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Sample records for short range force

  1. Short-range fundamental forces

    International Nuclear Information System (INIS)

    Antoniadis, I.; Baessler, S.; Buchner, M.; Fedorov, V.V.; Hoedl, S.; Nesvizhevsky, V.V.; Pignol, G.; Protasov, K.V.; Lambrecht, A.; Reynaud, S.; Sobolev, Y.

    2010-01-01

    We consider theoretical motivations to search for extra short-range fundamental forces as well as experiments constraining their parameters. The forces could be of two types: 1) spin-independent forces; 2) spin-dependent axion-like forces. Different experimental techniques are sensitive in respective ranges of characteristic distances. The techniques include measurements of gravity at short distances, searches for extra interactions on top of the Casimir force, precision atomic and neutron experiments. We focus on neutron constraints, thus the range of characteristic distances considered here corresponds to the range accessible for neutron experiments

  2. Short-range components of nuclear forces: Experiment versus mythology

    International Nuclear Information System (INIS)

    Kukulin, V. I.; Platonova, M. N.

    2013-01-01

    The present-day situation around the description of various (central, spin-orbit, and tensor) components of short-range nuclear forces is discussed. A traditional picture of these interactions based on the idea of one-meson exchange is contrasted against numerous results of recent experiments. As is shown in the present study, these results often deviate strongly from the predictions of traditional models. One can therefore state that such models are inapplicable to describing short-range nuclear forces and that it is necessary to go over from a traditional description to some alternative QCD-based (or QCD-motivated) picture. This means that, despite the widespread popularity of traditional concepts of short-range nuclear forces and their applicability in many particular cases, these concepts are not more than scientific myths that show their inconsistency when analyzed from the viewpoint of the modern experiment

  3. Effective quantum theories with short- and long-range forces

    International Nuclear Information System (INIS)

    Koenig, Sebastian

    2013-01-01

    At low energies, nonrelativistic quantum systems are essentially governed by their wave functions at large distances. For this reason, it is possible to describe a wide range of phenomena with short- or even finite-range interactions. In this thesis, we discuss several topics in connection with such an effective description and consider, in particular, modifications introduced by the presence of additional long-range potentials. In the first part we derive general results for the mass (binding energy) shift of bound states with angular momentum L ≥ 1 in a periodic cubic box in two and three spatial dimensions. Our results have applications to lattice simulations of hadronic molecules, halo nuclei, and Feshbach molecules. The sign of the mass shift can be related to the symmetry properties of the state under consideration. We verify our analytical results with explicit numerical calculations. Moreover, we discuss the case of twisted boundary conditions that arise when one considers moving bound states in finite boxes. The corresponding finite-volume shifts in the binding energies play an important role in the study of composite-particle scattering on the lattice, where they give rise to topological correction factors. While the above results are derived under the assumption of a pure finite-range interaction - and are still true up to exponentially small correction in the short-range case - in the second part we consider primarily systems of charged particles, where the Coulomb force determines the long-range part of the potential. In quantum systems with short-range interactions, causality imposes nontrivial constraints on low-energy scattering parameters. We investigate these causality constraints for systems where a long-range Coulomb potential is present in addition to a short-range interaction. The main result is an upper bound for the Coulomb-modified effective range parameter. We discuss the implications of this bound to the effective feld theory (EFT) for

  4. Short-range and long-range forces in quantum theory: selected topics

    International Nuclear Information System (INIS)

    Hiller, J.R.

    1980-01-01

    Short-range forces (SRF) are encountered when the effects of the parity-violating (PV) weak neutral current are considered in atomic systems. We consider these and other SRF that are associated with operators that contain delta functions. Identities which convert a delta-function matrix element to that of a global operator are reviewed. Past and possible future applications of such identities are described. It has been found that use of these identities can substantially improve the results obtained with less accurate wave functions. We present a further application to the hyperfine structure of the ground state of lithium where we again find that results are improved by the use of an identity. A long-range force (LRF) is here defined to be one that is associated with a potential V(r) that is asymptotically of the form lambda r - 1 (r 0 /r)/sup N-1/. We use a dispersion-theoretic approach to study LRF between hadrons due to two-glucon exchange within the framework of quantum chromodynamics. Such an LRF is usually related to the presence of a spectrum of physical states that extends to zero mass. A speculative scheme put forward by Feinberg and Sucher is used to avoid requiring the existence of massless gluons as observable particles. Semi-quantitative expressions for the two-glucon exchange potential between hadrons and, in particular, between two nucleons are obtained. Limits on two-gluon corrections to πp forward scattering dispersion relations are used to provide an upper bound for lambda, the coupling constant in the nucleon-nucleon potential. For N greater than or equal to 7, expected on heuristic grounds, we obtain the bound lambda less than or equal to 10 6 , which is very weak; gluon effects as treated here do not lead to significant effects in the dispersion-theoretic analysis of πp scattering

  5. Particle simulation algorithms with short-range forces in MHD and fluid flow

    International Nuclear Information System (INIS)

    Cable, S.; Tajima, T.; Umegaki, K.

    1992-07-01

    Attempts are made to develop numerical algorithms for handling fluid flows involving liquids and liquid-gas mixtures. In these types of systems, the short-range intermolecular interactions are important enough to significantly alter behavior predicted on the basis of standard fluid mechanics and magnetohydrodynamics alone. We have constructed a particle-in-cell (PIC) code for the purpose of studying the effects of these interactions. Of the algorithms considered, the one which has been successfully implemented is based on a MHD particle code developed by Brunel et al. In the version presented here, short range forces are included in particle motion by, first, calculating the forces between individual particles and then, to prevent aliasing, interpolating these forces to the computational grid points, then interpolating the forces back to the particles. The code has been used to model a simple two-fluid Rayleigh-Taylor instability. Limitations to the accuracy of the code exist at short wavelengths, where the effects of the short-range forces would be expected to be most pronounced

  6. Implementing Molecular Dynamics for Hybrid High Performance Computers - 1. Short Range Forces

    International Nuclear Information System (INIS)

    Brown, W. Michael; Wang, Peng; Plimpton, Steven J.; Tharrington, Arnold N.

    2011-01-01

    The use of accelerators such as general-purpose graphics processing units (GPGPUs) have become popular in scientific computing applications due to their low cost, impressive floating-point capabilities, high memory bandwidth, and low electrical power requirements. Hybrid high performance computers, machines with more than one type of floating-point processor, are now becoming more prevalent due to these advantages. In this work, we discuss several important issues in porting a large molecular dynamics code for use on parallel hybrid machines - (1) choosing a hybrid parallel decomposition that works on central processing units (CPUs) with distributed memory and accelerator cores with shared memory, (2) minimizing the amount of code that must be ported for efficient acceleration, (3) utilizing the available processing power from both many-core CPUs and accelerators, and (4) choosing a programming model for acceleration. We present our solution to each of these issues for short-range force calculation in the molecular dynamics package LAMMPS. We describe algorithms for efficient short range force calculation on hybrid high performance machines. We describe a new approach for dynamic load balancing of work between CPU and accelerator cores. We describe the Geryon library that allows a single code to compile with both CUDA and OpenCL for use on a variety of accelerators. Finally, we present results on a parallel test cluster containing 32 Fermi GPGPUs and 180 CPU cores.

  7. Molecular dynamics simulations of short-range force systems on 1024-node hypercubes

    International Nuclear Information System (INIS)

    Plimpton, S.J.

    1990-01-01

    In this paper, two parallel algorithms for classical molecular dynamics are presented. The first assigns each processor to a subset of particles; the second assigns each to a fixed region of 3d space. The algorithms are implemented on 1024-node hypercubes for problems characterized by short-range forces, diffusion (so that each particle's neighbors change in time), and problem size ranging from 250 to 10000 particles. Timings for the algorithms on the 1024-node NCUBE/ten and the newer NCUBE 2 hypercubes are given. The latter is found to be competitive with a CRAY-XMP, running an optimized serial algorithm. For smaller problems the NCUBE 2 and CRAY-XMP are roughly the same; for larger ones the NCUBE 2 is up to twice as fast. Parallel efficiencies of the algorithms and communication parameters for the two hypercubes are also examined

  8. Experimental Searches for Exotic Short-Range Forces Using Mechanical Oscillators

    Science.gov (United States)

    Weisman, Evan

    Experimental searches for forces beyond gravity and electromagnetism at short range have attracted a great deal of attention over the last decade. In this thesis I describe the test mass development for two new experiments searching for forces below 1 mm. Both modify a previous experiment that used 1 kHz mechanical oscillators as test masses with a stiff conducting shield between them to suppress backgrounds, a promising technique for probing exceptionally small distances at the limit of instrumental thermal noise. To further reduce thermal noise, one experiment will use plated silicon test masses at cryogenic temperatures. The other experiment, which searches for spin-dependent interactions, will apply the spin-polarizable material Dy3Fe5O 12 to the test mass surfaces. This material exhibits orbital compensation of the magnetism associated with its intrinsic electron spin, minimizing magnetic backgrounds. Several plated silicon test mass prototypes were fabricated using photolithography (useful in both experiments), and spin-dependent materials were synthesized with a simple chemical recipe. Both silicon and spin-dependent test masses demonstrate the mechanical and magnetic properties necessary for sensitive experiments. I also describe sensitivity calculations of another proposed spin-dependent experiment, based on a modified search for the electron electric dipole moment, which show unprecedented sensitivity to exotic monopole-dipole forces. Inspired by a finite element model, a study attempting to maximize detector quality factor versus geometry is also presented, with experimental results so far not explained by the model.

  9. Ionization induced by strong electromagnetic field in low dimensional systems bound by short range forces

    Energy Technology Data Exchange (ETDEWEB)

    Eminov, P.A., E-mail: peminov@mail.ru [Moscow State University of Instrument Engineering and Computer Sciences, 20 Stromynka Street, Moscow 2107996 (Russian Federation); National Research University Higher School of Economics, 3/12 Bolshoy Trekhsvyatskiy pereulok, Moscow 109028 (Russian Federation)

    2013-10-01

    Ionization processes for a two dimensional quantum dot subjected to combined electrostatic and alternating electric fields of the same direction are studied using quantum mechanical methods. We derive analytical equations for the ionization probability in dependence on characteristic parameters of the system for both extreme cases of a constant electric field and of a linearly polarized electromagnetic wave. The ionization probabilities for a superposition of dc and low frequency ac electric fields of the same direction are calculated. The impulse distribution of ionization probability for a system bound by short range forces is found for a superposition of constant and alternating fields. The total probability for this process per unit of time is derived within exponential accuracy. For the first time the influence of alternating electric field on electron tunneling probability induced by an electrostatic field is studied taking into account the pre-exponential term.

  10. Influence of retardation effects on photodisintegration of a quantum system bound by short-range forces

    International Nuclear Information System (INIS)

    Preobrazhenskii, M.A.; Golovinskii, P.A.

    1996-01-01

    Expressions for cross sections for multiphonon disintegration of quantum systems bound by short-range forces are obtained in the plane-wave approximation taking into account retardation effects. It is shown that, in the region of nonrelativistic energies, their contribution is factored, and the resulting universal factor is expressed for an arbitrary degree of process nonlinearity n in terms of elementary functions. Arguments of functions are determined only by the mode ω, the radiation spectrum width β, and the bound-state energy of a system. The dependence of the contribution of retardation effects on ω, β, and n is studied in detail. Analytical expressions for cross sections for multiquantum disintegration in the first nonvanishing order with respect to correlation interaction, which exactly take into account retardation effects, are obtained. It is shown that for two-quantum processes, the contribution of correlation effects is expressed in terms of a function representing an extension of dipole polarizability, whereas for n>2, it can be described in the dipole approximation

  11. Analysis of long- and short-range contribution to adhesion work in cardiac fibroblasts: An atomic force microscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Sbaizero, O., E-mail: sbaizero@units.it [Department of Engineering and Architecture, University of Trieste (Italy); University of Colorado Cardiovascular Institute, University of Colorado Denver, Aurora (United States); DelFavero, G. [Department of Engineering and Architecture, University of Trieste (Italy); Martinelli, V. [International Center for Genetic Engineering and Biotechnology, Trieste (Italy); Long, C.S.; Mestroni, L. [University of Colorado Cardiovascular Institute, University of Colorado Denver, Aurora (United States)

    2015-04-01

    Atomic force microscopy (AFM) for single-cell force spectroscopy (SCFS) and Poisson statistic were used to analyze the detachment work recorded during the removal of gold-covered microspheres from cardiac fibroblasts. The effect of Cytochalasin D, a disruptor of the actin cytoskeleton, on cell adhesion was also tested. The adhesion work was assessed using a Poisson analysis also derived from single-cell force spectroscopy retracting curves. The use of Poisson analysis to get adhesion work from AFM curves is quite a novel method, and in this case, proved to be effective to study the short-range and long-range contributions to the adhesion work. This method avoids the difficult identification of minor peaks in the AFM retracting curves by creating what can be considered an average adhesion work. Even though the effect of actin depolymerisation is well documented, its use revealed that control cardiac fibroblasts (CT) exhibit a work of adhesion at least 5 times higher than that of the Cytochalasin treated cells. However, our results indicate that in both cells short-range and long-range contributions to the adhesion work are nearly equal and the same heterogeneity index describes both cells. Therefore, we infer that the different adhesion behaviors might be explained by the presence of fewer membrane adhesion molecules available at the AFM tip–cell interface under circumstances where the actin cytoskeleton has been disrupted. - Highlights: • AFM force–deformation curve was used to characterize the cardiac fibroblast adhesion behavior. • The amount and nature of adhesion were assessed using a Poisson analysis applied to the AFM curve. • The work of adhesion for control cells was about four times higher than that of the Cyt-D treated cells. • Short- and long-range contributions to adhesion are nearly equal for both control and treated cells.

  12. 2H(p, pp) n reaction as a probe of the short-range nuclear force

    International Nuclear Information System (INIS)

    Haftel, M.I.; Petersen, E.L.; Wallace, J.M.

    1976-01-01

    We examine the feasibility of using the 2 H(p, pp) n reaction as a means of extracting information about the short-range behavior of the nuclear force not obtainable from N-N scattering experiments. To do this we use several separable potentials and examine the predicted cross section in various regions of phase space and for beam energies between 14 and 65 MeV. The questions that we address are likely to be insensitive to Coulomb effects. Both the form factor and the energy dependence of the potentials have been modified from the usual Yamaguchi form. The form of the energy dependence is chosen to obtain phase-shift equivalence for two different form factors while guaranteeing a unitary two-body scattering amplitude. The sensitivity of breakup results to the on-shell and off-shell aspects of the nuclear force is examined and discussed. Significant on-shell sensitivity occurs for breakup amplitudes in all states and for cross sections over all regions of phase space. Off-shell sensitivity appears only in the S = 1/2, L = 0 breakup amplitudes, with all S = 3/2 and all L > 0 amplitudes exhibiting negligible off-shell dependence. This result leads to only a very small (< or = 5%) off-shell sensitivity for quasifree scattering. However, cross sections far from quasifree scattering, and in particular cross sections in the final-state interaction region of phase space, exhibit as much as a 50% variation for phase-shift-equivalent potentials. This sensitivity is small at low beam energy and increases with increasing energy. The energy dependence at negative energies of one potential is also altered to adjust the triton binding energy. This enables us to compare phase-shift-equivalent potentials differing off shell but predicting the same triton binding energy. The energy dependence of this potential is somewhat unconventional. Fixing of the triton binding energy reduces the off-shell sensitivity appreciably only for E approximately-less-than 20 MeV

  13. How Confinement-Induced Structures Alter the Contribution of Hydrodynamic and Short-Ranged Repulsion Forces to the Viscosity of Colloidal Suspensions

    Directory of Open Access Journals (Sweden)

    Meera Ramaswamy

    2017-10-01

    Full Text Available Confined systems ranging from the atomic to the granular are ubiquitous in nature. Experiments and simulations of such atomic and granular systems have shown a complex relationship between the microstructural arrangements under confinement, the short-ranged particle stresses, and flow fields. Understanding the same correlation between structure and rheology in the colloidal regime is important due to the significance of such suspensions in industrial applications. Moreover, colloidal suspensions exhibit a wide range of structures under confinement that could considerably modify such force balances and the resulting viscosity. Here, we use a combination of experiments and simulations to elucidate how confinement-induced structures alter the relative contributions of hydrodynamic and short-range repulsive forces to produce up to a tenfold change in the viscosity. In the experiments we use a custom-built confocal rheoscope to image the particle configurations of a colloidal suspension while simultaneously measuring its stress response. We find that as the gap decreases below 15 particle diameters, the viscosity first decreases from its bulk value, shows fluctuations with the gap, and then sharply increases for gaps below 3 particle diameters. These trends in the viscosity are shown to strongly correlate with the suspension microstructure. Further, we compare our experimental results to those from two different simulations techniques, which enables us to determine the relative contributions of hydrodynamic and short-range repulsive stresses to the suspension rheology. The first method uses the lubrication approximation to find the hydrodynamic stress and includes a short-range repulsive force between the particles while the second is a Stokesian dynamics simulation that calculates the full hydrodynamic stress in the suspension. We find that the decrease in the viscosity at moderate confinements has a significant contribution from both the

  14. Short-range communication system

    Science.gov (United States)

    Alhorn, Dean C. (Inventor); Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

    2012-01-01

    A short-range communication system includes an antenna, a transmitter, and a receiver. The antenna is an electrical conductor formed as a planar coil with rings thereof being uniformly spaced. The transmitter is spaced apart from the plane of the coil by a gap. An amplitude-modulated and asynchronous signal indicative of a data stream of known peak amplitude is transmitted into the gap. The receiver detects the coil's resonance and decodes same to recover the data stream.

  15. Search for a spin-dependent short-range force between nucleons with a 3He/129Xe clock-comparison experiment

    International Nuclear Information System (INIS)

    Tullney, Kathlynne

    2014-01-01

    The standard model (SM) of particle physics describes all known particles and their interactions. However, the SM leaves many issues unresolved. For example, it only includes three of the four fundamental forces and does not clarify the question why in the strong interaction CP symmetry is violated due to its non-trivial vacuum structure is predicted (Θ-term), but experimentally unverifiable. The latter one is known as the strong CP-problem of quantum chromodynamics (QCD) and is solved by the Peccei-Quinn-Weinberg-Wilczek theory. This theory predicts a new and almost massless boson which is known as the axion. The axion feebly interacts with matter and therefore it is a good candidate for cold dark matter, too. Axions are produced by the Primakoff-effect, i.e. by conversion of photons which are scattered in the electromagnetic field, e.g. of atoms. The inverse Primakoff-effect, which converts axions to photons again, can be used for direct detection of galactic, solar, or laboratory axions. Cosmological and astrophysical observations constrain the mass of the axion from a few μeV to some meV (''axion mass window''). If the axion exists, then it mediates a CP violating, spin-dependent, short-range interaction between a fermion and the spin of another fermion. By verification of this interaction, the axion can be detected indirectly. In the framework of the present thesis an experiment to search for this spindependent short-range interaction was performed in the magnetically shielded room BMSR-2 of the Physikalisch-Technische Bundesanstalt Berlin. An ultra-sensitive low-field co-magnetometer was employed which is based on the detection of free precession of 3 He and 129 Xe nuclear spins using SQUIDs as low-noise magnetic flux detectors. The two nuclear spin polarized gases are filled into a glass cell which is immersed in a low magnetic field of about B 0 = 0.35 μT with absolute field gradients in the order of pT/cm. The spin precession frequencies of 3 He and 129

  16. Intentionally Short Range Communications (ISRC)

    Science.gov (United States)

    1993-05-01

    molecular oxygen in the atmosphere at 60 GHz (figure 9 LIppolito, 1981]). The MMW range is similar to that of the UV links. 3.3.1 Variable Range Similar to...option also requires that the signal be strong enough to overcome the noise from the solar and background sources, although the molecular oxygen and... emisions . Lasing will occur only within the cavity when the alignment is correct and not lasing othem ise. Such a cavity is dcteclable only when an observer

  17. Magnetic short range order in Gd

    International Nuclear Information System (INIS)

    Child, H.R.

    1976-01-01

    Quasielastic neutron scattering has been used to investigate magnetic short range order in Gd for 80 0 K 0 K. Short range order exists throughout this range from well below T/sub C/ = 291 0 K to well above it and can be reasonably well described by an anisotropic Orstein-Zernike form for chi

  18. Statistical Short-Range Guidance for Peak Wind Speed Forecasts on Kennedy Space Center/Cape Canaveral Air Force Station: Phase I Results

    Science.gov (United States)

    Lambert, Winifred C.; Merceret, Francis J. (Technical Monitor)

    2002-01-01

    This report describes the results of the ANU's (Applied Meteorology Unit) Short-Range Statistical Forecasting task for peak winds. The peak wind speeds are an important forecast element for the Space Shuttle and Expendable Launch Vehicle programs. The Keith Weather Squadron and the Spaceflight Meteorology Group indicate that peak winds are challenging to forecast. The Applied Meteorology Unit was tasked to develop tools that aid in short-range forecasts of peak winds at tower sites of operational interest. A 7 year record of wind tower data was used in the analysis. Hourly and directional climatologies by tower and month were developed to determine the seasonal behavior of the average and peak winds. In all climatologies, the average and peak wind speeds were highly variable in time. This indicated that the development of a peak wind forecasting tool would be difficult. Probability density functions (PDF) of peak wind speed were calculated to determine the distribution of peak speed with average speed. These provide forecasters with a means of determining the probability of meeting or exceeding a certain peak wind given an observed or forecast average speed. The climatologies and PDFs provide tools with which to make peak wind forecasts that are critical to safe operations.

  19. Short-range correlations with pseudopotentials

    International Nuclear Information System (INIS)

    Osman, A.

    1976-01-01

    Short-range correlations in nuclei are considered on an unitary-model operator approach. Short-range pseudopotentials have been added to achieve healing in the correlated wave functions. With the introduction of the pseudopotentials, correlated basis wave functions are constructed. The matrix element for effective interaction in nuclei is developed. The required pseudopotentials have been calculated for the Hamda-Johnston, Yale and Reid potentials and for the nuclear nucleon-nucleon potential A calculated by us according to meson exchange between nucleons. (Osman, A.)

  20. Magnetic short-range order in Gd

    International Nuclear Information System (INIS)

    Child, H.R.

    1978-01-01

    The magnetic short-range order in a ferromagnetic, isotopically enriched 160 Gd metal single crystal has been investigated by quasielastic scattering of 81-meV neutrons. Since Gd behaves as an S-state ion in the metal, little anisotropy is expected in its magnetic behavior. However, the data show that there is anisotropic short-range order present over a large temperature interval both above and below T/sub C/. The data have been analyzed in terms of an Ornstein-Zernike Lorentzian form with anisotropic correlation ranges. These correlation ranges as deduced from the observed data behave normally above T/sub C/ but seem to remain constant over a fairly large interval below T/sub C/ before becoming unobservable at lower temperatures. These observations suggest that the magnetic ordering in Gd may be a more complicated phenomenon than first believed

  1. Short range order of selenite glasses

    Czech Academy of Sciences Publication Activity Database

    Neov, S.; Gerasimova, I.; Yordanov, S.; Lakov, L.; Mikula, Pavol; Lukáš, Petr

    1999-01-01

    Roč. 40, č. 2 (1999), s. 111-112 ISSN 0031-9090 R&D Projects: GA AV ČR KSK1010104 Keywords : short range * selenite glasses Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.822, year: 1999

  2. Gauge hierarchy and long range forces

    International Nuclear Information System (INIS)

    Pal, P.B.; Keung, Wai-Yee; Chang, D.

    1990-01-01

    With the aid of simple examples, we show how a long range attractive force can arise in a gauge theory with a hierarchy. The force is due to the exchange of a Higgs boson whose mass and matter couplings are both naturally suppressed by the hierarchical mass ratio. Such bosons appear if there is an accidental global symmetry in the low-energy renormalizable Lagrangian after the high energy symmetry breaking. 6 refs

  3. Brownian motion in short range random potentials

    International Nuclear Information System (INIS)

    Romero, A.H.; Romero, A.H.; Sancho, J.M.

    1998-01-01

    A numerical study of Brownian motion of noninteracting particles in random potentials is presented. The dynamics are modeled by Langevin equations in the high friction limit. The random potentials are Gaussian distributed and short ranged. The simulations are performed in one and two dimensions. Different dynamical regimes are found and explained. Effective subdiffusive exponents are obtained and commented on. copyright 1998 The American Physical Society

  4. Narrow resonances and short-range interactions

    International Nuclear Information System (INIS)

    Gelman, Boris A.

    2009-01-01

    Narrow resonances in systems with short-range interactions are discussed in an effective field theory (EFT) framework. An effective Lagrangian is formulated in the form of a combined expansion in powers of a momentum Q 0 | 0 --a resonance peak energy. At leading order in the combined expansion, a two-body scattering amplitude is the sum of a smooth background term of order Q 0 and a Breit-Wigner term of order Q 2 (δε) -1 which becomes dominant for δε 3 . Such an EFT is applicable to systems in which short-distance dynamics generates a low-lying quasistationary state. The EFT is generalized to describe a narrow low-lying resonance in a system of charged particles. It is shown that in the case of Coulomb repulsion, a two-body scattering amplitude at leading order in a combined expansion is the sum of a Coulomb-modified background term and a Breit-Wigner amplitude with parameters renormalized by Coulomb interactions.

  5. Nonlocality and short-range wetting phenomena.

    Science.gov (United States)

    Parry, A O; Romero-Enrique, J M; Lazarides, A

    2004-08-20

    We propose a nonlocal interfacial model for 3D short-range wetting at planar and nonplanar walls. The model is characterized by a binding-potential functional depending only on the bulk Ornstein-Zernike correlation function, which arises from different classes of tubelike fluctuations that connect the interface and the substrate. The theory provides a physical explanation for the origin of the effective position-dependent stiffness and binding potential in approximate local theories and also obeys the necessary classical wedge covariance relationship between wetting and wedge filling. Renormalization group and computer simulation studies reveal the strong nonperturbative influence of nonlocality at critical wetting, throwing light on long-standing theoretical problems regarding the order of the phase transition.

  6. Nonlocality and Short-Range Wetting Phenomena

    Science.gov (United States)

    Parry, A. O.; Romero-Enrique, J. M.; Lazarides, A.

    2004-08-01

    We propose a nonlocal interfacial model for 3D short-range wetting at planar and nonplanar walls. The model is characterized by a binding-potential functional depending only on the bulk Ornstein-Zernike correlation function, which arises from different classes of tubelike fluctuations that connect the interface and the substrate. The theory provides a physical explanation for the origin of the effective position-dependent stiffness and binding potential in approximate local theories and also obeys the necessary classical wedge covariance relationship between wetting and wedge filling. Renormalization group and computer simulation studies reveal the strong nonperturbative influence of nonlocality at critical wetting, throwing light on long-standing theoretical problems regarding the order of the phase transition.

  7. Short range order in liquid pnictides

    International Nuclear Information System (INIS)

    Mayo, M; Makov, G; Yahel, E; Greenberg, Y

    2013-01-01

    Liquid pnictides have anomalous physical properties and complex radial distribution functions. The quasi-crystalline model of liquid structure is applied to interpret the three-dimensional structure of liquid pnictides. It is shown that all the column V elements can be characterized by a short range order lattice symmetry similar to that of the underlying solid, the A7 structure, which originates from a Peierls distorted simple cubic lattice. The evolution of the liquid structure down the column as well as its temperature and pressure dependence is interpreted by means of the effect of thermodynamic parameters on the Peierls distortion. Surprisingly, it is found that the Peierls effect increases with temperature and the nearest neighbour distances exhibit negative thermal expansion. (paper)

  8. Geophysical Tests for Intermediate-Range Forces

    Science.gov (United States)

    1993-11-01

    34Feeble intermediate-range Gravitation, 1989, 154. Topics: AG,T, A forces from higher dimensions", Physical Review 60. Bell J. S., Perring J. K., ൝r...M., 134 Bell J. S., 60, 61 Coleman R., 389 Beltran-Lopez V., 359 Cabibbo N., 64 Coleman R. A ., 135 Bender P. L., 540 Calafiura P., 106 Cook A . H...of Zh. Eksp. Teor. Fiz., Selen M. A ., Shoemaker F. C., Smith A . J. S., 1985,88, 1946-1949.] Topics: SD,E,+ Blackmore E. W., Bryman D. A ., Felawka L

  9. Unitarity corrections to short-range order long-range rapidity correlations

    CERN Document Server

    Capella, A

    1978-01-01

    Although the effective hadronic forces have short range in rapidity space, one nevertheless expects long-range dynamical correlations induced by unitarity constraints. This paper contains a thorough discussion of long-range rapidity correlations in high-multiplicity events. In particular, the authors analyze in detail the forward- backward multiplicity correlations, measured recently in the whole CERN ISR energy range. They find from these data that the normalized variance of the number n of exchanged cut Pomerons, ((n/(n)-1)/sup 2/) , is most probably in the range 0.32 to 0.36. They show that such a number is obtained from Reggeon theory in the eikonal approximation. The authors also predict a very specific violation of local compensation of charge in multiparticle events: The violation should appear in the fourth-order zone correlation function and is absent in the second-order correlation function, the only one measured until now. (48 refs).

  10. Short Range Air Defense in Army Divisions: Do We Really Need It

    National Research Council Canada - National Science Library

    Anderson, Charles

    2000-01-01

    Ever since the Soviet threat collapsed, coupled with the demonstrated, overwhelming, capability of our air forces during numerous operations in the 1990s, the relevance of the Short Range Air Defense (SHORAD...

  11. Numerical challenges of short range wake field calculations

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Thomas; Gjonaj, Erion; Weiland, Thomas [Technische Universitaet Darmstadt (Germany). Institut fuer Theorie Elektromagnetischer Felder (TEMF)

    2011-07-01

    For present and future accelerator projects with ultra short bunches the accurate and reliable calculation of short range wake fields is an important issue. However, the numerical calculation of short range wake fields is a numerical challenging task. The presentation gives an overview over the numerical challenges and techniques for short range wake field calculations. Finally, some simulation results obtained by the program PBCI developed at the TU Darmstadt are presented.

  12. Uncertainties in forces extracted from non-contact atomic force microscopy measurements by fitting of long-range background forces

    Directory of Open Access Journals (Sweden)

    Adam Sweetman

    2014-04-01

    Full Text Available In principle, non-contact atomic force microscopy (NC-AFM now readily allows for the measurement of forces with sub-nanonewton precision on the atomic scale. In practice, however, the extraction of the often desired ‘short-range’ force from the experimental observable (frequency shift is often far from trivial. In most cases there is a significant contribution to the total tip–sample force due to non-site-specific van der Waals and electrostatic forces. Typically, the contribution from these forces must be removed before the results of the experiment can be successfully interpreted, often by comparison to density functional theory calculations. In this paper we compare the ‘on-minus-off’ method for extracting site-specific forces to a commonly used extrapolation method modelling the long-range forces using a simple power law. By examining the behaviour of the fitting method in the case of two radically different interaction potentials we show that significant uncertainties in the final extracted forces may result from use of the extrapolation method.

  13. Kernel optimization for short-range molecular dynamics

    Science.gov (United States)

    Hu, Changjun; Wang, Xianmeng; Li, Jianjiang; He, Xinfu; Li, Shigang; Feng, Yangde; Yang, Shaofeng; Bai, He

    2017-02-01

    To optimize short-range force computations in Molecular Dynamics (MD) simulations, multi-threading and SIMD optimizations are presented in this paper. With respect to multi-threading optimization, a Partition-and-Separate-Calculation (PSC) method is designed to avoid write conflicts caused by using Newton's third law. Serial bottlenecks are eliminated with no additional memory usage. The method is implemented by using the OpenMP model. Furthermore, the PSC method is employed on Intel Xeon Phi coprocessors in both native and offload models. We also evaluate the performance of the PSC method under different thread affinities on the MIC architecture. In the SIMD execution, we explain the performance influence in the PSC method, considering the "if-clause" of the cutoff radius check. The experiment results show that our PSC method is relatively more efficient compared to some traditional methods. In double precision, our 256-bit SIMD implementation is about 3 times faster than the scalar version.

  14. Magnetic short range order and the exchange coupling in magnets

    International Nuclear Information System (INIS)

    Antropov, V.P.

    2006-01-01

    We discuss our recent results of time-dependent density functional simulations of magnetic properties of Fe and Ni at finite temperatures. These results indicated that a strong magnetic short range order is responsible for the magnetic properties of elementary Ni and any itinerant magnet in general. We demonstrated that one can use the value of the magnetic short range order parameter to produce new quantitative classification of magnets. We also discuss the nature of the exchange coupling and its connection with the short range order. The spin-wave like propagating and diffusive excitations in paramagnetic localized systems with small short range order have been predicted while in the itinerant systems the short range order is more complicated. The possible smallness of the quantum factor in the itinerant magnets with short range order is discussed

  15. Isobar configurations in nuclei and short range correlations

    CERN Document Server

    Weber, H J

    1979-01-01

    Recent results on short range correlations and isobar configurations are reviewed, and in particular a unitary version of the isobar model, coupling constants and rho -meson transition potentials, a comparison with experiments, the CERN N*-knockout from /sup 4/He, QCD and the NN interaction of short range. (42 refs).

  16. The MOLDY short-range molecular dynamics package

    Science.gov (United States)

    Ackland, G. J.; D'Mellow, K.; Daraszewicz, S. L.; Hepburn, D. J.; Uhrin, M.; Stratford, K.

    2011-12-01

    We describe a parallelised version of the MOLDY molecular dynamics program. This Fortran code is aimed at systems which may be described by short-range potentials and specifically those which may be addressed with the embedded atom method. This includes a wide range of transition metals and alloys. MOLDY provides a range of options in terms of the molecular dynamics ensemble used and the boundary conditions which may be applied. A number of standard potentials are provided, and the modular structure of the code allows new potentials to be added easily. The code is parallelised using OpenMP and can therefore be run on shared memory systems, including modern multicore processors. Particular attention is paid to the updates required in the main force loop, where synchronisation is often required in OpenMP implementations of molecular dynamics. We examine the performance of the parallel code in detail and give some examples of applications to realistic problems, including the dynamic compression of copper and carbon migration in an iron-carbon alloy. Program summaryProgram title: MOLDY Catalogue identifier: AEJU_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJU_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License version 2 No. of lines in distributed program, including test data, etc.: 382 881 No. of bytes in distributed program, including test data, etc.: 6 705 242 Distribution format: tar.gz Programming language: Fortran 95/OpenMP Computer: Any Operating system: Any Has the code been vectorised or parallelized?: Yes. OpenMP is required for parallel execution RAM: 100 MB or more Classification: 7.7 Nature of problem: Moldy addresses the problem of many atoms (of order 10 6) interacting via a classical interatomic potential on a timescale of microseconds. It is designed for problems where statistics must be gathered over a number of equivalent runs, such as

  17. Hard probes of short-range nucleon-nucleon correlations

    Energy Technology Data Exchange (ETDEWEB)

    J. Arrington, D. W. Higinbotham, G. Rosner, M. Sargsian

    2012-10-01

    The strong interaction of nucleons at short distances leads to a high-momentum component to the nuclear wave function, associated with short-range correlations between nucleons. These short-range, high-momentum structures in nuclei are one of the least well understood aspects of nuclear matter, relating to strength outside of the typical mean-field approaches to calculating the structure of nuclei. While it is difficult to study these short-range components, significant progress has been made over the last decade in determining how to cleanly isolate short-range correlations in nuclei. We have moved from asking if such structures exist, to mapping out their strength in nuclei and studying their microscopic structure. A combination of several different measurements, made possible by high-luminosity and high-energy accelerators, coupled with an improved understanding of the reaction mechanism issues involved in studying these structures, has led to significant progress, and provided significant new information on the nature of these small, highly-excited structures in nuclei. We review the general issues related to short-range correlations, survey recent experiments aimed at probing these short-range structures, and lay out future possibilities to further these studies.

  18. Impact of additional surface observation network on short range ...

    Indian Academy of Sciences (India)

    Stations (AWS) surface observations (temperature and moisture) on the short range forecast over the Indian ... models, which are able to resolve mesoscale fea- ... J. Earth Syst. Sci. ..... terization of the snow field in a cloud model; J. Climate.

  19. Measurements of short-range ordering in Ni3Al

    International Nuclear Information System (INIS)

    Okamoto, J.K.; Ahn, C.C.

    1992-01-01

    This paper reports on extended electron energy-loss fine structure (EXELFS) that has been used to measure short-range ordering in Ni 3 Al. Films of fcc Ni 3 Al with suppressed short-range order synthesized by vacuum evaporation of Ni 3 Al onto room temperature substrates. EXELFS data were taken from both Al K and Ni L 23 edges. The development of short-range order was observed after the samples were annealed for various times at temperatures below 350 degrees C. Upon comparison with ab initio planewave EXELFS calculations, it was found that the Warren-Cowley short-range order parameter a(1nn) changed by about -0.1 after 210 minutes of annealing at 150 degrees C

  20. A method of short range system analysis for nuclear utilities

    International Nuclear Information System (INIS)

    Eng, R.; Mason, E.A.; Benedict, M.

    1976-01-01

    An optimization procedure has been formulated and tested that is capable of solving for the optimal generation schedule of several nuclear power reactors in an electric power utility system, under short-range, resource-limited, conditions. The optimization procedure utilizes a new concept called the Opportunity Cost of Nuclear Power (OCNP) to optimally assign the resource-limited nuclear energy to the different weeks and hours in the short-range planning horizon. OCNP is defined as the cost of displaced energy when optimally distributed nuclear energy is marginally increased. Under resource-limited conditions, the short-range 'value' of nuclear power to a utility system is not its actual generation cost, but the cost of the next best alternative supply of energy, the OCNP. OCNP is a function of a week's system reserve capacity, the system's economic loading order, the customer demand function, and the nature of the available utility system generating units. The optimized OCNP value of the short-range planning period represents the utility's short-range energy replacement cost incurred when selling nuclear energy to a neighbouring utility. (author)

  1. Long range forces and limits on unparticle interactions

    International Nuclear Information System (INIS)

    Deshpande, N.G.; Hsu, Stephen D.H.; Jiang Jing

    2008-01-01

    Couplings between standard model particles and unparticles from a nontrivial scale invariant sector can lead to long range forces. If the forces couple to quantities such as baryon or lepton (electron) number, stringent limits result from tests of the gravitational inverse square law. These limits are much stronger than from collider phenomenology and astrophysics

  2. Search for an intermediate-range composition-dependent force

    International Nuclear Information System (INIS)

    Boynton, P.E.; Crosby, D.; Ekstrom, P.; Szumilo, A.

    1987-01-01

    We have conducted an experiment to detect a composition-dependent force with range λ between 10 m and 1 km, and find a statistically significant effect. If interpreted as arising from a new force, this result and other recent measurementes would be consistent in strength only if the coupling were predominantly to nuclear isospin

  3. Guidelines for Evaluation of Canadian Forces Indoor Firing Ranges

    National Research Council Canada - National Science Library

    Severs, Y

    1999-01-01

    Indoor Firing Ranges (IFR) within DND are typically used by Canadian Forces (CF) personnel, Cadets, RCMP, and civilian organizations for firing small bore weapons in support of both operational/ occupational and recreational requirements...

  4. Amorphous photonic crystals with only short-range order.

    Science.gov (United States)

    Shi, Lei; Zhang, Yafeng; Dong, Biqin; Zhan, Tianrong; Liu, Xiaohan; Zi, Jian

    2013-10-04

    Distinct from conventional photonic crystals with both short- and long-range order, amorphous photonic crystals that possess only short-range order show interesting optical responses owing to their unique structural features. Amorphous photonic crystals exhibit unique light scattering and transport, which lead to a variety of interesting phenomena such as isotropic photonic bandgaps or pseudogaps, noniridescent structural colors, and light localization. Recent experimental and theoretical advances in the study of amorphous photonic crystals are summarized, focusing on their unique optical properties, artificial fabrication, bionspiration, and potential applications. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. A short-range ensemble prediction system for southern Africa

    CSIR Research Space (South Africa)

    Park, R

    2012-10-01

    Full Text Available system for southern Africa R PARK, WA LANDMAN AND F ENGELBRECHT CSIR, PO Box 395, Pretoria, South Africa, 0001 Email: xxxxxxxxxxxxxx@csir.co.za ? www.csir.co.za INTRODUCTION This research has been conducted in order to develop a short-range ensemble... stream_source_info Park_2012.pdf.txt stream_content_type text/plain stream_size 7211 Content-Encoding ISO-8859-1 stream_name Park_2012.pdf.txt Content-Type text/plain; charset=ISO-8859-1 A short-range ensemble prediction...

  6. Small Device For Short-Range Antenna Measurements Using Optics

    DEFF Research Database (Denmark)

    Yanakiev, Boyan Radkov; Nielsen, Jesper Ødum; Christensen, Morten

    2011-01-01

    This paper gives a practical solution for implementing an antenna radiation pattern measurement device using optical fibers. It is suitable for anechoic chambers as well as short range channel sounding. The device is optimized for small size and provides a cheap and easy way to make optical antenna...

  7. Short-range/Long-range Integrated Target (SLIT) for Video Guidance Sensor Rendezvous and Docking

    Science.gov (United States)

    Roe, Fred D. (Inventor); Bryan, Thomas C. (Inventor)

    2009-01-01

    A laser target reflector assembly for mounting upon spacecraft having a long-range reflector array formed from a plurality of unfiltered light reflectors embedded in an array pattern upon a hemispherical reflector disposed upon a mounting plate. The reflector assembly also includes a short-range reflector array positioned upon the mounting body proximate to the long-range reflector array. The short-range reflector array includes three filtered light reflectors positioned upon extensions from the mounting body. The three filtered light reflectors retro-reflect substantially all incident light rays that are transmissive by their monochromatic filters and received by the three filtered light reflectors. In one embodiment the short-range reflector array is embedded within the hemispherical reflector,

  8. Thermodynamic properties of short-range square well fluid

    Science.gov (United States)

    López-Rendón, R.; Reyes, Y.; Orea, P.

    2006-08-01

    The interfacial properties of short-range square well fluid with λ =1.15, 1.25, and 1.375 were determined by using single canonical Monte Carlo simulations. Simulations were carried out in the vapor-liquid region. The coexistence curves of these models were calculated and compared to those previously reported in the literature and good agreement was found among them. We found that the surface tension curves for any potential model of short range form a single master curve when we plot γ* vs T /Tc. It is demonstrated that the critical reduced second virial coefficient B2* as a function of interaction range or Tc* is not constant.

  9. The nuclear contacts and short range correlations in nuclei

    Science.gov (United States)

    Weiss, R.; Cruz-Torres, R.; Barnea, N.; Piasetzky, E.; Hen, O.

    2018-05-01

    Atomic nuclei are complex strongly interacting systems and their exact theoretical description is a long-standing challenge. An approximate description of nuclei can be achieved by separating its short and long range structure. This separation of scales stands at the heart of the nuclear shell model and effective field theories that describe the long-range structure of the nucleus using a mean-field approximation. We present here an effective description of the complementary short-range structure using contact terms and stylized two-body asymptotic wave functions. The possibility to extract the nuclear contacts from experimental data is presented. Regions in the two-body momentum distribution dominated by high-momentum, close-proximity, nucleon pairs are identified and compared to experimental data. The amount of short-range correlated (SRC) nucleon pairs is determined and compared to measurements. Non-combinatorial isospin symmetry for SRC pairs is identified. The obtained one-body momentum distributions indicate dominance of SRC pairs above the nuclear Fermi-momentum.

  10. High-Capacity Short-Range Optical Communication Links

    DEFF Research Database (Denmark)

    Tatarczak, Anna

    Over the last decade, we have observed a tremendous spread of end-user mobile devices. The user base of a mobile application can grow or shrink by millions per day. This situation creates a pressing need for highly scalable server infrastructure; a need nowadays satisfied through cloud computing...... offered by data centers. As the popularity of cloud computing soars, the demand for high-speed, short-range data center links grows. Vertical cavity surface emitting lasers (VCSEL) and multimode fibers (MMF) prove especially well-suited for such scenarios. VCSELs have high modulation bandwidths......, we achieve 10 Gbps over 400 m and then conrm the approach in an optimized system at 25 Gbps over 300 m. The techniques described in this thesis leverage additional degrees of freedom to better utilize the available resources of short-range links. The proposed schemes enable higher speeds and longer...

  11. Schroedinger operators with point interactions and short range expansions

    International Nuclear Information System (INIS)

    Albeverio, S.; Hoeegh-Krohn, R.; Oslo Univ.

    1984-01-01

    We give a survey of recent results concerning Schroedinger operators with point interactions in R 3 . In the case where the point interactions are located at a discrete set of points we discuss results about the resolvent, the spectrum, the resonances and the scattering quantities. We also discuss the approximation of point interactions by short range local potentials (short range or low energy expansions) and the one electron model of a 3-dimensional crystal. Moreover we discuss Schroedinger operators with Coulomb plus point interactions, with applications to the determination of scattering lengths and of level shifts in mesic atoms. Further applications to the multiple well problem, to multiparticle systems, to crystals with random impurities, to polymers and quantum fields are also briefly discussed. (orig.)

  12. Recent results on short-range gravity experiment

    International Nuclear Information System (INIS)

    Hata, Maki; Akiyama, Takashi; Ikeda, Yuki; Kawamura, Hirokazu; Narita, Keigo; Ninomiya, Kazufumi; Ogawa, Naruya; Sato, Toshiaki; Seitaibashi, Etsuko; Sekiguchi, Yuta; Tsutsui, Ryosuke; Yazawa, Kazumasa; Murata, Jiro

    2009-01-01

    According to the ADD model, deviation from Newton's inverse square law is expected at below sub-millimeter scale. Present study is an experimental investigation of the Newton's gravitational law at a short range scale. We have developed an experimental setup using torsion balance bar, and succeeded to confirm the inverse square law at a centimeter scale. In addition, composition dependence of gravitational constant G is also tested at the centimeter scale, motivated to test the weak equivalence principle.

  13. Chemical and topological short-range order in metallic glasses

    International Nuclear Information System (INIS)

    Vincze, I.; Schaafsma, A.S.; Van der Woude, F.; Kemeny, T.; Lovas, A.

    1980-10-01

    Moessbauer spectroscopy is applied to the study of chemical short-range order in (Fe,Ni)B metallic glasses. It is found that the atomic arrangement in melt-quenched glasses closely resembles that of the crystalline counterparts (Fe 3 B is tetragonal, Ni 3 B is orthorombic). The distribution of transition metal atoms is not random at high Ni concentrations: Ni atoms prefer a neighbourhood with a higher boron coordination. (P.L.)

  14. Short-range correlations in quark and nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Froemel, Frank

    2007-06-15

    In the first part of this thesis, the role of short-range correlations in quark matter is explored within the framework of the Nambu-Jona-Lasinio model. Starting from a next-to-leading order expansion in the inverse number of the quark colors, a fully self-consistent model constructed that employs the close relations between spectral functions and self-energies. In contrast to the usual quasiparticle approximations, this approach allows the investigation of the collisional broadening of the quark spectral function. Numerical calculations at various chemical potentials and zero temperature show that the short-range correlations do not only induce a finite width of the spectral function but also have some influence on the structure of the chiral phase transition. In the second part of this thesis, the temperature and density dependence of the nucleon spectral function in symmetric nuclear matter is investigated. The short-range correlations can be well described by a simple, self-consistent model on the one-particle-two-hole and two-particle-one-hole level (1p2h, 2p1h). The thermodynamically consistent description of the mean-field properties of the nucleons is ensured by incorporating a Skyrme-type potential. Calculations at temperatures and densities that can also be found in heavy-ion collisions or supernova explosions and the formation of neutron stars show that the correlations saturate at high temperatures and densities. (orig.)

  15. Characterizing short-range vs. long-range spatial correlations in dislocation distributions

    Energy Technology Data Exchange (ETDEWEB)

    Chevy, Juliette, E-mail: juliette.chevy@gmail.com [Laboratoire de Glaciologie et Geophysique de l' Environnement-CNRS, 54 rue Moliere, 38402 St. Martin d' Heres (France)] [Laboratoire Science et Ingenierie des Materiaux et Procedes, Grenoble INP-CNRS-UJF, BP 75, 38402 St. Martin d' Heres Cedex (France); Fressengeas, Claude; Lebyodkin, Mikhail; Taupin, Vincent [Laboratoire de Physique et Mecanique des Materiaux, Universite Paul Verlaine-Metz/CNRS, Ile du Saulcy, 57045 Metz Cedex (France); Bastie, Pierre [Laboratoire de Spectrometrie Physique, BP 87, 38402 St. Martin d' Heres Cedex (France)] [Institut Laue Langevin, BP 156, 38042 Grenoble Cedex 9 (France); Duval, Paul [Laboratoire de Glaciologie et Geophysique de l' Environnement-CNRS, 54 rue Moliere, 38402 St. Martin d' Heres (France)

    2010-03-15

    Hard X-ray diffraction experiments have provided evidence of a strongly heterogeneous distribution of dislocation densities along the axis of cylindrical ice single crystals oriented for basal slip in torsion creep. The dislocation arrangements showed a complex scale-invariant character, which was analyzed by means of statistical and multifractal techniques. A trend to decreasing autocorrelation of the dislocation distribution was observed as deformation proceeds. At low strain levels, long-range spatial correlations control the distribution, but short-range correlations in relation with cross-slip progressively prevail when strain increases. This trend was reproduced by a model based on field dislocation dynamics, a theory accounting for both long-range elastic interactions and short-range interactions through transport of dislocation densities.

  16. Characterizing short-range vs. long-range spatial correlations in dislocation distributions

    International Nuclear Information System (INIS)

    Chevy, Juliette; Fressengeas, Claude; Lebyodkin, Mikhail; Taupin, Vincent; Bastie, Pierre; Duval, Paul

    2010-01-01

    Hard X-ray diffraction experiments have provided evidence of a strongly heterogeneous distribution of dislocation densities along the axis of cylindrical ice single crystals oriented for basal slip in torsion creep. The dislocation arrangements showed a complex scale-invariant character, which was analyzed by means of statistical and multifractal techniques. A trend to decreasing autocorrelation of the dislocation distribution was observed as deformation proceeds. At low strain levels, long-range spatial correlations control the distribution, but short-range correlations in relation with cross-slip progressively prevail when strain increases. This trend was reproduced by a model based on field dislocation dynamics, a theory accounting for both long-range elastic interactions and short-range interactions through transport of dislocation densities.

  17. Unsupervised learning in neural networks with short range synapses

    Science.gov (United States)

    Brunnet, L. G.; Agnes, E. J.; Mizusaki, B. E. P.; Erichsen, R., Jr.

    2013-01-01

    Different areas of the brain are involved in specific aspects of the information being processed both in learning and in memory formation. For example, the hippocampus is important in the consolidation of information from short-term memory to long-term memory, while emotional memory seems to be dealt by the amygdala. On the microscopic scale the underlying structures in these areas differ in the kind of neurons involved, in their connectivity, or in their clustering degree but, at this level, learning and memory are attributed to neuronal synapses mediated by longterm potentiation and long-term depression. In this work we explore the properties of a short range synaptic connection network, a nearest neighbor lattice composed mostly by excitatory neurons and a fraction of inhibitory ones. The mechanism of synaptic modification responsible for the emergence of memory is Spike-Timing-Dependent Plasticity (STDP), a Hebbian-like rule, where potentiation/depression is acquired when causal/non-causal spikes happen in a synapse involving two neurons. The system is intended to store and recognize memories associated to spatial external inputs presented as simple geometrical forms. The synaptic modifications are continuously applied to excitatory connections, including a homeostasis rule and STDP. In this work we explore the different scenarios under which a network with short range connections can accomplish the task of storing and recognizing simple connected patterns.

  18. Measured long-range repulsive Casimir–Lifshitz forces

    Science.gov (United States)

    Munday, J. N.; Capasso, Federico; Parsegian, V. Adrian

    2014-01-01

    Quantum fluctuations create intermolecular forces that pervade macroscopic bodies1–3. At molecular separations of a few nanometres or less, these interactions are the familiar van der Waals forces4. However, as recognized in the theories of Casimir, Polder and Lifshitz5–7, at larger distances and between macroscopic condensed media they reveal retardation effects associated with the finite speed of light. Although these long-range forces exist within all matter, only attractive interactions have so far been measured between material bodies8–11. Here we show experimentally that, in accord with theoretical prediction12, the sign of the force can be changed from attractive to repulsive by suitable choice of interacting materials immersed in a fluid. The measured repulsive interaction is found to be weaker than the attractive. However, in both cases the magnitude of the force increases with decreasing surface separation. Repulsive Casimir–Lifshitz forces could allow quantum levitation of objects in a fluid and lead to a new class of switchable nanoscale devices with ultra-low static friction13–15. PMID:19129843

  19. Measured long-range repulsive Casimir-Lifshitz forces.

    Science.gov (United States)

    Munday, J N; Capasso, Federico; Parsegian, V Adrian

    2009-01-08

    Quantum fluctuations create intermolecular forces that pervade macroscopic bodies. At molecular separations of a few nanometres or less, these interactions are the familiar van der Waals forces. However, as recognized in the theories of Casimir, Polder and Lifshitz, at larger distances and between macroscopic condensed media they reveal retardation effects associated with the finite speed of light. Although these long-range forces exist within all matter, only attractive interactions have so far been measured between material bodies. Here we show experimentally that, in accord with theoretical prediction, the sign of the force can be changed from attractive to repulsive by suitable choice of interacting materials immersed in a fluid. The measured repulsive interaction is found to be weaker than the attractive. However, in both cases the magnitude of the force increases with decreasing surface separation. Repulsive Casimir-Lifshitz forces could allow quantum levitation of objects in a fluid and lead to a new class of switchable nanoscale devices with ultra-low static friction.

  20. Aerodynamic Jump: A Short Range View for Long Rod Projectiles

    Directory of Open Access Journals (Sweden)

    Mark Bundy

    2001-01-01

    Full Text Available It is shown that aerodynamic jump for a nonspinning kinetic energy penetrator is not – as conventional definitions may infer – a discontinuous change in the direction of motion at the origin of free flight, nor is it the converse, a cumulative redirection over a domain of infinite extent. Rather, with the aid of an alternative kinematical definition, it is shown that aerodynamic jump for such a projectile is a localized redirection of the center-of-gravity motion, caused by the force of lift due to yaw over the relatively short region from entry into free flight until the yaw reaches its first maximum. A rigorous proof of this statement is provided, but the primary objective of this paper is to provide answers to the questions: what is aerodynamic jump, what does it mean, and what aspects of the flight trajectory does it refer to, or account for.

  1. Level shifts induced by a short-range potential

    International Nuclear Information System (INIS)

    Karnakov, B.M.; Mur, V.D.

    1984-01-01

    Formulas are derived which express the shifts of levels with energies Esub(n)sup((0)) << rsub(c)sup(-2) in a field Vsub(f)(r) induced by a short-range potential U(r) of radius rsub(c) in terms of the low energy scattering parameters (scattering length and effective radius) with a moment l in the potential. If the interaction between the particle and center is nonresonant, the method developed is identical to perturbation theory on the scattering length. The theory is extended to systems with random degeneracy (Vsub(f) is the Coulomb potential). Formulas describing quasi-intersection of terms are obtained for the case of resonance interaction with the center in a partial wave with l not equal to 0 when energetically close levels are present in both U and Vsub(f). Some features of the level shift are mentioned for the case when the level possesses an anomalously small coupling energy and its coresponding wave function becomes delocalized with decrease of the coupling energy to zero. The problem is discussed of the level shift when the potential Vsub(f) is a potential well surrounded by a weaklyt penetrable barrier. Some applications of the theory to a particle in the field of two short-range potentials or in the field of a short-range and Coulomb centers are considered. Formulas are also obtained for the shifts and widths of the Landau levels and of the shallow level with an arbitrary moment which perturbs the Landau levels

  2. The short range effective interaction and the spectra of calcium isotopes in (f-p) space

    International Nuclear Information System (INIS)

    Qing-ying, Z.; Shen-wu, L.; Jian-xin, W.

    1986-01-01

    In this work, the authors use a new type of extremely short range interaction, the double delta interaction (DDI) to calculate the low-lying spectra of calcium isotopes /sup 41/Ca through /sup 48/Ca. The configuration space (f-p) includes configurations ( f/sub 7/2//sup n/ ) and ( f/sub 7/2//sup n-1/2p/sub 3/2/). The calculated energies are compared with experimental data for 75 levels. For comparison, they also use usual modified surface delta interaction (MSDI) to calculate the same spectra aforementioned. It is clear that the results calculated with DDI are better than with MSDI. Therefore, in the short-range effective interaction the addition of body delta force to the modified surface delta force may improve the agreement with experiment. The authors believe that the conclusion will not be changed if one enlarges the shell model space

  3. Influence of short range ordering and clustering on transport properties

    International Nuclear Information System (INIS)

    Vigier, G.; Pelletier, J.M.

