Powered by Deep Web Technologies
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.


1

Carderock Large Cavitation Tunnel | Open Energy Information  

Open Energy Info (EERE)

Large Cavitation Tunnel Large Cavitation Tunnel Jump to: navigation, search Basic Specifications Facility Name Carderock Large Cavitation Tunnel Overseeing Organization United States Naval Surface Warfare Center Hydrodynamic Testing Facility Type Tunnel Length(m) 13.1 Beam(m) 3.0 Depth(m) 3.0 Water Type Freshwater Cost(per day) Contact POC Special Physical Features The Large Cavitation Channel was designed as a variable pressure, recirculating, cavitation tunnel with a very low acoustic background level; test section pressure: 3.5-414 kPa (0.03 to 4 atmospheres, 0.5 to 60 psia); air content: 10% to 100% saturation Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities None Channel/Tunnel/Flume Velocity(m/s) 18 Recirculating Yes Wind Capabilities

2

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

Open Energy Info (EERE)

2-ft Variable Pressure Cavitation Water Tunnel 2-ft Variable Pressure Cavitation Water Tunnel Jump to: navigation, search Basic Specifications Facility Name Carderock 2-ft Variable Pressure Cavitation Water Tunnel Overseeing Organization United States Naval Surface Warfare Center Hydrodynamic Testing Facility Type Tunnel Beam(m) 0.6 Depth(m) 0.6 Water Type Freshwater Cost(per day) Contact POC Special Physical Features The 2-Foot Variable Pressure Cavitation Water Tunnel is a vertical plane, closed recirculating, variable-speed, variable-pressure, open jet test section, closed jet test section, and semi-rectangular test section. Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities None Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Velocity(m/s) 17 Recirculating Yes

3

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

Open Energy Info (EERE)

Variable Pressure Cavitation Water Tunnel Variable Pressure Cavitation Water Tunnel Jump to: navigation, search Basic Specifications Facility Name Carderock 3-ft Variable Pressure Cavitation Water Tunnel Overseeing Organization United States Naval Surface Warfare Center Hydrodynamic Testing Facility Type Tunnel Beam(m) 0.7 Depth(m) 0.7 Water Type Freshwater Cost(per day) Contact POC Special Physical Features The 3-ft Variable Pressure Cavitation Water Tunnel is a vertical plane, closed recirculating with resorber, variable-speed, variable-pressure, two interchangeable circular test sections. Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities None Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Velocity(m/s) 25.8 Recirculating Yes Wind Capabilities Wind Capabilities None

4

Penn Large Water Tunnel | Open Energy Information  

Open Energy Info (EERE)

Penn Large Water Tunnel Penn Large Water Tunnel Jump to: navigation, search Basic Specifications Facility Name Penn Large Water Tunnel Overseeing Organization Pennsylvania State University Hydrodynamics Hydrodynamic Testing Facility Type Tunnel Length(m) 4.3 Beam(m) 1.2 Depth(m) 1.2 Water Type Freshwater Cost(per day) Contact POC Special Physical Features Closed loop; Turbulence level = 0.1%; Pressure range = 3-60psi; Controlled cavitation = # >0.1; Control Air content = >1ppm per mole Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities None Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Velocity(m/s) 16.8 Recirculating Yes Pressure Range(Psi) 3 - 60 Wind Capabilities Wind Capabilities None Control and Data Acquisition Description National Instruments steady 24 bit

5

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

E-Print Network [OSTI]

a high-speed video system. A fast photo detector is used to measure the scaling of the cavitation fluc- tuations by measuring the light scattered from cavitating bubbles in a small region of the flowUsing cavitation to measure statistics of low-pressure events in large-Reynolds-number turbulence A

La Porta, Arthur

6

Model of ventilation flows during large tunnel fires  

Science Journals Connector (OSTI)

In order to describe the reduction in the longitudinal airflow velocity due to the fire and hot gases resistances in a large tunnel fire, a theoretical model, taking into consideration the pressure losses over the fire source and obstructions, the thermal stack effects, and the hydraulic resistance induced by the tunnel walls, fire protection boards and a HGV trailer mock-up, is developed and validated using the large-scale tests data from the fire tests performed in the Runehamar tunnel with longitudinal ventilation in Norway 2003. Two large mobile fan units were used to create a longitudinal flow within the tunnel and prevent smoke backlayering upstream of the fire. One fan was located outside the entrance of the tunnel and the other inside the tunnel. The fire load consisted of a mock-up simulating a heavy goods vehicle (HGV) trailer creating a maximum heat release rates in the range of 66–202 MW. Two methods of calculating the mean temperature related to the thermal expansion and stack effect are proposed and compared.

Haukur Ingason; Anders Lönnermark; Ying Zhen Li

2012-01-01T23:59:59.000Z

7

Property:Channel/Tunnel/Flume | Open Energy Information  

Open Energy Info (EERE)

Channel/Tunnel/Flume Channel/Tunnel/Flume Jump to: navigation, search Property Name Channel/Tunnel/Flume Property Type String Pages using the property "Channel/Tunnel/Flume" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + Yes + 10-ft Wave Flume Facility + Yes + 11-ft Wave Flume Facility + None + 2 2-ft Flume Facility + Yes + 3 3-ft Wave Flume Facility + None + 5 5-ft Wave Flume Facility + Yes + 6 6-ft Wave Flume Facility + Yes + A Alden Large Flume + Yes + Alden Small Flume + Yes + Alden Tow Tank + None + Alden Wave Basin + None + B Breakwater Research Facility + None + Bucknell Hydraulic Flume + Yes + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + Yes + Carderock 3-ft Variable Pressure Cavitation Water Tunnel + Yes +

8

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)

Vacuum gaps with small tunnel currents at large electric field and its Vacuum gaps 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 Conference Room 137-226 Alfred Hubler, Department of Physics, University of Illinois, Urbana-Champaign We study tunnel currents and electric break down in vacuum gaps experimentally and theoretically. We find that electric field at break down in nano vacuum gaps is 3 order of magnitude larger than in macroscopic capacitors. Pointed electrodes increase the limiting field even further. Eigen states in the gap can help to reduce tunnel currents. We discuss applications of this technology for energy storage, charge storage, and power supplies. Speaker Bio: Professor Alfred Hubler is the director of the Center for

9

MHL High Speed Cavitation | Open Energy Information  

Open Energy Info (EERE)

High Speed Cavitation High Speed Cavitation Jump to: navigation, search Basic Specifications Facility Name MHL High Speed Cavitation Overseeing Organization University of Michigan Hydrodynamics Hydrodynamic Testing Facility Type Channel Length(m) 0.8 Beam(m) 0.2 Depth(m) 0.2 Cost(per day) $2000(+ Labor/Materials) Towing Capabilities Towing Capabilities Yes Maximum Velocity(m/s) 25.9 Wavemaking Capabilities Wavemaking Capabilities None Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Velocity(m/s) 25.9 Recirculating No Wind Capabilities Wind Capabilities None Control and Data Acquisition Description Custom Data Acquisition System using National Instruments hardware; system compatible with Planing Hull and Floating Beam Dynamometers Number of channels 16 Bandwidth(kHz) 20 Cameras Yes

10

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

11

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

12

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

13

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

14

Luminescence from hydrodynamic cavitation  

Science Journals Connector (OSTI)

...higher for monatomic gases than for more complicated...and polyatomic) gases, then the constituent...around 9000K for nitrogen and oxygen, and...ordinary diatomic gases. Only when the gas...hydrodynamic cavitation of water, containing dissolved...pressure. However, the solubility of xenon in water...

2011-01-01T23:59:59.000Z

15

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

16

Penn Small Water Tunnel | Open Energy Information  

Open Energy Info (EERE)

Water Tunnel Water Tunnel Jump to: navigation, search Basic Specifications Facility Name Penn Small Water Tunnel Overseeing Organization Pennsylvania State University Hydrodynamics Hydrodynamic Testing Facility Type Tunnel Length(m) 0.8 Beam(m) 0.3 Depth(m) 0.3 Water Type Freshwater Cost(per day) Contact POC Special Physical Features Closed loop; Turbulence level = 0.1%; Pressure range = 3-60psi; Controlled cavitation = # >0.1; Control Air content = >1ppm per mole Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities None Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Velocity(m/s) 21 Recirculating Yes Pressure Range(Psi) 3 - 60 Wind Capabilities Wind Capabilities None Control and Data Acquisition Description National Instruments dynamic analyzer, 24-bit

17

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

18

A method for desalination and water remediation by hydrodynamic cavitation  

Science Journals Connector (OSTI)

Water is becoming an increasingly valuable commodity with population growth demanding more and more amounts of this limited resource. Increased efforts are directed toward recycling and remediation as well as desalination of the large quantities of seawater available. Dr. Bertwin Langenecker was a pioneer in utilizing hydrodynamic cavitation in a variety of applications that would remove dissolved solids from water and other liquids. His combination of intense cavitation using a rotor-stator combination as well as simultaneously adding an adsorbent demonstrated impressive results in desalination and waste water remediation. In this presentation a description will be given of Dr. Langenecker’s technology as well as a sampling of some of his most impressive results. Speculations as to why this approach works as well as it does will be presented.

2013-01-01T23:59:59.000Z

19

A method for desalination and water remediation by hydrodynamic cavitation  

Science Journals Connector (OSTI)

Water is becoming an increasingly valuable commodity with population growth demanding more and more amounts of this limited resource. Increased efforts are directed toward recycling and remediation as well as desalination of the large quantities of seawater available. Dr. Bertwin Langenecker was a pioneer in utilizing hydrodynamic cavitation in a variety of applications that would remove dissolved solids from water and other liquids. His combination of intense cavitation using a rotor-stator combination as well as simultaneously adding an adsorbent demonstrated impressive results in desalination and waste water remediation. In this presentation a description will be given of Dr. Langenecker's technology as well as a sampling of some of his most impressive results. Speculations as to why this approach works as well as it does will be presented.

Lawrence A. Crum; Michael Skinner; Scott Zeilinger

2013-01-01T23:59:59.000Z

20

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

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

Wind tunnel simulation of exhaust recirculation in an air-cooling system at a large power plant  

Science Journals Connector (OSTI)

The recirculation of hot exhaust air and its dependence on wind direction was investigated as a cause of reduced efficiency in an air-cooled condenser (ACC). A method of simulating exhaust air recirculation at an ACC platform using a wind tunnel is presented, and applied to a proposed ACC addition at an existing power plant. It was found that wind speed and the height of an ACC platform have a significant impact on recirculation. Wind direction was also found to be significant, due to the interference of the buildings adjacent to the ACC platform. The mechanisms that cause recirculation are presented and analyzed, and the characteristics of the recirculating flow are described. It was found that when considering additions to existing power plants, the distance of the new ACC and power plant from the original buildings and structures has only a minor effect on the recirculation of the added ACC platform. Wind tunnel simulation is recommended in the initial design stage of new or renovated power plants with ACC systems to minimize exhaust recirculation.

Zhifu Gu; Xuerei Chen; William Lubitz; Yan Li; Wenlin Luo

2007-01-01T23:59:59.000Z

22

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.

Fomitchev-Zamilov, Max I

2012-01-01T23:59:59.000Z

23

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

24

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.

25

Analysis of bubble cavitation in ultrasound therapy by wavelet technique  

Science Journals Connector (OSTI)

Bubble cavitation is one of the major mechanisms for ultrasound treatment. To understand its characteristics, cavitation signals were picked up using passive cavitation detection and then analysed by wavelet transform. Although the Fast Fourier Transform (FFT) has been used widely in signal analysis, the absence of temporal information is one of its limitations. The inertial cavitation strength detected by wavelet method was ?60 folds higher than that using FFT. Furthermore, the relationship of waveform profile and acoustic pressure with the corresponding bubble cavitation were investigated. All together, wavelet approach could be new tool for studying bubble cavitation.

Yufeng Zhou

2008-01-01T23:59:59.000Z

26

Bubble Number in a Caviting Flow Henri Gouin  

E-Print Network [OSTI]

Bubble Number in a Caviting Flow Henri Gouin C.N.R.S. U.M.R. 6181 & Universit´e d of bubbles (a number of bubbles per unit of volume in the flow). The maximum intensity of cavitation; Bubble formation; Bubble dynamics; Cavitation. PACS: 47.55.Ca; 47.55.db; 47.55.dd; 47.55.dp 1

Paris-Sud XI, Université de

27

Spheroidal particles produced by cavitation erosion  

Science Journals Connector (OSTI)

... standard vibratory cavitation erosion apparatus and ASTM standard test procedures. Tests were conducted on annealed SAE 52100 steel (supplied by the Timken Company) in ... 52100 steel (supplied by the Timken Company) in SAE lOw non-detergent (Quaker State) lubricating oil and on aluminium 1100-F in distilled ...

STANELY W. DOROFF; RICHARD S. MILLER; ALAGU P. THIRUVENGADAM; VERNON C. WESTCOTT

1974-02-08T23:59:59.000Z

28

Wind-Tunnel Simulation of the Wake of a Large Wind Turbine in a Stable Boundary Layer. Part 1: The Boundary-Layer Simulation  

Science Journals Connector (OSTI)

Measurements have been made in both a neutral and a stable boundary layer as part of an investigation of the wakes of wind turbines in an offshore environment, in the EnFlo stratified flow wind tunnel. The wor...

Philip E. Hancock; Frauke Pascheke

2014-04-01T23:59:59.000Z

29

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...

30

Cavitation problem in heavy duty diesel engines: a literature review  

Science Journals Connector (OSTI)

This paper reviews the existing knowledge on cavitation in general and its effect on diesel engine cylinder liners. A brief definition of cavitation and various cavitation numbers are presented. Various effects involved in the formation, growth and collapse of bubbles are also characterized. The effects of pressure, temperature, and dissolved gas on bubble behaviour are mentioned. An attempt is made to study the various types of damage caused by cavitation on fluid flow machinery. The discussion highlights the amount of damage caused to diesel engine cylinder liners, and lists remedies suggested by numerous experts in the field.

Sunil Katragadda; Reda Bata

1994-01-01T23:59:59.000Z

31

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

32

Wind-Tunnel Simulation of the Wake of a Large Wind Turbine in a Stable Boundary Layer: Part 2, the Wake Flow  

Science Journals Connector (OSTI)

Measurements have been made in the wake of a model wind turbine in both a neutral and a stable atmospheric boundary layer, in the EnFlo stratified-flow wind tunnel, between 0.5 and 10 rotor diameters from the ...

Philip E. Hancock; Frauke Pascheke

2014-04-01T23:59:59.000Z

33

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.

34

Sequential resonant tunneling in quantum cascade lasers  

SciTech Connect (OSTI)

A model of sequential resonant tunneling transport among two-dimensional subbands that takes into account explicitly elastic scattering is investigated. It is compared to transport measurements performed on quantum cascade lasers, where resonant tunneling processes are known to be dominating. Excellent agreement is found between experiment and theory over a large range of current, temperature, and device structures.

Terazzi, Romain; Gresch, Tobias; Wittmann, Andreas; Faist, Jerome [Quantum Optoelectronics Group, Institute for Quantum Electronics, ETH, 8086 Zuerich (Switzerland)

2008-10-15T23:59:59.000Z

35

Coherence of resonant tunneling in heterostructures  

Science Journals Connector (OSTI)

A simple argument is put forward to substantiate the rule that either coherent resonant tunneling or sequential tunneling will occur according to whether the natural energy width for the former (in frequency units) is large compared to or small compared to the scattering frequency for an electron in the quantum-well two-dimensional subband based on the resonant quasilevel.

Peter J. Price

1987-07-15T23:59:59.000Z

36

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

37

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.

38

Crystalline Silicon under Acoustic Cavitation: From Mechanoluminescence to Amorphization  

Science Journals Connector (OSTI)

The physicochemical behavior of crystalline silicon under acoustic cavitation is investigated in water sparged with argon at low temperature (10 and 20 °C). Surprisingly, spectroscopic investigations reveal that argon (bubbling continuously through the ...

Matthieu Virot; Rachel Pflieger; Ekaterina V. Skorb; Johann Ravaux; Thomas Zemb; Helmuth Möhwald

2012-06-21T23:59:59.000Z

39

Acoustic cavitation: the fluid dynamics of non–spherical bubbles  

Science Journals Connector (OSTI)

...penetrating the bubble interior. 4. Bubble behaviour near an oscillating...clean jet penetrating a cavitation bubble in the direction of the oscillating...ent. First, the remarkable stability of the bubble motion--the presumably toroidal...

1999-01-01T23:59:59.000Z

40

On the importance of the effect of turbulence in cavitation inception tests of marine propellers  

Science Journals Connector (OSTI)

...in cavitation inception tests of marine propellers E. Korkut M. Atlar...Proc. Int. Conf. on Problems of Marine Propulsion, HYDRONAV'95, Gda nsk, Poland...cavitation inception and noise in marine propellers. PhD thesis, University...

2002-01-01T23:59:59.000Z

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.


41

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

42

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.

43

Dynamics of laser?induced cavitation bubbles  

Science Journals Connector (OSTI)

Bubbles in liquids can be formed in a variety of ways. A convenient method to produce a single bubble in a liquid is to focus a short pulse of laser light into the liquid. A bright light?emitting plasma of obviously high pressure expands forming a gas?vapor bubble. After some time bubble expansion stops at some maximum radius. From thereon the bubble starts to shrink driven by the ambient pressure and leading to a violent collapse possibly followed by rebounds. A mathematical model that describes the evolution of such a laser?induced cavitation bubble is presented. The model takes into account heat conduction of the liquid and gas phases evaporation and condensation processes of the liquid phase gas diffusion from the liquid into the bubble and compressibility of the liquid. A reasonable comparison of theoretical results with experimental data is obtained. [Work partially supported by Internationales Büro des BMBF (Contract RUS?133?1997) and European Commission (INCO?Copernicus Contract ERBIC15CT980141).

Iskander Akhatov; Nailya Vakhitova; Kamil Zakirov; Robert Mettin; Olgert Lindau; Werner Lauterborn

1999-01-01T23:59:59.000Z

44

Active cavitation detection of microbubble echocontrast agents in blood  

Science Journals Connector (OSTI)

Apfel’s active cavitation detector [Roy et al. J. Acoust. Soc. Am. 87 2451–2458 (1990)] has been improved to allow quantification of microbubble activity in reconstituted human blood. One?microsecond?long 20?MHz tone bursts are scattered from microbubbles undergoing transient cavitation at the focus of a pulsed 1?MHz transducer. The host medium consists either of human red blood cells suspended in autologous plasma or platelet?rich plasma with various concentrations of microbubble?based echocontrast agent present. The microbubble activity inferred from the backscattered tone bursts is compared to measured bioeffects (hemolysis platelet aggregation) in order to determine the physical basis for cavitational damage of blood components. Current results as a function of system parameters will be presented. [Work supported by NSF MSS?9253777.

Vilma E. Huertas; Inder Raj S. Makin; E. Carr Everbach

1994-01-01T23:59:59.000Z

45

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

46

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

47

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

48

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

49

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 must occur at temperatures below 140 MeV, consistent with the expectation of hadronisation in low temperature QCD.

Habich, Mathis

2014-01-01T23:59:59.000Z

50

Pseudoplastic deformation pits on polished ceramics due to cavitation erosion  

Science Journals Connector (OSTI)

In a previous study, pseudoplastic deformation pits created by cavitation exposure were reported in silicon nitride and zirconia. In this research, further comparison of the size and number of pits between several silicon nitride and zirconia materials is carried out. The pits are larger and much more numerous in silicon nitride than in zirconia although silicon nitride is harder than zirconia. An explanation of this phenomenon is given. Also, in the previous study it was reported that apparently a partially stabilized zirconia with yttria oxide developed a delay in the phase transformation from tetragonal to monoclinic after being exposed to cavitation. In this research, further experiments related with this phase transformation delay are carried out. Also, the phase transformation is verified with X-ray diffraction analysis. It is concluded that the “activation” of the partial stabilized zirconia happens regardless of the oxide used to stabilize it.

G. García-Atance Fatjó; M. Hadfield; K. Tabeshfar

2011-01-01T23:59:59.000Z

51

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

52

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

53

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

54

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

55

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

56

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

57

Tunnels for roads and motorways  

Science Journals Connector (OSTI)

...compromise. Such a solution also offers no protection to pedestrians and tunnel service personnel; this is a consideration...unit length of the tunnel but also its extent from portal to portal. Whereas motorways and trunk roads usually tolerate...

Alan Marshall Muir Wood

58

Roadway tunnel air quality models  

Science Journals Connector (OSTI)

Roadway tunnel air quality models ... Analysis of 13 tunnel studies quantifies the decline since 1961 in benzo[a]pyrene emitted into the air per km of travel by U.S. road vehicles. ...

Tai Y. Chang; Sara J. Rudy

1990-05-01T23:59:59.000Z

59

Bubble path in the wake of a cavitating propeller  

Science Journals Connector (OSTI)

Propellers that operate underwater at high rpm's cavitate at the tip. The tip cavitation creates air bubbles that are then swept downstream by the motion of the surrounding fluid. In this paper a theory is presented to predict the local velocity and the path of the bubble. The bubble motion is assumed to be governed by a group of terms due to the acceleration of the displaced fluid the convective term and the drag due to the cross?sectional area of the bubble. At very low and very high Reynolds numbers the equations have been solved in closed form. Results are presented for the bubble velocity and path for the following flow fields: (a) uniform axial flow field and (b) uniform flow field with an axially decaying swirling component. In all cases presented the bubble axial velocity component asymptotes to the free stream velocity; the manner in which it asymptotes is exponential at very low Reynolds numbers and algebraic at high Reynolds numbers. Bubble helical paths and velocity patterns are shown for different bubble sizes.

Mauro Picrucci

1988-01-01T23:59:59.000Z

60

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

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

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

62

Wear resistance of titanium-alloyed high-aluminum bronzes under cavitation  

Science Journals Connector (OSTI)

Aluminum-nickel bronzes are known to have a high cavitation-erosion resistance; this is especially true of bronzes containing 11–14% Al, which can be used to restore worn parts of hydraulic engines, marine engine...

Yu. N. Tsvetkov; L. I. Pogodaev

1994-02-01T23:59:59.000Z

63

Parallel computing of the underwater explosion cavitation effects on full-scale ship structures  

Science Journals Connector (OSTI)

As well as shock wave and bubble pulse loading, cavitation also has very significant influences on the dynamic response of surface ships and other near-surface marine structures to ... single computation and para...

Zhi Zong; Yanjie Zhao; Fan Ye; Haitao Li…

2012-12-01T23:59:59.000Z

64

Numerical and Experimental Investigation into Propulsion and Cavitation Performance of Marine Propeller  

Science Journals Connector (OSTI)

This paper discusses the application of the CFD to transitional and cavitating flow around marine propellers. Especially the emphasis is put on the adaption of the 3 equations turbulence model for the non-cavi...

Nobuhiro Hasuike; Shosaburo Yamasaki…

2013-01-01T23:59:59.000Z

65

The effects of nonlinear wave propagation on the stability of inertial cavitation  

E-Print Network [OSTI]

In the context of forecasting temperature and pressure fields in high-intensity focussed ultrasound, the accuracy of predictive models is critical for the safety and efficacy of treatment. In such fields inertial cavitation is often observed. Classically, estimations of cavitation thresholds have been based on the assumption that the incident wave at the surface of a bubble was the same as in the far-field, neglecting the effect of nonlinear wave propagation. By modelling the incident wave as a solution to Burgers' equation using weak shock theory, the effects of nonlinear wave propagation on inertial cavitation are investigated using both numerical and analytical techniques. From radius-time curves for a single bubble, it is observed that there is a reduction in the maximum size of a bubble undergoing inertial cavitation and that the inertial collapse occurs earlier in contrast with the classical case. Corresponding stability thresholds for a bubble whose initial radius is slightly below the critical Blake r...

Sinden, David; Saffari, Nader

2009-01-01T23:59:59.000Z

66

Program gives design data for multiple-orifice system to avoid cavitation  

SciTech Connect (OSTI)

Determining the sizes of and axial distances between orifices in a multiple-orifice system is addressed in this HP-41CV program. Accurate measurements of these parameters are critical to avoid cavitation.

Coksem, P.G.; Patel, I.D.

1985-04-15T23:59:59.000Z

67

Evidence for nuclear emissions during neutron seeded acoustic bubble cavitation  

Science Journals Connector (OSTI)

In cavitation experiments with deuterated acetone statistically significant tritium decay activity above background levels was detected. In addition evidence for statistically significant neutron emissions near 2.5 MeV was also observed as would be expected for deuterium–deuterium fusion. Control experiments with normal acetone did not result in tritium activity or neutron emissions. Hydrodynamic shock code simulations supported the observed data and indicated compressed hot (106–107 K) bubble implosion conditions as required for thermonuclear fusion reactions. Separate experiments with additional fluids are under way and results appear to support those observed with acetone. Scalability potential to higher yields as well as evidence for neutron?tritium branching ratios are presented.

2002-01-01T23:59:59.000Z

68

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

69

Ethanol injection induced cavitation and heating in tissue exposed to high intensity focused ultrasound  

Science Journals Connector (OSTI)

High Intensity Focused Ultrasound (HIFU) can ablatetumors located deep in the body through highly localized energy deposition and tissue heating at the target location. The volume of a HIFU-induced thermal lesion can be increased in the presence of cavitation. This study explores the effect of ethanol injection on cavitation and heating in tissue-mimicking phantoms and bovine liver tissues exposed to HIFU. The HIFU transducer (0.825 MHz) operated at seven acoustic power levels ranging from 1.3 W to 26.8 W. The cavitation events were quantified by B-mode ultrasound imaging needle hydrophone measurements and passive cavitation detection (PCD). Temperature in or near the focal zone was measured by thermocouples embedded in the samples. The onset of inertial cavitation in ethanol-treated phantoms and bovine liver tissues occurred at a lower power level than in the untreated samples (control). The cavitation occurrence in turn resulted in a sudden rise of temperature in ethanol-treated samples at a lower acoustic power than that in control. The results of this work indicate that the use of percutaneous ethanol injection prior to HIFU exposure may improve the HIFU therapeutic efficiency.

Chong Chen; Yunbo Liu; Subha Maruvada; Matthew Myers; Damir Khismatullin

2012-01-01T23:59:59.000Z

70

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

71

EVALUATION OF CAVITATION-CORROSION RESISTANCE AND RECIPROCATING WEAR RESISTANCE OF SURFACE COATED AND CRYOGENICALLY TREATED SILICON BRASS.  

E-Print Network [OSTI]

??Cavitation and corrosion resistance are important characteristics to consider in marine environments with flowing liquid. Impellers and propellers are used in many applications and are… (more)

Simmons, Nathan

2008-01-01T23:59:59.000Z

72

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

73

Wind Tunnel Studies of Martian Aeolian Processes  

Science Journals Connector (OSTI)

10 December 1974 research-article Wind Tunnel Studies of Martian Aeolian Processes...investigation is in progress which involves wind tunnel simulations, geologic field studies...aerodynamic lift and surface roughness. Wind tunnel simulations were conducted to determine...

1974-01-01T23:59:59.000Z

74

On Klein tunneling in graphene  

Science Journals Connector (OSTI)

The essential features of Klein tunneling of massless fermions in graphene may be treated in one dimension without the need for Dirac spinors. Two dimensions needs a spinor treatment and is investigated numerically which lets us compare tunneling through smooth potential barriers with that through idealized step potentials.

