Sample records for testing adiabatic contraction

  1. SSC Test Operations Contract Overview (United States)

    Kleim, Kerry D.


    This slide presentation reviews the Test Operations Contract at the Stennis Space Center (SSC). There are views of the test stands layouts, and closer views of the test stands. There are descriptions of the test stand capabilities, some of the other test complexes, the Cryogenic propellant storage facility, the High Pressure Industrial Water (HPIW) facility, and Fluid Component Processing Facility (FCPF).

  2. Test of adiabatic spin flippers for application at pulsed neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Kraan, W.H. E-mail:; Grigoriev, S.V.; Rekveldt, M.Th.; Fredrikze, H.; Vroege, C.F. de; Plomp, J


    Experimental results on the flipping efficiency are shown for a set of 2 V-coils as spin flipper and for a high-frequency flipper with adiabatic transition. The influence of the adiabaticity parameter is discussed. The merits of these adiabatic flippers are compared with the use of 'monochromatic' flippers, when operated in a beam from a pulsed neutron source. It is concluded that for 'long pulse' sources adiabatic flippers will be superior.

  3. Adiabatic, Shock, and Plastic Work Heating of Solids and the Cylinder Test

    National Research Council Canada - National Science Library

    Ruden, E


    Solids subjected to high pressures, shocks, and/or deformation experience an increase in internal energy density and temperature due to adiabatic compression, shock heating, and plastic work heating, respectively...

  4. On the coupling of wave and three-dimensional circulation models: Choice of theoretical framework, practical implementation and adiabatic tests (United States)

    Bennis, Anne-Claire; Ardhuin, Fabrice; Dumas, Franck

    Many theoretical approaches and implementations have been proposed for the coupling of the three-dimensional ocean circulation with waves. The theoretical models are reviewed and it is shown that the formulation in terms of the quasi-Eulerian velocity circumvents the essential difficulty of alternative formulations for the Lagrangian mean velocity. Namely, models based on this Lagrangian velocity require an estimation of wave-induced motions to first order in the horizontal gradients of the wave field in order to estimate the vertical flux of wave pseudo-momentum. So far, only three-dimensional wave models have been able to provide these estimates, and all published theories based on the simpler Airy theory are not consistent at the leading order, because they ignore or incorrectly estimate the vertical momentum flux. With an adiabatic example on a sloping bottom it is shown that this inconsistency produces very large spurious velocities. These errors are independent of the slope for the inviscid case, and are still significant when a realistic vertical mixing is applied. A quick diagnostic of the potential accuracy of a theoretical model is the vertical profile of the wave-induced forcing terms: if it is not uniform over depth in adiabatic conditions then it will produce spurious artificial flow patterns in conditions with shoaling waves. Although conceptually more challenging, the quasi-Eulerian velocity theories only introduce minor modifications of the solution procedure for the standard primitive equations: a modification of the surface boundary condition for the mass conservation, the addition of the Stokes drift in the tracer advection equations, and sources of momentum and turbulent kinetic energy with associated surface and bottom fluxes. All the necessary modifications of primitive equation models are given in detail. This implementation is illustrated with the MARS3D model, which passes the test of the adiabatic shoaling waves.

  5. Contract-Driven Testing of JavaScript Code (United States)

    Heidegger, Phillip; Thiemann, Peter

    JSConTest is a tool that enhances JavaScript with simple, type-like contracts and provides a framework for monitoring and guided random testing of programs against these contracts at the same time. Function contracts in JSConTest serve a dual role as specifications of the input/output behavior and as test case generators. Generation of test data for a contract is generally random, but it can be guided by annotations on the contract to achieve higher coverage. Annotations may indicate dependencies among parameters and the result or they may select lightweight program analyses, the results of which influence the choice of test data. A case study substantiates that JSConTest finds type-related errors with high probability.

  6. Contractions (United States)

    ... body for labor and delivery. Labor contractions signal the beginning of childbirth. What causes contractions? Braxton-Hicks (false ... of your last menstrual period.) Labor contractions signal the beginning of childbirth. These contractions come at regular intervals, ...

  7. Testing low-mode symmetry control with low-adiabat, extended pulse-lengths in BigFoot implosions on the National Ignition Facility (United States)

    Hohenberger, Matthias; Casey, D. T.; Thomas, C. A.; Baker, K. L.; Spears, B. K.; Khan, S. F.; Hurricane, O. A.; Callahan, D.


    The Bigfoot approach to indirect-drive inertial confinement fusion (ICF) has been developed as a compromise trading high-convergence and areal densities for high implosion velocities, large adiabats and hydrodynamic stability. Shape control and predictability are maintained by using relatively short laser pulses and merging the shocks within the DT-ice layer. These design choices ultimately limit the theoretically achievable performance, and one strategy to increase the 1-D performance is to reduce the shell adiabat by extending the pulse shape. However, this can result in loss of low-mode symmetry control, as the hohlraum ``bubble,'' the high-Z material launched by the outer-cone beams during the early part of the laser pulse, has more time to expand and will eventually intercept inner-cone beams preventing them from reaching the hohlraum waist, thus losing equatorial capsule drive. We report on experimental results exploring shape control and predictability with extended pulse shapes in BigFoot implosions. Prepared by LLNL under Contract DE-AC52-07NA27344.

  8. Contingency Contracting Officer Proficiency Assessment Test Development for Construction, Architect-Engineer, and Contingency Contracting (United States)


    AT&L Acquisition, Technology, and Logistics AT&LDS Army Training and Leader Development Strategy CCO Contingency Contracting Officer CLP...DEFINITIONS AND EXAMPLES 4. ANALYZE 4.1 DIFFERENTIATING Discriminating Distinguishing Focusing Selecting 4.2 ORGANIZING Finding Coherence Intergrating ... Logistics (AT&L)]), exposed failures occurring in expeditionary contracting operations. In order to rectify difficulties in the acquisition

  9. Adiabatic Cooling of Antiprotons

    CERN Document Server

    Gabrielse, G; McConnell, R; Richerme, P; Kalra, R; Novitski, E; Grzonka, D; Oelert, W; Sefzick, T; Zielinski, M; Fitzakerley, D; George, M C; Hessels, E A; Storry, C H; Weel, M; Mullers, A; Walz, J


    Adiabatic cooling is shown to be a simple and effective method to cool many charged particles in a trap to very low temperatures. Up to 3 x 10(6) (p) over bar are cooled to 3.5 K-10(3) times more cold (p) over bar and a 3 times lower (p) over bar temperature than previously reported. A second cooling method cools (p) over bar plasmas via the synchrotron radiation of embedded (p) over bar (with many fewer (p) over bar than (p) over bar) in preparation for adiabatic cooling. No (p) over bar are lost during either process-a significant advantage for rare particles.

  10. Semiconductor adiabatic qubits

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Malcolm S.; Witzel, Wayne; Jacobson, Noah Tobias; Ganti, Anand; Landahl, Andrew J.; Lilly, Michael; Nguyen, Khoi Thi; Bishop, Nathaniel; Carr, Stephen M.; Bussmann, Ezra; Nielsen, Erik; Levy, James Ewers; Blume-Kohout, Robin J.; Rahman, Rajib


    A quantum computing device that includes a plurality of semiconductor adiabatic qubits is described herein. The qubits are programmed with local biases and coupling terms between qubits that represent a problem of interest. The qubits are initialized by way of a tuneable parameter, a local tunnel coupling within each qubit, such that the qubits remain in a ground energy state, and that initial state is represented by the qubits being in a superposition of |0> and |1> states. The parameter is altered over time adiabatically or such that relaxation mechanisms maintain a large fraction of ground state occupation through decreasing the tunnel coupling barrier within each qubit with the appropriate schedule. The final state when tunnel coupling is effectively zero represents the solution state to the problem represented in the |0> and |1> basis, which can be accurately read at each qubit location.

  11. Quantum Adiabatic Brachistochrone (United States)

    Rezakhani, A. T.; Kuo, W.-J.; Hamma, A.; Lidar, D. A.; Zanardi, P.


    We formulate a time-optimal approach to adiabatic quantum computation (AQC). A corresponding natural Riemannian metric is also derived, through which AQC can be understood as the problem of finding a geodesic on the manifold of control parameters. This geometrization of AQC is demonstrated through two examples, where we show that it leads to improved performance of AQC, and sheds light on the roles of entanglement and curvature of the control manifold in algorithmic performance.

  12. Relaxation versus adiabatic quantum steady-state preparation (United States)

    Venuti, Lorenzo Campos; Albash, Tameem; Marvian, Milad; Lidar, Daniel; Zanardi, Paolo


    Adiabatic preparation of the ground states of many-body Hamiltonians in the closed-system limit is at the heart of adiabatic quantum computation, but in reality systems are always open. This motivates a natural comparison between, on the one hand, adiabatic preparation of steady states of Lindbladian generators and, on the other hand, relaxation towards the same steady states subject to the final Lindbladian of the adiabatic process. In this work we thus adopt the perspective that the goal is the most efficient possible preparation of such steady states, rather than ground states. Using known rigorous bounds for the open-system adiabatic theorem and for mixing times, we are then led to a disturbing conclusion that at first appears to doom efforts to build physical quantum annealers: relaxation seems to always converge faster than adiabatic preparation. However, by carefully estimating the adiabatic preparation time for Lindbladians describing thermalization in the low-temperature limit, we show that there is, after all, room for an adiabatic speedup over relaxation. To test the analytically derived bounds for the adiabatic preparation time and the relaxation time, we numerically study three models: a dissipative quasifree fermionic chain, a single qubit coupled to a thermal bath, and the "spike" problem of n qubits coupled to a thermal bath. Via these models we find that the answer to the "which wins" question depends for each model on the temperature and the system-bath coupling strength. In the case of the "spike" problem we find that relaxation during the adiabatic evolution plays an important role in ensuring a speedup over the final-time relaxation procedure. Thus, relaxation-assisted adiabatic preparation can be more efficient than both pure adiabatic evolution and pure relaxation.

  13. PIPER Continuous Adiabatic Demagnetization Refrigerator (United States)

    Kimball, Mark O.; Shirron, Peter J.; Canavan, Edgar R.; James, Bryan L.; Sampson, Michael A.; Letmate, Richard V.


    We report upon the development and testing of a 4-stage adiabatic demagnetization refrigerator (ADR) capable of continuous cooling at 0.100 Kelvin. This cooler is being built to cool the detector array aboard NASA's Primordial Inflation Polarization Explorer (PIPER) observatory. The goal of this balloon mission is to measure the primordial gravitational waves that should exist if the theory of cosmological inflation is correct. At altitude, the ADR will hold the array of transition-edge sensors at 100 mK continuously while periodically rejecting heat to a 1.2 K pumped helium bath. During testing on ground, the array is held at the same temperature but heat is rejected to a 4.2 K helium bath indicating the flexibility in this coolers design.

  14. Plasma adiabatic lapse rate

    CERN Document Server

    Amendt, Peter; Wilks, Scott


    The plasma analog of an adiabatic lapse rate (or temperature variation with height) in atmospheric physics is obtained. A new source of plasma temperature gradient in a binary ion species mixture is found that is proportional to the concentration gradient and difference in average ionization states . Application to inertial-confinement-fusion implosions indicates a potentially strong effect in plastic (CH) ablators that is not modeled with mainline (single-fluid) simulations. An associated plasma thermodiffusion coefficient is derived, and charge-state diffusion in a single-species plasma is also predicted.

  15. Geometrizing adiabatic quantum computation (United States)

    Rezakhani, Ali; Kuo, Wan-Jung; Hamma, Alioscia; Lidar, Daniel; Zanardi, Paolo


    A time-optimal approach to adiabatic quantum computation (AQC) is formulated. The corresponding natural Riemannian metric is also derived, through which AQC can be understood as the problem of finding a geodesic on the manifold of control parameters. We demonstrate this geometrization through some examples, where we show that it leads to improved performance of AQC, and sheds light on the roles of entanglement and curvature of the control manifold in algorithmic performance. The underlying connection with quantum phase transitions is also explored.

  16. Adiabatic quantum simulators

    Directory of Open Access Journals (Sweden)

    J. D. Biamonte


    Full Text Available In his famous 1981 talk, Feynman proposed that unlike classical computers, which would presumably experience an exponential slowdown when simulating quantum phenomena, a universal quantum simulator would not. An ideal quantum simulator would be controllable, and built using existing technology. In some cases, moving away from gate-model-based implementations of quantum computing may offer a more feasible solution for particular experimental implementations. Here we consider an adiabatic quantum simulator which simulates the ground state properties of sparse Hamiltonians consisting of one- and two-local interaction terms, using sparse Hamiltonians with at most three-local interactions. Properties of such Hamiltonians can be well approximated with Hamiltonians containing only two-local terms. The register holding the simulated ground state is brought adiabatically into interaction with a probe qubit, followed by a single diabatic gate operation on the probe which then undergoes free evolution until measured. This allows one to recover e.g. the ground state energy of the Hamiltonian being simulated. Given a ground state, this scheme can be used to verify the QMA-complete problem LOCAL HAMILTONIAN, and is therefore likely more powerful than classical computing.

  17. Adiabatic quantum computation (United States)

    Albash, Tameem; Lidar, Daniel A.


    Adiabatic quantum computing (AQC) started as an approach to solving optimization problems and has evolved into an important universal alternative to the standard circuit model of quantum computing, with deep connections to both classical and quantum complexity theory and condensed matter physics. This review gives an account of the major theoretical developments in the field, while focusing on the closed-system setting. The review is organized around a series of topics that are essential to an understanding of the underlying principles of AQC, its algorithmic accomplishments and limitations, and its scope in the more general setting of computational complexity theory. Several variants are presented of the adiabatic theorem, the cornerstone of AQC, and examples are given of explicit AQC algorithms that exhibit a quantum speedup. An overview of several proofs of the universality of AQC and related Hamiltonian quantum complexity theory is given. Considerable space is devoted to stoquastic AQC, the setting of most AQC work to date, where obstructions to success and their possible resolutions are discussed.

  18. Dispersive Readout of Adiabatic Phases (United States)

    Kohler, Sigmund


    We propose a protocol for the measurement of adiabatic phases of periodically driven quantum systems coupled to an open cavity that enables dispersive readout. It turns out that the cavity transmission exhibits peaks at frequencies determined by a resonance condition that involves the dynamical and the geometric phase. Since these phases scale differently with the driving frequency, one can determine them by fitting the peak positions to the theoretically expected behavior. For the derivation of the resonance condition and for a numerical study, we develop a Floquet theory for the dispersive readout of ac driven quantum systems. The feasibility is demonstrated for two test cases that generalize Landau-Zener-Stückelberg-Majorana interference to two-parameter driving.

  19. Geometry of the Adiabatic Theorem (United States)

    Lobo, Augusto Cesar; Ribeiro, Rafael Antunes; Ribeiro, Clyffe de Assis; Dieguez, Pedro Ruas


    We present a simple and pedagogical derivation of the quantum adiabatic theorem for two-level systems (a single qubit) based on geometrical structures of quantum mechanics developed by Anandan and Aharonov, among others. We have chosen to use only the minimum geometric structure needed for the understanding of the adiabatic theorem for this case.…

  20. Testing Intertemporal Substitution, Implicit Contracts, and Hours Restriction Models of the Labor Market Using Micro Data


    HAM, John C.; Reilly, Kevin T


    We present new tests of three theories of the labor market: intertemporal substitution, hours restrictions, and implicit contracts. The intertemporal substitution test we implement is an exclusion test robust to many specification errors and we consistently reject this model. We model hours restrictions as part of an endogenous switching model. We compare the implicit probit equation to an unrestricted probit equation for unemployment and reject the hours restriction model. For the implicit c...

  1. Do isokinetic angular velocity and contraction types affect the predictors of different anaerobic power tests? (United States)

    Yapici, Aysegul; Findikoglu, Gulin; Dundar, Ugur


    The purpose of this study was to investigate the most important predictor isokinetic muscle strength determined by different angular velocities and contraction types (i.e. concentric and eccentric) for selected anaerobic power tests in volleyball players. Twenty male and ten female amateur volleyball players participated in this study. Selected anaerobic power tests included Wingate Anaerobic Test (WAnT), squat jump (SJ) and countermovement jump (CMJ). Peak torque values were obtained at 60, 120, 240˚/s for concentric contraction of quadriceps (Qconc) and Hamstring (Hconc) and at 60˚/s for eccentric contraction of quadriceps (Qecc) and Hconc. Moderate to good correlations (r:0.409 to r:0.887) were found between anaerobic tests and isokinetic data including peak torque and total work of both Hconc and Qconc at 60, 120, 240°/s and Qecc at 60°/s (Pstrength of the relation increases with increasing angular velocity. However, both Qecc and Hconc were significant indicators for CMJ and SJ. Training with higher isokinetic angular velocities and with eccentric contraction is desirable in a training program that has a goal of improving anaerobic performance in volleyball players.

  2. Towards on-chip photon-pair bell tests: Spatial pump filtering in a LiNbO3 adiabatic coupler (United States)

    Solntsev, Alexander S.; Liu, Tong; Boes, Andreas; Nguyen, Thach G.; Wu, Che Wen; Setzpfandt, Frank; Mitchell, Arnan; Neshev, Dragomir N.; Sukhorukov, Andrey A.


    Nonlinear optical waveguides enable the integration of entangled photon sources and quantum logic gates on a quantum photonic chip. One of the major challenges in such systems is separating the generated entangled photons from the pump laser light. In this work, we experimentally characterize double-N-shaped nonlinear optical adiabatic couplers designed for the generation of spatially entangled photon pairs through spontaneous parametric down-conversion, while simultaneously providing spatial pump filtering and keeping photon-pair states pure. We observe that the pump photons at a wavelength of 671 nm mostly remain in the central waveguide, achieving a filtering ratio of over 20 dB at the outer waveguides. We also perform classical characterization at the photon-pair wavelength of 1342 nm and observe that light fully couples from an input central waveguide to the outer waveguides, showing on chip separation of the pump and the photon-pair wavelength.

  3. Adiabatic projection method for scattering and reactions on the lattice

    Energy Technology Data Exchange (ETDEWEB)

    Pine, Michelle; Lee, Dean [North Carolina State University, Department of Physics, Raleigh, NC (United States); Rupak, Gautam [Mississippi State University, Department of Physics and Astronomy and HPC2 Center for Computational Sciences, Mississippi State, MS (United States)


    We demonstrate and test the adiabatic projection method, a general new framework for calculating scattering and reactions on the lattice. The method is based upon calculating a low-energy effective theory for clusters which becomes exact in the limit of large Euclidean projection time. As a detailed example we calculate the adiabatic two-body Hamiltonian for elastic fermion-dimer scattering in lattice effective field theory. Our calculation corresponds to neutron-deuteron scattering in the spin-quartet channel at leading order in pionless effective field theory. We show that the spectrum of the adiabatic Hamiltonian reproduces the spectrum of the original Hamiltonian below the inelastic threshold to arbitrary accuracy. We also show that the calculated s -wave phase shift reproduces the known exact result in the continuum and infinite-volume limits. When extended to more than one scattering channel, the adiabatic projection method can be used to calculate inelastic reactions on the lattice in future work. (orig.)

  4. Adiabatic Cooling for Rovibrational Spectroscopy of Molecular Ions

    DEFF Research Database (Denmark)

    Fisher, Karin


    The field of cold molecular ions is a fast growing one, with applications in high resolution spectroscopy and metrology, the search for time variations of fundamental constants, cold chemistry and collisions, and quantum information processing, to name a few. The study of single molecular ions...... proposes to adiabatically relax the trapping potential, called adiabatic cooling, when performing rovibrational excitations of the molecular ion to reduce the energy spacing of the harmonic motional levels, thus increasing the likelihood of a motional transition. The work presented in this thesis covers...... the implementation of adiabatic cooling for the application of rovibrational spectroscopy on single molecular ions. This entailed constructing and testing a new DC supply capable of employing adiabatic ramps of the ion's axial frequency on the 100's of us timescale. The DC supply went through several iterations...

  5. Adiabatic regularization for spin-1/2 fields (United States)

    Landete, Aitor; Navarro-Salas, José; Torrentí, Francisco


    We extend the adiabatic regularization method to spin-1/2 fields. The ansatz for the adiabatic expansion for fermionic modes differs significantly from the WKB-type template that works for scalar modes. We give explicit expressions for the first adiabatic orders and analyze particle creation in de Sitter spacetime. As for scalar fields, the adiabatic method can be distinguished by its capability to overcome the UV divergences of the particle number operator. We also test the consistency of the extended method by working out the conformal and axial anomalies for a Dirac field in a Friedmann-Lemaître-Robertson-Walker spacetime, in exact agreement with those obtained from other renormalization prescriptions. We finally show its power by computing the renormalized stress-energy tensor for Dirac fermions in de Sitter space.

  6. Analysis of Adiabatic Batch Reactor

    Directory of Open Access Journals (Sweden)

    Erald Gjonaj


    Full Text Available A mixture of acetic anhydride is reacted with excess water in an adiabatic batch reactor to form an exothermic reaction. The concentration of acetic anhydride and the temperature inside the adiabatic batch reactor are calculated with an initial temperature of 20°C, an initial temperature of 30°C, and with a cooling jacket maintaining the temperature at a constant of 20°C. The graphs of the three different scenarios show that the highest temperatures will cause the reaction to occur faster.

  7. Test Governance Framework for Contracted IS Development: Software Management Processes in Social Context


    Doležel, Michal


    [Context] Outsourced information systems development (ISD) represents an important and widely used software delivery strategy for mid-size and large non-IT companies. In such companies, testing activities are conducted by a contracted party, and are hidden from continuous checks on the part of the client, who is typically only provided with insight during the system hand-over. Such an approach is risky; the testing activities might be executed in a loose and sloppy manner by the contractor. C...

  8. Transitionless driving on adiabatic search algorithm (United States)

    Oh, Sangchul; Kais, Sabre


    We study quantum dynamics of the adiabatic search algorithm with the equivalent two-level system. Its adiabatic and non-adiabatic evolution is studied and visualized as trajectories of Bloch vectors on a Bloch sphere. We find the change in the non-adiabatic transition probability from exponential decay for the short running time to inverse-square decay in asymptotic running time. The scaling of the critical running time is expressed in terms of the Lambert W function. We derive the transitionless driving Hamiltonian for the adiabatic search algorithm, which makes a quantum state follow the adiabatic path. We demonstrate that a uniform transitionless driving Hamiltonian, approximate to the exact time-dependent driving Hamiltonian, can alter the non-adiabatic transition probability from the inverse square decay to the inverse fourth power decay with the running time. This may open up a new but simple way of speeding up adiabatic quantum dynamics.

  9. Adiabatic continuous stirred tank reactor

    DEFF Research Database (Denmark)

    Schroll-Fleischer, Eskild; Wu, Hao; Huusom, Jakob Kjøbsted

    The present report documents the adiabatic CSTR experimental setup after it was refurbished in September 2017. The goal of the refurbishment was firstly to enable computer control of the experiment using the Open Process Control Unified Architecture (OPC-UA) standard, and secondly to improve...

  10. Quantum adiabatic Markovian master equations (United States)

    Albash, Tameem; Boixo, Sergio; Lidar, Daniel A.; Zanardi, Paolo


    We develop from first principles Markovian master equations suited for studying the time evolution of a system evolving adiabatically while coupled weakly to a thermal bath. We derive two sets of equations in the adiabatic limit, one using the rotating wave (secular) approximation that results in a master equation in Lindblad form, the other without the rotating wave approximation but not in Lindblad form. The two equations make markedly different predictions depending on whether or not the Lamb shift is included. Our analysis keeps track of the various time and energy scales associated with the various approximations we make, and thus allows for a systematic inclusion of higher order corrections, in particular beyond the adiabatic limit. We use our formalism to study the evolution of an Ising spin chain in a transverse field and coupled to a thermal bosonic bath, for which we identify four distinct evolution phases. While we do not expect this to be a generic feature, in one of these phases dissipation acts to increase the fidelity of the system state relative to the adiabatic ground state.

  11. Performance Contracting in Schools: Profit Motive Tested as Incentive to Learning. An Education U.S.A. Special Report. (United States)

    Mecklenburger, James

    This report attempts to cut through the rhetoric of both the opponents and the proponents of performance contracting and to bring the main issues into focus. The report (1) describes different kinds of contracts; (2) discusses testing problems; (3) gives a description of the Texarkana and Banneker elementary school projects; (4) provides sample…

  12. Studies in Chaotic adiabatic dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Jarzynski, C.


    Chaotic adiabatic dynamics refers to the study of systems exhibiting chaotic evolution under slowly time-dependent equations of motion. In this dissertation the author restricts his attention to Hamiltonian chaotic adiabatic systems. The results presented are organized around a central theme, namely, that the energies of such systems evolve diffusively. He begins with a general analysis, in which he motivates and derives a Fokker-Planck equation governing this process of energy diffusion. He applies this equation to study the {open_quotes}goodness{close_quotes} of an adiabatic invariant associated with chaotic motion. This formalism is then applied to two specific examples. The first is that of a gas of noninteracting point particles inside a hard container that deforms slowly with time. Both the two- and three-dimensional cases are considered. The results are discussed in the context of the Wall Formula for one-body dissipation in nuclear physics, and it is shown that such a gas approaches, asymptotically with time, an exponential velocity distribution. The second example involves the Fermi mechanism for the acceleration of cosmic rays. Explicit evolution equations are obtained for the distribution of cosmic ray energies within this model, and the steady-state energy distribution that arises when this equation is modified to account for the injection and removal of cosmic rays is discussed. Finally, the author re-examines the multiple-time-scale approach as applied to the study of phase space evolution under a chaotic adiabatic Hamiltonian. This leads to a more rigorous derivation of the above-mentioned Fokker-Planck equation, and also to a new term which has relevance to the problem of chaotic adiabatic reaction forces (the forces acting on slow, heavy degrees of freedom due to their coupling to light, fast chaotic degrees).

  13. Proposal for the award of two contracts for the cryogenic testing of HTS current leads

    CERN Document Server

    European Organization for Nuclear Research


    This document concerns the award of two contracts for the cryogenic testing of high-temperature superconducting (HTS) current leads. Following a call for tenders (IT-3303/AT/LHC) sent on 25 March 2004 to five firms in four Member States, CERN had received, by the closing date, two tenders from two firms in two Member States. The Finance Committee is invited to agree to the negotiation of contracts with: ENEA (IT), for the cryogenic testing of 269 HTS 6 kA current leads and 64 HTS 13 kA current leads, for an amount of 847 310 euros (1 319 387 Swiss francs), not subject to revision, with an option for additional cryogenic testing of HTS current leads for an amount of up to 169 462 euros (263 877 Swiss francs), not subject to revision, bringing the total amount to a maximum of 1 016 772 euros (1 583 264 Swiss francs), not subject to revision. The rate of exchange used is that stipulated in the tender. The UNIVERSITY OF SOUTHAMPTON (UK), for the cryogenic testing of 716 HTS 0.6 kA current leads, for an amount of ...

  14. A Many Particle Adiabatic Invariant

    DEFF Research Database (Denmark)

    Hjorth, Poul G.


    For a system of N charged particles moving in a homogeneous, sufficiently strong magnetic field, a many-particle adiabatic invariant constrains the collisional exchange of energy between the degrees of freedom perpendicular to and parallel to the magnetic field. A description of the phenomenon in...... in terms of Hamiltonian dynamics is given. The relation to the Equipartition Theorem of statistical Mechanics is briefly discussed....

  15. Quantum Computation by Adiabatic Evolution


    Farhi, Edward; Goldstone, Jeffrey; Gutmann, Sam; Sipser, Michael


    We give a quantum algorithm for solving instances of the satisfiability problem, based on adiabatic evolution. The evolution of the quantum state is governed by a time-dependent Hamiltonian that interpolates between an initial Hamiltonian, whose ground state is easy to construct, and a final Hamiltonian, whose ground state encodes the satisfying assignment. To ensure that the system evolves to the desired final ground state, the evolution time must be big enough. The time required depends on ...

  16. Adiabaticity in open quantum systems (United States)

    Venuti, Lorenzo Campos; Albash, Tameem; Lidar, Daniel A.; Zanardi, Paolo


    We provide a rigorous generalization of the quantum adiabatic theorem for open systems described by a Markovian master equation with time-dependent Liouvillian L (t ) . We focus on the finite system case relevant for adiabatic quantum computing and quantum annealing. Adiabaticity is defined in terms of closeness to the instantaneous steady state. While the general result is conceptually similar to the closed-system case, there are important differences. Namely, a system initialized in the zero-eigenvalue eigenspace of L (t ) will remain in this eigenspace with a deviation that is inversely proportional to the total evolution time T . In the case of a finite number of level crossings, the scaling becomes T-η with an exponent η that we relate to the rate of the gap closing. For master equations that describe relaxation to thermal equilibrium, we show that the evolution time T should be long compared to the corresponding minimum inverse gap squared of L (t ) . Our results are illustrated with several examples.

  17. Do macroeconomic contractions induce or 'harvest' suicides? A test of competing hypotheses. (United States)

    Gemmill, Alison; Falconi, April; Karasek, Deborah; Hartig, Terry; Anderson, Elizabeth; Catalano, Ralph


    Researchers often invoke a mortality displacement or 'harvesting' mechanism to explain mortality patterns, such that those with underlying health vulnerabilities die sooner than expected in response to environmental phenomena, such as heat waves, cold spells and air pollution. It is unclear if this displacement mechanism might also explain observed increases in suicide following economic contraction, or if suicides are induced in persons otherwise unlikely to engage in self-destructive behaviour. Here, we test two competing hypotheses explaining an observed increase in suicides following unemployment-induction or displacement. We apply time series methods to monthly suicide and unemployment data from Sweden for the years 2000-2011. Tests are conducted separately for working age (20-64 years old) men and women as well as older (aged 65 years and older) men and women. Displacement appeared among older men and women; an unexpected rise in unemployment predicted an increase in suicides 6 months later, followed by a significant decrease 8 months later. Induction appeared among working age men, but not among working age women; an unexpected rise in unemployment predicted an increase in suicides 4-6 months later. Displacement and induction both appear to have operated following unexpected labour market contractions in Sweden, though with different population segments. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to

  18. Feasibility of an Isometric Maximal Voluntary Contraction Test in Hematological Cancer Patients during Thrombocytopenia

    Directory of Open Access Journals (Sweden)

    Philipp Zimmer


    Full Text Available Introduction. Resistance training is rarely offered to hemato-oncological patients in the daily clinical routine due to its potential harmful impact on the cardiovascular system and the long periods of thrombocytopenia experienced by these patients. Therefore, it is important to determine a valid assessment to define and control resistance training. In this study, the feasibility of a maximal voluntary contraction (MVC test was investigated in hemato-oncological patients. This inexpensive assessment may be a practicable alternative to the one repetition maximum test which is currently described as the gold standard. Methods. 29 hemato-oncological patients with platelet counts between 30000/μL and 70000/μL were recruited for this pilot study. Complications like petechial bleedings, muscle convulsion, and pain were assessed using the Brief Pain Inventory before and 48 hours after the MVC test, which was performed unidirectionally for the quadriceps muscle. Results. We did not detect any statistically significant test-related exacerbations or pain development. Discussion. MVC testing seems to be a feasible method to control a resistance training program in hemato-oncological patients. Further studies need to extend their methods and, for example, compare the MVC test with the one repetition maximum test.

  19. Classical nuclear motion coupled to electronic non-adiabatic transitions. (United States)

    Agostini, Federica; Abedi, Ali; Gross, E K U


    Based on the exact factorization of the electron-nuclear wave function, we have recently proposed a mixed quantum-classical scheme [A. Abedi, F. Agostini, and E. K. U. Gross, Europhys. Lett. 106, 33001 (2014)] to deal with non-adiabatic processes. Here we present a comprehensive description of the formalism, including the full derivation of the equations of motion. Numerical results are presented for a model system for non-adiabatic charge transfer in order to test the performance of the method and to validate the underlying approximations.

  20. Predicting utility of exercise tests based on history/holter in patients with premature ventricular contractions. (United States)

    Robinson, Brad; Xie, Li; Temple, Joel; Octavio, Jenna; Srayyih, Maytham; Thacker, Deepika; Kharouf, Rami; Davies, Ryan; Gidding, Samuel S


    Premature ventricular contractions (PVCs) are considered benign in patients with structurally normal hearts, particularly if they suppress with exercise. Catecholaminergic polymorphic ventricular tachycardia (CPVT) requires exercise testing to unmask the malignant phenotype. We studied risk factors and Holter monitor variables to help predict the necessity of exercise testing in patients with PVCs. We retrospectively reviewed 81 patients with PVCs that suppressed at peak exercise and structurally normal hearts referred to the exercise laboratory in 2011. We reviewed 11 patients from 2003 to 2012 whose PVCs were augmented at peak exercise (mean age 13 ± 4 years; 52 % male, 180 exercise studies). We recorded clinical risk factors and comorbidities (family history of arrhythmia or sudden unexpected death [SUD], presence of syncope) and Holter testing parameters. Family history of VT or SUD (P = 0.011) and presence of VT on Holter (P = 0.011) were significant in predicting failure of PVCs to suppress at peak heart rate on exercise testing. Syncope was not statistically significant in predicting suppression (P = 0.18); however, CPVT was diagnosed in four patients with syncope during exercise. Quantity of PVCs, Lown grade, couplets on Holter, monomorphism, and PVC elimination at peak heart rate on Holter were not predictors of PVC suppression on exercise testing. Patients with syncope during exercise, family history of arrhythmia or SUD, or a Holter monitor showing VT warrant exercise testing to assess for CPVT.

  1. Sliding seal materials for adiabatic engines (United States)

    Lankford, J.


    The sliding friction coefficients and wear rates of promising carbide, oxide, and nitride materials were measured under temperature, environmental, velocity, loading conditions that are representative of the adiabatic engine environment. In order to provide guidance needed to improve materials for this application, the program stressed fundamental understanding of the mechanisms involved in friction and wear. Microhardness tests were performed on the candidate materials at elevated temperatures, and in atmospheres relevant to the piston seal application, and optical and electron microscopy were used to elucidate the micromechanisms of wear following wear testing. X-ray spectroscopy was used to evaluate interface/environment interactions which seemed to be important in the friction and wear process. Electrical effects in the friction and wear processes were explored in order to evaluate the potential usefulness of such effects in modifying the friction and wear rates in service. However, this factor was found to be of negligible significance in controlling friction and wear.

  2. Theory of Adiabatic Fountain Resonance (United States)

    Williams, Gary A.


    The theory of "Adiabatic Fountain Resonance" with superfluid ^4{He} is clarified. In this geometry a film region between two silicon wafers bonded at their outer edge opens up to a central region with a free surface. We find that the resonance in this system is not a Helmholtz resonance as claimed by Gasparini et al., but in fact is a fourth sound resonance. We postulate that it occurs at relatively low frequency because the thin silicon wafers flex appreciably from the pressure oscillations of the sound wave.

  3. Laser cooling by adiabatic transfer (United States)

    Norcia, Matthew; Cline, Julia; Bartolotta, John; Holland, Murray; Thompson, James


    We have demonstrated a new method of laser cooling applicable to particles with narrow linewidth optical transitions. This simple and robust cooling mechanism uses a frequency-swept laser to adiabatically transfer atoms between internal and motional states. The role of spontaneous emission is reduced (though is still critical) compared to Doppler cooling. This allows us to achieve greater slowing forces than would be possible with Doppler cooling, and may make this an appealing technique for cooling molecules. In this talk, I will present a demonstration of this technique in a cold strontium system. DARPA QUASAR, NIST, NSF PFC.

  4. Adiabatic theory for anisotropic cold molecule collisions

    Energy Technology Data Exchange (ETDEWEB)

    Pawlak, Mariusz [Schulich Faculty of Chemistry, Technion–Israel Institute of Technology, Haifa 32000 (Israel); Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Toruń (Poland); Shagam, Yuval; Narevicius, Edvardas [Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100 (Israel); Moiseyev, Nimrod [Schulich Faculty of Chemistry, Technion–Israel Institute of Technology, Haifa 32000 (Israel); Faculty of Physics, Technion–Israel Institute of Technology, Haifa 32000 (Israel)


    We developed an adiabatic theory for cold anisotropic collisions between slow atoms and cold molecules. It enables us to investigate the importance of the couplings between the projection states of the rotational motion of the atom about the molecular axis of the diatom. We tested our theory using the recent results from the Penning ionization reaction experiment {sup 4}He(1s2s {sup 3}S) + HD(1s{sup 2}) → {sup 4}He(1s{sup 2}) + HD{sup +}(1s) + e{sup −} [Lavert-Ofir et al., Nat. Chem. 6, 332 (2014)] and demonstrated that the couplings have strong effect on positions of shape resonances. The theory we derived provides cross sections which are in a very good agreement with the experimental findings.

  5. QCD string model for hybrid adiabatic potentials


    Kalashnikova, Yu. S.; Kuzmenko, D. S.


    Hybrid adiabatic potentials are considered in the framework of the QCD string model. The einbein field formalism is applied to obtain the large-distance behaviour of adiabatic potentials. The calculated excitation curves are shown to be the result of interplay between potential-type longitudinal and string-type transverse vibrations. The results are compared with recent lattice data.

  6. Normalizing shoulder EMG: An optimal set of maximum isometric voluntary contraction tests considering reproducibility. (United States)

    Schwartz, Cédric; Tubez, François; Wang, François-Charles; Croisier, Jean-Louis; Brüls, Olivier; Denoël, Vincent; Forthomme, Bénédicte


    Normalization of the electromyography (EMG) signal is often performed relatively to maximal voluntary activations (MVA) obtained during maximum isometric voluntary contraction (MVIC). The first aim was to provide an inter-session reproducible protocol to normalize the signal of eight shoulder muscles. The protocol should also lead to a level of activation >90% of MVA for >90% of the volunteers. The second aim was to evaluate the influence of the method used to extract the MVA from the EMG envelope on the normalized EMG signal. Thirteen volunteers performed 12 MVICs twice (one week interval). Several time constants (100ms to 2s) were compared when extracting the MVA from the EMG envelope. The EMG activity was also acquired during an arm elevation. Our results show that a combination of nine MVIC tests was required to meet our requirements including reproducibility. Both the number of MVIC tests and the size of the time constant influence the normalized EMG signal during the dynamic activity (variations up to 15%). A time constant of 1s was a good compromise to extract the MVA. These findings are valuable to improve the reproducibility of EMG signal normalization. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Adiabatic limit in perturbation theory

    CERN Document Server

    Epstein, H


    It is shown that, with correct mass and wave function renormalization, the time-ordered products for Wick polynomials T(L(y/sub 1/)...L(y/sub n/)) constructed by a method outlined in a previous paper (Epstein and Glaser, 1970) are such that the vectors of the form integral T(L(y/sub 1/)...L(y/sub n/)) g(y/sub 1/)...g(y/sub n/) psi dy/sub 1/...dy/sub n/ have limits when g tends to a constant, provided psi is chosen in a suitable dense domain. It follows that the S-matrix has unitary adiabatic limit as an operator-valued formal power series in Fock space. (4 refs).

  8. Adiabatic invariants of the extended KdV equation

    Energy Technology Data Exchange (ETDEWEB)

    Karczewska, Anna [Faculty of Mathematics, Computer Science and Econometrics, University of Zielona Góra, Szafrana 4a, 65-246 Zielona Góra (Poland); Rozmej, Piotr, E-mail: [Institute of Physics, Faculty of Physics and Astronomy, University of Zielona Góra, Szafrana 4a, 65-246 Zielona Góra (Poland); Infeld, Eryk [National Centre for Nuclear Research, Hoża 69, 00-681 Warszawa (Poland); Rowlands, George [Department of Physics, University of Warwick, Coventry, CV4 7A (United Kingdom)


    When the Euler equations for shallow water are taken to the next order, beyond KdV, momentum and energy are no longer exact invariants. (The only one is mass.) However, adiabatic invariants (AI) can be found. When the KdV expansion parameters are zero, exact invariants are recovered. Existence of adiabatic invariants results from general theory of near-identity transformations (NIT) which allow us to transform higher order nonintegrable equations to asymptotically equivalent (when small parameters tend to zero) integrable form. Here we present a direct method of calculations of adiabatic invariants. It does not need a transformation to a moving reference frame nor performing a near-identity transformation. Numerical tests show that deviations of AI from constant values are indeed small. - Highlights: • We suggest a new and simple method for calculating adiabatic invariants of second order wave equations. • It is easy to use and we hope that it will be useful if published. • Interesting numerics included.

  9. Partial evolution based local adiabatic quantum search (United States)

    Sun, Jie; Lu, Song-Feng; Liu, Fang; Yang, Li-Ping


    Recently, Zhang and Lu provided a quantum search algorithm based on partial adiabatic evolution, which beats the time bound of local adiabatic search when the number of marked items in the unsorted database is larger than one. Later, they found that the above two adiabatic search algorithms had the same time complexity when there is only one marked item in the database. In the present paper, following the idea of Roland and Cerf [Roland J and Cerf N J 2002 Phys. Rev. A 65 042308], if within the small symmetric evolution interval defined by Zhang et al., a local adiabatic evolution is performed instead of the original “global" one, this “new" algorithm exhibits slightly better performance, although they are progressively equivalent with M increasing. In addition, the proof of the optimality for this partial evolution based local adiabatic search when M = 1 is also presented. Two other special cases of the adiabatic algorithm obtained by appropriately tuning the evolution interval of partial adiabatic evolution based quantum search, which are found to have the same phenomenon above, are also discussed.

  10. Quantum adiabatic protocols using emergent local Hamiltonians. (United States)

    Modak, Ranjan; Vidmar, Lev; Rigol, Marcos


    We present two applications of emergent local Hamiltonians to speed up quantum adiabatic protocols for isolated noninteracting and weakly interacting fermionic systems in one-dimensional lattices. We demonstrate how to extract maximal work from initial band-insulating states, and how to adiabatically transfer systems from linear and harmonic traps into box traps. Our protocols consist of two stages. The first one involves a free expansion followed by a quench to an emergent local Hamiltonian. In the second stage, the emergent local Hamiltonian is "turned off" quasistatically. For the adiabatic transfer from a harmonic trap, we consider both zero- and nonzero-temperature initial states.

  11. Energy consumption for shortcuts to adiabaticity (United States)

    Torrontegui, E.; Lizuain, I.; González-Resines, S.; Tobalina, A.; Ruschhaupt, A.; Kosloff, R.; Muga, J. G.


    Shortcuts to adiabaticity let a system reach the results of a slow adiabatic process in a shorter time. We propose to quantify the "energy cost" of the shortcut by the energy consumption of the system enlarged by including the control device. A mechanical model where the dynamics of the system and control device can be explicitly described illustrates that a broad range of possible values for the consumption is possible, including zero (above the adiabatic energy increment) when friction is negligible and the energy given away as negative power is stored and reused by perfect regenerative braking.

  12. Thermoelectric Effects under Adiabatic Conditions

    Directory of Open Access Journals (Sweden)

    George Levy


    Full Text Available This paper investigates not fully explained voltage offsets observed by several researchers during the measurement of the Seebeck coefficient of high Z materials. These offsets, traditionally attributed to faulty laboratory procedures, have proven to have an irreducible component that cannot be fully eliminated in spite of careful laboratory procedures. In fact, these offsets are commonly observed and routinely subtracted out of commercially available Seebeck measurement systems. This paper offers a possible explanation based on the spontaneous formation of an adiabatic temperature gradient in the presence of a force field. The diffusion-diffusion heat transport mechanism is formulated and applied to predict two new thermoelectric effects. The first is the existence of a temperature gradient across a potential barrier in a semiconductor and the second is the Onsager reciprocal of the first, that is, the presence of a measureable voltage that arises across a junction when the temperature gradient is forced to zero by a thermal clamp. Suggested future research includes strategies for utilizing the new thermoelectric effects.

  13. Investigation of the low-temperature performance of asphalt mixtures via fatigue and linear contraction and creep test (United States)

    Liu, Conghui; Wu, Shaopeng; Li, Bo; Wang, Jingang


    Three types of asphalt mixtures, including asphalt concrete (AC), stone mastic asphalt (SMA) and porous asphalt (PA) with a 13mm gradation, are chosen to study the fatigue behavior, linear contraction and creep performance of them. The analysis of the experimental results is summarized as follows. The asphalt mixture exhibits longer fatigue life at low temperature than that at high temperature. But the fatigue life is more sensitive to the loading stress at low temperature. At the same time, the fatigue lives of all the three mixture gradations show decreasing trends with the increasing stress, which implies that restraining over-loading of highways is quite important. The linear contractive quotiety shows great distinction with the types of asphalt mixture gradations and temperature span, which indicates that modified asphalt and lower air voids can benefit to the contractive properties of asphalt mixtures at low temperature. Additionally, the linear contractive quotiety decreases with the falling of the temperature, meanwhile the distinctions between different temperature spans tend to slower. The creep test indicates that lower air voids and larger asphalt content are beneficial to the low temperature performance of asphalt.

  14. Test-retest reliability of muscle fiber conduction velocity and fractal dimension of surface EMG during isometric contractions. (United States)

    Beretta-Piccoli, Matteo; D'Antona, Giuseppe; Zampella, Cristian; Barbero, Marco; Clijsen, Ron; Cescon, Corrado


    The aim of this study was to determine the test-retest reliability of muscle fiber conduction velocity (CV) and fractal dimension (FD) obtained from multichannel surface electromyographic (sEMG) recordings. Forty healthy recreationally active subjects (20 men and 20 women) performed two elbow flexions on two trials with a 1 week interval. The first was a 20% maximal voluntary contraction (MVC) of 120 s, and the second at 60% MVC held until exhaustion. sEMG signals were detected from the biceps brachii, using bi-dimensional arrays. Initial values and slope of CV and FD were used for the reliability analysis. The intraclass correlation coefficient (ICC) values for the isometric contraction at 20% MVC were (-0.09) and 0.67 for CV and FD respectively; whereas the ICC values at 60% MVC were 0.78 and 0.82 for CV and FD respectively. The Bland Altman plots for the two isometric contractions showed a mean difference close to zero, with no evident outliers between the repeated measurements: at 20% MVC 0.001 53 for FD and  -0.0277 for CV, and at 60% MVC 0.006 66 for FD and 0.009 07 for CV. Overall, our findings suggest that during isometric fatiguing contractions, CV and FD slopes are reliable variables, with potential application in clinical populations.

  15. Assessment of total efficiency in adiabatic engines (United States)

    Mitianiec, W.


    The paper presents influence of ceramic coating in all surfaces of the combustion chamber of SI four-stroke engine on working parameters mainly on heat balance and total efficiency. Three cases of engine were considered: standard without ceramic coating, fully adiabatic combustion chamber and engine with different thickness of ceramic coating. Consideration of adiabatic or semi-adiabatic engine was connected with mathematical modelling of heat transfer from the cylinder gas to the cooling medium. This model takes into account changeable convection coefficient based on the experimental formulas of Woschni, heat conductivity of multi-layer walls and also small effect of radiation in SI engines. The simulation model was elaborated with full heat transfer to the cooling medium and unsteady gas flow in the engine intake and exhaust systems. The computer program taking into account 0D model of engine processes in the cylinder and 1D model of gas flow was elaborated for determination of many basic engine thermodynamic parameters for Suzuki DR-Z400S 400 cc SI engine. The paper presents calculation results of influence of the ceramic coating thickness on indicated pressure, specific fuel consumption, cooling and exhaust heat losses. Next it were presented comparisons of effective power, heat losses in the cooling and exhaust systems, total efficiency in function of engine rotational speed and also comparison of temperature inside the cylinder for standard, semi-adiabatic and full adiabatic engine. On the basis of the achieved results it was found higher total efficiency of adiabatic engines at 2500 rpm from 27% for standard engine to 37% for full adiabatic engine.

  16. Adiabatic quantum algorithm for search engine ranking. (United States)

    Garnerone, Silvano; Zanardi, Paolo; Lidar, Daniel A


    We propose an adiabatic quantum algorithm for generating a quantum pure state encoding of the PageRank vector, the most widely used tool in ranking the relative importance of internet pages. We present extensive numerical simulations which provide evidence that this algorithm can prepare the quantum PageRank state in a time which, on average, scales polylogarithmically in the number of web pages. We argue that the main topological feature of the underlying web graph allowing for such a scaling is the out-degree distribution. The top-ranked log(n) entries of the quantum PageRank state can then be estimated with a polynomial quantum speed-up. Moreover, the quantum PageRank state can be used in "q-sampling" protocols for testing properties of distributions, which require exponentially fewer measurements than all classical schemes designed for the same task. This can be used to decide whether to run a classical update of the PageRank.

  17. Adiabatic Quantum Algorithm for Search Engine Ranking (United States)

    Garnerone, Silvano; Zanardi, Paolo; Lidar, Daniel A.


    We propose an adiabatic quantum algorithm for generating a quantum pure state encoding of the PageRank vector, the most widely used tool in ranking the relative importance of internet pages. We present extensive numerical simulations which provide evidence that this algorithm can prepare the quantum PageRank state in a time which, on average, scales polylogarithmically in the number of web pages. We argue that the main topological feature of the underlying web graph allowing for such a scaling is the out-degree distribution. The top-ranked log⁡(n) entries of the quantum PageRank state can then be estimated with a polynomial quantum speed-up. Moreover, the quantum PageRank state can be used in “q-sampling” protocols for testing properties of distributions, which require exponentially fewer measurements than all classical schemes designed for the same task. This can be used to decide whether to run a classical update of the PageRank.

  18. Performance test results of helium gas circulator of mock-up test facility with full-scale reaction tube for HTTR hydrogen production system. Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Akira; Kato, Michio; Hayashi, Koji [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment] [and others


    Hydrogen production system by steam reforming of methane will be connected to the High Temperature Engineering Test Reactor (HTTR) of the Japan Atomic Energy Research Institute (JAERI) against development of nuclear heat utilization system. To obtain design and safety database of the HTTR hydrogen production system, mock-up test facility with full-scale reaction was constructed in FY 2001 and hydrogen of 120m{sup 3}N{sub /}h was successfully produced in overall performance test. This report describes performance test results of a helium gas circulator in this facility. The circulator performance curves regarding to pressure-rise, input power and adiabatic thermal efficiency at standard revolution number were made based on the measured flow-rate, temperature and pressure data in overall performance test. The circulator performance prediction code was made based on these performance curves. The code can calculate revolution number, electric power and temperature-rise of the circulator using flow-rate, inlet temperature, inlet pressure and pressure-rise data. The verification of the code was carried out with the test data in FY 2002. Total pressure loss of the helium gas circulation loop was also evaluated. The circulator should be operated in conditions such as pressure from 2.7MPa to 4.0MPa and flow-rate from 250g/s to 400g/s and at maximum pressure-rise of 250 kPa in test operation. It was confirmed in above verification and evaluations that the circulator had performance to satisfy above conditions within operation limitation of the circulator such as maximum input-power of 150 kW and maximum revolution number of 12,000 rpm. (author)

  19. Antenatal fetal assessment: contraction stress test, nonstress test, vibroacoustic stimulation, amniotic fluid volume, biophysical profile, and modified biophysical profile--an overview. (United States)

    Devoe, Lawrence D


    Antenatal fetal assessment was introduced into the United States in the 1970s. The initial antepartum test, the oxytocin challenge test, later renamed as the contraction stress test, became the gold standard for fetal surveillance. Its labor intensive requirements and contraindications made it inapplicable to some high-risk pregnancies. Other testing schemes were developed subsequently, the nonstress test and its alternative, vibroacoustic stimulation, the semiquantitative assessment of amniotic fluid volume, the biophysical profile and its modified version, the modified biophysical profile. This article is a brief critical review of these testing methods and focuses on the following: (1) physiologic bases; (2) testing methodologies; (3) supportive evidence from randomized controlled and observational trials; and (4) areas needing further investigation.

