometrical parameters.

Monaco, R.; Mygind, J.; Koshelets, V. P.; Dmitriev, P. [Istituto di Cibernetica del CNR, 80078 Pozzuoli (Italy) and Dipartimento di Fisica, Universita di Salerno, 84081 Baronissi (Italy); DTU Physics, Technical University of Denmark, B309, DK-2800 Lyngby (Denmark); Institute of Radio Engineering and Electronics, Russian Academy of Science, Mokhovaya 11, Bldg. 7, 125009 Moscow (Russian Federation)

2010-02-01T23:59:59.000Z

272

Potential for tunneling based on rock and soil melting. Abstracts  

SciTech Connect (OSTI)

The rock-melting drill was invented at Los Alamos Scientific Laboratory in 1960. Electrically heated, laboratory-scale drills were subsequently shown to penetrate igneous rocks at usefully high rates, with moderate power consumptions. The development of compact nuclear reactors and of heat pipes now makes possible the extension of this technology to much larger melting penetrators, potentially capable of producing holes up to several meters in diameter and several tens of kilometers long or deep. Development of a rapid, versatile, economical method of boring large, long shafts and tunnels offers solutions to many of man's most urgent ecological, scientific, raw-materials, and energy-supply problems. A melting method appears to be the most promising and flexible means of producing such holes. It is relatively insensitive to the composition, hardness, structure, and temperature of the rock, and offers the possibilities of producing self-supporting, glass-lined holes in almost any formation and (using a technique called lithofracturing) of eliminating the debris-removal problem by forcing molten rock into cracks created in the bore wall. Large rock-melting penetrators, called Electric Subterrenes or Nuclear Subterrenes according to the energy source used, are discussed in this report, together with problems anticipated in their development. It is concluded that this development is within the grasp of present technology.

Rowley, J.C.

1985-01-01T23:59:59.000Z

273

E-Print Network 3.0 - advanced wind-tunnel instrumentation Sample...  

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

wind-tunnel instrumentation Search Powered by Explorit Topic List Advanced Search Sample search results for: advanced wind-tunnel instrumentation Page: << < 1 2 3 4 5 > >> 1...

274

Bifurcation tunneling dynamics in the water trimer Frank N. Keutscha)  

E-Print Network [OSTI]

details of the hydrogen bond tunneling dynamics in the water trimer through excitation of intermolecular­6 and for a detailed molecular description of the associated hydrogen bond rear- rangement dynamics.7­35 Ultimately, weBifurcation tunneling dynamics in the water trimer Frank N. Keutscha) and Richard J. Saykallyb

Cohen, Ronald C.

275

TBM tunnel friction values for the Grizzly Powerhouse Project  

SciTech Connect (OSTI)

Tunnel boring machine (TBM) driven water conveyance tunnels are becoming increasingly more common. Despite advances in tunnel engineering and construction technology, hydraulic performance data for TBM driven tunnels remains relatively unavailable. At the Grizzly Powerhouse Project, the TBM driven water conveyance tunnel was designed using friction coefficients developed from a previous PG&E project. A range of coefficients were selected to bound the possible hydraulic performance variations of the water conveyance system. These friction coefficients, along with the water conveyance systems characteristics, and expected turbine characteristics, were used in a hydraulic transient analysis to determine the expected system pressure fluctuations, and surge chamber performance. During startup test data, these performance characteristics were measured to allow comparison to the original design assumptions. During construction of the tunnel, plaster casts were made of the actual excavated tunnel unlined and fiber reinforced shotcrete lined surfaces. These castings were used to measure absolute roughness of the surfaces so that a friction coefficient could be developed using the Moody diagram and compare them against the design values. This paper compares the assumed frictional coefficient with computed coefficients from headlosses measured during startup testing, and plaster cast measurement calculations. In addition, a comparison of coefficients will be presented for an other TBM driven water conveyance tunnel constructed in the 1980`s.

Stutsman, R.D. [Ensign & Buckley Consulting Engineers, Larkspur, CA (United States); Rothfuss, B.D. [Pacific Gas and Electric Co., San Francisco, CA (United States)

1995-12-31T23:59:59.000Z

276

High Tunnel Crop Production Tips Lewis W. Jett  

E-Print Network [OSTI]

. Specifically, high tunnels are passively vented, solar greenhouses covered with 1-2 layers of greenhouse perpendicular (at right angles) to the prevailing winds on your farm. Generally, this is a north-south direction supplemental heating systems? High tunnels should be designed and managed as passively vented and solar heated

Goodman, Robert M.

277

Chain Inflation via Rapid Tunneling in the Landscape  

E-Print Network [OSTI]

Chain inflation takes place in the string theory landscape as the universe tunnels rapidly through a series of ever lower energy vacua such as may be characterized by quantized changes in four form fluxes. The string landscape may be well suited to an early period of rapid tunneling, as required by chain inflation, followed by a later period of slow tunneling, such as may be required to explain today's dark energy and small cosmological constant. Each tunneling event (which can alternatively be thought of as a nucleation of branes) provides a fraction of an e-folding of inflation, so that hundreds of tunneling events provide the requisite amount of inflation. A specific example from M-theory compactification on manifolds with non-trivial three-cycles is presented.

Katherine Freese; James T. Liu; Douglas Spolyar

2006-12-07T23:59:59.000Z

278

Correlation between simulations and cavitation-induced erosion damage in Spallation Neutron Source target modules after operation  

SciTech Connect (OSTI)

An explicit finite element (FE) technique developed for estimating dynamic strain in the Spallation Neutron Source (SNS) mercury target module vessel is now providing insight into cavitation damage patterns observed in used targets. The technique uses an empirically developed material model for the mercury that describes liquid-like volumetric stiffness combined with a tensile pressure cut-off limit that approximates cavitation. The longest period each point in the mercury is at the tensile cut-off threshold is denoted its saturation time. Now, the pattern of saturation time can be obtained from these simulations and is being positively correlated with observed damage patterns and is interpreted as a qualitative measure of damage potential. Saturation time has been advocated by collaborators at J-Parc as a factor in predicting bubble nuclei growth and collapse intensity. The larger the ratio of maximum bubble size to nucleus, the greater the bubble collapse intensity to be expected; longer saturation times result in greater ratios. With the recent development of a user subroutine for the FE solver saturation time is now provided over the entire mercury domain. Its pattern agrees with spots of damage seen above and below the beam axis on the SNS inner vessel beam window and elsewhere. The other simulation result being compared to observed damage patterns is mercury velocity at the wall. Related R&D has provided evidence for the damage mitigation that higher wall velocity provides. In comparison to observations in SNS targets, inverse correlation of high velocity to damage is seen. In effect, it is the combination of the patterns of saturation time and low velocity that seems to match actual damage patterns.

Riemer, Bernie [ORNL] [ORNL; McClintock, David A [ORNL] [ORNL; Kaminskas, Saulius [ORNL] [ORNL; Abdou, Ashraf A [ORNL] [ORNL

2014-01-01T23:59:59.000Z

279

Small Gas Bubble Experiment for Mitigation of Cavitation Damage and Pressure Waves in Short-pulse Mercury Spallation Targets  

SciTech Connect (OSTI)

Populations of small helium gas bubbles were introduced into a flowing mercury experiment test loop to evaluate mitigation of beam-pulse induced cavitation damage and pressure waves. The test loop was developed and thoroughly tested at the Spallation Neutron Source (SNS) prior to irradiations at the Los Alamos Neutron Science Center - Weapons Neutron Research Center (LANSCE-WNR) facility. Twelve candidate bubblers were evaluated over a range of mercury flow and gas injection rates by use of a novel optical measurement technique that accurately assessed the generated bubble size distributions. Final selection for irradiation testing included two variations of a swirl bubbler provided by Japan Proton Accelerator Research Complex (J-PARC) collaborators and one orifice bubbler developed at SNS. Bubble populations of interest consisted of sizes up to 150 m in radius with achieved gas void fractions in the 10^-5 to 10^-4 range. The nominal WNR beam pulse used for the experiment created energy deposition in the mercury comparable to SNS pulses operating at 2.5 MW. Nineteen test conditions were completed each with 100 pulses, including variations on mercury flow, gas injection and protons per pulse. The principal measure of cavitation damage mitigation was surface damage assessment on test specimens that were manually replaced for each test condition. Damage assessment was done after radiation decay and decontamination by optical and laser profiling microscopy with damaged area fraction and maximum pit depth being the more valued results. Damage was reduced by flow alone; the best mitigation from bubble injection was between half and a quarter that of flow alone. Other data collected included surface motion tracking by three laser Doppler vibrometers (LDV), loop wall dynamic strain, beam diagnostics for charge and beam profile assessment, embedded hydrophones and pressure sensors, and sound measurement by a suite of conventional and contact microphones.

Wendel, Mark W [ORNL] [ORNL; Felde, David K [ORNL] [ORNL; Sangrey, Robert L [ORNL] [ORNL; Abdou, Ashraf A [ORNL] [ORNL; West, David L [ORNL] [ORNL; Shea, Thomas J [ORNL] [ORNL; Hasegawa, Shoichi [Japan Atomic Energy Agency (JAEA)] [Japan Atomic Energy Agency (JAEA); Kogawa, Hiroyuki [Japan Atomic Energy Agency (JAEA)] [Japan Atomic Energy Agency (JAEA); Naoe, Dr. Takashi [Japan Atomic Energy Agency (JAEA)] [Japan Atomic Energy Agency (JAEA); Farny, Dr. Caleb H. [Boston University] [Boston University; Kaminsky, Andrew L [ORNL] [ORNL

2014-01-01T23:59:59.000Z

280

Tunnel-injection GaN quantum dot ultraviolet light-emitting diodes  

SciTech Connect (OSTI)

We demonstrate a GaN quantum dot ultraviolet light-emitting diode that uses tunnel injection of carriers through AlN barriers into the active region. The quantum dot heterostructure is grown by molecular beam epitaxy on AlN templates. The large lattice mismatch between GaN and AlN favors the formation of GaN quantum dots in the Stranski-Krastanov growth mode. Carrier injection by tunneling can mitigate losses incurred in hot-carrier injection in light emitting heterostructures. To achieve tunnel injection, relatively low composition AlGaN is used for n- and p-type layers to simultaneously take advantage of effective band alignment and efficient doping. The small height of the quantum dots results in short-wavelength emission and are simultaneously an effective tool to fight the reduction of oscillator strength from quantum-confined Stark effect due to polarization fields. The strong quantum confinement results in room-temperature electroluminescence peaks at 261 and 340 nm, well above the 365 nm bandgap of bulk GaN. The demonstration opens the doorway to exploit many varied features of quantum dot physics to realize high-efficiency short-wavelength light sources.

Verma, Jai; Kandaswamy, Prem Kumar; Protasenko, Vladimir; Verma, Amit; Grace Xing, Huili; Jena, Debdeep [Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)] [Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)

2013-01-28T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Conceptual design for an electron-beam heated hypersonic wind tunnel  

SciTech Connect (OSTI)

There is a need for hypersonic wind-tunnel testing at about mach 10 and above using natural air and simulating temperatures and pressures which are prototypic of flight at 50 km altitude or below. With traditional wind-tunnel techniques, gas cooling during expansion results in exit temperatures which are too low. Miles, et al., have proposed overcoming this difficulty by heating the air with a laser beam as it expands in the wind-tunnel nozzle. This report discusses an alternative option of using a high-power electron beam to heat the air as it expands. In the e-beam heating concept, the electron beam is injected into the wind-tunnel nozzle near the exit and then is guided upstream toward the nozzle throat by a strong axial magnetic field. The beam deposits most of its power in the dense air near the throat where the expansion rate is greatest. A conceptual design is presented for a large-scale system which achieves Mach 14 for 0.1 seconds with an exit diameter of 2.8 meters. It requires 450 MW of electron beam power (5 MeV at 90 A). The guiding field is 500 G for most of the transport length and increases to 100 kG near the throat to converge the beam to a 1.0-cm diameter. The beam generator is a DC accelerator using a Marx bank (of capacitors) and a diode stack with a hot cathode. 14 refs. 38 figs., 9 tabs.

Lipinski, R.J.; Kensek, R.P.

1997-07-01T23:59:59.000Z

282

Multiple percolation tunneling staircase in metal-semiconductor nanoparticle composites  

SciTech Connect (OSTI)

Multiple percolation transitions are observed in a binary system of RuO{sub 2}-CaCu{sub 3}Ti{sub 4}O{sub 12} metal-semiconductor nanoparticle composites near percolation thresholds. Apart from a classical percolation transition, associated with the appearance of a continuous conductance path through RuO{sub 2} metal oxide nanoparticles, at least two additional tunneling percolation transitions are detected in this composite system. Such behavior is consistent with the recently emerged picture of a quantum conductivity staircase, which predicts several percolation tunneling thresholds in a system with a hierarchy of local tunneling conductance, due to various degrees of proximity of adjacent conducting particles distributed in an insulating matrix. Here, we investigate a different type of percolation tunneling staircase, associated with a more complex conductive and insulating particle microstructure of two types of non-spherical constituents. As tunneling is strongly temperature dependent, we use variable temperature measurements to emphasize the hierarchical nature of consecutive tunneling transitions. The critical exponents corresponding to specific tunneling percolation thresholds are found to be nonuniversal and temperature dependent.

Mukherjee, Rupam; Huang, Zhi-Feng; Nadgorny, Boris [Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201 (United States)

2014-10-27T23:59:59.000Z

283

ORGANIC RASPBERRY PRODUCTION UNDER HIGH TUNNELS Eric Hanson  

E-Print Network [OSTI]

, and applied to the surface in 2011 and 2012. Incorporated compost caused some salt. Both compost and fertilizer appeared to supply adequate nitrogen early for conventional raspberries under tunnels, which can exceed 18,000 lb per acre. Several

284

Ultrafast resolution of tunneling delay time ALEXANDRA S. LANDSMAN,,  

E-Print Network [OSTI]

laser physics; (020.4180) Multiphoton processes; (240.7040) Tunneling. http://dx.doi.org/10.1364/OPTICA Vol. 1, No. 5 / November 2014 / Optica 343 #12;Observable 1 is the polarization axis

Keller, Ursula

285

Effect of anisotropy in ground movements caused by tunnelling  

E-Print Network [OSTI]

This paper presents closed-form analytical solutions for estimating far-field ground deformations caused by shallow tunnelling in a linear elastic soil mass with cross-anisotropic stiffness properties. The solutions describe ...

Zymnis, Despina Maria

286

Tunneling from super- to normal-deformed minima in nuclei.  

SciTech Connect (OSTI)

An excited minimum, or false vacuum, gives rise to a highly elongated superdeformed (SD) nucleus. A brief review of superdeformation is given, with emphasis on the tunneling from the false to the true vacuum, which occurs in the feeding and decay of SD bands. During the feeding process the tunneling is between hot states, while in the decay it is from a cold to a hot state. The {gamma} spectra connecting SD and normal-deformed (ND) states provide information on several physics issues: the decay mechanism; the spin/parity quantum numbers, energies and microscopic structures of SD bands; the origin of identical SD bands; the quenching of pairing with excitation energy; and the chaoticity of excited ND states at 2.5-5 MeV. Other examples of tunneling in nuclei, which are briefly described, include the possible role of tunneling in {Delta}I = 4 bifurcation in SD bands, sub-barrier fusion and proton emitters.

Khoo, T. L.

1998-01-08T23:59:59.000Z

287

Effect of existing building on tunneling-induced ground movements  

E-Print Network [OSTI]

The goal of this thesis is to assess the influence of an existing structure on tunneling-induced ground movements. This is accomplished through 2D numerical simulations that are compared with similar prior studies reported ...

Law, Rachel Hoi-chee

2012-01-01T23:59:59.000Z

288

One Hair Postulate for Hawking Radiation as Tunneling Process  

E-Print Network [OSTI]

For Hawking radiation, treated as a tunneling process, the no-hair theorem of black hole together with the law of energy conservation is utilized to postulate that the tunneling rate only depends on the external qualities (e.g., the mass for the Schwarzschild black hole) and the energy of the radiated particle. This postulate is justified by the WKB approximation for calculating the tunneling probability. Based on this postulate, a general formula for the tunneling probability is derived without referring to the concrete form of black hole metric. This formula implies an intrinsic correlation between the successive processes of the black hole radiation of two or more particles. It also suggests a kind of entropy conservation and thus resolves the puzzle of black hole information loss in some sense.

H. Dong; Qing-yu Cai; X. F. Liu; C. P. Sun

2009-07-13T23:59:59.000Z

289

Theory of Extrinsic and Intrinsic Tunnelling in Cuprate Superconductors  

E-Print Network [OSTI]

A theory capable of explaining intrinsic and extrinsic tunnelling conductance in underdoped cuprates has been devised that accounts for the existence of two energy scales, their temperature and doping dependencies. The asymmetry and inhomogeneity seen in extrinsic (normal metal - superconductor (NS)) tunnelling and the normal-state gapped intrinsic (SS) conductance is explained, as well as the superconducting gap and normal state pseudogap and the temperature dependence of the full gap.

J. Beanland; A. S. Alexandrov

2010-05-03T23:59:59.000Z

290

Photon tunneling in the warp drive space-time  

E-Print Network [OSTI]

We simplify the warp drive space-time such that it becomes stationary and the distorsion becomes one-dimensional and static. We use this simplified space-time as the classical background space-time for a photon field. The Drummond&Hathrell action is then used in order to investigate the velocity effects on photons tunneling through the space-time distorsion. We speculate on whether or not all tunneling processes with photons induce faster than light effects.

Cramer, C R

1995-01-01T23:59:59.000Z

291

Two-Color Ultrafast Photoexcited Scanning Tunneling Microscopy  

SciTech Connect (OSTI)

We report on two-color two-photon photoexcitation of a metal surface driven by ultrafast laser pulses and detected with a scanning tunneling microscope (STM) tip as a proximate anode. Results are presented for two cases: (i) where the tip is retracted from the surface far enough to prohibit tunneling, and (ii) where the tip is within tunneling range of the surface. A delay-modulation technique is implemented to isolate the two-color photoemission from concurrent one-color two-photon photoemission and provide subpicosecond time-resolved detection. When applied with the tip in tunneling range, this approach effectively isolates the two-photon photoexcited current signal from the conventional tunneling current and enables subpicosecond time-resolved detection of the photoexcited surface electrons. The advantage of the two-color approach is highlighted by comparison with the one-color case where optical interference causes thermal modulation of the STM tip length, resulting in tunneling current modulations that are orders of magnitude larger than the current due to photoexcitation of surface electrons. By completely eliminating this interference, and thereby avoiding thermal modulation of the STM tip length, the two-color approach represents an important step toward the ultimate goal of simultaneous subnanometer and subpicosecond measurements of surface electron dynamics by ultrafast-laser-excited STM.

Camillone, N.; Dolocan, A.; Acharya, D.P.; Zahl, P.; Sutter, P.

2011-05-26T23:59:59.000Z

292

Tunneling conductance studies in the ion-beam sputtered CoFe/Mg/MgO/NiFe magnetic tunnel junctions  

SciTech Connect (OSTI)

Magnetic tunnel junctions consisting of CoFe(10 nm)/Mg(1 nm)/MgO(3.5 nm)/NiFe(10 nm) are grown at room temperature using dual ion beam sputtering via in-situ shadow masking. The effective barrier thickness and average barrier height are estimated to be 3.5 nm (2.9 nm) and 0.69 eV (1.09 eV) at 290 K (70 K), respectively. The tunnel magnetoresistance value of 0.2 % and 2.3 % was observed at 290 K and 60 K, respectively. The temperature dependence of tunneling conductance revealed the presence of localized states present within the forbidden gap of the MgO barrier leading to finite inelastic spin independent tunneling contributions, which degrade the TMR value.

Singh, Braj Bhusan; Chaudhary, Sujeet [Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India)

2013-06-03T23:59:59.000Z

293

Investigation of three-dimensional effects on a cavitating Venturi flow  

E-Print Network [OSTI]

of the speed of sound in the mixture), large density ratio between the liquid and the vapour phases, small capacity at constant pressure cbaro Minimum speed of sound in the mixture CDES Constant of the DES model 2 dynamic eddy viscosity Mixture density sat L Density of liquid at saturation sat V Density of vapour

Paris-Sud XI, Université de

294

Resonant tunneling with high peak to valley current ratio in SiO{sub 2}/nc-Si/SiO{sub 2} multi-layers at room temperature  

SciTech Connect (OSTI)

We have investigated carrier transport in SiO{sub 2}/nc-Si/SiO{sub 2} multi-layers by room temperature current-voltage measurements. Resonant tunneling signatures accompanied by current peaks are observed. Carrier transport in the multi-layers were analyzed by plots of ln(I/V{sup 2}) as a function of 1/V and ln(I) as a function of V{sup 1/2}. Results suggest that besides films quality, nc-Si and barrier sub-layer thicknesses are important parameters that restrict carrier transport. When thicknesses are both small, direct tunneling dominates carrier transport, resonant tunneling occurs only at certain voltages and multi-resonant tunneling related current peaks can be observed but with peak to valley current ratio (PVCR) values smaller than 1.5. When barrier thickness is increased, trap-related and even high field related tunneling is excited, causing that multi-current peaks cannot be observed clearly, only one current peak with higher PVCR value of 7.7 can be observed. While if the thickness of nc-Si is large enough, quantum confinement is not so strong, a broad current peak with PVCR value as high as 60 can be measured, which may be due to small energy difference between the splitting energy levels in the quantum dots of nc-Si. Size distribution in a wide range may cause un-controllability of the peak voltages.

Chen, D. Y., E-mail: cdy7659@126.com [Department of Physics, Nanjing National Laboratory of Microstructures and Key Laboratory of Advanced Photonic and Electronic, materials, Nanjing University, Nanjing 210093 (China); Nanjing University of posts and Telecommunications, Nanjing 210046 (China); Sun, Y.; He, Y. J. [Nanjing University of posts and Telecommunications, Nanjing 210046 (China); Xu, L.; Xu, J. [Department of Physics, Nanjing National Laboratory of Microstructures and Key Laboratory of Advanced Photonic and Electronic, materials, Nanjing University, Nanjing 210093 (China)

2014-01-28T23:59:59.000Z

295

Ventilation and Suppression Systems in Road Tunnels: Some Issues regarding their Appropriate Use in a Fire Emergency   

E-Print Network [OSTI]

Two important tunnel safety technologies are addressed. The majority of long road tunnels have ventilation systems. In the event of a fire in a tunnel, such systems will influence fire development in a number of different ...

Carvel, Ricky O; Rein, Guillermo; Torero, Jose L

296

Temperature study of Zero Bias Features using self-assembling tunnel junctions  

E-Print Network [OSTI]

The significant reduction in the conductance of a tunneling system near zero bias voltage is termed the Zero Bias Feature (ZBF). A ³He cryostat has been modified to incorporate a Self-Assembling Tunnel Junction (SATJ), capable of performing...

Savitski, Stephen Ronald

2012-06-07T23:59:59.000Z

297

E-Print Network 3.0 - aerothermal wind tunnel Sample Search Results  

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

aerothermal wind tunnel Search Powered by Explorit Topic List Advanced Search Sample search results for: aerothermal wind tunnel Page: << < 1 2 3 4 5 > >> 1 Pour l'obtention du...

298

E-Print Network 3.0 - aerosol wind tunnel Sample Search Results  

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

wind tunnel Search Powered by Explorit Topic List Advanced Search Sample search results for: aerosol wind tunnel Page: << < 1 2 3 4 5 > >> 1 LA-UR-00-3091 Approved for public...

