National Library of Energy BETA

Sample records for type tunnel lengthm

  1. Formation of tungsten coatings by gas tunnel type plasma spraying Akira Kobayashia,*, Shahram Sharafatb

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    Formation of tungsten coatings by gas tunnel type plasma spraying Akira Kobayashia,*, Shahram deposited as a coating, it can protect the substrate surface from high heat flux. In this study, tungsten (W) sprayed coatings were formed on stainless steel substrates by gas tunnel type plasma spraying at a short

  2. Improved source design for p-type tunnel field-effect transistors: Towards truly complementary logic

    SciTech Connect (OSTI)

    Verreck, Devin Groeseneken, Guido; Verhulst, Anne S.; Collaert, Nadine; Mocuta, Anda; Thean, Aaron; Sorée, Bart

    2014-12-15

    Complementary logic based on tunnel field-effect transistors (TFETs) would drastically reduce power consumption thanks to the TFET's potential to obtain a sub-60?mV/dec subthreshold swing (SS). However, p-type TFETs typically do not meet the performance of n-TFETs for direct bandgap III-V configurations. The p-TFET SS stays well above 60?mV/dec, due to the low density of states in the conduction band. We therefore propose a source configuration in which a highly doped region is maintained only near the tunnel junction. In the remaining part of the source, the hot carriers in the exponential tail of the Fermi-Dirac distribution are blocked by reducing the doping degeneracy, either with a source section with a lower doping concentration or with a heterostructure. We apply this concept to n-p-i-p configurations consisting of In{sub 0.53}Ga{sub 0.47}As and an InP-InAs heterostructure. 15-band quantum mechanical simulations predict that the configurations with our source design can obtain sub-60?mV/dec SS, with an on-current comparable to the conventional source design.

  3. A novel high capacity positive electrode material with tunnel-type structure for aqueous sodium-ion batteries

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

    Wang, Yuesheng; Mu, Linqin; Liu, Jue; Yang, Zhenzhong; Yu, Xiqian; Gu, Lin; Hu, Yong -Sheng; Li, Hong; Yang, Xiao -Qing; Chen, Liquan; et al

    2015-08-06

    In this study, aqueous sodium-ion batteries have shown desired properties of high safety characteristics and low-cost for large-scale energy storage applications such as smart grid, because of the abundant sodium resources as well as the inherently safer aqueous electrolytes. Among various Na insertion electrode materials, tunnel-type Na0.44MnO2 has been widely investigated as a positive electrode for aqueous sodium-ion batteries. However, the low achievable capacity hinders its practical applications. Here we report a novel sodium rich tunnel-type positive material with a nominal composition of Na0.66[Mn0.66Ti0.34]O2. The tunnel-type structure of Na0.44MnO2 obtained for this compound was confirmed by XRD and atomic-scale STEM/EELS.more »When cycled as positive electrode in full cells using NaTi2(PO4)3/C as negative electrode in 1M Na2SO4 aqueous electrolyte, this material shows the highest capacity of 76 mAh g-1 among the Na insertion oxides with an average operating voltage of 1.2 V at a current rate of 2C. These results demonstrate that Na0.66[Mn0.66Ti0.34]O2 is a promising positive electrode material for rechargeable aqueous sodium-ion batteries.« less

  4. Passivated Tunneling Contacts to N-Type Wafer Silicon and Their Implementation into High Performance Solar Cells: Preprint

    SciTech Connect (OSTI)

    Stradins, P.; Essig, S.; Nemeth, W.; Lee, B. G.; Young, D.; Norman, A.; Liu, Y.; Luo, J.-W.; Warren, E.; Dameron, A.; LaSalvia, V.; Page, M.; Rohatgi, A.; Upadhyaya, A.; Rounsaville, B.; Ok, Y.-W.; Glunz, S.; Benick, J.; Feldmann, F.; Hermle, M.

    2014-12-01

    We present a case that passivated contacts based on a thin tunneling oxide layer, combined with a transport layer with properly selected work function and band offsets, can lead to high efficiency c-Si solar cells. Passivated contacts contribute to cell efficiency as well as design flexibility, process robustness, and a simplified process flow. Material choices for the transport layer are examined, including transparent n-type oxides and n+-doped poly-Si. SiO2/n+-poly-Si full-area, induced-junction back surface field contacts to n-FZ and n-Cz Si are incorporated into high efficiency cells with deep, passivated boron emitters.

  5. Effect of unitary impurities on non-STM types of tunneling in high-T-c superconductors 

    E-Print Network [OSTI]

    Zhu, JX; Ting, CS; Hu, Chia-Ren.

    2000-01-01

    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...

  6. Type B Accident Investigation Board Report on the August 5, 1998, Load Haul Dump Accident at U16b Tunnel, Nevada Test Site

    Broader source: Energy.gov [DOE]

    Thisis theType B Accident Investigation Board report of an industrial accident at the Nevada Test site (NTS), U16b tunnel in which a Bechtel Nevada (BN) employee suffered a compressed skull fracture as a result of being struck onthe head by a valve and fitting assembly on the end of a hose whichhad been broken from a water pipe by a moving piece of construction equipment.

  7. Channel tunnel

    ScienceCinema (OSTI)

    None

    2011-04-25

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

  8. Property:Maximum Wave Length(m) | Open Energy Information

    Open Energy Info (EERE)

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  9. Universal Time Tunneling

    E-Print Network [OSTI]

    Guenter Nimtz

    2009-01-26

    How much time does a tunneling wave packet spent in traversing a barrier? Quantum mechanical calculations result in zero time inside a barrier . In the nineties analogous tunneling experiments with microwaves were carried out. The results agreed with quantum mechanical calculations. Electron tunneling time is hard to measure being extremely short and parasitic effects due to the electric charge of electrons may be dominant. However, quite recently the atomic ionization tunneling time has been measured. Experimental data of photonic, phononic, and electronic tunneling time is available now and will be presented. It appears that the tunneling time is a universal property independent of the field in question.

  10. Ti-substituted tunnel-type Na0.44MnO2 oxide as a negative electrode for aqueous sodium-ion batteries

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

    Wang, Yuesheng; Liu, Jue; Lee, Byungju; Qiao, Ruimin; Yang, Zhenzhong; Xu, Shuyin; Yu, Xiqian; Gu, Lin; Hu, Yong-Sheng; Yang, Wanli; et al

    2015-03-25

    The aqueous sodium-ion battery system is a safe and low-cost solution for large-scale energy storage, due to the abundance of sodium and inexpensive aqueous electrolytes. Although several positive electrode materials, e.g., Na0.44MnO2, were proposed, few negative electrode materials, e.g., activated carbon and NaTi2(PO4)3, are available. Here we show that Ti-substituted Na0.44MnO2 (Na0.44[Mn1-xTix]O2) with tunnel structure can be used as a negative electrode material for aqueous sodium-ion batteries. This material exhibits superior cyclability even without the special treatment of oxygen removal from the aqueous solution. Atomic-scale characterizations based on spherical aberration-corrected electron microscopy and ab initio calculations are utilized to accuratelymore »identify the Ti substitution sites and sodium storage mechanism. Ti substitution tunes the charge ordering property and reaction pathway, significantly smoothing the discharge/charge profiles and lowering the storage voltage. Both the fundamental understanding and practical demonstrations suggest that Na0.44[Mn1-xTix]O2 is a promising negative electrode material for aqueous sodium-ion batteries.« less

  11. Ti-substituted tunnel-type Na0.44MnO2 oxide as a negative electrode for aqueous sodium-ion batteries

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

    Wang, Yuesheng [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP); Liu, Jue [Brookhaven National Lab. (BNL), Upton, NY (United States); Lee, Byungju [Seoul National Univ. (Korea, Republic of); Qiao, Ruimin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source; Yang, Zhenzhong [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP); Xu, Shuyin [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP); Yu, Xiqian [Brookhaven National Lab. (BNL), Upton, NY (United States)] (ORCID:000000018513518X); Gu, Lin [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP); Hu, Yong-Sheng [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP)] (ORCID:0000000284306474); Yang, Wanli [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source] (ORCID:0000000306668063); Kang, Kisuk [Seoul National Univ. (Korea, Republic of); Li, Hong [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP)] (ORCID:000000028659086X); Yang, Xiao-Qing [Brookhaven National Lab. (BNL), Upton, NY (United States); Chen, Liquan [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP); Huang, Xuejie [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP)

    2015-03-25

    The aqueous sodium-ion battery system is a safe and low-cost solution for large-scale energy storage, due to the abundance of sodium and inexpensive aqueous electrolytes. Although several positive electrode materials, e.g., Na0.44MnO2, were proposed, few negative electrode materials, e.g., activated carbon and NaTi2(PO4)3, are available. Here we show that Ti-substituted Na0.44MnO2 (Na0.44[Mn1-xTix]O2) with tunnel structure can be used as a negative electrode material for aqueous sodium-ion batteries. This material exhibits superior cyclability even without the special treatment of oxygen removal from the aqueous solution. Atomic-scale characterizations based on spherical aberration-corrected electron microscopy and ab initio calculations are utilized to accurately identify the Ti substitution sites and sodium storage mechanism. Ti substitution tunes the charge ordering property and reaction pathway, significantly smoothing the discharge/charge profiles and lowering the storage voltage. Both the fundamental understanding and practical demonstrations suggest that Na0.44[Mn1-xTix]O2 is a promising negative electrode material for aqueous sodium-ion batteries.

  12. Tunnel Hunter: Detecting Application-Layer Tunnels with Statistical Fingerprinting

    E-Print Network [OSTI]

    Salgarelli, Luca

    Tunnel Hunter: Detecting Application-Layer Tunnels with Statistical Fingerprinting M. Dusi, M, Italy Abstract Application-layer tunnels nowadays represent a significant security threat for any network protected by firewalls and Application Layer Gateways. The encapsulation of protocols subject

  13. Tunneling of Polymer Particles

    E-Print Network [OSTI]

    A. Martín-Ruiz; E. Chan-López; A. Carbajal-Domínguez; J. Bernal

    2014-08-28

    In this paper we study the tunneling using a background independent (polymer) quantization scheme. We show that at low energies, for the tunneling through a single potential barrier, the polymer transmission coefficient and the polymer tunneling time converge to its quantum-mechanical counterparts in a clear fashion. As the energy approaches the maximum these polymer quantities abruptly decrease to zero. We use the transfer matrix method to study the tunneling through a series of identical potential barriers. We obtain that the transmission coefficients (polymer and quantum-mechanical) behave qualitatively in a similar manner, as expected. Finally we show that the polymer tunneling time exhibits anomalous peaks compared with the standard result. Numerical results are also presented.

  14. Ultrafast scanning tunneling microscopy

    SciTech Connect (OSTI)

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

    1995-09-01

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

  15. Fire Size in Tunnels 

    E-Print Network [OSTI]

    Carvel, Ricky O

    In recent years, a number of high profile accidental fires have occurred in several road and rail tunnels throughout the world. Many of these fires grew rapidly to catastrophic size and claimed many lives. The processes ...

  16. Numerical wind tunnels

    E-Print Network [OSTI]

    Souza, Paulo Victor Santos

    2015-01-01

    Flow of viscous fluids are not usually discussed in detail in general and basic courses of physics. This is due in part to the fact that the Navier-Stokes equation has analytical solution only for a few restricted cases, while more sophisticated problems can only be solved by numerical methods. In this text, we present a computer simulation of wind tunnel, i.e., we present a set of programs to solve the Navier-Stokes equation for an arbitrary object inserted in a wind tunnel. The tunnel enables us to visualize the formation of vortices behind object, the so-called von K\\'arm\\'an vortices, and calculate the drag force on the object. We believe that this numerical wind tunnel can support the teacher and allow a more elaborate discussion of viscous flow. The potential of the tunnel is exemplified by the study of the drag on a simplified model of wing whose angle of attack can be controlled. A link to download the programs that make up the tunnel appears at the end.

  17. Collegiate Wind Competition Wind Tunnel Specifications | Department...

    Energy Savers [EERE]

    Wind Tunnel Specifications Collegiate Wind Competition Wind Tunnel Specifications Collegiate Wind Competition Wind Tunnel Specifications Teams competing in the U.S. Department of...

  18. Risk analysis for tunneling projects

    E-Print Network [OSTI]

    Sousa. Rita L

    2010-01-01

    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 ...

  19. INTERBAND TUNNEL TRANSISTORS A Dissertation

    E-Print Network [OSTI]

    D and 2D semiconductors.................................13 2.3 Comparison of Zener tunneling current the design and modeling of semiconducting and graphene nanoribbon-based tunnel transistors, to understand-dimensional semiconductors are derived to establish the guidelines for tunnel transistor design. An analytic expression

  20. Ferroelectric tunneling element and memory applications which utilize the tunneling element

    DOE Patents [OSTI]

    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

    2010-07-20

    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.

  1. Tunnel | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-EnhancingEt Al., 2013)OpenEnergyTrailTrosky,EnergyTullahassee,TunicaTunnel Jump to:

  2. Nonorientable spacetime tunneling

    E-Print Network [OSTI]

    González-Diáz, P F; Gonzalez-Diaz, Pedro F.; Garay, Luis J.

    1999-01-01

    Misner space is generalized to have the nonorientable topology of a Klein bottle, and it is shown that in a classical spacetime with multiply connected space slices having such a topology, closed timelike curves are formed. Different regions on the Klein bottle surface can be distinguished which are separated by apparent horizons fixed at particular values of the two angular variables that eneter the metric. Around the throat of this tunnel (which we denote a Klein bottlehole), the position of these horizons dictates an ordinary and exotic matter distribution such that, in addition to the known diverging lensing action of wormholes, a converging lensing action is also present at the mouths. Associated with this matter distribution, the accelerating version of this Klein bottlehole shows four distinct chronology horizons, each with its own nonchronal region. A calculation of the quantum vacuum fluctuations performed by using the regularized two-point Hadamard function shows that each chronology horizon nests a...

  3. Tunneling of the 3rd kind

    E-Print Network [OSTI]

    Holger Gies; Joerg Jaeckel

    2009-04-03

    We study a new kind of tunneling of particles through a barrier particular to quantum field theory. Here, the particles traverse the barrier by splitting into a virtual pair of particles of a different species which interacts only very weakly with the barrier and can therefore pass through it. Behind the barrier, the pair recombines into a particle of the original species. As an example, we discuss the case where photons split into a pair of minicharged particles. This process could be observed in experiments of the light-shining-through-a-wall type and may be used to search for minicharged particles in laboratory experiments.

  4. Optical isolation via unidirectional resonant photon tunneling

    SciTech Connect (OSTI)

    Moccia, Massimo; Castaldi, Giuseppe; Galdi, Vincenzo; Alù, Andrea; Engheta, Nader

    2014-01-28

    We show that tri-layer structures combining epsilon-negative and magneto-optical material layers can exhibit unidirectional resonant photon tunneling phenomena that can discriminate between circularly polarized (CP) waves of given handedness impinging from opposite directions, or between CP waves with different handedness impinging from the same direction. This physical principle, which can also be interpreted in terms of a Fabry-Perot-type resonance, may be utilized to design compact optical isolators for CP waves. Within this framework, we derive simple analytical conditions and design formulae, and quantitatively assess the isolation performance, also taking into account the unavoidable imperfections and nonidealities.

  5. Flatback airfoil wind tunnel experiment.

    SciTech Connect (OSTI)

    Mayda, Edward A.; van Dam, C.P.; Chao, David D.; Berg, Dale E.

    2008-04-01

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

  6. Relativistic tunneling through opaque barriers

    SciTech Connect (OSTI)

    De Leo, Stefano; Leonardi, Vinicius [Department of Applied Mathematics, State University of Campinas, SP 13083-970, Campinas (Brazil)

    2011-02-15

    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.

  7. Reinventing the PN Junction: Dimensionality Effects on Tunneling Switches

    E-Print Network [OSTI]

    Agarwal, Sapan

    2012-01-01

    Effects on Tunneling Switches By Sapan Agarwal AEffects on Tunneling Switches Copyright © 2012 by SapanEffects on Tunneling Switches by Sapan Agarwal Doctor of

  8. Nonorientable spacetime tunneling

    E-Print Network [OSTI]

    Pedro F. Gonzalez-Diaz; Luis J. Garay

    1999-01-07

    Misner space is generalized to have the nonorientable topology of a Klein bottle, and it is shown that in a classical spacetime with multiply connected space slices having such a topology, closed timelike curves are formed. Different regions on the Klein bottle surface can be distinguished which are separated by apparent horizons fixed at particular values of the two angular variables that eneter the metric. Around the throat of this tunnel (which we denote a Klein bottlehole), the position of these horizons dictates an ordinary and exotic matter distribution such that, in addition to the known diverging lensing action of wormholes, a converging lensing action is also present at the mouths. Associated with this matter distribution, the accelerating version of this Klein bottlehole shows four distinct chronology horizons, each with its own nonchronal region. A calculation of the quantum vacuum fluctuations performed by using the regularized two-point Hadamard function shows that each chronology horizon nests a set of polarized hypersurfaces where the renormalized momentum-energy tensor diverges. This quantum instability can be prevented if we take the accelerating Klein bottlehole to be a generalization of a modified Misner space in which the period of the closed spatial direction is time-dependent. In this case, the nonchronal regions and closed timelike curves cannot exceed a minimum size of the order the Planck scale.

  9. Development of a wireless sensor unit for tunnel monitoring

    E-Print Network [OSTI]

    Cheekiralla, Sivaram M. S. L., 1980-

    2004-01-01

    In this thesis we describe the development of a wireless sensor module for tunnel monitoring. The tunnel in question is a part of the London Underground system. Construction of a new tunnel beneath the existing tunnel is ...

  10. Hybrid Inflation Exit through Tunneling

    E-Print Network [OSTI]

    Bjorn Garbrecht; Thomas Konstandin

    2006-10-24

    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.

  11. Enhanced tunneling through nonstationary barriers

    SciTech Connect (OSTI)

    Palomares-Baez, J. P.; Rodriguez-Lopez, J. L. [Advanced Materials Department, Instituto Potosino de Investigacion Cientifica y Tecnologica, San Luis Potosi, San Luis Potosi 78231 (Mexico); Ivlev, B. [Department of Physics and Astronomy and NanoCenter, University of South Carolina, Columbia, South Carolina 29208 (United States); Instituto de Fisica, Universidad Autonoma de San Luis Potosi, San Luis Potosi, San Luis Potosi 78000 (Mexico)

    2007-11-15

    Quantum tunneling through a nonstationary barrier is studied analytically and by a direct numerical solution of Schroedinger equation. Both methods are in agreement and say that the main features of the phenomenon can be described in terms of classical trajectories which are solutions of Newton's equation in complex time. The probability of tunneling is governed by analytical properties of a time-dependent perturbation and the classical trajectory in the plane of complex time. Some preliminary numerical calculations of Euclidean resonance (an easy penetration through a classical nonstationary barrier due to an underbarrier interference) are presented.

  12. Pyrotechnic ignition studies using a gun tunnel

    SciTech Connect (OSTI)

    Evans, N.A.

    1989-01-01

    A gun tunnel is being used to investigate the ignition characteristics of center-hole iron/potassium perchlorate thermal battery discs. Details are given of the construction, operation, and data reduction method for the gun tunnel. To simulate an igniter, this system can readily produce a pulse of hot argon at maximum pressures and temperatures up to P/sub max/ = 8 MPa and T/sub max/ = 4000K, respectively, with flow times of the order of 3 msec. For a single battery disc, a segment of the ignition boundary was found to lie in the region of T/sub max/ = 1200 to 1300K and 0.7 MPa < P/sub max/ < 2.0 MPa. The results also showed two types of ignition: prompt ignition, requiring an average delivered enthalpy /ovr /Delta/H//sub ig/ = 6 cal during an average flow time /ovr /Delta/t//sub ig/ = 0.7 msec, and delayed ignition, with /ovr /Delta/H//sub ig/ = 16 cal and /ovr /Delta/t//sub ig/ = 2.4 msec. In addition, near an ignition boundary, high speed motion photography showed the ignition delay increased to 6 msec with significant spatial non-uniformity. 1 ref., 6 figs.

  13. Monolithic interconnected module with a tunnel junction for enhanced electrical and optical performance

    DOE Patents [OSTI]

    Murray, Christopher S. (Bethel Park, PA); Wilt, David M. (Bay Village, OH)

    2000-01-01

    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%.

  14. Two types of the relation between the intensity and the life time of photoluminescence of core/shell semiconductor quantum dots: Important role of Coulomb field and tunneling transitions

    SciTech Connect (OSTI)

    Osad'ko, I. S.

    2014-10-28

    It has been recently found [Gh. Galland, Y. Ghosh, A. Steinbrück, M. Sykora, J. A. Hollingsworth, and V. I. Klimov, Nature (London) 479, 203 (2011)] that semiconductor core/shell nanocrystals (NCs) with blinking photoluminescence (PL) can be of “A” or “B” type. NCs of A-type exhibit correlation between the intensity of PL and the life time. In NCs of B-type such correlation is absent. Simple model based on combination of the charging model and the two-level system model is proposed for describing emissive properties of NCs of both types. The model invokes fluctuations of emission ability ?{sub em} of NC to explain the emissive properties of NCs of B-type. Our combined model is also in agreement with anticorrelation between the duration ?{sub off} of off intervals and PL life time t{sub off} in off intervals found recently for NCs of A-type in the experiment [A. A. Cordones, T. J. Bixby, and S. R. Leone, Nano Lett. 11, 3366 (2011)].

  15. Observing remnants by fermions' tunneling

    SciTech Connect (OSTI)

    Chen, D.Y.; Wu, H.W.; Yang, H. E-mail: iverwu@uestc.edu.cn

    2014-03-01

    The standard Hawking formula predicts the complete evaporation of black holes. In this paper, we introduce effects of quantum gravity into fermions' tunneling from Reissner-Nordstrom and Kerr black holes. The quantum gravity effects slow down the increase of Hawking temperatures. This property naturally leads to a residue mass in black hole evaporation. The corrected temperatures are affected by the quantum numbers of emitted fermions. Meanwhile, the temperature of the Kerr black hole is a function of ? due to the rotation.

  16. Hawking Radiation and Classical Tunneling

    E-Print Network [OSTI]

    Eugene R. Tracy; Dmitriy Zhigunov

    2015-09-26

    Acoustic waves in fluids undergoing the transition from sub- to supersonic flow satisfy governing equations similar to those for light waves in the immediate vicinity of a black hole event horizon. This acoustic analogy has been used by Unruh and others as a conceptual model for `Hawking radiation.' Here we use variational methods, originally introduced by Brizard for the study of linearized MHD, and ray phase space methods, to analyze linearized acoustics in the presence of background flows. The variational formulation endows the evolution equations with natural Hermitian and symplectic structures that prove useful for later analysis. We derive a $2\\times 2$ normal form governing the wave evolution in the vicinity of the `event horizon.' This shows that the acoustic model can be reduced locally (in ray phase space) to a standard (scalar) tunneling process weakly coupled to a unidirectional non-dispersive wave (the `incoming wave'). Given the normal form, the Hawking `thermal spectrum' can be derived by invoking standard tunneling theory, but only by ignoring the coupling to the incoming wave. Deriving the normal form requires a novel extension of the modular ray-based theory used previously to study tunneling and mode conversion in plasmas. We also discuss how ray phase space methods can be used to change representation, which brings the problem into a form where the wave functions are less singular than in the usual formulation, a fact that might prove useful in numerical studies.

  17. Quantum Tunneling of Massive Spin-1 Particles From Non-stationary Metrics

    E-Print Network [OSTI]

    I. Sakalli; A. Övgün

    2015-07-07

    Hawking radiation (HR) is invariant under the coordinate transformation, and it must be independent of the particle type emitting from the considered black hole (BH). From this fact, we focus on the HR of massive vector (spin-1) particles tunneling from Schwarzschild BH expressed in the Kruskal-Szekeres (KS) and dynamic Lemaitre (DL) coordinates. Using the Proca equation (PE) together with Hamilton-Jacobi (HJ) and WKB methods, we show that the tunneling rate, and its consequence Hawking temperature are well recovered by the quantum tunneling of the massive vector particles. This is the first example for the HR of the massive vector particles tunneling from a four dimensional BH expressed in non-stationary regular coordinates.

  18. Quantum Tunneling of Massive Spin-1 Particles From Non-stationary Metrics

    E-Print Network [OSTI]

    Sakalli, I

    2015-01-01

    Hawking radiation (HR) is invariant under the coordinate transformation, and it must be independent of the particle type emitting from the considered black hole (BH). From this fact, we focus on the HR of massive vector (spin-1) particles tunneling from Schwarzschild BH expressed in the Kruskal-Szekeres (KS) and dynamic Lemaitre (DL) coordinates. Using the Proca equation (PE) together with Hamilton-Jacobi (HJ) and WKB methods, we show that the tunneling rate, and its consequence Hawking temperature are well recovered by the quantum tunneling of the massive vector particles. This is the first example for the HR of the massive vector particles tunneling from a four dimensional BH expressed in non-stationary regular coordinates.

  19. Suppression criteria of parasitic mode oscillations in a gyrotron beam tunnel

    SciTech Connect (OSTI)

    Kumar, Nitin; Singh, Udaybir; Sinha, A. K.; Singh, T. P.

    2011-02-15

    This paper presents the design criteria of the parasitic mode oscillations suppression for a periodic, ceramic, and copper loaded gyrotron beam tunnel. In such a type of beam tunnel, the suppression of parasitic mode oscillations is an important design problem. A method of beam-wave coupling coefficient and its mathematical formulation are presented. The developed design criteria are used in the beam tunnel design of a 42 GHz gyrotron to be developed for the Indian TOKAMAK system. The role of the thickness and the radius of the beam tunnel copper rings to obtain the developed design criteria are also discussed. The commercially available electromagnetic code CST and the electron trajectory code EGUN are used for the simulations.

  20. Discrete tunneling current fluctuations in metalwatermetal tunnel S. Boussaad and B. Q. Xu

    E-Print Network [OSTI]

    Tao, Nongjian

    fluctuations to random trapping or escaping of a single electron in or from a localized state in the tunnel gap February 2003 We have studied electron tunneling through water between two metal electrodes supported. © 2003 American Institute of Physics. DOI: 10.1063/1.1566933 INTRODUCTION Electron tunneling through

  1. Wind tunnel performance data for the Darrieus wind turbine with...

    Office of Scientific and Technical Information (OSTI)

    Wind tunnel performance data for the Darrieus wind turbine with NACA 0012 blades Citation Details In-Document Search Title: Wind tunnel performance data for the Darrieus wind...

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

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

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

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

    SciTech Connect (OSTI)

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

    2013-06-01

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

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

    SciTech Connect (OSTI)

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

    2013-06-01

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

  5. Enhancing metal-insulator-insulator-metal tunnel diodes via defect enhanced direct tunneling

    SciTech Connect (OSTI)

    Alimardani, Nasir; Conley, John F.

    2014-08-25

    Metal-insulator-insulator-metal tunnel diodes with dissimilar work function electrodes and nanolaminate Al{sub 2}O{sub 3}-Ta{sub 2}O{sub 5} bilayer tunnel barriers deposited by atomic layer deposition are investigated. This combination of high and low electron affinity insulators, each with different dominant conduction mechanisms (tunneling and Frenkel-Poole emission), results in improved low voltage asymmetry and non-linearity of current versus voltage behavior. These improvements are due to defect enhanced direct tunneling in which electrons transport across the Ta{sub 2}O{sub 5} via defect based conduction before tunneling directly through the Al{sub 2}O{sub 3}, effectively narrowing the tunnel barrier. Conduction through the device is dominated by tunneling, and operation is relatively insensitive to temperature.

  6. Regularization of Tunneling Rates with Quantum Chaos

    E-Print Network [OSTI]

    Pecora, Louis M; Wu, Dong-Ho

    2012-01-01

    We study tunneling in various shaped, closed, two-dimensional, flat potential, double wells by calculating the energy splitting between symmetric and anti-symmetric state pairs. For shapes that have regular or nearly regular classical behavior (e.g. rectangular or circular) the tunneling rates vary greatly over wide ranges often by several orders of magnitude. However, for well shapes that admit more classically chaotic behavior (e.g. the stadium, the Sinai billiard) the range of tunneling rates narrows, often by orders of magnitude. This dramatic narrowing appears to come from destabilization of periodic orbits in the regular wells that produce the largest and smallest tunneling rates and causes the splitting vs. energy relation to take on a possibly universal shape. It is in this sense that we say the quantum chaos regularizes the tunneling rates.

  7. Tunneling magnetoresistance phenomenon utilizing graphene magnet electrode

    SciTech Connect (OSTI)

    Hashimoto, T.; Kamikawa, S.; Haruyama, J.; Soriano, D.; Pedersen, J. G.; Roche, S.

    2014-11-03

    Using magnetic rare-metals for spintronic devices is facing serious problems for the environmental contamination and the limited material-resource. In contrast, by fabricating ferromagnetic graphene nanopore arrays (FGNPAs) consisting of honeycomb-like array of hexagonal nanopores with hydrogen-terminated zigzag-type atomic structure edges, we reported observation of polarized electron spins spontaneously driven from the pore edge states, resulting in rare-metal-free flat-energy-band ferromagnetism. Here, we demonstrate observation of tunneling magnetoresistance (TMR) behaviors on the junction of cobalt/SiO{sub 2}/FGNPA electrode, serving as a prototype structure for future rare-metal free TMR devices using magnetic graphene electrodes. Gradual change in TMR ratios is observed across zero-magnetic field, arising from specified alignment between pore-edge- and cobalt-spins. The TMR ratios can be controlled by applying back-gate voltage and by modulating interpore distance. Annealing the SiO{sub 2}/FGNPA junction also drastically enhances TMR ratios up to ?100%.

  8. Hawking Radiation and Classical Tunneling

    E-Print Network [OSTI]

    Tracy, Eugene R

    2015-01-01

    Acoustic waves in fluids undergoing the transition from sub- to supersonic flow satisfy governing equations similar to those for light waves in the immediate vicinity of a black hole event horizon. This acoustic analogy has been used by Unruh and others as a conceptual model for `Hawking radiation.' Here we use variational methods, originally introduced by Brizard for the study of linearized MHD, and ray phase space methods, to analyze linearized acoustics in the presence of background flows. The variational formulation endows the evolution equations with natural Hermitian and symplectic structures that prove useful for later analysis. We derive a $2\\times 2$ normal form governing the wave evolution in the vicinity of the `event horizon.' This shows that the acoustic model can be reduced locally (in ray phase space) to a standard (scalar) tunneling process weakly coupled to a unidirectional non-dispersive wave (the `incoming wave'). Given the normal form, the Hawking `thermal spectrum' can be derived by invok...

  9. Methods for the fabrication of thermally stable magnetic tunnel junctions

    DOE Patents [OSTI]

    Chang, Y. Austin (Middleton, WI); Yang, Jianhua J. (Madison, WI); Ladwig, Peter F. (Hutchinson, MN)

    2009-08-25

    Magnetic tunnel junctions and method for making the magnetic tunnel junctions are provided. The magnetic tunnel junctions are characterized by a tunnel barrier oxide layer sandwiched between two ferromagnetic layers. The methods used to fabricate the magnetic tunnel junctions are capable of completely and selectively oxidizing a tunnel junction precursor material using an oxidizing gas containing a mixture of gases to provide a tunnel junction oxide without oxidizing the adjacent ferromagnetic materials. In some embodiments the gas mixture is a mixture of CO and CO.sub.2 or a mixture of H.sub.2 and H.sub.2O.

  10. 3D Pitot Tube Measurements and Calibration in the Wind Tunnel

    E-Print Network [OSTI]

    3D Pitot Tube Measurements and Calibration in the Wind Tunnel Center for Measurement Standards by CFD 9 #12;Copyright 2014 ITRI Omni-type 3D pitot tube Characterization of Pitot Tubes - Design of 3D.4) % · With grid No.4: T.I.= (1.7 to 4.4) % Grid-generated turbulent flow Calibration Facilities - Turbulence

  11. Shell-Tunneling Spectroscopy of the Single-Particle Energy Levels of

    E-Print Network [OSTI]

    Renewable Energy Laboratory, Golden, Colorado 80401, and Department of Applied Physics and ERATO Mesoscopic-tunneling spectroscopy provides the single-particle energy levels of the CdSe quantum dot. The results of both types). * Corresponding author. E-mail: Daniel@phys.uu.nl. University of Utrecht. National Renewable Energy Laboratory

  12. Rock mechanics design in mining and tunneling

    SciTech Connect (OSTI)

    Bieniawski, Z.T.

    1984-01-01

    This book introduces the design process as applied to rock mechanics aspects of underground mining and tunneling. Topics covered include a historical perspective, the design process in engineering, empirical methods of design, observational methods of design, and guided design.

  13. Scanning tunneling spectroscopy of unoccupied surface resonances

    E-Print Network [OSTI]

    Persson, Mats

    - induced series, produced when an electron is trapped in a potential well define* *d by the image Scanning tunneling spectroscopy of unoccupied surface resonances at free-electron-like metal surfaces. T. Fond'eny, S

  14. Tunneling as a Source for Quantum Chaos

    E-Print Network [OSTI]

    Ofir Flom; Asher Yahalom; Haggai Zilberberg; L. P. Horwitz; Jacob Levitan

    2015-07-17

    We use an one dimensional model of a square barrier embedded in an infinite potential well to demonstrate that tunneling leads to a complex behavior of the wave function and that the degree of complexity may be quantified by use of the spatial entropy function defined by S = -\\int |\\Psi(x,t)|^2 ln |\\Psi(x,t)|^2 dx. There is no classical counterpart to tunneling, but a decrease in the tunneling in a short time interval may be interpreted as an approach of a quantum system to a classical system. We show that changing the square barrier by increasing the height/width do not only decrease the tunneling but also slows down the rapid rise of the entropy function, indicating that the entropy growth is an essentially quantum effect.

  15. Photon tunnelling microscopy of polyethylene single crystals

    E-Print Network [OSTI]

    Srinivasarao, Mohan

    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

  16. Nondestructive Testing of Rail Tunnel Linings 

    E-Print Network [OSTI]

    Williams, Nathan Douglas

    2014-11-14

    potential problems and then test those areas with slow, detailed methods. This would provide a more thorough investigation of the tunnel lining’s health. Infrared thermography (IRT), ground penetrating radar (GPR), and ultrasonic tomography (UST) techniques...

  17. Screening and Tunneling at Metal-Surfaces 

    E-Print Network [OSTI]

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

    1973-01-01

    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 self- consistent can lead to unphysical...

  18. Modeling direct interband tunneling. I. Bulk semiconductors

    SciTech Connect (OSTI)

    Pan, Andrew; Chui, Chi On

    2014-08-07

    Interband tunneling is frequently studied using the semiclassical Kane model, despite uncertainty about its validity. Revisiting the physical basis of this formula, we find that it neglects coupling to other bands and underestimates transverse tunneling. As a result, significant errors can arise at low and high fields for small and large gap materials, respectively. We derive a simple multiband tunneling model to correct these defects analytically without arbitrary parameters. Through extensive comparison with band structure and quantum transport calculations for bulk InGaAs, InAs, and InSb, we probe the accuracy of the Kane and multiband formulas and establish the superiority of the latter. We also show that the nonlocal average electric field should be used when applying either of these models to nonuniform potentials. Our findings are important for efficient analysis and simulation of bulk semiconductor devices involving tunneling.

  19. Semiconductor tunnel junction with enhancement layer

    DOE Patents [OSTI]

    Klem, John F. (Sandia Park, NM); Zolper, John C. (Albuquerque, NM)

    1997-01-01

    The incorporation of a pseudomorphic GaAsSb layer in a runnel diode structure affords a new degree of freedom in designing runnel junctions for p-n junction device interconnects. Previously only doping levels could be varied to control the tunneling properties. This invention uses the valence band alignment band of the GaAsSb with respect to the surrounding materials to greatly relax the doping requirements for tunneling.

  20. Semiconductor tunnel junction with enhancement layer

    DOE Patents [OSTI]

    Klem, J.F.; Zolper, J.C.

    1997-10-21

    The incorporation of a pseudomorphic GaAsSb layer in a runnel diode structure affords a new degree of freedom in designing runnel junctions for p-n junction device interconnects. Previously only doping levels could be varied to control the tunneling properties. This invention uses the valence band alignment band of the GaAsSb with respect to the surrounding materials to greatly relax the doping requirements for tunneling. 5 figs.

  1. Le LHC, un tunnel cosmique

    ScienceCinema (OSTI)

    None

    2011-10-06

    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

  2. Method of fabricating a solar cell with a tunnel dielectric layer

    DOE Patents [OSTI]

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

    2015-08-18

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

  3. Method of fabricating a solar cell with a tunnel dielectric layer

    DOE Patents [OSTI]

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

    2012-12-18

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

  4. Method of fabricating a solar cell with a tunnel dielectric layer

    DOE Patents [OSTI]

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

    2014-04-29

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

  5. TABLE OF CONTENTS Underground Construction (Tunnels), Shafts and Caissons

    E-Print Network [OSTI]

    US Army Corps of Engineers

    EM 385-1-1 30 Nov 14 26-i Section 26 TABLE OF CONTENTS Underground Construction (Tunnels), Shafts ......................................................................................................... 26-16 26.F Shafts-1 SECTION 26 Underground Construction (Tunnels), Shafts and Caissons 26. General. This section applies

  6. Simulation of localized barrier defects in resonant tunneling diodes 

    E-Print Network [OSTI]

    Stoneberg, Jason Neal

    1995-01-01

    defect assisted tunneling as a possible current mechanism. This study attempts to ascertain the effects of defect potentials in the barriers on current in a simulation of a double barrier resonant tunneling diode. Results indicate that these defects could...