  20. Non-adiabatic rotational excitation of dipolar molecule under the ...

    Indian Academy of Sciences (India)

    adiabatically by half cycle pulse. (HCP) is controlled using the second ultrashort HCP. ... excited to create a rotational quantum wave packet, a .... Non-adiabatic rotational excitation of dipolar molecule under the influence of delayed pulses. 1215.

  1. Adiabatic pumping through interacting quantum dots


    Splettstoesser, Janine; Governale, Michele; König, Jürgen; Fazio, Rosario


    We present a general formalism to study adiabatic pumping through interacting quantum dots. We derive a formula that relates the pumped charge to the local, instantaneous Green function of the dot. This formula is then applied to the infinite-U Anderson model both for weak and strong tunnel-coupling strengths.

  2. Quantum Pumping and Adiabatic Transport in Nanostructures

    NARCIS (Netherlands)

    Wakker, G.M.M.


    This thesis consists of a theoretical exploration of quantum transport phenomena and quantum dynamics in nanostructures. Specifically, we investigate adiabatic quantum pumping of charge in several novel types of nanostructures involving open quantum dots or graphene. For a bilayer of graphene we

  3. Improving the positive feedback adiabatic logic familiy

    Directory of Open Access Journals (Sweden)

    J. Fischer


    Full Text Available Positive Feedback Adiabatic Logic (PFAL shows the lowest energy dissipation among adiabatic logic families based on cross-coupled transistors, due to the reduction of both adiabatic and non-adiabatic losses. The dissipation primarily depends on the resistance of the charging path, which consists of a single p-channel MOSFET during the recovery phase. In this paper, a new logic family called Improved PFAL (IPFAL is proposed, where all n- and pchannel devices are swapped so that the charge can be recovered through an n-channel MOSFET. This allows to decrease the resistance of the charging path up to a factor of 2, and it enables a significant reduction of the energy dissipation. Simulations based on a 0.13µm CMOS process confirm the improvements in terms of power consumption over a large frequency range. However, the same simple design rule, which enables in PFAL an additional reduction of the dissipation by optimal transistor sizing, does not apply to IPFAL. Therefore, the influence of several sources of dissipation for a generic IPFAL gate is illustrated and discussed, in order to lower the power consumption and achieve better performance.

  4. Semi adiabatic theory of seasonal Markov processes

    Energy Technology Data Exchange (ETDEWEB)

    Talkner, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)


    The dynamics of many natural and technical systems are essentially influenced by a periodic forcing. Analytic solutions of the equations of motion for periodically driven systems are generally not known. Simulations, numerical solutions or in some limiting cases approximate analytic solutions represent the known approaches to study the dynamics of such systems. Besides the regime of weak periodic forces where linear response theory works, the limit of a slow driving force can often be treated analytically using an adiabatic approximation. For this approximation to hold all intrinsic processes must be fast on the time-scale of a period of the external driving force. We developed a perturbation theory for periodically driven Markovian systems that covers the adiabatic regime but also works if the system has a single slow mode that may even be slower than the driving force. We call it the semi adiabatic approximation. Some results of this approximation for a system exhibiting stochastic resonance which usually takes place within the semi adiabatic regime are indicated. (author) 1 fig., 8 refs.

  5. Fixed-point adiabatic quantum search (United States)

    Dalzell, Alexander M.; Yoder, Theodore J.; Chuang, Isaac L.


    Fixed-point quantum search algorithms succeed at finding one of M target items among N total items even when the run time of the algorithm is longer than necessary. While the famous Grover's algorithm can search quadratically faster than a classical computer, it lacks the fixed-point property—the fraction of target items must be known precisely to know when to terminate the algorithm. Recently, Yoder, Low, and Chuang [Phys. Rev. Lett. 113, 210501 (2014), 10.1103/PhysRevLett.113.210501] gave an optimal gate-model search algorithm with the fixed-point property. Previously, it had been discovered by Roland and Cerf [Phys. Rev. A 65, 042308 (2002), 10.1103/PhysRevA.65.042308] that an adiabatic quantum algorithm, operating by continuously varying a Hamiltonian, can reproduce the quadratic speedup of gate-model Grover search. We ask, can an adiabatic algorithm also reproduce the fixed-point property? We show that the answer depends on what interpolation schedule is used, so as in the gate model, there are both fixed-point and non-fixed-point versions of adiabatic search, only some of which attain the quadratic quantum speedup. Guided by geometric intuition on the Bloch sphere, we rigorously justify our claims with an explicit upper bound on the error in the adiabatic approximation. We also show that the fixed-point adiabatic search algorithm can be simulated in the gate model with neither loss of the quadratic Grover speedup nor of the fixed-point property. Finally, we discuss natural uses of fixed-point algorithms such as preparation of a relatively prime state and oblivious amplitude amplification.

  6. η condensate of fermionic atom pairs via adiabatic state preparation. (United States)

    Kantian, A; Daley, A J; Zoller, P


    We discuss how an η condensate, corresponding to an exact excited eigenstate of the Fermi-Hubbard model, can be produced with cold atoms in an optical lattice. Using time-dependent density matrix renormalization group methods, we analyze a state preparation scheme beginning from a band insulator state in an optical superlattice. This state can act as an important test case, both for adiabatic preparation methods and the implementation of the many-body Hamiltonian, and measurements on the final state can be used to help detect associated errors.

  7. Premature Contractions (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Premature Contractions - PACs and PVCs Updated:Dec 15,2016 ... You felt this more-forceful beat. Types of premature contractions Premature atrial contractions (PACs) start in the ...

  8. Non-adiabatic perturbations in multi-component perfect fluids

    Energy Technology Data Exchange (ETDEWEB)

    Koshelev, N.A., E-mail: [Ulyanovsk State University, Leo Tolstoy str 42, 432970 (Russian Federation)


    The evolution of non-adiabatic perturbations in models with multiple coupled perfect fluids with non-adiabatic sound speed is considered. Instead of splitting the entropy perturbation into relative and intrinsic parts, we introduce a set of symmetric quantities, which also govern the non-adiabatic pressure perturbation in models with energy transfer. We write the gauge invariant equations for the variables that determine on a large scale the non-adiabatic pressure perturbation and the rate of changes of the comoving curvature perturbation. The analysis of evolution of the non-adiabatic pressure perturbation has been made for several particular models.

  9. Data report of BWR post-CHF tests. Transient core thermal-hydraulic test program. Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, Tadashi; Itoh, Hideo; Kiuchi, Toshio; Watanabe, Hironori; Kimura, Mamoru; Anoda, Yoshinari [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment


    JAERI has been performing transient core thermal-hydraulic test program. In the program, authors performed BWR/ABWR DBE simulation tests with a test facility, which can simulate BWR/ABWR transients. The test facility has a 4 x 4 bundle core simulator with 15-rod heaters and one non-heated rod. Through the tests, authors quantified the thermal safety margin for core cooling. In order to quantify the thermal safety margin, authors collected experimental data on post-CHF. The data are essential for the evaluation of clad temperature transient when core heat-up occurs during DBEs. In comparison with previous post-CHF tests, present experiments were performed in much wider experimental condition, covering high clad temperature, low to high pressure and low to high mass flux. Further, data at wider elevation (lower to higher elevation of core) were obtained in the present experiments, which make possible to discuss the effect of axial position on thermal-hydraulics, while previous works usually discuss the thermal-hydraulics at the position where the first heat-up occurs. This data report describes test procedure, test condition and major experimental data of post-CHF tests. (author)

  10. Ramsey numbers and adiabatic quantum computing. (United States)

    Gaitan, Frank; Clark, Lane


    The graph-theoretic Ramsey numbers are notoriously difficult to calculate. In fact, for the two-color Ramsey numbers R(m,n) with m, n≥3, only nine are currently known. We present a quantum algorithm for the computation of the Ramsey numbers R(m,n). We show how the computation of R(m,n) can be mapped to a combinatorial optimization problem whose solution can be found using adiabatic quantum evolution. We numerically simulate this adiabatic quantum algorithm and show that it correctly determines the Ramsey numbers R(3,3) and R(2,s) for 5≤s≤7. We then discuss the algorithm's experimental implementation, and close by showing that Ramsey number computation belongs to the quantum complexity class quantum Merlin Arthur.

  11. Comment on ``Adiabatic theory for the bipolaron'' (United States)

    Smondyrev, M. A.; Devreese, J. T.


    Comments are given on the application of the Bogoliubov-Tyablikov approach to the bipolaron problem in a recent paper by Lakhno [Phys. Rev. B 51, 3512 (1995)]. This author believes that his model (1) is the translation-invariant adiabatic theory of bipolarons and (2) gives asymptotically exact solutions in the adiabatic limit while the other approaches are considered as either phenomenological or variational in nature. Numerical results by Lakhno are in contradiction with all other papers published on the subject because his model leads to much lower energies. Thus, the author concludes that bipolarons ``are more stable than was considered before.'' We prove that both the analytical and the numerical results presented by Lakhno are wrong.

  12. Adiabatic Quantum Optimization for Associative Memory Recall (United States)

    Seddiqi, Hadayat; Humble, Travis


    Hopfield networks are a variant of associative memory that recall patterns stored in the couplings of an Ising model. Stored memories are conventionally accessed as fixed points in the network dynamics that correspond to energetic minima of the spin state. We show that memories stored in a Hopfield network may also be recalled by energy minimization using adiabatic quantum optimization (AQO). Numerical simulations of the underlying quantum dynamics allow us to quantify AQO recall accuracy with respect to the number of stored memories and noise in the input key. We investigate AQO performance with respect to how memories are stored in the Ising model according to different learning rules. Our results demonstrate that AQO recall accuracy varies strongly with learning rule, a behavior that is attributed to differences in energy landscapes. Consequently, learning rules offer a family of methods for programming adiabatic quantum optimization that we expect to be useful for characterizing AQO performance.

  13. Pulsed Adiabatic Photoassociation via Scattering Resonances


    Han, Alex C.; Shapiro, Evgeny A.; Shapiro, Moshe


    We develop the theory for the Adiabatic Raman Photoassociation (ARPA) of ultracold atoms to form ultracold molecules in the presence of scattering resonances. Based on a computational method in which we replace the continuum with a discrete set of "effective modes", we show that the existence of resonances greatly aids in the formation of deeply bound molecular states. We illustrate our general theory by computationally studying the formation of $^{85}$Rb$_2$ molecules from pairs of colliding...

  14. Adiabatic thermal models for planetary bodies (United States)

    Spohn, T.


    In a number of recent experiments it was found that the logarithmic derivative with respect to volume of the adiabatic temperature increase with pressure P to be an approximately constant quantity n. It was found that n decreases slightly with temperature, to be virtually unaffected by increasing pressure and to take values between 4 and 8 for a wide variety of materials. It is shown that these findings can be substantiated from thermodynamic arguments, finite strain theory, atomic potential theory and experimental data on the thermal expansion coefficient and the bulk modulus B. It will be shown that n is independent of pressure if it is exactly equal to dB/dP + 1. For these materials d log gamma/d log v = -1, where gamma is the thermodynamic Gruneisenparameter. It will increase with P during an isothermal transformation if n dB/dP + 1 and decrease of n dB/dP + 1. For most materials n is close to dB/dP and the changes will be slight if pressures do not become too extreme. During an adiabatic transformation n is virtually constant. Adiabatic thermal models for planetary bodies were calculated and are presented.

  15. Adiabatic heating in impulsive solar flares (United States)

    Maetzler, C.; Bai, T.; Crannell, C. J.; Frost, K. J.


    A study is made of adiabatic heating in two impulsive solar flares on the basis of dynamic X-ray spectra in the 28-254 keV range, H-alpha, microwave, and meter-wave radio observations. It is found that the X-ray spectra of the events are like those of thermal bremsstrahlung from single-temperature plasmas in the 10-60 keV range if photospheric albedo is taken into account. The temperature-emission correlation indicates adiabatic compression followed by adiabatic expansion and that the electron distribution remains isotropic. H-alpha data suggest compressive energy transfer. The projected areas and volumes of the flares are estimated assuming that X-ray and microwave emissions are produced in a single thermal plasma. Electron densities of about 10 to the 9th/cu cm are found for homogeneous, spherically symmetric sources. It is noted that the strong self-absorption of hot-plasma gyrosynchrotron radiation reveals low magnetic field strengths.

  16. Testing for Spanning with Futrures Contracts and Nontraded Assets : A General Approach

    NARCIS (Netherlands)

    Nijman, T.E.; de Roon, F.A.; Werker, B.J.M.


    This paper generalizes the notion of mean-variance spanning as de- ned in the seminal paper of Huberman & Kandel (1987) in three di- mensions.It is shown how regression techniques can be used to test for spanning for more general classes of utility functions, in case some as- sets are nontraded, and

  17. Testing the associations between different aspects of seafarers' employment contract and on-board internet access and their job and life satisfaction and health. (United States)

    Slišković, Ana; Penezić, Zvjezdan


    The aim of this study was to test for associations between different aspects of contract and on-board internet access and seafarers' satisfaction and health. Altogether 298 Croatian seafarers, all officers, employed on cargo ships, with a minimum work experience of two years with their current shipping company, participated in an online survey. The questionnaire included sociodemographic items, questions relating to their employment contract and internet access, and measures of job satisfaction, life satisfaction, mental health, and gastrointestinal and cardiovascular symptoms. Their job- and lifesatisfaction levels were higher for shorter duration on board, favourable ratio of work to non-work days, and compliance with the employment contract regarding the changes to work and non-work days. Mental health differed likewise but only in relation to two aspects of the contract: on-board duration and compliance with the contract. The level of gastrointestinal symptoms was lower in cases of shorter on-board duration and compliance with the contract, and in seafarers who have free, unlimited internet access on board. Lower level of cardiovascular symptoms was found in seafarers with free, unlimited internet access on board. Our findings suggest that in promoting satisfaction and health in seafaring, attention should be given to reducing on-board duration, compliance with the contract, and internet accessibility on board.

  18. Adiabatic correction to the energy of molecular systems: the CPHF equivalent of the Born Handy formula (United States)

    Svrček, M.; Baňacký, P.; Biskupič, S.; Noga, J.; Pelikán, P.; Zajac, A.


    The Born-Handy formula, recently shown by Kutzelnigg to be a rigorous expression for the calculation of the adiabatic correction, has been, on the level of a ground state SCF wavefunction, reformulated and linked to the coefficients of the standard coupled perturbed Hartree-Fock (CPHF) method. The contribution of the electron correlation via second-order perturbation theory is also presented. The solution of the corresponding secular equation of the nuclear motion enables the calculation of the adiabatic correction over the particular normal modes. The method offers the possibility of extending high-precision calculations of the adiabatic correction to more complex systems. Test calculations have been performed for H 2, HD and D 2 and the results are in satisfactory agreement with the exact figures.

  19. Sliding Seal Materials for Adiabatic Engines, Phase 2 (United States)

    Lankford, J.; Wei, W.


    An essential task in the development of the heavy-duty adiabatic diesel engine is identification and improvements of reliable, low-friction piston seal materials. In the present study, the sliding friction coefficients and wear rates of promising carbide, oxide, and nitride materials were measured under temperature, environmental, velocity, and loading conditions that are representative of the adiabatic engine environment. In addition, silicon nitride and partially stabilized zirconia disks were ion implanted with TiNi, Ni, Co, and Cr, and subsequently run against carbide pins, with the objective of producing reduced friction via solid lubrication at elevated temperature. In order to provide guidance needed to improve materials for this application, the program stressed fundamental understanding of the mechanisms involved in friction and wear. Electron microscopy was used to elucidate the micromechanisms of wear following wear testing, and Auger electron spectroscopy was used to evaluate interface/environment interactions which seemed to be important in the friction and wear process. Unmodified ceramic sliding couples were characterized at all temperatures by friction coefficients of 0.24 and above. The coefficient at 800 C in an oxidizing environment was reduced to below 0.1, for certain material combinations, by the ion implanation of TiNi or Co. This beneficial effect was found to derive from lubricious Ti, Ni, and Co oxides.

  20. Adiabaticity criterion and the shortest adiabatic mode transformer in a coupled-waveguide system. (United States)

    Sun, Xiankai; Liu, Hsi-Chun; Yariv, Amnon


    By analyzing the propagating behavior of the supermodes in a coupled-waveguide system, we have derived a universal criterion for designing adiabatic mode transformers. The criterion relates epsilon, the fraction of power scattered into the unwanted mode, to waveguide design parameters and gives the shortest possible length of an adiabatic mode transformer, which is approximately 2/piepsilon1/2 times the distance of maximal power transfer between the waveguides. The results from numerical calculations based on a transfer-matrix formalism support this theory very well.

  1. Bond selective chemistry beyond the adiabatic approximation

    Energy Technology Data Exchange (ETDEWEB)

    Butler, L.J. [Univ. of Chicago, IL (United States)


    One of the most important challenges in chemistry is to develop predictive ability for the branching between energetically allowed chemical reaction pathways. Such predictive capability, coupled with a fundamental understanding of the important molecular interactions, is essential to the development and utilization of new fuels and the design of efficient combustion processes. Existing transition state and exact quantum theories successfully predict the branching between available product channels for systems in which each reaction coordinate can be adequately described by different paths along a single adiabatic potential energy surface. In particular, unimolecular dissociation following thermal, infrared multiphoton, or overtone excitation in the ground state yields a branching between energetically allowed product channels which can be successfully predicted by the application of statistical theories, i.e. the weakest bond breaks. (The predictions are particularly good for competing reactions in which when there is no saddle point along the reaction coordinates, as in simple bond fission reactions.) The predicted lack of bond selectivity results from the assumption of rapid internal vibrational energy redistribution and the implicit use of a single adiabatic Born-Oppenheimer potential energy surface for the reaction. However, the adiabatic approximation is not valid for the reaction of a wide variety of energetic materials and organic fuels; coupling between the electronic states of the reacting species play a a key role in determining the selectivity of the chemical reactions induced. The work described below investigated the central role played by coupling between electronic states in polyatomic molecules in determining the selective branching between energetically allowed fragmentation pathways in two key systems.

  2. Narrow Linewidth Laser Cooling via Adiabatic Transfer (United States)

    Bartolotta, John; Holland, Murray; Norcia, Matthew; Thompson, James; Cline, Julia


    We simulate and provide a theoretical framework for a new cooling method applicable to particles with narrow-linewidth optical transitions. The particles are adiabatically transferred to lower momentum states upon interaction with counter-propagating laser beams that are repeatedly swept over the transition frequency. A reduced reliance on spontaneous emission (compared to Doppler cooling) allows for larger slowing forces. Cooling via a 7.6 kHz dipole forbidden transition in Strontium-88 is simulated using one-dimensional quantum jump and c-number Langevin equation methods. This ``sweep cooling'' mechanism also shows promise for application to systems lacking closed cycling transitions, such as molecules.

  3. Green's Functions and the Adiabatic Hyperspherical Method

    CERN Document Server

    Rittenhouse, Seth T; Greene, Chris H


    We address the few-body problem using the adiabatic hyperspherical representation. A general form for the hyperangular Green's function in $d$-dimensions is derived. The resulting Lippmann-Schwinger equation is solved for the case of three-particles with s-wave zero-range interactions. Identical particle symmetry is incorporated in a general and intuitive way. Complete semi-analytic expressions for the nonadiabatic channel couplings are derived. Finally, a model to describe the atom-loss due to three-body recombination for a three-component fermi-gas of $^{6}$Li atoms is presented.

  4. Inversion produced and reversed by adiabatic passage (United States)

    Liedenbaum, C.; Stolte, S.; Reuss, J.


    This report deals with non-linear effects produced in molecules by strong laser fields. The molecules experience these laser fields during their passage through the laser waists. We present results on rapid adiabatic passage processes which move the molecules up and down the energy ladder, the latter due to stimulated emission. Experimentally, stimulated emission is observed by opto-thermal detection of a molecular beam where de-excitation by stimulated emission leads to negative signals as compared to straightforward excitation processes. Two-level, three-level and multi-level systems are covered by the following discussion.

  5. The Effect of non-Hermiticity on Adiabatic Elimination


    Sharaf, Rahman; Dehghani, Mojgan; Darbari, Sara; Ramezani, Hamidreza


    We investigate the influence of non-Hermiticity on the adiabatic elimination in coupled waveguides. We show that adiabatic elimination is not affected when the system is in parity-time symmetric phase. However, in the broken phase the eliminated waveguide loses its darkness namely its amplitude starts increasing, which means adiabatic elimination does not hold in the broken phase. Our results can advance the control of the dynamics in coupled laser cavities, and help the design of controllabl...

  6. Job insecurity and well-being in the temporary workforce : Testing volition and contract expectations as boundary conditions

    NARCIS (Netherlands)

    Bernhard-Oettel, C.; Rigotti, T.; Clinton, M.; de Jong, J.P.


    This study investigates whether temporary contract volition and workers' expectations for contract renewal are boundary conditions to explain differences in temporary workers' job insecurity feelings and well-being. It is hypothesized that (1) low volition through higher job insecurity indirectly

  7. Magnesium Diboride Superconducting Coils for Adiabatic Demagnetization Refrigerators (ADR's) Project (United States)

    National Aeronautics and Space Administration — For Adiabatic Demagnetization Refrigerators (ADRs) in space applications, it is desirable to have very light weight, small diameter, high current density...

  8. Symmetry of the adiabatic condition in the piston problem

    Energy Technology Data Exchange (ETDEWEB)

    Anacleto, Joaquim; Ferreira, J M, E-mail: [Departamento de Fisica, Escola de Ciencias e Tecnologia, Universidade de Tras-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real (Portugal)


    This study addresses a controversial issue in the adiabatic piston problem, namely that of the piston being adiabatic when it is fixed but no longer so when it can move freely. It is shown that this apparent contradiction arises from the usual definition of adiabatic condition. The issue is addressed here by requiring the adiabatic condition to be compatible with the invariance of total entropy under a system-surroundings interchange. This paper also strengthens some recently published ideas concerning the concepts of heat and dissipative work, and is primarily intended for teachers and graduate students, as well as for all who are interested in this fascinating problem.

  9. An Adiabatic Phase-Matching Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lemery, Francois [DESY; Floettmann, Klaus [DESY; Piot, Philippe [Northern Illinois U.; Kaertner, Franz X. [Hamburg U.; Assmann, Ralph [DESY


    We present a general concept to accelerate non-relativistic charged particles. Our concept employs an adiabatically-tapered dielectric-lined waveguide which supports accelerating phase velocities for synchronous acceleration. We propose an ansatz for the transient field equations, show it satisfies Maxwell's equations under an adiabatic approximation and find excellent agreement with a finite-difference time-domain computer simulation. The fields were implemented into the particle-tracking program {\\sc astra} and we present beam dynamics results for an accelerating field with a 1-mm-wavelength and peak electric field of 100~MV/m. The numerical simulations indicate that a $\\sim 200$-keV electron beam can be accelerated to an energy of $\\sim10$~MeV over $\\sim 10$~cm. The novel scheme is also found to form electron beams with parameters of interest to a wide range of applications including, e.g., future advanced accelerators, and ultra-fast electron diffraction.

  10. Adiabatic Mass Loss Model in Binary Stars (United States)

    Ge, H. W.


    Rapid mass transfer process in the interacting binary systems is very complicated. It relates to two basic problems in the binary star evolution, i.e., the dynamically unstable Roche-lobe overflow and the common envelope evolution. Both of the problems are very important and difficult to be modeled. In this PhD thesis, we focus on the rapid mass loss process of the donor in interacting binary systems. The application to the criterion of dynamically unstable mass transfer and the common envelope evolution are also included. Our results based on the adiabatic mass loss model could be used to improve the binary evolution theory, the binary population synthetic method, and other related aspects. We build up the adiabatic mass loss model. In this model, two approximations are included. The first one is that the energy generation and heat flow through the stellar interior can be neglected, hence the restructuring is adiabatic. The second one is that he stellar interior remains in hydrostatic equilibrium. We model this response by constructing model sequences, beginning with a donor star filling its Roche lobe at an arbitrary point in its evolution, holding its specific entropy and composition profiles fixed. These approximations are validated by the comparison with the time-dependent binary mass transfer calculations and the polytropic model for low mass zero-age main-sequence stars. In the dynamical time scale mass transfer, the adiabatic response of the donor star drives it to expand beyond its Roche lobe, leading to runaway mass transfer and the formation of a common envelope with its companion star. For donor stars with surface convection zones of any significant depth, this runaway condition is encountered early in mass transfer, if at all; but for main sequence stars with radiative envelopes, it may be encountered after a prolonged phase of thermal time scale mass transfer, so-called delayed dynamical instability. We identify the critical binary mass ratio for the

  11. Quantum adiabatic algorithm for factorization and its experimental implementation. (United States)

    Peng, Xinhua; Liao, Zeyang; Xu, Nanyang; Qin, Gan; Zhou, Xianyi; Suter, Dieter; Du, Jiangfeng


    We propose an adiabatic quantum algorithm capable of factorizing numbers, using fewer qubits than Shor's algorithm. We implement the algorithm in a NMR quantum information processor and experimentally factorize the number 21. In the range that our classical computer could simulate, the quantum adiabatic algorithm works well, providing evidence that the running time of this algorithm scales polynomially with the problem size.

  12. Adiabatic heavy-ion fusion potentials for fusion at deep sub-barrier ...

    Indian Academy of Sciences (India)

    barrier energies has been examined. The adiabatic limit of fusion barriers has been determined from experimental data using the barrier penetration model. These adiabatic barriers are consistent with the adiabatic fusion barriers derived from ...

  13. Adiabatic logic future trend and system level perspective

    CERN Document Server

    Teichmann, Philip


    Adiabatic logic is a potential successor for static CMOS circuit design when it comes to ultra-low-power energy consumption. Future development like the evolutionary shrinking of the minimum feature size as well as revolutionary novel transistor concepts will change the gate level savings gained by adiabatic logic. In addition, the impact of worsening degradation effects has to be considered in the design of adiabatic circuits. The impact of the technology trends on the figures of merit of adiabatic logic, energy saving potential and optimum operating frequency, are investigated, as well as degradation related issues. Adiabatic logic benefits from future devices, is not susceptible to Hot Carrier Injection, and shows less impact of Bias Temperature Instability than static CMOS circuits. Major interest also lies on the efficient generation of the applied power-clock signal. This oscillating power supply can be used to save energy in short idle times by disconnecting circuits. An efficient way to generate the p...

  14. Adiabatic/diabatic polarization beam splitter (United States)

    DeRose, Christopher; Cai, Hong


    The various presented herein relate to an on-chip polarization beam splitter (PBS), which is adiabatic for the transverse magnetic (TM) mode and diabatic for the transverse electric (TE) mode. The PBS comprises a through waveguide and a cross waveguide, wherein an electromagnetic beam comprising TE mode and TM mode components is applied to an input port of the through waveguide. The PBS can be utilized to separate the TE mode component from the TM mode component, wherein the TE mode component exits the PBS via an output port of the through waveguide, and the TM mode component exits the PBS via an output port of the cross waveguide. The PBS has a structure that is tolerant to manufacturing variations and exhibits high polarization extinction ratios over a wide bandwidth.

  15. Reversible logic gate using adiabatic superconducting devices. (United States)

    Takeuchi, N; Yamanashi, Y; Yoshikawa, N


    Reversible computing has been studied since Rolf Landauer advanced the argument that has come to be known as Landauer's principle. This principle states that there is no minimum energy dissipation for logic operations in reversible computing, because it is not accompanied by reductions in information entropy. However, until now, no practical reversible logic gates have been demonstrated. One of the problems is that reversible logic gates must be built by using extremely energy-efficient logic devices. Another difficulty is that reversible logic gates must be both logically and physically reversible. Here we propose the first practical reversible logic gate using adiabatic superconducting devices and experimentally demonstrate the logical and physical reversibility of the gate. Additionally, we estimate the energy dissipation of the gate, and discuss the minimum energy dissipation required for reversible logic operations. It is expected that the results of this study will enable reversible computing to move from the theoretical stage into practical usage.

  16. Adiabatic vs. non-adiabatic determination of specific absorption rate of ferrofluids

    Energy Technology Data Exchange (ETDEWEB)

    Natividad, Eva [Instituto de Ciencia de Materiales de Aragon (CSIC-Universidad de Zaragoza), Sede Campus Rio Ebro, Maria de Luna, 3, 50018 Zaragoza (Spain); Castro, Miguel [Instituto de Ciencia de Materiales de Aragon (CSIC-Universidad de Zaragoza), Sede Campus Rio Ebro, Maria de Luna, 3, 50018 Zaragoza (Spain)], E-mail:; Mediano, Arturo [Grupo de Electronica de Potencia y Microelectronica (GEPM), Instituto de Investigacion en Ingenieria de Aragon (Universidad de Zaragoza), Maria de Luna, 3, 50018 Zaragoza (Spain)


    The measurement of temperature variations in adiabatic conditions allows the determination of the specific absorption rate of magnetic nanoparticles and ferrofluids from the correct incremental expression, SAR=(1/m{sub MNP})C({delta}T/{delta}t). However, when measurements take place in non-adiabatic conditions, one must approximate this expression by SAR{approx}C{beta}/m{sub MNP}, where {beta} is the initial slope of the temperature vs. time curve during alternating field application. The errors arising from the use of this approximation were estimated through several experiments with different isolating conditions, temperature sensors and sample-sensor contacts. It is concluded that small to appreciable errors can appear, which are difficult to infer or control.

  17. Adiabatic Rearrangement of Hollow PV Towers

    Directory of Open Access Journals (Sweden)

    Eric A Hendricks


    Full Text Available Diabatic heating from deep moist convection in the hurricane eyewall produces a towering annular structure of elevated potential vorticity (PV. This structure has been referred to as a hollow PV tower. The sign reversal of the radial gradient of PV satisfies the Charney-Stern necessary condition for combined barotropic-baroclinic instability. For thin enough annular structures, small perturbations grow exponentially, extract energy from the mean flow, and lead to hollow tower breakdown, with significant vortex structural and intensity change. The three-dimensional adiabatic rearrangements of two prototypical hurricane-like hollow PV towers (one thick and one thin are examined in an idealized framework. For both hollow towers, dynamic instability causes air parcels with high PV to be mixed into the eye preferentially at lower levels, where unstable PV wave growth rates are the largest. Little or no mixing is found to occur at upper levels. The mixing at lower and middle levels is most rapid for the breakdown of the thin hollow tower, consistent with previous barotropic results. For both hollow towers, this advective rearrangement of PV affects the tropical cyclone structure and intensity in a number of ways. First, the minimum central pressure and maximum azimuthal mean velocity simultaneously decrease, consistent with previous barotropic results. Secondly, isosurfaces of absolute angular momentum preferentially shift inward at low levels, implying an adiabatic mechanism by which hurricane eyewall tilt can form. Thirdly, a PV bridge, similar to that previously found in full-physics hurricane simulations, develops as a result of mixing at the isentropic levels where unstable PV waves grow most rapidly. Finally, the balanced mass field resulting from the PV rearrangement is warmer in the eye between 900 and 700 hPa. The location of this warming is consistent with observed warm anomalies in the eye, indicating that in certain instances the hurricane

  18. Wigner phase space distribution via classical adiabatic switching

    Energy Technology Data Exchange (ETDEWEB)

    Bose, Amartya [Department of Chemistry, University of Illinois, 600 S. Goodwin Avenue, Urbana, Illinois 61801 (United States); Makri, Nancy [Department of Chemistry, University of Illinois, 600 S. Goodwin Avenue, Urbana, Illinois 61801 (United States); Department of Physics, University of Illinois, 1110 W. Green Street, Urbana, Illinois 61801 (United States)


    Evaluation of the Wigner phase space density for systems of many degrees of freedom presents an extremely demanding task because of the oscillatory nature of the Fourier-type integral. We propose a simple and efficient, approximate procedure for generating the Wigner distribution that avoids the computational difficulties associated with the Wigner transform. Starting from a suitable zeroth-order Hamiltonian, for which the Wigner density is available (either analytically or numerically), the phase space distribution is propagated in time via classical trajectories, while the perturbation is gradually switched on. According to the classical adiabatic theorem, each trajectory maintains a constant action if the perturbation is switched on infinitely slowly. We show that the adiabatic switching procedure produces the exact Wigner density for harmonic oscillator eigenstates and also for eigenstates of anharmonic Hamiltonians within the Wentzel-Kramers-Brillouin (WKB) approximation. We generalize the approach to finite temperature by introducing a density rescaling factor that depends on the energy of each trajectory. Time-dependent properties are obtained simply by continuing the integration of each trajectory under the full target Hamiltonian. Further, by construction, the generated approximate Wigner distribution is invariant under classical propagation, and thus, thermodynamic properties are strictly preserved. Numerical tests on one-dimensional and dissipative systems indicate that the method produces results in very good agreement with those obtained by full quantum mechanical methods over a wide temperature range. The method is simple and efficient, as it requires no input besides the force fields required for classical trajectory integration, and is ideal for use in quasiclassical trajectory calculations.

  19. Polymorphic Contracts (United States)

    Belo, João Filipe; Greenberg, Michael; Igarashi, Atsushi; Pierce, Benjamin C.

    Manifest contracts track precise properties by refining types with predicates - e.g., {x : Int |x > 0 } denotes the positive integers. Contracts and polymorphism make a natural combination: programmers can give strong contracts to abstract types, precisely stating pre- and post-conditions while hiding implementation details - for example, an abstract type of stacks might specify that the pop operation has input type {x :α Stack |not ( empty x )} . We formalize this combination by defining FH, a polymorphic calculus with manifest contracts, and establishing fundamental properties including type soundness and relational parametricity. Our development relies on a significant technical improvement over earlier presentations of contracts: instead of introducing a denotational model to break a problematic circularity between typing, subtyping, and evaluation, we develop the metatheory of contracts in a completely syntactic fashion, omitting subtyping from the core system and recovering it post facto as a derived property.

  20. Electrical contracting

    CERN Document Server

    Neidle, Michael


    Electrical Contracting, Second Edition is a nine-chapter text guide for the greater efficiency in planning and completing installations for the design, installation and control of electrical contracts. This book starts with a general overview of the efficient cabling and techniques that must be employed for safe wiring design, as well as the cost estimation of the complete electrical contract. The subsequent chapters are devoted to other electrical contracting requirements, including electronic motor control, lighting, and electricity tariffs. A chapter focuses on the IEE Wiring Regulations an

  1. Intrinsic geometry of quantum adiabatic evolution and quantum phase transitions (United States)

    Rezakhani, A. T.; Abasto, D. F.; Lidar, D. A.; Zanardi, P.


    We elucidate the geometry of quantum adiabatic evolution. By minimizing the deviation from adiabaticity, we find a Riemannian metric tensor underlying adiabatic evolution. Equipped with this tensor, we identify a unified geometric description of quantum adiabatic evolution and quantum phase transitions that generalizes previous treatments to allow for degeneracy. The same structure is relevant for applications in quantum information processing, including adiabatic and holonomic quantum computing, where geodesics over the manifold of control parameters correspond to paths which minimize errors. We illustrate this geometric structure with examples, for which we explicitly find adiabatic geodesics. By solving the geodesic equations in the vicinity of a quantum critical point, we identify universal characteristics of optimal adiabatic passage through a quantum phase transition. In particular, we show that in the vicinity of a critical point describing a second-order quantum phase transition, the geodesic exhibits power-law scaling with an exponent given by twice the inverse of the product of the spatial and scaling dimensions.

  2. Constraints on the Adiabatic Temperature Change in Magnetocaloric Materials

    DEFF Research Database (Denmark)

    Nielsen, Kaspar Kirstein; Bahl, Christian Robert Haffenden; Smith, Anders


    The thermodynamics of the magnetocaloric effect implies constraints on the allowed variation in the adiabatic temperature change for a magnetocaloric material. An inequality for the derivative of the adiabatic temperature change with respect to temperature is derived for both first- and second......-order materials. For materials with a continuous adiabatic temperature change as a function of temperature, this inequality is shown to hold for all temperatures. However, discontinuous materials may violate the inequality. We compare our results with measured results in the literature and discuss...

  3. Approximability of optimization problems through adiabatic quantum computation

    CERN Document Server

    Cruz-Santos, William


    The adiabatic quantum computation (AQC) is based on the adiabatic theorem to approximate solutions of the Schrödinger equation. The design of an AQC algorithm involves the construction of a Hamiltonian that describes the behavior of the quantum system. This Hamiltonian is expressed as a linear interpolation of an initial Hamiltonian whose ground state is easy to compute, and a final Hamiltonian whose ground state corresponds to the solution of a given combinatorial optimization problem. The adiabatic theorem asserts that if the time evolution of a quantum system described by a Hamiltonian is l

  4. Contract out

    Energy Technology Data Exchange (ETDEWEB)

    Walker, S. (Independent Editorial and Technical Services, Oxford (United Kingdom))


    Mining companies opt to offer all or part of their operations out to contract mainly to reduce risk. Contract mining has been most popular in the Southern Hemisphere over the last 15 years, with some exceptions - contractors were often employed in the UK's opencast coal sector and some US coal operators have made extensive use of contract mining. The article discusses the pros and cons of outsourcing, giving examples of contracted out work in Australia (by Thiess Contractors) the USA (Morrison Knudsen), and the UK (Kie Mining). The author comments that successful contracting can only be achieved where both parties know where they stand and have a good working relationship. 2 photos.

  5. Adiabatic Quantum Computation with Neutral Atoms (United States)

    Biedermann, Grant


    We are implementing a new platform for adiabatic quantum computation (AQC)[2] based on trapped neutral atoms whose coupling is mediated by the dipole-dipole interactions of Rydberg states. Ground state cesium atoms are dressed by laser fields in a manner conditional on the Rydberg blockade mechanism,[3,4] thereby providing the requisite entangling interactions. As a benchmark we study a Quadratic Unconstrained Binary Optimization (QUBO) problem whose solution is found in the ground state spin configuration of an Ising-like model. In collaboration with Lambert Parazzoli, Sandia National Laboratories; Aaron Hankin, Center for Quantum Information and Control (CQuIC), University of New Mexico; James Chin-Wen Chou, Yuan-Yu Jau, Peter Schwindt, Cort Johnson, and George Burns, Sandia National Laboratories; Tyler Keating, Krittika Goyal, and Ivan Deutsch, Center for Quantum Information and Control (CQuIC), University of New Mexico; and Andrew Landahl, Sandia National Laboratories. This work was supported by the Laboratory Directed Research and Development program at Sandia National Laboratories

  6. On the persistence of adiabatic shear bands (United States)

    Boakye-Yiadom, S.; Bassim, M. N.; Al-Ameeri, S.


    It is generally agreed that the initiation and development of adiabatic shear bands (ASBs) are manifestations of damage in metallic materials subjected to high strain rates and large strains as those due to impact in a Hopkinson Bar system. Models for evolution of these bands have been described in the literature. One question that has not received attention is how persistent these bands are and whether their presence and effect can be reversed or eliminated by using a process of thermal (heat treatment) or thermo-mechanical treatment that would relieve the material from the high strain associated with ASBs and their role as precursors to crack initiation and subsequent failure. Since ASBs are more prevalent and more defined in BCC metals including steels, a study was conducted to investigate the best conditions of generating ASBs in a heat treatable steel, followed by determining the best conditions for heat treatment of specimens already damaged by the presence of ASBs in order to relieve the strains due to ASBs and restore the material to an apparent microstructure without the "scars" due to the previous presence of ASBs. It was found that heat treatment achieves the curing from ASBs. This presentation documents the process undertaken to achieve this objective.

  7. On the persistence of adiabatic shear bands

    Directory of Open Access Journals (Sweden)

    Bassim M.N.


    Full Text Available It is generally agreed that the initiation and development of adiabatic shear bands (ASBs are manifestations of damage in metallic materials subjected to high strain rates and large strains as those due to impact in a Hopkinson Bar system. Models for evolution of these bands have been described in the literature. One question that has not received attention is how persistent these bands are and whether their presence and effect can be reversed or eliminated by using a process of thermal (heat treatment or thermo-mechanical treatment that would relieve the material from the high strain associated with ASBs and their role as precursors to crack initiation and subsequent failure. Since ASBs are more prevalent and more defined in BCC metals including steels, a study was conducted to investigate the best conditions of generating ASBs in a heat treatable steel, followed by determining the best conditions for heat treatment of specimens already damaged by the presence of ASBs in order to relieve the strains due to ASBs and restore the material to an apparent microstructure without the “scars” due to the previous presence of ASBs. It was found that heat treatment achieves the curing from ASBs. This presentation documents the process undertaken to achieve this objective.

  8. Spherical collapse of a unified dark fluid with constant adiabatic sound speed (United States)

    Xu, Lixin


    In this paper, we test the spherical collapse of a unified dark fluid (UDF) which has constant adiabatic sound speed. By choosing the different values of model parameters B s and α, we show the non-linear collapse for UDF and baryons which are considered for their formation of the large scale structure of our Universe. The analyzed results show that larger values of α and B s make the structure formation faster and earlier.

  9. Spherical collapse of a unified dark fluid with constant adiabatic sound speed

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Lixin [Dalian University of Technology, Institute of Theoretical Physics, School of Physics and Optoelectronic Technology, Dalian (China); Dalian University of Technology, College of Advanced Science and Technology, Dalian (China)


    In this paper, we test the spherical collapse of a unified dark fluid (UDF) which has constant adiabatic sound speed. By choosing the different values of model parameters B{sub s} and {alpha}, we show the non-linear collapse for UDF and baryons which are considered for their formation of the large scale structure of our Universe. The analyzed results show that larger values of {alpha} and B{sub s} make the structure formation faster and earlier. (orig.)

  10. Spatial non-adiabatic passage using geometric phases

    Energy Technology Data Exchange (ETDEWEB)

    Benseny, Albert; Busch, Thomas [Okinawa Institute of Science and Technology Graduate University, Quantum Systems Unit, Okinawa (Japan); Kiely, Anthony; Ruschhaupt, Andreas [University College Cork, Department of Physics, Cork (Ireland); Zhang, Yongping [Okinawa Institute of Science and Technology Graduate University, Quantum Systems Unit, Okinawa (Japan); Shanghai University, Department of Physics, Shanghai (China)


    Quantum technologies based on adiabatic techniques can be highly effective, but often at the cost of being very slow. Here we introduce a set of experimentally realistic, non-adiabatic protocols for spatial state preparation, which yield the same fidelity as their adiabatic counterparts, but on fast timescales. In particular, we consider a charged particle in a system of three tunnel-coupled quantum wells, where the presence of a magnetic field can induce a geometric phase during the tunnelling processes. We show that this leads to the appearance of complex tunnelling amplitudes and allows for the implementation of spatial non-adiabatic passage. We demonstrate the ability of such a system to transport a particle between two different wells and to generate a delocalised superposition between the three traps with high fidelity in short times. (orig.)

  11. Magnesium Diboride Superconducting Coils for Adiabatic Demagnetization Refrigerators (ADR's) Project (United States)

    National Aeronautics and Space Administration — For Adiabatic Demagnetization Refrigerators(ADR's) for space it is desirable to have very light weight, small diameter, high current density superconducting wires...

  12. Adiabaticity and diabaticity in strong-field ionization

    CERN Document Server

    Karamatskou, Antonia; Santra, Robin


    If the photon energy is much less than the electron binding energy, ionization of an atom by a strong optical field is often described in terms of electron tunneling through the potential barrier resulting from the superposition of the atomic potential and the potential associated with the instantaneous electric component of the optical field. In the strict tunneling regime, the electron response to the optical field is said to be adiabatic, and nonadiabatic effects are assumed to be negligible. Here, we investigate to what degree this terminology is consistent with a language based on the so-called adiabatic representation. This representation is commonly used in various fields of physics. For electronically bound states, the adiabatic representation yields discrete potential energy curves that are connected by nonadiabatic transitions. When applying the adiabatic representation to optical strong-field ionization, a conceptual challenge is that the eigenstates of the instantaneous Hamiltonian form a continuu...

  13. Low-power adiabatic 9T static random access memory

    Directory of Open Access Journals (Sweden)

    Yasuhiro Takahashi


    Full Text Available In this paper, the authors propose a novel static random access memory (SRAM that employs the adiabatic logic principle. To reduce energy dissipation, the proposed adiabatic SRAM is driven by two trapezoidal-wave pulses. The cell structure of the proposed SRAM has two high-value resistors based on a p-type metal-oxide semiconductor transistor, a cross-coupled n-type metal-oxide semiconductor (NMOS pair and an NMOS switch to reduce the short-circuit current. The inclusion of a transmission-gate controlled by a write word line signal allows the proposed circuit to operate as an adiabatic SRAM during data writing. Simulation results show that the energy dissipation of the proposed SRAM is lower than that of a conventional adiabatic SRAM.

  14. Assessment of voluntary pelvic floor muscle contraction in continent and incontinent women using transperineal ultrasound, manual muscle testing and vaginal squeeze pressure measurements. (United States)

    Thompson, Judith A; O'Sullivan, Peter B; Briffa, N Kathryn; Neumann, Patricia


    The aims of the study were: (1) to assess women performing voluntary pelvic floor muscle (PFM) contractions, on initial instruction without biofeedback teaching, using transperineal ultrasound, manual muscle testing, and perineometry and (2) to assess for associations between the different measurements of PFM function. Sixty continent (30 nulliparous and 30 parous) and 60 incontinent (30 stress urinary incontinence (SUI) and 30 urge urinary incontinence (UUI)) women were assessed. Bladder neck depression during attempts to perform an elevating pelvic floor muscle (PFM) contraction occurred in 17% of continent and 30% of incontinent women. The UUI group had the highest proportion of women who depressed the bladder neck (40%), although this was not statistically significant (p=0.060). The continent women were stronger on manual muscle testing (p=0.001) and perineometry (p=0.019) and had greater PFM endurance (pelevation than the incontinent women (p=0.051). There was a moderate correlation between bladder neck movement during PFM contraction measured by ultrasound and PFM strength assessed by manual muscle testing (r=0.58, p=0.01) and perineometry (r=0.43, p=0.01). The observation that many women were performing PFM exercises incorrectly reinforces the need for individual PFM assessment with a skilled practitioner. The significant correlation between the measurements of bladder neck elevation during PFM contraction and PFM strength measured using MMT and perineometry supports the use of ultrasound in the assessment of PFM function; however, the correlation was only moderate and, therefore, indicates that the different measurement tools assess different aspects of PFM function. It is recommended that physiotherapists use a combination of assessment tools to evaluate the different aspects of PFM function that are important for continence. Ultrasound is useful to determine the direction of pelvic floor movement in the clinical assessment of pelvic floor muscle function

  15. Adiabatic Interactions of Manakov Solitons -- Effects of Cross-modulation


    Gerdjikov, V. S.; Todorov, M. D.; Kyuldjiev, A. V.


    We investigate the asymptotic behavior of the Manakov soliton trains perturbed by cross-modulation in the adiabatic approximation. The multisoliton interactions in the adiabatic approximation are modeled by a generalized Complex Toda chain (GCTC). The cross-modulation requires special treating for the evolution of the polarization vectors of the solitons. The numerical predictions of the Manakov system are compared with the perturbed GCTC. For certain set of initial parameters GCTC describes ...

  16. Quadratic fermionic interactions yield effective Hamiltonians for adiabatic quantum computing


    O'Hara, Michael J.; O'Leary, Dianne P.


    Polynomially-large ground-state energy gaps are rare in many-body quantum systems, but useful for adiabatic quantum computing. We show analytically that the gap is generically polynomially-large for quadratic fermionic Hamiltonians. We then prove that adiabatic quantum computing can realize the ground states of Hamiltonians with certain random interactions, as well as the ground states of one, two, and three-dimensional fermionic interaction lattices, in polynomial time. Finally, we use the J...

  17. Hybrid adiabatic potentials in the QCD string model


    Kalashnikova, Yu. S.; Kuzmenko, D. S.


    The short- and intermediate-distance behaviour of the hybrid adiabatic potentials is calculated in the framework of the QCD string model. The calculations are performed with the inclusion of Coulomb force. Spin-dependent force and the so-called string correction term are treated as perturbation at the leading potential-type regime. Reasonably good agreement with lattice measurements takes place for adiabatic curves excited with magnetic components of field strength correlators.

  18. Proposal for the award of a contract for the design, supply and installation at CERN of 12 cryogenic feed boxes for the testing of LHC magnets

    CERN Document Server


    This document concerns the award of a contract for the design, supply and installation at CERN of 12 cryogenic feed boxes for the testing of LHC magnets. A call for tenders (IT-2821/LHC/LHC) was sent on 25 February 2000 to 27 firms in eight Member States. By the closing date, CERN had received five tenders. The Finance Committee is invited to approve the negotiation of a contract with the firm AIR LIQUIDE DTA (FR), the lowest bidder complying with the specifications, for the design, supply and installation at CERN of 12 cryogenic feed boxes for the testing of LHC magnets for a total amount of 4 796 393 euros (7 535 100 Swiss francs), not subject to revision. The above amount in Swiss francs has been calculated using the rate of exchange indicated in the tender. The firm AIR LIQUIDE DTA (FR) has indicated the following distribution by country of the contract value covered by this adjudication proposal: ES-46%, DE-15% and FR-39%.

  19. Thermal explosion hazards on 18650 lithium ion batteries with a VSP2 adiabatic calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Jhu, Can-Yong [Doctoral Program, Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology (NYUST), 123, University Rd., Sec. 3, Douliou, Yunlin 64002, Taiwan, ROC (China); Wang, Yih-Wen, E-mail: [Department of Occupational Safety and Health, Jen-Teh Junior College of Medicine, Nursing and Management, 79-9, Sha-Luen-Hu, Xi-Zhou-Li, Houlong, Miaoli 35664, Taiwan, ROC (China); Shu, Chi-Min [Doctoral Program, Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology (NYUST), 123, University Rd., Sec. 3, Douliou, Yunlin 64002, Taiwan, ROC (China); Chang, Jian-Chuang; Wu, Hung-Chun [Material and Chemical Research Laboratories, Industrial Technology Research Institute (ITRI), Rm. 222, Bldg. 77, 2F, 195, Sec. 4, Chung Hsing Rd., Chutung, Hsinchu 31040, Taiwan, ROC (China)


    Thermal abuse behaviors relating to adiabatic runaway reactions in commercial 18650 lithium ion batteries (LiCoO{sub 2}) are being studied in an adiabatic calorimeter, vent sizing package 2 (VSP2). We select four worldwide battery producers, Sony, Sanyo, Samsung and LG, and tested their Li-ion batteries, which have LiCoO{sub 2} cathodes, to determine their thermal instabilities and adiabatic runaway features. The charged (4.2 V) and uncharged (3.7 V) 18650 Li-ion batteries are tested using a VSP2 with a customized stainless steel test can to evaluate their thermal hazard characteristics, such as the initial exothermic temperature (T{sub 0}), the self-heating rate (dT/dt), the pressure rise rate (dP/dt), the pressure-temperature profiles and the maximum temperature (T{sub max}) and pressure (P{sub max}). The T{sub max} and P{sub max} of the charged Li-ion battery during the runaway reaction reach 903.0 {sup o}C and 1565.9 psig (pound-force per square inch gauge), respectively. This result leads to a thermal explosion, and the heat of reaction is 26.2 kJ. The thermokinetic parameters of the reaction of LiCoO{sub 2} batteries are also determined using the Arrhenius model. The thermal reaction mechanism of the Li-ion battery (pack) proved to be an important safety concern for energy storage. Additionally, use of the VSP2 to classify the self-reactive ratings of the various Li-ion batteries demonstrates a new application of the adiabatic calorimetric methodology.