299

E-Print Network 3.0 - airfoil wind tunnel Sample Search Results  

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

wind tunnel Search Powered by Explorit Topic List Advanced Search Sample search results for: airfoil wind tunnel Page: << < 1 2 3 4 5 > >> 1 Flexible-Membrane Airfoils at Low...

300

E-Print Network 3.0 - altitude wind tunnel Sample Search Results  

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

wind tunnel Search Powered by Explorit Topic List Advanced Search Sample search results for: altitude wind tunnel Page: << < 1 2 3 4 5 > >> 1 For more than 45 years, The University...

Note: This page contains sample records for the topic "large cavitation tunnel" 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

E-Print Network 3.0 - ames wind tunnel Sample Search Results  

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

wind tunnel Search Powered by Explorit Topic List Advanced Search Sample search results for: ames wind tunnel Page: << < 1 2 3 4 5 > >> 1 IOWA STATE UNIVERSITY WIND SIMULATION AND...

302

Effects of tunneling on groundwater flow and swelling of clay-sulfate rocks  

E-Print Network [OSTI]

[1] Swelling of clay-sulfate rocks is a major threat in tunneling. It is triggered by the transformation of the sulfate mineral anhydrite into gypsum as a result of water inflow in anhydrite-containing layers after tunnel ...

Butscher, Christoph

303

Development of the resource model for the Decision Aids for Tunneling (DAT)  

E-Print Network [OSTI]

The Decision Aids for Tunneling (DAT) are a computer based method with which distributions of tunnel construction time and cost as well as required and produced resources can be estimated considering uncertainties in ...

Min, Sangyoon, 1973-

2008-01-01T23:59:59.000Z

304

Nanopillar Spin Filter Tunnel Junctions with Manganite Barriers  

E-Print Network [OSTI]

promising FI tunnel barrier material for SFTJ. In this work, we investigate the spin filtering properties of Sm0.75Sr0.25MnO3 (SSMO) manganite ultrathin films in LNO/SSMO/LNO tunnel junctions. SSMO films were grown by pulsed laser deposition (PLD) onto Sr... -plane rotation vis-à-vis the substrate, i.e. the alignment of [110] of orthorhombic SSMO with the [100] of the underlying cubic SrTiO3 (STO) substrate. Film thickness was calculated from both X-ray reflectivity (not shown) and diffraction fringes around the (004...

Prasad, Bhagwati; Egilmez, Mehmet; Schoofs, Frank; Fix, Thomas; Vickers, Mary E; Zhang, Wenrui; Jian, Jie; Wang, Haiyan; Blamire, Mark G

2014-04-17T23:59:59.000Z

305

Hawking temperature of rotating charged black strings from tunneling  

SciTech Connect (OSTI)

Thermal radiations from spherically symmetric black holes have been studied from the point of view of quantum tunneling. In this paper we extend this approach to study radiation of fermions from charged and rotating black strings. Using WKB approximation and Hamilton-Jacobi method we work out the tunneling probabilities of incoming and outgoing fermions and find the correct Hawking temperature for these objects. We show that in appropriate limits the results reduce to those for the uncharged and non-rotating black strings.

Ahmed, Jamil; Saifullah, K., E-mail: jamil_051@yahoo.com, E-mail: saifullah@qau.edu.pk [Department of Mathematics, Quaid-i-Azam University, Islamabad (Pakistan)

2011-11-01T23:59:59.000Z

306

Characteristics of high-transmission-probability tunnel junctions for use as particle detectors  

SciTech Connect (OSTI)

Interest in the problem of the galactic dark matter has stimulated development of particle detectors sensitive to very low energies. Superconducting tunnel junctions may be useful in such detectors. We describe here superconducting tunnel junctions with thin barriers which may be suitable for this purpose. We present I-V characteristics and data on the temperature dependence of the subgap tunneling current. We also present some scanning-electron-microscope observations of the thin films of the tunnel junctions.

Stricker, D.A.; Alba, G.P.; Anderson, C.C.; Bing, D.D.; Bland, R.W.; Dickson, S.C.; Dignan, T.G.; Gagnon, P.; Johnson, R.T.; Seneclauze, C.M.

1988-12-31T23:59:59.000Z

307

Characteristics of high-transmission-probability tunnel junctions for use as particle detectors  

SciTech Connect (OSTI)

Interest in the problem of the galactic dark matter has stimulated development of particle detectors sensitive to very low energies. Superconducting tunnel junctions may be useful in such detectors. We describe here superconducting tunnel junctions with thin barriers which may be suitable for this purpose. We present I-V characteristics and data on the temperature dependence of the subgap tunneling current. We also present some scanning-electron-microscope observations of the thin films of the tunnel junctions.

Stricker, D.A.; Alba, G.P.; Anderson, C.C.; Bing, D.D.; Bland, R.W.; Dickson, S.C.; Dignan, T.G.; Gagnon, P.; Johnson, R.T.; Seneclauze, C.M.

1988-01-01T23:59:59.000Z

308

Characteristics of high-transmission-probability tunnel junctions for use as particle detectors  

SciTech Connect (OSTI)

Interest in the problem of the galactic dark matter has stimulated development of particle detectors sensitive to very low energies. Superconducting tunnel junctions may be useful in such detectors. The authors describe superconducting tunnel junctions with thin barriers which may be suitable for this purpose. They present I-V characteristics and data on the temperature dependence of the subgap tunneling current. They also present some scanning-electron-microscope observations of the thin films of the tunnel junctions.

Stricker, D.A.; Alba, G.P.; Anderson, C.C.; Bing, D.D.; Bland, R.W.; Dickson, S.C.; Dignan, T.G.; Gagnon, P.; Johnson, R.T.; Seneclauze, C.M.

1989-03-01T23:59:59.000Z

309

Programming Wireless Sensor Networks with Logical Neighborhoods: A Road Tunnel Use Case  

E-Print Network [OSTI]

on sensed data, the system operates a variety of devices, such as ventilation fans inside the tunnel

Picco, Gian Pietro

310

Switching current measurements of large area Josephson tunnel junctions A. Wallraff,a)  

E-Print Network [OSTI]

the potential. This corresponds to a transition of the Josephson junction from a superconducting zero the system is coupled. Thermal activation TA in a current-biased Josephson junction has been studied both damping.11,12 At low temperatures the quantum mechanical properties of Josephson junctions have been

Wallraff, Andreas

311

Vacuum gaps with small tunnel currents at large electric field and its  

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 JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlongUpdates byUserUtility-Scale SolarProgrampotential

312

Natural Ventilation in Buildings: Measurement in a Wind Tunnel and Numerical Simulation with Large Eddy Simulation  

E-Print Network [OSTI]

save energy compared to mechanical ventilation systems. In building design the prediction save energy consumed by the heating, ventilating, and air- conditioning systems in a building. In a naturally ventilated building, air is driven in and out due to pressure differences produced by wind

Chen, Qingyan "Yan"

313

Molecularly Resolved Images of Peptide-Functionalized Gold Surfaces by Scanning Tunneling Microscopy  

E-Print Network [OSTI]

Molecularly Resolved Images of Peptide-Functionalized Gold Surfaces by Scanning Tunneling propargylglycine unnatural functional groups 20 Å apart and an alkanethiol self-assembled monolayer (SAM) on a gold-terminated surfaces were imaged by scanning tunneling microscopy (STM) using a low tunneling current of 10 p

Webb, Lauren J.

314

Observation of Turbulent Intermittency Scaling with Magnetic Helicity in an MHD Plasma Wind Tunnel  

E-Print Network [OSTI]

. An unstable spheromak injected into the MHD wind tunnel of the Swarthmore Spheromak Experiment displays-tunnel configuration of the Swarthmore Spheromak Experiment (SSX) [16,17] explores this possible relationship between indices. The scan is conducted on the wind-tunnel configuration of the Swarthmore Spheromak Experiment

Brown, Michael R.

315

Influence of dimensionality on deep tunneling rates: A study based on the hydrogen-nickel system  

E-Print Network [OSTI]

, such as hydrogen embrittlement, catalysis, and fuel storage.1 Moreover, tunneling draws fundamental interest sinceInfluence of dimensionality on deep tunneling rates: A study based on the hydrogen-nickel system hydrogen into a surface site of a nickel crystal is used to investigate deep tunneling phenomena. A method

Zeiri, Yehuda

316

Tracking an Aerodynamic Model in a Wind Tunnel with a Stereo High-speed Imaging System  

E-Print Network [OSTI]

Tracking an Aerodynamic Model in a Wind Tunnel with a Stereo High-speed Imaging System Lichuan Gui in wind tunnel tests with a stereo high-speed imaging system. The imaging system includes two high angle, pitch angle and yaw angle of the aerodynamic model in the wind tunnel. Tests and simulations were

Gui, Lichuan

317

Role of bias voltage and tunneling current in the perpendicular displacements of freestanding graphene via scanning  

E-Print Network [OSTI]

graphene via scanning tunneling microscopy Peng Xu, Steven D. Barber, Matthew L. Ackerman, James Kevin measurements of freestanding graphene as a function of applied bias voltage and tunneling current setpoint, the graphene approaches the STM tip, while, on the other hand, when the tunneling current is increased

Thibado, Paul M.

318

Developing a Practical Wind Tunnel Test Engineering Course for Undergraduate Aerospace Engineering Students  

E-Print Network [OSTI]

This thesis describes the development and assessment of an undergraduate wind tunnel test engineering course utilizing the 7ft by 10ft Oran W. Nicks Low Speed Wind Tunnel (LSWT). Only 5 other universities in the United States have a wind tunnel...

Recla, Benjamin Jeremiah

2013-04-19T23:59:59.000Z

319

Natural convection in tunnels at Yucca Mountain and impact on drift seepage  

SciTech Connect (OSTI)

The decay heat from radioactive waste that is to be disposed in the once proposed geologic repository at Yucca Mountain (YM) will significantly influence the moisture conditions in the fractured rock near emplacement tunnels (drifts). Additionally, large-scale convective cells will form in the open-air drifts and will serve as an important mechanism for the transport of vaporized pore water from the fractured rock in the drift center to the drift end. Such convective processes would also impact drift seepage, as evaporation could reduce the build up of liquid water at the tunnel wall. Characterizing and understanding these liquid water and vapor transport processes is critical for evaluating the performance of the repository, in terms of water-induced canister corrosion and subsequent radionuclide containment. To study such processes, we previously developed and applied an enhanced version of TOUGH2 that solves for natural convection in the drift. We then used the results from this previous study as a time-dependent boundary condition in a high-resolution seepage model, allowing for a computationally efficient means for simulating these processes. The results from the seepage model show that cases with strong natural convection effects are expected to improve the performance of the repository, since smaller relative humidity values, with reduced local seepage, form a more desirable waste package environment.

Halecky, N.; Birkholzer, J.T.; Peterson, P.

2010-04-15T23:59:59.000Z

320

Periodic orbit theory of chaotic tunneling Olivier Sigwarth  

E-Print Network [OSTI]

pre­ cisely in this organization into nearly cancelling combinations: cycle expansions are dominated Cvitanovi'c April 17, 1998 PACS: 03.20.+i, 03.65.Sq, 05.40.+j, 05.45.+b keywords: cycle expansions, periodic orbits, dynamical zeta functions, quantum tunneling. Abstract 1 cycle expansions. 1 Introduction

Cvitanovc', Predrag

Note: This page contains sample records for the topic "large cavitation tunnel" 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

The Tunnel Vision Syndrome: Challenging Computer Science Education  

E-Print Network [OSTI]

The Tunnel Vision Syndrome: Challenging Computer Science Education Reiner Hartenstein1 Professor levels from compilers over execution devices down to all levels of storage behavior, challenging all, and programming. Overcoming the von-Neumann- syndrome-based mind set would be a fascinating job for computer

Hartenstein, Reiner

322

area lhc tunnel: Topics by E-print Network  

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

Keith 2006-01-01 9 A High Luminosity e+e- Collider in the LHC tunnel to study the Higgs Boson HEP - Experiment (arXiv) Summary: We consider the possibility of a 120x120 GeV e+e-...

323

Scanning tunneling spectroscopy of suspended single-wall carbon nanotubes  

E-Print Network [OSTI]

Scanning tunneling spectroscopy of suspended single-wall carbon nanotubes B. J. LeRoy,a) S. G-wall carbon nanotubes that are freely suspended over a trench. The nanotubes were grown by chemical vapor on the freestanding portions of the nanotubes. Spatially resolved spectroscopy on the suspended portion of both

Dekker, Cees

324

Tunnel MOS Heterostructure Field Effect Transistor for RF Switching Applications  

E-Print Network [OSTI]

6 dry etching on the trap density and trap state energy of AlGaN surface are investigated using the GP/w- w method. Various tunneling mechanisms at different biases are then characterized in samples and compared with each other. To improve...

Rezanezhad Gatabi, Iman

2013-06-06T23:59:59.000Z

325

Exercice session Cargse, October 2008 Klein tunneling in graphene  

E-Print Network [OSTI]

Exercice session Cargèse, October 2008 Klein tunneling in graphene Pierre Allain and Jean-Noël Fuchs 1 Introduction : plane wave The goal is to compute the probability transmission T of a graphene 1 = n2 sin 2 for an electron in graphene and show that the optical index n is proportional

Paris-Sud 11, Université de

326

Quantum Terahertz Electrodynamics and Macroscopic Quantum Tunneling in Layered Superconductors  

E-Print Network [OSTI]

of macroscopic quantum tunneling (MQT) in stacks of intrinsic Josephson junctions. Because of the long numbers: 74.72.Hs, 74.78.Fk The recent surge of interest in stacks of intrinsic Josephson junctions of stacks of Josephson junctions in quantum electronics [6]. This requires a quantum theory capable

Nori, Franco

327

Particle pulses from superconducting aluminum tunnel junction detectors  

SciTech Connect (OSTI)

Superconducting aluminum tunnel junctions have been developed for use as particle detectors. This paper presents results on static characteristics of these devices. We also present results from tests of these detectors with 6-keV X-rays. An extrapolation of the properties of these detectors to one suitable for dark-matter detectors is discussed.

Stricker, D.A.; Bing, D.D.; Bland, R.W.; Dickson, S.C.; Dignan, T.; Johnson, R.T.; Lockhart, J.M.; Laws, K.; Simon, M.W.; Watson, R. (San Francisco State Univ., Physics and Astronomy Dept. San Francisco, CA (US))

1991-03-01T23:59:59.000Z

328

A Ray Tracing Algorithm for Intelligent Transport Systems in Tunnels  

E-Print Network [OSTI]

, Lund University, Lund, Sweden Abstract--It is well-known that the radio wave propagation mechanisms of time- varying power delay profile analysis. Secondly we introduce a RT tool that includes influence of the moving objects, to predict wave propagation mechanisms in the tunnel. In order to reduce computational

Zemen, Thomas

329

Tunneling control using classical non-linear oscillator  

SciTech Connect (OSTI)

A quantum particle is placed in symmetric double well potential which is coupled to a classical non-linear oscillator via a coupling function. With different spatial symmetry of the coupling and under various controlling fashions, the tunneling of the quantum particle can be enhanced or suppressed, or totally destroyed.

Kar, Susmita [Department of Physical Chemistry, Indian Association for the Cultivation of Science, Kolkata -700032 (India); Bhattacharyya, S. P., E-mail: pcspb@chem.iitb.ac.in [Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai- 400076 (India)

2014-04-24T23:59:59.000Z

330

Tunnel junction multiple wavelength light-emitting diodes  

DOE Patents [OSTI]

A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect. 5 figs.

Olson, J.M.; Kurtz, S.R.

1992-11-24T23:59:59.000Z

331

Tunnel junction multiple wavelength light-emitting diodes  

DOE Patents [OSTI]

A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect.

Olson, Jerry M. (Lakewood, CO); Kurtz, Sarah R. (Golden, CO)

1992-01-01T23:59:59.000Z

332

Macroscopic quantum tunneling and the 'cosmic' Josephson effect  

SciTech Connect (OSTI)

We discuss the possible influence of a cosmic magnetic field on the macroscopic quantum tunneling process associated, in a cosmological context, to the decay of the 'false vacuum'. We find a close analogy with the effects of an external magnetic field applied to a Josephson junction in the context of low-temperature/high-temperature superconducting devices.

Barone, A. [Dipartimento di Scienze Fisiche, Universita di Napoli 'Federico II', CNR-SPIN, Piazzale Tecchio 21, 80125 Napoli (Italy); Gasperini, M. [Dipartimento di Fisica, Universita di Bari, Via G. Amendola 173, 70126 Bari (Italy); INFN, Sezione di Bari, Bari (Italy); Rotoli, G. [Dipartimento di Ingegneria dell'Informazione, Seconda Universita di Napoli (SUN), Via Roma 29, 81031 Aversa (CE) (Italy)

2010-10-15T23:59:59.000Z

333

Primary Electronic Thermometry Using the Shot Noise of a Tunnel  

E-Print Network [OSTI]

. Lehnert,1,2 I. Siddiqi,1 R. J. Schoelkopf1 We present a thermometer based on the electrical noise from a tunnel junction. In this thermometer, temperature is related to the voltage across the junction thermometer over four orders of magnitude in temperature, with as high as 0.1% accuracy and 0.02% precision

334

Relation between quantum tunneling times for relativistic particles  

SciTech Connect (OSTI)

A general relation between the phase time (group delay) and the dwell time is derived for relativistic tunneling particles described by the Dirac equation. It is shown that the phase time equals the dwell time plus a self-interference delay which is a relativistic generalization of previous results.

Winful, Herbert G.; Ngom, Moussa; Litchinitser, Natalia M. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109-2122 (United States); Applied Physics Program, University of Michigan, 2477 Randall Laboratory, Ann Arbor, Michigan 48109-1120 (United States); Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109-2122 (United States)

2004-11-01T23:59:59.000Z

335

Theory of two-dimensional macroscopic quantum tunneling in a Josephson junction coupled with an LC circuit  

E-Print Network [OSTI]

We investigate classical thermal activation (TA) and macroscopic quantum tunneling (MQT) for a Josephson junction coupled with an LC circuit theoretically. The TA and MQT escape rate are calculated analytically by taking into account the two-dimensional nature of the classical and quantum phase dynamics. We find that the MQT escape rate is largely suppressed by the coupling to the LC circuit. On the other hand, this coupling gives rise to slight reduction of the TA escape rate. These results are relevant for the interpretation of a recent experiment on the MQT and TA phenomena in grain boundary YBCO Josephson junctions.

Shiro Kawabata; Takeo Kato; Thilo Bauch

2009-12-17T23:59:59.000Z

336

Strained-Si1-xGex/Si Band-to-Band Tunneling Transistors: Impact of Tunnel-Junction Germanium Composition and Doping Concentration on Switching Behavior  

E-Print Network [OSTI]

Strained pseudomorphic Si/Si [subscript 1-x]Ge [subscript x]/Si gate-controlled band-to-band tunneling (BTBT) devices have been analyzed with varying Ge composition up to 57% and p+ tunnel-junction (source) doping concentration ...

Antoniadis, Dimitri A.

337

Tunnel and Subsurface Void Detection and Range to Target Measurement  

SciTech Connect (OSTI)

Engineers and technicians at the Idaho National Laboratory invented, designed, built and tested a device capable of detecting and measuring the distance to, an underground void, or tunnel. Preliminary tests demonstrated positive detection of, and range to, a void thru as much as 30 meters of top-soil earth. Device uses acoustic driving point impedance principles pioneered by the Laboratory for well-bore physical properties logging. Data receipts recorded by the device indicates constructive-destructive interference patterns characteristic of acoustic wave reflection from a downward step-change in impedance mismatch. Prototype tests demonstrated that interference patterns in receipt waves could depict the patterns indicative of specific distances. A tool with this capability can quickly (in seconds) indicate the presence and depth/distance of a void or tunnel. Using such a device, border security and military personnel can identify threats of intrusion or weapons caches in most all soil conditions including moist and rocky.

Phillip B. West

2009-06-01T23:59:59.000Z

338

Hanford facility dangerous waste permit application, PUREX storage tunnels  

SciTech Connect (OSTI)

The Hanford Facility Dangerous Waste Permit Application is considered to be a single application organized into a General Information Portion (document number DOE/RL-91-28) and a Unit-Specific Portion. The scope of the Unit-Specific Portion is limited to Part B permit application documentation submitted for individual, operating treatment, storage, and/or disposal units, such as the PUREX Storage Tunnels (this document, DOE/RL-90-24). Both the General Information and Unit-Specific portions of the Hanford Facility Dangerous Waste Permit Application address the content of the Part B permit application guidance prepared by the Washington State Department of Ecology (Ecology 1996) and the US Environmental Protection Agency (40 Code of Federal Regulations 270), with additional information needs defined by the Hazardous and Solid Waste Amendments and revisions of Washington Administrative Code 173-303. For ease of reference, the Washington State Department of Ecology alpha-numeric section identifiers from the permit application guidance documentation (Ecology 1996) follow, in brackets, the chapter headings and subheadings. A checklist indicating where information is contained in the PUREX Storage Tunnels permit application documentation, in relation to the Washington State Department of Ecology guidance, is located in the Contents Section. Documentation contained in the General Information Portion is broader in nature and could be used by multiple treatment, storage, and/or disposal units (e.g., the glossary provided in the General Information Portion). Wherever appropriate, the PUREX Storage Tunnels permit application documentation makes cross-reference to the General Information Portion, rather than duplicating text. Information provided in this PUREX Storage Tunnels permit application documentation is current as of April 1997.

Price, S.M.

1997-09-08T23:59:59.000Z

339

Aluminum tunnel junction detector operation in an adiabatic demagnetization refrigerator  

SciTech Connect (OSTI)

Superconducting tunnel junction detectors are being developed as both particle and X-ray detectors. Aluminum junctions are desirable for detectors because of their strong native oxide barriers, and because the small energy gap of aluminum is a good match to ballistic phonons generated by particle interactions in single crystals of silicon or other low acoustic-loss insulating crystals. Aluminum tunnel junction detectors must be operated near 0.1 T{sub C} which is 110 mK for aluminum. To operate detectors at these temperatures, we have developed adiabatic demagnetization refrigerators (ADRs) for the laboratory and prototype ADRs for space based operation. These cryogenic systems are simpler, more convenient and more portable than most dilution refrigerators. We have demonstrated that the magnetic field of the ADR need not compromise the performance of aluminum tunnel junctions. We have recently initiated a program to develop superconducting tunnel junctions (STJs) as high resolution X-ray detectors and low energy threshold particle detectors. This complements our existing program in which we are developing high resolution X-ray microcalorimeter detectors. One of our goals for both of these cryogenic detector development efforts is to observe X-ray emission from cosmic sources. This requires a refrigeration system that can operate under zero gravity space flight conditions. For the microcalorimeter project, temperatures of 100 mK and below are required to sufficiently reduce the heat capacity of the device. We have therefore developed an adiabatic demagnetization refrigerator (ADR) system which can be configured for space flight.