T. R. Robinson

2012-01-01T23:59:59.000Z

75

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

76

Stability of bubbly liquids and its connection to the process of cavitation inception D. Fuster, K. Pham, and S. Zaleski  

E-Print Network [OSTI]

Stability of bubbly liquids and its connection to the process of cavitation inception D. Fuster, K.1063/1.1416497 Noise induced stabilization of chaotic oscillations of cavitation bubbles AIP Conf. Proc. 524, 519 (2000, 14 Apr 2014 16:11:36 #12;PHYSICS OF FLUIDS 26, 042002 (2014) Stability of bubbly liquids and its

Fuster, Daniel

77

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

Open Energy Info (EERE)

Velocity(m/s) Velocity(m/s) Jump to: navigation, search Property Name Velocity(m/s) Property Type String Pages using the property "Velocity(m/s)" Showing 21 pages using this property. A Alden Small Flume + >0.9 + B Bucknell Hydraulic Flume + 2.7 + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + 17 + Carderock 3-ft Variable Pressure Cavitation Water Tunnel + 25.8 + Carderock Circulating Water Channel + 5.2 + Carderock Large Cavitation Tunnel + 18 + Carderock Subsonic Wind Tunnel + 83.8 + D DeFrees Flume 1 + 2 + DeFrees Flume 2 + 2 + DeFrees Flume 3 + 2 + DeFrees Flume 4 + 2 + M MHL Free Surface Channel + 2 + MHL High Speed Cavitation + 25.9 + MHL Student Tunnel + 4.6 + P Penn Large Water Tunnel + 16.8 + Penn Small Water Tunnel + 21 + S SAFL Channel + 6.1 +

78

Vibratory cavitation erosion behavior of AISI 304 stainless steel in water at elevated temperatures  

Science Journals Connector (OSTI)

Abstract The cavitation erosion behavior of AISI 304 stainless steel was investigated using an ultrasonic vibratory apparatus at elevated temperatures and the morphologies of the eroded surface and the cross section were observed by scanning electron microscopy (SEM) and optical microscopy. The results show that the cumulative mass loss increases, shows a peak and then decreases with increase in liquid temperature. The cavitation damage of the eroded surface was relatively uniform at 20–60 °C and at 80 °C it was localized; the depth of local deeper pit at 80 °C was about 1.7 times deeper than at 50 °C. The initial results based on the cumulative mass loss could not predict the degree of cavitation damage, and the depth of local erosion pit may be an effective method for judging erosion damage.

Zhen Li; Jiesheng Han; Jinjun Lu; Jiansong Zhou; Jianmin Chen

2014-01-01T23:59:59.000Z

79

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

2014-02-27T23:59:59.000Z

80

Quantum Tunneling Affects Engine Performance  

Science Journals Connector (OSTI)

It is demonstrated that the effect of quantum tunneling corrections for the reaction HO2 + HO2 = H2O2 + O2 can have a noticeable impact on the performance of a high-fidelity model of a compression-ignition (e.g., diesel) engine, and that an accurate prediction of ignition delay time for the engine model requires an accurate estimation of the tunneling correction for this reaction. ... In this Letter we have demonstrated that a detailed understanding of the chemical dynamics of elementary reactions, including quantum tunneling, is necessary for an accurate description of the performance of compression-ignition engine models, and that something as fundamental as quantum tunneling corrections could make a noticeable difference on such a complex model. ... combustion and emissions in diesel engines. ...

Sibendu Som; Wei Liu; Dingyu D. Y. Zhou; Gina M. Magnotti; Raghu Sivaramakrishnan; Douglas E. Longman; Rex T. Skodje; Michael J. Davis

2013-05-29T23:59:59.000Z

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.


81

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

82

Relativistic tunneling through opaque barriers  

Science Journals Connector (OSTI)

We propose an analytical study of relativistic tunneling through opaque barriers. We obtain a closed formula for the phase time. This formula is in excellent agreement with the numerical simulations and corrects the standard formula obtained by the stationary phase method. An important result is found when the upper limit of the incoming energy distribution coincides with the upper limit of the tunneling zone. In this case, the phase time is proportional to the barrier width.

Stefano De Leo and Vinícius Leonardi

2011-02-28T23:59:59.000Z

83

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

84

MASON LAB B-7 WIND TUNNEL OPERATING INSTRUCTIONS Our wind tunnel is a low speed tunnel with a test section 15"x24" It has a digital controller  

E-Print Network [OSTI]

MASON LAB B-7 WIND TUNNEL OPERATING INSTRUCTIONS Our wind tunnel is a low speed tunnel with a test approximate wind tunnel speed in m/s (meters/second) and tunnel speed will go to that set point speed measure lift (~25 N) and drag (~8 N) PRECAUTIONS: ALL OBJECTS MUST BE SECURED BEFORE STARTING WIND TUNNEL

Haller, Gary L.

85

Effect of ethanol injection on cavitation and heating of tissues exposed to high-intensity focused ultrasound  

Science Journals Connector (OSTI)

Cavitation activity and temperature rise have been investigated in a tissue-mimicking material and excised bovine liver treated with ethanol and insonated with a 0.825 MHz focused acoustic transducer. The acoustic power was varied from 1.3 to 26.8 W to find the threshold leading to the onset of inertial cavitation. Cavitation events were quantified by three independent techniques: B-mode ultrasound imaging, needle hydrophone measurements and passive cavitation detection. Temperature in or near the focal zone was measured by thermocouples embedded in the samples. The results of this study indicate that the treatment of tissue phantoms and bovine liver samples with ethanol reduces their threshold power for inertial cavitation. This in turn leads to a sudden rise in temperature in ethanol-treated samples at a lower acoustic power than that in untreated ones. The analysis of passive cavitation detection data shows that once the threshold acoustic power is reached, inertial cavitation becomes a major contributor to acoustic scattering in ethanol-treated phantoms and bovine liver samples as compared to control. This study opens up the possibility of improved tumor ablation therapy via a combination of percutaneous ethanol injection and high-intensity focused ultrasound.

C Chen; Y Liu; S Maruvada; M Myers; D Khismatullin

2012-01-01T23:59:59.000Z

86

Investigations of Slow Motions of the SLAC Linac Tunnel  

SciTech Connect (OSTI)

Investigations of slow transverse motion of the linac tunnel of the Stanford Linear Collider have been performed over period of about one month in December 1999--January 2000. The linac laser alignment system, equipped with a quadrant photodetector, allowed submicron resolution measurement of the motion of the middle of the linac tunnel with respect to its ends. Measurements revealed two major sources responsible for the observed relative motion. Variation of the external atmospheric pressure was found to be the most significant cause of short wavelength transverse motion of the tunnel. The long wavelength component of the motion has been also observed to have a large contribution from tidal effects. The measured data are essential for determination of parameters for the Next Linear Collider.

Seryi, Andrei

2000-08-31T23:59:59.000Z

87

Ultrasonic emissions reveal individual cavitation bubbles in water-stressed wood  

Science Journals Connector (OSTI)

...the tree (radial plane), allowing most pits connecting conduits to be observed from...ert193 ) 13 Holbrook, NM , ET Ahrens, MJ Burns, and MA Zwieniecki. 2001 In vivo observation...Plasmodesmatal pores in the torus of bordered pit membranes affect cavitation resistance...

2014-01-01T23:59:59.000Z

88

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

E-Print Network [OSTI]

-vapor surface tension, if one phase is brought in the stability region of the other, it can be observed, to put the liquid under me- chanical tension. This allows us to study the nucleation of a bubble investigate the limiting mechanical tension negative pressure that liquid water can sustain before cavitation

Caupin, Frédéric

89

Tunneling spectroscopy study of YBa2Cu3O7 thin films using a cryogenic scanning tunneling microscope  

Science Journals Connector (OSTI)

We have measured reproducible tunneling spectra on YBa2Cu3O7 (Tc?85 K) thin films (thickness ?2 ?m) with a cryogenic scanning tunneling microscope. We find that the I-V curves are generally of three types. The most common type, featured in a large majority of the data, shows a region of high conductance at zero bias. The amplitude of this region is inversely proportional to the tunneling resistance between the tip and sample. It is possible that this can be explained in terms of Josephson effects within the films, although an alternative is given based on electronic self-energy corrections. Data showing capacitive charging steps are analyzed in terms of two ultrasmall tunnel junctions in series.. Theoretical fits to the data give specific values of the junction parameters that are consistent with the assumed geometry of the tip probing an individual grain of the film. The third type of I-V curves exhibits negative differential resistance. We conclude that this phenomenon is probably due to tunneling to localized states in the surface oxide. We also present and discuss data with energy-gap-like behavior; the best example gives ? to be about 27 mV.

R. Wilkins, M. Amman, R. E. Soltis, E. Ben-Jacob, and R. C. Jaklevic

1990-05-01T23:59:59.000Z

90

Ivar Giaever, Tunneling, and Superconductors  

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

Ivar Giaever, Tunneling, and Superconductors Ivar Giaever, Tunneling, and Superconductors Resources with Additional Information · Patents Ivar Giaever Courtesy of Rensselaer Polytechnic Institute 'Dr. Giaever received his engineering degree at the Norwegian Institute of Technology. After college, he emigrated to Canada, where he worked as a mechanical engineer with General Electric, and later transferred to GE's Development Center in Schenectady, N.Y. There, he shifted his interest to physics, and did graduate work at Rensselaer, receiving a Ph.D. in 1964. From 1958 to 1970, Dr. Giaever worked in the fields of thin films, tunneling, and superconductivity,'1 research that resulted in his receiving the Nobel Prize in Physics in 1973. '[I]n 1971, Dr. Giaever began studying the behavior of organic molecules at solid surfaces, and the interaction of cells with surfaces. In 1988, he became an Institute Professor of Science at Rensselaer.' 1

91

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

92

H and D Tunneling in Niobium  

Science Journals Connector (OSTI)

We performed low-temperature specific-heat measurements investigating tunneling of H and D trapped by O impurities in Nb. The results yield the first experimental values of tunneling matrix elements for both H and D in a metal.

H. Wipf and K. Neumaier

1984-04-09T23:59:59.000Z

93

Resonance tunneling spectroscopy of heteropoly compounds  

SciTech Connect (OSTI)

The electron tunneling spectra of phosphomolybdic and phosphomolybdovanadic acids have been measured using a scanning tunneling microscope. A new mechanism of negative differential resistance (NDR) formation in tunneling nanocontacts is established, which is general for all systems featuring the Wannier-Stark localization effect. A two-center inelastic resonance tunneling model is constructed, which allows the values of both electron and vibrational energy parameters to be determined from the measured spectra.

Dalidchik, F. I., E-mail: domfdal@mail.ru; Budanov, B. A.; Kolchenko, N. N.; Balashov, E. M.; Kovalevskii, S. A. [Russian Academy of Sciences, Semenov Institute of Chemical Physics (Russian Federation)

2012-12-15T23:59:59.000Z

94

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

95

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

96

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

97

SIMULATION AND MOCKUP OF SNS JET-FLOW TARGET WITH WALL JET FOR CAVITATION DAMAGE MITIGATION  

SciTech Connect (OSTI)

Pressure waves created in liquid mercury pulsed spallation targets at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory induce cavitation damage on the stainless steel target container. The cavitation damage is thought to limit the lifetime of the target for power levels at and above 1 MW. Severe through-wall cavitation damage on an internal wall near the beam entrance window has been observed in spent-targets. Surprisingly though, there is very little damage on the walls that bound an annular mercury channel that wraps around the front and outside of the target. The mercury flow through this channel is characterized by smooth, attached streamlines. One theory to explain this lack of damage is that the uni-directional flow biases the direction of the collapsing cavitation bubble, reducing the impact pressure and subsequent damage. The theory has been reinforced by in-beam separate effects data. For this reason, a second-generation SNS mercury target has been designed with an internal wall jet configuration intended to protect the concave wall where damage has been observed. The wall jet mimics the annular flow channel streamlines, but since the jet is bounded on only one side, the momentum is gradually diffused by the bulk flow interactions as it progresses around the cicular path of the target nose. Numerical simulations of the flow through this jet-flow target have been completed, and a water loop has been assembled with a transparent test target in order to visualize and measure the flow field. This paper presents the wall jet simulation results, as well as early experimental data from the test loop.

Wendel, Mark W [ORNL; Geoghegan, Patrick J [ORNL; Felde, David K [ORNL

2014-01-01T23:59:59.000Z

98

Surface modification by gas nitriding for improving cavitation erosion resistance of CP-Ti  

Science Journals Connector (OSTI)

Abstract Gas nitriding process has been used to increase the surface hardness of titanium, in this study we used this technique to improve the cavitation erosion resistance (Rce) of commercial purity titanium (CP-Ti). We also studied microstructure, phase constituents, hardness and the effect of processing parameters on Rce of the treated samples. The results indicated that the Rce of the treated samples was related to the processing parameters. The sample treated at 850 °C for 4 h has the highest Rce, which was attributed to the compound layer (CL) with a hard, dense and free-defects microstructure. With increasing the nitriding temperature and duration, the Rce of the treated samples decreased due to the excessive oxide and defects formed in the CL. When the CL was removed, the treated sample exhibited an excellent cavitation erosion behavior. It was supposed to be due to the existence of the residual compressive stresses field in the nitrogen diffusion zone, which played an important role in preventing microcracks initiation and propagation to interior for cavitation damage.

Haibin Li; Zhenduo Cui; Zhaoyang Li; Shengli Zhu; Xianjin Yang

2014-01-01T23:59:59.000Z

99

Space Institute Tunnel | Open Energy Information  

Open Energy Info (EERE)

Tunnel Tunnel Jump to: navigation, search Basic Specifications Facility Name Space Institute Tunnel Overseeing Organization University of Tennessee Hydrodynamic Testing Facility Type Tunnel Length(m) 1.5 Beam(m) 0.4 Depth(m) 0.5 Cost(per day) ~$1000 (Contact POC for estimate) Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities None Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Velocity(m/s) 0.9 Recirculating Yes Wind Capabilities Wind Capabilities None Control and Data Acquisition Description Computer with National Instruments SCXI DAS Chassis Number of channels 32 Bandwidth(kHz) Varies with number of channels and specific module/board Cameras Yes Available Sensors Flow, Strain, Turbulence Data Generation Capability

100

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

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

An Investigation on the Nature of Micro Cavitation Bubbles on the Movement of Undersea Vessels and Waves  

E-Print Network [OSTI]

To further understand their nature, micro cavitation bubbles were systematically diffused around the exterior of a test body (tube) fully submerged in a water tank. The primary purpose was to assess the feasibility of applying micro cavitation as a means of depth control for underwater vehicles, mainly but not limited to submarines. Ideally, the results would indicate the use of micro cavitation as a more efficient alternative to underwater vehicle depth control than the conventional ballast tank method. The current approach utilizes the Archimedes' principle of buoyancy to alter the density of the object affected, making it less than, or greater than the density of the surrounding fluid. However, this process is too slow for underwater vehicles to react to sudden obstacles inherent in their environment. Rather than altering its internal density, this research aimed to investigate the response that would occur if the density of its environment was manipulated instead. In theory, and in a hydrostatic fluid, di...

Anderson, Asalie; Hoffman, Derek; Mancas, Stefan C

2014-01-01T23:59:59.000Z

102

Temporal Trends in the Histology of the Rabbit Kidney after Cavitational Tissue Ablation  

Science Journals Connector (OSTI)

Tissue can be mechanically ablated through inertial cavitation generated by high intensity pulsed ultrasound. The ablation appears acutely as a fine slurry with absent cellular structure. Long?term effects and the evolution of histologic changes in disrupted tissue remain poorly understood. This study aimed to characterize the 0–60 day histology of cavitational ablation in a rabbit model. 29 New Zealand White rabbits were anesthetized and exposed to high intensity pulses of ultrasound (60000 pulses 20 usec duration 750 kHz 1 kHz PRF 18 MPa peak rarefactional pressure lower pole left kidney). Kidneys were harvested immediately from five rabbits. The others were recovered and the kidneys were harvested 1 2 7 20 or 60 days after treatment. Grossly kidneys from 0–2 days displayed subcapsular bruising near the exposure site and some hemorrhage in the adjacent perirenal fat; microscopically a disrupted acellular zone measuring 3–5 mm by 5–10 mm accompanied by local infiltration of neutrophils (acute inflammation) was seen. Kidneys harvested after 7 days displayed tubular dilatation adjacent to the targeted area and collagen deposition consistent with scar formation. Decreased collagen deposition decreased size of the disrupted zone and regeneration of the tubular basal cell layer of dilated tubules was evident by day 20. Kidneys harvested at 20 and 60 days had contour defects near the exposure site with an apparent volume loss. Cavitation causes orderly and predictable histologic changes. Local renal damage induced during histotripsy may be partially reversible. Further research is needed to identify the clinical correlates of the observed histologic findings.

Timothy L. Hall; Kathleen Kieran; J. Brian Fowlkes; Charles A. Cain; William W. Roberts

2007-01-01T23:59:59.000Z

103

Variable Temperature Ultra-High Vacuum Scanning Tunneling Microscope...  

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

Vacuum Scanning Tunneling Microscope The Omicron variable temperature ultra-high vacuum (UHV) scanning tunneling microscope (VTSTM) is designed to study the structure of both clean...

104

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...

105

Enzymes with Molecular Tunnels FRANK M. RAUSHEL,*,  

E-Print Network [OSTI]

Enzymes with Molecular Tunnels FRANK M. RAUSHEL,*, JAMES B. THODEN, AND HAZEL M. HOLDEN become feasible to examine complicated protein structures at high resolution. For those enzymes understanding of molecular tunnels ob- served in various enzyme systems. Introduction A revolution in biological

Holden, Hazel

106

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

107

Carderock Subsonic Wind Tunnel | Open Energy Information  

Open Energy Info (EERE)

Subsonic Wind Tunnel Subsonic Wind Tunnel Jump to: navigation, search Basic Specifications Facility Name Carderock Subsonic Wind Tunnel Overseeing Organization United States Naval Surface Warfare Center Hydrodynamic Testing Facility Type Tunnel Length(m) 4.3 Beam(m) 3.0 Depth(m) 2.4 Water Type Freshwater Cost(per day) Contact POC Special Physical Features The Subsonic Wind Tunnel is a continuous flow, closed-circuit facility with a closed jet test section. Test models may be supported by strut mounts using the external balance or by sting mounts using any of a wide selection of internal strain gauge balances. Adjustable surface planes are available for simulation of ground or water surfaces. Full-width floor and ceiling turntables provide additional flexibility in model mounting and manipulation.

108

MHL Student Tunnel | Open Energy Information  

Open Energy Info (EERE)

Student Tunnel Student Tunnel Jump to: navigation, search Basic Specifications Facility Name MHL Student Tunnel Overseeing Organization University of Michigan Hydrodynamics Hydrodynamic Testing Facility Type Channel Length(m) 1.4 Beam(m) 0.4 Depth(m) 0.3 Cost(per day) $2000(+ Labor/Materials) Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities None Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Velocity(m/s) 4.6 Recirculating No Wind Capabilities Wind Capabilities None Control and Data Acquisition Description Custom Data Acquisition System using National Instruments hardware; system compatible with Planing Hull and Floating Beam Dynamometers Number of channels 16 Bandwidth(kHz) 20 Cameras Yes Description of Camera Types Wide variety of analog & digital surface cameras; high speed above and underwater cameras

109

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

110

Microstructure and cavitation erosion characteristics of Al–Si alloy coating prepared by electrospark deposition  

Science Journals Connector (OSTI)

With a high-power electrospark deposition (ESD) processing unit, an Al–Si coating was prepared on ZL101 aluminum alloy substrate. The Al–Si coating was composed of many thin deposited layers with the thickness of 30–40 ?m and showed peculiar microstructural characteristics. The eutectic Si phase, which was homogenously distributed in the coating, existed in the form of latticed morphology with characteristics of being composed of many fine (~ 50 nm size) spherical Si particles. Hardness tests showed that the microhardness of the coating was in the range of 100–110 HV with a small fluctuation, which implied that the deposited coating possess a uniform strength through the whole coating. After 4 hours' cavitation erosion tests, the cumulative volume loss of Al–Si coating (9.03 mm3) was only 31.5% of the substrate (28.66 mm3), which indicated that the Al–Si coating possessed better cavitation erosion resistance than ZL101 substrate. The excellent performance of Al–Si coating was mainly attributed to the peculiar microstructure and the formation of fine spherical Si particles.

Wei-fu Wang; Mao-cai Wang; Feng-jiu Sun; Yu-gui Zheng; Jian-min Jiao

2008-01-01T23:59:59.000Z

111

Prediction of far-field acoustic emissions from cavitation clouds during shock wave lithotripsy for development of a clinical device  

Science Journals Connector (OSTI)

...lithotripter focal point. The power spectral density for each panel...generated when the lithotripter is fired, producing pickup on the device...measurement methods for high power/cavitating ultrasound fields...Field, and AJ Walton. 1988 Gas compression and jet formation...

2013-01-01T23:59:59.000Z

112

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

113

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

114

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

115

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

116

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

117

Decontamination of Hot Cells and Hot Pipe Tunnel at NASA's Plum Brook Reactor Facility  

SciTech Connect (OSTI)

The large scale decontamination of the concrete Hot Cells and Hot Pipe Tunnel at NASA's Plum Brook Reactor Facility demonstrates that novel management and innovative methods are crucial to ensuring that the successful remediation of the most contaminated facilities can be achieved with minimal risk to the project stakeholders. (authors)

Anderson, M.G.; Halishak, W.F. [MOTA Corporation, West Columbia, SC (United States)

2008-07-01T23:59:59.000Z

118

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

119

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

120

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

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

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

122

Computer simulations of cavitation collapses at high static pressure using hydrocode HYADES: Plasma conditions and shock waves in the liquid  

Science Journals Connector (OSTI)

Previously (JASA 121 pt.2 p. 3181) transient cavitation in high pressure spherical resonators was described. The phenomenon is characterized by cavitation events lasting a few ms (100 s acoustic cycles) in which a cavity (or cavities) collapse violently emitting flashes of light of widths ?1–40 nsec and spherical shock waves with amplitudes ?1–100 bars (depending on the static pressure) at a distance of 10 cm from the collapse. Both SL and shock amplitudes are proportional to the static pressure. The goal of these experiments is to investigate how the static pressure increases the intensity of acoustic cavitation collapse and whether thermonuclear fusion reactions are possible this way. The determination of plasma temperatures pressures and densities is therefore critical in making progress. Furthermore the amplitude and velocity of the shock waves can be used to determine the conditions at stagnation (end of collapse) assuming the cavity size at that time is known. To this end results of numerical simulations using HYADES plasma physics hydrocode will be presented with emphasis on the plasma conditions versus the amount of gas in the cavity and the static pressure as well as the amplitude and velocity of the outgoing shock waves generated after the collapse [Work supported by SMDC Contract No. W9113M?07?C?0178.

D. Felipe Gaitan; Ross A. Tessien; Robert A. Hiller; Jeff Alstadter

2007-01-01T23:59:59.000Z

123

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

124

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

125

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

126

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

127

Medically managed gout precipitating acute carpal tunnel syndrome  

Science Journals Connector (OSTI)

The most common compressive neuropathy affects the median nerve in the carpal tunnel; it is typically chronic and progressive. Acute carpal tunnel syndrome (ACTS), on the other hand, is a less frequently encounte...

Logan Carr; Sebastian Brooke; John Ingraham

2014-12-01T23:59:59.000Z

128

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...

129

EECBG Success Story: Saving Money in Reno's Wind Tunnels | Department...  

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

Tunnels June 28, 2010 - 3:24pm Addthis Located in one of Reno's natural wind tunnels, City Hall proved to be the perfect location for one of the city's nine new wind turbines. |...

130

Property:Recirculating | Open Energy Information  

Open Energy Info (EERE)

Recirculating Recirculating Jump to: navigation, search Property Name Recirculating Property Type String Pages using the property "Recirculating" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + No + 10-ft Wave Flume Facility + No + 5 5-ft Wave Flume Facility + No + 6 6-ft Wave Flume Facility + No + A Alden Large Flume + Yes + Alden Small Flume + No + B Bucknell Hydraulic Flume + Yes + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + Yes + Carderock 3-ft Variable Pressure Cavitation Water Tunnel + Yes + Carderock Large Cavitation Tunnel + Yes + Carderock Subsonic Wind Tunnel + Yes + Conte Large Flume + No + Conte Small Flume + No + D DeFrees Flume 1 + No + DeFrees Flume 2 + No + DeFrees Flume 3 + No +

131

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

132

Extended wearing trial of Trifield lens device for tunnel vision  

E-Print Network [OSTI]

Extended wearing trial of Trifield lens device for �tunnel vision� Russell L. Woods1 , Robert G rehabilitation device for tunnel vision in an extended wearing trial. Twelve patients with tunnel vision (5­22° wide) due to retinitis pigmentosa or choroideremia participated in the 5-visit wearing trial. To expand

Peli, Eli

133

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

134

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

135

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

136

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

137

TBM tunneling on the Yucca Mountain Project  

SciTech Connect (OSTI)

The US Department of Energy`s (DOE) Yucca Mountain Project (YMP) is a scientific endeavor to determine the suitability of Yucca Mountain for the first long-term, high-level nuclear waste repository in the United States. The current status of this long-term project from the construction perspective is described. A key element is construction of the Exploratory Studies Facility (ESF) Tunnel, which is being excavated with a 7.6 m (25 ft) diameter tunnel boring machine (TBM). Development of the ESF may include the excavation of over 15 km (9.3 mi) of tunnel varying in size from 3.0 to 7.6 m (10 to 25 ft). Prior to construction, extensive constructability reviews were an interactive part of the final design. The intent was to establish a constructable design that met the long-term stability requirements for radiological safety of a future repository, while maintaining flexibility for the scientific investigations and acceptable tunneling productivity.

Morris, J.P.; Hansmire, W.H. [Kiewit Construction Co., Las Vegas, NV (United States)]|[Parsons, Brinckerhoff, Quade and Douglas, Inc., Las Vegas, NV (United States)

1995-03-01T23:59:59.000Z

138

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

139

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

140

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.


141

Interpreting Attoclock Measurements of Tunnelling Times  

E-Print Network [OSTI]

We discuss measurements of time-delays during strong-field ionization of atoms using few-cycle circularly polarized laser pulses -- the attoclock setup. We perform numerical experiments for the benchmark system of the hydrogen atom and analyze them using fully quantum analytical theory with no ad-hoc assumptions or adjustable parameters. Excellent quantitative agreement between theory and ab initio simulations allows us to characterize time-delays measured by the attoclock, demonstrate that these delays are not related to tunnelling delays and are induced entirely by the interaction of the liberated electron with the long-range Coulomb potential of the ionic core. Our analysis gives access to 'ionization times' -- the times when an electron exits the tunnelling barrier created by the combination of the laser field and the core potential, showing that some of the key assumptions used in the semiclassical interpretation of the attoclock experiments do not always agree with the fully quantum analysis.

Torlina, Lisa; Kaushal, Jivesh; Muller, Harm Geert; Ivanov, Igor; Kheifets, Anatoli; Zielinski, Alejandro; Scrinzi, Armin; Ivanov, Misha; Smirnova, Olga

2014-01-01T23:59:59.000Z

142

Interpreting Attoclock Measurements of Tunnelling Times  

E-Print Network [OSTI]

We discuss measurements of time-delays during strong-field ionization of atoms using few-cycle circularly polarized laser pulses -- the attoclock setup. We perform numerical experiments for the benchmark system of the hydrogen atom and analyze them using fully quantum analytical theory with no ad-hoc assumptions or adjustable parameters. Excellent quantitative agreement between theory and ab initio simulations allows us to characterize time-delays measured by the attoclock, demonstrate that these delays are not related to tunnelling delays and are induced entirely by the interaction of the liberated electron with the long-range Coulomb potential of the ionic core. Our analysis gives access to 'ionization times' -- the times when an electron exits the tunnelling barrier created by the combination of the laser field and the core potential, showing that some of the key assumptions used in the semiclassical interpretation of the attoclock experiments do not always agree with the fully quantum analysis.