  20. Learning contracts

    Directory of Open Access Journals (Sweden)

    Nena Mijoč


    Full Text Available There are four different expressions to describe the method of learning, which increases the efficiency of adult learning. The article explains the translation of »learning contract« into Slovene as a method in adult learning area, which came in use in USA in 1970, also in organizations offering formal education. In the period of lifelong learning, when everyone is supposed to be able to learn efficiently from different sources it is even more important to have the skills to plan our learning. Learning contract develops these competencies and has already become established in organizations, which support learning processes. Learning contract is slowly gaining ground also to the area of formal education. Learning contract is an agreement in writing between two people, where one of them offers advice, the other undertakes the learning process. How do we prepare the agreement, who is responsible for its preparation and execution? Learning contract in writing explains objectives, techniques, strategies and how the learning process will be assessed. At the same time, learning is also limited in time. It is a strong motivational took, since it comprises needs of an individual and is adapted to the interests and learning style of a particular individual. This is especially suitable method for acquiring competencies, for field work and experiential learning at work. Learning contract is very suitable and efficient also for independent academical studies, especially when combined with the method of discussion.

  1. Thermal diffusivity and adiabatic limit temperature characterization of consolidate granular expanded perlite using the flash method (United States)

    Raefat, Saad; Garoum, Mohammed; Laaroussi, Najma; Thiam, Macodou; Amarray, Khaoula


    In this work experimental investigation of apparent thermal diffusivity and adiabatic limit temperature of expanded granular perlite mixes has been made using the flash technic. Perlite granulates were sieved to produce essentially three characteristic grain sizes. The consolidated samples were manufactured by mixing controlled proportions of the plaster and water. The effect of the particle size on the diffusivity was examined. The inverse estimation of the diffusivity and the adiabatic limit temperature at the rear face as well as the heat losses coefficients were performed using several numerical global minimization procedures. The function to be minimized is the quadratic distance between the experimental temperature rise at the rear face and the analytical model derived from the one dimension heat conduction. It is shown that, for all granulometry tested, the estimated parameters lead to a good agreement between the mathematical model and experimental data.

  2. Contract Renewal Information - all Contracts (United States)

    Department of Housing and Urban Development — Multifamily Portfolio datasets (section 8 contracts) - The information has been compiled from multiple data sources within FHA or its contractors. HUD oversees more...

  3. Service quality in contracted facilities. (United States)

    Rabbani, Fauziah; Pradhan, Nousheen Akber; Zaidi, Shehla; Azam, Syed Iqbal; Yousuf, Farheen


    The purpose of this paper is to explore the readiness of contracted and non-contracted first-level healthcare facilities in Pakistan to deliver quality maternal and neonatal health (MNH) care. A balanced scorecard (BSC) was used as the assessment framework. Using a cross-sectional study design, two rural health centers (RHCs) contracted out to Aga Khan Health Service, Pakistan were compared with four government managed RHCs. A BSC was designed to assess RHC readiness to deliver good quality MNH care. In total 20 indicators were developed, representing five BSC domains: health facility functionality, service provision, staff capacity, staff and patient satisfaction. Validated data collection tools were used to collect information. Pearson χ2, Fisher's Exact and the Mann-Whitney tests were applied as appropriate to detect significant service quality differences among the two facilities. Contracted facilities were generally found to be better than non-contracted facilities in all five BSC domains. Patients' inclination for facility-based delivery at contracted facilities was, however, significantly higher than non-contracted facilities (80 percent contracted vs 43 percent non-contracted, p=0.006). The study shows that contracting out initiatives have the potential to improve MNH care. This is the first study to compare MNH service delivery quality across contracted and non-contracted facilities using BSC as the assessment framework.

  4. Unit Testing Using Design by Contract and Equivalence Partitions, Extreme Programming and Agile Processes in Software Engineering

    DEFF Research Database (Denmark)

    Madsen, Per


    Extreme Programming [1] and in particular the idea of Unit Testing can improve the quality of the testing process. But still programmers need to do a lot of tiresome manual work writing test cases. If the programmers could get some automatic tool support enforcing the quality of test cases then t...... then the overall quality of the software would improve significantly.......Extreme Programming [1] and in particular the idea of Unit Testing can improve the quality of the testing process. But still programmers need to do a lot of tiresome manual work writing test cases. If the programmers could get some automatic tool support enforcing the quality of test cases...

  5. Response of quasi-adiabatic ions to magnetotail reconfigurations (United States)

    Delcourt, D.; Malova, H. V.; Zelenyi, L. M.


    Particles traveling in sharp field reversals like in the Earth's magnetotail may not conserve their magnetic moment (first adiabatic invariant) due to significant variation of the magnetic field on the length scale of their Larmor radius. Although their motion is non-adiabatic per say and differs from a regular helical one, some particles may experience negligible net change of magnetic moment, a behavior that is referred to as quasi-adiabatic [Büchner and Zelenyi, 1989] like in the well-known Speiser orbit [Speiser, 1965]. Such a behavior is more pronounced at specific values of the adiabaticity parameter κ (square root of the minimum curvature radius to maximum Larmor radius ratio) due to resonance between the slow gyromotion in the tail midplane and the fast oscillation in the direction perpendicular to it. On the other hand, during rapid reconfigurations of the magnetotail as observed during substorms, the impulsive electric field induced by the time-varying magnetic field may lead to non-adiabatic behaviors as well, with large variations of the magnetic moment for particles that have cyclotron periods comparable to the field variation time scale. In this case, the κ parameter that is used to characterize spatial non-adiabaticity cannot be used since magnetic field lines are rapidly evolving in time. We examine the response of quasi-adiabatic ions in the presence of such short-lived reconfigurations of the magnetic field lines using single particle calculations. We demonstrate that quasi-adiabatic ions may remain quasi-adiabatic while experiencing an impulsive energization under the effect of the induced electric field ; hence, their faster oscillations about the tail midplane and their higher resonance order. Systematic acceleration up to about 3VE (where VE is the peak ExB drift speed during field line reconfiguration) is found for the lowest energy particles. We show that, altogether, impulsive transport and energization may be responsible for short

  6. A scalable readout system for a superconducting adiabatic quantum optimization system (United States)

    Berkley, A. J.; Johnson, M. W.; Bunyk, P.; Harris, R.; Johansson, J.; Lanting, T.; Ladizinsky, E.; Tolkacheva, E.; Amin, M. H. S.; Rose, G.


    We have designed, fabricated and tested an XY-addressable readout system that is specifically tailored for the reading of superconducting flux qubits in an integrated circuit that could enable adiabatic quantum optimization. In such a system, the flux qubits only need to be read at the end of an adiabatic evolution when quantum mechanical tunneling has been suppressed, thus simplifying many aspects of the readout process. The readout architecture for an N-qubit adiabatic quantum optimization system comprises N hysteretic dc SQUIDs and N rf SQUID latches controlled by 2\\sqrt {N}+2 bias lines. The latching elements are coupled to the qubits and the dc SQUIDs are then coupled to the latching elements. This readout scheme provides two key advantages: first, the latching elements provide exceptional flux sensitivity that significantly exceeds what may be achieved by directly coupling the flux qubits to the dc SQUIDs using a practical mutual inductance. Second, the states of the latching elements are robust against the influence of ac currents generated by the switching of the hysteretic dc SQUIDs, thus allowing one to interrogate the latching elements repeatedly so as to mitigate the effects of stochastic switching of the dc SQUIDs. We demonstrate that it is possible to achieve single-qubit read error rates of < 10 - 6 with this readout scheme. We have characterized the system level performance of a 128-qubit readout system and have measured a readout error probability of 8 × 10 - 5 in the presence of optimal latching element bias conditions.

  7. Interplay between electric and magnetic effect in adiabatic polaritonic systems

    KAUST Repository

    Alabastri, Alessandro


    We report on the possibility of realizing adiabatic compression of polaritonic wave on a metallic conical nano-structure through an oscillating electric potential (quasi dynamic regime). By comparing this result with an electromagnetic wave excitation, we were able to relate the classical lighting-rod effect to adiabatic compression. Furthermore, we show that while the magnetic contribution plays a marginal role in the formation of adiabatic compression, it provides a blue shift in the spectral region. In particular, magnetic permeability can be used as a free parameter for tuning the polaritonic resonances. The peculiar form of adiabatic compression is instead dictated by both the source and the metal permittivity. The analysis is performed by starting from a simple electrostatic system to end with the complete electromagnetic one through intermediate situations such as the quasi-electrostatic and quasi-dynamic regimes. Each configuration is defined by a particular set of equations which allows to clearly determine the individual role played by the electric and magnetic contribution in the generation of adiabatic compression. We notice that these findings can be applied for the realization of a THz nano-metric generator. © 2013 Optical Society of America.

  8. Quantum tunneling, adiabatic invariance and black hole spectroscopy (United States)

    Li, Guo-Ping; Pu, Jin; Jiang, Qing-Quan; Zu, Xiao-Tao


    In the tunneling framework, one of us, Jiang, together with Han has studied the black hole spectroscopy via adiabatic invariance, where the adiabatic invariant quantity has been intriguingly obtained by investigating the oscillating velocity of the black hole horizon. In this paper, we attempt to improve Jiang-Han's proposal in two ways. Firstly, we once again examine the fact that, in different types (Schwarzschild and Painlevé) of coordinates as well as in different gravity frames, the adiabatic invariant I_adia = \\oint p_i dq_i introduced by Jiang and Han is canonically invariant. Secondly, we attempt to confirm Jiang-Han's proposal reasonably in more general gravity frames (including Einstein's gravity, EGB gravity and HL gravity). Concurrently, for improving this proposal, we interestingly find in more general gravity theories that the entropy of the black hole is an adiabatic invariant action variable, but the horizon area is only an adiabatic invariant. In this sense, we emphasize the concept that the quantum of the black hole entropy is more natural than that of the horizon area.

  9. Quantum tunneling, adiabatic invariance and black hole spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guo-Ping; Zu, Xiao-Tao [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); Pu, Jin [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); China West Normal University, College of Physics and Space Science, Nanchong (China); Jiang, Qing-Quan [China West Normal University, College of Physics and Space Science, Nanchong (China)


    In the tunneling framework, one of us, Jiang, together with Han has studied the black hole spectroscopy via adiabatic invariance, where the adiabatic invariant quantity has been intriguingly obtained by investigating the oscillating velocity of the black hole horizon. In this paper, we attempt to improve Jiang-Han's proposal in two ways. Firstly, we once again examine the fact that, in different types (Schwarzschild and Painleve) of coordinates as well as in different gravity frames, the adiabatic invariant I{sub adia} = circular integral p{sub i}dq{sub i} introduced by Jiang and Han is canonically invariant. Secondly, we attempt to confirm Jiang-Han's proposal reasonably in more general gravity frames (including Einstein's gravity, EGB gravity and HL gravity). Concurrently, for improving this proposal, we interestingly find in more general gravity theories that the entropy of the black hole is an adiabatic invariant action variable, but the horizon area is only an adiabatic invariant. In this sense, we emphasize the concept that the quantum of the black hole entropy is more natural than that of the horizon area. (orig.)

  10. Interplay between electric and magnetic effect in adiabatic polaritonic systems. (United States)

    Alabastri, Alessandro; Toma, Andrea; Liberale, Carlo; Chirumamilla, Manohar; Giugni, Andrea; De Angelis, Francesco; Das, Gobind; Di Fabrizio, Enzo; Zaccaria, Remo Proietti


    We report on the possibility of realizing adiabatic compression of polaritonic wave on a metallic conical nano-structure through an oscillating electric potential (quasi dynamic regime). By comparing this result with an electromagnetic wave excitation, we were able to relate the classical lighting-rod effect to adiabatic compression. Furthermore, we show that while the magnetic contribution plays a marginal role in the formation of adiabatic compression, it provides a blue shift in the spectral region. In particular, magnetic permeability can be used as a free parameter for tuning the polaritonic resonances. The peculiar form of adiabatic compression is instead dictated by both the source and the metal permittivity. The analysis is performed by starting from a simple electrostatic system to end with the complete electromagnetic one through intermediate situations such as the quasi-electrostatic and quasi-dynamic regimes. Each configuration is defined by a particular set of equations which allows to clearly determine the individual role played by the electric and magnetic contribution in the generation of adiabatic compression. We notice that these findings can be applied for the realization of a THz nano-metric generator.

  11. Global adiabaticity and non-Gaussianity consistency condition

    CERN Document Server

    Romano, Antonio Enea; Sasaki, Misao


    In the context of single-field inflation, the conservation of the curvature perturbation on comoving slices, $R_c$, on super-horizon scales is one of the assumptions necessary to derive the consistency condition between the squeezed limit of the bispectrum and the spectrum of the primordial curvature perturbation. However, the conservation of $R_c$ holds only after the perturbation has reached the adiabatic limit where the constant mode of $R_c$ dominates over the other (usually decaying) mode. In this case, the non-adiabatic pressure perturbation defined in the thermodynamic sense, $\\delta P_{nad}\\equiv\\delta P-c_w^2\\delta\\rho$ where $c_w^2=\\dot P/\\dot\\rho$, usually becomes also negligible on superhorizon scales. Therefore one might think that the adiabatic limit is the same as thermodynamic adiabaticity. This is in fact not true. In other words, thermodynamic adiabaticity is not a sufficient condition for the conservation of $R_c$ on super-horizon scales. In this paper, we consider models that satisfies $\\d...

  12. Agile Contracts

    DEFF Research Database (Denmark)

    Pries-Heje, Jan; Pries-Heje, Lene


    with “endless” re-negotiation of the requirements; you need a more flexible way to develop IS. A new way of coping with many changes is to use an agile development approach and a fixed budget and resources contract. This paper presents an example case. We analyse the case and design a guideline for how...

  13. High beta lasing in micropillar cavities with adiabatic layer design

    DEFF Research Database (Denmark)

    Lermer, M.; Gregersen, Niels; Lorke, M.


    We report on lasing in optically pumped adiabatic micropillar cavities, based on the AlAs/GaAs material system. A detailed study of the threshold pump power and the spontaneous emission β factor in the lasing regime for different diameters dc is presented. We demonstrate a reduction of the thresh......We report on lasing in optically pumped adiabatic micropillar cavities, based on the AlAs/GaAs material system. A detailed study of the threshold pump power and the spontaneous emission β factor in the lasing regime for different diameters dc is presented. We demonstrate a reduction...... of the threshold pump power by over 2 orders of magnitude from dc = 2.25 μm down to 0.95 μm. Lasing with β factors exceeding 0.5 shows that adiabatic micropillars are operating deeply in the cavity quantum electrodynamics regime....

  14. A Novel Cold Cathode Fluorescent Lamp with an Adiabatic Layer (United States)

    Nishimura, Kiyoshi; Yajima, Jun; Yuasa, Kunio

    A novel cold cathode fluorescent lamp (CCFL) with an adiabatic layer suitable for backlighting in PDAs (Personal Data Assistants) is described. The adiabatic layer (100-200 μm) is formed between a light tube and an outer tube and is filled with low-pressure gases. This raises the temperature of the light tube to the suitable value (50-70°C), which maximizes luminous efficacy even in low lamp wattage operation and at low ambient temperatures. The results of experiments and heat transfer analyses show that the optimum pressure in an adiabatic layer lies between 1Pa and 10Pa. At a pressure of less than 1Pa, the lamp temperature maintains a constant level because the conduction loss is lower than the radiation loss.

  15. Mode conversion using optical analogy of shortcut to adiabatic passage in engineered multimode waveguides. (United States)

    Lin, Tzung-Yi; Hsiao, Fu-Chen; Jhang, Yao-Wun; Hu, Chieh; Tseng, Shuo-Yen


    A shortcut to adiabatic mode conversion in multimode waveguides using optical analogy of stimulated Raman adiabatic passage is investigated. The design of mode converters using the shortcut scheme is discussed. Computer-generated planar holograms are used to mimic the shaped pulses used to speed up adiabatic passage in quantum systems based on the transitionless quantum driving algorithm. The mode coupling properties are analyzed using the coupled mode theory and beam propagation simulations. We show reduced device length using the shortcut scheme as compared to the common adiabatic scheme. Modal evolution in the shortened device indeed follows the adiabatic eigenmode exactly amid the violation of adiabatic criterion.

  16. On the adiabatic theorem when eigenvalues dive into the continuum

    DEFF Research Database (Denmark)

    Cornean, Decebal Horia; Jensen, Arne; Knörr, Hans Konrad

    For a Wigner-Weisskopf model of an atom consisting of a quantum dot coupled to an energy reservoir described by a three-dimensional Laplacian we study the survival probability of a bound state when the dot energy varies smoothly and adiabatically in time. The initial state corresponds to a discre...... eigenvalue which dives into the continuous spectrum and re-emerges from it as the dot energy is varied in time and finally returns to its initial value. Our main result is that for a large class of couplings, the survival probability of this bound state vanishes in the adiabatic limit....

  17. Proposal for the award of a contract for the design, supply, installation, commissioning and testing at CERN of eight helium dryer units for the LHC

    CERN Document Server


    This document concerns the award of a contract for the design, supply, installation, commissioning and testing at CERN of eight helium dryer units for the LHC. Following a market survey carried out among 42 firms in ten Member States, a call for tenders (IT-2722/LHC/LHC) was sent on 10 August 2000 to seven firms and three consortia, consisting of two firms each, in seven Member States. By the closing date, CERN had received five tenders from three firms and two consortia in five Member States. The Finance Committee is invited to agree to the negotiation of a contract with the firm COSMI (IT), the lowest bidder fulfilling the technical requirements, for the design, supply, installation, commissioning and testing at CERN of eight helium dryer units for a total amount of 3 514 779 euros, (5 307 329 Swiss francs), not subject to revision, with options for additional equipment for heating the adsorber bed and additional heat exchanger/condenser equipment, for an additional amount of 80 081 euros (120 923 Swiss fra...

  18. Proposal for the award of a contract for the supply, testing, installation and commissioning of the proximity cryogenic system for the ATLAS toroid magnet system

    CERN Document Server

    European Organization for Nuclear Research


    This document concerns the award of a contract for the supply, testing, installation and commissioning of the proximity cryogenic system for the ATLAS toroid magnet system. Following a market survey carried out among 61 firms in ten Member States and 14 firms in three non-Member States, a call for tenders (IT-2624/EP/ATLAS) was sent on 19 April 2002 to four firms and three consortia in six Member States and two firms in one non-Member State. By the closing date, CERN had received three tenders. The Finance Committee is invited to agree to the negotiation of a contract with AIR LIQUIDE ITALIA (IT), the lowest bidder, for the supply, testing, installation and commissioning of the proximity cryogenic system for the ATLAS toroid magnet system for a total amount not exceeding 2 840 000 euros (4 191 300 Swiss francs), not subject to revision. The rate of exchange which has been used is that stipulated in the tender. This procurement will be financed by the ATLAS Common Fund and CERN's contribution will not exceed 8...

  19. Female CFOs and loan contracting: Financial conservatism or gender discrimination? – An empirical test based on collateral clauses

    Directory of Open Access Journals (Sweden)

    Xixiong Xu


    Full Text Available Based on signaling and gender discrimination theory, we examine whether chief financial officer (CFO gender matters to bank–firm relationships and the designing of collateral clauses in bank loan contracting, and explore the potential path of influence. Data taken from Chinese listed companies between 2009 and 2012 indicate that (1 female-CFO-led firms are less likely to obtain credit loans than male-CFO-led firms; (2 female-CFO-led borrowers are more likely to be required to provide collateral for loans than male-CFO-led borrowers; and (3 banks are more inclined to claim mortgaging collateral when lending to female-CFO-led firms and prefer to guarantee collateral when lending to male-CFO-led firms. Female-CFO-led borrowers seem to be granted more unfavorable loan terms than male-CFO-led borrowers, supporting the hypothesis that female CFOs experience credit discrimination. Further analysis reveals that regional financial development helps to alleviate lending discrimination against female CFOs. Furthermore, female CFOs in SOEs are less likely than their non-SOE counterparts to experience gender discrimination in the credit market.

  20. Contract theory and EU Contract Law

    NARCIS (Netherlands)

    Hesselink, M.W.; Twigg-Flesner, C.


    This paper explores the relationship between contract theory and European contract law. In particular, it confronts the leading contract law theories with the main characteristics of EU contract law. The conclusion is that the two do not match well. In particular, monist normative contract theories

  1. The mechanoelectric feedback: a novel "calcium clamp" method, using tetanic contraction, for testing the role of the intracellular free calcium. (United States)

    Yaniv, Yael; Levy, Carmit; Landesberg, Amir


    Mechanical perturbations affect the membrane action potential, a phenomenon denoted as the mechanoelectric feedback (MEF), and may elicit cardiac arrhythmias. Two plausible mechanisms were suggested to explain this phenomenon: (i) stretch-activated channels (SACs) within the cell membrane and (ii) modulation of the action potential by the intracellular Ca(2+) (the Calcium hypothesis). The intracellular Ca(2+) varies mainly due to the effects of the mechanical perturbations on the affinity of troponin for calcium. The present study concentrates on the unique experimental methods that allow differentiating between the effects of SAC and Ca(2+) on the action potential. This is achieved by controlling the sarcomere lengths (SLs) independently of the intracellular Ca(2+) concentration, in the intact fiber. A dedicated experimental setup allowed simultaneous measurements of the membrane potential and the mechanical performance (Force and SL). The action potential was measured by voltage-sensitive dye (Di-4-ANEPPS). The SL was measured by laser diffraction technique and was controlled by a fast servomotor. The intracellular Ca(2+) was controlled (calcium clamp) by imposing stable tetanic contractions at various extracellular calcium concentrations ([Ca(2+)](0)s). Tetanus was obtained by 8 Hz stimulation in the presence of cyclopiazonic acid (CPA) (30 muM). Isolated trabeculae from a rat's right ventricle were studied at different SLs and [Ca(2+)](0)s. The experimental data strongly support the calcium hypothesis. Although the action potential duration (APD) decreases at longer SL, the [Ca(2+)](0) has a significantly larger effect on the APD. The APD decreases as the [Ca(2+)](0) increases. Understanding the underlying mechanism opens new research avenues for the development of therapeutic modalities for cardiac arrhythmias.

  2. Testing geopressured geothermal reservoirs in existing wells. Wells of Opportunity Program final contract report, 1980-1981

    Energy Technology Data Exchange (ETDEWEB)


    The geopressured-geothermal candidates for the Wells of Opportunity program were located by the screening of published information on oil industry activity and through direct contact with the oil and gas operators. This process resulted in the recommendation to the DOE of 33 candidate wells for the program. Seven of the 33 recommended wells were accepted for testing. Of these seven wells, six were actually tested. The first well, the No. 1 Kennedy, was acquired but not tested. The seventh well, the No. 1 Godchaux, was abandoned due to mechanical problems during re-entry. The well search activities, which culminated in the acceptance by the DOE of 7 recommended wells, were substantial. A total of 90,270 well reports were reviewed, leading to 1990 wells selected for thorough geological analysis. All of the reservoirs tested in this program have been restricted by one or more faults or permeability barriers. A comprehensive discussion of test results is presented.

  3. Digitized adiabatic quantum computing with a superconducting circuit. (United States)

    Barends, R; Shabani, A; Lamata, L; Kelly, J; Mezzacapo, A; Las Heras, U; Babbush, R; Fowler, A G; Campbell, B; Chen, Yu; Chen, Z; Chiaro, B; Dunsworth, A; Jeffrey, E; Lucero, E; Megrant, A; Mutus, J Y; Neeley, M; Neill, C; O'Malley, P J J; Quintana, C; Roushan, P; Sank, D; Vainsencher, A; Wenner, J; White, T C; Solano, E; Neven, H; Martinis, John M


    Quantum mechanics can help to solve complex problems in physics and chemistry, provided they can be programmed in a physical device. In adiabatic quantum computing, a system is slowly evolved from the ground state of a simple initial Hamiltonian to a final Hamiltonian that encodes a computational problem. The appeal of this approach lies in the combination of simplicity and generality; in principle, any problem can be encoded. In practice, applications are restricted by limited connectivity, available interactions and noise. A complementary approach is digital quantum computing, which enables the construction of arbitrary interactions and is compatible with error correction, but uses quantum circuit algorithms that are problem-specific. Here we combine the advantages of both approaches by implementing digitized adiabatic quantum computing in a superconducting system. We tomographically probe the system during the digitized evolution and explore the scaling of errors with system size. We then let the full system find the solution to random instances of the one-dimensional Ising problem as well as problem Hamiltonians that involve more complex interactions. This digital quantum simulation of the adiabatic algorithm consists of up to nine qubits and up to 1,000 quantum logic gates. The demonstration of digitized adiabatic quantum computing in the solid state opens a path to synthesizing long-range correlations and solving complex computational problems. When combined with fault-tolerance, our approach becomes a general-purpose algorithm that is scalable.

  4. Adiabatic CMB perturbations in pre-big bang string cosmology

    DEFF Research Database (Denmark)

    Enqvist, Kari; Sloth, Martin Snoager


    We consider the pre-big bang scenario with a massive axion field which starts to dominate energy density when oscillating in an instanton-induced potential and subsequently reheats the universe as it decays into photons, thus creating adiabatic CMB perturbations. We find that the fluctuations in ...

  5. Generalized Design Procedure for Short, Efficient Adiabatic Mode Converters (United States)


    ideally follow this trend. This gives an important rule of thumb in adiabatic mode converter design, in that beyond a certain "knee" significant increases...Each section of the linear taper between two cuts is stretched or squeezed based on the calcu- lated value from Eqn. 11. Fig. 2. Shapes of the two

  6. On adiabatic perturbation theory for the energy eigenvalue problem

    NARCIS (Netherlands)

    Michels, M.A.J.; Suttorp, L.G.


    The adiabatic perturbation formalism is used to derive several alternative expressions for the effective Hamiltonian of a discrete energy level. In the nondegenerate case these expressions may be cast in the form of linked-cluster expansions. The connection between the energy shifts and the

  7. Experimental adiabatic vortex ratchet effect in Nb films with ...

    Indian Academy of Sciences (India)

    Nb films grown on top of an array of asymmetric pinning centers show a vortex ratchet effect. A net flow of vortices is induced when the vortex lattice is driven by fluctuating forces on an array of pinning centers without reflection symmetry. This effect occurs in the adiabatic regime and it could be mimiced only by reversible DC ...

  8. Monte Carlo Simulation of Adiabatic Cooling and Nuclear Magnetism

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker; Viertiö, H. E.; Mouritsen, Ole G.


    in experimental studies of nuclear magnetism using adiabatic demagnetization methods. It is found that, although fluctuations reduce the transition temperatures by 40%, the isentropes are reduced by less than 10% relative to those calculated by mean-field theory. The dynamics of the ordering process following...

  9. Start up of an industrial adiabatic tubular reactor

    NARCIS (Netherlands)

    Verwijs, J.W.; Verwijs, J.W.; van den Berg, Henderikus; Westerterp, K.R.


    The dynamic behaviour of an adiabatic tubular plant reactor during the startup is demonstrated, together with the impact of a feed-pump failure of one of the reactants. A dynamic model of the reactor system is presented, and the system response is calculated as a function of

  10. Adiabatic and diabatic aerosol transport to the Jungfraujoch

    Energy Technology Data Exchange (ETDEWEB)

    Lugauer, M.; Baltensperger, U.; Furger, M.; Jost, D.T.; Schwikowski, M.; Gaeggeler, H.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)


    Synoptic scale vertical motion, here detected by the geopotential height of the 500 hPa surface, mainly accounts for the aerosol transport to the Jungfraujoch in winter. In summer, diabatic convection provides the dominant vertical transport mechanism. Nevertheless, synoptic scale adiabatic motion still determines whether diabatic convection can develop. (author) 2 figs., 2 refs.

  11. Perturbation to Noether Symmetries and Adiabatic Invariants for Birkhoffian Systems

    Directory of Open Access Journals (Sweden)

    Yi Zhang


    Full Text Available Based on El-Nabulsi dynamical model for a non-conservative system, the problem of perturbation to Noether symmetries and adiabatic invariants of a Birkhoffian system under the action of a small disturbance is proposed and studied. Firstly, the El-Nabulsi-Pfaff variational problem from extended exponentially fractional integral is presented and the El-Nabulsi-Birkhoff equations are established. Secondly, the definitions and the criterions criteria of the Noether symmetric transformations and quasisymmetric transformations of the Birkhoffian system are given, and the Noether theorems of the system are established, which reveal the inner relationship between the Noether symmetries and the conserved quantities. Thirdly, the perturbation of Noether symmetries under a small disturbance is studied, and corresponding adiabatic invariants are obtained. As special cases, the deductions in nonconservative Hamiltonian system and nonconservative Lagrangian system and standard Birkhoffian system are given. At the end of the paper, the case known as Hojman-Urrutia problem is discussed to investigate the Noether symmetries and the adiabatic invariants, the perturbation to Noether symmetries and the adiabatic invariants under El-Nabulsi dynamical model.

  12. Probing Entanglement in Adiabatic Quantum Optimization with Trapped Ions

    Directory of Open Access Journals (Sweden)

    Philipp eHauke


    Full Text Available Adiabatic quantum optimization has been proposed as a route to solve NP-complete problems, with a possible quantum speedup compared to classical algorithms. However, the precise role of quantum effects, such as entanglement, in these optimization protocols is still unclear. We propose a setup of cold trapped ions that allows one to quantitatively characterize, in a controlled experiment, the interplay of entanglement, decoherence, and non-adiabaticity in adiabatic quantum optimization. We show that, in this way, a broad class of NP-complete problems becomes accessible for quantum simulations, including the knapsack problem, number partitioning, and instances of the max-cut problem. Moreover, a general theoretical study reveals correlations of the success probability with entanglement at the end of the protocol. From exact numerical simulations for small systems and linear ramps, however, we find no substantial correlations with the entanglement during the optimization. For the final state, we derive analytically a universal upper bound for the success probability as a function of entanglement, which can be measured in experiment. The proposed trapped-ion setups and the presented study of entanglement address pertinent questions of adiabatic quantum optimization, which may be of general interest across experimental platforms.

  13. Fast Quasi-Adiabatic Gas Cooling: An Experiment Revisited (United States)

    Oss, S.; Gratton, L. M.; Calza, G.; Lopez-Arias, T.


    The well-known experiment of the rapid expansion and cooling of the air contained in a bottle is performed with a rapidly responsive, yet very cheap thermometer. The adiabatic, low temperature limit is approached quite closely and measured with our apparatus. A straightforward theoretical model for this process is also presented and discussed.…

  14. Adiabatic perturbation theory and geometry of periodically-driven systems (United States)

    Weinberg, Phillip; Bukov, Marin; D'Alessio, Luca; Polkovnikov, Anatoli; Vajna, Szabolcs; Kolodrubetz, Michael


    We give a systematic review of the adiabatic theorem and the leading non-adiabatic corrections in periodically-driven (Floquet) systems. These corrections have a two-fold origin: (i) conventional ones originating from the gradually changing Floquet Hamiltonian and (ii) corrections originating from changing the micro-motion operator. These corrections conspire to give a Hall-type linear response for non-stroboscopic (time-averaged) observables allowing one to measure the Berry curvature and the Chern number related to the Floquet Hamiltonian, thus extending these concepts to periodically-driven many-body systems. The non-zero Floquet Chern number allows one to realize a Thouless energy pump, where one can adiabatically add energy to the system in discrete units of the driving frequency. We discuss the validity of Floquet Adiabatic Perturbation Theory (FAPT) using five different models covering linear and non-linear few and many-particle systems. We argue that in interacting systems, even in the stable high-frequency regimes, FAPT breaks down at ultra slow ramp rates due to avoided crossings of photon resonances, not captured by the inverse-frequency expansion, leading to a counter-intuitive stronger heating at slower ramp rates. Nevertheless, large windows in the ramp rate are shown to exist for which the physics of interacting driven systems is well captured by FAPT.

  15. Reversibility and energy dissipation in adiabatic superconductor logic. (United States)

    Takeuchi, Naoki; Yamanashi, Yuki; Yoshikawa, Nobuyuki


    Reversible computing is considered to be a key technology to achieve an extremely high energy efficiency in future computers. In this study, we investigated the relationship between reversibility and energy dissipation in adiabatic superconductor logic. We analyzed the evolution of phase differences of Josephson junctions in the reversible quantum-flux-parametron (RQFP) gate and confirmed that the phase differences can change time reversibly, which indicates that the RQFP gate is physically, as well as logically, reversible. We calculated energy dissipation required for the RQFP gate to perform a logic operation and numerically demonstrated that the energy dissipation can fall below the thermal limit, or the Landauer bound, by lowering operation frequencies. We also investigated the 1-bit-erasure gate as a logically irreversible gate and the quasi-RQFP gate as a physically irreversible gate. We calculated the energy dissipation of these irreversible gates and showed that the energy dissipation of these gate is dominated by non-adiabatic state changes, which are induced by unwanted interactions between gates due to logical or physical irreversibility. Our results show that, in reversible computing using adiabatic superconductor logic, logical and physical reversibility are required to achieve energy dissipation smaller than the Landauer bound without non-adiabatic processes caused by gate interactions.

  16. Retractable Contracts

    Directory of Open Access Journals (Sweden)

    Franco Barbanera


    Full Text Available In calculi for modelling communication protocols, internal and external choices play dual roles. Two external choices can be viewed naturally as dual too, as they represent an agreement between the communicating parties. If the interaction fails, the past agreements are good candidates as points where to roll back, in order to take a different agreement. We propose a variant of contracts with synchronous rollbacks to agreement points in case of deadlock. The new calculus is equipped with a compliance relation which is shown to be decidable.

  17. Assessment of work-related muscle strain by using surface EMG during test contractions interposed between work periods of simulateted mushroom picking

    DEFF Research Database (Denmark)

    Ohashi, Jun-Ya; Blangsted, Anne Katrine; Nielsen, Pernille Kofoed


    minutes in the rest periods. EMGs were recorded from the trapezius, infraspinatus, deltoid, and erector spinae muscles. The amplitude of EMG (AEMG) and mean power frequency (MPF) of EMG were calculated. Each TC was divided equally into three parts. Ratings of perceived exertion (RPE) in the neck, shoulder......Surface electromyograms(EMG) during test contractions (TCs) were studied to assess the muscle strain in simulated mushroom picking. Additionally, the duration of the TC for the effective assessment was investigated. Nine female subjects performed standardized shoulder abduction and a stooped...... posture for one minute as TCs. Each experiment consisted of a 60-min rest, three work periods (W1-W3), a 30-min rest, and two work periods (W4 and W5) separated by a 30-min rest period. The duration of each work period was about 20 min. A total of 18 TCs was performed between the work periods and every 10...

  18. Optimal Normalization Tests for Muscle Activation of the Levator Scapulae, Pectoralis Minor, and Rhomboid Major: An Electromyography Study Using Maximum Voluntary Isometric Contractions. (United States)

    Castelein, Birgit; Cagnie, Barbara; Parlevliet, Thierry; Danneels, Lieven; Cools, Ann


    To identify maximum voluntary isometric contraction (MVIC) test positions for the deeper-lying scapulothoracic muscles (ie, levator scapulae, pectoralis minor, rhomboid major), and to provide a standard set of a limited number of test positions that generate an MVIC in all scapulothoracic muscles. Cross-sectional study. Physical and rehabilitation medicine department. Healthy subjects (N=21). Not applicable. Mean peak electromyographic activity from levator scapulae, pectoralis minor, and rhomboid major (investigated with fine-wire electromyography) and from upper trapezius, middle trapezius, lower trapezius, and serratus anterior (investigated with surface electromyography) during the performance of 12 different MVICs. The results indicated that various test positions generated similar high mean electromyographic activity and that no single test generated maximum activity for a specific muscle in all subjects. The results of this study support using a series of test positions for normalization procedures rather than a single exercise to increase the likelihood of recruiting the highest activity in the scapulothoracic muscles. A standard set of 5 test positions was identified as being sufficient for generating an MVIC of all scapulothoracic muscles: seated T, seated U 135°, prone T-thumbs up, prone V-thumbs up, and supine V-thumbs up. A standard set of test positions for normalization of scapulothoracic electromyographic data that also incorporates the levator scapulae, pectoralis minor, and rhomboid major muscles is 1 step toward a more comprehensive understanding of normal and abnormal muscle function of these muscles and will help to standardize the presentation of scapulothoracic electromyographic muscle activity. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  19. The effect of central contracts on the stability and performance of the England Test cricket team. [El efecto de contratos centrales sobre la estabilidad y el desempeño del equipo inglés de Test cricket].

    Directory of Open Access Journals (Sweden)

    Steven Bullough


    Full Text Available In 1999 the England and Wales Cricket Board (ECB decided to implement central contracts for elite player management to give them control over a group of players to represent the England national team in Test cricket. The purpose of this paper is to investigate the impact that this change in policy has had on the stability and performance of the England Test team, and discuss implications thereof. Using a sample of 13 seasons pre-central contracts (1987-1999 and 13 seasons post-central contracts (2000-2012, the results, from secondary analysis of England’s Test match scorecards from both sample periods, allowed investigation of team performance and stability. To gain a greater understanding of how central contracts impacted on the England Test side, eight interviews were also organised with key stakeholders in English cricket. The results showed that both the stability and performance of the England Test side improved considerably in the sample period post-central contracts (2000-2012 with a much greater consistency of selection (fewer changes per match alongside an improvement in England’s on-field performance (better win ratio and points per match. The paper identifies two key challenges facing the current player management system in England from domestic and external sources. Resumen En 1999 El Consejo de Cricket en Inglaterra y Gales (ECB – England and Wales Cricket Board decidió implementar contratos centrales para la dirección de jugadores de élite, con el fin de darle control sobre el grupo de jugadores que representan el equipo nacional de Inglaterra de Test cricket. El objetivo de este artículo es investigar el impacto que este cambio ha tenido sobre la estabilidad y el desempeño del equipo inglés de Test cricket y considerar sus implicaciones. Tras emplear una muestra de 13 temporadas antes de la firma de los contratos centrales (entre 1987 y 1999 y otras 13 temporadas después de su implementación (entre 2000 y 2012, los

  20. Adiabatic Evolution of an Open Quantum System in its Instantaneous Steady State (United States)

    Li, Dongxiao; Wu, Songlin; Shen, Hongzhi; Yi, Xuexi


    In this paper, we derive an adiabatic condition for an quantum system subject to environment. The adiabaticity defined here dicates that the open quantum system prepared initially in its steady state would adiabatically follow its instantaneous steady state. We find that if the driving on the open system does not induce transition between the eigenstates of the instantaneous steady state, the open system can evolve adiabatically. In order to examine the validity of the adiabatic condition, a two-band model is exemplified. The results show that the topological quantum phase transition presented in the two-band model is caused by the competition between the effect of decay and the spoiling of the adiabaticity. The geometric phase is also calculated and discussed when the adiabatic condition is satisfied.

  1. Experimental Adiabatic Quantum Factorization under Ambient Conditions Based on a Solid-State Single Spin System. (United States)

    Xu, Kebiao; Xie, Tianyu; Li, Zhaokai; Xu, Xiangkun; Wang, Mengqi; Ye, Xiangyu; Kong, Fei; Geng, Jianpei; Duan, Changkui; Shi, Fazhan; Du, Jiangfeng


    The adiabatic quantum computation is a universal and robust method of quantum computing. In this architecture, the problem can be solved by adiabatically evolving the quantum processor from the ground state of a simple initial Hamiltonian to that of a final one, which encodes the solution of the problem. Adiabatic quantum computation has been proved to be a compatible candidate for scalable quantum computation. In this Letter, we report on the experimental realization of an adiabatic quantum algorithm on a single solid spin system under ambient conditions. All elements of adiabatic quantum computation, including initial state preparation, adiabatic evolution (simulated by optimal control), and final state read-out, are realized experimentally. As an example, we found the ground state of the problem Hamiltonian S_{z}I_{z} on our adiabatic quantum processor, which can be mapped to the factorization of 35 into its prime factors 5 and 7.

  2. Reverse engineering of a nonlossy adiabatic Hamiltonian for non-Hermitian systems (United States)

    Wu, Qi-Cheng; Chen, Ye-Hong; Huang, Bi-Hua; Xia, Yan; Song, Jie


    We generalize the quantum adiabatic theorem to the non-Hermitian system and build a strict adiabaticity condition to make the adiabatic evolution nonlossy when taking into account the effect of the adiabatic phase. According to the strict adiabaticity condition, the nonadiabatic couplings and the effect of the imaginary part of adiabatic phase should be eliminated as much as possible. Also, the non-Hermitian Hamiltonian reverse-engineering method is proposed for adiabatically driving an artificial quantum state. A concrete two-level system is adopted to show the usefulness of the reverse-engineering method. We obtain the desired target state by adjusting extra rotating magnetic fields at a predefined time. Furthermore, the numerical simulation shows that certain noise and dissipation in the systems are no longer undesirable but play a positive role in the scheme. Therefore, the scheme is quite useful for quantum information processing in some dissipative systems.

  3. Adiabatic tapered optical fiber fabrication in two step etching (United States)

    Chenari, Z.; Latifi, H.; Ghamari, S.; Hashemi, R. S.; Doroodmand, F.


    A two-step etching method using HF acid and Buffered HF is proposed to fabricate adiabatic biconical optical fiber tapers. Due to the fact that the etching rate in second step is almost 3 times slower than the previous droplet etching method, terminating the fabrication process is controllable enough to achieve a desirable fiber diameter. By monitoring transmitted spectrum, final diameter and adiabaticity of tapers are deduced. Tapers with losses about 0.3 dB in air and 4.2 dB in water are produced. The biconical fiber taper fabricated using this method is used to excite whispering gallery modes (WGMs) on a microsphere surface in an aquatic environment. So that they are suitable to be used in applications like WGM biosensors.

  4. Fast forward of the adiabatic spin dynamics of entangled states (United States)

    Setiawan, Iwan; Eka Gunara, Bobby; Masuda, Shumpei; Nakamura, Katsuhiro


    We develop a fast-forward scheme of the adiabatic spin dynamics of quantum entangled states. We settle the quasiadiabatic dynamics by adding the regularization terms to the original Hamiltonian and then accelerate it with the use of a large time-scaling factor. Assuming the experimentally realizable candidate Hamiltonian consisting of the exchange interactions and magnetic field, we solve the regularization terms. These terms, multiplied by the velocity function, give rise to the state-dependent counterdiabatic terms. The scheme needs neither knowledge of full spectral properties of the system nor solving the initial- and boundary-value problem. Our fast forward Hamiltonian generates a variety of state-dependent counterdiabatic terms for each of adiabatic states, which can include the state-independent one. We highlight this fact by using minimum (two-spin) models for a simple transverse Ising model, quantum annealing, and generation of entanglement.

  5. Crack propagation of Ti alloy via adiabatic shear bands

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza, I., E-mail: [Instituto Tecnológico de Veracruz (Mexico); Villalobos, D. [Instituto Tecnológico de Veracruz (Mexico); Alexandrov, B.T. [The Ohio State University (United States)


    This study was focused on the characterization of the origin and mechanism of crack propagation as a result of hot induction bending of Ti alloy. Plates of Ti–6Al–4V alloy with 12.5 mm of thickness were submitted to hot induction bending below the beta transus temperature. Optical and scanning electron microscopy analysis showed crack formation in the tensile zone. Microstructural evidence showed that cracks propagate through the adiabatic shear bands by Dimple-Void mechanism. However, voids formation before shear banding also occurred. In both mechanisms adiabatic shear bands are formed via dynamic recrystallization where the alpha–beta interphase works as stress concentrator promoting the formation of dimples and voids.

  6. Non-adiabatic dynamics around a conical intersection with surface-hopping coupled coherent states. (United States)

    Humeniuk, Alexander; Mitrić, Roland


    A surface-hopping extension of the coupled coherent states-method [D. Shalashilin and M. Child, Chem. Phys. 304, 103-120 (2004)] for simulating non-adiabatic dynamics with quantum effects of the nuclei is put forward. The time-dependent Schrödinger equation for the motion of the nuclei is solved in a moving basis set. The basis set is guided by classical trajectories, which can hop stochastically between different electronic potential energy surfaces. The non-adiabatic transitions are modelled by a modified version of Tully's fewest switches algorithm. The trajectories consist of Gaussians in the phase space of the nuclei (coherent states) combined with amplitudes for an electronic wave function. The time-dependent matrix elements between different coherent states determine the amplitude of each trajectory in the total multistate wave function; the diagonal matrix elements determine the hopping probabilities and gradients. In this way, both interference effects and non-adiabatic transitions can be described in a very compact fashion, leading to the exact solution if convergence with respect to the number of trajectories is achieved and the potential energy surfaces are known globally. The method is tested on a 2D model for a conical intersection [A. Ferretti, J. Chem. Phys. 104, 5517 (1996)], where a nuclear wavepacket encircles the point of degeneracy between two potential energy surfaces and interferes with itself. These interference effects are absent in classical trajectory-based molecular dynamics but can be fully incorpo rated if trajectories are replaced by surface hopping coupled coherent states.

  7. A field theory characterization of interacting adiabatic particles in cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Arteaga, Daniel [Departament de Fisica Fonamental and Institut de Ciencies del Cosmos, Facultat de Fisica, Universitat de Barcelona, Av. Diagonal 647, 08028 Barcelona (Spain)], E-mail:


    We explore the adiabatic particle excitations of an interacting field in a cosmological background. By following the time evolution of the quantum state corresponding to the particle excitation, we show how the basic properties characterizing the particle propagation can be recovered from the two-point propagators. As an application, we study the background-induced dissipative effects on the propagation of a two-level atom in an expanding universe.

  8. Analysis of adiabatic transfer in cavity quantum electrodynamics

    Indian Academy of Sciences (India)


    Nov 27, 2015 ... We find that the fidelity of storage is better, the stronger the control field and the slower the rate of its switching off. On the contrary, unlike the adiabatic notion, retrieval is better with faster rates of switching on of an optimal control field. Also, for retrieval, the behaviour with dissipation is non-monotonic.

  9. The Adiabatic Piston and the Second Law of Thermodynamics (United States)

    Crosignani, Bruno; Di Porto, Paolo; Conti, Claudio


    A detailed analysis of the adiabatic-piston problem reveals peculiar dynamical features that challenge the general belief that isolated systems necessarily reach a static equilibrium state. In particular, the fact that the piston behaves like a perpetuum mobile, i.e., it never stops but keeps wandering, undergoing sizable oscillations, around the position corresponding to maximum entropy, has remarkable implications on the entropy variations of the system and on the validity of the second law when dealing with systems of mesoscopic dimensions.

  10. The adiabatic piston: a perpetuum mobile in the mesoscopic realm


    Crosignani, Bruno; Di Porto, Paolo; Conti, Claudio


    Abstract: A detailed analysis of the adiabatic-piston problem reveals, for a finely-tuned choice of the spatial dimensions of the system, peculiar dynamical features that challenge the statement that an isolated system necessarily reaches a time-independent equilibrium state. In particular, the piston behaves like a perpetuum mobile, i.e., it never comes to a stop but keeps wandering, undergoing sizeable oscillations around the position corresponding to maximum entropy; this has remarkable im...

  11. Performance test results of mock-up model test facility with a full-scale reaction tube for HTTR hydrogen production system. Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, Yoshiyuki; Hayashi, Koji; Kato, Michio [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment] [and others


    Research on a hydrogen production system by steam reforming of methane, chemical reaction; CH{sub 4} + H{sub 2}O {yields} 3H{sub 2}O + CO, has been carried out to couple with the HTTR for establishment of high-temperature nuclear heat utilization technology and contribution to hydrogen energy society in future. The mock-up test facility with a full-scale reaction tube test facility, a model simulating one reaction tube of a steam reformer of the HTTR hydrogen production system in full scale, was fabricated to perform tests on controllability, hydrogen production performance etc. under the same pressure and temperature conditions as those of the HTTR hydrogen production system. The design and fabrication of the test facility started from 1997, and the all components were installed until September in 2001. In a performance test conducted from October in 2001 to February in 2002, performance of each component was examined and hydrogen of 120m{sup 3}{sub N}/h was successfully produced with high-temperature helium gas. This report describes the performance test results on components performance, hydrogen production characteristics etc., and main troubles and countermeasures. (author)

  12. Non-Adiabatic Molecular Dynamics Methods for Materials Discovery

    Energy Technology Data Exchange (ETDEWEB)

    Furche, Filipp [Univ. of California, Irvine, CA (United States); Parker, Shane M. [Univ. of California, Irvine, CA (United States); Muuronen, Mikko J. [Univ. of California, Irvine, CA (United States); Roy, Saswata [Univ. of California, Irvine, CA (United States)


    The flow of radiative energy in light-driven materials such as photosensitizer dyes or photocatalysts is governed by non-adiabatic transitions between electronic states and cannot be described within the Born-Oppenheimer approximation commonly used in electronic structure theory. The non-adiabatic molecular dynamics (NAMD) methods based on Tully surface hopping and time-dependent density functional theory developed in this project have greatly extended the range of molecular materials that can be tackled by NAMD simulations. New algorithms to compute molecular excited state and response properties efficiently were developed. Fundamental limitations of common non-linear response methods were discovered and characterized. Methods for accurate computations of vibronic spectra of materials such as black absorbers were developed and applied. It was shown that open-shell TDDFT methods capture bond breaking in NAMD simulations, a longstanding challenge for single-reference molecular dynamics simulations. The methods developed in this project were applied to study the photodissociation of acetaldehyde and revealed that non-adiabatic effects are experimentally observable in fragment kinetic energy distributions. Finally, the project enabled the first detailed NAMD simulations of photocatalytic water oxidation by titania nanoclusters, uncovering the mechanism of this fundamentally important reaction for fuel generation and storage.

  13. Thermal reservoir sizing for adiabatic compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Kere, Amelie; Goetz, Vincent; Py, Xavier; Olives, Regis; Sadiki, Najim [Perpignan Univ. (France). PROMES CNRS UPR 8521; Mercier-Allart, Eric [EDF R et D, Chatou (France)


    Despite the operation of the two existing industrial facilities to McIntosh (Alabama), and for more than thirty years, Huntorf (Germany), electricity storage in the form of compressed air in underground cavern (CAES) has not seen the development that was expected in the 80s. The efficiency of this form of storage was with the first generation CAES, less than 50%. The evolving context technique can significantly alter this situation. The new generation so-called Adiabatic CAES (A-CAES) is to retrieve the heat produced by the compression via thermal storage, thus eliminating the necessity of gas to burn and would allow consideration efficiency overall energy of the order of 70%. To date, there is no existing installation of A-CAES. Many studies describe the principal and the general working mode of storage systems by adiabatic compression of air. So, efficiencies of different configurations of adiabatic compression process were analyzed. The aim of this paper is to simulate and analyze the performances of a thermal storage reservoir integrated in the system and adapted to the working conditions of a CAES.

  14. Proposal to negotiate, without competitive tendering, a contract for the manufacture, testing and delivery of 320 cryogenic helium mass flowmeters for the LHC

    CERN Document Server


    This document concerns the manufacture, testing and delivery of 320 cryogenic helium mass flowmeters for the LHC. Following a market survey (MS-2602/LHC/LHC) carried out amoung 37 firms in twelve Member States and six firms in two non-Member States, a price enquiry for qualifying prototypes was sent on 20 November 1998 to nine selected firms and the received prototypes were evaluated. As a result of this process a request for quotation was sent to one firm The Finance Committee is invited to agree to the negotiation of a contract with the firm EMERSON PROCESS MANAGEMENT/FISHER-ROSEMOUNT (CH), without competitive tendering, for the manufacture, testing and delivery of 320 cryogenic helium mass flowmeters for an amount of 1 804 840 Swiss francs, not subject to revision, with options for up to 10 additional cryogenic helium mass flowmeters and an extension of the guarantee period to five years for all units for an amount of 219 090 Swiss francs, not subject to revision, bringing the total amount to 2 023 930 Swi...