  7. Fabrication of magnetic tunnel junctions with epitaxial and textured ferromagnetic layers

    DOE Patents [OSTI]

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

    2008-11-11

    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.

  8. Global Tunnel Boring Machine Industry 2015 Market Research Report...

    Open Energy Info (EERE)

    Global Tunnel Boring Machine Industry 2015 Market Research Report Home There are currently no posts in this category. Syndicate content...

  9. Massachusetts Institute of Technology Wright Brothers Wind Tunnel

    E-Print Network [OSTI]

    Williams, Brian C.

    Institute of Technology Wright Brothers Wind Tunnel INFORMATION FOR USE BY INDUSTRY Revised July 2002 #12;ii MIT photograph/W. Litant A model is prepared for testing in the MIT Wright Brothers Wind Tunnel. #12 information and sketches of use to those planning a test program at the Wright Brothers Wind Tunnel have also

  10. Band-to-band tunneling in silicon diodes and tunnel transistors

    E-Print Network [OSTI]

    Teherani, James Towfik

    2010-01-01

    This work studies the effect of mechanically applied uniaxial strain on reverse-bias band-to-band tunneling current in n+/p+ vertical silicon diodes fabricated on {100} and {110} substrate orientations. The Band Structure ...

  11. Spin-polarized tunneling in MgO-based tunnel junctions with superconducting electrodes

    E-Print Network [OSTI]

    Schebaum, Oliver

    We prepared magnetic tunnel junctions with one ferromagnetic and one superconducting Al–Si electrode. Pure cobalt electrodes were compared with a Co–Fe–B alloy and the Heusler compound Co[subscript 2]FeAl. The polarization ...

  12. Transport properties in resonant tunneling heterostructures

    E-Print Network [OSTI]

    Presilla, Carlo

    Transport properties in resonant tunneling heterostructures Carlo Presillaa) Dipartimento di Fisica approximation in terms of instantaneous resonances to study the steady-state and time-dependent transport leads, in a natural way, to a transport model of large applicability consisting of reservoirs coupled

  13. Inelastic Tunneling Spectroscopy in Unconventional Superconductors

    E-Print Network [OSTI]

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

  14. B-Target Room Tunnel Redesigned

    SciTech Connect (OSTI)

    Esfandiari, Reza; /San Jose State U. /SLAC

    2010-08-25

    Several groups at SLAC National Accelerator Laboratory are currently working on a RF Modulator prototype for a future linear collider known as the International Linear Collider (ILC). The ILC runs using about a 1000 Klystrons which create high power carrier waves for the particle acceleration. Klystrons receive their electrical input power from modulators. In order to move beyond the prototype phase, the laboratory might expand its ground base further down a tunnel located at the End Station B (ESB) in order to house four new Klystron Modulator Test Stations. This area is known as the B-Target Room Tunnel, and the task was to redesign the tunnel layout for the upcoming changes. The project first began by collecting substantial amount of information about the prototyped project, the tunnel and the researchers feedback of what they would like to see in the upcoming design. Subsequent to numerous planning and presentations, one particular design was. Calculations for this design were then performed for the most complex aspects of the project. Based on the results of the calculations, specific sample beams, welds, bolts and materials were chosen for the possible future construction.

  15. A Historical Evaluation of the U12n Tunnel, Nevada national Security Site, Nye County, Nevada Part 2 of 2

    SciTech Connect (OSTI)

    Drollinger, Harold; Jones, Robert C; Bullard, Thomas F; Ashbaugh, Laurence J; Griffin, Wayne R

    2011-06-01

    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.

  16. A Historical Evaluation of the U12n Tunnel, Nevada National Security Site, Nye County, Nevada Part 1

    SciTech Connect (OSTI)

    Drollinger, Harold; Jones, Robert C; Bullard, Thomas F; Ashbaugh, Laurence J; Griffin, Wayne R

    2011-06-01

    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.

  17. Superpoissonian shot noise in organic magnetic tunnel junctions

    SciTech Connect (OSTI)

    Cascales, Juan Pedro; Martinez, Isidoro; Aliev, Farkhad G.; Hong, Jhen-Yong; Lin, Minn-Tsong; Szczepa?ski, Tomasz; Dugaev, Vitalii K.; Barna?, Józef

    2014-12-08

    Organic molecules have recently revolutionized ways to create new spintronic devices. Despite intense studies, the statistics of tunneling electrons through organic barriers remains unclear. Here, we investigate conductance and shot noise in magnetic tunnel junctions with 3,4,9,10-perylene-teracarboxylic dianhydride (PTCDA) barriers a few nm thick. For junctions in the electron tunneling regime, with magnetoresistance ratios between 10% and 40%, we observe superpoissonian shot noise. The Fano factor exceeds in 1.5–2 times the maximum values reported for magnetic tunnel junctions with inorganic barriers, indicating spin dependent bunching in tunneling. We explain our main findings in terms of a model which includes tunneling through a two level (or multilevel) system, originated from interfacial bonds of the PTCDA molecules. Our results suggest that interfaces play an important role in the control of shot noise when electrons tunnel through organic barriers.

  18. Magnetically amplified tunneling of the 3rd kind as a probe of minicharged particles

    E-Print Network [OSTI]

    Babette Döbrich; Holger Gies; Norman Neitz; Felix Karbstein

    2012-10-08

    We show that magnetic fields significantly enhance a new tunneling mechanism in quantum-field theories with photons coupling to fermionic minicharged particles. We propose a dedicated laboratory experiment of the light-shining-through-walls type that can explore a parameter regime comparable to and even beyond the best model-independent cosmological bounds. With present-day technology, such an experiment is particularly sensitive to minicharged particles with masses in and below the meV regime.

  19. Scanning tunneling microscope assembly, reactor, and system

    DOE Patents [OSTI]

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

    2014-11-18

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

  20. Gravitinos Tunneling From Traversable Lorentzian Wormholes

    E-Print Network [OSTI]

    Sakalli, I

    2015-01-01

    Recent research shows that Hawking radiation (HR) is also possible around the trapping horizon of a wormhole. In this article, we show that the HR of gravitino (spin-$3/2$) particles from the traversable Lorentzian wormholes (TLWH) reveals a negative Hawking temperature (HT). We first introduce the TLWH in the past outer trapping horizon geometry (POTHG). Next, we derive the Rarita-Schwinger equations (RSEs) for that geometry. Then, using both the Hamilton-Jacobi (HJ) ans\\"{a}tz and the WKB approximation in the quantum tunneling method, we obtain the probabilities of the emission/absorption modes. Finally, we derive the tunneling rate of the emitted gravitino particles, and succeed to read the HT of the TLWH.

  1. Gravitinos Tunneling From Traversable Lorentzian Wormholes

    E-Print Network [OSTI]

    I. Sakalli; A. Ovgun

    2015-08-12

    Recent research shows that Hawking radiation (HR) is also possible around the trapping horizon of a wormhole. In this article, we show that the HR of gravitino (spin-$3/2$) particles from the traversable Lorentzian wormholes (TLWH) reveals a negative Hawking temperature (HT). We first introduce the TLWH in the past outer trapping horizon geometry (POTHG). Next, we derive the Rarita-Schwinger equations (RSEs) for that geometry. Then, using both the Hamilton-Jacobi (HJ) ans\\"{a}tz and the WKB approximation in the quantum tunneling method, we obtain the probabilities of the emission/absorption modes. Finally, we derive the tunneling rate of the emitted gravitino particles, and succeed to read the HT of the TLWH.

  2. Windthrow Mechanics: Tree Winching and Wind Tunnel

    E-Print Network [OSTI]

    Mitchell, Stephen

    (Maple Ridge) July: Tree Winching in Prince George August: Second Wind Tunnel Session Plans for the year in Prince George Summary Averaged between 2 and 3 trees per day 18 Sx pulled (range 16-40 cm DBH) 13 Pl pulled (range 20-40 cm DBH) Grand total of 66 trees pulled in MKRF and Prince George #12;10/21/2003 8 #12

  3. Highly Charged Ion (HCI) Modified Tunnel Junctions

    SciTech Connect (OSTI)

    Pomeroy, J. M.; Grube, H. [Atomic Physics Division, National Institute of Standards and Technology (NIST) 100 Bureau Dr., MS 8423, Gaithersburg, MD 20899-8423 (United States)

    2009-03-10

    The neutralization energy carried by highly charged ions (HCIs) provides an alternative method for localizing energy on a target's surface, producing features and modifying surfaces with fluences and kinetic energy damage that are negligible compared to singly ionized atoms. Since each HCI can deposit an enormous amount of energy into a small volume of the surface (e.g., Xe{sup 44+} delivers 51 keV of neutralization energy per HCI), each individual HCI's interaction with the target can produce a nanoscale feature. Many studies of HCI-surface features have characterized some basic principles of this unique ion-surface interaction, but the activity reported here has been focused on studying ensembles of HCI features in ultra-thin insulating films by fabricating multi-layer tunnel junction devices. The ultra-thin insulating barriers allow current to flow by tunneling, providing a very sensitive means of detecting changes in the barrier due to highly charged ion irradiation and, conversely, HCI modification provides a method of finely tuning the transparency of the tunnel junctions that spans several orders of magnitude for devices produced from a single process recipe. Systematic variation of junction bias, temperature, magnetic field and other parameters provides determination of the transport mechanism, defect densities, and magnetic properties of these nano-features and this novel approach to device fabrication.

  4. 08 Oct 1999 Visualisatie Heinenoord Tunnel -Hack & Ozmutlu -LWI dag 1 VISUALISATIE

    E-Print Network [OSTI]

    Hack, Robert

    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

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

    E-Print Network [OSTI]

    Sh. Matsumoto; M. Yoshimura

    2003-07-18

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

  6. Enhancement of Spin-transfer torque switching via resonant tunneling

    SciTech Connect (OSTI)

    Chatterji, Niladri; Tulapurkar, Ashwin A.; Muralidharan, Bhaskaran

    2014-12-08

    We propose the use of resonant tunneling as a route to enhance the spin-transfer torque switching characteristics of magnetic tunnel junctions. The proposed device structure is a resonant tunneling magnetic tunnel junction based on a MgO-semiconductor heterostructure sandwiched between a fixed magnet and a free magnet. Using the non-equilibrium Green's function formalism coupled self consistently with the Landau-Lifshitz-Gilbert-Slonczewski equation, we demonstrate enhanced tunnel magneto-resistance characteristics as well as lower switching voltages in comparison with traditional trilayer devices. Two device designs based on MgO based heterostructures are presented, where the physics of resonant tunneling leads to an enhanced spin transfer torque thereby reducing the critical switching voltage by up to 44%. It is envisioned that the proof-of-concept presented here may lead to practical device designs via rigorous materials and interface studies.

  7. Self-contained instrument for measuring subterranean tunnel wall deflection

    DOE Patents [OSTI]

    Rasmussen, Donald Edgar (Kennewick, WA); Hof, Jr., Peter John (Richland, WA)

    1978-01-01

    The deflection of a subterranean tunnel is measured with a rod-like, self-contained instrument that is adapted to be inserted into a radially extending bore of the tunnel adjacent an end of the tunnel where the tunnel is being dug. One end of the instrument is anchored at the end of the bore remote from the tunnel wall, while the other end of the intrument is anchored adjacent the end of the wall in proximity to the tunnel wall. The two ends of the instrument are linearly displaceable relative to each other; the displacement is measured by a transducer means mounted on the instrument. Included in the instrument is a data storage means including a paper tape recorder periodically responsive to a parallel binary signal indicative of the measured displacement.

  8. Tunneling in Polymer Quantization and the Quantum Zeno Effect

    E-Print Network [OSTI]

    Durmus Ali Demir; Ozan Sargin

    2014-09-25

    As an application of the polymer quantization scheme, in this work we investigate the one dimensional quantum mechanical tunneling phenomenon from the perspective of polymer representation of a non-relativistic point particle and derive the transmission and reflection coefficients. Since any tunneling phenomenon inevitably evokes a tunneling time we attempt an analytical calculation of tunneling times by defining an operator well suited in discrete spatial geometry. The results that we come up with hint at appearance of the Quantum Zeno Effect in polymer framework.

  9. Spin Torques in Magnetic and Superconducting Tunnel Junctions

    E-Print Network [OSTI]

    Hoffman, Silas Eli

    2012-01-01

    Tunnel Junctions for Spintronic Memories and Beyond. ” IEEEto their application in spintronic devices. Injecting a spinforecasts a new kind of spintronic device that manipulates

  10. Electron tunneling studies of Mn12-Acetate 

    E-Print Network [OSTI]

    Ma, Lianxi

    2008-10-10

    laser deposition (PLD) was used to deposit two monolayers of Mn 12 -Acetate on thin Pt wires (diame- ter 0.001 in). The electron tunneling current was measured with typical bias voltages from -1 to 1 V at liquid helium temperature, 4.2 K. I, dI/dV, and d... 2 I/dV 2 signals were directly acquired with the aid of a current amplifier and two lock-in-amplifiers. Results show that the differential conductance is approximately 10 ?6 S for bias volt- ages 0.04 V ?|V |? 1 V and exhibits a strong voltage...

  11. Penn Small Water Tunnel | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsourceII JumpQuarterly Smart GridNorth Carolina:ParamountEnergySmall Water Tunnel Jump

  12. Tunneling of Graphene Massive Dirac Fermions through a Double Barrier

    E-Print Network [OSTI]

    Hocine Bahlouli; El Bouazzaoui Choubabi; Ahmed Jellal; Miloud Mekkaoui

    2011-10-04

    We study the tunneling of Dirac fermions in graphene through a double barrier potential allowing the carriers to have an effective mass inside the barrier as generated by a lattice miss-match with the boron nitride substrate. The consequences of this gap opening on the transmission are investigated. The realization of resonant tunneling conditions is also analyzed.

  13. Vibration-Assisted Electron Tunneling in C140 Transistors

    E-Print Network [OSTI]

    McEuen, Paul L.

    Vibration-Assisted Electron Tunneling in C140 Transistors A. N. Pasupathy, J. Park, C. Chang, A. V C140, a molecule with a mass-spring-mass geometry chosen as a model system to study electron-vibration coupling. We observe vibration-assisted tunneling at an energy corresponding to the stretching mode of C140

  14. Sensor integration study for a shallow tunnel detection system.

    SciTech Connect (OSTI)

    Yee, Mark L.; Abbott, Robert E.; Bonal, Nedra; Elbring, Gregory Jay; Senglaub, Michael E.

    2010-02-01

    During the past several years, there has been a growing recognition of the threats posed by the use of shallow tunnels against both international border security and the integrity of critical facilities. This has led to the development and testing of a variety of geophysical and surveillance techniques for the detection of these clandestine tunnels. The challenges of detection of these tunnels arising from the complexity of the near surface environment, the subtlety of the tunnel signatures themselves, and the frequent siting of these tunnels in urban environments with a high level of cultural noise, have time and again shown that any single technique is not robust enough to solve the tunnel detection problem in all cases. The question then arises as to how to best combine the multiple techniques currently available to create an integrated system that results in the best chance of detecting these tunnels in a variety of clutter environments and geologies. This study utilizes Taguchi analysis with simulated sensor detection performance to address this question. The analysis results show that ambient noise has the most effect on detection performance over the effects of tunnel characteristics and geological factors.

  15. High Tunnel Crop Production Tips Lewis W. Jett

    E-Print Network [OSTI]

    Goodman, Robert M.

    . Specifically, high tunnels are passively vented, solar greenhouses covered with 1-2 layers of greenhouse supplemental heating systems? High tunnels should be designed and managed as passively vented and solar heated structures. However, supplemental heat (propane space heaters, wood stoves, etc) can be used to protect

  16. ENGINEERING APPLICATIONS OF THE HIGHRESOLUTION SEISMIC TECHNIQUES: TUNNEL DRILLING

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    tomography were used for tunnel design in two different areas. Two seismic data acquisition experimentsENGINEERING APPLICATIONS OF THE HIGHRESOLUTION SEISMIC TECHNIQUES: TUNNEL DRILLING Álvarez. Tel. +34 93 409.54.10 Fax. +34 93 411.00.12 Email: rcarbo@ija.csic.es Seismic methologies has been

  17. Radio-frequency scanning tunnelling microscopy U. Kemiktarak1

    E-Print Network [OSTI]

    LETTERS Radio-frequency scanning tunnelling microscopy U. Kemiktarak1 , T. Ndukum3 , K. C. Schwab3 measurementsinmesoscopicelectronicsandmechanics. Broadband noise measurements across the tunnel junction using this radio-frequency STM available from nanoscale optical and electrical displacement detection tech- niques, and the radio

  18. Introduction The first practical supersonic wind tunnel, built by

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    #12;Introduction #12;The first practical supersonic wind tunnel, built by A. Busemann in Germany in the mid-1930s. #12;A large hypersonic wind tunnel at the U.S. Air Force Wright Aeronautical Laboratory, quasi-one-dimensional flow. #12;Energy Equation for steady, adiabatic, inviscid quasi-one dimensional

  19. Emptying and filling a tunnel bronze

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

    Marley, Peter M.; Abtew, Tesfaye A.; Farley, Katie E.; Horrocks, Gregory A.; Dennis, Robert V.; Zhang, Peihong; Banerjee, Sarbajit

    2015-01-13

    The classical orthorhombic layered phase of V2O5 has long been regarded as the thermodynamic sink for binary vanadium oxides and has found great practical utility as a result of its open framework and easily accessible redox states. Herein, we exploit a cation-exchange mechanism to synthesize a new stable tunnel-structured polymorph of V2O5 (?-V2O5) and demonstrate the subsequent ability of this framework to accommodate Li and Mg ions. The facile extraction and insertion of cations and stabilization of the novel tunnel framework is facilitated by the nanometer-sized dimensions of the materials, which leads to accommodation of strain without amorphization. The topotacticmore »approach demonstrated here indicates not just novel intercalation chemistry accessible at nanoscale dimensions but also suggests a facile synthetic route to ternary vanadium oxide bronzes (MxV2O5) exhibiting intriguing physical properties that range from electronic phase transitions to charge ordering and superconductivity.« less

  20. Computational Role of Multiqubit Tunneling in a Quantum Annealer

    E-Print Network [OSTI]

    Sergio Boixo; Vadim N. Smelyanskiy; Alireza Shabani; Sergei V. Isakov; Mark Dykman; Vasil S. Denchev; Mohammad Amin; Anatoly Smirnov; Masoud Mohseni; Hartmut Neven

    2015-02-20

    Quantum tunneling, a phenomenon in which a quantum state traverses energy barriers above the energy of the state itself, has been hypothesized as an advantageous physical resource for optimization. Here we show that multiqubit tunneling plays a computational role in a currently available, albeit noisy, programmable quantum annealer. We develop a non-perturbative theory of open quantum dynamics under realistic noise characteristics predicting the rate of many-body dissipative quantum tunneling. We devise a computational primitive with 16 qubits where quantum evolutions enable tunneling to the global minimum while the corresponding classical paths are trapped in a false minimum. Furthermore, we experimentally demonstrate that quantum tunneling can outperform thermal hopping along classical paths for problems with up to 200 qubits containing the computational primitive. Our results indicate that many-body quantum phenomena could be used for finding better solutions to hard optimization problems.

  1. Tunnel-injection GaN quantum dot ultraviolet light-emitting diodes

    SciTech Connect (OSTI)

    Verma, Jai; Kandaswamy, Prem Kumar; Protasenko, Vladimir; Verma, Amit; Grace Xing, Huili; Jena, Debdeep

    2013-01-28

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

  2. Resonant tunneling of fluctuation Cooper pairs

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

    Galda, Alexey; Mel'nikov, A. S.; Vinokur, V. M.

    2015-02-09

    Superconducting fluctuations have proved to be an irreplaceable source of information about microscopic and macroscopic material parameters that could be inferred from the experiment. According to common wisdom, the effect of thermodynamic fluctuations in the vicinity of the superconducting transition temperature, Tc, is to round off all of the sharp corners and discontinuities, which otherwise would have been expected to occur at Tc. Here we report the current spikes due to radiation-induced resonant tunneling of fluctuation Cooper pairs between two superconductors which grow even sharper and more pronounced upon approach to Tc. This striking effect offers an unprecedented tool formore »direct measurements of fluctuation Cooper pair lifetime, which is key to our understanding of the fluctuation regime, most notably to nature of the pseudogap state in high-temperature superconductors. Our finding marks a radical departure from the conventional view of superconducting fluctuations as a blurring and rounding phenomenon.« less

  3. Neuroreceptor Activation by Vibration-Assisted Tunneling

    E-Print Network [OSTI]

    Hoehn, Ross D; Neven, Hartmut; Kais, Sabre

    2015-01-01

    G protein-coupled receptors (GPCRs) constitute a large family of receptor proteins that sense molecular signals on the exterior of a cell and activate signal transduction pathways within the cell. Modeling how an agonist activates such a receptor is fundamental for an understanding of a wide variety of physiological processes and it is of tremendous value for pharmacology and drug design. Inelastic electron tunneling spectroscopy (IETS) has been proposed as a model for the mechanism by which olfactory GPCRs are activated by a bound agonist. We apply this hypothesis to GPCRs within the mammalian nervous system using quantum chemical modeling. We found that non-endogenous agonists of the serotonin receptor share a particular IET spectral aspect both amongst each other and with the serotonin molecule: a peak whose intensity scales with the known agonist potencies. We propose an experiential validation of this model by utilizing lysergic acid dimethylamide (DAM-57), an ergot derivative, and its deuterated isotopo...

  4. Low voltage tunneling magnetoresistance in CuCrO{sub 2}-based semiconductor heterojunctions at room temperature

    SciTech Connect (OSTI)

    Li, X. R.; Han, M. J.; Shan, C.; Hu, Z. G. Zhu, Z. Q.; Chu, J. H.; Wu, J. D.

    2014-12-14

    CuCrO{sub 2}-based heterojunction diodes with rectifying characteristics have been fabricated by combining p-type Mg-doped CuCrO{sub 2} and n-type Al-doped ZnO. It was found that the current for the heterojunction in low bias voltage region is dominated by the trap-assisted tunneling mechanism. Positive magnetoresistance (MR) effect for the heterojunction can be observed at room temperature due to the tunneling-induced antiparallel spin polarization near the heterostructure interface. The MR effect becomes enhanced with the magnetic field, and shows the maximum at a bias voltage around 0.5?V. The phenomena indicate that the CuCrO{sub 2}-based heterojunction is a promising candidate for low-power semiconductor spintronic devices.

  5. Computational modeling of electrophotonics nanomaterials: Tunneling in double quantum dots

    SciTech Connect (OSTI)

    Vlahovic, Branislav Filikhin, Igor

    2014-10-06

    Single electron localization and tunneling in double quantum dots (DQD) and rings (DQR) and in particular the localized-delocalized states and their spectral distributions are considered in dependence on the geometry of the DQDs (DQRs). The effect of violation of symmetry of DQDs geometry on the tunneling is studied in details. The cases of regular and chaotic geometries are considered. It will be shown that a small violation of symmetry drastically affects localization of electron and that anti-crossing of the levels is the mechanism of tunneling between the localized and delocalized states in DQRs.

  6. Modeling direct interband tunneling. II. Lower-dimensional structures

    SciTech Connect (OSTI)

    Pan, Andrew; Chui, Chi On

    2014-08-07

    We investigate the applicability of the two-band Hamiltonian and the widely used Kane analytical formula to interband tunneling along unconfined directions in nanostructures. Through comparisons with k·p and tight-binding calculations and quantum transport simulations, we find that the primary correction is the change in effective band gap. For both constant fields and realistic tunnel field-effect transistors, dimensionally consistent band gap scaling of the Kane formula allows analytical and numerical device simulations to approximate non-equilibrium Green's function current characteristics without arbitrary fitting. This allows efficient first-order calibration of semiclassical models for interband tunneling in nanodevices.

  7. Sequence-dependent spin-selective tunneling along double-stranded DNA

    E-Print Network [OSTI]

    Guo, Ai-Min

    2012-01-01

    We report spin-selective tunneling of electrons along natural and artificial double-stranded DNA (dsDNA) sandwiched by nonmagnetic leads. The results reveal that the spin polarization strongly depends on the dsDNA sequence and is dominated by its end segment. Both genomic and artificial dsDNA could be efficient spin filters. The spin-filtering effects are sensitive to point mutation which occurs in the end segment. These results are in good agreement with recent experiments and are robust against various types of disorder, and could help for designing DNA-based spintronic devices.

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

    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 potential applications for energy storage, charge storage and power supplies. Friday, May 27, 2011 - 4:00pm...

  9. Computational design and analysis of flatback airfoil wind tunnel experiment.

    SciTech Connect (OSTI)

    Mayda, Edward A.; van Dam, C.P.; Chao, David D.; Berg, Dale E.

    2008-03-01

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

  10. Resonant spin tunneling in randomly oriented nanospheres of Mn?? acetate

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

    Lendinez, S.; Billinge, S. J. L.; Zarzuela, R.; Tejada, J.; Terban, M. W.; Espin, J.; Imaz, I.; Maspoch, D.; Chudnovsky, E. M.

    2015-01-06

    We report measurements and theoretical analysis of resonant spin tunneling in randomly oriented nanospheres of a molecular magnet. Amorphous nanospheres of Mn?? acetate have been fabricated and characterized by chemical, infrared, TEM, X-ray, and magnetic methods. Magnetic measurements have revealed sharp tunneling peaks in the field derivative of the magnetization that occur at the typical resonant field values for the Mn?? acetate crystal in the field parallel to the easy axis.Theoretical analysis is provided that explains these observations. We argue that resonant spin tunneling in a molecular magnet can be established in a powder sample, without the need for amore »single crystal and without aligning the easy magnetization axes of the molecules. This is confirmed by re-analyzing the old data on a powdered sample of non-oriented micron-size crystals of Mn?? acetate. Our findings can greatly simplify the selection of candidates for quantum spin tunneling among newly synthesized molecular magnets.« less

  11. Response of continuous pipelines to tunnel induced ground deformations

    E-Print Network [OSTI]

    Ieronymaki, Evangelia S

    2011-01-01

    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, ...

  12. Quantum tunneling resonant electron transfer process in Lorentzian plasmas

    SciTech Connect (OSTI)

    Hong, Woo-Pyo; Jung, Young-Dae

    2014-08-15

    The quantum tunneling resonant electron transfer process between a positive ion and a neutral atom collision is investigated in nonthermal generalized Lorentzian plasmas. The result shows that the nonthermal effect enhances the resonant electron transfer cross section in Lorentzian plasmas. It is found that the nonthermal effect on the classical resonant electron transfer cross section is more significant than that on the quantum tunneling resonant charge transfer cross section. It is shown that the nonthermal effect on the resonant electron transfer cross section decreases with an increase of the Debye length. In addition, the nonthermal effect on the quantum tunneling resonant electron transfer cross section decreases with increasing collision energy. The variation of nonthermal and plasma shielding effects on the quantum tunneling resonant electron transfer process is also discussed.

  13. Resonant spin tunneling in randomly oriented nanospheres of Mn?? acetate

    SciTech Connect (OSTI)

    Lendinez, S. [Univ. de Barcelona, Barcelona, Spain (Europe); Billinge, S. J. L. [Columbia Univ., New York, NY (United States); Zarzuela, R. [Univ. de Barcelona, Barcelona, Spain (Europe); Tejada, J. [Univ. de Barcelona, Barcelona, Spain (Europe); Terban, M. W. [Columbia Univ., New York, NY (United States); Espin, J. [Univ. Autonoma Barcelona, Barcelona, Spain (Europe); Imaz, I. [Univ. Autonoma Barcelona, Barcelona, Spain (Europe); Maspoch, D. [Univ. Autonoma Barcelona, Barcelona, Spain (Europe); Chudnovsky, E. M. [City Univ. of New York, Bronx, NY (United States)

    2015-01-01

    We report measurements and theoretical analysis of resonant spin tunneling in randomly oriented nanospheres of a molecular magnet. Amorphous nanospheres of Mn?? acetate have been fabricated and characterized by chemical, infrared, TEM, X-ray, and magnetic methods. Magnetic measurements have revealed sharp tunneling peaks in the field derivative of the magnetization that occur at the typical resonant field values for the Mn?? acetate crystal in the field parallel to the easy axis.Theoretical analysis is provided that explains these observations. We argue that resonant spin tunneling in a molecular magnet can be established in a powder sample, without the need for a single crystal and without aligning the easy magnetization axes of the molecules. This is confirmed by re-analyzing the old data on a powdered sample of non-oriented micron-size crystals of Mn?? acetate. Our findings can greatly simplify the selection of candidates for quantum spin tunneling among newly synthesized molecular magnets.

  14. UNSTEADY WIND TUNNEL CONTROL OF STABILITY AND TRANSITION

    E-Print Network [OSTI]

    Fluid Mechanics #12;UNSTEADY WIND TUNNEL 3-D BOUNDARY LAYERS · CROSSFLOW ­ Swept Wing ­ Rotating Disk INSTABILITY MECHANISMS · Leading-edge contamination · Streamwise instabilities · Crossflow instabilities AT ASU · BASIC CROSSFLOW EXPERIMENT with Ray Dagenhart 1988, 1989 isolate crossflow mechanism from T

  15. Refurbishment and Testing Techniques in a Transonic Ludwieg Tunnel

    E-Print Network [OSTI]

    Texas at Arlington, University of

    Refurbishment and Testing Techniques in a Transonic Ludwieg Tunnel Thania S. Balcazar, Eric M recently been refurbished, an overview of the unique high Reynolds number facility at UT Arlington

  16. Design fires for tunnel water mist suppression systems 

    E-Print Network [OSTI]

    Carvel, Ricky O

    Water mist systems are unable to suppress or control large fires, therefore the ‘design fire’ for a water mist system in a tunnel should not be specified in terms of peak heat release rate, but rather in terms of the ...

  17. Brane tunneling and virtual brane-antibrane pairs

    E-Print Network [OSTI]

    Adam R. Brown

    2007-09-24

    We survey barrier penetration by quantum tunneling for four cases: nonrelativistic point particles, scalar fields, relativistic point particles, and DBI branes. We examine two novel features that arise for DBI brane tunneling: the rate can sometimes increase as the barrier gets higher; and the instanton "wrinkles". We show that these features can be understood as the effect of the quantum sea of virtual brane-antibrane pairs. This sea exponentially augments the decay rate, with possible cosmological consequences.

  18. Computational Role of Collective Tunneling in a Quantum Annealer

    E-Print Network [OSTI]

    Sergio Boixo; Vadim N. Smelyanskiy; Alireza Shabani; Sergei V. Isakov; Mark Dykman; Vasil S. Denchev; Mohammad Amin; Anatoly Smirnov; Masoud Mohseni; Hartmut Neven

    2015-02-19

    Quantum tunneling is a phenomenon in which a quantum state traverses energy barriers above the energy of the state itself. Tunneling has been hypothesized as an advantageous physical resource for optimization. Here we present the first experimental evidence of a computational role of multiqubit quantum tunneling in the evolution of a programmable quantum annealer. We develop a theoretical model based on a NIBA Quantum Master Equation to describe the multiqubit dissipative tunneling effects under the complex noise characteristics of such quantum devices. We start by considering a computational primitive, an optimization problem consisting of just one global and one false minimum. The quantum evolutions enable tunneling to the global minimum while the corresponding classical paths are trapped in a false minimum. In our study the non-convex potentials are realized by frustrated networks of qubit clusters with strong intra-cluster coupling. We show that the collective effect of the quantum environment is suppressed in the "critical" phase during the evolution where quantum tunneling "decides" the right path to solution. In a later stage dissipation facilitates the multiqubit tunneling leading to the solution state. The predictions of the model accurately describe the experimental data from the D-Wave Two quantum annealer at NASA Ames. In our computational primitive the temperature dependence of the probability of success in the quantum model is opposite to that of the classical paths with thermal hopping. Specifically, we provide an analysis of an optimization problem with sixteen qubits, demonstrating eight qubit tunneling that increases success probabilities. Furthermore, we report results for larger problems with up to 200 qubits that contain the primitive as subproblems.

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

    SciTech Connect (OSTI)

    Ohsawa, T.; Ikeda, S.; Hanyu, T.; Ohno, H.; Endoh, T.

    2014-05-07

    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 V{sub dd} in which a whole 256?kb cell array can be powered-on successfully. The minimum TMR ratio for the 4T2MTJ in 0.9?V?

  20. Neuroreceptor Activation by Vibration-Assisted Tunneling

    E-Print Network [OSTI]

    Ross D. Hoehn; David Nichols; Hartmut Neven; Sabre Kais

    2015-03-24

    G protein-coupled receptors (GPCRs) constitute a large family of receptor proteins that sense molecular signals on the exterior of a cell and activate signal transduction pathways within the cell. Modeling how an agonist activates such a receptor is fundamental for an understanding of a wide variety of physiological processes and it is of tremendous value for pharmacology and drug design. Inelastic electron tunneling spectroscopy (IETS) has been proposed as a model for the mechanism by which olfactory GPCRs are activated by a bound agonist. We apply this hypothesis to GPCRs within the mammalian nervous system using quantum chemical modeling. We found that non-endogenous agonists of the serotonin receptor share a particular IET spectral aspect both amongst each other and with the serotonin molecule: a peak whose intensity scales with the known agonist potencies. We propose an experiential validation of this model by utilizing lysergic acid dimethylamide (DAM-57), an ergot derivative, and its deuterated isotopologues; we also provide theoretical predictions for comparison to experiment. If validated our theory may provide new avenues for guided drug design and elevate methods of in silico potency/activity prediction.

  1. Recent progress in III-V based ferromagnetic semiconductors: Band structure, Fermi level, and tunneling transport

    SciTech Connect (OSTI)

    Tanaka, Masaaki; Ohya, Shinobu Nam Hai, Pham

    2014-03-15

    Spin-based electronics or spintronics is an emerging field, in which we try to utilize spin degrees of freedom as well as charge transport in materials and devices. While metal-based spin-devices, such as magnetic-field sensors and magnetoresistive random access memory using giant magnetoresistance and tunneling magnetoresistance, are already put to practical use, semiconductor-based spintronics has greater potential for expansion because of good compatibility with existing semiconductor technology. Many semiconductor-based spintronics devices with useful functionalities have been proposed and explored so far. To realize those devices and functionalities, we definitely need appropriate materials which have both the properties of semiconductors and ferromagnets. Ferromagnetic semiconductors (FMSs), which are alloy semiconductors containing magnetic atoms such as Mn and Fe, are one of the most promising classes of materials for this purpose and thus have been intensively studied for the past two decades. Here, we review the recent progress in the studies of the most prototypical III-V based FMS, p-type (GaMn)As and its heterostructures with focus on tunneling transport, Fermi level, and bandstructure. Furthermore, we cover the properties of a new n-type FMS, (In,Fe)As, which shows electron-induced ferromagnetism. These FMS materials having zinc-blende crystal structure show excellent compatibility with well-developed III-V heterostructures and devices.

  2. 2-dimensional hyperbolic medium for electrons and photons based on the array of tunnel-coupled graphene nanoribbons

    E-Print Network [OSTI]

    Iorsh, Ivan

    2015-01-01

    We study the electronic band structure and optical conductivity of an array of tunnel-coupled array of graphene nanoribbons. We show that due to the coupling of electronic edge states for the zigzag nanoribbon structure, the Fermi surface can become a hyperbola similarly to the case of the layered metal-dielectric structures, where the hyperbolic isofrequency contours originate from the coupling of localized surface plasmon polaritons. Moreover, we show that for both types of the ribbon edge, the optical response of the structure can be characterized by a uniaxial conductivity tensor, having principal components of the different signs. Therefore, the tunnel-coupled nanoribbon array can be regarded as a tunable hyperbolic metasurface.

  3. Clyde Tunnel refurbishment: Modelling the performance of the new lining system and drainage channel in the event of a fire 

    E-Print Network [OSTI]

    Carvel, Ricky O; Torero, Jose L

    2006-04-19

    The Clyde Tunnel in Glasgow, Scotland, is currently undergoing refurbishment. This refurbishment includes the installation of a new tunnel lining / fire protection system in both tunnel tubes. This lining system has ...

  4. H-CANYON AIR EXHAUST TUNNEL INSPECTION VEHICLE DEVELOPMENT

    SciTech Connect (OSTI)

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

    2011-05-24

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

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

    SciTech Connect (OSTI)

    Tuenge, Jason R.