Lisa Torlina; Felipe Morales; Jivesh Kaushal; Harm Geert Muller; Igor Ivanov; Anatoli Kheifets; Alejandro Zielinski; Armin Scrinzi; Misha Ivanov; Olga Smirnova

2014-02-23T23:59:59.000Z

143

08 Oct 1999 Visualisatie Heinenoord Tunnel -Hack & Ozmutlu -LWI dag 1 VISUALISATIE  

E-Print Network [OSTI]

08 Oct 1999 Visualisatie Heinenoord Tunnel - Hack & Ozmutlu - LWI dag 1 VISUALISATIE HEINENOORD applications in the Netherlands #12;08 Oct 1999 Visualisatie Heinenoord Tunnel - Hack & Ozmutlu - LWI dag 2 Visualisatie Heinenoord Tunnel - Hack & Ozmutlu - LWI dag 3 Heinenoord tunnel · Eerste geboorde tunnel

Hack, Robert

144

Using Daylight to Light the Access Zone of Road Tunnels  

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

Using Daylight to Light the Access Zone of Road Tunnels Using Daylight to Light the Access Zone of Road Tunnels Speaker(s): Eliyahu Ne'eman Date: March 4, 2003 - 12:00pm Location: Bldg. 90 Lighting guides for roadway tunnels specify relatively high luminances for the "access zone" into the tunnel. They are needed to allow the eyes of the driver sufficient time to adapt during the short period of the transition from the outdoor natural daylight levels to the fairly low luminances along the main length of the tunnel. Usually, the necessary high luminances are provided by rows of costly luminaries which consume a lot of electricity during peak use periods and need a good deal of maintenance. To save some electric power, controls are used to dim the lighting on cloudy hours. Daylight has been used for the access zone in several tunnels around the

145

Conte Large Flume | Open Energy Information  

Open Energy Info (EERE)

Conte Large Flume Conte Large Flume Overseeing Organization United States Geological Survey, LSC Hydrodynamic Testing Facility Type Flume Length(m) 38.1 Beam(m) 6.1 Depth(m) 5.2 Cost(per day) Contact POC Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities None Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Recirculating No Wind Capabilities Wind Capabilities None Control and Data Acquisition Description National Instruments LabView and other data acquisition systems Number of channels 12 Bandwidth(kHz) 44 Cameras Yes Number of Color Cameras 5 Description of Camera Types Conventional underwater video, 4; high speed (1000 fps), 1 Available Sensors Displacement, Flow, Pressure Range(psi), Thermal, Turbulence, Velocity Data Generation Capability

146

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

147

Control of dynamical tunneling in a bichromatically driven pendulum  

Science Journals Connector (OSTI)

We demonstrate that the avoided level crossing between the Floquet state associated with the chaotic part of classical phase space and a member of the quasidegenerate doublet may lead to the enhancement of the doublet splitting by several orders of magnitude. As a result of this interaction the two-level tunneling dynamics is replaced by the more intricate dynamics involving three states. It is shown that three-level tunneling is much more robust against symmetry breaking perturbations than is ordinary tunneling.

Miroslaw Latka, Paolo Grigolini, and Bruce J. West

1994-11-01T23:59:59.000Z

148

Invisibility of quantum systems to tunneling of matter waves  

E-Print Network [OSTI]

We show that an appropriate choice of the potential parameters in one-dimensional quantum systems allows for unity transmission of the tunneling particle at all incident tunneling energies, except at controllable exceedingly small incident energies. The corresponding dwell time and the transmission amplitude are indistinguishable from those of a free particle in the unity-transmission regime. This implies the possibility of designing quantum systems that are invisible to tunneling by a passing wave packet.

Sergio Cordero; Gaston Garcia-Calderon

2009-04-25T23:59:59.000Z

149

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

150

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...

151

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

152

The semiclassical tunneling probability in quantum cosmologies with varying speed of light  

E-Print Network [OSTI]

In quantum cosmology the closed universe can spontaneously nucleate out of the state with no classical space and time. The semiclassical tunneling nucleation probability can be estimated as $\\emph{P}\\sim\\exp(-\\alpha^2/\\Lambda)$ where $\\alpha$=const and $\\Lambda$ is the cosmological constant. In classical cosmology with varying speed of light c(t) (VSL) it is possible to solve the horizon problem, the flatness problem and the $\\Lambda$-problem if c=sa^n with s=const and n0. Thus, the semiclassical tunneling nucleation probability in VSL quantum cosmology is very different from this one in quantum cosmology with c=const. In particular, this one is strongly suppressed for large values of $\\Lambda$.

A. V. Yurov; V. A. Yurov

2004-10-23T23:59:59.000Z

153

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

154

E-Print Network 3.0 - analysing utility tunnels Sample Search...  

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

6 Merguerian, Charles; and Ozdemir, Levent, 2003, Rock Mass Properties and Hard Rock TBM Penetration Rate Investigations, Queens Tunnel Complex, NYC Water Tunnel 3, Stage 2: p....

155

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

156

High Tunnel Crop Production Tips Lewis W. Jett  

E-Print Network [OSTI]

used for producing a diversity of horticulture crops including vegetables, fruits, herbs and flowers the crop from an erratic environment where extremes in temperature, wind, rainfall, pests and light tunnel? High tunnels used for growing horticulture crops commercially are typically 20-30 ft wide and 100

Goodman, Robert M.

157

Vibration-Assisted Electron Tunneling in C140 Transistors  

Science Journals Connector (OSTI)

Vibration-Assisted Electron Tunneling in C140 Transistors ... When electrons travel through molecules, vibrational modes of the molecules can affect current flow. ... 1 Recently, effects of vibrations in single molecules have been measured using scanning tunneling microscopes,2 single-molecule transistors,3,4 and mechanical break junctions. ...

A. N. Pasupathy; J. Park; C. Chang; A. V. Soldatov; S. Lebedkin; R. C. Bialczak; J. E. Grose; L. A. K. Donev; J. P. Sethna; D. C. Ralph; P. L. McEuen

2005-01-07T23:59:59.000Z

158

Nonequilibrium electron tunneling in metal-insulator-metal junctions  

Science Journals Connector (OSTI)

The small structure in the conductance curve near zero bias of metal-insulator-metal tunnel junctions has been studied extensively. These experiments are analyzed in detail in a nonequilibrium model. It is shown that this type of zero-bias anomaly can be accounted for entirely by an electron bottleneck arising from the blocking of tunneling states due to nonzero electron relaxation times.

J. G. Adler; H. J. Kreuzer; J. Straus

1975-04-15T23:59:59.000Z

159

Saving Money in Reno's Wind Tunnels | Department of Energy  

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

Saving Money in Reno's Wind Tunnels Saving Money in Reno's Wind Tunnels Saving Money in Reno's Wind Tunnels June 28, 2010 - 5:14pm Addthis Located in one of Reno's natural wind tunnels, City Hall proved to be the perfect location for one of the city's nine new wind turbines. | Photo courtesy of the City of Reno Located in one of Reno's natural wind tunnels, City Hall proved to be the perfect location for one of the city's nine new wind turbines. | Photo courtesy of the City of Reno On the street level in Reno, it may be easy to forget that every time the breeze blows off the Truckee River and past the 17-story City Hall, the town is quietly saving money. But the $11,000 the city is expected to save each year from wind power will be a friendly reminder. Installed in early June, the two 1.5-kilowatt wind

160

MHK Technologies/Tunneled Wave Energy Converter TWEC | Open Energy  

Open Energy Info (EERE)

Tunneled Wave Energy Converter TWEC Tunneled Wave Energy Converter TWEC < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Tunneled Wave Energy Converter TWEC.jpg Technology Profile Primary Organization SeWave Ltd Project(s) where this technology is utilized *MHK Projects/TWEC Project Technology Resource Click here Wave Technology Type Click here Oscillating Water Column Technology Readiness Level Click here TRL 1-3: Discovery / Concept Definition / Early Stage Development & Design & Engineering Technology Description The Tunneled Wave Energy Converter TWEC utilizes the OWC principle through its use of a proposed bored out tunnel within a cliff side of the Faroe Islands Technology Dimensions Device Testing Date Submitted 10/8/2010 << Return to the MHK database homepage

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

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

162

Saving Money in Reno's Wind Tunnels | Department of Energy  

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

Money in Reno's Wind Tunnels Money in Reno's Wind Tunnels Saving Money in Reno's Wind Tunnels June 28, 2010 - 5:14pm Addthis Located in one of Reno's natural wind tunnels, City Hall proved to be the perfect location for one of the city's nine new wind turbines. | Photo courtesy of the City of Reno Located in one of Reno's natural wind tunnels, City Hall proved to be the perfect location for one of the city's nine new wind turbines. | Photo courtesy of the City of Reno On the street level in Reno, it may be easy to forget that every time the breeze blows off the Truckee River and past the 17-story City Hall, the town is quietly saving money. But the $11,000 the city is expected to save each year from wind power will be a friendly reminder. Installed in early June, the two 1.5-kilowatt wind

163

Observation of Fowler–Nordheim hole tunneling across an electron tunnel junction due to total symmetry filtering  

Science Journals Connector (OSTI)

Using a SrTiO3(001) barrier and La0.7Sr0.3MnO3(001) electrodes, we study the case of coherent spin-polarized tunneling of electrons that exhibit a symmetry mismatch with respect to the lower electron barrier height. Due to this mismatch, electrons with energy above this barrier height continue to tunnel thanks to total symmetry filtering. This allows us to observe symmetry-matched hole tunneling across this electron tunnel junction, and in particular spin-polarized oscillations in the Fowler-Nordheim hole regime above the hole barrier height, thereby enriching the present theoretical picture of coherent spin-polarized tunneling at finite bias.

M. Bowen, A. Barthélémy, V. Bellini, M. Bibes, P. Seneor, E. Jacquet, J.-P. Contour, and P. H. Dederichs

2006-04-27T23:59:59.000Z

164

Alden Large Flume | Open Energy Information  

Open Energy Info (EERE)

Flume Flume Jump to: navigation, search Basic Specifications Facility Name Alden Large Flume Overseeing Organization Alden Research Laboratory, Inc Hydrodynamic Testing Facility Type Flume Length(m) 24.4 Beam(m) 6.1 Depth(m) 3.0 Water Type Freshwater Cost(per day) $5000/week Towing Capabilities Towing Capabilities Yes Maximum Velocity(m/s) 0.9 Maximum Velocity with Constriction(m/s) 3 Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.0 Maximum Wave Height(m) at Wave Period(s) 0.0 Wave Period Range(s) 2.1 Current Velocity Range(m/s) 3.2 Programmable Wavemaking Yes Wavemaking Description Wave generators not yet designed Simulated Beach No Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Recirculating Yes Wind Capabilities Wind Capabilities Yes

165

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

166

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

167

Spin-Polarized Tunneling Spectroscopy in Tunnel Junctions with Half-Metallic Electrodes  

Science Journals Connector (OSTI)

We have studied the magnetoresistance (TMR) of tunnel junctions with electrodes of La2/3Sr1/3MnO3 and we show how the variation of the conductance and TMR with the bias voltage can be exploited to obtain precise information on the spin and energy dependence of the density of states. Our analysis leads to a quantitative description of the band structure of La2/3Sr1/3MnO3 including the energy gap ? between the Fermi level and the bottom of the t2g minority-spin band, in good agreement with data from spin-polarized inverse photoemission experiments. This shows the potential of magnetic tunnel junctions with half-metallic electrodes for spin-resolved spectroscopic studies.

M. Bowen, A. Barthélémy, M. Bibes, E. Jacquet, J.-P. Contour, A. Fert, F. Ciccacci, L. Duò, and R. Bertacco

2005-09-21T23:59:59.000Z

168

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

169

Bias dependence of tunnel magnetoresistance in spin filtering tunnel junctions: Experiment and theory  

Science Journals Connector (OSTI)

A spin filter is a type of magnetic tunnel junction in which only one of the electrodes is magnetic and the insulating barrier is ferro- or ferrimagnetic. We report on spin-dependent transport measurements and their theoretical analysis in epitaxial spin filters integrating a tunnel barrier of the high-Curie-temperature ferrimagnetic spinel NiFe2O4, with half-metallic La2?3Sr1?3MnO3 and Au electrodes. A positive tunnel magnetoresonance of up to ?50% is obtained at low temperature, which we find decreases with bias voltage. In view of these experimental results, we propose a theoretical treatment of the transport properties of spin filters with epitaxial magnetic barriers, based on an elliptical variation of the decay rates within the spin-dependent gaps in analogy with what was calculated for nonmagnetic barrier materials such as MgO or SrTiO3. Whereas the spin filtering efficiency for zero bias is of one sign, we show that this can easily change with bias; the degree of change hinges on the energy variation of the majority and minority spin decay rates of the transmission across the barrier. We point out some shortcomings of approaches based on models in which the transmission is related to spin-dependent barrier heights, and some implications for future experimental and theoretical research on spin filters.

U. Lüders, M. Bibes, S. Fusil, K. Bouzehouane, E. Jacquet, C. B. Sommers, J.-P. Contour, J.-F. Bobo, A. Barthélémy, A. Fert, and P. M. Levy

2007-10-16T23:59:59.000Z

170

Nanoelectronic devices—resonant tunnelling diodes  

Science Journals Connector (OSTI)

This paper reports that InAs/In0.53Ga0.47As/AlAs resonant tunnelling diodes have been grown on InP substrates by molecular beam epitaxy. Peak to valley current ratio of these devices is 17 at 300K. A peak current density of 3kA/cm2 has been obtained for diodes with AlAs barriers of ten monolayers and an In0.53Ga0.47As well of eight monolayers with four monolayers of InAs insert layer. The effects of growth interruption for smoothing potential barrier interfaces have been investigated by high resolution transmission electron microscope.

Zhang Yang; Zeng Yi-Ping; Ma Long; Wang Bao-Qiang; Zhu Zhan-Ping; Wang Liang-Chen; Yang Fu-Hua

2006-01-01T23:59:59.000Z

171

Dynamics of spin-flip photon-assisted tunneling  

Science Journals Connector (OSTI)

We present time-resolved measurements of spin-flip photon-assisted tunneling and spin-flip relaxation in a doubly occupied double quantum dot. The photon-assisted excitation rate as a function of magnetic field indicates that spin-orbit coupling is the dominant mechanism behind the spin-flip under the present conditions. We are able to extract the resulting effective “spin-flip tunneling” energy, which is found to be three orders of magnitude smaller than the regular spin-conserving tunneling energy. We also measure the relaxation and dephasing times of a qubit formed out of two two-electron states with different spin and charge configurations.

F. R. Braakman; J. Danon; L. R. Schreiber; W. Wegscheider; L. M. K. Vandersypen

2014-02-18T23:59:59.000Z

172

Sub-Kelvin scanning tunneling microscopy on magnetic molecules.  

E-Print Network [OSTI]

??Magnetic molecules have attracted lots interest. In this work, an ultra-stable and low noise scanning tunneling microscopy operating at 400 mK using He-3 (930 mK… (more)

Zhang, Lei

2012-01-01T23:59:59.000Z

173

1D-to-2D tunneling in electron waveguides  

Science Journals Connector (OSTI)

We present a comprehensive experimental study of the tunneling and transport characteristics of split-gate ‘‘leaky’’ one-dimensional (1D) electron waveguides implemented in AlxGa1-xAs/GaAs heterostructures. In a leaky electron waveguide, electrons can tunnel out of the 1D channel through a thin side wall barrier into an adjacent 2D electron bath. A sharp peak and valley structure is observed in the 1D-to-2D tunneling current as the carrier concentration is modulated in the 1D waveguide through the field-effect action of the split gates. A semiclassical model confirms that the tunneling features originate from the 1D subbands in the channel.

Cristopher C. Eugster; Jesús A. del Alamo; Michael R. Melloch; Michael J. Rooks

1993-11-15T23:59:59.000Z

174

Data dependence path reduction with tunneling load instructions  

Science Journals Connector (OSTI)

The technique for reducing the length of the data dependence path is presented. This technique,...tunneling-load..., utilizes the register specifier buffer in order to hide the load latency, and thus reduces the ...

Toshinori Sato

1997-01-01T23:59:59.000Z

175

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

176

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

177

Hybrid high-temperature superconductor-semiconductor tunnel diode  

E-Print Network [OSTI]

We report the demonstration of hybrid high-Tc-superconductor-semiconductor tunnel junctions, enabling new interdisciplinary directions in condensed matter research. The devices were fabricated by our newly-developed mechanical bonding technique, resulting in high-Tc-semiconductor planar junctions acting as superconducting tunnel diodes. Tunneling-spectra characterization of the hybrid junctions of Bi2Sr2CaCu2O8+{\\delta} combined with bulk GaAs, or a GaAs/AlGaAs quantum well, exhibits excess voltage and nonlinearity - in good agreement with theoretical predictions for a d-wave superconductor-normal material junction, and similar to spectra obtained in scanning tunneling microscopy. Additional junctions are demonstrated using Bi2Sr2CaCu2O8+{\\delta} combined with graphite or Bi2Te3. Our results pave the way for new methods in unconventional superconductivity studies, novel materials and quantum technology applications.

Alex Hayat; Parisa Zareapour; Shu Yang F. Zhao; Achint Jain; Igor G. Savelyev; Marina Blumin; Zhijun Xu; Alina Yang; G. D. Gu; Harry E. Ruda; Shuang Jia; R. J. Cava; Aephraim M. Steinberg; Kenneth S. Burch

2013-01-09T23:59:59.000Z

178

Hybrid High-Temperature-Superconductor–Semiconductor Tunnel Diode  

Science Journals Connector (OSTI)

We report the demonstration of hybrid high-Tc-superconductor–semiconductor tunnel junctions, enabling new interdisciplinary directions in condensed matter research. The devices are fabricated by our newly developed mechanical-bonding technique, resulting in high-Tc-superconductor–semiconductor tunnel diodes. Tunneling-spectra characterization of the hybrid junctions of Bi2Sr2CaCu2O8+? combined with bulk GaAs, or a GaAs/AlGaAs quantum well, exhibits excess voltage and nonlinearity, similarly to spectra obtained in scanning-tunneling microscopy, and is in good agreement with theoretical predictions for a d-wave-superconductor–normal-material junction. Additional junctions are demonstrated using Bi2Sr2CaCu2O8+? combined with graphite or Bi2Te3. Our results pave the way for new methods in unconventional superconductivity studies, novel materials, and quantum technology applications.

Alex Hayat; Parisa Zareapour; Shu Yang F. Zhao; Achint Jain; Igor G. Savelyev; Marina Blumin; Zhijun Xu; Alina Yang; G. D. Gu; Harry E. Ruda; Shuang Jia; R. J. Cava; Aephraim M. Steinberg; Kenneth S. Burch

2012-12-27T23:59:59.000Z

179

Plans for US wind tunnel set to take off  

Science Journals Connector (OSTI)

... world's largest and most sophisticated wind-tunnel complex, to be used by aircraft manufacturer Boeing to speed up the development of successors to the ... to speed up the development of successors to the Boeing 747 jumbo jet.

Colin Macilwain

1994-07-28T23:59:59.000Z

180

Response of continuous pipelines to tunnel induced ground deformations  

E-Print Network [OSTI]

This thesis develops analytical solutions for estimating the bending moments and axial loads in a buried pipeline due to ground movements caused by tunnel construction in soft ground. The solutions combine closed-form, ...

Ieronymaki, Evangelia S

2011-01-01T23:59:59.000Z

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.


181

Construction of an ultra-low temperature scanning tunneling microscope  

Science Journals Connector (OSTI)

We describe designs and specifications of an ultra-low temperature scanning tunneling microscope developed at ... works over a wide temperature range between 90 mK and 300 K with atomic resolution as...

Hiroshi Fukuyama; Hiroki Tan; Tetsuya Handa…

1996-01-01T23:59:59.000Z

182

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

183

Merguerian, Charles; and Ozdemir, Levent, 2003, Rock Mass Properties and Hard Rock TBM Penetration Rate Investigations, Queens Tunnel Complex, NYC Water Tunnel #3, Stage 2: p.  

E-Print Network [OSTI]

Properties and Hard Rock TBM Penetration Rate Investigations, Queens Tunnel Complex, NYC Water Tunnel #3 and established geological causes for decreased TBM penetration rates. 1 #12;INTRODUCTION Our combined geological penetration rates in granulite facies terranes. The Queens Tunnel TBM experienced poor penetration rates

Merguerian, Charles

184

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

185

Inverse Tunnel Magnetoresistance in Co/SrTiO3/La0.7Sr0.3MnO3: New Ideas on Spin-Polarized Tunneling  

Science Journals Connector (OSTI)

We report tunnel magnetoresistance (TMR) measurements on Co/SrTiO3/La0.7Sr0.3MnO3 junctions. The half-metallic La0.7Sr0.3MnO3 electrode is used as a spin analyzer. The large (-50%) inverse TMR indicates a negative spin polarization of Co, in agreement with the density of states (DOS) of the d band in Co. The bias dependence of the TMR, with a maximum inverse TMR at -0.4 V and a crossover to normal TMR above +0.8 V, reflects the structure of this DOS. Our results demonstrate that the choice of the insulating barrier can strongly influence and even reverse the spin polarization of tunneling electrons.

J. M. De Teresa, A. Barthélémy, A. Fert, J. P. Contour, R. Lyonnet, F. Montaigne, P. Seneor, and A. Vaurès

1999-05-24T23:59:59.000Z

186

Brookhaven and the Large Hadron Collider  

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

Brookhaven & the Large Hadron Collider Brookhaven & the Large Hadron Collider Home News Brookhaven & ATLAS ATLAS ATLAS Calorimeter ATLAS Muon Spectrometer Construction Computing Upgrades RHIC & LHC Education LHC tunnel ATLAS detector ATLAS detector RACF BNL built superconducting magnets Brookhaven & the LHC The world's most powerful particle accelerator, the Large Hadron Collider (LHC) in Switzerland, powers unprecedented explorations of the deepest mysteries of the universe. In addition to serving as the U.S. host laboratory for the ATLAS experiment at the LHC, Brookhaven National Lab plays multiple roles in this international collaboration, from construction and project management to data storage and distribution. ATLAS rendering Brookhaven and ATLAS Brookhaven physicists and engineers are participating in one of the most

187

Thermal derivation of the Coleman-De Luccia tunneling prescription  

SciTech Connect (OSTI)

We derive the rate for transitions between de Sitter vacua by treating the field theory on the static patch as a thermal system. This reproduces the Coleman-De Luccia formalism for calculating the rate, but leads to a modified interpretation of the bounce solution and a different prediction for the evolution of the system after tunneling. The bounce is seen to correspond to a sequence of configurations interpolating between initial and final configurations on either side of the tunneling barrier, all of which are restricted to the static patch. The final configuration, which gives the initial data on the static patch for evolution after tunneling, is obtained from one-half of a slice through the center of the bounce, while the other half gives the configuration before tunneling. The formalism makes no statement about the fields beyond the horizon. This approach resolves several puzzling aspects and interpretational issues concerning the Coleman-De Luccia and Hawking-Moss bounces. We work in the limit where the backreaction of matter on metric can be ignored, but argue that the qualitative aspects remain in the more general case. The extension to tunneling between anti-de Sitter vacua is discussed.

Brown, Adam R. [Physics Department, Columbia University, New York, New York 10027 (United States); Weinberg, Erick J. [Physics Department, Columbia University, New York, New York 10027 (United States); School of Physics, Korea Institute for Advanced Study, 207-43, Cheongnyangni2-dong, Dongdaemun-gu, Seoul 130-722 (Korea, Republic of)

2007-09-15T23:59:59.000Z

188

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

189

Getting Traffic Lights Talking to Improve Topeka's Traffic Tunnel |  

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

Getting Traffic Lights Talking to Improve Topeka's Traffic Tunnel Getting Traffic Lights Talking to Improve Topeka's Traffic Tunnel Getting Traffic Lights Talking to Improve Topeka's Traffic Tunnel October 8, 2010 - 11:16am Addthis Topeka is using Recovery Act funding to resynchronize 22 traffic lights. | Photo by Linda Voss Topeka is using Recovery Act funding to resynchronize 22 traffic lights. | Photo by Linda Voss Lindsay Gsell The five-lane 21st street corridor in Topeka is a hub for restaurants, shopping and entertainment. "This is where everyone in Topeka goes to shop," says Topeka resident Linda Voss. In addition to food and fun, the one-mile corridor is home to seven traffic lights-and for drivers, a potential traffic stop every 754 feet, or a little more than two football fields. "The traffic signals are a challenge to time in this area," says Voss,

190

Photon induced tunneling of electron through a graphene electrostatic barrier  

SciTech Connect (OSTI)

The influence of an external intense laser field on the tunneling transport (ballistic) of the Dirac fermions through a monolayer graphene electrostatic barrier is studied in the framework of the Floquet approach for a continuous wave, linearly polarized, monochromatic laser. The Klein tunneling is shown to be suppressed by the irradiation of a strong laser field, arising due to breaking of chiral symmetry. The symmetric nature of the field free angular transmission spectrum around the normal to the well-barrier interface is destroyed due to the additional coupling between the pseudo-spin and the time dependent vector potential. The energy distribution of the tunneling spectrum displays Fano resonance which is absent for a laser assisted conventional electrostatic barrier but similar to the case of quantum well structures, providing an optical tool to identify field free quasi bound states inside the graphene nanostructures.

Biswas, R. [Department of Physics, P.K. College, Contai, Purba Medinipur, West Bengal 721401 (India)] [Department of Physics, P.K. College, Contai, Purba Medinipur, West Bengal 721401 (India); Sinha, C. [Department of Theoretical Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)] [Department of Theoretical Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

2013-11-14T23:59:59.000Z

191

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 ...

Hagino, K

2012-01-01T23:59:59.000Z

192

Black hole quantum tunnelling and black hole entropy correction  

E-Print Network [OSTI]

Parikh-Wilczek tunnelling framework, which treats Hawking radiation as a tunnelling process, is investigated again. As the first order correction, the log-corrected entropy-area relation naturally emerges in the tunnelling picture if we consider the emission of a spherical shell. The second order correction of the emission rate for the Schwarzschild black hole is calculated too. In this level, the result is still in agreement with the unitary theory, however, the entropy of the black hole will contain three parts: the usual Bekenstein-Hawking entropy, the logarithmic term and the inverse area term. In our results the coefficient of the logarithmic term is -1. Apart from a coefficient, Our correction to the black hole entropy is consistent with that of loop quantum gravity.

Jingyi Zhang

2008-06-15T23:59:59.000Z

193

Coupling molecular spin states by photon-assisted tunneling  

E-Print Network [OSTI]

Artificial molecules containing just one or two electrons provide a powerful platform for studies of orbital and spin quantum dynamics in nanoscale devices. A well-known example of these dynamics is tunneling of electrons between two coupled quantum dots triggered by microwave irradiation. So far, these tunneling processes have been treated as electric dipole-allowed spin-conserving events. Here we report that microwaves can also excite tunneling transitions between states with different spin. In this work, the dominant mechanism responsible for violation of spin conservation is the spin-orbit interaction. These transitions make it possible to perform detailed microwave spectroscopy of the molecular spin states of an artificial hydrogen molecule and open up the possibility of realizing full quantum control of a two spin system via microwave excitation.

Schreiber, L R; Meunier, T; Calado, V; Danon, J; Taylor, J M; Wegscheider, W; Vandersypen, L M K

2010-01-01T23:59:59.000Z

194

Coupling molecular spin states by photon-assisted tunneling  

E-Print Network [OSTI]

Artificial molecules containing just one or two electrons provide a powerful platform for studies of orbital and spin quantum dynamics in nanoscale devices. A well-known example of these dynamics is tunneling of electrons between two coupled quantum dots triggered by microwave irradiation. So far, these tunneling processes have been treated as electric dipole-allowed spin-conserving events. Here we report that microwaves can also excite tunneling transitions between states with different spin. In this work, the dominant mechanism responsible for violation of spin conservation is the spin-orbit interaction. These transitions make it possible to perform detailed microwave spectroscopy of the molecular spin states of an artificial hydrogen molecule and open up the possibility of realizing full quantum control of a two spin system via microwave excitation.

L. R. Schreiber; F. R. Braakman; T. Meunier; V. Calado; J. Danon; J. M. Taylor; W. Wegscheider; L. M. K. Vandersypen

2010-10-27T23:59:59.000Z

195

Including Tunneling in Non-Born–Oppenheimer Simulations  

Science Journals Connector (OSTI)

Including Tunneling in Non-Born–Oppenheimer Simulations ... We note that tunneling may be included in the modeling of electronically nonadiabatic processes by other methods as well, for example, quantal wave packet methods where the wave packet is not restricted to follow a classical trajectory,(18) path integral dynamics,(19-21) and the initial value representation,(22) but these methods will require more development of efficient computational strategies for their practical application to complex systems, whereas the method proposed here has a cost comparable to non-Born–Oppenheimer (NBO) trajectory calculations that do not include tunneling. ... We also ran Born–Oppenheimer trajectories with the same total energy on the adiabatic ground state for comparison. ...

Jingjing Zheng; Rubén Meana-Pañeda; Donald G. Truhlar

2014-05-15T23:59:59.000Z

196

Diesel Bus Emissions Measured in a Tunnel Study  

Science Journals Connector (OSTI)

(iii) Time series of particle concentration levels measured at the tunnel's exit in general followed the trends of the traffic flow rate in the tunnel, with the concentration levels varied between 0.5 × 104 up to 8.0 × 104 particle cm-3. ... Emission factors of diesel-powered buses measured in this study and those reported from the literature (buses and trucks) of relevance to this study are presented in Table 2. Caution needs to be exercised when comparing the results since differences in testing conditions (tunnel, chassis dynamometer, steady state vs transient driving cycles, type of vehicle etc.), testing methods, and instrumentation applied. ... The higher value than measured in this study may be attributed to different driving cycle and the inclusion of diesel trucks in the tested sample. ...