  15. Contracting as a Science (United States)


    neoclassical theory to be classified as financial, physical, legal, human, organizational, informational, and relational. Each firm will have science theories applicable to contracting research, identify a contracting paradigm (or paradigms) and potential contracting theories and...principles, examine the nature of contracting research and practice, and present thoughts and ideas toward a general theory of contracting which, hopefully

  16. A One-Dimensional Flow Model with Adiabatic Friction for Rapid Estimation of Cold Spray Flow Conditions (United States)

    Ye, Hezhou; Yin, Yanhua; Wang, Jianfeng


    While commercially available computational fluid dynamic packages are employed nowadays to analyze the spraying behavior of the cold spray (CS) system and optimize the nozzle geometry design, using these packages is often prohibitive because of complex computational resource requirements and expensive copyright licenses. This paper proposes a quick and economical method for predicting the performance of the CS system, while asking for minimal computational resource. A one-dimensional adiabatic friction model with the consideration of friction was developed to calculate the critical pressure of nozzles under different expansion ratios and the gas/particle velocity at different spraying conditions. The accuracy of the critical pressure calculation was evidenced by polymeric nozzle destructive tests. The particle velocities achieved from the nozzles with different expansion ratios were measured and compared with the velocity values calculated by the model. The suggested adiabatic friction model is validated by the well-matched values between the calculated results and the experimental data.

  17. Adiabatic quantum computing with spin qubits hosted by molecules. (United States)

    Yamamoto, Satoru; Nakazawa, Shigeaki; Sugisaki, Kenji; Sato, Kazunobu; Toyota, Kazuo; Shiomi, Daisuke; Takui, Takeji


    A molecular spin quantum computer (MSQC) requires electron spin qubits, which pulse-based electron spin/magnetic resonance (ESR/MR) techniques can afford to manipulate for implementing quantum gate operations in open shell molecular entities. Importantly, nuclear spins, which are topologically connected, particularly in organic molecular spin systems, are client qubits, while electron spins play a role of bus qubits. Here, we introduce the implementation for an adiabatic quantum algorithm, suggesting the possible utilization of molecular spins with optimized spin structures for MSQCs. We exemplify the utilization of an adiabatic factorization problem of 21, compared with the corresponding nuclear magnetic resonance (NMR) case. Two molecular spins are selected: one is a molecular spin composed of three exchange-coupled electrons as electron-only qubits and the other an electron-bus qubit with two client nuclear spin qubits. Their electronic spin structures are well characterized in terms of the quantum mechanical behaviour in the spin Hamiltonian. The implementation of adiabatic quantum computing/computation (AQC) has, for the first time, been achieved by establishing ESR/MR pulse sequences for effective spin Hamiltonians in a fully controlled manner of spin manipulation. The conquered pulse sequences have been compared with the NMR experiments and shown much faster CPU times corresponding to the interaction strength between the spins. Significant differences are shown in rotational operations and pulse intervals for ESR/MR operations. As a result, we suggest the advantages and possible utilization of the time-evolution based AQC approach for molecular spin quantum computers and molecular spin quantum simulators underlain by sophisticated ESR/MR pulsed spin technology.

  18. Optimized sympathetic cooling of atomic mixtures via fast adiabatic strategies

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Stephen; Sundaram, Bala [Department of Physics, University of Massachusetts, Boston, Massachusetts 02125 (United States); Onofrio, Roberto [Dipartimento di Fisica ' ' Galileo Galilei' ' , Universita di Padova, Via Marzolo 8, Padova I-35131 (Italy); Department of Physics, University of Massachusetts, Boston, Massachusetts 02125 (United States); Institute for Theoretical Atomic, Molecular and Optical Physics (ITAMP), Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States)


    We discuss fast frictionless cooling techniques in the framework of sympathetic cooling of cold atomic mixtures. It is argued that optimal cooling of an atomic species--in which the deepest quantum degeneracy regime is achieved--may be obtained by means of sympathetic cooling with another species whose trapping frequency is dynamically changed to maintain constancy of the Lewis-Riesenfeld adiabatic invariant. Advantages and limitations of this cooling strategy are discussed, with particular regard to the possibility of cooling Fermi gases to a deeper degenerate regime.

  19. Adiabaticity and Reversibility Studies for Beam Splitting using Stable Resonances

    CERN Document Server

    Franchi, A; Giovannozzi, M


    At the CERN Proton Synchrotron, a series of beam experiments proved beam splitting by crossing the one-fourth resonance. Depending on the speed at which the horizontal resonance is crossed, the splitting process is more or less adiabatic, and a different fraction of the initial beam is trapped in the islands. Experiments prove that when the trapping process is reversed and the islands merged together, the final distribution features thick tails. The beam population in such tails is correlated to the speed of the resonance crossing and to the fraction of the beam trapped in the stable islands. Experiments and possible theoretical explanations are discussed.

  20. Designing single-qutrit quantum gates via tripod adiabatic passage

    Directory of Open Access Journals (Sweden)

    M. Amniat-Talab


    Full Text Available In this paper, we use stimulated Raman adiabatic passage technique to implement single-qutrit quantum gates in tripod systems. It is shown by using the Morris-Shore (MS transformation, the six-state problem with 5 pulsed fields can be reduced to a basis that decouples two states from the others. This imposes three pulses not connected to the initial condition with have the same shape. Using this method, the six-state penta-pod system is reduced to a tripod system. We can design single-qutrit quantum gates by ignoring the fragile dynamical phase, and by suitable design of Rabi frequencies of the effective Hamiltonian

  1. Adiabatic transport of qubits around a black hole

    CERN Document Server

    Viennot, David


    We consider localized qubits evolving around a black hole following a quantum adiabatic dynamics. We develop a geometric structure (based on fibre bundles) permitting to describe the quantum states of a qubit and the spacetime geometry in a single framework. The quantum decoherence induced by the black hole on the qubit is analysed in this framework (the role of the dynamical and geometric phases in this decoherence is treated), especially for the quantum teleportation protocol when one qubit falls to the event horizon. A simple formula to compute the fidelity of the teleportation is derived. The case of a Schwarzschild black hole is analysed.

  2. Adiabatic quantum computation and quantum annealing theory and practice

    CERN Document Server

    McGeoch, Catherine C


    Adiabatic quantum computation (AQC) is an alternative to the better-known gate model of quantum computation. The two models are polynomially equivalent, but otherwise quite dissimilar: one property that distinguishes AQC from the gate model is its analog nature. Quantum annealing (QA) describes a type of heuristic search algorithm that can be implemented to run in the ``native instruction set'''' of an AQC platform. D-Wave Systems Inc. manufactures {quantum annealing processor chips} that exploit quantum properties to realize QA computations in hardware. The chips form the centerpiece of a nov

  3. Ultrasonic velocity and adiabatic compressibility in dioxane-water mixtures (United States)

    Ciupe, A.; Auslaender, D.


    Using a method of diffraction of light on an ultrasonic beam, the velocity of ultrasounds and the adiabatic compressibility in dioxane-water mixtures were determined. The dependence of these quantities on the temperature (in the 15-50 C range) and on the concentration (0-100%) were studied. For each temperature there was found a velocity maximum and a compressibility minimum for a given value of the dioxane concentration. The different behavior of these mixtures is due to intense interactions between the molecules of the two liquids composing the mixture.

  4. The adiabatic piston: a perpetuum mobile in the mesoscopic realm (United States)

    Crosignani, Bruno; Porto, Paolo; Conti, Claudio


    A detailed analysis of the adiabatic-piston problem reveals, for a finely-tuned choice of the spatial dimensions of the system, peculiar dynamical features that challenge the statement that an isolated system necessarily reaches a time-independent equilibrium state. In particular, the piston behaves like a perpetuum mobile, i.e., it never comes to a stop but keeps wandering, undergoing sizeable oscillations around the position corresponding to maximum entropy; this has remarkable implications on the entropy changes of a mesoscopic isolated system and on the limits of validity of the second law of thermodynamics in the mesoscopic realm.

  5. The adiabatic piston: a perpetuum mobile in the mesoscopic realm

    Directory of Open Access Journals (Sweden)

    Claudio Conti


    Full Text Available Abstract: A detailed analysis of the adiabatic-piston problem reveals, for a finely-tuned choice of the spatial dimensions of the system, peculiar dynamical features that challenge the statement that an isolated system necessarily reaches a time-independent equilibrium state. In particular, the piston behaves like a perpetuum mobile, i.e., it never comes to a stop but keeps wandering, undergoing sizeable oscillations around the position corresponding to maximum entropy; this has remarkable implications on the entropy changes of a mesoscopic isolated system and on the limits of validity of the second law of thermodynamics in the mesoscopic realm.

  6. Adiabatic dynamics of one-dimensional classical Hamiltonian dissipative systems (United States)

    Pritula, G. M.; Petrenko, E. V.; Usatenko, O. V.


    A linearized plane pendulum with the slowly varying mass and length of string and the suspension point moving at a slowly varying speed is presented as an example of a simple 1D mechanical system described by the generalized harmonic oscillator equation, which is a basic model in discussion of the adiabatic dynamics and geometric phase. The expression for the pendulum geometric phase is obtained by three different methods. The pendulum is shown to be canonically equivalent to the damped harmonic oscillator. This supports the mathematical conclusion, not widely accepted in physical community, of no difference between the dissipative and Hamiltonian 1D systems.

  7. Tensile Deformation and Adiabatic Heating in Post-Yield Response of Polycarbonate (United States)


    ARL-TR-7531 ● NOV 2015 US Army Research Laboratory Tensile Deformation and Adiabatic Heating in Post-Yield Response of...Army Research Laboratory Tensile Deformation and Adiabatic Heating in Post-Yield Response of Polycarbonate by C. Allan Gunnarsson, Bryan Love...REPORT TYPE Final 3. DATES COVERED (From - To) January 2014–August 2015 4. TITLE AND SUBTITLE Tensile Deformation and Adiabatic Heating in Post

  8. Quantum gates in mesoscopic atomic ensembles based on adiabatic passage and Rydberg blockade


    Beterov, I. I.; Saffman, M.; Yakshina, E. A.; Zhukov, V. P.; Tretyakov, D. B.; Entin, V. M.; Ryabtsev, I. I.; Mansell, C. W.; MacCormick, C.; Bergamini, S.; Fedoruk, M. P.


    We present schemes for geometric phase compensation in adiabatic passage which can be used for the implementation of quantum logic gates with atomic ensembles consisting of an arbitrary number of strongly interacting atoms. Protocols using double sequences of stimulated Raman adiabatic passage (STIRAP) or adiabatic rapid passage (ARP) pulses are analyzed. Switching the sign of the detuning between two STIRAP sequences, or inverting the phase between two ARP pulses, provides state transfer wit...

  9. Test report of the melt spreading tests ECOKATS-V1 and ECOKATS-1. CONTRACT FIKS-CT1999-00003 - EX-VESSEL CORE MELT STABILIZATION RESEARCH

    Energy Technology Data Exchange (ETDEWEB)

    Alsmeyer, H.; Cron, T.; Foit, J.J.; Messemer, G.; Schmidt-Stiefel, S.; Haefner, W. [Becker Technologies, Eschborn (Germany); Kriscio, H.


    As one of the major tasks of the ECOSTAR project, two large-scale experiments on oxidic melt spreading were performed. The experimental conditions were selected to represent low flow rate of oxidic melt, released with low overheat, so that stop of the spreading process may occur during ongoing melt release, and spreading would be incomplete. Besides the basic experimental information on spreading of large melt masses under low flow conditions, the experiments were designed to be used for the final validation of spreading codes. After completion of the validation process, the computer programs would be able to predict with sufficient accuracy the spreading process in case of an accident, which is expected to occur under less critical conditions than the actual experiment. The report describes also the selection and characterization of the multi-component oxide melt, which simulates the ex-vessel oxide corium melt in an anticipated reactor accident. The melt was generated by a modified exothermic thermite reaction, and poured to the spreading surfaces under controlled conditions. To improve the information about the rheological behaviour of the selected oxide melt, a pre-test ECOKATS-V1 was performed in which the oxide melt was spread in a 1-d flow channel. Together with qualified spreading calculations, this experiment allowed for estimation of the initial viscosity of the melt and characterization of the rheological behaviour in the freezing range. Furthermore, significant information about the nature of the 1-d spreading process during onset of solidification as well as growth and failure of a front crust was gained. The large scale 2-d spreading experiment ECOKATS-1 was performed on a concrete surface, 4 m long and 3 m wide. 547 kg of oxide melt were released to the spreading surface during a period of 85 s. The melt and the spreading conditions were selected to represent the situation for which the melt stopped during the phase of melt inflow (incomplete

  10. Optical study of the use of recirculated gases for adiabatization of combustion process in the SIDI engine

    Directory of Open Access Journals (Sweden)

    Cieślik Wojciech


    Full Text Available Proper delivery of gaseous components of the charge into the combustion chamber enables controlling of combustion in the aspect of adiabatization of the process. The adiabatization obtained as result of surrounding of combustible mixture by recirculated exhaust gases should contribute to reducing formation of harmful components created during this process. The key issue here is the formation of radicals, which is not sufficiently recognized according fuels surrounded by non-combustible gases. The innovative nature of this work ensues from the experimental confirmation of so defined organizing of combustion process. Currently there are no tests concerning attempts of gas separation in the combustion chamber of engine with external source of ignition. Such separation would contribute to the increase of the adiabatization process while at the same time the combustion rate increases and reduces the combustion duration. This paper presents the next stage of research, which were preceded by simulation and experimental investigations. In the article the results of the impact of the strategy of non-combustible gas injections on combustion ratios for cylinder head with a centrally positioned ignition point have been discussed. The analysis has been based on the photo material for the period from the start of ignition to full coverage of the cylinder by the flame. Authors performed a comparative analysis (against the recorded images of the thermodynamic indexes of the combustion process obtained from the indicator traces.

  11. Fast adiabatic quantum state transfer and entanglement generation between two atoms via dressed states. (United States)

    Wu, Jin-Lei; Ji, Xin; Zhang, Shou


    We propose a dressed-state scheme to achieve shortcuts to adiabaticity in atom-cavity quantum electrodynamics for speeding up adiabatic two-atom quantum state transfer and maximum entanglement generation. Compared with stimulated Raman adiabatic passage, the dressed-state scheme greatly shortens the operation time in a non-adiabatic way. By means of some numerical simulations, we determine the parameters which can guarantee the feasibility and efficiency both in theory and experiment. Besides, numerical simulations also show the scheme is robust against the variations in the parameters, atomic spontaneous emissions and the photon leakages from the cavity.

  12. Fast adiabatic quantum state transfer and entanglement generation between two atoms via dressed states (United States)

    Wu, Jin-Lei; Ji, Xin; Zhang, Shou


    We propose a dressed-state scheme to achieve shortcuts to adiabaticity in atom-cavity quantum electrodynamics for speeding up adiabatic two-atom quantum state transfer and maximum entanglement generation. Compared with stimulated Raman adiabatic passage, the dressed-state scheme greatly shortens the operation time in a non-adiabatic way. By means of some numerical simulations, we determine the parameters which can guarantee the feasibility and efficiency both in theory and experiment. Besides, numerical simulations also show the scheme is robust against the variations in the parameters, atomic spontaneous emissions and the photon leakages from the cavity.

  13. Determination of Temperature Rise and Temperature Differentials of CEMII/B-V Cement for 20MPa Mass Concrete using Adiabatic Temperature Rise Data (United States)

    Chee Siang, GO


    Experimental test was carried out to determine the temperature rise characteristics of Portland-Fly-Ash Cement (CEM II/B-V, 42.5N) of Blaine fineness 418.6m2/kg and 444.6m2/kg respectively for 20MPa mass concrete under adiabatic condition. The estimation on adiabatic temperature rise by way of CIRIA C660 method (Construction Industry Research & Information Information) was adopted to verify and validate the hot-box test results by simulating the heat generation curve of the concrete under semi-adiabatic condition. Test result found that Portland fly-ash cement has exhibited decrease in the peak value of temperature rise and maximum temperature rise rate. The result showed that the temperature development and distribution profile, which is directly contributed from the heat of hydration of cement with time, is affected by the insulation, initial placing temperature, geometry and size of concrete mass. The mock up data showing the measured temperature differential is significantly lower than the technical specifications 20°C temperature differential requirement and the 27.7°C limiting temperature differential for granite aggregate concrete as stipulated in BS8110-2: 1985. The concrete strength test result revealed that the 28 days cubes compressive strength was above the stipulated 20MPa characteristic strength at 90 days. The test demonstrated that with proper concrete mix design, the use of Portland flyash cement, combination of chilled water and flake ice, and good insulation is effective in reducing peak temperature rise, temperature differential, and lower adiabatic temperature rise for mass concrete pours. As far as the determined adiabatic temperature rise result was concern, the established result could be inferred for in-situ thermal properties of 20MPa mass concrete application, as the result could be repeatable on account of similar type of constituent materials and concrete mix design adopted for permanent works at project site.

  14. Conditions for super-adiabatic droplet growth after entrainment mixing

    Directory of Open Access Journals (Sweden)

    F. Yang


    Full Text Available Cloud droplet response to entrainment and mixing between a cloud and its environment is considered, accounting for subsequent droplet growth during adiabatic ascent following a mixing event. The vertical profile for liquid water mixing ratio after a mixing event is derived analytically, allowing the reduction to be predicted from the mixing fraction and from the temperature and humidity for both the cloud and environment. It is derived for the limit of homogeneous mixing. The expression leads to a critical height above the mixing level: at the critical height the cloud droplet radius is the same for both mixed and unmixed parcels, and the critical height is independent of the updraft velocity and mixing fraction. Cloud droplets in a mixed parcel are larger than in an unmixed parcel above the critical height, which we refer to as the “super-adiabatic” growth region. Analytical results are confirmed with a bin microphysics cloud model. Using the model, we explore the effects of updraft velocity, aerosol source in the environmental air, and polydisperse cloud droplets. Results show that the mixed parcel is more likely to reach the super-adiabatic growth region when the environmental air is humid and clean. It is also confirmed that the analytical predictions are matched by the volume-mean cloud droplet radius for polydisperse size distributions. The findings have implications for the origin of large cloud droplets that may contribute to onset of collision–coalescence in warm clouds.

  15. An Adiabatic Quantum Algorithm for Determining Gracefulness of a Graph (United States)

    Hosseini, Sayed Mohammad; Davoudi Darareh, Mahdi; Janbaz, Shahrooz; Zaghian, Ali


    Graph labelling is one of the noticed contexts in combinatorics and graph theory. Graceful labelling for a graph G with e edges, is to label the vertices of G with 0, 1, ℒ, e such that, if we specify to each edge the difference value between its two ends, then any of 1, 2, ℒ, e appears exactly once as an edge label. For a given graph, there are still few efficient classical algorithms that determine either it is graceful or not, even for trees - as a well-known class of graphs. In this paper, we introduce an adiabatic quantum algorithm, which for a graceful graph G finds a graceful labelling. Also, this algorithm can determine if G is not graceful. Numerical simulations of the algorithm reveal that its time complexity has a polynomial behaviour with the problem size up to the range of 15 qubits. A general sufficient condition for a combinatorial optimization problem to have a satisfying adiabatic solution is also derived.



    Ana-Maria Florea; Constantin Giurca


    The contract is a legal instrument used to organize economic and social life. International trade agreement has certain features in order to ensure the international exchange of goods and services between the Contracting Parties. In terms of commercial contract, there is a foreign origin element, that gives the parties the right to determine the law to govern the contract. A fundamental aspect of commercial contract, in addition to that of determining the law applicable to judicial report est...

  17. Multiturn extraction and injection by means of adiabatic capture in stable islands of phase space

    CERN Document Server

    Cappi, R


    Recently a novel approach has been proposed for performing multiturn extraction from a circular machine. Such a technique consists of splitting the beam by means of stable islands created in transverse phase space by magnetic elements creating nonlinear fields, such as sextupoles and octupoles. Provided a slow time variation of the linear tune is applied, adiabatic with respect to the betatron motion, the islands can be moved in phase space and eventually charged particles may be trapped inside the stable structures. This generates a certain number of well-separated beamlets. Originally, this principle was successfully tested using a fourth-order resonance. In this paper the approach is generalized by considering other types of resonances as well as the possibility of performing multiple multiturn extractions. The results of numerical simulations are presented and described in detail. Of course, by time reversal, the proposed approach could be used also for multiturn injection.

  18. Accurate Non-adiabatic Quantum Dynamics from Pseudospectral Sampling of Time-dependent Gaussian Basis Sets

    CERN Document Server

    Heaps, Charles W


    Quantum molecular dynamics requires an accurate representation of the molecular potential energy surface from a minimal number of electronic structure calculations, particularly for nonadiabatic dynamics where excited states are required. In this paper, we employ pseudospectral sampling of time-dependent Gaussian basis functions for the simulation of non-adiabatic dynamics. Unlike other methods, the pseudospectral Gaussian molecular dynamics tests the Schr\\"{o}dinger equation with $N$ Dirac delta functions located at the centers of the Gaussian functions reducing the scaling of potential energy evaluations from $\\mathcal{O}(N^2)$ to $\\mathcal{O}(N)$. By projecting the Gaussian basis onto discrete points in space, the method is capable of efficiently and quantitatively describing nonadiabatic population transfer and intra-surface quantum coherence. We investigate three model systems; the photodissociation of three coupled Morse oscillators, the bound state dynamics of two coupled Morse oscillators, and a two-d...

  19. Film cooling adiabatic effectiveness measurements of pressure side trailing edge cooling configurations

    Directory of Open Access Journals (Sweden)

    R. Becchi


    Full Text Available Nowadays total inlet temperature of gas turbine is far above the permissible metal temperature; as a consequence, advanced cooling techniques must be applied to protect from thermal stresses, oxidation and corrosion the components located in the high pressure stages, such as the blade trailing edge. A suitable design of the cooling system for the trailing edge has to cope with geometric constraints and aerodynamic demands; state-of-the-art of cooling concepts often use film cooling on blade pressure side: the air taken from last compressor stages is ejected through discrete holes or slots to provide a cold layer between hot mainstream and the blade surface. With the goal of ensuring a satisfactory lifetime of blades, the design of efficient trailing edge film cooling schemes and, moreover, the possibility to check carefully their behavior, are hence necessary to guarantee an appropriate metal temperature distribution. For this purpose an experimental survey was carried out to investigate the film covering performance of different pressure side trailing edge cooling systems for turbine blades. The experimental test section consists of a scaled-up trailing edge model installed in an open loop suction type test rig. Measurements of adiabatic effectiveness distributions were carried out on three trailing edge cooling system configurations. The baseline geometry is composed by inclined slots separated by elongated pedestals; the second geometry shares the same cutback configuration, with an additional row of circular film cooling holes located upstream; the third model is equipped with three rows of in-line film cooling holes. Experiments have been performed at nearly ambient conditions imposing several blowing ratio values and using carbon dioxide as coolant in order to reproduce a density ratio close to the engine conditions (DR=1.52. To extend the validity of the survey a comparison between adiabatic effectiveness measurements and a prediction by

  20. Experimental Investigations on Conventional and Semi-Adiabatic Diesel Engine Using Simarouba Biodiesel as Fuel (United States)

    Ravi, M. U.; Reddy, C. P.; Ravindranath, K.


    In view of fast depletion of fossil fuels and the rapid rate at which the fuel consumption is taking place all over the world, scientists are searching for alternate fuels for maintaining the growth industrially and economically. Hence search for alternate fuel(s) has become imminent. Out of the limited options for internal combustion engines, the bio diesel fuel appears to be the best. Many advanced countries are implementing several biodiesel initiatives and developmental programmes in order to become self sufficient and reduce the import bills. Biodiesel is biodegradable and renewable fuel with the potential to enhance the performance and reduce engine exhaust emissions. This is due to ready usage of existing diesel engines, fuel distribution pattern, reduced emission profiles, and eco-friendly properties of biodiesel. Simarouba biodiesel (SBD), the methyl ester of Simarouba oil is one such alternative fuel which can be used as substitute to conventional petro-diesel. The present work involves experimental investigation on the use of SBD blends as fuel in conventional diesel engine and semi-adiabatic diesel engine. The oil was triple filtered to eliminate particulate matter and then transesterified to obtain biodiesel. The project envisaged aims at conducting analysis of diesel with SBD blends (10, 20, 30 and 40 %) in conventional engine and semi-adiabatic engine. Also it was decided to vary the injection pressure (180, 190 and 200 bar) and observe its effect on performance and also suggest better value of injection pressure. The engine was made semi adiabatic by coating the piston crown with partially stabilized zirconia (PSZ). Kirloskar AV I make (3.67 kW) vertical, single cylinder, water cooled diesel engine coupled to an eddy current dynamometer with suitable measuring instrumentation/accessories used for the study. Experiments were initially carried out using pure diesel fuel to provide base line data. The test results were compared based on the performance

  1. Adiabatic heavy-ion fusion potentials for fusion at deep sub-barrier ...

    Indian Academy of Sciences (India)

    Abstract. The recently reported unusual behaviour of fusion cross-sections at extreme sub-barrier energies has been examined. The adiabatic limit of fusion barriers has been determined from experimental data using the barrier penetration model. These adia- batic barriers are consistent with the adiabatic fusion barriers ...

  2. Job insecurity, union support and the intention to resign membership. A psychological contract perspective tested among union members in four European countries

    NARCIS (Netherlands)

    De Witte, Hans; Sverke, Magnus; Van Ruysseveldt, Joris; Goslinga, Sjoerd; Chirumbolo, Antonio; Hellgren, Johnny; Näswall, Katharina


    This paper explores the consequences of job insecurity among union members. Starting from the dominance of the instrumental motive for union membership, and using psychological contract theory, we hypothesize that the perception of job insecurity will correlate with a lower level of perceived union

  3. Quantum adiabatic computation with a constant gap is not useful in one dimension

    Energy Technology Data Exchange (ETDEWEB)

    Hastings, Matthew [Los Alamos National Laboratory


    We show that it is possible to use a classical computer to efficiently simulate the adiabatic evolution of a quantum system in one dimension with a constant spectral gap, starting the adiabatic evolution from a known initial product state. The proof relies on a recently proven area law for such systems, implying the existence of a good matrix product representation of the ground state, combined with an appropriate algorithm to update the matrix product state as the Hamiltonian is changed. This implies that adiabatic evolution with such Hamiltonians is not useful for universal quantum computation. Therefore, adiabatic algorithms which are useful for universal quantum computation either require a spectral gap tending to zero or need to be implemented in more than one dimension (we leave open the question of the computational power of adiabatic simulation with a constant gap in more than one dimension).


    Directory of Open Access Journals (Sweden)

    Liana Teodora PASCARIU


    Full Text Available Article examines whether all contracts of public persons are administrative contracts; in other words, if the administration may conclude contracts that, according to their legal nature, are not administrative. If we start from the definition of administrative contracts as it appears in Law no. 554/2004, these include contracts by public authorities which concern the enhancement of public property execution of works of public interest, public services, public procurement and other administrative contracts provided by special laws and subject to the jurisdiction of the administrative courts.

  5. Perspective: Stimulated Raman adiabatic passage: The status after 25 years (United States)

    Bergmann, Klaas; Vitanov, Nikolay V.; Shore, Bruce W.


    The first presentation of the STIRAP (stimulated Raman adiabatic passage) technique with proper theoretical foundation and convincing experimental data appeared 25 years ago, in the May 1st, 1990 issue of The Journal of Chemical Physics. By now, the STIRAP concept has been successfully applied in many different fields of physics, chemistry, and beyond. In this article, we comment briefly on the initial motivation of the work, namely, the study of reaction dynamics of vibrationally excited small molecules, and how this initial idea led to the documented success. We proceed by providing a brief discussion of the physics of STIRAP and how the method was developed over the years, before discussing a few examples from the amazingly wide range of applications which STIRAP now enjoys, with the aim to stimulate further use of the concept. Finally, we mention some promising future directions.

  6. Properties of a two stage adiabatic demagnetization refrigerator (United States)

    Fukuda, H.; Ueda, S.; Arai, R.; Li, J.; Saito, A. T.; Nakagome, H.; Numazawa, T.


    Currently, many space missions using cryogenic temperatures are being planned. In particular, high resolution sensors such as Transition Edge Sensors need very low temperatures, below 100 mK. It is well known that the adiabatic demagnetization refrigerator (ADR) is one of most useful tools for producing ultra-low temperatures in space because it is gravity independent. We studied a continuous ADR system consisting of 4 stages and demonstrated it could provide continuous temperatures around 100 mK. However, there was some heat leakage from the power leads which resulted in reduced cooling power. Our efforts to upgrade our ADR system are presented. We show the effect of using the HTS power leads and discuss a cascaded Carnot cycle consisting of 2 ADR units.

  7. Adiabatic ground state preparation in an expanding lattice (United States)

    Gazit, Snir; Olund, Chris; Yao, Norman


    We numerically investigate the newly proposed s-source framework for constructing ground state wave functions of gapped Hamiltonians. The key idea is to utilize the adiabatic principle to build a tensor network representation that smoothly interpolates between the ground state of system sizes L and 2L via an interleaved set of ancillary degrees of freedom. Repeatedly applying this procedure reproduces the thermodynamic limit. The scheme should be contrasted with conventional tensor network methods that rely on the variational principle to target the ground state by iteratively improving a variational energy. We introduce a simple yet flexible tensor network structure and an optimization protocol borrowing techniques from quantum control theory. We anticipate that this approach can, in principle, allow access to problems beyond current tensor network technology and even serve as an experimental scheme for ground state preparation in quantum engineered systems.

  8. Optical waveguide device with an adiabatically-varying width

    Energy Technology Data Exchange (ETDEWEB)

    Watts,; Michael R. (Albuquerque, NM), Nielson; Gregory, N [Albuquerque, NM


    Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a width that varies adiabatically between a minimum value and a maximum value of the width. One or more connecting members can be attached to the waveguide bend near the maximum value of the width thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the width. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.

  9. Quasi-adiabatic compression heating of selected foods (United States)

    Landfeld, Ales; Strohalm, Jan; Halama, Radek; Houska, Milan


    The quasi-adiabatic temperature increase due to compression heating, during high-pressure (HP) processing (HPP), was studied using specially designed equipment. The temperature increase was evaluated as the difference in temperature, during compression, between atmospheric pressure and nominal pressure. The temperature was measured using a thermocouple in the center of a polyoxymethylene cup, which contained the sample. Fresh meat balls, pork meat pate, and tomato purée temperature increases were measured at three initial temperature levels between 40 and 80 °C. Nominal pressure was either 400 or 500 MPa. Results showed that the fat content had a positive effect on temperature increases. Empirical equations were developed to calculate the temperature increase during HPP at different initial temperatures for pressures of 400 and 500 MPa. This thermal effect data can be used for numerical modeling of temperature histories of foods during HP-assisted pasteurization or sterilization processes.

  10. Towards generic adiabatic elimination for bipartite open quantum systems (United States)

    Azouit, R.; Chittaro, F.; Sarlette, A.; Rouchon, P.


    We consider a composite open quantum system consisting of a fast subsystem coupled to a slow one. Using the time scale separation, we develop an adiabatic elimination technique to derive at any order the reduced model describing the slow subsystem. The method, based on an asymptotic expansion and geometric singular perturbation theory, ensures the physical interpretation of the reduced second-order model by giving the reduced dynamics in a Lindblad form and the state reduction in Kraus map form. We give explicit second-order formulas for Hamiltonian or cascade coupling between the two subsystems. These formulas can be used to engineer, via a careful choice of the fast subsystem, the Hamiltonian and Lindbald operators governing the dissipative dynamics of the slow subsystem.

  11. Electron Correlation from the Adiabatic Connection for Multireference Wave Functions (United States)

    Pernal, Katarzyna


    An adiabatic connection (AC) formula for the electron correlation energy is derived for a broad class of multireference wave functions. The AC expression recovers dynamic correlation energy and assures a balanced treatment of the correlation energy. Coupling the AC formalism with the extended random phase approximation allows one to find the correlation energy only from reference one- and two-electron reduced density matrices. If the generalized valence bond perfect pairing model is employed a simple closed-form expression for the approximate AC formula is obtained. This results in the overall M5 scaling of the computation cost making the method one of the most efficient multireference approaches accounting for dynamic electron correlation also for the strongly correlated systems.

  12. Adiabatic pumping solutions in global AdS (United States)

    Carracedo, Pablo; Mas, Javier; Musso, Daniele; Serantes, Alexandre


    We construct a family of very simple stationary solutions to gravity coupled to a massless scalar field in global AdS. They involve a constantly rising source for the scalar field at the boundary and thereby we name them pumping solutions. We construct them numerically in D = 4. They are regular and, generically, have negative mass. We perform a study of linear and nonlinear stability and find both stable and unstable branches. In the latter case, solutions belonging to different sub-branches can either decay to black holes or to limiting cycles. This observation motivates the search for non-stationary exactly timeperiodic solutions which we actually construct. We clarify the role of pumping solutions in the context of quasistatic adiabatic quenches. In D = 3 the pumping solutions can be related to other previously known solutions, like magnetic or translationally-breaking backgrounds. From this we derive an analytic expression.

  13. Assignment of Side-Chain Conformation Using Adiabatic Energy Mapping, Free Energy Perturbation, and Molecular Dynamic Simulations

    DEFF Research Database (Denmark)

    Frimurer, Thomas M.; Günther, Peter H.; Sørensen, Morten Dahl


    adiabatic mapping, conformational change, essentialdynamics, free energy simulations, Kunitz type inhibitor *ga3(VI)......adiabatic mapping, conformational change, essentialdynamics, free energy simulations, Kunitz type inhibitor *ga3(VI)...

  14. Adiabatic perturbation theory for atoms and molecules in the low-frequency regime (United States)

    Martiskainen, Hanna; Moiseyev, Nimrod


    There is an increasing interest in the photoinduced dynamics in the low frequency, ω, regime. The multiphoton absorptions by molecules in strong laser fields depend on the polarization of the laser and on the molecular structure. The unique properties of the interaction of atoms and molecules with lasers in the low-frequency regime imply new concepts and directions in strong-field light-matter interactions. Here we represent a perturbational approach for the calculations of the quasi-energy spectrum in the low-frequency regime, which avoids the construction of the Floquet operator with extremely large number of Floquet channels. The zero-order Hamiltonian in our perturbational approach is the adiabatic Hamiltonian where the atoms/molecules are exposed to a dc electric field rather than to ac-field. This is in the spirit of the first step in the Corkum three-step model. The second-order perturbation correction terms are obtained when i ℏ ω ∂/∂ τ serves as a perturbation and τ is a dimensionless variable. The second-order adiabatic perturbation scheme is found to be an excellent approach for calculating the ac-field Floquet solutions in our test case studies of a simple one-dimensional time-periodic model Hamiltonian. It is straightforward to implement the perturbation approach presented here for calculating atomic and molecular energy shifts (positions) due to the interaction with low-frequency ac-fields using high-level electronic structure methods. This is enabled since standard quantum chemistry packages allow the calculations of atomic and molecular energy shifts due to the interaction with dc-fields. In addition to the shift of the energy positions, the energy widths (inverse lifetimes) can be obtained at the same level of theory. These energy shifts are functions of the laser parameters (low frequency, intensity, and polarization).

  15. Contingency Contracting Customer Guide (United States)


    deployed contracting officer to train individual customers on the process, the customer support guide provides the necessary explanations without...straining valuable manpower resources. The Contracting Deployment Customer Guide aids the customer in contingency situations and addresses purchase requests

  16. Contractibility of curves

    Directory of Open Access Journals (Sweden)

    Janusz Charatonik


    Full Text Available Results concerning contractibility of curves (equivalently: of dendroids are collected and discussed in the paper. Interrelations tetween various conditions which are either sufficient or necessary for a curve to be contractible are studied.

  17. Adiabatic-connection fluctuation-dissipation DFT for the structural properties of solids - The renormalized ALDA and electron gas kernels

    DEFF Research Database (Denmark)

    Patrick, Christopher E.; Thygesen, Kristian Sommer


    We present calculations of the correlation energies of crystalline solids and isolated systems within the adiabatic-connection fluctuation-dissipation formulation of density-functional theory. We perform a quantitative comparison of a set of model exchange-correlation kernels originally derived...... the kernels to inhomogeneous systems through a reciprocal-space averaging procedure, we calculate the lattice constants and bulk moduli of a test set of 10 solids consisting of tetrahedrally bonded semiconductors (C, Si, SiC), ionic compounds (MgO, LiCl, LiF), and metals (Al, Na, Cu, Pd). We also consider...

  18. Energy-Efficient and Secure S-Box circuit using Symmetric Pass Gate Adiabatic Logic

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Dinesh [University of Kentucky, Lexington; Thapliyal, Himanshu [ORNL; Mohammad, Azhar [University of Kentucky, Lexington; Singh, Vijay [University of Kentucky, Lexington; Perumalla, Kalyan S [ORNL


    Differential Power Analysis (DPA) attack is considered to be a main threat while designing cryptographic processors. In cryptographic algorithms like DES and AES, S-Box is used to indeterminate the relationship between the keys and the cipher texts. However, S-box is prone to DPA attack due to its high power consumption. In this paper, we are implementing an energy-efficient 8-bit S-Box circuit using our proposed Symmetric Pass Gate Adiabatic Logic (SPGAL). SPGAL is energy-efficient as compared to the existing DPAresistant adiabatic and non-adiabatic logic families. SPGAL is energy-efficient due to reduction of non-adiabatic loss during the evaluate phase of the outputs. Further, the S-Box circuit implemented using SPGAL is resistant to DPA attacks. The results are verified through SPICE simulations in 180nm technology. SPICE simulations show that the SPGAL based S-Box circuit saves upto 92% and 67% of energy as compared to the conventional CMOS and Secured Quasi-Adiabatic Logic (SQAL) based S-Box circuit. From the simulation results, it is evident that the SPGAL based circuits are energy-efficient as compared to the existing DPAresistant adiabatic and non-adiabatic logic families. In nutshell, SPGAL based gates can be used to build secure hardware for lowpower portable electronic devices and Internet-of-Things (IoT) based electronic devices.

  19. Contracting for Public Services

    DEFF Research Database (Denmark)

    Greve, Carsten

    strategic purchasing understanding markets communicating the contracting decision designing and drafting the contract the role of the consumer the regulation of service provision Illustrated throughout with practitioner case-studies from a range of OECD countries, this book presents an important new...... theoretical ‘contract management model' and a ‘mature contract model', and explores the mechanisms, formal rules and informal norms that influence the way governments contract for public services. This book is essential reading for all students of public management and all public service managers....

  20. On the adiabatic representation of Meyer-Miller electronic-nuclear dynamics. (United States)

    Cotton, Stephen J; Liang, Ruibin; Miller, William H


    The Meyer-Miller (MM) classical vibronic (electronic + nuclear) Hamiltonian for electronically non-adiabatic dynamics-as used, for example, with the recently developed symmetrical quasiclassical (SQC) windowing model-can be written in either a diabatic or an adiabatic representation of the electronic degrees of freedom, the two being a canonical transformation of each other, thus giving the same dynamics. Although most recent applications of this SQC/MM approach have been carried out in the diabatic representation-because most of the benchmark model problems that have exact quantum results available for comparison are typically defined in a diabatic representation-it will typically be much more convenient to work in the adiabatic representation, e.g., when using Born-Oppenheimer potential energy surfaces (PESs) and derivative couplings that come from electronic structure calculations. The canonical equations of motion (EOMs) (i.e., Hamilton's equations) that come from the adiabatic MM Hamiltonian, however, in addition to the common first-derivative couplings, also involve second-derivative non-adiabatic coupling terms (as does the quantum Schrödinger equation), and the latter are considerably more difficult to calculate. This paper thus revisits the adiabatic version of the MM Hamiltonian and describes a modification of the classical adiabatic EOMs that are entirely equivalent to Hamilton's equations but that do not involve the second-derivative couplings. The second-derivative coupling terms have not been neglected; they simply do not appear in these modified adiabatic EOMs. This means that SQC/MM calculations can be carried out in the adiabatic representation, without approximation, needing only the PESs and the first-derivative coupling elements. The results of example SQC/MM calculations are presented, which illustrate this point, and also the fact that simply neglecting the second-derivative couplings in Hamilton's equations (and presumably also in the Schr

  1. Contracts in distributed systems

    Directory of Open Access Journals (Sweden)

    Massimo Bartoletti


    Full Text Available We present a parametric calculus for contract-based computing in distributed systems. By abstracting from the actual contract language, our calculus generalises both the contracts-as-processes and contracts-as-formulae paradigms. The calculus features primitives for advertising contracts, for reaching agreements, and for querying the fulfilment of contracts. Coordination among principals happens via multi-party sessions, which are created once agreements are reached. We present two instances of our calculus, by modelling contracts as (i processes in a variant of CCS, and (ii as formulae in a logic. With the help of a few examples, we discuss the primitives of our calculus, as well as some possible variants.

  2. Adiabatic regularization and particle creation for spin one-half fields (United States)

    Landete, Aitor; Navarro-Salas, José; Torrentí, Francisco


    The extension of the adiabatic regularization method to spin-1/2 fields requires a self-consistent adiabatic expansion of the field modes. We provide here the details of such expansion, which differs from the WKB ansatz that works well for scalars, to firmly establish the generalization of the adiabatic renormalization scheme to spin-1/2 fields. We focus on the computation of particle production in de Sitter spacetime and obtain an analytic expression of the renormalized stress-energy tensor for Dirac fermions.

  3. Adiabatic pumping current in a graphene based normal-insulator-superconductor junction with Corbino disk structure

    Directory of Open Access Journals (Sweden)

    Elham Moomivand


    Full Text Available We investigate adiabatic pumping current in a graphene based normal-insulator-superconductor (NIS junction with Corbino disk structure. The adiabatic pumping current is generated by two electrostatic potentials, oscillating periodically and out of phase, applied to the insulating and superconducting regions. Using the extended Brouwer’s formula for the adiabatic pumping current, which is based on the scattering theory, the pumping current is obtained. The results of this calculation show the pumped current oscillates as a function of the barrier strength and it has maximums at resonances with a π/2 phase shift in comparison to the planar NIS junction.

  4. Conical Intersections Between Vibrationally Adiabatic Surfaces in Methanol (United States)

    Dawadi, Mahesh B.; Perry, David S.


    The discovery of a set of seven conical intersections (CI's) between vibrationally adiabatic surfaces in methanol is reported. The intersecting surfaces represent the energies of the two asymmetric CH stretch vibrations, νb{2} and νb{9}, regarded as adiabatic functions of the torsional angle, γ, and COH bend angle, ρ. One conical intersection, required by symmetry, is located at the C3v geometry where the COH group is linear (ρ = 0°); the other six are in eclipsed conformations with ρ = 62° and 94°. The three CI's at ρ = 62° are close to the equilibrium geometry (ρ = 71.4°), within the zero-point amplitude of the COH bending vibration. CI's between electronic surfaces have long been recognized as crucial conduits for ultrafast relaxation, and recently Hamm, and Stock have shown that vibrational CI's may also provide a mechanism for ultrafast vibrational relaxation. The ab initio data reported here are well described by an extended Zwanziger and Grant model for E ⊗ e Jahn-Teller systems in which Renner-Teller coupling is also active. However, in the present case, the distortion ρ from C3v symmetry is much larger than is typical in the Jahn-Teller coupling of electronic surfaces and accordingly higher-order terms in ρ are required. The present results are also consistent with the two-state model of Xu et al. The cusp-like features, which they found along the internal-rotation path, are explained in the context of the present work in terms of proximity to the CI's. The presence of multiple CI's near the torsional minimum energy path impacts the role of geometric phase in this three-fold internal-rotor system. When the dimensionality of the low-frequency space is extended to include the CO bond length as well as γ and ρ, the individual CI's become seams of CI's. It is shown that the CI's at ρ = 62° and 94° lie along the same seam of CI's in this higher dimensional space. P. Hamm and G. Stock, Phys. Rev. Lett., 109, 173201, (2012) P. Hamm, and G

  5. Expansionary fiscal contractions

    DEFF Research Database (Denmark)

    Bergman, Ulf Michael; Hutchison, Michael


    The Expansionary Fiscal Contraction (EFC) hypothesis predicts that a major fiscal consolidation leads to an economic expansion under certain circumstances. We test this hypothesis, and the implied non-linear responses of the economy to large and small changes in fiscal policy, using data from...... the 1983 Danish fiscal reform. We use a structural VAR/event study methodology following Blanchard and Perotti (2002) that explicitly allows us to distinguish between normally marginal changes in fiscal policy and comprehensive fiscal reforms. We find that 'marginal changes' in fiscal policy (expenditure...... and tax changes) have the expected Keynesian effects on output and consumption. However, we find no evidence that the large fiscal consolidation in Denmark slowed the economy after controlling for a host of exogenous shocks and business cycle effects. Rather, we find some support for the hypothesis...

  6. Nonequilibrium adiabatic molecular dynamics simulations of methane clathrate hydrate decomposition. (United States)

    Alavi, Saman; Ripmeester, J A


    Nonequilibrium, constant energy, constant volume (NVE) molecular dynamics simulations are used to study the decomposition of methane clathrate hydrate in contact with water. Under adiabatic conditions, the rate of methane clathrate decomposition is affected by heat and mass transfer arising from the breakup of the clathrate hydrate framework and release of the methane gas at the solid-liquid interface and diffusion of methane through water. We observe that temperature gradients are established between the clathrate and solution phases as a result of the endothermic clathrate decomposition process and this factor must be considered when modeling the decomposition process. Additionally we observe that clathrate decomposition does not occur gradually with breakup of individual cages, but rather in a concerted fashion with rows of structure I cages parallel to the interface decomposing simultaneously. Due to the concerted breakup of layers of the hydrate, large amounts of methane gas are released near the surface which can form bubbles that will greatly affect the rate of mass transfer near the surface of the clathrate phase. The effects of these phenomena on the rate of methane hydrate decomposition are determined and implications on hydrate dissociation in natural methane hydrate reservoirs are discussed.

  7. Resource efficient gadgets for compiling adiabatic quantum optimization problems (United States)

    Babbush, Ryan; O'Gorman, Bryan; Aspuru-Guzik, Alán


    We develop a resource efficient method by which the ground-state of an arbitrary k-local, optimization Hamiltonian can be encoded as the ground-state of a (k-1)-local optimization Hamiltonian. This result is important because adiabatic quantum algorithms are often most easily formulated using many-body interactions but experimentally available interactions are generally 2-body. In this context, the efficiency of a reduction gadget is measured by the number of ancilla qubits required as well as the amount of control precision needed to implement the resulting Hamiltonian. First, we optimize methods of applying these gadgets to obtain 2-local Hamiltonians using the least possible number of ancilla qubits. Next, we show a novel reduction gadget which minimizes control precision and a heuristic which uses this gadget to compile 3-local problems with a significant reduction in control precision. Finally, we present numerics which indicate a substantial decrease in the resources required to implement randomly generated, 3-body optimization Hamiltonians when compared to other methods in the literature.

  8. Thermodynamics analysis of refinery sludge gasification in adiabatic updraft gasifier. (United States)

    Ahmed, Reem; Sinnathambi, Chandra M; Eldmerdash, Usama; Subbarao, Duvvuri


    Limited information is available about the thermodynamic evaluation for biomass gasification process using updraft gasifier. Therefore, to minimize errors, the gasification of dry refinery sludge (DRS) is carried out in adiabatic system at atmospheric pressure under ambient air conditions. The objectives of this paper are to investigate the physical and chemical energy and exergy of product gas at different equivalent ratios (ER). It will also be used to determine whether the cold gas, exergy, and energy efficiencies of gases may be maximized by using secondary air injected to gasification zone under various ratios (0, 0.5, 1, and 1.5) at optimum ER of 0.195. From the results obtained, it is indicated that the chemical energy and exergy of producer gas are magnified by 5 and 10 times higher than their corresponding physical values, respectively. The cold gas, energy, and exergy efficiencies of DRS gasification are in the ranges of 22.9-55.5%, 43.7-72.4%, and 42.5-50.4%, respectively. Initially, all 3 efficiencies increase until they reach a maximum at the optimum ER of 0.195; thereafter, they decline with further increase in ER values. The injection of secondary air to gasification zone is also found to increase the cold gas, energy, and exergy efficiencies. A ratio of secondary air to primary air of 0.5 is found to be the optimum ratio for all 3 efficiencies to reach the maximum values.

  9. Hot-electron nanoscopy using adiabatic compression of surface plasmons

    KAUST Repository

    Giugni, Andrea


    Surface plasmon polaritons are a central concept in nanoplasmonics and have been exploited to develop ultrasensitive chemical detection platforms, as well as imaging and spectroscopic techniques at the nanoscale. Surface plasmons can decay to form highly energetic (or hot) electrons in a process that is usually thought to be parasitic for applications, because it limits the lifetime and propagation length of surface plasmons and therefore has an adverse influence on the functionality of nanoplasmonic devices. Recently, however, it has been shown that hot electrons produced by surface plasmon decay can be harnessed to produce useful work in photodetection, catalysis and solar energy conversion. Nevertheless, the surface-plasmon-to-hot-electron conversion efficiency has been below 1% in all cases. Here we show that adiabatic focusing of surface plasmons on a Schottky diode-terminated tapered tip of nanoscale dimensions allows for a plasmon-to-hot-electron conversion efficiency of ∼30%. We further demonstrate that, with such high efficiency, hot electrons can be used for a new nanoscopy technique based on an atomic force microscopy set-up. We show that this hot-electron nanoscopy preserves the chemical sensitivity of the scanned surface and has a spatial resolution below 50 nm, with margins for improvement.

  10. Adiabatically deformed ensemble: Engineering nonthermal states of matter (United States)

    Kennes, D. M.


    We propose a route towards engineering nonthermal states of matter, which show largely unexplored physics. The main idea relies on the adiabatic passage of a thermal ensemble under slow variations of the system Hamiltonian. If the temperature of the initial thermal ensemble is either zero or infinite, the ensemble after the passage is a simple thermal one with the same vanishing or infinite temperature. However, for any finite nonzero temperature, intriguing nonthermal ensembles can be achieved. We exemplify this in (a) a single oscillator, (b) a dimerized interacting one-dimensional chain of spinless fermions, (c) a BCS-type superconductor, and (d) the topological Kitaev chain. We solve these models with a combination of methods: either exactly, numerically using the density matrix renormalization group, or within an approximate functional renormalization group scheme. The designed states show strongly nonthermal behavior in each of the considered models. For example, for the chain of spinless fermions we exemplify how long-ranged nonthermal power-law correlations can be stabilized, and for the Kitaev chain we elucidate how the nonthermal ensemble can largely alter the transition temperature separating topological and trivial phases.

  11. Adiabatic interpretation of particle creation in a de Sitter universe

    Energy Technology Data Exchange (ETDEWEB)

    Molina-Paris, C.


    The choice of vacuum state for a quantum scalar field propagating in a de Sitter spacetime (massive and arbitrarily coupled to the gravitational field) is discussed. The problem of finite-time initial conditions for the mode functions is analyzed, as well as how these determine the vacuum state of the quantum system. The principle guiding the choice of vacuum state is the following: one wants the vacuum contribution to the energy-momentum tensor to contain all the ultraviolet divergent terms, so that the particle creation terms are finite, and covariantly conserved. There is a suitable set of modes (instantaneous adiabatic basis) in which this splitting of the expectation value of the energy-momentum tensor can be carried out. Numerical results are presented for different finite-time initial conditions (m = 0.6, {zeta} = 1/6). The nature of the particle creation effect is described and its relationship to the concept of a horizon crossing time is shown. These numerical results imply that back-reaction can be important and should be the subject of further research.