    1982-01-01

    The influence of short range ordering and clustering phenomena on the electrical resistivity p and the thermopower S is investigated both theoretically and experimentally. According to the considered alloys either increases or decreases of transport properties may be observed when deviations from a random distribution of solute atoms occur. These observations are explained with a model based on free electrons and Born approximations the importance of the potential choice is underlined; two kinds of description of the structure factor are investigated. A good semiquantitative agreement is obtained between computed results and experimental observations

  4. Dynamical arrest in dense short-ranged attractive colloids

    International Nuclear Information System (INIS)

    Foffi, G; Sciortino, F; Zaccarelli, E; Tartaglia, P

    2004-01-01

    We study thermodynamic and dynamic properties of model colloidal systems interacting with a hard core repulsion and a short-range attraction, and provide an overall picture of their phase diagrams which shows a very rich phenomenology. We focus on the slow dynamic properties of this model, investigating in detail the glass transition lines (both repulsive and attractive), the glass-glass transitions and the location of the higher order singularities. We discuss the relative location of the glass lines and of the metastable liquid-gas binodal, an issue relevant for the understanding of low density arrested states of matter

  5. Short-range quantitative precipitation forecasting using Deep Learning approaches

    Science.gov (United States)

    Akbari Asanjan, A.; Yang, T.; Gao, X.; Hsu, K. L.; Sorooshian, S.

    2017-12-01

    Predicting short-range quantitative precipitation is very important for flood forecasting, early flood warning and other hydrometeorological purposes. This study aims to improve the precipitation forecasting skills using a recently developed and advanced machine learning technique named Long Short-Term Memory (LSTM). The proposed LSTM learns the changing patterns of clouds from Cloud-Top Brightness Temperature (CTBT) images, retrieved from the infrared channel of Geostationary Operational Environmental Satellite (GOES), using a sophisticated and effective learning method. After learning the dynamics of clouds, the LSTM model predicts the upcoming rainy CTBT events. The proposed model is then merged with a precipitation estimation algorithm termed Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) to provide precipitation forecasts. The results of merged LSTM with PERSIANN are compared to the results of an Elman-type Recurrent Neural Network (RNN) merged with PERSIANN and Final Analysis of Global Forecast System model over the states of Oklahoma, Florida and Oregon. The performance of each model is investigated during 3 storm events each located over one of the study regions. The results indicate the outperformance of merged LSTM forecasts comparing to the numerical and statistical baselines in terms of Probability of Detection (POD), False Alarm Ratio (FAR), Critical Success Index (CSI), RMSE and correlation coefficient especially in convective systems. The proposed method shows superior capabilities in short-term forecasting over compared methods.

  6. Freely cooling granular gases with short-ranged attractive potentials

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Eric; Subramaniam, Shankar, E-mail: shankar@iastate.edu [Department of Mechanical Engineering, Center for Multiphase Flow Research, Iowa State University, Ames, Iowa 50011 (United States)

    2015-04-15

    We treat the case of an undriven gas of inelastic hard-spheres with short-ranged attractive potentials via an extension of the pseudo-Liouville operator formalism. New evolution equations for the granular temperature and coordination number are obtained. The granular temperature exhibits deviation from both Haff’s law and the case of long-ranged potentials. We verify this departure using soft-sphere discrete element method simulations. Excellent agreement is found for the duration of the simulation even beyond where exclusively binary collisions are expected. Simulations show the emergence of strong spatial-velocity correlations on the length scale of the last peak in the pair-correlation function but do not show strong correlations beyond this length scale. We argue that molecular chaos may remain an adequate approximation if the system is modelled as a Smoluchowski type equation with aggregation and break-up processes.

  7. Short, intermediate and long range order in amorphous ices

    Science.gov (United States)

    Martelli, Fausto; Torquato, Salvatore; Giovanbattista, Nicolas; Car, Roberto

    Water exhibits polyamorphism, i.e., it exists in more than one amorphous state. The most common forms of glassy water are the low-density amorphous (LDA) and the high-density amorphous (HDA) ices. LDA, the most abundant form of ice in the Universe, transforms into HDA upon isothermal compression. We model the transformation of LDA into HDA under isothermal compression with classical molecular dynamics simulations. We analyze the molecular structures with a recently introduced scalar order metric to measure short and intermediate range order. In addition, we rank the structures by their degree of hyperuniformity, i.e.,the extent to which long range density fluctuations are suppressed. F.M. and R.C. acknowledge support from the Department of Energy (DOE) under Grant No. DE-SC0008626.

  8. van der Waals forces in density functional theory: Perturbational long-range electron-interaction corrections

    International Nuclear Information System (INIS)

    Angyan, Janos G.; Gerber, Iann C.; Savin, Andreas; Toulouse, Julien

    2005-01-01

    Long-range exchange and correlation effects, responsible for the failure of currently used approximate density functionals in describing van der Waals forces, are taken into account explicitly after a separation of the electron-electron interaction in the Hamiltonian into short- and long-range components. We propose a 'range-separated hybrid' functional based on a local density approximation for the short-range exchange-correlation energy, combined with a long-range exact exchange energy. Long-range correlation effects are added by a second-order perturbational treatment. The resulting scheme is general and is particularly well adapted to describe van der Waals complexes, such as rare gas dimers

  9. Force induced unzipping of DNA with long range correlated noise

    International Nuclear Information System (INIS)

    Lam, Pui-Man; Zhen, Yi

    2011-01-01

    We derive and solve a Fokker–Planck equation for the stationary distribution of the free energy, in a model of unzipping of double-stranded DNA under external force. The autocorrelation function of the random DNA sequence can be of a general form, including long range correlations. In the case of Ornstein–Uhlenbeck noise, characterized by a finite correlation length, our result reduces to the exact result of Allahverdyan et al, with the average number of unzipped base pairs going as (X) ∼ 1/f 2 in the white noise limit, where f is the deviation from the critical force. In the case of long range correlated noise, where the integrated autocorrelation is divergent, we find that (X) is finite at f = 0, with its value decreasing as the correlations become of longer range. This shows that long range correlations actually stabilize the DNA sequence against unzipping. Our result is also in agreement with the findings of Allahverdyan et al obtained using numerical generation of the long range correlated noise

  10. Hybrid gesture recognition system for short-range use

    Science.gov (United States)

    Minagawa, Akihiro; Fan, Wei; Katsuyama, Yutaka; Takebe, Hiroaki; Ozawa, Noriaki; Hotta, Yoshinobu; Sun, Jun

    2012-03-01

    In recent years, various gesture recognition systems have been studied for use in television and video games[1]. In such systems, motion areas ranging from 1 to 3 meters deep have been evaluated[2]. However, with the burgeoning popularity of small mobile displays, gesture recognition systems capable of operating at much shorter ranges have become necessary. The problems related to such systems are exacerbated by the fact that the camera's field of view is unknown to the user during operation, which imposes several restrictions on his/her actions. To overcome the restrictions generated from such mobile camera devices, and to create a more flexible gesture recognition interface, we propose a hybrid hand gesture system, in which two types of gesture recognition modules are prepared and with which the most appropriate recognition module is selected by a dedicated switching module. The two recognition modules of this system are shape analysis using a boosting approach (detection-based approach)[3] and motion analysis using image frame differences (motion-based approach)(for example, see[4]). We evaluated this system using sample users and classified the resulting errors into three categories: errors that depend on the recognition module, errors caused by incorrect module identification, and errors resulting from user actions. In this paper, we show the results of our investigations and explain the problems related to short-range gesture recognition systems.

  11. Short range order in FeCo-X alloys

    International Nuclear Information System (INIS)

    Fultz, B.

    1988-01-01

    Moessbauer spectrometry was used to study the kinetics of chemical ordering in FeCo and in FeCo alloyed with ternary solutes. With respect to the binary FeCo alloy, the kinetics of B2 ordering were slowed when 2% of 4d- or 5d-series ternary solute atoms were present, but 3p- and 3d-series ternary solutes had little effect on ordering kinetics. The relaxation of order around the ternary solute atoms could be discerned in Moessbauer spectra, and it seems that the development of B2 short range order is influenced by structural relaxations around the ternary solute atoms. Different thermal treatments were shown to cause different relaxations of and correlations, suggesting that Moessbauer spectrometry can be used to identify different kinetic paths of ordering in ternary alloys. (orig.)

  12. Short-range disorder in pseudobinary ionic alloys

    International Nuclear Information System (INIS)

    Di Cicco, Andrea; Principi, Emiliano; Filipponi, Adriano

    2002-01-01

    The short-range distribution functions of the RbBr 1-x I x solid and molten ionic alloys have been accurately measured using multiple-edge refinement of the K-edge extended x-ray absorption fine structure spectra (EXAFS). The local structure is characterized by two well-defined first-neighbor peaks associated with the Rb-I and Rb-Br distributions, both for solid and liquid alloys. The distribution of distances in solid alloys gives experimental evidence to available theoretical models. In the liquid, the two distance distributions are found to be practically independent of the concentration x. The effect of different effective charge screening of the ions is observed in the molten systems for limiting concentrations

  13. Exploiting orbital effects for short-range extravehicular transfers

    Science.gov (United States)

    Williams, Trevor; Baughman, David

    The problem studied in this paper is that of using Simplified Aid for Extravehicular Activity (EVA) Rescue (SAFER) to carry out efficient short-range transfers from the payload bay of the Space Shuttle Orbiter to the vicinity of the underside of the vehicle, for instance for inspection and repair of thermal tiles or umbilical doors. Trajectories are shown to exist, for the shuttle flying noise forward and belly down, that take the astronaut to the vicinity of the underside with no thrusting after the initial push-off. However, these trajectories are too slow to be of practical interest, as they take roughly an hour to execute. Additionally, they are quite sensitive to errors in the initial push-off rates. To overcome both of these difficulties, trajectories are then studied which include a single in-flight impulse of small magnitude ( in the range 0.1 - 0.4 fps). For operational simplicity, this impulse is applied towards the Orbiter at the moment when the line-of -sight of the EVA crewmember is tangential to the underside of the vehicle. These trajectories are considerably faster than the non-impulsive ones: transit times of less than 10 minutes are achievable. Furthermore, the man-in-the-loop feedback scheme used for impulse timing greatly reduces the sensitivity to initial velocity errors. Finally, similar one-impulse trajectories are also shown to exist for the Orbiter in a gravity-gradient attitiude.

  14. Short range spread-spectrum radiolocation system and method

    Science.gov (United States)

    Smith, Stephen F.

    2003-04-29

    A short range radiolocation system and associated methods that allow the location of an item, such as equipment, containers, pallets, vehicles, or personnel, within a defined area. A small, battery powered, self-contained tag is provided to an item to be located. The tag includes a spread-spectrum transmitter that transmits a spread-spectrum code and identification information. A plurality of receivers positioned about the area receive signals from a transmitting tag. The position of the tag, and hence the item, is located by triangulation. The system employs three different ranging techniques for providing coarse, intermediate, and fine spatial position resolution. Coarse positioning information is provided by use of direct-sequence code phase transmitted as a spread-spectrum signal. Intermediate positioning information is provided by the use of a difference signal transmitted with the direct-sequence spread-spectrum code. Fine positioning information is provided by use of carrier phase measurements. An algorithm is employed to combine the three data sets to provide accurate location measurements.

  15. Combining 2-m temperature nowcasting and short range ensemble forecasting

    Directory of Open Access Journals (Sweden)

    A. Kann

    2011-12-01

    Full Text Available During recent years, numerical ensemble prediction systems have become an important tool for estimating the uncertainties of dynamical and physical processes as represented in numerical weather models. The latest generation of limited area ensemble prediction systems (LAM-EPSs allows for probabilistic forecasts at high resolution in both space and time. However, these systems still suffer from systematic deficiencies. Especially for nowcasting (0–6 h applications the ensemble spread is smaller than the actual forecast error. This paper tries to generate probabilistic short range 2-m temperature forecasts by combining a state-of-the-art nowcasting method and a limited area ensemble system, and compares the results with statistical methods. The Integrated Nowcasting Through Comprehensive Analysis (INCA system, which has been in operation at the Central Institute for Meteorology and Geodynamics (ZAMG since 2006 (Haiden et al., 2011, provides short range deterministic forecasts at high temporal (15 min–60 min and spatial (1 km resolution. An INCA Ensemble (INCA-EPS of 2-m temperature forecasts is constructed by applying a dynamical approach, a statistical approach, and a combined dynamic-statistical method. The dynamical method takes uncertainty information (i.e. ensemble variance from the operational limited area ensemble system ALADIN-LAEF (Aire Limitée Adaptation Dynamique Développement InterNational Limited Area Ensemble Forecasting which is running operationally at ZAMG (Wang et al., 2011. The purely statistical method assumes a well-calibrated spread-skill relation and applies ensemble spread according to the skill of the INCA forecast of the most recent past. The combined dynamic-statistical approach adapts the ensemble variance gained from ALADIN-LAEF with non-homogeneous Gaussian regression (NGR which yields a statistical mbox{correction} of the first and second moment (mean bias and dispersion for Gaussian distributed continuous

  16. Tailored long range forces on polarizable particles by collective scattering of broadband radiation

    International Nuclear Information System (INIS)

    Holzmann, D; Ritsch, H

    2016-01-01

    Collective coherent light scattering by polarizable particles creates surprisingly strong, long range inter-particle forces originating from interference of the light scattered by different particles. While for monochromatic laser beams this interaction decays with the inverse distance, we show here that in general the effective interaction range and geometry can be controlled by the illumination bandwidth and geometry. As generic example we study the modifications inter-particle forces within a 1D chain of atoms trapped in the field of a confined optical nanofiber mode. For two particles we find short range attraction as well as optical binding at multiple distances. The range of stable distances shrinks with increasing light bandwidth and for a very large bandwidth field as e.g. blackbody radiation. We find a strongly attractive potential up to a critical distance beyond which the force gets repulsive. Including multiple scattering can even lead to the appearance of a stable configuration at a large distance. Such broadband scattering forces should be observable contributions in ultra-cold atom interferometers or atomic clocks setups. They could be studied in detail in 1D geometries with ultra-cold atoms trapped along or within an optical nanofiber. Broadband radiation force interactions might also contribute in astrophysical scenarios as illuminated cold dust clouds. (paper)

  17. Short-range inverse-square law experiment in space

    International Nuclear Information System (INIS)

    Strayer, D.M.; Paik, H.J.; Moody, M.V.

    2003-01-01

    The objective of ISLES (inverse-square law experiment in space) is to perform a null test of Newton's law on the ISS with a resolution of one part in 10 5 at ranges from 100 mm to 1 mm. ISLES will be sensitive enough to detect axions with the strongest allowed coupling and to test the string-theory prediction with R>= 5 μm. To accomplish these goals on the rather noisy International Space Station, the experiment is set up to provide immunity from the vibrations and other common-mode accelerations. The measures to be applied for reducing the effects of disturbances will be described in this presentation. As designed, the experiment will be cooled to less than 2 K in NASA's low temperature facility the LTMPF, allowing superconducting magnetic levitation in microgravity to obtain very soft, low-loss suspension of the test masses. The low-damping magnetic levitation, combined with a low-noise SQUID, leads to extremely low intrinsic noise in the detector. To minimize Newtonian errors, ISLES employs a near-null source of gravity, a circular disk of large diameter-to-thickness ratio. Two test masses, also disk-shaped, are suspended on the two sides of the source mass at a distance of 100 μm to 1 mm. The signal is detected by a superconducting differential accelerometer, making a highly sensitive sensor of the gravity force generated by the source mass

  18. Short-range solar radiation forecasts over Sweden

    Directory of Open Access Journals (Sweden)

    T. Landelius

    2018-04-01

    Full Text Available In this article the performance for short-range solar radiation forecasts by the global deterministic and ensemble models from the European Centre for Medium-Range Weather Forecasts (ECMWF is compared with an ensemble of the regional mesoscale model HARMONIE-AROME used by the national meteorological services in Sweden, Norway and Finland. Note however that only the control members and the ensemble means are included in the comparison. The models resolution differs considerably with 18 km for the ECMWF ensemble, 9 km for the ECMWF deterministic model, and 2.5 km for the HARMONIE-AROME ensemble.The models share the same radiation code. It turns out that they all underestimate systematically the Direct Normal Irradiance (DNI for clear-sky conditions. Except for this shortcoming, the HARMONIE-AROME ensemble model shows the best agreement with the distribution of observed Global Horizontal Irradiance (GHI and DNI values. During mid-day the HARMONIE-AROME ensemble mean performs best. The control member of the HARMONIE-AROME ensemble also scores better than the global deterministic ECMWF model. This is an interesting result since mesoscale models have so far not shown good results when compared to the ECMWF models.Three days with clear, mixed and cloudy skies are used to illustrate the possible added value of a probabilistic forecast. It is shown that in these cases the mesoscale ensemble could provide decision support to a grid operator in terms of forecasts of both the amount of solar power and its probabilities.

  19. Folding of polymer chains with short-range binormal interactions

    International Nuclear Information System (INIS)

    Craig, A; Terentjev, E M

    2006-01-01

    We study the structure of chains which have anisotropic short-range contact interactions that depend on the alignment of the binormal vectors of chain segments. This represents a crude model of hydrogen bonding or 'stacking' interactions out of the plane of curvature. The polymers are treated as ribbon-like semi-flexible chains, where the plane of the ribbon is determined by the local binormal. We show that with dipole-dipole interactions between the binormals of contacting chain segments, mean-field theory predicts a first-order transition to a binormally aligned state. We describe the onset of this transition as a function of the temperature-dependent parameters that govern the chain stiffness and the strength of the binormal interaction, as well as the binormal alignment's coupling to chain collapse. We also examine a metastable state governing the folding kinetics. Finally, we discuss the possible mesoscopic structure of the aligned phase, and application of our model to secondary structure motifs like β-sheets and α-helices, as well as composite structures like β-(amyloid) fibrils

  20. Theoretical Investigation of Peak-Delay Force Reduction for Caissons Exposed to Non-breaking Short-Crested Waves

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.

    In nature coastal structures are exposed to oblique short-crested waves. The effect of wave incident angle on total wave force on a long caisson are twofold. The one is the force reduction due to the reduction of instantaneous point pressure on the caisson, named point-pressure force reduction....... The other is the force reduction due to the fact that the peak pressures do not occur simultaneously along the caisson, named peak-delay force reduction. These two reduction effects can also be expected with short-crested waves, as the short-crestedness of waves means the spreading of wave energy over...... a range of incident angles. The peak-delay force reduction, i.e. no simultaneous peak along caisson, is of particular interest because the equipment improvement in construction enables the building of considerably long caissons. In Japan length of caissons exceeds often 100m. This paper will concentrate...

  1. Long Range Forces between Atomic Impurities in Liquid Helium

    International Nuclear Information System (INIS)

    Dupont-Roc, J.

    2002-01-01

    Van der Waals or Casimir interaction between neutral quantum objects in their ground state is known to be universally attractive. This is not necessarily so when these objects are embedded in a polarizable medium. We show that atomic impurities in liquid helium may indeed realize repulsive forces, and even Van der Waals and Casimir forces with different signs. (author)

  2. Short-range correlations in an extended time-dependent mean-field theory

    International Nuclear Information System (INIS)

    Madler, P.

    1982-01-01

    A generalization is performed of the time-dependent mean-field theory by an explicit inclusion of strong short-range correlations on a level of microscopic reversibility relating them to realistic nucleon-nucleon forces. Invoking a least action principle for correlated trial wave functions, equations of motion for the correlation functions and the single-particle model wave function are derived in lowest order of the FAHT cluster expansion. Higher order effects as well as long-range correlations are consider only to the extent to which they contribute to the mean field via a readjusted phenomenological effective two-body interaction. The corresponding correlated stationary problem is investigated and appropriate initial conditions to describe a heavy ion reaction are proposed. The singleparticle density matrix is evaluated

  3. A novel nuclear dependence of nucleon–nucleon short-range correlations

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Hongkai [College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Wang, Rong, E-mail: rwang@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Lanzhou University, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Huang, Yin [Lanzhou University, Lanzhou 730000 (China); Chen, Xurong [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2017-06-10

    A linear correlation is found between the magnitude of nucleon–nucleon short-range correlations and the nuclear binding energy per nucleon with pairing energy removed. By using this relation, the strengths of nucleon–nucleon short-range correlations of some unmeasured nuclei are predicted. Discussions on nucleon–nucleon pairing energy and nucleon–nucleon short-range correlations are made. The found nuclear dependence of nucleon–nucleon short-range correlations may shed some lights on the short-range structure of nucleus.

  4. Ultra-low-power short-range radios

    CERN Document Server

    Chandrakasan, Anantha

    2015-01-01

    This book explores the design of ultra-low-power radio-frequency integrated circuits (RFICs), with communication distances ranging from a few centimeters to a few meters. Such radios have unique challenges compared to longer-range, higher-powered systems. As a result, many different applications are covered, ranging from body-area networks to transcutaneous implant communications and Internet-of-Things devices. A mix of introductory and cutting-edge design techniques and architectures which facilitate each of these applications are discussed in detail. Specifically, this book covers:.

  5. A Short-Range Distance Sensor with Exceptional Linearity

    Science.gov (United States)

    Simmons, Steven; Youngquist, Robert

    2013-01-01

    A sensor has been demonstrated that can measure distance over a total range of about 300 microns to an accuracy of about 0.1 nm (resolution of about 0.01 nm). This represents an exceptionally large dynamic range of operation - over 1,000,000. The sensor is optical in nature, and requires the attachment of a mirror to the object whose distance is being measured. This work resulted from actively developing a white light interferometric system to be used to measure the depths of defects in the Space Shuttle Orbiter windows. The concept was then applied to measuring distance. The concept later expanded to include spectrometer calibration. In summary, broadband (i.e., white) light is launched into a Michelson interferometer, one mirror of which is fixed and one of which is attached to the object whose distance is to be measured. The light emerging from the interferometer has traveled one of two distances: either the distance to the fixed mirror and back, or the distance to the moving mirror and back. These two light beams mix and produce an interference pattern where some wavelengths interfere constructively and some destructively. Sending this light into a spectrometer allows this interference pattern to be analyzed, yielding the net distance difference between the two paths. The unique feature of this distance sensor is its ability to measure accurately distance over a dynamic range of more than one million, the ratio of its range (about 300 microns) to its accuracy (about 0.1 nanometer). Such a large linear operating range is rare and arises here because both amplitude and phase-matching algorithms contribute to the performance. The sensor is limited by the need to attach a mirror of some kind to the object being tracked, and by the fairly small total range, but the exceptional dynamic range should make it of interest.

  6. Short-range intercellular calcium signaling in bone

    DEFF Research Database (Denmark)

    Jørgensen, Niklas R

    2005-01-01

    The regulation of bone turnover is a complex and finely tuned process. Many factors regulate bone remodeling, including hormones, growth factors, cytokines etc. However, little is known about the signals coupling bone formation to bone resorption, and how mechanical forces are translated...... into biological effects in bone. Intercellular calcium waves are increases in intracellular calcium concentration in single cells, subsequently propagating to adjacent cells, and can be a possible mechanism for the coupling of bone formation to bone resorption. The aim of the present studies was to investigate...... whether bone cells are capable of communicating via intercellular calcium signals, and determine by which mechanisms the cells propagate the signals. First, we found that osteoblastic cells can propagate intercellular calcium transients upon mechanical stimulation, and that there are two principally...

  7. Knowledge of Repetitions Range Affects Force Production in Trained Females

    Directory of Open Access Journals (Sweden)

    Israel Halperin, Saied J. Aboodarda, Fabien A. Basset, David G. Behm

    2014-12-01

    Full Text Available Most studies have examined pacing strategies with cyclical activities (running and cycling. It has been demonstrated that males employ different pacing strategies during repeated maximal voluntary contractions (MVCs dependent upon a known endpoint. Since different fatiguing mechanisms have been identified between the genders, it is not known if females use comparable pacing strategies. The purpose of this study was to examine if informing female subjects regarding the number of MVCs to perform would affect force and electromyography (EMG. Twenty well-trained females completed 3 fatiguing protocols in a randomized order. In the control condition participants were informed they would perform twelve MVCs and then actually completed twelve. In the unknown condition they were not told how many MVCs to perform but were stopped after twelve. In the deception condition they were initially informed to perform 6 MVCs, but after the 6th MVC they were asked to perform a few more MVCs and were stopped after twelve. During the first 6 MVCs, forces in the deception condition were greater compared to the unknown (p = 0.021, ES = 0.65, 5% and control (p = 0.022, ES = 0.42, 3% conditions. No differences were found between conditions in the last 6 MVCs. A main effect for repetitions showed force deficits during the first 6 MVCs (p = 0.000, ES = 1.81, 13% and last 6 MVCs (p = 0.05, ES = 0.34, 3%. No differences were found between conditions in biceps and triceps EMG. However, EMG decreased during the first 6 MVCs for biceps (p = 0.001, ES = 1.0, 14% and triceps (p = 0.001, ES = 0.76, 14% across conditions. No differences were found in the last 6 MVCs. The anticipation of performing fewer MVCs led to increased force, whereas no endpoint led to decreased force production.

  8. Embedded RFID Recorder in short-range wireless devices

    DEFF Research Database (Denmark)

    2010-01-01

    range communication devices. The problem is solved in that the portable communications device comprises a wireless communications interface for communicating with another device, a memory and an RFID-recorder for receiving an RFID-signal transmitted from an RFID-interrogator, wherein the device...... is adapted for storing individual received RFID-signals in the memory. An advantage of the invention is that it provides a relatively simple scheme for extracting information from a current environment of a portable communications device. The invention may e.g. be used for adapting listening devices, e...

  9. Spherical harmonic expansion of short-range screened Coulomb interactions

    Energy Technology Data Exchange (ETDEWEB)

    Angyan, Janos G [Laboratoire de Cristallographie et de Modelisation des Materiaux Mineraux et Biologiques, UMR 7036, CNRS-Universite Henri Poincare, BP 239, F-54506 Vandoeuvre-les-Nancy (France); Gerber, Iann [Laboratoire de Cristallographie et de Modelisation des Materiaux Mineraux et Biologiques, UMR 7036, CNRS-Universite Henri Poincare, BP 239, F-54506 Vandoeuvre-les-Nancy (France); Marsman, Martijn [Institut fuer Materialphysik and Center for Computational Materials Science, Universitaet Wien, Sensengasse 8, A-1090, Vienna (Austria)

    2006-07-07

    Spherical harmonic expansions of the screened Coulomb interaction kernel involving the complementary error function are required in various problems in atomic, molecular and solid state physics, like for the evaluation of Ewald-type lattice sums or for range-separated hybrid density functionals. A general analytical expression is derived for the kernel, which is non-separable in the radial variables. With the help of series expansions a separable approximate form is proposed, which is in close analogy with the conventional multipole expansion of the Coulomb kernel in spherical harmonics. The convergence behaviour of these expansions is studied and illustrated by the electrostatic potential of an elementary charge distribution formed by products of Slater-type atomic orbitals.

  10. Problem of long-range forces in the computer simulation of condensed media

    International Nuclear Information System (INIS)

    Ceperely, D.

    1980-07-01

    Simulation (both Monte Carlo and molecular dynamical) has become a powerful tool in the study of classical systems of particles interacting with short-range pair potentials. For systems involving long-range forces (e.g., Coulombic, dipolar, hydrodynamic) it is a different story. Relating infinite-system properties to the results of computer simulation involving relatively small numbers of particles, periodically replicated, raises difficult and challenging problems. The purpose of the workshop was to bring together a group of scientists, all of whom share a strong direct interest in clearly formulating and resolving these problems. There were 46 participants, most of whom have been actively engaged in simulations of Hamiltonian models of condensed media. A few participants were scientists who are not primarily concerned, themselves, with simulation, but who are deeply involved in the theory of such models

  11. Positional short-range order in the nematic phase of n BABAs

    Science.gov (United States)

    Usha Deniz, K.; Pepy, G.; Parette, G.; Keller, P.

    1991-10-01

    The positional short-range order, SRO ⊥, perpendicular to the nematic director n̂ has been studied in the fibre-type nematics, nBABAs, by neutron diffraction. SRO ⊥ is found to be dependent on other types of nematic short-range order but not on the orientational long-range order.

  12. Coloured quarks and the short range nucleon nucleon interaction

    International Nuclear Information System (INIS)

    Ribeiro, J.E.F.T.

    1978-02-01

    The strong repulsive core that exists in the scattering of two nucleons is studied with the help of the Resonating Group Method (R.G.M.), where the Pauli Principle of fermion antisymmetry is taken explicitly into account. The quark-quark potential is described in terms of colour (long range confining potential) and hyperfine interactions alone. The mass differences N*(1688) - N(938) and Δ(1236) = N(938) are used to fit the two free constants of the assumed quark potential. It is shown that although the Pauli Principle does not exclude ab initio a S state of two nucleons, a strong repulsive potential is, nevertheless, found. Two cases are studied in detail: The Isosinglet case (neutron proton scattering) and the Isotriplet one (identical nucleons). Phase shifts for each case are presented and the obtained relative wave functions are found consistent with the observed experimental features for the repulsive potential. Some formal results concerning an important class of operators characteristic of the present R.G.M. calculations are also presented. (author)

  13. Resonant tunnelling through short-range singular potentials

    International Nuclear Information System (INIS)

    Zolotaryuk, A V; Christiansen, P L; Iermakova, S V

    2007-01-01

    A three-parameter family of point interactions constructed from sequences of symmetric barrier-well-barrier and well-barrier-well rectangles is studied in the limit, when the rectangles are squeezed to zero width but the barrier height and the well depth become infinite (the zero-range limit). The limiting generalized potentials are referred to as the second derivative of Dirac's delta function ±λδ-prime(x) with a renormalized coupling constant λ > 0 or simply as ±δ-prime-like point interactions. As a result, a whole family of self-adjoint extensions of the one-dimensional Schroedinger operator is shown to exist, which results in full and partial resonant tunnelling through this class of singular potentials. The resonant tunnelling occurs for countable sets of interaction strength values in the λ-space which are the roots of several transcendental equations. The comparison with the previous results for δ'-like point interactions is also discussed

  14. Short-ranged memory model with preferential growth

    Science.gov (United States)

    Schaigorodsky, Ana L.; Perotti, Juan I.; Almeira, Nahuel; Billoni, Orlando V.

    2018-02-01

    In this work we introduce a variant of the Yule-Simon model for preferential growth by incorporating a finite kernel to model the effects of bounded memory. We characterize the properties of the model combining analytical arguments with extensive numerical simulations. In particular, we analyze the lifetime and popularity distributions by mapping the model dynamics to corresponding Markov chains and branching processes, respectively. These distributions follow power laws with well-defined exponents that are within the range of the empirical data reported in ecologies. Interestingly, by varying the innovation rate, this simple out-of-equilibrium model exhibits many of the characteristics of a continuous phase transition and, around the critical point, it generates time series with power-law popularity, lifetime and interevent time distributions, and nontrivial temporal correlations, such as a bursty dynamics in analogy with the activity of solar flares. Our results suggest that an appropriate balance between innovation and oblivion rates could provide an explanatory framework for many of the properties commonly observed in many complex systems.

  15. Current research efforts at JILA to test the equivalence principle at short ranges

    International Nuclear Information System (INIS)

    Faller, J.E.; Niebauer, T.M.; McHugh, M.P.; Van Baak, D.A.

    1988-01-01

    We are presently engaged in three different experiments to search for a possible breakdown of the equivalence principle at short ranges. The first of these experiments, which has been completed, is our so-called Galilean test in which the differential free-fall of two objects of differing composition was measured using laser interferometry. We observed that the differential acceleration of two test bodies was less than 5 parts in 10 billion. This experiment set new limits on a suggested baryon dependent ''Fifth Force'' at ranges longer than 1 km. With a second experiment, we are investigating substance dependent interactions primarily for ranges up to 10 meters using a fluid supported torsion balance; this apparatus has been built and is now undergoing laboratory tests. Finally, a proposal has been made to measure the gravitational signal associated with the changing water level at a large pumped storage facility in Ludington, Michigan. Measuring the gravitational signal above and below the pond will yield the value of the gravitational constant, G, at ranges from 10-100 m. These measurements will serve as an independent check on other geophysical measurements of G

  16. Combined short scale roughness and surface dielectric function gradient effects on the determination of tip-sample force in atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gusso, André, E-mail: gusso@metal.eeimvr.uff.br [Departamento de Ciências Exatas-EEIMVR, Universidade Federal Fluminense, Volta Redonda, RJ 27255-125 (Brazil)

    2013-11-11

    The contribution of tip roughness to the van der Waals force between an atomic force microscopy probe tip and the sample is calculated using the multilayer effective medium model, which allows us to consider the relevant case of roughness characterized by correlation length and amplitude in the nanometer scale. The effect of the surface dielectric function gradient is incorporated in the tip-sample force model. It is concluded that for rms roughness in the few nanometers range the effect of short scale tip roughness is quite significant.

  17. Short-range airborne transmission of expiratory droplets between two people

    DEFF Research Database (Denmark)

    Liu, Li; Li, Yuguo; Nielsen, Peter Vilhelm

    2017-01-01

    , ventilation, and breathing mode. Under the specific set of conditions studied, we found a substantial increase in airborne exposure to droplet nuclei exhaled by the source manikin when a susceptible manikin is within about 1.5 m of the source manikin, referred to as the proximity effect. The threshold...... distance of about 1.5 m distinguishes the two basic transmission processes of droplets and droplet nuclei, that is, short-range modes and the long-range airborne route. The short-range modes include both the conventional large droplet route and the newly defined short-range airborne transmission. We thus...... reveal that transmission occurring in close proximity to the source patient includes both droplet-borne (large droplet) and short-range airborne routes, in addition to the direct deposition of large droplets on other body surfaces. The mechanisms of the droplet-borne and short-range airborne routes...

  18. Properties of short-range and long-range correlation energy density functionals from electron-electron coalescence

    International Nuclear Information System (INIS)

    Gori-Giorgi, Paola; Savin, Andreas

    2006-01-01

    The combination of density-functional theory with other approaches to the many-electron problem through the separation of the electron-electron interaction into a short-range and a long-range contribution is a promising method, which is raising more and more interest in recent years. In this work some properties of the corresponding correlation energy functionals are derived by studying the electron-electron coalescence condition for a modified (long-range-only) interaction. A general relation for the on-top (zero electron-electron distance) pair density is derived, and its usefulness is discussed with some examples. For the special case of the uniform electron gas, a simple parametrization of the on-top pair density for a long-range only interaction is presented and supported by calculations within the ''extended Overhauser model.'' The results of this work can be used to build self-interaction corrected short-range correlation energy functionals

  19. Predicting Long-Range Traversability from Short-Range Stereo-Derived Geometry

    Science.gov (United States)

    Turmon, Michael; Tang, Benyang; Howard, Andrew; Brjaracharya, Max

    2010-01-01

    Based only on its appearance in imagery, this program uses close-range 3D terrain analysis to produce training data sufficient to estimate the traversability of terrain beyond 3D sensing range. This approach is called learning from stereo (LFS). In effect, the software transfers knowledge from middle distances, where 3D geometry provides training cues, into the far field where only appearance is available. This is a viable approach because the same obstacle classes, and sometimes the same obstacles, are typically present in the mid-field and the farfield. Learning thus extends the effective look-ahead distance of the sensors.

  20. Dependability investigation of wireless short range embedded systems: hardware platform oriented approach

    NARCIS (Netherlands)

    Senouci, B.; Kerkhoff, Hans G.; Annema, Anne J.; Bentum, Marinus Jan

    2015-01-01

    A new direction in short-range wireless applications has appeared in the form of high-speed data communication devices for distances of hundreds meters. Behind these embedded applications, a complex heterogeneous architecture is built. Moreover, these short range communications are introduced into

  1. 3-D Effects Force Reduction of Short-Crested Non-Breaking Waves on Caissons

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.

    1998-01-01

    The effect of wave short-crestedness on the horizontal wave force on a caisson is twofold. The one is the force reduction due to the reduction of point pressure on the caisson, named point-pressure reduction. The other is the force reduction due to the fact that the peak pressures do not occur si...

  2. Nuclear dynamics with the (finite range) Gogny force: flow effects

    International Nuclear Information System (INIS)

    Sebille, F.; Royer, G.; Schuck, P.; Gregoire, C.

    1988-01-01

    We introduce for the first time the effective finite range interaction of Gogny in the semi-classical description of heavy ion reactions based on the Landau-Vlasov equation. The characteristics of the flow for heavy ion collisions are studied as functions of the incident energy, the impact parameter and the mass number. The momentum dependence in the mean field together with the non linearities in the collision kernel decrease the flow in contradiction with other calculations; the origins of this discrepancy are studied in details

  3. Long-range forces and the Eoetvoes experiment

    International Nuclear Information System (INIS)

    Fischbach, E.; Sudarsky, D.; Szafer, A.; Talmadge, C.; Aronson, S.H.

    1988-01-01

    We present here the details of our reanalysis of the experiment of Eoetvoes, Pekar, and Fekete (EPF). After outlining our motivation for reexamining the EPF paper, we review the history of this experiment, which is described in some detail. A phenomenological framework is developed for describing the EPF and other similar experiments, and this then applied to analyzing the EPF data. We show that these data evidence a strong correlation between the measured fractional acceleration differences of various sample pairs of materials and the corresponding differences of baryon number-to-mass ratios. Such a correlation can result from a coupling of the test masses to an intermediate-range field whose source is baryon number, and it is shown that the properties of this field which emerge from geophysical data provide a fair description of the EPF results. We further demonstrate that no other known mechanism either conventional or otherwise, provides an adequate explanation of these data. Various experiments to check the EPF results are described, and in the Appendix we analyze the effects of local mass inhomogeneities which appear to represent the dominant sources in Eoetvoes-like experiments. copyright 1988 Academic Press, Inc

  4. Environmental Assessment (EA) for the Comprehensive Range Plan (CRP), Melrose Air Force Range (AFR), New Mexico

    Science.gov (United States)

    2011-07-01

    intensity, frequency, and duration. Sound is created by acoustic energy, which produces minute pressure waves that travel through a medium (like air...concave plains associated with playa lake basins. Slope ranges from zero to 1 percent. Olton Loams – Consist of very deep, well-drained, moderately slow...gently sloping plains and upper side slopes of playas and draws. Slopes range from zero to 5 percent. 3.5.2.2 Water Resources Surface Water – The most

  5. Methods for studying short-range order in solid binary solutions

    International Nuclear Information System (INIS)

    Beranger, Gerard

    1969-12-01

    The short range order definition and its characteristic parameters are first recalled. The different methods to study the short range order are then examined: X ray diffusion, electrical resistivity, specific heat and thermoelectric power, neutron diffraction, electron spin resonance, study of thermodynamic and mechanical properties. The theory of the X ray diffraction effects due to short range order and the subsequent experimental method are emphasized. The principal results obtained from binary Systems, by the different experimental techniques, are reported and briefly discussed. The Au-Cu, Li-Mg, Au-Ni and Cu-Zn Systems are moreover described. (author) [fr

  6. Miniature large range multi-axis force-torque sensor for biomechanical applications

    International Nuclear Information System (INIS)

    Brookhuis, R A; Sanders, R G P; Ma, K; Lammerink, T S J; De Boer, M J; Krijnen, G J M; Wiegerink, R J

    2015-01-01

    A miniature force sensor for the measurement of forces and moments at a human fingertip is designed and realized. Thin silicon pillars inside the sensor provide in-plane guidance for shear force measurement and provide the spring constant in normal direction. A corrugated silicon ring around the force sensitive area provides the spring constant in shear direction and seals the interior of the sensor. To detect all load components, capacitive read-out is used. A novel electrode pattern results in a large shear force sensitivity. The fingertip force sensor has a wide force range of up to 60 N in normal direction, ± 30 N in shear direction and a torque range of ± 25 N mm. (paper)

  7. Revision to dedicated short range communication roadside equipment specification - RSU 4.1.Bench Test Plan.

    Science.gov (United States)

    2017-04-28

    The document describes the overall process for evaluating Dedicated Short Range Communication (DSRC) Roadside Units (RSU) against USDOT RSU Specification 4.1 in preparation for field evaluation. The Test Cases contained in this document only evaluate...

  8. The pitfalls of short-range endemism: high vulnerability to ecological and landscape traps

    Directory of Open Access Journals (Sweden)

    Leanda D. Mason

    2018-05-01

    Full Text Available Ecological traps attract biota to low-quality habitats. Landscape traps are zones caught in a vortex of spiralling degradation. Here, we demonstrate how short-range endemic (SRE traits may make such taxa vulnerable to ecological and landscape traps. Three SRE species of mygalomorph spider were used in this study: Idiommata blackwalli, Idiosoma sigillatum and an undescribed Aganippe sp. Mygalomorphs can be long-lived (>43 years and select sites for permanent burrows in their early dispersal phase. Spiderlings from two species, I. blackwalli (n = 20 and Aganippe sp. (n = 50, demonstrated choice for microhabitats under experimental conditions, that correspond to where adults typically occur in situ. An invasive veldt grass microhabitat was selected almost exclusively by spiderlings of I. sigillatum. At present, habitat dominated by veldt grass in Perth, Western Australia, has lower prey diversity and abundance than undisturbed habitats and therefore may act as an ecological trap for this species. Furthermore, as a homogenising force, veldt grass can spread to form a landscape trap in naturally heterogeneous ecosystems. Selection of specialised microhabitats of SREs may explain high extinction rates in old, stable landscapes undergoing (human-induced rapid change.

  9. Magnetism and atomic short-range order in Ni-Rh alloys

    Science.gov (United States)

    Carnegie, D. W., Jr.; Claus, H.

    1984-07-01

    Low-field ac susceptibility measurements of Ni-Rh samples of various concentrations are presented. Giant effects of the metallurgical state on the magnetic ordering temperature are associated with changes in the degree of atomic short-range order. By careful control of this degree of short-range order, it is possible to demonstrate the existence of a spin-glass state in Ni-Rh alloys.

  10. Forces and stresses in cryoturbogenerator rotor in presence of short circuit

    International Nuclear Information System (INIS)

    Kovarskii, M.E.; Rubinraut, A.M.; Tsyrlin, A.L.

    1981-01-01

    A method is presented for determining the electrodynamic forces, mechanical stresses, and strains in the shells of a cryogenic-turbogenerator cryostat in the presence of an abrupt short circuit. The physical pattern of occurrence of forces in a cryostat shell is considered for capacitive, inductive, and active armature-current cases. It is shown that in addition to the radial component, there is a tangential component of the electrodynamic forces, with the interaction of the two components governing the strength in the presence of short circuits. Results are reported for mechanical-strength calculations, based on the proposed method, for a 200 kw cryogenic turbogenerator

  11. Free cooling of hard-spheres with short and long range interactions

    NARCIS (Netherlands)

    Gonzalez Briones, Sebastián; Thornton, Anthony Richard; Luding, Stefan

    2015-01-01

    We study the stability, the clustering and the phase-diagram of free cooling granular gases. The systems consist of mono-disperse particles with additional non-contact (long-range) interactions, and are simulated here by the event-driven molecular dynamics algorithm with discrete (short-range

  12. The effect of short-range spatial variability on soil sampling uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Perk, Marcel van der [Department of Physical Geography, Utrecht University, P.O. Box 80115, 3508 TC Utrecht (Netherlands)], E-mail: m.vanderperk@geo.uu.nl; De Zorzi, Paolo; Barbizzi, Sabrina; Belli, Maria [Agenzia per la Protezione dell' Ambiente e per i Servizi Tecnici (APAT), Servizio Laboratori, Misure ed Attivita di Campo, Via di Castel Romano, 100-00128 Roma (Italy); Fajgelj, Ales; Sansone, Umberto [International Atomic Energy Agency (IAEA), Agency' s Laboratories Seibersdorf, A-1400 Vienna (Austria); Jeran, Zvonka; Jacimovic, Radojko [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)

    2008-11-15

    This paper aims to quantify the soil sampling uncertainty arising from the short-range spatial variability of elemental concentrations in the topsoils of agricultural, semi-natural, and contaminated environments. For the agricultural site, the relative standard sampling uncertainty ranges between 1% and 5.5%. For the semi-natural area, the sampling uncertainties are 2-4 times larger than in the agricultural area. The contaminated site exhibited significant short-range spatial variability in elemental composition, which resulted in sampling uncertainties of 20-30%.

  13. The effect of short-range spatial variability on soil sampling uncertainty.

    Science.gov (United States)

    Van der Perk, Marcel; de Zorzi, Paolo; Barbizzi, Sabrina; Belli, Maria; Fajgelj, Ales; Sansone, Umberto; Jeran, Zvonka; Jaćimović, Radojko

    2008-11-01

    This paper aims to quantify the soil sampling uncertainty arising from the short-range spatial variability of elemental concentrations in the topsoils of agricultural, semi-natural, and contaminated environments. For the agricultural site, the relative standard sampling uncertainty ranges between 1% and 5.5%. For the semi-natural area, the sampling uncertainties are 2-4 times larger than in the agricultural area. The contaminated site exhibited significant short-range spatial variability in elemental composition, which resulted in sampling uncertainties of 20-30%.

  14. Environmental forcing metrics to quantify short-term foredune morphodynamics

    Science.gov (United States)

    Spore, N.; Conery, I.; Brodie, K. L.; Palmsten, M.

    2016-12-01

    Coastal foredunes evolve continuously due to competing aeolian and hydrodynamic processes. Onshore to shore-parallel winds transport sand to the dune while storm-driven surge and wave runup remove sand from the dune. Dune-growth requires periods of time when the wind exceeds a threshold velocity to initiate transport and the relative geometry of the dry beach to the wind direction to create large fetches. This study aims to derive an aeolian transport potential (ATP) metric from the precipitation, available fetch (a function of wind angle and dry-beach width), and a threshold wind speed to initiate transport. ATP is then combined with a hydrodynamic transport potential (HTP) metric, defined as the number of hours of wave impact to the foredune or upper beach, to assess the time-dependent magnitude of the forcing factors affecting morphological evolution of the foredune between monthly terrestrial lidar surveys.This study focuses on two distinctly different dune fields and their frontal or incipient dune ridges in Duck, NC at the USACE Field Research Facility (FRF): (1) an undisturbed, tall and narrow recently impacted dune with a near vertical face; and (2) an undisturbed, shorter and wider dune with gentler and more hummocky slopes. The two sites are separated by dune toe position were extracted from the DEMs and compared to the ATP and HTP values between the surveys to evaluate the dominant factors affecting sediment flux to the system.

  15. Short versus long range interactions and the size of two-body weakly bound objects

    International Nuclear Information System (INIS)

    Lombard, R.J.; Volpe, C.

    2003-01-01

    Very weakly bound systems may manifest intriguing ''universal'' properties, independent of the specific interaction which keeps the system bound. An interesting example is given by relations between the size of the system and the separation energy, or scaling laws. So far, scaling laws have been investigated for short-range and long-range (repulsive) potentials. We report here on scaling laws for weakly bound two-body systems valid for a larger class of potentials, i.e. short-range potentials having a repulsive core and long-range attractive potentials. We emphasize analogies and differences between the short- and the long-range case. In particular, we show that the emergence of halos is a threshold phenomenon which can arise when the system is bound not only by short-range interactions but also by long-range ones, and this for any value of the orbital angular momentum l. These results enlarge the image of halo systems we are accustomed to. (orig.)

  16. Searches for possible T-odd and P-odd short range interactions using polarized nuclei

    Directory of Open Access Journals (Sweden)

    Chu P. H.

    2014-03-01

    Full Text Available Various theories predict the possible existence of T-odd and P-odd shortrange forces between spin ½ fermions, proportional to S・r where S is the fermion spin and r is the separation between particles. We use ensembles of polarized nuclei and an un-polarized mass to search for such a force over sub-mm ranges. We established an improved upper bound on the product gsgpn of the scalar coupling to particles in the un-polarized mass and the pseudo-scalar coupling of polarized neutrons for force ranges from 10−4 to 10−2 m, corresponding to a mass range of 2・10−3 to 2・10−5 eV for the exchange boson [1].

  17. On the universality of the long-/short-range separation in multiconfigurational density-functional theory

    Science.gov (United States)

    Fromager, Emmanuel; Toulouse, Julien; Jensen, Hans Jørgen Aa.

    2007-02-01

    In many cases, the dynamic correlation can be calculated quite accurately and at a fairly low computational cost in Kohn-Sham density-functional theory (KS-DFT), using current standard approximate functionals. However, in general, KS-DFT does not treat static correlation effects (near degeneracy) adequately which, on the other hand, can be described in wave-function theory (WFT), for example, with a multiconfigurational self-consistent field (MCSCF) model. It is therefore of high interest to develop a hybrid model which combines the best of both WFT and DFT approaches. The merge of WFT and DFT can be achieved by splitting the two-electron interaction into long-range and short-range parts. The long-range part is then treated by WFT and the short-range part by DFT. In this work the authors consider the so-called "erf" long-range interaction erf(μr12)/r12, which is based on the standard error function, and where μ is a free parameter which controls the range of the long-/short-range decomposition. In order to formulate a general method, they propose a recipe for the definition of an optimal μopt parameter, which is independent of the approximate short-range functional and the approximate wave function, and they discuss its universality. Calculations on a test set consisting of He, Be, Ne, Mg, H2, N2, and H2O yield μopt≈0.4a.u.. A similar analysis on other types of test systems such as actinide compounds is currently in progress. Using the value of 0.4a.u. for μ, encouraging results are obtained with the hybrid MCSCF-DFT method for the dissociation energies of H2, N2, and H2O, with both short-range local-density approximation and PBE-type functionals.

  18. Range of Motion of the Ankle According to Pushing Force, Gender and Knee Position.

    Science.gov (United States)

    Cho, Kang Hee; Jeon, Yumi; Lee, Hyunkeun

    2016-04-01

    To investigate the difference of range of motion (ROM) of ankle according to pushing force, gender and knee position. One hundred and twenty-eight healthy adults (55 men, 73 women) between the ages of 20 and 51, were included in the study. One examiner measured the passive range of motion (PROM) of ankle by Dualer IQ Inclinometers and Commander Muscle Testing. ROM of ankle dorsiflexion (DF) and plantarflexion (PF) according to change of pushing force and knee position were measured at prone position. There was significant correlation between ROM and pushing force, the more pushing force leads the more ROM at ankle DF and ankle PF. Knee flexion of 90° position showed low PF angle and high ankle DF angle, as compared to the at neutral position of knee joint. ROM of ankle DF for female was greater than for male, with no significant difference. ROM of ankle PF for female was greater than male regardless of the pushing force. To our knowledge, this is the first study to assess the relationship between pushing force and ROM of ankle joint. There was significant correlation between ROM of ankle and pushing force. ROM of ankle PF for female estimated greater than male regardless of the pushing force and the number of measurement. The ROM of the ankle is measured differently according to the knee joint position. Pushing force, gender and knee joint position are required to be considered when measuring the ROM of ankle joint.

  19. UMER: An analog computer for dynamics of swarms interacting via long-range forces

    International Nuclear Information System (INIS)

    Kishek, R.A.; Bai, G.; Bernal, S.; Feldman, D.; Godlove, T.F.; Haber, I.; O'Shea, P.G.; Quinn, B.; Papadopoulos, C.; Reiser, M.; Stratakis, D.; Tian, K.; Tobin, C.J.; Walter, M.

    2006-01-01

    Some of the most challenging and interesting problems in nature involve large numbers of objects or particles mutually interacting through long-range forces. Examples range from galaxies and plasmas to flocks of birds and traffic flow on a highway. Even in cases where the form of the interacting force is precisely known, such as the 1/r 2 -dependent Coulomb and gravitational forces, such problems present a formidable theoretical and modeling challenge for large numbers of interacting bodies. This paper reports on a newly constructed, scaled particle accelerator that will serve as an experimental testbed for the dynamics of swarms interacting through long-range forces. Primarily designed for intense beam dynamics studies for advanced accelerators, the University of Maryland Electron Ring (UMER) design is described in detail and an update on commissioning is provided. An example application to a system other than a charged particle beam is discussed

  20. Double scattering of light from Biophotonic Nanostructures with short-range order

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Heeso; Liew, Seng Fatt; Saranathan, Vinodkumar; Prum, Richard O.; Mochrie, Simon G.J.; Dufresne, Eric R.; Cao, Hui (Yale)

    2010-07-28

    We investigate the physical mechanism for color production by isotropic nanostructures with short-range order in bird feather barbs. While the primary peak in optical scattering spectra results from constructive interference of singly-scattered light, many species exhibit secondary peaks with distinct characteristic. Our experimental and numerical studies show that these secondary peaks result from double scattering of light by the correlated structures. Without an analog in periodic or random structures, such a phenomenon is unique for short-range ordered structures, and has been widely used by nature for non-iridescent structural coloration.

  1. Short-range wireless communication fundamentals of RF system design and application

    CERN Document Server

    Bensky, Alan

    2004-01-01

    The Complete "Tool Kit” for the Hottest Area in RF/Wireless Design!Short-range wireless-communications over distances of less than 100 meters-is the most rapidly growing segment of RF/wireless engineering. Alan Bensky is an internationally recognized expert in short-range wireless, and this new edition of his bestselling book is completely revised to cover the latest developments in this fast moving field.You'll find coverage of such cutting-edge topics as: architectural trends in RF/wireless integrated circuits compatibility and conflict issues between differen

  2. Fluctuations in substitution type alloys and their analyses. Short-range order structures

    International Nuclear Information System (INIS)

    Iwasaki, Hiroshi; Ohshima, Ken-ichi

    2010-01-01

    This article is the fifth of the serial lecture, microstructures and fluctuations, in this magazine. The formula of X-ray diffuse scattering intensity was derived for binary alloys by introducing short-range order parameters. Diffuse scattering intensities for a single crystal Cu 3 Au were measured above critical temperature for ordering. The short-range parameters were obtained by a three-dimensional Fourier analysis. The long-range pair interaction between atoms was originated from the indirect screening interaction due to conduction electrons. A detailed study was made on short-range-order diffuse scattering from Cu 3 Au in the disordered state by electron diffraction. Fourfold splitting of the diffuse scattering was observed at 110 in the reciprocal lattice, and this result was attributed to the reflection of the form of the Fermi surface. The X-ray diffuse scattering intensity was measured at room temperature for disordered Cu-Pd alloys for the six composition of Pd. Twofold and fourfold splitting of diffuse scattering due to the short-range order (SRO) were observed at 100, 110 and equivalent positions respectively from alloys with more than 13.0at% Pd. The SRO parameters were determined from all the six alloys. For Cu-Pt alloys, the diffuse scattering originated from the correlation between Cu and Pt layers in direction was observed in addition to the one due to the reflection of the Fermi surface imaging. (author)

  3. Interplay of long-range and short-range Coulomb interactions in an Anderson-Mott insulator

    Science.gov (United States)

    Baćani, Mirko; Novak, Mario; Orbanić, Filip; Prša, Krunoslav; Kokanović, Ivan; Babić, Dinko

    2017-07-01

    In this paper, we tackle the complexity of coexisting disorder and Coulomb electron-electron interactions (CEEIs) in solids by addressing a strongly disordered system with intricate CEEIs and a screening that changes both with charge carrier doping level Q and temperature T . We report on an experimental comparative study of the T dependencies of the electrical conductivity σ and magnetic susceptibility χ of polyaniline pellets doped with dodecylbenzenesulfonic acid over a wide range. This material is special within the class of doped polyaniline by exhibiting in the electronic transport a crossover between a low-T variable range hopping (VRH) and a high-T nearest-neighbor hopping (NNH) well below room temperature. Moreover, there is evidence of a soft Coulomb gap ΔC in the disorder band, which implies the existence of a long-range CEEI. Simultaneously, there is an onsite CEEI manifested as a Hubbard gap U and originating in the electronic structure of doped polyaniline, which consists of localized electron states with dynamically varying occupancy. Therefore, our samples represent an Anderson-Mott insulator in which long-range and short-range CEEIs coexist. The main result of the study is the presence of a crossover between low- and high-T regimes not only in σ (T ) but also in χ (T ) , the crossover temperature T* being essentially the same for both observables over the entire doping range. The relatively large electron localization length along the polymer chains results in U being small, between 12 and 20 meV for the high and low Q , respectively. Therefore, the thermal energy at T* is sufficiently large to lead to an effective closing of the Hubbard gap and the consequent appearance of NNH in the electronic transport within the disorder band. ΔC is considerably larger than U , decreasing from 190 to 30 meV as Q increases, and plays the role of an activation energy in the NNH.

  4. Determination of thermodynamical coefficients for Mo-W alloys according to short-range order parameters

    International Nuclear Information System (INIS)

    Erokhin, L.N.; Mokrov, A.P.; Shivrin, O.N.; Khanina, N.I.