Milan Jamriska; Lidia Morawska; Steven Thomas; Congrong He

2004-11-12T23:59:59.000Z

197

TBM tunneling on the Yucca Mountain Project: Proceedings  

SciTech Connect (OSTI)

The US Department of Energy`s (DOE) Yucca Mountain Project (YMP) is a scientific endeavor to determine the suitability of Yucca Mountain for the first long term, high level nuclear waste repository in the United States. Status of this long-term project form the construction perspective is described. A key element is construction of the Exploratory Studies Facility (ESF), which is being excavated with a 7. 6 m(25 ft) diameter tunnel boring machine (TBM). Development of the ESF may include the excavation of over 15 km (9.3 mi) of tunnel varying in size from 3 to 7.6 m(10 to 25 ft). Prior to construction, extensive constructibility reviews were an interactive part of the final design. Intent was to establish a constructible design that met the long-term stability requirements for radiological safety of a future repository while maintaining flexibility for the scientific investigations and acceptable tunneling productivity.

Williamson, G.E.; Gowring, I.M. [ed.

1995-07-01T23:59:59.000Z

198

Numerical Simulation of Wind Tunnel Wall Effects on the Transonic Flow around an Airfoil Model  

Science Journals Connector (OSTI)

For wind tunnel measurements in closed-wall test sections, possible interference effects of the wind tunnel walls play an important role. Three-dimensional TAU simulations were performed for the transonic flow ar...

K. Richter; H. Rosemann

2013-01-01T23:59:59.000Z

199

Wind tunnel simulation of wind loading on a solid structure of revolution  

Science Journals Connector (OSTI)

The wind tunnel simulations of wind loading on a solid structure of revolution ... smooth and five rough surfaces were conducted using wind tunnel tests. Time-mean and fluctuating pressure ... distributions. The ...

Le-Tian Yang; Zhi-Fu Gu

2010-08-01T23:59:59.000Z

200

A NEW TUNNEL RISK ASSESSMENT PROCEDURE INTEGRATING SMOKE DISPERSION AND EVACUATION MODELS  

E-Print Network [OSTI]

dispersion, Evacuation, Computer model, Tenability, HVAC INTRODUCTION Because tunnels are complex Systems on harmonisation of minimum safety standards to guarantee a high level of safety for thé users of tunnels

Boyer, Edmond

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

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

202

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

203

Edge tunneling and transport in non-abelian fractional quantum Hall systems  

E-Print Network [OSTI]

Several aspects of tunneling at the edge of a fractional quantum Hall (FQH) state are studied. Most examples are given for the non- abelian filling fraction ? = 5 2 Moore-Read Pfaffian state. For tunneling between opposite ...

Overbosch, Bas Jorn

2008-01-01T23:59:59.000Z

204

Quantum Cascade Lasers: New Resonant Tunnelling Light Sources for the Mid-Infrared  

Science Journals Connector (OSTI)

15 October 1996 research-article Quantum Cascade Lasers: New Resonant Tunnelling Light Sources...Hutchinson A. Y. Cho Recent results on quantum cascade lasers are reviewed. In these quantum devices based on resonant tunnelling the...

1996-01-01T23:59:59.000Z

205

E-Print Network 3.0 - area lhc tunnel Sample Search Results  

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

lhc tunnel Search Powered by Explorit Topic List Advanced Search Sample search results for: area lhc tunnel Page: << < 1 2 3 4 5 > >> 1 US LHC Accelerator Project and Research...

206

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

207

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

208

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

209

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

210

Tunneling processes in asymmetric double barrier magnetic tunnel junctions with a thin top MgO layer  

SciTech Connect (OSTI)

Dynamic conductance dI/dV and inelastic electron tunneling spectroscopy (IETS) d{sup 2}I/dV{sup 2} have been measured at different temperatures for double barrier magnetic tunnel junctions with a thin top MgO layer. The resistance in the antiparallel state exhibits a normal tunnel-like behavior, while the resistance in the parallel state shows metallic-like transport, indicating the presence of pinholes in the thin top MgO layer. Three IETS peaks are the zero-bias anomaly, interface magnons, and barrier phonons in both the parallel and antiparallel states. The zero-bias anomaly is the strongest peak in the parallel state and its intensity decreases with temperature. The magnon has the largest intensity in the antiparallel state and its intensity also decreases with temperature. The origins of the dips and peaks in the dI/dV-V curve are also discussed.

Li, D. L.; Feng, J. F. [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); Yu, G. Q.; Guo, P.; Wei, H. X.; Han, X. F., E-mail: xfhan@aphy.iphy.ac.cn [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Chen, J. Y.; Coey, J. M. D. [CRANN and School of Physics, Trinity College, Dublin 2 (Ireland)

2013-12-07T23:59:59.000Z

211

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

212

Results of pressurized-slot measurements in the G-Tunnel underground facility  

SciTech Connect (OSTI)

A rock-mechanics field-testing program is underway at Sandia National Laboratories (SNL) as part of the YMP. SNL has the responsibility for assessing the repository design and performance as well as characterizing the geomechanical behavior of the rock. SNL has conducted field experiments in G-Tunnel in Rainier Mesa at the NTS, where tuffs similar to those at Yucca Mountain, the potential repository site, are found. Later experiments are planned as part of the YMP Exploratory Shaft investigations at Yucca Mountain. Major geomechanical factors in repository developments are determinations of the stress state and the deformability of the rock mass (described by the modulus of deformation). One feature of SNL`s rock-mechanics program was the development of a testing program for cutting thin slots in a jointed welded tuff and utilizing flatjacks for pressurizing these thin-slots on a relatively, large scale. Objectives in the pressurized-slot testing in G-Tunnel have been to apply and possibly improve methods for (1) utilizing the flatjack cancellation (FC) method for measuring stresses normal to the slot and (2) measuring the modulus of deformation of the jointed rock surrounding the slot. This paper discusses the results of field measurements in and around a single slot and evaluates potential applications and limitations. 10 refs., 1 fig., 4 tabs.

Zimmerman, R.M.; Mann, K.L.; Dodds, D.J.

1989-02-01T23:59:59.000Z

213

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

214

Department of Computer Engineering Spring 2010 Boeing Wind Tunnel Rotor Flight Simulator  

E-Print Network [OSTI]

PENNSTATE Department of Computer Engineering Spring 2010 Boeing Wind Tunnel Rotor Flight Simulator the construction of a wind tunnel rotor flight simulator. The program should allow the pilot to change the rotor and comfortable simulator with the following parts: A rotor controller, a wind tunnel controller, a graphical

Demirel, Melik C.

215

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

216

MAGNETIC QUANTUM TUNNELING AND RELATED PHENOMENA IN SINGLE MOLECULE MAGNETS Presentation  

E-Print Network [OSTI]

MAGNETIC QUANTUM TUNNELING AND RELATED PHENOMENA IN SINGLE MOLECULE MAGNETS Presentation A A A A A A MAGNETIC QUANTUM TUNNELING AND RELATED PHENOMENA IN SINGLE MOLECULE MAGNETS MAGNETIC QUANTUM TUNNELING AND RELATED PHENOMENA IN SINGLE MOLECULE MAGNETS ENRIQUE DEL BARCOENRIQUE DEL BARCO Physics Department - New

del Barco, Enrique

217

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

218

Superconducting phonon structure in the transition from tunneling to contact regime  

Science Journals Connector (OSTI)

We study the variation of the phonon structure in the conductance curves of superconducting variable-barrier junctions formed using a scanning tunneling microscope. The observed vanishing of this structure as the tunneling barrier decreases is explained as a result of the mixing of electronic states in the Andreev reflection process, whose importance increases as the tunneling barrier decreases.

J. G. Rodrigo; N. Agraït; C. Sirvent; S. Vieira

1994-09-01T23:59:59.000Z

219

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.

220

Improving sequencing by tunneling with multiplexing and cross-correlations  

E-Print Network [OSTI]

Sequencing by tunneling is a next-generation approach to read single-base information using electronic tunneling transverse to the single-stranded DNA (ssDNA) backbone while the latter is translocated through a narrow channel. The original idea considered a single pair of electrodes to read out the current and distinguish the bases [1, 2]. Here, we propose an improvement to the original sequencing by tunneling method, in which $N$ pairs of electrodes are built in series along a synthetic nanochannel. While the ssDNA is forced through the channel using a longitudinal field it passes by each pair of electrodes for long enough time to gather a minimum of $m$ tunneling current measurements, where $m$ is determined by the level of sequencing error desired. Each current time series for each nucleobase is then cross-correlated together, from which the DNA bases can be distinguished. We show using random sampling of data from classical molecular dynamics, that indeed the sequencing error is significantly reduced as t...

Boynton, P; Schuller, I K; Di Ventra, M

2014-01-01T23:59:59.000Z

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.


221

Macroscopic quantum tunnelling in a current biased Josephson junction  

SciTech Connect (OSTI)

We discuss in this work an attempt to answer experimentally the question: do macroscopic variables obey quantum mechanics. More precisely, this experiment deals with the question of quantum-mechanical tunnelling of a macroscopic variable, a subject related to the famous Schrodinger's cat problem in the theory of measurement.

Martinis, J.M.; Devoret, M.H.; Clarke, J.; Urbina, C.

1984-11-01T23:59:59.000Z

222

Modelling tunnelling-induced settlement of masonry buildings  

E-Print Network [OSTI]

Modelling tunnelling-induced settlement of masonry buildings H. J. Burd, MA DPhil, G. T. Houlsby in which green®eld settlements are imposed on a structual model of the build- ing. This process ignores on a structural model of the building to obtain an assessment of the expected damage. Burland and Wroth1 described

Augarde, Charles

223

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

224

Tuning the Thermal Properties of Magnetic Tunnel Junctions  

E-Print Network [OSTI]

study of this effect in MgO-based MTJs with spin-orbit coupling. We present theoretical calculations of the Tunneling Anisotropic Magneto-Seebeck effect using realistic band structures, and show that the thermal properties of MTJs are tunable via...

Amin, Vivek Pravin

2014-04-18T23:59:59.000Z

225

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

226

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

227

Wind and saltation driven particle resuspension in a wind tunnel  

SciTech Connect (OSTI)

To determine parameters of primary importance in wind and saltation driven resuspension of fine particles from surfaces, wind tunnel experiments were conducted to study the resuspension of small polydisperse particles (diameter <10 ..mu..m) by monodisperse saltation particles (diameter >80 ..mu..m). The experiments were designed to simulate the atmospheric boundary layer resuspension of fine particles. 3 refs., 1 tab.

Fairchild, C.I.; Tillery, M.I.; Wheat, L.D.; Redmond, D.J.

1985-01-01T23:59:59.000Z

228

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

229

Refurbishment and Testing Techniques in a Transonic Ludwieg Tunnel  

E-Print Network [OSTI]

and Astronautics 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 4 recently been refurbished, an overview of the unique high Reynolds number facility at UT Arlington at a fixed pressure. Although all of these strategies have been applied in transonic tunnels, advances

Texas at Arlington, University of

230

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

231

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

232

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

233

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

234

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

235

Nucleation of Superconductivity at a Tunneling Barrier of High Transmissivity  

Science Journals Connector (OSTI)

We present a calculation of the parallel critical field of a plane tunneling barrier in an otherwise homogeneous superconductor, valid for Tc-T?Tc. We have found a solution of the Ginzburg-Landau equation which satisfies the semiphenomenological boundary conditions proposed by de Gennes. The critical field is significantly lower than Hc3 when the tunneling current is of the same order of magnitude as the sheath current. When the ratio (tunneling current)/(sheath current) is small, it is proportional to ?(T). Since ?(T)?? at Tc, in principle the critical field of a tunneling barrier of any transmissivity must go to Hc2 as T?Tc, although in practice this may be impossible to observe for small transmissivities because of the finite transition width at Tc. For the pure-metal, specular-barrier model at a fixed temperature T not too close to Tc, most of the drop in critical field from Hc3 to Hc2 occurs for transmissivities in the range 0.01 to 0.1.The effect we have predicted, if experimentally confirmed, may be useful as a tool for investigating the electronic properties of grain boundaries in polycrystalline metal.

R. G. Boyd

1967-01-10T23:59:59.000Z

236

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

237

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

238

Strong Coupling Between Single-Electron Tunneling and Nanomechanical Motion  

Science Journals Connector (OSTI)

...tension, similar to the tuning of a guitar string (17). Our detection signal results...increasing the current. For a nanotube oscillating on resonance, the effective potential...force and the radio frequency (RF) oscillating driving force, single-electron tunneling...

G. A. Steele; A. K. Hüttel; B. Witkamp; M. Poot; H. B. Meerwaldt; L. P. Kouwenhoven; H. S. J. van der Zant

2009-08-28T23:59:59.000Z

239

Improving sequencing by tunneling with multiplexing and cross-correlations  

E-Print Network [OSTI]

Sequencing by tunneling is a next-generation approach to read single-base information using electronic tunneling transverse to the single-stranded DNA (ssDNA) backbone while the latter is translocated through a narrow channel. The original idea considered a single pair of electrodes to read out the current and distinguish the bases [1, 2]. Here, we propose an improvement to the original sequencing by tunneling method, in which $N$ pairs of electrodes are built in series along a synthetic nanochannel. While the ssDNA is forced through the channel using a longitudinal field it passes by each pair of electrodes for long enough time to gather a minimum of $m$ tunneling current measurements, where $m$ is determined by the level of sequencing error desired. Each current time series for each nucleobase is then cross-correlated together, from which the DNA bases can be distinguished. We show using random sampling of data from classical molecular dynamics, that indeed the sequencing error is significantly reduced as the number of pairs of electrodes, $N$, increases. Compared to the sequencing ability of a single pair of electrodes, cross-correlating $N$ pairs of electrodes is exponentially better due to the approximate log-normal nature of the tunneling current probability distributions. We have also used the Fenton-Wilkinson approximation to analytically describe the mean and variance of the cross-correlations that are used to distinguish the DNA bases. The method we suggest is particularly useful when the measurement bandwidth is limited, allowing a smaller electrode gap residence time while still promising to consistently identify the DNA bases correctly.

P. Boynton; A. V. Balatsky; I. K. Schuller; M. Di Ventra

2014-01-28T23:59:59.000Z

240

Effect of fluctuating wind direction on cross natural ventilation in buildings from large eddy simulation  

E-Print Network [OSTI]

wind direction, and the simulated results agree reasonably with the corresponding experimental data is the use of small-scale models in a wind tunnel to simulate natural ventilation. In general, the mean flow1 Effect of fluctuating wind direction on cross natural ventilation in buildings from large eddy

Chen, Qingyan "Yan"

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

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

242

Running Large Scale Jobs  

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

Running Large Scale Jobs Running Large Scale Jobs Users face various challenges with running and scaling large scale jobs on peta-scale production systems. For example, certain...

243

Property:Special Physical Features | Open Energy Information  

Open Energy Info (EERE)

Physical Features Physical Features Jump to: navigation, search Property Name Special Physical Features Property Type Text Pages using the property "Special Physical Features" Showing 25 pages using this property. (previous 25) (next 25) C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + The 2-Foot Variable Pressure Cavitation Water Tunnel is a vertical plane, closed recirculating, variable-speed, variable-pressure, open jet test section, closed jet test section, and semi-rectangular test section. Carderock 3-ft Variable Pressure Cavitation Water Tunnel + The 3-ft Variable Pressure Cavitation Water Tunnel is a vertical plane, closed recirculating with resorber, variable-speed, variable-pressure, two interchangeable circular test sections. Carderock Circulating Water Channel + The Circulating Water Channel is a vertical plane, open to the atmosphere test section with a free surface in a closed recirculating water circuit, variable speed, rectangular cross-sectional shape facility. There are 10 large viewing windows on either side of the test section at different elevations and 9 in the bottom; movable bridge spans the test section for ease and versatility in mounting models, rigging bridge is capable of taking towing loads at any one of numerous points up to 35,584 N

244

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.

245

Quantum tunneling of oxygen atoms on very cold surfaces  

E-Print Network [OSTI]

Any evolving system can change of state via thermal mechanisms (hopping a barrier) or via quantum tunneling. Most of the time, efficient classical mechanisms dominate at high temperatures. This is why an increase of the temperature can initiate the chemistry. We present here an experimental investigation of O-atom diffusion and reactivity on water ice. We explore the 6-25 K temperature range at sub-monolayer surface coverages. We derive the diffusion temperature law and observe the transition from quantum to classical diffusion. Despite of the high mass of O, quantum tunneling is efficient even at 6 K. As a consequence, the solid-state astrochemistry of cold regions should be reconsidered and should include the possibility of forming larger organic molecules than previously expected.

Minissale, M; Baouche, S; Chaabouni, H; Moudens, A; Dulieu, F; Accolla, M; Cazaux, S; Manico, G; Pirronello, V

2014-01-01T23:59:59.000Z

246

Recovering information of tunneling spectrum from Weakly Isolated Horizon  

E-Print Network [OSTI]

In this paper we investigate the properties of tunneling spectrum from weakly isolated horizon(WIH). We find that there are correlations among Hawking radiations from weakly isolated horizon, the information can be carried out in terms of correlations between sequential emissions, and the radiation is an entropy conservation process. We generalize Refs.[11-13]' results to a more general spacetime. Through revisiting the calculation of tunneling spectrum of weakly isolated horizon, we find that Ref.[12]'s requirement that radiating particles have the same angular momenta of unit mass as that of black hole is not needed, and the energy and angular momenta of emitting particles are very arbitrary which should be restricted only by keeping the cosmic censorship of black hole.

Ge-Rui Chen; Yong-Chang Huang

2014-06-02T23:59:59.000Z

247

Tunneling states in vitreous GeO2s  

Science Journals Connector (OSTI)

Ultrasonic measurements of the attenuation and the velocity variation have been carried out in amorphous GeO2 at low temperature (0.3–10 K) and high frequencies (80–210 MHz). From numerical fits to the tunneling model, the typical parameters of the tunneling states (TS) were determined and compared to those found for vitreous SiO2 . The study reveals that in a-GeO2 , which is considered as a close structural analog to a-SiO2 , although the density of states is found to be very similar in both materials, the coupling between the TS and the phonons is significantly smaller. In the model of coupled tetrahedra as the origin of the TS, this difference can be understood in view of the fact that numerical calculations about the vibrational characteristics of network amorphous solids indicate that the tetrahedra are more decoupled in vitreous GeO2 than in vitreous silica.

Christiane Laermans; Veerle Keppens; Robert Weeks

1997-02-01T23:59:59.000Z

248

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

249

Model for tunneling in many-particle systems  

Science Journals Connector (OSTI)

A model is proposed for studying tunneling in many-particle systems that is simple enough to solve and realistic enough to test various collective models of multidimensional barrier penetration. We find that the imaginary time dependent mean-field theory works very well in its domain of applicability, as does a continuum hopping approximation. The usual cranked mean field approximation is much less reliable.

P. Arve; G. F. Bertsch; J. W. Negele; G. Puddu

1987-11-01T23:59:59.000Z

250

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

251

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

2012-09-28T23:59:59.000Z

252

Conditional probabilities in quantum theory, and the tunneling time controversy  

E-Print Network [OSTI]

It is argued that there is a sensible way to define conditional probabilities in quantum mechanics, assuming only Bayes's theorem and standard quantum theory. These probabilities are equivalent to the ``weak measurement'' predictions due to Aharonov {\\it et al.}, and hence describe the outcomes of real measurements made on subensembles. In particular, this approach is used to address the question of the history of a particle which has tunnelled across a barrier. A {\\it gedankenexperiment} is presented to demonstrate the physically testable implications of the results of these calculations, along with graphs of the time-evolution of the conditional probability distribution for a tunneling particle and for one undergoing allowed transmission. Numerical results are also presented for the effects of loss in a bandgap medium on transmission and on reflection, as a function of the position of the lossy region; such loss should provide a feasible, though indirect, test of the present conclusions. It is argued that the effects of loss on the pulse {\\it delay time} are related to the imaginary value of the momentum of a tunneling particle, and it is suggested that this might help explain a small discrepancy in an earlier experiment.

Aephraim M. Steinberg

1995-02-02T23:59:59.000Z

253

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

254

Quantum tunneling and reflection of a molecule with a single bound state  

SciTech Connect (OSTI)

In this article, we present the results of studies on the quantum mechanical tunneling and reflection of a diatomic, homonuclear molecule with a single bound state incident upon a potential barrier. In the first study, we investigate the tunneling of a molecule using a time-dependent formulation. The molecular wave function is modeled as a Gaussian wave packet, and its propagation is calculated numerically using Crank-Nicholson integration. It is found that a molecule may transition between the bound state and an unbound state numerous times during the process of reflection from or transmission past the barrier. It is also found that, in addition to reflecting and transmitting, the molecule may also temporarily straddle the potential barrier in an unbound state. In the second study, we consider the case of a molecule incident in the bound state upon a step potential with energy less than the step. We show that in the limit where the binding energy e{sub 0} approaches zero and the step potential V{sub 0} goes to infinity, the molecule cannot remain in a bound state if the center of mass gets closer to the step than an arbitrarily large distance x{sub 0} which increases as the magnitude of e{sub 0} decreases, as V{sub 0} increases, or both. We also show that, for e{sub 0{yields}}0{sup -} and V{sub 0{yields}{infinity}}, if the molecule is incident in the bound state, it is reflected in the bound state with probability equal to unity, when the center of mass reaches the reflection distance x{sub 0}. We verify that the unbound states exhibit the expected physical behavior. We discuss some surprising results. Connections between our results and investigations done in cold atoms, excitons, Cooper pairs, and Rydberg atoms are discussed.

Kavka, Jeremy J.; Kerbrat, Danielle; Shegelski, Mark R. A. [Department of Physics, University of Northern British Columbia, Prince George, British Columbia V2N 4Z9 (Canada)

2010-02-15T23:59:59.000Z

255

Eliashberg Function in an Amorphous Simple Metal Alloy Sn1-Xcux Determined by Electron-Tunneling  

E-Print Network [OSTI]

dependence based on asymptotic expansions in different frequency re- gions. As discussed in a preliminary report of these tunneling measurements, the amorphous Sn& Cu system is the best characterized of simple metal amorphous superconductors and is well... between the experi- mental tunneling density of states and that calculated with u F(co). For most superconductors a quadratic dependence of n F(cu) below ui;?provides good agreement between the experimental and calculated tunneling density of states...

WATSON, PW; Naugle, Donald G.

1995-01-01T23:59:59.000Z

256

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

257

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

258

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......

259

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...

260

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.

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

Pressure dependence of tunneling and librational modes of coupled methyl groups in lithium acetate  

Science Journals Connector (OSTI)

The pressure dependence of the tunneling and librational modes of the coupled methyl groups in lithium acetate dihydrate was studied by inelastic neutron scattering...

A. Heidemann; J. Eckert; L. Passell…

1987-01-01T23:59:59.000Z

262

Tunneling of coupled methyl groups in lithium acetate: The isotope effect  

Science Journals Connector (OSTI)

We studied by high resolution inelastic neutron scattering the isotope effect of tunneling of coupled methyl groups in lithium acetate dihydrate (LIAC). Fully protonated, fully...

A. Heidemann; H. Friedrich; E. Günther…

1989-01-01T23:59:59.000Z

263

Luminescence from hydrodynamic cavitation  

Science Journals Connector (OSTI)

...vibrations, and may affect the efficiency of a hydraulic system, such as a pump or a turbine. The level of understanding...200-650nm response, quantum efficiency 20% at 400nm, rise time...300-820nm, peak quantum efficiency 20% at 420nm). The...

2011-01-01T23:59:59.000Z

264

Troll Phase 1, installation of large spools before pipelay  

SciTech Connect (OSTI)

Development of the Troll Phase 1 project required landfall--towards a gas conditioning plant on the Norwegian west coast--of both 36-in. wet gas fed (or import) pipelines and 40-inch dry gas export pipelines. The very uneven seabed necessitated both the driving of a 3.5 km long subsea tunnel system and extensive route preparations. The lateral separation of 142 to 163 m between subsea tunnel pipeline risers and offshore pipeline laydown was bridged by fabricating four large--147 to 186 tons--spools. These spools were installed gas-filled in unique single lifts using special sea fastening and guidance systems. The odd-shaped 3-D spool configurations were fabricated to match an extensively prepared seabed. The spools were installed after tunnel pipeline riser completion but before pipeline laydown to minimize the duration of underwater activities late in the season. Special support structures were fabricated to support hyperbaric welding and pipeline laydown operations. Accurate pipeline laydown facilitated simple and quick lift, shift and alignment operations, and all (seven) automated hyperbaric welds with the Pipeline Repair Systems (PRS) were completed on schedule without the use of pup-pieces. Diver support during these activities constituted a significant operation in itself.

Buchan, S. [Rockwater AS, Stavanger (Norway); Kuhlmann, J.H. [A/S Norske Shell, Bergen (Norway)

1996-12-01T23:59:59.000Z

265

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

266

Results from Point Contact Tunnelling Spectroscopy and Atomic Layer Deposition  

SciTech Connect (OSTI)

We have shown previously that magnetic niobium oxides can influence the superconducting density of states at the surface of cavity-grade niobium coupons. We will present recent results obtained by Point Contact Tunneling spectroscopy (PCT) on coupons removed from hot and cold spots in a niobium cavity, as well as a comparative study of magnetic oxides on mild baked/unbaked electropolished coupons. We will also describe recent results obtained from coated cavities, ALD films properties and new materials using Atomic Layer Deposition (ALD).

Proslier, Th. [Illinois Institute of Technology; Zasadzinski, J. [Illinois Institute of Technology; Ciovati, Gianluigi [JLAB; Kneisel, Peter K. [JLAB; Elam, J. W. [ANL; Norem, J. [ANL; Pellin, M. J. [ANL

2009-11-01T23:59:59.000Z

267

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

268

Nonlinear Photon-Assisted Tunneling Transport in Optical Gap Antennas  

Science Journals Connector (OSTI)

(16, 17) For instance, incoming photons can exchange energy with tunneling charges modifying thus the conductance of the barrier(18, 19) and strong-field effects were recently reported. ... (32) The height ? of the potential barriers can be directly deduced from these two minima. ... Two lock-in amplifiers referenced at Fmod and 2Fmod output a signal proportional to the differential conductance I? = Vac(?Ib/?Vb) of the gap antenna and signal proportional to the nonlinearity of the conductance I? = 1/4Vac2(?2Ib/?Vb2), respectively. ...

Arnaud Stolz; Johann Berthelot; Marie-Maxime Mennemanteuil; Gérard Colas des Francs; Laurent Markey; Vincent Meunier; Alexandre Bouhelier

2014-04-03T23:59:59.000Z

269

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.

270

Reynolds-Averaged Navier-Stokes Simulation of a 2D Circulation Control Wind Tunnel Experiment  

E-Print Network [OSTI]

Reynolds-Averaged Navier-Stokes Simulation of a 2D Circulation Control Wind Tunnel Experiment Brian airfoil. 2D and 3D simulation results are compared to a circulation control wind tunnel test conducted simulations are performed using a Reynolds-averaged Navier-Stokes (RANS) flow solver for a circulation control

Frey, Pascal

271

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

272

Ris-R-981(EN) Validation of a Wind Tunnel Testing  

E-Print Network [OSTI]

Risø-R-981(EN) Validation of a Wind Tunnel Testing Facility for Blade Surface Pressure Measurements April 1998 #12;Abstract This report concerns development and validation of a 2d testing facility for airfoil pressure measurements. The VELUX open jet wind tunnel was used with a test stand inserted

273

Metallic-nanoparticle assisted enhanced band-to-band tunneling current Deblina Sarkara)  

E-Print Network [OSTI]

Metallic-nanoparticle assisted enhanced band-to-band tunneling current Deblina Sarkara) and Kaustav) Metallic nanoparticle assisted band-to-band tunneling is proposed, and the impact of such nanoparticle that an asymmetric pinning is required to leverage maximum benefits from the insertion of metallic nanoparticles. VC

274

Aluminum oxide tunnel barriers for single electron memory devices Kameshwar K. Yadavallia,  

E-Print Network [OSTI]

oxide. These devices are characterized at 300 mK and show a definite threshold for tunneling through and storage dots in ultra thin poly-Si films [3], one-dimensional array of Al/ Al2O3 tunnel junctions [4], non aluminum oxide is deposited by atomic layer deposition. Measurements performed at 300 mK show nonvolatile

Orlov, Alexei

275

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

276

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

277

Nonequilibrium Phenomena in Electron Tunneling in Normal Metal-Insulator-Metal Junctions  

Science Journals Connector (OSTI)

Structure in the conductance of normal metal-insulator-metal junctions at very low bias is explained through a nonequilibrium treatment of the tunneling process. In particular, the related peak in the derivative d?(V)dV is quantitatively accounted for by the blocking of otherwise available electron tunneling states due to the finite electron relaxation rates in the metal electrodes.