    2011-06-28

    The U.S. Department of Energy is evaluating the Baker-Barry Tunnel as a potential GATEWAY Demonstrations project for deployment of solid-state lighting (SSL) technology. The National Park Service views this project as a possible proving ground and template for implementation of light-emitting diode (LED) luminaires in other tunnels, thereby expanding the estimated 40% energy savings from 132 MWh/yr to a much larger figure nationally. Most of the energy savings in this application is attributable to the instant-restrike capability of LED products and to their high tolerance for frequent on/off switching, used here to separately control either end of the tunnel during daytime hours. Some LED luminaires rival or outperform their high-intensity discharge (HID) counterparts in terms of efficacy, but options are limited, and smaller lumen packages preclude true one-for-one equivalence. However, LED products continue to improve in efficacy and affordability at a rate unmatched by other light source technologies; the estimated simple payback period of eight years (excluding installation costs and maintenance savings) can be expected to improve with time. The proposed revisions to the existing high-pressure sodium (HPS) lighting system would require slightly increased controls complexity and significantly increased luminaire types and quantities. In exchange, substantial annual savings (from reduced maintenance and energy use) would be complemented by improved quantity and quality of illumination. Although advanced lighting controls could offer additional savings, it is unclear whether such a system would prove cost-effective; this topic may be explored in future work.

  6. Spectral Properties and Dynamical Tunneling in Constant-Width Billiards

    E-Print Network [OSTI]

    B. Dietz; T. Guhr; B. Gutkin; M. Miski-Oglu; A. Richter

    2014-07-24

    We determine with unprecedented accuracy the lowest 900 eigenvalues of two quantum constant-width billiards from resonance spectra measured with flat, superconducting microwave resonators. While the classical dynamics of the constant-width billiards is unidirectional, a change of the direction of motion is possible in the corresponding quantum system via dynamical tunneling. This becomes manifest in a splitting of the vast majority of resonances into doublets of nearly degenerate ones. The fluctuation properties of the two respective spectra are demonstrated to coincide with those of a random-matrix model for systems with violated time-reversal invariance and a mixed dynamics. Furthermore, we investigate tunneling in terms of the splittings of the doublet partners. On the basis of the random-matrix model we derive an analytical expression for the splitting distribution which is generally applicable to systems exhibiting dynamical tunneling between two regions with (predominantly) chaotic dynamics.

  7. Relation between Tunneling and Particle Production in Vacuum Decay

    E-Print Network [OSTI]

    Laura Mersini

    1999-02-17

    The field-theoretical description of quantum fluctuations on the background of a tunneling field $\\sigma$ is revisited in the case of a functional Schrodinger approach. We apply this method in the case when quantum fluctuations are coupled to the $\\sigma$ field through a mass-squared term, which is 'time-dependent' since we include the dynamics of $\\sigma$ . The resulting mode functions of the fluctuation field, which determine the quantum state after tunneling, display a previously unseen resonance effect when their mode number is comparable to the curvature scale of the bubble. A detailed analysis of the relation between the excitations of the field about the true vacuum (interpreted as particle creation) and the phase shift coming from tunneling is presented.

  8. Internal Image Potential in Semiconductors - Effect on Scanning-Tunneling-Microscopy 

    E-Print Network [OSTI]

    HUANG, ZH; WEIMER, M.; Allen, Roland E.

    1993-01-01

    The tunneling of electrons from a semiconductor surface to a metal tip, across a vacuum gap, is influenced by two image interactions: an attractive image potential in the vacuum region, which lowers the apparent tunneling barrier, and a repulsive...

  9. EFFECT OF PREPARATION PARAMETERS ON LIGHT SENSITIVITY IN SUPERCONDUCTIVE TUNNEL JUNCTIONS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , Italy Résumé. 2014 Des jonctions « tunnel » supraconductrices utilisant du sulfure de cadmium et du al. [17] have considered semiconductor barriers for low capacitance tunnel junctions. Light can be depo- sited in ultra high vacuum systems without fear of contamination. Work

  10. Acoustics in the Klebanoff-Saric Wind Tunnel: Background Identification, Forcing, and Active Control 

    E-Print Network [OSTI]

    Kuester, Matthew

    2012-07-16

    Low disturbance wind tunnels, such as the Klebanoff–Saric Wind Tunnel (KSWT), offer an ideal environment to study boundary layer transition. In particular, the leading-edge receptivity of sound can be measured by creating acoustic disturbances...

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

    E-Print Network [OSTI]

    Min, Sangyoon, 1973-

    2008-01-01

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

  12. Calculation and design of tunnel ventilation systems using a two-scale modelling approach 

    E-Print Network [OSTI]

    Colella, Francesco; Rein, Guillermo; Borchiellini, Romano; Carvel, Ricky O; Torero, Jose L; Verda, Vittorio

    This paper develops a novel modelling approach for ventilation flow in tunnels at ambient conditions (i.e. cold flow). The complexity of full CFD models of low in tunnels or the inaccuracies of simplistic assumptions are ...

  13. Horizons and Tunneling in the Euclidean False Vacuum

    E-Print Network [OSTI]

    Kate Marvel; Neil Turok

    2007-12-17

    In the thin-wall approximation, the decay of a gravitating false vacuum to a lower-energy state is affected by the cosmological horizon structure in both spaces. The nucleation radius of a bubble of true vacuum depends on the surface tension of its boundary and equals the false vacuum cosmological horizon at a critical tension. We argue that there is no tunneling instanton solution beyond the critical tension and argue that there is therefore a bound on allowed membrane tension in theories which rely on semiclassical tunneling to relax the cosmological constant.

  14. Quantum tunneling, quantum computing, and high temperature superconductivity 

    E-Print Network [OSTI]

    Wang, Qian

    2005-02-17

    -1 QUANTUM TUNNELING, QUANTUM COMPUTING, AND HIGH TEMPERATURE SUPERCONDUCTIVITY A Dissertation by QIAN WANG Submitted to the O?ce of Graduate Studies of Texas A&M University in partial ful?llment of the requirements for the degree of DOCTOR OF PHILOSOPHY... December 2003 Major Subject: Physics QUANTUM TUNNELING, QUANTUM COMPUTING, AND HIGH TEMPERATURE SUPERCONDUCTIVITY A Dissertation by QIAN WANG Submitted to Texas A&M University in partial ful?llment of the requirements for the degree of DOCTOR OF PHILOSOPHY...

  15. Stacking fault induced tunnel barrier in platelet graphite nanofiber

    SciTech Connect (OSTI)

    Lan, Yann-Wen, E-mail: chiidong@phys.sinica.edu.tw, E-mail: ywlan@phys.sinica.edu.tw; Chang, Yuan-Chih; Chang, Chia-Seng; Chen, Chii-Dong, E-mail: chiidong@phys.sinica.edu.tw, E-mail: ywlan@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Chang, Wen-Hao [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Graduate Institute of Opto-Mechatronics, National Chung Cheng University, Chia-Yi 62102, Taiwan (China); Li, Yuan-Yao [Graduate Institute of Opto-Mechatronics, National Chung Cheng University, Chia-Yi 62102, Taiwan (China)

    2014-09-08

    A correlation study using image inspection and electrical characterization of platelet graphite nanofiber devices is conducted. Close transmission electron microscopy and diffraction pattern inspection reveal layers with inflection angles appearing in otherwise perfectly stacked graphene platelets, separating nanofibers into two domains. Electrical measurement gives a stability diagram consisting of alternating small-large Coulomb blockade diamonds, suggesting that there are two charging islands coupled together through a tunnel junction. Based on these two findings, we propose that a stacking fault can behave as a tunnel barrier for conducting electrons and is responsible for the observed double-island single electron transistor characteristics.

  16. Decoherence on Quantum Tunneling in the Multi-Dimensional Wave Function Approach

    E-Print Network [OSTI]

    Takahiro Tanaka

    1994-10-07

    We consider fundamental problems on the understanding of the tunneling phenomena in the context of the multi-dimensional wave function. In this paper, we reconsider the quantum state after tunneling and extend our previous formalism to the case when the quantum state before tunneling is in a squeezed state. Through considering this problem, we reveal that the quantum decoherence plays a crucial role to allow us of the concise description of the quantum state after tunneling.

  17. Resolved dynamics of single electron tunneling using the RF-SET Julie Helen Love

    E-Print Network [OSTI]

    Devoret, Michel H.

    .4 Tunneling Rates in the single Electron Trap . . . . . . . . . . . . . . . . . . . . . . . 49 5 CotunnellingAbstract Resolved dynamics of single electron tunneling using the RF-SET Julie Helen Love 2007 This thesis presents measurements of time resolved single electron tunneling events in a metallic thin film

  18. A Geologic Prediction Model For Tunneling By Photios G. Ioannou, A.M. ASCE

    E-Print Network [OSTI]

    A Geologic Prediction Model For Tunneling By Photios G. Ioannou, A.M. ASCE Abstract: Geologic to inflated costs. This paper presents a general model for the probabilistic prediction of tunnel geology. The geologic conditions along the tunnel alignment are modeled by a set of geologic parameters (such as rock

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

    E-Print Network [OSTI]

    Recla, Benjamin Jeremiah

    2013-04-19

    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...

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

    E-Print Network [OSTI]

    Snieder, Roel

    Seismic modeling and analysis of a prototype heated nuclear waste storage tunnel, Yucca Mountain rock surrounding a tunnel in Yucca Mountain tuff and com- pared the results with field data obtained waves diffracted around the tunnel in the region of changing velocity. INTRODUCTION The Yucca Mountain

  1. Wind Tunnel Data Fusion and Immersive Visualization: A Case Study Kurt Severance

    E-Print Network [OSTI]

    Laidlaw, David

    Wind Tunnel Data Fusion and Immersive Visualization: A Case Study Kurt Severance NASA Langley@cs.brown.edu ABSTRACT This case study describes the process of fusing the data from several wind tunnel experiments, Wind tunnel, Landing gear, Texture mapping, Image-based rendering, VRML. 1. INTRODUCTION Experimental

  2. 12 1092-3063/00/$10.00 2000 IEEE IEEE Concurrency Wisconsin Wind Tunnel II

    E-Print Network [OSTI]

    Wood, David A.

    12 1092-3063/00/$10.00 © 2000 IEEE IEEE Concurrency Wisconsin Wind Tunnel II: A Fast, Portable been painfully obvious to us as developers of two generations of parallel direct- execution simulators the Wisconsin Wind Tunnel II-- the successor to the original Wisconsin Wind Tunnel5--to a range of platforms

  3. REVIEW OF SCIENTIFIC INSTRUMENTS 82, 033510 (2011) Calibrated cylindrical Mach probe in a plasma wind tunnel

    E-Print Network [OSTI]

    Brown, Michael R.

    2011-01-01

    wind tunnel X. Zhang,1,a) D. Dandurand,1 T. Gray,1 M. R. Brown,1 and V. S. Lukin2 1 Department probe is described along with an independent calibration procedure in a magnetized plasma wind tunnel calibration method based on magnetic time-of-flight in a magnetized wind tunnel is pre- sented and a particle

  4. RESEARCH PAPER Centrifuge model test on the face stability of shallow tunnel

    E-Print Network [OSTI]

    Borja, Ronaldo I.

    RESEARCH PAPER Centrifuge model test on the face stability of shallow tunnel Gregor Idinger · Pelin on a small-scale tunnel model in a geotechnical centrifuge. By making use of symmetry, half of the tunnel wall and measured by digital image correlation. The results from centrifuge model tests were compared

  5. Semiclassical tunneling and magnetic flux effects on the circle

    E-Print Network [OSTI]

    Virginie Bonnaillie-Noël; Frédéric Hérau; Nicolas Raymond

    2015-08-26

    This paper is devoted to semiclassical tunneling estimates induced on the circle by a double well electric potential in the case when a magnetic field is added. When the two electric wells are connected by two geodesics for the Agmon distance, we highlight an oscillating factor (related to the circulation of the magnetic field) in the splitting estimate of the first two eigenvalues.

  6. Exercice session Cargse, October 2008 Klein tunneling in graphene

    E-Print Network [OSTI]

    Paris-Sud 11, Université de

    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

  7. Topeka’s “Green Light Tunnel” Saves Fuel and Time

    Broader source: Energy.gov [DOE]

    Topeka, Kansas is saving their motorists time and gasoline through the use of a real-time, adaptive "green light tunnel". A traffic signal system that synchronizes traffic lights in order to create a series of green lights that result in fewer stops and less travel time.

  8. Tunneling control using classical non-linear oscillator

    SciTech Connect (OSTI)

    Kar, Susmita; Bhattacharyya, S. P.

    2014-04-24

    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.

  9. INFLATABLE PLUG FOR THREAT MITIGATION IN TRANSPORTATION TUNNELS

    E-Print Network [OSTI]

    Barbero, Ever J.

    Internacional de Mètodes Numèrics a l'Enginyeria (CIMNE). Gran Capita s/n. Edifici C1. Campus Nord. UPC. 08034 at a cost of $40 million [2]. Although it is difficult to prevent all situations that can lead to initial protective devices and the cost of interrupting the tunnel operations to proceed with the required

  10. Wind and saltation driven particle resuspension in a wind tunnel

    SciTech Connect (OSTI)

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

    1985-01-01

    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.

  11. Tunnel junction multiple wavelength light-emitting diodes

    DOE Patents [OSTI]

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

    1992-01-01

    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.

  12. Tunnel junction multiple wavelength light-emitting diodes

    DOE Patents [OSTI]

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

    1992-11-24

    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.

  13. Illinois Wireless Wind Tunnel: A Testbed for Experimental Evaluation of

    E-Print Network [OSTI]

    Vaidya, Nitin

    Illinois Wireless Wind Tunnel: A Testbed for Experimental Evaluation of Wireless Networks Nitin H. Vaidya Jennifer Bernhard V. V. Veeravalli P. R. Kumar R. K. Iyer Department of Electrical and Computer of the testbed is to imple- ment "scaled" versions of wireless networks for the purpose of accurate repeatable

  14. Tunneling control by highfrequency driving Ilya Vorobeichik and Nimrod Moiseyev

    E-Print Network [OSTI]

    Moiseyev, Nimrod

    Tunneling control by high­frequency driving Ilya Vorobeichik and Nimrod Moiseyev Department @3# supports this hypothesis. However, in the limit of high­frequency driving, the Kramers systems in strong laser fields @1,2#. We show that high­frequency second­order perturbation theory based

  15. Metallic adhesion and tunnelling at the atomic A Schirmeisen1

    E-Print Network [OSTI]

    Grütter, Peter

    Metallic adhesion and tunnelling at the atomic scale A Schirmeisen1 , G Cross1 , A Stalder1 , P Gr scaling parameter of = 0.2 nm. We conclude that not only the apex atoms contribute to the adhesion forces are discussed. The study of metallic adhesion on the atomic scale lays the foundation for the understanding

  16. Investigation of Data Quality for Wind Tunnel Internal Balance Testing 

    E-Print Network [OSTI]

    Hidore, John Preston

    2013-04-04

    center of the tunnel. At the center of each strut is a 1.5-5 ACME screw, driven by a Baldor motor. The motor is connected to a Carson Manufacturing gearbox that provides a 22:1 torque multiplication ratio. The gear system between the gearbox and ACME...

  17. Charged fermions tunneling from accelerating and rotating black holes

    SciTech Connect (OSTI)

    Rehman, Mudassar; Saifullah, K., E-mail: mudassir051@yahoo.com, E-mail: saifullah@qau.edu.pk [Department of Mathematics, Quaid-i-Azam University, Islamabad (Pakistan)

    2011-03-01

    We study Hawking radiation of charged fermions from accelerating and rotating black holes with electric and magnetic charges. We calculate the tunneling probabilities of incoming and outgoing fermionic particles and find the Hawking temperature of these black holes. We also provide an explicit expression of the classical action for the massive and massless particles in the background of these black holes.

  18. Si/SiGe electron resonant tunneling diodes with graded spacer wells

    SciTech Connect (OSTI)

    Paul, D. J.; See, P.; Bates, R.; Griffin, N.; Coonan, B. P.; Redmond, G.; Crean, G. M.; Zozoulenko, I. V.; Berggren, K.-F.; Hollander, B.

    2001-06-25

    Resonant tunneling diodes have been fabricated using graded Si{sub 1{minus}x}Ge{sub x} (x=0.3{r_arrow}0.0) spacer wells and strained Si{sub 0.4}Ge{sub 0.6} barriers on a relaxed Si{sub 0.7}Ge{sub 0.3} n-type substrate which demonstrates negative differential resistance at up to 100 K. This design is aimed at reducing the voltage at which the peak current density is achieved. Peak current densities of 0.08A/cm{sup 2} with peak-to-valley current ratios of 1.67 have been achieved for a low peak voltage of 40 mV at 77 K. This represents an improvement of over an order of magnitude compared to previous work. {copyright} 2001 American Institute of Physics.

  19. Surface Preparation in Ultra High Vacuum for Scanning Tunneling Microscopy Surface Preparation in Ultra High Vacuum for Scanning Tunneling Microscopy

    E-Print Network [OSTI]

    Pohl, Karsten

    Department of Physics University of New Hampshire, Durham NH 03824 Ultra High Vacuum environments bring about removing the sample from the vacuum environment. New sets of tools must be developed that are usable within of the tunneling current the feedback electronic keeps the distance between tip and sample constant. Piezo electric

  20. SmartTunnel: Achieving Reliability in the Internet Yi Li, Yin Zhang, LiLi Qiu, Simon Lam

    E-Print Network [OSTI]

    Qiu, Lili

    1 SmartTunnel: Achieving Reliability in the Internet Yi Li, Yin Zhang, LiLi Qiu, Simon Lam's Internet. In this paper, we propose SmartTunnel, an end-to-end approach to achieving reliability. A SmartTunnel is a logical point-to-point tunnel between two end points that spans multiple physical network paths

  1. InGaAs/GaAsSb type-Il heterojunction vertical tunnel-FETs

    E-Print Network [OSTI]

    Yu, Tao, S.M. Massachusetts Institute of Technology

    2013-01-01

    The supply voltage (VDD) scaling of conventional CMOS technology is approaching its limit due to the physical limit of 60 mV/dec subthreshold swing (SS) at room temperature and the requirement for controlled leakage current. ...

  2. Tunnel and Subsurface Void Detection and Range to Target Measurement

    SciTech Connect (OSTI)

    Phillip B. West

    2009-06-01

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

  3. Blood Types

    E-Print Network [OSTI]

    Hacker, Randi; Tsutsui, William

    2007-03-14

    Sox spent a hundred mil to acquire pitcher Daisuke Matsuzaka; they probably weren't even aware that he is a Type O and that they make the best bankers, politicians and... you guessed it... professional baseball players. #ceas #hacker #japan #tsutsuien...

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

    SciTech Connect (OSTI)

    Wu, Cheng-Han; Wu, Chao-Hsin

    2014-10-27

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

  5. IEEE ELECTRON DEVICE LETTERS, VOL. 31, NO. 8, AUGUST 2010 809 New Process Development for Planar-Type

    E-Print Network [OSTI]

    Dagenais, Mario

    IEEE ELECTRON DEVICE LETTERS, VOL. 31, NO. 8, AUGUST 2010 809 New Process Development for Planar-Type CIC Tunneling Diodes Kwangsik Choi, Filiz Yesilkoy, Athanasios Chryssis, Mario Dagenais, Fellow, IEEE, and Martin Peckerar, Fellow, IEEE Abstract--A planar-type conductor­insulator­conductor tun- neling diode

  6. Subbarrier fusion reactions and many-particle quantum tunneling

    E-Print Network [OSTI]

    K. Hagino; N. Takigawa

    2012-10-17

    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.

  7. A 233 km tunnel for lepton and hadron colliders

    SciTech Connect (OSTI)

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

    2012-12-21

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

  8. Invariance of the Hamilton-Jacobi tunneling method for black holes and FRW model

    E-Print Network [OSTI]

    Yi-Xin Chen; Kai-Nan Shao

    2010-07-31

    In this paper we revisit the topic of Hawking radiation as tunneling. We show that the imaginary part of the action of the tunneling particle should be reconstructed in a covariant way, as a line integral along the classical forbidden trajectory of tunneling particles. As the quantum tunneling phenomenon, the probability of tunneling is related to the imaginary part of the action for the classical forbidden trajectory. We do the calculations for massless and massive particles, in Schwarzschild coordinate and Painlev?coordinate. The construction of particle action is invariant under coordinate transformations, so this method of calculation black hole tunneling does not have the so called "factor 2 problem". As an application, we find that the temperature of Hawking temperature of apparent horizon in a FRW universe is $T=\\frac{\\kappa}{2\\pi}$. Based on this result, we briefly discuss the unified first law of apparent horizon in FRW universe.

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

    SciTech Connect (OSTI)

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

    1992-04-01

    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.

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

    SciTech Connect (OSTI)

    NSTec Environmental Restoration

    2008-08-01

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

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

    SciTech Connect (OSTI)

    Tuenge, Jason R.

    2011-06-01

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

  12. Derived Types What Are Derived Types?

    E-Print Network [OSTI]

    Collett Jr., Jeffrey L.

    Derived Types #12;What Are Derived Types? As usual, a hybrid of two, unrelated concepts C++, Python orientation comes in #12;Simple Derived Types TYPE Wheel INTEGER :: spokes REAL :: diameter, width CHARACTER(LEN=15) :: material END TYPE Wheel That defines a derived type Wheel Using derived types needs a special

  13. Derived Types What Are Derived Types?

    E-Print Network [OSTI]

    Collett Jr., Jeffrey L.

    Derived Types #12;What Are Derived Types? As usual, a hybrid of two, unrelated concepts C object orientation comes in This course will only describe the former. #12;Simple Derived Types TYPE That defines a derived type Wheel Using derived types needs a special syntax TYPE(Wheel) :: w1 #12;More

  14. Single-Particle Tunneling in Doped Graphene-Insulator-Graphene Junctions R. M. Feenstra*

    E-Print Network [OSTI]

    Feenstra, Randall

    -insulator-graphene (GIG) tunnel junctions. * feenstra@cmu.edu djena@nd.edu ggu1@utk.edu Published in J. Appl. Phys. 111

  15. Comment on "Direct space-time observation of pulse tunneling in an electromagnetic band gap"

    E-Print Network [OSTI]

    G. Nimtz; A. A. Stahlhofen

    2008-01-13

    The investigation presented by Doiron, Hache, and Winful [Phys. Rev. A 76, 023823 (2007)] is not valid for the tunneling process as claimed in the paper.

  16. Type: Renewal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaicsStateof Energy TwoEvent at the Pu Facility,Type IV COPV1

  17. Low frequency noise measurements of resonant tunnel diodes 

    E-Print Network [OSTI]

    Villareal, Samuel Simon

    1988-01-01

    26 28 31 31 32 32 18a Bias dependence of 4. 5 KHz noise at 388 K under forward bias 33 Bias dependence of 4. 5 KHz noise at 388 K under inverted bias 33 lla Noise spectrum of RTD under 8. 46 V forward bias at 288 K 38 lib Noise spectrum...]. RTD applications include very fast switching devices, memory devices, logic gates, and high-frequency oscillators and detectors [4] ~ A resonant tunneling diode is simply an energy well sandwiched between two confining energy barriers. The RTD...

  18. Fabrication of a gated gallium arsenide heterostructure resonant tunneling diode 

    E-Print Network [OSTI]

    Kinard, William Brian

    1989-01-01

    , . ' 'CONTACT PAD' PLANAR I ZED POLYAM I DE RECTIFYI CONTACT N DBHS Pig. 2. f'utavvay vieiv of a gated gallium arsenide heterostructure resonant tunneling diode 1018 graded from 10 18 io" 10? (lightly doped) units=cm 8 ?graded from 10 to 18...FABRICATION OF A GATED GALLIL". tl ARSEXIDE HETEROSTRL CTL RF. RESONANT TF'XXELI'XG DIODE A Thesis bt ttrILLIAAI BRIA'. s KI'iARD Subnut ted to the Office of Graduate Studies of Texas AE;M Eniverstty tn partial fulfillment of the requirements...

  19. Observation of diamond turned OFHC copper using Scanning Tunneling Microscopy

    SciTech Connect (OSTI)

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

    1988-12-01

    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.

  20. Minimal Length Effects on Tunnelling from Spherically Symmetric Black Holes

    E-Print Network [OSTI]

    Benrong Mu; Peng Wang; Haitang Yang

    2015-01-24

    In this paper, we investigate effects of the minimal length on quantum tunnelling from spherically symmetric black holes using the Hamilton-Jacobi method incorporating the minimal length. We first derive the deformed Hamilton-Jacobi equations for scalars and fermions, both of which have the same expressions. The minimal length correction to the Hawking temperature is found to depend on the black hole's mass and the mass and angular momentum of emitted particles. Finally, we calculate a Schwarzschild black hole's luminosity and find the black hole evaporates to zero mass in infinite time.

  1. Minimal Length Effects on Tunnelling from Spherically Symmetric Black Holes

    E-Print Network [OSTI]

    Mu, Benrong; Yang, Haitang

    2015-01-01

    In this paper, we investigate effects of the minimal length on quantum tunnelling from spherically symmetric black holes using the Hamilton-Jacobi method incorporating the minimal length. We first derive the deformed Hamilton-Jacobi equations for scalars and fermions, both of which have the same expressions. The minimal length correction to the Hawking temperature is found to depend on the black hole's mass and the mass and angular momentum of emitted particles. Finally, we calculate a Schwarzschild black hole's luminosity and find the black hole evaporates to zero mass in infinite time.

  2. Merguerian, Charles, 1986a, Tunnel vision -A deep view of the bedrock geology of New York City (NYC).

    E-Print Network [OSTI]

    Merguerian, Charles

    Merguerian, Charles, 1986a, Tunnel vision - A deep view of the bedrock geology of New York City This Abstract: Merguerian, Charles, 1986a, Tunnel vision - A deep view of the bedrock geology of New York City

  3. Shot noise in tunneling through a single InAs quantum dot Frank Hohls

    E-Print Network [OSTI]

    Hohls, Frank

    Shot noise in tunneling through a single InAs quantum dot Frank Hohls , André Nauen , Niels Maire by measuring the shot noise of the current. We observe an approximately linear voltage dependence of both the shot noise, characterized by the Fano factor, and the tunneling current itself. We ascribe

  4. Interaction between surface structures and tunnelling in sand: centrifuge and computational modelling

    E-Print Network [OSTI]

    Giardina, Giorgia; DeJong, Matthew J.; Mair, Robert J.

    2015-07-30

    historische Geba¨ude am Beispiel einer neuen U-Bahnlinie in Rom, Geomechanics and Tunnelling 5 (3) (2012) 275–299. [36] G. Giardina, M. A. N. Hendriks, J. G. Rots, Sensitivity study on tunnelling induced damage to a masonry fac¸ade, Engineering Structures 89...

  5. A Tunnel Freezing Process with Adaptive Control A Stochastic Modeling Approach

    E-Print Network [OSTI]

    Gautam, Natarajan

    Statement and Research Objective Cryogenic freezing tunnels can be operated in a variety of modes. The needA Tunnel Freezing Process with Adaptive Control ­ A Stochastic Modeling Approach S. Ramakrishnan N University Park, PA 16802, U.S.A. Abstract The estimation of freezing times using various analytical

  6. Sharp Tunneling Peaks in a Parametric Oscillator: Quantum Resonances Missing in the Rotating Wave Approximation

    E-Print Network [OSTI]

    Dykman, Mark

    [1] to optical cav- ity modes [2], electrons in a Penning trap [3], and opto- and nanomechanicalSharp Tunneling Peaks in a Parametric Oscillator: Quantum Resonances Missing in the Rotating Wave March 2012; published 27 August 2012) We describe a new mechanism of tunneling between period

  7. Nonlinear resonant tunneling in systems coupled to quantum reservoirs Carlo Presilla

    E-Print Network [OSTI]

    Presilla, Carlo

    -dependent transport of interacting electrons in biased resonant-tunneling heterostructures. The resulting model and recognized as a consequence of the mutual interaction of the electrons trapped in the resonance.2,3 We showNonlinear resonant tunneling in systems coupled to quantum reservoirs Carlo Presilla Dipartimento

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

    E-Print Network [OSTI]

    Savitski, Stephen Ronald

    2000-01-01

    Inelastic Tunneling Spectroscopy (IETS). In a SATJ, a barrier gas is deposited in situ between two metal wires that can be remotely manipulated by a magnetic field, to vary the junction conductance. The ZBF is studied for platinum/neon/platinum tunnel...

  9. Low-temperature Scanning Tunneling Spectroscopy of Semiconductor Surfaces R. M. Feenstra1

    E-Print Network [OSTI]

    Feenstra, Randall

    1 Low-temperature Scanning Tunneling Spectroscopy of Semiconductor Surfaces R. M. Feenstra1 Low-temperature scanning tunneling spectroscopy measurements on semiconductor surface are described that measurements at low temperatures have been conducted. Most notably, discrete accumulation layer states have

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

    E-Print Network [OSTI]

    Kim, Jungwook

    2004-09-30

    ATP, the mutation appeared to interrupt the binding of the substrate. The ammonia tunnel has been engineered to contain a hole to further support the proposed role of the tunnel that it is utilized in guiding diffusion of ammonia from the site of glutamine...

  11. Assessment of Flow Efficiency Through a Closed Circuit Wind Tunnel with Recommendations for Improvements 

    E-Print Network [OSTI]

    Guthery, John

    2013-12-02

    Wind tunnels are designed for a certain range of test velocities and model sizes. The Oran W. Nicks Low Speed Wind Tunnel (LSWT) at Texas A&M, was designed to reach 200 mph (M=0.26) with its original 1250 hp motor and 7 x 10 ft test section. In 2012...

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

    E-Print Network [OSTI]

    Brown, Michael R.

    Observation of Turbulent Intermittency Scaling with Magnetic Helicity in an MHD Plasma Wind Tunnel. An unstable spheromak injected into the MHD wind tunnel of the Swarthmore Spheromak Experiment displays. Differences in magnetic intermittent character have been seen between fast and slow solar wind turbulence [2

  13. House Flies andPigManureVolatiles: Wind TunnelBehavioral Studiesand

    E-Print Network [OSTI]

    House Flies andPigManureVolatiles: Wind TunnelBehavioral Studiesand Electrophysiological pig manure were identified as electrophysiologically active on virgin female house fly (Muscadomstica of standards, and wind tunnel behavioral studies The pig manure volatiles eliciting responses from female

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

    E-Print Network [OSTI]

    Widnall, S. E.

    1972-01-01

    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 ...

  15. Wind Tunnels in Pheromone Research T. C ~ a k e r 'and C E. Linn. ~ r : ~

    E-Print Network [OSTI]

    Chapter 3 Wind Tunnels in Pheromone Research T. C ~ a k e r 'and C E. Linn. ~ r : ~ I. Introduction" conditions: flight through space from a distance of several meters or more in shifting wind fields. Upwind Agricultural Experiment Station, Geneva, New York. #12;#12;T. C. Baker and C. E. Linn, Jr, Wind Tunnels

  16. Josephson Junctions with Tunnel Barriers Grown Via In Situ Atomic Layer Deposition

    E-Print Network [OSTI]

    Elliot, Alan Jesson

    2014-12-31

    in the thermally oxidized tunnel barrier. In order to realize the full potential of JJ qubits, an alternative method to thermal oxidation must be found for tunnel barrier growth. This work explores using atomic layer deposition (ALD) for the growth of ultrathin...

  17. Authenticated Wireless Roaming via Tunnels: Making Mobile Guests Feel at Home

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    Authenticated Wireless Roaming via Tunnels: Making Mobile Guests Feel at Home Mark Manulis1|francois.koeune|olivier.bonaventure|jean-jacques.quisquater}@uclouvain.be Abstract. In wireless roaming a mobile device obtains a service from some foreign network while being. Such Wireless Roaming via Tunnels (WRT) offers several (security) benefits but states also new security

  18. INFLUENCE OF GEOMETRY ON THE MEAN FLOW WITHIN URBAN STREET CANYONS A COMPARISON OF WIND TUNNEL

    E-Print Network [OSTI]

    Savory, Eric

    INFLUENCE OF GEOMETRY ON THE MEAN FLOW WITHIN URBAN STREET CANYONS ­ A COMPARISON OF WIND TUNNEL. A comparison between numerical simulations and wind tunnel modelling has been per- formed to examine ); = Kinematic viscosity of air (m2 s-1 ). 1. Introduction Many different aspects of the wind flow within urban

  19. Wind Tunnel and Field Test of Three 2D Sonic Anemometers

    E-Print Network [OSTI]

    Wauben, Wiel

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

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

    SciTech Connect (OSTI)

    NSTec Environmental Restoration

    2009-07-01

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

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

    SciTech Connect (OSTI)

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

    1992-10-01

    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.

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

    E-Print Network [OSTI]

    Brückl, Ewald

    SAGEEP 2010 Keystone, Colorado http://www.eegs.org CONTINUOUS EXPLORATION AHEAD OF THE TUNNEL FACE BY TSWD - TUNNEL SEISMIC WHILE DRILLING EEGS' Annual Meeting Keystone, Colorado April 11-15, 2010 Ewald ahead of the tunnel face (Brückl et al., 2008). 353 #12;SAGEEP 2010 Keystone, Colorado http

  3. STUDY TYPES What is a "Study Type"?

    E-Print Network [OSTI]

    Dorf, Martin E.

    #12;STUDY TYPES What is a "Study Type"? A Study Type is a defined business process. Study Types work together to streamline workflow, track data & keep users informed. There are 2 Study Types in eCOMS: COMS and IACUC. The COMS Study: The COMS Study is an online form that a Principal Investigator fills

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

    SciTech Connect (OSTI)

    Laughton, Christopher; /Fermilab

    2000-01-01

    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.

  5. Physical properties and analytical models of band-to-band tunneling in low-bandgap semiconductors

    SciTech Connect (OSTI)

    Shih, Chun-Hsing Dang Chien, Nguyen

    2014-01-28

    Low-bandgap semiconductors, such as InAs and InSb, are widely considered to be ideal for use in tunnel field-effect transistors to ensure sufficient on-current boosting at low voltages. This work elucidates the physical and mathematical considerations of applying conventional band-to-band tunneling models in low-bandgap semiconductors, and presents a new analytical alternative for practical use. The high-bandgap tunneling generates most at maximum field region with shortest tunnel path, whereas the low-bandgap generations occur dispersedly because of narrow tunnel barrier. The local electrical field associated with tunneling-electron numbers dominates in low-bandgap materials. This work proposes decoupled electric-field terms in the pre-exponential factor and exponential function of generation-rate expressions. Without fitting, the analytical results and approximated forms exhibit great agreements with the sophisticated forms both in high- and low-bandgap semiconductors. Neither nonlocal nor local field is appropriate to be used in numerical simulations for predicting the tunneling generations in a variety of low- and high-bandgap semiconductors.

  6. The importance of Fe surface states for spintronic devices based on magnetic tunnel junctions

    SciTech Connect (OSTI)

    Chantis, Athanasios N

    2008-01-01

    In this article we give a review of our recent theoretical studies of the influence of Fe(001) surface (interface) states on spin-polarized electron transport across magnetic tunnel junctions with Fe electrodes. We show that minority-spin surface (interface) states are responsible for at least two effects which are important for spin electronics. First, they can produce a sizable tunneling anisotropic magnetoresistance in magnetic tunnel junctions with a single Fe electrode. The effect is driven by a Rashba shift of the resonant surface band when the magnetization changes direction. This can introduce a new class of spintronic devices, namely, tunneling magnetoresistance junctions with a single ferromagnetic electrode. Second, in Fe/GaAs(001) magnetic tunnel junctions minority-spin interface states produce a strong dependence of the tunneling current spin polarization on applied electrical bias. A dramatic sign reversal within a voltage range of just a few tenths of an eV is predicted. This explains the observed sign reversal of spin polarization in recent experiments of electrical spin injection in Fe/GaAs(001) and related reversal of tunneling magnetoresistance through vertical Fe/GaAs/Fe trilayers.

  7. Polarization-engineered GaN/InGaN/GaN tunnel diodes

    SciTech Connect (OSTI)

    Krishnamoorthy, Sriram; Nath, Digbijoy N.; Akyol, Fatih; Park, Pil Sung; Esposto, Michele; Rajan, Siddharth [Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States)

    2010-11-15

    We report on the design and demonstration of polarization-engineered GaN/InGaN/GaN tunnel junction diodes with high current density and low tunneling turn-on voltage. Wentzel-Kramers-Brillouin calculations were used to model and design tunnel junctions with narrow band gap InGaN-based barrier layers. N-polar p-GaN/In{sub 0.33}Ga{sub 0.67}N/n-GaN heterostructure tunnel diodes were grown using molecular beam epitaxy. Efficient interband tunneling was achieved close to zero bias with a high current density of 118 A/cm{sup 2} at a reverse bias of 1 V, reaching a maximum current density up to 9.2 kA/cm{sup 2}. These results represent the highest current density reported in III-nitride tunnel junctions and demonstrate the potential of III-nitride tunnel devices for a broad range of optoelectronic and electronic applications.

  8. Radioactive air emissions notice of construction for deactivation of the PUREX storage tunnel number 2

    SciTech Connect (OSTI)

    JOHNSON, R.E.