Labov, S.; Silver, E.; Le Gros, M. (Lawrence Livermore National Lab., CA (United States)); Bland, R.W.; Dickson, S.C.; Dignan, T.G.; Laws, K.; Johnson, R.T.; Simon, M.W.; Stricker, D.A.; Watson, R.M. (San Francisco State Univ., CA (United States)); Madden, N.; Landis, D. (Lawrence Berkeley Lab., CA (United States))

1992-01-30T23:59:59.000Z

340

Analysis of different tunneling mechanisms of In{sub x}Ga{sub 1?x}As/AlGaAs tunnel junction light-emitting transistors  

SciTech Connect (OSTI)

The electrical and optical characteristics of tunnel junction light-emitting transistors (TJLETs) with different indium mole fractions (x?=?5% and 2.5%) of the In{sub x}Ga{sub 1?x}As base-collector tunnel junctions have been investigated. Two electron tunneling mechanisms (photon-assisted or direct tunneling) provide additional currents to electrical output and resupply holes back to the base region, resulting in the upward slope of I-V curves and enhanced optical output under forward-active operation. The larger direct tunneling probability and stronger Franz-Keldysh absorption for 5% TJLET lead to higher collector current slope and less optical intensity enhancement when base-collector junction is under reverse-biased.

Wu, Cheng-Han [Graduate Institute of Electronics Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan (China); Wu, Chao-Hsin, E-mail: chaohsinwu@ntu.edu.tw [Graduate Institute of Electronics Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan (China); Graduate Institute of Photonics and Optoelectronics, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan (China)

2014-10-27T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Laser-driven relativistic tunneling from p-states  

E-Print Network [OSTI]

The tunneling ionization of an electron from a p-state in a highly charged ion in the relativistic regime is investigated in a linearly polarized strong laser field. In contrast to the case of an s-state, the tunneling ionization from the p-state is spin asymmetric. We have singled out two reasons for the spin asymmetry: first, the difference of the electron energy Zeeman splitting in the bound state and during tunneling, and second, the relativistic momentum shift along the laser propagation direction during the under-the barrier motion. Due to the latter, those states are predominantly ionized where the electron rotation is opposite to the electron relativistic shift during the under-the-barrier motion. We have investigated the dependence of the ionization rate on the laser intensity for different projections of the total angular momentum and identified the intensity parameter which governs this behaviour. The significant change of the ionization rate is originated from the different precession dynamics of the total angular momentum in the bound state at high and low intensities.

Michael Klaiber; Karen Z. Hatsagortsyan

2014-10-20T23:59:59.000Z

342

Subbarrier fusion reactions and many-particle quantum tunneling  

E-Print Network [OSTI]

Low energy heavy-ion fusion reactions are governed by quantum tunneling through the Coulomb barrier formed by a strong cancellation of the repulsive Coulomb force with the attractive nuclear interaction between the colliding nuclei. Extensive experimental as well as theoretical studies have revealed that fusion reactions are strongly influenced by couplings of the relative motion of the colliding nuclei to several nuclear intrinsic motions. Heavy-ion subbarrier fusion reactions thus provide a good opportunity to address a general problem on quantum tunneling in the presence of couplings, which has been a popular subject in the past decades in many branches of physics and chemistry. Here we review theoretical aspects of heavy-ion subbarrier fusion reactions from the view point of quantum tunneling in systems with many degrees of freedom. Particular emphases are put on the coupled-channels approach to fusion reactions, and the barrier distribution representation for multi-channel penetrability. We also discuss an application of the barrier distribution method to elucidation of the mechanism of dissociative adsorption of H$_2$ melecules in surface science.

K. Hagino; N. Takigawa

2012-10-17T23:59:59.000Z

343

MISTY ECHO Tunnel Dynamics Experiment--Data report: Volume 1; Yucca Mountain Site Characterization Project  

SciTech Connect (OSTI)

Tunnel damage resulting from seismic loading is an important issue for the Yucca Mountain nuclear waste repository. The tunnel dynamics experiment was designed to obtain and document ground motions, permanent displacements, observable changes in fracture patterns, and visible damage at ground motion levels of interest to the Yucca Mountain Project. Even though the maximum free-field loading on this tunnel was 28 g, the damage observed was minor. Fielding details, data obtained, and supporting documentation are reported.

Phillips, J.S.; Luke, B.A.; Long, J.W.; Lee, J.G.

1992-04-01T23:59:59.000Z

344

Facility Closure Report for T-Tunnel (U12t), Area 12, Nevada Test Site, Nevada  

SciTech Connect (OSTI)

This Facility Closure Report (FCR) has been prepared to document the actions taken to permanently close the remaining accessible areas of U12t-Tunnel (T-Tunnel) in Area 12 of the Nevada Test Site (NTS). The closure of T-Tunnel was a prerequisite to transfer facility ownership from the Defense Threat Reduction Agency (DTRA) to the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO). Closure of the facility was accomplished with the cooperation and concurrence of both NNSA/NSO and the Nevada Division of Environmental Protection (NDEP). The purpose of this FCR is to document that the closure of T-Tunnel complied with the closure requirements specified in the Facility Closure Plan for N- and T-Tunnels Area 12, Nevada Test Site (Appendix D) and that the facility is ready for transfer to NNSA/NSO. The Facility Closure Plan (FCP) is provided in Appendix D. T-Tunnel is located approximately 42 miles north of Mercury in Area 12 of the NTS (Figure 1). Between 1970 and 1987, T-Tunnel was used for six Nuclear Weapons Effects Tests (NWETs). The tunnel was excavated horizontally into the volcanic tuffs of Rainier Mesa. The T-Tunnel complex consists of a main access drift with two NWET containment structures, a Gas Seal Plug (GSP), and a Gas Seal Door (GSD) (Figure 2). The T-Tunnel complex was mothballed in 1993 to preserve the tunnel for resumption of testing, should it happen in the future, to stop the discharge of tunnel effluent, and to prevent unauthorized access. This was accomplished by sealing the main drift GSD.

NSTec Environmental Restoration

2008-08-01T23:59:59.000Z

345

Baker-Barry Tunnel Lighting: Evaluation of a Potential GATEWAY Demonstrations Project  

SciTech Connect (OSTI)

The U.S. Department of Energy (DOE) is evaluating the Baker-Barry Tunnel as a potential GATEWAY Demonstrations project for deployment of solid-state lighting (SSL) technology. The National Park Service (NPS) views this project as a possible proving ground and template for implementation of light-emitting diode (LED) luminaires in other NPS tunnels, thereby expanding the estimated 40% energy savings from 132 MWh/yr for this tunnel to a much larger figure national

Tuenge, Jason R.

2011-06-01T23:59:59.000Z

346

SciTech Connect: Passivated Tunneling Contacts to N-Type Wafer...  

Office of Scientific and Technical Information (OSTI)

Contacts to N-Type Wafer Silicon and Their Implementation into High Performance Solar Cells: Preprint Citation Details In-Document Search Title: Passivated Tunneling...

347

High performance vertical tunneling diodes using graphene/hexagonal boron nitride/graphene hetero-structure  

SciTech Connect (OSTI)

A tunneling rectifier prepared from vertically stacked two-dimensional (2D) materials composed of chemically doped graphene electrodes and hexagonal boron nitride (h-BN) tunneling barrier was demonstrated. The asymmetric chemical doping to graphene with linear dispersion property induces rectifying behavior effectively, by facilitating Fowler-Nordheim tunneling at high forward biases. It results in excellent diode performances of a hetero-structured graphene/h-BN/graphene tunneling diode, with an asymmetric factor exceeding 1000, a nonlinearity of ?40, and a peak sensitivity of ?12?V{sup ?1}, which are superior to contending metal-insulator-metal diodes, showing great potential for future flexible and transparent electronic devices.

Hwan Lee, Seung; Lee, Jia; Ho Ra, Chang; Liu, Xiaochi; Hwang, Euyheon [Samsung-SKKU Graphene Center (SSGC), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Department of Nano Science and Technology, SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Sup Choi, Min [Department of Nano Science and Technology, SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Hee Choi, Jun [Frontier Research Laboratory, Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd., Yongin, Gyeonggi-do 446-711 (Korea, Republic of); Zhong, Jianqiang; Chen, Wei [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Jong Yoo, Won, E-mail: yoowj@skku.edu [Samsung-SKKU Graphene Center (SSGC), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Department of Nano Science and Technology, SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)

2014-02-03T23:59:59.000Z

348

E-Print Network 3.0 - alloy tunneling barrier Sample Search Results  

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

through an insulating barrier with magnetic impurities O. Vvra,1,2, Summary: Josephson junction with a tunneling barrier formed by a paramagnetic insulator. We demonstrate......

349

GaAsSb-based heterojunction tunnel diodes for tandem solar cell interconnects  

SciTech Connect (OSTI)

We report a new approach to tunnel junctions that employs a pseudomorphic GaAsSb layer to obtain a band alignment at a InGaAs or InAlAs p-n junction favorable for forward bias tunneling. Since the majority of the band offset between GaAsSb and InGaAs or InAlAs is in the valence band, when an GaAsSb layer is placed at an InGaAs or InAlAs p-n junction the tunneling distance is reduced and the tunneling current is increased. For all doping levels studied, the presence of the GaAsSb-layer enhanced the forward tunneling characteristics. In fact, in a InGaAs/GaAsSb tunnel diode a peak tunneling current sufficient for a 1000 sun intercell interconnect was achieved with p = 1.5{times}l0{sup 18} cm{sup -3} while a similarly doped all-InGaAs diode was rectifying. This approach affords a new degree of freedom in designing tunnel junctions for tandem solar cell interconnects. Previously only doping levels could be varied to control the tunneling properties. Our approach relaxes the doping requirements by employing a GaAsSb-based heterojunction.

Zolper, J.C.; Klem, J.F.; Plut, T.A.; Tigges, C.P.

1995-01-01T23:59:59.000Z

350

Department of Mechanical and Nuclear Engineering Spring 2011 Wind Tunnel Automation Project  

E-Print Network [OSTI]

PENNSTATE Department of Mechanical and Nuclear Engineering Spring 2011 Wind Tunnel Automation Project Phase II - Automated Bike Turret Mount Overview SYNERGE LLC is a consulting company working

Demirel, Melik C.

351

Observation of diamond turned OFHC copper using Scanning Tunneling Microscopy  

SciTech Connect (OSTI)

Diamond turned OFHC copper samples have been observed within the past few months using the Scanning Tunneling Microscope. Initial results have shown evidence of artifacts which may be used to better understand the diamond turning process. The STM`s high resolution capability and three dimensional data representation allows observation and study of surface features unobtainable with conventional profilometry systems. Also, the STM offers a better quantitative means by which to analyze surface structures than the SEM. This paper discusses findings on several diamond turned OFHC copper samples having different cutting conditions. Each sample has been cross referenced using STM and SEM.

Grigg, D.A.; Russell, P.E.; Dow, T.A.

1988-12-01T23:59:59.000Z

352

Fabrication of a gated gallium arsenide heterostructure resonant tunneling diode  

E-Print Network [OSTI]

metallization process ivas required because separate potentials must be apphed to the top and base ol' the defined mesas. A potent&al is apphed to the top of the mesas to inject carriers for tunneling through the douhle barrier heterostructures A. rectifying... was a demetal/degrease cleanup process which re- moved any contamination that may have been nn the wal'er. This process ivas followed by deposition of AuGe/Ni on the ivafer's backside which ivill provide an ohmic contact after annealing. The backside...

Kinard, William Brian

1989-01-01T23:59:59.000Z

353

Automatic signal processing of front monitor radar for tunneling machines  

SciTech Connect (OSTI)

It is planned to install a front monitoring impulse radar on the surface of the rotating drill of tunneling machines in order to detect obstacles such as casing pipes of vertical borings. The conventional aperture synthesis technique can no more be applied to such cases because the radar image of a pipe dies not constituent a hyperbola as is the case for linear scanning radars. The authors have developed a special purpose signal processing algorithm with the aid of the discrete model fitting method, which can be used for any pattern of scanning. The details of the algorithm are presented together with the results of numerical simulations and test site experiments.

Sato, Toru [Kyoto Univ. (Japan). Dept. of Electronics and Communication] [Kyoto Univ. (Japan). Dept. of Electronics and Communication; Takeda, Kenya [NTT Co. Ltd., Chiba (Japan)] [NTT Co. Ltd., Chiba (Japan); Nagamatsu, Takashi [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)] [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan); Wakayama, Toshio [Mitsubishi Electric Corp., Kamakura, Kanagawa (Japan)] [Mitsubishi Electric Corp., Kamakura, Kanagawa (Japan); Kimura, Iwane [Osaka Inst. of Tech., Hirakata, Osaka (Japan)] [Osaka Inst. of Tech., Hirakata, Osaka (Japan); Shinbo, Tetsuya [Komatsu Co. Ltd., Kanagawa (Japan)] [Komatsu Co. Ltd., Kanagawa (Japan)

1997-03-01T23:59:59.000Z

354

Ris-R-999(EN) Wind Tunnel Test of the RIS-1  

E-Print Network [OSTI]

coefficients and wake rake pressure measurements provided the total drag coefficient. Wind tunnel corrections of blades for stall regulated wind turbines with a Reynolds number betweenRisø-R-999(EN) Wind Tunnel Test of the RISØ-1 Airfoil Peter Fuglsang, Ioannis Antoniou, Christian

355

Wind Tunnel and Field Test of Three 2D Sonic Anemometers  

E-Print Network [OSTI]

Wind Tunnel and Field Test of Three 2D Sonic Anemometers Wiel Wauben R&D Information and Observation Technology, KNMI September 17, 2007 #12;#12;Wind Tunnel and Field Test of Three 2D Sonic.....................................................................................................1 2. Wind sensors

Stoffelen, Ad

356

Direct injection tunnel spectroscopy of a p-n junction Edward M. Likovich,1  

E-Print Network [OSTI]

Direct injection tunnel spectroscopy of a p-n junction Edward M. Likovich,1 Kasey J. Russell,1,a tunnel injection of electrons. In contrast to the metal-base transistor design of conventional ballistic the semiconductor before they scatter and thermal- ize to the chemical potential of the base layer. For systems

Russell, Kasey

357

Oxygen driven reconstruction dynamics of Ni,,977... measured by time-lapse scanning tunneling microscopy  

E-Print Network [OSTI]

Oxygen driven reconstruction dynamics of Ni,,977... measured by time-lapse scanning tunneling-lapse scanning tunneling microscopy STM has been used to observe the oxygen induced reconstruction behavior of Ni for the merging of steps in the presence of small amounts of adsorbed oxygen, less than 2% of a monolayer. Point

Sibener, Steven

358

The development of a wind tunnel facility for the study of V/STOL noise  

E-Print Network [OSTI]

An open-jet wind tunnel operating within an anechoic chamber was developed for the purpose of the study of V/STOL noise mechanisms. An existing low-speed conventional hard-walled wind tunnel was modified to operate as an ...

Widnall, S. E.

1972-01-01T23:59:59.000Z

359

DETECTION OF GEOTHERMAL INTERFERENCE IN THE TUNNEL EXCAVATION USING MAGNETOTELLURICS TECHNIQUE  

E-Print Network [OSTI]

to the geo-engineers in order to devise safety measures suitable during construction of the tunnel of water and rock matrix heats the air in a tunnel that can make the working condition along. Hydropower generation has thus become a major source of power generation, especially in Himalayan region

Harinarayana, T.

360

Department of Mechanical and Nuclear Engineering Fall 2010 Wind Tunnel Automated Bicycle Adjustment System  

E-Print Network [OSTI]

PENN STATE Department of Mechanical and Nuclear Engineering Fall 2010 Wind Tunnel Automated Bicycle with the development of Aerofit's prototype portable wind tunnel used in the aerodynamic testing of bicycles was to automate this adjustment of the bicycle seat and aerobars in order to decrease the time for fitting each

Demirel, Melik C.

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Optical measurements of methyl group tunneling in molecular crystals: Temperature dependence of the nuclear spin conversion rate  

E-Print Network [OSTI]

) The tunneling methyl groups in dimethyl-s-tetrazine (DMST) doped single crystals of durene were investigated

362

Combined Experiment Phase 1. [Horizontal axis wind turbines: wind tunnel testing versus field testing  

SciTech Connect (OSTI)

How does wind tunnel airfoil data differ from the airfoil performance on an operating horizontal axis wind turbine (HAWT) The National Renewable Energy laboratory has been conducting a comprehensive test program focused on answering this question and understanding the basic fluid mechanics of rotating HAWT stall aerodynamics. The basic approach was to instrument a wind rotor, using an airfoil that was well documented by wind tunnel tests, and measure operating pressure distributions on the rotating blade. Based an the integrated values of the pressure data, airfoil performance coefficients were obtained, and comparisons were made between the rotating data and the wind tunnel data. Care was taken to the aerodynamic and geometric differences between the rotating and the wind tunnel models. This is the first of two reports describing the Combined Experiment Program and its results. This Phase I report covers background information such as test setup and instrumentation. It also includes wind tunnel test results and roughness testing.

Butterfield, C.P.; Musial, W.P.; Simms, D.A.

1992-10-01T23:59:59.000Z

363

Facility Closure Report for Tunnel U16a, Area 16, Nevada Test Site, Nevada  

SciTech Connect (OSTI)

U16a is not listed in the Federal Facility Agreement and Consent Order. The closure of U16a was sponsored by the Defense Threat Reduction Agency (DTRA) and performed with the cooperation of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the Nevada Division of Environmental Protection. This report documents closure of this site as identified in the DTRA Fiscal Year 2008 Statement of Work, Task 6.3. Closure activities included: · Removing and disposing of a shack and its contents · Disposing of debris from within the shack and in the vicinity of the tunnel entrance · Verifying that the tunnel is empty · Welding screened covers over tunnel vent holes to limit access and allow ventilation · Constructing a full-tunnel cross-section fibercrete bulkhead to prevent access to the tunnel Field activities were conducted from July to August 2008.

NSTec Environmental Restoration

2009-07-01T23:59:59.000Z

364

Axial Ge/Si nanowire heterostructure tunnel FETs.  

SciTech Connect (OSTI)

Axial Ge/Si heterostructure nanowires (NWs) allow energy band-edge engineering along the axis of the NW, which is the charge transport direction, and the realization of asymmetric devices for novel device architectures. This work reports on two significant advances in the area of heterostructure NWs and tunnel FETs: (i) the realization of 100% compositionally modulated Si/Ge axial heterostructure NWs with lengths suitable for device fabrication and (ii) the design and implementation of Schottky barrier tunnel FETs on these NWs for high-on currents and suppressed ambipolar behavior. Initial prototype devices with 10 nm PECVD SiN{sub x} gate dielectric resulted in a very high current drive in excess of 100 {micro}A/{micro}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios. Prior work on the synthesis of Ge/Si axial NW heterostructures through the VLS mechanism have resulted in axial Si/Si{sub 1-x}Ge{sub x} NW heterostructures with x{sub max} {approx} 0.3, and more recently 100% composition modulation was achieved with a solid growth catalyst. In this latter case, the thickness of the heterostructure cannot exceed few atomic layers due to the slow axial growth rate and concurrent radial deposition on the NW sidewalls leading to a mixture of axial and radial deposition, which imposes a big challenge for fabricating useful devices form these NWs in the near future. Here, we report the VLS growth of 100% doping and composition modulated axial Ge/Si heterostructure NWs with lengths appropriate for device fabrication by devising a growth procedure that eliminates Au diffusion on the NW sidewalls and minimizes random kinking in the heterostructure NWs as deduced from detailed microscopy analysis. Fig. 1 a shows a cross-sectional SEM image of epitaxial Ge/Si axial NW heterostructures grown on a Ge(111) surface. The interface abruptness in these Ge/Si heterostructure NWs is of the order of the NW diameter. Some of these NWs develop a crystallographic kink that is {approx}20{sup o} off the <111> axis at about 300 nm away from the Ge/Si interface. This provides a natural marker for placing the gate contact electrodes and gate metal at appropriate location for desired high-on current and reduced ambipolarity as shown in Fig. 2. The 1D heterostructures allow band-edge engineering in the transport direction, not easily accessible in planar devices, providing an additional degree of freedom for designing tunnel FETs (TFETs). For instance, a Ge tunnel source can be used for efficient electron/hole tunneling and a Si drain can be used for reduced back-tunneling and ambipolar behavior. Interface abruptness on the other hand (particularly for doping) imposes challenges in these structures and others for realizing high performance TFETs in p-i-n junctions. Since the metal-semiconductor contacts provide a sharp interface with band-edge control, we use properly designed Schottky contacts (aided by 3D Silvaco simulations) as the tunnel barriers both at the source and drain and utilize the asymmetry in the Ge/Si channel bandgap to reduce ambipolar transport behavior generally observed in TFETs. Fig. 3 shows the room-temperature transfer curves of a Ge/Si heterostructure TFET (H-TFET) for different V{sub DS} values showing a maximum on-current of {approx}7 {micro}A, {approx}170 mV/decade inverse subthreshold slope and 5 orders of magnitude I{sub on}/I{sub off} ratios for all V{sub DS} biases considered here. This high on-current value is {approx}1750 X higher than that obtained with Si p-i-n{sup +} NW TFETs and {approx}35 X higher than that obtained with CNT TFET. The I{sub on}/I{sub off} ratio and inverse subthreshold slope compare favorably to that of Si {approx} 10{sup 3} I{sub on}/I{sub off} and {approx} 800 mV/decade SS{sup -1} but lags behind those of CNT TFET due to poor PECVD nitride gate oxide quality ({var_epsilon}{sub r} {approx} 3-4). The asymmetry in the Schottky barrier heights used here eliminates the stringent requirements of abrupt doped interfaces used in p-i-n based TFETs, which is hard to achieve both in thin-film and

Dayeh, Shadi A. (Los Alamos National Laboratory); Gin, Aaron V.; Huang, Jian Yu; Picraux, Samuel Thomas (Los Alamos National Laboratory)

2010-03-01T23:59:59.000Z

365

Value engineering the construction of long tunnels in the dolomites of northern Illinois, United States of America  

SciTech Connect (OSTI)

Fermi National Accelerator Laboratory (Fermilab), a high-energy physics laboratory operated by the Universities Research Association for the US Department of Energy, is developing plans for the construction of accelerator tunnels. The accelerator designs vary as a function of particles accelerated, technologies used and energies targeted. However, all accelerators require the excavation of long tunnels, up to 700 km in length, and tunnel costs represent a major portion of project budgets. This paper documents the findings of two studies undertaken to identify tunnel cost-drivers and outlines steps taken to initiate the ''value engineering'' of the tunnels.

Laughton, Christopher; /Fermilab

2000-01-01T23:59:59.000Z

366

Ferroelectric modulation on resonant tunneling through perovskite double-barriers  

SciTech Connect (OSTI)

The negative differential resistance (NDR) due to resonance tunneling is achieved at room temperature in perovskite double-barrier heterostructures composed of a 10 unit-cell-thick SrTiO{sub 3} quantum well sandwiched in two 10 unit-cell-thick LaAlO{sub 3} barriers. The NDR occurs at 1.2?V and does not change with voltage cycling. When the paraelectric SrTiO{sub 3} quantum well is replaced by a ferroelectric BaTiO{sub 3}, the onset of the NDR can be modulated by polarization switching in the ultrathin BaTiO{sub 3}. A polarization pointing to the collector lowers the NDR voltage but a polarization pointing to the emitter increases it. The shift of the NDR voltage is ascribed to reversal of the extra electric field in the quantum well due to the polarization switching.