P. N. Trofimenkoff; H. J. Kreuzer; W. J. Wattamaniuk; J. G. Adler

1972-08-28T23:59:59.000Z

278

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.

279

Spin torque in magnetic tunnel junctions with asymmetric barriers  

Science Journals Connector (OSTI)

We derive expressions for both parallel and perpendicular components of spin transfer torque (STT) in magnetic tunnel junctions (MTJs), which have several important advantages over the currently available expressions: First they are derived in a more realistic approximation, resulting in excellent agreement with exact results even in the presence of resonant tunneling. Second, we show that they can be expressed in terms of the scattering matrix elements, which gives them a clear physical interpretation. Third, they are given entirely in terms of collinear quantities, which are readily available in existing transport codes. We use these expressions to investigate STT behavior in MTJs with asymmetric barriers at finite bias. The results show that lowering the barrier height in the bulk does not qualitatively change the behavior of STT. The absolute STT increases on account of the overall increase of the barrier transparency; however, the STT efficiency remains in the same range. At the same time, modifications of the interfaces can qualitatively change STT behavior. Thus, interface engineering can be used to control the bias dependence of STT and optimize the performance of STT-based devices.

Alan Kalitsov; Whasington Silvestre; Mairbek Chshiev; Julian P. Velev

2013-09-30T23:59:59.000Z

280

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

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

Topeka's "Green Light Tunnel" Saves Fuel and Time | Department of  

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

Topeka's "Green Light Tunnel" Saves Fuel and Time Topeka's "Green Light Tunnel" Saves Fuel and Time Topeka's "Green Light Tunnel" Saves Fuel and Time April 22, 2011 - 1:50pm Addthis Topeka, Kansas, has activated the first of three key traffic corridors to receive a "green light tunnel," a real-time adaptive traffic signal system that synchronizes signals to create a series of green lights for motorists. The result is fewer stops, less travel time and -- most importantly -- a lot of saved gasoline. Sallie Glaize Project Officer, Office of Energy Efficiency & Renewable Energy What does this project do? Saves motorists in Topeka time and money. The first of three key traffic corridors in Topeka, Kansas has received a "green light tunnel," a real-time adaptive traffic signal system that

282

Noise Sources and Room Acoustics of Closed Circuit Subsonic Wind Tunnels  

Science Journals Connector (OSTI)

The noise aspects of subsonic wind tunnels have been studied experimentally on full?scale and model?scale tunnels. In wind tunnels without acoustical treatment the driving fan and the boundary layer suction fan were found to be the dominant noise sources. The fan noise in the test section scales with the 6th power of the airspeed. Using this scaling one obtains a number the acoustical merit rating which permits one to compare the acoustical quality of different wind tunnels. Experimental results obtained in full scale as well as in scale models of closed circuit tunnels will be presented to illustrate the impulse response and spatial distribution of the sound pressure. Also the special instrumentation required for obtaining valid results will be discussed.

I. L. Vér

1973-01-01T23:59:59.000Z

283

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

284

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

285

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

286

Charge transport in purple membrane monolayers: A sequential tunneling approach  

E-Print Network [OSTI]

Current voltage (I-V) characteristics in proteins can be sensitive to conformational change induced by an external stimulus (photon, odour, etc.). This sensitivity can be used in medical and industrial applications besides shedding new light in the microscopic structure of biological materials. Here, we show that a sequential tunneling model of carrier transfer between neighbouring amino-acids in a single protein can be the basic mechanism responsible of the electrical properties measured in a wide range of applied potentials. We also show that such a strict correlation between the protein structure and the electrical response can lead to a new generation of nanobiosensors that mimic the sensorial activity of living species. To demonstrate the potential usefulness of protein electrical properties, we provide a microscopic interpretation of recent I-V experiments carried out in bacteriorhodopsin at a nanoscale length.

Eleonora Alfinito; Jean-Francois Millithaler; Lino Reggiani

2011-05-04T23:59:59.000Z

287

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

288

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

289

Photogeologic reconnaissance of X-tunnel at Little Skull Mountain  

SciTech Connect (OSTI)

On June 29, 1992, a magnitude 5.6 earthquake occurred immediately to the south of Little Skull Mountain; the depth of the shock was about 9 kilometers (6 miles). It is the location of an underground structure known as X-tunnel, that once supported deep basing studies for the Air Force in the 1980s. The Nevada Operations Office of US DOE authorized access to the facility on several occasions to allow technical specialists from the Yucca Mountain Site Characterization Project, including geoscientists and engineers, to gather information about possible damage related to the earthquake. Examination of the underground facility in the vicinity of Yucca Mountain indicated little or no damage to the facility. Photogeologic reconnaissance affirmed that the potential for damage to underground facilities is moderated and attenuated by depth below the ground surface.

Voegele, M.D. [SAIC, Las Vegas, NV (United States)

1993-12-31T23:59:59.000Z

290

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

291

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

292

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

293

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

294

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

295

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

296

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

297

Numerical simulation of solitary wave generation in a wind-water annular tunnel  

Science Journals Connector (OSTI)

We briefly describe laboratory experiments demonstrating wind-water solitary wave generation in a wind-water annular tunnel. A mathematical model of this phenomenon is constructed in the context of a shallow-w...

T. G. Elizarova; M. A. Istomina…

2012-11-01T23:59:59.000Z

298

Wind tunnel simulation of wind effect on a group of high Cooling towers  

Science Journals Connector (OSTI)

Aerodynamic interference between high cooling towers in the atmospheric boundary layer (ABL) and uniform flow has been discussed. For the 1/1000 ABL model set up in the 2.25m low speed wind tunnel at Peking Unive...

Yan Dachun; Li Chenxin

1987-02-01T23:59:59.000Z

299

Determination of erodible particles on cultivated soils by wind tunnel simulation  

Science Journals Connector (OSTI)

The erodible particle size distribution, diameter range and separate content of three soils from semi-arid regions of China were determined at different wind velocities through wind tunnel simulation and dry siev...

Lianyou Liu; Jianhua Wang; Xiaoyan Li; Yuzhang Liu; Wanquan Ta…

1998-10-01T23:59:59.000Z

300

Wind Tunnel Experiments and Numerical Simulation of Snow Drifting around an Avalanche Protecting Dam  

Science Journals Connector (OSTI)

To learn about wind flow and snow drifting around avalanche dams, ... experiments were done in the Jules Verne Climatic Wind Tunnel. The paper reports the results from numerical wind flow simulations that were do...

Skuli Thordarson

2002-12-01T23:59:59.000Z

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.


301

Predicting penetration rate of hard rock tunnel boring machine using fuzzy logic  

Science Journals Connector (OSTI)

Predicting the penetration rate of a tunnel boring machine (TBM) ... have been developed for the prediction of TBM penetration rates using traditional statistical analysis techniques. Soft computing ... fuzzy log...

Ebrahim Ghasemi; Saffet Yagiz…

2014-02-01T23:59:59.000Z

302

Atomic-Scale Chemical Imaging via Combination of Scanning Tunneling and Electron Energy Loss Spectroscopies  

E-Print Network [OSTI]

systems at atomic level Develop atomically resolved chemical imaging platform via combination of lowAtomic-Scale Chemical Imaging via Combination of Scanning Tunneling and Electron Energy Loss visualization of chemical reaction pathways to provide mechanistic understanding for catalytically important

303

Tunneling current of the contact between impurity-containing graphene nanoribbons  

SciTech Connect (OSTI)

The current-voltage characteristics of a tunneling contact between two graphene nanoribbons containing impurity atoms are obtained based on the previously calculated density of states. The dependences on the nanoribbon geometrical and energy characteristics are calculated.

Belonenko, M. B. [Volgograd Institute of Business (Laboratory of Nanotechnologies) (Russian Federation); Pak, A. V., E-mail: pak.anastasia@gmail.com; Lebedev, N. G. [Volgograd State University (Russian Federation)

2013-05-15T23:59:59.000Z

304

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

305

DOE/NV/26383-109 A Historical Evaluation of the U12t Tunnel,  

National Nuclear Security Administration (NNSA)

26383-109 A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada Prepared by Harold Drollinger, Robert C. Jones, and Thomas F. Bullard, Desert Research...

306

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

307

Resonant tunneling device with two-dimensional quantum well emitter and base layers  

DOE Patents [OSTI]

A double electron layer tunneling device is presented. Electrons tunnel from a two dimensional emitter layer to a two dimensional tunneling layer and continue traveling to a collector at a lower voltage. The emitter layer is interrupted by an isolation etch, a depletion gate, or an ion implant to prevent electrons from traveling from the source along the emitter to the drain. The collector is similarly interrupted by a backgate, an isolation etch, or an ion implant. When the device is used as a transistor, a control gate is added to control the allowed energy states of the emitter layer. The tunnel gate may be recessed to change the operating range of the device and allow for integrated complementary devices. Methods of forming the device are also set forth, utilizing epoxy-bond and stop etch (EBASE), pre-growth implantation of the backgate or post-growth implantation. 43 figs.

Simmons, J.A.; Sherwin, M.E.; Drummond, T.J.; Weckwerth, M.V.

1998-10-20T23:59:59.000Z

308

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

309

New Method to Study Spin Conversion of a Nuclear-Spin Rotor with Low Tunnel Splitting  

Science Journals Connector (OSTI)

A new method is developed to measure the spin-conversion time ?con in low-tunnel-frequency systems. The experiment uses field cycling and consists of three steps: saturation of the tunnel reservoir by Zeeman-tunnel resonance; waiting, away from resonance, during a variable time interval tW; and measurement of the decreased tunnel temperature TT, by use of a saturated Zeeman reservoir. A plot of TT vs tW yields ?con. ?con of CH3 rotors in copper acetate is measured at 15, 12.5, and 6 K and turns out to be extremely long, at least 20T1. This discrepancy is discussed and compared with the one found in lithium acetate.

Greta Vandemaele; Paul Coppens; Lieven Van Gerven

1986-03-17T23:59:59.000Z

310

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

311

Electronic structures at Magnetic Tunnel Junction interfaces: EELS experiments and FEFF calculations  

Science Journals Connector (OSTI)

Electron transfer between the electrodes in a Magnetic Tunnel Junction (MTJ) is spin-dependent and directly related to the relative orientation of the magnetization of the two ferromagnetic layers on each side...

K. March; D. Imhoff; G. Krill; C. Colliex

2008-01-01T23:59:59.000Z

312

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

E-Print Network [OSTI]

pairs of allosteric domains. No significant dependence of the specific catalytic activity on the protein concentration could be detected. The molecular tunnel within CPS was inspected in order to characterize the role on kinetic properties. Gln-22, Ala...

Kim, Jungwook

2004-09-30T23:59:59.000Z

313

Resonant tunneling device with two-dimensional quantum well emitter and base layers  

DOE Patents [OSTI]

A double electron layer tunneling device is presented. Electrons tunnel from a two dimensional emitter layer to a two dimensional tunneling layer and continue traveling to a collector at a lower voltage. The emitter layer is interrupted by an isolation etch, a depletion gate, or an ion implant to prevent electrons from traveling from the source along the emitter to the drain. The collector is similarly interrupted by a backgate, an isolation etch, or an ion implant. When the device is used as a transistor, a control gate is added to control the allowed energy states of the emitter layer. The tunnel gate may be recessed to change the operating range of the device and allow for integrated complementary devices. Methods of forming the device are also set forth, utilizing epoxy-bond and stop etch (EBASE), pre-growth implantation of the backgate or post-growth implantation.

Simmons, Jerry A. (Sandia Park, NM); Sherwin, Marc E. (Rockville, MD); Drummond, Timothy J. (Tijeras, NM); Weckwerth, Mark V. (Pleasanton, CA)

1998-01-01T23:59:59.000Z

314

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

315

The development of a low velocity wind tunnel with instrumentation for boundary layer investigations  

E-Print Network [OSTI]

THE DEVELOPMENT OF A LOW VELOCITY WIND TUNNEL WITH INSTRUMENTATION FOR BOUNDARY LAYER INVESTIGATIONS A Dissertation B y John Robert Massey Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial... fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY May 1958 Major Subject: Mechanical Engineering THE DEVELOPMENT OF A LOW VELOCITY WIND TUNNEL WITH INSTRUMENTATION FOR BOUNDARY LAYER INVESTIGATIONS A Dissertation By John Robert...

Massey, John Robert

2013-10-04T23:59:59.000Z

316

The relation between Hawking radiation via tunnelling and the laws of black hole thermodynamics  

E-Print Network [OSTI]

In Parikh and Wilczek's original works, the laws of black hole thermodynamics are not referred and it seems that there is no relation between Hawking radiation via tunnelling and the laws of black hole thermodynamics in their works. However, taking examples for the R-N black hole and the Kerr black hole, we find that they are correlated and even consistent if the tunnelling process is a reversible process.

Yapeng Hu; Jingyi Zhang; Zheng Zhao

2006-01-05T23:59:59.000Z

317

Meet with Large Businesses  

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

Meet with Large Businesses Meet with Large Businesses and learn about upcoming acquisitions! * Federal Energy Management Program (FEMP) * National Renewable Energy Laboratory (NREL) * Small Business Administration (SBA) * U.S. Department of Energy / Energy, Efficiency, and Renewable Energy (EERE) * U.S. Department of Energy / Golden Field Office (GFO) * Western Area Power Administration (WAPA) * Colorado Procurement Technical Assistance Center (PTAC)

318

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

319

Dynamic simulation of batch freezing tunnels for fish using Modelica  

Science Journals Connector (OSTI)

Fish products are frozen to preserve quality and extend shelf-life. However, freezing processes in the industry are typically very energy demanding and seldom optimized with regard to energy usage. During freezing, the operating conditions for the refrigeration cycle, as well as the driving temperature difference over the product changes significantly from start to finish. A complete transient model including a refrigeration plant, an air blast freezing tunnel and food products has been built, based on the Modelica programming language. The product model is discretized into uniform layers, described with equations for temperature dependent properties such as thermal conductivity and heat capacity. Normally, fan power represents about 25 – 30% of the total refrigeration requirement, but at the end of the freezing process, heat from the fans can represent up to 95-99% of the refrigeration load. The results from this model indicates that a 33% reduction in total power consumption, with a penalty of 14% longer freezing time is possible with better operation of the fan. In general, this model can be a useful tool for visualization of energy saving measures. It combines a product model with a refrigeration system, demonstrating the effect of process modification on both single components and overall process performance.

Harald Taxt Walnum; Trond Andresen; Kristina Widell

2011-01-01T23:59:59.000Z

320

Applied large eddy simulation  

Science Journals Connector (OSTI)

...2971-2983. doi:10.1098/rsta.2008.0303 . Audio Supplement Audio Supplement Audio files from the Applied large eddy simulation...fidelity. | Whittle Laboratory, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ...

2009-01-01T23:59:59.000Z

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.


321

Hawking radiation as tunneling and the unified first law of thermodynamics at the apparent horizon in the FRW universe  

E-Print Network [OSTI]

Relations between the tunneling rate and the unified first law of thermodynamics at the apparent horizon of the FRW universe are investigated. The tunneling rate arises as a consequence of the unified first law of thermodynamics in such a dynamical system. The analysis shows obviously how the tunneling is intimately connected with the unified first law of thermodynamics through the principle of conservation of energy.

Ke-Xia Jiang; San-Min Ke; Dan-Tao Peng; Jun Feng

2008-12-16T23:59:59.000Z

322

Property:Cameras | Open Energy Information  

Open Energy Info (EERE)

Property Property Edit with form History Facebook icon Twitter icon » Property:Cameras Jump to: navigation, search Property Name Cameras Property Type Text Pages using the property "Cameras" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + None 10-ft Wave Flume Facility + None 11-ft Wave Flume Facility + None 2 2-ft Flume Facility + None 3 3-ft Wave Flume Facility + None 5 5-ft Wave Flume Facility + None 6 6-ft Wave Flume Facility + None A Alden Large Flume + Yes Alden Small Flume + Yes Alden Tow Tank + Yes Alden Wave Basin + Yes B Breakwater Research Facility + None C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + None Carderock 3-ft Variable Pressure Cavitation Water Tunnel + None Carderock Circulating Water Channel + None

323

Property:Wavemaking Capabilities | Open Energy Information  

Open Energy Info (EERE)

Wavemaking Capabilities Wavemaking Capabilities Jump to: navigation, search Property Name Wavemaking Capabilities Property Type String Pages using the property "Wavemaking Capabilities" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + Yes + 10-ft Wave Flume Facility + Yes + 11-ft Wave Flume Facility + Yes + 2 2-ft Flume Facility + Yes + 3 3-ft Wave Flume Facility + Yes + 5 5-ft Wave Flume Facility + Yes + 6 6-ft Wave Flume Facility + Yes + A Alden Large Flume + Yes + Alden Small Flume + Yes + Alden Tow Tank + None + Alden Wave Basin + Yes + B Breakwater Research Facility + Yes + Bucknell Hydraulic Flume + None + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + None + Carderock 3-ft Variable Pressure Cavitation Water Tunnel + None +

324

Property:Wind Capabilities | Open Energy Information  

Open Energy Info (EERE)

Capabilities Capabilities Jump to: navigation, search Property Name Wind Capabilities Property Type String Pages using the property "Wind Capabilities" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + None + 10-ft Wave Flume Facility + None + 11-ft Wave Flume Facility + Yes + 2 2-ft Flume Facility + None + 3 3-ft Wave Flume Facility + None + 5 5-ft Wave Flume Facility + None + 6 6-ft Wave Flume Facility + None + A Alden Large Flume + Yes + Alden Small Flume + Yes + Alden Tow Tank + Yes + Alden Wave Basin + Yes + B Breakwater Research Facility + None + Bucknell Hydraulic Flume + None + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + None + Carderock 3-ft Variable Pressure Cavitation Water Tunnel + None +

325

Property:Towing Capabilities | Open Energy Information  

Open Energy Info (EERE)

Towing Capabilities Towing Capabilities Jump to: navigation, search Property Name Towing Capabilities Property Type String Pages using the property "Towing Capabilities" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + None + 10-ft Wave Flume Facility + None + 11-ft Wave Flume Facility + None + 2 2-ft Flume Facility + None + 3 3-ft Wave Flume Facility + None + 5 5-ft Wave Flume Facility + None + 6 6-ft Wave Flume Facility + None + A Alden Large Flume + Yes + Alden Small Flume + None + Alden Tow Tank + Yes + Alden Wave Basin + None + B Breakwater Research Facility + None + Bucknell Hydraulic Flume + Yes + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + None + Carderock 3-ft Variable Pressure Cavitation Water Tunnel + None +

326

Property:Test Services | Open Energy Information  

Open Energy Info (EERE)

Services Services Jump to: navigation, search Property Name Test Services Property Type String Pages using the property "Test Services" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + Yes + 10-ft Wave Flume Facility + Yes + 11-ft Wave Flume Facility + Yes + 2 2-ft Flume Facility + Yes + 3 3-ft Wave Flume Facility + Yes + 5 5-ft Wave Flume Facility + Yes + 6 6-ft Wave Flume Facility + Yes + A Alden Large Flume + Yes + Alden Small Flume + Yes + Alden Tow Tank + Yes + Alden Wave Basin + Yes + B Breakwater Research Facility + None + Bucknell Hydraulic Flume + Yes + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + None + Carderock 3-ft Variable Pressure Cavitation Water Tunnel + None + Carderock Circulating Water Channel + None +

327

Property:Special Characteristics | Open Energy Information  

Open Energy Info (EERE)

Characteristics Characteristics Jump to: navigation, search Property Name Special Characteristics Property Type String Pages using the property "Special Characteristics" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + None + 10-ft Wave Flume Facility + None + 11-ft Wave Flume Facility + Yes + 2 2-ft Flume Facility + None + 3 3-ft Wave Flume Facility + None + 5 5-ft Wave Flume Facility + None + 6 6-ft Wave Flume Facility + Yes + A Alden Large Flume + Yes + Alden Small Flume + Yes + Alden Tow Tank + None + Alden Wave Basin + Yes + B Breakwater Research Facility + None + Bucknell Hydraulic Flume + Yes + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + None + Carderock 3-ft Variable Pressure Cavitation Water Tunnel + None +

328

Property:Real-Time | Open Energy Information  

Open Energy Info (EERE)

Real-Time Real-Time Jump to: navigation, search Property Name Real-Time Property Type String Pages using the property "Real-Time" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + No + 10-ft Wave Flume Facility + No + 11-ft Wave Flume Facility + No + 2 2-ft Flume Facility + No + 3 3-ft Wave Flume Facility + No + 5 5-ft Wave Flume Facility + No + 6 6-ft Wave Flume Facility + No + A Alden Large Flume + Yes + Alden Small Flume + Yes + Alden Tow Tank + Yes + Alden Wave Basin + Yes + B Breakwater Research Facility + No + Bucknell Hydraulic Flume + No + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + No + Carderock 3-ft Variable Pressure Cavitation Water Tunnel + No + Carderock Circulating Water Channel + No +

329

Category:Testing Facilities | Open Energy Information  

Open Energy Info (EERE)

Facilities Facilities Jump to: navigation, search This category is defined by the form Testing Facility. Subcategories This category has only the following subcategory. H [×] Hydrodynamic Testing Facility Type‎ 9 pages Pages in category "Testing Facilities" The following 82 pages are in this category, out of 82 total. 1 1.5-ft Wave Flume Facility 10-ft Wave Flume Facility 11-ft Wave Flume Facility 2 2-ft Flume Facility 3 3-ft Wave Flume Facility 5 5-ft Wave Flume Facility 6 6-ft Wave Flume Facility A Alden Large Flume Alden Small Flume Alden Tow Tank Alden Wave Basin B Breakwater Research Facility Bucknell Hydraulic Flume C Carderock 2-ft Variable Pressure Cavitation Water Tunnel Carderock 3-ft Variable Pressure Cavitation Water Tunnel Carderock Circulating Water Channel

330

The Yucca Mountain Project prototype air-coring test, U12g tunnel, Nevada test site  

SciTech Connect (OSTI)

The Prototype Air-Coring Test was conducted at the Nevada Test Site (NTS) G-Tunnel facility to evaluate standard coring techniques, modified slightly for air circulation, for use in testing at a prospective nuclear waste repository at Yucca Mountain, Nevada. Air-coring technology allows sampling of subsurface lithology with minimal perturbation to ambient characteristic such as that required for exploratory holes near aquifers, environmental applications, and site characterization work. Two horizontal holes were cored, one 50 ft long and the other 150 ft long, in densely welded fractured tuff to simulate the difficult drilling conditions anticipated at Yucca Mountain. Drilling data from seven holes on three other prototype tests in nonwelded tuff were also collected for comparison. The test was used to establish preliminary standards of performance for drilling and dust collection equipment and to assess procedural efficiencies. The Longyear-38 drill achieved 97% recovery for HQ-size core (-2.5 in.), and the Atlas Copco dust collector (DCT-90) captured 1500 lb of fugitive dust in a mine environment with only minor modifications. Average hole production rates were 6-8 ft per 6-h shift in welded tuff and almost 20 ft per shift on deeper holes in nonwelded tuff. Lexan liners were successfully used to encapsulate core samples during the coring process and protect core properties effectively. The Prototype Air-Coring Test demonstrated that horizontal air coring in fractured welded tuff (to at least 150 ft) can be safely accomplished by proper selection, integration, and minor modification of standard drilling equipment, using appropriate procedures and engineering controls. The test also indicated that rig logistics, equipment, and methods need improvement before attempting a large-scale dry drilling program at Yucca Mountain.

Ray, J.M. [Los Alamos National Lab., NM (United States); Newsom, J.C. [Newsom Industries, Citrus Heights, CA (United States)

1994-12-01T23:59:59.000Z

331

On the Potential Use of Small Scale Fire Tests for Screening Steiner Tunnel Results for Spray Foam Insulation.  

E-Print Network [OSTI]

??The goal of this study is to assess the potential of using bench-scale fire testing to screen materials for the Steiner tunnel fire test. It… (more)

Didomizio, Matthew

2013-01-01T23:59:59.000Z

332

Chemical beam epitaxy growth of AlGaAs/GaAs tunnel junctions using trimethyl aluminium for multijunction solar cells  

SciTech Connect (OSTI)

AlGaAs/GaAs tunnel junctions for use in high concentration multijunction solar cells were designed and grown by chemical beam epitaxy (CBE) using trimethyl aluminium (TMA) as the p-dopant source for the AlGaAs active layer. Controlled hole concentration up to 4?10{sup 20} cm{sup ?3} was achieved through variation in growth parameters. Fabricated tunnel junctions have a peak tunneling current up to 6140 A/cm{sup 2}. These are suitable for high concentration use and outperform GaAs/GaAs tunnel junctions.

Paquette, B.; DeVita, M.; Turala, A.; Kolhatkar, G.; Boucherif, A.; Jaouad, A.; Aimez, V.; Arès, R. [Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, Sherbrooke, Québec (Canada)] [Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, Sherbrooke, Québec (Canada); Wilkins, M.; Wheeldon, J. F.; Walker, A. W.; Hinzer, K. [Centre for Research in Photonics, University of Ottawa, Ottawa, ON (Canada)] [Centre for Research in Photonics, University of Ottawa, Ottawa, ON (Canada); Fafard, S. [Cyrium Technologies Inc., Ottawa, ON (Canada)] [Cyrium Technologies Inc., Ottawa, ON (Canada)

2013-09-27T23:59:59.000Z

333

Sustainable heat extraction from abandoned mine tunnels: A numerical model  

Science Journals Connector (OSTI)

Abandoned mines are often associated with enduring liabilities which involve significant costs for decades after the decommissioning of the mine. Using a decommissioned mine as a geothermal resource can offset the environmental costs by supplying green heat to the communities living in and around the mine area. In this paper a numerical assessment of geothermal heat extraction from underground mine workings using an open loop geothermal system is carried out. In this study our focus is on fully flooded mines where the heat flow from the rock mass to the mine cavities is dominantly controlled by conduction in the rock mass. The sustainable heat flux into the mine workings is assessed using a transient two-dimensional axisymmetric heat transfer model. Finite volume method is applied to solve the model and simulate the transient temperature fields in the rock mass and within the water (flowing through cavities). The model is capable of controlling the rate of heat extraction through continuous adjustment of the rate of water flow through the mine. Sustainable rate of heat extraction is calculated for seasonally varied heat loads and for different project life cycles. It is shown that with proper resource management each kilometre of a typical deep underground mine tunnel can produce about 150?kW of usable heat in a sustainable manner. The model is validated by comparing its results with other published models and realistic data available from Springhill mine Nova Scotia Canada. It is found that the sustainable heat extraction is controlled dominantly by virgin rock temperature thermal conductivity of the rock mass and seasonal heat load variations.

S. A. Ghoreishi Madiseh; Mory M. Ghomshei; F. P. Hassani; F. Abbasy

2012-01-01T23:59:59.000Z

334

Application of artificial neural networks to the prediction of tunnel boring machine penetration rate  

Science Journals Connector (OSTI)

Abstract Rate of penetration of a Tunnel Boring Machine (TBM) in a rock environment is generally a key parameter for the successful accomplishment of a tunneling project. This paper presents the results of a study into the application of an Artificial Neural Network (ANN) technique for modeling the penetration rate of tunnel boring machines. A database, including actual, measured TBM penetration rates, uniaxial compressive strengths of the rock, the distance between planes of weakness in the rock mass and rock quality designation was established. Data collected from three different TBM projects (the Queens Water Tunnel, USA, the Karaj-Tehran water transfer tunnel, Iran, and the Gilgel Gibe II hydroelectric project, Ethiopia). A five-layer ANN was found to be optimum, with an architecture of three neurons in the input layer, 9, 7 and 3 neurons in the first, second and third hidden layers, respectively, and one neuron in the output layer. The correlation coefficient determined for penetration rate predicted by the ANN was 0.94.