    1986-01-01

    A method is proposed for determining thermodynamical coefficients according to short-range order parameters. The method approbation for Mo-W alloys has shown a good agreement between the thermodynamical and diffusion data. The Mo-W system in the concentration range under study is close to the ideal one. The calculated relative error of determination of interdiffusion coefficients in alloys of the Mo-W system does not exceed 16%

  5. In-medium short-range dynamics of nucleons: Recent theoretical and experimental advances

    Energy Technology Data Exchange (ETDEWEB)

    Atti, Claudio Ciofi degli, E-mail: ciofi@pg.infn.it

    2015-08-14

    The investigation of in-medium short-range dynamics of nucleons, usually referred to as the study of short-range correlations (SRCs), is a key issue in nuclear and hadronic physics. As a matter of fact, even in the simplified assumption that the nucleus could be described as a system of protons and neutrons interacting via effective nucleon–nucleon (NN) interactions, several non trivial problems arise concerning the description of in-medium (NN short-range dynamics, namely: (i) the behavior of the NN interaction at short inter-nucleon distances in medium cannot be uniquely constrained by the experimental NN scattering phase shifts due to off-shell effects; (ii) by rigorous renormalization group (RG) techniques entire families of phase equivalent interactions differing in the short-range part can be derived; (iii) the in-medium NN interaction may be, in principle, different from the free one; (iv) when the short inter-nucleon separation is of the order of the nucleon size, the question arises of possible effects from quark and gluon degrees of freedom. For more than fifty years, experimental evidence of SRCs has been searched by means of various kinds of nuclear reactions, without however convincing results, mainly because the effects of SRCs arise from non observable quantities, like, e.g., the momentum distributions, and have been extracted from observable cross sections where short- and long-range effects, effects from nucleonic and non nucleonic degrees of freedom, and effects from final state interaction, could not be unambiguously separated out. Recent years, however, were witness of new progress in the field: from one side, theoretical and computational progress has allowed one to solve ab initio the many-nucleon non relativistic Schrödinger equation in terms of realistic NN interactions, obtaining realistic microscopic wave functions, unless the case of parametrized wave functions used frequently in the past, moreover the development of advanced

  6. Functional framework and hardware platform for dependability study in short range wireless embedded systems

    NARCIS (Netherlands)

    Senouci, B.; Annema, Anne J.; Bentum, Marinus Jan; Kerkhoff, Hans G.

    2011-01-01

    A new direction in short-range wireless applications has appeared in the form of high-speed data communication devices for distances of a few meters. Behind these embedded applications, a complex Hardware/Software architecture is built. Dependability is one of the major challenges in these systems.

  7. Short-range clustering and decomposition in copper-nickel and copper-nickel-iron alloys

    International Nuclear Information System (INIS)

    Aalders, T.J.A.

    1982-07-01

    The thermodynamic equilibrium state of short-range clustering and the kinetics of short-range clustering and decomposition has been studied for a number of CuNi(Fe)-alloys by means of neutron scattering. The validity of the theories, which are usually applied to describe spinodal decomposition, nucleation and growth, coarsening etc., was investigated. It was shown that for the investigated substances the conventional theory of spinodal decomposition is valid for the relaxation of short-range clustering only for the case that the initial and final states do not differ too much. The dynamical scaling procedure described by Lebowitz et al. did not lead to a time-independent scaled function F(x) for the relaxation of short-range clustering, for the early stages of decomposition and for the case that an alloy, which was already decomposed at the quench temperature T 1 , was annealed at a temperature T 2 (T 1 ). For the later stages of decomposition, however, the scaling procedure was indeed successful. The coarsening of the alloys could, except for the later stages, be described by the Lifshitz-Slyozov theory. (Auth.)

  8. Neutron diffraction study on the medium and short-range order of ternary chalcogenide glasses

    Czech Academy of Sciences Publication Activity Database

    Neov, S.; Gerasimova, I.; Skordeva, E.; Arsova, D.; Pamukchieva, V.; Mikula, Pavol; Lukáš, Petr; Sonntag, R.

    1999-01-01

    Roč. 34, - (1999), s. 3669-3676 ISSN 0022-2461 R&D Projects: GA ČR GV202/97/K038 Keywords : neutron diffraction * short-range order * chalcogenide glasses Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.786, year: 1999

  9. EXAFS, Determination of Short Range Order and Local Structures in Materials

    NARCIS (Netherlands)

    Koningsberger, D.C.; Prins, R.

    1981-01-01

    Extended X-ray Absorption Fine Structure (EXAFS) is a powerful method of determining short range order and local structures in materials using X-ray photons produced by a synchrotron light source, or in-house by a high intensity rotating anode X-ray generator. The technique has provided valuable

  10. Status of the dedicated short-range communications technology and applications : report to Congress.

    Science.gov (United States)

    2015-07-01

    This report responds to a Congressional request for an assessment of the 5.9 Gigahertz (GHz) Dedicated Short Range : Communications (DSRC) in accordance with the requirements provided by Congress in the Moving Ahead for Progress in the : 21st Century...

  11. Electronically driven short-range lattice instability: Possible role in superconductive pairing

    International Nuclear Information System (INIS)

    Szasz, A.

    1991-01-01

    A superconducting pairing mechanism is suggested, mediating by collective and coherent cluster fluctuations in the materials. The model, based on a geometrical frustration, proposes a dynamic effect driven by a special short-range electronic instability. Experimental support for this model is discussed

  12. Electronically driven short-range lattice instability: Cluster effects in superconductors

    International Nuclear Information System (INIS)

    Szasz, A.

    1991-01-01

    In the first part of this series, short- and medium-range interactions in superconductors were investigated. In this paper a discussion is made on the cluster-mass dependence of the superconductive transition temperature and the relevant phenomenon of electron localization. A comparison with experiments is given; the predictions fit well to the observations

  13. Anomalous X-ray scattering studies of short-, intermediate- and extended-range order in glasses

    International Nuclear Information System (INIS)

    Price, D.L.; Saboungi, M.L.; Armand, P.; Cox, D.E.

    1998-01-01

    The authors present the formalism of anomalous x-ray scattering as applied to partial structure analysis of disordered materials, and give an example of how the technique has been applied, together with that of neutron diffraction, to investigate short-, intermediate- and extended-range order in vitreous germania and rubidium germanate

  14. Investigations of multiphoton excitation and ionization in a short range potential

    International Nuclear Information System (INIS)

    Susskind, S.M.; Cowley, S.C.; Valeo, E.J.

    1989-02-01

    We introduce an approach to the study of excitation and ionization for a system with a short range potential. In particular, analytical and numerical results are presented for the multiphoton ionization rate, under strong field conditions, of an electron confined by a δ-function potential. 9 refs., 3 figs

  15. Investigations of multiphoton excitation and ionization in a short range potential

    Energy Technology Data Exchange (ETDEWEB)

    Susskind, S.M.; Cowley, S.C.; Valeo, E.J.

    1989-02-01

    We introduce an approach to the study of excitation and ionization for a system with a short range potential. In particular, analytical and numerical results are presented for the multiphoton ionization rate, under strong field conditions, of an electron confined by a delta-function potential. 9 refs., 3 figs.

  16. Fluid–fluid coexistence in colloidal systems with short-ranged strongly directional attraction

    NARCIS (Netherlands)

    Kern, N.; Frenkel, D.

    2003-01-01

    We present a systematic numerical study of the phase behavior of square-well fluids with a "patchy" short-ranged attraction. In particular, we study the effect of the size and number of attractive patches on the fluid–fluid coexistence. The model that we use is a generalization of the hard sphere

  17. Push-off forces in elite short-track speed skating.

    Science.gov (United States)

    van der Kruk, Eline; Reijne, Marco M; de Laat, Bjorn; Veeger, DirkJan H E J

    2018-05-30

    This study performed an analysis of the push-off forces of elite-short-track speed skaters using a new designed instrumented short-track speed skate with the aim to improve short-track skating performance. Four different skating strokes were distinguished for short-track speed skaters at speed. The strokes differed in stroke time, force level in both normal and lateral directions, and the centre of pressure (COP) on the blade. Within the homogeneous group of male elite speed skaters (N = 6), diversity of execution of the force patterns in the four phases of skating was evident, while skating at the same velocities. The male participants (N = 6) with a better personal record (PR) kept the COP more to the rear of their blades while hanging into the curve (r = 0.82, p < 0.05), leaving the curve (r = 0.86, p < 0.05), and entering the straight (r = 0.76, p < 0.10). Furthermore, the male skaters with a better PR showed a trend of a lower lateral peak force while entering the curve (r = 0.74, p < 0.10). Females showed a trend towards applying higher body weight normalised lateral forces than the males, while skating at imposed lower velocities.

  18. Short-time dynamics of lysozyme solutions with competing short-range attraction and long-range repulsion: Experiment and theory

    Science.gov (United States)

    Riest, Jonas; Nägele, Gerhard; Liu, Yun; Wagner, Norman J.; Godfrin, P. Douglas

    2018-02-01

    Recently, atypical static features of microstructural ordering in low-salinity lysozyme protein solutions have been extensively explored experimentally and explained theoretically based on a short-range attractive plus long-range repulsive (SALR) interaction potential. However, the protein dynamics and the relationship to the atypical SALR structure remain to be demonstrated. Here, the applicability of semi-analytic theoretical methods predicting diffusion properties and viscosity in isotropic particle suspensions to low-salinity lysozyme protein solutions is tested. Using the interaction potential parameters previously obtained from static structure factor measurements, our results of Monte Carlo simulations representing seven experimental lysoyzme samples indicate that they exist either in dispersed fluid or random percolated states. The self-consistent Zerah-Hansen scheme is used to describe the static structure factor, S(q), which is the input to our calculation schemes for the short-time hydrodynamic function, H(q), and the zero-frequency viscosity η. The schemes account for hydrodynamic interactions included on an approximate level. Theoretical predictions for H(q) as a function of the wavenumber q quantitatively agree with experimental results at small protein concentrations obtained using neutron spin echo measurements. At higher concentrations, qualitative agreement is preserved although the calculated hydrodynamic functions are overestimated. We attribute the differences for higher concentrations and lower temperatures to translational-rotational diffusion coupling induced by the shape and interaction anisotropy of particles and clusters, patchiness of the lysozyme particle surfaces, and the intra-cluster dynamics, features not included in our simple globular particle model. The theoretical results for the solution viscosity, η, are in qualitative agreement with our experimental data even at higher concentrations. We demonstrate that semi

  19. A short model excitation of an asymmetric force free superconducting transmission line magnet

    Energy Technology Data Exchange (ETDEWEB)

    Wake, M.; Sato, H.; /KEK, Tsukuba; Carcagno, R.; Foster, W.; Hays, S.; Kashikhin, V.; Oleck, A.; Piekarz, H.; Rabehl, R,; /Fermilab

    2005-09-01

    A short model of asymmetric force free magnet with single beam aperture was tested at Fermilab together with the excitation test of VLHC transmission line magnet. The design concept of asymmetric force free superconducting magnet was verified by the test. The testing reached up to 104 kA current and no indication of force imbalance was observed. Since the model magnet length was only 10cm, A 0.75m model was constructed and tested at KEK with low current to ensure the validity of the design. The cool down and the excitation at KEK were also successful finding very small thermal contraction of the conductor and reasonable field homogeneity.

  20. TMI-2 Lessons Learned Task Force status report and short-term recommendations

    International Nuclear Information System (INIS)

    1979-07-01

    Review of the Three Mile Island accident by the TMI-2 Lessons Learned Task Force has disclosed a number of actions in the areas of design and analysis and plant operations that the Task Force recommends be required in the short term to provide substantial additional protection which is required for the public health and safety. All nuclear power plants in operation or in various stages of construction or licensing action are affected to varying degrees by the specific recommendations. The Task Force is continuing work in areas of general safety criteria, systems design requirements, nuclear power plant operations, and nuclear power plant licensing

  1. Age differences in visual search for compound patterns: long- versus short-range grouping.

    Science.gov (United States)

    Burack, J A; Enns, J T; Iarocci, G; Randolph, B

    2000-11-01

    Visual search for compound patterns was examined in observers aged 6, 8, 10, and 22 years. The main question was whether age-related improvement in search rate (response time slope over number of items) was different for patterns defined by short- versus long-range spatial relations. Perceptual access to each type of relation was varied by using elements of same contrast (easy to access) or mixed contrast (hard to access). The results showed large improvements with age in search rate for long-range targets; search rate for short-range targets was fairly constant across age. This pattern held regardless of whether perceptual access to a target was easy or hard, supporting the hypothesis that different processes are involved in perceptual grouping at these two levels. The results also point to important links between ontogenic and microgenic change in perception (H. Werner, 1948, 1957).

  2. Study of an Ising model with competing long- and short-range interactions

    International Nuclear Information System (INIS)

    Loew, U.; Emery, V.J.; Fabricius, K.; Kivelson, S.A.

    1994-01-01

    A classical spin-one lattice gas model is used to study the competition between short-range ferromagnetic coupling and long-range antiferromagnetic Coulomb interactions. The model is a coarse-grained representation of frustrated phase separation in high-temperature superconductors. The ground states are determined for the complete range of parameters by using a combination of numerical and analytical techniques. The crossover between ferromagnetic and antiferromagnetic states proceeds via a rich structure of highly symmetric striped and checkerboard phases. There is no devil's staircase behavior because mixtures of stripes with different period phase separate

  3. Characteristics of III-nitride based laser diode employed for short range underwater wireless optical communications

    Science.gov (United States)

    Xue, Bin; Liu, Zhe; Yang, Jie; Feng, Liangsen; Zhang, Ning; Wang, Junxi; Li, Jinmin

    2018-03-01

    An off-the-shelf green laser diode (LD) was measured to investigate its temperature dependent characteristics. Performance of the device was severely restricted by rising temperature in terms of increasing threshold current and decreasing modulation bandwidth. The observation reveals that dynamic characteristics of the LD is sensitive to temperature. Influence of light attenuation on the modulation bandwidth of the green LD was also studied. The impact of light attenuation on the modulation bandwidth of the LD in short and low turbid water channel was not obvious while slight difference in modulation bandwidth under same injection level was observed between water channel and free space even at short range.

  4. A finite range pairing force for density functional theory in superfluid nuclei

    International Nuclear Information System (INIS)

    Tian, Y.; Ma, Z.Y.; Ring, P.

    2009-01-01

    The problem of pairing in the 1 S 0 channel of finite nuclei is revisited. In nuclear matter forces of separable form can be adjusted to the bare nuclear force, to any phenomenological pairing interaction such as the Gogny force or to exact solutions of the gap equation. In finite nuclei, because of translational invariance, such forces are no longer separable. Using well-known techniques of Talmi and Moshinsky we expand the matrix elements in a series of separable terms, which converges quickly preserving translational invariance and finite range. In this way the complicated problem of a cut-off at large momenta or energies inherent in other separable or zero range pairing forces is avoided. Applications in the framework of the relativistic Hartree-Bogoliubov approach show that the pairing properties are depicted on almost the same footing as by the original pairing interaction not only in nuclear matter, but also in finite nuclei. This simple separable force can be easily applied for the investigation of pairing properties in nuclei far from stability as well as for further investigations going beyond mean field theory.

  5. Long-range dipolar order and dispersion forces in polar liquids

    Science.gov (United States)

    Besford, Quinn Alexander; Christofferson, Andrew Joseph; Liu, Maoyuan; Yarovsky, Irene

    2017-11-01

    Complex solvation phenomena, such as specific ion effects, occur in polar liquids. Interpretation of these effects in terms of structure and dispersion forces will lead to a greater understanding of solvation. Herein, using molecular dynamics, we probe the structure of polar liquids through specific dipolar pair correlation functions that contribute to the potential of mean force that is "felt" between thermally rotating dipole moments. It is shown that unique dipolar order exists at separations at least up to 20 Å for all liquids studied. When the structural order is compared with a dipolar dispersion force that arises from local co-operative enhancement of dipole moments, a strong agreement is found. Lifshitz theory of dispersion forces was compared with the structural order, where the theory is validated for all liquids that do not have significant local dipole correlations. For liquids that do have significant local dipole correlations, specifically liquid water, Lifshitz theory underestimates the dispersion force by a factor of 5-10, demonstrating that the force that leads to the increased structure in liquid water is missed by Lifshitz theory of van der Waals forces. We apply similar correlation functions to an ionic aqueous system, where long-range order between water's dipole moment and a single chloride ion is found to exist at 20 Å of separation, revealing a long-range perturbation of water's structure by an ion. Furthermore, we found that waters within the 1st, 2nd, and 3rd solvation shells of a chloride ion exhibit significantly enhanced dipolar interactions, particularly with waters at larger distances of separation. Our results provide a link between structures, dispersion forces, and specific ion effects, which may lead to a more robust understanding of solvation.

  6. Force-induced unzipping of DNA with long-range correlated sequence

    OpenAIRE

    Allahverdyan, A. E.; Gevorkian, Zh. S.

    2002-01-01

    We consider force-induced unzipping transition for a heterogeneous DNA model with a long-range correlated base-sequence. It is shown that as compared to the uncorrelated situation, long-range correlations smear the unzipping phase-transition, change its universality class and lead to non-self-averaging: the averaged behavior strongly differs from the typical ones. Several basic scenarios for this typical behavior are revealed and explained. The results can be relevant for explaining the biolo...

  7. Magnetic susceptibility as a method of investigation of short-range order in strongly nonstoichiometric carbides

    International Nuclear Information System (INIS)

    Nazarova, S.Z.; Gusev, A.I.

    2001-01-01

    Magnetic susceptibility in disordered and ordered carbides of transition metals (M = Ti, Zr, Hf, Nb, Ta) was studied, the results are generalized. It was ascertained that the change in carbide susceptibility induced by deviation from stoichiometry stems from specific features of electronic spectra of the compounds. The use of magnetic susceptibility for determining structural disorder-order transitions is discussed. It is shown that change in the contribution made by orbital paramagnetism, resulting from short-range order formation, is the reason of decrease in susceptibility of nonstoichiometric carbides during the ordering. Experimentally obtained data on susceptibility permitted evaluating short- and far-range order parameters in NbC y , TaC y , TiC y and HfC y carbides [ru

  8. Attractive short-range interatomic potential in the lattice dynamics of niobium and tantalum

    International Nuclear Information System (INIS)

    Onwuagba, B.N.; Pal, S.

    1987-01-01

    It is shown in the framework of the pseudopotential approach that there is a sizable attractive short-range component of the interatomic potential due to the s-d interaction which has the same functional form in real space as the Born-Mayer repulsion due to the overlap of core electron wave functions centred on neighbouring ions. The magnitude of this attractive component is such as to completely cancel the conventional Born-Mayer repulsion, making the resultant short-range interatomic potential attractive rather than repulsive. Numerical calculations show that the attractive interatomics potential, which represents the local-field correction, leads to a better understanding of the occurrence of the soft modes in the phonon dispersion curves of niobium and tantalum

  9. Short-range order in amorphous thin films of indium selenides

    International Nuclear Information System (INIS)

    Zakharov, V.P.; Poltavtsev, Yu.G.; Sheremet, G.P.

    1982-01-01

    A structure of the short-range order and a character of interatomic interactions in indium selenides Insub(1-x)Sesub(x) with 0.333 <= x <= 0.75, obtained in the form of amorphous films 0.05-0.80 μm thick are studied using electron diffraction method. It is found out that mostly tetrahedrical coordination of nearest neighbours in the vicinity of indium atoms is characteristic for studied amorphous films, and coordination of selenium atoms is different. Amorphous film with x=0.75 posesses a considereably microheterogeneous structure of the short-range order, which is characterized by the presence of microunclusions of amorphous selenium and atoms of indium, octohedrically coordinated by selenium atoms

  10. Structure of the short-range atomic order of WO3 amorphous films

    International Nuclear Information System (INIS)

    Olevskij, S.S.; Sergeev, M.S.; Tolstikhina, A.L.; Avilov, A.S.; Shkornyakov, S.M.; Semiletov, S.A.

    1984-01-01

    To study the causes of electrochromism manifestation in thin tungsten oxide films, the structure of WO 3 amorphous films has been investigated. The films were obtained by three different methods: by W(CO) 6 tungsten carbonyl pyrolysis, by high-frequency ion-plasma sputtering of a target prepared by WO 3 powder sintering, and by WO 3 powder thermal evaporation. Monocrystalline wafers of silicon and sodium chloride were used as substrates. The structure of short-range order in WO 3 amorphous films varies versus, the method of preparation in compliance with the type of polyhedral elements, (WO 6 , WO 5 ) and with the character of their packing (contacts via edges or vertices). Manifestation of electroc ro mism in WO 3 films prepared by varions methods and having different structure of short-range order is supposed to be realized through various mechanisms. One cannot exclude a potential simultaneous effect of the two coloration mechanisms

  11. Study of the effect of short ranged ordering on the magnetism in FeCr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jena, Ambika Prasad, E-mail: apjena@bose.res.in [Department of Condensed Matter and Materials Science, S N Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake City, Kolkata 700098 (India); Sanyal, Biplab, E-mail: biplab.sanyal@physics.uu.se [Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); Mookerjee, Abhijit, E-mail: abhijit.mookerjee61@gmail.com [Department of Condensed Matter and Materials Science, S N Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake City, Kolkata 700098 (India)

    2014-01-15

    For the study of magnetism in systems where the local environment plays an important role, we propose a marriage between the Monte Carlo simulation and Zunger's special quasi-random structures. We apply this technique on disordered FeCr alloys and show that our estimates of the transition temperature is in good agreement with earlier experiments. - Highlights: • The magnetism in FeCr is sensitively depended on the ordering of the atoms : disordered or with short ranged ordering. • This work uses the SQS technique suggested by Zunger has been used to generate various degrees of short range ordering in FeCr. • The electronic structure and pair energies have been obatined from first principles ASR and Lichtenstein methods. • The effect of chemical ordering on magnetic ordering is studied in detail. • Only those situations where the chemical ordering is complete have been studied.

  12. Study of the effect of short ranged ordering on the magnetism in FeCr alloys

    International Nuclear Information System (INIS)

    Jena, Ambika Prasad; Sanyal, Biplab; Mookerjee, Abhijit

    2014-01-01

    For the study of magnetism in systems where the local environment plays an important role, we propose a marriage between the Monte Carlo simulation and Zunger's special quasi-random structures. We apply this technique on disordered FeCr alloys and show that our estimates of the transition temperature is in good agreement with earlier experiments. - Highlights: • The magnetism in FeCr is sensitively depended on the ordering of the atoms : disordered or with short ranged ordering. • This work uses the SQS technique suggested by Zunger has been used to generate various degrees of short range ordering in FeCr. • The electronic structure and pair energies have been obatined from first principles ASR and Lichtenstein methods. • The effect of chemical ordering on magnetic ordering is studied in detail. • Only those situations where the chemical ordering is complete have been studied

  13. Short-Range Noncontact Sensors for Healthcare and Other Emerging Applications: A Review

    Directory of Open Access Journals (Sweden)

    Changzhan Gu

    2016-07-01

    Full Text Available Short-range noncontact sensors are capable of remotely detecting the precise movements of the subjects or wirelessly estimating the distance from the sensor to the subject. They find wide applications in our day lives such as noncontact vital sign detection of heart beat and respiration, sleep monitoring, occupancy sensing, and gesture sensing. In recent years, short-range noncontact sensors are attracting more and more efforts from both academia and industry due to their vast applications. Compared to other radar architectures such as pulse radar and frequency-modulated continuous-wave (FMCW radar, Doppler radar is gaining more popularity in terms of system integration and low-power operation. This paper reviews the recent technical advances in Doppler radars for healthcare applications, including system hardware improvement, digital signal processing, and chip integration. This paper also discusses the hybrid FMCW-interferometry radars and the emerging applications and the future trends.

  14. Joint Maneuver Test Range on Eglin Air Force Base, Florida Final Environmental Assessment

    Science.gov (United States)

    2009-12-14

    ir Force B ase, Florida Page 3-2 Final E nvironm ental A ssessm ent A ffected E nvironm ent W ater R esources Figure 3-1. Physical and...nvironm ent W ater R esources Figure 3-2. Physical and Biological Resources Within Range B-9 Existing Components 14. Hills!Qoss Slope Legend --Creek

  15. Analysing the Possible Ways for Short-Term Forcing Gas Turbine Engines in Auxiliary Power Unit

    Directory of Open Access Journals (Sweden)

    N. I. Trotskii

    2016-01-01

    Full Text Available Using a gas turbine energy unit as an example, the article discusses possible ways for forcing the short-term gas turbine engines (GTE. The introduction explains the need for forcing the air transport and marine GTE in specific driving conditions and offers the main methods. Then it analyzes the three main short-term forcing methods according to GTE power, namely: precompressor water injection, a short-term rise in temperature after the combustion chamber, and feeding an additional compressed air into combustion chamber from the reserve cylinders.The analysis of the water injection method to force a GTE presents the main provisions and calculation results of the cycle, as a function of engine power on the amount of water injected into compressor inlet. It is shown that with water injection into compressor inlet in an amount of 1% of the total airflow there is a 17% power increase in the compressor. It also lists the main implementation problems of this method and makes a comparison with the results of other studies on the water injection into compressor.Next, the article concerns the GTE short-term forcing method through the pre-turbine short-term increase in the gas temperature. The article presents the calculation results of the cycle as a function of the power and the fuel-flow rate on the gas temperature at the turbine inlet. It is shown that with increasing temperature by 80 degrees the engine power increases by 11.2% and requires 11% more fuel. In the analysis of this method arises an issue of thermal barrier coating on the blade surface. The article discusses the most common types of coatings and their main shortcomings. It lists the main challenges and some ways of their solving when using this method to implement the short-term forcing.The last method under consideration is GTE short-term forcing by feeding the compressed air into the combustion chamber from the additional reserve cylinders. It should be noted that this method is

  16. Neutrino-Nucleus Interactions and the Short-Range Structure of Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Cavanna, F. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Palamara, O. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Schiavilla, R. [Old Dominion Univ., Norfolk, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Soderberg, M. [Syracuse Univ., NY (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Wiringa, R. B. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-01-08

    Improvements in theoretical modeling of Short Range structures and phenomena, and comparisons with data, will require sustained collaboration between nuclear theorists and neutrino experimentalists. The extensive history of studying this area of nuclear physics in electron- and hadron-scattering experiments, coupled with the transformative capabilities of LArTPCs to identify neutrinos, will provide a ripe opportunity for new discoveries that will further our understanding of the nucleus.

  17. Probing the short range behavior of nuclei with high PT photo- and electro-nuclear reactions

    International Nuclear Information System (INIS)

    Laget, J.M.

    1990-01-01

    The short range behavior of the nucleus and the use of the nucleus as a filter are studied. Special emphasis is given to photon and hadron induced reactions. The components of the nuclear wave function are described. The evidences of hard scattering processes in reactions induced by real photons as well as by hadrons on free nucleus are reviewed. The spin observables are also investigated. The perspectives opened by these studies in the nuclear environment are considered

  18. Short-range order of amorphous FeNiB alloy after neutron irradiation

    International Nuclear Information System (INIS)

    Miglierini, M.; Sitek, J.; Baluch, S.; Cirak, J.; Lipka, J.

    1990-01-01

    Transmission Moessbauer spectroscopy was used to study irradiation-induced changes in the short-range order of an amorphous Fe 80-x Ni x B 20 alloy. Neutron irradiation led to an increase of the width of a hyperfine field distribution implying atomic rearrangement towards disordering. Changes in a mean value of a HFD and Moessbauer line areas can be associated with a reorientation of spins due to radiation damage. (orig.)

  19. Short range correlations in the pion s-wave self-energy of pionic atoms

    OpenAIRE

    Salcedo, L. L.; Holinde, K.; Oset, E.; Schütz, C.

    1995-01-01

    We evaluate the contribution of second order terms to the pion-nucleus s-wave optical potential of pionic atoms generated by short range nuclear correlation. The corrections are sizeable because they involve the isoscalar s-wave $\\pi N$ amplitude for half off-shell situations where the amplitude is considerably larger than the on-shell one. In addition, the s-wave optical potential is reanalyzed by looking at all the different conventional contributions together lowest order, Pauli corrected ...

  20. Directional and short-range ordering kinetics in metallic alloys, crystalline and amorphous

    International Nuclear Information System (INIS)

    Hillairet, J.

    1985-01-01

    This presentation describes the methods (resistometric and anelastic) based on analysis of stress-induced directional ordering and short-range ordering and their application to the study of metallic alloys, crystalline and amorphous. It focuses on the determination of the atomic mobility and point defect properties. It discusses also the structural information which can be gained by Zener relaxation studies about the order-disorder transition and self-induced directional ordering phenomena

  1. Short-range order in InSb amorphized under ion bombardment

    International Nuclear Information System (INIS)

    Pavlov, P.V.; Tetel'baum, D.I.; Gerasimov, A.I.

    1979-01-01

    The investigation of short-range order is carried out in polycrystal InSb films, irradiated with Ne + ions with E=150 keV and with the 2x10 15 ion/cm 2 dose. The data are obtained testifying to the film amorphization, the cause of which is the defect storage but not the local melting. Stability of the obtained amorphous phase at the room temperature is noted

  2. Role of long- and short-range hydrophobic, hydrophilic and charged residues contact network in protein’s structural organization

    Directory of Open Access Journals (Sweden)

    Sengupta Dhriti

    2012-06-01

    higher interaction strength between amino acids, give extra stability to the tertiary structure of the thermophiles. All the subnetworks at different length scales (ARNs, LRNs and SRNs show assortativity mixing property of their participating amino acids. While there exists a significant higher percentage of hydrophobic subclusters over others in ARNs and LRNs; we do not find the assortative mixing behaviour of any the subclusters in SRNs. The clustering coefficient of hydrophobic subclusters in long-range network is the highest among types of subnetworks. There exist highly cliquish hydrophobic nodes followed by charged nodes in LRNs and ARNs; on the other hand, we observe the highest dominance of charged residues cliques in short-range networks. Studies on the perimeter of the cliques also show higher occurrences of hydrophobic and charged residues’ cliques. Conclusions The simple framework of protein contact networks and their subnetworks based on London van der Waals force is able to capture several known properties of protein structure as well as can unravel several new features. The thermophiles do not only have the higher number of long-range interactions; they also have larger cluster of connected residues at higher interaction strengths among amino acids, than their mesophilic counterparts. It can reestablish the significant role of long-range hydrophobic clusters in protein folding and stabilization; at the same time, it shed light on the higher communication ability of hydrophobic subnetworks over the others. The results give an indication of the controlling role of hydrophobic subclusters in determining protein’s folding rate. The occurrences of higher perimeters of hydrophobic and charged cliques imply the role of charged residues as well as hydrophobic residues in stabilizing the distant part of primary structure of a protein through London van der Waals interaction.

  3. Angular correlation between short-range. cap alpha. particles and. gamma. quanta

    Energy Technology Data Exchange (ETDEWEB)

    Kul' chitskii, L A; Latyshev, G D; Bulyginskii, D G

    1949-01-01

    Chang (Phys. Rev. 69, 60(1946); 70, 632(1946)) has found that the intensities of short-range ..cap alpha.. rays of Po and Ra are considerably higher than the values given by the Geiger-Nuttall law. This can be explained by assuming surface vibrations of ..cap alpha..-radioactive nuclei, which produce deformations and corresponding lowerings of the potential barrier in certain directions. In this case an angular correlation should exist between the short-range ..cap alpha.. ray and the accompanying ..gamma.. quantum. The authors checked this conclusion by applying the coincidence method to the ..cap alpha.. and ..gamma.. radiations of a mixture of RdTh (/sup 228/Th) and ThC (/sup 212/Bi). Maxima of coincidence numbers occur at angles 45 and 135 deg., with lesser maxima at 0 and 180 deg. Theoretical considerations show that in cases (like the one investigated) where the nuclear spin before and after the ..cap alpha.. and ..gamma.. emissions is zero, the angular correlations are uniquely determined whatever the deformation caused by the vibration; in other cases, the correlation depends on the kind of deformation. Therefore, it would be interesting to investigate the case of Pa, whose nuclear spin is not zero and the decay exhibits intensive groups of short-range ..cap alpha.. particles.

  4. Highly excited bound-state resonances of short-range inverse power-law potentials

    Energy Technology Data Exchange (ETDEWEB)

    Hod, Shahar [The Ruppin Academic Center, Emeq Hefer (Israel); The Hadassah Academic College, Jerusalem (Israel)

    2017-11-15

    We study analytically the radial Schroedinger equation with long-range attractive potentials whose asymptotic behaviors are dominated by inverse power-law tails of the form V(r) = -β{sub n}r{sup -n} with n > 2. In particular, assuming that the effective radial potential is characterized by a short-range infinitely repulsive core of radius R, we derive a compact analytical formula for the threshold energy E{sub l}{sup max} = E{sub l}{sup max}(n, β{sub n}, R), which characterizes the most weakly bound-state resonance (the most excited energy level) of the quantum system. (orig.)

  5. The Spectrum of Particles with Short-Ranged Interactions in a Harmonic Trap

    Directory of Open Access Journals (Sweden)

    Metsch B. Ch.

    2010-04-01

    Full Text Available The possibility to control short-ranged interactions of cold gases in optical traps by Feshbachresonances makes these systems ideal candidates to study universal scaling properties and Efimov physics. The spectrum of particles in a trap, idealised by a harmonic oscillator potential, in the zero range limit with 2- and 3-particle contact interactions is studied numerically. The Hamiltonian is regularised by restricting the oscillator basis and the coupling constants are tuned such that the ground state energies of the 2- and 3-particle sector are reproduced [1],[2]. Results for 2-, 3-, and 4 particle systems are presented and compared to exact results [3],[4].

  6. Towards highest peak intensities for ultra-short MeV-range ion bunches

    OpenAIRE

    Simon Busold; Dennis Schumacher; Christian Brabetz; Diana Jahn; Florian Kroll; Oliver Deppert; Ulrich Schramm; Thomas E. Cowan; Abel Blažević; Vincent Bagnoud; Markus Roth

    2015-01-01

    A laser-driven, multi-MeV-range ion beamline has been installed at the GSI Helmholtz center for heavy ion research. The high-power laser PHELIX drives the very short (picosecond) ion acceleration on ?m scale, with energies ranging up to 28.4?MeV for protons in a continuous spectrum. The necessary beam shaping behind the source is accomplished by applying magnetic ion lenses like solenoids and quadrupoles and a radiofrequency cavity. Based on the unique beam properties from the laser-driven so...

  7. Short Range Correlations in Nuclei at Large xbj through Inclusive Quasi-Elastic Electron Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Zhihong [Univ. of Virginia, Charlottesville, VA (United States)

    2013-12-01

    The experiment, E08-014, in Hall-A at Jefferson Lab aims to study the short-range correlations (SRC) which are necessary to explain the nuclear strength absent in the mean field theory. The cross sections for 2H, 3He, 4He, 12C, 40Ca and 48Ca, were measured via inclusive quasi-elastic electron scattering from these nuclei in a Q2 range between 0.8 and 2.8 (GeV/c)2 for x>1. The cross section ratios of heavy nuclei to 2H were extracted to study two-nucleon SRC for 1

  8. Short-arc orbit determination using coherent X-band ranging data

    Science.gov (United States)

    Thurman, S. W.; Mcelrath, T. P.; Pollmeier, V. M.

    1992-01-01

    The use of X-band frequencies in ground-spacecraft and spacecraft-ground telecommunication links for current and future robotic interplanetary missions makes it possible to perform ranging measurements of greater accuracy than previously obtained. It is shown that ranging data of sufficient accuracy, when acquired from multiple stations, can sense the geocentric angular position of a distant spacecraft. The application of high-accuracy S/X-band and X-band ranging to orbit determination with relatively short data arcs is investigated in planetary approach and encounter scenarios. Actual trajectory solutions for the Ulysses spacecraft constructed from S/X-band ranging and Doppler data are presented; error covariance calculations are used to predict the performance of X-band ranging and Doppler data. The Ulysses trajectory solutions indicate that the aim point for the spacecraft's February 1992 Jupiter encounter was predicted to a geocentric accuracy of 0.20 to 0.23/microrad. Explicit modeling of range bias parameters for each station pass is shown to largely remove systematic ground system calibration errors and transmission media effects from the Ulysses range measurements, which would otherwise corrupt the angle finding capabilities of the data. The Ulysses solutions were found to be reasonably consistent with the theoretical results, which suggest that angular accuracies of 0.08 to 0.1/microrad are achievable with X-band ranging.

  9. CMOS Receiver Front-ends for Gigabit Short-Range Optical Communications

    CERN Document Server

    Aznar, Francisco; Calvo Lopez, Belén

    2013-01-01

    This book describes optical receiver solutions integrated in standard CMOS technology, attaining high-speed short-range transmission within cost-effective constraints.  These techniques support short reach applications, such as local area networks, fiber-to-the-home and multimedia systems in cars and homes. The authors show how to implement the optical front-end in the same technology as the subsequent digital circuitry, leading to integration of the entire receiver system in the same chip.  The presentation focuses on CMOS receiver design targeting gigabit transmission along a low-cost, standardized plastic optical fiber up to 50m in length.  This book includes a detailed study of CMOS optical receiver design – from building blocks to the system level. Reviews optical communications, including long-haul transmission systems and emerging applications focused on short-range; Explains necessary fundamentals, such as characteristics of a data signal, system requirements affecting receiver design and key par...

  10. The long and short run forcing variables of purchasing power parity of ASEAN-5

    OpenAIRE

    Abdalrahman AbuDalu; Elsadig Musa Ahmed

    2013-01-01

    This study examines the long-run and short-run forcing variables of purchasing power parity (PPP) for ASEAN-5 currencies vis-a-vis the U.S. dollar, i.e., their real effective exchange rate (REER). This study uses the autoregressive distributed lag (ARDL) approach to co-integration over the period 1991:Q1 – 2006:Q2. Our empirical results suggest that the domestic money supply (M1) is a significant long run forcing variable for the REERs of Malaysia, Indonesia, the Philippines, and Singapore. H...

  11. Models with short- and long-range interactions: the phase diagram and the reentrant phase

    International Nuclear Information System (INIS)

    Dauxois, Thierry; Lori, Leonardo; Ruffo, Stefano; De Buyl, Pierre

    2010-01-01

    We study the phase diagram of two different Hamiltonians with competing local, nearest-neighbour, and mean-field couplings. The first example corresponds to the HMF Hamiltonian with an additional short-range interaction. The second example is a reduced Hamiltonian for dipolar layered spin structures, with a new feature with respect to the first example: the presence of anisotropies. The two examples are solved in both the canonical and the microcanonical ensemble using a combination of the min–max method with the transfer operator method. The phase diagrams present typical features of systems with long-range interactions: ensemble inequivalence, negative specific heat and temperature jumps. Moreover, for a given range of parameters, we report the signature of phase reentrance. This can also be interpreted as the presence of azeotropy with the creation of two first-order phase transitions with ensemble inequivalence, as one parameter is varied continuously

  12. An Empirical Path-Loss Model for Wireless Channels in Indoor Short-Range Office Environment

    Directory of Open Access Journals (Sweden)

    Ye Wang

    2012-01-01

    Full Text Available A novel empirical path-loss model for wireless indoor short-range office environment at 4.3–7.3 GHz band is presented. The model is developed based on the experimental datum sampled in 30 office rooms in both line of sight (LOS and non-LOS (NLOS scenarios. The model is characterized as the path loss to distance with a Gaussian random variable X due to the shadow fading by using linear regression. The path-loss exponent n is fitted by the frequency using power function and modeled as a frequency-dependent Gaussian variable as the standard deviation σ of X. The presented works should be available for the research of wireless channel characteristics under universal indoor short-distance environments in the Internet of Things (IOT.

  13. High-resolution and large dynamic range nanomechanical mapping in tapping-mode atomic force microscopy

    International Nuclear Information System (INIS)

    Sahin, Ozgur; Erina, Natalia

    2008-01-01

    High spatial resolution imaging of material properties is an important task for the continued development of nanomaterials and studies of biological systems. Time-varying interaction forces between the vibrating tip and the sample in a tapping-mode atomic force microscope contain detailed information about the elastic, adhesive, and dissipative response of the sample. We report real-time measurement and analysis of the time-varying tip-sample interaction forces with recently introduced torsional harmonic cantilevers. With these measurements, high-resolution maps of elastic modulus, adhesion force, energy dissipation, and topography are generated simultaneously in a single scan. With peak tapping forces as low as 0.6 nN, we demonstrate measurements on blended polymers and self-assembled molecular architectures with feature sizes at 1, 10, and 500 nm. We also observed an elastic modulus measurement range of four orders of magnitude (1 MPa to 10 GPa) for a single cantilever under identical feedback conditions, which can be particularly useful for analyzing heterogeneous samples with largely different material components.

  14. Resistance to alveolar shape change limits range of force propagation in lung parenchyma.

    Science.gov (United States)

    Ma, Baoshun; Smith, Bradford J; Bates, Jason H T

    2015-06-01

    We have recently shown that if the lung parenchyma is modeled in 2 dimensions as a network of springs arranged in a pattern of repeating hexagonal cells, the distortional forces around a contracting airway propagate much further from the airway wall than classic continuum theory predicts. In the present study we tested the hypothesis that this occurs because of the negligible shear modulus of a hexagonal spring network. We simulated the narrowing of an airway embedded in a hexagonal network of elastic alveolar walls when the hexagonal cells of the network offered some resistance to a change in shape. We found that as the forces resisting shape change approach about 10% of the forces resisting length change of an individual spring the range of distortional force propagation in the spring network fell of rapidly as in an elastic continuum. We repeated these investigations in a 3-dimensional spring network composed of space-filling polyhedral cells and found similar results. This suggests that force propagation away from a point of local parenchymal distortion also falls off rapidly in real lung tissue. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Intermediate- and short-range order in phosphorus-selenium glasses

    International Nuclear Information System (INIS)

    Bytchkov, Aleksei; Hennet, Louis; Price, David L.; Miloshova, Mariana; Bychkov, Eugene; Kohara, Shinji

    2011-01-01

    State-of-the-art neutron and x-ray diffraction measurements have been performed to provide a definitive picture of the intermediate- and short-range structures of P x Se 1-x glasses spanning two glass regions, x 0.025-0.54 and 0.64-0.84. Liquid P 4 Se 3 and amorphous red P and Se were also measured. Detailed information was obtained about the development with increasing phosphorous concentration of intermediate-range order on the length scale ∼6 A ring , based on the behavior of the first sharp diffraction peak. Attention is also paid to the feature in the structure factor at 7.5 A ring -1 , identified in earlier numerical simulations, provides further evidence of the existence of molecular units. The real-space transforms yield a reliable statistical picture of the changing short-range order as x increases, using the information about types and concentrations of local structural units provided by previous NMR measurements to interpret the trends observed.

  16. Short-range contacts govern the performance of industry-relevant battery cathodes

    Science.gov (United States)

    Morelly, Samantha L.; Alvarez, Nicolas J.; Tang, Maureen H.

    2018-05-01

    Fundamental understanding of how processing affects composite battery electrode structure and performance is still lacking, especially for industry-relevant electrodes with low fractions of inactive material. This work combines rheology, electronic conductivity measurements, and battery rate capability tests to prove that short-range electronic contacts are more important to cathode rate capability than either ion transport or long-range electronic conductivity. LiNi0.33Mn0.33Co0.33O2, carbon black, and polyvinylidene difluoride in 1-methyl-2-pyrrolidinone represent a typical commercial electrode with films. Improvements in battery rate capability at constant electrode porosity do not correlate to electronic conductivity, but rather show an optimum fraction of free carbon. Simple comparison of rate capability in electrodes with increased total carbon loading (3 wt%) shows improvement for all fractions of free carbon. These results clearly indicate that ion transport cannot be limiting and highlight the critical importance of short-range electronic contacts for controlling battery performance.

  17. Short range part of the NN interaction: Equivalent local potentials from quark exchange kernels

    International Nuclear Information System (INIS)

    Suzuk, Y.; Hecht, K.T.

    1983-01-01

    To focus on the nature of the short range part of the NN interaction, the intrinsically nonlocal interaction among the quark constituents of colorless nucleons is converted to an equivalent local potential using resonating group kernels which can be evaluated in analytic form. The WKB approximation based on the Wigner transform of the nonlocal kernels has been used to construct the equivalent potentials without recourse to the long range part of the NN interaction. The relative importance of the various components of the exchange kernels can be examined: The results indicate the importance of the color magnetic part of the exchange kernel for the repulsive part in the (ST) = (10), (01) channels, in particular since the energy dependence of the effective local potentials seems to be set by this term. Large cancellations of color Coulombic and quark confining contributions, together with the kinetic energy and norm exchange terms, indicate that the exact nature of the equivalent local potential may be sensitive to the details of the parametrization of the underlying quark-quark interaction. The equivalent local potentials show some of the characteristics of the phenomenological short range terms of the Paris potential

  18. Towards highest peak intensities for ultra-short MeV-range ion bunches

    Science.gov (United States)

    Busold, Simon; Schumacher, Dennis; Brabetz, Christian; Jahn, Diana; Kroll, Florian; Deppert, Oliver; Schramm, Ulrich; Cowan, Thomas E.; Blažević, Abel; Bagnoud, Vincent; Roth, Markus

    2015-01-01

    A laser-driven, multi-MeV-range ion beamline has been installed at the GSI Helmholtz center for heavy ion research. The high-power laser PHELIX drives the very short (picosecond) ion acceleration on μm scale, with energies ranging up to 28.4 MeV for protons in a continuous spectrum. The necessary beam shaping behind the source is accomplished by applying magnetic ion lenses like solenoids and quadrupoles and a radiofrequency cavity. Based on the unique beam properties from the laser-driven source, high-current single bunches could be produced and characterized in a recent experiment: At a central energy of 7.8 MeV, up to 5 × 108 protons could be re-focused in time to a FWHM bunch length of τ = (462 ± 40) ps via phase focusing. The bunches show a moderate energy spread between 10% and 15% (ΔE/E0 at FWHM) and are available at 6 m distance to the source und thus separated from the harsh laser-matter interaction environment. These successful experiments represent the basis for developing novel laser-driven ion beamlines and accessing highest peak intensities for ultra-short MeV-range ion bunches. PMID:26212024

  19. Towards highest peak intensities for ultra-short MeV-range ion bunches

    Science.gov (United States)

    Busold, Simon; Schumacher, Dennis; Brabetz, Christian; Jahn, Diana; Kroll, Florian; Deppert, Oliver; Schramm, Ulrich; Cowan, Thomas E.; Blažević, Abel; Bagnoud, Vincent; Roth, Markus

    2015-07-01

    A laser-driven, multi-MeV-range ion beamline has been installed at the GSI Helmholtz center for heavy ion research. The high-power laser PHELIX drives the very short (picosecond) ion acceleration on μm scale, with energies ranging up to 28.4 MeV for protons in a continuous spectrum. The necessary beam shaping behind the source is accomplished by applying magnetic ion lenses like solenoids and quadrupoles and a radiofrequency cavity. Based on the unique beam properties from the laser-driven source, high-current single bunches could be produced and characterized in a recent experiment: At a central energy of 7.8 MeV, up to 5 × 108 protons could be re-focused in time to a FWHM bunch length of τ = (462 ± 40) ps via phase focusing. The bunches show a moderate energy spread between 10% and 15% (ΔE/E0 at FWHM) and are available at 6 m distance to the source und thus separated from the harsh laser-matter interaction environment. These successful experiments represent the basis for developing novel laser-driven ion beamlines and accessing highest peak intensities for ultra-short MeV-range ion bunches.

  20. Possible manifestation of long range forces in high energy hadron collisions

    International Nuclear Information System (INIS)

    Kuraev, Eh.A.; Ferro, P.; Trentadue, L.

    1997-01-01

    Pion-pion and photon-photon scattering are discussed.. We obtain, starting from the impact representation introduced by Cheng and Wu a new contribution to the high energy hadron-hadron scattering amplitude for small transferred momentum q 2 of the form is (q 2 /m 4 )ln(-q 2 /m 2 ). This behaviour may be interpreted as a manifestation of long transverse-range forces between hadrons which, for ρ>> m -1 fall off as ρ -4 . We consider the examples of pion and photon scattering with photons converted in the intermediate state to two pairs of quarks interacting by exchanging two gluon colorless state. A phenomenological approach for proton impact factor is used to analyze proton-proton scattering. The analysis of the lowest order radiative corrections for the case of photon-photon scattering is done. We discuss the possibility of observing the effects of these long range forces

  1. The INF (Intermediate-Range Nuclear Forces) Controversy: A Confluence of Foreign and Domestic Interests.

    Science.gov (United States)

    1986-09-01

    Socialist Party, PASOK , in 1981, on a platform of withdrawing Greece from NATO and expelling US forces from Greece . 5 3 Schwartz, p. 73. 47 Turkey was...Portugal, Greece , and Turkey (Spain was not a NATO member in 1979). Basing any of the new INF weapons in Portugal would have had limited effect because...of range limitations (not - as pronounced, but similar to the IRBMs deployed in Western . Europe in the late 1950s). As for Greece , anti-Americanism

  2. Robust approach to maximize the range and accuracy of force application in atomic force microscopes with nonlinear position-sensitive detectors

    International Nuclear Information System (INIS)

    Silva, E C C M; Vliet, K J van

    2006-01-01

    The atomic force microscope is used increasingly to investigate the mechanical properties of materials via sample displacement under an applied force. However, both the extent of forces attainable and the accuracy of those forces measurements are significantly limited by the optical lever configuration that is commonly used to infer nanoscale deflection of the cantilever. We present a robust and general approach to characterize and compensate for the nonlinearity of the position-sensitive optical device via data processing, requiring no modification of existing instrumentation. We demonstrate that application of this approach reduced the maximum systematic error on the gradient of a force-displacement response from 50% to 5%, and doubled the calibrated force application range. Finally, we outline an experimental protocol that optimizes the use of the quasi-linear range of the most commonly available optical feedback configurations and also accounts for the residual systematic error, allowing the user to benefit from the full detection range of these indirect force sensors

  3. A first-principles study of short range order in Cu-Zn

    International Nuclear Information System (INIS)

    Slutter, M.; Turchi, P.E.A.; Johnson, D.D.; Nicholson, D.M.; Stocks, G.M.; Pinski, F.J.

    1990-01-01

    Recently, measurements of short-range order (SRO) diffuse neutron scattering intensity have been performed on quenched Cu-Zn alloys with 22.4 to 31.1 atomic percent (a/o) Zn, and pair interactions were obtained by inverse Monte Carlo simulation. These results are compared to SRO intensities and effective pair interactions obtained from first-principles electronic structure calculations. The theoretical SRO intensities were calculated with the cluster variation method (CVM) in the tetrahedron-octahedron approximation with first-principles pain interactions as input. More generally, phase stability in the Cu-Zn alloy system is discussed, using ab-initio energetic properties

  4. Link Design Rules for Cost-Effective Short-Range Radio Over Multimode Fiber Systems

    DEFF Research Database (Denmark)

    Visani, Davide; Tartarini, Giovanni; Petersen, Martin Nordal

    2010-01-01

    Referring to short-range radio over multimode fiber links, we find out important guidelines for the realization of cost-effective intensity modulated directly detected systems. Since the quality of today's connectors is considerably higher than in the past, we demonstrate that two important...... parameters of the system are the finite detecting area of the photodiode and the laser frequency chirp. Furthemore, we show that the use of the central launch technique inherently determines a lower impact of modal noise fluctuations with respect to the offset launch one. This makes CL more convenient...

  5. Short-range order and local conservation of quantum numbers in multiparticle production

    International Nuclear Information System (INIS)

    Le Bellac, M.

    1976-01-01

    These lectures discuss the implications of the hypotheses of short-range order (SRO) and local conservation of quantum numbers (LCQN) for multiple production of elementary particles at high energies. The consequences of SRO for semi-inclusive correlations and the distribution of rapidity gaps are derived, essentially in the framework of the cluster model. Then the experimental status of local conservation of charge and transverse momentum is reviewed. Finally, by making use of the unitarity relation, it is shown that LCQN has important consequences for the elastic amplitude. The derivation is given both in a model-independent way, and in specific multiperiheral models. (Author)

  6. OTDM Networking for Short Range High-Capacity Highly Dynamic Networks

    DEFF Research Database (Denmark)

    Medhin, Ashenafi Kiros

    This PhD thesis aims at investigating the possibility of designing energy-efficient high-capacity (up to Tbit/s) optical network scenarios, leveraging on the effect of collective switching of many bits simultaneously, as is inherent in high bit rate serial optical data signals. The focus...... is on short range highly dynamic networks, catering to data center needs. The investigation concerns optical network scenarios, and experimental implementations of high bit rate serial data packet generation and reception, scalable optical packet labeling, simple optical label extraction and stable ultra...

  7. Perturbation theory for short-range weakly-attractive potentials in one dimension

    Energy Technology Data Exchange (ETDEWEB)

    Amore, Paolo, E-mail: paolo.amore@gmail.com [Facultad de Ciencias, CUICBAS, Universidad de Colima, Bernal Díaz del Castillo 340, Colima, Colima (Mexico); Fernández, Francisco M., E-mail: fernande@quimica.unlp.edu.ar [INIFTA (UNLP, CONICET), Division Química Teórica, Blvd. 113 S/N, Sucursal 4, Casilla de Correo 16, 1900 La Plata (Argentina)

    2017-03-15

    We have obtained the perturbative expressions up to sixth order for the energy of the bound state in a one dimensional, arbitrarily weak, short range finite well, applying a method originally developed by Gat and Rosenstein Ref. [1]. The expressions up to fifth order reproduce the results already known in the literature, while the sixth order had not been calculated before. As an illustration of our formulas we have applied them to two exactly solvable problems and to a nontrivial problem.

  8. Study of the short-range 3He structure from the dd→3Hen reaction

    International Nuclear Information System (INIS)

    Ladygin, V.P.; Ladygina, N.V.

    1995-01-01

    An experiment on studying of the tensor analysing power C 0,NN,0,0 and spin correlation C N,N,0,0 due to the transverse polarization of both initial particles from the dd→ 3 Hen reaction has been proposed. Those polarization observables are very sensitive to the short-range 3 He structure. This experiment is proposed to be done at the LHE Accelerator Complex using both a polarized deuteron beam and a polarized deuterium target. 25 refs., 2 figs

  9. Influence of short range chemical order on density of states in α-ZrNi

    International Nuclear Information System (INIS)

    Duarte Junior, J.

    1986-01-01

    Calculations of the density of electronic states for amorphous alloys of ZrNi and ZrCu with different chemical order degrees, in order to verify the effect of chemical ordering on this property, are presented. The results obtained for ZrCu shown that the density of states at Fermi level do not vary significantly with the ordering. The results for ZrNi shown that the introduction of short range chemical order can decrease significantly the density of states at Fermi level, leading to better agreement with experimental results. (M.C.K.) [pt

  10. Measurement based scenario analysis of short-range distribution system planning

    DEFF Research Database (Denmark)

    Chen, Peiyuan; Bak-Jensen, Birgitte; Chen, Zhe

    2009-01-01

    This paper focuses on short-range distribution system planning using a probabilistic approach. Empirical probabilistic distributions of load demand and distributed generations are derived from the historical measurement data and incorporated into the system planning. Simulations with various...... feasible scenarios are performed based on a local distribution system at Støvring in Denmark. Simulation results provide more accurate and insightful information for the decision-maker when using the probabilistic analysis than using the worst-case analysis, so that a better planning can be achieved....

  11. EXAFS study of short range order in Fe-Zr amorphous alloys

    International Nuclear Information System (INIS)

    Fernandez-Gubieda, M.L.; Gorria, P.; Barandiaran, J.M.; Barquin, L.F.

    1995-01-01

    Room temperature X-ray absorption spectra on Fe K-edge have been performed in Fe 100-x-y Zr x B y and Fe 86 Zr 7 Cu 1 B 6 alloys (x=7, 7.7, 9; y=0, 2, 4, 6). Fe-Fe coordination number and interatomic distances do not change in any sample. However, small changes in the Fe-Zr short range order, which could explain the evolution of the magnetic properties, have been observed. (orig.)

  12. Numerical study of the glass-glass transition in short-ranged attractive colloids

    International Nuclear Information System (INIS)

    Zaccarelli, Emanuela; Sciortino, Francesco; Tartaglia, Piero

    2004-01-01

    We report extensive numerical simulations in the glass region for a simple model of short-ranged attractive colloids, the square well model. We investigate the behaviour of the density autocorrelation function and of the static structure factor in the region of temperatures and packing fractions where a glass-glass transition is expected according to theoretical predictions. We strengthen our observations by studying both waiting time and history dependence of the numerical results. We provide evidence supporting the possibility that activated bond-breaking processes destabilize the attractive glass, preventing the full observation of a sharp glass-glass kinetic transition

  13. Comparison of impact forces, accelerations and ankle range of motion in surfing-related landing tasks.

    Science.gov (United States)

    Lundgren, Lina E; Tran, Tai T; Nimphius, Sophia; Raymond, Ellen; Secomb, Josh L; Farley, Oliver R L; Newton, Robert U; Sheppard, Jeremy M

    2016-01-01

    This study aimed to describe the impact forces, accelerations and ankle range of motion in five different landing tasks that are used in training and testing for competitive surfing athletes, to assist coaches in the prescription of landing task progression and monitoring training load. Eleven competitive surfing athletes aged 24 ± 7 years participated, and inertial motion sensors were fixed to the anterior aspect of the feet, mid-tibial shafts, sacrum and eighth thoracic vertebrae on these athletes. Three tasks were performed landing on force plates and two tasks in a modified gymnastics set-up used for land-based aerial training. Peak landing force, resultant peak acceleration and front and rear side ankle dorsiflexion ranges of motion during landing were determined. The peak acceleration was approximately 50% higher when performing aerial training using a mini-trampoline and landing on a soft-density foam board, compared to a similar landing off a 50 cm box. Furthermore, the ankle ranges of motion during the gymnastic type landings were significantly lower than the other landing types (P ≤ 0.05 and P ≤ 0.001), for front and rear sides, respectively. Conclusively, increased task complexity and specificity of the sport increased the tibial peak acceleration, indicating greater training load.