Du, Ruifang; Qiu, Xiangbiao; Li, Aidong; Wu, Di, E-mail: diwu@nju.edu.cn [National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093 (China)

2014-04-07T23:59:59.000Z

367

Relativistic tunneling picture of electron-positron pair creation  

E-Print Network [OSTI]

The common tunneling picture of electron-positron pair creation in a strong electric field is generalized to pair creation in combined crossed electric and magnetic fields. This enhanced picture, being symmetric for electrons and positrons, is formulated in a gauge-invariant and Lorentz-invariant manner for quasistatic fields. It may be used to infer qualitative features of the pair creation process. In particular, it allows for an intuitive interpretation of how the presence of a magnetic field modifies and, in particular cases, even enhances pair creation. The creation of electrons and positrons from the vacuum may be assisted by an energetic photon, which can also be incorporated into this picture of pair creation.

Anton Wöllert; Michael Klaiber; Heiko Bauke; Christoph H. Keitel

2015-03-19T23:59:59.000Z

368

High energy storage capacitor by embedding tunneling nano-structures  

DOE Patents [OSTI]

In an All-Electron Battery (AEB), inclusions embedded in an active region between two electrodes of a capacitor provide enhanced energy storage. Electrons can tunnel to/from and/or between the inclusions, thereby increasing the charge storage density relative to a conventional capacitor. One or more barrier layers is present in an AEB to block DC current flow through the device. The AEB effect can be enhanced by using multi-layer active regions having inclusion layers with the inclusions separated by spacer layers that don't have the inclusions. The use of cylindrical geometry or wrap around electrodes and/or barrier layers in a planar geometry can enhance the basic AEB effect. Other physical effects that can be employed in connection with the AEB effect are excited state energy storage, and formation of a Bose-Einstein condensate (BEC).

Holme, Timothy P; Prinz, Friedrich B; Van Stockum, Philip B

2014-11-04T23:59:59.000Z

369

Heat engine driven by three-body photon tunneling  

E-Print Network [OSTI]

Near-field heat engines are devices that convert the evanescent thermal field supported by a primary source into usable mechanical energy. By analyzing the thermodynamic performance of three-body near-field heat engines, we demonstrate that the power they supply can be substantially larger than that of two-body systems, showing so their strong potential for energy harvesting. Theoretical limits for energy and entropy fluxes in three-body systems are discussed and compared with their corresponding two-body counterparts. Such considerations confirm that the thermodynamic availability in energy-conversion processes driven by three-body photon tunneling can exceed the thermodynamic availability in two-body systems.

Latella, Ivan; Rubi, J Miguel; Biehs, Svend-Age; Ben-Abdallah, Philippe

2015-01-01T23:59:59.000Z

370

Axial Ge/Si nanowire heterostructure tunnel FETs  

SciTech Connect (OSTI)

The vapor-liquid-solid (VLS) growth of semiconductor nanowires allows doping and composition modulation along their axis and the realization of axial 1 D heterostructures. This provides additional flexibility in energy band-edge engineering along the transport direction which is difficult to attain by planar materials growth and processing techniques. We report here on the design, growth, fabrication, and characterization of asymmetric heterostructure tunnel field-effect transistors (HTFETs) based on 100% compositionally modulated Si/Ge axial NWs for high on-current operation and low ambipolar transport behavior. We discuss the optimization of band-offsets and Schottky barrier heights for high performance HTFETs and issues surrounding their experimental realization. Our HTFET devices with 10 nm PECVD SiN{sub x} gate dielectric resulted in a measured current drive exceeding 100 {mu}A/{mu}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios.

Picraux, Sanuel T [Los Alamos National Laboratory; Daych, Shadi A [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

371

Thermal spin-transfer torque in magnetic tunnel junctions (invited)  

SciTech Connect (OSTI)

The thermal spin-transfer torque (TSTT) is an effect to switch the magnetic free layer in a magnetic tunnel junction by a temperature gradient only. We present ab initio calculations of the TSTT. In particular, we discuss the influence of magnetic layer composition by considering Fe{sub x}Co{sub 1–x} alloys. Further, we compare the TSTT to the bias voltage driven STT and discuss the requirements for a possible thermal switching. For example, only for very thin barriers of 3 monolayers MgO, a thermal switching is imaginable. However, even for such a thin barrier, the TSTT is still too small for switching at the moment and further optimization is needed. In particular, the TSTT strongly depends on the composition of the ferromagnetic layer. In our current study, it turns out that at the chosen thickness of the ferromagnetic layer, pure Fe gives the highest thermal spin-transfer torque.

Heiliger, Christian, E-mail: christian.heiliger@physik.uni-giessen.de; Franz, C.; Czerner, Michael [I. Physikalisches Institut, Justus Liebig University, Giessen (Germany)

2014-05-07T23:59:59.000Z

372

Theory of multiphoton and tunnel ionization in a bichromatic field  

SciTech Connect (OSTI)

The imaginary-time method [6, 7] is used to calculate the multiphoton and tunnel ionization probabilities for atoms in a laser radiation field part of which is converted into the second harmonic. We assume that the first harmonic has a linear or elliptical polarization and the second harmonic is polarized linearly, with its polarization vector making an arbitrary angle with that of the first harmonic. The mean momentum of the photoelectrons knocked out from atoms is shown to depend on the phase shift between the first and second harmonics and their mutual polarization and to be identically equal to zero for a monochromatic field. An important difference between the case of elliptical polarization and the case of linear polarization of both harmonics is the absence of conditions under which the conditions for dominance of one of the two generation mechanisms considered here can be identified during the generation of terahertz radiation from the region of optical breakdown in a gas.

Bagulov, D. S., E-mail: bagulov-denis@yandex.ru [Novosibirsk State University (Russian Federation); Kotelnikov, I. A., E-mail: I.A.Kotelnikov@inp.nsk.ru [Russian Academy of Sciences, Siberian Branch, Budger Institute of Nuclear Physics (Russian Federation)

2013-01-15T23:59:59.000Z

373

IEEE Trans Ultrason Ferroelectr Freq Control . Author manuscript Combined passive detection and ultrafast active imaging of cavitation  

E-Print Network [OSTI]

Gateaué ô Abstract The activation of natural gas nuclei to induce larger and ultrafast active imaging over a large volume and with the same multi-element probe. Bubble nucleation ; ultrasonography ; Phantoms, Imaging ; Sheep ; Signal Processing, Computer-Assisted ; Transducers ; Ultrasonography

Paris-Sud XI, Université de

374

Simulation of Enhanced-Explosive Devices in Chambers and Tunnels  

SciTech Connect (OSTI)

Introduction: Shock-dispersed fuel (SDF) explosives use a small chemical charge to disperse a combustible fuel that burns in the post-detonation environment. The energy released in the combustion process has the potential for generating higher pressures and temperatures than conventional explosives. However, the development of these types of novel explosive systems requires a detailed understanding of all of the modes of energy release. Objective: The objective of this project is develop a simulation capability for predicting explosion and combustion phase of SDF charges and apply that capability to quantifying the behavior of these types of explosives. Methodology: We approximate the dynamics of an SDF charge using high Reynolds number, fast chemistry model that effectively captures the thermodynamic behavior of SDF charges and accurately models the key modes of energy release. The overall computational model is combined with Adaptive Mesh Refinement (AMR) , implemented in a parallel adaptive framework suited to the massively parallel computer systems. Results: We have developed a multiphase version of the model and used it to simulate an SDF charge in which the dispersed fuel is aluminum flakes. Flow visualizations show that the combustion field is turbulent for the chamber and tunnel cases studied. During the 3 milli-seconds of simulation, over 90% of the Al fuel was consumed for the chamber case, while about 40% was consumed in the tunnel case in agreement with Al-SDF experiments. Significance to DoD: DoD has a requirement to develop enhanced energetic materials to support future military systems. The SDF charges described here utilize the combustion mechanism to increase energy per gram of fuel by a factor of 7 to 10 over conventional (detonating) charges, and increase the temperature of the explosion cloud to 2,000-4,000 K (depending on the SDF fuel). Accurate numerical simulation of such SDF explosions allows one to understand the energy release mechanism, and thereby design full-scale systems with greatly improved explosive efficiency.

Bell, J B; Kuhl, A L; Beckner, V E

2007-06-05T23:59:59.000Z

375

Imaging of buried phosphorus nanostructures in silicon using scanning tunneling microscopy  

SciTech Connect (OSTI)

We demonstrate the locating and imaging of single phosphorus atoms and phosphorus dopant nanostructures, buried beneath the Si(001) surface using scanning tunneling microscopy. The buried dopant nanostructures have been fabricated in a bottom-up approach using scanning tunneling microscope lithography on Si(001). We find that current imaging tunneling spectroscopy is suited to locate and image buried nanostructures at room temperature and with residual surface roughness present. From these studies, we can place an upper limit on the lateral diffusion during encapsulation with low-temperature Si molecular beam epitaxy.

Oberbeck, Lars [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); TOTAL Marketing Services, New Energies, La Défense 10, 92069 Paris La Défense Cedex (France); Reusch, Thilo C. G.; Hallam, Toby; Simmons, Michelle Y., E-mail: n.curson@ucl.ac.uk, E-mail: michelle.simmons@unsw.edu.au [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); Schofield, Steven R. [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); London Centre for Nanotechnology, UCL, London WC1H 0AH (United Kingdom); Department of Physics and Astronomy, UCL, London WC1E 6BT (United Kingdom); Curson, Neil J., E-mail: n.curson@ucl.ac.uk, E-mail: michelle.simmons@unsw.edu.au [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); London Centre for Nanotechnology, UCL, London WC1H 0AH (United Kingdom); Department of Electronic and Electrical Engineering, UCL, London WC1E 7JE (United Kingdom)

2014-06-23T23:59:59.000Z

376

Giant intrinsic tunnel magnetoresistance in manganite thin films etched with antidot arrays  

SciTech Connect (OSTI)

Huge intrinsic tunnel magnetoresistance effects at low field are demonstrated in macroscopic La{sub 0.33}Pr{sub 0.34}Ca{sub 0.33}MnO{sub 3} thin films etched with periodic antidot arrays, and a highest magnetoresistance ratio (about 1600%) is achieved at 58?K. Such giant tunnel magnetoresistance effect might originate from delicate phase separation and coherent transport under the applied periodic spatial confinement. Strong transport fluctuation is also revealed in such systems due to phase competition. Our findings pave a way to realize tunnel magnetoresistance devices based on electronically phase separated materials with spatial modulations.

Li, Hui; Li, Lin; Li, Long; Liang, Haixing; Cheng, Long; Zhai, Xiaofang [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei 230026 (China); Zeng, Changgan, E-mail: cgzeng@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2014-02-24T23:59:59.000Z

377

The effect of environmental coupling on tunneling of quasiparticles in Josephson junctions  

E-Print Network [OSTI]

We study quasiparticle tunneling in Josephson tunnel junctions embedded in an electromagnetic environment. We identify tunneling processes that transfer electrical charge and couple to the environment in a way similar to that of normal electrons, and processes that mix electrons and holes and are thus creating charge superpositions. The latter are sensitive to the phase difference between the superconductor and are thus limited by phase diffusion even at zero temperature. We show that the environmental coupling is suppressed in many environments, thus leading to lower quasiparticle decay rates and thus better superconductor qubit coherence than previously expected. Our approach is nonperturbative in the environmental coupling strength.

Mohammad H. Ansari; Frank K. Wilhelm; Urbasi Sinha; Aninda Sinha

2013-11-07T23:59:59.000Z

378

Elimination of two level fluctuators in superconducting quantum bits by an epitaxial tunnel barrier  

SciTech Connect (OSTI)

Quantum computing based on Josephson junction technology is considered promising due to its scalable architecture. However, decoherence is a major obstacle. Here, we report evidence for improved Josephson quantum bits (qubits) using a single-crystal Al{sub 2}O{sub 3} tunnel barrier. We have found an {approx}80% reduction in the density of the spectral splittings that indicate the existence of two-level fluctators (TLFs) in amorphous tunnel barriers. The residual {approx}20% TLFs can be attributed to interfacial effects that may be further reduced by different electrode materials. These results show that decoherence sources in the tunnel barrier of Josephson qubits can be identified and eliminated.

Oh, Seongshik [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Department of Physics, University of Illinois, Urbana, Illinois 61801 (United States); Cicak, Katarina; Kline, Jeffrey S.; Sillanpaeae, Mika A.; Osborn, Kevin D.; Whittaker, Jed D.; Simmonds, Raymond W.; Pappas, David P. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

2006-09-01T23:59:59.000Z

379

Direct space-time observation of pulse tunneling in an electromagnetic band gap  

SciTech Connect (OSTI)

We present space-time-resolved measurements of electromagnetic pulses tunneling through a coaxial electromagnetic band gap structure. The results show that during the tunneling process the field distribution inside the barrier is an exponentially decaying standing wave whose amplitude increases and decreases as it slowly follows the temporal evolution of the input pulse. At no time is a pulse maximum found inside the barrier, and hence the transmitted peak is not the incident peak that has propagated to the exit. The results support the quasistatic interpretation of tunneling dynamics and confirm that the group delay is not the traversal time of the input pulse peak.

Doiron, Serge; Hache, Alain [Department de physique et d'astronomie, Universite de Moncton, Moncton, New Brunswick, E1A 3E9 (Canada); Winful, Herbert G. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109-2122 (United States)

2007-08-15T23:59:59.000Z

380

Effects of Be acceptors on the spin polarization of carriers in p-i-n resonant tunneling diodes  

SciTech Connect (OSTI)

In this paper, we have investigated the effect of Be acceptors on the electroluminescence and the spin polarization in GaAs/AlAs p-i-n resonant tunneling diodes. The quantum well emission comprise two main lines separated by ?20?meV attributed to excitonic and Be-related transitions, which intensities show remarkably abrupt variations at critical voltages, particularly at the electron resonant peak where it shows a high-frequency bistability. The circular-polarization degree of the quantum-well electroluminescence also shows strong and abrupt variations at the critical bias voltages and it attains relatively large values (of ??75% at 15?T). These effects may be explored to design novel devices for spintronic applications such as a high-frequency spin-oscillators.

Awan, I. T.; Galvão Gobato, Y. [Departamento de Física, Universidade Federal de São Carlos (UFSCAR) 13560-905, São Carlos, SP (Brazil); Galeti, H. V. A. [Departamento de Engenharia Elétrica, Universidade Federal de São Carlos 13560-905, São Carlos, SP (Brazil); Brasil, M. J. S. P. [Institute of Physics Gleb Wataghin, UNICAMP, Campinas (Brazil); Taylor, D.; Henini, M. [School of Physics and Astronomy, Nottingham Nanotechnology and Nanoscience Centre, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

2014-08-07T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Tunnel determinants from spectral zeta functions. Instanton effects in quantum mechanics  

SciTech Connect (OSTI)

In this paper we develop an spectral zeta function regularization procedure on the determinants of instanton fluctuation operators that describe the semi-classical order of tunnel effects between degenerate vacua.

Izquierdo, A. Alonso [Departamento de Matematica Aplicada and IUFFyM, Universidad de Salamanca (Spain); Guilarte, J. Mateos [Departamento de Fisica Fundamental and IUFFyM, Universidad de Salamanca (Spain)

2014-07-23T23:59:59.000Z

382

Earth pressure balance (EPB) tunneling induced settlements in the Tren Urbano Project, Rio Piedras, Puerto Rico  

E-Print Network [OSTI]

Underground construction of the Rio Piedras section of the Tren Urbano project involved the construction of twin tunnels (6.3m diameter) with Earth Pressure Balance machines in weathered alluvial soil. The depth of the ...

Abrams, Alejandro J

2007-01-01T23:59:59.000Z

383

Evaluation of analytical methods to interpret ground deformations due to soft ground tunneling  

E-Print Network [OSTI]

An in depth study was undertaken to evaluate the effectiveness of analytical solutions in describing ground movements induced by soft ground tunneling. The analytical solutions that were examined consider both isotropic ...

Zymnis, Despina M

2009-01-01T23:59:59.000Z

384

Wind Tunnel and Flight Testing of Active Flow Control on a UAV  

E-Print Network [OSTI]

Active flow control has been extensively explored in wind tunnel studies but successful in-flight implementation of an active flow control technology still remains a challenge. This thesis presents implementation of active flow control technology...

Babbar, Yogesh

2011-08-08T23:59:59.000Z

385

Coherence of resonant-tunneling transport in terahertz quantum-cascade lasers  

E-Print Network [OSTI]

We develop simple density-matrix models to describe the role of coherence in resonant-tunneling (RT) transport of quantum-cascade lasers (QCLs). Specifically, we investigate the effects of coherent coupling between the ...

Kumar, Sushil

386

Wind Tunnel Tests of Parabolic Trough Solar Collectors: March 2001--August 2003  

SciTech Connect (OSTI)

Conducted extensive wind-tunnel tests on parabolic trough solar collectors to determine practical wind loads applicable to structural design for stress and deformation, and local component design for concentrator reflectors.

Hosoya, N.; Peterka, J. A.; Gee, R. C.; Kearney, D.

2008-05-01T23:59:59.000Z

387

Investigation of the tunneling emitter bipolar transistor as spin-injector into silicon  

E-Print Network [OSTI]

In this thesis is discussed the tunneling emitter bipolar transistor as a possible spin-injector into silicon. The transistor has a metallic emitter which as a spin-injector will be a ferromagnet. Spin-polarized electrons ...

Van Veenhuizen, Marc Julien

2010-01-01T23:59:59.000Z

388

Scanning tunneling microscopy investigation of the TiO2 anatase ,,101... surface Wilhelm Hebenstreit,1  

E-Print Network [OSTI]

of tunneling sites in STM. Titanium dioxide (TiO2) is a versatile material that finds uses as a promoter. Fourfold-coordinated Ti atoms at step edges are preferred adsorption sites and allow the identification

Diebold, Ulrike

389

Resonant escape over an oscillating barrier in underdamped Josephson tunnel junctions  

E-Print Network [OSTI]

The escape from a metastable state over an oscillating barrier of an underdamped Josephson tunnel junction has been experimentally investigated with oscillation frequency well separated from the plasma frequency of the ...

Han, Siyuan; Yu, Yang

2003-09-01T23:59:59.000Z

390

Common-path interference and oscillatory Zener tunneling in bilayer graphene p-n junctions  

E-Print Network [OSTI]

Interference and tunneling are two signature quantum effects that are often perceived as the yin and yang of quantum mechanics: a particle simultaneously propagating along several distinct classical paths versus a particle ...

Nandkishore, Rahul Mahajan

391

Scanning tunneling microscopic studies of SiO2 thin film supported metal nano-clusters  

E-Print Network [OSTI]

This dissertation is focused on understanding heterogeneous metal catalysts supported on oxides using a model catalyst system of SiO2 thin film supported metal nano-clusters. The primary technique applied to this study is scanning tunneling...

Min, Byoung Koun

2005-11-01T23:59:59.000Z

392

Tunnel Boring Machine (TBM) performance in Singapore's Mass Rapid Transit (MRT) system  

E-Print Network [OSTI]

Singapore's Mass Rapid Transit (MRT) network is one of the largest public works projects undertaken by the Singapore government. This thesis summarizes and evaluates the performance of Tunnel Boring Machine (TBM) construction ...

Chong, Wanling

2013-01-01T23:59:59.000Z

393

Wind Tunnel Blockage Corrections: An Application to Vertical-Axis Wind Turbines.  

E-Print Network [OSTI]

?? An investigation into wake and solid blockage effects of Vertical-Axis Wind Turbines (VAWTs) in closed test-section wind tunnel testing is described. Static wall pressures… (more)

Ross, Ian Jonathan

2010-01-01T23:59:59.000Z

394

Development of a Digital Controller for a Vertical Wind Tunnel (VWT) Prototype to Mitigate Ball Fluctuations  

E-Print Network [OSTI]

The objective of this research was to mitigate fluctuations of a levitated ping pong ball within a vertical wind tunnel (VWT) prototype. This was made possible by remodeling the VWT system with its inherent nonlinear characteristics instead...

Silva, Ramon A.

2011-08-08T23:59:59.000Z

395

An Updated Procedure for Tare and Interference Wind Tunnel Testing of Strut-Mounted Models  

E-Print Network [OSTI]

to the presence of wind tunnel walls. The standard correction procedure adjusts for the presence of these boundaries using approximations based on linear potential flow theory. Separately,tare and interference removal involves the linear subtraction of mounting...

Kutz, Douglas M

2014-05-02T23:59:59.000Z

396

Fire modeling for Building 221-T - T Plant Canyon Deck and Railroad Tunnel  

SciTech Connect (OSTI)

This report was prepared by Hughes Associates, Inc. to document the results of fire models for building 221-T Canyon Deck and Railroad Tunnel. Backup data is contained in document No. WHC-SD-CP-ANAL-010, Rev. 0.

Oar, D.L.

1994-09-29T23:59:59.000Z

397

Shock-Dispersed-Fuel Charges: Combustion in Chambers and Tunnels  

SciTech Connect (OSTI)

In previous studies we have investigated after-burning effects of a fuel-rich explosive (TNT). In that case the detonation only releases about 30% of the available energy, but generates a hot cloud of fuel that can burn in the ambient air, thus evoking an additional energy release that is distributed in space and time. The current series of small-scale experiments can be looked upon as a natural generalization of this mechanism: a booster charge disperses a (non-explosive) fuel, provides mixing with air and, by means of the hot detonation products, the energy to ignite the fuel. The current version of our miniature Shock-Dispersed-Fuel (SDF) charges consists of a spherical booster charge of 0.5 g PETN, embedded in a paper cylinder of approximately 2.2 cm, which is filled with powdered fuel compositions. The main compositions studied up to now contain aluminum flakes, hydrocarbon powders like polyethylene or hexosen (sucrose) and/or carbon particles. These charges were studied in four different chambers: two cylindrical vessels of 6.6-1 and 40.5-1 volume with a height-to-diameter ratio of approximately 1, a rectangular chamber of 41 (10.5 x 10.5 x 38.6 cm) and a 299.6 cm long tunnel model with a cross section of 8 x 8 cm (volume 19.21) closed at both ends.

Neuwald, P; Reichenbach, H; Kuhl, A L

2003-04-22T23:59:59.000Z

398

Emission of Microwave Photon Pairs by a Tunnel Junction  

E-Print Network [OSTI]

Generation and control of non-classical electromagnetic fields is of crucial importance for quantum information physics. While usual methods for the production of such fields rely on a non-linearity (of a crystal, a Josephson junction, etc.), a recent experiment performed on a normal conductor, a tunnel junction under microwave irradiation, has unveiled an alternative: the use of electron shot noise in a quantum conductor\\cite{PAN_squeezing}. Here we show that such a device can emit \\emph{pairs of microwave photons} of different frequencies with a rate as high as that of superconducting Josephson junctions\\cite{Flurin}. This results in intensity fluctuations of the photon field at two different frequencies being correlated below the photon shot noise,i.e. two-mode amplitude squeezing. Our experiment constitutes a fundamental step towards the understanding of electronic noise in terms of quantum optics, and shows that even a normal conductor could be used as a resource for quantum information processing.

Jean-Charles Forgues; Christian Lupien; Bertrand Reulet

2014-03-21T23:59:59.000Z

399

Photon-assisted tunneling with non-classical light  

E-Print Network [OSTI]

Among the most exciting recent advances in the field of superconducting quantum circuits is the ability to coherently couple microwave photons in low-loss cavities to quantum electronic conductors (e.g.~semiconductor quantum dots or carbon nanotubes). These hybrid quantum systems hold great promise for quantum information processing applications; even more strikingly, they enable exploration of completely new physical regimes. Here we study theoretically the new physics emerging when a quantum electronic conductor is exposed to non-classical microwaves (e.g.~squeezed states, Fock states). We study this interplay in the experimentally-relevant situation where a superconducting microwave cavity is coupled to a conductor in the tunneling regime. We find the quantum conductor acts as a non-trivial probe of the microwave state; in particular, the emission and absorption of photons by the conductor is characterized by a non-positive definite quasi-probability distribution. This negativity has a direct influence on the conductance of the conductor.