Gholamnejad JAVAD; Tayarani NARGES

2010-01-01T23:59:59.000Z

335

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

336

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

337

CFD investigation of effects of wind tunnel walls on flow properties over S809 airfoil  

Science Journals Connector (OSTI)

This article researches CFD simulations of the subsonic wind tunnel at Xi'an Jiaotong University's Laboratory of Thermal Turbo-machines. The wind tunnel cross section measures 800×600 mm2 and the simulations are conducted on a wind tunnel with a 375 mm chord S809 airfoil at the Reynolds number of one million. The angles of attack for the 2D airfoil range from 0 to 22 degrees. In another set of 2D simulations a 750 mm chord airfoil is calculated in open-air with no walls restricting airflow. The pressure fields flow patterns and lift and drag coefficients are compared with each other to show the blockage effects in the wind tunnel. As the results show the wind tunnel walls directly cause the flow to stream faster and increase the lift and drag values. Another consequence of this channeled flow is that the separated area expands. Moreover the commencement of the separation also occurs at a smaller angle of attack.

2013-01-01T23:59:59.000Z

338

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

339

Performance analysis of AlGaAs/GaAs tunnel junctions for ultra-high concentration photovoltaics  

Science Journals Connector (OSTI)

An n++-GaAs/p++-AlGaAs tunnel junction with a peak current density of 10?100 A cm?2 is developed. This device is a tunnel junction for multijunction solar cells, grown lattice-matched on standard GaAs or Ge substrates, with the highest peak current density ever reported. The voltage drop for a current density equivalent to the operation of the multijunction solar cell up to 10?000 suns is below 5 mV. Trap-assisted tunnelling is proposed to be behind this performance, which cannot be justified by simple band-to-band tunnelling. The metal-organic vapour-phase epitaxy growth conditions, which are in the limits of the transport-limited regime, and the heavy tellurium doping levels are the proposed origins of the defects enabling trap-assisted tunnelling. The hypothesis of trap-assisted tunnelling is supported by the observed annealing behaviour of the tunnel junctions, which cannot be explained in terms of dopant diffusion or passivation. For the integration of these tunnel junctions into a triple-junction solar cell, AlGaAs barrier layers are introduced to suppress the formation of parasitic junctions, but this is found to significantly degrade the performance of the tunnel junctions. However, the annealed tunnel junctions with barrier layers still exhibit a peak current density higher than 2500 A cm?2 and a voltage drop at 10?000 suns of around 20 mV, which are excellent properties for tunnel junctions and mean they can serve as low-loss interconnections in multijunction solar cells working at ultra-high concentrations.

I García; I Rey-Stolle; C Algora

2012-01-01T23:59:59.000Z

340

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

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

The Large Hadron Collider  

Science Journals Connector (OSTI)

...fully from the space available in...the machine construction. The superconducting...for a single sector, the whole...therefore, as the heating increases...was made, a sector was powered...is a slight heating during ramp...Collider. | The construction of the Large...the limited space available in...

2012-01-01T23:59:59.000Z

342

Adsorbate surface diffusion: The role of incoherent tunneling in light particle motion  

E-Print Network [OSTI]

The role of incoherent tunneling in the diffusion of light atoms on surfaces is investigated. With this purpose, a Chudley-Elliot master equation constrained to nearest neighbors is considered within the Grabert-Weiss approach to quantum diffusion in periodic lattices. This model is applied to recent measurements of atomic H and D on Pt(111), rendering friction coefficients that are in the range of those available in the literature for other species of adsorbates. A simple extension of the model has also been considered to evaluate the relationship between coverage and tunneling, and therefore the feasibility of the approach. An increase of the tunneling rate has been observed as the surface coverage decreases.

A. S. Sanz; R. Martinez-Casado; S. Miret-Artes

2012-07-13T23:59:59.000Z

343

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

344

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

345

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

346

Quantitative determination of local potential values in inhomogeneously doped semiconductors by scanning tunneling microscopy  

Science Journals Connector (OSTI)

Local potential changes arising from nanoscale three-dimensional spatial fluctuations in the dopant distribution in Zn-doped GaAs were investigated quantitatively by scanning tunneling microscopy and spectroscopy at (110) cleavage surfaces. Tunneling spectra measured in areas with different local doping concentration show apparent shifts of the valence band edge and apparent changes of the band gap. A quantitative analysis, combined with band bending and tunnel current simulations, demonstrates that these effects arise from tip-induced band bending that modulates the real potential changes. It is illustrated how exact potential changes between locally high and low doped areas can be determined. It is found that the local potential fluctuations in three-dimensionally doped semiconductors are approximately one order of magnitude smaller that those observed in two-dimensionally doped semiconductors.

P. H. Weidlich, R. E. Dunin-Borkowski, and Ph. Ebert

2011-08-29T23:59:59.000Z

347

Nanoscale chemical imaging using synchrotron x-ray enhanced scanning tunneling microscopy  

SciTech Connect (OSTI)

The combination of synchrotron radiation with scanning tunneling microscopy provides a promising new concept for chemical imaging of nanoscale structures. It employs detection of local x-ray absorption, which directly yields chemical, electronic, and magnetic sensitivity. The study of the tip current in the far field (800 nm tip/sample separation) shows that insulator-coated tips have to be considered in order to reduce the background from stray photoelectron. A picture of the different channels contributing to the x-ray enhanced STM process is proposed. If during electron tunneling the sample is illuminated with monochromatic x-rays, characteristic absorption will arise, and core electrons are excited, which might modulate the conventional tunnel current and facilitate chemical imaging at the nanoscale.

Rose, Volker; Freeland, John W. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2010-06-23T23:59:59.000Z

348

Negative differential resistance in electron tunneling in ultrathin films near the two-dimensional limit  

SciTech Connect (OSTI)

We report on our observation of negative differential resistance (NDR) in electron tunneling conductance in atomic-scale ultrathin Ag films on Si(111) substrates. NDR was observed by scanning tunneling spectroscopy measurements. The tunneling conductance depends on the electronic local density of states (LDOS) of the sample. We show that the sample bias voltage, at which negative differential resistance and peak negative conductance occur, depends on the film thickness. This can be understood from the variation in the LDOS of the Ag films as a function of film thickness down to the two-dimensional limit of one atomic layer. First principles density functional theory calculations have been used to explain the results.

Batabyal, R.; Abdul Wasey, A. H. M.; Mahato, J. C.; Das, Debolina; Roy, A.; Das, G. P.; Dev, B. N. [Department of Materials Science, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032 (India)

2013-01-21T23:59:59.000Z

349

Synchronization of coupled single-electron circuits based on nanoparticles and tunneling junctions  

Science Journals Connector (OSTI)

We explore theoretically the synchronization properties of a device composed of coupled single-electron circuits whose building blocks are nanoparticles interconnected with tunneling junctions. Elementary nanoscillators can be achieved by a single-electron tunneling cell where the relaxation oscillation is induced by the tunneling. We develop a model to describe the synchronization of the nanoscillators and present sample calculations to demonstrate that the idea is feasible and could readily find applications. Instead of considering a particular system we analyze the general properties of the device making use of an ideal model that emphasizes the essential characteristics of the concept. We define an order parameter for the system as a whole and demonstrate phase synchronization for sufficiently high values of the coupling resistance.

Javier Cervera; José A. Manzanares; Salvador Mafé

2009-01-01T23:59:59.000Z

350

Simulation of the SCI Transport Layer on the Wisconsin Wind Tunnel Douglas C. Burger and James R. Goodman  

E-Print Network [OSTI]

1 Simulation of the SCI Transport Layer on the Wisconsin Wind Tunnel Douglas C. Burger and James R. The Wisconsin Wind Tunnel (WWT) [11] is one such parallel simulator, which runs on a Thinking Machines CM-5. WWT-Performance Low-Cost Computing," March 1995. Abstract Parallel simulation of parallel machines is fast becom- ing

Burger, Doug

351

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

352

The scanning tunnelling microscope as an operative tool: doing physics and chemistry with single atoms and molecules  

Science Journals Connector (OSTI)

...as an operative tool: doing physics and chemistry with single atoms...Switzerland 3 Department of Physics and Astronomy, Ohio University...2 level. As the CO hopping rate depends linearly on the tunnelling...of the tunnelling current passes through the 2 orbital and the...

2004-01-01T23:59:59.000Z

353

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

354

Bloodworth, Houlsby, Burd and Augarde Three-dimensional Modelling of the Interaction Between Buildings and Tunnelling Operations  

E-Print Network [OSTI]

Between Buildings and Tunnelling Operations A.G. Bloodworth, Southampton University, formerly Oxford, Settlements Conference theme: Effects of building stiffness, different configurations and time ABSTRACT of the interaction between masonry buildings and ground movements induced by tunnelling. The focus has been

Augarde, Charles

355

Implicit Large Eddy Simulation  

National Nuclear Security Administration (NNSA)

Implicit Implicit Large Eddy Simulation (ILES) for High Reynolds Number Flows Len Margolin Applied Physics Division Los Alamos National Laboratory Collaborators: 1. Bill Rider (LANL) 2. Piotr Smolarkiewicz (NCAR) 3. Andrzej Wysogrodski (NCAR) 4. Fernando Grinstein (NRL) len@lanl.gov 1 Implicit Large Eddy Simulation Outline: * What is ILES? * What are its advantages? * Historical perspective * Why does it work? * Some examples len@lanl.gov 2 What is ILES ILES is the direct application of a fluid solver to a high Reynolds number fluid flow with no explicit turbulence model. · The truncation terms of the algorithm serve as an effective model of the effects of the unresolved scales. · Fluid solvers based on Nonoscillatory Finite Volume (NFV) approximations work effectively for ILES. · Fluid solvers based on pseudospectral methods, leapfrog methods, advective form methods, etc. do not work

356

Numerical simulation and wind tunnel studies of pollution dispersion in an isolated street canyon  

Science Journals Connector (OSTI)

A three dimensional numerical modelling study of an urban isolated street canyon are done using Computational Fluid Dynamics (CFD) software FLUENT. The concentration predictions of FLUENT are compared with the Environmental Wind Tunnel (EWT) test results conducted at Indian Institute of Technology, Delhi for the Aspect Ratio (AR) of 1 and 1.5 at perpendicular wind direction. In FLUENT, three different kâ??? turbulence models, i.e., standard, Renormalisation Group (RNG) and realisable, are used. RNG model has been found to be best matched with the wind tunnel results (d = 0.80) for AR = 1, showing that for separated flows, it works best.

Seema Awasthi; K.K. Chaudhry

2009-01-01T23:59:59.000Z

357

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

358

Modern Rutherford Experiment: Tunneling of the Most Neutron-Rich Nucleus  

SciTech Connect (OSTI)

A modern variation of the Rutherford experiment to probe the tunneling of exotic nuclear matter from the measurement of the residues formed in the bombardment of {sup 197}Au by extremely neutron-rich {sup 8}He nuclei is presented. Using a novel off-beam technique the most precise and accurate measurements of fusion and neutron transfer involving reaccelerated unstable beams are reported. The results show unusual behavior of the tunneling of {sup 8}He compared to that for lighter helium isotopes, highlighting the role of the intrinsic structure of composite many-body quantum systems and pairing correlations.

Lemasson, A.; Navin, A.; Rejmund, M.; France, G. de; Jacquot, B.; Raabe, R.; Schmitt, C. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Shrivastava, A. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Keeley, N. [Department of Nuclear Reactions, The Andrzej Soltan Institute for Nuclear Studies, ul. Hoza 69, PL-00-681 Warsaw (Poland); Zelevinsky, V. [NSCL and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824-1321 (United States); Bhattacharyya, S. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India); Chatterjee, A. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Nanal, V.; Pillay, R. G. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India)

2009-12-04T23:59:59.000Z

359

Selective coherent destruction of tunneling in a quantum-dot array  

Science Journals Connector (OSTI)

The coherent manipulation of quantum states is one of the main tasks required in quantum computation. In this paper we demonstrate that it is possible to control coherently the electronic position of a particle in a quantum-dot array. By tuning an external ac electric field we can selectively suppress the tunneling between dots, trapping the particle in a determined region of the array. The problem is treated nonperturbatively by a time-dependent Hamiltonian in the effective mass approximation and using Floquet theory. We find that the quasienergy spectrum exhibits crossings and anticrossings at certain field intensities that result in the selective suppression of tunneling.

J. M. Villas-Bôas, Sergio E. Ulloa, and Nelson Studart

2004-07-08T23:59:59.000Z

360

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

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

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

363

An easy-to-implement filter for separating photo-excited signals from topography in scanning tunneling microscopy  

SciTech Connect (OSTI)

In order to achieve elemental and chemical sensitivity in scanning tunneling microscopy (STM), synchrotron x-rays have been applied to excite core-level electrons during tunneling. The x-ray photo-excitations result in tip currents that are superimposed onto conventional tunneling currents. While carrying important physical information, the varying x-ray induced currents can destabilize the feedback loop causing it to be unable to maintain a constant tunneling current, sometimes even causing the tip to retract fully or crash. In this paper, we report on an easy-to-implement filter circuit that can separate the x-ray induced currents from conventional tunneling currents, thereby allowing simultaneous measurements of topography and chemical contrasts. The filter and the schematic presented here can also be applied to other variants of light-assisted STM such as laser STM.

Wang Kangkang; Rosenmann, Daniel; Holt, Martin; Winarski, Robert; Hla, Saw-Wai [Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Rose, Volker [Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

2013-06-15T23:59:59.000Z

364

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

365

Tunneling in a linear B2H6-HCI dimer Carl Chuang, T. D. Klots, FL S. Ruoff, Tryggvi Emilsson, and H. S. Gutowsky  

E-Print Network [OSTI]

February 1991; accepted 23 April 1991) Rotational spectra have been observed for eight isotopic species homonuclear in the boron were observed to tunnel while those with "B"BH, or DC1 did not. The tunneling splits?, DJ, H, (B-C), and DJK constants determined for '`B,H,-H3'C1 are for the A, tunneling state 1273

366

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

367

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

368

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...

369

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

370

Not all wireless sensor networks are created equal: A comparative study on tunnels  

Science Journals Connector (OSTI)

Wireless sensor networks (WSNs) are envisioned for a number of application scenarios. Nevertheless, the few in-the-field experiences typically focus on the features of a specific system, and rarely report about the characteristics of the target environment, ... Keywords: Wireless sensor networks, link quality, low-power wireless communications, network topologies, topology characterization, tunnel environment

Luca Mottola; Gian Pietro Picco; Matteo Ceriotti; ?tefan Gun?; Amy L. Murphy

2010-08-01T23:59:59.000Z

371

Wind-Tunnel Simulation of Pedestrian-Level Wind in Los Angeles Bruce R. White  

E-Print Network [OSTI]

Wind-Tunnel Simulation of Pedestrian-Level Wind in Los Angeles Bruce R. White University-level winds within the South Coast Air Basin, a 6,000-square mile area that includes Orange County, most of Los Angeles and Riverside Counties. Working with the city of Los Angeles officials guidelines for wind

White, Bruce

372

A support vector regression model for predicting tunnel boring machine penetration rates  

Science Journals Connector (OSTI)

Abstract With widespread increasing applications of mechanized tunneling in almost all ground conditions, prediction of tunnel boring machine (TBM) performance is required for time planning, cost control and choice of excavation method in order to make tunneling economical. Penetration rate is a principal measure of full-face TBM performance and is used to evaluate the feasibility of the machine and predict advance rate of excavation. This research aims at developing a regression model to predict penetration rate of TBM in hard rock conditions based on a new artificial intelligence (AI) algorithm namely support vector regression (SVR). For this purpose, the Queens Water Tunnel, in New York City, was selected as a case study to test the proposed model. In order to find out the optimum values of the parameters and prevent over-fitting, 80% of the total data were selected randomly for training set and the rest were kept for testing the model. According to the results, it can be said that the proposed model is a useful and reliable means to predict TBM penetration rate provided that a suitable dataset exists. From the prediction results of training and testing samples, the squared correlation coefficient (R2) between the observed and predicted values of the proposed model was obtained 0.99 and 0.95, respectively, which shows a high conformity between predicted and actual penetration rate.

Satar Mahdevari; Kourosh Shahriar; Saffet Yagiz; Mohsen Akbarpour Shirazi

2014-01-01T23:59:59.000Z

373

Development and management of a radon assessment strategy suitable for underground railway tunnelling projects  

Science Journals Connector (OSTI)

......annum for the duration of each project. INTRODUCTION The construction...best practice at the time of project development and for tunnelling...national authorities are at liberty to choose a different (lower...throughout the duration of the project. Pylon radon gas and radon......

C. J. Purnell; G. Frommer; K. Chan; A. A. Auch

2004-04-01T23:59:59.000Z

374

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

375

Complexity, tunneling, and geometrical symmetry L. P. Horwitz,1,2,3  

E-Print Network [OSTI]

Department of Physics, Bar-Ilan University, Ramat-Gan 52900, Israel 3 School of Physics, Raymond and Beverly classical chaotic behavior and the rate of tunneling in the corresponding quantum system. The conclu- sion or to the left , certain positions are passed where the system becomes strongly near-degenerate. These positions

Ashkenazy, Yossi "Yosef"

376

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

377

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"

378

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

379

Narrow band defect luminescence from Al-doped ZnO probed by scanning tunneling cathodoluminescence  

E-Print Network [OSTI]

Institute of Physics. Related Articles Effect of CdS film thickness on the photoexcited carrier lifetime of TiO2/CdS core-shell nanowires Appl. Phys. Lett. 99, 153111 (2011) Current underestimationNarrow band defect luminescence from Al-doped ZnO probed by scanning tunneling cathodoluminescence

Russell, Kasey

380

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

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

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

382

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

383

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.

384

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

385

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.

386

Tunneling Spectroscopy of the Elementary Excitations in a One-Dimensional Wire  

Science Journals Connector (OSTI)

...first order, B shifts the dispersions of the modes in the UQWR, Eui(B,k), by kB-=-eBd/ (ui enumerates the modes of the...unless there is a k that satisfies the tunneling condition: Eui(B,k -kB)-=-Elj(B,k) -eVsd, for which one wire...

O. M. Auslaender; A. Yacoby; R. de Picciotto; K. W. Baldwin; L. N. Pfeiffer; K. W. West

2002-02-01T23:59:59.000Z

387

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

388

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

389

Seismic modeling and analysis of a prototype heated nuclear waste storage tunnel, Yucca Mountain, Nevada  

E-Print Network [OSTI]

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 weaponsSeismic modeling and analysis of a prototype heated nuclear waste storage tunnel, Yucca Mountain

Snieder, Roel

390

Competing order and the asymmetric tunneling spectrum in high temperature cuprate superconductors  

E-Print Network [OSTI]

Competing order and the asymmetric tunneling spectrum in high temperature cuprate superconductors- terplay between them are two major tasks in this field. In high temperature cuprate superconductors temperature superconductors remains a challenging puzzle to be solved. A comprehensive theory to understand

Hu, Jiangping

391

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

392

Single Molecule Dissociation by Tunneling Electrons B. C. Stipe, M. A. Rezaei, and W. Ho  

E-Print Network [OSTI]

Single Molecule Dissociation by Tunneling Electrons B. C. Stipe, M. A. Rezaei, and W. Ho Laboratory­ scope was used to image and dissociate single O2 molecules on the Pt(111) surface in the temperature­ molecular chemical reaction one molecule at a time. More specifically, we have imaged a single O 2 molecule

Persson, Mats

393

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.

394

hal-00284650,version1-3Jun2008 Coulomb blockade for an oscillating tunnel junction  

E-Print Network [OSTI]

L and of a constant resistance Z() = R. With little modifications the theory applies also to incoherent transport and study the coupling between electronic transport and me- chanical degrees of freedom.1,2 The elementary of freedom. The effect of the position dependence of the tunneling resistance has been already considered

Paris-Sud XI, Université de

395

How an interacting many-body system tunnels through a potential barrier to open space  

Science Journals Connector (OSTI)

...space can serve as an atomic laser, i.e., emit bosons coherently, but only...1998 ) Quantum tunneling in nuclear fusion . Rev Mod Phys 70 : 77 – 100 . 8 Keller...Einstein condensation and the atom laser . Rev Mod Phys 74 : 1131 – 1151 . 12 Dunningham...T Esslinger T ( 1999 ) Atom laser with a cw output coupler . Phys...

Axel U.J. Lode; Alexej I. Streltsov; Kaspar Sakmann; Ofir E. Alon; Lorenz S. Cederbaum

2012-01-01T23:59:59.000Z

396

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

397

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

398

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

399

Low-frequency magnetic and resistance noise in magnetic tunnel junctions  

Science Journals Connector (OSTI)

We have studied the voltage fluctuations of current-biased, micron-scale magnetic tunnel junctions. We find that the spectral power density is 1/f-like at low frequencies and becomes frequency independent at high frequencies. The frequency-independent background noise is due to Johnson-Nyquist noise and shot noise mechanisms. The nature of the 1/f noise has its origin in two different mechanisms. In the magnetic hysteresis loops this noise power is strongly field-dependent and is due to thermal magnetization fluctuations in both the “free” and “fixed” magnetic layers. We attribute these magnetic fluctuations to thermally excited hopping of magnetic domain walls between pinning sites. At high temperatures, this magnetic noise is found to track the dc resistance susceptibility but it is not in quantitative agreement with the fluctuation dissipation relation, indicating that the magnetic structure is not in equilibrium. A second mechanism for the 1/f noise, connected with defects in the tunnel barrier but not related to the overall magnetization fluctuations, was found at fields for which the magnetic structure in the free and fixed layers is well aligned. We attribute this noise to electron trapping processes having thermally activated kinetics and a broad distribution of activation energies. Below ?25 K the noise power is temperature independent suggesting that the kinetics are dominated by tunneling. Our results show that the thermal stability of both the magnetic layers and the quality of the tunnel barrier are important factors in reducing the low-frequency noise in magnetic tunnel junctions.

L. Jiang; E. R. Nowak; P. E. Scott; J. Johnson; J. M. Slaughter; J. J. Sun; R. W. Dave

2004-02-13T23:59:59.000Z

400

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

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

Enhancement of the effective tunnel mass in ultrathin silicon dioxide layers  

Science Journals Connector (OSTI)

Based on the results of three-dimensional atomistic tight-binding calculations we argue that the effective tunnel mass of SiO 2 employed as a fitting parameter in standard transfer-matrix multiple-scattering theory calculations increases strongly as the oxide thickness is decreased (we find more than 50% mass enhancement upon reduction of the oxide thickness from 4 to 1 nm). At least five factors usually neglected in effective-mass-based calculations can contribute to this effect: the nonparabolicity of the complex bands in the gap of SiO 2 the gradual (rather than abrupt) change of the electrostatic potential across the Si/SiO 2 interface a possible image force correction the presence of native defects in the oxide and the effective-mass approximation itself. Very good quantitative agreement between the theoretical predictions for the thickness dependence of the mass enhancement and corresponding results from transfer matrix fits to experimental currents is obtained if defect densities smaller than 10 10 ? cm ?2 and a small image force correction are assumed. Since the present findings imply significant errors (1–2 orders of magnitude) in tunnel currents through ultrathin oxides calculated with a single thickness-independent tunnel mass an explicit parametrization of the thickness dependence for use in multiple-scattering calculations is suggested. For 4 nm thin oxides we obtain a tunnel mass of 0.35?m 0 (0.48?m 0 ) if a parabolic (nonparabolic) dispersion of the complex bands in the band gap of the oxide is adopted. Furthermore the mass at the conduction band bottom of SiO 2 is found to be different from the tunnel mass and estimated to be 0.39?m 0 in good agreement with previous measurements. The calculations also yield an estimate of the errors in oxide thicknesses obtained from current–voltage fitting which are found to agree well with available experimental data.

M. Städele; F. Sacconi; A. Di Carlo; P. Lugli

2003-01-01T23:59:59.000Z

402

Tunnel MOS Heterostructure Field Effect Transistor for RF Switching Applications  

E-Print Network [OSTI]

. ..................................................................................... 5 Figure 4. The lattices of N-face and Ga-face gallium nitride. .......................................... 10 Figure 5. The lattice constants and bandgaps of III-nitride semiconductors and their alloys... semiconductors and particularly Gallium Nitride (GaN) are gaining a lot of attention for high speed and high power switching applications due to their large critical breakdown electric fields, high mobility and high saturated electron velocity [1, 2]. GaN has...

Rezanezhad Gatabi, Iman

2013-06-06T23:59:59.000Z

403

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

404

Design of a 6-DoF Robotic Platform for Wind Tunnel Tests of Floating Wind Turbines  

Science Journals Connector (OSTI)

Abstract Sophisticated computational aero-hydro-elastic tools are being developed for simulating the dynamics of Floating Offshore Wind Turbines (FOWTs). The reliabilty of such prediction tools for designers requires experimental validation. To this end, due to the lack of a large amount of full scale data available, scale tests represent a remarkable tool. Moreover, due to the combined aerodynamic and hydrodynamic contributions to the dynamics of FOWTs, experimental tests should take into account both. This paper presents the design process of a 6-Degrees-of-Freedom robot for simulating the dynamics of \\{FOWTs\\} in wind tunnel scale experiments, as a complementary approach with respect to ocean wind-wave basin scale tests. Extreme events were considered for the definition of the robot requirements and performance. A general overview on the possible design solutions is reported, then the machine architecture as well as the kinematic and dynamic analysis is discussed. Also a motion task related to a 5-MW Floating Offshore Wind Turbine nominal operating condition was considered and then the ability of the robot to reproduce such motions verified in terms of maximum displacements, forces and power, to be within the design boundaries.

I. Bayati; M. Belloli; D. Ferrari; F. Fossati; H. Giberti

2014-01-01T23:59:59.000Z

405

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

406

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

407

A co-crystal of polyoxometalates exhibiting single-molecule magnet behavior: the structural origin of a large magnetic anisotropy  

SciTech Connect (OSTI)

A polyoxometalate-based {MnIII3MnIV} single-molecule magnet exhibits a large axial anisotropy (D = ?0.86 cm?1) resulting from a near-parallel alignment of Jahn–Teller axes. Its rigorous three-fold symmetry (i.e. rhombicity E ? 0) and increased intercluster separation via co-crystallization effectively hamper quantum tunnelling of the magnetization. Graphical abstract: A co-crystal of polyoxometalates exhibiting single-molecule magnet behavior: the structural origin of a large magnetic anisotropy

Fang, Xikui; McCallum, Kendall; Pratt III, Harry D.; Anderson, Travis M.; Dennis, Kevin; Luban, Marshall

2012-03-29T23:59:59.000Z

408

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

409

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

410

Proximity effect and hot-electron diffusion in Ag/Al{sub 2}O{sub 3}/Al tunnel junctions  

SciTech Connect (OSTI)

We have fabricated Ag/Al{sub 2}O{sub 3}/Al tunnel junctions on Si substrates using a new process. This process was developed to fabricate superconducting tunnel junctions (STJs) on the surface of a superconductor. These junctions allow us to study the proximity effect of a superconducting Al film on a normal metal trapping layer. In addition, these devices allow us to measure the hot-electron diffusion constant using a single junction. Lastly these devices will help us optimize the design and fabrication of tunnel junctions on the surface of high-Z, ultra-pure superconducting crystals. 5 refs., 8 figs.