  14. Force control tasks with pure haptic feedback promote short-term focused attention.

    Science.gov (United States)

    Wang, Dangxiao; Zhang, Yuru; Yang, Xiaoxiao; Yang, Gaofeng; Yang, Yi

    2014-01-01

    Focused attention has great impact on our quality of life. Our learning, social skills and even happiness are closely intertwined with our capacity for focused attention. Attention promotion is replete with examples of training-induced increases in attention capability, most of which rely on visual and auditory stimulation. Pure haptic stimulation to increase attention capability is rarely found. We show that accurate force control tasks with pure haptic feedback enhance short-term focused attention. Participants were trained by a force control task in which information from visual and auditory channels was blocked, and only haptic feedback was provided. The trainees were asked to exert a target force within a pre-defined force tolerance for a specific duration. The tolerance was adaptively modified to different levels of difficulty to elicit full participant engagement. Three attention tests showed significant changes in different aspects of focused attention in participants who had been trained as compared with those who had not, thereby illustrating the role of haptic-based sensory-motor tasks in the promotion of short-term focused attention. The findings highlight the potential value of haptic stimuli in brain plasticity and serve as a new tool to extend existing computer games for cognitive enhancement.

  15. Structure factor of polymers interacting via a short range repulsive potential: Application to hairy wormlike micelles

    International Nuclear Information System (INIS)

    Massiera, Gladys; Ramos, Laurence; Ligoure, Christian; Pitard, Estelle

    2003-01-01

    We use the random phase approximation to compute the structure factor S(q) of a solution of chains interacting through a soft and short range repulsive potential V. Above a threshold polymer concentration, whose magnitude is essentially controlled by the range of the potential, S(q) exhibits a peak whose position depends on the concentration. We take advantage of the close analogy between polymers and wormlike micelles and apply our model, using a Gaussian function for V, to quantitatively analyze experimental small angle neutron scattering profiles of solutions of hairy wormlike micelles. These samples, which consist in surfactant self-assembled flexible cylinders decorated by amphiphilic copolymer, provide indeed an appropriate experimental model system to study the structure of sterically interacting polymer solutions

  16. A New Theoretical Analysis of the Effects of Short Range Correlations in Inclusive Lepton Scattering

    Science.gov (United States)

    Benedetta Mezzetti, Chiara; Ciofi Degli Atti, Claudio

    2009-05-01

    Recently, evidence of short range correlations (SRC) has been provided by experimental data on inclusive lepton A(e, e')X scattering by the observation of a scaling behavior of the ratios of the cross sections on heavy nuclei to those on the deuteron and ^3He. Other attempts to get information on SRC rely on the concept of Y-scaling, whose interest has been renewed by new Jlab data. A new approach to Y-scaling, relying on the definition of a new relativistic scaling variable which incorporates the momentum dependence of the excitation energy of the (A - 1) system is presented, with the resulting scaling function being closely related to the longitudinal momentum distributions. Taking into account final state interaction effects, the new analysis of experimental data on nuclei, ranging from ^3He to Nuclear Matter, provides unique information on the nucleon momentum distributions and confirms the analysis in terms of cross section ratios.

  17. Will high-resolution global ocean models benefit coupled predictions on short-range to climate timescales?

    Science.gov (United States)

    Hewitt, Helene T.; Bell, Michael J.; Chassignet, Eric P.; Czaja, Arnaud; Ferreira, David; Griffies, Stephen M.; Hyder, Pat; McClean, Julie L.; New, Adrian L.; Roberts, Malcolm J.

    2017-12-01

    As the importance of the ocean in the weather and climate system is increasingly recognised, operational systems are now moving towards coupled prediction not only for seasonal to climate timescales but also for short-range forecasts. A three-way tension exists between the allocation of computing resources to refine model resolution, the expansion of model complexity/capability, and the increase of ensemble size. Here we review evidence for the benefits of increased ocean resolution in global coupled models, where the ocean component explicitly represents transient mesoscale eddies and narrow boundary currents. We consider lessons learned from forced ocean/sea-ice simulations; from studies concerning the SST resolution required to impact atmospheric simulations; and from coupled predictions. Impacts of the mesoscale ocean in western boundary current regions on the large-scale atmospheric state have been identified. Understanding of air-sea feedback in western boundary currents is modifying our view of the dynamics in these key regions. It remains unclear whether variability associated with open ocean mesoscale eddies is equally important to the large-scale atmospheric state. We include a discussion of what processes can presently be parameterised in coupled models with coarse resolution non-eddying ocean models, and where parameterizations may fall short. We discuss the benefits of resolution and identify gaps in the current literature that leave important questions unanswered.

  18. Distinct Short-Range Order Is Inherent to Small Amorphous Calcium Carbonate Clusters (<2 nm)

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Shengtong [Physical Chemistry, University of Konstanz, Universitätsstrasse 10 78457 Konstanz Germany; School of Chemical Engineering, State Key Laboratory of Chemical Engineering, Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, 130 Meilong Road Shanghai 200237 P.R. China; Chevrier, Daniel M. [Department of Chemistry and Institute for Research in Materials, Dalhousie University, Halifax Nova Scotia B3H 4R2 Canada; Zhang, Peng [Department of Chemistry and Institute for Research in Materials, Dalhousie University, Halifax Nova Scotia B3H 4R2 Canada; Gebauer, Denis [Physical Chemistry, University of Konstanz, Universitätsstrasse 10 78457 Konstanz Germany; Cölfen, Helmut [Physical Chemistry, University of Konstanz, Universitätsstrasse 10 78457 Konstanz Germany

    2016-09-09

    Amorphous intermediate phases are vital precursors in the crystallization of many biogenic minerals. While inherent short-range orders have been found in amorphous calcium carbonates (ACCs) relating to different crystalline forms, it has never been clarified experimentally whether such orders already exist in very small clusters less than 2 nm in size. Here, we studied the stability and structure of 10,12-pentacosadiynoic acid (PCDA) protected ACC clusters with a core size of ca. 1.4 nm consisting of only seven CaCO3 units. Ligand concentration and structure are shown to be key factors in stabilizing the ACC clusters. More importantly, even in such small CaCO3 entities, a proto-calcite short-range order can be identified but with a relatively high degree of disorder that arises from the very small size of the CaCO3 core. Our findings support the notion of a structural link between prenucleation clusters, amorphous intermediates, and final crystalline polymorphs, which appears central to the understanding of polymorph selection.

  19. Quantifying indices of short- and long-range white matter connectivity at each cortical vertex.

    Directory of Open Access Journals (Sweden)

    Maria Carmela Padula

    Full Text Available Several neurodevelopmental diseases are characterized by impairments in cortical morphology along with altered white matter connectivity. However, the relationship between these two measures is not yet clear. In this study, we propose a novel methodology to compute and display metrics of white matter connectivity at each cortical point. After co-registering the extremities of the tractography streamlines with the cortical surface, we computed two measures of connectivity at each cortical vertex: the mean tracts' length, and the proportion of short- and long-range connections. The proposed measures were tested in a clinical sample of 62 patients with 22q11.2 deletion syndrome (22q11DS and 57 typically developing individuals. Using these novel measures, we achieved a fine-grained visualization of the white matter connectivity patterns at each vertex of the cortical surface. We observed an intriguing pattern of both increased and decreased short- and long-range connectivity in 22q11DS, that provides novel information about the nature and topology of white matter alterations in the syndrome. We argue that the method presented in this study opens avenues for additional analyses of the relationship between cortical properties and patterns of underlying structural connectivity, which will help clarifying the intrinsic mechanisms that lead to altered brain structure in neurodevelopmental disorders.

  20. Polyamorphism and substructure of short-range order in amorphous boron films

    International Nuclear Information System (INIS)

    Palatnik, L.S.; Nechitajlo, A.A.; Koz'ma, A.A.

    1981-01-01

    The structure and substructure of boron amorphous films are studied in detail. Amorphous condensate of Bsup(a) boron is built of the same (but only disorientedly located) 12 B icosahedrons as boron crystalline modifications: B 105 -equilibrium β-rhombic, metastable: B 50 -tetragonal, B 12 -α-rhombohedral Coordination number for Bsup(a) (Z 1 =6.4) is lower than in B 105 (Z 1 =6.6) but higher than in B 50 modification (Z 1 =6.1). In crystalline modifications B 105 , B 50 , B 12 coordination numbers ω in first coordination spheres of icosahedrons are equal to ν 105 =6+4.6=10.6; ν 50 =10+3=14; ν 12 =6 respectively. Both amorphous modifications of boron Bsub(1)sup(a) and Bsub(15)sup(a) are analogs to B 50 in respect of the short-range order of icosahedron location. The difference between them is in ''substructure'' of short-range order: part of boron atoms (approximately 12%) do not occupy the vertices (so that vacancies appear) and enter the emptinesses between icosahedrons. In other words, the structure B 50 is the model basis of both amorphous phases [ru

  1. Optimal design of a vehicle magnetorheological damper considering the damping force and dynamic range

    International Nuclear Information System (INIS)

    Nguyen, Quoc-Hung; Choi, Seung-Bok

    2009-01-01

    This paper presents an optimal design of a passenger vehicle magnetorheological (MR) damper based on finite element analysis. The MR damper is constrained in a specific volume and the optimization problem identifies the geometric dimensions of the damper that minimize an objective function. The objective function consists of the damping force, the dynamic range, and the inductive time constant of the damper. After describing the configuration of the MR damper, the damping force and dynamic range are obtained on the basis of the Bingham model of an MR fluid. Then, the control energy (power consumption of the damper coil) and the inductive time constant are derived. The objective function for the optimization problem is determined based on the solution of the magnetic circuit of the initial damper. Subsequently, the optimization procedure, using a golden-section algorithm and a local quadratic fitting technique, is constructed via commercial finite element method parametric design language. Using the developed optimization tool, optimal solutions of the MR damper, which are constrained in a specific cylindrical volume defined by its radius and height, are determined and a comparative work on damping force and inductive time constant between the initial and optimal design is undertaken

  2. Long-range force and moment calculations in multiresolution simulations of molecular systems

    International Nuclear Information System (INIS)

    Poursina, Mohammad; Anderson, Kurt S.

    2012-01-01

    Multiresolution simulations of molecular systems such as DNAs, RNAs, and proteins are implemented using models with different resolutions ranging from a fully atomistic model to coarse-grained molecules, or even to continuum level system descriptions. For such simulations, pairwise force calculation is a serious bottleneck which can impose a prohibitive amount of computational load on the simulation if not performed wisely. Herein, we approximate the resultant force due to long-range particle-body and body-body interactions applicable to multiresolution simulations. Since the resultant force does not necessarily act through the center of mass of the body, it creates a moment about the mass center. Although this potentially important torque is neglected in many coarse-grained models which only use particle dynamics to formulate the dynamics of the system, it should be calculated and used when coarse-grained simulations are performed in a multibody scheme. Herein, the approximation for this moment due to far-field particle-body and body-body interactions is also provided.

  3. New spin source to search for scalar-pseudoscalar couplings at short range

    International Nuclear Information System (INIS)

    Hammond, G. D.; Pulido Paton, A.; Speake, C. C.; Trenkel, C.; Rochester, G. K.; Shaul, D.; Sumner, T. J.

    2008-01-01

    We describe the design and performance of a new source of polarized spins that can be employed in experiments that search for macroscopic interactions between particles with intrinsic spin. In this article we concentrate on the analysis of the performance of the spin source in generating putative scalar-pseudoscalar forces. We outline two methods of calculating the magnitude of such forces and compare the predictions of the models. We discuss the manufacture of the spin source and the measurements that we have carried out in order to place upper limits on systematic effects that would limit the sensitivity of such searches. We have shown, in a recent article to Physical Review Letters [G. D. Hammond, C. C. Speake, C. Trenkel, and A. Pulido-Paton, Phys. Rev. Lett. 98, 081101 (2007)], that the combination of the spin source together with the torque sensitivity of our torsion balance improves constraints on the coupling strength of macroscopic scalar-pseudoscalar interactions by 10 orders of magnitude at a range of 1 mm. This paper further supports that work and provides a detailed description and characterization of the spin source

  4. Toward Structure Prediction for Short Peptides Using the Improved SAAP Force Field Parameters

    Directory of Open Access Journals (Sweden)

    Kenichi Dedachi

    2013-01-01

    Full Text Available Based on the observation that Ramachandran-type potential energy surfaces of single amino acid units in water are in good agreement with statistical structures of the corresponding amino acid residues in proteins, we recently developed a new all-atom force field called SAAP, in which the total energy function for a polypeptide is expressed basically as a sum of single amino acid potentials and electrostatic and Lennard-Jones potentials between the amino acid units. In this study, the SAAP force field (SAAPFF parameters were improved, and classical canonical Monte Carlo (MC simulation was carried out for short peptide models, that is, Met-enkephalin and chignolin, at 300 K in an implicit water model. Diverse structures were reasonably obtained for Met-enkephalin, while three folded structures, one of which corresponds to a native-like structure with three native hydrogen bonds, were obtained for chignolin. The results suggested that the SAAP-MC method is useful for conformational sampling for the short peptides. A protocol of SAAP-MC simulation followed by structural clustering and examination of the obtained structures by ab initio calculation or simply by the number of the hydrogen bonds (or the hardness was demonstrated to be an effective strategy toward structure prediction for short peptide molecules.

  5. On the skill of various ensemble spread estimators for probabilistic short range wind forecasting

    Science.gov (United States)

    Kann, A.

    2012-05-01

    A variety of applications ranging from civil protection associated with severe weather to economical interests are heavily dependent on meteorological information. For example, a precise planning of the energy supply with a high share of renewables requires detailed meteorological information on high temporal and spatial resolution. With respect to wind power, detailed analyses and forecasts of wind speed are of crucial interest for the energy management. Although the applicability and the current skill of state-of-the-art probabilistic short range forecasts has increased during the last years, ensemble systems still show systematic deficiencies which limit its practical use. This paper presents methods to improve the ensemble skill of 10-m wind speed forecasts by combining deterministic information from a nowcasting system on very high horizontal resolution with uncertainty estimates from a limited area ensemble system. It is shown for a one month validation period that a statistical post-processing procedure (a modified non-homogeneous Gaussian regression) adds further skill to the probabilistic forecasts, especially beyond the nowcasting range after +6 h.

  6. A UHF RFID system with on-chip-antenna tag for short range communication

    International Nuclear Information System (INIS)

    Peng Qi; Zhang Chun; Zhao Xijin; Wang Zhihua

    2015-01-01

    A UHF RF identification system based on the 0.18 μm CMOS process has been developed for short range and harsh size requirement applications, which is composed of a fully integrated tag and a special reader. The whole tag chip with the antenna takes up an area of 0.36 mm 2 , which is smaller than other reported tags with an on-chip antenna (OCA) using the standard CMOS process. A self-defined protocol is proposed to reduce the power consumption, and minimize the size of the tag. The specialized SOC reader system consists of the RF transceiver, digital baseband, MCU and host interface. Its power consumption is about 500 mW. Measurement results show that the system's reading range is 2 mm with 20 dBm reader output power. With an inductive antenna printed on a paper substrate around the OCA tag, the reading range can be extended from several centimeters to meters, depending on the shape and size of the inductive antenna. (paper)

  7. Structural study of liquids with strong short-range correlation in the atomic distribution

    International Nuclear Information System (INIS)

    Uzuki, Kenji

    1976-01-01

    Structure factors of liquids and amorphous solids having a relatively high degree of ordering in their short-range structures have been measured over a wide range of scattering vectors by means of the T-O-F neutron diffraction using epithermal pulsed neutrons generated by an electron linear accelerator. It has been shown in the case of liquid CS 2 that the size and shape of a molecule existing in the liquid phase are determined from the behaviour of the structure factor in the range of high scattering vectors, and that the structure factor in the region of low scattering vectors informs on inter-molecular orientational and center-center correlations in the liquid state. Moreover, based on highly resoluted radial distribution functions, a free rotating chain model has been discussed for chain molecules contained in liquid Se, and a splitting of the nearest neighbour Pd-Pd and Pd-Si correlation has been clearly found in the amorphous Pdsub(0.8) - Sisub(0.2) alloy. (orig./HK) [de

  8. Short, intermediate and mesoscopic range order in sulfur-rich binary glasses

    International Nuclear Information System (INIS)

    Bychkov, E.; Miloshova, M.; Price, D.L.; Benmore, C.J.; Lorriaux, A.

    2006-01-01

    Pulsed neutron and high-energy X-ray diffraction, small-angle neutron scattering, Raman spectroscopy and DSC were used to study structural changes on the short, intermediate and mesoscopic range scale for sulfur-rich AsS x (x (ge) 1.5) and GeS x (x (ge) 2) glasses. Two structural regions were found in the both systems. (1) Between stoichiometric (As 2 S 3 and GeS 2 ) and 'saturated' (AsS 2.2 and GeS 2.7 ) compositions, excessive sulfur atoms form sulfur dimers and/or short chains, replacing bridging sulfur in corner-sharing AsS 3/2 and GeS 4/2 units. (2) Above the 'saturated' compositions at (As) x system) appear in the glass network. The glasses become phase separated with the domains of 20-50 (angstrom), presumably enriched with sulfur rings. The longer chains Sn are not stable and crystallize to c-S 8 on ageing of a few days to several months, depending on composition.

  9. Evidence for short range corelations from high Q2 (e,e') reactions

    International Nuclear Information System (INIS)

    Strikman, M.I.; Frankfurt, L.L.; Sargayan, M.M.

    1994-01-01

    For many years now short-range correlations (SRC) in nuclei have been considered as an essential feature of the nuclear wave function. At high energy (e,e') reactions, where Q 2 > 1 (GeV/c) 2 , x = Q 2 /2mq o > 1 and 1 GeV > q o > 300 ∼ 400 MeV the scattering from low momentum nucleons is kinematically suppressed and there the evidence of SRC expected to be more prominent. These reactions have been intensively investigated during the last decade or so at SLAC on both light and heavy nuclei. The above kinematics allows one to compute the cross section through the processes local in space. To explain this the authors analyse the representation of the cross section as a Fourier transform of the commutator of electromagnetic currents and see that the major contribution in the cross section is given by the region of integration

  10. Improving Short-Range Ensemble Kalman Storm Surge Forecasting Using Robust Adaptive Inflation

    KAUST Repository

    Altaf, Muhammad

    2013-08-01

    This paper presents a robust ensemble filtering methodology for storm surge forecasting based on the singular evolutive interpolated Kalman (SEIK) filter, which has been implemented in the framework of the H∞ filter. By design, an H∞ filter is more robust than the common Kalman filter in the sense that the estimation error in the H∞ filter has, in general, a finite growth rate with respect to the uncertainties in assimilation. The computational hydrodynamical model used in this study is the Advanced Circulation (ADCIRC) model. The authors assimilate data obtained from Hurricanes Katrina and Ike as test cases. The results clearly show that the H∞-based SEIK filter provides more accurate short-range forecasts of storm surge compared to recently reported data assimilation results resulting from the standard SEIK filter.

  11. Higher-order glass-transition singularities in systems with short-ranged attractive potentials

    International Nuclear Information System (INIS)

    Goetze, W; Sperl, M

    2003-01-01

    Within the mode-coupling theory for the evolution of structural relaxation, the A 4 -glass-transition singularities are identified for systems of particles interacting with a hard-sphere repulsion complemented by different short-ranged potentials: Baxter's singular potential regularized by a large-wavevector cut-off, a model for the Asakura-Oosawa depletion attraction, a triangular potential, a Yukawa attraction, and a square-well potential. The regular potentials yield critical packing fractions, critical Debye-Waller factors, and critical amplitudes very close to each other. The elastic moduli and the particle localization lengths for corresponding states of the Yukawa system and the square-well system may differ by up to 20 and 10%, respectively

  12. Mass dependence of short-range correlations in nuclei and the EMC effect

    Directory of Open Access Journals (Sweden)

    Cosyn Wim

    2014-03-01

    Full Text Available We sketch an approximate method to quantify the number of correlated pairs in any nucleus A. It is based on counting independent-particle model (IPM nucleon-nucleon pairs in a relative S-state with no radial excitation. We show that IPM pairs with those quantum numbers are most prone to short-range correlations and are at the origin of the high-momentum tail of the nuclear momentum distributions. Our method allows to compute the a2 ratios extracted from inclusive electron scattering. Furthermore, our results reproduce the observed linear correlation between the number of correlated pairs and the magnitude of the EMC effect. We show that the width of the pair center-ofmass distribution in exclusive two-nucleon knockout yields information on the quantum numbers of the pairs.

  13. Cellular Controlled Short-Range Communication for Cooperative P2P Networking

    DEFF Research Database (Denmark)

    Fitzek, Frank H. P.; Katz, Marcos; Zhang, Qi

    2009-01-01

    -range communication network among cooperating mobile and wireless devices. The role of the mobile device will change, from being an agnostic entity in respect to the surrounding world to a cognitive device. This cognitive device is capable of being aware of the neighboring devices as well as on the possibility......This article advocates a novel communication architecture and associated collaborative framework for future wireless communication systems. In contrast to the dominating cellular architecture and the upcoming peer-to-peer architecture, the new approach envisions a cellular controlled short...... to establish cooperation with them. The novel architecture together with several possible cooperative strategies will bring clear benefits for the network and service providers, mobile device manufacturers and also end users....

  14. Short-Range Electron Transfer in Reduced Flavodoxin: Ultrafast Nonequilibrium Dynamics Coupled with Protein Fluctuations.

    Science.gov (United States)

    Kundu, Mainak; He, Ting-Fang; Lu, Yangyi; Wang, Lijuan; Zhong, Dongping

    2018-05-03

    Short-range electron transfer (ET) in proteins is an ultrafast process on the similar timescales as local protein-solvent fluctuations thus the two dynamics are coupled. Here, we use semiquinone flavodoxin and systematically characterized the photoinduced redox cycle with eleven mutations of different aromatic electron donors (tryptophan and tyrosine) and local residues to change redox properties. We observed the forward and backward ET dynamics in a few picoseconds, strongly following a stretched behavior resulting from a coupling between local environment relaxations and these ET processes. We further observed the hot vibrational-state formation through charge recombination and the subsequent cooling dynamics also in a few picoseconds. Combined with the ET studies in oxidized flavodoxin, these results coherently reveal the evolution of the ET dynamics from single to stretched exponential behaviors and thus elucidate critical timescales for the coupling. The observed hot vibration-state formation is robust and should be considered in all photoinduced back ET processes in flavoproteins.

  15. The dependence of the nuclear charge form factor on short range correlations and surface fluctuation effects

    International Nuclear Information System (INIS)

    Massen, S. E.; Garistov, V. P.; Grypeos, M. E.

    1996-01-01

    The effects of nuclear surface fluctuations on harmonic oscillator elastic charge form factor of light nuclei are investigated, simultaneously approximating the short-range correlations through a Jastrow correlation factor. Inclusion of the surface fluctuation effects within this description, by truncating the cluster expansion at the two-body part, is found to improve somewhat the fit to the elastic charge form-factor of 16 O and 40 Ca. However, the convergence of the cluster expansion is expected to deteriorate. An additional finding is that surface-fluctuation correlations produce a drastic change in the asymptotic behaviour of the point-proton form-factor, which now falls off quite slowly (i.e. as const.q -4 ) at large values of the momentum transfer q

  16. Thermal algebraic-decay charge liquid driven by competing short-range Coulomb repulsion

    Science.gov (United States)

    Kaneko, Ryui; Nonomura, Yoshihiko; Kohno, Masanori

    2018-05-01

    We explore the possibility of a Berezinskii-Kosterlitz-Thouless-like critical phase for the charge degrees of freedom in the intermediate-temperature regime between the charge-ordered and disordered phases in two-dimensional systems with competing short-range Coulomb repulsion. As the simplest example, we investigate the extended Hubbard model with on-site and nearest-neighbor Coulomb interactions on a triangular lattice at half filling in the atomic limit by using a classical Monte Carlo method, and find a critical phase, characterized by algebraic decay of the charge correlation function, belonging to the universality class of the two-dimensional XY model with a Z6 anisotropy. Based on the results, we discuss possible conditions for the critical phase in materials.

  17. Interlayer exchange coupling in Er|Tb superlattices mediated by short range incommensurate Er order

    International Nuclear Information System (INIS)

    Pfuhl, E; Brueckel, T; Voigt, J; Mattauch, S; Korolkov, D

    2010-01-01

    We study the magnetic correlations in Er|Tb superlattices by means of off-specular scattering of polarized neutrons. We show here the co-existence of inhomogeneous magnetic states: i) ferromagnetic order of moments within the Tb layers below 230 K (FM), correlation length of about 10 bilayer, ii) an incommensurate modulated magnetic order, restricted to single Er layers and iii) antiferromagnetic coupling of ferromagnetic layers below 70K (AFC). Polarised off-specular neutron scattering under grazing incidence reveals that i) magnetic fluctuations appear when the sample is cooled below 70 K, ii) these fluctuations lead to AFC, when the sample is cooled to 10 K, which iii) persists, when the sample is subsequently heated up to 45 K, while the order is not present during the cooling cycle. Also the short range incommensurate order changes accordingly, implying that the magnetic order in the Er layers mediates the interlayer coupling between ferromagnetic Tb layers.

  18. Controlling Short-Range Interactions by Tuning Surface Chemistry in HDPE/Graphene Nanoribbon Nanocomposites.

    Science.gov (United States)

    Sadeghi, Soheil; Zehtab Yazdi, Alireza; Sundararaj, Uttandaraman

    2015-09-03

    Unique dispersion states of nanoparticles in polymeric matrices have the potential to create composites with enhanced mechanical, thermal, and electrical properties. The present work aims to determine the state of dispersion from the melt-state rheological behavior of nanocomposites based on carbon nanotube and graphene nanoribbon (GNR) nanomaterials. GNRs were synthesized from nitrogen-doped carbon nanotubes via a chemical route using potassium permanganate and some second acids. High-density polyethylene (HDPE)/GNR nanocomposite samples were then prepared through a solution mixing procedure. Different nanocomposite dispersion states were achieved using different GNR synthesis methods providing different surface chemistry, interparticle interactions, and internal compartments. Prolonged relaxation of flow induced molecular orientation was observed due to the presence of both carbon nanotubes and GNRs. Based on the results of this work, due to relatively weak interactions between the polymer and the nanofillers, it is expected that short-range interactions between nanofillers play the key role in the final dispersion state.

  19. Short-range structure and thermal properties of lead tellurite glasses

    Science.gov (United States)

    Hirdesh, Kaur, Amarjot; Khanna, Atul; Gonzàlez, Fernando

    2017-05-01

    PbO-TeO2 glasses having composition: xPbO-(100 - x)TeO2 (x = 10, 15 and 20 mol%) were prepared by melt quenching and characterized by X-ray diffraction, density measurements, differential scanning calorimetry and Raman spectroscopy. Glass density increases from 5.89 to 6.22 g cm-3 with increase in PbO concentration from 10 to 20 mol%, due to the replacement of TeO2 by heavier PbO. DSC studies found that glass transition temperature (Tg) decreases from a value of 295°C to 281°C. Raman studies found that glass short-range structure consists of TeO4 and TeO3 structural units and that PbO modifies the network by the structural transformation: TeO4 to TeO3.

  20. Short-range structure and thermal properties of barium tellurite glasses

    Science.gov (United States)

    Kaur, Amarjot; Khanna, Atul; Gonzàlez, Fernando

    2017-05-01

    BaO-TeO2 glasses containing 10 to 20 BaO mol% were prepared and characterized by X-ray diffraction, density measurements, differential scanning calorimetry and Raman spectroscopy. Glass density decreases with increase in BaO concentration from 10 to 20 mol%, due to replacement of heavier TeO2 by lighter BaO, however glass transition temperature (Tg) increases significantly from a value of 318°C to 327°C due to increase in average single bond enthalpy of the tellurite network. Raman studies found that glass short-range structure consists of TeO4 and TeO3 structural units and BaO modifies the network by producing the structural transformation: TeO4→ TeO3.

  1. Polarizable embedding with a multiconfiguration short-range density functional theory linear response method

    DEFF Research Database (Denmark)

    Hedegård, Erik D.; Olsen, Jógvan Magnus Haugaard; Knecht, Stefan

    2015-01-01

    . To demonstrate the capabilities of PE-MC-srDFT, we also investigated the retinylidene Schiff base chromophore embedded in the channelrhodopsin protein. While using a much more compact reference wave function in terms of active space, our PE-MC-srDFT approach yields excitation energies comparable in quality......We present here the coupling of a polarizable embedding (PE) model to the recently developed multiconfiguration short-range density functional theory method (MC-srDFT), which can treat multiconfigurational systems with a simultaneous account for dynamical and static correlation effects. PE......-MC-srDFT is designed to combine efficient treatment of complicated electronic structures with inclusion of effects from the surrounding environment. The environmental effects encompass classical electrostatic interactions as well as polarization of both the quantum region and the environment. Using response theory...

  2. Improving Short-Range Ensemble Kalman Storm Surge Forecasting Using Robust Adaptive Inflation

    KAUST Repository

    Altaf, Muhammad; Butler, T.; Luo, X.; Dawson, C.; Mayo, T.; Hoteit, Ibrahim

    2013-01-01

    This paper presents a robust ensemble filtering methodology for storm surge forecasting based on the singular evolutive interpolated Kalman (SEIK) filter, which has been implemented in the framework of the H∞ filter. By design, an H∞ filter is more robust than the common Kalman filter in the sense that the estimation error in the H∞ filter has, in general, a finite growth rate with respect to the uncertainties in assimilation. The computational hydrodynamical model used in this study is the Advanced Circulation (ADCIRC) model. The authors assimilate data obtained from Hurricanes Katrina and Ike as test cases. The results clearly show that the H∞-based SEIK filter provides more accurate short-range forecasts of storm surge compared to recently reported data assimilation results resulting from the standard SEIK filter.

  3. Utilizing Context in Location-Aware Short-Range Wireless Communication

    Directory of Open Access Journals (Sweden)

    Vesa A. Korhonen

    2010-01-01

    Full Text Available We discuss how a short-range wireless communication service implemented for modern mobile communication devices can provide additional value for both the consumer and the service/product provider. When used as an information search tool, such systems allow services and products being promoted at the location they are available. For the customer, it may provide a “digitally augmented vision”, an enhanced view to the current environment. With data filtering and search rules, this may provide a self-manageable context, where the user's own personal environment and preferences to the features available in the current surroundings cooperate with a direct connection to the web-based social media. A preliminary design for such service is provided. The conclusion is that the method can generate additional revenue to the company and please the customers' buying process. In addition to the marketing, the principles described here are also applicable to other forms of human interaction.

  4. 79 GHz UWB automotive short range radar – Spectrum allocation and technology trends

    Directory of Open Access Journals (Sweden)

    H.-L. Bloecher

    2009-05-01

    Full Text Available Automotive UWB (Ultra-Wideband short range radar (SSR is on the market as a key technology for novel comfort and safety systems. SiGe based 79 GHz UWB SRR will be a definite candidate for the long term substitution of the 24 GHz UWB SRR. This paper will give an overview of the finished BMBF joint project KOKON and the recently started successing project RoCC, which concentrate on the development of this technology and sensor demonstrators. In both projects, the responsibilities of Daimler AG deal with application based sensor specification, test and evaluation of realized sensor demonstrators. Recent UWB SRR frequency regulation approaches and activitites will be introduced. Furthermore, some first results of Daimler activities within RoCC will be presented, dealing with the packaging and operation of these sensors within the complex car environment.

  5. Short-range wakefields generated in the blowout regime of plasma-wakefield acceleration

    Science.gov (United States)

    Stupakov, G.

    2018-04-01

    In the past, calculation of wakefields generated by an electron bunch propagating in a plasma has been carried out in linear approximation, where the plasma perturbation can be assumed small and plasma equations of motion linearized. This approximation breaks down in the blowout regime where a high-density electron driver expels plasma electrons from its path and creates a cavity void of electrons in its wake. In this paper, we develop a technique that allows us to calculate short-range longitudinal and transverse wakes generated by a witness bunch being accelerated inside the cavity. Our results can be used for studies of the beam loading and the hosing instability of the witness bunch in plasma-wakefield and laser-wakefield acceleration.

  6. Multi-channel, passive, short-range anti-aircraft defence system

    Science.gov (United States)

    Gapiński, Daniel; Krzysztofik, Izabela; Koruba, Zbigniew

    2018-01-01

    The paper presents a novel method for tracking several air targets simultaneously. The developed concept concerns a multi-channel, passive, short-range anti-aircraft defence system based on the programmed selection of air targets and an algorithm of simultaneous synchronisation of several modified optical scanning seekers. The above system is supposed to facilitate simultaneous firing of several self-guided infrared rocket missiles at many different air targets. From the available information, it appears that, currently, there are no passive self-guided seekers that fulfil such tasks. This paper contains theoretical discussions and simulations of simultaneous detection and tracking of many air targets by mutually integrated seekers of several rocket missiles. The results of computer simulation research have been presented in a graphical form.

  7. Direct separation of short range order in intermixed nanocrystalline and amorphous phases

    International Nuclear Information System (INIS)

    Frenkel, Anatoly I.; Kolobov, Alexander V.; Robinson, Ian K.; Cross, Julie O.; Maeda, Yoshihito; Bouldin, Charles E.

    2002-01-01

    Diffraction anomalous fine-structure (DAFS) and extended x-ray absorption fine-structure (EXAFS) measurements were combined to determine short range order (SRO) about a single atomic type in a sample of mixed amorphous and nanocrystalline phases of germanium. EXAFS yields information about the SRO of all Ge atoms in the sample, while DAFS determines the SRO of only the ordered fraction. We determine that the first-shell distance distribution is bimodal; the nanocrystalline distance is the same as the bulk crystal, to within 0.01(2) A ring , but the mean amorphous Ge-Ge bond length is expanded by 0.076(19) Angstrom. This approach can be applied to many systems of mixed amorphous and nanocrystalline phases

  8. Contribution of silicon recombination properties in resolution of short-range particle detectors

    International Nuclear Information System (INIS)

    Verbitskaya, E.M.; Eremin, V.K.; Malyarenko, A.M.; Strokan, N.B.; Sukhanov, V.L.

    1987-01-01

    Tracks of short-range particles represent dense clusters of electron-hole pairs 2-4 μm in diameter and 20-30 μm long. Thus, conditions for charge carrier transport in microscopic Si volume are discovered at registration of each particle. Statistical distribution by the specimen square of the main parameter - lifetime of charge carriers (τ) is disclosed as a result of particle chaotic hitting the detector. Analytical description for the shape of the spectral line of the detector is found in the assumption of Gauss distribution τ. The function is applied to the analysis of detector spectra with maximum energy resolution, for which contributions to the shape of the line of the fundamental factors and nonperfection of Si or of the detector structure as a whole are comparable. Excess fluctuations of α-particle energy transformation to the charge of electron-hole pairs are found relatively to adopted values

  9. Contribution of silicon recombination properties in resolution of short-range particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Verbitskaya, E M; Eremin, V K; Malyarenko, A M; Strokan, N B; Sukhanov, V L

    1987-10-01

    Tracks of short-range particles represent dense clusters of electron-hole pairs 2-4 ..mu..m in diameter and 20-30 ..mu..m long. Thus, conditions for charge carrier transport in microscopic Si volume are discovered at registration of each particle. Statistical distribution by the specimen square of the main parameter - lifetime of charge carriers (tau) is disclosed as a result of particle chaotic hitting the detector. Analytical description for the shape of the spectral line of the detector is found in the assumption of Gauss distribution tau. The function is applied to the analysis of detector spectra with maximum energy resolution, for which contributions to the shape of the line of the fundamental factors and nonperfection of Si or of the detector structure as a whole are comparable. Excess fluctuations of ..cap alpha..-particle energy transformation to the charge of electron-hole pairs are found relatively to adopted values.

  10. Dependence of Coulomb Sum Rule on the Short Range Correlation by Using Av18 Potential

    Science.gov (United States)

    Modarres, M.; Moeini, H.; Moshfegh, H. R.

    The Coulomb sum rule (CSR) and structure factor are calculated for inelastic electron scattering from nuclear matter at zero and finite temperature in the nonrelativistic limit. The effect of short-range correlation (SRC) is presented by using lowest order constrained variational (LOCV) method and the Argonne Av18 and Δ-Reid soft-core potentials. The effects of different potentials as well as temperature are investigated. It is found that the nonrelativistic version of Bjorken scaling approximately sets in at the momentum transfer of about 1.1 to 1.2 GeV/c and the increase of temperature makes it to decrease. While different potentials do not significantly change CSR, the SRC improves the Coulomb sum rule and we get reasonably close results to both experimental data and others theoretical predictions.

  11. n-p Short-Range Correlations from (p,2p+n) Measurements

    Science.gov (United States)

    Tang, A.; Watson, J. W.; Aclander, J.; Alster, J.; Asryan, G.; Averichev, Y.; Barton, D.; Baturin, V.; Bukhtoyarova, N.; Carroll, A.; Gushue, S.; Heppelmann, S.; Leksanov, A.; Makdisi, Y.; Malki, A.; Minina, E.; Navon, I.; Nicholson, H.; Ogawa, A.; Panebratsev, Yu.; Piasetzky, E.; Schetkovsky, A.; Shimanskiy, S.; Zhalov, D.

    2003-01-01

    We studied the 12C(p,2p+n) reaction at beam momenta of 5.9, 8.0, and 9.0 GeV/c. For quasielastic (p,2p) events pf, the momentum of the knocked-out proton before the reaction, was compared (event by event) with pn, the coincident neutron momentum. For |pn|>kF=0.220 GeV/c (the Fermi momentum) a strong back-to-back directional correlation between pf and pn was observed, indicative of short-range n-p correlations. From pn and pf we constructed the distributions of c.m. and relative motion in the longitudinal direction for correlated pairs. We also determined that 49±13% of events with |pf|>kF had directionally correlated neutrons with |pn|>kF.

  12. Observation of short range three-particle correlations in e+e- annihilations at LEP energies

    CERN Document Server

    Abreu, P; Adye, T; Agasi, E; Ajinenko, I; Aleksan, Roy; Alekseev, G D; Allport, P P; Almehed, S; Alvsvaag, S J; Amaldi, Ugo; Amato, S; Andreazza, A; Andrieux, M L; Antilogus, P; Apel, W D; Arnoud, Y; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barate, R; Barbiellini, Guido; Bardin, Dimitri Yuri; Barker, G J; Baroncelli, A; Barrio, J A; Bartl, Walter; Barão, F; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Belous, K S; Benvenuti, Alberto C; Berggren, M; Bertrand, D; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bloch, D; Blume, M; Blyth, S; Bocci, V; Bolognese, T; Bonesini, M; Bonivento, W; Booth, P S L; Borisov, G; Bosio, C; Bosworth, S; Botner, O; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenner, R A; Bricman, C; Brillault, L; Brown, R C A; Brunet, J M; Brückman, P; Bugge, L; Buran, T; Buys, A; Bärring, O; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cankocak, K; Cao, F; Carena, F; Carrilho, P; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Cerrito, L; Chabaud, V; Charpentier, P; Chaussard, L; Chauveau, J; Checchia, P; Chelkov, G A; Chierici, R; Chochula, P; Chorowicz, V; Cindro, V; Collins, P; Contreras, J L; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; D'Almagne, B; Da Silva, W; Dahl-Jensen, Erik; Dahm, J; Dam, M; Damgaard, G; Daum, A; Dauncey, P D; Davenport, Martyn; De Angelis, A; De Boeck, H; De Brabandere, S; De Clercq, C; De Lotto, B; De Min, A; De Paula, L S; De Saint-Jean, C; Defoix, C; Della Ricca, G; Delpierre, P A; Demaria, N; Di Ciaccio, Lucia; Dijkstra, H; Djama, F; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Dufour, Y; Dupont, F; Dönszelmann, M; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Ershaidat, N; Erzen, B; Espirito-Santo, M C; Falk, E; Fassouliotis, D; Feindt, Michael; Fenyuk, A; Ferrer, A; Filippas-Tassos, A; Firestone, A; Fischer, P A; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frenkiel, P; Fries, D E C; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Föth, H; Fürstenau, H; Galloni, A; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gibbs, M; Gillespie, D; Gokieli, R; Golob, B; Gopal, Gian P; Gorn, L; Gracco, Valerio; Graziani, E; Grosdidier, G; Gunnarsson, P; Guy, J; Guz, Yu; Górski, M; Günther, M; Haedinger, U; Hahn, F; Hahn, M; Hahn, S; Hajduk, Z; Hallgren, A; Hamacher, K; Hao, W; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Higón, E; Hilke, Hans Jürgen; Hill, T S; Holmgren, S O; Holt, P J; Holthuizen, D J; Houlden, M A; Huet, K; Hultqvist, K; Ioannou, P; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Joram, Christian; Juillot, P; Jönsson, L B; Jönsson, P E; Kaiser, M; Kalmus, George Ernest; Kapusta, F; Karlsson, M; Karvelas, E; Katargin, A; Katsanevas, S; Katsoufis, E C; Keränen, R; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klein, H; Klovning, A; Kluit, P M; Kokkinias, P; Koratzinos, M; Kostyukhin, V; Kourkoumelis, C; Kramer, P H; Krammer, Manfred; Kreuter, C; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Królikowski, J; Kubinec, P; Kucewicz, W; Kurvinen, K L; Kuznetsov, O; Köhne, J H; Köne, B; La Vaissière, C de; Lacasta, C; Laktineh, I; Lamblot, S; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Lapin, V; Last, I; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leitner, R; Lemoigne, Y; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Liko, D; Lindner, R; Lipniacka, A; Lippi, I; Lokajícek, M; Loken, J G; Loukas, D; Lutz, P; Lyons, L; López, J M; López-Aguera, M A; López-Fernandez, A; Lörstad, B; MacNaughton, J N; Maehlum, G; Maio, A; Malychev, V; Mandl, F; Marco, J; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Maron, T; Martí i García, S; Martínez-Rivero, C; Martínez-Vidal, F; Maréchal, B; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; Medbo, J; Meroni, C; Meyer, W T; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Monge, M R; Morettini, P; Mundim, L M; Murray, W J; Muryn, B; Myagkov, A; Myatt, Gerald; Mönig, K; Møller, R; Müller, H; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Negri, P; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nieuwenhuizen, M; Nikolaenko, V; Niss, P; Nomerotski, A; Normand, Ainsley; Némécek, S; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Ouraou, A; Paganini, P; Paganoni, M; Pagès, P; Palka, H; Papadopoulou, T D; Pape, L; Parkes, C; Parodi, F; Passeri, A; Pegoraro, M; Peralta, L; Pernegger, H; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Plaszczynski, S; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Prest, M; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rames, J; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Renton, P B; Resvanis, L K; Richard, F; Richardson, J; Rinaudo, G; Ripp, I; Romero, A; Roncagliolo, I; Ronchese, P; Roos, L; Rosenberg, E I; Rosso, E; Roudeau, Patrick; Rovelli, T; Ruhlmann-Kleider, V; Ruiz, A; Rídky, J; Rückstuhl, W; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sannino, M; Schneider, H; Schyns, M A E; Sciolla, G; Scuri, F; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Shellard, R C; Siccama, I; Siegrist, P; Simonetti, S; Simonetto, F; Sissakian, A N; Sitár, B; Skaali, T B; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sokolov, A; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Squarcia, S; Stanescu, C; Stapnes, Steinar; Stavitski, I; Stepaniak, K; Stichelbaut, F; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Stäck, H; Szczekowski, M; Szeptycka, M; Sánchez, J; Tabarelli de Fatis, T; Tavernet, J P; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Toet, D Z; Tomaradze, A G; Tomé, B; Tortora, L; Tranströmer, G; Treille, D; Trischuk, W; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tyndel, M; Tzamarias, S; Ullaland, O; Valenti, G; Vallazza, E; Van Eldik, J; Van der Velde, C; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vlasov, E; Vodopyanov, A S; Vrba, V; Wahlen, H; Walck, C; Wehr, A; Weierstall, M; Weilhammer, Peter; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Woschnagg, K; Yip, K; Yushchenko, O P; Zach, F; Zacharatou-Jarlskog, C; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zito, M; Zontar, D; Zuberi, R; Zucchelli, G C; Zumerle, G; de Boer, Wim; van Apeldoorn, G W; van Dam, P; Åsman, B; Österberg, K; Überschär, B; Überschär, S

    1995-01-01

    \\def\\tpc{three-particle correlation} \\def\\twopc{two-particle correlation} Measurements are presented of short range three-particle correlations in e^+ e^- annihilations at LEP using data collected by the DELPHI detector. %The jet structure is studied using three-particle correlation functions. At small values of the four-momentum difference, strong three-particle correlations are observed for like-sign (+++ and ---) and for unlike-sign (++- and +--) pion combinations which are not a consequence of two-particle correlations. A possible explanation of the observed effects in like-sign combinations is the existence of higher order Bose-Einstein interference, which significantly changes the particle distributions in jets.

  13. Neutrino-Pair Exchange Long-Range Force Between Aggregate Matter

    OpenAIRE

    Segarra, A.

    2016-01-01

    We study the long-range force arising between two neutral---of electric charge---aggregates of matter due to a neutrino-pair exchange, in the limit of zero neutrino mass. The conceptual basis for the construction of the effective potential comes from the coherent scattering amplitude at low values of t. This amplitude is obtained using the methodology of an unsubtracted dispersion relation in t at threshold for s, where (s, t) are the Lorentz invariant scattering variables. The ultraviolet be...

  14. Development of a quartz tuning-fork-based force sensor for measurements in the tens of nanoNewton force range during nanomanipulation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Oiko, V. T. A., E-mail: oiko@ifi.unicamp.br; Rodrigues, V.; Ugarte, D. [Instituto de Física “Gleb Wataghin,” Univ. Estadual de Campinas (UNICAMP), Campinas 13083-859 (Brazil); Martins, B. V. C. [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada); Silva, P. C. [Laboratório Nacional de Nanotecnologia, CNPEM, Campinas 13083-970 (Brazil)

    2014-03-15

    Understanding the mechanical properties of nanoscale systems requires new experimental and theoretical tools. In particular, force sensors compatible with nanomechanical testing experiments and with sensitivity in the nN range are required. Here, we report the development and testing of a tuning-fork-based force sensor for in situ nanomanipulation experiments inside a scanning electron microscope. The sensor uses a very simple design for the electronics and it allows the direct and quantitative force measurement in the 1–100 nN force range. The sensor response is initially calibrated against a nN range force standard, as, for example, a calibrated Atomic Force Microscopy cantilever; subsequently, applied force values can be directly derived using only the electric signals generated by the tuning fork. Using a homemade nanomanipulator, the quantitative force sensor has been used to analyze the mechanical deformation of multi-walled carbon nanotube bundles, where we analyzed forces in the 5–40 nN range, measured with an error bar of a few nN.

  15. Searching for Short Range Correlations Using (e,e'NN) Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bin [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2003-02-01

    Electron induced two nucleon knockout reactions (e,e'pp) and (e,e'np) were performed for 3He, 4He, and 12C nuclei with incident energies of 2.261 GeV and 4.461 GeV using the CLAS detector at Jefferson Lab. Events with missing momenta lower than the Fermi level and missing energies smaller than the pion threshold were studied. The residual system was assumed to be a spectator and the process was considered as a quasi-free knockout of an NN pair. The data showed that the initial momentum extends up to 800 MeV/c with considerable strength. The cross sections for 3He(e,e'pp)n were compared to the calculations of J.M. Laget. It was found that the final state interactions (FSI) and the meson exchange currents (MEC) dominate the cross sections and the short range properties of the NN pair were substantially undermined. However, the node of the S state wave function of the pp pair at around 400 MeV/c initial momentum starts to be recognizable in the 4.461 GeV data. The data and the theory suggest that with higher momentum transfers, especially in the region xBj > 1, the competing processes such as FSI and MEC will be less important and the detailed study of the short-range properties of nucleons inside nuclei will be more desirable.

  16. Air defense planning for an area with the use of very short range air defense sets

    Directory of Open Access Journals (Sweden)

    Tadeusz Pietkiewicz

    2017-12-01

    Full Text Available This paper presents a heuristic method of planning the deployment of very short-range anti-air missile and artillery sets (VSHORAD around an area (‘protected area’ in order to protect it. A function dependent on the distance between the earliest feasible points of destroying targets and the centre of the protected area was taken as an objective function. This is a different indicator from those commonly used in the literature, and based on the likelihood of a defense zone penetration by means of an air attack (MAA: the kill probability of the MAA and the probability of area losses. The model constraints resulted directly from the restrictions imposed by real air defense systems and the nature of the area being defended. This paper assumes that the VSHORAD system operates as a part of a general, superordinate air defense command and control system based on the idea of network-centric warfare, which provides the VSHORAD system with a recognized air picture, air defense plans, and combat mission specifications. The presented method has been implemented. The final part of the paper presents the computational results. Keywords: optimal planning, air defense system, area installation protection, deployment of very short range anti-air missile and artillery sets (VSHORAD

  17. Effects of short range ΔN interaction on observables of the πNN system

    International Nuclear Information System (INIS)

    Alexandrou, C.; Blankleider, B.

    1990-01-01

    The inadequacy of standard few-body approaches in describing the πNN system has motivated searches for the responsible missing mechanism. In the case of πd scattering, it has recently been asserted that an additional short range ΔN interaction can account for essentially all the discrepancies between a few-body calculation and experimental data. This conclusion, however, has been based on calculations where a phenomenological ΔN interaction is added only in Born term to background few-body amplitudes. In the present work we investigate the effect of including such a ΔN interaction to all orders within a unitary few-body calculation of the πNN system. Besides testing the validity of adding the ΔN interaction in Born term in πd scattering, our fully coupled approach also enables us to see the influence of the same ΔN interaction on the processes NN→πd and NN→NN. For πd elastic scattering, we find that the higher order ΔN interaction terms can have as much influence on πd observables as the lowest order contribution alone. Moreover, we find that the higher order contributions tend to cancel the effect obtained by adding the ΔN interaction in Born term only. The effect of the same ΔN interaction on NN→πd and NN→NN appears to be as significant as in πd→πd, suggesting that future investigations of the short range ΔN interaction should be done in the context of the fully coupled πNN system

  18. Very-short range forecasting system for 2018 Pyeonchang Winter Olympic and Paralympic games

    Science.gov (United States)

    Nam, Ji-Eun; Park, Kyungjeen; Kim, Minyou; Kim, Changhwan; Joo, Sangwon

    2016-04-01

    The 23rd Olympic Winter and the 13th Paralympic Winter Games will be held in Pyeongchang, Republic of Korea respectively from 9 to 25 February 2018 and from 9 to 18 February 2018. The Korea Meteorological Administration (KMA) and the National Institute for Meteorological Science (NIMS) have the responsibility to provide weather information for the management of the Games and the safety of the public. NIMS will carry out a Forecast Demonstration Project (FDP) and a Research and Development Project (RDP) which will be called ICE-POP 2018. These projects will focus on intensive observation campaigns to understand severe winter weathers over the Pyeongchang region, and the research results from the RDP will be used to improve the accuracy of nowcasting and very short-range forecast systems during the Games. To support these projects, NIMS developed Very-short range Data Assimilation and Prediction System (VDAPS), which is run in real time with 1 hour cycling interval and up to 12 hour forecasts. The domain is covering Korean Peninsular and surrounding seas with 1.5km horizontal resolution. AWS, windprofiler, buoy, sonde, aircraft, scatwinds, and radar radial winds are assimilated by 3DVAR on 3km resolution inner domain. The rain rate is converted into latent heat and initialized via nudging. The visibility data are also assimilated with the addition of aerosol control variable. The experiments results show the improvement in rainfall over south sea of Korean peninsula. In order to reduce excessive rainfalls during first 2 hours due to the reduced cycling interval, the data assimilation algorithm is optimized.

  19. Bottom boundary layer forced by finite amplitude long and short surface waves motions

    Science.gov (United States)

    Elsafty, H.; Lynett, P.

    2018-04-01

    A multiple-scale perturbation approach is implemented to solve the Navier-Stokes equations while including bottom boundary layer effects under a single wave and under two interacting waves. In this approach, fluid velocities and the pressure field are decomposed into two components: a potential component and a rotational component. In this study, the two components are exist throughout the entire water column and each is scaled with appropriate length and time scales. A one-way coupling between the two components is implemented. The potential component is assumed to be known analytically or numerically a prior, and the rotational component is forced by the potential component. Through order of magnitude analysis, it is found that the leading-order coupling between the two components occurs through the vertical convective acceleration. It is shown that this coupling plays an important role in the bottom boundary layer behavior. Its effect on the results is discussed for different wave-forcing conditions: purely harmonic forcing and impurely harmonic forcing. The approach is then applied to derive the governing equations for the bottom boundary layer developed under two interacting wave motions. Both motions-the shorter and the longer wave-are decomposed into two components, potential and rotational, as it is done in the single wave. Test cases are presented wherein two different wave forcings are simulated: (1) two periodic oscillatory motions and (2) short waves interacting with a solitary wave. The analysis of the two periodic motions indicates that nonlinear effects in the rotational solution may be significant even though nonlinear effects are negligible in the potential forcing. The local differences in the rotational velocity due to the nonlinear vertical convection coupling term are found to be on the order of 30% of the maximum boundary layer velocity for the cases simulated in this paper. This difference is expected to increase with the increase in wave

  20. 33 CFR 334.640 - Gulf of Mexico south of Apalachee Bay, Fla.; Air Force rocket firing range.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Gulf of Mexico south of Apalachee Bay, Fla.; Air Force rocket firing range. 334.640 Section 334.640 Navigation and Navigable Waters... REGULATIONS § 334.640 Gulf of Mexico south of Apalachee Bay, Fla.; Air Force rocket firing range. (a) The...

  1. Short-Range Prediction of Monsoon Precipitation by NCMRWF Regional Unified Model with Explicit Convection

    Science.gov (United States)

    Mamgain, Ashu; Rajagopal, E. N.; Mitra, A. K.; Webster, S.

    2018-03-01

    There are increasing efforts towards the prediction of high-impact weather systems and understanding of related dynamical and physical processes. High-resolution numerical model simulations can be used directly to model the impact at fine-scale details. Improvement in forecast accuracy can help in disaster management planning and execution. National Centre for Medium Range Weather Forecasting (NCMRWF) has implemented high-resolution regional unified modeling system with explicit convection embedded within coarser resolution global model with parameterized convection. The models configurations are based on UK Met Office unified seamless modeling system. Recent land use/land cover data (2012-2013) obtained from Indian Space Research Organisation (ISRO) are also used in model simulations. Results based on short-range forecast of both the global and regional models over India for a month indicate that convection-permitting simulations by the high-resolution regional model is able to reduce the dry bias over southern parts of West Coast and monsoon trough zone with more intense rainfall mainly towards northern parts of monsoon trough zone. Regional model with explicit convection has significantly improved the phase of the diurnal cycle of rainfall as compared to the global model. Results from two monsoon depression cases during study period show substantial improvement in details of rainfall pattern. Many categories in rainfall defined for operational forecast purposes by Indian forecasters are also well represented in case of convection-permitting high-resolution simulations. For the statistics of number of days within a range of rain categories between `No-Rain' and `Heavy Rain', the regional model is outperforming the global model in all the ranges. In the very heavy and extremely heavy categories, the regional simulations show overestimation of rainfall days. Global model with parameterized convection have tendency to overestimate the light rainfall days and

  2. Interlot variations of transition temperature range and force delivery in copper-nickel-titanium orthodontic wires.

    Science.gov (United States)

    Pompei-Reynolds, Renée C; Kanavakis, Georgios

    2014-08-01

    The manufacturing process for copper-nickel-titanium archwires is technique sensitive. The primary aim of this investigation was to examine the interlot consistency of the mechanical properties of copper-nickel-titanium wires from 2 manufacturers. Wires of 2 sizes (0.016 and 0.016 × 0.022 in) and 3 advertised austenite finish temperatures (27°C, 35°C, and 40°C) from 2 manufacturers were tested for transition temperature ranges and force delivery using differential scanning calorimetry and the 3-point bend test, respectively. Variations of these properties were analyzed for statistical significance by calculating the F statistic for equality of variances for transition temperature and force delivery in each group of wires. All statistical analyses were performed at the 0.05 level of significance. Statistically significant interlot variations in austenite finish were found for the 0.016 in/27°C (P = 0.041) and 0.016 × 0.022 in/35°C (P = 0.048) wire categories, and in austenite start for the 0.016 × 0.022 in/35°C wire category (P = 0.01). In addition, significant variations in force delivery were found between the 2 manufacturers for the 0.016 in/27°C (P = 0.002), 0.016 in/35.0°C (P = 0.049), and 0.016 × 0.022 in/35°C (P = 0.031) wires. Orthodontic wires of the same material, dimension, and manufacturer but from different production lots do not always have similar mechanical properties. Clinicians should be aware that copper-nickel-titanium wires might not always deliver the expected force, even when they come from the same manufacturer, because of interlot variations in the performance of the material. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  3. Exploring flavor-dependent long-range forces in long-baseline neutrino oscillation experiments

    Science.gov (United States)

    Chatterjee, Sabya Sachi; Dasgupta, Arnab; Agarwalla, Sanjib Kumar

    2015-12-01

    The Standard Model gauge group can be extended with minimal matter content by introducing anomaly free U(1) symmetry, such as L e - L μ or L e - L τ . If the neutral gauge boson corresponding to this abelian symmetry is ultra-light, then it will give rise to flavor-dependent long-range leptonic force, which can have significant impact on neutrino oscillations. For an instance, the electrons inside the Sun can generate a flavor-dependent long-range potential at the Earth surface, which can suppress the ν μ → ν e appearance probability in terrestrial experiments. The sign of this potential is opposite for anti-neutrinos, and affects the oscillations of (anti-)neutrinos in different fashion. This feature invokes fake CP-asymmetry like the SM matter effect and can severely affect the leptonic CP-violation searches in long-baseline experiments. In this paper, we study in detail the possible impacts of these long-range flavor-diagonal neutral current interactions due to L e - L μ symmetry, when (anti-)neutrinos travel from Fermilab to Homestake (1300 km) and CERN to Pyhäsalmi (2290 km) in the context of future high-precision superbeam facilities, DUNE and LBNO respectively. If there is no signal of long-range force, DUNE (LBNO) can place stringent constraint on the effective gauge coupling α eμ < 1.9 × 10-53 (7.8 × 10-54) at 90% C.L., which is almost 30 (70) times better than the existing bound from the Super-Kamiokande experiment. We also observe that if α eμ ≥ 2 × 10-52, the CP-violation discovery reach of these future facilities vanishes completely. The mass hierarchy measurement remains robust in DUNE (LBNO) if α eμ < 5 × 10-52 (10-52).