J. -R. Souquet; M. J. Woolley; Julien Gabelli; Pascal Simon; Aashish A. Clerk

2014-08-05T23:59:59.000Z

400

Some investigations on the enhancement of boiling heat transfer from planer surface embedded with continuous open tunnels  

SciTech Connect (OSTI)

Boiling heat transfer from a flat surface can be enhanced if continuous open tunnel type structures are embedded in it. Further, improvement of boiling heat transfer from such surfaces has been tried by two separate avenues. At first, inclined tunnels are embedded over the solid surface and an effort is made to optimize the tunnel inclination for boiling heat transfer. Surfaces are manufactured in house with four different inclinations of the tunnels with or without a reentrant circular pocket at the end of the tunnel. Experiments conducted in the nucleate boiling regime showed that 45 deg inclination of the tunnels for both with and without base geometry provides the highest heat transfer coefficient. Next, active fluid rotation was imposed to enhance the heat transfer from tunnel type surfaces with and without the base geometry. Rotational speed imparted by mechanical stirrer was varied over a wide range. It was observed that fluid rotation enhances the heat transfer coefficient only up to a certain value of stirrer speed. Rotational speed values, beyond this limit, reduce the boiling heat transfer severely. A comparison shows that embedding continuous tunnel turns out to be a better option for the increase of heat transfer coefficient compared to the imposition of fluid rotation. But the behavior of inclined tunnels under the action of fluid rotation is yet to be established and can be treated as a future scope of the work. (author)

Das, A.K.; Das, P.K.; Saha, P. [Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur 721 302 (India)

2010-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Developing a CD-CBM Anticipatory Approach for Cavitation - Defining a Model-Based Descriptor Consistent Across Processes, Phase 1 Final Report Context-Dependent Prognostics and Health Assessment: A New Paradigm for Condition-based Maintenance SBIR Topic No. N98-114  

SciTech Connect (OSTI)

The objective of this research, and subsequent testing, was to identify specific features of cavitation that could be used as a model-based descriptor in a context-dependent condition-based maintenance (CD-CBM) anticipatory prognostic and health assessment model. This descriptor is based on the physics of the phenomena, capturing the salient features of the process dynamics. The test methodology and approach were developed to make the cavitation features the dominant effect in the process and collected signatures. This would allow the accurate characterization of the salient cavitation features at different operational states. By developing such an abstraction, these attributes can be used as a general diagnostic for a system or any of its components. In this study, the particular focus will be pumps. As many as 90% of pump failures are catastrophic. They seem to be operating normally and fail abruptly without warning. This is true whether the failure is sudden hardware damage requiring repair, such as a gasket failure, or a transition into an undesired operating mode, such as cavitation. This means that conventional diagnostic methods fail to predict 90% of incipient failures and that in addressing this problem, model-based methods can add value where it is actually needed.

Allgood, G.O.; Dress, W.B.; Kercel, S.W.

1999-06-01T23:59:59.000Z

402

Performance limits of tunnel transistors based on mono-layer transition-metal dichalcogenides  

SciTech Connect (OSTI)

Performance limits of tunnel field-effect transistors based on mono-layer transition metal dichalcogenides are investigated through numerical quantum mechanical simulations. The atomic mono-layer nature of the devices results in a much smaller natural length ?, leading to much larger electric field inside the tunneling diodes. As a result, the inter-band tunneling currents are found to be very high as long as ultra-thin high-k gate dielectric is possible. The highest on-state driving current is found to be close to 600??A/?m at V{sub g}?=?V{sub d}?=?0.5?V when 2?nm thin HfO{sub 2} layer is used for gate dielectric, outperforming most of the conventional semiconductor tunnel transistors. In the five simulated transition-metal dichalcogenides, mono-layer WSe{sub 2} based tunnel field-effect transistor shows the best potential. Deep analysis reveals that there is plenty room to further enhance the device performance by either geometry, alloy, or strain engineering on these mono-layer materials.

Jiang, Xiang-Wei, E-mail: xwjiang@semi.ac.cn; Li, Shu-Shen [State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2014-05-12T23:59:59.000Z

403

Theory of steady-state plane tunneling-assisted impact ionization waves  

SciTech Connect (OSTI)

The effect of band-to-band and trap-assisted tunneling on the properties of steady-state plane ionization waves in p{sup +}-n-n{sup +} structures is theoretically analyzed. It is shown that such tunneling-assisted impact ionization waves do not differ in a qualitative sense from ordinary impact ionization waves propagating due to the avalanche multiplication of uniformly distributed seed electrons and holes. The quantitative differences of tunneling-assisted impact ionization waves from impact ionization waves are reduced to a slightly different relation between the wave velocity u and the maximum field strength E{sub M} at the front. It is shown that disregarding impact ionization does not exclude the possibility of the existence of tunneling-assisted ionization waves; however, their structure radically changes, and their velocity strongly decreases for the same E{sub M}. A comparison of the dependences u(E{sub M}) for various ionization-wave types makes it possible to determine the conditions under which one of them is dominant. In conclusion, unresolved problems concerning the theory of tunneling-assisted impact ionization waves are discussed and the directions of further studies are outlined.

Kyuregyan, A. S., E-mail: ask@vei.ru [Lenin All-Russian Electrical-Engineering Institute (Russian Federation)

2013-07-15T23:59:59.000Z

404

A Historical Evaluation of the U16a Tunnel, Nevada National Security Site, Nye County, Nevada Volume 1  

SciTech Connect (OSTI)

This report presents a historical evaluation of the U16a Tunnel on the Nevada National Security Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency. The U16a Tunnel was used for underground nuclear weapons effects tests in Shoshone Mountain in Area 16 of the Nevada National Security Site. Six nuclear tests were conducted in the U16a Tunnel from 1962 to 1971. These tests are Marshmallow, Gum Drop, Double Play, Ming Vase, Diamond Dust, and Diamond Mine. The U.S. Department of Defense Threat Reduction Agency, with participation from Lawrence Livermore National Laboratory and Las Alamos National Laboratory, sponsored the tests. Fifteen high explosives tests were also conducted at the tunnel. Two were calibration tests during nuclear testing and the remaining were U.S. Department of Defense, Defense Threat Reduction Agency tunnel defeat tests. The U16a Tunnel complex is on the top and slopes of Shoshone Mountain, encompassing an area of approximately 16.7 hectares (41.1 acres). Major modifications to the landscape are a result of three principal activities, road construction and maintenance, mining activities related to development of the tunnel complex, and site preparation for activities related to testing. Forty-seven cultural features were recorded at the portal and on the slopes of Shoshone Mountain. At the portal area, features relate to the mining, construction, testing, and general every day operational support activities within the tunnel. These include concrete foundations for buildings, equipment pads, and rail lines. Features on the slopes above the tunnel relate to tunnel ventilation, borehole drilling, and data recording. Feature types include soil-covered bunkers, concrete foundations, instrument cable holes, drill holes, and ventilation shafts. The U16a Tunnel complex is eligible to the National Register of Historic Places under criteria a and c, consideration g of 36 CFR Part 60.4 as a historic landscape. Scientific research conducted at the tunnel has made significant contributions to the broad patterns of our history, particularly in regard to the Cold War era that was characterized by competing social, economic, and political ideologies between the former Soviet Union and the United States. The tunnel also possesses distinctive construction and engineering methods for conducting underground nuclear tests. The Desert Research Institute recommends that the U16a Tunnel area be left in place in its current condition and that the U16a Tunnel historic landscape be included in the Nevada National Security Site monitoring program and monitored on a regular basis.

Jones, robert C [DRI; Drollinger, Harold [DRI; Bullard, Thomas F [DRI; Ashbaugh, Laurence J [DRI; Griffin, Wayne R [DRI

2013-06-01T23:59:59.000Z

405

A Historical Evaluation of the U16a Tunnel, Nevada National Security Site, Nye County, Nevada Volume 2  

SciTech Connect (OSTI)

This report presents a historical evaluation of the U16a Tunnel on the Nevada National Security Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency. The U16a Tunnel was used for underground nuclear weapons effects tests in Shoshone Mountain in Area 16 of the Nevada National Security Site. Six nuclear tests were conducted in the U16a Tunnel from 1962 to 1971. These tests are Marshmallow, Gum Drop, Double Play, Ming Vase, Diamond Dust, and Diamond Mine. The U.S. Department of Defense Threat Reduction Agency, with participation from Lawrence Livermore National Laboratory and Las Alamos National Laboratory, sponsored the tests. Fifteen high explosives tests were also conducted at the tunnel. Two were calibration tests during nuclear testing and the remaining were U.S. Department of Defense, Defense Threat Reduction Agency tunnel defeat tests. The U16a Tunnel complex is on the top and slopes of Shoshone Mountain, encompassing an area of approximately 16.7 hectares (41.1 acres). Major modifications to the landscape are a result of three principal activities, road construction and maintenance, mining activities related to development of the tunnel complex, and site preparation for activities related to testing. Forty-seven cultural features were recorded at the portal and on the slopes of Shoshone Mountain. At the portal area, features relate to the mining, construction, testing, and general every day operational support activities within the tunnel. These include concrete foundations for buildings, equipment pads, and rail lines. Features on the slopes above the tunnel relate to tunnel ventilation, borehole drilling, and data recording. Feature types include soil-covered bunkers, concrete foundations, instrument cable holes, drill holes, and ventilation shafts. The U16a Tunnel complex is eligible to the National Register of Historic Places under criteria a and c, consideration g of 36 CFR Part 60.4 as a historic landscape. Scientific research conducted at the tunnel has made significant contributions to the broad patterns of our history, particularly in regard to the Cold War era that was characterized by competing social, economic, and political ideologies between the former Soviet Union and the United States. The tunnel also possesses distinctive construction and engineering methods for conducting underground nuclear tests. The Desert Research Institute recommends that the U16a Tunnel area be left in place in its current condition and that the U16a Tunnel historic landscape be included in the Nevada National Security Site monitoring program and monitored on a regular basis.

Jones, Roberrt C [DRI; Drollinger, Harold [DRI

2013-06-01T23:59:59.000Z

406

New Hypersonic Shock Tunnel at the Laboratory of Aerothermodynamics and Hypersonics Prof. Henry T. Nagamatsu  

SciTech Connect (OSTI)

The new 0.60-m. nozzle exit diameter hypersonic shock tunnel was designed to study advanced air-breathing propulsion system such as supersonic combustion and/or laser technologies. In addition, it may be used for hypersonic flow studies and investigations of the electromagnetic (laser) energy addition for flow control. This new hypersonic shock tunnel was designed and installed at the Laboratory for of Aerothermodynamics and Hypersonics Prof. Henry T. Nagamatsu, IEAv-CTA, Brazil. The design of the tunnel enables relatively long test times, 2-10 milliseconds, suitable for the experiments performed at the laboratory. Free stream Mach numbers ranging from 6 to 25 can be produced and stagnation pressures and temperatures up to 360 atm. and up to 9,000 K, respectively, can be generated. Shadowgraph and schlieren optical techniques will be used for flow visualization.

Toro, P. G. P.; Minucci, M. A. S.; Chanes, J. B. Jr; Oliveira, A. C.; Gomes, F. A. A.; Myrabo, L. N.; Nagamatsu, Henry T. [Laboratory of Aerothermodynamics and Hypersonics. Institute for Advanced Studies. IEAv-CTA. Rod. dos Tamoios km 5.5. Putim. Sao Jose dos Campos-SP 12228-001 (Brazil); Department of Mechanical, Aerospace, and Nuclear Engineering. Rensselaer Polytechnic Institute (RPI), Troy, NY, 12180-3590 (United States)

2008-04-28T23:59:59.000Z

407

Intermediate-band photosensitive device with quantum dots having tunneling barrier embedded in organic matrix  

DOE Patents [OSTI]

A plurality of quantum dots each have a shell. The quantum dots are embedded in an organic matrix. At least the quantum dots and the organic matrix are photoconductive semiconductors. The shell of each quantum dot is arranged as a tunneling barrier to require a charge carrier (an electron or a hole) at a base of the tunneling barrier in the organic matrix to perform quantum mechanical tunneling to reach the respective quantum dot. A first quantum state in each quantum dot is between a lowest unoccupied molecular orbital (LUMO) and a highest occupied molecular orbital (HOMO) of the organic matrix. Wave functions of the first quantum state of the plurality of quantum dots may overlap to form an intermediate band.

Forrest, Stephen R. (Ann Arbor, MI)

2008-08-19T23:59:59.000Z

408

Tunneling dynamics of bosonic Josephson junctions assisted by a cavity field  

E-Print Network [OSTI]

We study the interplay between the dynamics of a Bose-Einstein condensate in a double-well potential and that of an optical cavity mode. The cavity field is superimposed to the double-well potential and affects the atomic tunneling processes. The cavity field is driven by a laser red detuned from the bare cavity resonance; the dynamically changing spatial distribution of the atoms can shift the cavity in and out of resonance. At resonance the photon number is hugely enhanced and the atomic tunneling becomes amplified. The Josephson junction equations are revisited and the phase diagram is calculated. We find new solutions with finite imbalance and at the same time a lack of self-trapping solutions due to the emergence of a new separatrix resulting from enhanced tunneling.

G. Szirmai; G. Mazzarella; L. Salasnich

2015-01-13T23:59:59.000Z

409

Subthreshold-swing physics of tunnel field-effect transistors Wei Cao, Deblina Sarkar, Yasin Khatami, Jiahao Kang, and Kaustav Banerjee  

E-Print Network [OSTI]

Subthreshold-swing physics of tunnel field-effect transistors Wei Cao, Deblina Sarkar, Yasin) Subthreshold-swing physics of tunnel field-effect transistors Wei Cao, Deblina Sarkar, Yasin Khatami, Jiahao

410

Effects of diesel exhaust on the microbiota within a tuffaceous tunnel system  

SciTech Connect (OSTI)

The abundance and distribution of microbiota that may be impacted by diesel and diesel exhaust were investigated from three depths into the walls and invert (floor) of U12n tunnel at Rainier Mesa, Nevada Test Site, a potential geological analog of Yucca Mountain. Enumerations included total cell counts, and numbers of aerobic heterotrophic, sulfate-reducing, nitrate-reducing, and diesel-degrading bacteria. Additionally, the disappearance of total petroleum hydrocarbons was determined in microcosms containing subsurface materials that were amended with diesel fuel. Results revealed that microbes capable of utilizing diesel and diesel combustion products were present in the subsurface in both the walls and the invert of the tunnel. The abundance of specific bacterial types in the tunnel invert, a perturbed environment, was greater than that observed in the tunnel wall. Few trends of microbial distribution either into the tunnel wall or the invert were noted with the exception of aerobic heterotrophic abundance which increased with depth into the wall and decreased with depth into the invert. No correlation between microbiota and a specific introduced chemical species have yet been determined. The potential for microbial contamination of the tunnel wall during sampling was determined to be negligible by the use of fluorescently labeled latex spheres (1{mu}m in dia.) as tracers. Results indicate that additional investigations might be needed to examine the microbiota and their possible impacts on the geology and geochemistry of the subsurface, both indigenous microbiota and those microorganisms that will likely be introduced by anthropogenic activity associated with the construction of a high-level waste repository.

Haldeman, D.L.; Lagadinos, T.; Amy, P.S. [Univ. of Nevada, Las Vegas, NV (United States); Hersman, L. [Los Alamos National Lab., NM (United States); Meike, A. [Lawrence Livermore National Lab., Livermore, CA (United States)

1996-08-01T23:59:59.000Z

411

Tunneling density of states of high Tc superconductors d-wave BCS model vs. SU(2) slave boson model  

E-Print Network [OSTI]

Tunneling density of states of high Tc superconductors d-wave BCS model vs. SU(2) slave boson model conductance curves in the superconducting state at zero temperature. Comparing the two results obtained via Tunneling spectroscopy has been one of the funda- mental tools in studying the superconducting state

Wen, Xiao-Gang

412

Synthesis and structure of Al clusters supported on TiO2,,110...: A scanning tunneling microscopy study  

E-Print Network [OSTI]

Synthesis and structure of Al clusters supported on TiO2,,110...: A scanning tunneling microscopy, Texas 77843-3255 Received 14 October 1997; accepted 6 April 1998 Al clusters supported on TiO2(110) have been investigated using scanning tunneling microscopy. Al interacts strongly with the TiO2(110) surface

Goodman, Wayne

413

Ultrafast metal-insulator varistors based on tunable Al2O3 tunnel junctions Michael A. Weimer,1,2  

E-Print Network [OSTI]

Ultrafast metal-insulator varistors based on tunable Al2O3 tunnel junctions Michael A. Weimer,1; accepted 4 April 2008; published online 21 April 2008 Ultrafast metal-insulator varistors have been oxide varistors. These characteristics result from the Fowler­Nordheim tunneling of electrons through

George, Steven M.

414

Z .Tunnelling and Underground Space Technology 16 2001 107 114 Experimental investigation on the breakage of hard rock by  

E-Print Network [OSTI]

Z .Tunnelling and Underground Space Technology 16 2001 107 114 Experimental investigation, shearing and complete clean- ing of the crushed zone would raise the rate of penetra- tion and maximize bitTunnelling and Underground Space Technology 16 2001 107 114108 Fig. 1. Layout of PDC button and waterjets. The depth of cuts

415

Role of midgap states in the inelastic tunneling between a d-wave superconductor and a normal metal  

E-Print Network [OSTI]

IT mediated by the phonons in the barrier or of the electrodes at the barrier. Unlike in N-N tunneling, where the excitable mode frequencies are revealed in d² I/d²V, here dI/dV is already sufficient to reveal the same. Comparing with N-S (s-wave) tunneling...

Wei,Hongduo

2012-06-07T23:59:59.000Z

416

Far-infrared laser vibration-rotation-tunneling spectroscopy of the propane-water compkx: Torsional dynamics of the hydrogen  

E-Print Network [OSTI]

Far-infrared laser vibration-rotation-tunneling spectroscopy of the propane-water compkx: Torsional 1993) The far-infrared laservibration-rotation-tunneling (FIR-VRT) spectrumof the propane-water complex calculations. In the present paper and in its counterpart,13we present our results for the water-propane

Cohen, Ronald C.

417

Note: Long-range scanning tunneling microscope for the study of nanostructures on insulating substrates  

SciTech Connect (OSTI)

The scanning tunneling microscope (STM) is a powerful tool for studying the electronic properties at the atomic level, however, it is of relatively small scanning range and the fact that it can only operate on conducting samples prevents its application to study heterogeneous samples consisting of conducting and insulating regions. Here we present a long-range scanning tunneling microscope capable of detecting conducting micro and nanostructures on insulating substrates using a technique based on the capacitance between the tip and the sample and performing STM studies.

Molina-Mendoza, Aday J., E-mail: aday.molina@uam.es [Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Rodrigo, José G.; Rubio-Bollinger, Gabino [Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Condensed Matter Physics Center (IFIMAC) and Instituto Universitario de Ciencia de Materiales “Nicolás Cabrera,” Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Island, Joshua; Burzuri, Enrique; Zant, Herre S. J. van der [Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft (Netherlands); Agraït, Nicolás [Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain) [Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Condensed Matter Physics Center (IFIMAC) and Instituto Universitario de Ciencia de Materiales “Nicolás Cabrera,” Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Instituto Madrileño de Estudios Avanzados en Nanociencia IMDEA-Nanociencia, E-28049 Madrid (Spain)

2014-02-15T23:59:59.000Z

418

1D-1D tunneling between vertically coupled GaAs/AlGaAs quantum wires.  

SciTech Connect (OSTI)

We report low-dimensional transport and tunneling in an independently contacted vertically coupled quantum wire system, with a 7.5 nm barrier between the wires. The derivative of the linear conductance shows evidence for both single wire occupation and coupling between the wires. This provides a map of the subband occupation that illustrates the control that we have over the vertically coupled double quantum wires. Preliminary tunneling results indicate a sharp 1D-1D peak in conjunction with a broad 2D-2D background signal. This 1D-1D peak is sensitively dependent on the top and bottom split gate voltage.

Seamons, John Andrew; Lilly, Michael Patrick; Reno, John Louis; Bielejec, Edward Salvador

2004-07-01T23:59:59.000Z

419

Tunnelling of relativistic particles from new type black hole in new massive gravity  

SciTech Connect (OSTI)

In the framework of the three dimensional New Massive Gravity theory introduced by Bergshoeff, Hohm and Townsend, we analyze the behavior of relativistic spin-1/2 and spin-0 particles in the New-type Black Hole backgroud, solution of the New Massive Gravity.We solve Dirac equation for spin-1/2 and Klein-Gordon equation for spin-0. Using Hamilton-Jacobi method, we discuss tunnelling probability and Hawking temperature of the spin-1/2 and spin-0 particles for the black hole. We observe that the tunnelling probability and Hawking temperature are same for the spin-1/2 and spin-0.

Gecim, Ganim; Sucu, Yusuf, E-mail: ganimgecim@akdeniz.edu.tr, E-mail: ysucu@akdeniz.edu.tr [Department of Physics, Akdeniz University, Antalya (Turkey)

2013-02-01T23:59:59.000Z

420

Monolithic interconnected module with a tunnel junction for enhanced electrical and optical performance  

DOE Patents [OSTI]

An improved thermophotovoltaic (TPV) n/p/n device is provided. Monolithic Interconnected Modules (MIMS), semiconductor devices converting infrared radiation to electricity, have been developed with improved electrical and optical performance. The structure is an n-type emitter on a p-type base with an n-type lateral conduction layer. The incorporation of a tunnel junction and the reduction in the amount of p-type material used results in negligible parasitic absorption, decreased series resistance, increased voltage and increased active area. The novel use of a tunnel junction results in the potential for a TPV device with efficiency greater than 24%.

Murray, Christopher S. (Bethel Park, PA); Wilt, David M. (Bay Village, OH)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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

A micrometer-size movable light emitting area in a resonant tunneling light emitting diode  

SciTech Connect (OSTI)

We report on the fabrication of a micrometer-size movable light emitting area in a GaAs/AlAs quantum well resonant tunneling p-i-n diode. The spatial position of the micrometer-size light emitting area shifts linearly with increasing applied bias, up to 30??m for a bias increment of 0.2?V. Also, the simultaneous resonant tunneling injection of both electrons and holes into the quantum well states is achieved at specific positions of the diode, thus resulting in a tenfold increase of the electroluminescence intensity.

Pettinari, G., E-mail: giorgio.pettinari@cnr.it [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); National Research Council (CNR), Institute for Photonics and Nanotechnologies (IFN-CNR), Via Cineto Romano 42, 00156 Roma (Italy); Balakrishnan, N.; Makarovsky, O.; Campion, R. P.; Patanè, A. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)] [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Polimeni, A.; Capizzi, M. [CNISM-Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185 Roma (Italy)] [CNISM-Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185 Roma (Italy)

2013-12-09T23:59:59.000Z

423

Local tunneling characteristics near a grain boundary of a d-wave superconductor as probed by a normal-metal or a low-Tc-superconductor STM tip  

E-Print Network [OSTI]

We studied the local single-particle tunneling characteristics [as observed with scanning tunnel microscopy (STM)] for N D and S D tunneling, where N is a normal metal, S is a s-wave superconductor, and D is a d-wave superconductor with a {100...