  12. On the construction of diabatic and adiabatic potential energy surfaces based on ab initio valence bond theory. (United States)

    Song, Lingchun; Gao, Jiali


    A theoretical model is presented for deriving effective diabatic states based on ab initio valence bond self-consistent field (VBSCF) theory by reducing the multiconfigurational VB Hamiltonian into an effective two-state model. We describe two computational approaches for the optimization of the effective diabatic configurations, resulting in two ways of interpreting such effective diabatic states. In the variational diabatic configuration (VDC) method, the energies of the diabatic states are variationally minimized. In the consistent diabatic configuration (CDC) method, both the configuration coefficients and orbital coefficients are simultaneously optimized to minimize the adiabatic ground-state energy in VBSCF calculations. In addition, we describe a mixed molecular orbital and valence bond (MOVB) approach to construct the CDC diabatic and adiabatic states for a chemical reaction. Note that the VDC-MOVB method has been described previously. Employing the symmetric S(N)2 reaction between NH(3) and CH(3)NH(3)(+) as a test system, we found that the results from ab initio VBSCF and from ab initio MOVB calculations using the same basis set are in good agreement, suggesting that the computationally efficient MOVB method is a reasonable model for VB simulations of condensed phase reactions. The results indicate that CDC and VDC diabatic states converge, respectively, to covalent and ionic states as the molecular geometries are distorted from the minimum of the respective diabatic state along the reaction coordinate. Furthermore, the resonance energy that stabilizes the energy of crossing between the two diabatic states, resulting in the transition state of the adiabatic ground-state reaction, has a strong dependence on the overlap integral between the two diabatic states and is a function of both the exchange integral and the total diabatic ground-state energy.

  13. A counterexample and a modification to the adiabatic approximation theorem in quantum mechanics (United States)

    Gingold, H.


    A counterexample to the adiabatic approximation theorem is given when degeneracies are present. A formulation of an alternative version is proposed. A complete asymptotic decomposition for n dimensional self-adjoint Hamiltonian systems is restated and used.

  14. Amplitudes of solar-like oscillations in red giants: Departures from the quasi-adiabatic approximation

    Directory of Open Access Journals (Sweden)

    Barban C.


    Full Text Available CoRoT and Kepler measurements reveal us that the amplitudes of solar-like oscillations detected in red giant stars scale from stars to stars in a characteristic way. This observed scaling relation is not yet fully understood but constitutes potentially a powerful diagnostic about mode physics. Quasi-adiabatic theoretical scaling relations in terms of mode amplitudes result in systematic and large differences with the measurements performed for red giant stars. The use of a non-adiabatic intensity-velocity relation derived from a non-adiabatic pulsation code significantly reduces the discrepancy with the CoRoT measurements. The origin of the remaining difference is still unknown. Departure from adiabatic eigenfunction is a very likely explanation that is investigated in the present work using a 3D hydrodynamical model of the surface layers of a representative red giant star.

  15. New staff contract policy

    CERN Multimedia

    HR Department


    Following discussion at TREF and on the recommendation of the Finance Committee, Council approved a new staff contract policy, which became effective on 1 January 2006. Its application is covered by a new Administrative Circular No. 2 (Rev. 3) 'Recruitment, appointment and possible developments regarding the contractual position of staff members'. The revised circular replaces the previous Circulars No. 9 (Rev. 3) 'Staff contracts' and No. 2 (Rev. 2) 'Guidelines and procedures concerning recruitment and probation period for staff members'. The main features of the new contract policy are as follows: The new policy provides chances for long-term employment for all staff recruits staying for four years without distinguishing between those assigned to long-term or short-term activities when joining CERN. In addition, it presents a number of simplifications for the award of ICs. There are henceforth only 2 types of contract: Limited Duration (LD) contracts for all recruitment and Indefinite Contracts (IC) for...

  16. Adiabatic Low-Pass J Filters for Artifact Suppression in Heteronuclear NMR

    DEFF Research Database (Denmark)

    Meier, Sebastian; Benie, Andrew J; Duus, Jens Øllgaard


    NMR artifact purging: Modern NMR experiments depend on efficient coherence transfer pathways for their sensitivity and on suppression of undesired pathways leading to artifacts for their spectral clarity. A novel robust adiabatic element suppresses hard-to-get-at artifacts.......NMR artifact purging: Modern NMR experiments depend on efficient coherence transfer pathways for their sensitivity and on suppression of undesired pathways leading to artifacts for their spectral clarity. A novel robust adiabatic element suppresses hard-to-get-at artifacts....

  17. Contracting in crisis intervention. (United States)

    Nelson, Z P; Mowry, D D


    The use of contracts in the social services is an important area that needs to be looked at. This paper is concerned specifically with the use of contracts in one particular part of social services: crisis intervention. Contracts that define the working relationship between the client and mental health counselor can be beneficial for both when they attempt to solve the problems that contributed to the crisis situation. There are five benefits to be gained from the use of contracts in crisis intervention and they are briefly discussed.

  18. Smart contracts sobre Bitcoin


    Andreu Alemany, Josep Miquel


    El present treball final de màster realitza una introducció als smart contracts. El treball introdueix el concepte de contracte intel·ligent, els seus usos i alguns exemples existents. Seguidament proporciona les nocions necessàries de les transaccions del protocol Bitcoin per poder implementar un contracte intel·ligent, usant la blockchain que ofereix el protocol. Per últim, s'explica la implementació d'un contracte intel·ligent usant bitcoin: un canal de micropagaments. El presente traba...

  19. On the response of quasi-adiabatic particles to magnetotail reconfigurations (United States)

    Delcourt, Dominique C.; Malova, Helmi V.; Zelenyi, Lev M.


    We investigate the response of quasi-adiabatic particles to dynamical reconfigurations of the magnetotail field lines. Although they travel through a sharp field reversal with a characteristic length scale smaller than their Larmor radii, these quasi-adiabatic particles experience a negligible net change in magnetic moment. We examine the robustness of such a quasi-adiabatic behavior in the presence of a large surging electric field induced by magnetic field line reconfiguration as observed during the expansion phase of substorms. We demonstrate that, although such a short-lived electric field can lead to substantial nonadiabatic heating, quasi-adiabaticity is conserved for particles with velocities larger than the peak ExB drift speed. Because of the time-varying character of the magnetic field, it is not possible to use the adiabaticity parameter κ in a straightforward manner to characterize the particle behavior. We rather consider a κ parameter that is averaged over equatorial crossings. We demonstrate that particles intercepting the field reversal in the early stage of the magnetic transition may experience significant energization and enhanced oscillating motion in the direction normal to the midplane. In contrast, particles interacting with the field reversal in the late stage of the magnetic transition experience weaker energization and slower oscillations about the midplane. We show that quasi-adiabatic particles accelerated during such events can lead to energy-time dispersion signatures at low altitudes as is observed in the plasma sheet boundary layer.

  20. On the response of quasi-adiabatic particles to magnetotail reconfigurations

    Directory of Open Access Journals (Sweden)

    D. C. Delcourt


    Full Text Available We investigate the response of quasi-adiabatic particles to dynamical reconfigurations of the magnetotail field lines. Although they travel through a sharp field reversal with a characteristic length scale smaller than their Larmor radii, these quasi-adiabatic particles experience a negligible net change in magnetic moment. We examine the robustness of such a quasi-adiabatic behavior in the presence of a large surging electric field induced by magnetic field line reconfiguration as observed during the expansion phase of substorms. We demonstrate that, although such a short-lived electric field can lead to substantial nonadiabatic heating, quasi-adiabaticity is conserved for particles with velocities larger than the peak ExB drift speed. Because of the time-varying character of the magnetic field, it is not possible to use the adiabaticity parameter κ in a straightforward manner to characterize the particle behavior. We rather consider a κ parameter that is averaged over equatorial crossings. We demonstrate that particles intercepting the field reversal in the early stage of the magnetic transition may experience significant energization and enhanced oscillating motion in the direction normal to the midplane. In contrast, particles interacting with the field reversal in the late stage of the magnetic transition experience weaker energization and slower oscillations about the midplane. We show that quasi-adiabatic particles accelerated during such events can lead to energy–time dispersion signatures at low altitudes as is observed in the plasma sheet boundary layer.

  1. Perpendicular Diffusion Coefficient of Comic Rays: The Presence of Weak Adiabatic Focusing (United States)

    Wang, J. F.; Qin, G.; Ma, Q. M.; Song, T.; Yuan, S. B.


    The influence of adiabatic focusing on particle diffusion is an important topic in astrophysics and plasma physics. In the past, several authors have explored the influence of along-field adiabatic focusing on the parallel diffusion of charged energetic particles. In this paper, using the unified nonlinear transport theory developed by Shalchi and the method of He and Schlickeiser, we derive a new nonlinear perpendicular diffusion coefficient for a non-uniform background magnetic field. This formula demonstrates that the particle perpendicular diffusion coefficient is modified by along-field adiabatic focusing. For isotropic pitch-angle scattering and the weak adiabatic focusing limit, the derived perpendicular diffusion coefficient is independent of the sign of adiabatic focusing characteristic length. For the two-component model, we simplify the perpendicular diffusion coefficient up to the second order of the power series of the adiabatic focusing characteristic quantity. We find that the first-order modifying factor is equal to zero and that the sign of the second order is determined by the energy of the particles.

  2. Perpendicular Diffusion Coefficient of Comic Rays: The Presence of Weak Adiabatic Focusing

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J. F.; Ma, Q. M.; Song, T.; Yuan, S. B. [Research Department of Biomedical Engineering, Institute of Electrical Engineering, Chinese Academy of Science, Beijing 100190 (China); Qin, G., E-mail:, E-mail: [School of Science, Harbin Institute of Technology, Shenzhen 518055 (China)


    The influence of adiabatic focusing on particle diffusion is an important topic in astrophysics and plasma physics. In the past, several authors have explored the influence of along-field adiabatic focusing on the parallel diffusion of charged energetic particles. In this paper, using the unified nonlinear transport theory developed by Shalchi and the method of He and Schlickeiser, we derive a new nonlinear perpendicular diffusion coefficient for a non-uniform background magnetic field. This formula demonstrates that the particle perpendicular diffusion coefficient is modified by along-field adiabatic focusing. For isotropic pitch-angle scattering and the weak adiabatic focusing limit, the derived perpendicular diffusion coefficient is independent of the sign of adiabatic focusing characteristic length. For the two-component model, we simplify the perpendicular diffusion coefficient up to the second order of the power series of the adiabatic focusing characteristic quantity. We find that the first-order modifying factor is equal to zero and that the sign of the second order is determined by the energy of the particles.

  3. Proposal for the award of a contract, without competitive tendering, for the manufacture and testing of 360 000 field strip cathodes for the drift tube chambers of the CMS muon detector

    CERN Document Server


    The Finance Committee is invited to authorize CERN to negotiate on behalf of the Participating Institutes of the CMS Collaboration a contract, without competitive tendering, with the JOINT INSTITUTE FOR NUCLEAR RESEARCH (JINR), Dubna, Russia, for the manufacture and testing of 360 000 field strip cathodes for the drift tube chambers of the CMS Muon Detector, for a total amount of 140 000 US dollars, not subject to revision. At the present rate of exchange, this amount is equivalent to approximately 210 000 Swiss francs.

  4. Medicare program; prospective payment system for federally qualified health centers; changes to contracting policies for rural health clinics; and changes to Clinical Laboratory Improvement Amendments of 1988 enforcement actions for proficiency testing referral. Final rule with comment period. (United States)


    This final rule with comment period implements methodology and payment rates for a prospective payment system (PPS) for federally qualified health center (FQHC) services under Medicare Part B beginning on October 1, 2014, in compliance with the statutory requirement of the Affordable Care Act. In addition, it establishes a policy which allows rural health clinics (RHCs) to contract with nonphysician practitioners when statutory requirements for employment of nurse practitioners and physician assistants are met, and makes other technical and conforming changes to the RHC and FQHC regulations. Finally, this final rule with comment period implements changes to the Clinical Laboratory Improvement Amendments (CLIA) regulations regarding enforcement actions for proficiency testing (PT) referrals.

  5. Removal of radon by aeration testing of various aeration techniques for small water works. For European Commission under Contract No FI4PCT960054 TENAWA project

    CERN Document Server

    Salonen, L; Mehtonen, J; Mjoenes, L; Raff, O; Turunen, H


    Capability of various aeration techniques to remove radon from water in small waterworks was studied as a part of project (Treatment Techniques for Removing Natural Radionuclides from Drinking Water), which was carried out during 1997-1999 on a cost-shared basis (contract No. F14PCT960054) with The European Commission (CEC) under the supervision of the Directorate-General XII Radiation Protection Research Unit. In TENAWA project both laboratory and field experiments were performed in order to find reliable methods and equipment for removing natural radionuclides from ground water originating either from private wells or small waterworks. Because such techniques are more often needed in private households than at waterworks, the main emphasis of the research was aimed to solve the water treatment problems related to the private water supplies, especially bedrock wells. Radon was the most important radionuclide to be removed from water at waterworks whereas the removal of other radionuclides ( sup 2 sup 3 sup 4...

  6. General background conditions for K-bounce and adiabaticity

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Antonio Enea [University of Crete, Department of Physics, Heraklion (Greece); Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); Universidad de Antioquia, Instituto de Fisica, A.A.1226, Medellin (Colombia)


    We study the background conditions for a bounce uniquely driven by a single scalar field model with a generalized kinetic term K(X), without any additional matter field. At the background level we impose the existence of two turning points where the derivative of the Hubble parameter H changes sign and of a bounce point where the Hubble parameter vanishes. We find the conditions for K(X) and the potential which ensure the above requirements. We then give the examples of two models constructed according to these conditions. One is based on a quadratic K(X), and the other on a K(X) which is avoiding divergences of the second time derivative of the scalar field, which may otherwise occur. An appropriate choice of the initial conditions can lead to a sequence of consecutive bounces, or oscillations of H. In the region where these models have a constant potential they are adiabatic on any scale and because of this they may not conserve curvature perturbations on super-horizon scales. While at the perturbation level one class of models is free from ghosts and singularities of the classical equations of motion, in general gradient instabilities are present around the bounce time, because the sign of the squared speed of sound is opposite to the sign of the time derivative of H. We discuss how this kind of instabilities could be avoided by modifying the Lagrangian by introducing Galilean terms in order to prevent a negative squared speed of sound around the bounce. (orig.)

  7. Adiabat_1ph 3.0 and the MAGMA website: educational and research tools for studying the petrology and geochemistry of plate margins (United States)

    Antoshechkina, P. M.; Asimow, P. D.


    Adiabat_1ph is a menu-driven front-end to the MELTS, pMELTS and pHMELTS models of thermodynamic equilibrium in silicate systems. Its public release in late 2004 was described in a software brief in G3 (doi:10.1029/2004GC000816). The software package is available for Windows, MacOS X, and Linux and includes Perl scripts that, if desired, will allow almost complete automation of the calculation process. Adiabat_1ph 3.0 is scheduled for release in October 2010 and includes, for the first time, an option to double-click the run_adiabat.command script and to drag and drop file names from a browser (e.g. Explorer on Windows, Finder on Mac). This alternative mode of operation is particularly suited for teaching at undergraduate and graduate levels, as well as for quick, ad hoc, calculations for research purposes. The original method of invoking the program from the command line is retained for more intensive applications. Version 3.0 is the first to specifically target the Windows 7 and Snow Leopard platforms. The release also includes new features that are relevant to the study of plate margins. The Marianas Trough forms the southern part of the Izu-Bonin-Marianas (IBM) arc system, one of the chosen areas of focus for the MARGINS Subduction Factory initiative. Attempts to model the complicated hydrous fractionation trends observed in this region were the motivation for adding modified versions of the ‘reverse-fractionation’ and ‘amoeba’ routines (see doi:10.1016/S0012-821X(04)00058-5) into adiabat_1ph. The ‘amoeba’ scheme, which varies a trial parental melt composition until forward fractionation yields a specified target composition, has been extended so the best-fit liquid line of descent of a group of samples can be found. We have tested the adiabat_1ph versions using glass compositions from the 9N area of the East Pacific Rise and melt inclusions from the Siqueiros Fracture Zone (see Antoshechkina et al., this meeting). One of the first user requested

  8. Contracting out local services

    DEFF Research Database (Denmark)

    Petersen, Ole Helby; Houlberg, Kurt; Ring Christensen, Lasse


    Governments face a fundamental choice between in-house production and contracting out for the delivery of services to citizens. This article examines the importance of ideology, fiscal pressure, and size for contracting out in technical and social services. The analysis builds on a panel data set...... that the size effect is contingent on the transaction cost characteristics of the service....

  9. Gas contracts in transition

    Energy Technology Data Exchange (ETDEWEB)

    Wright, A.J. [Delhi Gas Pipeline Corp., Dallas, TX (United States)


    The transition of gas marketing by producers from a regulated and structured market to an open competitive and commodity market has created new challenges for attorneys drafting gas sales contracts. This article examines the following related topics: Interruptible contracts; pricing provisions; transport imbalances.

  10. BOT Outsourcing Contracts

    DEFF Research Database (Denmark)

    Ørberg Jensen, Peter D.; Petersen, Bent


    -firm linkages) and develop three scenarios for the implications for vendor firms. We find that BOT contracts, under certain circumstances, may imply benefits of process and knowledge upgrading for the emerging market vendor firm. However, given different sets of circumstances, engaging in a BOT contract carries...

  11. Partnering and contracting

    DEFF Research Database (Denmark)

    Bohnstedt, Kristian Ditlev


    Purpose - Partnering is often, by economists, and construction managerial literature related to more incomplete contracts. This can be explained by seeing partnering as something that neutralizes opportunism. The aim is to uncover whether partnering neutralizes opportunism when there is an incomp......Purpose - Partnering is often, by economists, and construction managerial literature related to more incomplete contracts. This can be explained by seeing partnering as something that neutralizes opportunism. The aim is to uncover whether partnering neutralizes opportunism when...... there is an incomplete contract or reduces transaction costs for renegotiation of complete contracts when new information arises. Design - The study is a cross-sectional design comprising document analysis and interviews. Findings - Firstly that partnering does not necessarily entail more incomplete contracts, which...... contradicts the incomplete contracting theory. Secondly, in complete contract setting partnering can be motivated when seen as a willingness to renegotiate complete contracts i.e. partnering lowers transaction costs for renegotiation. Partnering can make it rational for one party to accept disadvantageous...

  12. Contracting for Telecommunications Systems. (United States)

    Brautigam, Arthur W.


    Reasons for changing telephone systems at colleges and universities and the preparation and evaluation of requests for proposals (RFP) are discussed. The negotiation and monitoring of the contract are also addressed. It is noted that contracting for a new telecommunications system is extremely complex. Reasons for changing systems include cost…

  13. Contracting Productivity Growth

    NARCIS (Netherlands)

    Francois, P.; Roberts, J.


    In this paper, we analyze the interactions between growth and the contracting environment in the production sector.Allowing incompleteness in contracting implies that viable production relationships for firms and workers, and therefore the profitability of industries, depend on the rates of

  14. Contract Teachers in India (United States)

    Goyal, Sangeeta; Pandey, Priyanka


    In this paper, we use non-experimental data from government schools in Uttar Pradesh and Madhya Pradesh, two of the largest Indian states, to present average school outcomes by contract status of teachers. We find that contract teachers are associated with higher effort than civil service teachers with permanent tenures, before as well as after…

  15. Contract Training for Industry. (United States)

    Averill, Donald F.


    Describes contract training whereby industries arrange with community colleges, technical institutes, and vocational schools to prepare employees for specific job assignments. Indicates that industrial training performed under contract with public institutions should be encouraged in favor of expansion of training that industry performs for…

  16. Development of an adiabatic calorimeter in the range 54K-273K in frame of a scientific collaboration LNE-NIS (United States)

    Ahmed, M. G.; Hermier, Y.


    The National Institute for Standards (NIS), in cooperation with the French National Metrology Institute (LNE-CNAM), has recently developed a new adiabatic calorimeter, to realize the International Temperature Scale of 1990 (ITS-90) in the temperature range between 54 K and 273 K using Capsule Standard Platinum Resistance Thermometers (CSPRTs). The work has been realized through an international scientific-cooperation project "IMHOTEP" between the two sides. The new calorimeter comprises a cylindrical double-wall vacuum-tight stainless steel Dewar that withstands evacuation on the liquid nitrogen to reach a temperature close to the oxygen triple point. The thermal shield accommodates a multi-compartment cell containing the oxygen and argon triple-points cells. The temperature control for best adiabatic conditions is achieved through PID software, running under LABVIEW environment. Two calorimeters have been constructed. The first one was installed at LNE-CNAM and tested for optimum adiabatic conditions. The system was then transferred to NIS. The second calorimeter was tested and stayed at LNE-CNAM. Experiments, at NIS, showed the possibility of reaching a temperature close to the oxygen triple point. Uncertainties for CSPRTs calibrations were 0.27 and 0.25 mK for triple points of oxygen and argon respectively.

  17. Contribution to contract theory

    Directory of Open Access Journals (Sweden)

    Pantelić Svetlana


    Full Text Available Oliver Hart and Bengt Holmstrom share the Nobel Prize in Economic Sciences for 2016, awarded to them by Sveriges Riksbank. They have been rewarded for their work in enhancing the design of contracts, i.e. arrangements connecting employers with employees or companies with clients, in other words, for their contribution to contract theory in the 1970s and 1980s. Their analysis of optimal contractual arrangements lays an intellectual foundation for designing policies and institutions in many areas, from bankruptcy legislation to political constitutions. Hart is an expert in contract theory, theory of the firm, corporate finance, and law and economics. His contribution to contract theory is exquisite when it comes to designing contracts which cover eventualities that cannot be precisely specified in advance.

  18. Bunker purchasing with contracts

    DEFF Research Database (Denmark)

    Plum, Christian Edinger Munk; Neergaard Jensen, Peter; Pisinger, David


    constraints such as capacity limits, reserve requirements and sulphur content. Contracts are often used for bunker purchasing, ensuring supply and often giving a discounted price. A contract can supply any vessel in a period and port, and is thus a shared resource between vessels, which must be distributed...... optimally to reduce overall costs. The Bunker Purchasing with Contracts Problem has been formulated as a mixed integer programme, which has been Dantzig-Wolfe decomposed. To solve it, a novel column generation algorithm has been developed. The algorithm has been run on a series of real-world instances...... with up to 500+ vessels and 500+ contracts, and provide near optimal solutions. This makes it possible for a major liner shipping company to plan bunker purchasing on a global level, and provides an efficient tool for assessing new contracts....


    Directory of Open Access Journals (Sweden)

    Blanca Giorgiana GRAMA


    Full Text Available The psychological contract became known as a research paradigm within corporate research, providing a broad framework which explains the employee-company relations. Despite all this, there are still many debates on the concept and a series of criticism were expressed that led to the necessity of some more rigorous theoretical and empirical analysis. The psychological contract refers to the unwritten, implicit expectations that employees have from the company and vice versa; it is that which defines the things the employee expects from the employer. Consequently, each of the parties involved in the contract may have different perceptions on these commitments and obligations. Thus the psychological contract may be regarded as an exchange relation between the employer and the employee. Breaking the psychological contract affects the performance, the morale, and the motivation of the staff in a negative manner. The information presented in this paper is intended to contribute to the theoretical and methodological development of the concept.

  20. Comparing contracting performance: Culture, competition, contracts, capabilities and collaboration in UK and Scandinavia

    DEFF Research Database (Denmark)

    Lindholst, Andrej Christian

    One key question for the last three decades of public management reforms is whether country differences between radical and modest reform approaches make a difference for performance in a reformed public sector. This paper compares differences in the implementation and performance of contracting...... out, i.e. private delivery of public services, between the United Kingdom and Scandinavia. The reform approach in the United Kingdom are argued to have generated a ‘deep’ contracting culture embedding stronger contracting institutions than the more ‘shallow’ contracting cultures in Scandinavia....... Hypotheses are suggested for the role of culture, competition, contracts, capabilities and collaboration for contracting performance between and across the countries. Arguments are tested against data from on four comparable national surveys of private delivery of park and road maintenance services in local...

  1. Flow regimes of adiabatic gas-liquid two-phase under rolling conditions (United States)

    Yan, Chaoxing; Yan, Changqi; Sun, Licheng; Xing, Dianchuan; Wang, Yang; Tian, Daogui


    Characteristics of adiabatic air/water two-phase flow regimes under vertical and rolling motion conditions were investigated experimentally. Test sections are two rectangular ducts with the gaps of 1.41 and 10 mm, respectively, and a circular tube with 25 mm diameter. Flow regimes were recorded by a high speed CCD-camera and were identified by examining the video images. The experimental results indicate that the characteristics of flow patterns in 10 mm wide rectangular duct under vertical condition are very similar to those in circular tube, but different from the 1.41 mm wide rectangular duct. Channel size has a significant influence on flow pattern transition, boundary of which in rectangular channels tends asymptotically towards that in the circular tube with increasing the width of narrow side. Flow patterns in rolling channels are similar to each other, nevertheless, the effect of rolling motion on flow pattern transition are significantly various. Due to the remarkable influences of the friction shear stress and surface tension in the narrow gap duct, detailed flow pattern maps of which under vertical and rolling conditions are indistinguishable. While for the circular tube with 25 mm diameter, the transition from bubbly to slug flow occurs at a higher superficial liquid velocity and the churn flow covers more area on the flow regime map as the rolling period decreases.

  2. Asymmetric adiabatic couplers for fully-integrated broadband quantum-polarization state preparation. (United States)

    Chung, Hung-Pin; Huang, Kuang-Hsu; Wang, Kai; Yang, Sung-Lin; Yang, Shih-Yuan; Sung, Chun-I; Solntsev, Alexander S; Sukhorukov, Andrey A; Neshev, Dragomir N; Chen, Yen-Hung


    Spontaneous parametric down-conversion (SPDC) is a widely used method to generate entangled photons, enabling a range of applications from secure communication to tests of quantum physics. Integrating SPDC on a chip provides interferometric stability, allows to reduce a physical footprint, and opens a pathway to true scalability. However, dealing with different photon polarizations and wavelengths on a chip presents a number of challenging problems. In this work, we demonstrate an on-chip polarization beam-splitter based on z-cut titanium-diffused lithium niobate asymmetric adiabatic couplers (AAC) designed for integration with a type-II SPDC source. Our experimental measurements reveal unique polarization beam-splitting regime with the ability to tune the splitting ratios based on wavelength. In particular, we measured a splitting ratio of 17 dB over broadband regions (>60 nm) for both H- and V-polarized lights and a specific 50%/50% splitting ratio for a cross-polarized photon pair from the AAC. The results show that such a system can be used for preparing different quantum polarization-path states that are controllable by changing the phase-matching conditions in the SPDC over a broad band. Furthermore, we propose a fully integrated electro-optically tunable type-II SPDC polarization-path-entangled state preparation circuit on a single lithium niobate photonic chip.

  3. Coherent state mapping ring polymer molecular dynamics for non-adiabatic quantum propagations (United States)

    Chowdhury, Sutirtha N.; Huo, Pengfei


    We introduce the coherent-state mapping ring polymer molecular dynamics (CS-RPMD), a new method that accurately describes electronic non-adiabatic dynamics with explicit nuclear quantization. This new approach is derived by using coherent-state mapping representation for the electronic degrees of freedom (DOF) and the ring-polymer path-integral representation for the nuclear DOF. The CS-RPMD Hamiltonian does not contain any inter-bead coupling term in the state-dependent potential and correctly describes electronic Rabi oscillations. A classical equation of motion is used to sample initial configurations and propagate the trajectories from the CS-RPMD Hamiltonian. At the time equivalent to zero, the quantum Boltzmann distribution (QBD) is recovered by reweighting the sampled distribution with an additional phase factor. In a special limit that there is one bead for mapping variables and multiple beads for nuclei, CS-RPMD satisfies detailed balance and preserves an approximate QBD. Numerical tests of this method with a two-state model system show very good agreement with exact quantum results over a broad range of electronic couplings.

  4. Three-dimensional stochastic modeling of radiation belts in adiabatic invariant coordinates (United States)

    Zheng, Liheng; Chan, Anthony A.; Albert, Jay M.; Elkington, Scot R.; Koller, Josef; Horne, Richard B.; Glauert, Sarah A.; Meredith, Nigel P.


    A 3-D model for solving the radiation belt diffusion equation in adiabatic invariant coordinates has been developed and tested. The model, named Radbelt Electron Model, obtains a probabilistic solution by solving a set of Itô stochastic differential equations that are mathematically equivalent to the diffusion equation. This method is capable of solving diffusion equations with a full 3-D diffusion tensor, including the radial-local cross diffusion components. The correct form of the boundary condition at equatorial pitch angle α0=90° is also derived. The model is applied to a simulation of the October 2002 storm event. At α0 near 90°, our results are quantitatively consistent with GPS observations of phase space density (PSD) increases, suggesting dominance of radial diffusion; at smaller α0, the observed PSD increases are overestimated by the model, possibly due to the α0-independent radial diffusion coefficients, or to insufficient electron loss in the model, or both. Statistical analysis of the stochastic processes provides further insights into the diffusion processes, showing distinctive electron source distributions with and without local acceleration.

  5. Coherent reverberation model based on adiabatic normal mode theory in a range dependent shallow water environment (United States)

    Li, Zhenglin; Zhang, Renhe; Li, Fenghua


    Ocean reverberation in shallow water is often the predominant background interference in active sonar applications. It is still an open problem in underwater acoustics. In recent years, an oscillation phenomenon of the reverberation intensity, due to the interference of the normal modes, has been observed in many experiments. A coherent reverberation theory has been developed and used to explain this oscillation phenomenon [F. Li et al., Journal of Sound and Vibration, 252(3), 457-468, 2002]. However, the published coherent reverberation theory is for the range independent environment. Following the derivations by F. Li and Ellis [D. D. Ellis, J. Acoust. Soc. Am., 97(5), 2804-2814, 1995], a general reverberation model based on the adiabatic normal mode theory in a range dependent shallow water environment is presented. From this theory the coherent or incoherent reverberation field caused by sediment inhomogeneity and surface roughness can be predicted. Observations of reverberation from the 2001 Asian Sea International Acoustic Experiment (ASIAEX) in the East China Sea are used to test the model. Model/data comparison shows that the coherent reverberation model can predict the experimental oscillation phenomenon of reverberation intensity and the vertical correlation of reverberation very well.

  6. Choreographies and Behavioural Contracts on the Way to Dynamic Updates

    Directory of Open Access Journals (Sweden)

    Mario Bravetti


    Full Text Available We survey our work on choreographies and behavioural contracts in multiparty interactions. In particular theories of behavioural contracts are presented which enable reasoning about correct service composition (contract compliance and service substitutability (contract refinement preorder under different assumptions concerning service communication: synchronous address or name based communication with patient non-preemptable or impatient invocations, or asynchronous communication. Correspondingly relations between behavioural contracts and choreographic descriptions are considered, where a contract for each communicating party is, e.g., derived by projection. The considered relations are induced as the maximal preoders which preserve contract compliance and global traces: we show maximality to hold (permitting services to be discovered/substituted independently for each party when contract refinement preorders with all the above asymmetric communication means are considered and, instead, not to hold if the standard symmetric CCS/pi-calculus communication is considered (or when directly relating choreographies to behavioral contracts via a preorder, no matter the communication mean. The obtained maximal preorders are then characterized in terms of a new form of testing, called compliance testing, where not only tests must succeed but also the system under test (thus relating to controllability theory, and compared with classical preorders such as may/must testing, trace inclusion, etc. Finally, recent work about adaptable choreographies and behavioural contracts is presented, where the theory above is extended to update mechanisms allowing choreographies/contracts to be modified at run-time by internal (self-adaptation or external intervention.

  7. Capsule contraction syndrome

    Directory of Open Access Journals (Sweden)

    Mesut COŞKUN


    Full Text Available Capsule contraction syndrome occurs after fibrous metaplasia of lens proteins that leads to capsular bag contraction. Excessive front capsular wrinkling is seen in capsule contraction syndrome and there is an imbalance between powers supplying capsular integrity. This situation leads to zonular weakness. Capsule contraction syndrome is associated with pseudoexfoliation, older age, uveitis, pars planitis and myotonic muscular dystrophy. In order to decrease the risk of capsule contraction syndrome, front capsulerhexis area should be open as 5.5-6 mm diameter and a curysoft intraocular lens should be used. In order to prevent lens epithelial proliferation and metaplasia, lens epithelial cells at inferior surface of front capsule should be aspirated carefully. If postoperative capsular contraction detected, front capsulotomy should be performed by Nd-YAG laser at postoperative 2 to 3 weeks. In patients that Nd-YAG laser is unsuccessful, capsular tension should be decreased by surgical microincisions. In present study, we evaluated etiology, prevention and management of capsule contraction syndrome in the light of actual literature knowledge.


    Directory of Open Access Journals (Sweden)

    Alisa A. BELU


    Full Text Available A chattel mortgage contract is the expression of a real guarantee that gives the creditor precedence over other creditors, in addition to the general pledge upon the belongings of the debtor. It refers to the sale of mortgaged movable assets, exclusively or prioritized in favor of the mortgaging creditor, in case the debtor does not comply with his / her commitments, under the signed mortgage contract. Beginning from this purpose, shared by both sides (as the chattel mortgage contract is synallagmatic, in case the debtor is unable to fulfill his / her commitments, the sides reach a situation of enforcement of the signed chattel mortgage contract. Given the legal status of the chattel mortgage contract [Art. 2387-2477 Noul Cod Civil , Universul Juridic, Bucureşti, 2016, ISBN 978-606-673-792-0], the principle of binding force of the contract and the principle according to which signed legal conventions will entail legal effects, the Romanian law maker developed the proper legal framework for the enforcement of the chattel mortgage contract. [art. 622 si urm. Noul Cod de Procedură Civilă, ed. Hamangiu, Bucureşti, 2016, ISBN 978-606-27-0459-9].

  9. Challenging Adiabatic Time-dependent Density Functional Theory with a Hubbard Dimer: The Case of Time-Resolved Long-Range Charge Transfer

    CERN Document Server

    Fuks, Johanna I


    We explore an asymmetric two-fermion Hubbard dimer to test the accuracy of the adiabatic approximation of time-dependent density functional theory in modelling time-resolved charge transfer. We show that the model shares essential features of a ground state long-range molecule in real-space, and by applying a resonant field we show that the model also reproduces essential traits of the CT dynamics. The simplicity of the model allows us to propagate with an "adiabatically-exact" approximation, i.e. one that uses the exact ground-state exchange-correlation functional, and compare with the exact propagation. This allows us to study the impact of the time-dependent charge-transfer step feature in the exact correlation potential of real molecules on the resulting dynamics. Tuning the parameters of the dimer allows a study both of charge-transfer between open-shell fragments and between closed-shell fragments. We find that the adiabatically-exact functional is unable to properly transfer charge, even in situations ...

  10. Efficient shortcuts to adiabatic passage for three-dimensional entanglement generation via transitionless quantum driving. (United States)

    He, Shuang; Su, Shi-Lei; Wang, Dong-Yang; Sun, Wen-Mei; Bai, Cheng-Hua; Zhu, Ai-Dong; Wang, Hong-Fu; Zhang, Shou


    We propose an effective scheme of shortcuts to adiabaticity for generating a three-dimensional entanglement of two atoms trapped in a cavity using the transitionless quantum driving (TQD) approach. The key point of this approach is to construct an effective Hamiltonian that drives the dynamics of a system along instantaneous eigenstates of a reference Hamiltonian to reproduce the same final state as that of an adiabatic process within a much shorter time. In this paper, the shortcuts to adiabatic passage are constructed by introducing two auxiliary excited levels in each atom and applying extra cavity modes and classical fields to drive the relevant transitions. Thereby, the three-dimensional entanglement is obtained with a faster rate than that in the adiabatic passage. Moreover, the influences of atomic spontaneous emission and photon loss on the fidelity are discussed by numerical simulation. The results show that the speed of entanglement implementation is greatly improved by the use of adiabatic shortcuts and that this entanglement implementation is robust against decoherence. This will be beneficial to the preparation of high-dimensional entanglement in experiment and provides the necessary conditions for the application of high-dimensional entangled states in quantum information processing.

  11. Selective excitation in a three-state system using a hybrid adiabatic-nonadiabatic interaction

    CERN Document Server

    Song, Yunheung; Jo, Hanlae; Ahn, Jaewook


    The chirped-pulse interaction in the adiabatic coupling regime induces cyclic permutations of the energy states of a three-level system in the $V$-type configuration, which process is known as the three-level chirped rapid adiabatic passage. Here we show that a spectral hole in a chirped pulse can turn on and off one of the two adiabatic crossing points of this process, reducing the system to an effective two-level system. The given hybrid adiabatic-nonadiabatic transition results in selective excitation of the three-level system, controlled by the laser intensity and spectral position of the hole as well as the sign of the chirp parameter. Experiments are performed with shaped femtosecond laser pulses and the three lowest energy-levels (5S$_{1/2}$, 5P$_{1/2}$, and 5P$_{3/2}$) of atomic rubidium ($^{85}$Rb), of which the result shows good agreement with the theoretically analyzed dynamics. The result indicates that our method, being combined with the ordinary chirped-RAP, implements an adiabatic transitions b...

  12. Predicting the effect of relaxation during frequency-selective adiabatic pulses. (United States)

    Pfaff, Annalise R; McKee, Cailyn E; Woelk, Klaus


    Adiabatic half and full passages are invaluable for achieving uniform, B1-insensitive excitation or inversion of macroscopic magnetization across a well-defined range of NMR frequencies. To accomplish narrow frequency ranges with adiabatic pulses (<100Hz), long pulse durations at low RF power levels are necessary, and relaxation during these pulses may no longer be negligible. A numerical, discrete recursive combination of the Bloch equations for longitudinal and transverse relaxation with the optimized equation for adiabatic angular motion of magnetization is used to calculate the trajectory of magnetization including its relaxation during adiabatic hyperbolic secant pulses. The agreement of computer-calculated data with experimental results demonstrates that, in non-viscous, small-molecule fluids, it is possible to model magnetization and relaxation by considering standard T1 and T2 relaxation in the traditional rotating frame. The proposed model is aimed at performance optimizations of applications in which these pulses are employed. It differs from previous reports which focused on short high-power adiabatic pulses and relaxation that is governed by dipole-dipole interactions, cross polarization, or chemical exchange. Copyright © 2017. Published by Elsevier Inc.

  13. Temporary labour contracts

    CERN Document Server


    The five contracts for Temporary Labour assignments on the CERN site (L020/PE, L021/PE, L022/PE, L023/PE and L024/PE) approved by the Finance Committee in March 1996 (CERN/FC/3857) will reach the end of their initial three-year contractual period at the end of December 1999. Following the satisfactory execution of these contracts during this period, CERN requests approval to extend them from January 2000 for the first of the two years foreseen in the original adjudication. The Finance Committee is invited: - to take note that the three-year expenditure for Temporary Labour contracts from 1997 to 1999 will not exceed 19 100 000 Swiss francs, compared to the 18 900 000 Swiss francs estimated at the time of the adjudication in March 1996; - to approve an extension of the present Temporary Labour contracts for the year 2000 for a total amount not exceeding 6 000 000 Swiss francs.

  14. Premature Ventricular Contractions (PVCs) (United States)

    ... Premature ventricular contractions (PVCs) Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  15. Superfund Contract Laboratory Program (United States)

    The Contract Laboratory Program (CLP) is a national network of EPA personnel, commercial laboratories, and support contractors whose primary mission is to provide data of known and documented quality to the Superfund program.

  16. Contracting the Facebook API

    Directory of Open Access Journals (Sweden)

    Ben Rubinger


    Full Text Available In recent years, there has been an explosive growth in the popularity of online social networks such as Facebook. In a new twist, third party developers are now able to create their own web applications which plug into Facebook and work with Facebook's "social" data, enabling the entire Facebook user base of more than 400 million active users to use such applications. These client applications can contain subtle errors that can be hard to debug if they misuse the Facebook API. In this paper we present an experience report on applying Microsoft's new code contract system for the .NET framework to the Facebook API.We wrote contracts for several classes in the Facebook API wrapper which allows Microsoft .NET developers to implement Facebook applications. We evaluated the usefulness of these contracts during implementation of a new Facebook application. Our experience indicates that having code contracts provides a better and quicker software development experience.

  17. Contractor for geopressured-geothermal sites: Final contract report, Volume 1, fiscal years 1986--1990 (5 years), testing of wells through October 1990

    Energy Technology Data Exchange (ETDEWEB)


    Field tests and studies were conducted to determine the production behavior of geopressured-geothermal reservoirs and their potential as future energy sources. Results are presented for Gladys McCall Site, Pleasant Bayou Site, and Hulin Site.

  18. An unsatisfactory contract policy

    CERN Multimedia

    Association du personnel


    For the last 15 years contract policy has been one of the top priorities of CERN staff, as expressed in successive surveys initiated by the Staff Association. In one’s professional life, having some forward vision of one’s career prospects is the key to loyalty and motivation. On the contrary, instability about the future is always at the root of anxiety, conflicts, or even health problems. A good employer must therefore balance the needs of the Company and those of its employees. CERN’s current contract policy, as described in the Administrative Circular No 2, states that staff members should first obtain a limited duration (LD) contract of up to five years. Then, if they want to stay in the Organization, staff members must apply, usually once a year, and before the end of their LD contract, for an indefinite contract (IC) post. All candidates for an IC post are considered by the Review Board for the award of indefinite contracts (Review Board) which will choose the most suita...

  19. Twist angle determination in liquid crystal displays by location of local adiabatic points (United States)

    Moreno, Ignacio; Bennis, Noureddine; Davis, Jeffrey A.; Ferreira, Carlos


    In this work we present a method for the determination of the twist angle of an arbitrary twisted nematic liquid crystal spatial light modulator. The method is based on the location of local adiabatic points, i.e., situations in which the liquid crystal SLM acts only as a rotation device. For these cases, the rotation induced on the polarization of the incident beam is equal to the twist angle. Consequently, the twist angle can be determined with high precision. We show that local adiabatic regime may be achieved in two ways, either by changing the incident beam wavelength, or by applying a voltage to the electrodes of the display. However, the simple model that describes the SLM in the off-state, may break down when a voltage is applied to the display, and it may affect the local adiabatic behaviour. We present theoretical and experimental results.

  20. Rabi oscillations produced by adiabatic pulse due to initial atomic coherence. (United States)

    Svidzinsky, Anatoly A; Eleuch, Hichem; Scully, Marlan O


    If an electromagnetic pulse is detuned from atomic transition frequency by amount Δ>1/τ, where τ is the turn-on time of the pulse, then atomic population adiabatically follows the pulse intensity without causing Rabi oscillations. Here we show that, if initially, the atom has nonzero coherence, then the adiabatic pulse yields Rabi oscillations of atomic population ρaa(t), and we obtain analytical solutions for ρaa(t). Our findings can be useful for achieving generation of coherent light in the backward direction in the QASER scheme in which modulation of the coupling between light and atoms is produced by Rabi oscillations. Initial coherence can be created by sending a short resonant pulse into the medium followed by a long adiabatic pulse, which leads to the light amplification in the backward direction.

  1. Optimal control of the power adiabatic stroke of an optomechanical heat engine. (United States)

    Bathaee, M; Bahrampour, A R


    We consider the power adiabatic stroke of the Otto optomechanical heat engine introduced in Phys. Rev. Lett. 112, 150602 (2014)PRLTAO0031-900710.1103/PhysRevLett.112.150602. We derive the maximum extractable work of both optomechanical normal modes in the minimum time while the system experiences quantum friction effects. We show that the total work done by the system in the power adiabatic stroke is optimized by a bang-bang control. The time duration of the power adiabatic stroke is of the order of the inverse of the effective optomechanical-coupling coefficient. The optimal phase-space trajectory of the Otto cycle for both optomechanical normal modes is also obtained.

  2. Analysis of adiabatic trapping for quasi-integrable area-preserving maps

    CERN Document Server

    Bazzani, A; Giovannozzi, M; Hernalsteens, C


    Trapping phenomena involving non-linear resonances have been considered in the past in the framework of adiabatic theory. Several results are known for continuous-time dynamical systems generated by Hamiltonian flows in which the combined effect of non-linear resonances and slow time-variation of some system parameters is considered. The focus of this paper is on discrete-time dynamical systems generated by two-dimensional symplectic maps. The possibility of extending the results of neo-adiabatic theory to quasi-integrable area-preserving maps is discussed. Scaling laws are derived, which describe the adiabatic transport as a function of the system parameters using a probabilistic point of view. These laws can be particularly relevant for physical applications. The outcome of extensive numerical simulations showing the excellent agreement with the analytical estimates and scaling laws is presented and discussed in detail.

  3. Bifurcation-based adiabatic quantum computation with a nonlinear oscillator network. (United States)

    Goto, Hayato


    The dynamics of nonlinear systems qualitatively change depending on their parameters, which is called bifurcation. A quantum-mechanical nonlinear oscillator can yield a quantum superposition of two oscillation states, known as a Schrödinger cat state, via quantum adiabatic evolution through its bifurcation point. Here we propose a quantum computer comprising such quantum nonlinear oscillators, instead of quantum bits, to solve hard combinatorial optimization problems. The nonlinear oscillator network finds optimal solutions via quantum adiabatic evolution, where nonlinear terms are increased slowly, in contrast to conventional adiabatic quantum computation or quantum annealing, where quantum fluctuation terms are decreased slowly. As a result of numerical simulations, it is concluded that quantum superposition and quantum fluctuation work effectively to find optimal solutions. It is also notable that the present computer is analogous to neural computers, which are also networks of nonlinear components. Thus, the present scheme will open new possibilities for quantum computation, nonlinear science, and artificial intelligence.

  4. Protecting and accelerating adiabatic passage with time-delayed pulse sequences

    CERN Document Server

    Sampedro, Pablo; Sola, Ignacio R


    Using numerical simulations of two-photon electronic absorption with femtosecond pulses in Na$_2$ we show that: i) it is possible to avoid the characteristic saturation or dumped Rabi oscillations in the yield of absorption by time-delaying the laser pulses; ii) it is possible to accelerate the onset of adiabatic passage by using the vibrational coherence starting in a wave packet; and iii) it is possible to prepare the initial wave packet in order to achieve full state-selective transitions with broadband pulses. The findings can be used, for instance, to achieve ultrafast adiabatic passage by light-induced potentials and understand its intrinsic robustness.

  5. Adiabatic response and quantum thermoelectrics for ac-driven quantum systems (United States)

    Ludovico, María Florencia; Battista, Francesca; von Oppen, Felix; Arrachea, Liliana


    We generalize the theory of thermoelectrics to include coherent electron systems under adiabatic ac driving, accounting for quantum pumping of charge and heat, as well as for the work exchanged between the electron system and driving potentials. We derive the relevant response coefficients in the adiabatic regime and show that they obey generalized Onsager reciprocity relations. We analyze the consequences of our generalized thermoelectric framework for quantum motors, generators, heat engines, and heat pumps, characterizing them in terms of efficiencies and figures of merit. We illustrate these concepts in a model for a quantum pump.

  6. Spectroscopy of the Rotating Kaluza-Klein Spacetime via Revisited Adiabatic Invariant Quantity (United States)

    Yu, Li; Qi, De-Jiang


    In this paper, we have investigated the spectroscopy of the rotating Kaluza-Klein spacetime by applying Bohr-Sommerfeld quantization rule and the first law of thermodynamics. we derived the expression of the adiabatic invariant quantity in the dragged-Painlevé coordinate system. Then, via revisited adiabatic invariant quantity, we derive the area and entropy spectra of the spacetime. We obtained the area spectrum of the Kaluza-Klein spacetime is {Δ } A=8π {lP2}, and the entropy spectrum is Δ S = 2 π. This result is consistent with the Bekenstein's original result, which imply the entropy and horizon area are discrete and equidistant for the spacetime.

  7. Hydrodynamic instabilities at ablation front: numerical investigation on stabilization by adiabat shaping

    Energy Technology Data Exchange (ETDEWEB)

    Olazabal-Loume, M.; Hallo, L. [Bordeaux-1 Univ., CELIA UMR 5107, 33 - Talence (France)


    This study deals with the hydrodynamic stability of a planar target in the context of inertial confinement fusion direct drive. Recently, different schemes have been proposed in order to reduce ablative Rayleigh-Taylor growth. They are based on the target adiabatic shaping in the ablation zone. In this work, we consider an adiabatic shaping scheme by relaxation: a prepulse is followed by a relaxation period where the laser is turned off. A numerical study is performed with a perturbation code dedicated to the linear stability analysis. The simulations show stabilizing effects of the relaxation scheme on the linear Rayleigh-Taylor growth rate. Influence of the picket parameters is also discussed. (authors)

  8. Magnetic Skyrmion Transport in a Nanotrack With Spatially Varying Damping and Non-adiabatic Torque


    Zhang, Xichao; Xia, Jing; Zhao, G. P.; Liu, Xiaoxi; Zhou, Yan


    Reliable transport of magnetic skyrmions is required for any future skyrmion-based information processing devices. Here we present a micromagnetic study of the in-plane current-driven motion of a skyrmion in a ferromagnetic nanotrack with spatially sinusoidally varying Gilbert damping and/or non-adiabatic spin-transfer torque coefficients. It is found that the skyrmion moves in a sinusoidal pattern as a result of the spatially varying Gilbert damping and/or non-adiabatic spin-transfer torque ...

  9. Rapid adiabatic passage in quantum dots: Influence of scattering and dephasing

    DEFF Research Database (Denmark)

    Schuh, K.; Jahnke, F.; Lorke, Michael


    Theoretical investigations for the realization of population inversion of semiconductor quantum dot ground-state transitions by means of adiabatic passage with chirped optical pulses are presented. While the inversion due to Rabi oscillations depends sensitively on the resonance condition......, the pulse area, as well as on the absence of carrier scattering and dephasing, we find that adiabatic passage is surprisingly insensitive to the excitation conditions and carrier scattering effects. Quantum kinetic models for the interaction of quantum-dot carriers with longitudinal optical phonons are used...

  10. Performance Limits of Nanoelectromechanical Switches (NEMS-Based Adiabatic Logic Circuits

    Directory of Open Access Journals (Sweden)

    Samer Houri


    Full Text Available This paper qualitatively explores the performance limits, i.e., energy vs. frequency, of adiabatic logic circuits based on nanoelectromechanical (NEM switches. It is shown that the contact resistance and the electro-mechanical switching behavior of the NEM switches dictate the performance of such circuits. Simplified analytical expressions are derived based on a 1-dimensional reduced order model (ROM of the switch; the results given by this simplified model are compared to classical CMOS-based, and sub-threshold CMOS-based adiabatic logic circuits. NEMS-based circuits and CMOS-based circuits show different optimum operating conditions, depending on the device parameters and circuit operating frequency.

  11. Local T2 measurement employing longitudinal Hadamard encoding and adiabatic inversion pulses in porous media. (United States)

    Vashaee, S; Newling, B; Balcom, B J


    Band selective adiabatic inversion radio frequency pulses were employed for multi-slice T2 distribution measurements in porous media samples. Multi-slice T2 measurement employing longitudinal Hadamard encoding has an inherent sensitivity advantage over slice-by-slice local T2 measurements. The slice selection process is rendered largely immune to B1 variation by employing hyperbolic secant adiabatic inversion pulses, which simultaneously invert spins in several well-defined slices. While Hadamard encoding is well established for local spectroscopy, the current work is the first use of Hadamard encoding for local T2 measurement. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Transient Particle Energies in Shortcuts to Adiabatic Expansions of Harmonic Traps. (United States)

    Cui, Yang-Yang; Chen, Xi; Muga, J G


    The expansion of a harmonic potential that holds a quantum particle may be realized without any final particle excitation but much faster than adiabatically via "shortcuts to adiabaticity" (STA). While ideally the process time can be reduced to zero, practical limitations and constraints impose minimal finite times for the externally controlled time-dependent frequency protocols. We examine the role of different time-averaged energies (total, kinetic, potential, nonadiabatic) and of the instantaneous power in characterizing or selecting different protocols. Specifically, we prove a virial theorem for STA processes, set minimal energies (or times) for given times (or energies), and discuss their realizability by means of Dirac impulses or otherwise.

  13. Localization and adiabatic pumping in a generalized Aubry-André-Harper model (United States)

    Liu, Fangli; Ghosh, Somnath; Chong, Y. D.


    A generalization of the Aubry-André-Harper (AAH) model is developed, containing a tunable phase shift between on-site and off-diagonal modulations. A localization transition can be induced by varying just this phase, keeping all other model parameters constant. The complete localization phase diagram is obtained. Unlike the original AAH model, the generalized model can exhibit a transition between topologically trivial band structures and topologically nontrivial band structures containing protected boundary states. These boundary states can be pumped across the system by adiabatic variations in the phase shift parameter. The model can also be used to demonstrate the phenomenon of adiabatic pumping breakdown due to localization.