Netel, H., Jochum, J., Labov, S.E., Mears, C.A., Frank, M. [Physics and Space Technology Directorate, Lawrence Livermore National Lab., CA (United States); Chow, D., Lindeman, M.A., Hiller, L.J. [California Univ., Davis, CA (United States). Dept. of Applied Science

1997-02-18T23:59:59.000Z

411

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

412

Airfoil family design for large offshore wind turbine blades  

Science Journals Connector (OSTI)

Wind turbine blades size has scaled-up during last years due to wind turbine platform increase especially for offshore applications. The EOLIA project 2007-2010 (Spanish Goverment funded project) was focused on the design of large offshore wind turbines for deep waters. The project was managed by ACCIONA Energia and the wind turbine technology was designed by ACCIONA Windpower. The project included the design of a wind turbine airfoil family especially conceived for large offshore wind turbine blades, in the order of 5MW machine. Large offshore wind turbines suffer high extreme loads due to their size, in addition the lack of noise restrictions allow higher tip speeds. Consequently, the airfoils presented in this work are designed for high Reynolds numbers with the main goal of reducing blade loads and mantainig power production. The new airfoil family was designed in collaboration with CENER (Spanish National Renewable Energy Centre). The airfoil family was designed using a evolutionary algorithm based optimization tool with different objectives, both aerodynamic and structural, coupled with an airfoil geometry generation tool. Force coefficients of the designed airfoil were obtained using the panel code XFOIL in which the boundary layer/inviscid flow coupling is ineracted via surface transpiration model. The desing methodology includes a novel technique to define the objective functions based on normalizing the functions using weight parameters created from data of airfoils used as reference. Four airfoils have been designed, here three of them will be presented, with relative thickness of 18%, 21%, 25%, which have been verified with the in-house CFD code, Wind Multi Block WMB, and later validated with wind tunnel experiments. Some of the objectives for the designed airfoils concern the aerodynamic behavior (high efficiency and lift, high tangential coefficient, insensitivity to rough conditions, etc.), others concern the geometry (good for structural design, compatibility for the different airfoil family members, etc.) and with the ultimate objective that the airfoils will reduce the blade loads. In this paper the whole airfoil design process and the main characteristics of the airfoil family are described. Some force coefficients for the design Reynolds number are also presented. The new designed airfoils have been studied with computational calculations (panel method code and CFD) and also in a wind tunnel experimental campaign. Some of these results will be also presented in this paper.

B Méndez; X Munduate; U San Miguel

2014-01-01T23:59:59.000Z

413

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

414

Prediction of TBM penetration rate using intact and mass rock properties (case study: Zagros long tunnel, Iran)  

Science Journals Connector (OSTI)

In this paper, the correlations between the different measurements of rock brittleness (i.e., B 1, B 2, B 3, and BI) and the penetration rate (PR) of tunnel boring machin...

S. D. Mohammadi; M. Torabi-Kaveh; M. Bayati

2014-05-01T23:59:59.000Z

415

Numerical simulation of ground movements and structural forces in lining for Earth Pressure Balance (EPB) tunneling in clay  

E-Print Network [OSTI]

This thesis describes the development of a 3D finite element model for representing mechanized tunnel construction using an Earth Pressure Balance (EPB) machine in clay. The model uses the commercial FE code, Plaxis 3D, ...

Founta, Vasiliki

2013-01-01T23:59:59.000Z

416

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

417

Scanning tunneling microscopy on unpinned GaN(11¯00) surfaces: Invisibility of valence-band states  

Science Journals Connector (OSTI)

We investigated the origins of the tunnel current in scanning tunneling microscopy (STM) and spectroscopy experiments on GaN(11¯00) surfaces. By calculating the tunnel currents in the presence of a tip-induced band bending for unpinned n-type GaN(11¯00) surfaces, we demonstrate that only conduction-band states are observed at positive and negative voltage polarities independent of the doping concentration. Valence-band states remain undetectable because tunneling out of the electron-accumulation zone in conduction-band states dominates by four orders of magnitude. As a result band-gap sizes cannot be determined by STM on unpinned GaN(11¯00) surfaces. Appropriate band-edge positions and gap sizes can be determined on pinned surfaces.

Ph. Ebert, L. Ivanova, and H. Eisele

2009-08-24T23:59:59.000Z

418

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

419

Tunneling oxide engineering by ion implantation of nitrogen for 3D vertical silicon pillar SONOS flash memory  

Science Journals Connector (OSTI)

The electrical characteristics of silicon-oxide-nitride-oxide-silicon (SONOS) flash memory with a 3D vertical silicon pillar structure were studied. As an alternative method for the formation of the tunneling oxide, nitrogen ion implantation was applied to thermally grown pure silicon dioxide with a low energy (5 keV). The devices show significant improvement in the erase characteristics compared to conventional tunneling oxide. Secondary ion mass spectrometry was used to analyze the nitrogen distribution within tunnel oxide, and the improved erase properties can be attributed to the incorporation of about 4.8% nitrogen (2 × 1021 atoms/cm3) into the tunnel oxide formed by nitrogen ion implantation.

Jae-Sub Oh; Seong-Dong Yang; Sang-Youl Lee; Young-Su Kim; Min-Ho Kang; Sung-Kyu Lim; Hi-Deok Lee; Ga-Won Lee

2013-01-01T23:59:59.000Z

420

Coupled tunnelling motion of a pair of methyl groups in lithium acetate studied by inelastic neutron scattering  

Science Journals Connector (OSTI)

The tunnelling and torsional motions of methyl groups in lithium acetate dihydrate (CH3COOLi·2H2O) have been studied in detail by incoherent inelastic neutron scattering. The results are interpreted by a model of...

S. Clough; A. Heidemann; A. H. Horsewill…

1984-01-01T23:59:59.000Z

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 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

422

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

423

A wind-tunnel investigation of the wind speed and turbulence characteristics close to the ground over various escarpment shapes  

Science Journals Connector (OSTI)

A wind-tunnel investigation of the wind flow over two-dimensional forward-facing escarpments ... into the effects of local topography on the wind flow close to the ground. Four sharp ... -wire anemometer. The mod...

A. J. Bowen; D. Lindley

1977-10-01T23:59:59.000Z

424

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

425

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

426

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

427

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

428

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

429

CALIFORNIA ENERGY Large HVAC Building  

E-Print Network [OSTI]

CALIFORNIA ENERGY COMMISSION Large HVAC Building Survey Information Database of Buildings over 100 Design of Large Commercial HVAC Systems research project, one of six research elements in the Integrated Design of Large Commercial HVAC Systems Integrated Design of Small Commercial HVAC Systems Integrated

430

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

431

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

432

Electronic structure of wurtzite II-VI compound semiconductor cleavage surfaces studied by scanning tunneling microscopy  

Science Journals Connector (OSTI)

We report atomically resolved scanning tunneling microscopy (STM) images of cleavage surfaces of wurtzite II-VI compound semiconductors. CdSe(112¯0), CdSe(101¯0), and CdS(101¯0) were investigated. The STM images confirm a 1×1 reconstruction for all surfaces. At negative and positive sample voltages the occupied and empty dangling-bond states above anions and cations, respectively, dominate the contrast of the STM images. No states in the band gap were found. The electronic structure of the surface permits the observation of dopant atoms in subsurface layers and thus also cross-sectional scanning tunneling microscopy studies of point defects and heterostructures.

B. Siemens, C. Domke, Ph. Ebert, and K. Urban

1997-11-15T23:59:59.000Z

433

Tunneling current modulation by Ge incorporation into Si oxide films for flash memory applications  

SciTech Connect (OSTI)

Current-voltage characteristic for a Ge-incorporated Si oxide was investigated. Current enhancement was observed for the electric field larger than 10 MV/cm. Such a current enhancement only under high electric field is expected to improve programming performance without deteriorating reading performance. From secondary ion mass spectrometry and hard x-ray photoelectron spectroscopy analyses and current simulation, it is concluded that the Ge impurity in Ge{sup 4+} state around the tunnel oxide/substrate interface enhances the current by trap-assisted tunneling. The programming current enhancement induced by the Ge incorporation is expected to be one of the promising solutions for the next-generation flash memory.

Ito, Toshihide; Mitani, Yuuichiro; Nakasaki, Yasushi; Koike, Masahiro [Corporate Research and Development Center, Toshiba Corporation, Saiwai-ku, Kawasaki 212-8582 (Japan); Konno, Takuya; Matsuba, Hiroshi [Corporate Manufacturing Engineering Center, Toshiba Corporation, Isogo-ku, Yokohama 235-0017 (Japan); Kai, Tetsuya; Kaneko, Wakana; Ozawa, Yoshio [Device Process Development Center, Corporate Research and Development Center, Toshiba Corporation, Isogo-ku, Yokohama 235-8522 (Japan)

2012-02-13T23:59:59.000Z

434

Wind tunnel experiments of a newly developed two-bladed Savonius-style wind turbine  

Science Journals Connector (OSTI)

Abstract Wind tunnel experiments have been conducted with a newly developed two-bladed Savonius-style wind turbine specifically meant for a small-scale energy conversion. This novel shape of the turbine blade is evolved from a series of experiments with different types of blades in the recent past. The developed two-bladed turbine is tested in an open type test section and its performance is assessed in terms of power and torque coefficients. Experiments have also been conducted with other standard blades such as semi-circular, semi-elliptic, Benesh and Bach types in order to have a direct comparison. In this study, all the reported experimental data are inclusive of wind tunnel blockage corrections. Further, the effects of Reynolds number on the dynamic and static characteristics are also discussed. The present investigation demonstrates a gain of 34.8% in maximum power coefficient with the newly developed two-bladed turbine.

Sukanta Roy; Ujjwal K. Saha

2015-01-01T23:59:59.000Z

435

Trend of tunnel magnetoresistance and variation in threshold voltage for keeping data load robustness of metal–oxide–semiconductor/magnetic tunnel junction hybrid latches  

Science Journals Connector (OSTI)

The robustness of data load of metal–oxide–semiconductor/magnetic tunnel junction (MOS/MTJ) hybrid latches at power-on is examined by using Monte Carlo simulation with the variations in magnetoresistances for MTJs and in threshold voltages for MOSFETs involved in 90?nm technology node. Three differential pair type spin-transfer-torque-magnetic random access memory cells (4T2MTJ 6T2MTJ and 8T2MTJ) are compared for their successful data load at power-on. It is found that the 4T2MTJ cell has the largest pass area in the shmoo plot in TMR ratio (tunnel magnetoresistance ratio) and Vdd in which a whole 256?kb cell array can be powered-on successfully. The minimum TMR ratio for the 4T2MTJ in 0.9?V?

S. Ikeda; T. Hanyu; H. Ohno

2014-01-01T23:59:59.000Z

436

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

437

Examination of the cu/si(111) 5×5 structure by scanning tunneling microscopy  

Science Journals Connector (OSTI)

The incommensurate 5×5 Cu/Si(111) structure has been examined by scanning tunneling microscopy. Images show that the surface structure is not well described as a hexagonal copper layer modulated at the Si(111) periodicity. Rather, the surface breaks up into 5×5 subunits which pack at spacings varying from 5 to 7 lattice constants, implying that substrate-adsorbate interactions dominate lateral interactions within the Cu adlayer.

R. J. Wilson; S. Chiang; F. Salvan

1988-12-15T23:59:59.000Z

438

Tunneling Model of Phase Changes in Tetragonal Rare-Earth Crystals  

Science Journals Connector (OSTI)

The crystal-field theory for a rare-earth ion in tetragonal symmetry is studied in a semiclassical description. The low-lying quantum states are interpreted as tunneling states between classical minima. At low temperatures, spontaneous lattice distortions occur to lower some of the minima relative to others. The model is applied to DyVO4 and TbVO4 and is shown to lead to a good understanding of why they show phase changes and unusual paramagnetic properties.

E. Pytte and K. W. H. Stevens

1971-09-27T23:59:59.000Z

439

Spin Dynamics and Quantum Tunneling in Fe8 Nanomagnet and in AFM Rings by NMR  

SciTech Connect (OSTI)

In this thesis, our main interest has been to investigate the spin dynamics and quantum tunneling in single molecule magnets (SMMs), For this we have selected two different classes of SMMs: a ferrimagnetic total high spin S = 10 cluster Fe8 and antiferromagnetic (AFM) ring-type clusters. For Fe8, our efforts have been devoted to the investigation of the quantum tunneling of magnetization in the very low temperature region. The most remarkable experimental finding in Fe8 is that the nuclear spin-lattice relaxation rate (1/T{sub l}) at low temperatures takes place via strong collision mechanism, and thus it allows to measure directly the tunneling rate vs T and H for the first time. For AFM rings, we have shown that 1/T{sub l} probes the thermal fluctuations of the magnetization in the intermediate temperature range. We find that the fluctuations are dominated by a single characteristic frequency which has a power law T-dependence indicative of fluctuations due to electron-acoustic phonon interactions.

Seung-Ho-Baek

2004-12-19T23:59:59.000Z

440

Electron tunneling characteristics of a cubic quantum dot, (PbS){sub 32}  

SciTech Connect (OSTI)

The electron transport properties of the cubic quantum dot, (PbS){sub 32}, are investigated. The stability of the quantum dot has been established by recent scanning tunneling microscope experiments [B. Kiran, A. K. Kandalam, R. Rallabandi, P. Koirala, X. Li, X. Tang, Y. Wang, H. Fairbrother, G. Gantefoer, and K. Bowen, J. Chem. Phys. 136(2), 024317 (2012)]. In spite of the noticeable energy band gap (?2 eV), a relatively high tunneling current for (PbS){sub 32} is predicted affirming the observed bright images for (PbS){sub 32}. The calculated I-V characteristics of (PbS){sub 32} are predicted to be substrate-dependent; (PbS){sub 32} on the Au (001) exhibits the molecular diode-like behavior and the unusual negative differential resistance effect, though this is not the case with (PbS){sub 32} on the Au (110). Appearance of the conduction channels associated with the hybridized states of quantum dot and substrate together with their asymmetric distribution at the Fermi level seem to determine the tunneling characteristics of the system.

Gupta, Sanjeev K., E-mail: sanjeevg@mtu.edu, E-mail: haiying.he@valpo.edu; Banyai, Douglas; Pandey, Ravindra [Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States)] [Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States); He, Haiying, E-mail: sanjeevg@mtu.edu, E-mail: haiying.he@valpo.edu [Department of Physics and Astronomy, Valparaiso University, Valparaiso, Indiana 46383 (United States)] [Department of Physics and Astronomy, Valparaiso University, Valparaiso, Indiana 46383 (United States); Kandalam, Anil K. [Department of Physics, West Chester University of Pennsylvania, West Chester, Pennsylvania 19383 (United States)] [Department of Physics, West Chester University of Pennsylvania, West Chester, Pennsylvania 19383 (United States)

2013-12-28T23:59:59.000Z

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.


441

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

442

LARGE-APERTURE D- ACCELERATORS  

E-Print Network [OSTI]

Vignetted current profile at accelerator entrance aperture 'LARGE-APERTURE D" ACCELERATORS* 0. A. Anderson" " Lawrencen i a 9-1720 Abstract Accelerator designs are described for

Anderson, O.A.

2010-01-01T23:59:59.000Z

443

Taking the 'Large' out of Large Hadron Collider: Computational Breakthrough  

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

Home » News & Publications » News » Science News » Taking the 'Large' out of Large Hadron Collider Taking the 'Large' out of Large Hadron Collider Computational breakthrough hastens modeling of 'tabletop accelerators' August 9, 2010 | Tags: Accelerator Science Contact: Margie Wylie | mwylie@lbl.gov | 510-486-7421 mori1 This 3D simulation shows how laser pulses create plasma wakes that propel electrons forward, much as a surfer is propelled forward by an ocean wave. Laser wakefield acceleration promises electron accelerators that are thousands of times more powerful than, yet a fraction the size of, conventional radio frequency devices. Particle accelerators like the Large Hadron Collider (LHC) at CERN are the big rock stars of high-energy physics-really big. The LHC cost nearly

444

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

445

Continuously-tuned tunneling behaviors of ferroelectric tunnel junctions based on BaTiO{sub 3}/La{sub 0.67}Sr{sub 0.33}MnO{sub 3} heterostructure  

SciTech Connect (OSTI)

In this work, we fabricate BaTiO{sub 3}/La{sub 0.67}Sr{sub 0.33}MnO{sub 3} (BTO/LSMO) ferroelectric tunnel junction on (001) SrTiO{sub 3} substrate by pulsed laser deposition method. Combining piezoresponse force and conductive-tip atomic force microscopy, we demonstrate robust and reproducible polarization-controlled tunneling behaviors with the resulting tunneling electroresistance value reaching about 10{sup 2} in ultrathin BTO films (?1.2 nm) at room temperature. Moreover, local poling areas with different conductivity are finally achieved by controlling the relative proportion of upward and downward domains, and different poling areas exhibit stable transport properties.

Ou, Xin; Xu, Bo, E-mail: xubonju@gmail.com; Yin, Qiaonan; Xia, Yidong; Yin, Jiang; Liu, Zhiguo [National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 (China)] [National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 (China); Gong, Changjie; Lan, Xuexin [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China)] [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China)

2014-05-15T23:59:59.000Z

446

Cost estimating projects for large cutter and hopper dredges  

E-Print Network [OSTI]

, or impeller may occur. Net positive suction head (NPSH) is the head available to the pump above the vapor pressure (Herbich, 1992). If the required net positive suction head PPSH) is greater than the available NPSH cavitation occurs. The required NPSH... is taken &om the pump curve for the first pump in the system The required NPSH is a function of flowrate and impeller speed. As the flowrate and impeller speed increase so does the required NPSM The available NPSH is determmed using an equation that is a...

Belesimo, Francesco John

2000-01-01T23:59:59.000Z

447

Tunneling images of the 5×5 surface reconstruction on Ge-Si(111)  

Science Journals Connector (OSTI)

Germanium-silicon alloys can be prepared on crystalline silicon (111) substrates and have been observed to have 5×5 surface reconstructions. We present tunneling images of this surface which show that is has strong similarities to the Si(111)7×7 reconstruction. A model related to that proposed by Takayanagi, Ytaniahiro, and Kobayashi accounts for the general features of the observed reconstruction. In addition the surface is observed to have periodic vertical modulations which indicate an ordered Ge-Si surface alloy.

R. S. Becker; J. A. Golovchenko; B. S. Swartzentruber

1985-12-15T23:59:59.000Z

448

Magnetotransport in Zener tunneling regime in a high-mobility two-dimensional hole gas  

Science Journals Connector (OSTI)

In a high-mobility two-dimensional hole gas (2DHG) in C-doped (001) GaAs/Al0.4Ga0.6As quantum wells, we observe sharp features in the differential magnetoresistance, which we interpret as the Zener-tunneling peak and valley associated with the commensuration transition of Landau orbits. Comparison of data with that in GaAs/Al0.3Ga0.7As 2D electron gas suggests that the amplitude of Zener oscillations in a 2DHG is strongly damped. The data indicate the significant role of band structures in nonlinear transport in 2D electronic systems.

Yanhua Dai; Z. Q. Yuan; C. L. Yang; R. R. Du; M. J. Manfra; L. N. Pfeiffer; K. W. West

2009-07-20T23:59:59.000Z

449

Metastable States and Macroscopic Quantum Tunneling in a Cold-Atom Josephson Ring  

SciTech Connect (OSTI)

We study macroscopic properties of a system of weakly interacting neutral bosons confined in a ring-shaped potential with a Josephson junction. We derive an effective low energy action for this system and evaluate its properties. In particular, we find that the system possesses a set of metastable current-carrying states and evaluate the rates of transitions between these states due to macroscopic quantum tunneling and thermal activation mechanism. Finally, we discuss signatures of different metastable states in the time-of-flight images and argue that the effect is observable within currently available experimental technique.

Solenov, Dmitry; Mozyrsky, Dmitry [Theoretical Division (T-4), Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2010-04-16T23:59:59.000Z

450

Metastable states and macroscopic quantum tunneling in a cold atom josephson ring  

SciTech Connect (OSTI)

We study macroscopic properties of a system of weakly interacting neutral bosons confined in a ring-shaped potential with a Josephson junction. We derive an effective low energy action for this system and evaluate its properties. In particular we find that the system possesses a set of metastable current-carrying states and evaluate the rates of transitions between these states due to macroscopic quantum tunneling. Finally we discuss signatures of different metastable states in the time-of-flight images and argue that the effect is observable within currently available experimental technique.

Solenov, Dmitry [Los Alamos National Laboratory; Mozyrsky, Dmitry [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

451

Spent Fuel Transportation Cask Response to the Caldecott Tunnel Fire Scenario  

SciTech Connect (OSTI)

On April 7, 1982, a tank truck and trailer carrying 8,800 gallons of gasoline was involved in an accident in the Caldecott tunnel on State Route 24 near Oakland, California. The tank trailer overturned and subsequently caught fire. 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 analyses to determine the possible regulatory implications of this particular event for the transportation of spent nuclear fuel by truck. The Fire Dynamics Simulator (FDS) code developed by National Institute of Standards and Technology (NIST) was used to determine the thermal environment in the Caldecott tunnel during the fire. The FDS results were used to define boundary conditions for a thermal transient model of a truck transport cask containing spent nuclear fuel. The Nuclear Assurance Corporation (NAC) Legal Weight Truck (LWT) transportation cask was selected for this evaluation, as it represents a typical truck (over-the-road) cask, and can be used to transport a wide variety of spent nuclear fuels. Detailed analysis of the cask response to the fire was performed using the ANSYS® computer code to evaluate the thermal performance of the cask design in this fire scenario. This report describes the methods and approach used to assess the thermal response of the selected cask design to the conditions predicted in the Caldecott tunnel fire. The results of the analysis are presented in detail, with an evaluation of the cask response to the fire. The staff concluded that some components of smaller transportation casks resembling the NAC LWT, despite placement within an ISO container, could degrade significantly. Small transportation casks similar to the NAC LWT would probably experience failure of seals in this severe accident scenario. USNRC staff evaluated the radiological consequences of the cask response to the Caldecott tunnel fire. Although some components heated up beyond their service temperatures, the staff determined that there would be no significant release as a result of the fire for the NAC LWT and similar casks.

Adkins, Harold E.; Koeppel, Brian J.; Cuta, Judith M.

2007-01-01T23:59:59.000Z

452

A 2-Liter, 2000 MPa Air Source for the Radiatively Driven Hypersonic Wind Tunnel  

SciTech Connect (OSTI)

The A2 LITE is a 2 liter, 2000 MPa, 750 K ultra-high pressure (UHP) vessel used to demonstrate UHP technology and to provide an air flow for wind tunnel nozzle development. It is the largest volume UHP vessel in the world. The design is based on a 100:1 pressure intensification using a hydraulic ram as a low pressure driver and a three-layer compound cylinder UHP section. Active control of the 900 mm piston stroke in the 63.5 mm bore permits pressure-time profiles ranging from static to constant pressure during flow through a 1 mm throat diameter nozzle for 1 second.

Costantino, M; Lofftus, D

2002-05-30T23:59:59.000Z

453

Tunneling dynamics and phase transition of a Bose-Fermi mixture in a double well  

Science Journals Connector (OSTI)

The coherent nonlinear tunneling dynamics of a boson-fermion mixture in a double-well potential is studied in this paper. Four types of phase are found for the mixture. The first one is two species localizing in different potential wells. The second one is two species coexisting in the same well. The third one is two species equally populated in two wells. The fourth one is one species equally populated in two wells while the other species is in one well. The phase transitions among these four states have been investigated. The interspecies and intraspecies interactions as well as bosonic and fermionic numbers can dramatically affect these phase transitions.

Peng-Tang Qi and Wen-Shan Duan

2011-09-22T23:59:59.000Z

454

An analysis of the induced flow downstream between oscillating wings in a wind tunnel  

E-Print Network [OSTI]

AN ANALYSIS OF THE INDUCED FLOW DOWNSTREAM BETWEEN OSCILLATING WINGS IN A WIND TIMBAL A Thesis by BARRY ERWIN MORGAN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1970 Major Subject; Aerospace Engineering AN ANALYSIS OF THE INDUCED FLOW DOWNSTREAM BETWEEN OSCILLATING WINGS IN A WIND TUNNEL A Thesis by BARRY ERWIN MORGAN Approved as to style and content by: rman of Committee) (Hea of Depart ent...

Morgan, Barry Erwin

2012-06-07T23:59:59.000Z

455

Electric-field dependence of pairing temperature and tunneling in high-temperature superconductors  

Science Journals Connector (OSTI)

Using the Bethe-Salpeter equation including high electric fields, the dependence of the critical temperature of onsetting superconductivity on the applied field is calculated analytically. The critical temperature of pairing is shown to increase with the applied field strength. This is a new field effect and could contribute to the explanation of recent experiments on field-induced superconductivity. From the field dependence of the Bethe-Salpeter equation, the two-particle bound-state solution is obtained as a resonance with a tunneling probability analogous to the WKB solution of a single particle confined in a potential and coupled to an electrical field.

K. Morawetz

2002-11-27T23:59:59.000Z

456

Superconductive fluctuations in the density of states and tunneling resistance in high-Tc superconductors  

Science Journals Connector (OSTI)

The effect of superconductive fluctuations on the density of states and tunneling resistance is revisited in the case of dirty superconductors and derived for clean samples with and without pair-breaking sources. For clean superconductors new features appear in the density of states. In particular, with respect to the commonly known dirty case, the fluctuation effects manifest themselves on a new scale of energy with a different power-law behavior as function of T-Tc. The relevance of these results for high-Tc superconductors is analyzed.

C. Di Castro, R. Raimondi, C. Castellani, and A. A. Varlamov

1990-12-01T23:59:59.000Z

457

Tunneling in all-high-Tc edge junctions with deposited barriers  

Science Journals Connector (OSTI)

All-high-Tc-material edge junctions consisting of laser-ablated Y-Ba-Cu-O electrodes and an in situ rf-sputter-deposited MgO barrier have been fabricated whose I-V characteristics show tunneling-related effects. These include a junction resistance with an exponential dependence on the nominal-barrier thickness, gaplike structure observed in the conductance curves, and Josephson effects. These properties are very sensitive to the choice of materials-processsing method for the junction interfaces.

R. B. Laibowitz, R. P. Robertazzi, R. H. Koch, A. Kleinsasser, J. R. Kirtley, J. M. Viggiano, R. L. Sandstrom, and W. J. Gallagher

1992-12-01T23:59:59.000Z

458

Nanometer-scale tunnel formation in metallic glass by helium ion irradiation  

SciTech Connect (OSTI)

We have shown that upon high fluence helium ion irradiation, metallic glass Cu{sub 50}Zr{sub 45}Ti{sub 5} becomes highly porous at the depth of the helium projected range. The resulting porous region is characterized by the formation of a tunnel like structure and self-linkage of nanometer size gas bubbles. Furthermore, the irradiation leads to the formation of nanometer size Cu{sub x}Zr{sub y} crystals that are randomly distributed. The results of this study indicate that the He-filled bubbles have attractive interactions and experience considerable mobility. Movement of the bubbles is believed to be assisted by ballistic collisions.

Shao Lin [Department of Nuclear Engineering, Texas A and M University, College Station, Texas 77843 (United States); Materials Science and Engineering Program, Texas A and M University, College Station, Texas 77843 (United States); Gorman, Brian P. [Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401 (United States); Aitkaliyeva, Assel [Materials Science and Engineering Program, Texas A and M University, College Station, Texas 77843 (United States); David Theodore, N. [CHD-Fab, Freescale Semiconductor, Inc., Chandler, Arizona 85224 (United States); Xie Guoqiang [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

2012-07-23T23:59:59.000Z

459

Spin-polarized currents in the tunnel contact of a normal conductor and a two-dimensional topological insulator  

SciTech Connect (OSTI)

The spin filtering of electrons tunneling from the edge states of a two-dimensional topological insulator into a normal conductor under a magnetic field (external or induced due to proximity to a magnetic insulator) is studied. Calculations are performed for a tunnel contact of finite length between the topological insulator and an electronic multimode quantum strip. It is shown that the flow of tunneling electrons is split in the strip, so that spin-polarized currents arise in its left and right branches. These currents can be effectively controlled by the contact voltage and the chemical potential of the system. The presence of a magnetic field, which splits the spin subbands of the electron spectrum in the strip, gives rise to switching of the spin current between the strip branches.

Sukhanov, A. A., E-mail: AASukhanov@yandex.ru; Sablikov, V. A. [Russian Academy of Sciences, Kotel'nikov Institute of Radio Engineering and Electronics (Fryazino branch) (Russian Federation)] [Russian Academy of Sciences, Kotel'nikov Institute of Radio Engineering and Electronics (Fryazino branch) (Russian Federation)

2013-11-15T23:59:59.000Z

460

Large Sheet Process Consolidation Project  

E-Print Network [OSTI]

The purpose of this project is to reduce labor costs through the consolidation of large sheet processes into the Beta and Alpha manufacturing plants. The consolidation of equipment and departments will allow for the reduction of indirect labor...