    1999-10-11

    The Plutonium-Uranium Extraction (PUREX) Plant Storage Tunnel Number 2 (hereafter referred to as the PUREX Tunnel) was built in 1964. Since that time, the PUREX Tunnel has been used for storage of radioactive and mixed waste. In 1991, the PUREX Plant ceased operations and was transitioned to deactivation. The PUREX Tunnel continued to receive PUREX Plant waste material for storage during transition activities. Before 1995, a decision was made to store radioactive and mixed waste in the PUREX Tunnel generated from other onsite sources, on a case-by-case basis. This notice of construction (NOC) describes the activities associated with the reactivation of the PUREX Tunnel ventilation system and the transfer of up to 3.5 million curies (MCi) of radioactive waste to the PUREX Tunnel from any location on the Hanford Site. The unabated total effective dose equivalent (TEDE) estimated for the hypothetical offsite maximally exposed individual (MEI) is 5.6 E-2 millirem (mrem). The abated TEDE conservatively is estimated to account for 1.9 E-5 mrem to the MEI. The following text provides information requirements of Appendix A of Washington Administrative Code (WAC) 246-247 (requirements 1 through 18).

  9. Cavity-enhanced resonant tunneling photodetector at telecommunication wavelengths

    SciTech Connect (OSTI)

    Pfenning, Andreas Hartmann, Fabian; Langer, Fabian; Höfling, Sven; Kamp, Martin; Worschech, Lukas

    2014-03-10

    An AlGaAs/GaAs double barrier resonant tunneling diode (RTD) with a nearby lattice-matched GaInNAs absorption layer was integrated into an optical cavity consisting of five and seven GaAs/AlAs layers to demonstrate cavity enhanced photodetection at the telecommunication wavelength 1.3??m. The samples were grown by molecular beam epitaxy and RTD-mesas with ring-shaped contacts were fabricated. Electrical and optical properties were investigated at room temperature. The detector shows maximum photocurrent for the optical resonance at a wavelength of 1.29??m. At resonance a high sensitivity of 3.1×10{sup 4} A/W and a response up to several pA per photon at room temperature were found.

  10. A normal metal tunnel-junction heat diode

    SciTech Connect (OSTI)

    Fornieri, Antonio, E-mail: antonio.fornieri@sns.it; Martínez-Pérez, María José; Giazotto, Francesco, E-mail: giazotto@sns.it [NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa (Italy)

    2014-05-05

    We propose a low-temperature thermal rectifier consisting of a chain of three tunnel-coupled normal metal electrodes. We show that a large heat rectification is achievable if the thermal symmetry of the structure is broken and the central island can release energy to the phonon bath. The performance of the device is theoretically analyzed and, under the appropriate conditions, temperature differences up to ?200 mK between the forward and reverse thermal bias configurations are obtained below 1?K, corresponding to a rectification ratio R?2000. The simplicity intrinsic to its design joined with the insensitivity to magnetic fields make our device potentially attractive as a fundamental building block in solid-state thermal nanocircuits and in general-purpose cryogenic electronic applications requiring energy management.

  11. Insensitivity of tunneling anisotropic magnetoresistance to non-magnetic electrodes

    SciTech Connect (OSTI)

    Wang, Y. Y.; Song, C. Wang, G. Y.; Zeng, F.; Pan, F.

    2013-11-11

    Ferromagnetic electrodes play a crucial role in magnetoresistance effect and spin injection, whereas the essential features of non-magnetic metal electrodes in spintronics are commonly ignored except for their electrical conductivity. Here, we verify that the room-temperature tunneling anisotropic magnetoresistance (TAMR) behavior in antiferromagnet-based [Pt/Co]/IrMn/AlO{sub x}/metal (metal?=?Pt, Au, Cu, Al) junctions is insensitive to the top metal electrodes. Similar out-of-plane signals are detected for different electrodes, in contrast to the varied shapes of in-plane TAMR curves which are most likely attributed to the differences in the multidomain structure of the magnetic electrode. This would add a different dimension to spintronics.

  12. Isotope effect in tunnelling ionization of neutral hydrogen molecules

    E-Print Network [OSTI]

    Wang, X; Atia-Tul-Noor, A; Hu, B T; Kielpinski, D; Sang, R T; Litvinyuk, I V

    2015-01-01

    It has been recently predicted theoretically that due to nuclear motion light and heavy hydrogen molecules exposed to strong electric field should exhibit substantially different tunneling ionization rates (O.I. Tolstikhin, H.J. Worner and T. Morishita, Phys. Rev. A 87, 041401(R) (2013) [1]). We studied that isotope effect experimentally by measuring relative ionization yields for each species in a mixed H2/D2 gas jet interacting with intense femtosecond laser pulses. In a reaction microscope apparatus we detected ionic fragments from all contributing channels (single ionization, dissociation, and sequential double ionization) and determined the ratio of total single ionization yields for H2 and D2. The measured ratio agrees quantitatively with the prediction of the generalized weak-field asymptotic theory in an apparent failure of the frozen-nuclei approximation.

  13. Ferroelectric modulation on resonant tunneling through perovskite double-barriers

    SciTech Connect (OSTI)

    Du, Ruifang; Qiu, Xiangbiao; Li, Aidong; Wu, Di

    2014-04-07

    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.

  14. Heat engine driven by three-body photon tunneling

    E-Print Network [OSTI]

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

    2015-01-01

    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.

  15. Compensation of radiation damages for SOI pixel detector via tunneling

    E-Print Network [OSTI]

    Yamada, Miho; Kurachi, Ikuo

    2015-01-01

    We are developing monolithic pixel detectors based on SOI technology for high energy physics, X-ray applications and so on.To employ SOI pixel detector on such radiation environments, we have to solve effects of total ionization damages (TID) for transistors which are enclosed in oxide layer.The holes which are generated and trapped in the oxide layers after irradiation affect characteristics of near-by transistors due to its positive electric field.Annealing and radiation of ultraviolet are not realistic to remove trapped holes for a fabricated detector due to thermal resistance of components and difficulty of handling. We studied compensation of TID effects by tunneling using a high-voltage. For decrease of trapped holes, applied high-voltage to buried p-well which is under oxide layer to inject the electrons into the oxide layer.In this report, recent progress of this study is shown.

  16. Tunneling under Coherent Control by Sequences of Unitary Pulses

    E-Print Network [OSTI]

    Rajdeep Saha; Victor S. Batista

    2010-09-07

    A general coherent control scenario to suppress, or accelerate, tunneling of quantum states decaying into a continuum, is investigated. The method is based on deterministic, or stochastic, sequences of unitary pulses that affect the underlying interference phenomena responsible for quantum dynamics, without inducing decoherence, or collapsing the coherent evolution of the system. The influence of control sequences on the ensuing quantum dynamics is analyzed by using perturbation theory to first order in the control pulse fields and compared to dynamical decoupling (DD) protocols and sequences of pulses that collapse the coherent evolution and induce quantum Zeno (QZE) or quantum anti-Zeno effects (AZE). The analysis reveals a subtle interplay between coherent and incoherent phenomena and demonstrating that dynamics analogous to evolution due to QZE or AZE can be generated from stochastic sequences of unitary pulses when averaged over all possible realizations.

  17. Relativistic tunneling picture of electron-positron pair creation

    E-Print Network [OSTI]

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

    2015-03-19

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

  18. High energy storage capacitor by embedding tunneling nano-structures

    DOE Patents [OSTI]

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

    2014-11-04

    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).

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

    E-Print Network [OSTI]

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

    2013-11-07

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

  20. Tunneling time calculations for general finite wavepackets based on the presence time formalism

    E-Print Network [OSTI]

    O. del Barco; M. Ortuño; V. Gasparian

    2015-05-31

    We analyze the tunneling time problem via the presence time formalism. With this method we reproduce previous results for very long wavepackets and we are able to calculate the tunneling time for general wavepackets of arbitrary shape and length. The tunneling time for a general wavepacket is equal to the average over the energy components of the standard phase time. With this approach we can also calculate the time uncertainty. We have checked that the results obtained with this approach agree extremely well with numerical simulations of the wavepacket evolution.

  1. Finite element analysis of floatation of rectangular tunnels following earthquake induced liquefaction

    E-Print Network [OSTI]

    Madabhushi, S. S. C.; Madabhushi, S. P. G.

    2014-10-29

    , R., Yang, D. and Naesgaard, E. (2003). Centrifuge modeling for seismic retrofit design of an immersed tube tunnel. Journal of Physical Modelling of Geotechnics 3, No. 2, 23-32. [8] Chou, J.C., Kutter, B.L., Travasarou, T. and Chacko, J.M. (2011... during a major earthquake. Seismic behavior of tunnels and other underground structures can be studied using numerical analyses or physical testing. Cilingir and Madabhushi [1,2,3] investigated the seismic response of square tunnels using both dynamic...

  2. Characterization of aluminum oxide tunnel barriers by combining transport measurements and transmission electron microscopy imaging

    SciTech Connect (OSTI)

    Aref, T.; Averin, A.; Nguyend, H. Q.; Pekola, J. P.; Dijken, S. van; Yao, L. D.; Ferring, A.; Koberidze, M.; Nieminen, R. M.

    2014-08-21

    We present two approaches for studying the uniformity of a tunnel barrier. The first approach is based on measuring single-electron and two-electron tunneling in a hybrid single-electron transistor. Our measurements indicate that the effective area of a conduction channel is about one order of magnitude larger than predicted by theoretical calculations. With the second method, transmission electron microscopy, we demonstrate that variations in the barrier thickness are a plausible explanation for the larger effective area and an enhancement of higher order tunneling processes.

  3. Dynamical tunneling of a Bose-Einstein condensate in periodically driven systems

    E-Print Network [OSTI]

    R. K. Shrestha; J. Ni; W. K. Lam; G. S. Summy; S. Wimberger

    2013-09-13

    We report measurements of dynamical tunneling rates of a Bose-Einstein condensate across a barrier in classical phase space. The atoms are initially prepared in quantum states that extend over a classically regular island region. We focus on the specific system of quantum accelerator modes of the kicked rotor in the presence of gravity. Our experimental data is supported by numerical simulations taking into account imperfections mainly from spontaneous emission. Furthermore, we predict experimentally accessible parameter ranges over which direct tunneling could be readily observed if spontaneous emission was further suppressed. Altogether, we provide a proof-of-principle for the experimental accessibility of dynamical tunneling rates in periodically driven systems.

  4. ScanningTunneling Luminescence of Grain Boundaries in Cu(In,Ga)Se2

    SciTech Connect (OSTI)

    Romero, M. J.; Jiang, C.-S.; Al-Jassim, M. M.; Noufi, R.

    2005-01-01

    At the Laboratory, photon emission in semiconductors has been mapped in the nanoscale using scanning tunneling microscopy (STM). In this Solar Program Review Meeting, we report on the latest results obtained in Cu(In,Ga)Se2 (CIGS) thin films by this adapted STM. Scanning tunneling luminescence (STL) spectroscopy suggests that photons are emitted near the surface of CIGS. STL is excited either by (1) diffusion of tunneling electrons and subsequent recombination with available holes in CIGS or (2) impact ionization by hot electrons. Which process becomes predominant depends on the voltage applied to the STM tip. Photon mapping shows electronically active, extended defects near the surface of CIGS thin films.

  5. Determining Exchange Splitting in a Magnetic Semiconductor by Spin-Filter Tunneling

    SciTech Connect (OSTI)

    Santos, T. S.; Moodera, J. S.; Venkataraman, K.; Negusse, E.; Holroyd, J.; Dvorak, J.; Liberati, M.; Idzerda, Y. U.; Arenholz, E.

    2008-06-24

    A large exchange splitting of the conduction band in ultrathin films of the ferromagnetic semiconductor EuO was determined quantitatively, by using EuO as a tunnel barrier and fitting the current-voltage characteristics and temperature dependence to tunneling theory. This exchange splitting leads to different tunnel barrier heights for spin-up and spin-down electrons, and is large enough to produce a near fully spin-polarized current. Moreover, the magnetic properties of these ultrathin films (<6 nm) show a reduction in Curie temperature with decreasing thickness, in agreement with theoretical calculation [R. Schiller et al., Phys. Rev. Lett. 86, 3847 (2001)].

  6. Assignment Types UTS LIBRARY

    E-Print Network [OSTI]

    University of Technology, Sydney

    Assignment Types UTS LIBRARY February 2013 Academic Writing Guide Part 2 ­ Assignment Types: This section outlines the basic types of written assignments, providing structural elements and examples. #12;2 II. Assignment Types 1. Essay Writing

  7. A Study of Fire Durability for a Road Tunnel: Comparing CFD and Simple Analytical Models 

    E-Print Network [OSTI]

    Reszka, Pedro; Steinhaus, Thomas; Biteau, Hubert; Carvel, Ricky O; Rein, Guillermo; Torero, Jose L

    The durability of various typical tunnel sections in the event of a prescribed 100 MW fire has been assessed. Cast-iron sections, pre-cast concrete sections and in-situ concrete cut and cover sections are all considered ...

  8. Vehicular emission of volatile organic compounds (VOCs) from a tunnel study in Hong Kong

    E-Print Network [OSTI]

    2009-01-01

    7504, 2009 petroleum gas (LPG), gasoline, and diesel are thevehicles, while diesel and LPG fueled vehicles accounted forShing Mun Tunnel, Hong Kong LPG, gasoline, and diesel ethene

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

    SciTech Connect (OSTI)

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

    2008-05-01

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

  10. Dynamic response of flexible square tunnels: testing and validation of existing design methodologies

    E-Print Network [OSTI]

    Tsinidis, G.; Pitilakis, K.; Madabhushi, G.; Heron, C.

    2015-03-20

    regarding the seismic response of rectangular embedded structures and to calibrate currently available design methods. The soil–tunnel system response was recorded with an extensive instrumentation array, comprising miniature accelerometers, pressure cells...

  11. Creating deformations and tunnels in a surface using layered geometry with adaptive filtering 

    E-Print Network [OSTI]

    Brooks, Jacob Kirk

    2005-11-01

    With this thesis, I present a method for creating footprints and tunnels in a surface through the use of layered geometry. Rather than using a single geometric surface, deformations are created through the interaction of a polygonal object...

  12. Evaluation of propulsor aerodynamic performance for powered aircraft wind tunnel experiments

    E-Print Network [OSTI]

    Siu, Nina M

    2015-01-01

    This thesis describes a methodology to convert electrical power measurements to propulsor mechanical ow power for a 1:11-scale, powered wind tunnel model of an advanced civil aircraft utilizing boundary layer ingestion ...

  13. THE QUEENS TUNNEL COMPLEX: A NEWLY DISCOVERED GRANULITE FACIES FORDHAM ORTHOGNEISS COMPLEX

    E-Print Network [OSTI]

    Merguerian, Charles

    Tunnel project. The Brocks' subsequent studies of the rocks (hand-specimen petrography, thin-section petrography, whole-rock geochemistry, and zircon U- Pb dating) have all confirmed their initial correlation

  14. Demonstration of forward inter-band tunneling in GaN by polarization engineering

    SciTech Connect (OSTI)

    Krishnamoorthy, Sriram; Park, Pil Sung; Rajan, Siddharth

    2011-12-05

    We report on the design, fabrication, and characterization of GaN interband tunnel junction showing forward tunneling characteristics. We have achieved very high forward tunneling currents (153 mA/cm{sup 2} at 10 mV, and 17.7 A/cm{sup 2} peak current) in polarization-engineered GaN/InGaN/GaN heterojunction diodes grown by plasma assisted molecular beam epitaxy. We also report the observation of repeatable negative differential resistance in interband III-Nitride tunnel junctions, with peak-valley current ratio of 4 at room temperature. The forward current density achieved in this work meets the typical current drive requirements of a multi-junction solar cell.

  15. Structural Fluctuations, Spin, Reorganization Energy, and Tunneling Energy Control of Intramolecular Electron Transfer

    E-Print Network [OSTI]

    Kurnikova, Maria

    calculations of electronic couplings, molecular dynamics simulations of molecular geometries, and Poisson exists to interpret electron-transfer (ET) reactions and their dependence upon molecular structure.1Structural Fluctuations, Spin, Reorganization Energy, and Tunneling Energy Control

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

    E-Print Network [OSTI]

    Kutz, Douglas M

    2014-05-02

    Despite advances in modern computing and simulation, wind tunnel testing remains the most trusted method for determining aerodynamic vehicle behavior. Corrections are applied to accurately obtain results representative of free-air performance due...

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

    E-Print Network [OSTI]

    Babbar, Yogesh

    2011-08-08

    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...

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

    DOE Patents [OSTI]

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

    1998-01-01

    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.

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

    E-Print Network [OSTI]

    Nandkishore, Rahul Mahajan

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

  20. Background Simulation Experiment Conclusion Hysteresis in the Nonlinear Tunnelling of Light

    E-Print Network [OSTI]

    Petta, Jason

    Background Simulation Experiment Conclusion Hysteresis in the Nonlinear Tunnelling of Light Through of Light Through a Barrier #12;Background Simulation Experiment Conclusion Outline 1 Background Nonlinear of Light Through a Barrier #12;Background Simulation Experiment Conclusion Nonlinear Optics Nonlinear

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

    E-Print Network [OSTI]

    Silva, Ramon A.

    2011-08-08

    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...

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

    E-Print Network [OSTI]

    Min, Byoung Koun

    2005-11-01

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

  3. Highly Efficient Midinfrared On-Chip Electrical Generation of Graphene Plasmons by Inelastic Electron Tunneling Excitation

    E-Print Network [OSTI]

    Ooi, Kelvin J A; Hsieh, Chang Yu; Tan, Dawn T H; Ang, Lay Kee

    2015-01-01

    Inelastic electron tunneling provides a low-energy pathway for the excitation of surface plasmons and light emission. We theoretically investigate tunnel junctions based on metals and graphene. We show that graphene is potentially a highly efficient material for tunneling excitation of plasmons because of its narrow plasmon linewidths, strong emission, and large tunability in the midinfrared wavelength regime. Compared to gold and silver, the enhancement can be up to 10 times for similar wavelengths and up to 5 orders at their respective plasmon operating wavelengths. Tunneling excitation of graphene plasmons promises an efficient technology for on-chip electrical generation and manipulation of plasmons for graphene-based optoelectronics and nanophotonic integrated circuits.

  4. Ultra-high vacuum scanning tunneling microscopy and theoretical studies of 1-halohexane monolayers

    E-Print Network [OSTI]

    Berne, Bruce J.

    . In accordance with the higher degree of disorder observed in scanning tunneling microscopy images of 1 of the interactions governing 2D self-organization. Simple functionalized hydrocarbon molecules are known to form self

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

    SciTech Connect (OSTI)

    Oar, D.L.

    1994-09-29

    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.

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

    E-Print Network [OSTI]

    Van Veenhuizen, Marc Julien

    2010-01-01

    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 ...

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

    E-Print Network [OSTI]

    Wilkins, James R., IV

    2012-01-01

    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 ...

  8. Troll Phase I pipelines: Tie-ins to the subsea tunnel

    SciTech Connect (OSTI)

    Hove, F.; Kuhlmann, H.

    1995-12-31

    Subsea approaches to the Norwegian coast are characterized by very rugged topography. Landfall of offshore pipelines therefore often require dedicated subsea tunnel and pipeline tie in concepts. To land the 36 inch and 40 inch offshore pipelines associated with the Troll Phase 1 development, a 4 km long landfall tunnel was constructed terminating at a water depth of 165 m with vertical shaft connections to the seabed. This paper describes the design of the Troll Phase 1 tie-ins of offshore to tunnel pipeline sections. These comprise two main elements, i.e. 180 Te tie-in spools -- which are installed between the offshore pipelines and the piercing shafts -- and prefabricated 450 Te riser bundles -- which are installed into the vertical tunnel piercing shafts.

  9. The monitoring of an existing cast iron tunnel with distributed fibre optic sensing (DFOS)

    E-Print Network [OSTI]

    Gue, C. Y.; Wilcock, M.; Alhaddad, M. M.; Elshafie, M. Z. E. B.; Soga, K.; Mair, R. J.

    2015-03-29

    complex, is less problematic as technology has developed. Nonetheless, the effects of tunnelling on adjacent structures remain challenging as they are not well understood; in practice, with surging demand for transport infrastructure in urban environments... the continuous gluing method less practical. Direct line of sight along the intrados surface at the tunnel crown was not possible with the flanges and existing electrical conduits in place. Continuous gluing would have required the fibre optic cable to be bent...

  10. Massive vector particles tunneling from Kerr and Kerr-Newman black holes

    E-Print Network [OSTI]

    Li, Xiang-Qian

    2015-01-01

    In this paper, we investigate the Hawking radiation of massive spin-1 particles from 4-dimensional Kerr and Kerr-Newman black holes. By applying the Hamilton-Jacobi ansatz and the WKB approximation to the field equations of the massive bosons in Kerr and Kerr-Newman space-time, the quantum tunneling method is successfully implemented. As a result, we obtain the tunneling rate of the emitted vector particles and recover the standard Hawking temperature of both the two black holes.

  11. Massive vector particles tunneling from Kerr and Kerr-Newman black holes

    E-Print Network [OSTI]

    Xiang-Qian Li; Ge-Rui Chen

    2015-07-13

    In this paper, we investigate the Hawking radiation of massive spin-1 particles from 4-dimensional Kerr and Kerr-Newman black holes. By applying the Hamilton-Jacobi ansatz and the WKB approximation to the field equations of the massive bosons in Kerr and Kerr-Newman space-time, the quantum tunneling method is successfully implemented. As a result, we obtain the tunneling rate of the emitted vector particles and recover the standard Hawking temperature of both the two black holes.

  12. Electromagnetic model for near-field microwave microscope with atomic resolution: Determination of tunnel junction impedance

    SciTech Connect (OSTI)

    Reznik, Alexander N.

    2014-08-25

    An electrodynamic model is proposed for the tunneling microwave microscope with subnanometer space resolution as developed by Lee et al. [Appl. Phys. Lett. 97, 183111 (2010)]. Tip-sample impedance Z{sub a} was introduced and studied in the tunneling and non-tunneling regimes. At tunneling breakdown, the microwave current between probe and sample flows along two parallel channels characterized by impedances Z{sub p} and Z{sub t} that add up to form overall impedance Z{sub a}. Quantity Z{sub p} is the capacitive impedance determined by the near field of the probe and Z{sub t} is the impedance of the tunnel junction. By taking into account the distance dependences of effective tip radius r{sub 0}(z) and tunnel resistance R{sub t}(z)?=?Re[Z{sub t}(z)], we were able to explain the experimentally observed dependences of resonance frequency f{sub r}(z) and quality factor Q{sub L}(z) of the microscope. The obtained microwave resistance R{sub t}(z) and direct current tunnel resistance R{sub t}{sup dc}(z) exhibit qualitatively similar behavior, although being largely different in both magnitude and the characteristic scale of height dependence. Interpretation of the microwave images of the atomic structure of test samples proved possible by taking into account the inductive component of tunnel impedance ImZ{sub t}?=??L{sub t}. Relation ?L{sub t}/R{sub t}???0.235 was obtained.

  13. The fluid dynamics of a miniature dilution tunnel for internal-combustion engine aerosol measurement

    SciTech Connect (OSTI)

    Kommer, Eric M.; Puzinauskas, Paulius V.; Buckley, Steven G.

    2007-11-15

    This paper investigates the fluid dynamics of a particular mini-dilution tunnel using LDV, flow visualization, a tracer sample technique and CFD. The mini-dilution tunnel studied had a 3.175 mm inside diameter tube discharging on the centerline of the tunnel where the diameter increases in a single step to 7.62 cm. The large diameter portion of the tunnel was 75 cm long. Most of the testing was performed at a flow rate of 15 l/min. The experimental investigation indicates that the flow field in the particular dilution tunnel tested has a persistent jet throughout its length, and this confined jet creates eddy recirculation zones which may cause the temperature and dilution histories of particles trapped in these eddies to be significantly different than particles which remain in the jet until extracted by the sample probe. Similarly, the location of the sample probe could also affect measured size distribution profiles, particularly if it were moved in or out of the path of the persistent jet. In addition to the simple tunnel geometry with a single abrupt expansion, a conical diffuser and a perforated plate were separately tested to investigate their effects on the tunnel fluid dynamics. The particular diffuser tested appeared to cause the jet to stall and therefore led to an even more unpredictable path for the fluid within. Limited testing with the perforated plate indicated that it increased the jet deceleration and laminarization, and therefore could lead to a more predictable flow path for aerosol sampled from the tunnel. (author)

  14. Can p-channel tunnel field-effect transistors perform as good as n-channel?

    SciTech Connect (OSTI)

    Verhulst, A. S. Pourghaderi, M. A.; Collaert, N.; Thean, A. V.-Y.; Verreck, D.; Van de Put, M.; Groeseneken, G.; Sorée, B.

    2014-07-28

    We show that bulk semiconductor materials do not allow perfectly complementary p- and n-channel tunnel field-effect transistors (TFETs), due to the presence of a heavy-hole band. When tunneling in p-TFETs is oriented towards the gate-dielectric, field-induced quantum confinement results in a highest-energy subband which is heavy-hole like. In direct-bandgap IIIV materials, the most promising TFET materials, phonon-assisted tunneling to this subband degrades the subthreshold swing and leads to at least 10× smaller on-current than the desired ballistic on-current. This is demonstrated with quantum-mechanical predictions for p-TFETs with tunneling orthogonal to the gate, made out of InP, In{sub 0.53}Ga{sub 0.47}As, InAs, and a modified version of In{sub 0.53}Ga{sub 0.47}As with an artificially increased conduction-band density-of-states. We further show that even if the phonon-assisted current would be negligible, the build-up of a heavy-hole-based inversion layer prevents efficient ballistic tunneling, especially at low supply voltages. For p-TFET, a strongly confined n-i-p or n-p-i-p configuration is therefore recommended, as well as a tensily strained line-tunneling configuration.

  15. A Typed Operational Semantics for Type Theory 

    E-Print Network [OSTI]

    Goguen, Healfdene

    Untyped reduction provides a natural operational semantics for type theory. Normalization results say that such a semantics is sound. However, this reduction does not take type information into account and gives no information ...

  16. Selective p-i-n photodetector with resonant tunneling

    SciTech Connect (OSTI)

    Mil'shtein, S.; Wilson, S.; Pillai, A.

    2014-05-15

    There are different fundamental approaches to designing selective photodetectors, where the selectivity of optical spectra is produced by a filtering aperture. However, manufacturing of multilayered filters is cumbersome for epitaxial technology. In the current study, we offer a novel approach in design of selective photodetectors. A p-i-n photodetector with superlattices in top n-layer becomes transparent for photons where h?<>E{sub ng}+E{sub n1}, the light will be absorbed, simultaneously producing high energy (hot) electrons. The designed thickness of the structure does prevent thermal relaxation of high energy electrons by thus enhancing the selectivity of the photodetector. However the most important selectivity element is the resonant tunneling which does happen only for electrons occupying E{sub n1} energy levels as they transfer to levels E{sub i1}aligned under reverse biasing.

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

    SciTech Connect (OSTI)

    Sobolik, Steven Ronald; Bartel, Lewis Clark

    2010-11-01

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

  18. Assessment of tunnel ground conditions for a two-year stand-by period, January 1994. UTAP report

    SciTech Connect (OSTI)

    1994-01-28

    This report summarizes observations, assessment of ground conditions, and recommendations pertaining to the Collider main ring tunnel at the Superconducting Super Collider (SSC).

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

    SciTech Connect (OSTI)

    Paquette, B.; DeVita, M.; Turala, A.; Kolhatkar, G.; Boucherif, A.; Jaouad, A.; Aimez, V.; Arès, R.; Wilkins, M.; Wheeldon, J. F.; Walker, A. W.; Hinzer, K.; Fafard, S.

    2013-09-27

    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.

  20. Increased efficiency in multijunction solar cells through the incorporation of semimetallic ErAs nanoparticles into the tunnel junction

    SciTech Connect (OSTI)

    Zide, J.M.O.; Kleiman-Shwarsctein, A.; Strandwitz, N.C.; Zimmerman, J.D.; Steenblock-Smith, T.; Gossard, A.C.; Forman, A.; Ivanovskaya, A.; Stucky, G.D.

    2006-04-17

    We report the molecular beam epitaxy growth of Al{sub 0.3}Ga{sub 0.7}As/GaAs multijunction solar cells with epitaxial, semimetallic ErAs nanoparticles at the interface of the tunnel junction. The states provided by these nanoparticles reduce the bias required to pass current through the tunnel junction by three orders of magnitude, and therefore drastically reduce the voltage losses in the tunnel junction. We have measured open-circuit voltages which are 97% of the sum of the constituent cells, which result in nearly double the efficiency of our multijunction cell with a conventional tunnel junction.

  1. Types of Commissioning

    Broader source: Energy.gov [DOE]

    Several commissioning types exist to address the specific needs of equipment and systems across both new and existing buildings. The following commissioning types provide a good overview.

  2. Postdoc Appointment Types

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

    Appointment Types Postdoc Appointment Types Most postdocs will be offered a postdoctoral research associate appointment. Each year, approximately 30 Postdoctoral Fellow...

  3. Tunneling time in attosecond experiments and time-energy uncertainty relation

    E-Print Network [OSTI]

    Ossama Kullie

    2015-07-24

    In this work we present a theoretical model supported with a physical reasoning leading to a relation which performs an excellent estimation for the tunneling time in attosecond and strong field experiments, where we address the important case of the He-atom \\cite{Eckle:2008s,Eckle:2008}. Our tunneling time estimation is found by utilizing the time-energy uncertainty relation and represents a quantum clock. The tunneling time is also featured as the time of passage (at the exit of the tunnel) similarly to the Einstein's {\\it photon box Gedanken experiment}. Our work tackles an important study case for the theory of time in quantum mechanics and is very promising for the search for a (general) time operator in quantum mechanics. The work can be seen as a new fundamental step in dealing with the tunneling time in strong field and ultra-fast science, and is appealing for more elaborate treatments using quantum wave packet dynamics and especially for complex atoms and molecules.

  4. Types of Lights Types of Lights

    E-Print Network [OSTI]

    1 Types of Lights Types of Lights q So far we have studied point lights ­ Radiate in all direc7ons q Other lights ­ Direc7onal lights (posi7on-independent) ­ Spotlights #12;2 Direc1onal Lights q Shine in a single, uniform direc7on q All rays

  5. Large-scale fabrication of BN tunnel barriers for graphene spintronics

    SciTech Connect (OSTI)

    Fu, Wangyang; Makk, Péter; Maurand, Romain; Bräuninger, Matthias; Schönenberger, Christian

    2014-08-21

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

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

    SciTech Connect (OSTI)

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

    2014-04-21

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

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

    DOE Patents [OSTI]

    Forrest, Stephen R. (Ann Arbor, MI)

    2008-08-19

    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.

  8. Dark Matter Hawking Radiation? Dark Spinors Tunnelling in String Theory Black Holes

    E-Print Network [OSTI]

    Cavalcanti, R T

    2015-01-01

    The Hawking radiation spectrum of Kerr-Sen axion-dilaton black holes is derived, in the context of dark spinors tunnelling across the horizon. Since a black hole has a well defined temperature, it should radiate in principle all the standard model particles, similar to a black body at that temperature. We investigate the tunnelling of mass dimension one spin-1/2 dark fermions, that are beyond the standard model and are prime candidates to the dark matter. Their interactions with the standard model matter and gauge fields are suppressed by at least one power of unification scale, being restricted just to the Higgs field and to the graviton likewise. The tunnelling method for the emission and absorption of mass dimension one particles across the event horizon of Kerr-Sen axion-dilaton black holes is shown here to provide further evidence for the universality of black hole radiation, further encompassing particles beyond the standard model.

  9. Dark Matter Hawking Radiation? Dark Spinors Tunnelling in String Theory Black Holes

    E-Print Network [OSTI]

    R. T. Cavalcanti; Roldao da Rocha

    2015-07-14

    The Hawking radiation spectrum of Kerr-Sen axion-dilaton black holes is derived, in the context of dark spinors tunnelling across the horizon. Since a black hole has a well defined temperature, it should radiate in principle all the standard model particles, similar to a black body at that temperature. We investigate the tunnelling of mass dimension one spin-1/2 dark fermions, that are beyond the standard model and are prime candidates to the dark matter. Their interactions with the standard model matter and gauge fields are suppressed by at least one power of unification scale, being restricted just to the Higgs field and to the graviton likewise. The tunnelling method for the emission and absorption of mass dimension one particles across the event horizon of Kerr-Sen axion-dilaton black holes is shown here to provide further evidence for the universality of black hole radiation, further encompassing particles beyond the standard model.

  10. Multiferroic tunnel junctions and ferroelectric control of magnetic state at interface (invited)

    SciTech Connect (OSTI)

    Yin, Y. W.; Raju, M.; Li, Qi; Hu, W. J.; Burton, J. D.; Gruverman, A.; Tsymbal, E. Y.; Kim, Y.-M.; Borisevich, A. Y.; Pennycook, S. J.; Yang, S. M.; Noh, T. W.; Li, X. G.; Zhang, Z. D.

    2015-05-07

    As semiconductor devices reach ever smaller dimensions, the challenge of power dissipation and quantum effect place a serious limit on the future device scaling. Recently, a multiferroic tunnel junction (MFTJ) with a ferroelectric barrier sandwiched between two ferromagnetic electrodes has drawn enormous interest due to its potential applications not only in multi-level data storage but also in electric field controlled spintronics and nanoferronics. Here, we present our investigations on four-level resistance states, giant tunneling electroresistance (TER) due to interfacial magnetoelectric coupling, and ferroelectric control of spin polarized tunneling in MFTJs. Coexistence of large tunneling magnetoresistance and TER has been observed in manganite/(Ba, Sr)TiO{sub 3}/manganite MFTJs at low temperatures and room temperature four-resistance state devices were also obtained. To enhance the TER for potential logic operation with a magnetic memory, La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/BaTiO{sub 3}/La{sub 0.5}Ca{sub 0.5}MnO{sub 3} /La{sub 0.7}Sr{sub 0.3}MnO{sub 3} MFTJs were designed by utilizing a bilayer tunneling barrier in which BaTiO{sub 3} is ferroelectric and La{sub 0.5}Ca{sub 0.5}MnO{sub 3} is close to ferromagnetic metal to antiferromagnetic insulator phase transition. The phase transition occurs when the ferroelectric polarization is reversed, resulting in an increase of TER by two orders of magnitude. Tunneling magnetoresistance can also be controlled by the ferroelectric polarization reversal, indicating strong magnetoelectric coupling at the interface.

  11. International Journal of Rock Mechanics & Mining Sciences 45 (2008) 11951210 Consolidation settlements above deep tunnels in fractured crystalline

    E-Print Network [OSTI]

    Eberhardt, Erik

    2008-01-01

    settlements above deep tunnels in fractured crystalline rock: Part 1--Investigations above the Gotthard highway tunnel C. Zangerla,b,Ã, K.F. Evansa , E. Eberhardta,c , S. Loewa a Engineering Geology, Swiss Management, Grabenweg 3, A-6020 Innsbruck, Austria c Geological Engineering/Earth and Ocean Sciences

  12. International Journal of Rock Mechanics & Mining Sciences 45 (2008) 12111225 Consolidation settlements above deep tunnels in fractured

    E-Print Network [OSTI]

    Eberhardt, Erik

    2008-01-01

    settlements above deep tunnels in fractured crystalline rock: Part 2--Numerical analysis of the Gotthard highway tunnel case study C. Zangerla,b,Ã, E. Eberhardta,c , K.F. Evansa , S. Loewa a Engineering Geology Hazard Management, Innsbruck, Austria c Geological Engineering/Earth and Ocean Sciences, University

  13. Mechanisms of Molecular Manipulation with the Scanning Tunneling Microscope at Room Temperature: Chlorobenzene=Si111-7 7

    E-Print Network [OSTI]

    Persson, Mats

    of negative (or positive) ion resonances of the chemisorbed molecule by the tunneling electrons (or holes- scale structures which can be employed to trap electrons in ``textbook'' quantum boxes [2Mechanisms of Molecular Manipulation with the Scanning Tunneling Microscope at Room Temperature

  14. Non-Hermitian scattering theory: Resonant tunneling probability amplitude in a quantum dot Hadas Barkay, Edvardas Narevicius, and Nimrod Moiseyev*

    E-Print Network [OSTI]

    Narevicius, Edvardas

    properties of quantum dots, phenomena such as tunneling of electrons must be characterized. Phase, in a manner that enabled them to control the potential of the electrons trapped in it by varying the plungerNon-Hermitian scattering theory: Resonant tunneling probability amplitude in a quantum dot Hadas

  15. IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 45, NO. 6, JUNE 1998 1361 Degradation of Thin Tunnel Gate Oxide

    E-Print Network [OSTI]

    Schroder, Dieter K.

    IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 45, NO. 6, JUNE 1998 1361 Degradation of Thin Tunnel. Schroder, Fellow, IEEE Abstract-- The degradation of thin tunnel gate oxide under constant Fowler charge trapping is usually dominant at low QQQinjinjinj followed by negative charge trapping at high

  16. PHYSICAL REVIEW B VOLUME 43, NUMBER 6 15 FEBRUARY 1991-II Nonlinear feedback oscillations in resonant tunneling through double barriers

    E-Print Network [OSTI]

    Presilla, Carlo

    ) We analyze the dynamical evolution of the resonant tunneling of an ensemble of electrons through the dynamics of RT of ballistic electrons in the presence of the potential created by the charge trapped within in resonant tunneling through double barriers C. Presilla Scuola del Dottorato di Ricerca in Fisica dell

  17. A Novel Si-Tunnel FET based SRAM Design for Ultra Low-Power 0.3V VDD Applications

    E-Print Network [OSTI]

    Yener, Aylin

    A Novel Si-Tunnel FET based SRAM Design for Ultra Low-Power 0.3V VDD Applications J. Singh, K-Band Tunnel Field Effect Transistors (TFETs) in SRAMs at ultra low supply voltages. The uni design using Si- TFETs for reliable operation with low leakage at ultra low voltages. We also demonstrate

  18. On the Selection of Optimal Diverse AS-Paths for Inter-Domain IP/(G)MPLS Tunnel Provisioning

    E-Print Network [OSTI]

    Rougier, Jean-Louis

    On the Selection of Optimal Diverse AS-Paths for Inter-Domain IP/(G)MPLS Tunnel Provisioning of diverse AS paths can be computed, in order to proactively increase the success rate of tunnel set these services beyond domain boundaries, particularly for critical inter-AS VPNs, TV transport or voice gateways

  19. Far-infrared laser vibration-rotation-tunneling spectroscopy of the propane-water compkx: Torsional dynamics of the hydrogen

    E-Print Network [OSTI]

    Elrod, Matthew J.

    Far-infrared laser vibration-rotation-tunneling spectroscopy of the propane-water compkx: Torsional 1993) The far-infrared laservibration-rotation-tunneling (FIR-VRT) spectrumof the propane-water complex calculations. In the present paper and in its counterpart,13we present our results for the water-propane

  20. Theory of Graphene-Insulator-Graphene Tunnel Junctions S. C. de la Barrera, Qin Gao, and R. M. Feenstra

    E-Print Network [OSTI]

    Feenstra, Randall

    to vertical graphene-insulator-graphene (GIG) tunneling structures. The first such report dealt with coupled electrodes, the single-particle tunneling characteristics of GIG devices can be highly nonlinear.3 The reason by Britnell et al. from GIG junctions did not display any NDR.4 Indeed, their theoretical description

  1. Instructions for MicroCFD 2D Virtual Wind Tunnel Version 1.9 Professional Edition 2015 MicroCFD

    E-Print Network [OSTI]

    Rohde, Axel

    , and the one-to-one mapping between flow cell and pixel will be lost. 4. A 96 DPI setting should only be used is loaded. 2. Set Tunnel Length, flow parameters, gas properties, simulation Time Step and Stop Time, or use the preset values. The Tunnel Length should be about four to five times the Model Length for slender shapes

  2. Instructions for MicroCFD 2D Virtual Wind Tunnel Version 1.9 Educational Edition 2015 MicroCFD

    E-Print Network [OSTI]

    Rohde, Axel

    -to-one mapping between flow cell and pixel will be lost. 4. A 96 DPI setting should only be used if the maximum is loaded. 2. Set Tunnel Length, flow parameters, gas properties, simulation Time Step and Stop Time, or use the preset values. The Tunnel Length should be about four to five times the Model Length for slender shapes

  3. A WIND TUNNEL INVESTIGATION OF THE INFLUENCE OF SOLAR-INDUCED WALL-HEATING ON THE FLOW REGIME

    E-Print Network [OSTI]

    Savory, Eric

    -section canyon model in a wind tunnel. For reference purposes, the neutral case (no wall heating), has also been viscosity of air (m2 s-1 ) 1. Introduction The wind flow field within urban areas has been studiedA WIND TUNNEL INVESTIGATION OF THE INFLUENCE OF SOLAR-INDUCED WALL-HEATING ON THE FLOW REGIME

  4. Negative differential resistance in GaN tunneling hot electron transistors

    SciTech Connect (OSTI)

    Yang, Zhichao; Nath, Digbijoy; Rajan, Siddharth

    2014-11-17

    Room temperature negative differential resistance is demonstrated in a unipolar GaN-based tunneling hot electron transistor. Such a device employs tunnel-injected electrons to vary the electron energy and change the fraction of reflected electrons, and shows repeatable negative differential resistance with a peak to valley current ratio of 7.2. The device was stable when biased in the negative resistance regime and tunable by changing collector bias. Good repeatability and double-sweep characteristics at room temperature show the potential of such device for high frequency oscillators based on quasi-ballistic transport.

  5. Note: Long-range scanning tunneling microscope for the study of nanostructures on insulating substrates

    SciTech Connect (OSTI)

    Molina-Mendoza, Aday J.; Rodrigo, José G.; Rubio-Bollinger, Gabino; Island, Joshua; Burzuri, Enrique; Zant, Herre S. J. van der; Agraït, Nicolás; Condensed Matter Physics Center and Instituto Universitario de Ciencia de Materiales “Nicolás Cabrera,” Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid; Instituto Madrileño de Estudios Avanzados en Nanociencia IMDEA-Nanociencia, E-28049 Madrid

    2014-02-15

    The scanning tunneling microscope (STM) is a powerful tool for studying the electronic properties at the atomic level, however, it is of relatively small scanning range and the fact that it can only operate on conducting samples prevents its application to study heterogeneous samples consisting of conducting and insulating regions. Here we present a long-range scanning tunneling microscope capable of detecting conducting micro and nanostructures on insulating substrates using a technique based on the capacitance between the tip and the sample and performing STM studies.

  6. Multi-electron dynamics in the tunnel ionization of correlated quantum systems

    E-Print Network [OSTI]

    Hollstein, Maximilian

    2015-01-01

    The importance of multi-electron dynamics during the tunnel ionization of a correlated quantum system is investigated. By comparison of the solution of the time-dependent Schr\\"odinger equation (TDSE) with the time-dependent configuration interaction singles approach (TDCIS), we demonstrate the importance of a multi-electron description of the tunnel ionization process especially for weakly confined quantum systems. Within this context, we observe that adiabatic driving by an intense light field can even enhance the correlations between still trapped electrons.

  7. Applications of the Tunneling Method to Particle Decay and Radiation from Naked Singularities

    E-Print Network [OSTI]

    Roberto Di Criscienzo; Luciano Vanzo; Sergio Zerbini

    2010-01-26

    Following recent literature on dS instability in presence of interactions, we study the decay of massive particles in general FRW models and the emission from naked singularities either associated with 4D charged black holes or with 2D shock waves, by means of the Hamilton--Jacobi tunneling method. It is shown that the two-dimensional semi-classical tunneling amplitude from a naked singularity computed in that way is the same as the one-loop result of quantum field theory.

  8. Reduced low frequency noise in electron beam evaporated MgO magnetic tunnel junctions

    SciTech Connect (OSTI)

    Diao, Z.; Feng, J. F.; Kurt, H.; Feng, G.; Coey, J. M. D. [CRANN and School of Physics, Trinity College, Dublin 2 (Ireland)

    2010-05-17

    We compare low frequency noise in magnetic tunnel junctions with MgO barriers prepared by electron-beam evaporation with those prepared by radiofrequency sputtering, both showing a high tunneling magnetoresistance. The normalized noise parameter in the parallel state of junctions with evaporated barriers is at least one order of magnitude lower than that in junctions with sputtered barriers, and exhibits a weaker bias dependence. The lowest normalized noise is in the 10{sup -11} mum{sup 2} range. A lower density of oxygen vacancies acting as charge trap states in the evaporated MgO is responsible for the lower noise.

  9. Quantum heat engine based on photon-assisted Cooper pair tunneling

    E-Print Network [OSTI]

    Patrick P. Hofer; J. -R. Souquet; Aashish A. Clerk

    2015-12-07

    We propose and analyze a simple mesoscopic quantum heat engine that exhibits both high-power and high-efficiency. The system consists of a biased Josephson junction coupled to two microwave cavities, with each cavity coupled to a thermal bath. Resonant Cooper pair tunnelling occurs with the exchange of photons between cavities, and a temperature difference between the baths can naturally lead to a current against the voltage, and hence work. As a consequence of the unique properties of Cooper-pair tunneling, the heat current is completely separated from the charge current. This combined with the strong energy-selectivity of the process leads to an extremely high efficiency.

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

    SciTech Connect (OSTI)

    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)

    2014-03-24

    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.

  11. A micrometer-size movable light emitting area in a resonant tunneling light emitting diode

    SciTech Connect (OSTI)

    Pettinari, G., E-mail: giorgio.pettinari@cnr.it [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); National Research Council (CNR), Institute for Photonics and Nanotechnologies (IFN-CNR), Via Cineto Romano 42, 00156 Roma (Italy); Balakrishnan, N.; Makarovsky, O.; Campion, R. P.; Patanè, A. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)] [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Polimeni, A.; Capizzi, M. [CNISM-Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185 Roma (Italy)] [CNISM-Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185 Roma (Italy)

    2013-12-09

    We report on the fabrication of a micrometer-size movable light emitting area in a GaAs/AlAs quantum well resonant tunneling p-i-n diode. The spatial position of the micrometer-size light emitting area shifts linearly with increasing applied bias, up to 30??m for a bias increment of 0.2?V. Also, the simultaneous resonant tunneling injection of both electrons and holes into the quantum well states is achieved at specific positions of the diode, thus resulting in a tenfold increase of the electroluminescence intensity.

  12. Using tevatron magnets for HE-LHC or new ring in LHC tunnel

    SciTech Connect (OSTI)

    Piekarz, Henryk; /Fermilab

    2011-08-01

    Two injector accelerator options for HE-LHC of p{sup +} - p{sup +} collisions at 33 TeV cms energy are briefly outlined. One option is based on the Super-SPS (S-SPS) accelerator in the SPS tunnel, and the other one is based on the LER (Low-Energy-Ring) accelerator in the LHC tunnel. Expectations of performance of the main arc accelerator magnets considered for the construction of the S-SPS and of the LER accelerators are used to tentatively devise some selected properties of these accelerators as potential injectors to HE-LHC.

  13. Estimation of potential radiation damage to electronics units in the CLIC tunnel

    E-Print Network [OSTI]

    Patapenka, Andrei

    2014-01-01

    An electronic unit is required for each CLIC “Two Beam Module”. This study aims to estimate the potential damage due to the prompt radiation to the electronics units installed inside the CLIC Main Linac tunnel. Sets of Monte-Carlo simulations have been done to estimate damage to electronics installed at various locations inside the tunnel. Continuous and point beam losses have been considered for CLIC Main and Drive beams. Lead and iron in combination with a polyethylene layer were investigated as a possible shielding. The upper limits of the estimated quantities are presented for stand alone and shielded electronics.

  14. Tunneling of Vector Particles from Lorentzian Wormholes in 3+1 Dimensions

    E-Print Network [OSTI]

    Sakalli, I

    2015-01-01

    In this article, we consider the Hawking radiation (HR) of vector (massive spin-1) particles from the traversable Lorentzian wormholes (TLWH) in 3+1 dimensions. We start by providing the Proca equations for the TLWH. Using the Hamilton-Jacobi (HJ)ans\\"{a}tz with the WKB approximation in the quantum tunneling method, we obtain the probabilities of the emission/absorption modes. Then, we derive the tunneling rate of the emitted vector particles and manage to read the standard Hawking temperature of the TLWH. The result obtained represents a negative temperature, which is also discussed.

  15. Tunnelling of scalar and Dirac particles from squashed charged rotating Kaluza-Klein black holes

    E-Print Network [OSTI]

    M. M. Stetsko

    2014-10-08

    Thermal radiation of scalar particles and Dirac fermions from squashed charged rotating five-dimensional black holes is considered. To obtain temperature of the black holes we use the tunnelling method. In case of scalar particles we make use of the Hamilton-Jacobi equation. To consider tunnelling of fermions the Dirac equation was investigated. The examination shows that radial parts of the action for scalar particles and fermions in quasi-classical limit in the vicinity of horizon are almost the same and as a consequence it gives rise to the identical expressions for the temperature in both cases.

  16. Tunneling of Vector Particles from Lorentzian Wormholes in 3+1 Dimensions

    E-Print Network [OSTI]

    I. Sakalli; A. Ovgun

    2015-05-08

    In this article, we consider the Hawking radiation (HR) of vector (massive spin-1) particles from the traversable Lorentzian wormholes (TLWH) in 3+1 dimensions. We start by providing the Proca equations for the TLWH. Using the Hamilton-Jacobi (HJ)ans\\"{a}tz with the WKB approximation in the quantum tunneling method, we obtain the probabilities of the emission/absorption modes. Then, we derive the tunneling rate of the emitted vector particles and manage to read the standard Hawking temperature of the TLWH. The result obtained represents a negative temperature, which is also discussed.

  17. Novel Contrast Mechanism in Cross-Sectional Scanning Tunneling Microscopy of GaSb/GaAs Type-II Nanostructures

    E-Print Network [OSTI]

    Feenstra, Randall

    very interesting both for fundamental physics23 and applications as e.g. charge storage devices24-II Nanostructures R. Timm,1, R. M. Feenstra,2 H. Eisele,1 A. Lenz,1 L. Ivanova,1 E. Lenz,3 and M. D¨ahne1 1, sharply defined contrast of the nanostructure at negative sample bias, but a smoothly broadened contrast

  18. Effects of boron composition on tunneling magnetoresistance ratio and microstructure of CoFeB/MgO/CoFeB pseudo-spin-valve magnetic tunnel junctions

    SciTech Connect (OSTI)

    Kodzuka, M.; Ohkubo, T.; Hono, K.; Ikeda, S.; Ohno, H.; Gan, H. D.

    2012-02-15

    The effect of B concentration on the tunneling magnetoresistance (TMR) of (Co{sub 25}Fe{sub 75}){sub 100-x}B{sub x}/MgO/(Co{sub 25}Fe{sub 75}){sub 100-x}B{sub x} (x = 22 and 33) pseudo-spin-valve (P-SV) magnetic tunnel junctions (MTJs) was investigated. The TMR ratios for optimally annealed MTJs with x = 22 and 33 were 340% and 170%, respectively, at room temperature. High resolution transmission electron microscopy (HRTEM) observation showed a weaker (001) texture in the MgO barrier in the MTJ with x = 33. The bottom electrode was not fully crystallized even with a considerable amount of B in the (Co{sub 25}Fe{sub 75}){sub 67}B{sub 33}, while good epitaxy was observed between (001) textured MgO and (Co{sub 25}Fe{sub 75}){sub 78}B{sub 22} electrodes.

  19. 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]

    Zhao, Hongwei

    2005-08-29

    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 ...

  20. InGaAs tunnel diodes for the calibration of semi-classical and quantum mechanical band-to-band tunneling models

    SciTech Connect (OSTI)

    Smets, Quentin; Verreck, Devin; Vandervorst, Wilfried; Groeseneken, Guido; Heyns, Marc M. [Imec, Kapeldreef 75, 3001 Heverlee (Belgium); KULeuven, 3001 Leuven (Belgium); Verhulst, Anne S.; Rooyackers, Rita; Merckling, Clément; Simoen, Eddy; Collaert, Nadine; Thean, Voon Y. [Imec, Kapeldreef 75, 3001 Heverlee (Belgium); Van De Put, Maarten; Sorée, Bart [Imec, Kapeldreef 75, 3001 Heverlee (Belgium); Universiteit Antwerpen, 2020 Antwerpen (Belgium)

    2014-05-14

    Promising predictions are made for III-V tunnel-field-effect transistor (FET), but there is still uncertainty on the parameters used in the band-to-band tunneling models. Therefore, two simulators are calibrated in this paper; the first one uses a semi-classical tunneling model based on Kane's formalism, and the second one is a quantum mechanical simulator implemented with an envelope function formalism. The calibration is done for In{sub 0.53}Ga{sub 0.47}As using several p+/intrinsic/n+ diodes with different intrinsic region thicknesses. The dopant profile is determined by SIMS and capacitance-voltage measurements. Error bars are used based on statistical and systematic uncertainties in the measurement techniques. The obtained parameters are in close agreement with theoretically predicted values and validate the semi-classical and quantum mechanical models. Finally, the models are applied to predict the input characteristics of In{sub 0.53}Ga{sub 0.47}As n- and p-lineTFET, with the n-lineTFET showing competitive performance compared to MOSFET.

  1. Types of Reuse

    Broader source: Energy.gov [DOE]

    The following provides greater detail regarding the types of reuse pursued for LM sites. It should be noted that many actual reuses combine several types of the uses listed below.

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

    E-Print Network [OSTI]

    Russell, Kasey

    of the optical gap and Burstein-Moss shift in CdO thin films: A consequence of extended misuse of 2-versusNarrow band defect luminescence from Al-doped ZnO probed by scanning tunneling cathodoluminescence-like opto-electronic properties Appl. Phys. Lett. 99, 141917 (2011) Oxygen enhanced ferromagnetism in Cr-doped

  3. Shot noise in tunneling through a quantum dot array G. Kiesslich*; 1

    E-Print Network [OSTI]

    Hohls, Frank

    Shot noise in tunneling through a quantum dot array G. Kiesslich*; 1 , A. Wacker1 , E. Schæll1 , A 2003 PACS 72.70.+m, 73.40.Gk, 73.63.Kv The shot noise suppression in a sample containing a layer be qualitatively reproduced by an analy- tical expression. 1 Introduction Shot noise measurements provide

  4. Semi-epitaxial magnetic tunnel transistor: Effect of electron energy and temperature

    E-Print Network [OSTI]

    Bayreuther, Günther

    ; published online 6 May 2005 A magnetic tunnel transistor with spin-valve metallic base and epitaxial collector leakage. © 2005 American Institute of Physics. DOI: 10.1063/1.1853892 I. INTRODUCTION The hot-electron spin-valve transistor was introduced by Monsma et al. in 1995.1 Since then, interest in hot

  5. Exciplex funnel resonances in chemical reaction dynamics: The nonadiabatic tunneling case associated with an avoided

    E-Print Network [OSTI]

    Truhlar, Donald G

    Exciplex funnel resonances in chemical reaction dynamics: The nonadiabatic tunneling case mechanical calculations on a one-dimensional model of a chemical reaction with an electronically excited diabat and metastable trapping (resonances). Particular emphasis is placed on the eect of the funnel

  6. Decay of the Cosmological Constant. Equivalence of Quantum Tunneling and Thermal Activation in Two Spacetime Dimensions

    E-Print Network [OSTI]

    Andres Gomberoff; Marc Henneaux; Claudio Teitelboim

    2005-01-19

    We study the decay of the cosmological constant in two spacetime dimensions through production of pairs. We show that the same nucleation process looks as quantum mechanical tunneling (instanton) to one Killing observer and as thermal activation (thermalon) to another. Thus, we find another striking example of the deep interplay between gravity, thermodynamics and quantum mechanics which becomes apparent in presence of horizons.

  7. Spontaneous emission from a two--level atom tunneling in a double--well potential

    E-Print Network [OSTI]

    Daniel Braun; John Martin

    2007-10-26

    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.

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

    E-Print Network [OSTI]

    Webb, Lauren J.

    propargylglycine unnatural functional groups 20 Å apart and an alkanethiol self-assembled monolayer (SAM) on a gold-terminated surfaces in which a structured -helical peptide is chemically bonded to an alkanethiol self-assembledMolecularly Resolved Images of Peptide-Functionalized Gold Surfaces by Scanning Tunneling

  9. Axisymmetric, High-, Steady-State Plasma Torus: A "Wind-Tunnel" to Develop Whole Device Models

    E-Print Network [OSTI]

    Mauel, Michael E.

    Axisymmetric, High-, Steady-State Plasma Torus: A "Wind-Tunnel" to Develop Whole Device Models Mike College, Hanover, NH White Paper for the 2015 DOE Integrated Simulations Workshop (Topics: C, D) Motivation The development of experimentally-validated whole device models is a grand challenge of fusion

  10. Improving Tor using a TCP-over-DTLS Tunnel Joel Reardon

    E-Print Network [OSTI]

    Goldberg, Ian

    Improving Tor using a TCP-over-DTLS Tunnel Joel Reardon Google Switzerland GmbH Brandschenkestrasse. Waterloo, ON, Canada iang@cs.uwaterloo.ca Abstract The Tor network gives anonymity to Internet users by re. This interference greatly contributes to Tor's notorious latency problems. Our solution is to use a TCP

  11. Mechanically-Induced Resistive Switching in Ferroelectric Tunnel C.-W. Bark,

    E-Print Network [OSTI]

    Eom, Chang Beom

    ferroelectricsmaterials with a stable polarization that can be switched by an external electric fieldhave generated considerable interest due to rich physics associated with their fundamental properties and high potential of ferroelectric tunnel junctions (FTJ). Conventionally, the application of an electric field above the coercive

  12. The benzene molecule as a molecular resonant-tunneling transistor M. Di Ventraa)

    E-Print Network [OSTI]

    Pantelides, Sokrates T.

    The benzene molecule as a molecular resonant-tunneling transistor M. Di Ventraa) and S. T of transport through a benzene-1, 4-dithiolate molecule with a third capacitive terminal gate . We find rectification was demonstrated in 1993.2 More recently, Reed et al. investigated the benzene-1, 4-dithiol rings

  13. Modelling a Car Safety Controller in Road Tunnels using Hybrid Petri Nets A. Bobbio[1

    E-Print Network [OSTI]

    Horváth, András

    Modelling a Car Safety Controller in Road Tunnels using Hybrid Petri Nets A. Bobbio[1] , M this specific issue and proposes a hybrid modeling approach based on fluid Petri nets (FPN). An FPN is used that FPN is a valid paradigm to model the dynamics of a car in a detailed way. 1 Introduction In the last

  14. PHYSICAL REVIEW B 84, 205316 (2011) Mechanically probing coherent tunneling in a double quantum dot

    E-Print Network [OSTI]

    Clerk, Aashish

    2011-01-01

    J. Gardner,1 S. D. Bennett,2 and A. A. Clerk1 1 Department of Physics, McGill University, Montr´eal the charge-transfer line. In this regime, the presence of coherent tunneling implies that the DQD energy

  15. Quantum corrected non-thermal radiation spectrum from the tunnelling mechanism

    E-Print Network [OSTI]

    Subenoy Chakraborty; Subhajit Saha; Christian Corda

    2015-05-28

    Tunnelling mechanism is today considered a popular and widely used method in describing Hawking radiation. However, in relation to black hole (BH) emission, this mechanism is mostly used to obtain the Hawking temperature by comparing the probability of emission of an outgoing particle with the Boltzmann factor. On the other hand, Banerjee and Majhi reformulated the tunnelling framework deriving a black body spectrum through the density matrix for the outgoing modes for both the Bose-Einstein distribution and the Fermi-Dirac distribution. In contrast, Parikh and Wilczek introduced a correction term performing an exact calculation of the action for a tunnelling spherically symmetric particle and, as a result, the probability of emission of an outgoing particle corresponds to a non-strictly thermal radiation spectrum. Recently, one of us (C. Corda) introduced a BH effective state and was able to obtain a non-strictly black body spectrum from the tunnelling mechanism corresponding to the probability of emission of an outgoing particle found by Parikh and Wilczek. The present work introduces the quantum corrected effective temperature and the corresponding quantum corrected effective metric is written using Hawking's periodicity arguments. Thus, we obtain further corrections to the non-strictly thermal BH radiation spectrum as the final distributions take into account both the BH dynamical geometry during the emission of the particle and the quantum corrections to the semiclassical Hawking temperature.

  16. Tunneling evidence of half-metallicity in epitaxial films of ferromagnetic perovskite manganites and ferrimagnetic magnetite

    E-Print Network [OSTI]

    Yeh, Nai-Chang

    Tunneling evidence of half-metallicity in epitaxial films of ferromagnetic perovskite manganites with the perovskite manganites are discussed. © 1998 American Institute of Physics. S0021-8979 98 45811-0 Half magnetoresistance CMR in the perovskite manganites, Ln1 xMxMnO3 Ln: trivalent rare earth ions, M divalent alkaline

  17. Charged fermion tunnelling from electrically and magnetically charged rotating black hole in de Sitter space

    E-Print Network [OSTI]

    M. M. Stetsko

    2013-06-10

    Thermal radiation of electrically charged fermions from rotating black hole with electric and magnetic charges in de Sitter space is considered. The tunnelling probabilities for outgoing and incoming particles are obtained and the Hawking temperature is calculated. The relation for the classical action for the particles in the black hole's background is also found.

  18. Realization of a four-step molecular switch in scanning tunneling microscope manipulation

    E-Print Network [OSTI]

    Hla, Saw-Wai

    world, plant molecules like chlorophyll-a are given special interest in the quest for green energy that all reversible switching mechanisms are initiated by a single tunneling-electron energy-a. Chlorophyll-a induces green color in plant leaves and is a key ingredient in photosynthesis, one of the most

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

    E-Print Network [OSTI]

    Feenstra, Randall

    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

  20. Wind tunnel testing of a generic telescope enclosure Tait S. Pottebaum*a

    E-Print Network [OSTI]

    MacMynowski, Douglas G. - MacMynowski, Douglas G.

    -buffeting, wind tunnel, DPIV 1. INTRODUCTION Various design studies are currently underway for the next generation that CFD can be used with confidence in future design work. Keywords: Extremely-Large-Telescopes, Wind with confidence in future design work. For an 80m diameter telescope dome in a 12m/s external wind (roughly the 85

  1. Surface-to-tunnel seismic tomography studies at Yucca Mountain, Nevada

    E-Print Network [OSTI]

    Korneev, Valeri A.

    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

  2. Dynamic Pressure Improvements to Closed-Circuit Wind Tunnels with Flow Quality Analysis 

    E-Print Network [OSTI]

    Herring, Alexander

    2015-03-31

    Experiment Station Low-Speed Wind Tunnel (LSWT) was limited through available power to a dynamic pressure of 120 psf. The addition of a higher power motor, construction of a new, smaller test section, diffuser liners to prevent flow separation, and increased...

  3. Cross-sectional scanning tunneling microscopy of mixed-anion semiconductor heterostructures

    E-Print Network [OSTI]

    Yu, Edward T.

    a detailed understanding of atomic- to nanometer-scale properties of semiconductor materials and devices of semiconductor materials and devices at the atomic to nanometer scale. Cross-sectional scanning tunneling and electronic properties in semiconductor epitaxial and device structures with spatial resolution at or near

  4. Tunneling control by high-frequency driving Ilya Vorobeichik and Nimrod Moiseyev

    E-Print Network [OSTI]

    Moiseyev, Nimrod

    Tunneling control by high-frequency driving Ilya Vorobeichik and Nimrod Moiseyev Department supports this hypothesis. However, in the limit of high-frequency driving, the Kramers-Henneberger KH os laser fields 1,2 . We show that high-frequency second-order perturbation theory based on the KH frame

  5. WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    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 vertical-axis wind turbines (VAWT) have attracted a great deal of attention, because of their potential

  6. Benchmark of aerodynamic cycling helmets using a refined wind tunnel test protocol for helmet drag research

    E-Print Network [OSTI]

    Sidelko, Stephanie

    2007-01-01

    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 ...

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

    E-Print Network [OSTI]

    Russell, Kasey

    Direct injection tunnel spectroscopy of a p-n junction Edward M. Likovich,1 Kasey J. Russell,1,a barrier, the collector current of a direct- injection device could be larger than that of a metal-base device by roughly P PBC 1-PQM -1 400. Parasitic effects in the direct-injection device may slightly

  8. Exploiting Metal Coating of Carbon Nanotubes for Scanning Tunneling Microscopy Probes Yuya MURATA1

    E-Print Network [OSTI]

    Hasegawa, Shuji

    Exploiting Metal Coating of Carbon Nanotubes for Scanning Tunneling Microscopy Probes Yuya MURATA1, 2005; published July 26, 2005) By exploiting the metal coating of carbon nanotube (CNT) tips for electrical nanoprobes. A CNT glued to a W tip was uniformly coated with a thin W layer 3­6 nm thick. Using

  9. Resonant spin tunneling in randomly oriented nanospheres of Mn12 acetate

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

    Lendínez, S.; Zarzuela, R.; Tejada, J.; Terban, M. W.; Billinge, S. J. L.; Espin, J.; Imaz, I.; Maspoch, D.; Chudnovsky, E. M.

    2015-01-06

    We report measurements and theoretical analysis of resonant spin tunneling in randomly oriented nanospheres of a molecular magnet. Amorphous nanospheres of Mn?? acetate have been fabricated and characterized by chemical, infrared, TEM, X-ray, and magnetic methods. Magnetic measurements have revealed sharp tunneling peaks in the field derivative of the magnetization that occur at the typical resonant field values for the Mn?? acetate crystal in the field parallel to the easy axis.Theoretical analysis is provided that explains these observations. We argue that resonant spin tunneling in a molecular magnet can be established in a powder sample, without the need for amore »single crystal and without aligning the easy magnetization axes of the molecules. This is confirmed by re-analyzing the old data on a powdered sample of non-oriented micron-size crystals of Mn?? acetate. In conclusion, our findings can greatly simplify the selection of candidates for quantum spin tunneling among newly synthesized molecular magnets.« less

  10. Measurement of the Equivalent Thermal Resistance of Rooftop Lawns in a Hot-Climate Wind Tunnel 

    E-Print Network [OSTI]

    Meng, Q.; Zhang, Y.; Zhang, L.

    2006-01-01

    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...

  11. Current Collapse in Tunneling Transport through Benzene M. H. Hettler,1

    E-Print Network [OSTI]

    Current Collapse in Tunneling Transport through Benzene M. H. Hettler,1 W. Wenzel,1 M. R. Wegewijs; published 20 February 2003) We investigate the electrical transport through a system of benzene coupled model for the electrons of the benzene is derived that includes general two-body interactions. After

  12. Simultaneous topographic and elemental chemical and magnetic contrast in scanning tunneling microscopy

    DOE Patents [OSTI]

    Rose, Volker; Preissner, Curt A; Hla, Saw-Wai; Wang, Kangkang; Rosenmann, Daniel

    2014-09-30

    A method and system for performing simultaneous topographic and elemental chemical and magnetic contrast analysis in a scanning, tunneling microscope. The method and system also includes nanofabricated coaxial multilayer tips with a nanoscale conducting apex and a programmable in-situ nanomanipulator to fabricate these tips and also to rotate tips controllably.

  13. Interface characterization of epitaxial Fe/MgO/Fe magnetic tunnel junctions

    SciTech Connect (OSTI)

    Wang, Shouguo; Ward, R. C. C.; Zhang, Xiaoguang; Kohn, A.; Ma, Q. L.; Zhang, J.; Liu, H. F.; Han, Prof. X. F.

    2012-01-01

    Following predictions by first-principles theory of huge tunnel magnetoresistance (TMR) effect in epitaxial Fe/MgO/Fe magnetic tunnel junctions (MTJs), measured magnetoresistance (MR) ratio about 200% at room temperature (RT) have been reported in MgO-based epitaxial MTJs. Recently, MR ratio of about 600% has been reported at RT in MgO-based amorphous MTJs with core structure of CoFeB/MgO/CoFeB grown by magnetron sputtering with amorphous CoFeB layers. The sputtered CoFeB/MgO/CoFeB MTJs shows a great potential application in spintronic devices. Although epitaxial structure will probably not be used in devices, it remains an excellent model system to compare theoretical calculations with experimental results and to enhance our understanding of the spin dependent tunneling. Both theoretical calculations and experimental results clearly indicate that the interfacial structure plays a crucial role on coherent tunneling across single crystalMgO barrier, especially in epitaxial MgO-based MTJs grown by molecular beam epitaxy (MBE). Surface X-ray diffraction, Auger electron spectroscopy, X-ray absorption spectra, and X-ray magnetic circular dichroism have been used for interface characterization. However, no consistent viewpoint has been reached, and this is still an open issue. In this article, recent studies on the interface characterization in MgO-based epitaxial MTJs will be introduced, with a focus on research by X-ray photoelectron spectroscopy, high resolution transmission electron microscopy, and spin dependent tunneling spectroscopy.

  14. Integrating atomic layer deposition and ultra-high vacuum physical vapor deposition for in situ fabrication of tunnel junctions

    SciTech Connect (OSTI)

    Elliot, Alan J., E-mail: alane@ku.edu, E-mail: jwu@ku.edu; Malek, Gary A.; Lu, Rongtao; Han, Siyuan; Wu, Judy Z., E-mail: alane@ku.edu, E-mail: jwu@ku.edu [Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045 (United States); Yu, Haifeng; Zhao, Shiping [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-07-15

    Atomic Layer Deposition (ALD) is a promising technique for growing ultrathin, pristine dielectrics on metal substrates, which is essential to many electronic devices. Tunnel junctions are an excellent example which require a leak-free, ultrathin dielectric tunnel barrier of typical thickness around 1 nm between two metal electrodes. A challenge in the development of ultrathin dielectric tunnel barriers using ALD is controlling the nucleation of dielectrics on metals with minimal formation of native oxides at the metal surface for high-quality interfaces between the tunnel barrier and metal electrodes. This poses a critical need for integrating ALD with ultra-high vacuum (UHV) physical vapor deposition. In order to address these challenges, a viscous-flow ALD chamber was designed and interfaced to an UHV magnetron sputtering chamber via a load lock. A sample transportation system was implemented for in situ sample transfer between the ALD, load lock, and sputtering chambers. Using this integrated ALD-UHV sputtering system, superconductor-insulator-superconductor (SIS) Nb-Al/Al{sub 2}O{sub 2}/Nb Josephson tunnel junctions were fabricated with tunnel barriers of thickness varied from sub-nm to ?1 nm. The suitability of using an Al wetting layer for initiation of the ALD Al{sub 2}O{sub 3} tunnel barrier was investigated with ellipsometry, atomic force microscopy, and electrical transport measurements. With optimized processing conditions, leak-free SIS tunnel junctions were obtained, demonstrating the viability of this integrated ALD-UHV sputtering system for the fabrication of tunnel junctions and devices comprised of metal-dielectric-metal multilayers.

  15. TYPES OF NONIMMIGRANT VISAS Type Description

    E-Print Network [OSTI]

    for pleasure and cannot receive any type of payments. C-1*, Aliens in travel status while travelling directly through the C-2*, United States. C-3* D-1 Alien crewman on shore leave or transferring to another vessel is grounds for deportation. E-1 Aliens who conduct trade or inventories between the United States

  16. Magnetic tunnel junctions for magnetic field sensor by using CoFeB sensing layer capped with MgO film

    SciTech Connect (OSTI)

    Takenaga, Takashi, E-mail: takenaga@leap.or.jp; Tsuzaki, Yosuke; Yoshida, Chikako; Yamazaki, Yuichi; Hatada, Akiyoshi; Nakabayashi, Masaaki; Iba, Yoshihisa; Takahashi, Atsushi; Noshiro, Hideyuki; Tsunoda, Koji; Aoki, Masaki; Furukawa, Taisuke; Fukumoto, Hiroshi; Sugii, Toshihiro [Low-power Electronics Association and Project (LEAP), Tsukuba 305-8569 (Japan)

    2014-05-07

    We evaluated MgO-based magnetic tunnel junctions (MTJs) for magnetic field sensors with spin-valve-type structures in the CoFeB sensing layer capped by an MgO film in order to obtain both top and bottom interfaces of MgO/CoFeB exhibiting interfacial perpendicular magnetic anisotropy (PMA). Hysteresis of the CoFeB sensing layer in these MTJs annealed at 275?°C was suppressed at a thickness of the sensing layer below 1.2?nm by interfacial PMA. We confirmed that the CoFeB sensing layers capped with MgO suppress the thickness dependences of both the magnetoresistance ratio and the magnetic behaviors of the CoFeB sensing layer more than that of the MTJ with a Ta capping layer. MgO-based MTJs with MgO capping layers can improve the controllability of the characteristics for magnetic field sensors.

  17. 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]

    Zhao, HW; Hu, Chia-Ren.

    2000-01-01

    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...

  18. Nitrogen-doped cuprous oxide as a p-type hole-transporting layer in thin-film solar cells

    E-Print Network [OSTI]

    Nitrogen-doped cuprous oxide as a p-type hole- transporting layer in thin-film solar cells Yun Seog-transparent tunnel junction to a back-contact. We fabricate Cu2O-based heterojunction thin-film solar cells-factor and power conversion efficiency of the solar cells. Cu2O:N thin-films may also be useful in other

  19. Design procedures for coal mine tunnels. Open file report 1 Oct 79-31 Dec 82 (final)

    SciTech Connect (OSTI)

    Bieniawski, Z.T.

    1983-03-31

    Although coal mine tunnels such as the main haulageways or roadways are the lifelines of coal mines, little attention has been paid to them in the United States in terms of preconstruction planning and design. This report summarizes the results of a 3-year research project aimed at improving the design procedures for coal mine tunnels. A new design approach was developed for this purpose and roof-support design charts were prepared for mine tunnels and their intersections. Analytical studies, 'base friction' model experiments, and in situ rock stress measurements were performed during this research.

  20. Typed Self-Optimization

    E-Print Network [OSTI]

    Brown, Matt

    2013-01-01

    type T y[O]. The operator IsIs is self-applicative, in thatargument t is any of Is[O] or IsIs, and otherwise behavesproof constant introduced by IsIs proves that the type of t

  1. Tunneling zero-bias anomaly in the quasiballistic regime A. M. Rudin, I. L. Aleiner, and L. I. Glazman

    E-Print Network [OSTI]

    Glazman, Leonid

    tunneling conduc- tance is suppressed at small biases. This effect appears to be quite universal: it shows to our knowledge. The main purpose of this paper is to show that interaction does lead to a significant

  2. Quantitative study of macroscopic quantum tunneling in a dc SQUID: A system with two degrees of freedom

    E-Print Network [OSTI]

    Li, Shaoxiong; Yu, Yang; Zhang, Y.; Qiu, W.; Han, Siyuan; Wang, Z.