  4. Long-range forces affecting equilibrium inertial focusing behavior in straight high aspect ratio microfluidic channels

    Energy Technology Data Exchange (ETDEWEB)

    Reece, Amy E.; Oakey, John, E-mail: joakey@uwyo.edu [Department of Chemical Engineering, University of Wyoming, Laramie, Wyoming 82071 (United States)

    2016-04-15

    The controlled and directed focusing of particles within flowing fluids is a problem of fundamental and technological significance. Microfluidic inertial focusing provides passive and precise lateral and longitudinal alignment of small particles without the need for external actuation or sheath fluid. The benefits of inertial focusing have quickly enabled the development of miniaturized flow cytometers, size-selective sorting devices, and other high-throughput particle screening tools. Straight channel inertial focusing device design requires knowledge of fluid properties and particle-channel size ratio. Equilibrium behavior of inertially focused particles has been extensively characterized and the constitutive phenomena described by scaling relationships for straight channels of square and rectangular cross section. In concentrated particle suspensions, however, long-range hydrodynamic repulsions give rise to complex particle ordering that, while interesting and potentially useful, can also dramatically diminish the technique’s effectiveness for high-throughput particle handling applications. We have empirically investigated particle focusing behavior within channels of increasing aspect ratio and have identified three scaling regimes that produce varying degrees of geometrical ordering between focused particles. To explore the limits of inertial particle focusing and identify the origins of these long-range interparticle forces, we have explored equilibrium focusing behavior as a function of channel geometry and particle concentration. Experimental results for highly concentrated particle solutions identify equilibrium thresholds for focusing that scale weakly with concentration and strongly with channel geometry. Balancing geometry mediated inertial forces with estimates for interparticle repulsive forces now provide a complete picture of pattern formation among concentrated inertially focused particles and enhance our understanding of the fundamental limits

  5. Performance analysis of dedicated short range communications technology and overview of the practicability for developing countries

    Directory of Open Access Journals (Sweden)

    Vandana Bassoo

    2015-12-01

    Full Text Available Vehicular communication is a widely researched field and aims at developing technologies that may complement systems such as the advanced driver assistance systems. It is therefore important to analyse and infer on the performance of vehicular technologies for different driving and on-road criteria. This study considers the dedicated short range communications technology and more precisely the IEEE 802.11p standard for a performance and practicability analysis. There is also the proposal of a new classification scheme for typical driving conditions, which includes the main categories of Emergency and Safety scenarios while sub-classifications of Critical and Preventive Safety also exist. The scheme is used to build up scenarios as well as related equations relevant to developing countries for practical network simulation. The results obtained indicate that the relative speed of nodes is a determining factor in the overall performance and effectiveness of wireless vehicular communication systems. Moreover, delay values of low order were observed while an effective communication range of about 800 m was calculated for highway scenarios. The research thus indicates suitability of the system for an active use in collision avoidance even though independent factors such as climatic conditions and driver behaviour may affect its effectiveness in critical situations.

  6. Monte Carlo simulation of atomic short range order and cluster formation in two dimensional model alloys

    International Nuclear Information System (INIS)

    Rojas T, J.; Instituto Peruano de Energia Nuclear, Lima; Manrique C, E.; Torres T, E.

    2002-01-01

    Using monte Carlo simulation have been carried out an atomistic description of the structure and ordering processes in the system Cu-Au in a two-dimensional model. The ABV model of the alloy is a system of N atoms A and B, located in rigid lattice with some vacant sites. In the model we assume pair wise interactions between nearest neighbors with constant ordering energy J = 0,03 eV. The dynamics was introduced by means of a vacancy that exchanges of place with any atom of its neighbors. The simulations were carried out in a square lattice with 1024 and 4096 particles, using periodic boundary conditions to avoid border effects. We calculate the first two parameters of short range order of Warren-Cowley as function of the concentration and temperature. It was also studied the probabilities of formation of different atomic clusters that consist of 9 atoms as function of the concentration of the alloy and temperatures in a wide range of values. In some regions of temperature and concentration it was observed compositional and thermal polymorphism

  7. Short-range second order screened exchange correction to RPA correlation energies

    Science.gov (United States)

    Beuerle, Matthias; Ochsenfeld, Christian

    2017-11-01

    Direct random phase approximation (RPA) correlation energies have become increasingly popular as a post-Kohn-Sham correction, due to significant improvements over DFT calculations for properties such as long-range dispersion effects, which are problematic in conventional density functional theory. On the other hand, RPA still has various weaknesses, such as unsatisfactory results for non-isogyric processes. This can in parts be attributed to the self-correlation present in RPA correlation energies, leading to significant self-interaction errors. Therefore a variety of schemes have been devised to include exchange in the calculation of RPA correlation energies in order to correct this shortcoming. One of the most popular RPA plus exchange schemes is the second order screened exchange (SOSEX) correction. RPA + SOSEX delivers more accurate absolute correlation energies and also improves upon RPA for non-isogyric processes. On the other hand, RPA + SOSEX barrier heights are worse than those obtained from plain RPA calculations. To combine the benefits of RPA correlation energies and the SOSEX correction, we introduce a short-range RPA + SOSEX correction. Proof of concept calculations and benchmarks showing the advantages of our method are presented.

  8. Short-range structure of barium tellurite glasses and its correlation with stress-optic response

    Science.gov (United States)

    Kaur, Amarjot; Khanna, Atul; Fábián, Margit

    2018-06-01

    The atomic parameters of metal ion-oxygen speciation such as bond-lengths and nearest neighbor distances for Ba-O, Te-O and O-O pairs, co-ordination numbers and bond angle distributions for O-Ba-O, O-Te-O and O-O-O linkages are determined by neutron diffraction and Reverse Monte Carlo simulations on the series of xBaO-(100-x)TeO2 glasses containing 10, 15 and 20 mol% BaO. The glass network depolymerizes and the average Te-O co-ordination number decreases from 3.60 ± 0.02 to 3.48 ± 0.02 with increase in BaO concentration. Te-O bond lengths are in the range: 1.97 ± 0.01–1.92 ± 0.01 Å. Ba2+ is mostly in octahedral coordination and the Ba-O bond lengths are in the range: 2.73 ± 0.01 to 2.76 ± 0.03 Å. Te-O co-ordination number is also determined by Raman spectroscopy and it shows good agreement with the neutron data. The short-range structural properties i.e. metal ion coordination number (Nc) and bond lengths (d) were correlated with the stress-optic response. The bonding characteristic, Br values were determined from the structural data of xBaO-(100-x)TeO2 glasses and were used to predict the stress-induced birefringence properties.

  9. Does an electronic continuum correction improve effective short-range ion-ion interactions in aqueous solution?

    Science.gov (United States)

    Bruce, Ellen E.; van der Vegt, Nico F. A.

    2018-06-01

    Non-polarizable force fields for hydrated ions not always accurately describe short-range ion-ion interactions, frequently leading to artificial ion clustering in bulk aqueous solutions. This can be avoided by adjusting the nonbonded anion-cation or cation-water Lennard-Jones parameters. This approach has been successfully applied to different systems, but the parameterization is demanding owing to the necessity of separate investigations of each ion pair. Alternatively, polarization effects may effectively be accounted for using the electronic continuum correction (ECC) of Leontyev et al. [J. Chem. Phys. 119, 8024 (2003)], which involves scaling the ionic charges with the inverse square-root of the water high-frequency dielectric permittivity. ECC has proven to perform well for monovalent salts as well as for divalent salts in water. Its performance, however, for multivalent salts with higher valency remains unexplored. The present work illustrates the applicability of the ECC model to trivalent K3PO4 and divalent K2HPO4 in water. We demonstrate that the ECC models, without additional tuning of force field parameters, provide an accurate description of water-mediated interactions between salt ions. This results in predictions of the osmotic coefficients of aqueous K3PO4 and K2HPO4 solutions in good agreement with experimental data. Analysis of ion pairing thermodynamics in terms of contact ion pair (CIP), solvent-separated ion pair, and double solvent-separated ion pair contributions shows that potassium-phosphate CIP formation is stronger with trivalent than with divalent phosphate ions.

  10. Potential of Mean Force between Ions Infinitely Diluted Simple Short-Range Models of Aqueous Electrolytes

    Czech Academy of Sciences Publication Activity Database

    Vlček, Lukáš; Nezbeda, Ivo

    2005-01-01

    Roč. 8, č. 2 (2005), s. 261-270 ISSN 1607-324X R&D Projects: GA ČR(CZ) GA203/02/0764 Institutional research plan: CEZ:AV0Z40720504 Keywords : aqueou selecrolytes * ssr model * primitive water Subject RIV: CF - Physical ; Theoretical Chemistry

  11. Ground reaction force and 3D biomechanical characteristics of walking in short-leg walkers.

    Science.gov (United States)

    Zhang, Songning; Clowers, Kurt G; Powell, Douglas

    2006-12-01

    Short-leg walking boots offer several advantages over traditional casts. However, their effects on ground reaction forces (GRF) and three-dimensional (3D) biomechanics are not fully understood. The purpose of the study was to examine 3D lower extremity kinematics and joint dynamics during walking in two different short-leg walking boots. Eleven (five females and six males) healthy subjects performed five level walking trials in each of three conditions: two testing boot conditions, Gait Walker (DeRoyal Industries, Inc.) and Equalizer (Royce Medical Co.), and one pair of laboratory shoes (Noveto, Adidas). A force platform and a 6-camera Vicon motion analysis system were used to collect GRFs and 3D kinematic data during the testing session. A one-way repeated measures analysis of variance (ANOVA) was used to evaluate selected kinematic, GRF, and joint kinetic variables (p<0.05). The results revealed that both short-leg walking boots were effective in minimizing ankle eversion and hip adduction. Neither walker increased the bimodal vertical GRF peaks typically observed in normal walking. However, they did impose a small initial peak (<1BW) earlier in the stance phase. The Gait Walker also exhibited a slightly increased vertical GRF during midstance. These characteristics may be related to the sole materials/design, the restriction of ankle movements, and/or the elevated heel heights of the tested walkers. Both walkers appeared to increase the demand on the knee extensors while they decreased the demand of the knee and hip abductors based on the joint kinetic results.

  12. Study of short range order in alloy of glassy metals and effect of neutron irradiation on them

    International Nuclear Information System (INIS)

    Habibi, S.; Banaee, N.; Salman, M.; Gupta, A.; Principi, G.

    2000-04-01

    In this paper, we have studied a series of glassy metals with composition Fe 78-x Ni x Si 8 B 14 with x=0, 15, 25,38,53, 58. We have used Moessbauer spectroscopy to get information about short range order and local structure in these alloys. The specimens are exposed to neutron irradiation to perturb local structure and their short range order. The hyperfine parameters obtained from spectra before and after n-irradiation and are compared

  13. Short range order of Mg-Cd-alloys during the transition from the solid to the molten state

    International Nuclear Information System (INIS)

    Boos, A.; Steeb, S.

    1977-01-01

    Recently a method was published for the determination of short range order parameters in binary melts and also a method for the determination of the concentration of different structures which form such a melt. These methods are used in the present work to evaluate the atomic structure of Mg-Cd-melts and to reval the changes in short range order during the melting process. (orig.) [de

  14. Detector with internal gain for short-wave infrared ranging applications

    Science.gov (United States)

    Fathipour, Vala; Mohseni, Hooman

    2017-09-01

    Abstarct.Highly sensitive photon detectors are regarded as the key enabling elements in many applications. Due to the low photon energy at the short-wave infrared (SWIR), photon detection and imaging at this band are very challenging. As such, many efforts in photon detector research are directed toward improving the performance of the photon detectors operating in this wavelength range. To solve these problems, we have developed an electron-injection (EI) technique. The significance of this detection mechanism is that it can provide both high efficiency and high sensitivity at room temperature, a condition that is very difficult to achieve in conventional SWIR detectors. An EI detector offers an overall system-level sensitivity enhancement due to a feedback stabilized internal avalanche-free gain. Devices exhibit an excess noise of unity, operate in linear mode, require bias voltage of a few volts, and have a cutoff wavelength of 1700 nm. We review the material system, operating principle, and development of EI detectors. The shortcomings of the first-generation devices were addressed in the second-generation detectors. Measurement on second-generation devices showed a high-speed response of ˜6 ns rise time, low jitter of less than 20 ps, high amplification of more than 2000 (at optical power levels larger than a few nW), unity excess noise factor, and low leakage current (amplified dark current ˜10 nA at a bias voltage of -3 V and at room temperature. These characteristics make EI detectors a good candidate for high-resolution flash light detection and ranging (LiDAR) applications with millimeter scale depth resolution at longer ranges compared with conventional p-i-n diodes. Based on our experimentally measured device characteristics, we compare the performance of the EI detector with commercially available linear mode InGaAs avalanche photodiode (APD) as well as a p-i-n diode using a theoretical model. Flash LiDAR images obtained by our model show that the EI

  15. Direct-Bandgap InAs Quantum-Dots Have Long-Range Electron--Hole Exchange Whereas Indirect Gap Si Dots Have Short-Range Exchange

    International Nuclear Information System (INIS)

    Juo, J.W.; Franceschetti, A.; Zunger, A.

    2009-01-01

    Excitons in quantum dots manifest a lower-energy spin-forbidden 'dark' state below a spin-allowed 'bright' state; this splitting originates from electron-hole (e-h) exchange interactions, which are strongly enhanced by quantum confinement. The e-h exchange interaction may have both a short-range and a long-range component. Calculating numerically the e-h exchange energies from atomistic pseudopotential wave functions, we show here that in direct-gap quantum dots (such as InAs) the e-h exchange interaction is dominated by the long-range component, whereas in indirect-gap quantum dots (such as Si) only the short-range component survives. As a result, the exciton dark/bright splitting scales as 1/R 2 in InAs dots and 1/R 3 in Si dots, where R is the quantum-dot radius.

  16. Long-Range Lightning Products for Short Term Forecasting of Tropical Cyclogenesis

    Science.gov (United States)

    Businger, S.; Pessi, A.; Robinson, T.; Stolz, D.

    2010-12-01

    This paper will describe innovative graphical products derived in real time from long-range lightning data. The products have been designed to aid in short-term forecasting of tropical cyclone development for the Tropical Cyclone Structure Experiment 2010 (TCS10) held over the western Pacific Ocean from 17 August to 17 October 2010 and are available online at http://www.soest.hawaii.edu/cgi-bin/pacnet/tcs10.pl. The long-range lightning data are from Vaisala’s Global Lightning Data 360 (GLD360) network and include time, location, current strength, polarity, and data quality indication. The products currently provided in real time include i. Infrared satellite imagery overlaid with lighting flash locations, with color indication of current strength and polarity (shades of blue for negative to ground and red for positive to ground). ii. A 15x15 degree storm-centered tile of IR imagery overlaid with lightning data as in i). iii. A pseudo reflectivity product showing estimates of radar reflectivity based on lightning rate - rain rate conversion derived from TRMM and PacNet data. iv. A lightning history product that plots each hour of lightning flash locations in a different color for a 12-hour period. v. Graphs of lightning counts within 50 or 300 km radius, respectively, of the storm center vs storm central sea-level pressure. vi. A 2-D graphic showing storm core lightning density along the storm track. The first three products above can be looped to gain a better understanding of the evolution of the lightning and storm structure. Examples of the graphics and their utility will be demonstrated and discussed. Histogram of lightning counts within 50 km of the storm center and graph of storm central pressure as a function of time.

  17. Adult mouse motor units develop almost all of their force in the subprimary range: a new all-or-none strategy for force recruitment?

    Science.gov (United States)

    Manuel, Marin; Heckman, C J

    2011-10-19

    Classical studies of the mammalian neuromuscular system have shown an impressive adaptation match between the intrinsic properties of motoneurons and the contractile properties of their motor units. In these studies, the rate at which motoneurons start to fire repetitively corresponds to the rate at which individual twitches start to sum, and the firing rate increases linearly with the amount of excitation ("primary range") up to the point where the motor unit develops its maximal force. This allows for the gradation of the force produced by a motor unit by rate modulation. In adult mouse motoneurons, however, we recently described a regime of firing ("subprimary range") that appears at lower excitation than what is required for the primary range, a finding that might challenge the classical conception. To investigate the force production of mouse motor units, we simultaneously recorded, for the first time, the motoneuron discharge elicited by intracellular ramps of current and the force developed by its motor unit. We showed that the motor unit developed nearly its maximal force during the subprimary range. This was found to be the case regardless of the input resistance of the motoneuron, the contraction speed, or the tetanic force of the motor unit. Our work suggests that force modulation in small mammals mainly relies on the number of motor units that are recruited rather than on rate modulation of individual motor units.

  18. Objectives for next generation of practical short-range atmospheric dispersion models

    International Nuclear Information System (INIS)

    Olesen, H.R.; Mikkelsen, T.

    1992-01-01

    The proceedings contains papers from the workshop ''Objectives for Next Generation of Practical Short-Range Atmospheric Dispersion Models''. They deal with two types of models, namely models for regulatory purposes and models for real-time applications. The workshop was the result of an action started in 1991 for increased cooperation and harmonization within atmospheric dispersion modelling. The focus of the workshop was on the management of model development and the definition of model objectives, rather than on detailed model contents. It was the intention to identify actions that can be taken in order to improve the development and use of atmospheric dispersion models. The papers in the proceedings deal with various topics within the broad spectrum of matters related to up-to-date practical models, such as their scientific basis, requirements for model input and output, meteorological preprocessing, standardisation within modelling, electronic information exchange as a potentially useful tool, model evaluation and data bases for model evaluation. In addition to the papers, the proceedings contain summaries of the discussions at the workshop. These summaries point to a number of recommended actions which can be taken in order to improve ''modelling culture''. (AB)

  19. Evidence for short range corelations from high Q{sup 2} (e,e{prime}) reactions

    Energy Technology Data Exchange (ETDEWEB)

    Strikman, M.I. [Pennsylvania State Univ., University Park, PA (United States); Frankfurt, L.L.; Sargayan, M.M. [Tel Aviv Univ. (Iceland)] [and others

    1994-04-01

    For many years now short-range correlations (SRC) in nuclei have been considered as an essential feature of the nuclear wave function. At high energy (e,e{prime}) reactions, where Q{sup 2} > 1 (GeV/c){sup 2}, x = Q{sup 2}/2mq{sub o} > 1 and 1 GeV > q{sub o}> 300 {approximately} 400 MeV the scattering from low momentum nucleons is kinematically suppressed and there the evidence of SRC expected to be more prominent. These reactions have been intensively investigated during the last decade or so at SLAC on both light and heavy nuclei. The above kinematics allows one to compute the cross section through the processes local in space. To explain this the authors analyse the representation of the cross section as a Fourier transform of the commutator of electromagnetic currents and see that the major contribution in the cross section is given by the region of integration.

  20. Dissipative NEGF methodology to treat short range Coulomb interaction: Current through a 1D nanostructure.

    Science.gov (United States)

    Martinez, Antonio; Barker, John R; Di Prieto, Riccardo

    2018-06-13

    A methodology describing Coulomb blockade in the Non-equilibrium Green Function formalism is presented. We carried out ballistic and dissipative simulations through a 1D quantum dot using an Einstein phonon model. Inelastic phonons with different energies have been considered. The methodology incorporates the short-range Coulomb interaction between two electrons through the use of a two-particle Green's function. Unlike previous work, the quantum dot has spatial resolution i.e. it is not just parameterized by the energy level and coupling constants of the dot. Our method intends to describe the effect of electron localization while maintaining an open boundary or extended wave function. The formalism conserves the current through the nanostructure. A simple 1D model is used to explain the increase of mobility in semi-crystalline polymers as a function of the electron concentration. The mechanism suggested is based on the lifting of energy levels into the transmission window as a result of the local electron-electron repulsion inside a crystalline domain. The results are aligned with recent experimental findings. Finally, as a proof of concept, we present a simulation of a low temperature resonant structure showing the stability diagram in the Coulomb blockade regime. . © 2018 IOP Publishing Ltd.

  1. Short-range order clustering in BCC Fe-Mn alloys induced by severe plastic deformation

    Science.gov (United States)

    Shabashov, V. A.; Kozlov, K. A.; Sagaradze, V. V.; Nikolaev, A. L.; Lyashkov, K. A.; Semyonkin, V. A.; Voronin, V. I.

    2018-03-01

    The effect of severe plastic deformation, namely, high-pressure torsion (HPT) at different temperatures and ball milling (BM) at different time intervals, has been investigated by means of Mössbauer spectroscopy in Fe100-xMnx (x = 4.1, 6.8, 9) alloys. Deformation affects the short-range clustering (SRC) in BCC lattice. Two processes occur: destruction of SRC by moving dislocations and enhancement of the SRC by migration of non-equilibrium defects. Destruction of SRC prevails during HPT at 80-293 K; whereas enhancement of SRC dominates at 473-573 K. BM starts enhancing the SRC formation at as low as 293 K due to local heating at impacts. The efficiency of HPT in terms of enhancing SRC increases with increasing temperature. The authors suppose that at low temperatures, a significant fraction of vacancies are excluded from enhancing SRC because of formation of mobile bi- and tri-vacancies having low efficiency of enhancing SRC as compared to that of mono vacancies. Milling of BCC Fe100-xMnx alloys stabilises the BCC phase with respect to α → γ transition at subsequent isothermal annealing because of a high degree of work hardening and formation of composition inhomogeneity.

  2. Probing short-range correlations in asymmetric nuclei with quasi-free pair knockout reactions

    Science.gov (United States)

    Stevens, Sam; Ryckebusch, Jan; Cosyn, Wim; Waets, Andreas

    2018-02-01

    Short-range correlations (SRC) in asymmetric nuclei with an unusual neutron-to-proton ratio can be studied with quasi-free two-nucleon knockout processes following the collision between accelerated ions and a proton target. We derive an approximate factorized cross section for those SRC-driven p (A ,p‧N1N2) reactions. Our reaction model hinges on the factorization properties of SRC-driven A (e ,e‧N1N2) reactions for which strong indications are found in theory-experiment comparisons. In order to put our model to the test we compare its predictions with results of 12C (p ,p‧ pn) measurements conducted at Brookhaven National Laboratory (BNL) and find a fair agreement. The model can also reproduce characteristic features of SRC-driven two-nucleon knockout reactions, like back-to-back emission of the correlated nucleons. We study the asymmetry dependence of nuclear SRC by providing predictions for the ratio of proton-proton to proton-neutron knockout cross sections for the carbon isotopes 9-15C thereby covering neutron excess values (N - Z) / Z between -0.5 and +0.5.

  3. Short-range ferromagnetism in alloy ribbons of Fe-Cr-Si-Nb-(Ag, Cu)

    Energy Technology Data Exchange (ETDEWEB)

    THANH, P. Q.; HOA, N. Q.; CHAU, N. [Vietnam National University, Hanoi (Viet Nam); HUU, C. X. [Danang University of Technology, Danang (Viet Nam); NGO, D. T. [Technical University of Denmark, Kgs. Lyngby (Denmark); PHAN, T. L. [Chungbuk National University, Cheongju (Korea, Republic of)

    2014-04-15

    We have studied the magnetic properties of two amorphous alloy ribbons Fe{sub 72}Cr{sub 6}Si{sub 4}Nb{sub 5}B{sub 12}Ag{sub 1} (FCSNB-Ag) and Fe{sub 72}Cr{sub 6}Si{sub 4}Nb{sub 5}B{sub 12}Cu{sub 1} (FCSNB-Cu), prepared by using a melt-spinning technique. Magnetization (M) measurements for various temperatures (T) and magnetic fields (H) indicate that ferromagnetic-paramagnetic (FM-PM) phase transitions take place in FCSNB-Ag and FCSNB-Cu at Curie temperatures (T{sub C} ) of about 308.3 K and 322.5 K, respectively. Analyses of M - H data at different temperatures in the vicinity of the FM-PM phase transition based on the modified Arrott plot method and scaling hypothesis yielded the exponent values of β = 0.369 ± 0.005, γ = 1.359 ± 0.005 and δ = 4.7 ± 0.1 for FCSNB-Ag, and β = 0.376 ± 0.002, γ = 1.315 ± 0.006 and δ = 4.5 ± 0.1 for FCSNB-Cu. Compared with the values from theoretical models, these values are close to those expected for the 3D Heisenberg model, demonstrating the existence of short-range FM order in the amorphous alloy ribbons.

  4. Meta-heuristic CRPS minimization for the calibration of short-range probabilistic forecasts

    Science.gov (United States)

    Mohammadi, Seyedeh Atefeh; Rahmani, Morteza; Azadi, Majid

    2016-08-01

    This paper deals with the probabilistic short-range temperature forecasts over synoptic meteorological stations across Iran using non-homogeneous Gaussian regression (NGR). NGR creates a Gaussian forecast probability density function (PDF) from the ensemble output. The mean of the normal predictive PDF is a bias-corrected weighted average of the ensemble members and its variance is a linear function of the raw ensemble variance. The coefficients for the mean and variance are estimated by minimizing the continuous ranked probability score (CRPS) during a training period. CRPS is a scoring rule for distributional forecasts. In the paper of Gneiting et al. (Mon Weather Rev 133:1098-1118, 2005), Broyden-Fletcher-Goldfarb-Shanno (BFGS) method is used to minimize the CRPS. Since BFGS is a conventional optimization method with its own limitations, we suggest using the particle swarm optimization (PSO), a robust meta-heuristic method, to minimize the CRPS. The ensemble prediction system used in this study consists of nine different configurations of the weather research and forecasting model for 48-h forecasts of temperature during autumn and winter 2011 and 2012. The probabilistic forecasts were evaluated using several common verification scores including Brier score, attribute diagram and rank histogram. Results show that both BFGS and PSO find the optimal solution and show the same evaluation scores, but PSO can do this with a feasible random first guess and much less computational complexity.

  5. Two-dimensional quasistatic stationary short range surface plasmons in flat nanoprisms.

    Science.gov (United States)

    Nelayah, J; Kociak, M; Stéphan, O; Geuquet, N; Henrard, L; García de Abajo, F J; Pastoriza-Santos, I; Liz-Marzán, L M; Colliex, C

    2010-03-10

    We report on the nanometer scale spectral imaging of surface plasmons within individual silver triangular nanoprisms by electron energy loss spectroscopy and on related discrete dipole approximation simulations. A dependence of the energy and intensity of the three detected modes as function of the edge length is clearly identified both experimentally and with simulations. We show that for experimentally available prisms (edge lengths ca. 70 to 300 nm) the energies and intensities of the different modes show a monotonic dependence as function of the aspect ratio of the prisms. For shorter or longer prisms, deviations to this behavior are identified thanks to simulations. These modes have symmetric charge distribution and result from the strong coupling of the upper and lower triangular surfaces. They also form a standing wave in the in-plane direction and are identified as quasistatic short range surface plasmons of different orders as emphasized within a continuum dielectric model. This model explains in simple terms the measured and simulated energy and intensity changes as function of geometric parameters. By providing a unified vision of surface plasmons in platelets, such a model should be useful for engineering of the optical properties of metallic nanoplatelets.

  6. Interplay between short-range correlated disorder and Coulomb interaction in nodal-line semimetals

    Science.gov (United States)

    Wang, Yuxuan; Nandkishore, Rahul M.

    2017-09-01

    In nodal-line semimetals, Coulomb interactions and short-range correlated disorder are both marginal perturbations to the clean noninteracting Hamiltonian. We analyze their interplay using a weak-coupling renormalization group approach. In the clean case, the Coulomb interaction has been found to be marginally irrelevant, leading to Fermi liquid behavior. We extend the analysis to incorporate the effects of disorder. The nodal line structure gives rise to kinematical constraints similar to that for a two-dimensional Fermi surface, which plays a crucial role in the one-loop renormalization of the disorder couplings. For a twofold degenerate nodal loop (Weyl loop), we show that disorder flows to strong coupling along a unique fixed trajectory in the space of symmetry inequivalent disorder couplings. Along this fixed trajectory, all symmetry inequivalent disorder strengths become equal. For a fourfold degenerate nodal loop (Dirac loop), disorder also flows to strong coupling, however, the strengths of symmetry inequivalent disorder couplings remain different. We show that feedback from disorder reverses the sign of the beta function for the Coulomb interaction, causing the Coulomb interaction to flow to strong coupling as well. However, the Coulomb interaction flows to strong coupling asymptotically more slowly than disorder. Extrapolating our results to strong coupling, we conjecture that at low energies nodal line semimetals should be described by a noninteracting nonlinear sigma model. We discuss the relation of our results with possible many-body localization at zero temperatures in such materials.

  7. Short-range order studies in nonstoichiometric transition metal carbides and nitrides by neutron diffuse scattering

    International Nuclear Information System (INIS)

    Priem, Thierry

    1988-01-01

    Short-range order in non-stoichiometric transition metal carbides and nitrides (TiN 0.82 , TiC 0.64 , TiC 0.76 , NbC 0.73 and NbC 0.83 ) was investigated by thermal neutron diffuse scattering on G4-4 (L.L.B - Saclay) and D10 (I.L.L. Grenoble) spectrometers. From experimental measurements, we have found that metalloid vacancies (carbon or nitrogen) prefer the f.c.c. third neighbour positions. Ordering interaction energies were calculated within the Ising model framework by three approximations: mean field (Clapp and Moss formula), Monte-Carlo simulation, Cluster variation Method. The energies obtained by the two latter methods are very close, and in qualitative agreement with theoretical values calculated from the band structure. Theoretical phase diagrams were calculated from these ordering energies for TiN x and TiC x ; three ordered structures were predicted, corresponding to compositions Ti 6 N 5 Ti 2 C and Ti 3 C 2 . On the other hand, atomic displacements are induced by vacancies. The metal first neighbours were found to move away from a vacancy, whereas the second neighbours move close to it. Near neighbour atomic displacements were theoretically determined by the lattice statics formalism with results in good agreement with experiment. (author) [fr

  8. A model for short and medium range dispersion of radionuclides released to the atmosphere

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1979-09-01

    A Working Group was established to give practical guidance on the estimation of the dispersion of radioactive releases to the atmosphere. The dispersion is estimated in the short and medium range, that is from about 100 m to a few tens of kilometres from the source, and is based upon a Gaussian plume model. A scheme is presented for categorising atmospheric conditions and values of the associated dispersion parameters are given. Typical results are presented for releases in specific meteorological conditions and a scheme is included to allow for durations of release of up to 24 hours. Consideration has also been given to predicting longer term average concentrations, typically annual averages, and results are presented which facilitate site specific calculations. The results of the models are extended to 100 km from the source, but the increasing uncertainty with which results may be predicted beyond a few tens of kilometres from the source is emphasised. Three technical appendices provide some of the rationale behind the decisions made in adopting the various models in the proposed dispersion scheme. (author)

  9. Demonstration of micro-projection enabled short-range communication system for 5G.

    Science.gov (United States)

    Chou, Hsi-Hsir; Tsai, Cheng-Yu

    2016-06-13

    A liquid crystal on silicon (LCoS) based polarization modulated image (PMI) system architecture using red-, green- and blue-based light-emitting diodes (LEDs), which offers simultaneous micro-projection and high-speed data transmission at nearly a gigabit, serving as an alternative short-range communication (SRC) approach for personal communication device (PCD) application in 5G, is proposed and experimentally demonstrated. In order to make the proposed system architecture transparent to the future possible wireless data modulation format, baseband modulation schemes such as multilevel pulse amplitude modulation (M-PAM), M-ary phase shift keying modulation (M-PSK) and M-ary quadrature amplitude modulation (M-QAM) which can be further employed by more advanced multicarrier modulation schemes (such as DMT, OFDM and CAP) were used to investigate the highest possible data transmission rate of the proposed system architecture. The results demonstrated that an aggregative data transmission rate of 892 Mb/s and 900 Mb/s at a BER of 10^(-3) can be achieved by using 16-QAM baseband modulation scheme when data transmission were performed with and without micro-projection simultaneously.

  10. Large magnetoelectric coupling in magnetically short-range ordered Bi₅Ti₃FeO₁₅ film.

    Science.gov (United States)

    Zhao, Hongyang; Kimura, Hideo; Cheng, Zhenxiang; Osada, Minoru; Wang, Jianli; Wang, Xiaolin; Dou, Shixue; Liu, Yan; Yu, Jianding; Matsumoto, Takao; Tohei, Tetsuya; Shibata, Naoya; Ikuhara, Yuichi

    2014-06-11

    Multiferroic materials, which offer the possibility of manipulating the magnetic state by an electric field or vice versa, are of great current interest. However, single-phase materials with such cross-coupling properties at room temperature exist rarely in nature; new design of nano-engineered thin films with a strong magneto-electric coupling is a fundamental challenge. Here we demonstrate a robust room-temperature magneto-electric coupling in a bismuth-layer-structured ferroelectric Bi₅Ti₃FeO₁₅ with high ferroelectric Curie temperature of ~1000 K. Bi₅Ti₃FeO₁₅ thin films grown by pulsed laser deposition are single-phase layered perovskit with nearly (00l)-orientation. Room-temperature multiferroic behavior is demonstrated by a large modulation in magneto-polarization and magneto-dielectric responses. Local structural characterizations by transmission electron microscopy and Mössbauer spectroscopy reveal the existence of Fe-rich nanodomains, which cause a short-range magnetic ordering at ~620 K. In Bi₅Ti₃FeO₁₅ with a stable ferroelectric order, the spin canting of magnetic-ion-based nanodomains via the Dzyaloshinskii-Moriya interaction might yield a robust magneto-electric coupling of ~400 mV/Oe·cm even at room temperature.

  11. Short-Range-Order for fcc-based Binary Alloys Revisited from Microscopic Geometry

    Science.gov (United States)

    Yuge, Koretaka

    2018-04-01

    Short-range order (SRO) in disordered alloys is typically interpreted as competition between chemical effect of negative (or positive) energy gain by mixing constituent elements and geometric effects comes from difference in effective atomic radius. Although we have a number of theoretical approaches to quantitatively estimate SRO at given temperatures, it is still unclear to systematically understand trends in SRO for binary alloys in terms of geometric character, e.g., effective atomic radius for constituents. Since chemical effect plays significant role on SRO, it has been believed that purely geometric character cannot capture the SRO trends. Despite these considerations, based on the density functional theory (DFT) calculations on fcc-based 28 equiatomic binary alloys, we find that while conventional Goldschmidt or DFT-based atomic radius for constituents have no significant correlation with SRO, atomic radius for specially selected structure, constructed purely from information about underlying lattice, can successfully capture the magnitude of SRO. These facts strongly indicate that purely geometric information of the system plays central role to determine characteristic disordered structure.

  12. Electronic structure of disordered binary alloys with short range correlation in Bethe lattice

    International Nuclear Information System (INIS)

    Moreno, I.F.

    1987-01-01

    The determination of the electronic structure of a disordered material along the tight-binding model when applied to a Bethe lattice. The diagonal as well as off-diagonal disorder, are considered. The coordination number on the Bethe is fixed lattice to four (Z=4) that occurs in most compound semiconductors. The main proposal was to study the conditions under which a relatively simple model of a disordered material, i.e, a binary alloy, could account for the basic properties of transport or more specifically for the electronic states in such systems. By using a parametrization of the pair probability the behaviour of the electronic density of states (DOS) for different values of the short range order parameter, σ, which makes possible to treat the segregated, random and alternating cases, was analysed. In solving the problem via the Green function technique in the Wannier representation a linear chain of atoms was considered and using the solution of such a 1-D system the problem of the Bethe lattice which is constructed using such renormalized chains as elements, was solved. The results indicate that the obtained DOS are strongly dependent on the correlation assumed for the occupancy in the lattice. (author) [pt

  13. Short-range order analysis and some physical properties of InxSe1-x glasses

    International Nuclear Information System (INIS)

    El-Kabany, N.

    2012-01-01

    Bulk In x Se 1-x (with x=5-25 at%) glasses were prepared using the melt-quench technique. Short range order(SRO) was examined by the X-ray diffraction using Cu(k α ) radiation in the wave vector interval 0.28≤k≤6.5 A 0-1 .The SRO parameters have been obtained from the radial distribution function. The inter-atomic distance obtained from the first and second peak are r 1 =0.263 and r 2 =0.460 nm, which is equivalent In-Se and Se-Se bond length. The fundamental structural unit for the studied glasses is In 2 Se 3 pyramid. Using the differential scanning calorimetry (DSC), the crystallization mechanism of In x Se 1-x chalcogenide glass has been studied. The glass transition activation energy (E g ) is 289±0.3 kj/mol.There is a correlation amongst the glass forming ability, bond strength and the number of lone pair electrons. The utility of the Gibbs-Di Marzio relation was achieved by estimating T g theoretically.

  14. Measurement of transparency ratios for protons from short-range correlated pairs

    Science.gov (United States)

    Hen, O.; Hakobyan, H.; Shneor, R.; Piasetzky, E.; Weinstein, L. B.; Brooks, W. K.; May-Tal Beck, S.; Gilad, S.; Korover, I.; Beck, A.; Adhikari, K. P.; Aghasyan, M.; Amaryan, M. J.; Anefalos Pereira, S.; Arrington, J. R.; Baghdasaryan, H.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Bono, J.; Boiarinov, S.; Briscoe, W. J.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Cole, P. L.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dodge, G. E.; Doughty, D.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fleming, J. A.; Gabrielyan, M. Y.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guo, L.; Hafidi, K.; Harrison, N.; Heddle, D.; Hicks, K.; Holtrop, M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joo, K.; Keller, D.; Khandaker, M.; Khetarpal, P.; Kim, A.; Klein, F. J.; Koirala, S.; Kubarovsky, A.; Kubarovsky, V.; Kuhn, S. E.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Martinez, D.; Mayer, M.; McKinnon, B.; Mineeva, T.; Mokeev, V.; Montgomery, R. A.; Moutarde, H.; Munevar, E.; Munoz Camacho, C.; Mustapha, B.; Nadel-Turonski, P.; Nasseripour, R.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Pappalardo, L. L.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Phelps, E.; Phillips, J. J.; Pisano, S.; Pivnyuk, N.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Protopopescu, D.; Puckett, A. J. R.; Raue, B. A.; Rimal, D.; Ripani, M.; Ritchie, B. G.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Schott, D.; Schumacher, R. A.; Seraydaryan, H.; Sharabian, Y. G.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stepanyan, S.; Strauch, S.; Taiuti, M.; Tang, W.; Taylor, C. E.; Tian, Ye; Tkachenko, S.; Ungaro, M.; Vernarsky, B.; Vlassov, A.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zheng, X.; Zonta, I.

    2013-05-01

    Nuclear transparency, Tp (A), is a measure of the average probability for a struck proton to escape the nucleus without significant re-interaction. Previously, nuclear transparencies were extracted for quasi-elastic A (e ,e‧ p) knockout of protons with momentum below the Fermi momentum, where the spectral functions are well known. In this Letter we extract a novel observable, the transparency ratio, Tp (A) /Tp(12 C), for knockout of high-missing-momentum protons from the breakup of short-range correlated pairs (2N-SRC) in Al, Fe and Pb nuclei relative to C. The ratios were measured at momentum transfer Q2 ⩾ 1.5(GeV /c) 2 and xB ⩾ 1.2 where the reaction is expected to be dominated by electron scattering from 2N-SRC. The transparency ratios of the knocked-out protons coming from 2N-SRC breakup are 20-30% lower than those of previous results for low missing momentum. They agree with Glauber calculations and agree with renormalization of the previously published transparencies as proposed by recent theoretical investigations. The new transparencies scale as A - 1 / 3, which is consistent with dominance of scattering from nucleons at the nuclear surface.

  15. Zero mass field quantization and Kibble's long-range force criterion for the Goldstone theorem

    International Nuclear Information System (INIS)

    Wright, S.H.

    1981-01-01

    The central theme of the dissertation is an investigation of the long-range force criterion used by Kibble in his discussion of the Goldstone Theorem. This investigation is broken up into the following sections: I. Introduction. Spontaneous symmetry breaking, the Goldstone Theorem and the conditions under which it holds are discussed. II. Massless Wave Expansions. In order to make explicit calculations of the operator commutators used in applying Kibble's criterion, it is necessary to work out the operator expansions for a massless field. Unusual results are obtained which include operators corresponding to classical macroscopic field modes. III. The Kibble Criterion for Simple Models Exhibiting Spontaneously Broken Symmetries. The results of the previous section are applied to simple models with spontaneously broken symmetries, namely, the real scalar massless field and the Goldstone model without gauge coupling. IV. The Higgs Mechanism in Classical Field Theory. It is shown that the Higgs Mechanism has a simple interpretation in terms of classical field theory, namely, that it arises from a derivative coupling term between the Goldstone fields and the gauge fields. V. The Higgs Mechanism and Kibble's Criterion. This section draws together the material discussed in sections II to IV. Explicit calculations are made to evaluate Kibble's criterion on a Goldstone-Higgs type of model in the Coulomb gauge. It is found, as expected, that the criterion is not met, but not for reasons relating to the range of the mediating force. By referring to the findings of sections III and IV, it is concluded that the common denominator underlying both the Higgs Mechanism and the failure of Kibble's criterion is a structural aspect of the field equations: derivative coupling between fields

  16. Protein adsorption on tailored substrates: long-range forces and conformational changes

    Energy Technology Data Exchange (ETDEWEB)

    Bellion, M; Santen, L [Department of Theoretical Physics, Saarland University, 66041 Saarbruecken (Germany); Mantz, H; Haehl, H; Quinn, A; Nagel, A; Gilow, C; Weitenberg, C; Schmitt, Y; Jacobs, K [Department of Experimental Physics, Saarland University, 66041 Saarbruecken (Germany)], E-mail: k.jacobs@physik.uni-saarland.de

    2008-10-08

    Adsorption of proteins onto solid surfaces is an everyday phenomenon that is not yet fully understood. To further the current understanding, we have performed in situ ellipsometry studies to reveal the adsorption kinetics of three different proteins, lysozyme, {alpha}-amylase and bovine serum albumin. As substrates we offer Si wafers with a controlled Si oxide layer thickness and a hydrophilic or hydrophobic surface functionalization, allowing the tailoring of the influence of short- and long-range interactions. Our studies show that not only the surface chemistry determines the properties of an adsorbed protein layer but also the van der Waals contributions of a composite substrate. We compare the experimental findings to results of a colloidal Monte Carlo approach that includes conformational changes of the adsorbed proteins induced by density fluctuations.

  17. German writers and the Intermediate-range Nuclear Forces debate in the 1980s

    International Nuclear Information System (INIS)

    Stokes, A.M.

    1991-01-01

    In 1979, NATO announced its decision to deploy American intermediate-range nuclear missiles throughout Western Europe. From then until 1987, when the historic Intermediate-range Nuclear forces (INF) treaty provided for the withdrawal of these weapons as well as those deployed by the Soviets in Eastern Europe, the issue of nuclear weapons preoccupied many Europeans, particularly Germans. Beginning in 1980, fear of nuclear war, with the two Germanies as a potential battlefield, mobilized the largest peace movement that the Federal Republic had witnessed since the fifties, occasioned a massive increase in peace propaganda in East Germany, and brought to public notice that country's first unofficial peace movement. Throughout most of the eighties, writers in both German states opposed missile deployment. This study examines their aims and achievements in this effort and investigates the implications of political engagement for the aesthetic production of selected authors. Analysis of press reports, writers' speeches, interviews, essays and literary texts yielded the following results: INF deployment motivated writers of all political persuasions to take up a variety of peace-oriented pursuits

  18. Short-Range-Order Mineral Physical Protection On Black Carbon Stabilization

    Science.gov (United States)

    Liang, B.; Weng, Y. T.; Wang, C. C.; Song, Y. F.; Lehmann, J.; Wang, C. H.

    2015-12-01

    Soil organic matter is one of the largest reservoirs in global carbon cycle, and black carbon (BC) represents a chemical resistant component. Black C plays an important role in global climate change. Generally considered recalcitrant due to high aromaticity, the reactive surface and functional groups of BC are crucial for carbon sequestration in soils. Mineral sorption and physical protection is an important mechanism for BC long term stabilization and sequestration in environments. Previous studies on mineral protection of BC were limited to analysis techniques in two-dimensions, for example, by SEM, TEM, and NanoSIMS. Little is known about the scope of organo-mineral association, the in-situ distribution and forms of minerals, and the ultimate interplay of BC and minerals. The aim of this study is to investigate the three-dimensional interaction of organic C and minerals in submicron scale using synchrotron-based Transmission X-ray Microcopy (TXM) and Fourier-Transform Infrared Spectroscopy (FTIR). Abundant poorly-crystallined nano-minerals particles were observed. These short-range-order (SRO) minerals also aggregate into clusters and sheets, and form envelops-like structures on the surface of BC. On top of large surface contact area, the intimate interplay between BC and minerals reinforces the stability of both organic C and minerals, resulting from chemical bonding through cation bridging and ligand exchange. The mineral protection enhances BC stabilization and sequestration and lowers its bioavailability in environment. The results suggest that mineral physical protection for BC sequestration may be more important than previous understanding.

  19. 2D fluorescence spectra measurement of six kinds of bioagents simulants by short range Lidar

    Science.gov (United States)

    Sanpedro, Man

    2018-02-01

    Pantoea agglomerans (Pan), Staphylococcus aureus (Sta), Bacillus globigii (BG) and Escherichia coli (EH), these four kinds of bioagents simulants of were cultured and then their growth curves were measured, the generation time was 0.99h, 0.835h, 1.07h and 1.909h, respectively. A small short range fluorescence lidar working at wavelengths of 266nm and 355nm was designed and used to measure the two-dimensional fluorescence spectra of bioagents simulants in the amino acid segment and NADH segment, respectively. In a controllable fluorescence measurement chamber, the two-dimensional fluorescence spectra of vegetative liquid bacterial aerosols as well as BSA and OVA, two protein toxinic simulants were measured with a resolution of 4nm. The two-dimensional fluorescence spectral shape of Pan, Sta, EH and BG, BSA and OVA were consistent with the standard fluorescent component tryptophan in the amino acid band with FWHM of 60nm, but the central wavelength of the fluorescence spectra of these simulants blue/purple shifted obviously as affected by the external biochemical environment, concentration and ratio of different bacterial internal fluorophores, so the energy level between the excited state and the ground state of the fluorescence molecule increased. Differently, weak NADH fluorescence spectra with 100nm FWHM inside the four vegetative bacteria aerosols were detected, but Rayleigh scattering, Raman scattering contribution of water, nitrogen in the fluorescence spectra could not be effectively extracted. The second - order derivative fluorescence spectra of four simulants showed that the high - order processing and recognition of the fluorescence spectra was feasible.

  20. Fungal biomineralization of montmorillonite and goethite to short-range-ordered minerals

    Science.gov (United States)

    Li, Huan; Hu, Shuijin; Polizzotto, Matthew L.; Chang, Xiaoli; Shen, Qirong; Ran, Wei; Yu, Guanghui

    2016-10-01

    Highly reactive nano-scale minerals, e.g., short-range-ordered minerals (SROs) and other nanoparticles, play an important role in soil carbon (C) retention. Yet, the mechanisms that govern biomineralization from bulk minerals to highly reactive nano-scale minerals remain largely unexplored, which critically hinders our efforts toward managing nano-scale minerals for soil C retention. Here we report the results from a study that explores structural changes during Aspergillus fumigatus Z5 transformation of montmorillonite and goethite to SROs. We examined the morphology and structure of nano-scale minerals, using high-resolution transmission electron microscopy, time-resolved solid-state 27Al and 29Si NMR, and Fe K-edge X-ray absorption fine structure spectroscopy combined with two dimensional correlation spectroscopy (2D COS) analysis. Our results showed that after a 48-h cultivation of montmorillonite and goethite with Z5, new biogenic intracellular and extracellular reactive nano-scale minerals with a size of 3-5 nm became abundant. Analysis of 2D COS further suggested that montmorillonite and goethite were the precursors of the dominant biogenic nano-scale minerals. Carbon 1s near edge X-ray absorption fine structure (NEXAFS) spectra and their deconvolution results demonstrated that during fungus Z5 growth, carboxylic C (288.4-289.1 eV) was the dominant organic group, accounting for approximately 34% and 59% in the medium and aggregates, respectively. This result suggested that high percentage of the production of organic acids during the growth of Z5 was the driving factor for structural changes during biomineralization. This is, to the best of our knowledge, the first report of the structural characterization of nano-scale minerals by 2D COS, highlighting its potential to elucidate biomineralization pathways and thus identify the precursors of nano-scale minerals.

  1. Limited-area short-range ensemble predictions targeted for heavy rain in Europe

    Directory of Open Access Journals (Sweden)

    K. Sattler

    2005-01-01

    Full Text Available Inherent uncertainties in short-range quantitative precipitation forecasts (QPF from the high-resolution, limited-area numerical weather prediction model DMI-HIRLAM (LAM are addressed using two different approaches to creating a small ensemble of LAM simulations, with focus on prediction of extreme rainfall events over European river basins. The first ensemble type is designed to represent uncertainty in the atmospheric state of the initial condition and at the lateral LAM boundaries. The global ensemble prediction system (EPS from ECMWF serves as host model to the LAM and provides the state perturbations, from which a small set of significant members is selected. The significance is estimated on the basis of accumulated precipitation over a target area of interest, which contains the river basin(s under consideration. The selected members provide the initial and boundary data for the ensemble integration in the LAM. A second ensemble approach tries to address a portion of the model-inherent uncertainty responsible for errors in the forecasted precipitation field by utilising different parameterisation schemes for condensation and convection in the LAM. Three periods around historical heavy rain events that caused or contributed to disastrous river flooding in Europe are used to study the performance of the LAM ensemble designs. The three cases exhibit different dynamic and synoptic characteristics and provide an indication of the ensemble qualities in different weather situations. Precipitation analyses from the Deutsche Wetterdienst (DWD are used as the verifying reference and a comparison of daily rainfall amounts is referred to the respective river basins of the historical cases.

  2. Control of strength and stability of emulsion-gels by a combination of long- and short-range interactions

    NARCIS (Netherlands)

    Blijdenstein, T.B.J.; Hendriks, W.P.G.; Linden, van der E.; Vliet, van T.; Aken, van G.A.

    2003-01-01

    This paper discusses the change in phase behavior and mechanical properties of oil-in-water emulsion gels brought about by variation of long- and short-range attractive interactions. The model system studied consisted of oil droplets stabilized by the protein -lactoglobulin (-lg). A long-range

  3. Short range order and phase separation in Ti-rich Ti-Al alloys

    International Nuclear Information System (INIS)

    Liew, H.J.

    1999-01-01

    of the reaction over a range of scales, from the atomic level on which order occurs through to large scale precipitates. Ti-15at%Al displays a phase separation mechanism involving both ordering and chemical phase decomposition which occurs in a time and temperature range that is readily accessible experimentally. Hence this alloy is an appropriate model system on which to conduct fundamental investigations into a complex decomposition mechanism and its kinetics. Both experimental and modelling results show that short range order develops rapidly in the alloy, and is followed by the formation and growth of congruent long range ordered regions of DO 19 structure. At a later stage composition variations form and increase in amplitude through a spinodal mechanism. From these findings, it cannot be ruled out that the observed decomposition sequence is due solely to the kinetics of ordering being more rapid than those of chemical phase separation. However, there are some indications which suggest that a thermodynamic criterion is operating, such that the onset of chemical phase separation occurs only after ordering has been achieved to some extent. The observed mechanism is fully consistent in appearance with the class of reactions known as conditional spinodals. (author)

  4. Photon Pressure Force on Space Debris TOPEX/Poseidon Measured by Satellite Laser Ranging

    Science.gov (United States)

    Kucharski, D.; Kirchner, G.; Bennett, J. C.; Lachut, M.; Sośnica, K.; Koshkin, N.; Shakun, L.; Koidl, F.; Steindorfer, M.; Wang, P.; Fan, C.; Han, X.; Grunwaldt, L.; Wilkinson, M.; Rodríguez, J.; Bianco, G.; Vespe, F.; Catalán, M.; Salmins, K.; del Pino, J. R.; Lim, H.-C.; Park, E.; Moore, C.; Lejba, P.; Suchodolski, T.

    2017-10-01

    The (TOPography EXperiment) TOPEX/Poseidon (T/P) altimetry mission operated for 13 years before the satellite was decommissioned in January 2006, becoming a large space debris object at an altitude of 1,340 km. Since the end of the mission, the interaction of T/P with the space environment has driven the satellite's spin dynamics. Satellite laser ranging (SLR) measurements collected from June 2014 to October 2016 allow for the satellite spin axis orientation to be determined with an accuracy of 1.7°. The spin axis coincides with the platform yaw axis (formerly pointing in the nadir direction) about which the body rotates in a counterclockwise direction. The combined photometric and SLR data collected over the 11 year time span indicates that T/P has continuously gained rotational energy at an average rate of 2.87 J/d and spins with a period of 10.73 s as of 19 October 2016. The satellite attitude model shows a variation of the cross-sectional area in the Sun direction between 8.2 m2 and 34 m2. The direct solar radiation pressure is the main factor responsible for the spin-up of the body, and the exerted photon force varies from 65 μN to 228 μN around the mean value of 138.6 μN. Including realistic surface force modeling in orbit propagation algorithms will improve the prediction accuracy, giving better conjunction warnings for scenarios like the recent close approach reported by the ILRS Space Debris Study Group—an approximate 400 m flyby between T/P and Jason-2 on 20 June 2017.

  5. A force measurement system based on an electrostatic sensing and actuating technique for calibrating force in a micronewton range with a resolution of nanonewton scale

    International Nuclear Information System (INIS)

    Chen, Sheng-Jui; Pan, Sheau-Shi

    2011-01-01

    This paper introduces a force measurement system recently established at the Center for Measurement Standards, Industrial Technology Research Institute for calibrating forces in a micronewton range with a resolution of a few nanonewtons. The force balance consists of a monolithic flexure stage and a specially made capacitor for electrostatic sensing and actuating. The capacitor is formed by three electrodes which can be utilized as a capacitive position sensor and an electrostatic force actuator at the same time. Force balance control is implemented with a digital controller by which the signal of the stage deflection is acquired, filtered and fed back to the electrostatic force driver to bring the flexure stage to the null position. The detailed description of the apparatus including the design of a monolithic flexure stage, principle of capacitive position sensing/electrostatic actuation and the force balance control is given in the paper. Finally, we present the results of electrostatic force calibration and the weighing of a 1 mg wire weight

  6. Chiral approach to nuclear matter: Role of explicit short-range NN-terms

    International Nuclear Information System (INIS)

    Fritsch, S.; Kaiser, N.