  14. Trigonometric protocols for shortcuts to adiabatic transport of cold atoms in anharmonic traps (United States)

    Li, Jing; Zhang, Qi; Chen, Xi


    Shortcuts to adiabaticity have been proposed to speed up the ;slow; adiabatic transport of ultracold atoms. Their realizations, using inverse engineering protocols, provide families of trajectories with appropriate boundary conditions. These trajectories can be optimized with respect to the operation time and the energy input. In this paper we propose trigonometric protocols for fast and robust atomic transport, taking into account cubic or quartic anharmonicities of the trapping potential. Numerical analysis demonstrates that this choice of the trajectory minimizes the final residual energy efficiently, and shows extraordinary robustness against anharmonic parameters. These results might be of interest for the state-of-the-art experiments on ultracold atoms and ions.

  15. High effective neutralizer for negative hydrogen and deuterium ion beams on base of nonresonance adiabatic trap of photons (United States)

    Popov, S. S.; Atluhanov, M. G.; Burdakov, A. V.; Ivanov, A. A.; Kolmogorov, A. V.; Ushkova, M. Yu.


    High efficiency of negative ion beam neutralization by using a photon target is presented in this work. The target was designed and manufactured on principles of nonresonance adiabatic confinement of photons. This photon trap shaped a long arc blended with end spherical mirrors. The arc part consists several cylinder mirrors. Trap sizes was about 30×50×250 mm3. A photon flux from an industrial fiber laser (λ =1070 nm, Δλ=7nm, P=2.1 kW) was injected into trap normally to one cylinder mirror through small entrance hole with angular spread about 3 degree. Test negative ion beams were passed through photon confinement region and suppressing ion current was registered. These experiments has been carried out with H-, D- beams. High neutralization degree more than 95% has been demonstrated.

  16. Multi-turn extraction and injection by means of adiabatic capture in stable islands of phase space

    CERN Document Server

    Cappi, R


    Recently a novel approach has been proposed aimed at performing multi-turn extraction from a circular machine. Such a technique consists of splitting the beam by means of stable islands created in transverse phase space by magnetic elements creating nonlinear fields, such as sextupoles and octupoles. Provided a slow time-variation of the linear tune is applied, adiabatic with respect to the betatron motion, the islands can be moved in phase space and eventually charged particles may be trapped inside the stable structures. This generates a certain number of well-separated beamlets. Originally, this principle was successfully tested using a fourth-order resonance. In this paper the approach is generalised by considering other type of resonances as well as the possibility of performing multiple multi-turn extractions. The results of numerical simulations are presented and described in detail. Of course, by time-reversal, the proposed approach could be used also for multi-turn injection.


    CERN Multimedia

    Human Resources Division


    The Director-General has decided to review staff members in professional categories 2 to 5 satisfying the criteria for consideration for the award of an indefinite contract, in accordance with Article R II 1.20 of the Staff Regulations. Staff members holding a fixed-term contract which it has been decided not to renew will not be considered. The following stages are foreseen: 1. Candidates qualifying for review in accordance with Article R II 1.20 of the Staff Regulations and the Administrative Circular N° 9 will be contacted by Human Resources Division. 2. The criteria as to when staff members qualify for review are described in Administrative Circular N° 9. These include the following: staff members who are in their fourth year of service on a fixed-term contract; in addition, for staff members having three years or more of previous relevant service in the Organization on a contract of limited duration (or term-contract) and upon proposal by the division leader concerned, consideration fo...

  18. Energetics of contraction. (United States)

    Barclay, C J


    Muscles convert energy from ATP into useful work, which can be used to move limbs and to transport ions across membranes. The energy not converted into work appears as heat. At the start of contraction heat is also produced when Ca(2+) binds to troponin-C and to parvalbumin. Muscles use ATP throughout an isometric contraction at a rate that depends on duration of stimulation, muscle type, temperature and muscle length. Between 30% and 40% of the ATP used during isometric contraction fuels the pumping Ca(2+) and Na(+) out of the myoplasm. When shortening, muscles produce less force than in an isometric contraction but use ATP at a higher rate and when lengthening force output is higher than the isometric force but rate of ATP splitting is lower. Efficiency quantifies the fraction of the energy provided by ATP that is converted into external work. Each ATP molecule provides 100 zJ of energy that can potentially be converted into work. The mechanics of the myosin cross-bridge are such that at most 50 zJ of work can be done in one ATP consuming cycle; that is, the maximum efficiency of a cross-bridge is ∼50%. Cross-bridges in tortoise muscle approach this limit, producing over 90% of the possible work per cycle. Other muscles are less efficient but contract more rapidly and produce more power. © 2015 American Physiological Society.


    CERN Multimedia

    Division des ressources humaines


    The Director-General has decided to review staff members in professional categories 2 to 5 satisfying the criteria for consideration for the award of an indefinite contract, in accordance with Article R II 1.20 of the Staff Regulations. Staff members holding a fixed-term contract which it has been decided not to renew will not be considered. The following stages are foreseen:1.\tCandidates qualifying for review in accordance with Article R II 1.20 of the Staff Regulations and the Administrative Circular N° 9 will be contacted by Human Resources Division. 2.\tThe criteria as to when staff members qualify for review are described in Administrative Circular N° 9. These include the following:staff members who are in their fourth year of service on a fixed-term contract;in addition, for staff members having three years or more of previous relevant service in the Organization on a contract of limited duration (or term-contract) and upon proposal by the division leader concerned, consid...

  20. Army Contract Writing System (ACWS) (United States)


    2016 Major Automated Information System Annual Report Army Contract Writing System (ACWS) Defense Acquisition Management Information Retrieval...Program Information Program Name Army Contract Writing System (ACWS) DoD Component Army Responsible Office Program Manager References MAIS...UNCLASSIFIED 4 Program Description The Army Contract Writing System (ACWS) will be the Army’s single, next-generation, enterprise-wide contract writing

  1. Ab initio treatment of the chemical reaction precursor complex Br(2P)-HCN. 1. Adiabatic and diabatic potential surfaces

    NARCIS (Netherlands)

    Fishchuk, A.V.; Merritt, J.M.; Avoird, A. van der


    The three adiabatic potential surfaces of the Br(P-2)-HCN complex that correlate to the P-2 ground state of the Br atom were calculated ab initio. With the aid of a geometry-dependent diabatic mixing angle, also calculated ab initio, these adiabatic potential surfaces were transformed into a set of

  2. Ultrahigh field single-refocused diffusion weighted imaging using a matched-phase adiabatic spin echo (MASE). (United States)

    Dyvorne, Hadrien; O'Halloran, Rafael; Balchandani, Priti


    To improve ultrahigh field diffusion-weighted imaging (DWI) in the presence of inhomogeneous transmit B1 field by designing a novel semi-adiabatic single-refocused DWI technique. A 180° slice-selective, adiabatic radiofrequency (RF) pulse of 4 ms duration was designed using the adiabatic Shinnar-Le Roux algorithm. A matched-phase slice-selective 90° RF pulse of 8 ms duration was designed to compensate the nonlinear phase of the adiabatic 180° RF pulse. The resulting RF pulse combination, matched-phase adiabatic spin echo (MASE), was integrated into a single-shot echo planar DWI sequence. The performance of this sequence was compared with single-refocused Stejskal-Tanner (ST), twice-refocused spin echo (TRSE) and twice-refocused adiabatic spin echo (TRASE) in simulations, phantoms, and healthy volunteers at 7 Tesla (T). In regions with inhomogeneous B1 , MASE resulted in increased signal intensity compared with ST (up to 64%). Moderate increase in specific absorption rate (35-39%) was observed for adiabatic RF pulses. MASE resulted in higher signal homogeneity at 7T, leading to improved visualization of measures derived from diffusion-weighted images such as white matter tractography and track density images. Efficient adiabatic SLR pulses can be adapted to single-refocused DWI, leading to substantially improved signal uniformity when compared with conventional acquisitions. © 2015 Wiley Periodicals, Inc.

  3. Thermodynamic optimisation and computational analysis of irreversibilities in a small-scale wood-fired circulating fluidised bed adiabatic combustor

    CSIR Research Space (South Africa)

    Baloyi, J


    Full Text Available An analysis of irreversibilities generated due to combustion in an adiabatic combustor burning wood was conducted. This was done for a reactant mixture varying from a rich to a lean mixture. A non-adiabatic non-premixed combustion model of a...

  4. Towards 1H-MRSI of the human brain at 7T with slice-selective adiabatic refocusing pulses.

    NARCIS (Netherlands)

    Scheenen, T.W.J.; Heerschap, A.; Klomp, D.W.J.


    OBJECTIVE: To explore the possibilities of proton spectroscopic imaging (1H-MRSI) of the human brain at 7 Tesla with adiabatic refocusing pulses. MATERIALS AND METHODS: A combination of conventional slice selective excitation and two pairs of slice selective adiabatic refocusing pulses (semi-LASER)

  5. Amending Contracts for Choreographies

    Directory of Open Access Journals (Sweden)

    Laura Bocchi


    Full Text Available Distributed interactions can be suitably designed in terms of choreographies. Such abstractions can be thought of as global descriptions of the coordination of several distributed parties. Global assertions define contracts for choreographies by annotating multiparty session types with logical formulae to validate the content of the exchanged messages. The introduction of such constraints is a critical design issue as it may be hard to specify contracts that allow each party to be able to progress without violating the contract. In this paper, we propose three methods that automatically correct inconsistent global assertions. The methods are compared by discussing their applicability and the relationships between the amended global assertions and the original (inconsistent ones.


    CERN Multimedia

    Training & Development Group; Linda Orr-Easo; Tel. 72460; Nathalie Dumeaux; Tel. 78144


    We are pleased to announce the launch of a new training on: Procurement and Contract Management (This seminar will be run by CERN experts in French or in English) Level 1 The aim is to raise awareness of the key issues involved. Date : 8 June 2001 This level is open to everyone. Participants should register via our Web page as soon as possible. Level 2 To develop the skills needed to effectively manage contracts, from the Technical, Commercial and Legal aspects. Dates : Three days, Autumn 2001 This Level is open to those who are/will be more directly responsible for procurement and contract management. Participants should have followed Level 1. For a description of the seminar, please consult:   Level 1: Level 2:

  7. Dry Block Calibrator Using Heat Flux Sensors and an Adiabatic Shield (United States)

    Hohmann, M.; Marin, S.; Schalles, M.; Krapf, G.; Fröhlich, T.


    The main problems of conventional dry block calibrators are axial temperature gradients and calibration results which are strongly influenced by the geometry and the thermal properties of the thermometers under test. To overcome these disadvantages, a new dry block calibrator with improved homogeneity of the inner temperature field was developed for temperatures in the range from room temperature up to . The inner part of the dry block calibrator is a cylindrical normalization block which is divided into three parts in the axial direction. Between these parts, heat flux sensors are placed to measure the heat flux in the axial direction inside the normalization block. Each part is attached to a separate tube-shaped heating zone of which the heating power can be controlled in a way that the axial heat flux measured by means of the heat flux sensors is zero. Additionally, an internal reference thermometer is used to control the absolute value of the temperature inside the normalization block. To minimize the radial heat flux, an adiabatic shield is constructed which is composed of a secondary heating zone that encloses the whole assembly. For rapid changes of the set point from high to low temperatures, the design contains an additional ventilation system to cool the normalization block. The present paper shows the operating principle as well as the results of the design process, in which numerical simulations based on the finite element method were used to evaluate and optimize the design of the dry block calibrator. The final optimized design can be used to build a prototype of the dry block calibrator.

  8. Statutes and contracts

    DEFF Research Database (Denmark)

    Trosborg, Anna


    This paper is concerned with the language used in legal speech acts in legislative texts and contracts in the field of English Contract Law. The central objects of study are regulative functions with a particular view to establishing realization patterns of the rhetorical functions of directive...... and commissive acts. The findings show that the language of the law characteristically selects patterns of regulative distinct from, for example, the patterns typically selected in everyday conversational English. The characteristics of the language of the law can be interpreted within the adherence to legal...

  9. Do contracts help?

    DEFF Research Database (Denmark)

    Tumennasan, Norovsambuu

    Economists perceive moral hazard as an undesirable problem because it undermines efficiency. Carefully designed contracts can mitigate the moral hazard problem, but this assumes that a team is already formed. This paper demonstrates that these contracts are sometimes the reason why teams do...... transfers, then moral hazard affects stability positively in a large class of games. For example, a stable team structure exists if teams produce public goods or if the quota is two. However, these existence results no longer hold if efforts are verifiable....

  10. Terminal-shock and restart control of a Mach 2.5, axisymmetric, mixed compression inlet with 40 percent internal contraction. [wind tunnel tests (United States)

    Baumbick, R. J.


    Results of experimental tests conducted on a supersonic, mixed-compression, axisymmetric inlet are presented. The inlet is designed for operation at Mach 2.5 with a turbofan engine (TF-30). The inlet was coupled to either a choked orifice plate or a long duct which had a variable-area choked exit plug. Closed-loop frequency responses of selected diffuser static pressures used in the terminal-shock control system are presented. Results are shown for Mach 2.5 conditions with the inlet coupled to either the choked orifice plate or the long duct. Inlet unstart-restart traces are also presented. High-response inlet bypass doors were used to generate an internal disturbance and also to achieve terminal-shock control.

  11. Non-adiabatic collisions in H + O2 system: An ab initio study

    Indian Academy of Sciences (India)


    mentioned above. The degeneracy of the second and the third CT channels which also belongs to the Π symmetry in the collinear approach, is also lifted into A′ and A″ as shown in figure 2. The adiabatic PECs for the same three orientations as shown in figure 2, but as a function of r (internu- clear distance of the diatom) ...

  12. Preparation of Quantum States of H2 using Stark-induced Adiabatic Raman Passage (SARP) (United States)


    The Journal of Chemical Physics , (07 2011): 24201. doi: Nandini Mukherjee...Richard N. Zare. Can stimulated Raman pumping cause large population transfers in isolated molecules?, The Journal of Chemical Physics , (11 2011): 0...population to a selected rovibrational state of H2 by Stark-induced adiabatic Raman passage, THE JOURNAL OF CHEMICAL PHYSICS , (02 2013): 51101.

  13. Non-adiabatic radiative collapse of a relativistic star under different ...

    Indian Academy of Sciences (India)

    We examine the role of space-time geometry in the non-adiabatic collapse of a star dissipating energy in the form of radial heat flow, studying its evolution under different initial conditions. The collapse of a star filled with a homogeneous perfect fluid is compared with that of a star filled with inhomogeneous imperfect fluid ...

  14. Adiabatic flame temperature of sodium combustion and sodium-water reaction

    Energy Technology Data Exchange (ETDEWEB)

    Okano, Y.; Yamaguchi, A. [Japan Nuclear Cycle Development Institute, Ibaraki (Japan)


    In this paper, background information of sodium fire and sodium-water reaction accidents of LMFBR (liquid metal fast breeder reactor) is mentioned at first. Next, numerical analysis method of GENESYS is described in detail. Next, adiabatic flame temperature and composition of sodium combustion are analyzed, and affect of reactant composition, such oxygen and moisture, is discussed. Finally, adiabatic reaction zone temperature and composition of sodium-water reaction are calculated, and affects of reactant composition, sodium vaporization, and pressure are stated. Chemical equilibrium calculation program for generic chemical system (GENESYS) is developed in this study for the research on adiabatic flame temperature of sodium combustion and adiabatic reaction zone temperature of sodium-water reaction. The maximum flame temperature of the sodium combustion is 1,950 K at the standard atmospheric condition, and is not affected by the existence of moisture. The main reaction product is Na{sub 2}O{sub (l)}, and in combustion in moist air, with NaOH{sub (g)}. The maximum reaction zone temperature of the sodium-water reaction is 1,600 K, and increases with the system pressure. The main products are NaOH{sub (g)}, NaOH{sub (l)} and H2{sub (g)}. Sodium evaporation should be considered in the cases of sodium-rich and high pressure above 10 bar.

  15. Between ethylene and polyenes--the non-adiabatic dynamics of cis-dienes

    DEFF Research Database (Denmark)

    Kuhlman, Thomas Scheby; Glover, William J; Mori, Toshifumi


    Using Ab Initio Multiple Spawning (AIMS) with a Multi-State Multi-Reference Perturbation theory (MS-MR-CASPT2) treatment of the electronic structure, we have simulated the non-adiabatic excited state dynamics of cyclopentadiene (CPD) and 1,2,3,4-tetramethyl-cyclopentadiene (Me4-CPD) following exc...

  16. Saline Cavern Adiabatic Compressed Air Energy Storage Using Sand as Heat Storage Material

    Directory of Open Access Journals (Sweden)

    Martin Haemmerle


    Full Text Available Adiabatic compressed air energy storage systems offer large energy storage capacities and power outputs beyond 100MWel. Salt production in Austria produces large caverns which are able to hold pressure up to 100 bar, thus providing low cost pressurized air storage reservoirs for adiabatic compressed air energy storage plants. In this paper the results of a feasibility study is presented, which was financed by the Austrian Research Promotion Agency, with the objective to determine the adiabatic compressed air energy storage potential of Austria’s salt caverns. The study contains designs of realisable plants with capacities between 10 and 50 MWel, applying a high temperature energy storage system currently developed at the Institute for Energy Systems and Thermodynamics in Vienna. It could be shown that the overall storage potential of Austria’s salt caverns exceeds a total of 4GWhel in the year 2030 and, assuming an adequate performance of the heat exchanger, that a 10MWel adiabatic compressed air energy storage plant in Upper Austria is currently feasible using state of the art thermal turbomachinery which is able to provide a compressor discharge temperature of 400 °C.

  17. Adiabatic superconducting cells for ultra-low-power artificial neural networks

    Directory of Open Access Journals (Sweden)

    Andrey E. Schegolev


    Full Text Available We propose the concept of using superconducting quantum interferometers for the implementation of neural network algorithms with extremely low power dissipation. These adiabatic elements are Josephson cells with sigmoid- and Gaussian-like activation functions. We optimize their parameters for application in three-layer perceptron and radial basis function networks.

  18. Correction for adiabatic effects in lethe calculated instantaneous gas consumption of scuba dives

    NARCIS (Netherlands)

    Schellart, Nico A. M.; Le Péchon, Jean-Claude


    Introduction: In scuba-diving practice, instantaneous gas consumption is generally calculated from the fall in cylinder pressure without considering the effects of water temperature (heat transfer) and adiabatic processes. We aimed to develop a simple but precise method for calculating the

  19. An integrated optic adiabatic TE/TM mode splitter on silicon

    NARCIS (Netherlands)

    de Ridder, R.M.; Sander, A.F.M.; Driessen, A.; Fluitman, J.H.J.


    A compact integrated optic fundamental TE/TM mode splitter, based on the mode-sorting characteristics of an asymmetrical adiabatic Y junction of optical waveguides exhibiting shape birefringence, operating at 1550 nm, has been designed using the discrete sine method (DSM) and the beam propagation

  20. Modelling of an adiabatic trickle-bed reactor with phase change

    DEFF Research Database (Denmark)

    Ramirez Castelan, Carlos Eduardo; Hidalgo-Vivas, Angelica; Brix, Jacob


    This paper describes a modelling approach of the behavior of trickle-bed reactors used for catalytic hydrotreating of oil fractions. A dynamic plug-flow heterogeneous one-dimensional adiabatic model was used to describe the main reactions present in the hydrotreating process: hydrodesulfurization...

  1. Adiabatic partition effect on natural convection heat transfer inside a square cavity

    DEFF Research Database (Denmark)

    Mahmoudi Nezhad, Sajjad; Rezaniakolaei, Alireza; yousefi, Tooraj


    A steady state and two-dimensional laminar free convection heat transfer in a partitioned cavity with horizontal adiabatic and isothermal side walls is investigated using both experimental and numerical approaches. The experiments and numerical simulations are carried out using a Mach-Zehnder int...

  2. Adiabatic quantum pumping in normal-metal–insulator–superconductor junctions in a monolayer of graphene

    NARCIS (Netherlands)

    Alos-Palop, M.; Blaauboer, M.


    We investigate adiabatic quantum pumping through a normal-metal–“insulator”–superconductor (NIS) junction in a monolayer of graphene. The pumped current is generated by periodic modulation of two gate voltages, applied to the insulating and superconducting regions, respectively. In the bilinear

  3. Mathematical Model of a Lithium-Bromide/Water Absorption Refrigeration System Equipped with an Adiabatic Absorber

    Directory of Open Access Journals (Sweden)

    Salem M. Osta-Omar


    Full Text Available The objective of this paper is to develop a mathematical model for thermodynamic analysis of an absorption refrigeration system equipped with an adiabatic absorber using a lithium-bromide/water (LiBr/water pair as the working fluid. The working temperature of the generator, adiabatic absorber, condenser, evaporator, the cooling capacity of the system, and the ratio of the solution mass flow rate at the circulation pump to that at the solution pump are used as input data. The model evaluates the thermodynamic properties of all state points, the heat transfer in each component, the various mass flow rates, and the coefficient of performance (COP of the cycle. The results are used to investigate the effect of key parameters on the overall performance of the system. For instance, increasing the generator temperatures and decreasing the adiabatic absorber temperatures can increase the COP of the cycle. The results of this mathematical model can be used for designing and sizing new LiBr/water absorption refrigeration systems equipped with an adiabatic absorber or for optimizing existing aforementioned systems.

  4. Relativistic Adiabatic Time-Dependent Density Functional Theory Using Hybrid Functionals and Noncollinear Spin Magnetization

    DEFF Research Database (Denmark)

    Bast, Radovan; Jensen, Hans Jørgen Aagaard; Saue, Trond


    We report an implementation of adiabatic time-dependent density functional theory based on the 4-component relativistic Dirac-Coulomb Hamiltonian and a closed-shell reference. The implementation includes noncollinear spin magnetization and full derivatives of functionals, including hybrid general...

  5. Energy-Saving Benefits of Adiabatic Humidification in the Air Conditioning Systems of Semiconductor Cleanrooms

    Directory of Open Access Journals (Sweden)

    Min-Suk Jo


    Full Text Available This paper aimed to evaluate the applicability of adiabatic humidification in the heating, ventilation, and air conditioning (HVAC systems of semiconductor cleanrooms. Accurate temperature and humidity control are essential in semiconductor cleanrooms and high energy consumption steam humidification is commonly used. Therefore, we propose an adiabatic humidification system employing a pressurized water atomizer to reduce the energy consumption. The annual energy consumption of three different HVAC systems were analyzed to evaluate the applicability of adiabatic humidification. The studied cases were as follows: (1 CASE 1: a make-up air unit (MAU with a steam humidifier, a dry cooling coil (DCC, and a fan filter unit (FFU; (2 CASE 2: a MAU with the pressurized water atomizer, a DCC, and a FFU; and (3 CASE 3: a MAU, a DCC, and a FFU, and the pressurized water atomizer installed in the return duct. The energy saving potential of adiabatic humidification over steam humidification has been proved, with savings of 8% and 23% in CASE 2 and CASE 3 compared to CASE 1, respectively. Furthermore, the pressurized water atomizer installed in the return duct exhibits greater energy saving effect than when installed in the MAU.

  6. Non-adiabatic molecular dynamic simulations of opening reaction of molecular junctions

    Czech Academy of Sciences Publication Activity Database

    Zobač, Vladimír; Lewis, J.P.; Jelínek, Pavel


    Roč. 27, č. 28 (2016), 1-8, č. článku 285202. ISSN 0957-4484 R&D Projects: GA ČR(CZ) GA14-02079S Institutional support: RVO:68378271 Keywords : non-adiabatic molecular dynamics * molecular junctions * molecular switches * DFT Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.440, year: 2016

  7. Gas phase adiabatic electron affinities of cyclopenta-fused polycyclic aromatic hydrocarbons

    NARCIS (Netherlands)

    Todorov, P.D.; Koper, C.; van Lenthe, J.H.; Jenneskens, L.W.


    The B3LYP/DZP++ adiabatic electron affinity (AEA) of nine (non)-alternant polycyclic aromatic hydrocarbons are reported and discussed. Calculations became feasible for molecules this size by projecting out the near-linearly dependent part of the one-electron basis. Non-alternant PAH consisting of an

  8. 3 CFR - Government Contracting (United States)


    ... contract oversight could reduce such sums significantly. Government outsourcing for services also raises... commercial services used by the Government, such as transportation, food, and maintenance. Office of... governmental functions. Agencies and departments must operate under clear rules prescribing when outsourcing is...

  9. Culture and Contract Laws

    DEFF Research Database (Denmark)

    Lando, Ole


    In the article it is argued that the wish to preserve the cultural values of national law should not prevent the EU from preparing a Code or an Optional Instrument. The no-code countries on the British Isles and in Scandinavia are the most ardent opponents to the idea of unifying European Contract...

  10. Muscle contraction and force

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline; Risbo, Jens; Pierzynowski, Stefan G.


    Muscle contraction studies often focus solely on myofibres and the proteins known to be involved in the processes of sarcomere shortening and cross-bridge cycling, but skeletal muscle also comprises a very elaborate ancillary network of capillaries, which not only play a vital role in terms of nu...... contributor to force transfer within muscular tissue....

  11. Joint Contingency Contracting (United States)


    parents, Ellsworth K. Johnson, Jr. and Helen E. Johnson, for their lifelong love and support. Mom, thanks for always being there when I needed you...Hurricanes Charley , Jeanne and Andrew are examples of domestic disaster emergency relief. 2. Phases of Contingency Contracting Contingency

  12. Construction Contract Provisions Analysis. (United States)


    tractor, and localized variations characteristic of the subsurface materials of the region are anticipated and if encountered, such variations will...34Contract drawings, maps, and specification. On larger projects, provide one set of sepias , both large scale and reduced, in addition to the contact

  13. Cognition and Incomplete Contracts


    Jean Tirole


    Thinking about contingencies, designing covenants, and seeing through their implications is costly. Parties to a contract accordingly use heuristics and leave it incomplete. The paper develops a model of limited cognition and examines its consequences for contractual design. (JEL D23, D82, D86, L22)

  14. Steady-State Multiplicity Features of an Adiabatic Fixed-Bed Reactor with Langmuir-Hinshelwood Kinetics; CO or CO2 Methanation

    DEFF Research Database (Denmark)

    Wedel, Stig; Lues, Dan


    The steady-state multiplicity features of an adiabatic fixed bed reactor were Investigated experimentally by the methanation of either CO or CO2 as test reactions. No more than two stable steady states were found at any operating conditions. The Langmuir-Hinshelwood kinetics of these reactions...... caused the conversion along the lower branch to decrease with increasing feed concentration. The experimental results have been explained and simulated by a one-dimensional two-phase model which accounts for axial dispersion as well as inter- and intraphase transport resistances. The surface describing...

  15. Practical concepts in Contract Law


    Ehsan, zarrokh


    A contract is a legally binding exchange of promises or agreement between parties that the law will enforce. Contract law is based on the Latin phrase pacta sunt servanda (literally, promises must be kept) [1]. Breach of a contract is recognised by the law and remedies can be provided. Almost everyone makes contracts everyday. Sometimes written contracts are required, e.g., when buying a house [2]. However the vast majority of contracts can be and are made orally, like buying a law text book,...

  16. Employee contract issues for dermatologists. (United States)

    Brown, Christopher E; Indest, George F


    Employees and employers routinely face negotiating and preparing physician employment contracts. It is important for both sides to know and understand the basic information on what a comprehensive employment contract for a dermatologist should contain. There are various employment contract provisions from both the employee's perspective and the employer's perspective that must be considered when preparing physician employment contracts. This article provides basic advice and recommendations on requirements that should be included in such contracts. It suggests legal pitfalls that can be avoided through various contract clauses.

  17. 30 CFR 36.47 - Tests of exhaust-gas cooling system. (United States)


    ... at the final temperature. Water in excess of that required for adiabatic saturation shall be... before the exhaust gas is diluted with air, shall not exceed 170 °F. or the temperature of adiabatic saturation, if this temperature is lower. (d) Water consumed in cooling the exhaust gas under the test...

  18. Navy construction contract regulations vs. the Board of Contract Appeals.


    McMurray, Thomas David


    Approved for public release; distribution is unlimited This thesis addresses construction contracting in the United States Navy. It compares the Government construction contract regulations with decisions by the Boards of Contract Appeals. Nine topics are researched including submittal reviews, profit, change orders and changes, notices to proceed, acceleration, beneficial occupancy, weather delays, and extended overhead. The Boards' decisions are used to understand...

  19. Contracts for dispatchable power

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, E.P.; Stoft, S.; Marnay, C.; Berman, D.


    Competitive bidding for electric power is maturing. Increasing numbers of utilities are soliciting proposals from private suppliers. The amount of capacity being sought is increasing, and potential suppliers appear to be abundant. Analysis of these developments still remains limited. Evidence on the behavior of this market is scarce and sketchy. The underlying economic principles that are shaping the market have not clearly been articulated. In this report we examine the economics of competitive bidding both empirically and analytically. Previous study of this market has focused on the evaluation criteria specified in Requests for Proposals (RFPs), and highly aggregated summary statistics on participation and results. We continue the examination of RFPs, but also survey the details of long term contracts that have emerged from competitive bidding. Contracts provide a new level of specific detail that has not been previously available. 68 refs., 13 figs., 25 tabs.

  20. Russian Contract Procurement Document

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, J G


    This contract supports the enhancement of physical protection or nuclear material control and accounting systems at institutes or enterprises of the newly independent states under the material protection control and accounting (MPC&A) program. The contract is entered into pursuant to the MPC&A Program, a gratuitous technical assistance program, in accordance with the bilateral Agreements between the Russian Federation and the United States of America concerning the Safe and Secure Transportation, Storage and Destruction of Weapons and the Prevention of Weapons Proliferation of June 1992, as extended and amended by Protocol signed of June 1999, Agreement between the Government of the Russian Federation regarding Cooperation in the Area of Nuclear Materials Physical Protection, Control and Accounting of October 1999 and the Russian Federation law of May 1999 on the taxation exemption of gratuitous technical assistance with Russian Federation under registration No.DOE001000.

  1. Monte Carlo modeling of Lead-Cooled Fast Reactor in adiabatic equilibrium state

    Energy Technology Data Exchange (ETDEWEB)

    Stanisz, Przemysław, E-mail:; Oettingen, Mikołaj, E-mail:; Cetnar, Jerzy, E-mail:


    Graphical abstract: - Highlights: • We present the Monte Carlo modeling of the LFR in the adiabatic equilibrium state. • We assess the adiabatic equilibrium fuel composition using the MCB code. • We define the self-adjusting process of breeding gain by the control rod operation. • The designed LFR can work in the adiabatic cycle with zero fuel breeding. - Abstract: Nuclear power would appear to be the only energy source able to satisfy the global energy demand while also achieving a significant reduction of greenhouse gas emissions. Moreover, it can provide a stable and secure source of electricity, and plays an important role in many European countries. However, nuclear power generation from its birth has been doomed by the legacy of radioactive nuclear waste. In addition, the looming decrease in the available resources of fissile U235 may influence the future sustainability of nuclear energy. The integrated solution to both problems is not trivial, and postulates the introduction of a closed-fuel cycle strategy based on breeder reactors. The perfect choice of a novel reactor system fulfilling both requirements is the Lead-Cooled Fast Reactor operating in the adiabatic equilibrium state. In such a state, the reactor converts depleted or natural uranium into plutonium while consuming any self-generated minor actinides and transferring only fission products as waste. We present the preliminary design of a Lead-Cooled Fast Reactor operating in the adiabatic equilibrium state with the Monte Carlo Continuous Energy Burnup Code – MCB. As a reference reactor model we apply the core design developed initially under the framework of the European Lead-cooled SYstem (ELSY) project and refined in the follow-up Lead-cooled European Advanced DEmonstration Reactor (LEADER) project. The major objective of the study is to show to what extent the constraints of the adiabatic cycle are maintained and to indicate the phase space for further improvements. The analysis

  2. Preliminary Results Towards Contract Monitorability

    Directory of Open Access Journals (Sweden)

    Annalizz Vella


    Full Text Available This paper discusses preliminary investigations on the monitorability of contracts for web service descriptions. There are settings where servers do not guarantee statically whether they satisfy some specified contract, which forces the client (i.e., the entity interacting with the server to perform dynamic checks. This scenario may be viewed as an instance of Runtime Verification, where a pertinent question is whether contracts can be monitored for adequately at runtime, otherwise stated as the monitorability of contracts. We consider a simple language of finitary contracts describing both clients and servers, and develop a formal framework that describes server contract monitoring. We define monitor properties that potentially contribute towards a comprehensive notion of contract monitorability and show that our simple contract language satisfies these properties.

  3. Utility Energy Services Contracts Guide

    Energy Technology Data Exchange (ETDEWEB)



    The UESC Guide is a compilation of samples and templates developed as a resource to help contracting officers implement task orders for UESCs under existing U.S. General Services Administration areawide contracts.


    CERN Multimedia

    Technical Training; Tel. 74460


    SPL is organizing Training Sessions on the Contract Follow Up application. CFU is a Web based tool, developped and supported by the Administrative Information Services. It allows the creation of Divisional Requests and the follow up of their processing, from the Market Survey to the Invitation to Tender or Price Enquiry, approval by the Finance Committee, up to the actual signature of a Contract, acccording to the CERN Purchasing procedures. It includes a document management component. It also provides link with other AIS applications such as BHT and EDH. The course is primarily intended for DPOs, Contract Technical responsibles in the division and their assistants, but is beneficial to anybody involved in the follow up of such Purchasing Procedures. This course is free of charge, but application is necessary. The details of the course may be found at General information of CFU may be found at The dates of t...

  5. The interpretation of administrative contracts

    Directory of Open Access Journals (Sweden)

    Cătălin-Silviu SĂRARU


    Full Text Available The article analyzes the principles of interpretation for administrative contracts, in French law and in Romanian law. In the article are highlighted derogations from the rules of contract interpretation in common law. Are examined the exceptions to the principle of good faith, the principle of common intention (willingness of the parties, the principle of good administration, the principle of extensive interpretation of the administrative contract. The article highlights the importance and role of the interpretation in administrative contracts.

  6. Why radiologists lose their hospital contracts: is your contract secure? (United States)

    Muroff, Lawrence R


    Previously, a hospital contract meant tenure for the incumbent group of radiologists; however, those days are long gone. Exclusive contracts have morphed into exclusive contracts with carve-outs. Turf erosion has become a fact of life for radiology practices. Now radiologists are losing their hospital contracts in record numbers. Group size, though helpful for a variety of reasons, does not ensure that a practice will be secure in its hospital setting. The reasons that groups lose their hospital contracts are varied, and in this paper, the author discusses the most common ones. Suggestions to help practices avoid this unfortunate fate are presented.

  7. Pressure drop in contraction flow

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz

    This note is a supplement to Dynamic of Polymeric Liquids (DPL) page 178. DPL gives an equation for the pressure drop in a tapered (and circular) contraction, valid only at low angles. Here the general definition of contraction flow (the Bagley correction) and a more general method to find...... the pressure drop in a contraction are given....

  8. Transnational Law of Public Contracts

    NARCIS (Netherlands)

    Audit, M.; Schill, S.W.


    Public contracts were traditionally conceived as instruments of domestic public law and used within markets confined to the territory of the state party to the contract. Globalization, however, subjects public contracting to an increasing number of processes that take place at a transnational level

  9. Ultrafast hydrogen migration in acetylene cation driven by non-adiabatic effects. (United States)

    Madjet, Mohamed El-Amine; Li, Zheng; Vendrell, Oriol


    Non-adiabatic dynamics of the acetylene cation is investigated using mixed quantum-classical dynamics based on trajectory surface hopping. To describe the non-adiabatic effects, two surface hopping methods are used, namely, Tully's fewest switches and Landau-Zener surface hopping. Similarities and differences between the results based on those two methods are discussed. We find that the photoionization of acetylene into the first excited state A(2)Σg(+) drives the molecule from the linear structure to a trans-bent structure. Through a conical intersection the acetylene cation can relax back to either the ground state of acetylene or vinylidene. We conclude that hydrogen migration always takes place after non-radiative electronic relaxation to the ground state of the monocation. Based on the analysis of correlation functions we identify coherent oscillations between acetylene and vinylidene with a period of about 70 fs after the electronic relaxation.

  10. A quantum-walk-inspired adiabatic algorithm for solving graph isomorphism problems (United States)

    Tamascelli, Dario; Zanetti, Luca


    We present a quantum algorithm for solving graph isomorphism problems that is based on an adiabatic protocol. We use a collection of continuous time quantum walks, each one generated by an XY Hamiltonian, to visit the configuration space. In this way we avoid a diffusion over all the possible configurations and significantly reduce the dimensionality of the accessible Hilbert space. Within this restricted space, the graph isomorphism problem can be translated into searching for a satisfying assignment to a 2-SAT (satisfiable) formula and mapped onto a 2-local Hamiltonian without resorting to perturbation gadgets or projective techniques. We present an analysis of the time for execution of the algorithm on small graph isomorphism problem instances and discuss the issue of an implementation of the proposed adiabatic scheme on current quantum computing hardware.

  11. Adiabatic nanofocusing: Spectroscopy, transport and imaging investigation of the nano world

    KAUST Repository

    Giugni, Andrea


    Adiabatic compression plays a fundamental role in the realization of localized enhanced electromagnetic field hot spots, it provides the possibility to focus at nanoscale optical excitation. It differs from the well-known lightning rod effect since it is based on the lossless propagation of surface plasmon polaritons (SPPs) up to a nano-sized metal tip where the energy density is largely enhanced. Here we discuss two important applications of adiabatic compression: Raman and hot electron spectroscopy at nanometric resolution. The underlying phenomena are the conversion of SPPs into photons or hot electrons. New scanning probe spectroscopy techniques along with experimental results are discussed. We foresee that these techniques will play a key role in relating the functional and structural properties of matter at the nanoscale.

  12. Optically driven Rabi oscillations and adiabatic passage of single electron spins in diamond. (United States)

    Golter, D Andrew; Wang, Hailin


    Rabi oscillations and adiabatic passage of single electron spins in a diamond nitrogen vacancy center are demonstrated with two Raman-resonant optical pulses that are detuned from the respective dipole optical transitions. We show that the optical spin control is nuclear-spin selective and can be robust against rapid decoherence, including radiative decay and spectral diffusion, of the underlying optical transitions. A direct comparison between the Rabi oscillation and the adiabatic passage, along with a detailed theoretical analysis, provides significant physical insights into the connections and differences between these coherent spin processes and also elucidates the role of spectral diffusion in these processes. The optically driven coherent spin processes enable the use of nitrogen vacancy excited states to mediate coherent spin-phonon coupling, opening the door to combining optical control of both spin and mechanical degrees of freedom.

  13. DFT Study on Adiabatic and Vertical Ionization Potentials of Graphene Sheets

    Directory of Open Access Journals (Sweden)

    Igor K. Petrushenko


    Full Text Available Adiabatic and vertical ionization potentials (IPs of finite-size graphene sheets as a function of size were determined by using density functional theory. In the case of graphene a very moderate gap between vertical and adiabatic IPs was observed, whereas for coronene molecule as a model compound these values differ considerably. The ionization process induces large changes in the structure of the studied sheets of graphene; “horizontal” and “vertical” bond lengths have different patterns of alternation. It was also established that the HOMO electron density distribution in the neutral graphene sheet affects its size upon ionization. The evolution of IPs of graphene sheets towards their work functions was discussed.

  14. The adiabatic strictly-correlated-electrons functional: kernel and exact properties. (United States)

    Lani, Giovanna; Di Marino, Simone; Gerolin, Augusto; van Leeuwen, Robert; Gori-Giorgi, Paola


    We investigate a number of formal properties of the adiabatic strictly-correlated electrons (SCE) functional, relevant for time-dependent potentials and for kernels in linear response time-dependent density functional theory. Among the former, we focus on the compliance to constraints of exact many-body theories, such as the generalised translational invariance and the zero-force theorem. Within the latter, we derive an analytical expression for the adiabatic SCE Hartree exchange-correlation kernel in one dimensional systems, and we compute it numerically for a variety of model densities. We analyse the non-local features of this kernel, particularly the ones that are relevant in tackling problems where kernels derived from local or semi-local functionals are known to fail.

  15. Non-adiabatic corrections to the energies of the pure vibrational states of H2 (United States)

    Bubin, Sergiy; Leonarski, Filip; Stanke, Monika; Adamowicz, Ludwik


    Nonrelativistic energies of all fifteen pure vibrational states of the H molecule have been recalculated with much higher accuracy than before. In the calculations we employed explicitly correlated Gaussian functions and an approach where the Born-Oppenheimer (BO) approximation is not assumed. The wave function of each state was expanded in terms of 10 000 Gaussians whose nonlinear parameters were optimized using a procedure involving the analytical energy gradient. The obtained non-BO energies combined with the recent BO adiabatic energies of Pachucki and Komasa [K. Pachucki, J. Komasa, J. Chem. Phys. 129 (2008) 034102] allowed us to determine new improved values of the non-adiabatic corrections for the considered states.

  16. Adiabatic measurements of magneto-caloric effects in pulsed high magnetic fields up to 55 T (United States)

    Kihara, T.; Kohama, Y.; Hashimoto, Y.; Katsumoto, S.; Tokunaga, M.


    Magneto-caloric effects (MCEs) measurement system in adiabatic condition is proposed to investigate the thermodynamic properties in pulsed magnetic fields up to 55 T. With taking the advantage of the fast field-sweep rate in pulsed field, adiabatic measurements of MCEs were carried out at various temperatures. To obtain the prompt response of the thermometer in the pulsed field, a thin film thermometer is grown directly on the sample surfaces. The validity of the present setup was demonstrated in the wide temperature range through the measurements on Gd at about room temperature and on Gd3Ga5O12 at low temperatures. The both results show reasonable agreement with the data reported earlier. By comparing the MCE data with the specific heat data, we could estimate the entropy as functions of magnetic field and temperature. The results demonstrate the possibility that our approach can trace the change in transition temperature caused by the external field.

  17. First-order derivative couplings between excited states from adiabatic TDDFT response theory. (United States)

    Ou, Qi; Bellchambers, Gregory D; Furche, Filipp; Subotnik, Joseph E


    We present a complete derivation of derivative couplings between excited states in the framework of adiabatic time-dependent density functional response theory. Explicit working equations are given and the resulting derivative couplings are compared with derivative couplings from a pseudo-wavefunction ansatz. For degenerate excited states, i.e., close to a conical intersection (CI), the two approaches are identical apart from an antisymmetric overlap term. However, if the difference between two excitation energies equals another excitation energy, the couplings from response theory exhibit an unphysical divergence. This spurious behavior is a result of the adiabatic or static kernel approximation of time-dependent density functional theory leading to an incorrect analytical structure of the quadratic response function. Numerical examples for couplings close to a CI and for well-separated electronic states are given.

  18. Adiabatically reduced magnetohydrodynamic equations for a cylindrical plasma with an anisotropic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Nebogatov, V. A.; Pastukhov, V. P., E-mail: [National Research Centre Kurchatov Institute (Russian Federation)


    A closed set of reduced equations describing low-frequency nonlinear flute magnetohydrodynamic (MHD) convection and the resulting nondiffusive processes of particle and energy transport in a weakly collisional cylindrical plasma with an anisotropic pressure is derived. The Chew-Goldberger-Low anisotropic magnetohydrodynamics is used as the basic dynamic model, because this model is applicable to describing flute convection in a cylindrical plasma column even in the low-frequency limit. The reduced set of equations was derived using the method of adiabatic separation of fast and slow motions. It is shown that the structure of the adiabatic transformation and the corresponding velocity field are identical to those obtained earlier in the isotropic MHD model. However, the derived heat transfer equations differ drastically from the isotropic pressure model. In particular, they indicate a tendency toward maintaining different radial profiles of the longitudinal and transverse pressures.

  19. Structural mechanisms of formation of adiabatic shear bands

    Directory of Open Access Journals (Sweden)

    Mikhail Sokovikov


    Full Text Available The paper focuses on the experimental and theoretical study of plastic deformation instability and localization in materials subjected to dynamic loading and high-velocity perforation. We investigate the behavior of samples dynamically loaded during Hopkinson-Kolsky pressure bar tests in a regime close to simple shear conditions. Experiments were carried out using samples of a special shape and appropriate test rigging, which allowed us to realize a plane strain state. Also, the shear-compression specimens proposed in were investigated. The lateral surface of the samples was investigated in a real-time mode with the aid of a high-speed infra-red camera CEDIP Silver 450M. The temperature field distribution obtained at different time made it possible to trace the evolution of plastic strain localization. Use of a transmission electron microscope for studying the surface of samples showed that in the regions of strain localization there are parts taking the shape of bands and honeycomb structure in the deformed layer. The process of target perforation involving plug formation and ejection was investigated using a high-speed infra-red camera. A specially designed ballistic set-up for studying perforation was used to test samples in different impulse loading regimes followed by plastic flow instability and plug ejection. Changes in the velocity of the rear surface at different time of plug ejection were analyzed by Doppler interferometry techniques. The microstructure of tested samples was analyzed using an optical interferometer-profilometer and a scanning electron microscope. The subsequent processing of 3D deformation relief data enabled estimation of the distribution of plastic strain gradients at different time of plug formation and ejection. It has been found that in strain localization areas the subgrains are elongated taking the shape of bands and undergo fragmentation leading to the formation of super-microcrystalline structure, in which the

  20. Entering the contract research industry in India. (United States)

    Joseph, Jamila


    India is getting to be known as a hot destination for executing clinical trials. It is witnessing the frenzied entry of pharma sponsor companies and contract research organizations and the movement of Indian non-healthcare groups into clinical research. In this mad melee, what are the determinants of success? How real is the promise of clinical research in India and what will make or break a new entrant in this business? This article attempts to describe these challenges and focuses on the resilient success criteria that the contract clinical research industry in India has tested every newcomer against.

  1. Adiabatic and Hamiltonian computing on a 2D lattice with simple two-qubit interactions


    Lloyd, Seth; Terhal, Barbara


    We show how to perform universal Hamiltonian and adiabatic computing using a time-independent Hamiltonian on a 2D grid describing a system of hopping particles which string together and interact to perform the computation. In this construction, the movement of one particle is controlled by the presence or absence of other particles, an effective quantum field effect transistor that allows the construction of controlled-NOT and controlled-rotation gates. The construction translates into a mode...

  2. High-Energy, Multi-Octave-Spanning Mid-IR Sources via Adiabatic Difference Frequency Generation (United States)


    ABSTRACT The creation of energetic , arbitrarily shapeable, multi-octave-spanning, coherent sources of short-wave, mid-wave, and long-wave mid-IR...plan. We have evaluated a brand-new concept in nonlinear optics, adiabatic difference frequency generation (ADFG) for the efficient transfer of...generation: limited bandwidth and limited conversion efficiency . 15. SUBJECT TERMS Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 Page 1 of

  3. A scalable control system for a superconducting adiabatic quantum optimization processor (United States)

    Johnson, M. W.; Bunyk, P.; Maibaum, F.; Tolkacheva, E.; Berkley, A. J.; Chapple, E. M.; Harris, R.; Johansson, J.; Lanting, T.; Perminov, I.; Ladizinsky, E.; Oh, T.; Rose, G.


    We have designed, fabricated and operated a scalable system for applying independently programmable time-independent, and limited time-dependent flux biases to control superconducting devices in an integrated circuit. Here we report on the operation of a system designed to supply 64 flux biases to devices in a circuit designed to be a unit cell for a superconducting adiabatic quantum optimization system. The system requires six digital address lines, two power lines, and a handful of global analog lines.

  4. Constructing diabatic representations using adiabatic and approximate diabatic data – Coping with diabolical singularities

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaolei, E-mail:; Yarkony, David R., E-mail: [Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218 (United States)


    We have recently introduced a diabatization scheme, which simultaneously fits and diabatizes adiabatic ab initio electronic wave functions, Zhu and Yarkony J. Chem. Phys. 140, 024112 (2014). The algorithm uses derivative couplings in the defining equations for the diabatic Hamiltonian, H{sup d}, and fits all its matrix elements simultaneously to adiabatic state data. This procedure ultimately provides an accurate, quantifiably diabatic, representation of the adiabatic electronic structure data. However, optimizing the large number of nonlinear parameters in the basis functions and adjusting the number and kind of basis functions from which the fit is built, which provide the essential flexibility, has proved challenging. In this work, we introduce a procedure that combines adiabatic state and diabatic state data to efficiently optimize the nonlinear parameters and basis function expansion. Further, we consider using direct properties based diabatizations to initialize the fitting procedure. To address this issue, we introduce a systematic method for eliminating the debilitating (diabolical) singularities in the defining equations of properties based diabatizations. We exploit the observation that if approximate diabatic data are available, the commonly used approach of fitting each matrix element of H{sup d} individually provides a starting point (seed) from which convergence of the full H{sup d} construction algorithm is rapid. The optimization of nonlinear parameters and basis functions and the elimination of debilitating singularities are, respectively, illustrated using the 1,2,3,4{sup 1}A states of phenol and the 1,2{sup 1}A states of NH{sub 3}, states which are coupled by conical intersections.

  5. Photonic crystal waveguides: out-of-plane losses and adiabatic modal conversion


    Palamaru, Mirel; Lalanne, Philippe


    International audience; An accurate model for the out-of-plane radiation losses occurring when a guided wave propagating in a conventional waveguide impinges on a photonic crystal waveguide is presented. The model makes clear that the losses originate from insertion losses resulting from a mode mismatch. A generic taper structure realizing an adiabatic modal conversion is proposed and validated through numerical computations for cavities with large Q's and large peak transmission.

  6. Adiabatic radio-frequency potentials for the coherent manipulation of matter waves

    DEFF Research Database (Denmark)

    Lesanovsky, Igor; Schumm, Thorsten; Hofferberth, S.


    Adiabatic dressed state potentials are created when magnetic substates of trapped atoms are coupled by a radio-frequency field. We discuss their theoretical foundations and point out fundamental advantages over potentials purely based on static fields. The enhanced flexibility enables one...... to implement numerous configurations, including double wells, Mach-Zehnder, and Sagnac interferometers which even allows for internal state-dependent atom manipulation. These can be realized using simple and highly integrated wire geometries on atom chips....

  7. General laser interaction theory in atom-diatom systems for both adiabatic and nonadiabatic cases. (United States)

    Li, Xuan; Brue, Daniel A; Parker, Gregory A; Chang, Sin-Tarng


    This paper develops the general theory for laser fields interacting with bimolecular systems. In this study, we choose to use the multipolar gauge on the basis of gauge invariance. We consider both the adiabatic and nonadiabatic cases and find they produce similar interaction pictures. As an application of this theory, we present the study of rovibrational energy transfer in Ar + CO collisions in the presence of an intense laser field.

  8. Deterministic single-atom excitation via adiabatic passage and Rydberg blockade


    Beterov, I. I.; Tretyakov, D. B.; Entin, V. M.; Yakshina, E. A.; Ryabtsev, I. I.; MacCormick, C.; Bergamini, S.


    We propose to use adiabatic rapid passage with a chirped laser pulse in the strong dipole blockade regime to deterministically excite only one Rydberg atom from randomly loaded optical dipole traps or optical lattices. The chirped laser excitation is shown to be insensitive to the random number \\textit{N} of the atoms in the traps. Our method overcomes the problem of the $\\sqrt {N} $ dependence of the collective Rabi frequency, which was the main obstacle for deterministic single-atom excitat...