Zhao, Hongwei

2005-08-29T23:59:59.000Z

424

Inelastic tunneling conductance and magnetoresistance investigations in dual ion-beam sputtered CoFeB(110)/MgO/CoFeB (110) magnetic tunnel junctions  

SciTech Connect (OSTI)

Magnetic tunnel junctions (MTJs) comprising Ta(5)/NiFe(5)/IrMn(15)/CoFeB(5)/Mg(1)/MgO(3.5)/ CoFeB(5)/Ta(5)/Ag(20) (thickness in nm) with (110) oriented CoFeB layers are grown using dual ion beam sputtering. The tunnel magnetoresistance (TMR) of MTJs is found to be significantly bias dependent and exhibits zero bias anomaly (ZBA) which is attributed to the presence of magnetic impurities or diffusion of Mn from antiferromagnetic IrMn in the barrier. Adjacent to the ZBA, two peaks at 24?±?3?mV and 34?±?3?mV are also observed, which differ both in intensity as well as their position in the antiparallel and parallel magnetic states, suggesting that they are due to magnon excitations. In addition to this, a phonon peak at 65?±?3?mV is also observed. The effect of temperature on the inelastic and elastic tunneling contributions is studied in detail in 25–300?K range using the Glazman and Matveev model. Ten series of localized states are found to be involved in hopping conduction in the forbidden gap of MgO barrier. The effect of presence of such inelastic channels is found to be insignificant at low temperatures yielding sizeable enhancement in TMR.

Bhusan Singh, Braj; Chaudhary, Sujeet, E-mail: sujeetc@physics.iitd.ac.in [Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110 016 (India)

2014-04-21T23:59:59.000Z

425

Composting Large Animal Carcasses  

E-Print Network [OSTI]

Disposing of large animal carcasses can be a problem for agricultural producers. Composting is a simple, low-cost method that yields a useful product that can be used as fertilizer. In this publication you'll learn the basics of composting, how...

Auvermann, Brent W.; Mukhtar, Saqib; Heflin, Kevin

2006-10-31T23:59:59.000Z

426

CALCULATIONS OF FIRE SMOKE BEHAVIOUR IN LONG RAIL TUNNELS S. DARON, E. RUFFIN  

E-Print Network [OSTI]

2000-13 CALCULATIONS OF FIRE SMOKE BEHAVIOUR IN LONG RAIL TUNNELS S. DAÃ?RON, E. RUFFIN INERIS Parc in complex underground networks, we want to implement a coupling between a ID ventilation code and a CFD model or a zone model. The project consists in 3 main steps: the development of a ID ventilation code

Paris-Sud XI, Université de

427

Spontaneous emission from a two--level atom tunneling in a double--well potential  

E-Print Network [OSTI]

We study a two-level atom in a double--well potential coupled to a continuum of electromagnetic modes (black body radiation in three dimensions at zero absolute temperature). Internal and external degrees of the atom couple due to recoil during emission of a photon. We provide a full analysis of the problem in the long wavelengths limit up to the border of the Lamb-Dicke regime, including a study of the internal dynamics of the atom (spontaneous emission), the tunneling motion, and the electric field of the emitted photon. The tunneling process itself may or may not decohere depending on the wavelength corresponding to the internal transition compared to the distance between the two wells of the external potential, as well as on the spontaneous emission rate compared to the tunneling frequency. Interference fringes appear in the emitted light from a tunneling atom, or an atom in a stationary coherent superposition of its center--of--mass motion, if the wavelength is comparable to the well separation, but only if the external state of the atom is post-selected.

Daniel Braun; John Martin

2007-10-26T23:59:59.000Z

428

Investigation of Terahertz Vibration-Rotation Tunneling Spectra for the Water Octamer  

E-Print Network [OSTI]

Investigation of Terahertz Vibration-Rotation Tunneling Spectra for the Water Octamer Jeremy O, and Richard J. Saykally*, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom Department of Chemistry, University of California, Berkeley, California 94720

Cohen, Ronald C.

429

Surface-to-tunnel seismic tomography studies at Yucca Mountain, Nevada  

E-Print Network [OSTI]

Surface-to-tunnel seismic tomography studies at Yucca Mountain, Nevada Roland Gritto, Valeri A in the proposed nuclear waste repository area at Yucca Mountain, Nevada. A 5-km-long source line and a 3-km-long receiver line were located on top of Yucca Mountain ridge and inside the Exploratory Study Facility (ESF

Korneev, Valeri A.

430

Resonant tunneling and the bimodal symmetric fission of sup 258 Fm  

SciTech Connect (OSTI)

The concept of resonant tunneling is invoked to explain the sharp drop in the measured spontaneous-fission half-life when going from {sup 256}Fm to {sup 258}Fm. Various consequences of such a suggestion on the other observed characteristics of the bimodal symmetric fission of {sup 258}Fm are briefly discussed.

Bhandari, B.S. (Department of Physics, Faculty of Science, University of Garyounis, Benghazi, Libya (LY))

1991-02-25T23:59:59.000Z

431

Low resistivity of Pt silicide nanowires measured using double-scanning-probe tunneling microscope  

E-Print Network [OSTI]

experimentally shown to be conductive.8­10 However, RE metal silicide NWs are easily oxidized, so that inert NWs similarly to RE metal silicide NWs.11 It is essential to study the electrical properties, especiallyLow resistivity of Pt silicide nanowires measured using double-scanning- probe tunneling microscope

Kim, Sehun

432

TESLA-FEL 2007-02 Radiation dosimetry in FLASH Tunnel using  

E-Print Network [OSTI]

1 TESLA-FEL 2007-02 Radiation dosimetry in FLASH Tunnel using Passive dosimeters Bhaskar Mukherjee, Radiation dosimetry, Radiation effect, Superconducting Cavities, XFEL 1. INTRODUCTION In April 2006, at DESY-term basis. Conventional radiation monitoring devices are usually bulky and the associated nuclear

433

Angular domain optical imaging of turbid media using enhanced micro-tunnel filter arrays  

E-Print Network [OSTI]

performed in tissue mimicking phantoms using a 2-cm thick optical cell with 0.25% IntralipidTM and a near infrared laser. This paper also presents experimental results of the angular domain imaging system employing novel micro-tunnel arrays with minimal internal reflection which can accept the non- scattered

Chapman, Glenn H.

434

WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES  

E-Print Network [OSTI]

1 WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES J. J. Miau*1 were carried out to study the aerodynamic performance of three vertical axis wind turbines (VAWTs. On the other hand, the characteristics of unsteady flow around the helical wind turbine were studied with a hot

Leu, Tzong-Shyng "Jeremy"

435

Benchmark of aerodynamic cycling helmets using a refined wind tunnel test protocol for helmet drag research  

E-Print Network [OSTI]

The study of aerodynamics is very important in the world of cycling. Wind tunnel research is conducted on most of the equipment that is used by a rider and is a critical factor in the advancement of the sport. However, to ...

Sidelko, Stephanie

2007-01-01T23:59:59.000Z

436

Decay of the cosmological constant: Equivalence of quantum tunneling and thermal activation in two spacetime dimensions  

SciTech Connect (OSTI)

We study the decay of the cosmological constant in two spacetime dimensions through production of pairs. We show that the same nucleation process looks as quantum-mechanical tunneling (instanton) to one Killing observer and as thermal activation (thermalon) to another. Thus, we find another striking example of the deep interplay between gravity, thermodynamics and quantum mechanics which becomes apparent in presence of horizons.

Gomberoff, Andres; Henneaux, Marc; Teitelboim, Claudio [Centro de Estudios Cientificos (CECS), Valdivia (Chile); Physique Theorique et Mathematique, Universite Libre de Bruxelles and International Solvay Institutes, ULB Campus Plaine C.P. 231, B-1050 Brussels (Belgium); Centro de Estudios Cientificos (CECS), Valdivia (Chile); Centro de Estudios Cientificos (CECS), Valdivia (Chile)

2005-03-15T23:59:59.000Z

437

Tunable few-electron double quantum dots and Klein tunnelling in ultraclean carbon nanotubes  

E-Print Network [OSTI]

Tunable few-electron double quantum dots and Klein tunnelling in ultraclean carbon nanotubes G. A. Steele*, G. Gotz and L. P. Kouwenhoven Quantum dots defined in carbon nanotubes are a platform for both with highly tunable barriers1 , but disorder has prevented tunable nanotube- based quantum-dot devices from

438

Nonequilibrium Tunneling Spectroscopy in Carbon Nanotubes Yung-Fu Chen,1  

E-Print Network [OSTI]

of the local electron distribution functions, and hence energy relaxation rates, in nanotubes that have biasNonequilibrium Tunneling Spectroscopy in Carbon Nanotubes Yung-Fu Chen,1 Travis Dirks,1 Gassem Al; published 23 January 2009) We report measurements of the nonequilibrium electron energy distribution

Birge, Norman

439

Length control of individual carbon nanotubes by nanostructuring with a scanning tunneling microscope  

E-Print Network [OSTI]

and quantum-size energy-level splitting.6,7 The quantum transport properties of nanotubes strongly dependLength control of individual carbon nanotubes by nanostructuring with a scanning tunneling of carbon nanotubes. Individual carbon nanotubes can be locally cut by applying a voltage pulse to the tip

440

Observation of spin-dependent quantum well resonant tunneling in textured CoFeB layers  

SciTech Connect (OSTI)

We report the observation of spin-dependent quantum well (QW) resonant tunneling in textured CoFeB free layers of single MgO magnetic tunnel junctions (MTJs). The inelastic electron tunneling spectroscopy spectra clearly show the presence of resonant oscillations in the parallel configuration, which are related with the appearance of majority-spin ?{sub 1} QW states in the CoFeB free layer. To gain a quantitative understanding, we calculated QW state positions in the voltage-thickness plane using the so-called phase accumulation model (PAM) and compared the PAM solutions with the experimental resonant voltages observed for a set of MTJs with different CoFeB free layer thicknesses (t{sub fl}?=?1.55, 1.65, 1.95, and 3.0?nm). An overall good agreement between experiment and theory was obtained. An enhancement of the tunnel magnetoresistance with bias is observed in a bias voltage region corresponding to the resonant oscillations.

Teixeira, J. M., E-mail: jmteixeira@fc.up.pt; Costa, J. D.; Ventura, J.; Sousa, J. B. [IFIMUP and IN-Institute of Nanoscience and Nanotechnology, and Departamento de Fisica e Astronomia, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Wisniowski, P. [Department of Electronics, AGH University of Science and Technology, 30-059 Krakow (Poland); Freitas, P. P. [INESC-MN and IN-Institute of Nanoscience and Nanotechnology, Rua Alves Redol, 9-1, 1000-029 Lisbon (Portugal)

2014-03-17T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Speech Enhancement of Noisy Speech Using Log-Spectral Amplitude Estimator and Harmonic Tunneling  

E-Print Network [OSTI]

Speech Enhancement of Noisy Speech Using Log-Spectral Amplitude Estimator and Harmonic Tunneling we present a two stage noise reduction algo- rithm for speech enhancement. The speech noise removal and decreases the performance of speech coding and speech recog- nition systems. In speech enhancement

Wichmann, Felix

442

Close-in blasting at the TRI-MET light rail tunnels in Portland, Oregon  

SciTech Connect (OSTI)

Frontier/Traylor Joint Venture is presently constructing a section of the Tri-County Metropolitan Transit District of Oregon`s (TRI-MET) Westside Light Rail System. This new section will extend Portland`s existing transit system to the western suburbs of Beaverton and Hillsboro. The drill-blast excavations at this project include 10,000 feet of 20 foot tunnel, 18 cross passages, three shafts, an underground railway station, and a U-wall open cut. From a blast designer`s perspective, this job has been extremely challenging. Blast vibration is limited to 0.5 ips at 200 feet or at the nearest structure, and airblast is limited to 129 dB--linear peak and 96 dB--C scale. The tunnels pass under heavily built up areas and have top of tunnel to surface cover distances as low as 70 feet. Surface blasting in the 26,000 cubic yard U-wall excavation was limited to five short nighttime periods due to its proximity to the very busy highway 26. This paper describes the techniques that were used to develop safe blasting designs for the TRI-MET Surface blasts and tunnel rounds. It also discusses the measures that were necessary to mitigate noise, vibration, and flyrock.

Revey, G.F.; Painter, D.Z.

1995-12-31T23:59:59.000Z

443

Crossover from tunneling to meta.llic behavior in superconductofgsemiconductor contacts  

E-Print Network [OSTI]

-dominated transport at the superconductor-semiconductor contacts as Schottky barrier thickness decreases of such a crossover in a thin-film structure, and are of interest for investigations of hybrid superconductor-semiconductorCrossover from tunneling to meta.llic behavior in superconductofgsemiconductor contacts A. W

Woodall, Jerry M.

444

Electromagnetic Realization of Orders-of-Magnitude Tunneling Enhancement in a DoubleWell System  

E-Print Network [OSTI]

Tun Ltd., MTM Scientific Industries Center, Building 22, P.O. Box 15017, Haifa 31905, Israel (Received 1 in Refs. [8,13] that the tunneling enhancement can also be obtained in a weakly driven system fabricated using planar silica over silicon technology. The waveguides' core was made from a silica

Narevicius, Edvardas

445

Simultaneous topographic and elemental chemical and magnetic contrast in scanning tunneling microscopy  

DOE Patents [OSTI]

A method and system for performing simultaneous topographic and elemental chemical and magnetic contrast analysis in a scanning, tunneling microscope. The method and system also includes nanofabricated coaxial multilayer tips with a nanoscale conducting apex and a programmable in-situ nanomanipulator to fabricate these tips and also to rotate tips controllably.

Rose, Volker; Preissner, Curt A; Hla, Saw-Wai; Wang, Kangkang; Rosenmann, Daniel

2014-09-30T23:59:59.000Z

446

Modelling a Car Safety Controller in Road Tunnels using Hybrid Petri Nets A. Bobbio[1  

E-Print Network [OSTI]

Modelling a Car Safety Controller in Road Tunnels using Hybrid Petri Nets A. Bobbio[1] , M this specific issue and proposes a hybrid modeling approach based on fluid Petri nets (FPN). An FPN is used that FPN is a valid paradigm to model the dynamics of a car in a detailed way. 1 Introduction In the last

Horváth, András

447

Giant higher harmonic generation in mesoscopic metal wires and rings interrupted by tunnel junctions  

E-Print Network [OSTI]

Giant higher harmonic generation in mesoscopic metal wires and rings interrupted by tunnel 5046, 2600 GA Delft, The Netherlands Received 19 December 1997 Higher harmonic generation in mesoscopic is biased with a sinusoidal varying current, we observe giant higher harmon- ics in the conductance

van Oudenaarden, Alexander

448

Predicted scanning tunneling microscopy images of carbon nanotubes with atomic vacancies  

E-Print Network [OSTI]

Predicted scanning tunneling microscopy images of carbon nanotubes with atomic vacancies Arkady V STM images of both metallic and semiconducting single-wall carbon nanotubes with atomic vacancies predict that vacancies should result in the formation of hillock-like features in STM images of metallic

Krasheninnikov, Arkady V.

449

SUPERCONDUCTING TUNNEL JUNCTION BOLOMETERS J. CLARKE, G. I. HOFFER and P. L. RICHARDS  

E-Print Network [OSTI]

69 SUPERCONDUCTING TUNNEL JUNCTION BOLOMETERS J. CLARKE, G. I. HOFFER and P. L. RICHARDS DepartmentIioration possible de ces performances. Abstract. 2014 Two new types of superconducting infrared bolometer doped germanium, are widely used as sensitive broadband infrared detectors. Superconducting bolometers

Boyer, Edmond

450

Measurement of the Equivalent Thermal Resistance of Rooftop Lawns in a Hot-Climate Wind Tunnel  

E-Print Network [OSTI]

rooftop lawn. A hot-climate wind tunnel experiment was carried out in order to obtain and analyze the heat and moisture transport in the rooftop lawn. Furthermore, a calculation with the energy conservation equation was carried out using the results...

Meng, Q.; Zhang, Y.; Zhang, L.

2006-01-01T23:59:59.000Z

451

Seismic modeling and analysis of a prototype heated nuclear waste storage tunnel, Yucca Mountain, Nevada  

E-Print Network [OSTI]

Seismic modeling and analysis of a prototype heated nuclear waste storage tunnel, Yucca Mountain was heated to replicate the effects of long-term storage of decaying nuclear waste and to study the effects for the long- term storage of high-level nuclear waste from reactors and decom- missioned atomic weapons

Snieder, Roel

452

Resonance tunneling of cooper pairs in a superconductor-polymer-superconductor josephson junction  

SciTech Connect (OSTI)

It is shown that the superconducting current flowing though a polymer in a superconductor-polymer-superconductor Josephson structure is due to resonant tunneling of Cooper pairs. The critical current and the thickness of the polymer in which the superconducting current is observed depend on the coherence length of a Cooper pair in the superconductor contacting the polymer.

Ionov, A. I., E-mail: ionov@tuch.ioffe.ru [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

2013-05-15T23:59:59.000Z

453

Thoughts on entropic gravity in the Parikh-Wilczek tunneling model of Hawking radiation  

E-Print Network [OSTI]

In this letter, we use the Parikh-Wilczek tunneling model of Hawking radiation to illustrate that a reformulation of Verlinde's entropic gravity is needed to derive the Newton's law for a temperature-varying screen, demanded by the conservation of energy. Furthermore, the entropy stored in the holographic screen is shown to be additive and its temperature dependence can be obtained.

Wen-Yu Wen

2014-05-28T23:59:59.000Z

454

GROUND MOVEMENTS DUE TO SHALLOW TUNNELS IN SOFT GROUND: 1. ANALYTICAL SOLUTIONS  

E-Print Network [OSTI]

use of numerical analyses, particularly non-linear finite element methods, over a period of more than. Deformation fields based on the superposition of fundamental, singularity solutions are shown to differ only of very shallow tunnels. The Authors demonstrate a simplified method to account for soil plasticity

Entekhabi, Dara

455

Policy Name: Golf Carts in Tunnels Originating/Responsible Department: Facilities Management and Planning  

E-Print Network [OSTI]

to their manager or department head all incidents involving injury to persons or damage to property. ReportingPolicy Name: Golf Carts in Tunnels Originating/Responsible Department: Facilities Management and Planning Approval Authority: Senior Management Committee Date of Original Policy: October 2008 Last Updated

Carleton University

456

Geology of the Trans-Missouri River Tunnel project, Kansas City, Missouri  

SciTech Connect (OSTI)

The geology of the Missouri River Valley at Kansas City is interpreted from the borehole and construction site data along the route of the Trans-Missouri River Tunnel, a 4.4 km long water tunnel constructed at a depth of 90--97.5 m below the floodplain of the Missouri River. The data from the site investigation is used to construct a detailed stratigraphic cross-section of the subsurface units to a depth of 120 m and extending in a north-south direction the length of the tunnel. The rock section is divided into 2 broad categories, (a) alluvium and (b) bedrock. The alluvium (Pleistocene-Holocene) fills the Missouri River Valley to a depth of 38 m along the tunnel route. An exception is a deep narrow channel near the center of the valley, the alluvium is 55 m thick and the lower several meters of the channel is filled with glacial till( ). The alluvium rests unconformably on Pennsylvanian bedrock consisting of thin strata arranged in cyclical sequences or cyclothems and belonging to the following groups in ascending order: Upper Cherokee, Marmaton and Lower Pleasanton. The test drill core data made it possible to conduct a detailed analysis of the subsurface stratigraphy. Of major importance is the stratigraphic position of a thick channel-fill deposit in the Labette Formation, Marmaton Group, a producing horizon in several small oil and gas fields in western Missouri and eastern Kansas. The 327.6 cm dia. bore for the essentially horizontal tunnel is constructed in predominately silty and sandy gray shale located stratigraphically near the Cherokee-Marmaton contact and in younger channel-fill deposits.

Gentile, R.J. (Univ. of Missouri, Kansas City, MO (United States). Dept. of Geosciences)

1993-03-01T23:59:59.000Z

457

Titanium Silicide Islands on Atomically Clean Si(100): Identifying Single Electron Tunneling Effects  

E-Print Network [OSTI]

Titanium silicide islands have been formed by the ultrahigh vacuum deposition of thin films of titanium (< 2 nm) on atomically clean Si(100) substrates followed by annealing to ~800 degrees C. Scanning tunneling microscopy (STM) and scanning tunneling spectroscopy have been performed on these islands to record current-voltage (I-V) curves. Because each island forms a double barrier tunnel junction (DBTJ) structure with the STM tip and the substrate, they would be expected to exhibit single electron tunneling (SET) according to the orthodox model of SET. Some of the islands formed are small enough (diameter < 10 nm) to exhibit SET at room temperature and evidence of SET has been identified in some of the I-V curves recorded from these small islands. Those curves are analyzed within the framework of the orthodox model and are found to be consistent with that model, except for slight discrepancies of the shape of the I-V curves at current steps. However, most islands that were expected to exhibit SET did not do so, and the reasons for the absence of observable SET are evaluated. The most likely reasons for the absence of SET are determined to be a wide depletion region in the substrate and Schottky barrier lowering due to Fermi level pinning by surface states of the clean silicon near the islands. The results establish that although the Schottky barrier can act as an effective tunnel junction in a DBTJ structure, the islands may be unreliable in future nanoelectronic devices. Therefore, methods are discussed to improve the reliability of future devices.

Joseph L. Tedesco; J. E. Rowe; Robert J. Nemanich

2010-07-28T23:59:59.000Z

458

Estimation of deformation and stiffness of fractures close to tunnels using data from single-hole hydraulic testing and grouting  

SciTech Connect (OSTI)

Sealing of tunnels in fractured rocks is commonly performed by pre- or post-excavation grouting. The grouting boreholes are frequently drilled close to the tunnel wall, an area where rock stresses can be low and fractures can more easily open up during grout pressurization. In this paper we suggest that data from hydraulic testing and grouting can be used to identify grout-induced fracture opening, to estimate fracture stiffness of such fractures, and to evaluate its impact on the grout performance. A conceptual model and a method are presented for estimating fracture stiffness. The method is demonstrated using grouting data from four pre-excavation grouting boreholes at a shallow tunnel (50 m) in Nygard, Sweden, and two post-excavation grouting boreholes at a deep tunnel (450 m) in Aespoe HRL, Sweden. The estimated stiffness of intersecting fractures for the boreholes at the shallow Nygard tunnel are low (2-5 GPa/m) and in agreement with literature data from field experiments at other fractured rock sites. Higher stiffness was obtained for the deeper tunnel boreholes at Aespoe which is reasonable considering that generally higher rock stresses are expected at greater depths. Our method of identifying and evaluating the properties and impact of deforming fractures might be most applicable when grouting takes place in boreholes adjacent to the tunnel wall, where local stresses might be low and where deforming (opening) fractures may take most of the grout.

Fransson, A.; Tsang, C.-F.; Rutqvist, J.; Gustafson, G.