Johnson, Keith

2005-12-16T23:59:59.000Z

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

Extra-Large Memory Nodes  

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

need. Interactive Jobs with X-windows Forwarding To use large analytical tools such as Matlab, you can request an interactive job with X-windows forwarding enabled. Running the...

462

Electron tunneling characteristics on La[subscript 0.7]Sr[subscript 0.3]MnO[subscript 3] thin-film surfaces at high temperature  

E-Print Network [OSTI]

We report on the electron tunneling characteristics on La0.7Sr0.3MnO3 (LSM) thin-film surfaces up to 580?°C in 10[superscript ?3]?mbar oxygen pressure, using scanning tunneling microscopy/spectroscopy (STM/STS). A thresholdlike ...

Katsiev, Khabiboulakh

463

Riad, EPS Structures Innovations on Central Artery/Tunnel (CA/T) Project 2005 BSCES-GEO-INSTITUTE RECENT ADVANCES IN GEOTECHNICAL  

E-Print Network [OSTI]

Riad, EPS Structures Innovations on Central Artery/Tunnel (CA/T) Project 2005 BSCES-GEO-INSTITUTE RECENT ADVANCES IN GEOTECHNICAL ENGINEERING Seminar 1 EPS STRUCTURES INNOVATIONS ON CENTRAL ARTERY/TUNNEL (CA/T) PROJECT Hany L. Riad, Ph.D., P.E. (1) Abstract The use of Expanded Polystyrene (EPS) in block

Horvath, John S.

464

Danger of Tunnels on Al Aqsa Mosque Buildings For more than 40 years, the city of Jerusalem has faced accelerated historical transformation on  

E-Print Network [OSTI]

Danger of Tunnels on Al Aqsa Mosque Buildings Abstract For more than 40 years, the city tunnels under Al Aqsa Mosque and the Arab historical town to weaken the foundation of buildings. This research highlights Palestinian, Israeli and international important reports about the excavations under Al

465

Extracellular-vesicle type of volume transmission and tunnelling-nanotube type of wiring transmission add a new dimension to brain neuro-glial networks  

Science Journals Connector (OSTI)

...Extracellular-vesicle type of volume transmission and tunnelling-nanotube...catecholaminergic cell line) PrPSc spread between...found a prion-like transmission of protein aggregates...Tunneling nanotubes: a new route for the exchange of...Fuxe, K. 1992 Volume transmission in the brain. Am...

2014-01-01T23:59:59.000Z

466

Department of Energy assessment of the Large Hadron Collider  

SciTech Connect (OSTI)

This report summarizes the conclusions of the committee that assessed the cost estimate for the Large Hadron Collider (LHC). This proton-proton collider will be built at CERN, the European Laboratory for Particle Physics near Geneva, Switzerland. The committee found the accelerator-project cost estimate of 2.3 billion in 1995 Swiss francs, or about $2 billion US, to be adequate and reasonable. The planned project completion date of 2005 also appears achievable, assuming the resources are available when needed. The cost estimate was made using established European accounting procedures. In particular, the cost estimate does not include R and D, prototyping and testing, spare parts, and most of the engineering labor. Also excluded are costs for decommissioning the Large Electron-Positron collider (LEP) that now occupies the tunnel, modifications to the injector system, the experimental areas, preoperations costs, and CERN manpower. All these items are assumed by CERN to be included in the normal annual operations budget rather than the construction budget. Finally, contingency is built into the base estimate, in contrast to Department of Energy (DOE) estimates that explicitly identify contingency. The committee`s charge, given by Dr. James F. Decker, Deputy Directory of the DOE Office of Energy Research, was to understand the basis for the LHC cost estimate, identify uncertainties, and judge the overall validity of the estimate, proposed schedule, and related issues. The committee met at CERN April 22--26, 1996. The assessment was based on the October 1995 LHC Conceptual Design Report or ``Yellow Book,`` cost estimates and formal presentations made by the CERN staff, site inspection, detailed discussions with LHC technical experts, and the committee members` considerable experience.

NONE

1996-06-01T23:59:59.000Z

467

Low-temperature magnetic characterization of optimum and etch-damaged in-plane magnetic tunnel junctions  

SciTech Connect (OSTI)

We describe low-temperature characterization of magnetic tunnel junctions (MTJs) patterned by reactive ion etching for spin-transfer-torque magnetic random access memory. Magnetotransport measurements of typical MTJs show increasing tunneling magnetoresistance (TMR) and larger coercive fields as temperature is decreased down to 10 K. However, MTJs selected from the high-resistance population of an MTJ array exhibit stable intermediate magnetic states when measured at low temperature and show TMR roll-off below 100 K. These non-ideal low-temperature behaviors arise from edge damage during the etch process and can have negative impacts on thermal stability of the MTJs.

Kan, Jimmy J.; Gottwald, Matthias; Fullerton, Eric E. [Center for Magnetic Recording Research, University of California, San Diego, La Jolla, California 92093 (United States)] [Center for Magnetic Recording Research, University of California, San Diego, La Jolla, California 92093 (United States); Lee, Kangho; Kang, Seung H. [Advanced Technology, Qualcomm, Inc., San Diego, California 92121 (United States)] [Advanced Technology, Qualcomm, Inc., San Diego, California 92121 (United States)

2013-09-21T23:59:59.000Z

468

Room temperature electron transport properties of single C{sub 60} studied using scanning tunneling microscope and reak junctions.  

SciTech Connect (OSTI)

We report the measurements of the electron transport of an individual C{sub 60} molecule through the combination of two experimental efforts. The nanometer-sized junctions were fabricated using electromigration combined with electron beam lithography and shadow effect evaporation. We performed the scanning tunneling microscopy/spectroscopy measurements of dispersed C{sub 60} molecules which were deposited on a highly ordered pyrolytic graphite substrate. The single electron tunneling through a single C{sub 60} molecule due to the Coulomb blockage effect is observed at room temperature.

Cheng, R.; Carvell, J.; Fradin, F. Y.; Indiana Univ.-Purdue Univ. at Indianapolis

2010-09-15T23:59:59.000Z

469

Josephson scanning tunneling microscopy -- a local and direct probe of the superconducting order parameter  

SciTech Connect (OSTI)

Direct measurements of the superconducting superfluid on the surface of vacuum-cleaved Bi2Sr2CaCu2O8+delta (BSCCO) samples are reported. These measurements are accomplished via Josephson tunneling into the sample using a novel scanning tunneling microscope (STM) equipped with a superconducting tip. The spatial resolution of the STM of lateral distances less than the superconducting coherence length allows it to reveal local inhomogeneities in the pair wavefunction of the BSCCO. Instrument performance is demonstrated first with Josephson measurements of Pb films followed by the layered superconductor NbSe2. The relevant measurement parameter, the Josephson ICRN product, is discussed within the context of both BCS superconductors and the high transition temperature superconductors. The local relationship between the ICRN product and the quasiparticle density of states (DOS) gap are presented within the context of phase diagrams for BSCCO. Excessive current densities can be produced with these measurements and have been found to alter the local DOS in the BSCCO. Systematic studies of this effect were performed to determine the practical measurement limits for these experiments. Alternative methods for preparation of the BSCCO surface are also discussed.

Kimura, Hikari; Dynes, Robert; Barber Jr., Richard. P.; Ono, S.; Ando, Y.

2009-09-01T23:59:59.000Z

470

Tunneling probability for the birth of an asymptotically de Sitter universe  

SciTech Connect (OSTI)

In the present work, we quantize a closed Friedmann-Robertson-Walker model in the presence of a positive cosmological constant and radiation. It gives rise to a Wheeler-DeWitt equation for the scale factor which has the form of a Schroedinger equation for a potential with a barrier. We solve it numerically and determine the tunneling probability for the birth of a asymptotically DeSitter, inflationary universe, initially, as a function of the mean energy of the initial wave function. Then, we verify that the tunneling probability increases with the cosmological constant, for a fixed value of the mean energy of the initial wave function. Our treatment of the problem is more general than previous ones, based on the WKB approximation. That is the case because we take into account the fact that the scale factor (a) cannot be smaller than zero. It means that, one has to introduce an infinity potential wall at a=0, which forces any wave packet to be zero there. That condition introduces new results, in comparison with previous works.

Acacio de Barros, J. [CSLI, 220 Panama Street, Stanford University, Stanford, California 94305-4115 (United States); Correa Silva, E. V.; Monerat, G. A.; Oliveira-Neto, G. [Departamento de Matematica e Computacao, Faculdade de Tecnologia, Universidade do Estado do Rio de Janeiro, Rodovia Presidente Dutra Km 298, Polo Industrial, CEP 27537-000, Resende-RJ (Brazil); Ferreira Filho, L. G. [Departamento de Mecanica e Energia, Faculdade de Tecnologia, Universidade do Estado do Rio de Janeiro, Rodovia Presidente Dutra Km 298, Polo Industrial, CEP 27537-000, Resende-RJ (Brazil); Romildo, P. Jr. [Departamento de Fisica, Instituto de Ciencias Exatas, Universidade Federal de Juiz de Fora, CEP 36036-330, Juiz de Fora, Minas Gerais (Brazil)

2007-05-15T23:59:59.000Z

471

Spontaneous tunneling and near-infrared-induced interconversion between the amino-hydroxy conformers of cytosine  

SciTech Connect (OSTI)

Spontaneous and near-infrared/infrared (NIR/IR)-induced interconversions between two amino-hydroxy conformers of monomeric cytosine have been investigated for the compound isolated in a low-temperature argon matrix. Combined use of a laser source (which provides narrowband NIR radiation) and a broadband NIR/IR source of excitation light allowed a detailed investigation of mutual conversions of the two conformers in question. The experiments carried out within the current work demonstrated that upon broadband NIR/IR irradiation (with the IR source of FTIR spectrometer) the population ratio of the two amino-hydroxy conformers changes towards a ratio corresponding to a photostationary state. Evolution of the conformer population ratio towards the photostationary ratio occurred independent of the initial ratio of conformers, which could be prepared by a population shift (in favor of one of the forms) induced by narrowband NIR excitation. Moreover, spontaneous tunneling conversion of the higher-energy conformer into a lower-energy form was observed for cytosine isolated in a low-temperature argon matrix kept in the dark. This process is slow and occurs on a time scale of days. The tunneling process, studied for matrix-isolated cytosine, clearly follows a dispersive type of kinetics rather than the classical monoexponential kinetics.

Reva, Igor; Fausto, Rui [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Nowak, Maciej J.; Lapinski, Leszek [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)

2012-02-14T23:59:59.000Z

473

LARGE DISPLAY RESEARCH As large displays become more affordable, researchers  

E-Print Network [OSTI]

-hung displays. A precipitous price drop has also occurred in the last few years, and the average computer are investigating their effects on productivity, and techniques for making the large display user experience more effective. Recent work has demonstrated significant productivity benefits, but has also identified numerous

Rajamani, Sriram K.

474

Property:Water Type | Open Energy Information  

Open Energy Info (EERE)

Type Type Jump to: navigation, search Property Name Water Type Property Type String Pages using the property "Water Type" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + Freshwater + 10-ft Wave Flume Facility + Freshwater + 11-ft Wave Flume Facility + Freshwater + 2 2-ft Flume Facility + Freshwater + 3 3-ft Wave Flume Facility + Freshwater + 5 5-ft Wave Flume Facility + Freshwater + 6 6-ft Wave Flume Facility + Freshwater + A Alden Large Flume + Freshwater + Alden Small Flume + Freshwater + Alden Tow Tank + Freshwater + Alden Wave Basin + Freshwater + B Breakwater Research Facility + Freshwater + Bucknell Hydraulic Flume + Freshwater + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + Freshwater +

475

Norwegian Marine Technology Research Institute Partnership for the future  

E-Print Network [OSTI]

;Greener operations Offshore renewable energy Autonomous surveillance Oil & gas in deeper water involvement «Ulstein X-bow» Revolutionary ship design Ship Model Towing Tank (1939) Cavitation Tunnel (1965

Nørvåg, Kjetil

476

Large Magnetization at Carbon Surfaces  

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

Large Magnetization at Carbon 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 element. Now, another use has been found: magnets. One would not expect pure carbon to be magnetic, but for more than ten years scientists have suspected that carbon can be made to be magnetic by doping it with nonmagnetic materials, changing its order ever so slightly. Years ago, the first x-ray images obtained using the scanning transmission x-ray microscope at ALS Beamline 11.0.2 provided valuable insight into how proton irradiation can cause carbon to transform into a ferromagnetic material. Now, researchers are using x-ray spectroscopy at ALS Beamline 4.0.2 to study the magnetism of proton-irradiated graphite surfaces in order to understand the effects of hydrogen (i.e. protons) on the electronic structure of carbon. In studying the properties of electrons responsible for magnetic order in graphite, researchers found that a very large magnetic moment is essentially switched on when hydrogen atoms are incorporated at the surface of graphite.

477

Splitting and Confirming Large File  

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

Splitting and Confirming Large File Splitting and Confirming Large File Name: Bradley C. Status: Student Age: 16 Location: N/A Country: N/A Date: June 2003 Question: I just calculated one billion digits of pi on my PC, how do I confirm them? I cannot access them because the file size is 1.28 GB, my ram is only 512 MB, meaning none of my word processor's will touch it. Is it possible to split the document, somehow? Then how do I confirm the digits? Replies: Checking the correctness of large numbers -- transcendental numbers like 'pi', or a large prime -- is not easy because there are many sources of error that are difficult to detect, or track down. Some, but by no means all are: 1. How "good" (that is convergent) is the algorithm? If, for example the algorithm is some sort of infinite series, there is always a truncation error, because you cannot compute an infinite number of terms in a finite amount of time. The further out you go in the algorithm, the more significant these errors become.

478

Riddell Revolution Speed Adult Large  

E-Print Network [OSTI]

Available: Adult Football Helmet Detailed Ratings May 2012 Riddell 360 Sample 1 2 3 Size Adult Large Adult.237 0.239 Overall STAR 0.239 Best Available: A total of 15 adult football helmet models that have been values. Helmet Ratings #12;Adult Football Helmet Detailed Ratings May 2012 Schutt ION 4D Sample 1 2 3

Lu, Chang

479

A wind tunnel boundary-layer simulation of wind flow over complex terrain: Effect of terrain and model construction  

Science Journals Connector (OSTI)

The report presents the results of a wind-tunnel study of the flow of the natural wind over complex terrain. A 1:4000 undistorted scale model of Gebbies Pass in the South Island of New Zealand was prepared and...

D. Neal; D. C. Stevenson; D. Lindley

1981-11-01T23:59:59.000Z

480

Frustration in the Si(111) ‘‘pseudo 5×5’’ Cu structure directly observed by scanning tunneling microscopy  

Science Journals Connector (OSTI)

Frustration in a surface structure has been observed in real space and time using the scanning tunneling microscope. The frustration is revealed as an instability of an inherent feature in the Si(111) ‘‘pseudo 5×5’’ Cu structure. A possible origin of the frustration is proposed.

K. Mortensen

1991-01-28T23:59:59.000Z

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.


481

Adapting to Limitations of a Wind Tunnel Test Facility in the Aerodynamic Testing of a new UAV  

E-Print Network [OSTI]

Adapting to Limitations of a Wind Tunnel Test Facility in the Aerodynamic Testing of a new UAV Dr K section for aerodynamic tests of aircraft models and aerodynamic devices. Improvements over the years have aerodynamic testing facility, albeit with much reduced capability. This paper reports on initial progress

Wong, K. C.

482

Electrically Tunable Macroscopic Quantum Tunneling in a Graphene-Based Josephson Junction Gil-Ho Lee,1  

E-Print Network [OSTI]

Electrically Tunable Macroscopic Quantum Tunneling in a Graphene-Based Josephson Junction Gil.1103/PhysRevLett.107.146605 PACS numbers: 72.80.Vp, 73.40.Ã?c, 74.45.+c, 85.25.Cp A Josephson junction [1 the fabri- cation of nanostructured proximity-coupled Josephson junctions based on conducting spacers

Lee, Hu-Jong

483

Scanning tunneling spectroscopy on crossed carbon nanotubes J. W. Janssen, S. G. Lemay, L. P. Kouwenhoven, and C. Dekker  

E-Print Network [OSTI]

the nanotubes and their binding energy to a supporting gold substrate. More importantly, our STS studies showScanning tunneling spectroscopy on crossed carbon nanotubes J. W. Janssen, S. G. Lemay, L. P Delft, The Netherlands Received 3 October 2001; published 8 March 2002 Crossing nanotubes were

Dekker, Cees

484

Measuring charge trap occupation and energy level in CdSe/ZnS quantum dots using a scanning tunneling microscope  

E-Print Network [OSTI]

We use a scanning tunneling microscope to probe single-electron charging phenomena in individual CdSe/ZnS (core/shell) quantum dots (QDs) at room temperature. The QDs are deposited on top of a bare Au thin film and form a ...

Bulovic, Vladimir

485

Faraday Discuss., 1994,97,35-41 Far-IR Vibration-Rotation-Tunnelling Spectroscopy of the  

E-Print Network [OSTI]

. The theoretical equi- librium geometry of the water trimer is a hydrogen-bonded ring in which each water acts' is accomplished by rotating one water monomer (shaded) about its donated hydrogen bond. The pathway connectsFaraday Discuss., 1994,97,35-41 Far-IR Vibration-Rotation-Tunnelling Spectroscopy of the Water

Cohen, Ronald C.

486

Quasi-bound levels, transmission and resonant tunneling in heterostructures with double and multi rectangular, trapezoidal, triangular barriers  

Science Journals Connector (OSTI)

In this work quasi-bound level energies, energy dependence of the transmission coefficients and negative differential resistance properties are studied in double and multi-barrier structures. Various barrier types such as rectangular, trapezoidal and ... Keywords: Double-barrier structures, Peak to valley ratio, Resonant tunneling diodes, Trapezoidal barrier, Triangular barrier

F. Nutku

2014-06-01T23:59:59.000Z

487

Concept tests: Wind tunnel tests in controlled wind Comparison tests: Free field comparison to 3D sonic anemometer  

E-Print Network [OSTI]

: Measurements with three 1D sonics and one azimuth sensor Advantage: Pure virginal wind in front of wind turbine, and for wind, power performance and loads verification Full scale tests: Measurements on 3,6MW wind turbineConcept tests: Wind tunnel tests in controlled wind Comparison tests: Free field comparison to 3D

488

Scanning tunneling microscope tip as a positionable contact: Probing a Josephson-junction array at subkelvin temperatures  

E-Print Network [OSTI]

Scanning tunneling microscope tip as a positionable contact: Probing a Josephson-junction arrayK. The STM enables us to probe the structure, a Josephson-junction array, at various positions. Examples of such systems are two- dimensional electron gases and Josephson junction arrays.1

489

SAGEEP 2010 Keystone, Colorado http://www.eegs.org CONTINUOUS EXPLORATION AHEAD OF THE TUNNEL FACE BY TSWD -  

E-Print Network [OSTI]

out for over 20 years to investigate the rock ahead of a tunnel face and made a contribution to reduce and the main geological structure was well resolved. Geophysical issues which need further investigation quality, similar circumstances can lead to persistent interruptions and expensive remedial measures during

Brückl, Ewald

490

Low Speed Virtual Wind Tunnel Simulation For Educational Studies In Introducing Computational Fluid Dynamics And Flow Visualization  

E-Print Network [OSTI]

, the Low Speed Virtual Wind Tunnel simulation is created. This program cuts down on the require information from the user in order to perform a simulation. The program is capable of taking an airfoil coordinates that is generated according to the user...

Yang, Cher-Chiang

2008-05-05T23:59:59.000Z

491

Attributable Risk of Carpal Tunnel Syndrome in the General Population: Implications for Intervention Programs in the Workplace  

E-Print Network [OSTI]

sponsor. Word count text: 3182 excluding Abstract, References and Tables Word count Abstract: 224; Tables: 2 inserm-00425478,version1-9Feb2011 Author manuscript, published in "Scandinavian journal of work, environment & health 35, 5 (2009) 342-8" #12;2 ABSTRACT: Objectives Carpal tunnel syndrome (CTS) represents

Paris-Sud XI, Université de

492

Exergy Analysis of the Cryogenic Helium Distribution System for the Large Hadron Collider (LHC)  

E-Print Network [OSTI]

The Large Hadron Collider (LHC) at CERN features the world’s largest helium cryogenic system, spreading over the 26.7 km circumference of the superconducting accelerator. With a total equivalent capacity of 145 kW at 4.5 K including 18 kW at 1.8 K, the LHC refrigerators produce an unprecedented exergetic load, which must be distributed efficiently to the magnets in the tunnel over the 3.3 km length of each of the eight independent sectors of the machine. We recall the main features of the LHC cryogenic helium distribution system at different temperature levels and present its exergy analysis, thus enabling to qualify second-principle efficiency and identify main remaining sources of irreversibility..

Claudet, S; Tavian, L; Wagner, U; 10.1063/1.3422294

2010-01-01T23:59:59.000Z

493

EXERGY ANALYSIS OF THE CRYOGENIC HELIUM DISTRIBUTION SYSTEM FOR THE LARGE HADRON COLLIDER (LHC)  

SciTech Connect (OSTI)

The Large Hadron Collider (LHC) at CERN features the world's largest helium cryogenic system, spreading over the 26.7 km circumference of the superconducting accelerator. With a total equivalent capacity of 145 kW at 4.5 K including 18 kW at 1.8 K, the LHC refrigerators produce an unprecedented exergetic load, which must be distributed efficiently to the magnets in the tunnel over the 3.3 km length of each of the eight independent sectors of the machine. We recall the main features of the LHC cryogenic helium distribution system at different temperature levels and present its exergy analysis, thus enabling to qualify second-principle efficiency and identify main remaining sources of irreversibility.

Claudet, S.; Lebrun, Ph.; Tavian, L.; Wagner, U. [CERN, CH-1211, Geneva, 23 (Switzerland)

2010-04-09T23:59:59.000Z

494

Health and safety evaluation of a modified tunnel-borer design for application to single-entry coal-mine development  

SciTech Connect (OSTI)

The health and safety analysis is part of an overall effort to identify and develop innovative underground coal extraction systems. The single-entry tunnel borer system was initially considered an innovative approach to underground mining because it exhibited a means of increasing the speed and efficiency of entry development by reducing the number of entries. However, to be considered a truly advanced system, the tunnel borer had to meet distinct safety criteria as well. The objective was to examine the tunnel borer design and determine whether it offset major health hazards, and satisfied the prescribed safety levels. As a baseline for comparison, the tunnel borer was compared against the continuous mining entry driving system. The results of the health analysis indicated that while the tunnel borer design offered improvements in dust control through the use of water sprays, a higher face ventilation rate, and the application of spalling rather than the conventional grinding process, it interjected an additional mutagenic is and toxic compound into the environment through the use of shotcrete. The tunnel borer system easily conformed with the prescribed fatality limit, but exceeded the required limits for disabling and overall injuries. It also exhibited projected disabling and overall injury rates considerably higher than existing continuous mining injury rates. Consequently, the tunnel borer system was not considered an advanced system.

Zimmerman, W. F.

1982-02-15T23:59:59.000Z

495

Tunneling density of states as a function of thickness in superconductor/ strong ferromagnet bilayers  

SciTech Connect (OSTI)

We have made an experimental study of the tunneling density of states (DOS) in strong ferromagnetic thin films (CoFe) in proximity with a thick superconducting film (Nb) as a function of d{sub F}, the ferromagnetic thickness. Remarkably, we find that as d{sub F} increases, the superconducting DOS exhibits a scaling behavior in which the deviations from the normal-state conductance have a universal shape that decreases exponentially in amplitude with characteristic length d* {approx} 0.4 nm. We do not see oscillations in the DOS as a function of d{sub F}, as expected from predictions based on the Usadel equations, although an oscillation in T{sub c}(d{sub F}) has been seen in the same materials.

Reymond, S.

2010-04-29T23:59:59.000Z

496

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

Science Journals Connector (OSTI)

The intermittency in turbulent magnetic field fluctuations has been observed to scale with the amount of magnetic helicity injected into a laboratory plasma. An unstable spheromak injected into the MHD wind tunnel of the Swarthmore Spheromak Experiment displays turbulent magnetic and plasma fluctuations as it relaxes into a Taylor state. The level of intermittency of this turbulence is determined by finding the flatness of the probability distribution function of increments for magnetic pickup coil fluctuations B?(t). The intermittency increases with the injected helicity, but spectral indices are unaffected by this variation. While evidence is provided which supports the hypothesis that current sheets and reconnection sites are related to the generation of this intermittent signal, the true nature of the observed intermittency remains unknown.

D.?A. Schaffner; A. Wan; M.?R. Brown

2014-04-25T23:59:59.000Z

497

Method and apparatus for differential spectroscopic atomic-imaging using scanning tunneling microscopy  

DOE Patents [OSTI]

A Method and apparatus for differential spectroscopic atomic-imaging is disclosed for spatial resolution and imaging for display not only individual atoms on a sample surface, but also bonding and the specific atomic species in such bond. The apparatus includes a scanning tunneling microscope (STM) that is modified to include photon biasing, preferably a tuneable laser, modulating electronic surface biasing for the sample, and temperature biasing, preferably a vibration-free refrigerated sample mounting stage. Computer control and data processing and visual display components are also included. The method includes modulating the electronic bias voltage with and without selected photon wavelengths and frequency biasing under a stabilizing (usually cold) bias temperature to detect bonding and specific atomic species in the bonds as the STM rasters the sample. This data is processed along with atomic spatial topography data obtained from the STM raster scan to create a real-time visual image of the atoms on the sample surface.

Kazmerski, Lawrence L. (Lakewood, CO)

1990-01-01T23:59:59.000Z

498

Giant electrocaloric effect in asymmetric ferroelectric tunnel junctions at room temperature  

SciTech Connect (OSTI)

Room-temperature electrocaloric properties of Pt/BaTiO{sub 3}/SrRuO{sub 3} ferroelectric tunnel junctions (FTJs) are studied by using a multiscale thermodynamic model. It is found that there is a divergence in the adiabatic temperature change ?T for the two opposite polarization orientations. This difference under a typical writing voltage of 3?V can reach over 1?K as the barrier thickness decreases. Thanks to the ultrahigh external stimulus, a giant electrocaloric effect (1.53?K/V) with ?T being over 4.5?K can be achieved at room temperature, which demonstrates the perspective of FTJs as a promising solid-state refrigeration.

Liu, Yang, E-mail: liuyangphy52@gmail.com; Infante, Ingrid C.; Dkhil, Brahim, E-mail: brahim.dkhil@ecp.fr [Laboratoire Structures, Propriétés et Modélisation des Solides, UMR 8580 CNRS-Ecole Centrale Paris, Grande Voie des Vignes, Châtenay-Malabry Cedex 92295 (France); Lou, Xiaojie [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049 (China)

2014-02-24T23:59:59.000Z

499

Black hole fireworks: quantum-gravity effects outside the horizon spark black to white hole tunneling  

E-Print Network [OSTI]

We show that there is a classical metric satisfying the Einstein equations outside a finite spacetime region where matter collapses into a black hole and then emerges from a white hole. We compute this metric explicitly. We show how quantum theory determines the (long) time for the process to happen. A black hole can thus quantum-tunnel into a white hole. For this to happen, quantum gravity should affect the metric also in a small region outside the horizon: we show that contrary to what is commonly assumed, this is not forbidden by causality or by the semiclassical approximation, because quantum effects can pile up over a long time. This scenario alters radically the discussion on the black hole information puzzle.

Hal M. Haggard; Carlo Rovelli

2014-07-06T23:59:59.000Z

500

Construction of a Dilution Refrigerator Based Ultra-Low Temperature Scanning Tunneling Microscope  

Science Journals Connector (OSTI)

We constructed a dilution refrigerator based ultra-low temperature scanning tunneling microscope (ULT-STM) which works at temperatures down to 20 mK, in magnetic fields up to 6 T and in ultrahigh vacuum (UHV). One can load samples/tips, which are prepared in a UHV chamber, to an STM head maintaining the low temperature and UHV conditions. After then they can be cooled back to the base temperature in several hours. We report results of a test measurement on a superconducting NbSe2 sample as well as recent STM/STS studies on graphite samples such as observations of the Landau quantization and visualization of the possible localized states in magnetic fields.

Hiroshi Kambara; Tomohiro Matsui; Yasuhiro Niimi; Hiroshi Fukuyama

2006-01-01T23:59:59.000Z