    2004-01-01

    We extend a recent chiral approach to nuclear matter by including the most general (momentum-independent) NN-contact interaction. Iterating this two-parameter contact vertex with itself and with one-pion exchange the emerging energy per particle exhausts all terms possible up to and including fourth order in the small momentum expansion. Two (isospin-dependent) cut-offs Λ 0,1 are introduced to regularize the (linear) divergences of some three-loop in-medium diagrams. The equation of state of pure neutron matter, anti E n (k n ), can be reproduced very well up to quite high neutron densities of ρ n =0.5 fm -3 by adjusting the strength of a repulsive nn-contact interaction. Binding and saturation of isospin-symmetric nuclear matter is a generic feature of our perturbative calculation. Fixing the maximum binding energy per particle to - anti E(k f0 )=15.3 MeV we find that any possible equilibrium density ρ 0 lies below ρ 0 max =0.191 fm -3 . The additional constraint from the neutron matter equation of state leads however to a somewhat too low saturation density of ρ 0 =0.134 fm -3 . We also investigate the effects of the NN-contact interaction on the complex single-particle potential U(p,k f )+iW(p,k f ). We find that the effective nucleon mass at the Fermi surface is bounded from below by M * (k f0 ) ≥1.4 M. This property keeps the critical temperature of the liquid-gas phase transition at somewhat too high values T c ≥21 MeV. The downward bending of the asymmetry energy A(k f ) above nuclear-matter saturation density is a generic feature of the approximation to fourth order. We furthermore investigate the effects of the NN-contact interaction on the (vector-∇ρ) 2 -term in the nuclear energy density functional E[ρ,τ]. Altogether, there is within this complete fourth-order calculation no ''magic'' set of adjustable short-range parameters with which one could reproduce simultaneously and accurately all semi-empirical properties of nuclear matter. In

  7. Research of Short-range Missile Motion in Terms of Different Wind Loads

    Directory of Open Access Journals (Sweden)

    A. N. Klishin

    2015-01-01

    Full Text Available When modeling the aircraft motion it is advisable to choose a particular model of the Earth, depending both on the task and on the required accuracy of calculation. The article describes various models of the Earth, such as the flat Earth with a plane-parallel field of gravity, spherical and non-rotating Earth with a plane-parallel field of gravity, spherical and non-rotating Earth with a central gravitational field, spherical and non-rotating Earth, taking into account the polar flattening of the Earth, spherical Earth based compression and polar daily rotation. The article also considers the influence of these models on the motion of the selected aircraft.To date, there is technical equipment to provide highly accurate description of the Earthshape, gravitational field, etc. The improved accuracy of the Earth model description results in more correct description of the trajectory and motion parameters of a ballistic missile. However, for short ranges (10-20 km this accuracy is not essential, and, furthermore, it increases time of calculation. Therefore, there is a problem of choosing the optimal description of the Earth parameters.The motion in the model of the Earth, which takes into account a daily rotation of the planet and polar flattening, is discussed in more detail, and the geographical latitude impact on coordinates of the points of fall of a ballistic missile is analyzed on the basis of obtained graphs.The article individually considers a problem of the wind effect on the aircraft motion and defines dependences of the missile motion on the parameters of different wind loads, such as wind speed and height of its action.A mathematical model of the missile motion was built and numerically integrated, using the Runge-Kutta 4th order method, for implementation and subsequent analysis.Based on the analysis of the calculation results in the abovementioned models of the Earth, differences in impact of these models on the parameters of the

  8. Wetting at the nanometer scale: effects of long-range forces and substrate heterogeneities

    International Nuclear Information System (INIS)

    Checco, Antonio

    2003-01-01

    Wetting phenomena on the nano-scale remain poorly understood in spite of their growing theoretical and practical interest. In this context, the present work aimed at studying partial wetting of nanometer-sized alkane droplets on 'model' surfaces build by self-assembly of organic monolayers. For this purpose a novel technique, based on 'noncontact' Atomic Force Microscopy (AFM), has been developed to image, with minimal artefacts, drops of adjustable size directly condensed on so- lid surfaces. We have thus shown that contact angle of alkanes, wetting a weakly heterogeneous, silanized substrate, noticeably decreases from its macroscopic value for droplets sizes in the submicron range. The line tension, arising in this case from purely dispersive long-range interactions between the liquid and the substrate, is theoretically too weak to be responsible for the observed effect. Therefore we have supposed that contact angle is affected by mesoscopic chemical heterogeneities of the substrate whenever the droplets size becomes sufficiently small. This scenario has been supported by numerical simulations based on a simplified model of the spatial distribution of surface defects. Similar experiments, performed on different substrates (monolayers made of alkane-thiols self-assembled on gold and of alkyl chains covalently bound onto a silicon surface), have also shown that wetting on small scales is strongly affected by minimal physical and chemical surface heterogeneities. Finally, to provide further examples of the potential of the above mentioned AFM technique, we have studied the wettability of nano-structured surfaces and the local wetting properties of hair. (author) [fr

  9. Short Range-Ordered Minerals: Insight into Aqueous Alteration Processes on Mars

    Science.gov (United States)

    Ming, Douglas W.; Morris, R. V.; Golden, D. C.

    2011-01-01

    Short range-ordered (SRO) aluminosilicates (e.g., allophane) and nanophase ferric oxides (npOx) are common SRO minerals derived during aqueous alteration of basaltic materials. NpOx refers to poorly crystalline or amorphous alteration products that can be any combination of superparamagnetic hematite and/or goethite, akaganeite, schwertmannite, ferrihydrite, iddingsite, and nanometer-sized ferric oxide particles that pigment palagonitic tephra. Nearly 30 years ago, SRO phases were suggested as alteration phases on Mars based on similar spectral properties for altered basaltic tephra on the slopes of Mauna Kea in Hawaii and Martian bright regions measured by Earth-based telescopes. Detailed characterization of altered basaltic tephra on Mauna Kea have identified a variety of alteration phases including allophane, npOx, hisingerite, jarosite, alunite, hematite, goethite, ferrihydrite, halloysite, kaolinite, smectite, and zeolites. The presence of npOx and other Fe-bearing minerals (jarosite, hematite, goethite) was confirmed by the M ssbauer Spectrometer onboard the Mars Exploration Rovers. Although the presence of allophane has not been definitely identified on Mars robotic missions, chemical analysis by the Spirit and Opportunity rovers and thermal infrared spectral orbital measurements suggest the presence of allophane or allophane-like phases on Mars. SRO phases form under a variety of environmental conditions on Earth ranging from cold and arid to warm and humid, including hydrothermal conditions. The formation of SRO aluminosilicates such as allophane (and crystalline halloysite) from basaltic material is controlled by several key factors including activity of water, extent of leaching, Si activity in solution, and available Al. Generally, a low leaching index (e.g., wet-dry cycles) and slightly acidic to alkaline conditions are necessary. NpOx generally form under aqueous oxidative weathering conditions, although thermal oxidative alteration may occasional be

  10. Lead Free Frangible Ammunition Exposure at United States Air Force Small Arms Firing Ranges, 2005 - 2007

    National Research Council Canada - National Science Library

    Moran, Michael P; Ott, Darrin K

    2008-01-01

    ...) has performed related to health concerns expressed by Security Forces Combat Arms (CATM) instructors regarding exposure to contaminants generated during the discharge of lead free frangible ammunition...

  11. NETWORK DESIGN IN CLOSE-RANGE PHOTOGRAMMETRY WITH SHORT BASELINE IMAGES

    Directory of Open Access Journals (Sweden)

    L. Barazzetti

    2017-08-01

    Full Text Available The avaibility of automated software for image-based 3D modelling has changed the way people acquire images for photogrammetric applications. Short baseline images are required to match image points with SIFT-like algorithms, obtaining more images than those necessary for “old fashioned” photogrammetric projects based on manual measurements. This paper describes some considerations on network design for short baseline image sequences, especially on precision and reliability of bundle adjustment. Simulated results reveal that the large number of 3D points used for image orientation has very limited impact on network precision.

  12. Generating a stationary infinite range tractor force via a multimode optical fibre

    Science.gov (United States)

    Ebongue, C. A.; Holzmann, D.; Ostermann, S.; Ritsch, H.

    2017-06-01

    Optical fibres confine and guide light almost unattenuated and thus convey light forces to polarizable nano-particles over very long distances. Radiation pressure forces arise from scattering of guided photons into free space while gradient forces are based on coherent scattering between different fibre modes or propagation directions. Interestingly, even scattering between co-propagating modes induces longitudinal forces as the transverse confinement of the light modes creates mode dependent longitudinal wave-vectors and photon momenta. We generalize a proven scattering matrix based approach to calculate single as well as inter-particle forces to include several forward and backward propagating modes. We show that an injection of the higher order mode only in a two mode fibre will induce a stationary tractor force against the injection direction, when the mode coupling to the lower order mode dominates against backscattering and free space losses. Generically this arises for non-absorbing particles at the centre of a waveguide. The model also gives improved predictions for inter-particle forces in evanescent nanofibre fields as experimentally observed recently. Surprisingly strong tractor forces can also act on whole optically bound arrays.

  13. Scalable improvement of SPME multipolar electrostatics in anisotropic polarizable molecular mechanics using a general short-range penetration correction up to quadrupoles.

    Science.gov (United States)

    Narth, Christophe; Lagardère, Louis; Polack, Étienne; Gresh, Nohad; Wang, Qiantao; Bell, David R; Rackers, Joshua A; Ponder, Jay W; Ren, Pengyu Y; Piquemal, Jean-Philip

    2016-02-15

    We propose a general coupling of the Smooth Particle Mesh Ewald SPME approach for distributed multipoles to a short-range charge penetration correction modifying the charge-charge, charge-dipole and charge-quadrupole energies. Such an approach significantly improves electrostatics when compared to ab initio values and has been calibrated on Symmetry-Adapted Perturbation Theory reference data. Various neutral molecular dimers have been tested and results on the complexes of mono- and divalent cations with a water ligand are also provided. Transferability of the correction is adressed in the context of the implementation of the AMOEBA and SIBFA polarizable force fields in the TINKER-HP software. As the choices of the multipolar distribution are discussed, conclusions are drawn for the future penetration-corrected polarizable force fields highlighting the mandatory need of non-spurious procedures for the obtention of well balanced and physically meaningful distributed moments. Finally, scalability and parallelism of the short-range corrected SPME approach are addressed, demonstrating that the damping function is computationally affordable and accurate for molecular dynamics simulations of complex bio- or bioinorganic systems in periodic boundary conditions. Copyright © 2016 Wiley Periodicals, Inc.

  14. Impacts of Amazonia biomass burning aerosols assessed from short-range weather forecasts

    Directory of Open Access Journals (Sweden)

    S. R. Kolusu

    2015-11-01

    Full Text Available The direct radiative impacts of biomass burning aerosols (BBA on meteorology are investigated using short-range forecasts from the Met Office Unified Model (MetUM over South America during the South American Biomass Burning Analysis (SAMBBA. The impacts are evaluated using a set of three simulations: (i no aerosols, (ii with monthly mean aerosol climatologies and (iii with prognostic aerosols modelled using the Coupled Large-scale Aerosol Simulator for Studies In Climate (CLASSIC scheme. Comparison with observations show that the prognostic CLASSIC scheme provides the best representation of BBA. The impacts of BBA are quantified over central and southern Amazonia from the first and second day of 2-day forecasts during 14 September–3 October 2012. On average, during the first day of the forecast, including prognostic BBA reduces the clear-sky net radiation at the surface by 15 ± 1 W m−2 and reduces net top-of-atmosphere (TOA radiation by 8 ± 1 W m−2, with a direct atmospheric warming of 7 ± 1 W m−2. BBA-induced reductions in all-sky radiation are smaller in magnitude: 9.0 ± 1 W m−2 at the surface and 4.0 ± 1 W m−2 at TOA. In this modelling study the BBA therefore exert an overall cooling influence on the Earth–atmosphere system, although some levels of the atmosphere are directly warmed by the absorption of solar radiation. Due to the reduction of net radiative flux at the surface, the mean 2 m air temperature is reduced by around 0.1 ± 0.02 °C. The BBA also cools the boundary layer (BL but warms air above by around 0.2 °C due to the absorption of shortwave radiation. The overall impact is to reduce the BL depth by around 19 ± 8 m. These differences in heating lead to a more anticyclonic circulation at 700 hPa, with winds changing by around 0.6 m s−1. Inclusion of climatological or prognostic BBA in the MetUM makes a small but significant improvement in forecasts of temperature and relative humidity, but improvements were

  15. Long-range versus short-range correlations in the two-neutron transfer reaction 64Ni(18O,16O)66Ni

    Science.gov (United States)

    Paes, B.; Santagati, G.; Vsevolodovna, R. Magana; Cappuzzello, F.; Carbone, D.; Cardozo, E. N.; Cavallaro, M.; García-Tecocoatzi, H.; Gargano, A.; Ferreira, J. L.; Lenzi, S. M.; Linares, R.; Santopinto, E.; Vitturi, A.; Lubian, J.

    2017-10-01

    Recently, various two-neutron transfer studies using the (18O,16O) reaction were performed with a large success. This was achieved because of a combined use of the microscopic quantum description of the reaction mechanism and of the nuclear structure. In the present work we use this methodology to study the two-neutron transfer reaction of the 18O+64Ni system at 84 MeV incident energy, to the ground and first 2+ excited state of the residual 66Ni nucleus. All the experimental data were measured by the large acceptance MAGNEX spectrometer at the Instituto Nazionale di Fisica Nucleare -Laboratori Nazionali del Sud (Italy). We have performed exact finite range cross section calculations using the coupled channel Born approximation (CCBA) and coupled reaction channel (CRC) method for the sequential and direct two-neutron transfers, respectively. Moreover, this is the first time that the formalism of the microscopic interaction boson model (IBM-2) was applied to a two-neutron transfer reaction. From our results we conclude that for two-neutron transfer to the ground state of 66Ni, the direct transfer is the dominant reaction mechanism, whereas for the transfer to the first excited state of 66Ni, the sequential process dominates. A competition between long-range and short-range correlations is discussed, in particular, how the use of two different models (Shell model and IBM's) help to disentangle long- and short-range correlations.

  16. Short- and long-range energy strategies for Japan and the world after the Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Muraoka, K.; Wagner, F.; Yamagata, Y.; Donné, A.J.H.

    2016-01-01

    The accident at the Fukushima Dai-ichi nuclear power station in 2011 has caused profound effects on energy policies in Japan and worldwide. This is particularly because it occurred at the time of the growing awareness of global warming forcing measures towards decarbonised energy production, namely the use of fossil fuels has to be drastically reduced from the present level of more than 80% by 2050. A dilemma has now emerged because nuclear power, a CO 2 -free technology with proven large-scale energy production capability, lost confidence in many societies, especially in Japan and Germany. As a consequence, there is a world-wide effort now to expand renewable energies (REs), specifically photo-voltaic (PV) and wind power. However, the authors conjecture that PV and wind power can provide only up to a 40% share of the electricity production as long as sufficient storage is not available. Beyond this level, the technological (high grid power) and economic problems (large surplus production) grow. This is the result of the analysis of the growing use of REs in the electricity systems for Germany and Japan. The key element to overcome this situation is to develop suitable energy storage technologies. This is particularly necessary when electricity will become the main energy source because also transportation, process heat and heating, will be supplied by it. Facing the difficulty in replacing all fossil fuels in all countries with different technology standards, a rapid development of carbon capture and storage (CCS) might also be necessary. Therefore, for the short-range strategy up to 2050, all meaningful options have to be developed. For the long-range strategy beyond 2050, new energy sources (such as thermonuclear fusion, solar fuels and nuclear power—if inherently safe concepts will gain credibility of societies again), and large-scale energy storage systems based on novel concepts (such as large-capacity batteries and hydrogen) is required. It is acknowledged

  17. Short- and long-range energy strategies for Japan and the world after the Fukushima nuclear accident

    Science.gov (United States)

    Muraoka, K.; Wagner, F.; Yamagata, Y.; Donné, A. J. H.

    2016-01-01

    The accident at the Fukushima Dai-ichi nuclear power station in 2011 has caused profound effects on energy policies in Japan and worldwide. This is particularly because it occurred at the time of the growing awareness of global warming forcing measures towards decarbonised energy production, namely the use of fossil fuels has to be drastically reduced from the present level of more than 80% by 2050. A dilemma has now emerged because nuclear power, a CO2-free technology with proven large-scale energy production capability, lost confidence in many societies, especially in Japan and Germany. As a consequence, there is a world-wide effort now to expand renewable energies (REs), specifically photo-voltaic (PV) and wind power. However, the authors conjecture that PV and wind power can provide only up to a 40% share of the electricity production as long as sufficient storage is not available. Beyond this level, the technological (high grid power) and economic problems (large surplus production) grow. This is the result of the analysis of the growing use of REs in the electricity systems for Germany and Japan. The key element to overcome this situation is to develop suitable energy storage technologies. This is particularly necessary when electricity will become the main energy source because also transportation, process heat and heating, will be supplied by it. Facing the difficulty in replacing all fossil fuels in all countries with different technology standards, a rapid development of carbon capture and storage (CCS) might also be necessary. Therefore, for the short-range strategy up to 2050, all meaningful options have to be developed. For the long-range strategy beyond 2050, new energy sources (such as thermonuclear fusion, solar fuels and nuclear power—if inherently safe concepts will gain credibility of societies again), and large-scale energy storage systems based on novel concepts (such as large-capacity batteries and hydrogen) is required. It is acknowledged

  18. SHORT-RANGE WAKEFIELD IN A FLAT PILLBOX CAVITY GENERATED BY A SUB-RELATIVISTIC BEAM BUNCH

    International Nuclear Information System (INIS)

    WANG, H.; PALMER, R.B.; GALLARDO, J.

    2001-01-01

    The short-range wakefield between two parallel conducting plates generated by a sub-relativistic beam bunch has been solved analytically by the image charge method in time domain. Comparing with the traditional modal analysis in frequency domain, this algorithm simplifies the mathematics and reveals in greater details the physics of electromagnetic field generation, propagation, reflection and causality. The calculated results have an excellent agreement with MAFIA and ABC1 simulations in all range of beam velocities

  19. Space Technology Demonstrations Using Low Cost, Short-Schedule Airborne and Range Facilities at the Dryden Flight Research Center

    Science.gov (United States)

    Carter, John; Kelly, John; Jones, Dan; Lee, James

    2013-01-01

    There is a national effort to expedite advanced space technologies on new space systems for both government and commercial applications. In order to lower risk, these technologies should be demonstrated in a relevant environment before being installed in new space systems. This presentation introduces several low cost, short schedule space technology demonstrations using airborne and range facilities available at the Dryden Flight Research Center.

  20. On-chip patch antenna on InP substrate for short-range wireless communication at 140 GHz

    DEFF Research Database (Denmark)

    Dong, Yunfeng; Johansen, Tom Keinicke; Zhurbenko, Vitaliy

    2017-01-01

    This paper presents the design of an on-chip patch antenna on indium phosphide (InP) substrate for short-range wireless communication at 140 GHz. The antenna shows a simulated gain of 5.3 dBi with 23% bandwidth at 140 GHz and it can be used for either direct chip-to-chip communication or chip...

  1. Two-nucleon electromagnetic current in chiral effective field theory: One-pion exchange and short-range contributions

    International Nuclear Information System (INIS)

    Koelling, S.; Epelbaum, E.; Krebs, H.; Meissner, U.-G.

    2011-01-01

    We derive the leading one-loop contribution to the one-pion exchange and short-range two-nucleon electromagnetic current operator in the framework of chiral effective field theory. The derivation is carried out using the method of unitary transformation. Explicit results for the current and charge densities are given in momentum and coordinate space.

  2. Systematic validation and atomic force microscopy of non-covalent short oligonucleotide barcode microarrays.

    Directory of Open Access Journals (Sweden)

    Michael A Cook

    Full Text Available BACKGROUND: Molecular barcode arrays provide a powerful means to analyze cellular phenotypes in parallel through detection of short (20-60 base unique sequence tags, or "barcodes", associated with each strain or clone in a collection. However, costs of current methods for microarray construction, whether by in situ oligonucleotide synthesis or ex situ coupling of modified oligonucleotides to the slide surface are often prohibitive to large-scale analyses. METHODOLOGY/PRINCIPAL FINDINGS: Here we demonstrate that unmodified 20mer oligonucleotide probes printed on conventional surfaces show comparable hybridization signals to covalently linked 5'-amino-modified probes. As a test case, we undertook systematic cell size analysis of the budding yeast Saccharomyces cerevisiae genome-wide deletion collection by size separation of the deletion pool followed by determination of strain abundance in size fractions by barcode arrays. We demonstrate that the properties of a 13K unique feature spotted 20 mer oligonucleotide barcode microarray compare favorably with an analogous covalently-linked oligonucleotide array. Further, cell size profiles obtained with the size selection/barcode array approach recapitulate previous cell size measurements of individual deletion strains. Finally, through atomic force microscopy (AFM, we characterize the mechanism of hybridization to unmodified barcode probes on the slide surface. CONCLUSIONS/SIGNIFICANCE: These studies push the lower limit of probe size in genome-scale unmodified oligonucleotide microarray construction and demonstrate a versatile, cost-effective and reliable method for molecular barcode analysis.

  3. An improved visualization-based force-measurement technique for short-duration hypersonic facilities

    Energy Technology Data Exchange (ETDEWEB)

    Laurence, Stuart J.; Karl, Sebastian [Institute of Aerodynamics and Flow Technology, Spacecraft Section, German Aerospace Center (DLR), Goettingen (Germany)

    2010-06-15

    This article is concerned with describing and exploring the limitations of an improved version of a recently proposed visualization-based technique for the measurement of forces and moments in short-duration hypersonic wind tunnels. The technique is based on tracking the motion of a free-flying body over a sequence of high-speed visualizations; while this idea is not new in itself, the use of high-speed digital cinematography combined with a highly accurate least-squares tracking algorithm allows improved results over what have been previously possible with such techniques. The technique precision is estimated through the analysis of artificially constructed and experimental test images, and the resulting error in acceleration measurements is characterized. For wind-tunnel scale models, position measurements to within a few microns are shown to be readily attainable. Image data from two previous experimental studies in the T5 hypervelocity shock tunnel are then reanalyzed with the improved technique: the uncertainty in the mean drag acceleration is shown to be reduced to the order of the flow unsteadiness, 2-3%, and time-resolved acceleration measurements are also shown to be possible. The response time of the technique for the configurations studied is estimated to be {proportional_to}0.5 ms. Comparisons with computations using the DLR TAU code also yield agreement to within the overall experimental uncertainty. Measurement of the pitching moment for blunt geometries still appears challenging, however. (orig.)

  4. Short-Range Sensor for Underwater Robot Navigation using Line-lasers and Vision

    DEFF Research Database (Denmark)

    Hansen, Peter Nicholas; Nielsen, Mikkel Cornelius; Christensen, David Johan

    2015-01-01

    This paper investigates a minimalistic laser-based range sensor, used for underwater inspection by Autonomous Underwater Vehicles (AUV). This range detection system system comprise two lasers projecting vertical lines, parallel to a camera’s viewing axis, into the environment. Using both lasers...

  5. Dynamic verification of newton's law and the principal limits in measuring intermediate-range forces

    International Nuclear Information System (INIS)

    Kolosnitsyn, N.I.; Luo Jun; Melnikov, V.N.

    1992-01-01

    According to the controversial results of recent experiments for fifth force, a classification of all possible types of theories leading to non-Newtonian forces is presented. The theoretical analysis shows that if the interaction potential differs from the Newton's law the interactions of macro-and micro-bodies are in general distinguishable. The calculation also shows that Long's result can be improved by several orders if the new method proposed is used

  6. Resonance oscillations of nonreciprocal long-range van der Waals forces between atoms in electromagnetic fields

    Science.gov (United States)

    Sherkunov, Yury

    2018-03-01

    We study theoretically the van der Waals interaction between two atoms out of equilibrium with an isotropic electromagnetic field. We demonstrate that at large interatomic separations, the van der Waals forces are resonant, spatially oscillating, and nonreciprocal due to resonance absorption and emission of virtual photons. We suggest that the van der Waals forces can be controlled and manipulated by tuning the spectrum of artificially created random light.

  7. Effect of Jahn-Teller distortion on the short range magnetic order in copper ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Abdellatif, M.H., E-mail: Mohamed.abdellatif@iit.it [Nanostrctures Department, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy); Innocenti, Claudia [INSTM—Department of Chemistry, University of Florence, via della Lastruccia 3, I-50019 Sesto Fiorentino, FI (Italy); Liakos, Ioannis [Nanostrctures Department, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy); Scarpellini, Alice; Marras, Sergio [Nanochemistry Department, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy); Salerno, Marco [Nanostrctures Department, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy)

    2017-02-15

    Copper ferrite of spinel crystal structure was synthesized in the form of nano-particles using citrate-gel auto-combustion method. The sample morphology and composition were identified using scanning electron microscopy, X-ray diffraction, and X-ray spectroscopy. The latter technique reveals an inverse spinel structure with Jahn-Teller tetragonal distortion. The static magnetization was measured using vibrating sample magnetometer. Magnetic force microscopy was used in combination with the magnetization data to demonstrate the finite size effect of the magnetic spins and their casting behavior due to the introduction of copper ions in the tetrahedral magnetic sub-lattices, which results in tetragonal distorting the spinel structure of the copper ferrite. The magnetic properties of materials are a result of the collective behavior of the magnetic spins, and magnetic force microscopy can probe the collective behavior of the magnetic spins in copper ferrite, yet providing a sufficient resolution to map the effects below the micrometer size scale, such as the magnetic spin canting. A theoretical study was done to clarify the finite size effect of Jahn-Teller distortion on the magnetic properties of the material. When the particles are in the nano-scale, below the single domain size, their magnetic properties are very sensitive to their size change. - Highlights: • The spin canting due to Jahn-Teller distortion in Copper ferrite can be detected using magnetic force microscope. • The contrast in the magnetic AFM image can be analyzed to give information not only about the surface spins but also about the canting of the core spins inside the aggregated cluster of magnetic nanoparticle.

  8. Introducing a new family of short-range potentials and their numerical solutions using the asymptotic iteration method

    Science.gov (United States)

    Assi, I. A.; Sous, A. J.

    2018-05-01

    The goal of this work is to derive a new class of short-range potentials that could have a wide range of physical applications, specially in molecular physics. The tridiagonal representation approach has been developed beyond its limitations to produce new potentials by requiring the representation of the Schrödinger wave operator to be multidiagonal and symmetric. This produces a family of Hulthén potentials that has a specific structure, as mentioned in the introduction. As an example, we have solved the nonrelativistic wave equation for the new four-parameter short-range screening potential numerically using the asymptotic iteration method, where we tabulated the eigenvalues for both s -wave and arbitrary l -wave cases in tables.

  9. Correlation of optical energy gap with the nearest neighbour short range order in amorphous V2O5 films

    International Nuclear Information System (INIS)

    Dhawan, Sahil; Vedeshwar, Agnikumar G; Tandon, R P

    2011-01-01

    The optical and structural properties of well characterized vacuum-evaporated amorphous V 2 O 5 films were studied in the thickness range 5-500 nm. The structural analyses show that V-O, O-O and V-V nearest neighbour distances defining the short range order vary nonlinearly with film thickness. The optical absorption shows thickness-dependent energy gap (E g ) and the nonlinear behaviour of thickness-dependent E g is similar to that of nearest neighbour distance with film thickness. The E g correlates linearly very well with all the three nearest neighbour distances. The variation of E g with film thickness is attributed to the residual stress in the film which causes the changes in short range order. The change in E g corresponding to the change in V-O distance was found to be 35 eV nm -1 . This change is almost three times of that with V-V distance.

  10. Stability of a Short Rayleigh Range Laser Resonator with Misaligned or Distorted Mirrors

    CERN Document Server

    Crooker, Peter P; Colson, William B

    2004-01-01

    Motivated by the prospect of constructing an FEL with short Rayleigh length in a high-vibration shipboard environment, we have studied the effect of mirror vibration and distortion on the behavior of the fundamental optical mode of a cold-cavity resonator. A tilt or transverse shift of a mirror causes the optical mode to rock sinusoidally about the original resonator axis. A longitudinal mirror shift or a change in the mirror’s radius of curvature causes the beam diameter at a mirror to dilate and contract with successive impacts. Results from both ray-tracing techniques and wavefront propagation simulations are in excellent agreement.

  11. Short (

    NARCIS (Netherlands)

    Telleman, Gerdien; den Hartog, Laurens

    2013-01-01

    Aim: This systematic review assessed the implant survival rate of short (<10 mm) dental implants installed in partially edentulous patients. A case report of a short implant in the posterior region have been added. Materials and methods: A search was conducted in the electronic databases of MEDLINE

  12. A short-range weather prediction system for South Africa based on a multi-model approach

    CSIR Research Space (South Africa)

    Landman, S

    2012-10-01

    Full Text Available stream_source_info Landman5_2012.pdf.txt stream_content_type text/plain stream_size 44898 Content-Encoding ISO-8859-1 stream_name Landman5_2012.pdf.txt Content-Type text/plain; charset=ISO-8859-1 1 A short... to be skillful. Moreover, the system outscores the forecast skill of the individual models. Keywords: short-range, ensemble, forecasting, precipitation, multi-model, verification Tel: +27 12 367 6054...

  13. Mathematical Model and Calibration Experiment of a Large Measurement Range Flexible Joints 6-UPUR Six-Axis Force Sensor

    Directory of Open Access Journals (Sweden)

    Yanzhi Zhao

    2016-08-01

    Full Text Available Nowadays improving the accuracy and enlarging the measuring range of six-axis force sensors for wider applications in aircraft landing, rocket thrust, and spacecraft docking testing experiments has become an urgent objective. However, it is still difficult to achieve high accuracy and large measuring range with traditional parallel six-axis force sensors due to the influence of the gap and friction of the joints. Therefore, to overcome the mentioned limitations, this paper proposed a 6-Universal-Prismatic-Universal-Revolute (UPUR joints parallel mechanism with flexible joints to develop a large measurement range six-axis force sensor. The structural characteristics of the sensor are analyzed in comparison with traditional parallel sensor based on the Stewart platform. The force transfer relation of the sensor is deduced, and the force Jacobian matrix is obtained using screw theory in two cases of the ideal state and the state of flexibility of each flexible joint is considered. The prototype and loading calibration system are designed and developed. The K value method and least squares method are used to process experimental data, and in errors of kind Ι and kind II linearity are obtained. The experimental results show that the calibration error of the K value method is more than 13.4%, and the calibration error of the least squares method is 2.67%. The experimental results prove the feasibility of the sensor and the correctness of the theoretical analysis which are expected to be adopted in practical applications.

  14. Mathematical Model and Calibration Experiment of a Large Measurement Range Flexible Joints 6-UPUR Six-Axis Force Sensor.

    Science.gov (United States)

    Zhao, Yanzhi; Zhang, Caifeng; Zhang, Dan; Shi, Zhongpan; Zhao, Tieshi

    2016-08-11

    Nowadays improving the accuracy and enlarging the measuring range of six-axis force sensors for wider applications in aircraft landing, rocket thrust, and spacecraft docking testing experiments has become an urgent objective. However, it is still difficult to achieve high accuracy and large measuring range with traditional parallel six-axis force sensors due to the influence of the gap and friction of the joints. Therefore, to overcome the mentioned limitations, this paper proposed a 6-Universal-Prismatic-Universal-Revolute (UPUR) joints parallel mechanism with flexible joints to develop a large measurement range six-axis force sensor. The structural characteristics of the sensor are analyzed in comparison with traditional parallel sensor based on the Stewart platform. The force transfer relation of the sensor is deduced, and the force Jacobian matrix is obtained using screw theory in two cases of the ideal state and the state of flexibility of each flexible joint is considered. The prototype and loading calibration system are designed and developed. The K value method and least squares method are used to process experimental data, and in errors of kind Ι and kind II linearity are obtained. The experimental results show that the calibration error of the K value method is more than 13.4%, and the calibration error of the least squares method is 2.67%. The experimental results prove the feasibility of the sensor and the correctness of the theoretical analysis which are expected to be adopted in practical applications.

  15. Short- and medium-range order in a Zr73Pt27 glass: Experimental and simulation studies

    International Nuclear Information System (INIS)

    Wang, S.Y.; Wang, C.Z.; Li, M.Z.; Huang, L.; Ott, R.T.; Kramer, M.J.; Sordelet, D.J.; Ho, K.M.

    2008-01-01

    The structure of a Zr 73 Pt 27 metallic glass, which forms a Zr 5 Pt 3 (Mn 5 Si 3 -type) phase having local atomic clusters with distorted icosahedral coordination during the primary crystallization, has been investigated by means of x-ray diffraction and combining ab initio molecular-dynamics (MD) and reverse Monte Carlo (RMC) simulations. The ab initio MD simulation provides an accurate description of short-range structural and chemical ordering in the glass. A three-dimensional atomistic model of 18?000 atoms for the glass structure has been generated by the RMC method utilizing both the structure factor S(k) from x-ray diffraction experiment and the partial pair-correlation functions from ab initio MD simulation. Honeycutt and Andersen index and Voronoi cell analyses, respectively, were used to characterize the short- and medium-range order in the atomistic structure models generated by ab initio MD and RMC simulations. The ab initio results show that an icosahedral type of short-range order is predominant in the glass state. Furthermore, analysis of the atomic model from the constrained RMC simulations reveals that the icosahedral-like clusters are packed in arrangements having higher-order correlations, thus establishing medium-range topological order up to two or three cluster shells.

  16. Decreased long- and short-range functional connectivity at rest in drug-naive major depressive disorder.

    Science.gov (United States)

    Guo, Wenbin; Liu, Feng; Chen, Jindong; Wu, Renrong; Zhang, Zhikun; Yu, Miaoyu; Xue, Zhimin; Zhao, Jingping

    2016-08-01

    Abnormal functional connectivity has been observed in major depressive disorder. Anatomical distance may affect functional connectivity in patients with major depressive disorder. However, whether and how anatomical distance affects functional connectivity at rest remains unclear in drug-naive patients with major depressive disorder. Forty-four patients with major depressive disorder, as well as 44 age-, sex- and education-matched healthy controls, underwent resting-state functional magnetic resonance imaging scanning. Regional functional connectivity strength was calculated for each voxel in the whole brain, which was further divided into short- and long-range functional connectivity strength. The patients showed decreased long-range positive functional connectivity strength in the right inferior parietal lobule, as well as decreased short-range positive functional connectivity strength in the right insula and right superior temporal gyrus relative to those of the controls. No significant correlations existed between abnormal functional connectivity strength and the clinical variables of the patients. The findings revealed that anatomical distance decreases long- and short-range functional connectivity strength in patients with major depressive disorder, which may underlie the neurobiology of major depressive disorder. © The Royal Australian and New Zealand College of Psychiatrists 2015.

  17. Ionization from short-range potential under action of electromagnetic field of complex configuration

    CERN Document Server

    Rodionov, V N; Kravtsova, G A

    2002-01-01

    The transcendental equation for the complex energy is obtained on the basis of the exactly solvable 3D model of the short-acting potential and the Green time function in the intensive electromagnetic field, constituting the combination of the constant magnetic field and the circular-polarization wave field. The electron quasistationary states parameters in the delta-potential with an account of the action of the intensive external field of complex configuration are calculated. The problem on the possibility of stabilizing the bound states decay of the spinor and scalar particles through the intensive magnetic field is clarified. It is established that the obtained results regime the reexamination of the accepted notion on the stabilizing role of the strong magnetic field by the atoms ionization

  18. Short-range dynamics and prediction of mesoscale flow patterns in the MISTRAL field experiment

    Energy Technology Data Exchange (ETDEWEB)

    Weber, R.O.; Kaufmann, P.; Talkner, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    In a limited area of about 50 km by 50 km with complex topography, wind measurements on a dense network were performed during the MISTRAL field experiment in 1991-1992. From these data the characteristic wind fields were identified by an automated classification method. The dynamics of the resulting twelve typical regional flow patterns is studied. It is discussed how transitions between the flow patterns take place and how well the transition probabilities can be described in the framework of a Markov model. Guided by this discussion, a variety of prediction models were tested which allow a short-term forecast of the flow pattern type. It is found that a prediction model which uses forecast information from the synoptic scale has the best forecast skill. (author) 2 figs., 7 refs.

  19. Stresses in the plantar region for long- and short-range throws in women basketball players.

    Science.gov (United States)

    Pau, Massimiliano; Ciuti, Carla

    2013-01-01

    This study aimed to assess plantar pressure pattern modifications caused by short- and long-distance shots in women basketball players. To this end, 24 experienced national- and regional-level basketball players performed 3 trials of 4 technical gestures (free throw, jump stop shot, three-point shot and lay-up) barefoot on a pressure platform placed in fixed positions on the court. Raw data were processed to calculate location and magnitude of pressure peaks in three sub-regions (forefoot, midfoot and rearfoot), and the increase ratio was calculated relative to plantar pressure measured during a static bipedal and unipedal upright stance. The results showed significant increases (ptraining and rehabilitation protocols.

  20. Spectrally and Spatially Resolved Smith-Purcell Radiation in Plasmonic Crystals with Short-Range Disorder

    Directory of Open Access Journals (Sweden)

    I. Kaminer

    2017-01-01

    Full Text Available Electrons interacting with plasmonic structures can give rise to resonant excitations in localized plasmonic cavities and to collective excitations in periodic structures. We investigate the presence of resonant features and disorder in the conventional Smith-Purcell effect (electrons interacting with periodic structures and observe the simultaneous excitation of both the plasmonic resonances and the collective excitations. For this purpose, we introduce a new scanning-electron-microscope-based setup that allows us to probe and directly image new features of electron-photon interactions in nanophotonic structures like plasmonic crystals with strong disorder. Our work creates new possibilities for probing nanostructures with free electrons, with potential applications that include tunable sources of short-wavelength radiation and plasmonic-based particle accelerators.

  1. Short-Range Temporal Interactions in Sleep; Hippocampal Spike Avalanches Support a Large Milieu of Sequential Activity Including Replay.

    Directory of Open Access Journals (Sweden)

    J Matthew Mahoney

    Full Text Available Hippocampal neural systems consolidate multiple complex behaviors into memory. However, the temporal structure of neural firing supporting complex memory consolidation is unknown. Replay of hippocampal place cells during sleep supports the view that a simple repetitive behavior modifies sleep firing dynamics, but does not explain how multiple episodes could be integrated into associative networks for recollection during future cognition. Here we decode sequential firing structure within spike avalanches of all pyramidal cells recorded in sleeping rats after running in a circular track. We find that short sequences that combine into multiple long sequences capture the majority of the sequential structure during sleep, including replay of hippocampal place cells. The ensemble, however, is not optimized for maximally producing the behavior-enriched episode. Thus behavioral programming of sequential correlations occurs at the level of short-range interactions, not whole behavioral sequences and these short sequences are assembled into a large and complex milieu that could support complex memory consolidation.

  2. TDMA X-band FMCW MIMO radar for short range surveillance applications

    NARCIS (Netherlands)

    Belfiori, F.; Maas, A.P.M.; Hoogeboom, P.; Rossum, W.L. van

    2011-01-01

    The work presented in this paper was aimed at the design of a compact radar device to be used for private area surveillance applications. The radar is connected to a pan tilt zoom camera and it provides the camera system with high accuracy position information (bearing and range) of moving targets;

  3. A short-range weather prediction system for South Africa based on a ...

    African Journals Online (AJOL)

    The accurate prediction of rainfall events, in terms of their timing, location and rainfall depth, is important to a wide range of social and economic applications. At many operational weather prediction centres, as is also the case at the South African Weather Service, forecasters use deterministic model outputs as guidance to ...

  4. Short-Range Correlated Magnetic Core-Shell CrO₂/Cr₂O₃ Nanorods: Experimental Observations and Theoretical Considerations.

    Science.gov (United States)

    Gandhi, Ashish C; Li, Tai-Yue; Chan, Ting Shan; Wu, Sheng Yun

    2018-05-09

    With the evolution of synthesis and the critical characterization of core-shell nanostructures, short-range magnetic correlation is of prime interest in employing their properties to develop novel devices and widespread applications. In this regard, a novel approach of the magnetic core-shell saturated magnetization (CSSM) cylinder model solely based on the contribution of saturated magnetization in one-dimensional CrO₂/Cr₂O₃ core-shell nanorods (NRs) has been developed and applied for the determination of core-diameter and shell-thickness. The nanosized effect leads to a short-range magnetic correlation of ferromagnetic core-CrO₂ extracted from CSSM, which can be explained using finite size scaling method. The outcome of this study is important in terms of utilizing magnetic properties for the critical characterization of core-shell nanomagnetic materials.

  5. Changes in structure of the short-range order of the InP melt when heated

    International Nuclear Information System (INIS)

    Glazov, V.M.; Dovletov, K.; Nashel'skij, A.Ya.; Mamedov, M.M.

    1977-01-01

    An investigation of the temperature dependence of the InP viscosity has indicated an ''after-melting'' effect similar to that observed in other A 3 V 5 compounds having a sphalerite structure. The termodynamic parameters of the viscous flow of indium phosphide melt have been calculated, and a suggestion has been made on the loosening of the short-range order structure of the melt during the period preceding solidification. With the similarity in the behaviour of InP and of A 3 Sb compound melts as a basis, a suggestion has been put forward that the influence of the thermal dissociation upon the character of the changes in the short-range order structure directly after transition from the solid to the liquid phase is negligible

  6. Handbook of ultra-wideband short-range sensing theory, sensors, applications

    CERN Document Server

    Sachs, Jürgen

    2013-01-01

    Ranging from the theoretical basis of UWB sensors via implementation issues to applications, this much-needed book bridges the gap between designers and appliers working in civil engineering, biotechnology, medical engineering, robotic, mechanical engineering, safety and homeland security. From the contents: * History * Signal and systems in time and frequency domain * Propagation of electromagnetic waves (in frequency and time domain) * UWB-Principles * UWB-antennas and applicators * Data processing * Applications.

  7. Monolithically integrated quantum dot optical modulator with Semiconductor optical amplifier for short-range optical communications

    Science.gov (United States)

    Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Kawanishi, Tetsuya

    2015-04-01

    A monolithically integrated quantum dot (QD) optical gain modulator (OGM) with a QD semiconductor optical amplifier (SOA) was successfully developed. Broadband QD optical gain material was used to achieve Gbps-order high-speed optical data transmission, and an optical gain change as high as approximately 6-7 dB was obtained with a low OGM voltage of 2.0 V. Loss of optical power due to insertion of the device was also effectively compensated for by the SOA section. Furthermore, it was confirmed that the QD-OGM/SOA device helped achieve 6.0-Gbps error-free optical data transmission over a 2.0-km-long photonic crystal fiber. We also successfully demonstrated generation of Gbps-order, high-speed, and error-free optical signals in the >5.5-THz broadband optical frequency bandwidth larger than the C-band. These results suggest that the developed monolithically integrated QD-OGM/SOA device will be an advantageous and compact means of increasing the usable optical frequency channels for short-reach communications.

  8. Investigation into short-range order, electric conductivity and optical absorption edge of indium selenide thin amorphous films

    International Nuclear Information System (INIS)

    Bilyj, M.N.; Didyk, G.V.; Stetsiv, Ya.I.; Yurechko, R.Ya.

    1980-01-01

    Thin amorphous films of InSe have been obtained by the method of discrete vacuum evaporation of about 10 -2 Pa. The short-range order is investigated according to the radial distribution curves. The temperature and film thickness are shown to affect the character of conductivity. The width of the forbidden band determined by the fundamental absorption edge is found to depend on the time of film annealing

  9. Electron irradiation effect on short-range ordering in Cu-Al and Ag-Al alloys

    International Nuclear Information System (INIS)

    Kulish, N.P.; Mel'nikova, N.A.; Petrenko, P.V.; Ryabishchuk, A.L.; Tatarov, A.A.

    1990-01-01

    Method of X-ray diffuse scattering is used to study short-range order variation in Cu-Al and Ag-Al alloys under radiation effect and the following heat treatment. Irradiation was carried out at -40 deg C by 1.6 MeV electrons, fluence of 5x10 7 cm -2 and 0.5 MeV gamma-rays, the dose being 10 7 pH

  10. Assessment of oscillator strengths with multiconfigurational short-range density functional theory for electronic excitations in organic molecules

    DEFF Research Database (Denmark)

    Hedegård, Erik Donovan

    2017-01-01

    considered the large collection of organic molecules whose excited states were investigated with a range of electronic structure methods by Thiel et al. As a by-product of our calculations of oscillator strengths, we also obtain electronic excitation energies, which enable us to compare the performance......We have in a series of recent papers investigated electronic excited states with a hybrid between a complete active space self-consistent field (CASSCF) wave function and density functional theory (DFT). This method has been dubbed the CAS short-range DFT method (CAS–srDFT). The previous papers...

  11. Santa Rosa Island Final Range Environmental Assessment, Revision 1. Eglin Air Force Base, Florida

    Science.gov (United States)

    2012-03-01

    west coast; 3) Dry Tortugas , Florida, Subpopulation; 4) Florida Panhandle Subpopulation occurring at Eglin AFB and the beaches near Panama City; and... Tortugas , florida, Subpopulation, (4) Northwest florida Subpopulation occurring at Eglin Ai r Force Base and the beaches near Panama City; and (5...annually from 1995 and 2005 (FWC/FWRI sea turtle nesting database and unpublished data). A nearly complete census of the Dry Tortugas Subpopulation

  12. Long-range synchronization and local desynchronization of alpha oscillations during visual short-term memory retention in children.

    Science.gov (United States)

    Doesburg, Sam M; Herdman, Anthony T; Ribary, Urs; Cheung, Teresa; Moiseev, Alexander; Weinberg, Hal; Liotti, Mario; Weeks, Daniel; Grunau, Ruth E

    2010-04-01

    Local alpha-band synchronization has been associated with both cortical idling and active inhibition. Recent evidence, however, suggests that long-range alpha synchronization increases functional coupling between cortical regions. We demonstrate increased long-range alpha and beta band phase synchronization during short-term memory retention in children 6-10 years of age. Furthermore, whereas alpha-band synchronization between posterior cortex and other regions is increased during retention, local alpha-band synchronization over posterior cortex is reduced. This constitutes a functional dissociation for alpha synchronization across local and long-range cortical scales. We interpret long-range synchronization as reflecting functional integration within a network of frontal and visual cortical regions. Local desynchronization of alpha rhythms over posterior cortex, conversely, likely arises because of increased engagement of visual cortex during retention.

  13. Localization of short-range acoustic and seismic wideband sources: Algorithms and experiments

    Science.gov (United States)

    Stafsudd, J. Z.; Asgari, S.; Hudson, R.; Yao, K.; Taciroglu, E.

    2008-04-01

    We consider the determination of the location (source localization) of a disturbance source which emits acoustic and/or seismic signals. We devise an enhanced approximate maximum-likelihood (AML) algorithm to process data collected at acoustic sensors (microphones) belonging to an array of, non-collocated but otherwise identical, sensors. The approximate maximum-likelihood algorithm exploits the time-delay-of-arrival of acoustic signals at different sensors, and yields the source location. For processing the seismic signals, we investigate two distinct algorithms, both of which process data collected at a single measurement station comprising a triaxial accelerometer, to determine direction-of-arrival. The direction-of-arrivals determined at each sensor station are then combined using a weighted least-squares approach for source localization. The first of the direction-of-arrival estimation algorithms is based on the spectral decomposition of the covariance matrix, while the second is based on surface wave analysis. Both of the seismic source localization algorithms have their roots in seismology; and covariance matrix analysis had been successfully employed in applications where the source and the sensors (array) are typically separated by planetary distances (i.e., hundreds to thousands of kilometers). Here, we focus on very-short distances (e.g., less than one hundred meters) instead, with an outlook to applications in multi-modal surveillance, including target detection, tracking, and zone intrusion. We demonstrate the utility of the aforementioned algorithms through a series of open-field tests wherein we successfully localize wideband acoustic and/or seismic sources. We also investigate a basic strategy for fusion of results yielded by acoustic and seismic arrays.

  14. Kinetic arrest and glass-glass transition in short-ranged attractive colloids

    International Nuclear Information System (INIS)

    Sztucki, M.; Narayanan, T.; Belina, G.; Moussaied, A.; Pignon, F.; Hoekstra, H.

    2006-01-01

    A thermally reversible repulsive hard-sphere to sticky-sphere transition was studied in a model colloidal system over a wide volume fraction range. The static microstructure was obtained from high resolution small angle x-ray scattering, the colloid dynamics was probed by dynamic x-ray and light scattering, and supplementary mechanical properties were derived from bulk rheology. At low concentration, the system shows features of gas-liquid type phase separation. The bulk phase separation is presumably interrupted by a gelation transition at the intermediate volume fraction range. At high volume fractions, fluid-attractive glass and repulsive glass-attractive glass transitions are observed. It is shown that the volume fraction of the particles can be reliably deduced from the absolute scattered intensity. The static structure factor is modeled in terms of an attractive square-well potential, using the leading order series expansion of Percus-Yevick approximation. The ensemble-averaged intermediate scattering function shows different levels of frozen components in the attractive and repulsive glassy states. The observed static and dynamic behavior are consistent with the predictions of a mode-coupling theory and numerical simulations for a square-well attractive system

  15. Transverse deflections in a cavity due to the short-range longitudinal wake

    International Nuclear Information System (INIS)

    Bane, K

    2003-01-01

    Consider an ultra-relativistic electron bunch passing through a (cylindrically symmetric) multi-cell linac cavity that is filled with fundamental mode rf. It is well known that this bunch--on entering the cavity--experiences a focusing kick, and--on exiting the cavity--a defocusing kick, even though the mode is cylindrically symmetric. The effects of these kicks in linacs tend to be significant only in low energy regions. Tracking computer programs such as MAD [1] and LIAR [2] include a simple model of these kicks, one based on calculations of W.H. Panofsky [3]. According to this model the effect is represented by two thin lenses positioned at the ends of the cavity, with the strength of the lenses dependent on the accelerating gradient in the cavity. However, a beam will itself excite wakefields that modify its energy gain in a cavity, a modification that depends also on longitudinal position within the bunch. The program LIAR extends Panofsky's rf kick model to include this modification to the effective gradient experienced by different parts of the beam. In this report we investigate how the wakefields affect the rf cavity kicks. In particular, we are interested in the case when the wakefields are a significant perturbation to the problem, such as when, for example, the beam traverses an empty cavity (one with no rf). In this report we have shown that one can calculate the transverse kicks when one knows the time-dependent variation of the longitudinal wake forces on axis. The variation in gradient due to wakefields, however, will in general differ from that due to normal rf acceleration. In particular, transients at the ends of structures, and--for constant gradient structures--an increase in gradient amplitude from beginning to end of the cavity, will mean that the model of focusing/defocusing edges, used for rf acceleration, will be inaccurate. Finally, we conclude that the method LIAR uses to treat the effect of rf focusing in the presence of wakefields on

  16. The effect of Cs-137 short-range spatial variability on soil after the Chernobyl disaster

    Science.gov (United States)

    Martynenko, Vladimir; Vakulovsky, Sergey; Linnik, Vitaly

    2014-05-01

    After the Chernobyl accident of 1986, large areas of Russia were contaminated by 137Cs. Post-depositional redistribution of 137Cs fallout across the land surface resulting from mechanical, physical, chemical, and biological processes operating in the soil system and the grain size selectivity associated with soil erosion and sediment transport processes. Therefore of uppermost importance are data on evaluating 137Cs variability at short distances, obtained at the early period after the accident. Measurements of 137Cs deposit at the territory of Russia exposed to radioactive contamination were mainly conducted with the help of air-gamma survey, and were verified by soil sampling on test plots with size 10x10 m with control soil sampling using "envelope" method of fivefold soil sampling (1 sampling at the centre and 4 along the edges of the plot under study). Presented here are evaluation data of 137Cs contamination, obtained in the Bryansk, Yaroslav and Rostov regions in 1991. Test plots were selected at the distance of 50-100 m away from a road on matted areas with undisturbed soil structure. Test routes of sampling were made perpendicularly to directions crossing basic traces of radioactive contamination. Sampling measurements were carried out at Canberra and Ortec gamma spectrometers. Each of the 5 samples of the "envelope" was measured separately, soil mixing was not applied. 137Cs value for the Bryansk Region varied from 2,6 kBq/m2 to 2294 kBq/m2, at the territories of the Yaroslav and Rostov regions 137Cs value varied from 0,44 kBq/m2 to 5,1 kBq/m2 and 0,56 kBq/m2 to 22,2 kBq/m2, respectively. Statistical analysis of 137Cs deposit at different plots is a solid argumentation in favour of nonuniform distribution in various landscapes and at a different distance from the Chernobyl NPP. Such nonuniformity of 137Cs soil contamination in the limits of 10 m of the plot is most likely to be related to initial aerosol contamination nonuniformity at the moment of

  17. Investigation of Multiconfigurational Short-Range Density Functional Theory for Electronic Excitations in Organic Molecules

    DEFF Research Database (Denmark)

    Hubert, Mickaël; Hedegård, Erik D.; Jensen, Hans Jørgen Aa

    2016-01-01

    -srDFT for a selected benchmark set of electronic excitations of organic molecules, covering the most common types of organic chromophores. This investigation confirms the expectation that the MC-srDFT method is accurate for a broad range of excitations and comparable to accurate wave function methods such as CASPT2......Computational methods that can accurately and effectively predict all types of electronic excitations for any molecular system are missing in the toolbox of the computational chemist. Although various Kohn-Sham density-functional methods (KS-DFT) fulfill this aim in some cases, they become...... and double excitations have been promising, it is nevertheless important that the accuracy of MC-srDFT is at least comparable to the best KS-DFT methods also for organic molecules that are typically of single-reference character. In this paper we therefore systematically investigate the performance of MC...

  18. StereoBox: A Robust and Efficient Solution for Automotive Short-Range Obstacle Detection

    Directory of Open Access Journals (Sweden)

    Alberto Broggi

    2007-07-01

    Full Text Available This paper presents a robust method for close-range obstacle detection with arbitrarily aligned stereo cameras. System calibration is performed by means of a dense grid to remove perspective and lens distortion after a direct mapping between image pixels and world points. Obstacle detection is based on the differences between left and right images after transformation phase and with a polar histogram, it is possible to detect vertical structures and to reject noise and small objects. Found objects' world coordinates are transmitted via CAN bus; the driver can also be warned through an audio interface. The proposed algorithm can be useful in different automotive applications, requiring real-time segmentation without any assumption on background. Experimental results proved the system to be robust in several envitonmental conditions. In particular, the system has been tested to investigate presence of obstacles in blind spot areas around heavy goods vehicles (HGVs and has been mounted on three different prototypes at different heights.

  19. StereoBox: A Robust and Efficient Solution for Automotive Short-Range Obstacle Detection

    Directory of Open Access Journals (Sweden)

    Broggi Alberto

    2007-01-01

    Full Text Available This paper presents a robust method for close-range obstacle detection with arbitrarily aligned stereo cameras. System calibration is performed by means of a dense grid to remove perspective and lens distortion after a direct mapping between image pixels and world points. Obstacle detection is based on the differences between left and right images after transformation phase and with a polar histogram, it is possible to detect vertical structures and to reject noise and small objects. Found objects' world coordinates are transmitted via CAN bus; the driver can also be warned through an audio interface. The proposed algorithm can be useful in different automotive applications, requiring real-time segmentation without any assumption on background. Experimental results proved the system to be robust in several envitonmental conditions. In particular, the system has been tested to investigate presence of obstacles in blind spot areas around heavy goods vehicles (HGVs and has been mounted on three different prototypes at different heights.

  20. Formation and transformation of a short range ordered iron carbonate precursor

    DEFF Research Database (Denmark)

    Dideriksen, Knud; Frandsen, Cathrine; Bovet, Nicolas

    2015-01-01

    (II) with varying pH produced broad peaks in X-ray diffraction and contained dominantly Fe and CO3 when probed with X-ray photoelectron spectroscopy. Reduced pair distribution function (PDF) analysis shows only peaks corresponding to interatomic distances below 15Å, reflecting a material with no long range...... structural order. Moreover, PDF peak positions differ from those for known iron carbonates and hydroxides. Mössbauer spectra also deviate from those expected for known iron carbonates and suggest a less crystalline structure. These data show that a previously unidentified iron carbonate precursor phase...... formed. Its coherent scattering domains determined from PDF analysis are slightly larger than for amorphous calcium carbonate, suggesting that the precursor could be nanocrystalline. Replica exchange molecular dynamics simulations of Fe-carbonate polynuclear complexes yield PDF peak positions that agree...

  1. Analysis of short time-space range seismicity patterns in Italy

    Directory of Open Access Journals (Sweden)

    M. Imotof

    1997-06-01

    Full Text Available In our paper we analyze the data base obtained from the observations of the Italian Seismological Network from 1975 to 1994 by using a simple algotithm to determine the rate of occurrence of seismic events condi- tioned by the occurrence of previous events after a period of quiescence. The number of observed pairs of earthquakes depends on several parameters: the magnitude threshold of the two events, the spatial and tempo- ral ranges of the quiescence period preceding the first (non aftershock event, the time elapsed between the first and the second events and the spatial dimension of the alarm area. The Akaike information criterion was adopted to assess the optimal set of space-time parameters used in the definition of non-aftershock (events not related to a stronger previous one. In Central Italy, the rate of M ³3.8 earthquakes preceded by at least one M ~ 3.3 foreshock within 14.1 km and 2 days is 30%, while the rate of M ~ 3.3 earthquakes followed by a M ~ 3.8 mainshock in the same space time range is 7%. We observed that the probability that an earthquake of magnitude MI will be followed by an earthquake of magnitude M2 (success rate fits the law log À = a+b (Mi -M2 with b approximately equal to l. By computing the success rate for given values of magnitude threshold of the first and the second events over a dense grid of spatial coordinates, we obtained maps of this feature over the investigated area. The results of this process document variations larger than a factor of five in the success rate over the Italian territory.