2010-05-01T23:59:59.000Z

459

Highly transparent low capacitance plasma enhanced atomic layer deposition Al{sub 2}O{sub 3}-HfO{sub 2} tunnel junction engineering  

SciTech Connect (OSTI)

The development of metallic single electron transistor (SET) depends on the downscaling and the electrical properties of its tunnel junctions. These tunnel junctions should insure high tunnel current levels, low thermionic current, and low capacitance. The authors use atomic layer deposition to fabricate Al{sub 2}O{sub 3} and HfO{sub 2} thin layers. Tunnel barrier engineering allows the achievement of low capacitance Al{sub 2}O{sub 3} and HfO{sub 2} tunnel junctions using optimized annealing and plasma exposure conditions. Different stacks were designed and fabricated to increase the transparency of the tunnel junction while minimizing thermionic current. This tunnel junction is meant to be integrated in SET to enhance its electrical properties (e.g., operating temperature, I{sub ON}/I{sub OFF} ratio)

El Hajjam, Khalil, E-mail: khalil.el-hajjam@insa-lyon.fr [INL, INSA, UMR CNRS 5270, 7 Avenue Jean Capelle, 69621 Villeurbanne Cedex, France and Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, 3000 Boulevard Université, Sherbrooke, J1K OA5, Québec (Canada); Baboux, Nicolas; Calmon, Francis [INL, INSA, UMR CNRS 5270, 7 Avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Souifi, Abdelkader [Laboratoire Nanotechnologies Nanosystèmes (LN2)-CNRS UMI-3463, Université de Sherbrooke, 3000 Boulevard Université, Sherbrooke, J1K OA5, Québec (Canada); Poncelet, Olivier; Francis, Laurent A. [ICTEAM, ELEN, UCL, Place du Levant 3, 1348 Louvain-la-Neuve (Belgium); Ecoffey, Serge; Drouin, Dominique [Laboratoire Nanotechnologies Nanosystèmes (LN2)-CNRS UMI-3463, Université de Sherbrooke, 3000 Boulevard Université, Sherbrooke, J1K OA5, Québec, Canada and Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, 3000 Boulevard Université, Sherbrooke, J1K OA5, Québec (Canada)

2014-01-15T23:59:59.000Z

460

Local tunneling characteristics near a grain boundary of a d-wave superconductor as probed by a normal-metal or a low-T-c-superconductor STM tip  

E-Print Network [OSTI]

We study the local single-particle tunneling characteristics [as observed with scanning tunnel microscopy (STM)] for N-D and S-D tunneling, where D is a d-wave superconductor with a {100}{110} grain boundary. The tunneling Hamiltonian method is used...

Zhao, HW; Hu, Chia-Ren.

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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

Tunneling and nonlinear transport in a vertically coupled GaAs/AlGaAs double quantum wire system.  

SciTech Connect (OSTI)

We report low-dimensional tunneling in an independently contacted vertically coupled quantum wire system. This nanostructure is fabricated in a high quality GaAs/AlGaAs parallel double quantum well heterostructure. Using a unique flip chip technique to align top and bottom split gates to form low-dimensional constrictions in each of the independently contacted quantum wells we explicitly control the subband occupation of the individual wires. In addition to the expected two-dimensional (2D)-2D tunneling results, we have found additional tunneling features that are related to the one-dimensional quantum wires.

Seamons, John Andrew; Lilly, Michael Patrick; Reno, John Louis; Bielejec, Edward Salvador

2004-11-01T23:59:59.000Z

462

Role of Coulomb blockade and spin-flip scattering in tunneling magnetoresistance of FeCo-Si-O nanogranular films  

SciTech Connect (OSTI)

In this work, we report the effect of FeCo atomic fraction (0.33 < x < 0.54) and temperature on the electrical, magnetic, and tunneling magnetoresistance (TMR) properties of FeCo-Si-O granular films prepared by atom beam sputtering technique. Glancing angle x-ray diffraction and TEM studies reveal that films are amorphous in nature. The dipole-dipole interactions (particle-matrix mixing) is evident from zero-field cooled and field-cooled magnetic susceptibility measurements and the presence of oxides (mainly Fe-related) is observed by x-ray photoelectron spectroscopy analysis. The presence of Fe-oxides is responsible for the observed reduction of saturation magnetization and rapid increase in coercivity below 50 K. TMR has been observed in a wide temperature range, and a maximum TMR of -4.25% at 300 K is observed for x = 0.39 at a maximum applied field of 60 kOe. The fast decay of maximum TMR at high temperatures and lower TMR values at 300 K when compared to P{sub FeCo}{sup 2}/(1+P{sub FeCo}{sup 2}), where P{sub FeCo} is the spin polarization of FeCo are in accordance with a theoretical model that includes spin-flip scattering processes. The temperature dependent study of TMR effect reveals a remarkably enhanced TMR at low temperatures. The TMR value varies from -2.1% at 300 K to -14.5% at 5 K for x = 0.54 and a large MR value of -18.5% at 5 K for x = 0.39 is explained on the basis of theoretical models involving Coulomb blockade effects. Qualitatively particle-matrix mixing and the presence of Fe-oxides seems to be the source of spin-flip scattering, responsible for fast decay of TMR at high temperatures. A combination of higher order tunneling (in Coulomb blockade regime) and spin-flip scattering (high temperature regime) explains the temperature dependent TMR of these films.

Kumar, Hardeep; Ghosh, Santanu [Nanostech Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India); Buerger, Danilo; Zhou, Shengqiang; Groetzschel, Rainer; Schmidt, Heidemarie [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Li, Lin [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100 871 (China); Kabiraj, Debdulal; Avasthi, Devesh Kumar [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

2011-04-01T23:59:59.000Z

463

Design considerations for a large aperture high field superconducting dipole  

SciTech Connect (OSTI)

The final phase of the Fermilab upgrade proposal calls for a new ring of superconducting magnets to be placed in the existing Main Accelerator tunnel. The goal of this design study is to specify a high field dipole (HFD) that is capable of supporting fixed target operation (ramping, resonant extraction) at a field of 6.6T (1.5 Tev) and colliding beam physics at 8.0T (1.8 Tev). The magnetic field quality at high field is set by the large amplitude orbits associated with resonant extraction. The field quality must therefore be at least as good as the existing Tevatron magnets which fulfill these criteria. The high fields and large aperture of this magnet result in large forces on the coil and collar assemblies. Therefore, the cold mass design must be able to sustain these forces while providing sufficient cooling to the coils during 4.2 K fixed target operation, and a minimum heat load during 1.8 K collider operation. The design work is still in progress but a cosine-theta, cold-iron dipole with a 70mm inner diameter coil has been tentatively adopted. This report presents details on the conductor and cable parameters, coil cross-section, projected manufacturing tolerances, iron yoke design, and cold mass assembly. 4 refs., 5 figs., 1 tab.

Harfoush, F.; Ankenbrandt, C.; Harrison, M.; Kerby, J.; Koepke, K.; Mantsch, P.; Nicol, T.; Riddiford, A.; Theilacker, J.

1989-03-01T23:59:59.000Z

464

Gyrokinetic large eddy simulations  

SciTech Connect (OSTI)

The large eddy simulation approach is adapted to the study of plasma microturbulence in a fully three-dimensional gyrokinetic system. Ion temperature gradient driven turbulence is studied with the GENE code for both a standard resolution and a reduced resolution with a model for the sub-grid scale turbulence. A simple dissipative model for representing the effect of the sub-grid scales on the resolved scales is proposed and tested. Once calibrated, the model appears to be able to reproduce most of the features of the free energy spectra for various values of the ion temperature gradient.

Morel, P.; Navarro, A. Banon; Albrecht-Marc, M.; Carati, D. [Statistical and Plasma Physics Laboratory, Universite Libre de Bruxelles, Bruxelles 1050 (Belgium); Merz, F.; Goerler, T.; Jenko, F. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany)

2011-07-15T23:59:59.000Z

465

Calibration of the Merrill-G.A.L.C.I.T. wind-tunnel, and a suggestion for a variable cross-section on a small high-speed wind-tunnel.  

E-Print Network [OSTI]

??Speed, power and flow inclination calibration tests run in the Merrill-GALCIT wind-tunnel are described and results presented. A description of the new balance-system is included.… (more)

Schwarzenbach, Jean Christophe

1942-01-01T23:59:59.000Z

466

Large Business Development Program (Illinois)  

Broader source: Energy.gov [DOE]

The Large Business Development Program, administered by the Illinois Department of Commerce and Economic Opportunity, provides grants to large businesses for bondable business activities, including...

467

Large Magnetization at Carbon Surfaces  

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

Large Magnetization at Carbon Surfaces Large Magnetization at Carbon Surfaces Print Wednesday, 31 August 2011 00:00 From organic matter to pencil lead, carbon is a versatile...

468

Large Spectral Library Problem  

SciTech Connect (OSTI)

Hyperspectral imaging produces a spectrum or vector at each image pixel. These spectra can be used to identify materials present in the image. In some cases, spectral libraries representing atmospheric chemicals or ground materials are available. The challenge is to determine if any of the library chemicals or materials exist in the hyperspectral image. The number of spectra in these libraries can be very large, far exceeding the number of spectral channels collected in the ¯eld. Suppose an image pixel contains a mixture of p spectra from the library. Is it possible to uniquely identify these p spectra? We address this question in this paper and refer to it as the Large Spectral Library (LSL) problem. We show how to determine if unique identi¯cation is possible for any given library. We also show that if p is small compared to the number of spectral channels, it is very likely that unique identi¯cation is possible. We show that unique identi¯cation becomes less likely as p increases.

Chilton, Lawrence K.; Walsh, Stephen J.

2008-10-03T23:59:59.000Z

469

A Historical Evaluation of the U12n Tunnel, Nevada national Security Site, Nye County, Nevada Part 2 of 2  

SciTech Connect (OSTI)

This report presents a historical evaluation of the U12n Tunnel on the Nevada National Security Site (NNSS) in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12n Tunnel was one of a series of tunnels used for underground nuclear weapons effects tests in Rainier and Aqueduct Mesas. A total of 22 nuclear tests were conducted in the U12n Tunnel from 1967 to 1992. These tests include Midi Mist, Hudson Seal, Diana Mist, Misty North, Husky Ace, Ming Blade, Hybla Fair, Mighty Epic, Diablo Hawk, Miners Iron, Huron Landing, Diamond Ace, Mini Jade, Tomme/Midnight Zephyr, Misty Rain, Mill Yard, Diamond Beech, Middle Note, Misty Echo, Mineral Quarry, Randsburg, and Hunters Trophy. DTRA sponsored all tests except Tomme and Randsburg which were sponsored by the Lawrence Livermore National Laboratory. Midnight Zephyr, sponsored by DTRA, was an add on experiment to the Tomme test. Eleven high explosive tests were also conducted in the tunnel and included a Stemming Plan Test, the Pre-Mill Yard test, the two seismic Non-Proliferation Experiment tests, and seven Dipole Hail tests. The U12n Tunnel complex is composed of the portal and mesa areas, encompassing a total area of approximately 600 acres (240 hectares). Major modifications to the landscape have resulted from four principal activities. These are road construction and maintenance, mining activities related to development of the tunnel complex, site preparation for activities related to testing, and construction of retention ponds. A total of 202 cultural features were recorded for the portal and mesa areas. At the portal area, features relate to the mining, construction, testing, and general everyday operational support activities within the tunnel. These include concrete foundations for buildings, ventilation equipment, air compressors, communications equipment, mining equipment, rail lines, retention ponds to impound tunnel effluent, and storage containers. Features on the mesa above the tunnel generally relate to tunnel ventilation and cooling, borehole drilling, and data recording facilities. Feature types include concrete foundations, instrument cable holes, drill holes, equipment pads, ventilation shafts, and ventilation equipment. The U12n Tunnel complex is eligible to the National Register of Historic Places under criteria a and c, consideration g of 36 CFR Part 60.4 as a historic landscape. Scientific research conducted at the tunnel has made significant contributions to the broad patterns of our history, particularly in regard to the Cold War era that was characterized by competing social, economic, and political ideologies between the former Soviet Union and the United States. The tunnel also possesses distinctive construction and engineering methods for conducting underground nuclear tests. The Desert Research Institute recommends that the U12n Tunnel area be left in place in its current condition and that the U12n Tunnel historic landscape be included in the NNSS monitoring program and monitored for disturbances or alterations on a regular basis.

Drollinger, Harold [DRI; Jones, Robert C [DRI; Bullard, Thomas F [DRI; Ashbaugh, Laurence J [DRI; Griffin, Wayne R

2011-06-01T23:59:59.000Z

470

Quantitative study of macroscopic quantum tunneling in a dc SQUID: A system with two degrees of freedom  

E-Print Network [OSTI]

To test whether the theory of macroscopic quantum tunneling (MQT) is applicable to systems with 2 degrees of freedom, we experimentally investigated the switching current distribution of a dc SQUID. Using sample parameters determined from...

Li, Shaoxiong; Yu, Yang; Zhang, Y.; Qiu, W.; Han, Siyuan; Wang, Z.

2002-08-01T23:59:59.000Z

471

A Historical Evaluation of the U12n Tunnel, Nevada National Security Site, Nye County, Nevada Part 1  

SciTech Connect (OSTI)

This report presents a historical evaluation of the U12n Tunnel on the Nevada National Security Site (NNSS) in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12n Tunnel was one of a series of tunnels used for underground nuclear weapons effects tests in Rainier and Aqueduct Mesas. A total of 22 nuclear tests were conducted in the U12n Tunnel from 1967 to 1992. These tests include Midi Mist, Hudson Seal, Diana Mist, Misty North, Husky Ace, Ming Blade, Hybla Fair, Mighty Epic, Diablo Hawk, Miners Iron, Huron Landing, Diamond Ace, Mini Jade, Tomme/Midnight Zephyr, Misty Rain, Mill Yard, Diamond Beech, Middle Note, Misty Echo, Mineral Quarry, Randsburg, and Hunters Trophy. DTRA sponsored all tests except Tomme and Randsburg which were sponsored by the Lawrence Livermore National Laboratory. Midnight Zephyr, sponsored by DTRA, was an add on experiment to the Tomme test. Eleven high explosive tests were also conducted in the tunnel and included a Stemming Plan Test, the Pre-Mill Yard test, the two seismic Non-Proliferation Experiment tests, and seven Dipole Hail tests. The U12n Tunnel complex is composed of the portal and mesa areas, encompassing a total area of approximately 600 acres (240 hectares). Major modifications to the landscape have resulted from four principal activities. These are road construction and maintenance, mining activities related to development of the tunnel complex, site preparation for activities related to testing, and construction of retention ponds. A total of 202 cultural features were recorded for the portal and mesa areas. At the portal area, features relate to the mining, construction, testing, and general everyday operational support activities within the tunnel. These include concrete foundations for buildings, ventilation equipment, air compressors, communications equipment, mining equipment, rail lines, retention ponds to impound tunnel effluent, and storage containers. Features on the mesa above the tunnel generally relate to tunnel ventilation and cooling, borehole drilling, and data recording facilities. Feature types include concrete foundations, instrument cable holes, drill holes, equipment pads, ventilation shafts, and ventilation equipment. The U12n Tunnel complex is eligible to the National Register of Historic Places under criteria a and c, consideration g of 36 CFR Part 60.4 as a historic landscape. Scientific research conducted at the tunnel has made significant contributions to the broad patterns of our history, particularly in regard to the Cold War era that was characterized by competing social, economic, and political ideologies between the former Soviet Union and the United States. The tunnel also possesses distinctive construction and engineering methods for conducting underground nuclear tests. The Desert Research Institute recommends that the U12n Tunnel area be left in place in its current condition and that the U12n Tunnel historic landscape be included in the NNSS monitoring program and monitored for disturbances or alterations on a regular basis.

Drollinger, Harold [DRI; Jones, Robert C [DRI; Bullard, Thomas F [DRI; Ashbaugh, Laurence J [DRI; Griffin, Wayne R [DRI

2011-06-01T23:59:59.000Z

472

Earth pressure balance (EPB) shield tunneling in Bangkok : ground response and prediction of surface settlements using artificial neural networks  

E-Print Network [OSTI]

Although Earth Pressure Balance (EPB) shields have been used for several decades, very little information exists about the actual mechanisms of shield-ground interaction. The ground response mechanism induced by EPB tunneling ...

Suwansawat, Suchatvee, 1972-

2002-01-01T23:59:59.000Z

473

Silicon field-effect transistor based on quantum tunneling J. FL Tucker, Chinlee Wang, and P. Scott Carney  

E-Print Network [OSTI]

configuration, the gate could be offset in order to permit a shallow implant of the finished device to convert a commercial package, SEMICAD,' together with our own cal- culation of tunneling and thermionic emission

Bhargava, Rohit

474

Prediction of net bedload transport rates obtained in oscillating water tunnels and applicability to real surf zone waves  

E-Print Network [OSTI]

Experimental studies of sediment transport rates due to near shore waves are often conducted in oscillating water tunnels (OWTs). In an OWT, the oscillatory motion produced by the piston propagates almost instantaneously ...

Gonzalez-Rodriguez, David

475

Effect of unitary impurities on non-STM types of tunneling in high-T-c superconductors  

E-Print Network [OSTI]

Based on an extended Hubbard model, we present calculations of both the local (i.e., single-site) and spatially averaged differential tunneling conductance in d-wave superconductors containing nonmagnetic impurities in the unitary limit. Out results...

Zhu, JX; Ting, CS; Hu, Chia-Ren.

2000-01-01T23:59:59.000Z

476

Large Superconducting Magnet Systems  

E-Print Network [OSTI]

The increase of energy in accelerators over the past decades has led to the design of superconducting magnets for both accelerators and the associated detectors. The use of Nb?Ti superconducting materials allows an increase in the dipole field by up to 10 T compared with the maximum field of 2 T in a conventional magnet. The field bending of the particles in the detectors and generated by the magnets can also be increased. New materials, such as Nb3Sn and high temperature superconductor (HTS) conductors, can open the way to higher fields, in the range 13–20 T. The latest generations of fusion machines producing hot plasma also use large superconducting magnet systems.

Védrine, P

2014-01-01T23:59:59.000Z

477

A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 6 of 6  

SciTech Connect (OSTI)

This report presents a historical evaluation of the U12t Tunnel on the Nevada Test Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12t Tunnel is one of a series of tunnels used for underground nuclear weapons effects tests on the east side of Rainier and Aqueduct Mesas. Six nuclear weapons effects tests, Mint Leaf, Diamond Sculls, Husky Pup, Midas Myth/Milagro, Mighty Oak, and Mission Ghost, and one high explosive test, SPLAT, were conducted within the U12t Tunnel from 1970 to 1987. All six of the nuclear weapons effects tests and the high explosive test were sponsored by DTRA. Two conventional weapons experiments, Dipole Knight and Divine Eagle, were conducted in the tunnel portal area in 1997 and 1998. These experiments were sponsored by the Defense Special Weapons Agency. The U12t Tunnel complex is composed of the Portal and Mesa Areas and includes an underground tunnel with a main access drift and nine primary drifts, a substantial tailings pile fronting the tunnel portal, a series of discharge ponds downslope of the tailings pile, and two instrumentation trailer parks and 16 drill holes on top of Aqueduct Mesa. A total of 89 cultural features were recorded: 54 at the portal and 35 on the mesa. In the Portal Area, cultural features are mostly concrete pads and building foundations; other features include the portal, rail lines, the camel back, ventilation and cooling system components, communication equipment, and electrical equipment. On the mesa are drill holes, a few concrete pads, a loading ramp, and electrical equipment.

Harold Drollinger; Robert C. Jones; and Thomas F. Bullard; Desert Research Institute, Laurence J. Ashbaugh, Southern Nevada Courier Service and Wayne R. Griffin, Stoller-Navarro Joint Venture

2009-02-01T23:59:59.000Z

478

Design of a high angle of attack robotic sting mount for tests in a low speed wind tunnel  

E-Print Network [OSTI]

AMPLIFIER SPECIFICATIONS . 92 97 G PROGRAM FLOWCHART: HIALST 100 H HARS INSTALLATION PROCEDURES 118 I ASSEMBLY DRAWINGS J ACKNOWLEDGEMENTS 137 142 VITA 143 LIST OF TABLES Table Page 1 Wear psd plastic materials considered 2 Maximum predicted... wings level in the tunnel to minimize effects on lateral-directional coefficients. 4. A 36 inch long model must be maintained near the center of the tunnel where the dynamic pressure variation does not exceed 0. 4%. 5. The mechanical system must...

Kubler, Tommy Jack

1989-01-01T23:59:59.000Z

479

A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 1 of 6  

SciTech Connect (OSTI)

This report presents a historical evaluation of the U12t Tunnel on the Nevada Test Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12t Tunnel is one of a series of tunnels used for underground nuclear weapons effects tests on the east side of Rainier and Aqueduct Mesas. Six nuclear weapons effects tests, Mint Leaf, Diamond Sculls, Husky Pup, Midas Myth/Milagro, Mighty Oak, and Mission Ghost, and one high explosive test, SPLAT, were conducted within the U12t Tunnel from 1970 to 1987. All six of the nuclear weapons effects tests and the high explosive test were sponsored by DTRA. Two conventional weapons experiments, Dipole Knight and Divine Eagle, were conducted in the tunnel portal area in 1997 and 1998. These experiments were sponsored by the Defense Special Weapons Agency. The U12t Tunnel complex is composed of the Portal and Mesa Areas and includes an underground tunnel with a main access drift and nine primary drifts, a substantial tailings pile fronting the tunnel portal, a series of discharge ponds downslope of the tailings pile, and two instrumentation trailer parks and 16 drill holes on top of Aqueduct Mesa. A total of 89 cultural features were recorded: 54 at the portal and 35 on the mesa. In the Portal Area, cultural features are mostly concrete pads and building foundations; other features include the portal, rail lines, the camel back, ventilation and cooling system components, communication equipment, and electrical equipment. On the mesa are drill holes, a few concrete pads, a loading ramp, and electrical equipment.

Harold Drollinger; Robert C. Jones; and Thomas F. Bullard; Desert Research Institute, Laurence J. Ashbaugh, Southern Nevada Courier Service and Wayne R. Griffin, Stoller-Navarro Joint Venture

2009-02-01T23:59:59.000Z

480

A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 2 of 6  

SciTech Connect (OSTI)

This report presents a historical evaluation of the U12t Tunnel on the Nevada Test Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12t Tunnel is one of a series of tunnels used for underground nuclear weapons effects tests on the east side of Rainier and Aqueduct Mesas. Six nuclear weapons effects tests, Mint Leaf, Diamond Sculls, Husky Pup, Midas Myth/Milagro, Mighty Oak, and Mission Ghost, and one high explosive test, SPLAT, were conducted within the U12t Tunnel from 1970 to 1987. All six of the nuclear weapons effects tests and the high explosive test were sponsored by DTRA. Two conventional weapons experiments, Dipole Knight and Divine Eagle, were conducted in the tunnel portal area in 1997 and 1998. These experiments were sponsored by the Defense Special Weapons Agency. The U12t Tunnel complex is composed of the Portal and Mesa Areas and includes an underground tunnel with a main access drift and nine primary drifts, a substantial tailings pile fronting the tunnel portal, a series of discharge ponds downslope of the tailings pile, and two instrumentation trailer parks and 16 drill holes on top of Aqueduct Mesa. A total of 89 cultural features were recorded: 54 at the portal and 35 on the mesa. In the Portal Area, cultural features are mostly concrete pads and building foundations; other features include the portal, rail lines, the camel back, ventilation and cooling system components, communication equipment, and electrical equipment. On the mesa are drill holes, a few concrete pads, a loading ramp, and electrical equipment.