  9. Adiabatic approximation for the evolution generated by an A-uniformly pseudo-Hermitian Hamiltonian (United States)

    Wang, Wenhua; Cao, Huaixin; Chen, Zhengli


    We discuss an adiabatic approximation for the evolution generated by an A-uniformly pseudo-Hermitian Hamiltonian H(t). Such a Hamiltonian is a time-dependent operator H(t) similar to a time-dependent Hermitian Hamiltonian G(t) under a time-independent invertible operator A. Using the relation between the solutions of the evolution equations H(t) and G(t), we prove that H(t) and H† (t) have the same real eigenvalues and the corresponding eigenvectors form two biorthogonal Riesz bases for the state space. For the adiabatic approximate solution in case of the minimum eigenvalue and the ground state of the operator H(t), we prove that this solution coincides with the system state at every instant if and only if the ground eigenvector is time-independent. We also find two upper bounds for the adiabatic approximation error in terms of the norm distance and in terms of the generalized fidelity. We illustrate the obtained results with several examples.

  10. Oscillating potential well in the complex plane and the adiabatic theorem (United States)

    Longhi, Stefano


    A quantum particle in a slowly changing potential well V (x ,t ) =V ( x -x0(ɛ t ) ) , periodically shaken in time at a slow frequency ɛ , provides an important quantum mechanical system where the adiabatic theorem fails to predict the asymptotic dynamics over time scales longer than ˜1 /ɛ . Specifically, we consider a double-well potential V (x ) sustaining two bound states spaced in frequency by ω0 and periodically shaken in a complex plane. Two different spatial displacements x0(t ) are assumed: the real spatial displacement x0(ɛ t ) =A sin(ɛ t ) , corresponding to ordinary Hermitian shaking, and the complex one x0(ɛ t ) =A -A exp(-i ɛ t ) , corresponding to non-Hermitian shaking. When the particle is initially prepared in the ground state of the potential well, breakdown of adiabatic evolution is found for both Hermitian and non-Hermitian shaking whenever the oscillation frequency ɛ is close to an odd resonance of ω0. However, a different physical mechanism underlying nonadiabatic transitions is found in the two cases. For the Hermitian shaking, an avoided crossing of quasienergies is observed at odd resonances and nonadiabatic transitions between the two bound states, resulting in Rabi flopping, can be explained as a multiphoton resonance process. For the complex oscillating potential well, breakdown of adiabaticity arises from the appearance of Floquet exceptional points at exact quasienergy crossing.

  11. Ultra Low Power Adiabatic Logic Using Diode Connected DC Biased PFAL Logic

    Directory of Open Access Journals (Sweden)

    Akash Agrawal


    Full Text Available With the continuous scaling down of technology in the field of integrated circuit design, low power dissipation has become one of the primary focuses of the research. With the increasing demand for low power devices, adiabatic logic gates prove to be an effective solution. This paper briefs on different adiabatic logic families such as ECRL (Efficient Charge Recovery Logic, 2N-2N2P and PFAL (Positive Feedback Adiabatic Logic, and presents a new proposed circuit based on the PFAL logic circuit. The aim of this paper is to simulate various logic gates using PFAL logic circuits and with the proposed logic circuit, and hence to compare the effectiveness in terms of average power dissipation and delay at different frequencies. This paper further presents implementation of C17 and C432 benchmark circuits, using the proposed logic circuit and the conventional PFAL logic circuit to compare effectiveness of the proposed logic circuit in terms of average power dissipation at different frequencies. All simulations are carried out by using HSPICE Simulator at 65 nm technology at different frequency ranges. Finally, average power dissipation characteristics are plotted with the help of graphs, and comparisons are made between PFAL logic family and new proposed PFAL logic family.

  12. Specific absorption rate determination of magnetic nanoparticles through hyperthermia measurements in non-adiabatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Coïsson, M. [INRIM, strada delle Cacce 91, 10135 Torino (Italy); Barrera, G. [INRIM, strada delle Cacce 91, 10135 Torino (Italy); University of Torino, Chemistry Department, via P. Giuria 7, 10125 Torino (Italy); Celegato, F.; Martino, L.; Vinai, F. [INRIM, strada delle Cacce 91, 10135 Torino (Italy); Martino, P. [Politronica srl, via Livorno 60, 10144 Torino (Italy); Ferraro, G. [Center for Space Human Robotics, Istituto Italiano di Tecnologia - IIT, corso Trento 21, 10129 Torino (Italy); Tiberto, P. [INRIM, strada delle Cacce 91, 10135 Torino (Italy)


    An experimental setup for magnetic hyperthermia operating in non-adiabatic conditions is described. A thermodynamic model that takes into account the heat exchanged by the sample with the surrounding environment is developed. A suitable calibration procedure is proposed that allows the experimental validation of the model. Specific absorption rate can then be accurately determined just from the measurement of the sample temperature at the equilibrium steady state. The setup and the measurement procedure represent a simplification with respect to other systems requiring calorimeters or crucial corrections for heat flow. Two families of magnetic nanoparticles, one superparamagnetic and one characterised by larger sizes and static hysteresis, have been characterised as a function of field intensity, and specific absorption rate and intrinsic loss power have been obtained. - Highlights: • Development and thermodynamic modelling of a hyperthermia setup operating in non-adiabatic conditions. • Calibration of the experimental setup and validation of the model. • Accurate measurement of specific absorption rate and intrinsic loss power in non-adiabatic conditions.

  13. Impact of Turbocharger Non-Adiabatic Operation on Engine Volumetric Efficiency and Turbo Lag

    Directory of Open Access Journals (Sweden)

    S. Shaaban


    Full Text Available Turbocharger performance significantly affects the thermodynamic properties of the working fluid at engine boundaries and hence engine performance. Heat transfer takes place under all circumstances during turbocharger operation. This heat transfer affects the power produced by the turbine, the power consumed by the compressor, and the engine volumetric efficiency. Therefore, non-adiabatic turbocharger performance can restrict the engine charging process and hence engine performance. The present research work investigates the effect of turbocharger non-adiabatic performance on the engine charging process and turbo lag. Two passenger car turbochargers are experimentally and theoretically investigated. The effect of turbine casing insulation is also explored. The present investigation shows that thermal energy is transferred to the compressor under all circumstances. At high rotational speeds, thermal energy is first transferred to the compressor and latter from the compressor to the ambient. Therefore, the compressor appears to be “adiabatic” at high rotational speeds despite the complex heat transfer processes inside the compressor. A tangible effect of turbocharger non-adiabatic performance on the charging process is identified at turbocharger part load operation. The turbine power is the most affected operating parameter, followed by the engine volumetric efficiency. Insulating the turbine is recommended for reducing the turbine size and the turbo lag.

  14. Zero-point energy, tunnelling, and vibrational adiabaticity in the Mu + H2 reaction (United States)

    Mielke, Steven L.; Garrett, Bruce C.; Fleming, Donald G.; Truhlar, Donald G.


    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 in this journal of the thermal and vibrationally state-selected 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 non-adiabatic transitions cannot be understood by considering tunnelling 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.

  15. (Non-adiabatic) string creation on nice slices in Schwarzschild black holes (United States)

    Puhm, Andrea; Rojas, Francisco; Ugajin, Tomonori


    Nice slices have played a pivotal role in the discussion of the black hole information paradox as they avoid regions of strong spacetime curvature and yet smoothly cut through the infalling matter and the outgoing Hawking radiation, thus, justifying the use of low energy field theory. To avoid information loss it has been argued recently, however, that local effective field theory has to break down at the horizon. To assess the extent of this breakdown in a UV complete framework we study string-theoretic effects on nice slices in Schwarzschild black holes. Our purpose is two-fold. First, we use nice slices to address various open questions and caveats of [1] where it was argued that boost-enhanced non-adiabatic string-theoretic effects at the horizon could provide a dynamical mechanism for the firewall. Second, we identify two non-adiabatic effects on nice slices in Schwarzschild black holes: pair production of open strings near the horizon enhanced by the presence of the infinite tower of highly excited string states and a late-time non-adiabatic effect intrinsic to nice slices.

  16. Adiabatic reduction of a model of stochastic gene expression with jump Markov process. (United States)

    Yvinec, Romain; Zhuge, Changjing; Lei, Jinzhi; Mackey, Michael C


    This paper considers adiabatic reduction in a model of stochastic gene expression with bursting transcription considered as a jump Markov process. In this model, the process of gene expression with auto-regulation is described by fast/slow dynamics. The production of mRNA is assumed to follow a compound Poisson process occurring at a rate depending on protein levels (the phenomena called bursting in molecular biology) and the production of protein is a linear function of mRNA numbers. When the dynamics of mRNA is assumed to be a fast process (due to faster mRNA degradation than that of protein) we prove that, with appropriate scalings in the burst rate, jump size or translational rate, the bursting phenomena can be transmitted to the slow variable. We show that, depending on the scaling, the reduced equation is either a stochastic differential equation with a jump Poisson process or a deterministic ordinary differential equation. These results are significant because adiabatic reduction techniques seem to have not been rigorously justified for a stochastic differential system containing a jump Markov process. We expect that the results can be generalized to adiabatic methods in more general stochastic hybrid systems.

  17. Kinetically constrained ring-polymer molecular dynamics for non-adiabatic chemical reactions. (United States)

    Menzeleev, Artur R; Bell, Franziska; Miller, Thomas F


    We extend ring-polymer molecular dynamics (RPMD) to allow for the direct simulation of general, electronically non-adiabatic chemical processes. The kinetically constrained (KC) RPMD method uses the imaginary-time path-integral representation in the set of nuclear coordinates and electronic states to provide continuous equations of motion that describe the quantized, electronically non-adiabatic dynamics of the system. KC-RPMD preserves the favorable properties of the usual RPMD formulation in the position representation, including rigorous detailed balance, time-reversal symmetry, and invariance of reaction rate calculations to the choice of dividing surface. However, the new method overcomes significant shortcomings of position-representation RPMD by enabling the description of non-adiabatic transitions between states associated with general, many-electron wavefunctions and by accurately describing deep-tunneling processes across asymmetric barriers. We demonstrate that KC-RPMD yields excellent numerical results for a range of model systems, including a simple avoided-crossing reaction and condensed-phase electron-transfer reactions across multiple regimes for the electronic coupling and thermodynamic driving force.

  18. Extension of the adiabatic regularization method to spin-1/2 fields (United States)

    Landete, Aitor


    The adiabatic regularization method was designed by L. Parker [1] for scalar fields in order to to subtract the potentially UV divergences that appear in the particle number operator. After that the method was generalized [2] to remove, in a consistent way, the UV divergences that appear in the expectation value of the stress-energy tensor in homogeneous cosmological backgrounds. We are going to provide here the extension of the adiabatic regularization method to spin-1/2 fields first given in [3]. In order to achieve this extension we will show the generalization of the adiabatic expansion for fermionic fields which differs significantly from the WKB-type expansion that works for the scalar modes. We will also show the consistency of the extended method computing well-known results, computed by other renormalization methods for a Dirac field in a FLRW spacetime, like the conformal and axial anomalies. Finally we will compute the expectation value of the stress-energy tensor for a Dirac field in a de Sitter spacetime.

  19. Low-Power Adiabatic Computing with Improved Quasistatic Energy Recovery Logic

    Directory of Open Access Journals (Sweden)

    Shipra Upadhyay


    Full Text Available Efficiency of adiabatic logic circuits is determined by the adiabatic and non-adiabatic losses incurred by them during the charging and recovery operations. The lesser will be these losses circuit will be more energy efficient. In this paper, a new approach is presented for minimizing power consumption in quasistatic energy recovery logic (QSERL circuit which involves optimization by removing the nonadiabatic losses completely by replacing the diodes with MOSFETs whose gates are controlled by power clocks. Proposed circuit inherits the advantages of quasistatic ERL (QSERL family but is with improved power efficiency and driving ability. In order to demonstrate workability of the newly developed circuit, a 4 × 4 bit array multiplier circuit has been designed. A mathematical expression to calculate energy dissipation in proposed inverter is developed. Performance of the proposed logic (improved quasistatic energy recovery logic (IQSERL is analyzed and compared with CMOS and reported QSERL in their representative inverters and multipliers in VIRTUOSO SPECTRE simulator of Cadence in 0.18 μm UMC technology. In our proposed (IQSERL inverter the power efficiency has been improved to almost 20% up to 50 MHz and 300 fF external load capacitance in comparison to CMOS and QSERL circuits.

  20. Unilateral muscle contractions enhance creative thinking. (United States)

    Goldstein, Abraham; Revivo, Ketty; Kreitler, Michal; Metuki, Nili


    Following the notion of relative importance of the right hemisphere (RH) in creative thinking, we explored the possibility of enhancing creative problem solving by artificially activating the RH ahead of time using unilateral hand contractions. Participants attempted to complete the Remote Associates Test after squeezing a ball with either their left or right hand. As predicted, participants who contracted their left hand (thus activating the RH) achieved higher scores than those who used their right hand and those who did not contract either hand. Our findings indicate that tilting the hemispheric balance toward the processing mode of one hemisphere by motor activation can greatly influence the outcome of thought processes. Regardless of the specific mechanism involved, this technique has the potential for acting as a therapeutic or remedial manipulation and could have wide applications in aiding individuals with language impairments or other disorders that are believed to be related to hemispheric imbalances.

  1. The Lanthanide Contraction Revisited (United States)

    Seitz, Michael; Oliver, Allen G.; Raymond, Kenneth N.


    A complete, isostructural series of complexes with La-Lu (except Pm) with the ligand TREN-1,2-HOIQO has been synthesized and structurally characterized by means of single-crystal X-ray analysis. All complexes are 1D-polymeric species in the solid state, with the lanthanide being in an eight-coordinate, distorted trigonal-dodecahedral environment with a donor set of eight unique oxygen atoms. This series constitutes the first complete set of isostructural complexes from La-Lu (without Pm) with a ligand of denticity greater than two. The geometric arrangement of the chelating moieties slightly deviates across the lanthanide series, as analyzed by a shape parameter metric based on the comparison of the dihedral angles along all edges of the coordination polyhedron. The apparent lanthanide contraction in the individual Ln-O bond lengths deviates considerably from the expected quadratic decrease that was found previously in a number of complexes with ligands of low denticity. The sum of all bond lengths around the trivalent metal cation, however, is more regular, showing an almost ideal quadratic behavior across the entire series. The quadratic nature of the lanthanide contraction is derived theoretically from Slater’s model for the calculation of ionic radii. In addition, the sum of all distances along the edges of the coordination polyhedron show exactly the same quadratic dependence as the Ln-X bond lengths. The universal validity of this coordination sphere contraction, concomitant with the quadratic decrease in Ln-X bond lengths, was confirmed by reexamination of four other, previously published series of lanthanide complexes. Due to the importance of multidentate ligands for the chelation of rare-earth metals, this result provides a significant advance for the prediction and rationalization of the geometric features of the corresponding lanthanide complexes, with great potential impact for all aspects of lanthanide coordination. PMID:17705483

  2. The Lanthanide Contraction Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, Michael; Oliver, Allen G.; Raymond, Kenneth N.


    A complete, isostructural series of lanthanide complexes (except Pm) with the ligand TREN-1,2-HOIQO has been synthesized and structurally characterized by means of single-crystal X-ray analysis. All complexes are 1D-polymeric species in the solid state, with the lanthanide being in an eight-coordinate, distorted trigonal-dodecahedral environment with a donor set of eight unique oxygen atoms. This series constitutes the first complete set of isostructural lanthanide complexes with a ligand of denticity greater than two. The geometric arrangement of the chelating moieties slightly deviates across the lanthanide series, as analyzed by a shape parameter metric based on the comparison of the dihedral angles along all edges of the coordination polyhedron. The apparent lanthanide contraction in the individual Ln-O bond lengths deviates considerably from the expected quadratic decrease that was found previously in a number of complexes with ligands of low denticity. The sum of all bond lengths around the trivalent metal cation, however, is more regular, showing an almost ideal quadratic behavior across the entire series. The quadratic nature of the lanthanide contraction is derived theoretically from Slater's model for the calculation of ionic radii. In addition, the sum of all distances along the edges of the coordination polyhedron show exactly the same quadratic dependency as the Ln-X bond lengths. The universal validity of this coordination sphere contraction, concomitant with the quadratic decrease in Ln-X bond lengths, was confirmed by reexamination of four other, previously published, almost complete series of lanthanide complexes. Due to the importance of multidentate ligands for the chelation of rare-earth metals, this result provides a significant advance for the prediction and rationalization of the geometric features of the corresponding lanthanide complexes, with great potential impact for all aspects of lanthanide coordination.

  3. Adiabatic thermostatistics of the two parameter entropy and the role of Lambert's W-function in its applications


    Chandrashekar, R.; Segar, J


    A unified framework to describe the adiabatic class of ensembles in the generalized statistical mechanics based on Schwammle-Tsallis two parameter (q, q') entropy is proposed. The generalized form of the equipartition theorem, virial theorem and the adiabatic theorem are derived. Each member of the class of ensembles is illustrated using the classical nonrelativistic ideal gas and we observe that the heat functions could be written in terms of the Lambert's W-function in the large N limit. In...

  4. Contracting singular horseshoe (United States)

    Morales, C. A.; San Martín, B.


    We suggest a notion of hyperbolicity adapted to the geometric Rovella attractor (Robinson 2012 An Introduction to Dynamical Systems—Continuous and Discrete (Pure and Applied Undergraduate Texts vol 19) 2nd edn (Providence, RI: American Mathematical Society)) . More precisely, we call a partially hyperbolic set asymptotically sectional-hyperbolic if its singularities are hyperbolic and if its central subbundle is asymptotically sectional expanding outside the stable manifolds of the singularities. We prove that there are highly chaotic flows with Rovella-like singularities exhibiting this kind of hyperbolicity. We shall call them contracting singular horseshoes.

  5. Negotiating Efficient PPP Contracts

    DEFF Research Database (Denmark)

    Tvarnø, Christina D.

    should consider tendering out PPP projects in the spirit of joint utility because joint utility can increase the concept of more value for money; the cornerstone of the PPP concept. This paper discusses the positive gains from negotiation and compares it with the upcoming possibilities in the EU public....... Joint utility can increase the concept of more value for money; the cornerstone of the PPP concept. The paper draws upon existing legal content regarding collaboration and common goals and game theory to explain the benefits from implementing similar clauses in PPP contracts....

  6. Adiabatic flow curves of metallic materials at high strain rates

    Energy Technology Data Exchange (ETDEWEB)

    El-Magd, E. [Technische Hochschule Aachen (Germany); Scholles, H. [Rheinmetall Industrie GmbH, Unterluess (Germany); Weisshaupt, H. [Rheinmetall Industrie GmbH, Unterluess (Germany)


    Dynamic compression tests are carried out on Armco iron, Cr-V-steel, Ni-Cr-Mo-V-steel, an austenitic Ni-Cr-Mo-steel, tantalum, nickel and Ni{sub 3}Al and magnesium. The flow curves are analysed to determine the influence of the deformation energy which is transformed into heat on the flow behaviour and mechanical stability. Not only the material properties but also the conditions of friction between the specimen and the compresion tool are found to have a greate influence on the flow stress reduction and stability. High frictional forces promote mechanical instability of materials with low strain hardening and low strain rate sensitivity. (orig.) [Deutsch] Schlagdruckversuche werden an Armcoeisen, CrV-Stahl, NiCr-MoV-Stahl, austenitischen NiCrMo-Stahl, Tantal, Nickel, Ni{sub 3}Al und Magnesium durchgefuehrt. Die ermittelten Fliesskurven werden analysiert, um den Einfluss der in Waerme umgewandelte Verformungsarbeit auf das Fliessverhalten und die mechanische Stabilitaet zu erfassen. Nicht nur die Werkstoffeigenschaften sondern auch die Reibungsbedingungen erweisen sich als massgebliche Einflussgroessen fuer Fliessspannungsabnahme und die Stabilitaet. Hohe Reibungskraefte foerdern die Verformungslokalisierung und die mechanische Instabilitaet von Werkstoffen mit niedriger Verfestigung und niedriger Geschwindigkeitsempfindlichkeit. (orig.)

  7. An application of miniscale experiments on Earth to refine microgravity analysis of adiabatic multiphase flow in space (United States)

    Rothe, Paul H.; Martin, Christine; Downing, Julie


    Adiabatic two-phase flow is of interest to the design of multiphase fluid and thermal management systems for spacecraft. This paper presents original data and unifies existing data for capillary tubes as a step toward assessing existing multiphase flow analysis and engineering software. Comparisons of theory with these data once again confirm the broad accuracy of the theory. Due to the simplicity and low cost of the capillary tube experiments, which were performed on earth, we were able to closely examine for the first time a flow situation that had not previously been examined appreciably by aircraft tests. This is the situation of a slug flow at high quality, near transition to annular flow. Our comparison of software calculations with these data revealed overprediction of pipeline pressure drop by up to a factor of three. In turn, this finding motivated a reexamination of the existing theory, and then development of a new analytical and is in far better agreement with the data. This sequence of discovery illustrates the role of inexpensive miniscale modeling on earth to anticipate microgravity behavior in space and to complete and help define needs for aircraft tests.

  8. Defining Acquisition and Contracting Terms Associated with Contract Administration (United States)


    Riemer Handbook of Government Contract Administration, the Armed Services Pricing Manual ( ASPM ), and AFIT’s Govern- ment Contract Law course and case book...these duties into general categories, as outlined in the ASPM and Government Contract Cost (16:B-3) (36:25-7,GL-3). NCMA’s Desktop Guide to Basic...processes by listing exactly how an audit is carried out and what it determines. For example, Arnavas, Rishe, and the ASPM conclude that an au- dit is

  9. Project management plan for Contract Management Information System (CONTRACT)

    Energy Technology Data Exchange (ETDEWEB)

    Severud, K.J.


    The office of the Vice President of A/E Construction for ICF Kaiser has requested that OSHA compliance statistics be made available to management for companies subcontracting to the ICF Kaiser Company. In addition, a need to better manage contract administrative data for the Contracts Administration and the Construction Management Projects organizations has been identified. The Contract Management Information System is being developed to achieve these objectives. This document provides a Project Management Plan for development of the Contract Management Administration System (CONTRACT) by Design Services DAD/CAE Support. The Project Management Plan describes the project work breakdown structure, safety and quality considerations, with associated cost, schedule and project management information. The CONTRACT System is intended to aid the ICF Kaiser divisions with tracking of A/E subcontractor information to include general contract administration information used by the Contracts Administration organization, contract and safety performance data used by the Construction Management Projects and office of the organization and Vice President of A/E Construction.

  10. 48 CFR 716.406 - Contract clauses. (United States)


    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 716.406 Section 716.406 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost Reimbursement Contracts 716.406 Contract clauses. The...

  11. 48 CFR 1416.405 - Contract clauses. (United States)


    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 1416.405 Section 1416.405 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Incentive Contracts 1416.405 Contract clauses. The BPC, without the power...

  12. 48 CFR 732.111 - Contract clauses. (United States)


    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 732.111... CONTRACTING REQUIREMENTS CONTRACT FINANCING General 732.111 Contract clauses. (a) (b) USAID may obtain short... indefinite quantity contracts that are a combination of contract types. Rather than using the fixed-price...

  13. 48 CFR 916.307 - Contract clauses. (United States)


    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 916.307 Section 916.307 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost-Reimbursement Contracts 916.307 Contract clauses. (g) Insert the...

  14. Hyperbolic contraction measuring systems for extensional flow (United States)

    Nyström, M.; Tamaddon Jahromi, H. R.; Stading, M.; Webster, M. F.


    In this paper an experimental method for extensional measurements on medium viscosity fluids in contraction flow is evaluated through numerical simulations and experimental measurements. This measuring technique measures the pressure drop over a hyperbolic contraction, caused by fluid extension and fluid shear, where the extensional component is assumed to dominate. The present evaluative work advances our previous studies on this experimental method by introducing several contraction ratios and addressing different constitutive models of varying shear and extensional response. The constitutive models included are those of the constant viscosity Oldroyd-B and FENE-CR models, and the shear-thinning LPTT model. Examining the results, the impact of shear and first normal stress difference on the measured pressure drop are studied through numerical pressure drop predictions. In addition, stream function patterns are investigated to detect vortex development and influence of contraction ratio. The numerical predictions are further related to experimental measurements for the flow through a 15:1 contraction ratio with three different test fluids. The measured pressure drops are observed to exhibit the same trends as predicted in the numerical simulations, offering close correlation and tight predictive windows for experimental data capture. This result has demonstrated that the hyperbolic contraction flow is well able to detect such elastic fluid properties and that this is matched by numerical predictions in evaluation of their flow response. The hyperbolical contraction flow technique is commended for its distinct benefits: it is straightforward and simple to perform, the Hencky strain can be set by changing contraction ratio, non-homogeneous fluids can be tested, and one can directly determine the degree of elastic fluid behaviour. Based on matching of viscometric extensional viscosity response for FENE-CR and LPTT models, a decline is predicted in pressure drop for

  15. Some ancestors of contraction analysis

    DEFF Research Database (Denmark)

    Jouffroy, Jerome


    Contraction analysis is a recent tool for analyzing the convergence behavior of nonlinear systems in state-space form (see Lohmiller and Slotine [16] for the main reference). However, it seems that earlier results derived by mathematicians in the 1950s closely match some of the results...... of contraction analysis. In this paper, we review and place into perspective some references of this era, and relate them with contraction....

  16. Methodological remarks on contraction theory

    DEFF Research Database (Denmark)

    Jouffroy, Jerome; Slotine, Jean-Jacques E.

    classical examples traditionally addressed using Lyapunov theory. Even in these cases, contraction tools can often yield significantly simplified analysis. The examples include adaptive control, robotics, and a proof of convergence of the deterministic Extended Kalman Filter.......Because contraction analysis stems from a differential and incremental framework, the nature and methodology of contraction-based proofs are significantly different from those of their Lyapunov-based counterparts. This paper specifically studies this issue, and illustrates it by revisiting some...

  17. Performance contracts for police forces


    Ben Vollaard


    In 2003, the government will enter into performance contracts with each of the 25 regional police forces. The performance contracts establish a direct link between meeting a number of quantitative performance targets and financial incentives. A major improvement in police performance is necessary to meet the objective of 20 to 25 percent less criminal and disorderly behavior by 2006. A closer look at the performance contracts learns that they may not be the most appropriate policy instrument ...

  18. The Danish Contracting System

    DEFF Research Database (Denmark)

    Bonke, Sten; Levring, Peter

    development trends are indicated. A third section describes the contemporary external, regulative framework of construction projects. In the two final sections the construction process is decomposed with regard to 1)phases and activities and 2)procurement forms, actors and functions.......The paper is mainly concerned with the institutional framework of the Danish construction industry, describing structures, rules and actors' roles within a perspective of nationally defined procedural guidelines on construction projects. These aspects are treated under the concept of a "contracting...... system". After a short introduction to the structure and activities of the industry the post-war development is reviewed, in particular emphasising the importance of the early industrialisation process which in an international perspective represents quite unique features. Furthermore the most recent...

  19. Forthcoming indefinite contract review procedure

    CERN Multimedia

    Human Resources Department


    The vacancy notices for posts opened with a view to the award of an indefinite contract will be published in early April 2011. In the meantime, the list of posts to be opened this spring is available at the following address: Indefinite contract posts - spring 2011 A second exercise will take place in autumn 2011 and, as of 2012, the indefinite contract award procedure will only be held once a year, in autumn. For more information please consult:  

  20. Simplifying Contract-Violating Traces

    Directory of Open Access Journals (Sweden)

    Christian Colombo


    Full Text Available Contract conformance is hard to determine statically, prior to the deployment of large pieces of software. A scalable alternative is to monitor for contract violations post-deployment: once a violation is detected, the trace characterising the offending execution is analysed to pinpoint the source of the offence. A major drawback with this technique is that, often, contract violations take time to surface, resulting in long traces that are hard to analyse. This paper proposes a methodology together with an accompanying tool for simplifying traces and assisting contract-violation debugging.

  1. Uterine Contraction Modeling and Simulation (United States)

    Liu, Miao; Belfore, Lee A.; Shen, Yuzhong; Scerbo, Mark W.


    Building a training system for medical personnel to properly interpret fetal heart rate tracing requires developing accurate models that can relate various signal patterns to certain pathologies. In addition to modeling the fetal heart rate signal itself, the change of uterine pressure that bears strong relation to fetal heart rate and provides indications of maternal and fetal status should also be considered. In this work, we have developed a group of parametric models to simulate uterine contractions during labor and delivery. Through analysis of real patient records, we propose to model uterine contraction signals by three major components: regular contractions, impulsive noise caused by fetal movements, and low amplitude noise invoked by maternal breathing and measuring apparatus. The regular contractions are modeled by an asymmetric generalized Gaussian function and least squares estimation is used to compute the parameter values of the asymmetric generalized Gaussian function based on uterine contractions of real patients. Regular contractions are detected based on thresholding and derivative analysis of uterine contractions. Impulsive noise caused by fetal movements and low amplitude noise by maternal breathing and measuring apparatus are modeled by rational polynomial functions and Perlin noise, respectively. Experiment results show the synthesized uterine contractions can mimic the real uterine contractions realistically, demonstrating the effectiveness of the proposed algorithm.

  2. Distributed capillary adiabatic tissue homogeneity model in parametric multi-channel blind AIF estimation using DCE-MRI. (United States)

    Kratochvíla, Jiří; Jiřík, Radovan; Bartoš, Michal; Standara, Michal; Starčuk, Zenon; Taxt, Torfinn


    One of the main challenges in quantitative dynamic contrast-enhanced (DCE) MRI is estimation of the arterial input function (AIF). Usually, the signal from a single artery (ignoring contrast dispersion, partial volume effects and flow artifacts) or a population average of such signals (also ignoring variability between patients) is used. Multi-channel blind deconvolution is an alternative approach avoiding most of these problems. The AIF is estimated directly from the measured tracer concentration curves in several tissues. This contribution extends the published methods of multi-channel blind deconvolution by applying a more realistic model of the impulse residue function, the distributed capillary adiabatic tissue homogeneity model (DCATH). In addition, an alternative AIF model is used and several AIF-scaling methods are tested. The proposed method is evaluated on synthetic data with respect to the number of tissue regions and to the signal-to-noise ratio. Evaluation on clinical data (renal cell carcinoma patients before and after the beginning of the treatment) gave consistent results. An initial evaluation on clinical data indicates more reliable and less noise sensitive perfusion parameter estimates. Blind multi-channel deconvolution using the DCATH model might be a method of choice for AIF estimation in a clinical setup. © 2015 Wiley Periodicals, Inc.

  3. Subchannel Scale Thermal-Hydraulic Analysis of Rod Bundle Geometry under Single-phase Adiabatic Conditions Using CUPID

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Seok Jong; Park, Goon Cherl; Cho, Hyoung Kyu [KAERI, Daejeon (Korea, Republic of)


    In Korea, subchannel analysis code, MATRA has been developed by KAERI (Korea Atomic Energy Research Institute). MATRA has been used for reactor core T/H design and DNBR (Departure from Nucleate Boiling Ratio) calculation. Also, the code has been successfully coupled with neutronics code and fuel analysis code. However, since major concern of the code is not the accident simulation, some features of the code are not optimized for the accident conditions, such as the homogeneous model for two-phase flow and spatial marching method for numerical scheme. For this reason, in the present study, application of CUPID for the subchannel scale T/H analysis in rod bundle geometry was conducted. CUPID is a component scale T/H analysis code which adopts three dimensional two-fluid three-field model developed by KAERI. In this paper, the validation results of the CUPID code for subchannel scale rod bundle analysis at single phase adiabatic conditions were presented. At first, the physical models required for a subchannel scale analysis were implemented to CUPID. In the future, the scope of validation tests will be extended to diabetic and two phase flow conditions and required models will be implemented into CUPID.

  4. Psychological contract types as moderator in the breach-violation and violation-burnout relationships. (United States)

    Jamil, Amber; Raja, Usman; Darr, Wendy


    This research examined the relationships between perceived psychological contract breach, felt violation, and burnout in a sample (n = 361) of employees from various organizations in Pakistan. The moderating role of contract types in these relationships was also tested. Findings supported a positive association between perceived psychological contract breach and felt violation and both were positively related to burnout. Transactional and relational contracts moderated the felt violation-burnout relationship. Scores on relational contract type tended to be higher than for transactional contract type showing some contextual influence.

  5. Adiabatic Charts (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — WBAN-31 is a form on which the Weather Bureau, Army and Navy recorded weather observations in the upper air as observed by rawinsonde and radiosonde. The collection...

  6. Principles of contracting; Grundlagen des Contracting. Waermecontracting - worauf es ankommt

    Energy Technology Data Exchange (ETDEWEB)

    Meixner, H. [HessenENERGIE, Gesellschaft fuer Rationelle Energienutzung mbH, Wiesbaden (Germany)


    Contracting has established itself as a permanent factor in the debate about energy policy and the energy industry. In a survey of senior managers in the German energy sector on the trends and services which will gain heavily in importance from 2002 to 2004, contracting occupied a prime position, immediately after 'New services in general' and 'Multi-utility' and far ahead of 'Electricity trading' or 'Telecommunications/Power lines'. Energy policy expectations of contracting are high and a lot of confidence is being placed in this service. Similarly long-term planning perspectives to those usual for energy generation facilities (e.g. power stations) must thus be facilitated for investment in saving energy. In its original version, contracting is only intended for the implementation of investments dedicated purely to saving energy, if possible, and accompanying measures by third parties. The amortisation of investments made by the contractor from the savings which can be made on energy costs is disputed. In parallel to such 'economy contracting' (also known as 'performance contracting'), energy supply contracting (also known as plant contracting or the supply of useful energy) has predominantly emerged, with a stronger orientation towards ordinary customer energy supply contracts. The user commissions an energy utility to provide the useful energy required. The utility frequently also assumes investment in the necessary technical plant, including planning, finance and operation - analogous to the supply of district heating. Various forms of finance contracting also exist which tend towards leasing and contracting models for the management of existing technical installations, which does not anticipate any (major) investment by the contractor. (orig.) [German] In den 90er Jahren hat Contracting 'Karriere' gemacht - allerdings eher der Begriff als die Sache, die er bezeichnet. Inzwischen sind aber

  7. Symmetry-broken effects on electron momentum spectroscopy caused by adiabatic vibration (United States)

    Zhu, Yinghao; Ma, Xiaoguang; Lou, Wenhua; Wang, Meishan; Yang, Chuanlu


    The vibronic coupling effect is usually studied by invoking the breakdown of Born-Oppenheimer approximation. The present study shows that the symmetry-broken effect induced by nuclei vibrations can also lead strong impact on the electronic states under the framework of Born-Oppenheimer approximation. This adiabatic-invoking vibrational effect on electron momentum spectroscopy of ethylene (C2H4), ethane (C2H6) and methanol (CH3OH) was studied with quantum mechanical method. The results show that electron momentum spectroscopy of localized electrons, especially core electrons in axial symmetric geometry molecules can be affected unusually and strongly by several asymmetric vibrational modes.

  8. Generalized adiabatic polaron hopping: Meyer-Neldel compensation and Poole-Frenkel behavior. (United States)

    Emin, David


    The commonly employed adiabatic treatment of polaron hopping is extended to treat the continuous alteration of a carrier wave function with the atoms' movements and a carrier's long-range interaction with a polar surrounding. These features, respectively, introduce carrier-induced softening of the atoms' vibrations and a hopping activation energy that depends on hopping distance. The Meyer-Neldel compensation effect results from carrier-induced softening of vibrations. Poole-Frenkel behavior emerges for electric-field driven polaron hopping in ionic and polar media.

  9. Adiabatically switched-on electrical bias and the Landauer-Buttiker formula

    DEFF Research Database (Denmark)

    Cornean, Horia; Duclos, P.; Nenciu, G.


    Consider a three dimensional system which looks like a cross connected pipe system, i.e., a small sample coupled to a finite number of leads. We investigate the current running through this system, in the linear response regime, when we adiabatically turn on an electrical bias between leads....... The main technical tool is the use of a finite volume regularization, which allows us to define the current coming out of a lead as the time derivative of its charge. We finally prove that in virtually all physically interesting situations, the conductivity tensor is given by a Landauer-Büttiker type...

  10. Adiabatically switched-on electrical bias in continuous systems, and the Landauer-Büttiker formula

    DEFF Research Database (Denmark)

    Cornean, Horia; Duclos, Pierre; Nenciu, Gheorghe

    Consider a three dimensional system which looks like a cross-connected pipe system, i.e. a small sample coupled to a finite number of leads. We investigate the current running through this system, in the linear response regime, when we adiabatically turn on an electrical bias between leads....... The main technical tool is the use of a finite volume regularization, which allows us to define the current coming out of a lead as the time derivative of its charge. We finally prove that in virtually all physically interesting situations, the conductivity tensor is given by a Landauer-Büttiker type...

  11. Short-length and robust polarization rotators in periodically poled lithium niobate via shortcuts to adiabaticity. (United States)

    Chen, Xi; Wang, Hong-Wei; Ban, Yue; Tseng, Shuo-Yen


    Conventional narrowband spectrum polarization devices are short but not robust, based on quasi-phase matching (QPM) technique, in periodically poled lithium niobate (PPLN) crystal. In this paper, we propose short-length and robust polarization rotators by using shortcuts to adiabaticity. Beyond the QPM condition, the electric field and period of PPLN crystal are designed in terms of invariant dynamics, and further optimized with respect to input wavelength/refractive index variations. In addition, the stability of conversion efficiency on the electric field and period of PPLN crystal is also discussed. As a consequence, the optimal shortcuts are fast as well as robust, which provide broadband spectrum polarization devices with short length.

  12. Adiabatic density perturbations and matter generation from the minimal supersymmetric standard model. (United States)

    Enqvist, Kari; Kasuya, Shinta; Mazumdar, Anupam


    We propose that the inflaton is coupled to ordinary matter only gravitationally and that it decays into a completely hidden sector. In this scenario both baryonic and dark matter originate from the decay of a flat direction of the minimal supersymmetric standard model, which is shown to generate the desired adiabatic perturbation spectrum via the curvaton mechanism. The requirement that the energy density along the flat direction dominates over the inflaton decay products fixes the flat direction almost uniquely. The present residual energy density in the hidden sector is typically shown to be small.

  13. Adiabatic wall temperature and heat transfer coefficient influenced by separated supersonic flow

    Directory of Open Access Journals (Sweden)

    Leontiev Alexander


    Full Text Available Investigations of supersonic air flow around plane surface behind a rib perpendicular to the flow direction are performed. Research was carried out for free stream Mach number 2.25 and turbulent flow regime - Rex>2·107. Rib height was varied in range from 2 to 8 mm while boundary layer thickness at the nozzle exit section was about 6 mm. As a result adiabatic wall temperature and heat transfer coefficient are obtained for flow around plane surface behind a rib incontrast with the flow around plane surface without any disturbances.

  14. Direct measurement of energetic electrons coupling to an imploding low-adiabat inertial confinement fusion capsule. (United States)

    Döppner, T; Thomas, C A; Divol, L; Dewald, E L; Celliers, P M; Bradley, D K; Callahan, D A; Dixit, S N; Harte, J A; Glenn, S M; Haan, S W; Izumi, N; Kyrala, G A; LaCaille, G; Kline, J K; Kruer, W L; Ma, T; MacKinnon, A J; McNaney, J M; Meezan, N B; Robey, H F; Salmonson, J D; Suter, L J; Zimmerman, G B; Edwards, M J; MacGowan, B J; Kilkenny, J D; Lindl, J D; Van Wonterghem, B M; Atherton, L J; Moses, E I; Glenzer, S H; Landen, O L


    We have imaged hard x-ray (>100 keV) bremsstrahlung emission from energetic electrons slowing in a plastic ablator shell during indirectly driven implosions at the National Ignition Facility. We measure 570 J in electrons with E>100 keV impinging on the fusion capsule under ignition drive conditions. This translates into an acceptable increase in the adiabat α, defined as the ratio of total deuterium-tritium fuel pressure to Fermi pressure, of 3.5%. The hard x-ray observables are consistent with detailed radiative-hydrodynamics simulations, including the sourcing and transport of these high energy electrons.

  15. Quantification of the effect of hysteresis on the adiabatic temperature change in magnetocaloric materials

    DEFF Research Database (Denmark)

    von Moos, Lars; Bahl, Christian R.H.; Nielsen, Kaspar Kirstein


    description of the phase transition at varying magnetic fields and temperatures. Using detailed experimental property data, a Preisach type model is used to describe the thermal hysteresis effects and simulate the material under realistic working conditions. We find that the adiabatic temperature change......We quantify the effect of hysteresis on the performance of the magnetocaloric first order material Gd5Si2Ge2 undergoing an ideal active magnetic regenerator (AMR) cycle. The material is carefully characterized through magnetometry (VSM) and calorimetry (DSC) in order to enable an accurate model...

  16. Deterministic single-atom excitation via adiabatic passage and Rydberg blockade (United States)

    Beterov, I. I.; Tretyakov, D. B.; Entin, V. M.; Yakshina, E. A.; Ryabtsev, I. I.; MacCormick, C.; Bergamini, S.


    We propose to use adiabatic rapid passage with a chirped laser pulse in the strong dipole blockade regime to deterministically excite only one Rydberg atom from randomly loaded optical dipole traps or optical lattices. The chirped laser excitation is shown to be insensitive to the random number N of the atoms in the traps. Our method overcomes the problem of the N dependence of the collective Rabi frequency, which was the main obstacle for deterministic single-atom excitation in the ensembles with unknown N, and can be applied for single-atom loading of dipole traps and optical lattices.

  17. Adiabatic capture theory applied to N+NH-->N2+H at low temperature. (United States)

    Frankcombe, Terry J; Nyman, Gunnar


    The adiabatic capture centrifugal sudden approximation (ACCSA) has been applied to the ground state reaction N+NH-->N2+H over the temperature range 2-300 K using an existent potential energy surface. The resultant thermal rate constants are in agreement with available rate constants from quasi-classical trajectory calculations but are significantly larger than the available experimentally derived rate. The calculated rate constants monotonically increase with increasing temperature but could only be approximately described with a simple Arrhenius-like form. Subtle quantum effects are evident in the initial rotational state resolved cross sections and rate constants.

  18. Adiabatic tapered optical fiber fabrication for exciting whispering gallery modes in microcavities (United States)

    Chenari, Z.; Latifi, H.; Hashemi, R. S.; Doroudmand, F.


    This article demonstrates an investigation and analysis of a tapered fiber fabrication using an etchant droplet method. To achieve precise control on process, a two-step etching method is proposed (using 48% concentration of HF acid and Buffered HF) which results in low-loss adiabatic tapered fiber. A spectrum analysis monitoring in addition to a microscopy system was used to verify the etching progress. Tapers with losses less than 0.4 dB in air and 4.5 dB in water are demonstrated. A biconical fiber taper fabricated using this method was used to excite the WGMs on a microsphere surface in aquatic environment.

  19. Adiabatic cooling of a tunable Bose-Fermi mixture in an optical lattice

    DEFF Research Database (Denmark)

    Sørensen, Ole Søe; Nygaard, Nicolai; Blakie, P.B.


    We consider an atomic Fermi gas confined in a uniform optical lattice potential, where the atoms can pair into molecules via a magnetic field controlled narrow Feshbach resonance. Thus by adjusting the magnetic field the portion of fermionic and bosonic particles in the system can be continuously...... varied. We analyze the statistical mechanics of this system and consider the interplay of the lattice physics with the atom-molecule conversion. We study the entropic behavior of the system and characterize the temperature changes that occur during adiabatic ramps across the Feshbach resonance. We show...... that an appropriate choice of filling fraction can be used to reduce the system temperature during such ramps....

  20. Implementation of one-qubit holonomic rotation gate by adiabatic passage

    Directory of Open Access Journals (Sweden)

    R Nader-Ali


    Full Text Available We propose a robust scheme, using tripod stimulated Raman adiabatic passage, to generate one-qubit rotation gate. In this scheme, a four-level atom interacts with three resonant laser pulses and time evolution of the corresponding coherent system is designed such that the rotation gate is implemented at the end of process. Rotation angle in this gate is holonomic and has a geometrical basis in the parameter space. We also explore the effect of spontaneous emission on the population transfer with numerical solution of Schrödinger and Liouville equations.

  1. Adiabatic tapered optical fiber Fabry-Perot structure as a refractive index sensor (United States)

    Ranjbar-Naeini, O. R.; Chenari, Z.; Zarafshani, P.; Jafari, F.; Latifi, H.


    In this article, an Adiabatic Tapered Optical Fiber - Fabry Perot (ATOF-FP) Sensor is introduced as a simple refractive index sensor. This FP Cavity relies upon reflection from two cleave ends of ATOF sensor's arms. Its spectrum was investigated with Distributed Feedback (DFB) tunable laser and photo detector. With analyzing the change in Optical Transmission Power (OTP) versus refractive index changes, the sensitivity of ATOF was -66.21 dB/RIU. In addition, the visibility of FP was studied. Its RI sensitivity was -0.975 1/RIU. The sensor resolution was 2.3 × 10-5 RIU with consideration of minimum detectable signal of acquisition system.

  2. Exact analysis of gate noise effects on non-adiabatic transformations of spin-orbit qubits (United States)

    Ulčakar, Lara; Ramšak, Anton


    We considered various types of potential noise in gates controlling non-adiabatic holonomic transformations of spin-qubits in one and two-dimensional systems with the Rashba interaction. It is shown how exact results can be derived for deviations of spin rotation angle and fidelity of the qubit transformation after a completed transformation. Errors in initial values of gate potentials and time-dependent drivings are considered and exact results for white gate noise are derived and analysed in detail. It is demonstrated how the drivings can be tuned to optimise the final fidelity of the transformation and to minimise the variances of qubit transformations.

  3. Deterministic single-atom excitation via adiabatic passage and Rydberg blockade

    Energy Technology Data Exchange (ETDEWEB)

    Beterov, I. I.; Tretyakov, D. B.; Entin, V. M.; Yakshina, E. A.; Ryabtsev, I. I.; MacCormick, C.; Bergamini, S. [A. V. Rzhanov Institute of Semiconductor Physics SB RAS, Prospekt Lavrentieva 13, 630090 Novosibirsk (Russian Federation); Open University, Walton Hall, Milton Keynes MK6 7AA (United Kingdom)


    We propose to use adiabatic rapid passage with a chirped laser pulse in the strong dipole blockade regime to deterministically excite only one Rydberg atom from randomly loaded optical dipole traps or optical lattices. The chirped laser excitation is shown to be insensitive to the random number N of the atoms in the traps. Our method overcomes the problem of the {radical}(N) dependence of the collective Rabi frequency, which was the main obstacle for deterministic single-atom excitation in the ensembles with unknown N, and can be applied for single-atom loading of dipole traps and optical lattices.

  4. Highly Sensitive Refractive Index Sensor Based on Adiabatically Tapered Microfiber Long Period Gratings

    Directory of Open Access Journals (Sweden)

    Choong Leng Ng


    Full Text Available We demonstrate a refractive index sensor based on a long period grating (LPG inscribed in a special photosensitive microfiber with double-clad profile. The fiber is tapered gradually enough to ensure the adiabaticity of the fiber taper. In other words, the resulting insertion loss is sufficiently small. The boron and germanium co-doped inner cladding makes it suitable for inscribing gratings into its tapered form. The manner of wavelength shift for refractive indices (RIs differs from conventional LPG, and the refractive index detection limit is 1.67 × 10−5.

  5. Quantum crystal growing: adiabatic preparation of a bosonic antiferromagnet in the presence of a parabolic inhomogeneity

    DEFF Research Database (Denmark)

    Gammelmark, Søren; Eckardt, André


    We theoretically study the adiabatic preparation of an antiferromagnetic phase in a mixed Mott insulator of two bosonic atom species in a one-dimensional optical lattice. In such a system one can engineer a tunable parabolic inhomogeneity by controlling the difference of the trapping potentials f...... that during the preparation finite size effects will play a crucial role for a system of realistic size. The experiment that we propose can be realized, for example, using atomic mixtures of rubidium 87 with potassium 41, or ytterbium 168 with ytterbium 174....

  6. Pure spin current induced by adiabatic quantum pumping in zigzag-edged graphene nanoribbons

    Energy Technology Data Exchange (ETDEWEB)

    Souma, Satofumi, E-mail:; Ogawa, Matsuto [Department of Electrical and Electronic Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan)


    We show theoretically that pure spin current can be generated in zigzag edged graphene nanoribbons through the adiabatic pumping by edge selective pumping potentials. The origin of such pure spin current is the spin splitting of the edge localized states, which are oppositely spin polarized at opposite edges. In the proposed device, each edge of the ribbon is covered by two independent time-periodic local gate potentials with a definite phase difference, inducing the edge spin polarized current. When the pumping phase difference is opposite in sign between two edges, the total charge currents is zero and the pure edge spin current is generated.

  7. The Primordial Inflation Polarization ExploreR Continuous Adiabatic Demagnetization Refrigerator (United States)

    Pawlyk, Samuel; Ade, Peter; Benford, Dominic; Bennett, Charles; Chuss, David; Datta, Rahul; Dotson, Jessie; Essinger-Hileman, Thomas; Fixsen, Dale; Halpern, Mark; Hilton, Gene; Hinshaw, Gary; Irwin, Kent; Jhabvala, Christine; Kimball, Mark; Kogut, Al; Lowe, Luke; McMahon, Jeff; Miller, Timothy; Mirel, Paul; Moseley, Samuel Harvey; Rodriguez, Samelys; Sharp, Elmer; Shirron, Peter; Staguhn, Johannes G.; Sullivan, Dan; Switzer, Eric; Taraschi, Peter; Tucker, Carole; Wollack, Edward; Walts, Alexander


    The Primordial Inflation Polarization ExploreR (PIPER) uses a Continuous Adiabatic Demagnetization Refrigerator (CADR) to cool its detectors. The CADR consists of four independent stages with adjacent stages connected by gas gap (GG) or superconducting (SC) heat switches. The three warm stages cycle to transfer heat from the 100 mK detector package to the 1.5 K liquid helium bath. The coldest stage maintains a continuous temperature of 100 mK for the detector package with 10 uW cooling power. We describe the mechanical, electrical, and software design of the CADR and present recent results.

  8. Plasmonic black gold by adiabatic nanofocusing and absorption of light in ultra-sharp convex grooves

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Novikov, Sergey M.; Stær, Tobias Holmgaard


    of surface plasmon excitations involved. Nonresonant absorption has so far been achieved by using combined nano- and micro-structural surface modifications and with composite materials involving metal nanoparticles embedded in dielectric layers. Here we realize nonresonant light absorption in a well......-defined geometry by using ultra-sharp convex metal grooves via adiabatic nanofocusing of gap surface plasmon modes excited by scattering off subwavelength-sized wedges. We demonstrate experimentally that two-dimensional arrays of sharp convex grooves in gold ensure efficient (>87%) broadband (450-850 nm...

  9. Magnetization Process and Adiabatic Demagnetization of the Antiferromagnetic Spin-1/2 Heisenberg Cubic Cluster


    Strecka, Jozef; Cisarova, Jana


    A full energy spectrum of the spin-1/2 Heisenberg cubic cluster is used to investigate a low-temperature magnetization process and adiabatic demagnetization of this zero-dimensional 2x2x2 quantum spin system. It is shown that the antiferromagnetic spin-1/2 Heisenberg cube exhibits at low enough temperatures a stepwise magnetization curve with four intermediate plateaux at zero, one quarter, one half, and three quarters of the saturation magnetization. We have also found the enhanced magnetoca...

  10. On CNC commuting contractive tuples

    Indian Academy of Sciences (India)

    The characteristic function has been an important tool for studying completely non-unitary contractions on Hilbert spaces. In this note, we consider completely non-coisometric contractive tuples of commuting operators on a Hilbert space H . We show that the characteristic function, which is now an operator-valued analytic ...


    The Contract Administrative Tracking System (CATS) was developed in response to an ORD NHEERL, Mid-Continent Ecology Division (MED)-recognized need for an automated tracking and retrieval system for Cost Reimbursable Level of Effort (CR/LOE) Contracts. CATS is an Oracle-based app...