  2. Short-Range Vital Signs Sensing Based on EEMD and CWT Using IR-UWB Radar

    Directory of Open Access Journals (Sweden)

    Xikun Hu

    2016-11-01

    Full Text Available The radar sensor described realizes healthcare monitoring capable of detecting subject chest-wall movement caused by cardiopulmonary activities and wirelessly estimating the respiration and heartbeat rates of the subject without attaching any devices to the body. Conventional single-tone Doppler radar can only capture Doppler signatures because of a lack of bandwidth information with noncontact sensors. In contrast, we take full advantage of impulse radio ultra-wideband (IR-UWB radar to achieve low power consumption and convenient portability, with a flexible detection range and desirable accuracy. A noise reduction method based on improved ensemble empirical mode decomposition (EEMD and a vital sign separation method based on the continuous-wavelet transform (CWT are proposed jointly to improve the signal-to-noise ratio (SNR in order to acquire accurate respiration and heartbeat rates. Experimental results illustrate that respiration and heartbeat signals can be extracted accurately under different conditions. This noncontact healthcare sensor system proves the commercial feasibility and considerable accessibility of using compact IR-UWB radar for emerging biomedical applications.

  3. A short and long range study of mullite-zirconia-zircon composites

    Energy Technology Data Exchange (ETDEWEB)

    Rendtorff, Nicolas M.; Conconi, Maria S.; Aglietti, Esteban F. [Centro de Tecnologia de Recursos Minerales y Ceramica (CETMIC: CONICET-CIC) (Argentina); Chain, Cecilia Y.; Pasquevich, Alberto F. [Universidad Nacional de La Plata, Departamento de Fisica, IFLP, Facultad de Ciencias Exactas (Argentina); Rivas, Patricia C. [CONICET (Argentina); Martinez, Jorge A., E-mail: toto@fisica.unlp.edu.ar; Caracoche, Maria C. [Universidad Nacional de La Plata, Departamento de Fisica, IFLP, Facultad de Ciencias Exactas (Argentina)

    2010-06-15

    In the field of refractory materials, ceramics containing mullite-zirconia are the basis of those most used in the industry of glass and steel. It is known that the addition of zircon improves the behavior of the refractory used in service. Knowing that some mullite-zirconia composites properties as fracture strength and the elastic modulus E are associated with the material microstructure integrity, the eventual thermal decomposition of zircon into zirconia and silica could seriously alter the material elastic properties. In this paper the phase content of a series of mullite-zirconia-zircon (3Al{sub 2}O{sub 3}.2SiO{sub 2}-ZrO{sub 2}-ZrSiO{sub 4}) composites is determined at atomic level via perturbed angular correlations (PAC) and compared with that derived from the long range X-ray diffraction technique. PAC results on the as-prepared materials indicate that all nominal zircon is present and that it involves two types of nanoconfigurations, one of them describing aperiodic regions. The thermomechanical properties already reported for these materials could be related to the crystalline to aperiodic zircon concentrations ratio they exhibit.

  4. Natural gels: crystal-chemistry of short range ordered components in Al, Fe, and Si systems

    International Nuclear Information System (INIS)

    Ildefonse, Ph.; Calas, G.

    1997-01-01

    In this review, the most important inorganic natural gels are presented: opal, aluminosilicate (allophanes) and hydrous iron oxides and silicates. It is demonstrated that natural gels are ordered at the atomic scale. In allophanes, Al is distributed between octahedral and tetrahedral sites. The amount of Al increases as Al/Si ratio decreases. Si-rich allophane have a local structure around Al and Si very different of that is known in kaolinite or halloysite. Transformation of Si-rich allophanes to crystallized minerals implies dissolution-recrystallization processes. On the contrary, in iron silicate with Fe/Si = 0.72, Si and Fe environments are close to those found in nontronite. The gel transformation to Fe-smectite may occur by long range ordering during ageing. In ferric silicate gels, the similarity of local structure around Fe in poorly ordered precursors and what is known in crystallized minerals suggests a solid transformation during ageing. This difference between iron and aluminium is mainly due to the ability of Al to enter both tetrahedral and octahedral sites, while the affinity of iron for octahedral sites is higher at low temperature

  5. An interferometric radar sensor for monitoring the vibrations of structures at short ranges

    Directory of Open Access Journals (Sweden)

    Luzi Guido

    2018-01-01

    Full Text Available The Real-Aperture-Radar (RAR interferometry technique consolidated in the last decade as an operational tool for the monitoring of large civil engineering structures as bridges, towers, and buildings. In literature, experimental campaigns collected through a well-known commercial equipment have been widely documented, while the cases where different types of sensors have been tested are a few. On the bases of some experimental tests, a new sensor working at high frequency, providing some improved performances, is here discussed. The core of the proposed system is an off-the-shelf, linear frequency modulated continuous wave device. The development of this apparatus is aimed at achieving a proof-of-concept, tackling operative aspects related to the development of a low cost and reliable system. The capability to detect the natural frequencies of a lightpole has been verified; comparing the results of the proposed sensor with those ones obtained through a commercial system based on the same technique, a more detailed description of the vibrating structure has been achieved. The results of this investigation confirmed that the development of sensors working at higher frequencies, although deserving deeper studies, is very promising and could open new applications demanding higher spatial resolutions at close ranges.

  6. Wind field reconstruction from nacelle-mounted lidar short-range measurements

    Directory of Open Access Journals (Sweden)

    A. Borraccino

    2017-05-01

    Full Text Available Profiling nacelle lidars probe the wind at several heights and several distances upstream of the rotor. The development of such lidar systems is relatively recent, and it is still unclear how to condense the lidar raw measurements into useful wind field characteristics such as speed, direction, vertical and longitudinal gradients (wind shear. In this paper, we demonstrate an innovative method to estimate wind field characteristics using nacelle lidar measurements taken within the induction zone. Model-fitting wind field reconstruction techniques are applied to nacelle lidar measurements taken at multiple distances close to the rotor, where a wind model is combined with a simple induction model. The method allows robust determination of free-stream wind characteristics. The method was applied to experimental data obtained with two different types of nacelle lidar (five-beam Demonstrator and ZephIR Dual Mode. The reconstructed wind speed was within 0.5 % of the wind speed measured with a mast-top-mounted cup anemometer at 2.5 rotor diameters upstream of the turbine. The technique described in this paper overcomes measurement range limitations of the currently available nacelle lidar technology.

  7. Elastic properties and short-range structural order in mixed network former glasses.

    Science.gov (United States)

    Wang, Weimin; Christensen, Randilynn; Curtis, Brittany; Hynek, David; Keizer, Sydney; Wang, James; Feller, Steve; Martin, Steve W; Kieffer, John

    2017-06-21

    Elastic properties of alkali containing glasses are of great interest not only because they provide information about overall structural integrity but also they are related to other properties such as thermal conductivity and ion mobility. In this study, we investigate two mixed-network former glass systems, sodium borosilicate 0.2Na 2 O + 0.8[xBO 1.5 + (1 - x)SiO 2 ] and sodium borogermanate 0.2Na 2 O + 0.8[xBO 1.5 + (1 - x)GeO 2 ] glasses. By mixing network formers, the network topology can be changed while keeping the network modifier concentration constant, which allows for the effect of network structure on elastic properties to be analyzed over a wide parametric range. In addition to non-linear, non-additive mixed-glass former effects, maxima are observed in longitudinal, shear and Young's moduli with increasing atomic number density. By combining results from NMR spectroscopy and Brillouin light scattering with a newly developed statistical thermodynamic reaction equilibrium model, it is possible to determine the relative proportions of all network structural units. This new analysis reveals that the structural characteristic predominantly responsible for effective mechanical load transmission in these glasses is a high density of network cations coordinated by four or more bridging oxygens, as it provides for establishing a network of covalent bonds among these cations with connectivity in three dimensions.

  8. Ultra-short laser pulse ablation using shear-force feedback: Femtosecond laser induced breakdown spectroscopy feasibility study

    International Nuclear Information System (INIS)

    Samek, Ota; Kurowski, Andre; Kittel, Silke; Kukhlevsky, Sergei; Hergenroeder, Roland

    2005-01-01

    This work reports on a feasibility study of proximity ablation using femtosecond pulses. Ultra-short pulses were launched to a bare tapered optical fiber and delivered to the sample. The tip-sample distance was controlled by means of shear-force feedback. Consequently, ablation craters with submicrometer dimensions were obtained. Potential analytical applications for Laser Induced Breakdown Spectroscopy (LIBS) technique, such as e.g. inclusions in steel or bio cells, are suggested

  9. Competition between crystallization and glassification for particles with short-ranged attraction. Possible applications to protein crystallization

    Science.gov (United States)

    Zaccarelli, E.; Sciortino, F.; Tartaglia, P.; Foffi, G.; McCullagh, G. D.; Lawlor, A.; Dawson, K. A.

    2002-11-01

    We discuss the phase behaviour of spherical hard-core particles, with an attractive potential, as described by a hard-core Yukawa model. The ratio of the range of the attraction to the diameter of the particles is an important control parameter of the problem. Upon decreasing the range of the attraction, the phase diagram changes quite significantly, with the liquid-gas transition becoming metastable, and the crystal being in equilibrium with the fluid, with no intervening liquid. We also study the glass transition lines and, crucially, find that the situation, being very simple for pure repulsive potentials, becomes much richer in competition between glass and crystal phases for short-range attractions. Also a transition between attractive and repulsive glass appears somewhat in analogy with the isostructural equilibrium transition between two crystals.

  10. Chapter 4: Pulsating Wave Loads Section 4.3: 3D Effects Force Reduction of Short-Crested Non-Breaking Waves on Caissons

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Liu, Zhou

    1999-01-01

    The effect of wave short-crestedness on the horizontal wave force on a caisson is twofold. The one is the force reduction due to the reduction of point pressure on the caisson, named point-pressure reduction. The other is the force reduction due to the fact that the peak pressures do not occur si...

  11. Evolution of short range order in Ar: Liquid to glass and solid transitions-A computational study

    Science.gov (United States)

    Shor, Stanislav; Yahel, Eyal; Makov, Guy

    2018-04-01

    The evolution of the short range order (SRO) as a function of temperature in a Lennard-Jones model liquid with Ar parameters was determined and juxtaposed with thermodynamic and kinetic properties obtained as the liquid was cooled (heated) and transformed between crystalline solid or glassy states and an undercooled liquid. The Lennard-Jones system was studied by non-equilibrium molecular dynamics simulations of large supercells (approximately 20000 atoms) rapidly cooled or heated at selected quenching rates and at constant pressure. The liquid to solid transition was identified by discontinuities in the atomic volume and molar enthalpy; the glass transition temperature range was identified from the temperature dependence of the self-diffusion. The SRO was studied within the quasi-crystalline model (QCM) framework and compared with the Steinhardt bond order parameters. Within the QCM it was found that the SRO evolves from a bcc-like order in the liquid through a bct-like short range order (c/a=1.2) in the supercooled liquid which persists into the glass and finally to a fcc-like ordering in the crystalline solid. The variation of the SRO that results from the QCM compares well with that obtained with Steinhardt's bond order parameters. The hypothesis of icosahedral order in liquids and glasses is not supported by our results.

  12. Short-range order in the quantum XXZ honeycomb lattice material BaCo2(PO4)2

    Science.gov (United States)

    Nair, Harikrishnan S.; Brown, J. M.; Coldren, E.; Hester, G.; Gelfand, M. P.; Podlesnyak, A.; Huang, Q.; Ross, K. A.

    2018-04-01

    We present observations of highly frustrated quasi-two-dimensional (2D) magnetic correlations in the honeycomb lattice layers of the Seff =1 /2 compound γ -BaCo2(PO4)2 (γ -BCPO). Specific heat shows a broad peak comprised of two weak kink features at TN 1˜6 K and TN 2˜3.5 K, the relative weights of which can be modified by sample annealing. Neutron powder diffraction measurements reveal short range quasi-2D order that is established below TN 1 and TN 2, at which two separate, incompatible, short range magnetic orders onset: commensurate antiferromagnetic correlations with correlation length ξc=60 ±2 Å (TN 1) and in quasi-2D helical domains with ξh=350 ±11 Å (TN 2). The ac magnetic susceptibility response lacks frequency dependence, ruling out spin freezing. Inelastic neutron scattering data on γ -BCPO is compared with linear spin wave theory, and two separate parameter regions of the XXZ J1-J2-J3 model with ferromagnetic nearest-neighbor exchange J1 are favored, both near regions of high classical degeneracy. High energy coherent excitations (˜10 meV) persist up to at least 40 K, suggesting strong in-plane correlations persist above TN. These data show that γ -BCPO is a rare highly frustrated, quasi-2D Seff =1 /2 honeycomb lattice material which resists long range magnetic order and spin freezing.

  13. A NEUTRON DIFFRACTION DETERMINATION OF SHORT RANGE ORDER IN A Ni63.7Zr36.3 GLASS

    OpenAIRE

    Bellissent , R.; Bigot , J.; Calvayrac , Y.; Lefebvre , S.; Quivy , A.

    1985-01-01

    A precise determination of the three partial structure factors for the eutectic composition Ni63.7Zr36.3 has been carried out using neutron diffraction on three isotopically substituted glasses. The use of a "zero alloy" yields a direct determination of the Bhatia-Thornton structure factor SCC. Evidence for the existence of strong chemical short-range order and a clear size effect is obtained. Due to this chemical order, the partial structure factors cannot be consistent with the ones calcula...

  14. Mean-Field Theory of Electrical Double Layer In Ionic Liquids with Account of Short-Range Correlations

    International Nuclear Information System (INIS)

    Goodwin, Zachary A.H.; Feng, Guang; Kornyshev, Alexei A.

    2017-01-01

    We develop the theory of the electrical double layer in ionic liquids as proposed earlier by Kornyshev (2007). In the free energy function we keep the so called ‘short-range correlation terms’ which were omitted there. With some simplifying assumptions, we arrive at a modified expression for differential capacitance, which makes differential capacitance curves less sharply depending on electrode potential and having smaller values at extrema than in the previous theory. This brings the results closer to typical experimental observations, and makes it appealing to use this formalism for treatment of experimental data. Implications on Debye length and the extent of ion paring in ionic liquids are then briefly discussed.

  15. Tennessee Army National Guard (TNARNG) Range Expansion at Arnold Air Force Base, Tennessee. Environmental Assessment

    Science.gov (United States)

    2012-11-01

    Ecological Services Field Office for the U.S. Fish and Wildlife Service (USFWS). The Tennessee Historical Commission, State Historic Preservation Office...Alternate) 12 SEAVAN sites Prefabricated – no new construction required CACTF (Primary) Road network 0 1,800 n/a n/a Gravel pads for pre-fab...management to prevent undesirable ecosystem changes. Recognizing the ecological NOVEMBER 2012 | EA_2013_TNARNG_Range_Expansion Page 3-6 and economic

  16. Short-term occupancy and abundance dynamics of the Oregon spotted frog (Rana pretiosa) across its core range

    Science.gov (United States)

    Adams, Michael J.; Pearl, Christopher A.; Mccreary, Brome; Galvan, Stephanie

    2014-01-01

    The Oregon spotted frog (Rana pretiosa) occupies only a fraction of its original range and is listed as Threatened under the Endangered Species Act. We surveyed 93 sites in a rotating frame design (2010–13) in the Klamath and Deschutes Basins, Oregon, which encompass most of the species’ core extant range. Oregon spotted frogs are declining in abundance and probability of site occupancy. We did not find an association between the probability that Oregon spotted frogs disappear from a site (local extinction) and any of the variables hypothesized to affect Oregon spotted frog occupancy. This 4-year study provides baseline data, but the 4-year period was too short to draw firm conclusions. Further study is essential to understand how habitat changes and management practices relate to the status and trends of this species.

  17. Laser-induced short- and long-range orderings of Co nanoparticles on SiO2

    International Nuclear Information System (INIS)

    Favazza, C.; Trice, J.; Krishna, H.; Kalyanaraman, R.; Sureshkumar, R.

    2006-01-01

    Laser irradiation of ultrathin Co films leads to pattern formation by dewetting with short-range order (SRO) as well as long-range order (LRO). When a 1.5 nm thick Co film is irradiated by a single laser beam, a monomodal size distribution of particles with average diameter of 31±10 nm and nearest-neighbor spacing of 75 nm is observed. Moreover, melting by two-beam interference irradiation produces LRO as well as SRO giving a quasi-two-dimensional arrangement of nanoparticles. The SRO is attributed to spinodal dewetting while the LRO is conjectured to be induced by in-plane interfacial tension gradients. Laser-induced dewetting of metals could be a simple technique to fabricate ordered metal nanoarrays

  18. SSB of Scale Symmetry, Fermion Families and Quintessence without the Long-Range Force Problem

    Science.gov (United States)

    Guendelman, E. I.; Kaganovich, A. B.

    We study a scale-invariant two measures theory where a dilaton field φ has no explicit potentials. The scale transformations include the translation of a dilaton φ-->φ+ const. The theory demonstrates a new mechanism for generation of the exponential potential: in the conformal Einstein frame (CEF), after SSB of scale invariance, the theory develops the exponential potential and, in general, the nonlinear kinetic term is generated as well. The scale symmetry does not allow the appearance of terms breaking the exponential shape of the potential that solves the problem of the flatness of the scalar field potential in the context of quintessential scenarios. As examples, two different possibilities for the choice of the dimensionless parameters are presented where the theory permits to get interesting cosmological results. For the first choice, the theory has standard scaling solutions for φ usually used in the context of the quintessential scenario. For the second choice, the theory allows three different solutions, one of which is a scaling solution with equation of state pφ=wρφ where w is predicted to be restricted by -1force'' is absent. For the third type of particles, a fermionic self-interaction appears as a result of SSB of scale invariance.

  19. Solvent-shared pairs of densely charged ions induce intense but short-range supra-additive slowdown of water rotation.

    Science.gov (United States)

    Vila Verde, Ana; Santer, Mark; Lipowsky, Reinhard

    2016-01-21

    The question "Can ions exert supra-additive effects on water dynamics?" has had several opposing answers from both simulation and experiment. We address this ongoing controversy by investigating water reorientation in aqueous solutions of two salts with large (magnesium sulfate) and small (cesium chloride) effects on water dynamics using molecular dynamics simulations and classical, polarizable models. The salt models are reparameterized to reproduce properties of both dilute and concentrated solutions. We demonstrate that water rotation in concentrated MgSO4 solutions is unexpectedly slow, in agreement with experiment, and that the slowdown is supra-additive: the observed slowdown is larger than that predicted by assuming that the resultant of the extra forces induced by the ions on the rotating water molecules tilts the free energy landscape associated with water rotation. Supra-additive slow down is very intense but short-range, and is strongly ion-specific: in contrast to the long-range picture initially proposed based on experiment, we find that intense supra-additivity is limited to water molecules directly bridging two ions in solvent-shared ion pair configuration; in contrast to a non-ion-specific origin to supra-additive effects proposed from simulations, we find that the magnitude of supra-additive slowdown strongly depends on the identity of the cations and anions. Supra-additive slowdown of water dynamics requires long-lived solvent-shared ion pairs; long-lived ion pairs should be typical for salts of multivalent ions. We discuss the origin of the apparent disagreement between the various studies on this topic and show that the short-range cooperative slowdown scenario proposed here resolves the existing controversy.

  20. Altered long-range alpha-band synchronization during visual short-term memory retention in children born very preterm.

    Science.gov (United States)

    Doesburg, Sam M; Ribary, Urs; Herdman, Anthony T; Miller, Steven P; Poskitt, Kenneth J; Moiseev, Alexander; Whitfield, Michael F; Synnes, Anne; Grunau, Ruth E

    2011-02-01

    Children born very preterm, even when intelligence is broadly normal, often experience selective difficulties in executive function and visual-spatial processing. Development of structural cortical connectivity is known to be altered in this group, and functional magnetic resonance imaging (fMRI) evidence indicates that very preterm children recruit different patterns of functional connectivity between cortical regions during cognition. Synchronization of neural oscillations across brain areas has been proposed as a mechanism for dynamically assigning functional coupling to support perceptual and cognitive processing, but little is known about what role oscillatory synchronization may play in the altered neurocognitive development of very preterm children. To investigate this, we recorded magnetoencephalographic (MEG) activity while 7-8 year old children born very preterm and age-matched full-term controls performed a visual short-term memory task. Very preterm children exhibited reduced long-range synchronization in the alpha-band during visual short-term memory retention, indicating that cortical alpha rhythms may play a critical role in altered patterns functional connectivity expressed by this population during cognitive and perceptual processing. Long-range alpha-band synchronization was also correlated with task performance and visual-perceptual ability within the very preterm group, indicating that altered alpha oscillatory mechanisms mediating transient functional integration between cortical regions may be relevant to selective problems in neurocognitive development in this vulnerable population at school age. Copyright © 2010 Elsevier Inc. All rights reserved.

  1. Modeling Short-Range Soil Variability and its Potential Use in Variable-Rate Treatment of Experimental Plots

    Directory of Open Access Journals (Sweden)

    A Moameni

    2011-02-01

    Full Text Available Abstract In Iran, the experimental plots under fertilizer trials are managed in such a way that the whole plot area uniformly receives agricultural inputs. This could lead to biased research results and hence to suppressing of the efforts made by the researchers. This research was conducted in a selected site belonging to the Gonbad Agricultural Research Station, located in the semiarid region, northeastern Iran. The aim was to characterize the short-range spatial variability of the inherent and management-depended soil properties and to determine if this variation is large and can be managed at practical scales. The soils were sampled using a grid 55 m apart. In total, 100 composite soil samples were collected from topsoil (0-30 cm and were analyzed for calcium carbonate equivalent, organic carbon, clay, available phosphorus, available potassium, iron, copper, zinc and manganese. Descriptive statistics were applied to check data trends. Geostatistical analysis was applied to variography, model fitting and contour mapping. Sampling at 55 m made it possible to split the area of the selected experimental plot into relatively uniform areas that allow application of agricultural inputs with variable rates. Keywords: Short-range soil variability, Within-field soil variability, Interpolation, Precision agriculture, Geostatistics

  2. Ultra-low-power and ultra-low-cost short-range wireless receivers in nanoscale CMOS

    CERN Document Server

    Lin, Zhicheng; Martins, Rui Paulo

    2016-01-01

    This book provides readers with a description of state-of-the-art techniques to be used for ultra-low-power (ULP) and ultra-low-cost (ULC), short-range wireless receivers. Readers will learn what is required to deploy these receivers in short-range wireless sensor networks, which are proliferating widely to serve the internet of things (IoT) for “smart cities.” The authors address key challenges involved with the technology and the typical tradeoffs between ULP and ULC. Three design examples with advanced circuit techniques are described in order to address these trade-offs, which specially focus on cost minimization. These three techniques enable respectively, cascading of radio frequency (RF) and baseband (BB) circuits under an ultra-low-voltage (ULV) supply, cascoding of RF and BB circuits in current domain for current reuse, and a novel function-reuse receiver architecture, suitable for ULV and multi-band ULP applications such as the sub-GHz ZigBee. ·         Summarizes the state-of-the-art i...

  3. Short-range correlations control the G/K and Poisson ratios of amorphous solids and metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Zaccone, Alessio; Terentjev, Eugene M. [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

    2014-01-21

    The bulk modulus of many amorphous materials, such as metallic glasses, behaves nearly in agreement with the assumption of affine deformation, namely that the atoms are displaced just by the amount prescribed by the applied strain. In contrast, the shear modulus behaves as for nonaffine deformations, with additional displacements due to the structural disorder which induce a marked material softening to shear. The consequence is an anomalously large ratio of the bulk modulus to the shear modulus for disordered materials characterized by dense atomic packing, but not for random networks with point atoms. We explain this phenomenon with a microscopic derivation of the elastic moduli of amorphous solids accounting for the interplay of nonaffinity and short-range particle correlations due to excluded volume. Short-range order is responsible for a reduction of the nonaffinity which is much stronger under compression, where the geometric coupling between nonaffinity and the deformation field is strong, whilst under shear this coupling is weak. Predictions of the Poisson ratio based on this model allow us to rationalize the trends as a function of coordination and atomic packing observed with many amorphous materials.

  4. Impact of preindustrial to present-day changes in short-lived pollutant emissions on atmospheric composition and climate forcing

    Science.gov (United States)

    Naik, Vaishali; Horowitz, Larry W.; Fiore, Arlene M.; Ginoux, Paul; Mao, Jingqiu; Aghedo, Adetutu M.; Levy, Hiram

    2013-07-01

    We describe and evaluate atmospheric chemistry in the newly developed Geophysical Fluid Dynamics Laboratory chemistry-climate model (GFDL AM3) and apply it to investigate the net impact of preindustrial (PI) to present (PD) changes in short-lived pollutant emissions (ozone precursors, sulfur dioxide, and carbonaceous aerosols) and methane concentration on atmospheric composition and climate forcing. The inclusion of online troposphere-stratosphere interactions, gas-aerosol chemistry, and aerosol-cloud interactions (including direct and indirect aerosol radiative effects) in AM3 enables a more complete representation of interactions among short-lived species, and thus their net climate impact, than was considered in previous climate assessments. The base AM3 simulation, driven with observed sea surface temperature (SST) and sea ice cover (SIC) over the period 1981-2007, generally reproduces the observed mean magnitude, spatial distribution, and seasonal cycle of tropospheric ozone and carbon monoxide. The global mean aerosol optical depth in our base simulation is within 5% of satellite measurements over the 1982-2006 time period. We conduct a pair of simulations in which only the short-lived pollutant emissions and methane concentrations are changed from PI (1860) to PD (2000) levels (i.e., SST, SIC, greenhouse gases, and ozone-depleting substances are held at PD levels). From the PI to PD, we find that changes in short-lived pollutant emissions and methane have caused the tropospheric ozone burden to increase by 39% and the global burdens of sulfate, black carbon, and organic carbon to increase by factors of 3, 2.4, and 1.4, respectively. Tropospheric hydroxyl concentration decreases by 7%, showing that increases in OH sinks (methane, carbon monoxide, nonmethane volatile organic compounds, and sulfur dioxide) dominate over sources (ozone and nitrogen oxides) in the model. Combined changes in tropospheric ozone and aerosols cause a net negative top

  5. A Sinusoidal Applied Electric Potential can Induce a Long-Range, Steady Electrophoretic Force

    Science.gov (United States)

    Amrei, Seyyed Hashemi; Ristenpart, William D.; Miller, Greg R.

    2017-11-01

    We use the standard electrokinetic model to numerically investigate the electric field in aqueous solutions between parallel electrodes under AC polarization. In contrast to prior work, we invoke no simplifying assumptions regarding the applied voltage, frequency, or mismatch in ionic mobilities. We find that the nonlinear electromigration terms significantly contribute to the overall shape of the electric potential vs. time, which at sufficiently high applied potentials develops multi-modal peaks. More surprisingly, we find that electrolytes with non-equal mobilities yield an electric field with non-zero time average at large distances from the electrodes. Our calculations indicate this long-range electric field suffices to levitate colloidal particles many microns away from the electrode against the gravitational field, in accord with experimental observations of such behavior (Woehl et al., PRX, 2015). Moreover, the results indicate that particles will aggregate laterally near electrodes in some electrolytes but separate in others, helping explain a longstanding but not well understood phenomenon.

  6. Multi-actuation and PI control: A simple recipe for high-speed and large-range atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Soltani Bozchalooi, I., E-mail: isoltani@mit.edu; Youcef-Toumi, K.

    2014-11-15

    High speed atomic force microscopy enables observation of dynamic nano-scale processes. However, maintaining a minimal interaction force between the sample and the probe is challenging at high speed specially when using conventional piezo-tubes. While rigid AFM scanners are operational at high speeds with the drawback of reduced tracking range, multi-actuation schemes have shown potential for high-speed and large-range imaging. Here we present a method to seamlessly incorporate additional actuators into conventional AFMs. The equivalent behavior of the resulting multi-actuated setup resembles that of a single high-speed and large-range actuator with maximally flat frequency response. To achieve this, the dynamics of the individual actuators and their couplings are treated through a simple control scheme. Upon the implementation of the proposed technique, commonly used PI controllers are able to meet the requirements of high-speed imaging. This forms an ideal platform for retroactive enhancement of existing AFMs with minimal cost and without compromise on the tracking range. A conventional AFM with tube scanner is retroactively enhanced through the proposed method and shows an order of magnitude improvement in closed loop bandwidth performance while maintaining large range. The effectiveness of the method is demonstrated on various types of samples imaged in contact and tapping modes, in air and in liquid. - Highlights: • We present a novel method to incorporate extra actuators into conventional AFMs. • A maximally flat frequency response is achieved for the out of plane piezo-motion. • Commonly used PI or PID control is enabled to handle high speed AFM imaging. • An order of magnitude improvement in closed loop bandwidth performance is obtained. • High speed imaging is achieved on a large range piezo-tube.

  7. Multi-actuation and PI control: A simple recipe for high-speed and large-range atomic force microscopy

    International Nuclear Information System (INIS)

    Soltani Bozchalooi, I.; Youcef-Toumi, K.

    2014-01-01

    High speed atomic force microscopy enables observation of dynamic nano-scale processes. However, maintaining a minimal interaction force between the sample and the probe is challenging at high speed specially when using conventional piezo-tubes. While rigid AFM scanners are operational at high speeds with the drawback of reduced tracking range, multi-actuation schemes have shown potential for high-speed and large-range imaging. Here we present a method to seamlessly incorporate additional actuators into conventional AFMs. The equivalent behavior of the resulting multi-actuated setup resembles that of a single high-speed and large-range actuator with maximally flat frequency response. To achieve this, the dynamics of the individual actuators and their couplings are treated through a simple control scheme. Upon the implementation of the proposed technique, commonly used PI controllers are able to meet the requirements of high-speed imaging. This forms an ideal platform for retroactive enhancement of existing AFMs with minimal cost and without compromise on the tracking range. A conventional AFM with tube scanner is retroactively enhanced through the proposed method and shows an order of magnitude improvement in closed loop bandwidth performance while maintaining large range. The effectiveness of the method is demonstrated on various types of samples imaged in contact and tapping modes, in air and in liquid. - Highlights: • We present a novel method to incorporate extra actuators into conventional AFMs. • A maximally flat frequency response is achieved for the out of plane piezo-motion. • Commonly used PI or PID control is enabled to handle high speed AFM imaging. • An order of magnitude improvement in closed loop bandwidth performance is obtained. • High speed imaging is achieved on a large range piezo-tube

  8. Long range Debye-Hückel correction for computation of grid-based electrostatic forces between biomacromolecules

    International Nuclear Information System (INIS)

    Mereghetti, Paolo; Martinez, Michael; Wade, Rebecca C

    2014-01-01

    Brownian dynamics (BD) simulations can be used to study very large molecular systems, such as models of the intracellular environment, using atomic-detail structures. Such simulations require strategies to contain the computational costs, especially for the computation of interaction forces and energies. A common approach is to compute interaction forces between macromolecules by precomputing their interaction potentials on three-dimensional discretized grids. For long-range interactions, such as electrostatics, grid-based methods are subject to finite size errors. We describe here the implementation of a Debye-Hückel correction to the grid-based electrostatic potential used in the SDA BD simulation software that was applied to simulate solutions of bovine serum albumin and of hen egg white lysozyme. We found that the inclusion of the long-range electrostatic correction increased the accuracy of both the protein-protein interaction profiles and the protein diffusion coefficients at low ionic strength. An advantage of this method is the low additional computational cost required to treat long-range electrostatic interactions in large biomacromolecular systems. Moreover, the implementation described here for BD simulations of protein solutions can also be applied in implicit solvent molecular dynamics simulations that make use of gridded interaction potentials

  9. Neutron star mergers as a probe of modifications of general relativity with finite-range scalar forces

    Science.gov (United States)

    Sagunski, Laura; Zhang, Jun; Johnson, Matthew C.; Lehner, Luis; Sakellariadou, Mairi; Liebling, Steven L.; Palenzuela, Carlos; Neilsen, David

    2018-03-01

    Observations of gravitational radiation from compact binary systems provide an unprecedented opportunity to test general relativity in the strong field dynamical regime. In this paper, we investigate how future observations of gravitational radiation from binary neutron star mergers might provide constraints on finite-range forces from a universally coupled massive scalar field. Such scalar degrees of freedom (d.o.f.) are a characteristic feature of many extensions of general relativity. For concreteness, we work in the context of metric f (R ) gravity, which is equivalent to general relativity and a universally coupled scalar field with a nonlinear potential whose form is fixed by the choice of f (R ). In theories where neutron stars (or other compact objects) obtain a significant scalar charge, the resulting attractive finite-range scalar force has implications for both the inspiral and merger phases of binary systems. We first present an analysis of the inspiral dynamics in Newtonian limit, and forecast the constraints on the mass of the scalar and charge of the compact objects for the Advanced LIGO gravitational wave observatory. We then perform a comparative study of binary neutron star mergers in general relativity with those of a one-parameter model of f (R ) gravity using fully relativistic hydrodynamical simulations. These simulations elucidate the effects of the scalar on the merger and postmerger dynamics. We comment on the utility of the full waveform (inspiral, merger, postmerger) to probe different regions of parameter space for both the particular model of f (R ) gravity studied here and for finite-range scalar forces more generally.

  10. Higher order structure of short immunostimulatory oligonucleotides studied by atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Dionne C.G., E-mail: dionne.c.g.klein@ntnu.no [Department of Physics, Norwegian University of Science and Technology, N-7491, Trondheim (Norway); Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, N-7489, Trondheim (Norway); Latz, Eicke [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, N-7489, Trondheim (Norway); Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605 (United States); Institute of Innate Immunity, University Hospitals, University of Bonn, Sigmund-Freud-Str. 25, 53127 Bonn (Germany); Espevik, Terje [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, N-7489, Trondheim (Norway); Stokke, Bjorn T. [Department of Physics, Norwegian University of Science and Technology, N-7491, Trondheim (Norway)

    2010-05-15

    Immunostimulatory CpG-DNA activates the innate immune system by binding to Toll-like receptor 9. Structurally different CpG-containing oligonucleotides trigger a different type of immune response while activating the same receptor. We therefore investigated the higher order structure of two different classes of immunostimulatory CpG-DNA. Class A, which contains a partly self-complementary sequence and poly-G ends, forms duplexes and nanoparticles in salt solution, while class B, which does not contain these features and is purely linear, does not form a duplex or nanoparticles. Results obtained here by high-resolution atomic force microscopy of classes A and B CpG-DNA, reflect these differences in secondary structure. Detailed structural analysis of the atomic force microscopy topographs is presented for two different sample preparation methods.

  11. Higher order structure of short immunostimulatory oligonucleotides studied by atomic force microscopy

    International Nuclear Information System (INIS)

    Klein, Dionne C.G.; Latz, Eicke; Espevik, Terje; Stokke, Bjorn T.

    2010-01-01

    Immunostimulatory CpG-DNA activates the innate immune system by binding to Toll-like receptor 9. Structurally different CpG-containing oligonucleotides trigger a different type of immune response while activating the same receptor. We therefore investigated the higher order structure of two different classes of immunostimulatory CpG-DNA. Class A, which contains a partly self-complementary sequence and poly-G ends, forms duplexes and nanoparticles in salt solution, while class B, which does not contain these features and is purely linear, does not form a duplex or nanoparticles. Results obtained here by high-resolution atomic force microscopy of classes A and B CpG-DNA, reflect these differences in secondary structure. Detailed structural analysis of the atomic force microscopy topographs is presented for two different sample preparation methods.

  12. Next neighbors effect along the Ca-Sr-Ba-åkermanite join: Long-range vs. short-range structural features

    Science.gov (United States)

    Dondi, Michele; Ardit, Matteo; Cruciani, Giuseppe

    2013-06-01

    An original approach has been developed herein to explore the correlations between short- and long-range structural properties of solid solutions. X-ray diffraction (XRD) and electronic absorption spectroscopy (EAS) data were combined on a (Ca,Sr,Ba)2(Mg0.7Co0.3)Si2O7 join to determine average and local distances, respectively. Instead of varying the EAS-active ion concentration along the join, as has commonly been performed in previous studies, the constant replacement of Mg2+ by a minimal fraction of a similar size cation (Co2+) has been used to assess the effects of varying second-nearest neighbor cations (Ca, Sr, Ba) on the local distances of the first shell. A comparison between doped and un-doped series has shown that, although the overall symmetry of the Co-centered T1-site was retained, greater relaxation occurs at the CoO4 tetrahedra which become increasingly large and more distorted than the MgO4 tetrahedra. This is indicated by an increase in both the quadratic elongation (λT1) and the bond angle variance (σ2T1) distortion indices, as the whole structure expands due to an increase in size in the second-nearest neighbors. This behavior highlights the effect of the different electronic configurations of Co2+ (3d7) and Mg2+ (2p6) in spite of their very similar ionic size. Furthermore, although the overall symmetry of the Co-centered T1-site is retained, relatively limited (Co2+-O occur along the solid solution series and large changes are found in molar absorption coefficients showing that EAS Co2+-bands are highly sensitive to change in the local structure.

  13. Design and control of multi-actuated atomic force microscope for large-range and high-speed imaging

    Energy Technology Data Exchange (ETDEWEB)

    Soltani Bozchalooi, I.; Careaga Houck, A. [Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); AlGhamdi, J. [Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Department of Chemistry, College of Science, University of Dammam, Dammam (Saudi Arabia); Youcef-Toumi, K. [Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

    2016-01-15

    This paper presents the design and control of a high-speed and large-range atomic force microscopy (AFM). A multi-actuation scheme is proposed where several nano-positioners cooperate to achieve the range and speed requirements. A simple data-based control design methodology is presented to effectively operate the AFM scanner components. The proposed controllers compensate for the coupled dynamics and divide the positioning responsibilities between the scanner components. As a result, the multi-actuated scanner behavior is equivalent to that of a single X–Y–Z positioner with large range and high speed. The scanner of the designed AFM is composed of five nano-positioners, features 6 μm out-of-plane and 120 μm lateral ranges and is capable of high-speed operation. The presented AFM has a modular design with laser spot size of 3.5 μm suitable for small cantilever, an optical view of the sample and probe, a conveniently large waterproof sample stage and a 20 MHz data throughput for high resolution image acquisition at high imaging speeds. This AFM is used to visualize etching of calcite in a solution of sulfuric acid. Layer-by-layer dissolution and pit formation along the crystalline lines in a low pH environment is observed in real time. - Highlights: • High-speed AFM imaging is extended to large lateral and vertical scan ranges. • A general multi-actuation approach to atomic force microscopy is presented. • A high-speed AFM is designed and implemented based on the proposed method. • Multi-actuator control is designed auxiliary to a PID unit to maintain flexibility. • Influence of calcite crystal structure on dissolution is visualized in video form.

  14. Effect of short-range ordering on the electrical conductivity and superconducting properties of Nb6C5 single crystals

    International Nuclear Information System (INIS)

    Utkina, T.G.

    1995-01-01

    Niobium carbide, NbC x , belongs to the family of so called interstital phases. Metal atoms form a face-centered cubic lattice, whose octahedral interstices are occupied by carbon atoms. The fraction (1 - x) of interstices remain vacant, and this determines the nonstoichiometry of these phases: most of them are characterized by a wide homogeneity range, 0.70 m ≅ 3308 - 3886 K). In contrast, the metalloid atoms exhibit high mobility at relatively low temperatures. For compositions close to Nb 6 C 5 (0.81 O-D ≅ 1300 K. The presence of vacancies in the carbon sublattice considerably affects the physical properties of carbides, which depend not only on total vacancy concentration but also on their distribution, i.e., on the degree of ordering (both short-range and long-range order) in the metalloid sublattice. The purpose of this work is to study the effects of such ordering on the superconducting properties of Nb 6 C 5 single crystals

  15. Digital predistortion of 75–110 GHz W-band frequency multiplier for fiber wireless short range access systems

    DEFF Research Database (Denmark)

    Zhao, Ying; Deng, Lei; Pang, Xiaodan

    2011-01-01

    be effectively pre-compensated. Without using costly W-band components, a transmission system with 26km fiber and 4m wireless transmission operating at 99.6GHz is experimentally validated. Adjacent-channel power ratio (ACPR) improvements for IQ-modulated vector signals are guaranteed and transmission......We present a W-band fiber-wireless transmission system based on a nonlinear frequency multiplier for high-speed wireless short range access applications. By implementing a baseband digital signal predistortion scheme, intensive nonlinear distortions induced in a sextuple frequency multiplier can...... performances for fiber and wireless channels are studied. This W-band predistortion technique is a promising candidate for applications in high capacity wireless-fiber access systems....

  16. Analyses of kinetic glass transition in short-range attractive colloids based on time-convolutionless mode-coupling theory.

    Science.gov (United States)

    Narumi, Takayuki; Tokuyama, Michio

    2017-03-01

    For short-range attractive colloids, the phase diagram of the kinetic glass transition is studied by time-convolutionless mode-coupling theory (TMCT). Using numerical calculations, TMCT is shown to recover all the remarkable features predicted by the mode-coupling theory for attractive colloids: the glass-liquid-glass reentrant, the glass-glass transition, and the higher-order singularities. It is also demonstrated through the comparisons with the results of molecular dynamics for the binary attractive colloids that TMCT improves the critical values of the volume fraction. In addition, a schematic model of three control parameters is investigated analytically. It is thus confirmed that TMCT can describe the glass-glass transition and higher-order singularities even in such a schematic model.

  17. Relationship between Magnetic Anisotropy below Pseudogap Temperature and Short-Range Antiferromagnetic Order in High-Temperature Cuprate Superconductor

    Science.gov (United States)

    Morinari, Takao

    2018-06-01

    The central issue in high-temperature cuprate superconductors is the pseudogap state appearing below the pseudogap temperature T*, which is well above the superconducting transition temperature. In this study, we theoretically investigate the rapid increase of the magnetic anisotropy below the pseudogap temperature detected by the recent torque-magnetometry measurements on YBa2Cu3Oy [Y. Sato et al., 10.1038/nphys4205" xlink:type="simple">Nat. Phys. 13, 1074 (2017)]. Applying the spin Green's function formalism including the Dzyaloshinskii-Moriya interaction arising from the buckling of the CuO2 plane, we obtain results that are in good agreement with the experiment and find a scaling relationship. Our analysis suggests that the characteristic temperature associated with the magnetic anisotropy, which coincides with T*, is not a phase transition temperature but a crossover temperature associated with the short-range antiferromagnetic order.

  18. One-level modeling for diagnosing surface winds over complex terrain. II - Applicability to short-range forecasting

    Science.gov (United States)

    Alpert, P.; Getenio, B.; Zak-Rosenthal, R.

    1988-01-01

    The Alpert and Getenio (1988) modification of the Mass and Dempsey (1985) one-level sigma-surface model was used to study four synoptic events that included two winter cases (a Cyprus low and a Siberian high) and two summer cases. Results of statistical verification showed that the model is not only capable of diagnosing many details of surface mesoscale flow, but might also be useful for various applications which require operative short-range prediction of the diurnal changes of high-resolution surface flow over complex terrain, for example, in locating wildland fires, determining the dispersion of air pollutants, and predicting changes in wind energy or of surface wind for low-level air flights.

  19. Short-range order in ab initio computer generated amorphous and liquid Cu–Zr alloys: A new approach

    International Nuclear Information System (INIS)

    Galván-Colín, Jonathan; Valladares, Ariel A.; Valladares, Renela M.; Valladares, Alexander

    2015-01-01

    Using ab initio molecular dynamics and a new approach based on the undermelt-quench method we generated amorphous and liquid samples of Cu x Zr 100−x (x=64, 50, 36) alloys. We characterized the topology of our resulting structures by means of the pair distribution function and the bond-angle distribution; a coordination number distribution was also calculated. Our results for both amorphous and liquids agree well with experiment. Dependence of short-range order with the concentration is reported. We found that icosahedron-like geometry plays a major role whenever the alloys are Cu-rich or Zr-rich disregarding if the samples are amorphous or liquid. The validation of these results, in turn would let us calculate other properties so far disregarded in the literature

  20. Short-range order in ab initio computer generated amorphous and liquid Cu–Zr alloys: A new approach

    Energy Technology Data Exchange (ETDEWEB)

    Galván-Colín, Jonathan, E-mail: jgcolin@ciencias.unam.mx [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, México, D.F. 04510, México (Mexico); Valladares, Ariel A., E-mail: valladar@unam.mx [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, México, D.F. 04510, México (Mexico); Valladares, Renela M.; Valladares, Alexander [Facultad de Ciencias, Universidad Nacional Autónoma de México, Apartado Postal 70-542, México, D.F. 04510, México (Mexico)

    2015-10-15

    Using ab initio molecular dynamics and a new approach based on the undermelt-quench method we generated amorphous and liquid samples of Cu{sub x}Zr{sub 100−x} (x=64, 50, 36) alloys. We characterized the topology of our resulting structures by means of the pair distribution function and the bond-angle distribution; a coordination number distribution was also calculated. Our results for both amorphous and liquids agree well with experiment. Dependence of short-range order with the concentration is reported. We found that icosahedron-like geometry plays a major role whenever the alloys are Cu-rich or Zr-rich disregarding if the samples are amorphous or liquid. The validation of these results, in turn would let us calculate other properties so far disregarded in the literature.

  1. Short-range order in alloys of nickel with the elements of group VIII of the periodic table

    International Nuclear Information System (INIS)

    Khwaja, F.A.

    1981-08-01

    Experimental measurements of the diffuse X-ray scattering intensity were performed on alloys of Ni with Rh and Os. The atomic short-range order (SRO) parameters αsub(i) and the size-effect parameters βsub(i) were calculated from these measurements. It is established that SRO and size-effect exist in Ni-Rh and Ni-Os alloys analogously as in a few other alloys of Ni with the elements of group VIII of the periodic table. The experimental data was interpreted theoretically by calculating the interaction energies from the pseudo-potentials and the effective valencies of the individual components of the systems studied. It was found that theoretically calculated values of the interaction energies for these alloys are inconsistent with the experimentally determined sign of the SRO parameter. (author)

  2. Large drainages from short-lived glacial lakes in the Teskey Range, Tien Shan Mountains, Central Asia

    Science.gov (United States)

    Narama, Chiyuki; Daiyrov, Mirlan; Duishonakunov, Murataly; Tadono, Takeo; Sato, Hayato; Kääb, Andreas; Ukita, Jinro; Abdrakhmatov, Kanatbek

    2018-04-01

    Four large drainages from glacial lakes occurred during 2006-2014 in the western Teskey Range, Kyrgyzstan. These floods caused extensive damage, killing people and livestock as well as destroying property and crops. Using satellite data analysis and field surveys of this area, we find that the water volume that drained at Kashkasuu glacial lake in 2006 was 194 000 m3, at western Zyndan lake in 2008 was 437 000 m3, at Jeruy lake in 2013 was 182 000 m3, and at Karateke lake in 2014 was 123 000 m3. Due to their subsurface outlet, we refer to these short-lived glacial lakes as the tunnel-type, a type that drastically grows and drains over a few months. From spring to early summer, these lakes either appear, or in some cases, significantly expand from an existing lake (but non-stationary), and then drain during summer. Our field surveys show that the short-lived lakes form when an ice tunnel through a debris landform gets blocked. The blocking is caused either by the freezing of stored water inside the tunnel during winter or by the collapse of ice and debris around the ice tunnel. The draining then occurs through an opened ice tunnel during summer. The growth-drain cycle can repeat when the ice-tunnel closure behaves like that of typical supraglacial lakes on debris-covered glaciers. We argue here that the geomorphological characteristics under which such short-lived glacial lakes appear are (i) a debris landform containing ice (ice-cored moraine complex), (ii) a depression with water supply on a debris landform as a potential lake basin, and (iii) no visible surface outflow channel from the depression, indicating the existence of an ice tunnel. Applying these characteristics, we examine 60 depressions (> 0.01 km2) in the study region and identify here 53 of them that may become short-lived glacial lakes, with 34 of these having a potential drainage exceeding 10 m3 s-1 at peak discharge.

  3. Large drainages from short-lived glacial lakes in the Teskey Range, Tien Shan Mountains, Central Asia

    Directory of Open Access Journals (Sweden)

    C. Narama

    2018-04-01

    Full Text Available Four large drainages from glacial lakes occurred during 2006–2014 in the western Teskey Range, Kyrgyzstan. These floods caused extensive damage, killing people and livestock as well as destroying property and crops. Using satellite data analysis and field surveys of this area, we find that the water volume that drained at Kashkasuu glacial lake in 2006 was 194 000  m3, at western Zyndan lake in 2008 was 437 000 m3, at Jeruy lake in 2013 was 182 000 m3, and at Karateke lake in 2014 was 123 000 m3. Due to their subsurface outlet, we refer to these short-lived glacial lakes as the tunnel-type, a type that drastically grows and drains over a few months. From spring to early summer, these lakes either appear, or in some cases, significantly expand from an existing lake (but non-stationary, and then drain during summer. Our field surveys show that the short-lived lakes form when an ice tunnel through a debris landform gets blocked. The blocking is caused either by the freezing of stored water inside the tunnel during winter or by the collapse of ice and debris around the ice tunnel. The draining then occurs through an opened ice tunnel during summer. The growth–drain cycle can repeat when the ice-tunnel closure behaves like that of typical supraglacial lakes on debris-covered glaciers. We argue here that the geomorphological characteristics under which such short-lived glacial lakes appear are (i a debris landform containing ice (ice-cored moraine complex, (ii a depression with water supply on a debris landform as a potential lake basin, and (iii no visible surface outflow channel from the depression, indicating the existence of an ice tunnel. Applying these characteristics, we examine 60 depressions (> 0.01 km2 in the study region and identify here 53 of them that may become short-lived glacial lakes, with 34 of these having a potential drainage exceeding 10 m3 s−1 at peak discharge.

  4. Experimental Study of Wave Forces on Vertical Circular Cylinders in Long and Short Crested Sea

    DEFF Research Database (Denmark)

    Høgedal, Michael

    on the safe side, as the directional spreading of the wave field Ieads to reduced horizontal velocities and acceleration; in the fluid and hence a reduction of the resultant and in-line wave forces on the structure. The directional spreading of the horizontal velocity field generally causes an increase...... with miniature pressure transducers. The experiments were carried out in the 3-D wave tank in the Hydraulics & Coastal Engineering Laboratory at Aalborg University and in the off-shore basin at the Danish Hydraulic Institute....

  5. The effect of glenosphere diameter in reverse shoulder arthroplasty on muscle force, joint load, and range of motion.

    Science.gov (United States)

    Langohr, G Daniel G; Giles, Joshua W; Athwal, George S; Johnson, James A

    2015-06-01

    Little is known about the effects of glenosphere diameter on shoulder joint loads. The purpose of this biomechanical study was to investigate the effects of glenosphere diameter on joint load, load angle, and total deltoid force required for active abduction and range of motion in internal/external rotation and abduction. A custom, instrumented reverse shoulder arthroplasty implant system capable of measuring joint load and varying glenosphere diameter (38 and 42 mm) and glenoid offset (neutral and lateral) was implanted in 6 cadaveric shoulders to provide at least 80% power for all variables. A shoulder motion simulator was used to produce active glenohumeral and scapulothoracic motion. All implant configurations were tested with active and passive motion with joint kinematics, loads, and moments recorded. At neutral and lateralized glenosphere positions, increasing diameter significantly increased joint load (+12 ± 21 N and +6 ± 9 N; P  .8). Passive internal rotation was reduced with increased diameter at both neutral and lateralized glenosphere positions (-6° ± 6° and -12° ± 6°; P  .05). At neutral glenosphere position, increasing diameter increased the maximum angles of both adduction (+1° ± 1°; P = .03) and abduction (+8° ± 9°; P < .05). Lateralization also increased abduction range of motion compared with neutral (P < .01). Although increasing glenosphere diameter significantly increased joint load and deltoid force, the clinical impact of these changes is presently unclear. Internal rotation, however, was reduced, which contradicts previous bone modeling studies, which we postulate is due to increased posterior capsular tension as it is forced to wrap around a larger 42 mm implant assembly. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  6. Intervening in Short-Warning Conflicts The Role of a Rapidly Employable Joint Force

    National Research Council Canada - National Science Library

    2000-01-01

    ...). In many plausible military interventions along the ill-defined spectrum of small scale to large scale conflicts, long range precision fires alone would not be sufficient, and the JTFs would need...

  7. Design of a self-aligned, wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with 10 nm magnetic force microscope resolution

    Energy Technology Data Exchange (ETDEWEB)

    Karcı, Özgür [NanoMagnetics Instruments Ltd., Hacettepe - İvedik OSB Teknokent, 1368. Cad., No: 61/33, 06370, Yenimahalle, Ankara (Turkey); Department of Nanotechnology and Nanomedicine, Hacettepe University, Beytepe, 06800 Ankara (Turkey); Dede, Münir [NanoMagnetics Instruments Ltd., Hacettepe - İvedik OSB Teknokent, 1368. Cad., No: 61/33, 06370, Yenimahalle, Ankara (Turkey); Oral, Ahmet, E-mail: orahmet@metu.edu.tr [Department of Physics, Middle East Technical University, 06800 Ankara (Turkey)

    2014-10-01

    We describe the design of a wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with a self-aligned fibre-cantilever mechanism. An alignment chip with alignment groves and a special mechanical design are used to eliminate tedious and time consuming fibre-cantilever alignment procedure for the entire temperature range. A low noise, Michelson fibre interferometer was integrated into the system for measuring deflection of the cantilever. The spectral noise density of the system was measured to be ~12 fm/√Hz at 4.2 K at 3 mW incident optical power. Abrikosov vortices in BSCCO(2212) single crystal sample and a high density hard disk sample were imaged at 10 nm resolution to demonstrate the performance of the system.

  8. Design of a self-aligned, wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with 10 nm magnetic force microscope resolution

    International Nuclear Information System (INIS)

    Karcı, Özgür; Dede, Münir; Oral, Ahmet

    2014-01-01

    We describe the design of a wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with a self-aligned fibre-cantilever mechanism. An alignment chip with alignment groves and a special mechanical design are used to eliminate tedious and time consuming fibre-cantilever alignment procedure for the entire temperature range. A low noise, Michelson fibre interferometer was integrated into the system for measuring deflection of the cantilever. The spectral noise density of the system was measured to be ∼12 fm/√Hz at 4.2 K at 3 mW incident optical power. Abrikosov vortices in BSCCO(2212) single crystal sample and a high density hard disk sample were imaged at 10 nm resolution to demonstrate the performance of the system

  9. Primer and short-range releaser pheromone properties of premolt female urine from the shore crab Carcinus maenas.

    Science.gov (United States)

    Ekerholm, Mattias; Hallberg, Eric

    2005-08-01

    The European shore crab Carcinus maenas is considered to rely on a female pheromone when mating. Evidence, however, is scarce on how the urine pheromone in itself affects males. We investigated male primer and releaser responses to female pheromones with methods that minimized effects from females, delivering female urine either as a pump-generated plume or deposited on a polyurethane sponge. We delivered the pheromone at different concentrations in far, near, and close/contact range to get a picture of how distance affects behavioral response. Our results show that substances in premolt female urine (PMU) function as primer and potent short-range releaser pheromones. Based on the olfactometer and sponge tests, we conclude that PMU stimulus in itself is sufficient to elicit increased search and mating-specific behaviors such as posing, posing search, cradle carrying, and stroking. Pheromone concentrations do not seem to be important for attenuating search and posing as long as the level is above a certain threshold concentration. Instead, pheromone levels seem to play a role in male acceptance of females, recruiting more males to respond, and generating better responses with increasing concentration.

  10. Short-range remote spectral sensor using mid-infrared semiconductor lasers with orthogonal code-division multiplexing approach

    Science.gov (United States)

    Morbi, Zulfikar; Ho, D. B.; Ren, H.-W.; Le, Han Q.; Pei, Shin Shem

    2002-09-01

    Demonstration of short-range multispectral remote sensing, using 3 to 4-micrometers mid- infrared Sb semiconductor lasers based on code-division multiplexing (CDM) architecture, is described. The system is built on a principle similar to intensity- modulated/direct-detection optical-CDMA for communications, but adapted for sensing with synchronous, orthogonal codes to distinguish different wavelength channels with zero interchannel correlation. The concept is scalable for any number of channels, and experiments with a two-wavelength system are conducted. The CDM-signal processing yielded a white-Gaussian-like system noise that is found to be near the theoretical level limited by the detector fundamental intrinsic noise. With sub-mW transmitter average power, the system was able to detect an open-air acetylene gas leak of 10-2 STP ft3/hr from 10-m away with time-varying, random, noncooperative backscatters. A similar experiment detected and positively distinguished hydrocarbon oil contaminants on water from bio-organic oils and detergents. Projection for more advanced systems suggests a multi-kilometer-range capability for watt-level transmitters, and hundreds of wavelength channels can also be accommodated for active hyperspectral remote sensing application.