    2002-08-01

    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...

  3. Earth pressure balance (EPB) shield tunneling in Bangkok : ground response and prediction of surface settlements using artificial neural networks

    E-Print Network [OSTI]

    Suwansawat, Suchatvee, 1972-

    2002-01-01

    Although Earth Pressure Balance (EPB) shields have been used for several decades, very little information exists about the actual mechanisms of shield-ground interaction. The ground response mechanism induced by EPB tunneling ...

  4. A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 1 of 6

    SciTech Connect (OSTI)

    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

    2009-02-01

    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.

  5. A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 5 of 6

    SciTech Connect (OSTI)

    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

    2009-02-01

    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.

  6. A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 6 of 6

    SciTech Connect (OSTI)

    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

    2009-02-01

    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.

  7. A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 2 of 6

    SciTech Connect (OSTI)

    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

    2009-02-01

    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.

  8. Vacuum Tunneling in an Electroweak Model in Extra Dimensions With an External Flux

    E-Print Network [OSTI]

    Aaron J. Roy

    2009-04-14

    With the standard system for an SU(2) Higgs field in M_4 X S_1, the top and bottom component of the Higgs spinor have exactly the same coeficients for the quadratic and quadric terms. This makes the vacuum degenerate and thus there are no tunneling effects to zeroth order in radiative corrections of the vector gauge felds in the standard model with this extra dimensional geometry. However, if we include an external magnetic flux that permeates our manifold, then the top component of the Higgs spinor will have an additional term in its coefficient due to this theoretical flux with the usual charge assignments for the standard model. This extra term gives rise to two nondegenerate vacuum states for the resulting potential. We will compute the tunneling probability per unit time per unit volume between these vacuum states for the zero modes of our system as well as investigate the masses for the fields of the model using the false vacuum.

  9. Charge transport in molecular junctions: From tunneling to hopping with the probe technique

    E-Print Network [OSTI]

    Kilgour, Michael

    2015-01-01

    We demonstrate that a simple phenomenological approach can be used to simulate electronic conduction in molecular wires under thermal effects induced by the surrounding environment. This "Landauer-B\\"uttiker's probe technique" can properly replicate different transport mechanisms: phase coherent nonresonant tunneling, ballistic behavior, and hopping conduction, to provide results consistent with experiments. Specifically, our simulations with the probe method recover the following central characteristics of charge transfer in molecular wires: (i) The electrical conductance of short wires falls off exponentially with molecular length, a manifestation of the tunneling (superexchange) mechanism. Hopping dynamics overtakes superexchange in long wires demonstrating an ohmic-like behavior. (ii) In off-resonance situations, weak dephasing effects facilitate charge transfer. Under large dephasing the electrical conductance is suppressed. (iii) At high enough temperatures, $k_BT/\\epsilon_B>1/25$, with $\\epsilon_B$ as ...

  10. Improved tunneling magnetoresistance at low temperature in manganite junctions grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Werner, R.; Kleiner, R.; Koelle, D.; Petrov, A. Yu.; Davidson, B. A.; Mino, L. Alvarez

    2011-04-18

    We report resistance versus magnetic field measurements for a La{sub 0.65}Sr{sub 0.35}MnO{sub 3}/SrTiO{sub 3}/La{sub 0.65}Sr{sub 0.35}MnO{sub 3} tunnel junction grown by molecular-beam epitaxy, that show a large field window of extremely high tunneling magnetoresistance (TMR) at low temperature. Scanning the in-plane applied field orientation through 360 deg., the TMR shows fourfold symmetry, i.e., biaxial anisotropy, aligned with the crystalline axis but not the junction geometrical long axis. The TMR reaches {approx}1900% at 4 K, corresponding to an interfacial spin polarization of >95% assuming identical interfaces. These results show that uniaxial anisotropy is not necessary for large TMR, and lay the groundwork for future improvements in TMR in manganite junctions.

  11. Hamilton-Jacobi Tunneling Method for Dynamical Horizons in Different Coordinate Gauges

    E-Print Network [OSTI]

    Roberto Di Criscienzo; Sean A. Hayward; Mario Nadalini; Luciano Vanzo; Sergio Zerbini

    2009-12-03

    Previous work on dynamical black hole instability is further elucidated within the Hamilton-Jacobi method for horizon tunneling and the reconstruction of the classical action by means of the null-expansion method. Everything is based on two natural requirements, namely that the tunneling rate is an observable and therefore it must be based on invariantly defined quantities, and that coordinate systems which do not cover the horizon should not be admitted. These simple observations can help to clarify some ambiguities, like the doubling of the temperature occurring in the static case when using singular coordinates, and the role, if any, of the temporal contribution of the action to the emission rate. The formalism is also applied to FRW cosmological models, where it is observed that it predicts the positivity of the temperature naturally, without further assumptions on the sign of the energy.

  12. Tumor exosomes induce tunneling nanotubes in lipid raft-enriched regions of human mesothelioma cells

    SciTech Connect (OSTI)

    Thayanithy, Venugopal; Babatunde, Victor; Dickson, Elizabeth L.; Wong, Phillip; Oh, Sanghoon; Ke, Xu; Barlas, Afsar; Fujisawa, Sho; Romin, Yevgeniy; Moreira, André L.; Downey, Robert J.; Steer, Clifford J.; Subramanian, Subbaya; Manova-Todorova, Katia; Moore, Malcolm A.S.; Lou, Emil

    2014-04-15

    Tunneling nanotubes (TnTs) are long, non-adherent, actin-based cellular extensions that act as conduits for transport of cellular cargo between connected cells. The mechanisms of nanotube formation and the effects of the tumor microenvironment and cellular signals on TnT formation are unknown. In the present study, we explored exosomes as potential mediators of TnT formation in mesothelioma and the potential relationship of lipid rafts to TnT formation. Mesothelioma cells co-cultured with exogenous mesothelioma-derived exosomes formed more TnTs than cells cultured without exosomes within 24–48 h; and this effect was most prominent in media conditions (low-serum, hyperglycemic medium) that support TnT formation (1.3–1.9-fold difference). Fluorescence and electron microscopy confirmed the purity of isolated exosomes and revealed that they localized predominantly at the base of and within TnTs, in addition to the extracellular environment. Time-lapse microscopic imaging demonstrated uptake of tumor exosomes by TnTs, which facilitated intercellular transfer of these exosomes between connected cells. Mesothelioma cells connected via TnTs were also significantly enriched for lipid rafts at nearly a 2-fold higher number compared with cells not connected by TnTs. Our findings provide supportive evidence of exosomes as potential chemotactic stimuli for TnT formation, and also lipid raft formation as a potential biomarker for TnT-forming cells. - Highlights: • Exosomes derived from malignant cells can stimulate an increased rate in the formation of tunneling nanotubes. • Tunneling nanotubes can serve as conduits for intercellular transfer of these exosomes. • Most notably, exosomes derived from benign mesothelial cells had no effect on nanotube formation. • Cells forming nanotubes were enriched in lipid rafts at a greater number compared with cells not forming nanotubes. • Our findings suggest causal and potentially synergistic association of exosomes and tunneling nanotubes in cancer.

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

    SciTech Connect (OSTI)

    Puthen-Veettil, B. Patterson, R.; König, D.; Conibeer, G.; Green, M. A.

    2014-10-28

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

  14. Terahertz time domain interferometry of a SIS tunnel junction and a quantum point contact

    SciTech Connect (OSTI)

    Karadi, C [Univ. of California, Berkeley, CA (United States). Dept. of Physics

    1995-09-01

    The author has applied the Terahertz Time Domain Interferometric (THz-TDI) technique to probe the ultrafast dynamic response of a Superconducting-Insulating-Superconducting (SIS) tunnel junction and a Quantum Point Contact (QPC). The THz-TDI technique involves monitoring changes in the dc current induced by interfering two picosecond electrical pulses on the junction as a function of time delay between them. Measurements of the response of the Nb/AlO{sub x}/Nb SIS tunnel junction from 75--200 GHz are in full agreement with the linear theory for photon-assisted tunneling. Likewise, measurements of the induced current in a QPC as a function of source-drain voltage, gate voltage, frequency, and magnetic field also show strong evidence for photon-assisted transport. These experiments together demonstrate the general applicability of the THz-TDI technique to the characterization of the dynamic response of any micron or nanometer scale device that exhibits a non-linear I-V characteristic. 133 refs., 49 figs.

  15. Hybrid type checking

    E-Print Network [OSTI]

    Flanagan, C

    2006-01-01

    O’Callahan and J. -D. Choi. Hybrid dynamic data race detec-subtyping is sound, the hybrid compilation algorithmHybrid Type Checking Cormac Flanagan Department of Computer

  16. Fejer-type inequalities

    E-Print Network [OSTI]

    Mitroi, F C

    2011-01-01

    The aim of this paper is to present some new Fejer-type results for convex functions. Improvements of Young's inequality (the arithmetic-geometric mean inequality) and other applications to special means are pointed as well.

  17. Spent Fuel Transportation Package Response to the Baltimore Tunnel Fire Scenario

    SciTech Connect (OSTI)

    Adkins, Harold E.; Cuta, Judith M.; Koeppel, Brian J.; Guzman, Anthony D.; Bajwa, Christopher S.

    2006-11-15

    On July 18, 2001, a freight train carrying hazardous (non-nuclear) materials derailed and caught fire while passing through the Howard Street railroad tunnel in downtown Baltimore, Maryland. The United States Nuclear Regulatory Commission (USNRC), one of the agencies responsible for ensuring the safe transportation of radioactive materials in the United States, undertook an investigation of the train derailment and fire to determine the possible regulatory implications of this particular event for the transportation of spent nuclear fuel by railroad. Shortly after the accident occurred, the USNRC met with the National Transportation Safety Board (NTSB, the U.S. agency responsible for determining the cause of transportation accidents), to discuss the details of the accident and the ensuing fire. Following these discussions, the USNRC assembled a team of experts from the National Institute of Standards and Technology (NIST), the Center for Nuclear Waste Regulatory Analyses (CNWRA), and Pacific Northwest National Laboratory (PNNL) to determine the thermal conditions that existed in the Howard Street tunnel fire and analyze the effects of this fire on various spent fuel transportation package designs. The Fire Dynamics Simulator (FDS) code, developed by NIST, was used to determine the thermal environment present in the Howard Street tunnel during the fire. The FDS results were used as boundary conditions in the COBRA-SFS and ANSYS® computer codes to evaluate the thermal performance of different package designs. The staff concluded that larger transportation packages resembling the HOLTEC Model No. HI STAR 100 and TransNuclear Model No. TN-68 would withstand a fire with thermal conditions similar to those that existed in the Baltimore tunnel fire event with only minor damage to peripheral components. This is due to their sizable thermal inertia and design specifications in compliance with currently imposed regulatory requirements. The staff also concluded that some components of smaller transportation packages resembling the NAC Model No. LWT, despite placement within an ISO container, could degrade. USNRC staff evaluated the radiological consequences of the package responses to the Baltimore tunnel fire. Though components in some packages heated up beyond their service temperatures, the staff determined that there would be no significant dose as a result of the fire for any of these and similar packages.

  18. Infrared detection with high-{Tc} bolometers and response of Nb tunnel junctions to picosecond voltage pulses

    SciTech Connect (OSTI)

    Verghese, S.

    1993-05-01

    Oxide superconductors with high critical temperature {Tc} make sensitive thermometers for several types of infrared bolometers. The authors built composite bolometers with YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thermometers on sapphire substrates which have higher sensitivity than competing thermal detectors which operate at temperatures above 77 K. A 1 x 1 mm bolometer with gold black serving as the radiation absorber has useful sensitivity for wavelengths 20--100 {mu}m. A 3 x 3 mm bolometer with a bismuth film as the absorber operates from 20--100 {mu}m. High-{Tc} bolometers which are fabricated with micromachining techniques on membranes of Si or Si{sub 3}N{sub 4} have potential application to large-format arrays which are used for infrared imaging. A nonisothermal high-{Tc} bolometer can be fabricated on a membrane of yttria-stabilized zirconia (YSZ) which is in thermal contact with the heat sink along the perimeter of the membrane. A thermal analysis indicates that the YSZ membrane bolometer can have improved sensitivity compared to the sapphire bolometer for spectrometer applications. The quasiparticle tunneling current in a superconductor-insulator-superconductor (SIS) junction is highly nonlinear in the applied voltage. The authors have made the first measurement of the linear response of the quasiparticle current in a Nb/AlO{sub x}/Nb junction over a broad bandwidth from 75--200 GHz. Nonlinear measurements made with these pulses may provide information about the quasiparticle lifetime. Preliminary data from such measurements are presented.

  19. 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]

    2012-01-01

    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

  20. Proposal for the award of a contract for undertaking the industrial electrical installations in the LEP surface buildings, shafts and access tunnels

    E-Print Network [OSTI]

    1984-01-01

    Proposal for the award of a contract for undertaking the industrial electrical installations in the LEP surface buildings, shafts and access tunnels

  1. Type Ia Supernovae

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired SolarAbout /Two Electron Holes in HematiteType Ia Supernovae Type Ia

  2. Agreement Type Union

    National Nuclear Security Administration (NNSA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouthReporteeo | National Nucleara min [Type the abstract of theType

  3. Basics, types Evolution

    E-Print Network [OSTI]

    Crenshaw, Michael

    to nuclear fusion. · Novae radiate primarily in the UV to X-ray region. · Types: ­ Classical Novae: only one is hot enough for explosive fusion. For classical novae, this happens on a time scale of 103 ­ 105 years. · Thermonuclear runaway (TNR): capture of protons by heavy elements (CNO cycle), happens in seconds #12;5 Novae

  4. High-stability cryogenic scanning tunneling microscope based on a closed-cycle cryostat

    SciTech Connect (OSTI)

    Hackley, Jason D.; Kislitsyn, Dmitry A.; Beaman, Daniel K.; Nazin, George V.; Ulrich, Stefan

    2014-10-15

    We report on the design and operation of a cryogenic ultra-high vacuum (UHV) scanning tunneling microscope (STM) coupled to a closed-cycle cryostat (CCC). The STM is thermally linked to the CCC through helium exchange gas confined inside a volume enclosed by highly flexible rubber bellows. The STM is thus mechanically decoupled from the CCC, which results in a significant reduction of the mechanical noise transferred from the CCC to the STM. Noise analysis of the tunneling current shows current fluctuations up to 4% of the total current, which translates into tip-sample distance variations of up to 1.5 picometers. This noise level is sufficiently low for atomic-resolution imaging of a wide variety of surfaces. To demonstrate this, atomic-resolution images of Au(111) and NaCl(100)/Au(111) surfaces, as well as of carbon nanotubes deposited on Au(111), were obtained. Thermal drift analysis showed that under optimized conditions, the lateral stability of the STM scanner can be as low as 0.18 Å/h. Scanning Tunneling Spectroscopy measurements based on the lock-in technique were also carried out, and showed no detectable presence of noise from the closed-cycle cryostat. Using this cooling approach, temperatures as low as 16 K at the STM scanner have been achieved, with the complete cool-down of the system typically taking up to 12 h. These results demonstrate that the constructed CCC-coupled STM is a highly stable instrument capable of highly detailed spectroscopic investigations of materials and surfaces at the atomic scale.

  5. Spent Fuel Transportation Cask Response to the Caldecott Tunnel Fire Scenario

    SciTech Connect (OSTI)

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

    2007-01-01

    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.

  6. Time delay of wave packets during their tunnelling through a quantum diode

    SciTech Connect (OSTI)

    Ivanov, N A; Skalozub, V V

    2014-04-28

    A modified saddle-point method is used to investigate the process of propagation of a wave packet through a quantum diode. A scattering matrix is constructed for the structure in question. The case of tunnelling of a packet with a Gaussian envelope through the diode is considered in detail. The time delay and the shape of the wave packet transmitted are calculated. The dependence of the delay time on the characteristics of the input packet and the internal characteristics of the quantum diode is studied. Possible applications of the results obtained are discussed. (laser applications and other topics in quantum electronics)

  7. Dynamical properties of three terminal magnetic tunnel junctions: Spintronics meets spin-orbitronics

    SciTech Connect (OSTI)

    Tomasello, R.; Carpentieri, M.; Finocchio, G.

    2013-12-16

    This Letter introduces a micromagnetic model able to characterize the magnetization dynamics in three terminal magnetic tunnel junctions, where the effects of spin-transfer torque and spin-orbit torque are taken into account. Our results predict that the possibility to separate electrically those two torque sources is very promising from a technological point of view for both next generation of nanoscale spintronic oscillators and microwave detectors. A scalable synchronization scheme based on the parallel connection of those three terminal devices is also proposed.

  8. Error propagation equations for estimating the uncertainty in high-speed wind tunnel test results

    SciTech Connect (OSTI)

    Clark, E.L.

    1994-07-01

    Error propagation equations, based on the Taylor series model, are derived for the nondimensional ratios and coefficients most often encountered in high-speed wind tunnel testing. These include pressure ratio and coefficient, static force and moment coefficients, dynamic stability coefficients, and calibration Mach number. The error equations contain partial derivatives, denoted as sensitivity coefficients, which define the influence of free-steam Mach number, M{infinity}, on various aerodynamic ratios. To facilitate use of the error equations, sensitivity coefficients are derived and evaluated for five fundamental aerodynamic ratios which relate free-steam test conditions to a reference condition.

  9. Numerical modeling of laser tunneling ionization in explicit particle-in-cell codes

    SciTech Connect (OSTI)

    Chen, M.; Cormier-Michel, E.; Geddes, C.G.R.; Bruhwiler, D.L.; Yu, L.L.; Esarey, E.; Schroeder, C.B.; Leemans, W.P.

    2013-03-01

    Methods for the calculation of laser tunneling ionization in explicit particle-in-cell codes used for modeling laser–plasma interactions are compared and validated against theoretical predictions. Improved accuracy is obtained by using the direct current form for the ionization rate. Multi level ionization in a single time step and energy conservation have been considered during the ionization process. The effects of grid resolution and number of macro-particles per cell are examined. Implementation of the ionization algorithm in two different particle-in-cell codes is compared for the case of ionization-based electron injection in a laser–plasma accelerator.

  10. Bi-Sr-Ca-Cu-O surface studied by means of scanning tunnelling microscope

    SciTech Connect (OSTI)

    Witek, A.; Dabkowski, A.; Rauluszkiewicz, J.

    1989-03-10

    Surface topography of the high-T/sub c/ superconductor BiSrCaCu/sub 2/O/sub x/ has been investigated by means of scanning tunnelling microscope. The measurements were performed on the natural surface of ceramics material in air at room temperature. It can be deduced from the surface images, that bulk orthorhombic crystal structure extends to the surface. The surface seems to be uniform metallic in character and not drastically contaminated. Regular steps observed on the surface correspond to the dimension of the unit cell in z direction or its multiples.

  11. Global Tunnel Boring Machine Industry 2015 Market Research Report | OpenEI

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar2-0057-EA Jump to:ofEniaElectric JumpAtlas forCommunity Tunnel Boring

  12. Energy.gov Page Types

    Broader source: Energy.gov [DOE]

    Learn about the standard page types available in the Energy.gov Drupal content management system. For information about other available page types, or to request a new kind of page type, contact...

  13. Practical pluggable types for Java

    E-Print Network [OSTI]

    Papi, Matthew M

    2008-01-01

    This paper introduces the Checker Framework, which supports adding pluggable type systems to the Java language in a backward-compatible way. A type system designer defines type qualifiers and their semantics, and a compiler ...

  14. Window Types | Department of Energy

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

    aluminum or vinyl cladding reduces maintenance requirements. Types of Window Glazing or Glass In addition to choosing a frame type, you will need to consider what type of glazing...

  15. Spin-filtering effect of thin Al{sub 2}O{sub 3} barrier on tunneling magnetoresistance

    SciTech Connect (OSTI)

    Joo, Sungjung; Jung, K. Y.; Jun, K. I.; Shin, K. H.; Kim, D. S.; Hong, J. K.; Rhie, K. E-mail: krhie@korea.ac.kr; Lee, B. C. E-mail: krhie@korea.ac.kr

    2014-04-14

    Tunneling magnetoresistance (TMR) dependence on the Al{sub 2}O{sub 3} barrier thickness was investigated for CoFe/Al{sub 2}O{sub 3}/CoFe magnetic tunnel junctions (MTJs). MTJs with very thin Al{sub 2}O{sub 3} layers were grown by inserting an amorphous FeZr buffer layer whose role is only to reduce the roughness of bottom electrode. The TMR decreased as the thickness of the Al{sub 2}O{sub 3} layer was reduced. The results are analyzed with the dependence of the spin-filtering effect on the Al{sub 2}O{sub 3} thickness. It was found that a simple model of separating sp- and d-like electrons does not work, and it may suggest that the tunneling electrons are in rather hybridized state.

  16. Dust around Type Ia supernovae

    E-Print Network [OSTI]

    Wang, Lifan

    2005-01-01

    Dust around Type Ia supernovae Lifan Wang 1,2 LawrenceIa. Subject headings: Supernovae: General, Dust, Extinctionline) bands for Type Ia supernovae. (a), upper panel, shows

  17. FULL-SCALE, WIND TUNNEL AND CFD WIND ENGINEERING STUDIES A variety of methods can be used to obtain wind engineering design information. These include

    E-Print Network [OSTI]

    Savory, Eric

    FULL-SCALE, WIND TUNNEL AND CFD WIND ENGINEERING STUDIES A variety of methods can be used to obtain wind engineering design information. These include codes of practice, full-scale, wind tunnel are listed in the table below: Table 1. Relative advantages and disadvantages of wind engineering techniques

  18. Facility for low-temperature spin-polarized-scanning tunneling microscopy studies of magnetic/spintronic materials prepared in situ by nitride molecular beam epitaxy

    E-Print Network [OSTI]

    Facility for low-temperature spin-polarized-scanning tunneling microscopy studies of magnetic/spintronic (2014) Facility for low-temperature spin-polarized-scanning tunneling microscopy studies of magnetic/spintronic, and spintronic applications, it is compelling to investigate these systems using the powerful technique of spin

  19. Physics PhD scholarship available in one the worlds top 10 cities Scanning Tunneling Microscopy studies of rare earth nitrides and related materials

    E-Print Network [OSTI]

    Hickman, Mark

    studies of rare earth nitrides and related materials This is an opportunity to explore how new rare earth nitride materials can be made and how they can be probed using scanning tunneling microscopy. Scanning Tunneling Microscopy is a powerful tool to obtain both atomic resolution imaging of the surface of materials

  20. A Vision-based Method for On-Road Truck Height Measurement in Proactive Prevention of 2 Collision with Overpasses and Tunnels

    E-Print Network [OSTI]

    Dai, Fei; Park, Man-Woo; Sandidge, Matthew; Brilakis, Ioannis

    2014-11-26

    Television, 2012 490 (http://www.metro.us/philadelphia/news/local/2012/08/14/large-truck-strikes-signs-in-tip-oneill-491 tunnel/). 492 [6] J. Brooks, Stuck truck in Burnley Tunnel cost Victorians $1 million, 3AW, 2013 493 (http://www.3aw.com.au/blogs/neil...

  1. Strong Room-temperature Negative Transconductance In An Axial Si/Ge Hetero-nanowire Tunneling Field-effect Transistor

    SciTech Connect (OSTI)

    Zhang, Peng; Le, Son T.; Hou, Xiaoxiao; Zaslavsky, A.; Perea, Daniel E.; Dayeh, Shadi A.; Picraux, Samuel T.

    2014-08-11

    We report on room-temperature negative transconductance (NTC) in axial Si/Ge hetero-nanowire tunneling field-effect transistors (TFETs). The NTC produces a current peak-to-valley ratio > 45, a high value for a Si-based device. We characterize the NTC characteristics over a range of gate VG and drain VD voltages, finding that NTC persists down to VD = –50 mV. The physical mechanism responsible for the NTC is the VG-induced depletion in the p-Ge section that eventually reduces the maximum electric field that triggers the tunneling ID, as confirmed via three-dimensional TCAD simulations.

  2. Alignment-dependent fluorescence emission induced by tunnel ionization of carbon dioxide from lower-lying orbitals

    E-Print Network [OSTI]

    Yao, Jinping; Jia, Xinyan; Hao, Xiaolei; Zeng, Bin; Jing, Chenrui; Chu, Wei; Ni, Jielei; Zhang, Haisu; Xie, Hongqiang; Zhang, Chaojin; Zhao, Zengxiu; Chen, Jing; Liu, Xiaojun; Cheng, Ya; Xu, Zhizhan

    2013-01-01

    We show that fluorescence emission induced by strong field tunnel ionization of carbon dioxide from its lower-lying orbitals exhibits a peculiar molecular alignment dependence. The experimentally measured alignment-dependence of the fluorescence agrees with the alignment-dependence of the ionization probability calculated in the framework of the strong field approximation. Our results demonstrate the feasibility of an all-optical approach for shedding more light on the ionization mechanisms of molecules from their lower-lying orbitals in tunnel ionization regime.

  3. Manipulation of subsurface carbon nanoparticles in Bi?Sr?CaCu?O8+? using a scanning tunneling microscope

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

    Stollenwerk, A. J.; Gu, G.; Hurley, N.; Beck, B.; Spurgeon, K.; Kidd, T. E.

    2015-03-01

    We present evidence that subsurface carbon nanoparticles in Bi?Sr?CaCu?O8+? can be manipulated with nanometer precision using a scanning tunneling microscope. High resolution images indicate that most of the carbon particles remain subsurface after transport observable as a local increase in height as the particle pushes up on the surface. Tunneling spectra in the vicinity of these protrusions exhibit semiconducting characteristics with a band gap of approximately 1.8 eV, indicating that the incorporation of carbon locally alters the electronic properties near the surface.

  4. Design of a high angle of attack robotic sting mount for tests in a low speed wind tunnel 

    E-Print Network [OSTI]

    Kubler, Tommy Jack

    1989-01-01

    DESIGN OF A HIGH ANGLE OF ATTACK ROBOTIC STING MOUNT FOR TESTS IN A LOW SPEED WIND TUNNEL A Thesis by TOMMY JACK KUBLER Submitted to the Oflice of Graduate Studies of Texas AJcM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1989 Major Subject: Aerospace Engineering DESIGN OF A HIGH ANGLE OF ATTACK ROBOTIC STING MOUNT FOR TESTS IN A IOW SPEED WIND TUNNEL A Thesis bv TOMMY JACK KHBLER Approved as to style and content by: Thomas C...

  5. Patency of Femoral Tunneled Hemodialysis Catheters and Factors Predictive of Patency Failure

    SciTech Connect (OSTI)

    Burton, Kirsteen R. [University Health Network, University of Toronto, Department of Medical Imaging, Division of Vascular and Interventional Radiology (Canada); Guo, Lancia L. Q. [University of Calgary, Department of Radiology (Canada); Tan, Kong T.; Simons, Martin E.; Sniderman, Kenneth W.; Kachura, John R.; Beecroft, John R.; Rajan, Dheeraj K., E-mail: dheeraj.rajan@uhn.on.ca [University Health Network, University of Toronto, Department of Medical Imaging, Division of Vascular and Interventional Radiology (Canada)

    2012-12-15

    Purpose: To determine the patency rates of and factors associated with increased risk of patency failure in patients with femoral vein tunneled hemodialysis catheters. Methods: All femoral tunneled catheter insertions from 1996 to 2006 were reviewed, during which time 123 catheters were inserted. Of these, 66 were exchanges. Patients with femoral catheter failure versus those with femoral catheter patency were compared. Confounding factors, such as demographic and procedural factors, were incorporated and assessed using univariate and multivariable Cox proportional hazards regression analyses. Results: Mean catheter primary patency failure time was 96.3 days (SE 17.9 days). Primary patency at 30, 60, 90, and 180 days was 53.8%, 45.4%, 32.1%, and 27.1% respectively. Crude rates of risk of catheter failure did not suggest a benefit for patients receiving catheters introduced from one side versus the other, but more cephalad location of catheter tip was associated with improved patency. Multivariate analysis showed that patients whose catheters were on the left side (p = 0.009), were of increasing age at the time of insertion (p = 0.002) and that those who had diabetes (p = 0.001) were at significantly greater risk of catheter failure. The catheter infection rate was 1.4/1000 catheter days. Conclusion: Patients who were of a more advanced age and had diabetes were at greater risk of femoral catheter failure, whereas those who received femoral catheters from the right side were less at risk of catheter failure.

  6. Power and efficiency analysis of a realistic resonant tunneling diode thermoelectric

    SciTech Connect (OSTI)

    Agarwal, Akshay; Muralidharan, Bhaskaran, E-mail: bm@ee.iitb.ac.in [Centre of Excellence in Nanoelectronics, Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India)

    2014-07-07

    Low-dimensional systems with sharp features in the density of states have been proposed as a means for improving the efficiency of thermoelectric devices. Quantum dot systems, which offer the sharpest density of states achievable, however, suffer from low power outputs while bulk (3-D) thermoelectrics, while displaying high power outputs, offer very low efficiencies. Here, we analyze the use of a resonant tunneling diode structure that combines the best of both aspects, that is, density of states distortion with a finite bandwidth due to confinement that aids the efficiency and a large number of current carrying transverse modes that enhances the total power output. We show that this device can achieve a high power output (?0.3?MW?m{sup 2}) at efficiencies of ?40% of the Carnot efficiency due to the contribution from these transverse momentum states at a finite bandwidth of kT?2. We then provide a detailed analysis of the physics of charge and heat transport with insights on parasitic currents that reduce the efficiency. Finally, a comparison between the resonant tunneling diode and a quantum dot device with comparable bandwidth reveals that a similar performance requires ultra-dense areal quantum dot densities of ?10{sup 12}/cm{sup 2}.

  7. Tunnel Field-Effect Transistors in 2D Transition Metal Dichalcogenide Materials

    E-Print Network [OSTI]

    Ilatikhameneh, Hesameddin; Novakovic, Bozidar; Klimeck, Gerhard; Rahman, Rajib; Appenzeller, Joerg

    2015-01-01

    In this work, the performance of Tunnel Field-Effect Transistors (TFETs) based on two-dimensional Transition Metal Dichalcogenide (TMD) materials is investigated by atomistic quantum transport simulations. One of the major challenges of TFETs is their low ON-currents. 2D material based TFETs can have tight gate control and high electric fields at the tunnel junction, and can in principle generate high ON-currents along with a sub-threshold swing smaller than 60 mV/dec. Our simulations reveal that high performance TMD TFETs, not only require good gate control, but also rely on the choice of the right channel material with optimum band gap, effective mass and source/drain doping level. Unlike previous works, a full band atomistic tight binding method is used self-consistently with 3D Poisson equation to simulate ballistic quantum transport in these devices. The effect of the choice of TMD material on the performance of the device and its transfer characteristics are discussed. Moreover, the criteria for high ON...

  8. Magnetotransport in MgO-based magnetic tunnel junctions grown by molecular beam epitaxy (invited)

    SciTech Connect (OSTI)

    Andrieu, S. Bonell, F.; Hauet, T.; Montaigne, F.; Lefevre, P.; Bertran, F.

    2014-05-07

    The strong impact of molecular beam epitaxy growth and Synchrotron Radiation characterization tools in the understanding of fundamental issues in nanomagnetism and spintronics is illustrated through the example of fully epitaxial MgO-based Magnetic Tunnel Junctions (MTJs). If ab initio calculations predict very high tunnel magnetoresistance (TMR) in such devices, some discrepancy between theory and experiments still exists. The influence of imperfections in real systems has thus to be considered like surface contaminations, structural defects, unexpected electronic states, etc. The influence of possible oxygen contamination at the Fe/MgO(001) interface is thus studied, and is shown to be not so detrimental to TMR as predicted by ab initio calculations. On the contrary, the decrease of dislocations density in the MgO barrier of MTJs using Fe{sub 1?x}V{sub x} electrodes is shown to significantly increase TMR. Finally, unexpected transport properties in Fe{sub 1?X}Co{sub x}/MgO/Fe{sub 1?X}Co{sub x} (001) are presented. With the help of spin and symmetry resolved photoemission and ab initio calculation, the TMR decrease for Co content higher than 25% is shown to come from the existence of an interface state and the shift of the empty ?1 minority spin state towards the Fermi level.

  9. Atomic-scale electrochemistry on the surface of a manganite by scanning tunneling microscopy

    SciTech Connect (OSTI)

    Vasudevan, Rama K. Tselev, Alexander; Baddorf, Arthur P.; Gianfrancesco, Anthony G.

    2015-04-06

    The doped manganese oxides (manganites) have been widely studied for their colossal magnetoresistive effects, for potential applications in oxide spintronics, electroforming in resistive switching devices, and are materials of choice as cathodes in modern solid oxide fuel cells. However, little experimental knowledge of the dynamics of the surfaces of perovskite manganites at the atomic scale exists. Here, through in-situ scanning tunneling microscopy (STM), we demonstrate atomic resolution on samples of La{sub 0.625}Ca{sub 0.375}MnO{sub 3} grown on (001) SrTiO{sub 3} by pulsed laser deposition. Furthermore, by applying triangular DC waveforms of increasing amplitude to the STM tip, and measuring the tunneling current, we demonstrate the ability to both perform and monitor surface electrochemical processes at the atomic level, including formation of oxygen vacancies and removal and deposition of individual atomic units or clusters. Our work paves the way for better understanding of surface oxygen reactions in these systems.

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

    SciTech Connect (OSTI)

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

    2010-04-15

    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.

  11. A 2-terminal perovskite/silicon multijunction solar cell enabled by a silicon tunnel Jonathan P. Mailoa, Colin D. Bailie, Eric C. Johlin, Eric T. Hoke, Austin J. Akey, William H. Nguyen, Michael D.

    E-Print Network [OSTI]

    McGehee, Michael

    A 2-terminal perovskite/silicon multijunction solar cell enabled by a silicon tunnel junction epitaxy growth of AlGaAs/GaAs tunnel junctions using trimethyl aluminium for multijunction solar cells AIP of high bandgap tunnel junctions for multijunction solar cells Appl. Phys. Lett. 103, 103503 (2013); 10

  12. Wind Tunnel 

    E-Print Network [OSTI]

    Unknown

    2011-08-17

    A new approach to high-field dipole design is being developed at Texas A&M University. The goal of the development is to facilitate the use of high-field conductors (Nb3 and Bi-2212) and to manage Lorentz stress and ...

  13. Wind Tunnel 

    E-Print Network [OSTI]

    Unknown

    2011-08-17

    The increased interest in the offshore wind resource in both industry and academic and the extension of the wind field where offshore wind turbine can be deployed has stimulated quite a number of offshore wind turbines concepts. This thesis presents...

  14. Wind Tunnel 

    E-Print Network [OSTI]

    Unknown

    2011-08-17

    Simulation of Cooling Effect of Wind Tower on Passively Ventilated Building John Seryak Kelly Kissock Project Engineer Associate Professor Department of Mechanical and Aerospace Engineering University of Dayton... Dayton, Ohio ABSTRACT Traditional buildings are cooled and ventilated by mechanically induced drafts. Natural ventilation aspires to cool and ventilate a building by natural means, such as cross ventilation or wind towers, without mechanical...

  15. Dependency of tunneling magneto-resistance on Fe insertion-layer thickness in Co{sub 2}Fe{sub 6}B{sub 2}/MgO-based magnetic tunneling junctions

    SciTech Connect (OSTI)

    Chae, Kyo-Suk; Park, Jea-Gun

    2015-04-21

    For Co{sub 2}Fe{sub 6}B{sub 2}/MgO-based perpendicular magnetic tunneling junctions spin valves with [Co/Pd]{sub n}-synthetic-antiferromagnetic (SyAF) layers, the tunneling-magneto-resistance (TMR) ratio strongly depends on the nanoscale Fe insertion-layer thickness (t{sub Fe}) between the Co{sub 2}Fe{sub 6}B{sub 2} pinned layer and MgO tunneling barrier. The TMR ratio rapidly increased as t{sub Fe} increased up to 0.4?nm by improving the crystalline linearity of a MgO tunneling barrier and by suppressing the diffusion of Pd atoms from a [Co/Pd]{sub n}-SyAF. However, it abruptly decreased by further increasing t{sub Fe} in transferring interfacial-perpendicular magnetic anisotropy into the IMA characteristic of the Co{sub 2}Fe{sub 6}B{sub 2} pinned layer. Thus, the TMR ratio peaked at t{sub Fe}?=?0.4?nm: i.e., 120% at 29???m{sup 2}.