Harold Drollinger; Robert C. Jones; and Thomas F. Bullard; Desert Research Institute, Laurence J. Ashbaugh, Southern Nevada Courier Service and Wayne R. Griffin, Stoller-Navarro Joint Venture

2009-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "large cavitation tunnel" 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.


481

A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 3 of 6  

SciTech Connect (OSTI)

This report presents a historical evaluation of the U12t Tunnel on the Nevada Test Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12t Tunnel is one of a series of tunnels used for underground nuclear weapons effects tests on the east side of Rainier and Aqueduct Mesas. Six nuclear weapons effects tests, Mint Leaf, Diamond Sculls, Husky Pup, Midas Myth/Milagro, Mighty Oak, and Mission Ghost, and one high explosive test, SPLAT, were conducted within the U12t Tunnel from 1970 to 1987. All six of the nuclear weapons effects tests and the high explosive test were sponsored by DTRA. Two conventional weapons experiments, Dipole Knight and Divine Eagle, were conducted in the tunnel portal area in 1997 and 1998. These experiments were sponsored by the Defense Special Weapons Agency. The U12t Tunnel complex is composed of the Portal and Mesa Areas and includes an underground tunnel with a main access drift and nine primary drifts, a substantial tailings pile fronting the tunnel portal, a series of discharge ponds downslope of the tailings pile, and two instrumentation trailer parks and 16 drill holes on top of Aqueduct Mesa. A total of 89 cultural features were recorded: 54 at the portal and 35 on the mesa. In the Portal Area, cultural features are mostly concrete pads and building foundations; other features include the portal, rail lines, the camel back, ventilation and cooling system components, communication equipment, and electrical equipment. On the mesa are drill holes, a few concrete pads, a loading ramp, and electrical equipment.

Harold Drollinger; Robert C. Jones; and Thomas F. Bullard; Desert Research Institute, Laurence J. Ashbaugh, Southern Nevada Courier Service and Wayne R. Griffin, Stoller-Navarro Joint Venture

2009-02-01T23:59:59.000Z

482

A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 4 of 6  

SciTech Connect (OSTI)

This report presents a historical evaluation of the U12t Tunnel on the Nevada Test Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12t Tunnel is one of a series of tunnels used for underground nuclear weapons effects tests on the east side of Rainier and Aqueduct Mesas. Six nuclear weapons effects tests, Mint Leaf, Diamond Sculls, Husky Pup, Midas Myth/Milagro, Mighty Oak, and Mission Ghost, and one high explosive test, SPLAT, were conducted within the U12t Tunnel from 1970 to 1987. All six of the nuclear weapons effects tests and the high explosive test were sponsored by DTRA. Two conventional weapons experiments, Dipole Knight and Divine Eagle, were conducted in the tunnel portal area in 1997 and 1998. These experiments were sponsored by the Defense Special Weapons Agency. The U12t Tunnel complex is composed of the Portal and Mesa Areas and includes an underground tunnel with a main access drift and nine primary drifts, a substantial tailings pile fronting the tunnel portal, a series of discharge ponds downslope of the tailings pile, and two instrumentation trailer parks and 16 drill holes on top of Aqueduct Mesa. A total of 89 cultural features were recorded: 54 at the portal and 35 on the mesa. In the Portal Area, cultural features are mostly concrete pads and building foundations; other features include the portal, rail lines, the camel back, ventilation and cooling system components, communication equipment, and electrical equipment. On the mesa are drill holes, a few concrete pads, a loading ramp, and electrical equipment.

Harold Drollinger; Robert C. Jones; and Thomas F. Bullard; Desert Research Institute, Laurence J. Ashbaugh, Southern Nevada Courier Service and Wayne R. Griffin, Stoller-Navarro Joint Venture

2009-02-01T23:59:59.000Z

483

A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 5 of 6  

SciTech Connect (OSTI)

This report presents a historical evaluation of the U12t Tunnel on the Nevada Test Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12t Tunnel is one of a series of tunnels used for underground nuclear weapons effects tests on the east side of Rainier and Aqueduct Mesas. Six nuclear weapons effects tests, Mint Leaf, Diamond Sculls, Husky Pup, Midas Myth/Milagro, Mighty Oak, and Mission Ghost, and one high explosive test, SPLAT, were conducted within the U12t Tunnel from 1970 to 1987. All six of the nuclear weapons effects tests and the high explosive test were sponsored by DTRA. Two conventional weapons experiments, Dipole Knight and Divine Eagle, were conducted in the tunnel portal area in 1997 and 1998. These experiments were sponsored by the Defense Special Weapons Agency. The U12t Tunnel complex is composed of the Portal and Mesa Areas and includes an underground tunnel with a main access drift and nine primary drifts, a substantial tailings pile fronting the tunnel portal, a series of discharge ponds downslope of the tailings pile, and two instrumentation trailer parks and 16 drill holes on top of Aqueduct Mesa. A total of 89 cultural features were recorded: 54 at the portal and 35 on the mesa. In the Portal Area, cultural features are mostly concrete pads and building foundations; other features include the portal, rail lines, the camel back, ventilation and cooling system components, communication equipment, and electrical equipment. On the mesa are drill holes, a few concrete pads, a loading ramp, and electrical equipment.

Harold Drollinger; Robert C. Jones; and Thomas F. Bullard; Desert Research Institute, Laurence J. Ashbaugh, Southern Nevada Courier Service and Wayne R. Griffin, Stoller-Navarro Joint Venture

2009-02-01T23:59:59.000Z

484

Mathematical Caricature of Large Waves  

E-Print Network [OSTI]

The Kadomtsev-Petviiashvili equation is considered as a mathematical caricature of large and rogue waves.

Mikhail Kovalyov

2014-03-21T23:59:59.000Z

485

Electrical characteristics and interface structure of magnetic tunnel junctions with hafnium oxyfluoride barrier  

SciTech Connect (OSTI)

We have studied the effects of fluorine inclusion on the electrical transport characteristics and interface structure of the hafnium oxide barrier in a magnetic tunnel junction. The tunneling magnetoresistance (TMR) and resistance-area (RA) as a function of oxidation time show that the TMR ratio of the hafnium oxyfluoride barrier is higher (8.3%) than that of the hafnium oxide barrier (5.7%) at their optimum conditions, and the oxyfluoride barrier junctions maintain a high TMR ratio even when the RA product increases by three orders of magnitude. X-ray photoelectron spectroscopy analysis shows that the fluorine atoms in the oxyfluoride barrier play an important role in the formation of a barrier with uniform composition. We believe that the initial fluoride layer is causing the subsequent oxygen diffusion to slow down, resulting in the formation of a defect-free hafnium oxide layer. These results are consistent with what we have found for aluminum oxyfluoride barriers.

Yu, Y.Y.; Kim, D.S.; Char, K. [Center for Strongly Correlated Materials Research and School of Physics, Seoul National University, Seoul 151-742 (Korea, Republic of)

2004-12-01T23:59:59.000Z

486

Bohm-Aharonov and Kondo effects on tunneling currents in a mesoscopic ring  

SciTech Connect (OSTI)

We present an analysis of the Kondo effect on the Bohm-Aharonov oscillations of the tunneling currents in a mesoscopic ring with a quantum dot inserted in one of its arms. The system is described by an Anderson-impurity tight-binding Hamiltonian where the electron-electron interaction is restricted to the dot. The currents are obtained using nonequilibrium Green functions calculated through a cumulant diagrammatic expansion in the chain approximation. It is shown that at low temperature, even with the system out of resonance, the Kondo peak provides a channel for the electron to tunnel through the dot, giving rise to the Bohm-Aharonov oscillations of the current. At high temperature these oscillations are important only if the dot level is aligned to the Fermi level, when the resonance condition is satisfied. {copyright} {ital 1997} {ital The American Physical Society}

Davidovich, M.A. [Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, Caixa Postal 38071, 22452-970 Rio de Janeiro, Rio de Janeiro, (Brasil)] [Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, Caixa Postal 38071, 22452-970 Rio de Janeiro, Rio de Janeiro, (Brasil); Anda, E.V. [Instituto de Fisica, Universidade Federal Fluminense, Niteroi, RJ Brasil, Avenida Litoranea s/n, Gragoata, 24210-340 Niteroi, Rio de Janeiro, (Brasil)] [Instituto de Fisica, Universidade Federal Fluminense, Niteroi, RJ Brasil, Avenida Litoranea s/n, Gragoata, 24210-340 Niteroi, Rio de Janeiro, (Brasil); Iglesias, J.R. [Instituto de Fisica, Univerisdade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-970, Porto Alegre, Rio Grande do Sul, (Brasil)] [Instituto de Fisica, Univerisdade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-970, Porto Alegre, Rio Grande do Sul, (Brasil); Chiappe, G. [Departamento de Fisica, Universidad de Buenos Aires, Caixa Postal 1428-Nunez, Buenos Aires (Argentina)] [Departamento de Fisica, Universidad de Buenos Aires, Caixa Postal 1428-Nunez, Buenos Aires (Argentina)

1997-03-01T23:59:59.000Z

487

Topological Quantum Computation by Manipulating Quantum Tunneling Effect of the Toric Codes  

E-Print Network [OSTI]

Quantum computers are predicted to utilize quantum states to perform memory and to process tasks far faster than those of conventional classical computers. In this paper we show a new road towards building fault tolerance quantum computer by tuning quantum tunneling effect of the degenerate quantum states in topological order, instead of by braiding anyons. Using a designer Hamiltonian - the Wen-Plaquette model as an example, we study its quantum tunneling effect of the toric codes and show how to control the toric code to realize topological quantum computation (TQC). In particular, we give a proposal to the measurement of TQC. In the end the realization of the Wen-Plaquette model in cold atoms is discussed.

Su-Peng Kou

2008-06-10T23:59:59.000Z

488

Synthesis, fabrication and characterization of Ge/Si axial nanowire heterostructure tunnel FETs  

SciTech Connect (OSTI)

Axial Ge/Si heterostructure nanowires allow energy band-edge engineering along the axis of the nanowire, which is the charge transport direction, and the realization of asymmetric devices for novel device architectures. This work reports on two advances in the area of heterostructure nanowires and tunnel FETs: (i) the realization of 100% compositionally modulated Si/Ge axial heterostructure nanowires with lengths suitable for device fabrication and (ii) the design and implementation of Schottky barrier tunnel FETs on these nanowires for high-on currents and suppressed ambipolar behavior. Initial prototype devices resulted in a current drive in excess of 100 {micro}A/{micro}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios. These results demonstrate the potential of such asymmetric heterostructures (both in the semiconductor channel and metal-semiconductor barrier heights) for low-power and high performance electronics.

Picraux, Samuel T [Los Alamos National Laboratory; Dayeh, Shadi A [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

489

Spectroscopy and capacitance measurements of tunneling resonances in an Sb-implanted point contact.  

SciTech Connect (OSTI)

We fabricated a split-gate defined point contact in a double gate enhancement mode Si-MOS device, and implanted Sb donor atoms using a self-aligned process. E-beam lithography in combination with a timed implant gives us excellent control over the placement of dopant atoms, and acts as a stepping stone to focused ion beam implantation of single donors. Our approach allows us considerable latitude in experimental design in-situ. We have identified two resonance conditions in the point contact conductance as a function of split gate voltage. Using tunneling spectroscopy, we probed their electronic structure as a function of temperature and magnetic field. We also determine the capacitive coupling between the resonant feature and several gates. Comparison between experimental values and extensive quasi-classical simulations constrain the location and energy of the resonant level. We discuss our results and how they may apply to resonant tunneling through a single donor.

Wendt, Joel Robert; Rahman, Rajib; Ten Eyck, Gregory A.; Eng, Kevin; Carroll, Malcolm S.; Young, Ralph Watson; Lilly, Michael Patrick; Stalford, Harold Lenn; Bishop, Nathaniel; Bielejec, Edward Salvador

2010-08-01T23:59:59.000Z

490

Macroscopic quantum tunneling in small Josephson junctions in a magnetic field.  

SciTech Connect (OSTI)

We study the phenomenon of macroscopic quantum tunneling (MQT) in small Josephson junctions (JJ) with an externally applied magnetic field. The latter results in the appearance of the Fraunhofer type modulation of the current density along the barrier. The problem of MQT for a pointlike JJ is reduced to the motion of the quantum particle in the washboard potential. In the case of a finite size JJ under consideration, this problem corresponds to a MQT in a potential which itself, besides the phase, depends on space variables. The general expression for the crossover temperature To between thermally activated and macroscopic quantum tunneling regimes and the escaping time {tau}{sub esc} have been calculated.

Ovchinnikov, Yu. N.; Barone, A.; Varlamov, A. A.; Materials Science Division; Max-Planck Inst. for Physics of Complex Systems; Landau Inst. Theoretical Physics; Univ. di Napoli Federico II; Coherentia-INFM, CNR

2007-01-01T23:59:59.000Z

491

Laser control of free-carrier density in solids through field-enhanced multiphonon tunneling recombination  

SciTech Connect (OSTI)

Enhancement of multiphonon tunneling recombination of free carriers in strong laser fields is shown to offer a mechanism whereby ultrafast carrier-density dynamics in a semiconductor can be controlled by properly shaped laser pulses. This regime of laser-solid interaction enables an ultrafast switching of optical and electric properties of semiconductor materials, suggesting new strategies for laser micromachining and nanomachining, optical data processing, and ultrafast plasmonics.

Zheltikov, A. M.; Voronin, A. A. [Department of Physics, International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation); Shneider, M. N.; Miles, R. B. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544-5263 (United States)

2011-02-01T23:59:59.000Z

492

Evaluation of PM10 and Total Suspended Particulate Sampler Performance Through Wind Tunnel Testing  

E-Print Network [OSTI]

.................................................... 86 APPENDIX F SHARP-EDGE ORIFICE METER CALIBRATION PROCEDURE ................................................................................ 89 APPENDIX G TEXAS A&M WIND TUNNEL OPERATION PROCEDURE ... 92 APPENDIX H MALVER MASTERSIZER 2000... Velocity Uniformity ?10% for 2, 8 and 24 km/h Measurement 1) Minimum of 12 test points 2) Monitoring techniques: precision? 2% ; accuracy ? 5% Aerosol Concentration Uniformity ?10% of the mean Measurement ? 5 evenly spaced isokinetic samplers...

Thelen, Mary Katherine

2011-10-21T23:59:59.000Z

493

Coherent generation of nonclassical light on a chip via photon-induced tunneling and blockade  

E-Print Network [OSTI]

We report the observation of nonclassical light generated via photon blockade in a photonic crystal cavity with a strongly coupled quantum dot. By tuning the frequency of the probe laser with respect to the cavity and quantum dot resonance we can probe the system in either photon blockade or photon-induced tunneling regime. The transition from one regime to the other is confirmed by the measurement of the second order correlation that changes from anti-bunching to bunching.

Andrei Faraon; Ilya Fushman; Dirk Englund; Nick Stoltz; Pierre Petroff; Jelena Vuckovic

2008-04-17T23:59:59.000Z

494

Nonlinear tunneling of optical soliton in 3 coupled NLS equation with symbolic computation  

SciTech Connect (OSTI)

We investigated the soliton solution for N coupled nonlinear Schrödinger (CNLS) equations. These equations are coupled due to the cross-phase-modulation (CPM). Lax pair of this system is obtained via the Ablowitz–Kaup–Newell–Segur (AKNS) scheme and the corresponding Darboux transformation is constructed to derive the soliton solution. One and two soliton solutions are generated. Using two soliton solutions of 3 CNLS equation, nonlinear tunneling of soliton for both with and without exponential background has been discussed. Finally cascade compression of optical soliton through multi-nonlinear barrier has been discussed. The obtained results may have promising applications in all-optical devices based on optical solitons, study of soliton propagation in birefringence fiber systems and optical soliton with distributed dispersion and nonlinearity management. -- Highlights: •We consider the nonlinear tunneling of soliton in birefringence fiber. •3-coupled NLS (CNLS) equation with variable coefficients is considered. •Two soliton solutions are obtained via Darboux transformation using constructed Lax pair. •Soliton tunneling through dispersion barrier and well are investigated. •Finally, cascade compression of soliton has been achieved.

Mani Rajan, M.S., E-mail: senthilmanirajanofc@gmail.com [Department of Physics, Anna University, Madurai Region, Ramanathapuram (India); Mahalingam, A. [Department of Physics, Anna University, Chennai - 600 025 (India); Uthayakumar, A. [Department of Physics, Presidency College, Chennai - 600 005 (India)

2014-07-15T23:59:59.000Z

495

Reactivation of the Shock-Tunnel Facility at Fort Cronkhite. Final report  

SciTech Connect (OSTI)

This final report describes the results of work undertaken to reactivate the Shock Tunnel Facility at Battery Townsley, Fort Cronkhite, Marin County, California. The facility has been reactivated and can not be utilized for blast testing. The major emphasis will be testing of concepts pertaining to programs of interest to the Federal Emergency Management Agency (FEMA) and in particular to civil defense oriented research. However, a wide variety of testing requirements can be accommodated. For example, past programs at the facility have included: tests of debris from trees subjected to blast for Bell Telephone Laboratories; tests of the response of aluminum hull panels to blast loading and of the response of a model surface effects ship for the Naval Ship Research and Development center, and tests of the response of a radome prototype to blast loading conducted for ANCOM (the radome manufacturer). The Shock Tunnel Facility is located in a former coastal defense 16-inch gun emplacement constructed by the US Army beginning in 1938. It was converted in 1967 to serve as a facility for full-scale testing of the loading and response of structural elements and civil defense equipment. It remained in operation until November 1976 when Battery Townsley was turned over to the National Park Service. Work under the present purchase order consisted of the following major tasks: (I) cleanup and secure the facility, (II) reactivate the shock tunnel, and (III) design permanent facility improvements. (WHK)

Not Available

1982-05-01T23:59:59.000Z

496

Large scale tracking algorithms.  

SciTech Connect (OSTI)

Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

Hansen, Ross L.; Love, Joshua Alan; Melgaard, David Kennett; Karelitz, David B.; Pitts, Todd Alan; Zollweg, Joshua David; Anderson, Dylan Z.; Nandy, Prabal; Whitlow, Gary L.; Bender, Daniel A.; Byrne, Raymond Harry

2015-01-01T23:59:59.000Z

497

Optimal basis set for ab-initio calculations of energy levels in tunneling structures, using the covariance matrix of the wave functions  

E-Print Network [OSTI]

The paper proposes a method to obtain the optimal basis set for solving the self consistent field (SCF) equations for large atomic systems in order to calculate the energy barriers in tunneling structures, with higher accuracy and speed. Taking into account the stochastic-like nature of the samples of all the involved wave functions for many body problems, a statistical optimization is made by considering the covariance matrix of these samples. An eigenvalues system is obtained and solved for the optimal basis set and by inspecting the rapidly decreasing eigenvalues one may seriously reduce the necessary number of vectors that insures an imposed precision. This leads to a potentially significant improvement in the speed of the SCF calculations and accuracy, as the statistical properties of a large number of wave functions in an large spatial domain may be considered. The eigenvalue problem has to be solved only few times, so that the amount of time added may be much smaller that the overall iterating SCF calculations. A simple implementation of the method is presented for a situation where the analytical solution is known, and the results are encouraging.

Sever Spanulescu

2009-12-15T23:59:59.000Z

498

Spent Fuel Transportation Package Response to the Baltimore Tunnel Fire Scenario  

SciTech Connect (OSTI)

On July 18, 2001, a freight train carrying hazardous (non-nuclear) materials derailed and caught fire while passing through the Howard Street railroad tunnel in downtown Baltimore, Maryland. The United States Nuclear Regulatory Commission (USNRC), one of the agencies responsible for ensuring the safe transportation of radioactive materials in the United States, undertook an investigation of the train derailment and fire to determine the possible regulatory implications of this particular event for the transportation of spent nuclear fuel by railroad. Shortly after the accident occurred, the USNRC met with the National Transportation Safety Board (NTSB, the U.S. agency responsible for determining the cause of transportation accidents), to discuss the details of the accident and the ensuing fire. Following these discussions, the USNRC assembled a team of experts from the National Institute of Standards and Technology (NIST), the Center for Nuclear Waste Regulatory Analyses (CNWRA), and Pacific Northwest National Laboratory (PNNL) to determine the thermal conditions that existed in the Howard Street tunnel fire and analyze the effects of this fire on various spent fuel transportation package designs. The Fire Dynamics Simulator (FDS) code, developed by NIST, was used to determine the thermal environment present in the Howard Street tunnel during the fire. The FDS results were used as boundary conditions in the COBRA-SFS and ANSYS® computer codes to evaluate the thermal performance of different package designs. The staff concluded that larger transportation packages resembling the HOLTEC Model No. HI STAR 100 and TransNuclear Model No. TN-68 would withstand a fire with thermal conditions similar to those that existed in the Baltimore tunnel fire event with only minor damage to peripheral components. This is due to their sizable thermal inertia and design specifications in compliance with currently imposed regulatory requirements. The staff also concluded that some components of smaller transportation packages resembling the NAC Model No. LWT, despite placement within an ISO container, could degrade. USNRC staff evaluated the radiological consequences of the package responses to the Baltimore tunnel fire. Though components in some packages heated up beyond their service temperatures, the staff determined that there would be no significant dose as a result of the fire for any of these and similar packages.

Adkins, Harold E.; Cuta, Judith M.; Koeppel, Brian J.; Guzman, Anthony D.; Bajwa, Christopher S.

2006-11-15T23:59:59.000Z

499

Conductance enhancement due to interface magnons in electron-beam evaporated MgO magnetic tunnel junctions with CoFeB free layer deposited at different pressure  

SciTech Connect (OSTI)

Electron-beam evaporated MgO-based magnetic tunnel junctions have been fabricated with the CoFeB free layer deposited at Ar pressure from 1 to 4?mTorr, and their tunneling process has been studied as a function of temperature and bias voltage. By changing the growth pressure, the junction dynamic conductance dI/dV, inelastic electron tunneling spectrum d{sup 2}I/dV{sup 2}, and tunneling magnetoresistance vary with temperature. Moreover, the low-energy magnon cutoff energy E{sub C} derived from the conductance versus temperature curve agrees with interface magnon energy obtained directly from the inelastic electron tunneling spectrum, which demonstrates that interface magnons are involved in the electron tunneling process, opening an additional conductance channel and thus enhancing the total conductance.

Guo, P.; Yu, G. Q.; Wei, H. X.; Han, X. F., E-mail: jiafengfeng@aphy.iphy.ac.cn, E-mail: xfhan@aphy.iphy.ac.cn [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Li, D. L.; Feng, J. F., E-mail: jiafengfeng@aphy.iphy.ac.cn, E-mail: xfhan@aphy.iphy.ac.cn [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); CRANN and School of Physics, Trinity College, Dublin 2 (Ireland); Kurt, H. [CRANN and School of Physics, Trinity College, Dublin 2 (Ireland); Department of Engineering Physics, Istanbul Medeniyet University, 34720 Istanbul (Turkey); Chen, J. Y.; Coey, J. M. D. [CRANN and School of Physics, Trinity College, Dublin 2 (Ireland)

2014-10-21T23:59:59.000Z

500

Proposal for the award of a contract for dismantling, removal and packaging of the existing Heating, Ventilation and Air-Conditioning (HVAC) systems in the PS tunnel  

E-Print Network [OSTI]

Proposal for the award of a contract for dismantling, removal and packaging of the existing Heating, Ventilation and Air-Conditioning (HVAC) systems in the PS tunnel

2012-01-01T23:59:59.000Z