  12. Policing Mechanisms in Agricultural Contracts (United States)

    Wolf, Steven; Hueth, Brent; Ligon, Ethan


    In this paper we focus on mechanisms of coordination in agricultural contracts. Our approach is intended to advance understanding of social relations of production and distribution of power in agrofood systems. Through an analysis of contracts between farmers and intermediaries (e.g., processors, shippers, consignment agents) for California fruits…

  13. Contract Training in Community Colleges. (United States)

    Suchorski, Joan M.

    One of the most significant developments in higher education over the past decade has been the increased linkages between colleges and other organizations and institutions. A prominent and fast-growing form of linkage is contract training. Contract training refers to an arrangement in which a business, a government agency, or a community…

  14. 7 CFR 1726.404 - Non-site specific construction contract closeout. (United States)


    .... 1726.404 Section 1726.404 Agriculture Regulations of the Department of Agriculture (Continued) RURAL... contracts executed on RUS Form 790. (a) Final test of equipment supplied under a construction contract. If equipment is supplied under a construction contract, the borrower (acting through its engineer, if...

  15. Performance-Driven Interface Contract Enforcement for Scientific Components

    Energy Technology Data Exchange (ETDEWEB)

    Dahlgren, Tamara Lynn [Univ. of California, Davis, CA (United States)


    Performance-driven interface contract enforcement research aims to improve the quality of programs built from plug-and-play scientific components. Interface contracts make the obligations on the caller and all implementations of the specified methods explicit. Runtime contract enforcement is a well-known technique for enhancing testing and debugging. However, checking all of the associated constraints during deployment is generally considered too costly from a performance stand point. Previous solutions enforced subsets of constraints without explicit consideration of their performance implications. Hence, this research measures the impacts of different interface contract sampling strategies and compares results with new techniques driven by execution time estimates. Results from three studies indicate automatically adjusting the level of checking based on performance constraints improves the likelihood of detecting contract violations under certain circumstances. Specifically, performance-driven enforcement is better suited to programs exercising constraints whose costs are at most moderately expensive relative to normal program execution.

  16. The adiabatic/entropy decomposition in $P(\\phi^I,X^{IJ})$ theories with multiple sound speeds

    CERN Document Server

    Longden, Chris


    We consider $P(\\phi^I,X^{IJ})$ theories of multi-field inflation and ask the question of how to define the adiabatic and entropy perturbations, widely used in calculating the curvature and isocurvature power spectra, in this general context. It is found that when the field perturbations propagate with different speeds, these adiabatic and entropy modes are not generally the fundamental (most natural to canonically quantise) degrees of freedom that propagate with a single speed. The alternative fields which do propagate with a single speed are found to be a rotation in field space of the adiabatic and entropy perturbations. We show how this affects the form of the horizon-crossing power spectrum, when there is not a single "adiabatic sound speed" sourcing the curvature perturbation. Special cases of our results are discussed, including $P(X)$ theories where the adiabatic and entropy perturbations are fundamental. We finally look at physical motivations for considering multi-speed models of inflation, particula...

  17. Choreography Synthesis as Contract Agreement

    Directory of Open Access Journals (Sweden)

    Julien Lange


    Full Text Available We propose a formal model for distributed systems, where each participant advertises its requirements and obligations as behavioural contracts, and where multiparty sessions are started when a set of contracts allows to synthesise a choreography. Our framework is based on the CO2 calculus for contract-oriented computing, and borrows concepts and results from the session type literature. It supports sessions where the number of participants is not determined beforehand, and keeps CO2's ability to rule out participants that are culpable if contracts are not fulfilled at runtime. We show that we have progress and session fidelity in CO2, as a result of the honesty of participants — i.e., their ability to always adhere to their contracts.

  18. Contracting and Performance in Agencies

    DEFF Research Database (Denmark)

    Bjørnholt, Bente; Houlberg Salomonsen, Heidi; Rennison, Betina Wolfgang

    , documentary and interview data. To measure the degree of performance as the degree of goal attainment, all agency contracts for 2008 as well as the subsequent ‘enterprise accounts’ defining the goal attainment have been collected. There were 62 agencies in 2008, 58 of which had a contract. Goal attainment......As part of New Public Management (NPM), contracting represents a supplement to the traditional hierarchical and rule-based managing of relations between actors in order to improve performance (Fortin and van Hassel 2000; Greve and Ejersbo 2002; Drewry et al. 2005; Verhoest 2005). To various degrees...... contracts combine some degree of managerial autonomy and influence on goal setting in return for a consistent and congruent system of control and monitoring. Internal contracts are often finalized within the ‘shadow of hierarchy’ between mutually dependent parties in a long-term, co-operation-based...

  19. Mechanobiology of lymphatic contractions. (United States)

    Munn, Lance L


    The lymphatic system is responsible for controlling tissue fluid pressure by facilitating flow of lymph (i.e. the plasma and cells that enter the lymphatic system). Because lymph contains cells of the immune system, its transport is not only important for fluid homeostasis, but also immune function. Lymph drainage can occur via passive flow or active pumping, and much research has identified the key biochemical and mechanical factors that affect output. Although many studies and reviews have addressed how tissue properties and fluid mechanics (i.e. pressure gradients) affect lymph transport [1-3] there is less known about lymphatic mechanobiology. As opposed to passive mechanical properties, mechanobiology describes the active coupling of mechanical signals and biochemical pathways. Lymphatic vasomotion is the result of a fascinating system affected by mechanical forces exerted by the flowing lymph, including pressure-induced vessel stretch and flow-induced shear stresses. These forces can trigger or modulate biochemical pathways important for controlling the lymphatic contractions. Here, I review the current understanding of lymphatic vessel function, focusing on vessel mechanobiology, and summarize the prospects for a comprehensive understanding that integrates the mechanical and biomechanical control mechanisms in the lymphatic system. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. INFINITY construction contract signed (United States)


    Key state and community leaders celebrated April 6 with the signing of a construction contract for the state-of-the-art INFINITY Science Center planned near John C. Stennis Space Center in south Mississippi. Gulfport Mayor George Schloegel (l to r), chair of non-profit INFINITY Science Center Inc., was joined for the signing ceremony at the Hancock Bank in Gulfport by Virginia Wagner, sister of late Hancock Bank President Leo Seal Jr.; and Roy Anderson III, president and CEO of Roy Anderson Corp. Seal was the first chair of INFINITY Science Center Inc., which has led in development of the project. Roy Anderson Corp. plans to begin construction on the 72,000-square-foot, $28 million science and education center in May. The Mississippi Department of Transportation (MDOT) also is set to begin construction of a $2 million access road to the new center. The April 6 ceremony was attended by numerous officials, including former Stennis Space Center Directors Jerry Hlass and Roy Estess; Mississippi Senate President Pro Tempore Billy Hewes, R-Gulfport; Mississippi Rep. Diane Peranich, D-Pass Christian; and MDOT Southern District Commissioner Wayne Brown.

  1. [Ulysses contract in psychiatry]. (United States)

    Daverio, Andrea; Piazzi, Gioia; Saya, Anna


    Over the last twenty years we have witnessed a growing focus on the rights of the ill people. The debate on informed consent and a new redefinition of the therapeutic relationship is constantly evolving. With this article, we propose a critical literature review of the so-called "Ulysses contract" or "psychiatric advance directives". It refers to the will that a subject expresses in writing, or orally, about the treatments he or she wishes or does not wish to be subject to if the time comes when it may be impossible to express his/her consent. This can especially occur in those with psychiatric disorders with serious clinical involvement and remitting-relapse (typically bipolar disorder, but also chronic delusional disorders and schizophrenia). In this context, the question is whether during intercritical periods the patient may or may not leave instructions to their care-givers. This aspect opens up to a series of interdisciplinary problems. In this article, we want to show the complexity of this debate from a clinical, ethical, legal and psychodynamic point of view, emphasizing the strengths and the major criticisms of the psychiatric advance directives for each area.

  2. Validation and test report

    DEFF Research Database (Denmark)

    Pedersen, Jens Meldgaard; Andersen, T. Bull


    . As a consequence of extensive movement artefacts seen during dynamic contractions, the following validation and test report consists of a report that investigates the physiological responses to a static contraction in a standing and a supine position. Eight subjects performed static contractions of the ankle...

  3. 48 CFR 1516.307 - Contract clauses. (United States)


    ...-reimbursement contracts when an anticipatory cost letter has been issued on the project. (b) The Contracting... such a provision would be detrimental to ensuring proper contract performance. (c) The Contracting... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Contract clauses. 1516.307...

  4. Ontologies for commitment-based smart contracts

    NARCIS (Netherlands)

    de Kruijff, Joost; Weigand, Hans; Panetto, H; Debruyne, C.; Gaaloul, W.; Papazoglou, M.; Paschke, A.; Ardagna, C.A.; Meersman, R.


    Smart contracts gain rapid exposure since the inception of blockchain technology. Yet there is no unified ontology for smart contracts. Being categorized as coded contracts or substitutes of conventional legal contracts, there is a need to reduce the conceptual ambiguity of smart contracts. We

  5. 48 CFR 811.503 - Contract clause. (United States)


    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clause. 811.503... ACQUISITION PLANNING DESCRIBING AGENCY NEEDS Liquidated Damages 811.503 Contract clause. When the contracting... contracting officer must include the clause in 852.211-74, Liquidated damages, in the contract. ...

  6. 48 CFR 822.305 - Contract clause. (United States)


    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clause. 822.305... PROGRAMS APPLICATION OF LABOR LAWS TO GOVERNMENT ACQUISITIONS Contract Work Hours and Safety Standards Act 822.305 Contract clause. The contracting officer shall insert the clause at 852.222-70, Contract Work...

  7. 48 CFR 837.403 - Contract clause. (United States)


    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clause. 837.403... OF CONTRACTING SERVICE CONTRACTING Nonpersonal Health Care Services 837.403 Contract clause. The contracting officer shall insert the clause at 852.237-7, Indemnification and medical liability insurance, in...

  8. Role of adiabaticity in controlling alkali-metal fine-structure mixing induced by rare gases (United States)

    Eshel, Ben; Cardoza, Joseph A.; Weeks, David E.; Perram, Glen P.


    The collision cross sections for alkali-metal-rare-gas spin orbit mixing between the n2P3 /2→n2P1 /2 levels trend strongly with the Massey parameter, or adiabaticity of the collisions. The strength of the interaction, as characterized by the C6 dispersion coefficient, is a secondary influence on the rates. An analytic expression for the probability of energy transfer in alkali-metal-rare-gas collisions is derived using time-dependent perturbation theory. The model agrees well with a broad literature survey of the observed temperature-dependent cross sections. A simple interaction potential successfully organizes the alkali-metal-rare-gas database. The rates become very large for high-lying states, as the collisions are quite sudden and the radius of the valence electron is large. In contrast, the highly adiabatic cesium 62P mixing rates are six to eight orders of magnitude smaller. The mixing rate for the Rb-He diode pumped alkali laser system varies from 0.20 -1.53 ×10-11cm 3/at .s for T =279 -893 K .

  9. Adiabatic Shear Localization and Microstructure in Ultrafine Grained Aluminum Alloy at Cryogenic Temperature (United States)

    Ma, Rui; Wang, Bingfeng; Zhang, Xiaoyong; Zhou, Bingqing


    Adiabatic shear localization plays an important role in the deformation and failure of ultrafine grained 6061 aluminum alloy processed by friction stir processing. To understand the effects of temperature and strain on adiabatic shear localization in the ultrafine grained 6061 aluminum alloy, it has been investigated dynamic mechanical behavior of ultrafine grained 6061 aluminum alloy under the controlled shock loading experiments. Deformation characteristics and microstructures in the shear band were performed by optical microscopy and transmission electron microscopy. The shear band in the ultrafine grained aluminum alloy is a long and straight band distinguished from the matrix. The width of the shear band decreases with increasing nominal strain. The results show that the grains in the boundary of the shear band are highly elongated along the shear direction and form the elongated cell structures (0.2 μ in width), and the core of the shear band consists of a number of recrystallized equiaxed grains 0.2-0.3 μ in diameters and the second phases distribute in both the boundary and the inner of the equiaxed new grains. The calculated temperature in the shear band is about 692 K. Rotational dynamic recrystallization mechanism is responsible for the formation of the microstructure in the shear band.

  10. Time Scale for Adiabaticity Breakdown in Driven Many-Body Systems and Orthogonality Catastrophe (United States)

    Lychkovskiy, Oleg; Gamayun, Oleksandr; Cheianov, Vadim


    The adiabatic theorem is a fundamental result in quantum mechanics, which states that a system can be kept arbitrarily close to the instantaneous ground state of its Hamiltonian if the latter varies in time slowly enough. The theorem has an impressive record of applications ranging from foundations of quantum field theory to computational molecular dynamics. In light of this success it is remarkable that a practicable quantitative understanding of what "slowly enough" means is limited to a modest set of systems mostly having a small Hilbert space. Here we show how this gap can be bridged for a broad natural class of physical systems, namely, many-body systems where a small move in the parameter space induces an orthogonality catastrophe. In this class, the conditions for adiabaticity are derived from the scaling properties of the parameter-dependent ground state without a reference to the excitation spectrum. This finding constitutes a major simplification of a complex problem, which otherwise requires solving nonautonomous time evolution in a large Hilbert space.

  11. Rapid Manipulation of Bose-Einstein Condensates using Shortcuts to Adiabaticity (United States)

    Samson, E. Carlo; Ryu, Changhyun; Boshier, Malcolm; Del Campo, Adolfo


    We are investigating practical methods based on shortcuts to adiabaticity (STA) for rapid manipulation of BECs. STA is an emergent field in quantum science that develops nonadiabatic protocols to drive a system into a target state much faster than the conventional slow adiabatic process. The first STA method that we are developing involves the ultrafast expansion (or compression) of a trapped BEC, as initially proposed by Del Campo and Boshier. We discuss our experimental implementation of this protocol, and our studies of the BEC dynamics and the fidelity of the final state. The other STA method is a launching protocol, in which we accelerate a trapped BEC to a target speed. We show through numerical GPE simulations that the target speed can be achieved in short durations and short launching distances with minimal excitations to the BEC, despite the nonadiabatic nature of the method. We also present initial results from the experimental implementation of this launching protocol. These STA-based experimental techniques would prove beneficial in systems that require fast initial state preparation and cycle time, without loss of coherence nor emergence of perturbations, such as in matter wave circuits, atom interferometry, and quantum heat engines. Supported by LANL/LDRD.

  12. Controlling vibrational cooling with zero-width resonances: An adiabatic Floquet approach (United States)

    Leclerc, Arnaud; Viennot, David; Jolicard, Georges; Lefebvre, Roland; Atabek, Osman


    In molecular photodissociation, some specific combinations of laser parameters (wavelength and intensity) lead to unexpected zero-width resonances (ZWRs) with, in principle, infinite lifetimes. Their potential to induce basic quenching mechanisms has recently been devised in the laser control of vibrational cooling through filtration strategies [O. Atabek et al., Phys. Rev. A 87, 031403(R) (2013), 10.1103/PhysRevA.87.031403]. A full quantum adiabatic control theory based on the adiabatic Floquet Hamiltonian is developed to show how a laser pulse could be envelope-shaped and frequency-chirped so as to protect a given initial vibrational state against dissociation, taking advantage of its continuous transport on the corresponding ZWR all along the pulse duration. As compared with previous control scenarios that actually suffered from nonadiabatic contamination, drastically different and much more efficient filtration goals are achieved. A semiclassical analysis helps us to find and interpret a complete map of ZWRs in the laser parameter plane. In addition, the choice of a given ZWR path, among the complete series identified by the semiclassical approach, turns out to be crucial for the cooling scheme, targeting a single vibrational state population left at the end of the pulse, while all others have almost completely decayed. The illustrative example, which has the potential to be transposed to other diatomics, is Na2 prepared by photoassociation in vibrationally hot but translationally and rotationally cold states.

  13. Non-adiabatic effects in elementary reaction processes at metal surfaces (United States)

    Alducin, M.; Díez Muiño, R.; Juaristi, J. I.


    Great success has been achieved in the modeling of gas-surface elementary processes by the use of the Born-Oppenheimer approximation. However, in metal surfaces low energy electronic excitations are generated even by thermal and hyperthermal molecules due to the absence of band gaps in the electronic structure. This shows the importance of performing dynamical simulations that incorporate non-adiabatic effects to analyze in which way they affect most common gas-surface reactions. Here we review recent theoretical developments in this problem and their application to the study of the effect of electronic excitations in the adsorption and relaxation of atoms and molecules in metal surfaces, in scattering processes, and also in recombinative processes between impinging atoms and adsorbates at the surface. All these studies serve us to establish what properties of the gas-surface interaction favor the excitation of low-energy electron-hole pairs. A general observation is that the nature of these excitations usually requires long lasting interactions at the surface in order to observe deviations from the adiabatic behaviour. We also provide the basis of the local density friction approximation (LDFA) that have been used in all these studies, and show how it has been employed to perform ab initio molecular dynamics with electronic friction (AIMDEF). As a final remark, we will shortly review on recent applications of the LDFA to successfully simulate desorption processes induced by intense femtosecond laser pulses.

  14. Adiabatic quenches and characterization of amplitude excitations in a continuous quantum phase transition. (United States)

    Hoang, Thai M; Bharath, Hebbe M; Boguslawski, Matthew J; Anquez, Martin; Robbins, Bryce A; Chapman, Michael S


    Spontaneous symmetry breaking occurs in a physical system whenever the ground state does not share the symmetry of the underlying theory, e.g., the Hamiltonian. This mechanism gives rise to massless Nambu-Goldstone modes and massive Anderson-Higgs modes. These modes provide a fundamental understanding of matter in the Universe and appear as collective phase or amplitude excitations of an order parameter in a many-body system. The amplitude excitation plays a crucial role in determining the critical exponents governing universal nonequilibrium dynamics in the Kibble-Zurek mechanism (KZM). Here, we characterize the amplitude excitations in a spin-1 condensate and measure the energy gap for different phases of the quantum phase transition. At the quantum critical point of the transition, finite-size effects lead to a nonzero gap. Our measurements are consistent with this prediction, and furthermore, we demonstrate an adiabatic quench through the phase transition, which is forbidden at the mean field level. This work paves the way toward generating entanglement through an adiabatic phase transition.

  15. Semiclassical (SC) Description of Electronically Non-AdiabaticDynamics via the Initial Value Representation (IVR)

    Energy Technology Data Exchange (ETDEWEB)

    Ananth, V.; Venkataraman, C.; Miller, W.H.


    The initial value representation (IVR) of semiclassical (SC) theory is used in conjunction with the Meyer-Miller/Stock-Thoss description of electronic degrees of freedom in order to treat electronically non-adiabatic processes. It is emphasized that the classical equations of motion for the nuclear and electronic degrees of freedom that emerge in this description are precisely the Ehrenfest equations of motion (the force on the nuclei is the force averaged over the electronic wavefunction), but that the trajectories given by these equations of motion do not have the usual shortcomings of the traditional Ehrenfest model when they are used within the SC-IVR framework. For example, in the traditional Ehrenfest model (a mixed quantum-classical approach) the nuclear motion emerges from a non-adiabatic encounter on an average potential energy surface (a weighted average according to the population in the various electronic states), while the SC-IVR describes the correct correlation between electronic and nuclear dynamics, i.e., the nuclear motion is on one potential energy surface or the other depending on the electronic state. Calculations using forward-backward versions of SC-IVR theory (FB-IVR) are presented to illustrate this behavior. An even more approximate version of the SC-IVR, the linearized approximation (LSC-IVR), is slightly better than the traditional Ehrenfest model, but since it cannot describe quantum coherence effects, the LSC-IVR is also not able to describe the correct correlation between nuclear and electronic dynamics.

  16. A subgradient approach for constrained binary optimization via quantum adiabatic evolution (United States)

    Karimi, Sahar; Ronagh, Pooya


    Outer approximation method has been proposed for solving the Lagrangian dual of a constrained binary quadratic programming problem via quantum adiabatic evolution in the literature. This should be an efficient prescription for solving the Lagrangian dual problem in the presence of an ideally noise-free quantum adiabatic system. However, current implementations of quantum annealing systems demand methods that are efficient at handling possible sources of noise. In this paper, we consider a subgradient method for finding an optimal primal-dual pair for the Lagrangian dual of a constrained binary polynomial programming problem. We then study the quadratic stable set (QSS) problem as a case study. We see that this method applied to the QSS problem can be viewed as an instance-dependent penalty-term approach that avoids large penalty coefficients. Finally, we report our experimental results of using the D-Wave 2X quantum annealer and conclude that our approach helps this quantum processor to succeed more often in solving these problems compared to the usual penalty-term approaches.

  17. Dissipation in adiabatic quantum computers: lessons from an exactly solvable model (United States)

    Keck, Maximilian; Montangero, Simone; Santoro, Giuseppe E.; Fazio, Rosario; Rossini, Davide


    We introduce and study the adiabatic dynamics of free-fermion models subject to a local Lindblad bath and in the presence of a time-dependent Hamiltonian. The merit of these models is that they can be solved exactly, and will help us to study the interplay between nonadiabatic transitions and dissipation in many-body quantum systems. After the adiabatic evolution, we evaluate the excess energy (the average value of the Hamiltonian) as a measure of the deviation from reaching the final target ground state. We compute the excess energy in a variety of different situations, where the nature of the bath and the Hamiltonian is modified. We find robust evidence of the fact that an optimal working time for the quantum annealing protocol emerges as a result of the competition between the nonadiabatic effects and the dissipative processes. We compare these results with the matrix-product-operator simulations of an Ising system and show that the phenomenology we found also applies for this more realistic case.

  18. Adiabatic preparation of Rydberg crystals in a cold lattice gas: Influence of atomic relaxations (United States)

    Petrosyan, David; Molmer, Klaus; Fleischhauer, Michael


    Strong, long-range interactions between atoms in high-lying Rydberg states make them attractive systems for the studies of ordered phases and phase transitions of interacting many-body systems. Different approaches have been explored, both theoretically and experimentally, for the preparation of crystalline order of Rydberg excitations in spatially-extended ensembles of cold atoms. These include direct (near-)resonant laser excitation of interacting Rydberg states in a lattice gas, and adiabatic preparation of crystalline phases of Rydberg excitations in a one-dimensional optical lattice by adiabatic frequency sweep of the excitation laser. We show, however, that taking into account realistic relaxation processes affecting the atoms severely complicates the prospects of attaining sizable crystals of Rydberg excitations in laser-driven atomic media. Our many-body simulations well reproduce the experimental observations of spatial ordering of Rydberg excitations in driven dissipative lattice gases, as well as highly sub-Poissonian probability distribution of the excitation number. We find that the excitations essentially form liquid rather than crystal phases with long-range order.

  19. Thermodynamic Analysis of Three Compressed Air Energy Storage Systems: Conventional, Adiabatic, and Hydrogen-Fueled

    Directory of Open Access Journals (Sweden)

    Hossein Safaei


    Full Text Available We present analyses of three families of compressed air energy storage (CAES systems: conventional CAES, in which the heat released during air compression is not stored and natural gas is combusted to provide heat during discharge; adiabatic CAES, in which the compression heat is stored; and CAES in which the compression heat is used to assist water electrolysis for hydrogen storage. The latter two methods involve no fossil fuel combustion. We modeled both a low-temperature and a high-temperature electrolysis process for hydrogen production. Adiabatic CAES (A-CAES with physical storage of heat is the most efficient option with an exergy efficiency of 69.5% for energy storage. The exergy efficiency of the conventional CAES system is estimated to be 54.3%. Both high-temperature and low-temperature electrolysis CAES systems result in similar exergy efficiencies (35.6% and 34.2%, partly due to low efficiency of the electrolyzer cell. CAES with high-temperature electrolysis has the highest energy storage density (7.9 kWh per m3 of air storage volume, followed by A-CAES (5.2 kWh/m3. Conventional CAES and CAES with low-temperature electrolysis have similar energy densities of 3.1 kWh/m3.

  20. Gate Leakage Reduction by Clocked Power Supply of Adiabatic Logic Circuits

    Directory of Open Access Journals (Sweden)

    Ph. Teichmann


    Full Text Available Losses due to gate-leakage-currents become more dominant in new technologies as gate leakage currents increase exponentially with decreasing gate oxide thickness. The most promising Adiabatic Logic (AL families use a clocked power supply with four states. Hence, the full VDD voltage drops over an AL gate only for a quarter of the clock cycle, causing a full gate leakage only for a quarter of the clock period. The rising and falling ramps of the clocked power supply lead to an additional energy consumption by gate leakage. This energy is smaller than the fraction caused by the constant VDD drop, because the gate leakage exponentially depends on the voltage across the oxide. To obtain smaller energy consumption, Improved Adiabatic Logic (IAL has been introduced. IAL swaps all n- and p-channel transistors. The logic blocks are built of p-channel devices which show gate tunneling currents significantly smaller than in n-channel devices. Using IAL instead of conventional AL allows an additional reduction of the energy consumption caused by gate leakage. Simulations based on a 90nm CMOS process show a lowering in gate leakage energy consumption for AL by a factor of 1.5 compared to static CMOS. For IAL the factor is up to 4. The achievable reduction varies depending on the considered AL family and the complexity of the gate.

  1. Taple-top imaging of the non-adiabatically driven isomerization in the acetylene cation (United States)

    Beaulieu, Samuel; Ibrahim, Heide; Wales, Benji; Schmidt, Bruno E.; Thiré, Nicolas; Bisson, Éric; Hebeisen, Christoph T.; Wanie, Vincent; Giguere, Mathieu; Kieffer, Jean-Claude; Sanderson, Joe; Schuurman, Michael S.; Légaré, François


    One of the primary goals of modern ultrafast science is to follow nuclear and electronic evolution of molecules as they undergo a photo-chemical reaction. Most of the interesting dynamics phenomena in molecules occur when an electronically excited state is populated. When the energy difference between electronic ground and excited states is large, Free Electron Laser (FEL) and HHG-based VUV sources were, up to date, the only light sources able to efficiently initiate those non-adiabatic dynamics. We have developed a simple table-top approach to initiate those rich dynamics via multiphoton absorption. As a proof of principle, we studied the ultrafast isomerization of the acetylene cation. We have chosen this model system for isomerization since the internal conversion mechanism which leads to proton migration is still under debate since decades. Using 266 nm multiphoton absorption as a pump and 800 nm induced Coulomb Explosion as a probe, we have shoot the first high-resolution molecular movie of the non-adiabatically driven proton migration in the acetylene cation. The experimental results are in excellent agreement with high level ab initio trajectory simulations.

  2. From sudden quench to adiabatic dynamics in the attractive Hubbard model (United States)

    Mazza, Giacomo


    We study the crossover between the sudden quench limit and the adiabatic dynamics of superconducting states in the attractive Hubbard model. We focus on the dynamics induced by the change of the attractive interaction during a finite ramp time. The ramp time is varied in order to track the evolution of the dynamical phase diagram from the sudden quench to the equilibrium limit. Two different dynamical regimes are realized for quenches towards weak and strong coupling interactions. At weak coupling the dynamics depends only on the energy injected into the system, whereas a dynamics retaining memory of the initial state takes place at strong coupling. We show that this is related to a sharp transition between a weak and a strong coupling quench dynamical regime, which defines the boundaries beyond which a dynamics independent from the initial state is recovered. Comparing the dynamics in the superconducting and nonsuperconducting phases, we argue that this is due to the lack of an adiabatic connection to the equilibrium ground state for nonequilibrium superconducting states in the strong coupling quench regime.

  3. Changing role of carrier gas in formation of ethanol clusters by adiabatic expansion (United States)

    Abu-samha, Mahmoud; Ryding, Mauritz J.; Uggerud, Einar; Sæthre, Leif J.; Børve, Knut J.


    Adiabatic expansion of molecular vapors is a celebrated method for producing pure and mixed clusters of relevance in both applied and fundamental studies. The present understanding of the relationship between experimental conditions and the structure of the clusters formed is incomplete. We explore the role of the backing/carrier gas during adiabatic expansion of ethanol vapors with regard to cluster production and composition. Single-component clusters of ethanol were produced over a wide size-range by varying the rare gas (He, Ar) backing pressure, with Ar being more efficient than He in promoting the formation of pure ethanol clusters. However, at stagnation pressures Ps>1.34 (4 ) bar and temperature 49 (2) °C, synchrotron-based valence and inner-shell photoelectron spectroscopy reveals condensation of Ar carrier gas on the clusters. Theoretical calculations of cluster geometries as well as chemical shifts in carbon 1s ionization energies confirm that the experimental observations are consistent with an ethanol core covered by an outer shell of argon. Experiments on the 1-propanol/Ar system display a similar pattern as described for ethanol/Ar, indicating a broader range of validity of the results.

  4. The production of radioisotopes for medical applications by the adiabatic resonance crossing (ARC) technique

    CERN Document Server

    Froment, P; Delbar, T; Ryckewaert, G; Tilquin, I; Vervier, J


    The Transmutation by Adiabatic Resonance Crossing (TARC) technique has been proposed by Rubbia (Resonance enhanced neutron captures for element activation and waste transmutation, CERN-LHC/97-0040EET, 1997; TARC collaboration, Neutron-driven nuclear transmutation by adiabatic resonance crossing, CERN-SL-99-036EET, 1999; Abanades et al., Nucl. Instr. and Meth. A 487 (2002) 577) for element activation and waste transmutation. We investigate the possibility to use this technique for the industrial production of **9**9Mo and **1**2**5Xe by resonance neutron capture in **9**8Mo and **1**2**4Xe, respectively. Their daughters, i.e. **9**9**mTc and **1**2**5I, are widely used in medical applications. The high neutron flux needed is produced by bombarding a thick Be target with 65 or 75 MeV proton beam (few microamperes). This target is placed at the centre of a large cubic lead assembly (1.6 m side, purity: 99.999%). The neutrons are progressively slowed down by elastic scattering on lead, and their energies "scan" t...

  5. Test

    DEFF Research Database (Denmark)

    Bendixen, Carsten


    Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers.......Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers....

  6. Non-adiabatic approach to optical conductivity in the one-dimensional half-filled Holstein model

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qin; Zheng, Hang


    The optical conductivity in the one-dimensional half-filled Holstein model of spin-((1)/(2)) electrons is investigated by developing an analytical non-adiabatic approach based on the unitary transformation method. The non-adiabatic effects due to finite phonon frequency {omega}{sub 0}>0 are treated through an energy-dependent electron-phonon scattering function {delta}(k',k) and the Green's function method is used to implement the perturbation treatment. The calculated optical conductivity and the density of states of electrons do not have the inverse-square-root singularity but have a peak above the gap edge and there exists a significant tail below the peak. This indicates that due to the non-adiabatic effects the Peierls gap shifts and the optical excitation spectrum does not peak at the correspondingly renormalized gap edge.

  7. Hamiltonian Dynamics and Adiabatic Invariants for Time-Dependent Superconducting Qubit-Oscillators and Resonators in Quantum Computing Systems

    Directory of Open Access Journals (Sweden)

    Jeong Ryeol Choi


    Full Text Available An adiabatic invariant, which is a conserved quantity, is useful for studying quantum and classical properties of dynamical systems. Adiabatic invariants for time-dependent superconducting qubit-oscillator systems and resonators are investigated using the Liouville-von Neumann equation. At first, we derive an invariant for a simple superconducting qubit-oscillator through the introduction of its reduced Hamiltonian. Afterwards, an adiabatic invariant for a nanomechanical resonator linearly interfaced with a superconducting circuit, via a coupling with a time-dependent strength, is evaluated using the technique of unitary transformation. The accuracy of conservation for such invariant quantities is represented in detail. Based on the results of our developments in this paper, perturbation theory is applicable to the research of quantum characteristics of more complicated qubit systems that are described by a time-dependent Hamiltonian involving nonlinear terms.

  8. Food and drink serving contract

    Directory of Open Access Journals (Sweden)

    Veselinović Janko


    Full Text Available Food and drink catering service is almost as old as the civilization itself. Even though this vocation is a part of the catering activity, Serbian law does not foresee this contract section as personalized. Key legal sources for this kind of contract are business customs. Food and drink serving contract is a mixed-type contract and its legal nature is very interesting due to its complexity. Specific for this contract is the fact that it is not an ordinary service, but also an activity which requires a degree of culinary skills, knowledge of customs of other nations, as well as other skills. The very category of a good professional in business economy / hospitality industry is very dynamic, as it needs to be evaluated according to all given circumstances, which may be rather unpredictable. By considering the legal nature, but also the rights and obligations of the contracting parties, we tried to point to the questions that require a special attention. Legal sources that indirectly refer to food and drink serving contracts were taken into account. Apart from the Law on Obligatory Relations, we also considered here the Law on Tourism also pointing to the comparative law and jurisprudence.

  9. Analysis of the 314th contracting squadrons contract management capability using the Contract Management Maturity Model (CMMM)


    Jackson, Carl J.


    MBA Professional Report This research project provides an assessment of the contract management capability of the 314th Contracting Squadron located at Little Rock Air Force Base, Arkansas. The assessment uses a questionnaire covering the six phases of the contract management process. The purpose of this research project is to analyze the 314th Contracting Squadron contracting processes and requirement target areas for improvement efforts by the application of the Contract Management M...

  10. Experimental Verification of Neutron Phenomenology in Lead and Transmutation by Adiabatic Resonance Crossing in Accelerator Driven Systems: a Short Summary

    CERN Document Server

    Abánades, A; Andriamonje, Samuel A; Angelopoulos, Angelos; Apostolakis, Alcibiades J; Arnould, H; Belle, E; Bompas, C A; Brozzi, Delecurgo; Bueno, J; Buono, S; Carminati, F; Casagrande, Federico; Cennini, P; Collar, J I; Cerro, E; Del Moral, R; Díez, S; Dumps, Ludwig; Eleftheriadis, C; Embid, M; Fernández, R; Gálvez, J; García, J; Gelès, C; Giorni, A; González, E; González, O; Goulas, I; Heuer, R D; Hussonnois, M; Kadi, Y; Karaiskos, P; Kitis, G; Klapisch, Robert; Kokkas, P; Lacoste, V; Le Naour, C; Lèpez, C; Loiseaux, J M; Martínez-Val, J M; Méplan, O; Nifenecker, H; Oropesa, J; Papadopoulos, I M; Pavlopoulos, P; Pérez-Enciso, E; Pérez-Navarro, A; Perlado, M; Placci, A; Poza, M; Revol, Jean Pierre Charles; Rubbia, Carlo; Rubio, J A; Sakelliou, L; Saldaña, F; Savvidis, E; Schussler, F; Sirvent, C; Tamarit, J; Trubert, D; Tzima, A; Viano, J B; Vieira, S L; Vlachoudis, V; Zioutas, Konstantin; CERN. Geneva. SPS and LEP Division


    The Transmutation by Adiabatic Resonance Crossing (TARC) experiment was carried out as PS211 at the CERN PS from 1996 to 1999. Energy and space distributions of spallation neutrons (from 2.5 and 3.57 GeV/c CERN proton beams) slowing down in a 3.3x3.3x3 m3 lead volume and neutron capture rates on long-lived fission fragements 99Tc and 129I demonstrate that Adiabatic Resonance Crossing (ARC) can be used to eliminate efficiently such nuclear waste and validate innovative simulation.

  11. Investigations on mixture preparation for two phase adiabatic pressure drop of R134a flowing in 5 mm diameter channel (United States)

    Muszyński, Tomasz; Andrzejczyk, Rafał; Dorao, Carlos A.


    The article presents detailed two-phase adiabatic pressure drops data for refrigerant R134a. Study cases have been set for a mass flux varying from 200 to 400 kg/m2s, at the saturation temperature of 19.4 °C. Obtained experimental data was compared with the available correlations from the literature for the frictional pressure drop during adiabatic flow. Influence of mixture preparation on pressure drop was investigated, for varying inlet subcooling temperature in the heated section. The flow patterns have also been obtained by means of a high-speed camera placed in the visualization section and compared with literature observations.

  12. 48 CFR 2446.710 - Contract clauses. (United States)


    ... CONTRACT MANAGEMENT QUALITY ASSURANCE Warranties 2446.710 Contract clauses. (c)(1) The contracting officer may include a clause substantially the same as FAR 52.246-19, Warranty of Systems and Equipment under...

  13. Bottomland Hardwood Planting: Example Contract Specifications

    National Research Council Canada - National Science Library

    Humprey, Monica


    This technical note provides an example of contract specifications that can be used as a template by USACE biologists, engineers, or contracting officers for contracting the planting of bottomland hardwood (BLH) seedlings...

  14. 78 FR 11699 - International Mail Contract (United States)


    ... International Mail Contract AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: The Commission is... entered into an additional International Business Reply Service (IBRS) Competitive Contract 3 negotiated... Equivalent International Business Reply Service Competitive Contract 3 Negotiated Service Agreement, February...

  15. 78 FR 11237 - International Mail Contract (United States)


    ... International Mail Contract AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: The Commission is noticing a recent Postal Service filing concerning an additional Global Reseller Expedited Package Contract... entered into an additional Global Reseller Expedited Package Contracts 1 negotiated service agreement...

  16. 77 FR 54937 - International Mail Postal Contract (United States)


    ... COMMISSION International Mail Postal Contract AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY... (2) asks the Commission to include the new contract within the International Business Reply Service... Functionally Equivalent International Business Reply Service Competitive Contract 3 Negotiated Settlement...

  17. Utility Energy Services Contracts: Enabling Documents

    Energy Technology Data Exchange (ETDEWEB)



    Utility Energy Services Contracts: Enabling Documents provides materials that clarify the authority for Federal agencies to enter into utility energy services contracts (UESCs), as well as sample documents and resources to ease utility partnership contracting.

  18. Predicting Commitment Forms From Psychological Contract Breach ...

    African Journals Online (AJOL)

    Measures to be taken by management at equilibrating employees' psychological contract breach, reducing labour turnover and increasing commitment are suggested. Keywords: Mergers, acquisition, Commitment, psychological contract breach, and psychological contract violation, human resource management.

  19. 40 CFR 35.970 - Contract enforcement. (United States)


    ... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.970 Contract... technical or legal involvement in any contract dispute will not make EPA a party to any contract entered...

  20. 24 CFR 983.206 - HAP contract amendments (to add or substitute contract units). (United States)


    ... substitute contract units). 983.206 Section 983.206 Housing and Urban Development Regulations Relating to... Contract § 983.206 HAP contract amendments (to add or substitute contract units). (a) Amendment to substitute contract units. At the discretion of the PHA and subject to all PBV requirements, the HAP contract...

  1. Smooth Sailing with Contract Services. (United States)

    Fickes, Michael


    Discusses how to make the contract services relationship work smoothly for educational facilities. Covers topics of food, child care, and transportation services, along with a brief explanation of the benefits of outsourcing on-campus amenities. (GR)

  2. Next Indefinite Contract review exercise

    CERN Multimedia


    Dear Colleagues, We are pleased to inform you that the 2013 LD2IC exercise (selection process for the conversion of limited-duration contracts to indefinite contracts) was officially launched last week.  The vacancy notices for posts opened with a view to the award of indefinite contracts will be published on 9 August 2013 for a period of four weeks (until 8 September 2013). The CERN Contract Review Boards (candidate interviews) will be held between the end of September and mid-November. The LD to IC procedure, Frequently Asked Questions and a calendar for the exercise are now available in the Admin e-guide. In addition, general information sessions on the procedure will be organised for candidates on the following dates: Information on the location of these sessions will be provided in due course on the CERN announcements page. HR Department

  3. Framework for Structuring Procurement Contracts

    Directory of Open Access Journals (Sweden)

    Lena Borg


    Full Text Available The aim of this paper is to propose a new framework for structuring contract types and payment methods. Concerning procurement contracts, the first important new feature of this framework is a stepwise structure with three main steps in the contract design: (1 what will be procured—should the contract only include construction, or should it include both construction and operation/maintenance (2 who will do the detailed design of the premise and (3 how many contractors will the client use? The second important new feature of this framework is that both step 2 and step 3 include a continuum of alternatives. Concerning payment methods, the new framework is primarily based on how the specific risks of the project are shared. These frameworks can be useful for policy formulation in that they can help to avoid some problematic ways of formulating policies.

  4. Multifamily Assistance Section 8 Contracts (United States)

    Department of Housing and Urban Development — he information regarding the Multifamily Assistance and Section 8 contracts, and properties is being furnished for the convenience of interested parties. The...

  5. Non-renewal of contracts

    CERN Multimedia

    Association du personnel


    A new illegal practice is appearing in certain sectors of the Organization: the non-renewal of renewable three-year limited-duration (LD) contracts, despite a more than satisfactory performance and an obvious commitment to the Organization.

  6. Construction contracts law and management

    CERN Document Server

    Hughes, Will; Murdoch, John


    The fifth edition of this bestselling textbook has been thoroughly revised to provide the most up-to-date and comprehensive coverage of the legislation, administration and management of construction contracts. It now includes comparisons of working with JCT, NEC3, and FIDIC contracts throughout. Introducing this topic at the core of construction law and management, this book provides students with a one-stop reference on construction contracts. Significant new material covers: procurement tendering developments in dispute settlement commentary on all key legislation, case law and contract amendments In line with new thinking in construction management research, this authoritative guide is essential reading for every construction undergraduate and an extremely useful source of reference for practitioners.

  7. Determinants of Service Contract Outcomes (United States)


    limited to applications of service quality in business-to-consumer (B2C) contexts. The five dimensions of service quality do not always fit B2B ...Buyers of customer-defined B2B services often state service expectations in requirement documents that are incorporated into contracts. Within public...centrality of relational exchange, any study of B2B exchange should include the effects of relational norms. When contracting for services, proper

  8. 7 CFR 1780.61 - Construction contracts. (United States)


    ... AGRICULTURE (CONTINUED) WATER AND WASTE LOANS AND GRANTS Planning, Designing, Bidding, Contracting... will be obtained prior to their use. (b) Contract review and concurrence. The owner's attorney will...

  9. Covenant Violations and Dynamic Loan Contracting

    DEFF Research Database (Denmark)

    Freudenberg, Felix; Imbierowicz, Björn; Saunders, Anthony


    This paper examines the dynamic allocation of control rights in private debt contracts of firms. We show that a covenant violation in the prior loan contract implies a stigma for borrowers which results in stricter loan contract terms in subsequent new loan contracts. Our analyses reject potentia......This paper examines the dynamic allocation of control rights in private debt contracts of firms. We show that a covenant violation in the prior loan contract implies a stigma for borrowers which results in stricter loan contract terms in subsequent new loan contracts. Our analyses reject...

  10. 48 CFR 39.103 - Modular contracting. (United States)


    ... section implements Section 5202, Incremental Acquisition of Information Technology, of the Clinger-Cohen... circumstances (e.g., indefinite delivery, indefinite quantity contracts, single contract with options...

  11. Management of Contracts for F110 Engine Procurements

    National Research Council Canada - National Science Library

    Granetto, Paul


    .... The Administrative Contracting Office, Defense Contract Management Agency at the General Electric Aircraft Engine plant in Cincinnati, Ohio, was responsible for contract administration functions after contract award.

  12. CFD modelling and validation of upward bubbly flow in an adiabatic vertical pipe using the quadrature method of moments

    Energy Technology Data Exchange (ETDEWEB)

    Peña-Monferrer, C., E-mail: [Institute for Energy Engineering, Universitat Politècnica de València, 46022 València (Spain); Passalacqua, A., E-mail: [Department of Mechanical Engineering, Iowa State University, Ames, IA 50011 (United States); Chiva, S., E-mail: [Department of Mechanical Engineering and Construction, Universitat Jaume I, 12080 Castelló de la Plana (Spain); Muñoz-Cobo, J.L., E-mail: [Institute for Energy Engineering, Universitat Politècnica de València, 46022 València (Spain)


    Highlights: • A population balance equation solved with QMOM approximation is implemented in OpenFOAM. • Available models for interfacial forces and bubble induced turbulence are analyzed. • A vertical pipe flow is simulated for different bubbly flow conditions. • Two-phase flow characteristics in vertical pipes are properly predicted. - Abstract: An Eulerian–Eulerian approach was investigated to model adiabatic bubbly flow with CFD techniques. In the framework of the OpenFOAM{sup ®} software, a two-fluid model solver was modified to include a population balance equation, solved with the quadrature method of moments approximation to predict upward bubbly flow in vertical pipes considering the polydisperse nature of two-phase flow. Some progress have been made recently solving population balance equations in OpenFOAM{sup ®} and this research aims to extend its application to the case of vertical pipes under different conditions of liquid and gas velocities. In order to test the solver for nuclear applications, interfacial forces and bubble induced turbulence models were included to provide to this solver the capability to correctly predict the behavior of the continuous and disperse phases. Two-phase flow experiments with different superficial velocities of gas and liquid are used to validate the model and its implementation. Radial profiles of void fraction, gas and liquid velocities, Sauter mean diameter and turbulence intensity are compared to the computational results. These results are in satisfactory agreement with the experiments, showing the capability of the solver to predict two-phase flow characteristics.

  13. Orienting polar molecules without hexapoles: Optical state selection with adiabatic orientation (United States)

    Schäfer, Tim; Bartels, Nils; Hocke, Nils; Yang, Xueming; Wodtke, Alec M.


    A pedagogic review of technology used to orient polar molecules is presented to place in context the report of a new approach to this problem. Laboratory frame orientation of polar molecules is achieved by state-specific optical pumping in a region free of electric fields followed by adiabatic transport into a static electric field. This approach overcomes some of the limitations of the more common hexapole focusing method. In particular the method is nearly insensitive to the kinetic energy of the sample. We demonstrate production of oriented samples of NO (μel = 0.15 D) with translational energies above 1 eV in both high- and low-field seeking states. The method can be extended to many other classes of molecules, including near symmetric tops and ions.

  14. Manipulation of ultracold atoms in dressed adiabatic radio-frequency potentials

    DEFF Research Database (Denmark)

    Lesanovsky, Igor; Hofferberth, S.; Schmiedmayer, Jörg


    We explore properties of atoms whose magnetic hyperfine sublevels are coupled by an external magnetic radio frequency (rf) field. We perform a thorough theoretical analysis of this driven system and present a number of systematic approximations which eventually give rise to dressed adiabatic radio...... frequency potentials. The predictions of this analytical investigation are compared to numerically exact results obtained by a wave packet propagation. We outline the versatility and flexibility of this class of potentials and demonstrate their potential use to build atom optical elements such as double...... wells, interferometers, and ringtraps. Moreover, we perform simulations of interference experiments carried out in rf induced double-well potentials. We discuss how the nature of the atom-field coupling mechanism gives rise to a decrease of the interference contrast....

  15. Radioanalytical prediction of radiative capture in 99Mo production via transmutation adiabatic resonance crossing by cyclotron

    CERN Document Server

    Khorshidi, Abdollah; Pazirandeh, Ali; Tenreiro, Claudio; Kadi, Yacine


    In this study, the transmutation adiabatic resonance crossing (TARC) concept was estimated in Mo-99 radioisotope production via radiative capture reaction in two designs. The TARC method was composed of moderating neutrons in lead or a composition of lead and water. Additionally, the target was surrounded by a moderator assembly and a graphite reflector district. Produced neutrons were investigated by (p,xn) interactions with 30 MeV and 300 mu A proton beam on tungsten, beryllium, and tantalum targets. The Mo-99 production yield was related to the moderator property, cross section, and sample positioning inside the distinct region of neutron storage as must be proper to achieve gains. Gathered thermal flux of neutrons can contribute to molybdenum isotope production. Moreover, the sample positioning to gain higher production yield was dependent on a greater flux in the length of thermal neutrons and region materials inside the moderator or reflector. When the sample radial distance from Be was 38 cm inside the...

  16. Application of magnetic resonance force microscopy cyclic adiabatic inversion for a single-spin measurement

    CERN Document Server

    Berman, G P; Chapline, G; Gurvitz, S A; Hammel, P C; Pelekhov, D V; Suter, A; Tsifrinovich, V I


    We consider the process of a single-spin measurement using magnetic resonance force microscopy (MRFM) with a cyclic adiabatic inversion (CAI). This technique is also important for different applications, including a measurement of a qubit state in quantum computation. The measurement takes place through the interaction of a single spin with a cantilever modelled by a quantum oscillator in a coherent state in a quasi-classical range of parameters. The entire system is treated rigorously within the framework of the Schroedinger equation. For a many-spin system our equations accurately describe conventional MRFM experiments involving CAI of the spin system. Our computer simulations of the quantum spin-cantilever dynamics show that the probability distribution for the cantilever position develops two asymmetric peaks with the total relative probabilities mainly dependent on the initial angle between the directions of the average spin and the effective magnetic field, in the rotating frame. We show that each of th...

  17. Adiabatic Gasification and Pyrolysis of Coffee Husk Using Air-Steam for Partial Oxidation

    Directory of Open Access Journals (Sweden)

    Catalina Rodriguez


    Full Text Available Colombian coffee industry produces about 0.6 million tons of husk (CH per year which could serve as feedstock for thermal gasification to produce gaseous and liquid fuels. The current paper deals with: (i CH adiabatic gasification modeling using air-steam blends for partial oxidation and (ii experimental thermogravimetric analysis to determine the CH activation energy (E. The Chemical Equilibrium with Applications Program (CEA, developed by NASA, was used to estimate the effect of equivalence ratio (ER and steam to fuel ratio (S : F on equilibrium temperature and gas composition of ~150 species. Also, an atom balance model was developed for comparison purposes. The results showed that increased ER and (S : F ratios produce mixtures that are rich in H2 and CO2 but poor in CO. The value for the activation energy was estimated to be 221 kJ/kmol.

  18. Rapid Adiabatic Preparation of Injective Projected Entangled Pair States and Gibbs States (United States)

    Ge, Yimin; Molnár, András; Cirac, J. Ignacio


    We propose a quantum algorithm for many-body state preparation. It is especially suited for injective projected entangled pair states and thermal states of local commuting Hamiltonians on a lattice. We show that for a uniform gap and sufficiently smooth paths, an adiabatic runtime and circuit depth of O (polylog N ) can be achieved for O (N ) spins. This is an almost exponential improvement over previous bounds. The total number of elementary gates scales as O (N p o l y l o g N ) . This is also faster than the best known upper bound of O (N2) on the mixing times of Monte Carlo Markov chain algorithms for sampling classical systems in thermal equilibrium.

  19. Investigation of spontaneous Brillouin scattering generation based on non-adiabatic microfibres (United States)

    Zarei, A.; Jasim, A. A.; Harun, S. W.; Ahmad, H.


    Brillouin Stokes and anti-Stokes generation is successfully demonstrated in backward direction using a non-adiabatic microfibre as the gain medium. The Stokes light wavelength is up-shifted by 0.088 nm (10 GHz) from the BP wavelength as monitored by using an optical spectrum analyzer. The Brillouin scattering can also be enhanced by employing a microfibre based inline Mach-Zehnder interferometer (IMZI) as the gain medium due to its stronger multimode interference effect. It is shown that the microfibre geometry plays an important role in the spontaneous Brillouin scattering generation and gain bandwidth broadening due to its effect on irritation of the acoustic modes inside the microfibre.

  20. Recall Performance for Content-Addressable Memory Using Adiabatic Quantum Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Imam, Neena [ORNL; Humble, Travis S. [ORNL; McCaskey, Alex [ORNL; Schrock, Jonathan [ORNL; Hamilton, Kathleen E. [ORNL


    A content-addressable memory (CAM) stores key-value associations such that the key is recalled by providing its associated value. While CAM recall is traditionally performed using recurrent neural network models, we show how to solve this problem using adiabatic quantum optimization. Our approach maps the recurrent neural network to a commercially available quantum processing unit by taking advantage of the common underlying Ising spin model. We then assess the accuracy of the quantum processor to store key-value associations by quantifying recall performance against an ensemble of problem sets. We observe that different learning rules from the neural network community influence recall accuracy but performance appears to be limited by potential noise in the processor. The strong connection established between quantum processors and neural network problems supports the growing intersection of these two ideas.