  16. Lithologic and Structural Constraints on TBM Tunneling in New York City p. 704-724 in Hutton, John D. and Rogstad, W. Dave, eds., Rapid Excavation and Tunneling Conference, 2005

    E-Print Network [OSTI]

    Merguerian, Charles

    Lithologic and Structural Constraints on TBM Tunneling in New York City p. 704-724 in Hutton, John York City (NYC), rock mass texture and mineralogy are important factors in predicting TBM penetration 11590 charlesm@dukelabs.com ABSTRACT In medium- to high-grade metamorphic terrains such as found in New

  17. American Institute of Aeronautics and Astronautics Wind Tunnel Validation of a CFD-Based Aero-Optics Model

    E-Print Network [OSTI]

    Gordeyev, Stanislav

    American Institute of Aeronautics and Astronautics 1 Wind Tunnel Validation of a CFD-Based Aero Air Force Academy, Colorado Spring, CO Abstract: A computational fluid dynamics (CFD)-based aero LATFORMS at high subsonic Mach numbers introduce aero-optic disturbances caused when free shear layers

  18. Design of a new reactor-like high temperature near ambient pressure scanning tunneling microscope for catalysis studies

    E-Print Network [OSTI]

    Tao, Franklin Feng; Nguyen, Luan; Zhang, Shiran

    2013-01-01

    Here, we present the design of a new reactor-like high-temperature near ambient pressure scanning tunneling microscope (HT-NAP-STM) for catalysis studies. This HT-NAP-STM was designed for exploration of structures of catalyst surfaces at atomic...

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

    E-Print Network [OSTI]

    Hummon, M. R.

    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 ...

  20. arXiv:cond-mat/0301277v115Jan2003 RESONANT COOPER-PAIR TUNNELING: COUNTING STATISTICS

    E-Print Network [OSTI]

    Clerk, Aashish

    in the current noise was predicted at the Josephson energy. In this paper, we look specifically at the statisticsarXiv:cond-mat/0301277v115Jan2003 RESONANT COOPER-PAIR TUNNELING: COUNTING STATISTICS AND FREQUENCY Haven, CT 06520-8284 Abstract We discuss the counting statistics and current noise associated

  1. Is spin transport through molecules really occurring in organic spin valves? A combined magnetoresistance and inelastic electron tunnelling spectroscopy study

    SciTech Connect (OSTI)

    Galbiati, Marta; Tatay, Sergio; Delprat, Sophie; Khanh, Hung Le; Deranlot, Cyrile; Collin, Sophie; Seneor, Pierre Mattana, Richard Petroff, Frédéric

    2015-02-23

    Molecular and organic spintronics is an emerging research field which combines the versatility of chemistry with the non-volatility of spintronics. Organic materials have already proved their potential as tunnel barriers (TBs) or spacers in spintronics devices showing sizable spin valve like magnetoresistance effects. In the last years, a large effort has been focused on the optimization of these organic spintronics devices. Insertion of a thin inorganic tunnel barrier (Al{sub 2}O{sub 3} or MgO) at the bottom ferromagnetic metal (FM)/organic interface seems to improve the spin transport efficiency. However, during the top FM electrode deposition, metal atoms are prone to diffuse through the organic layer and potentially short-circuit it. This may lead to the formation of a working but undesired FM/TB/FM magnetic tunnel junction where the organic plays no role. Indeed, establishing a protocol to demonstrate the effective spin dependent transport through the organic layer remains a key issue. Here, we focus on Co/Al{sub 2}O{sub 3}/Alq{sub 3}/Co junctions and show that combining magnetoresistance and inelastic electron tunnelling spectroscopy measurements one can sort out working “organic” and short-circuited junctions fabricated on the same wafer.

  2. J. CHEM. FARADAY TRANS., 1994, 90(12), 1715-1725 1715 Variational Transition-state Theory and Semiclassical Tunnelling

    E-Print Network [OSTI]

    Truhlar, Donald G

    calculations to the reaction path or swath. An alter- native is the direct dynamics method in which electronic and Semiclassical Tunnelling Calculations with Interpolated Corrections:A New Approach to Interfacing Electronic,H +CD, reactions are included. 1. Introduction The progress of electronic structure theory in providing

  3. InGaN/GaN tunnel junctions for hole injection in GaN light emitting diodes

    SciTech Connect (OSTI)

    Krishnamoorthy, Sriram, E-mail: krishnamoorthy.13@osu.edu, E-mail: rajan@ece.osu.edu; Akyol, Fatih [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Rajan, Siddharth, E-mail: krishnamoorthy.13@osu.edu, E-mail: rajan@ece.osu.edu [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

    2014-10-06

    InGaN/GaN tunnel junction contacts were grown using plasma assisted molecular beam epitaxy (MBE) on top of a metal-organic chemical vapor deposition (MOCVD)-grown InGaN/GaN blue (450?nm) light emitting diode. A voltage drop of 5.3?V at 100?mA, forward resistance of 2 × 10{sup ?2} ? cm{sup 2}, and a higher light output power compared to the reference light emitting diodes (LED) with semi-transparent p-contacts were measured in the tunnel junction LED (TJLED). A forward resistance of 5?×?10{sup ?4} ? cm{sup 2} was measured in a GaN PN junction with the identical tunnel junction contact as the TJLED, grown completely by MBE. The depletion region due to the impurities at the regrowth interface between the MBE tunnel junction and the MOCVD-grown LED was hence found to limit the forward resistance measured in the TJLED.

  4. Atomic-resolution study of Mn tetramer clusters using scanning tunneling Rong Yang, Haiqiang Yang, and Arthur R. Smitha

    E-Print Network [OSTI]

    Atomic-resolution study of Mn tetramer clusters using scanning tunneling microscopy Rong Yang clusters is investigated. The clusters are composed of a quadrant array of Mn atoms forming a tetramer of manganese nitride, on which are stabilized peri- odic, self-organized array of MnN-bonded Mn tetramer clus

  5. Wind tunnel simulation of wind effects and associated displacement hazards on flat surface construction materials such as plywood 

    E-Print Network [OSTI]

    Madeley, Jack T.

    1996-01-01

    decking material with the air stream flowing over the stack until top sheet separated or lifted from the stack. Next, a half-scale model was placed in the test section of the tunnel with pressure ports attached to a high speed sampling transducer...

  6. Preservation of coherence for a two-level atom tunneling through a squeezed vacuum with finite bandwidth

    SciTech Connect (OSTI)

    Bhattacharya, Samyadeb Roy, Sisir

    2014-09-15

    Tunneling of a two-state particle through a squeezed vacuum is considered. It has been shown that repetitive measurement or interaction with the external field can preserve the coherence. Moreover, the coherence time in terms of the squeezing parameters has been calculated. A specific condition is derived, under which the coherence is sustainable.

  7. Parallel Computer Research in the Wisconsin Wind Tunnel Project Mark D. Hill, James R. Larus, and David A. Wood

    E-Print Network [OSTI]

    Lipasti, Mikko H.

    range, networks of workstations (NOWs) offer lower hardware cost than an MPP by building on commodity. An important by-product of this research has been innovative tools, such as the Wiscon- sin Wind Tunnel that parallel computer hardware can be more cost-effective than a uniprocessor, because (a) it often uses

  8. Abstract--This research creates a steady headwind at a user position in the scaled Treadport Active Wind Tunnel (TPAWT).

    E-Print Network [OSTI]

    Hollerbach, John M.

    Active Wind Tunnel (TPAWT). The TPAWT adds a wind display system to the previously developed Treadport gain theorem with a dynamic extension is then modified to provide wind angle feedback control. A conditional angular rate-switching controller is added to reduce wind angle oscillations at the user

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

    E-Print Network [OSTI]

    Ciobanu, Cristian

    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

  10. EXPERIMENTAL AND SIMULATED SCANNING TUNNELING MICROSCOPY OF THE CLEAVED Rb1/3WO3 (0001) SURFACE

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    EXPERIMENTAL AND SIMULATED SCANNING TUNNELING MICROSCOPY OF THE CLEAVED Rb1/3WO3 (0001) SURFACE of cleaved (0001) surfaces of the hexagonal tungsten bronze, Rbl/ 3WO3 , show two distinct contrast patterns bronze (HTB), Rbl/ 3WO3 [5]. The structure of this compound, originally determined by Magndli [6

  11. Pluggable type-checking for custom type qualifiers in Java

    E-Print Network [OSTI]

    Papi, Matthew M.

    2007-09-17

    We have created a framework for adding custom type qualifiers to the Javalanguage in a backward-compatible way. The type system designer definesthe qualifiers and creates a compiler plug-in that enforces theirsemantics. ...

  12. PICTURE GROUPS OF FINITE TYPE AND COHOMOLOGY IN TYPE An

    E-Print Network [OSTI]

    Igusa, Kiyoshi

    PICTURE GROUPS OF FINITE TYPE AND COHOMOLOGY IN TYPE An KIYOSHI IGUSA, KENT ORR, GORDANA TODOROV a picture group. We construct a finite CW complex which is shown in another paper [10] to be a K(, 1) for this picture group. In [5] another independent proof was given for this fact in the special case of type

  13. Abstract Data Types 5 Algebraic Theory of Abstract Data Types

    E-Print Network [OSTI]

    Berger, Ulrich

    stack top: stack elts The following is an algebra for the signature STACK. Algebra SeqN Carriers N, N43 Part II Abstract Data Types #12;44 5 Algebraic Theory of Abstract Data Types An Abstract Data Type (ADT) is a collection of objects and functions, that is, an algebra, where one ignores how

  14. Tunnel-injection quantum dot deep-ultraviolet light-emitting diodes with polarization-induced doping in III-nitride heterostructures

    SciTech Connect (OSTI)

    Verma, Jai Islam, S. M.; Protasenko, Vladimir; Kumar Kandaswamy, Prem; Xing, Huili; Jena, Debdeep

    2014-01-13

    Efficient semiconductor optical emitters in the deep-ultraviolet spectral window are encountering some of the most deep rooted problems of semiconductor physics. In III-Nitride heterostructures, obtaining short-wavelength photon emission requires the use of wide bandgap high Al composition AlGaN active regions. High conductivity electron (n-) and hole (p-) injection layers of even higher bandgaps are necessary for electrical carrier injection. This approach requires the activation of very deep dopants in very wide bandgap semiconductors, which is a difficult task. In this work, an approach is proposed and experimentally demonstrated to counter the challenges. The active region of the heterostructure light emitting diode uses ultrasmall epitaxially grown GaN quantum dots. Remarkably, the optical emission energy from GaN is pushed from 365?nm (3.4?eV, the bulk bandgap) to below 240?nm (>5.2?eV) because of extreme quantum confinement in the dots. This is possible because of the peculiar bandstructure and band alignments in the GaN/AlN system. This active region design crucially enables two further innovations for efficient carrier injection: Tunnel injection of carriers and polarization-induced p-type doping. The combination of these three advances results in major boosts in electroluminescence in deep-ultraviolet light emitting diodes and lays the groundwork for electrically pumped short-wavelength lasers.

  15. Electrical spin injection into InGaAs/GaAs quantum wells: A comparison between MgO tunnel barriers grown by sputtering and molecular beam epitaxy methods

    SciTech Connect (OSTI)

    Barate, P.; Zhang, T. T.; Vidal, M.; Renucci, P.; Marie, X.; Amand, T. [Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 avenue de Rangueil, 31077 Toulouse (France); Liang, S.; Devaux, X.; Hehn, M.; Mangin, S.; Lu, Y., E-mail: yuan.lu@univ-lorraine.fr [Institut Jean Lamour, UMR 7198, CNRS-Nancy Université, BP 239, 54506 Vandoeuvre (France); Frougier, J.; Jaffrès, H.; George, J. M. [Unité Mixte de Physique CNRS/Thales and Université Paris-Sud 11, 1 avenue A. Fresnel, 91767 Palaiseau (France); Xu, B.; Wang, Z. [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, P. O. Box 912, Beijing 100083 (China); Zheng, Y. [Institut des NanoSciences de Paris, UPMC, CNRS UMR 7588, 4 place Jussieu, 75005 Paris (France); Tao, B. [Institut Jean Lamour, UMR 7198, CNRS-Nancy Université, BP 239, 54506 Vandoeuvre (France); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190 (China); Han, X. F. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190 (China)

    2014-07-07

    An efficient electrical spin injection into an InGaAs/GaAs quantum well light emitting diode is demonstrated thanks to a CoFeB/MgO spin injector. The textured MgO tunnel barrier is fabricated by two different techniques: sputtering and molecular beam epitaxy. The maximal spin injection efficiency is comparable for both methods. Additionally, the effect of annealing is also investigated for the two types of samples. Both samples show the same trend: an increase of the electroluminescence circular polarization (P{sub c}) with the increase of annealing temperature, followed by a saturation of P{sub c} beyond 350?°C annealing. Since the increase of P{sub c} starts well below the crystallization temperature of the full CoFeB bulk layer, this trend could be mainly due to an improvement of chemical structure at the top CoFeB/MgO interface. This study reveals that the control of CoFeB/MgO interface is essential for an optimal spin injection into semiconductor.

  16. Effect of tunnel injection through the Schottky gate on the static and noise behavior of GaInAs/AlInAs high electron mobility transistor

    SciTech Connect (OSTI)

    Moro-Melgar, Diego; Mateos, Javier González, Tomás Vasallo, Beatriz G.

    2014-12-21

    By using a Monte Carlo simulator, the influence of the tunnel injection through the Schottky contact at the gate electrode of a GaInAs/AlInAs High Electron Mobility Transistor (HEMT) has been studied in terms of the static and noise performance. The method used to characterize the quantum tunnel current has been the Wentzel-Kramers-Brillouin (WKB) approach. The possibility of taking into account the influence of the image charge effect in the potential barrier height has been included as well. Regarding the static behavior, tunnel injection leads to a decrease in the drain current I{sub D} due to an enhancement of the potential barrier controlling the carrier transport through the channel. However, the pinch-off is degraded due to the tunneling current. Regarding the noise behavior, since the fluctuations in the potential barrier height caused by the tunnel-injected electrons are strongly coupled with the drain current fluctuations, a significant increase in the drain-current noise takes place, even when the tunnel effect is hardly noticeable in the static I-V characteristics, fact that must be taken into account when designing scaled HEMT for low-noise applications. In addition, tunnel injection leads to the appearance of full shot noise in the gate current.

  17. Mode-hopping mechanism generating colored noise in a magnetic tunnel junction based spin torque oscillator

    SciTech Connect (OSTI)

    Sharma, Raghav; Dürrenfeld, P.; Iacocca, E.; Heinonen, O. G.; Åkerman, J.; Muduli, P. K.

    2014-09-29

    The frequency noise spectrum of a magnetic tunnel junction based spin torque oscillator is examined where multiple modes and mode-hopping events are observed. The frequency noise spectrum is found to consist of both white noise and 1/f frequency noise. We find a systematic and similar dependence of both white noise and 1/f frequency noise on bias current and the relative angle between the reference and free layers, which changes the effective damping and hence the mode-hopping behavior in this system. The frequency at which the 1/f frequency noise changes to white noise increases as the free layer is aligned away from the anti-parallel orientation w.r.t the reference layer. These results indicate that the origin of 1/f frequency noise is related to mode-hopping, which produces both white noise as well as 1/f frequency noise similar to the case of ring lasers.

  18. Nonequilibrium theory of a hot-electron bolometer with normal metal-insulator-superconductor tunnel junction

    SciTech Connect (OSTI)

    Golubev, Dmitri; Kuzmin, Leonid

    2001-06-01

    The operation of the hot-electron bolometer with normal metal-insulator-superconductor (NIS) tunnel junction as a temperature sensor is analyzed theoretically. The responsivity and the noise equivalent power (NEP) of the bolometer are obtained numerically for typical experimental parameters. Relatively simple approximate analytical expressions for these values are derived. The time constant of the device is also found. We demonstrate that the effect of the electron cooling by the NIS junction, which serves as a thermometer, can improve the sensitivity. This effect is also useful in the presence of the finite background power load. We discuss the effect of the correlation of the shot noise and the heat flow noise in the NIS junction. {copyright} 2001 American Institute of Physics.

  19. Scanning tunneling microscopy reveals LiMnAs is a room temperature anti-ferromagnetic semiconductor

    SciTech Connect (OSTI)

    Wijnheijmer, A. P.; Koenraad, P. M.; Marti, X.; Holy, V.; Cukr, M.; Novak, V.; Jungwirth, T.

    2012-03-12

    We performed scanning tunneling microscopy and spectroscopy on a LiMnAs(001) thin film epitaxially grown on an InAs(001) substrate by molecular beam epitaxy. While the in situ cleavage exposed only the InAs(110) non-polar planes, the cleavage continued into the LiMnAs thin layer across several facets. We combined both topography and current mappings to confirm that the facets correspond to LiMnAs. By spectroscopy we show that LiMnAs has a band gap. The band gap evidenced in this study, combined with the known Neel temperature well above room temperature, confirms that LiMnAs is a promising candidate for exploring the concepts of high temperature semiconductor spintronics based on antiferromagnets.

  20. Three-terminal magnetic tunneling junction device with perpendicular anisotropy CoFeB sensing layer

    SciTech Connect (OSTI)

    Honjo, H. Nebashi, R.; Tokutome, K.; Miura, S.; Sakimura, N.; Sugibayashi, T.; Fukami, S.; Kinoshita, K.; Murahata, M.; Kasai, N.; Ishihara, K.; Ohno, H.

    2014-05-07

    We demonstrated read and write characteristics of a three terminal memory device with a perpendicular anisotropy-free layer of a strip of [Co/Ni] and a low-switching perpendicular-anisotropy CoFeB/MgO sensing layer. This new design of the cell results in a small cell area. The switching magnetic field of the sensing layer can be decreased by changing sputtering gas for the Ta-cap from Ar to Kr. An electron energy-loss spectroscopy analysis of the cross-section of the magnetic tunneling junction (MTJ) revealed that the boron content in CoFeB with a Kr-sputtered Ta-cap was smaller than that with an Ar-sputtered one. A change in resistance for the MTJ was observed that corresponded to the magnetic switching of the Co/Ni wire and its magnetoresistance ratio and critical current were 90% and 0.8?mA, respectively.

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

    DOE Patents [OSTI]

    Kazmerski, Lawrence L. (Lakewood, CO)

    1990-01-01

    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.

  2. Chiral tunneling through generic one-dimensional potential barriers in bilayer graphene

    E-Print Network [OSTI]

    V. Kleptsyn; A. Okunev; I. Schurov; D. Zubov; M. I. Katsnelson

    2015-07-28

    We study tunneling of charge carriers in single- and bilayer graphene. We propose an explanation for non-zero "magic angles" with 100% transmission for the case of symmetric potential barrier, as well as for their almost-survival for slightly asymmetric barrier in the bilayer graphene known previously from numerical simulations. Most importantly, we demonstrate that these magic angles are not protected in the case of bilayer and give an explicit example of a barrier with very small electron transmission probability for any angles. This means that one can lock charge carriers by a p-n-p (or n-p-n) junction without opening energy gap. This creates new opportunities for the construction of graphene transistors.

  3. In situ scanning tunneling microscope tip treatment device for spin polarization imaging

    DOE Patents [OSTI]

    Li, An-Ping [Oak Ridge, TN; Jianxing, Ma [Oak Ridge, TN; Shen, Jian [Knoxville, TN

    2008-04-22

    A tip treatment device for use in an ultrahigh vacuum in situ scanning tunneling microscope (STM). The device provides spin polarization functionality to new or existing variable temperature STM systems. The tip treatment device readily converts a conventional STM to a spin-polarized tip, and thereby converts a standard STM system into a spin-polarized STM system. The tip treatment device also has functions of tip cleaning and tip flashing a STM tip to high temperature (>2000.degree. C.) in an extremely localized fashion. Tip coating functions can also be carried out, providing the tip sharp end with monolayers of coating materials including magnetic films. The device is also fully compatible with ultrahigh vacuum sample transfer setups.

  4. Four-probe measurements with a three-probe scanning tunneling microscope

    SciTech Connect (OSTI)

    Salomons, Mark [National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta T6G 2M9 (Canada)] [National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta T6G 2M9 (Canada); Martins, Bruno V. C.; Zikovsky, Janik; Wolkow, Robert A., E-mail: rwolkow@ualberta.ca [National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta T6G 2M9 (Canada); Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1 (Canada)

    2014-04-15

    We present an ultrahigh vacuum (UHV) three-probe scanning tunneling microscope in which each probe is capable of atomic resolution. A UHV JEOL scanning electron microscope aids in the placement of the probes on the sample. The machine also has a field ion microscope to clean, atomically image, and shape the probe tips. The machine uses bare conductive samples and tips with a homebuilt set of pliers for heating and loading. Automated feedback controlled tip-surface contacts allow for electrical stability and reproducibility while also greatly reducing tip and surface damage due to contact formation. The ability to register inter-tip position by imaging of a single surface feature by multiple tips is demonstrated. Four-probe material characterization is achieved by deploying two tips as fixed current probes and the third tip as a movable voltage probe.

  5. On the role of disorder on graphene and graphene nanoribbon-based vertical tunneling transistors

    SciTech Connect (OSTI)

    Ghobadi, Nayereh; Pourfath, Mahdi E-mail: pourfath@iue.tuwien.ac.at

    2014-11-14

    In this work, the characteristics of vertical tunneling field-effect transistors based on graphene (VTGFET) and graphene nanoribbon heterostructure (VTGNRFET) in the presence of disorder are theoretically investigated. An statistical analysis based on an atomistic tight-binding model for the electronic bandstructure along with the non-equilibrium Green's function formalism are employed. We study the dependence of the averaged density of states, transmission probability, on- and off-state conductances, on/off conductance ratio, and transfer characteristics on the substrate induced potential fluctuations and vacancies. In addition, the variabilities of the device characteristics due to the presence of disorder are evaluated. It can be inferred from the results that while introducing vacancies cause a relatively modest suppression of the transmission probability, potential fluctuations lead to the significant increase of transmission probability and conductance of the device. Moreover, the results show that the transport properties of VTGFET are more robust against disorder compared to VTGNRFET.

  6. Thermal creep assisted dust lifting on Mars: Wind tunnel experiments for the entrainment threshold velocity

    E-Print Network [OSTI]

    Küpper, Markus

    2015-01-01

    In this work we present laboratory measurements on the reduction of the threshold friction velocity necessary for lifting dust if the dust bed is illuminated. Insolation of a porous soil establishes a temperature gradient. At low ambient pressure this gradient leads to thermal creep gas flow within the soil. This flow leads to a sub-surface overpressure which supports lift imposed by wind. The wind tunnel was run with Mojave Mars Simulant and air at 3, 6 and 9 mbar, to cover most of the pressure range at martian surface levels. Our first measurements imply that the insolation of the martian surface can reduce the entrainment threshold velocity between 4 % and 19 % for the conditions sampled with our experiments. An insolation activated soil might therefore provide additional support for aeolian particle transport at low wind speeds.

  7. Power-Law Energy Splitting Generated By Tunneling Between Non-smooth Tori

    E-Print Network [OSTI]

    Z. Q. Bai

    2001-12-20

    We discuss the energy level splitting $\\Delta\\epsilon$ due to quantum tunneling between congruent tori in phase space. In analytic cases, it is well known that $\\Delta\\epsilon$ decays faster than power of $\\hbar$ in the semi-classical limit. This is not true in non-smooth cases, specifically, when the tori are connected by line on which the Hamiltonian is not smooth. Under the assumption that the non-smoothness depends only upon the x- or p-coordinate, the leading term in the semi-classical expansion of $\\Delta\\epsilon$ is derived, which shows that $\\Delta \\epsilon$ decays as $\\hbar^{k+1}$ when $\\hbar\\to 0$ with k being the order of non-smoothness.

  8. Evaluate and characterize mechanisms controlling transport, fate and effects of army smokes in an aerosol wind tunnel: Transport, transformations, fate and terrestrial ecological effects of fog oil obscurant smokes: Final report

    SciTech Connect (OSTI)

    Cataldo, D.A.; Van Voris, P.; Ligotke, M.W.; Fellows, R.J.; McVeety, B.D.; Li, Shu-mei W.; Bolton, H. Jr.; Fredrickson, J.K.

    1989-01-01

    The terrestrial transport, chemical fate, and ecological effects of fog oil (FO) smoke obscurants were evaluated under controlled wind tunnel conditions. The primary objectives of this research program are to characterize and assess the impacts of smoke and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States; (2) physical and chemical properties of soils representative of these training sites; and (3) soil microbiological and invertebrate communities. Impacts and dose/responses were evaluated based on an exposure scenario, including exposure duration, exposure rate, and sequential cumulative dosing. Key to understanding the environmental impacts of fog oil smoke/obscurants is establishing the importance of environmental parameters, such as relative humidity and wind speed on airborne aerosol characteristics and deposition to receptor surfaces. Direct and indirect biotic effects were evaluated using five plant species and three soil types. 29 refs., 35 figs., 32 tabs.

  9. Tornado type wind turbines

    DOE Patents [OSTI]

    Hsu, Cheng-Ting (Ames, IA)

    1984-01-01

    A tornado type wind turbine has a vertically disposed wind collecting tower with spaced apart inner and outer walls and a central bore. The upper end of the tower is open while the lower end of the structure is in communication with a wind intake chamber. An opening in the wind chamber is positioned over a turbine which is in driving communication with an electrical generator. An opening between the inner and outer walls at the lower end of the tower permits radially flowing air to enter the space between the inner and outer walls while a vertically disposed opening in the wind collecting tower permits tangentially flowing air to enter the central bore. A porous portion of the inner wall permits the radially flowing air to interact with the tangentially flowing air so as to create an intensified vortex flow which exits out of the top opening of the tower so as to create a low pressure core and thus draw air through the opening of the wind intake chamber so as to drive the turbine.

  10. Annotated Type Systems Program Analysis

    E-Print Network [OSTI]

    Palsberg, Jens

    Danish Summary xi 1 Introduction 1 1.1 The Standard Type System . . . . . . . . . . . . . . . . . 3 1 . . . . . . . . . . . . . . . . . . 36 2.1.3 The Conjunction Type System . . . . . . . . . . . . 37 2.2 The Power of tAnnotated Type Systems for Program Analysis Kirsten Lackner Solberg Computer Science Department

  11. PROGRAMMING WITH TYPES A Dissertation

    E-Print Network [OSTI]

    Weirich, Stephanie

    WITH TYPES Stephanie Claudene Weirich, Ph.D. Cornell University 2002 Run-time type analysis, facilities to support type analysis often require complicated language semantics that allow little freedom to list. Steve's parents Arthur and Deborah Zdancewic have encouraged me as long as I have known them. I

  12. On the valve nature of a monolayer of aligned molecular magnets in tunneling spin-polarized electrons: Towards organic molecular spintronics

    SciTech Connect (OSTI)

    Chakrabarti, Sudipto; Pal, Amlan J.

    2014-01-06

    We form a monolayer of magnetic organic molecules and immobilize their moments pointing either upwards or downwards with respect to the substrate through an electrostatic-binding process. Such a monolayer is probed with a scanning tunneling microscope tip, which is also magnetized with the magnetization vector pointing towards (or away from) apex of the tip. From spin-polarized tunneling current, we show that the current was higher when magnetization vectors of the tip and molecules were parallel as compared to that when they were anti-parallel. We show that for tunneling of spin-polarized electrons, aligned organic molecular magnets can act as a valve.

  13. University of Alberta SafeType: Detecting Type Violations for Type-Based Alias

    E-Print Network [OSTI]

    Amaral, José Nelson

    University of Alberta SafeType: Detecting Type Violations for Type-Based Alias Analysis of C Edmonton, Alberta Permission is hereby granted to the University of Alberta Libraries to reproduce single, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other

  14. TYPE OF OPERATION R Research & Development T& Facility Type

    Office of Legacy Management (LM)

    -- R Research & Development T& Facility Type 0 Production scale testing a Pilat scale Y-. Bench Scale Process i Theoretical Studies Sample & Analysis 0 Productian 0 Disposal...

  15. 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 Aqsa Mosque, with the objective to pursue its dangerous influence on the structure of Islamic buildings

  16. Comment on: Direct space-time observation of pulse tunneling in an electromagnetic band gap, S.Doiron,A.Hache,H.Winful

    E-Print Network [OSTI]

    G. Nimtz; A. A. Stahlhofen

    2007-10-26

    The title of this article is misleading. The authors have investigated a resonator but not a tunneling barrier see also Refs.\\cite{Winful2} The measured superluminal group velocity and discussed is that studied on a Lorentz-Lorenz oscillator by Sommerfeld and Brillouin a hundred years ago \\cite{Brillouin}. It is similar to the faster than light experiment by Wang et al. based also on anomalous dispersion with a complex refractive index of a resonator \\cite{Wang}. Tunneling, however, is understood and performed by electromagnetic evanescent modes or by tunneling solutions of the Schr\\"odinger equation, which have purely imaginary wave numbers. The latter includes a purely imaginary refractive index. Signals with purely evanescent frequency components can travel at a superluminal velocity \\cite{NimtzH,Nimtz1}. Inside the barrier tunneling proceeds even instantaneously, i.e.by a process described by virtual photons \\cite{Stahlhofen}.

  17. Magnetization switching in a CoFeB/MgO magnetic tunnel junction by combining spin-transfer torque and electric field-effect

    SciTech Connect (OSTI)

    Kanai, S.; Nakatani, Y.; Yamanouchi, M.; Ikeda, S.; Sato, H.; Matsukura, F.; Ohno, H.

    2014-05-26

    We propose and demonstrate a scheme for magnetization switching in magnetic tunnel junctions, in which two successive voltage pulses are applied to utilize both spin-transfer torque and electric field effect. Under this switching scheme, a CoFeB/MgO magnetic tunnel junction with perpendicular magnetic easy axis is shown to switch faster than by spin-transfer torque alone and more reliably than that by electric fields alone.

  18. An efficient atomistic quantum mechanical simulation on InAs band-to-band tunneling field-effect transistors

    SciTech Connect (OSTI)

    Wang, Zhi [State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Jiang, Xiang-Wei; Li, Shu-Shen [State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wang, Lin-Wang, E-mail: lwwang@lbl.gov [Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2014-03-24

    We have presented a fully atomistic quantum mechanical simulation method on band-to-band tunneling (BTBT) field-effect transistors (FETs). Our simulation approach is based on the linear combination of bulk band method with empirical pseudopotentials, which is an atomist method beyond the effective-mass approximation or k.p perturbation method, and can be used to simulate real-size devices (?10{sup 5} atoms) efficiently (?5 h on a few computational cores). Using this approach, we studied the InAs dual-gate BTBT FETs. The I-V characteristics from our approach agree very well with the tight-binding non-equilibrium Green's function results, yet our method costs much less computationally. In addition, we have studied ways to increase the tunneling current and analyzed the effects of different mechanisms for that purpose.

  19. Quantum noise with exchange and tunneling: Predictions for a two-particle scattering experiment with time-dependent oscillatory potentials

    E-Print Network [OSTI]

    Enrique Colomés; Damiano Marian; Xavier Oriols

    2015-11-02

    Quantum noise with exchange and tunneling is studied within time-dependent wave packets. A novel expression for the quantum noise of two identical particles injected simultaneously from opposite sides of a tunneling barrier is presented. Such quantum noise expression provides a physical (non-spurious) explanation for the experimental detection of two electrons at the same side under static potentials. Numerical simulations of the two-particle scattering probabilities in a double barrier potential with an oscillatory well are performed. The dependence of the quantum noise on the electron energy and oscillatory frequency are analyzed. The peculiar behaviour of the dependence of the quantum noise on such parameters is proposed as a test about the soundness of this novel quantum noise expression, for either static or oscillatory potentials.

  20. Constraining the Natural MSSM through tunneling to color-breaking vacua at zero and non-zero temperature

    E-Print Network [OSTI]

    J. E. Camargo-Molina; B. Garbrecht; B. O'Leary; W. Porod; F. Staub

    2014-09-01

    We re-evaluate the constraints on the parameter space of the minimal supersymmetric standard model from tunneling to charge- and/or color-breaking minima, taking into account thermal corrections. We pay particular attention to the region known as the Natural MSSM, where the masses of the scalar partners of the top quarks are within an order of magnitude or so of the electroweak scale. These constraints arise from the interaction between these scalar tops and the Higgs fields, which allows the possibility of parameter points having deep charge- and color-breaking true vacua. In addition to requiring that our electro-weak-symmetry-breaking, yet QCD- and electromagnetism-preserving vacuum has a sufficiently long lifetime at zero temperature, also demanding stability against thermal tunneling further restricts the allowed parameter space.

  1. Heun equation, Teukolsky equation, and type-D metrics

    E-Print Network [OSTI]

    D. Batic; H. Schmid

    2007-01-15

    Starting with the whole class of type-D vacuum backgrounds with cosmological constant we show that the separated Teukolsky equation for zero rest-mass fields with spin $s=\\pm 2$ (gravitational waves), $s=\\pm 1$ (electromagnetic waves) and $s=\\pm 1/2$ (neutrinos) is an Heun equation in disguise.

  2. Maintenance Types | Department of Energy

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

    requirements of any physical asset within its operating context. Chapter 5 of the Federal Energy Management Program's O&M Best Practices Guide outlines these maintenance types in...

  3. Portfolio Manager Space Type Discussion

    Broader source: Energy.gov [DOE]

    This presentation, given through the DOE's Technical Assistance Program (TAP), provides a discussion about space/type in regards to the Portfolio Manager Initiative.

  4. Window Types | Department of Energy

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

    its U-factor. There are advantages and disadvantages to all types of frame materials, but vinyl, wood, fiberglass, and some composite frame materials provide greater...

  5. Portfolio Manager Space Type Discussion

    Broader source: Energy.gov [DOE]

    This presentation, given through the DOE's Technical Assitance Program (TAP), provides a discussion about space/type in regards to the Portfolio Manager Initiative.

  6. Methane dissociative chemisorption and detailed balance on Pt(111): Dynamical constraints and the modest influence of tunneling

    SciTech Connect (OSTI)

    Donald, S. B.; Navin, J. K.; Harrison, I.

    2013-12-07

    A dynamically biased (d-) precursor mediated microcanonical trapping (PMMT) model of the activated dissociative chemisorption of methane on Pt(111) is applied to a wide range of dissociative sticking experiments, and, by detailed balance, to the methane product state distributions from the thermal associative desorption of adsorbed hydrogen with coadsorbed methyl radicals. Tunneling pathways were incorporated into the d-PMMT model to better replicate the translational energy distribution of the desorbing methane product from the laser induced thermal reaction of coadsorbed hydrogen and methyl radicals occurring near T{sub s} = 395 K. Although tunneling is predicted to be inconsequential to the thermal dissociative chemisorption of CH{sub 4} on Pt(111) at the high temperatures of catalytic interest, once the temperature drops to 395 K the tunneling fraction of the reactive thermal flux reaches 15%, and as temperatures drop below 275 K the tunneling fraction exceeds 50%. The d-PMMT model parameters of (E{sub 0} = 58.9?kJ/mol,?s = 2,??{sub v} = 0.40) describe the apparent threshold energy for CH{sub 4}/Pt(111) dissociative chemisorption, the number of surface oscillators involved in the precursor complex, and the efficacy of molecular vibrational energy to promote reaction, relative to translational energy directed along the surface normal. Molecular translations parallel to the surface and rotations are treated as spectator degrees of freedom. Transition state vibrational frequencies are derived from generalized gradient approximation-density functional theory electronic structure calculations. The d-PMMT model replicates the diverse range of experimental data available with good fidelity, including some new effusive molecular beam and ambient gas dissociative sticking measurements. Nevertheless, there are some indications that closer agreement between theory and experiments could be achieved if a surface efficacy less than one was introduced into the modeling as an additional dynamical constraint.

  7. The multiconfigurational time-dependent Hartree for fermions: Implementation, exactness and application to few-fermion tunneling to open space

    E-Print Network [OSTI]

    Elke Fasshauer; Axel U. J. Lode

    2015-10-10

    We report on an implementation of the multiconfigurational time-dependent Hartree method (MCTDH) for spin-polarized fermions (MCTDHF). Our approach is based on a mapping for opera- tors in Fock space that allows a compact and efficient application of the Hamiltonian and solution of the MCTDHF equations of motion. Our implementation extends, builds on and exploits the recursive implementation of MCTDH for bosons (R-MCTDHB) package. Together with R-MCTDHB, the present implementation of MCTDHF forms the MCTDH-X package. We benchmark the accuracy of the algorithm with the harmonic interaction model and a time-dependent generalization thereof. These models consider parabolically trapped particles that interact through a harmonic interaction potential. We demonstrate, that MCTDHF is capable of solving the time-dependent many-fermion Schr\\"odinger equation to an in principle arbitrary degree of precision and can hence yield numerically exact results even in the case of Hamiltonians with time-dependent one-body and two-body potentials. As an application we study the problem of two initially parabolically confined and charged fermions tunneling through a barrier to open space. We demonstrate the validity of a model proposed previously for the many-body tunneling to open space of bosonic particles with contact interactions [Proc. Natl. Acad. Sci. USA 109, 13521-13525 (2012)]. The many-fermion tunneling can be built up from sequentially happening single-fermion tunneling processes. The characteristic momenta of these processes are determined by the chemical potentials of trapped subsystems of smaller particle numbers: the escaped fermions convert the different chemical potentials into kinetic energy.

  8. Tunneling of the 3rd Kind: A Test of the Effective Non-locality of Quantum Field Theory

    E-Print Network [OSTI]

    Simon A. Gardiner; Holger Gies; Joerg Jaeckel; Chris J. Wallace

    2013-04-09

    Integrating out virtual quantum fluctuations in an originally local quantum field theory results in an effective theory which is non-local. In this Letter we argue that tunneling of the 3rd kind - where particles traverse a barrier by splitting into a pair of virtual particles which recombine only after a finite distance - provides a direct test of this non-locality. We sketch a quantum-optical setup to test this effect, and investigate observable effects in a simple toy model.

  9. Recrossing and tunnelling in the kinetics study of the OH + CH4 -> H2O + CH3 reaction

    E-Print Network [OSTI]

    Suleimanov, Yury V

    2015-01-01

    Thermal rate constants and several kinetic isotope effects were evaluated for the OH + CH4 hydrogen abstraction reaction using two kinetics approaches, ring polymer molecular dynamics (RPMD), and variational transition state theory with multidimensional tunnelling(VTST/MT), based on a refined full-dimensional analytical potential energy surface, PES-2014, in the temperature range 200-2000 K. For the OH + CH4 reaction, at low temperatures, T = 200 K, where the quantum tunnelling effect is more important, RPMD overestimates the experimental rate constants due to problems associated with PES-2014 in the deep tunnelling regime and to the known overestimation of this method in asymmetric reactions, while VTST/MT presents a better agreement, differences about 10%, due to compensation of several factors, inaccuracy of PES-2014 and ignoring anharmonicity. In the opposite extreme, T = 1000 K, recrossing effects play the main role, and the difference between both methods is now smaller, by a factor of 1.5. Given that R...

  10. Nominalization, Predication and Type Containment

    E-Print Network [OSTI]

    Kamareddine, Fairouz

    of Eindhoven, for their nancial support and hospitality during the academic year 1991{92. yKlein's work has by the uk Economic and Social Research Council. 1 #12;Abstract In an attempt to accommodate natural language, by assigning each expression a family of types. Another line of work has moved in the direction of type

  11. Archived Reference Building Type: Warehouse

    Broader source: Energy.gov [DOE]

    Here you will find past versions of the commercial reference building models for existing buildings constructed in or after 1980, organized by building type and location. A summary of building types and climate zones is available for reference. Current versions are also available.

  12. Archived Reference Building Type: Warehouse

    Broader source: Energy.gov [DOE]

    Here you will find past versions of the commercial reference building models for existing buildings constructed before 1980, organized by building type and location. A summary ofbuilding types and climate zones is available for reference. Current versions are also available.

  13. Field Wind Tunnel Assessment of the Potential for Wind Transport of Soils at Clean Slate 1

    SciTech Connect (OSTI)

    Lancaster, Nicholas [DRI; Gillespie, David [DRI; Hokett, Sam [DRI; Metzger, Steve [DRI

    2005-02-01

    Field wind tunnel studies conducted in May, June, and November 1997 on the remediated area at Clean Slate 1 provide information on the resuspension of dust from untreated surfaces and those stabilized with the co-polymer "Agrilok". A total of 24 valid datasets were obtained and provide information on the total flux of dust in a "worst case" scenario. The test conducted indicate that the surfaces treated with Agrilok are resistant to erosion and resuspension of fine particles by wind action in all but extreme cases. Most of the material emitted by these surfaces is probably derived from resuspension of dust deposited by natural processes with a minor contribution from disturbance during remediation activities. The concentration of 239Pu in in emitted dust was very low. In combination with the low dust fluxes from the treated surfaces, this resulted in a low activity flux of 239Pu from these surfaces. The results of this study strongly suggest that the techniques for remediating these surfaces are effective in minimizing the flux of dust that may contain 239Pu .

  14. A 30 mK, 13.5 T scanning tunneling microscope with two independent tips

    SciTech Connect (OSTI)

    Roychowdhury, Anita [Laboratory for Physical Sciences, College Park, Maryland 20742 (United States) [Laboratory for Physical Sciences, College Park, Maryland 20742 (United States); Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, Maryland 20740 (United States); Gubrud, M. A.; Dana, R.; Dreyer, M. [Laboratory for Physical Sciences, College Park, Maryland 20742 (United States)] [Laboratory for Physical Sciences, College Park, Maryland 20742 (United States); Anderson, J. R.; Lobb, C. J.; Wellstood, F. C. [Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, Maryland 20740 (United States)] [Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, Maryland 20740 (United States)

    2014-04-15

    We describe the design, construction, and performance of an ultra-low temperature, high-field scanning tunneling microscope (STM) with two independent tips. The STM is mounted on a dilution refrigerator and operates at a base temperature of 30 mK with magnetic fields of up to 13.5 T. We focus on the design of the two-tip STM head, as well as the sample transfer mechanism, which allows in situ transfer from an ultra high vacuum preparation chamber while the STM is at 1.5 K. Other design details such as the vibration isolation and rf-filtered wiring are also described. Their effectiveness is demonstrated via spectral current noise characteristics and the root mean square roughness of atomic resolution images. The high-field capability is shown by the magnetic field dependence of the superconducting gap of Cu{sub x}Bi{sub 2}Se{sub 3}. Finally, we present images and spectroscopy taken with superconducting Nb tips with the refrigerator at 35 mK that indicate that the effective temperature of our tips/sample is approximately 184 mK, corresponding to an energy resolution of 16 ?eV.

  15. Influence of hydrogen patterning gas on electric and magnetic properties of perpendicular magnetic tunnel junctions

    SciTech Connect (OSTI)

    Jeong, J. H.; Endoh, T.; Kim, Y.; Kim, W. K.; Park, S. O.

    2014-05-07

    To identify the degradation mechanism in magnetic tunnel junctions (MTJs) using hydrogen, the properties of the MTJs were measured by applying an additional hydrogen etch process and a hydrogen plasma process to the patterned MTJs. In these studies, an additional 50?s hydrogen etch process caused the magnetoresistance (MR) to decrease from 103% to 14.7% and the resistance (R) to increase from 6.5?k? to 39?k?. Moreover, an additional 500?s hydrogen plasma process decreased the MR from 103% to 74% and increased R from 6.5?k? to 13.9?k?. These results show that MTJs can be damaged by the hydrogen plasma process as well as by the hydrogen etch process, as the atomic bonds in MgO may break and react with the exposed hydrogen gas. Compounds such as MgO hydrate very easily. We also calculated the damaged layer width (DLW) of the patterned MTJs after the hydrogen etching and plasma processes, to evaluate the downscaling limitations of spin-transfer-torque magnetic random-access memory (STT-MRAM) devices. With these calculations, the maximum DLWs at each side of the MTJ, generated by the etching and plasma processes, were 23.8?nm and 12.8?nm, respectively. This result validates that the hydrogen-based MTJ patterning processes cannot be used exclusively in STT-MRAMs beyond 20?nm.

  16. Zero-point energy, tunneling, and vibrational adiabaticity in the Mu + H2 reaction

    SciTech Connect (OSTI)

    Mielke, Steven L.; Garrett, Bruce C.; Fleming, Donald G.; Truhlar, Donald G.

    2015-01-09

    Abstract: Isotopic substitution of muonium for hydrogen provides an unparalleled opportunity to deepen our understanding of quantum mass effects on chemical reactions. A recent topical review [Aldegunde et al., Mol. Phys. 111, 3169 (2013)] of the thermal and vibrationally-stateselected reaction of Mu with H2 raises a number of issues that are addressed here. We show that some earlier quantum mechanical calculations of the Mu + H2 reaction, which are highlighted in this review and which have been used to benchmark approximate methods, are in error by as much as 19% in the low-temperature limit. We demonstrate that an approximate treatment of the Born–Oppenheimer diagonal correction that was used in some recent studies is not valid for treating the vibrationally-state-selected reaction. We also discuss why vibrationally adiabatic potentials that neglect bend zero-point energy are not a useful analytical tool for understanding reaction rates and why vibrationally nonadiabatic transitions cannot be understood by considering tunneling through vibrationally adiabatic potentials. Finally, we present calculations on a hierarchical family of potential energy surfaces to assess the sensitivity of rate constants to the quality of the potential surface.

  17. Scanning tunneling microscopy/spectroscopy of picene thin films formed on Ag(111)

    SciTech Connect (OSTI)

    Yoshida, Yasuo, E-mail: yyoshida@issp.u-tokyo.ac.jp; Yokosuka, Takuya; Hasegawa, Yukio, E-mail: hasegawa@issp.u-tokyo.ac.jp [The Institute of Solid State Physics, The University of Tokyo, Kashiwa 277-8581 (Japan); Yang, Hung-Hsiang [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Huang, Hsu-Sheng; Guan, Shu-You; Su, Wei-Bin; Chang, Chia-Seng [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China); Yanagisawa, Susumu [Department of Physics and Earth Science Department, University of the Ryukyus, 1 Nishihara, Okinawa 903-0213 (Japan); Lin, Minn-Tsong [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Hoffmann, Germar [The Institute of Solid State Physics, The University of Tokyo, Kashiwa 277-8581 (Japan); Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2014-09-21

    Using ultrahigh-vacuum low-temperature scanning tunneling microscopy and spectroscopy combined with first principles density functional theory calculations, we have investigated structural and electronic properties of pristine and potassium (K)-deposited picene thin films formed in situ on a Ag(111) substrate. At low coverages, the molecules are uniformly distributed with the long axis aligned along the [112{sup ¯}] direction of the substrate. At higher coverages, ordered structures composed of monolayer molecules are observed, one of which is a monolayer with tilted and flat-lying molecules resembling a (11{sup ¯}0) plane of the bulk crystalline picene. Between the molecules and the substrate, the van der Waals interaction is dominant with negligible hybridization between their electronic states; a conclusion that contrasts with the chemisorption exhibited by pentacene molecules on the same substrate. We also observed a monolayer picene thin film in which all molecules were standing to form an intermolecular ? stacking. Two-dimensional delocalized electronic states are found on the K-deposited ? stacking structure.

  18. Unveiling Stability Criteria of DNA-Carbon Nanotubes Constructs by Scanning Tunneling Microscopy and Computational Modeling

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

    Kilina, Svetlana; Yarotski, Dzmitry A.; Talin, A. Alec; Tretiak, Sergei; Taylor, Antoinette J.; Balatsky, Alexander V.

    2011-01-01

    We present a combined approach that relies on computational simulations and scanning tunneling microscopy (STM) measurements to reveal morphological properties and stability criteria of carbon nanotube-DNA (CNT-DNA) constructs. Application of STM allows direct observation of very stable CNT-DNA hybrid structures with the well-defined DNA wrapping angle of 63.4 ° and a coiling period of 3.3?nm. Using force field simulations, we determine how the DNA-CNT binding energy depends on the sequence and binding geometry of a single strand DNA. This dependence allows us to quantitatively characterize the stability of a hybrid structure with an optimal ?-stacking between DNA nucleotides andmore »the tube surface and better interpret STM data. Our simulations clearly demonstrate the existence of a very stable DNA binding geometry for (6,5) CNT as evidenced by the presence of a well-defined minimum in the binding energy as a function of an angle between DNA strand and the nanotube chiral vector. This novel approach demonstrates the feasibility of CNT-DNA geometry studies with subnanometer resolution and paves the way towards complete characterization of the structural and electronic properties of drug-delivering systems based on DNA-CNT hybrids as a function of DNA sequence and a nanotube chirality. « less

  19. Field Wind Tunnel Assessment of the Potential for Wind Transport of Soils

    SciTech Connect (OSTI)

    Lancaster, Nicholas [Desert Research Inst. (DRI), Reno, NV (United States); Metzger, Steve [Desert Research Inst. (DRI), Reno, NV (United States)

    2005-02-01

    This report documents a series of field experiments carried out in the Double Tracks area of the Tonopah Test Range in June, July, and August 1996 and March and July 1997. The aim of the experiments was to: (1) determine the wind speeds necessary to entrain surface particles from excavated surfaces in the study area and (2) determine dust emissions from surfaces that had been stabilized permanently by planted natural vegetation. This investigation assessed the potential for wind transport of surface soils, including resuspension and emission of dust sized particles from areas of surface heavy metal contamination, following site remediation, as well as the actual emissions from these areas. The remediation site is located in Area 73 of the Tonopah Test Range. The goal of the field experiments was to measure the velocities with which boundary layer winds might initiate dust emissions from the affected site, and to gage the effectiveness of surface stabilization procedures to prevent such emissions. Particle movement measurements were generated through the use of a portable wind tunnel laid directly on the excavated surface.

  20. Implications of the Baltimore Rail Tunnel Fire for Full-Scale Testing of Shipping Casks

    SciTech Connect (OSTI)

    Halstead, R. J.; Dilger, F.

    2003-02-25

    The U.S. Nuclear Regulatory Commission (NRC) does not currently require full-scale physical testing of shipping casks as part of its certification process. Stakeholders have long urged NRC to require full-scale testing as part of certification. NRC is currently preparing a full-scale casktesting proposal as part of the Package Performance Study (PPS) that grew out of the NRC reexamination of the Modal Study. The State of Nevada and Clark County remain committed to the position that demonstration testing would not be an acceptable substitute for a combination of full-scale testing, scale-model tests, and computer simulation of each new cask design prior to certification. Based on previous analyses of cask testing issues, and on preliminary findings regarding the July 2001 Baltimore rail tunnel fire, the authors recommend that NRC prioritize extra-regulatory thermal testing of a large rail cask and the GA-4 truck cask under the PPS. The specific fire conditions and other aspects of the full-scale extra-regulatory tests recommended for the PPS are yet to be determined. NRC, in consultation with stakeholders, must consider past real-world accidents and computer simulations to establish temperature failure thresholds for cask containment and fuel cladding. The cost of extra-regulatory thermal testing is yet to be determined. The minimum cost for regulatory thermal testing of a legal-weight truck cask would likely be $3.3-3.8 million.

  1. New approaches for modeling type Ia supernovae

    E-Print Network [OSTI]

    Zingale, Michael; Almgren, Ann S.; Bell, John B.; Day, Marcus S.; Rendleman, Charles A.; Woosley, Stan

    2007-01-01

    runaway in Type Ia supernovae: How to run away? oIgnition in Type Ia Supernovae. II. A Three- dimensionalnumber modeling of type Ia supernovae. I. hydrodynamics.

  2. P-type gallium nitride

    DOE Patents [OSTI]

    Rubin, Michael (Berkeley, CA); Newman, Nathan (Montara, CA); Fu, Tracy (Berkeley, CA); Ross, Jennifer (Pleasanton, CA); Chan, James (Berkeley, CA)

    1997-01-01

    Several methods have been found to make p-type gallium nitride. P-type gallium nitride has long been sought for electronic devices. N-type gallium nitride is readily available. Discovery of p-type gallium nitride and the methods for making it will enable its use in ultraviolet and blue light-emitting diodes and lasers. pGaN will further enable blue photocathode elements to be made. Molecular beam epitaxy on substrates held at the proper temperatures, assisted by a nitrogen beam of the proper energy produced several types of p-type GaN with hole concentrations of about 5.times.10.sup.11 /cm.sup.3 and hole mobilities of about 500 cm.sup.2 /V-sec, measured at 250.degree. K. P-type GaN can be formed of unintentionally-doped material or can be doped with magnesium by diffusion, ion implantation, or co-evaporation. When applicable, the nitrogen can be substituted with other group III elements such as Al.

  3. P-type gallium nitride

    DOE Patents [OSTI]

    Rubin, M.; Newman, N.; Fu, T.; Ross, J.; Chan, J.

    1997-08-12

    Several methods have been found to make p-type gallium nitride. P-type gallium nitride has long been sought for electronic devices. N-type gallium nitride is readily available. Discovery of p-type gallium nitride and the methods for making it will enable its use in ultraviolet and blue light-emitting diodes and lasers. pGaN will further enable blue photocathode elements to be made. Molecular beam epitaxy on substrates held at the proper temperatures, assisted by a nitrogen beam of the proper energy produced several types of p-type GaN with hole concentrations of about 5{times}10{sup 11} /cm{sup 3} and hole mobilities of about 500 cm{sup 2} /V-sec, measured at 250 K. P-type GaN can be formed of unintentionally-doped material or can be doped with magnesium by diffusion, ion implantation, or co-evaporation. When applicable, the nitrogen can be substituted with other group III elements such as Al. 9 figs.

  4. Direct experimental evidence for the reversal of carrier type upon hydrogen intercalation in epitaxial graphene/SiC(0001)

    SciTech Connect (OSTI)

    Rajput, S., E-mail: srajput@uwm.edu; Li, Y. Y.; Li, L. [Department of Physics, University of Wisconsin, Milwaukee, Wisconsin 53211 (United States)

    2014-01-27

    Raman spectroscopy and scanning tunneling microscopy/spectroscopy measurements are performed to determine the atomic structure and electronic properties of H-intercalated graphene/SiC(0001) obtained by annealing the as-grown epitaxial graphene in hydrogen atmosphere. While the as-grown graphene is found to be n-type with the Dirac point (E{sub D}) at 450 and 350?meV below Fermi level for the 1st and 2nd layer, the H-intercalated graphene is p-type with E{sub D} at 320 and 200?meV above. In addition, ripples are observed in the now quasi-free standing graphene decoupled from the SiC substrate. This causes fluctuations in the Dirac point that directly follow the undulations of the ripples, resulting in electron and hole puddles in the H-intercalated graphene/SiC(0001)

  5. Issues in Type IIA Uplifting

    E-Print Network [OSTI]

    Renata Kallosh; Masoud Soroush

    2007-06-09

    Moduli stabilization in the type IIA massive string theory so far was achieved only in the AdS vacua. The uplifting to dS vacua has not been performed as yet: neither the analogs of type IIB anti-D3 brane at the tip of the conifold, nor the appropriate D-terms have been identified. The hope was recently expressed that the F-term uplifting may work. We investigate this possibility in the context of a simplified version of the type IIA model developed in hep-th/0505160 and find that the F-term does not uplift the AdS vacua to dS vacua with positive CC. Thus it remains a challenging task to find phenomenologically acceptable vacua in the type IIA string theory.

  6. 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)

    Chen, D. Y.; Sun, Y.; He, Y. J.; Xu, L.; Xu, J.

    2014-01-28

    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.

  7. A continuum model with a percolation threshold and tunneling-assisted interfacial conductivity for carbon nanotube-based nanocomposites

    SciTech Connect (OSTI)

    Wang, Yang; Weng, George J., E-mail: weng@jove.rutgers.edu [Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, New Jersey 08903 (United States); Meguid, Shaker A. [Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8 (Canada); Hamouda, Abdel Magid [Department of Mechanical and Industrial Engineering, Qatar University, Doha (Qatar)

    2014-05-21

    A continuum model that possesses several desirable features of the electrical conduction process in carbon-nanotube (CNT) based nanocomposites is developed. Three basic elements are included: (i) percolation threshold, (ii) interface effects, and (iii) tunneling-assisted interfacial conductivity. We approach the first one through the selection of an effective medium theory. We approach the second one by the introduction of a diminishing layer of interface with an interfacial conductivity to build a 'thinly coated' CNT. The third one is introduced through the observation that interface conductivity can be enhanced by electron tunneling which in turn can be facilitated with the formation of CNT networks. We treat this last issue in a continuum fashion by taking the network formation as a statistical process that can be represented by Cauchy's probability density function. The outcome is a simple and yet widely useful model that can simultaneously capture all these fundamental characteristics. It is demonstrated that, without considering the interface effect, the predicted conductivity would be too high, and that, without accounting for the additional contribution from the tunneling-assisted interfacial conductivity, the predicted conductivity beyond the percolation threshold would be too low. It is with the consideration of all three elements that the theory can fully account for the experimentally measured data. We further use the developed model to demonstrate that, despite the anisotropy of the intrinsic CNT conductivity, it is its axial component along the CNT direction that dominates the overall conductivity. This theory is also proved that, even with a totally insulating matrix, it is still capable of delivering non-zero conductivity beyond the percolation threshold.

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

    E-Print Network [OSTI]

    Stephen, Alton Lee

    1968-01-01

    FE7 SE'BID 1'"Y AND PB I '&NAEY DLS1GN STUDY POR A H. GH V' LOCITY, 10iif DFN ITY BIND UNNEL UT1LI71NG THE THEP". AL CREEP EFFECT A Thesis Alton Lee Steghens, Jr. Submitted to the Graduate College of the Texas AKN University in partial fulf... illment o- the regui ements for the degree NASTEP. 0 SCIENCE Aug st 1968 Yajor Subject: A rospa. e Engineering FEASIBILITY AND PRELIMINARY DESIGN STUDY FOR A HIGH VELOCITY, LOW DENSITY HIND TUNNEL UTILIZING THE THERiMAL CREEP EFFECT A Thesis Alton...

  9. A variable-temperature nanostencil compatible with a low-temperature scanning tunneling microscope/atomic force microscope

    SciTech Connect (OSTI)

    Steurer, Wolfram, E-mail: wst@zurich.ibm.com; Gross, Leo; Schlittler, Reto R.; Meyer, Gerhard [IBM Research-Zurich, 8803 Rüschlikon (Switzerland)] [IBM Research-Zurich, 8803 Rüschlikon (Switzerland)

    2014-02-15

    We describe a nanostencil lithography tool capable of operating at variable temperatures down to 30 K. The setup is compatible with a combined low-temperature scanning tunneling microscope/atomic force microscope located within the same ultra-high-vacuum apparatus. The lateral movement capability of the mask allows the patterning of complex structures. To demonstrate operational functionality of the tool and estimate temperature drift and blurring, we fabricated LiF and NaCl nanostructures on Cu(111) at 77 K.

  10. Type Checking Type Classes Tobias Nipkow and Christian Prehofer

    E-Print Network [OSTI]

    . The judgement : fC1 ::: Cng is a compact form of the conjunction : C1 ^ ::: ^ : Cn. Alternatively we may think of fC1 ::: Cng as a notation for C1 \\ :::\\ Cn, the intersection of the types belonging to the classes C

  11. Type Ia Supernova Explosion Models

    E-Print Network [OSTI]

    W. Hillebrandt; J. C. Niemeyer

    2000-06-21

    Because calibrated light curves of Type Ia supernovae have become a major tool to determine the local expansion rate of the Universe and also its geometrical structure, considerable attention has been given to models of these events over the past couple of years. There are good reasons to believe that perhaps most Type Ia supernovae are the explosions of white dwarfs that have approached the Chandrasekhar mass, M_ch ~ 1.39 M_sun, and are disrupted by thermonuclear fusion of carbon and oxygen. However, the mechanism whereby such accreting carbon-oxygen white dwarfs explode continues to be uncertain. Recent progress in modeling Type Ia supernovae as well as several of the still open questions are addressed in this review. Although the main emphasis will be on studies of the explosion mechanism itself and on the related physical processes, including the physics of turbulent nuclear combustion in degenerate stars, we also discuss observational constraints.

  12. Zangerl, C., Eberhardt, E., Loew, S., Evans, K., Coupled hydromechanical modelling of surface subsidence in crystalline rock masses due to tunnel drainage. ISRM 2003Technology roadmap for rock mechanics, South African Institute of Mining and Metallurgy, 2

    E-Print Network [OSTI]

    Eberhardt, Erik

    subsidence in crystalline rock masses due to tunnel drainage. ISRM 2003­Technology roadmap for rock mechanics subsidence in crystalline rock masses due to tunnel drainage C. Zangerl, E. Eberhardt, S. Loew, K.F. Evans are rarely observed and in the past, geotechnical engineers would not expect substantial subsidence to occur

  13. Dark fleshed varieties (Bing type) in regular type, light fleshed varieties (Rainier type) in italics Sweet Cherries

    E-Print Network [OSTI]

    Dark fleshed varieties (Bing type) in regular type, light fleshed varieties (Rainier type and Royalton. For more information about these and other varieties, visit our web site at www

  14. Manipulation of subsurface carbon nanoparticles in Bi2Sr2CaCu2O8+? using a scanning tunneling microscope

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

    Stollenwerk, A. J.; Hurley, N.; Beck, B.; Spurgeon, K.; Kidd, T. E.; Gu, G.

    2015-03-19

    In this study, we present evidence that subsurface carbon nanoparticles in Bi?Sr?CaCu?O8+? can be manipulated with nanometer precision using a scanning tunneling microscope. High resolution images indicate that most of the carbon particles remain subsurface after transport observable as a local increase in height as the particle pushes up on the surface. Tunneling spectra in the vicinity of these protrusions exhibit semiconducting characteristics with a band gap of approximately 1.8 eV, indicating that the incorporation of carbon locally alters the electronic properties near the surface.

  15. High photo-excited carrier multiplication by charged InAs dots in AlAs/GaAs/AlAs resonant tunneling diode

    E-Print Network [OSTI]

    Wangping Wang; Ying Hou; Dayuan Xiong; Ning Li; Wei Lu

    2007-10-15

    We present an approach for the highly sensitive photon detection based on the quantum dots (QDs) operating at temperature of 77K. The detection structure is based on an AlAs/GaAs/AlAs double barrier resonant tunneling diode combined with a layer of self-assembled InAs QDs (QD-RTD). A photon rate of 115 photons per second had induced 10nA photocurrent in this structure, corresponding to the photo-excited carrier multiplication factor of 10^7. This high multiplication factor is achieved by the quantum dot induced memory effect and the resonant tunneling tuning effect of QD-RTD structure.

  16. LER-LHC injector workshop summary and super-ferric fast cycling injector in the SPS tunnel

    SciTech Connect (OSTI)

    Ambrosio, Giorgio; Hays, Steven; Huang, Yuenian; Johnstone, John; Kashikhin, Vadim; MacLachlan, James; Mokhov, Nikolai; Piekarz, Henryk; Sen, Tanaji; Shiltsev, Vladimir; de Rijk, Gijsbert; /CERN

    2007-03-01

    A Workshop on Low Energy Ring (LER) in the LHC tunnel as main injector was convened at CERN on October 11-12, 2006. We present the outline of the LER based on the presentations, and respond to the raised questions and discussions including the post-workshop studies. We also outline the possibility of using the LER accelerator technologies for the fast cycling injector accelerator in the SPS tunnel (SF-SPS). A primary goal for the LER (Low Energy Ring) injector accelerator is to inject 1.5 TeV proton beams into the LHC, instead of the current injection scheme with 0.45 TeV beams from the SPS. At this new energy, the field harmonics [1] of the LHC magnets are sufficiently satisfactory to prevent the luminosity losses expected to appear when applying the transfer of the 0.45 TeV SPS beams. In addition, a feasibility study of batch slip stacking in the LER has been undertaken with a goal of increasing in this way the LHC luminosity by up to a factor of 4. A combined luminosity increase may, therefore, be in the range of an order of magnitude. In the long term, the LER injector accelerator would greatly facilitate the implementation of a machine, which doubles the LHC energy (DLHC).

  17. Types of JavaO Types: Types A, B, C are

    E-Print Network [OSTI]

    Börger, Egon

    .Meth(Exps) | super.Meth(Exps) Copyright c 2002 Robert F. St¨ark, Computer Science Department, ETH Z[ ] Serializable. If A B and A, B are reference types, then A[ ] B[ ]. Copyright c 2002 Robert F. St¨ark, Computer not equal (references) Copyright c 2002 Robert F. St¨ark, Computer Science Department, ETH Z

  18. Operational Semantics and Polymorphic Type Inference 

    E-Print Network [OSTI]

    Tofte, Mads

    1988-01-01

    Three languages with polymorphic type disciplines are discussed, namely the ?-calculus with Milner's polymorphic type discipline; a language with imperative features (polymorphic references); and a skeletal module language ...

  19. Tridiagonal pairs of Krawtchouk type

    E-Print Network [OSTI]

    Ito, Tatsuro

    2007-01-01

    Let $K$ denote an algebraically closed field with characteristic 0 and let $V$ denote a vector space over $K$ with finite positive dimension. Let $A,A^*$ denote a tridiagonal pair on $V$ with diameter $d$. We say that $A,A^*$ has Krawtchouk type whenever the sequence $\\lbrace d-2i\\rbrace_{i=0}^d$ is a standard ordering of the eigenvalues of $A$ and a standard ordering of the eigenvalues of $A^*$. Assume $A,A^*$ has Krawtchouk type. We show that there exists a nondegenerate symmetric bilinear form $$ on $V$ such that $= $ and $= $ for $u,v\\in V$. We show that the following tridiagonal pairs are isomorphic: (i) $A,A^*$; (ii) $-A,-A^*$; (iii) $A^*,A$; (iv) $-A^*,-A$. We give a number of related results and conjectures.

  20. Type Ia Supernovae: Spectroscopic Surprises

    E-Print Network [OSTI]

    David Branch

    2003-10-23

    Recent observations have extended the range of diversity among spectra of Type Ia supernovae. I briefly discuss SN Ia explosion models in the spectroscopic context, the observed diversity, and some recent results from direct analysis with the Synow code for one normal and two peculiar SNe Ia. Relating the observational manifestations of diversity to their physical causes is looking like an ever more challenging problem.

  1. Quantum-corrected self-dual black hole entropy in tunneling formalism with GUP

    E-Print Network [OSTI]

    M. A. Anacleto; F. A. Brito; E. Passos

    2015-07-30

    In this paper we focus on the Hamilton-Jacobi method to determine the entropy of a self-dual black hole by using linear and quadratic GUPs(generalized uncertainty principles). We have obtained the Bekenstein-Hawking entropy of self-dual black holes and its quantum corrections that are logarithm and also of several other types.

  2. Quantum-corrected self-dual black hole entropy in tunneling formalism with GUP

    E-Print Network [OSTI]

    Anacleto, M A; Passos, E

    2015-01-01

    In this paper we focus on the Hamilton-Jacobi method to determine the entropy of a self-dual black hole by using linear and quadratic GUPs(generalized uncertainty principles). We have obtained the Bekenstein-Hawking entropy of self-dual black holes and its quantum corrections that are logarithm and also of several other types.

  3. Shot noise in resonant tunneling through a zero-dimensional state with a complex energy spectrum A. Nauen,* F. Hohls, J. Konemann, and R. J. Haug

    E-Print Network [OSTI]

    Hohls, Frank

    Shot noise in resonant tunneling through a zero-dimensional state with a complex energy spectrum A; published 30 March 2004 We investigate the noise properties of a GaAs /AlxGa1 xAs resonant discuss the suppression of the shot noise in the framework of a coupled two-state system. For large bias

  4. Comparison of decoherence and Zeno dynamics from the context of weak measurement for a two level atom tunneling through squeezed vacuum

    E-Print Network [OSTI]

    Samyadeb Bhattacharya

    2014-10-22

    Decay parameter of coherence and population inversion are calculated from the master equation of a two level atom tunneling through a squeezed vacuum. Using those parameters, the timescales for decoherence and zeno effect are calculated in the weak measurement scheme. By comparing those timescales, a certain condition has been found for sustainable coherent dynamics.

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

    E-Print Network [OSTI]

    Horvath, John S.

    /TUNNEL (CA/T) PROJECT Hany L. Riad, Ph.D., P.E. (1) Abstract The use of Expanded Polystyrene (EPS) in block-molded in a dense urban environment. 1.0 INTRODUCTION The use of EPS on the C09C2 construction contract of CA as lightweight fill material in the United States. This construction contract consists primarily of viaducts

  6. Distinction between the Poole-Frenkel and tunneling models of electric-field-stimulated carrier emission from deep levels in semiconductors

    E-Print Network [OSTI]

    Ganichev, Sergey

    Distinction between the Poole-Frenkel and tunneling models of electric-field-stimulated carrier of the defects. However, only a limited number of defects can be satisfac- torily described by the Poole-Frenkel theory. An electric field dependence different from that expected from the Poole-Frenkel theory has been

  7. Wind Tunnel Aerodynamic Tests of Six Airfoils for Use on Small Wind Turbines; Period of Performance: October 31, 2002--January 31, 2003

    SciTech Connect (OSTI)

    Selig, M. S.; McGranahan, B. D.

    2004-10-01

    Wind Tunnel Aerodynamic Tests of Six Airfoils for Use on Small Wind Turbinesrepresents the fourth installment in a series of volumes documenting the ongoing work of th University of Illinois at Urbana-Champaign Low-Speed Airfoil Tests Program. This particular volume deals with airfoils that are candidates for use on small wind turbines, which operate at low Reynolds numbers.

  8. Thermal Rates of Hydrogen Exchange of Methane with Zeolite: A Direct ab Initio Dynamics Study on the Importance of Quantum Tunneling Effects

    E-Print Network [OSTI]

    Truong, Thanh N.

    methods need potential energy information only at the stationary points, and thus they may be used the minimum energy path (MEP). The ZCT method restricts tunneling path to be along the MEP, whereas the SCTThermal Rates of Hydrogen Exchange of Methane with Zeolite: A Direct ab Initio Dynamics Study

  9. Systematic Modulation of Quantum (Electron) Tunneling Behavior by Atomic Layer Deposition on Nanoparticulate SnO2 and TiO2

    E-Print Network [OSTI]

    Systematic Modulation of Quantum (Electron) Tunneling Behavior by Atomic Layer Deposition were conformally created on SnO2 and TiO2 photo- electrodes via atomic layer deposition (ALD undesired, additional conduits for ET.13 In contrast, atomic layer deposition (ALD),14-19 which typically

  10. Terahertz vibration-rotation-tunneling spectroscopy of the water tetramer-d8: Combined analysis of vibrational bands at 4.1 and 2.0 THz

    E-Print Network [OSTI]

    Cohen, Ronald C.

    Terahertz vibration-rotation-tunneling spectroscopy of the water tetramer-d8: Combined analysis in the global fit of the water trimer. The detailed understanding of the water tetramer evolving from this work calculated concentrations of water trimers, tetramers, and pentamers of 1012 , 1011 , and 1010 cm-3

  11. Terahertz Laser Vibration-Rotation Tunneling Spectroscopy of the Water Tetramer Jeff D. Cruzan, Mark R. Viant, Mac G. Brown, and Richard J. Saykally*

    E-Print Network [OSTI]

    Cohen, Ronald C.

    Terahertz Laser Vibration-Rotation Tunneling Spectroscopy of the Water Tetramer Jeff D. Cruzan, which increase nonlinearly with increasing J, were found in both D2O and H2O tetramer spectra. Evidence of 1% of the total stabilization energy of the tetramer and pentamer.12-21 Xantheas' recent MP2

  12. Atomic-scale movement induced in nanoridges by scanning tunneling microscopy on epitaxial graphene grown on 4H-SiC(0001)

    E-Print Network [OSTI]

    Thibado, Paul M.

    in which forward and reverse images are simultaneously recorded. An apparent 100% enlarged graphene lattice of top- gated, electrically isolated devices, and furthermore, it is already available in the form tunneling microscopy (STM) studies have confirmed this interpretation and have shown that the large ridges

  13. The thermoelectric properties of molecular junctions can now be investigated with scanning tunnelling microscopy. Such experiments provide insights into charge transport in single

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    The thermoelectric properties of molecular junctions can now be investigated with scanning . They used a scanning tunnelling microscope (STM) to investigate thermoelectricity -- the voltage generated that thermoelectric measurements by STM provide a solution to this problem MOLECULAR ELECTRONICS Charges feel the heat

  14. Wheel-type magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, J.A.

    1982-01-20

    The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load.

  15. Wheel-type magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, J.A.

    1983-10-11

    The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load. 7 figs.

  16. Window Types | Department of Energy

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann Jackson About1996HowFOAShowingFuelWeatherize » AirareAbout Key ActivitiesWindow Types

  17. Window Types | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: Alternative FuelsofProgram: Report1538-1950DepartmentWaveWind Program R&DResearchWindow Types

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

    E-Print Network [OSTI]

    References 38 A1 Measurement survey 39 A1.1 Measurement types 39 A1.2 Data file naming convention 40 A1 1-3 Pitot tube measurement a Airfoil section measurement j Jet outlet measurement m Mean value min al., 1998 [1]. The Risø-1 airfoil was designed in 1993 and is intended for use on the outer part

  19. Closure Report for Corrective Action Unit 481: Area 12 T-Tunnel Conditional Release Storage Yard, Nevada Test Site, Nevada

    SciTech Connect (OSTI)

    NSTec Environmental Restoration

    2008-11-01

    Corrective Action Unit (CAU) 481 is identified in the Federal Facility Agreement and Consent Order (FFACO) as Area 12 T-Tunnel Conditional Release Storage Yard. CAU 481 is located in Area 12 of the Nevada Test Site, which is approximately 65 miles northwest of Las Vegas, Nevada. This CAU consists of one Corrective Action Site (CAS), CAS 12-42-05, Housekeeping Waste. CAU 481 closure activities were conducted by the Defense Threat Reduction Agency from August 2007 through July 2008 according to the FFACO and Revision 3 of the Sectored Clean-up Work Plan for Housekeeping Category Waste Sites. Closure activities included removal and disposal of construction debris and low-level waste. Drained fluids, steel, and lead was recycled as appropriate. Waste generated during closure activities was appropriately managed and disposed.

  20. Interfacial spin-filter assisted spin transfer torque effect in Co/BeO/Co magnetic tunnel junction

    SciTech Connect (OSTI)

    Tang, Y.-H. Chu, F.-C.

    2015-03-07

    The first-principles calculation is employed to demonstrate the spin-selective transport properties and the non-collinear spin-transfer torque (STT) effect in the newly proposed Co/BeO/Co magnetic tunnel junction. The subtle spin-polarized charge transfer solely at O/Co interface gives rise to the interfacial spin-filter (ISF) effect, which can be simulated within the tight binding model to verify the general expression of STT. This allows us to predict the asymmetric bias behavior of non-collinear STT directly via the interplay between the first-principles calculated spin current densities in collinear magnetic configurations. We believe that the ISF effect, introduced by the combination between wurtzite-BeO barrier and the fcc-Co electrode, may open a new and promising route in semiconductor-based spintronics applications.