  11. Development and application of a water calorimeter for the absolute dosimetry of short-range particle beams

    Science.gov (United States)

    Renaud, J.; Rossomme, S.; Sarfehnia, A.; Vynckier, S.; Palmans, H.; Kacperek, A.; Seuntjens, J.

    2016-09-01

    In this work, we describe a new design of water calorimeter built to measure absorbed dose in non-standard radiation fields with reference depths in the range of 6-20 mm, and its initial testing in clinical electron and proton beams. A functioning calorimeter prototype with a total water equivalent thickness of less than 30 mm was constructed in-house and used to obtain measurements in clinical accelerator-based 6 MeV and 8 MeV electron beams and cyclotron-based 60 MeV monoenergetic and modulated proton beams. Corrections for the conductive heat transfer due to dose gradients and non-water materials was also accounted for using a commercial finite element method software package. Absorbed dose to water was measured with an associated type A standard uncertainty of approximately 0.4% and 0.2% for the electron and proton beam experiments, respectively. In terms of thermal stability, drifts were on the order of a couple of hundred µK min-1, with a short-term variation of 5-10 µK. Heat transfer correction factors ranged between 1.021 and 1.049. The overall combined standard uncertainty on the absorbed dose to water was estimated to be 0.6% for the 6 MeV and 8 MeV electron beams, as well as for the 60 MeV monoenergetic protons, and 0.7% for the modulated 60 MeV proton beam. This study establishes the feasibility of developing an absorbed dose transfer standard for short-range clinical electrons and protons and forms the basis for a transportable dose standard for direct calibration of ionization chambers in the user’s beam. The largest contributions to the combined standard uncertainty were the positioning (⩽0.5%) and the correction due to conductive heat transfer (⩽0.4%). This is the first time that water calorimetry has been used in such a low energy proton beam.

  12. Simulation study of signal formation in position sensitive planar p-on-n silicon detectors after short range charge injection

    International Nuclear Information System (INIS)

    Peltola, T.; Eremin, V.; Verbitskaya, E.; Härkönen, J.

    2017-01-01

    Segmented silicon detectors (micropixel and microstrip) are the main type of detectors used in the inner trackers of Large Hadron Collider (LHC) experiments at CERN. Due to the high luminosity and eventual high fluence of energetic particles, detectors with fast response to fit the short shaping time of 20–25 ns and sufficient radiation hardness are required. Charge collection measurements carried out at the Ioffe Institute have shown a reversal of the pulse polarity in the detector response to short-range charge injection. Since the measured negative signal is about 30–60% of the peak positive signal, the effect strongly reduces the CCE even in non-irradiated detectors. For further investigation of the phenomenon the measurements have been reproduced by TCAD simulations. As for the measurements, the simulation study was applied for the p-on-n strip detectors similar in geometry to those developed for the ATLAS experiment and for the Ioffe Institute designed p-on-n strip detectors with each strip having a window in the metallization covering the p + implant, allowing the generation of electron-hole pairs under the strip implant. Red laser scans across the strips and the interstrip gap with varying laser diameters and Si-SiO 2 interface charge densities ( Q f ) were carried out. The results verify the experimentally observed negative response along the scan in the interstrip gap. When the laser spot is positioned on the strip p + implant the negative response vanishes and the collected charge at the active strip increases respectively. The simulation results offer a further insight and understanding of the influence of the oxide charge density in the signal formation. The main result of the study is that a threshold value of Q f , that enables negligible losses of collected charges, is defined. The observed effects and details of the detector response for different charge injection positions are discussed in the context of Ramo's theorem.

  13. Simulation study of signal formation in position sensitive planar p-on-n silicon detectors after short range charge injection

    Science.gov (United States)

    Peltola, T.; Eremin, V.; Verbitskaya, E.; Härkönen, J.

    2017-09-01

    Segmented silicon detectors (micropixel and microstrip) are the main type of detectors used in the inner trackers of Large Hadron Collider (LHC) experiments at CERN. Due to the high luminosity and eventual high fluence of energetic particles, detectors with fast response to fit the short shaping time of 20-25 ns and sufficient radiation hardness are required. Charge collection measurements carried out at the Ioffe Institute have shown a reversal of the pulse polarity in the detector response to short-range charge injection. Since the measured negative signal is about 30-60% of the peak positive signal, the effect strongly reduces the CCE even in non-irradiated detectors. For further investigation of the phenomenon the measurements have been reproduced by TCAD simulations. As for the measurements, the simulation study was applied for the p-on-n strip detectors similar in geometry to those developed for the ATLAS experiment and for the Ioffe Institute designed p-on-n strip detectors with each strip having a window in the metallization covering the p+ implant, allowing the generation of electron-hole pairs under the strip implant. Red laser scans across the strips and the interstrip gap with varying laser diameters and Si-SiO2 interface charge densities (Qf) were carried out. The results verify the experimentally observed negative response along the scan in the interstrip gap. When the laser spot is positioned on the strip p+ implant the negative response vanishes and the collected charge at the active strip increases respectively. The simulation results offer a further insight and understanding of the influence of the oxide charge density in the signal formation. The main result of the study is that a threshold value of Qf, that enables negligible losses of collected charges, is defined. The observed effects and details of the detector response for different charge injection positions are discussed in the context of Ramo's theorem.

  14. Drag on a Satellite Moving across a Spherical Galaxy: Tidal and Frictional Forces in Short-lived Encounters

    Science.gov (United States)

    Colpi, Monica; Pallavicini, Andrea

    1998-07-01

    The drag force on a satellite of mass M moving with speed V in the gravitational field of a spherically symmetric background of stars is computed. During the encounter, the stars are subject to a time-dependent force that alters their equilibrium. The resulting distortion in the stellar density field acts back to produce a force FΔ that decelerates the satellite. This force is computed using a perturbative technique known as linear response theory. In this paper, we extend the formalism of linear response to derive the correct expression for the back-reaction force FΔ that applies when the stellar system is described by an equilibrium one-particle distribution function. FΔ is expressed in terms of a suitable correlation function that couples the satellite dynamics to the unperturbed dynamics of the stars. At time t, the force depends upon the whole history of the composite system. In the formalism, we account for the shift of the stellar center of mass resulting from linear momentum conservation. The self-gravity of the response is neglected since it contributes to a higher order in the perturbation. Linear response theory applies also to the case of a satellite orbiting outside the spherical galaxy. The case of a satellite moving on a straight line, at high speed relative to the stellar dispersion velocity, is explored. We find that the satellite during its passage raises (1) global tides in the stellar distribution and (2) a wake, i.e., an overdense region behind its trail. If the satellite motion is external to the galaxy, it suffers a dissipative force that is not exclusively acting along V but acquires a component along R, the position vector relative to the center of the spherical galaxy. We derive the analytical expression of the force in the impulse approximation. In penetrating short-lived encounters, the satellite moves across the stellar distribution and the transient wake excited in the density field is responsible for most of the deceleration. We

  15. Vertical ground reaction force in stationary running in water and on land: A study with a wide range of cadences.

    Science.gov (United States)

    de Brito Fontana, Heiliane; Ruschel, Caroline; Dell'Antonio, Elisa; Haupenthal, Alessandro; Pereira, Gustavo Soares; Roesler, Helio

    2018-04-01

    The aim of this study was to analyze the effect of cadence, immersion level as well as body density on the vertical component (Fy max ) of ground reaction force (GRF) during stationary running (SR). In a controlled, laboratory study, thirty-two subjects ran at a wide range of cadences (85-210 steps/min) in water, immersed to the hip and to the chest, and on dry land. Fy max. was verified by a waterproof force measurement system and predicted based on a statistical model including cadence, immersion ratio and body density. The effect of cadence was shown to depend on the environment: while Fy max increases linearly with increasing cadence on land; in water, Fy max reaches a plateau at both hip and chest immersions. All factors analyzed, cadence, immersion level and body density affected Fy max significantly, with immersion (aquatic × land environment) showing the greatest effect. In water, different cadences may lead to bigger changes in Fy max than the changes obtained by moving subjects from hip to chest immersion. A regression model able to predict 69% of Fy max variability in water was proposed and validated. Cadence, Immersion and body density affect Fy max in a significant and non-independent way. Besides a model of potential use in the prescription of stationary running in water, our analysis provides insights into the different responses of GRF to changes in exercise parameters between land and aquatic environment. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Uniform selection as a primary force reducing population genetic differentiation of cavitation resistance across a species range.

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste Lamy

    Full Text Available BACKGROUND: Cavitation resistance to water stress-induced embolism determines plant survival during drought. This adaptive trait has been described as highly variable in a wide range of tree species, but little is known about the extent of genetic and phenotypic variability within species. This information is essential to our understanding of the evolutionary forces that have shaped this trait, and for evaluation of its inclusion in breeding programs. METHODOLOGY: We assessed cavitation resistance (P(50, growth and carbon isotope composition in six Pinus pinaster populations in a provenance and progeny trial. We estimated the heritability of cavitation resistance and compared the distribution of neutral markers (F(ST and quantitative genetic differentiation (Q(ST, for retrospective identification of the evolutionary forces acting on these traits. RESULTS/DISCUSSION: In contrast to growth and carbon isotope composition, no population differentiation was found for cavitation resistance. Heritability was higher than for the other traits, with a low additive genetic variance (h(2 (ns = 0.43±0.18, CV(A = 4.4%. Q(ST was significantly lower than F(ST, indicating uniform selection for P(50, rather than genetic drift. Putative mechanisms underlying Q(ST

  17. Uniform Selection as a Primary Force Reducing Population Genetic Differentiation of Cavitation Resistance across a Species Range

    Science.gov (United States)

    Lamy, Jean-Baptiste; Bouffier, Laurent; Burlett, Régis; Plomion, Christophe; Cochard, Hervé; Delzon, Sylvain

    2011-01-01

    Background Cavitation resistance to water stress-induced embolism determines plant survival during drought. This adaptive trait has been described as highly variable in a wide range of tree species, but little is known about the extent of genetic and phenotypic variability within species. This information is essential to our understanding of the evolutionary forces that have shaped this trait, and for evaluation of its inclusion in breeding programs. Methodology We assessed cavitation resistance (P 50), growth and carbon isotope composition in six Pinus pinaster populations in a provenance and progeny trial. We estimated the heritability of cavitation resistance and compared the distribution of neutral markers (F ST) and quantitative genetic differentiation (Q ST), for retrospective identification of the evolutionary forces acting on these traits. Results/Discussion In contrast to growth and carbon isotope composition, no population differentiation was found for cavitation resistance. Heritability was higher than for the other traits, with a low additive genetic variance (h2 ns = 0.43±0.18, CVA = 4.4%). Q ST was significantly lower than F ST, indicating uniform selection for P 50, rather than genetic drift. Putative mechanisms underlying QST

  18. Long- and short-term selective forces on malaria parasite genomes

    KAUST Repository

    Nygaard, Sanne

    2010-09-09

    Plasmodium parasites, the causal agents of malaria, result in more than 1 million deaths annually. Plasmodium are unicellular eukaryotes with small ~23 Mb genomes encoding ~5200 protein-coding genes. The protein-coding genes comprise about half of these genomes. Although evolutionary processes have a significant impact on malaria control, the selective pressures within Plasmodium genomes are poorly understood, particularly in the non-protein-coding portion of the genome. We use evolutionary methods to describe selective processes in both the coding and non-coding regions of these genomes. Based on genome alignments of seven Plasmodium species, we show that protein-coding, intergenic and intronic regions are all subject to purifying selection and we identify 670 conserved non-genic elements. We then use genome-wide polymorphism data from P. falciparum to describe short-term selective processes in this species and identify some candidate genes for balancing (diversifying) selection. Our analyses suggest that there are many functional elements in the non-genic regions of these genomes and that adaptive evolution has occurred more frequently in the protein-coding regions of the genome. © 2010 Nygaard et al.

  19. Effects of chiral three-nucleon forces on 4He-nucleus scattering in a wide range of incident energies

    Science.gov (United States)

    Toyokawa, Masakazu; Yahiro, Masanobu; Matsumoto, Takuma; Kohno, Michio

    2018-02-01

    An important current subject is to clarify the properties of chiral three-nucleon forces (3NFs) not only in nuclear matter but also in scattering between finite-size nuclei. Particularly for elastic scattering, this study has just started and the properties are not understood for a wide range of incident energies (E_in). We investigate basic properties of chiral 3NFs in nuclear matter with positive energies by using the Brueckner-Hartree-Fock method with chiral two-nucleon forces at N3LO and 3NFs at NNLO, and analyze the effects of chiral 3NFs on 4He elastic scattering from targets ^{208}Pb, ^{58}Ni, and ^{40}Ca over a wide range of 30 ≲ E_in/A_P ≲ 200 MeV by using the g-matrix folding model, where A_P is the mass number of the projectile. In symmetric nuclear matter with positive energies, chiral 3NFs make the single-particle potential less attractive and more absorptive. The effects mainly come from the Fujita-Miyazawa 2π-exchange 3NF and become slightly larger as E_in increases. These effects persist in the optical potentials of 4He scattering. As for the differential cross sections of 4He scattering, chiral-3NF effects are large for E_in/A_P ≳ 60 MeV and improve the agreement of the theoretical results with the measured ones. Particularly for E_in/A_P ≳ 100 MeV, the folding model reproduces measured differential cross sections pretty well. Cutoff (Λ) dependence is investigated for both nuclear matter and 4He scattering by considering two cases of Λ=450 and 550 MeV. The uncertainty coming from the dependence is smaller than chiral-3NF effects even at E_in/A_P=175 MeV.

  20. Single-Chip Fully Integrated Direct-Modulation CMOS RF Transmitters for Short-Range Wireless Applications

    Directory of Open Access Journals (Sweden)

    M. Jamal Deen

    2013-08-01

    Full Text Available Ultra-low power radio frequency (RF transceivers used in short-range application such as wireless sensor networks (WSNs require efficient, reliable and fully integrated transmitter architectures with minimal building blocks. This paper presents the design, implementation and performance evaluation of single-chip, fully integrated 2.4 GHz and 433 MHz RF transmitters using direct-modulation power voltage-controlled oscillators (PVCOs in addition to a 2.0 GHz phase-locked loop (PLL based transmitter. All three RF transmitters have been fabricated in a standard mixed-signal CMOS 0.18 µm technology. Measurement results of the 2.4 GHz transmitter show an improvement in drain efficiency from 27% to 36%. The 2.4 GHz and 433 MHz transmitters deliver an output power of 8 dBm with a phase noise of −122 dBc/Hz at 1 MHz offset, while drawing 15.4 mA of current and an output power of 6.5 dBm with a phase noise of −120 dBc/Hz at 1 MHz offset, while drawing 20.8 mA of current from 1.5 V power supplies, respectively. The PLL transmitter delivers an output power of 9 mW with a locking range of 128 MHz and consumes 26 mA from 1.8 V power supply. The experimental results demonstrate that the RF transmitters can be efficiently used in low power WSN applications.

  1. Storm Identification, Tracking and Forecasting Using High-Resolution Images of Short-Range X-Band Radar

    Directory of Open Access Journals (Sweden)

    Sajid Shah

    2015-05-01

    Full Text Available Rain nowcasting is an essential part of weather monitoring. It plays a vital role in human life, ranging from advanced warning systems to scheduling open air events and tourism. A nowcasting system can be divided into three fundamental steps, i.e., storm identification, tracking and nowcasting. The main contribution of this work is to propose procedures for each step of the rain nowcasting tool and to objectively evaluate the performances of every step, focusing on two-dimension data collected from short-range X-band radars installed in different parts of Italy. This work presents the solution of previously unsolved problems in storm identification: first, the selection of suitable thresholds for storm identification; second, the isolation of false merger (loosely-connected storms; and third, the identification of a high reflectivity sub-storm within a large storm. The storm tracking step of the existing tools, such as TITANand SCIT, use only up to two storm attributes, i.e., center of mass and area. It is possible to use more attributes for tracking. Furthermore, the contribution of each attribute in storm tracking is yet to be investigated. This paper presents a novel procedure called SALdEdA (structure, amplitude, location, eccentricity difference and areal difference for storm tracking. This work also presents the contribution of each component of SALdEdA in storm tracking. The second order exponential smoothing strategy is used for storm nowcasting, where the growth and decay of each variable of interest is considered to be linear. We evaluated the major steps of our method. The adopted techniques for automatic threshold calculation are assessed with a 97% goodness. False merger and sub-storms within a cluster of storms are successfully handled. Furthermore, the storm tracking procedure produced good results with an accuracy of 99.34% for convective events and 100% for stratiform events.

  2. Short-range order in Fe-based metallic glasses: Wide-angle X-ray scattering studies

    International Nuclear Information System (INIS)

    Babilas, Rafał; Hawełek, Łukasz; Burian, Andrzej

    2014-01-01

    The local atomic structure of the Fe 80 B 20 , Fe 70 Nb 10 B 20 and Fe 62 Nb 8 B 30 glasses prepared in the form of ribbons has been studied by wide-angle X-ray scattering. Structural information about the amorphous ribbons has been derived from analysis of the radial distribution functions using the least-squares curve-fitting method. The obtained structural parameters indicate that Fe–Fe, Fe–B, Fe–Nb and Nb–B contributions are involved in the near-neighbor coordination spheres. The possible similarities of the local atomic arrangement in the investigated glasses and the crystalline Fe 3 B, Fe 23 B 6 and bcc Fe structures are also discussed. - Graphical abstract: Pair distribution functions (a) and best-fit model and experimental radial distribution functions for Fe 80 B 20 (b), Fe 70 Nb 10 B 20 (c) and Fe 62 Nb 8 B 30 (d) metallic glasses. - Highlights: • The short-range ordering in the Fe-based metallic glasses is presented. • The results of RDF function have been analyzed using the least-squares method. • The Fe–Fe, Fe–B, Fe–Nb or Nb–B contributions are involved in coordination spheres. • The structural unit is distorted triangular prism containing B, Fe or Nb atoms. • Similarities of atomic arrangement in glassy and crystalline structures are discussed

  3. Analog Circuit Design Low Voltage Low Power; Short Range Wireless Front-Ends; Power Management and DC-DC

    CERN Document Server

    Roermund, Arthur; Baschirotto, Andrea

    2012-01-01

    The book contains the contribution of 18 tutorials of the 20th workshop on Advances in Analog Circuit Design.  Each part discusses a specific to-date topic on new and valuable design ideas in the area of analog circuit design. Each part is presented by six experts in that field and state of the art information is shared and overviewed. This book is number 20 in this successful series of Analog Circuit Design, providing valuable information and excellent overviews of Low-Voltage Low-Power Data Converters - Chaired by Prof. Anderea Baschirotto, University of Milan-Bicocca Short Range Wireless Front-Ends - Chaired by Prof. Arthur van Roermund, Eindhoven University of Technology Power management and DC-DC - Chaired by Prof. M. Steyaert, Katholieke University Leuven Analog Circuit Design is an essential reference source for analog circuit designers and researchers wishing to keep abreast with the latest development in the field. The tutorial coverage also makes it suitable for use in an advanced design.

  4. Critical current measurements of high-temperature superconducting short samples at a wide range of temperatures and magnetic fields

    Science.gov (United States)

    Ma, Hongjun; Liu, Huajun; Liu, Fang; Zhang, Huahui; Ci, Lu; Shi, Yi; Lei, Lei

    2018-01-01

    High-Temperature Superconductors (HTS) are potential materials for high-field magnets, low-loss transmission cables, and Superconducting Magnetic Energy Storage (SMES) due to their high upper critical magnetic field (Hc2) and critical temperature (Tc). The critical current (Ic) of HTS, which is one of the most important parameters for superconductor application, depends strongly on the magnetic fields and temperatures. A new Ic measurement system that can carry out accurate Ic measurement for HTS short samples with various temperatures (4.2-80 K), magnetic fields (0-14 T), and angles of the magnetic field (0°-90°) has been developed. The Ic measurement system mainly consists of a measurement holder, temperature-control system, background magnet, test cryostat, data acquisition system, and DC power supply. The accuracy of temperature control is better than ±0.1 K over the 20-80 K range and ±0.05 K when measured below 20 K. The maximum current is over 1000 A with a measurement uncertainty of 1%. The system had been successfully used for YBa2Cu3O7-x(YBCO) tapes Ic determination with different temperatures and magnetic fields.

  5. On the transition from short-range diffusion-limited to collision-limited growth in alloy solidification

    International Nuclear Information System (INIS)

    Aziz, M.J.; Boettinger, W.J.

    1994-01-01

    Short-range diffusion-limited growth, collision-limited growth, and the transition between the two regimes are explained as natural consequences of a single model for the kinetics of alloy solidification. Analytical expressions are developed for the velocity-undercooling function of a planar interface during dilute alloy solidification, using Turnbull's collision-limited growth model and the Continuous Growth Solute Trapping Model of Aziz and Kaplan both with and without a solute drag effect. The interface mobility, -dv/dT, is shown to be very high (proportional to the speed of sound) if the alloy is sufficiently dilute or if the growth rate is sufficiently rapid for nearly complete solute trapping. The interface mobility is reduced by the three orders of magnitude (becoming proportional to the diffusive speed) at intermediate growth rates where partial solute trapping occurs. Differences in low velocity predictions of the models with and without solute drag are also discussed. Comparison of the results of the analytical expressions to numerical solutions of the non-dilute kinetic model for Al-Be alloys shows that the dilute approximation breaks down at melt compositions on the order of 10 at.%. Similar variations in the interface mobility are shown for the disorder-trapping model of Boettinger and Aziz

  6. Critical current measurements of high-temperature superconducting short samples at a wide range of temperatures and magnetic fields.

    Science.gov (United States)

    Ma, Hongjun; Liu, Huajun; Liu, Fang; Zhang, Huahui; Ci, Lu; Shi, Yi; Lei, Lei

    2018-01-01

    High-Temperature Superconductors (HTS) are potential materials for high-field magnets, low-loss transmission cables, and Superconducting Magnetic Energy Storage (SMES) due to their high upper critical magnetic field (H c2 ) and critical temperature (T c ). The critical current (I c ) of HTS, which is one of the most important parameters for superconductor application, depends strongly on the magnetic fields and temperatures. A new I c measurement system that can carry out accurate I c measurement for HTS short samples with various temperatures (4.2-80 K), magnetic fields (0-14 T), and angles of the magnetic field (0°-90°) has been developed. The I c measurement system mainly consists of a measurement holder, temperature-control system, background magnet, test cryostat, data acquisition system, and DC power supply. The accuracy of temperature control is better than ±0.1 K over the 20-80 K range and ±0.05 K when measured below 20 K. The maximum current is over 1000 A with a measurement uncertainty of 1%. The system had been successfully used for YBa 2 Cu 3 O 7-x (YBCO) tapes I c determination with different temperatures and magnetic fields.

  7. Development and Short-Range Testing of a 100 kW Side-Illuminated Millimeter-Wave Thermal Rocket

    Science.gov (United States)

    Bruccoleri, Alexander; Eilers, James A.; Lambot, Thomas; Parkin, Kevin

    2015-01-01

    The objective of the phase described here of the Millimeter-Wave Thermal Launch System (MTLS) Project was to launch a small thermal rocket into the air using millimeter waves. The preliminary results of the first MTLS flight vehicle launches are presented in this work. The design and construction of a small thermal rocket with a planar ceramic heat exchanger mounted along the axis of the rocket is described. The heat exchanger was illuminated from the side by a millimeter-wave beam and fed propellant from above via a small tank containing high pressure argon or nitrogen. Short-range tests where the rocket was launched, tracked, and heated with the beam are described. The rockets were approximately 1.5 meters in length and 65 millimeters in diameter, with a liftoff mass of 1.8 kilograms. The rocket airframes were coated in aluminum and had a parachute recovery system activated via a timer and Pyrodex. At the rocket heat exchanger, the beam distance was 40 meters with a peak power intensity of 77 watts per square centimeter. and a total power of 32 kilowatts in a 30 centimeter diameter circle. An altitude of approximately 10 meters was achieved. Recommendations for improvements are discussed.

  8. Correlation between short-range order, optical properties and UV-absorption ability in tellurate glasses; Poster M7

    Energy Technology Data Exchange (ETDEWEB)

    Burger, H; Tews, W; Vogel, W; Kozhukharov, V [Jena Univ. (Germany)

    1989-01-01

    Tellurate glasses, with as second components Al[sub 2]O[sub 3], PbO, PbF[sub 2], PbCl[sub 2], PbBr[sub 2], PbSO[sub 4], ZnO, B[sub 2]O[sub 3], P[sub 2]O[sub 5], Li[sub 2]O, Na[sub 2]O, K[sub 2]O, MgO and BaO as well as some glasses from ternary TeO[sub 2]-P[sub 2]O[sub 5]-RO systems (R is Pb, Ba and Zn ions), have been investigated. Transmittance spectra in UV and VIS region of some selected glasses have been measured. A correlation between optical properties and UV absorption edge of the transmittance have been done. Using p[sup 31]-NMR spectroscopy the structural changes on short-range level order are studied. A strong influence on the refraction and dispersion values as well as UV-absorption ability of the glasses is established. For p[sup 31] -NMR spectroscopy investigations of crystalline phosphotellurites and related phosphotellurite glasses the TeO[sub 2]-P[sub 2]O[sub 5B]aO ternary system have been chosen. (author).

  9. Improvement of Surface Temperature Prediction Using SVR with MOGREPS Data for Short and Medium range over South Korea

    Science.gov (United States)

    Lim, S. J.; Choi, R. K.; Ahn, K. D.; Ha, J. C.; Cho, C. H.

    2014-12-01

    As the Korea Meteorology Administration (KMA) has operated Met Office Global and Regional Ensemble Prediction System (MOGREPS) with introduction of Unified Model (UM), many attempts have been made to improve predictability in temperature forecast in last years. In this study, post-processing method of MOGREPS for surface temperature prediction is developed with machine learning over 52 locations in South Korea. Past 60-day lag time was used as a training phase of Support Vector Regression (SVR) method for surface temperature forecast model. The selected inputs for SVR are followings: date and surface temperatures from Numerical Weather prediction (NWP), such as GDAPS, individual 24 ensemble members, mean and median of ensemble members for every 3hours for 12 days.To verify the reliability of SVR-based ensemble prediction (SVR-EP), 93 days are used (from March 1 to May 31, 2014). The result yielded improvement of SVR-EP by RMSE value of 16 % throughout entire prediction period against conventional ensemble prediction (EP). In particular, short range predictability of SVR-EP resulted in 18.7% better RMSE for 1~3 day forecast. The mean temperature bias between SVR-EP and EP at all test locations showed around 0.36°C and 1.36°C, respectively. SVR-EP is currently extending for more vigorous sensitivity test, such as increasing training phase and optimizing machine learning model.

  10. The range and effectiveness of short-term measures to reduce traffic emissions during high air pollution episodes

    International Nuclear Information System (INIS)

    Elsom, Derek M.

    1999-01-01

    Concern for continuing poor urban air quality, caused primarily by motor vehicles emissions, and the slow progress being made towards reducing total vehicle emissions by long-term measures, such as improving fuel and vehicle technologies, has prompted some authorities to try to reduce the severity and duration of high air pollution episodes by implementing short-term traffic restraint measures. This paper reviews the range of episodic air quality management schemes applied in cities around the world and comments on the effectiveness of such schemes. The difficulty of targeting vehicles according to the contribution they make to the air quality problem is highlighted. The problem of some schemes simply causing a displacement of the area of excessive vehicle emissions rather than reducing total emissions is reviewed. Rapid developments in telematics and improved urban air quality and traffic monitoring networks (e.g. Urban Traffic Management and Control systems) may offer significant improvements in the effectiveness of episodic management schemes in the future. (Author)

  11. Short-ranged structural rearrangement and enhancement of mechanical properties of organosilicate glasses induced by ultraviolet radiation

    International Nuclear Information System (INIS)

    Iacopi, F.; Travaly, Y.; Eyckens, B.; Waldfried, C.; Abell, T.; Guyer, E.P.; Gage, D.M.; Dauskardt, R.H.; Sajavaara, T.; Houthoofd, K.; Grobet, P.; Jacobs, P.; Maex, K.

    2006-01-01

    The short-ranged bonding structure of organosilicate glasses can vary to a great extent and is directly linked to the mechanical properties of the thin film material. The combined action of ultraviolet (UV) radiation and thermal activation is shown to generate a pronounced rearrangement in the bonding structure of thin organosilicate glass films involving no significant compositional change or film densification. Nuclear magnetic resonance spectroscopy indicates loss of -OH groups and an increase of the degree of cross-linking of the organosilicate matrix for UV-treated films. Fourier transform infrared spectroscopy shows a pronounced enhancement of the Si-O-Si network bond structure, indicating the formation of more energetically stable silica bonds. Investigation with x-ray reflectivity and ellipsometric porosimetry indicated only minor film densification. As a consequence, the mechanical properties of microporous organosilicate dielectric films are substantially enhanced while preserving the organosilicate nature and pristine porosity of the films. UV-treated films show an increase in elastic modulus and hardness of more than 40%, and a similar improvement in fracture energy compared to untreated films. A minor increase in material dielectric constant from 3.0 to 3.15 was observed after UV treatment. This mechanism is of high relevance for the application of organosilicate glasses as dielectric materials for microelectronics interconnects, for which a high mechanical stability and a low dielectric constant are both essential film requirements

  12. Interplay of short-range correlations and nuclear symmetry energy in hard-photon production from heavy-ion reactions at Fermi energies

    Science.gov (United States)

    Yong, Gao-Chan; Li, Bao-An

    2017-12-01

    Within an isospin- and momentum-dependent transport model for nuclear reactions at intermediate energies, we investigate the interplay of the nucleon-nucleon short-range correlations (SRCs) and nuclear symmetry energy Esym(ρ ) on hard-photon spectra in collisions of several Ca isotopes on 112Sn and 124Sn targets at a beam energy of 45 MeV/nucleon. It is found that over the whole spectra of hard photons studied, effects of the SRCs overwhelm those owing to the Esym(ρ ) . The energetic photons come mostly from the high-momentum tails (HMTs) of single-nucleon momentum distributions in the target and projectile. Within the neutron-proton dominance model of SRCs based on the consideration that the tensor force acts mostly in the isosinglet and spin-triplet nucleon-nucleon interaction channel, there are equal numbers of neutrons and protons, thus a zero isospin asymmetry in the HMTs. Therefore, experimental measurements of the energetic photons from heavy-ion collisions at Fermi energies have the great potential to help us better understand the nature of SRCs without any appreciable influence by the uncertain Esym(ρ ) . These measurements will be complementary to but also have some advantages over the ongoing and planned experiments using hadronic messengers from reactions induced by high-energy electrons or protons. Because the underlying physics of SRCs and Esym(ρ ) are closely correlated, a better understanding of the SRCs will, in turn, help constrain the nuclear symmetry energy more precisely in a broad density range.

  13. Crossover Scaling of Apparent First-order Wetting in Two-dimensional Systems with Short-ranged Forces.

    Czech Academy of Sciences Publication Activity Database

    Parry, A.O.; Malijevský, Alexandr

    2016-01-01

    Roč. 93, č. 6 (2016), s. 062802 ISSN 2470-0045 R&D Projects: GA ČR GA13-09914S Grant - others:EPSRC(GB) EP/L0205641/1 Institutional support: RVO:67985858 Keywords : planar ising ferromagnet * line tension * functional renormalization Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.366, year: 2016

  14. Toward Improving Short-Range Fog Prediction in Data-Denied Areas Using the Air Force Weather Agency Mesoscale Ensemble

    Science.gov (United States)

    2012-09-01

    hre - del’k:it( K) vitual t~ hre del’k:I:(K) all sl:e-s, a ll rnerrbers (exc l 1 S...2 01 vitual t~ hre del’k:l(K) vitual t~ hre del’k:l(K) all sit~s. atl~(e-xcl1 S& 17) all sit~s. atl~(e-xcl 1 S& 17) vitual t~ hre del’k:l(K) vitual...t~ hre del’k:l(K) all sit~s. a tl~(e-xcl1 S& 17) all sit~s. atl~(e-xcl 1 S& 17) vitual t~ hre del’k:l(K) vitual t~ hre del’k:l(K) 166

  15. Short- and medium-range order of atomic structure and electronic properties of arsenic salinide and sulphide amorphous films

    International Nuclear Information System (INIS)

    Sarsembinov, Sh.Sh.; Prikhodko, O.Yu.; Ryaguzov, A.P.; Maksimova, S.Ya.; Ushanov, V.Zh.

    2004-01-01

    Full text: The relationship between short- and medium-range order of atomic structure and electronic properties is the object of invariable attention of disordered matter physics. This problem is the most important for non-crystalline semiconductors, and specifically for chalcogenide glassy semiconductors (ChGS) films due to low co-ordination of atoms, which leads to lability of their structure. In this report we present results of atomic structure, electric, optical properties and carrier drift investigation in amorphous films of As 2 Se 3 and As 2 S 3 prepared by thermal evaporation in a vacuum (TE films) and by RF ion-plasma sputtering (RF films). These techniques strongly differing in the conditions of substance vaporization and condensation atoms on a substrate. The short- and medium-range order of the films atomic structure has been studied by X-ray diffraction analysis using the CuKα radiation (λ=1.5418 Angstrom) and by Raman spectroscopy. Raman spectra were measured at room temperature on Perkin-Elmer Spectrum GX Raman FT-IR Spectrometer (180 deg. backscattering). Vibrational modes were excited vertically polarized light of DPY Nd:YAG laser (1.064 μm). The radii of the first and second coordination spheres, number of the nearest neighbours of As and Se (S) atoms in the first coordination sphere, dimension of the medium-range order domain and 'quasi-period' in that region have been determined for the studied samples. The identification of the structural units in matrix of the film has been carried out, too. It is established that the films prepared by different methods have differences in the parameters of short- and medium range orders. It follows from the comparative analysis of Raman spectra that spectrum of RF films is significantly more complex than that of glass and TE films. The matrix of RF films contains, along with the structural units AsSe 3/2 (AsS 3/2 ) inherent in TE films and glass, other structural units with As and Se (S) excess. It may be

  16. Short-time scale coupling between thermohaline and meteorological forcing in the Ría de Pontevedra

    Directory of Open Access Journals (Sweden)

    Paula C. Pardo

    2001-07-01

    Full Text Available Two cruises were performed in May-June and October-November 1997 in the Ría de Pontevedra under strong downwelling conditions. Temperature and salinity data were recorded in short sampling periods to describe the changes in thermohaline property distribution in a short time scale. In order to obtain the residual fluxes in the Ría, a bi-dimensional non-stationary salt and thermal-energy weight averaged box-model was applied. Outputs from this kinematic model were compared with Upwelling Index, river flow and density gradient, resulting in a good multiple correlation, which proves the strong coupling between thermohaline properties and meteorological variability. Ekman forcing affects the whole area but mainly controls the dynamics of outer zones. The intensity of its effect on the circulation pattern within the Ría depends on the grade of stratification of the water bodies. River flow is more relevant in inner parts. According to estimated spatially averaged velocities, water residence time is lower than two weeks in outer parts of the Ría, and decreases toward the inner zones.

  17. Simulation Assisted Analysis of the Intrinsic Stiffness for Short DNA Molecules Imaged with Scanning Atomic Force Microscopy.

    Directory of Open Access Journals (Sweden)

    Haowei Wang

    Full Text Available Studying the mechanical properties of short segments of dsDNA can provide insight into various biophysical phenomena, from DNA looping to the organization of nucleosomes. Scanning atomic force microscopy (AFM is able to acquire images of single DNA molecules with near-basepair resolution. From many images, one may use equilibrium statistical mechanics to quantify the intrinsic stiffness (or persistence length of the DNA. However, this approach is highly dependent upon both the correct microscopic polymer model and a correct image analysis of DNA contours. These complications have led to significant debate over the flexibility of dsDNA at short length scales. We first show how to extract accurate measures of DNA contour lengths by calibrating to DNA traces of simulated AFM data. After this calibration, we show that DNA adsorbed on an aminopropyl-mica surface behaves as a worm-like chain (WLC for contour lengths as small as ~20 nm. We also show that a DNA binding protein can modify the mechanics of the DNA from that of a WLC.

  18. Short-range phenotypic divergence among genetically distinct parapatric populations of an Australian funnel-web spider.

    Science.gov (United States)

    Wong, Mark K L; Woodman, James D; Rowell, David M

    2017-07-01

    Speciation involves divergence at genetic and phenotypic levels. Where substantial genetic differentiation exists among populations, examining variation in multiple phenotypic characters may elucidate the mechanisms by which divergence and speciation unfold. Previous work on the Australian funnel-web spider Atrax sutherlandi Gray (2010; Records of the Australian Museum 62 , 285-392; Mygalomorphae: Hexathelidae: Atracinae) has revealed a marked genetic structure along a 110-kilometer transect, with six genetically distinct, parapatric populations attributable to past glacial cycles. In the present study, we explore variation in three classes of phenotypic characters (metabolic rate, water loss, and morphological traits) within the context of this phylogeographic structuring. Variation in metabolic and water loss rates shows no detectable association with genetic structure; the little variation observed in these rates may be due to the spiders' behavioral adaptations (i.e., burrowing), which buffer the effects of climatic gradients across the landscape. However, of 17 morphological traits measured, 10 show significant variation among genetic populations, in a disjunct manner that is clearly not latitudinal. Moreover, patterns of variation observed for morphological traits serving different organismic functions (e.g., prey capture, burrowing, and locomotion) are dissimilar. In contrast, a previous study of an ecologically similar sympatric spider with little genetic structure indicated a strong latitudinal response in 10 traits over the same range. The congruence of morphological variation with deep phylogeographic structure in Tallaganda's A. sutherlandi populations, as well as the inconsistent patterns of variation across separate functional traits, suggest that the spiders are likely in early stages of speciation, with parapatric populations independently responding to local selective forces.

  19. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. (a...

  20. Building a QC Database of Meteorological Data From NASA KSC and the United States Air Force's Eastern Range

    Science.gov (United States)

    Brenton, James C.; Barbre, Robert E.; Orcutt, John M.; Decker, Ryan K.

    2018-01-01

    The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) Natural Environments Branch (EV44) has provided atmospheric databases and analysis in support of space vehicle design and day-of-launch operations for NASA and commercial launch vehicle programs launching from the NASA Kennedy Space Center (KSC), co-located on the United States Air Force's Eastern Range (ER) at the Cape Canaveral Air Force Station. The ER is one of the most heavily instrumented sites in the United States measuring various atmospheric parameters on a continuous basis. An inherent challenge with the large databases that EV44 receives from the ER consists of ensuring erroneous data are removed from the databases, and thus excluded from launch vehicle design analyses. EV44 has put forth great effort in developing quality control (QC) procedures for individual meteorological instruments; however, no standard QC procedures for all databases currently exist resulting in QC databases that have inconsistencies in variables, methodologies, and periods of record. The goal of this activity is to use the previous efforts by EV44 to develop a standardized set of QC procedures from which to build flags within the meteorological databases from KSC and the ER, while maintaining open communication with end users from the launch community to develop ways to improve, adapt and grow the QC database. Details of the QC checks are described. The flagged data points will be plotted in a graphical user interface (GUI) as part of a manual confirmation that the flagged data do indeed need to be removed from the archive. As the rate of launches increases with additional launch vehicle programs, more emphasis is being placed to continually update and check weather databases for data quality before use in launch vehicle design and certification analyses.

  1. Thermal ageing and short-range ordering of Alloy 690 between 350 and 550 °C

    Energy Technology Data Exchange (ETDEWEB)

    Mouginot, Roman, E-mail: roman.mouginot@aalto.fi [Aalto University School of Engineering, Department of Mechanical Engineering, Otakaari 4, 02150 Espoo (Finland); Sarikka, Teemu [Aalto University School of Engineering, Department of Mechanical Engineering, Otakaari 4, 02150 Espoo (Finland); Heikkilä, Mikko [University of Helsinki, Laboratory of Inorganic Chemistry, A.I.Virtasen Aukio 1, 00560 Helsinki (Finland); Ivanchenko, Mykola; Ehrnstén, Ulla [VTT Technical Research Centre of Finland LTD, Kemistintie 3, 02150 Espoo (Finland); Kim, Young Suk; Kim, Sung Soo [Korea Atomic Energy Research Institute, Daedeok-Daero, 989-111, Yuseong, Daejeon, 34057 (Korea, Republic of); Hänninen, Hannu [Aalto University School of Engineering, Department of Mechanical Engineering, Otakaari 4, 02150 Espoo (Finland)

    2017-03-15

    Thermal ageing of Alloy 690 triggers an intergranular (IG) carbide precipitation and is known to promote an ordering reaction causing lattice contraction. It may affect the long-term primary water stress corrosion cracking (PWSCC) resistance of pressurized water reactor (PWR) components. Four conditions of Alloy 690 (solution annealed, cold-rolled and/or heat-treated) were aged between 350 and 550 °C for 10 000 h and characterized. Although no direct observation of ordering was made, variations in hardness and lattice parameter were attributed to the formation of short-range ordering (SRO) in all conditions with a peak level at 420 °C, consistent with the literature. Prior heat treatment induced ordering before thermal ageing. At higher temperatures, stress relaxation, recrystallization and α-Cr precipitation were observed in the cold-worked samples, while a disordering reaction was inferred in all samples based on a decrease in hardness. IG precipitation of M{sub 23}C{sub 6} carbides increased with increasing ageing temperature in all conditions, as well as diffusion-induced grain boundary migration (DIGM). - Highlights: • SRO was suggested in Alloy 690 with 9.18 wt% Fe after thermal ageing at 350, 420 and 475 °C. • Prior thermal treatment promoted SRO before ageing. • Cold work led to recrystallization and precipitation of α-Cr upon ageing at 550 °C. • Thermal ageing promoted IG precipitation of Cr-rich M{sub 23}C{sub 6} carbides and DIGM.

  2. Short and medium range structures of 80GeSe2–20Ga2Se3 chalcogenide glasses

    Science.gov (United States)

    Petracovschi, Elena; Calvez, Laurent; Cormier, Laurent; Le Coq, David; Du, Jincheng

    2018-05-01

    The short and medium range structures of 80GeSe2–20Ga2Se3 (or Ge23.5Ga11.8Se64.7) chalcogenide glasses have been studied by combining ab initio molecular dynamics (AIMD) simulations and experimental neutron diffraction studies. The structure factor and total correlation function were calculated from glass structures generated from AIMD simulations and compared with neutron diffraction experiments showing reasonable agreement. The atomic structures of ternary chalcogenide glasses were analyzed in detail, and it was found that gallium atoms are four-fold coordinated by selenium (Se) and form [GaSe4] tetrahedra. Germanium atoms on average also have four-fold coordination, among which Se is 3.5 with the remaining being Ge–Ge homo-nuclear bonds. Ga and Ge tetrahedra link together mainly through corner-sharing and some edge-sharing of Se. No homo-nuclear bonds were observed among Ga atoms or between Ge and Ga. In addition, Se–Se homo-nuclear bonds and Se chains with various lengths were observed. A small fraction of Se atom triclusters that bond to three cations of Ge and Ga were also observed, confirming earlier proposals from 77Se solid state nuclear magnetic resonance studies. Furthermore, the electronic structures of ternary chalcogenide glasses were studied in terms of atomic charge and electronic density of states in order to gain insights into the chemical bonding and electronic properties, as well as to provide an explanation of the observed atomic structures in these ternary chalcogenide glasses.

  3. Elastic strain relaxation in interfacial dislocation patterns: II. From long- and short-range interactions to local reactions

    Science.gov (United States)

    Vattré, A.

    2017-08-01

    The long- and short-range interactions as well as planar reactions between two infinitely periodic sets of crossing dislocations are investigated using anisotropic elasticity theory in face- (fcc) and body- (bcc) centered cubic materials. Two preliminary cases are proposed to examine the substantial changes in the elastic stress states and the corresponding strain energies due to a slight rearrangement in the internal dislocation geometries and characters. In general, significant differences and discrepancies resulting from the considered cubic crystal structure and the approximation of isotropic elasticity are exhibited. In a third scenario, special attention is paid to connecting specific internal dislocation structures from the previous cases with non-equilibrium configurations predicted by the quantized Frank-Bilby equation for the (111) fcc and (110) bcc twist grain boundaries. The present solutions lead to the formation of energetically favorable dislocation junctions with non-randomly strain-relaxed configurations of lower energy. In particular, the local dislocation interactions and reactions form equilibrium hexagonal-shaped patterns with planar three-fold dislocation nodes without producing spurious far-field stresses.Numerical application results are presented from a selection of cubic metals including aluminum, copper, tantalum, and niobium. In contrast to the fcc materials, asymmetric dislocation nodes occur in the anisotropic bcc cases, within which the minimum-energy paths for predicting the fully strain-relaxed dislocation patterns depend on the Zener anisotropic factor with respect to unity. The associated changes in the dislocation structures as well as the removal of the elastic strain energy upon relaxations are quantified and also discussed.

  4. On the universality of the long-/short-range separation in multiconfigurational density-functional theory. II. Investigating f0 actinide species

    DEFF Research Database (Denmark)

    Fromager, Emmanuel; Réal, Florent; Wåhlin, Pernilla

    2009-01-01

    In a previous paper [Fromager , J. Chem. Phys. 126, 074111 (2007)], some of the authors proposed a recipe for choosing the optimal value of the mu parameter that controls the long-range/short-range separation of the two-electron interaction in hybrid multiconfigurational self-consistent field sho...

  5. Wide range local resistance imaging on fragile materials by conducting probe atomic force microscopy in intermittent contact mode

    Energy Technology Data Exchange (ETDEWEB)

    Vecchiola, Aymeric [Laboratoire de Génie électrique et électronique de Paris (GeePs), UMR 8507 CNRS-CentraleSupélec, Paris-Sud and UPMC Universities, 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette (France); Concept Scientific Instruments, ZA de Courtaboeuf, 2 rue de la Terre de Feu, 91940 Les Ulis (France); Unité Mixte de Physique CNRS-Thales UMR 137, 1 avenue Augustin Fresnel, 91767 Palaiseau (France); Chrétien, Pascal; Schneegans, Olivier; Mencaraglia, Denis; Houzé, Frédéric, E-mail: frederic.houze@geeps.centralesupelec.fr [Laboratoire de Génie électrique et électronique de Paris (GeePs), UMR 8507 CNRS-CentraleSupélec, Paris-Sud and UPMC Universities, 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette (France); Delprat, Sophie [Unité Mixte de Physique CNRS-Thales UMR 137, 1 avenue Augustin Fresnel, 91767 Palaiseau (France); UPMC, Université Paris 06, 4 place Jussieu, 75005 Paris (France); Bouzehouane, Karim; Seneor, Pierre; Mattana, Richard [Unité Mixte de Physique CNRS-Thales UMR 137, 1 avenue Augustin Fresnel, 91767 Palaiseau (France); Tatay, Sergio [Molecular Science Institute, University of Valencia, 46980 Paterna (Spain); Geffroy, Bernard [Lab. Physique des Interfaces et Couches minces (PICM), UMR 7647 CNRS-École polytechnique, 91128 Palaiseau (France); Lab. d' Innovation en Chimie des Surfaces et Nanosciences (LICSEN), NIMBE UMR 3685 CNRS-CEA Saclay, 91191 Gif-sur-Yvette (France); and others

    2016-06-13

    An imaging technique associating a slowly intermittent contact mode of atomic force microscopy (AFM) with a home-made multi-purpose resistance sensing device is presented. It aims at extending the widespread resistance measurements classically operated in contact mode AFM to broaden their application fields to soft materials (molecular electronics, biology) and fragile or weakly anchored nano-objects, for which nanoscale electrical characterization is highly demanded and often proves to be a challenging task in contact mode. Compared with the state of the art concerning less aggressive solutions for AFM electrical imaging, our technique brings a significantly wider range of resistance measurement (over 10 decades) without any manual switching, which is a major advantage for the characterization of materials with large on-sample resistance variations. After describing the basics of the set-up, we report on preliminary investigations focused on academic samples of self-assembled monolayers with various thicknesses as a demonstrator of the imaging capabilities of our instrument, from qualitative and semi-quantitative viewpoints. Then two application examples are presented, regarding an organic photovoltaic thin film and an array of individual vertical carbon nanotubes. Both attest the relevance of the technique for the control and optimization of technological processes.

  6. High-energy X-ray study of short range order and phase transformations in titanium-vanadium

    International Nuclear Information System (INIS)

    Ramsteiner, I.B.

    2005-01-01

    This work presents a study of configurational correlations and phase transformations in the binary alloy Ti-V, using high-energy X-ray diffraction. The experiments have been performed at the European Synchrotron Radiation Facility (ESRF) in Grenoble. The high-energy (60-100 keV) technique developed recently allows in-situ measurements on bulk material in transmission geometry. The first part of the thesis discusses multiple scattering effects which might occur with this method. These effects are experimentally verified and discussed. Special emphasis is put on the questions, whether they affect the results obtained with this method, and how they can be avoided. Understanding alloys on the most fundamental level requires knowledge about the atomic interaction potentials. Competing with entropy, these potentials determine the configurational short range order in a disordered alloy, which generates together with static and dynamic distortions the diffuse scattering. The thesis presents measurements and calculations of the diffuse scattering patterns of Ti-V. The calculations, taking into account configurational correlations, static distortions induced by atomic size mismatch and thermal diffuse scattering, agree with the experimental data. Structural transformations in Ti-V are carefully characterized using high-energy x-ray diffraction in combination with the complementary transmission electron microscopy (TEM). While the first technique allows to study the phenomena in-situ and time-resolved, TEM yields real space images and chemical information about the phases. Ti-V near the equiatomic composition is a beta-Ti-alloy. The body centered cubic beta phase is retained at room temperature by fast quenching. Aging the material below the phase transformation temperature, however, leads to the precipitation of hexagonal alpha titanium. Another transformation process confusing earlier works is identified as TiC formation from carbon impurities in the material. In addition

  7. The role of the form factor and short-range correlation in the relativistic Hartree-Fock model for nuclear matter

    International Nuclear Information System (INIS)

    Hu, J.; Toki, H.; Wen, W.; Shen, H.

    2010-01-01

    The role of the form factor and short-range correlation in nuclear matter is studied within the relativistic Hartree-Fock approximation. We take, first, the mean-field approximation for meson fields and obtain the fluctuation terms of mesons to be used for the Fock energies. We introduce form factors in the meson-nucleon coupling vertices to take into account the finite-size effect of the nucleon. We use further the unitary correlation operator method for the treatment of the short-range correlation. The form factors of the size (Λ∝1.0 -2.0 GeV) of the nucleon-nucleon interaction cut down largely the contribution of the ρ-meson in the Fock term. The short-range correlation effect is not large but has a significant effect on the pion and ρ-meson energies in the relativistic Hartree-Fock approximation for nuclear matter. (orig.)

  8. The role of the form factor and short-range correlation in the relativistic Hartree-Fock model for nuclear matter

    Science.gov (United States)

    Hu, J.; Toki, H.; Wen, W.; Shen, H.

    2010-03-01

    The role of the form factor and short-range correlation in nuclear matter is studied within the relativistic Hartree-Fock approximation. We take, first, the mean-field approximation for meson fields and obtain the fluctuation terms of mesons to be used for the Fock energies. We introduce form factors in the meson-nucleon coupling vertices to take into account the finite-size effect of the nucleon. We use further the unitary correlation operator method for the treatment of the short-range correlation. The form factors of the size ( Λ ˜ 1.0 -2.0GeV) of the nucleon-nucleon interaction cut down largely the contribution of the ρ -meson in the Fock term. The short-range correlation effect is not large but has a significant effect on the pion and ρ -meson energies in the relativistic Hartree-Fock approximation for nuclear matter.

  9. Effect of Short-term Forced Exercise on Naloxone Induced Withdrawal Symptoms in Morphine Addicted Male Rats

    Directory of Open Access Journals (Sweden)

    KH Saadipour

    2008-01-01

    Full Text Available ABSTRACT: Introduction & Objective: Opioid dependence has been causing limitation in usage of morphine and other opioid drugs in pain control. The aim of this study was to assess the effect of short-term forced exercise on withdrawal syndrome in morphine addicted male rats. Materials & Methods: This experimental study was done in the physiology research center of Ahwas Jondishapour University of Medical Sciences. Twenty four young male Wistar rats, weighing 200-300gr, were randomly divided into four groups: no addiction and no exercise, no addiction and exercise, addiction and no exercise and addiction and exercise. The exercise groups underwent treadmill forced exercise for ten days. The first five days morphine was administrated (ip twice daily with increasing dose (5، 10، 20، 40, 50 mg/kg to addicted groups. Also single dose (50mg/kg of morphine was administrated to them on the 10th day of exercise. After administration of naloxone hydrochloride the withdrawal symptoms were evaluated for 5 minutes. The findings of this study were analyzed by SPSS software and One- way ANOVA (Tukey test. Results: The findings of this study showed that the withdrawal symptoms was elevated in exercise and addicted groups in comparison with control group (p<0.05 , p<0.01. However, most of withdrawal symptoms decreased in addicted and exercise group in comparison with addicted and no exercise group (p<0.01, p<0.001. Conclusion: The exercise could increase endogenous opioid and withdrawal symptoms in animals but reduce withdrawal symptoms in addicted and exercise groups compared to addicted and no exercise group. Its mechanism might be related to down regulation and low sensitivity of opioid receptors

  10. Ternary fluid mixture confined between surfaces: Surface-induced phase transition and long-range oscillatory forces

    NARCIS (Netherlands)

    Banerjee, S.; Mulder, P.; Kleijn, J.M.; Cohen Stuart, M.A.

    2012-01-01

    Surface forces between a soft cellulose surface and a hard silica particle were measured in wet hexane with or without the addition of a surfactant. In the absence of a surfactant, the adhesion force was enhanced as a result of capillary condensation of water. The effect of the surfactant in

  11. The Importance of Short- and Long-Range Exchange on Various Excited State Properties of DNA Monomers, Stacked Complexes, and Watson-Crick Pairs.

    Science.gov (United States)

    Raeber, Alexandra E; Wong, Bryan M

    2015-05-12

    We present a detailed analysis of several time-dependent DFT (TD-DFT) methods, including conventional hybrid functionals and two types of nonempirically tuned range-separated functionals, for predicting a diverse set of electronic excitations in DNA nucleobase monomers and dimers. This large and extensive set of excitations comprises a total of 50 different transitions (for each tested DFT functional) that includes several n → π and π → π* valence excitations, long-range charge-transfer excitations, and extended Rydberg transitions (complete with benchmark calculations from high-level EOM-CCSD(T) methods). The presence of localized valence excitations as well as extreme long-range charge-transfer excitations in these systems poses a serious challenge for TD-DFT methods that allows us to assess the importance of both short- and long-range exchange contributions for simultaneously predicting all of these various transitions. In particular, we find that functionals that do not have both short- and full long-range exchange components are unable to predict the different types of nucleobase excitations with the same accuracy. Most importantly, the current study highlights the importance of both short-range exchange and a nonempirically tuned contribution of long-range exchange for accurately predicting the diverse excitations in these challenging nucleobase systems.

  12. Distribution of motor unit potential velocities in short static and prolongd dynamic contractions at low forces: Use of the within-subject's skewness and standard deviation variables

    NARCIS (Netherlands)

    Klaver-Krol, E.G.; Henriquez, N.R.; Oosterloo, Sebe J.; Klaver, P.; Bos, J.M.; Zwarts, M.J.

    2007-01-01

    Behaviour of motor unit potential (MUP) velocities in relation to (low) force and duration was investigated in biceps brachii muscle using a surface electrode array. Short static tests of 3.8 s (41 subjects) and prolonged dynamic tests (prolonged tests) of 4 min (30 subjects) were performed as

  13. Short- and long-range polar order contributions to the Ferroelectric phase of Ca.sup.2+./sup. doped SrTiO.sub.3./sub.

    Czech Academy of Sciences Publication Activity Database

    Markovin, P.A.; Trepakov, Vladimír; Guzhva, M.E.; Razdobarin, A.G.; Tagantsev, A. K.; Andreev, D. A.; Dejneka, Alexandr

    2016-01-01

    Roč. 3, č. 11 (2016), s. 1-12, č. článku 115705. ISSN 2053-1591 R&D Projects: GA ČR GA15-13778S Institutional support: RVO:68378271 Keywords : quantum paraelectrics * impurities and defects * low-temperature polar state * ferroelectric phase * long-range order * short-range Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.068, year: 2016

  14. Cost-effective up to 40 Gbit/s transmission performance of 1310 nm directly modulated lasers for short to medium range distances

    NARCIS (Netherlands)

    Huiszoon, B.; Jonker, R.J.W.; Bennekom, van P.K.; Khoe, G.D.; Waardt, de H.

    2005-01-01

    This paper presents successful 20 and 40 Gb/s potentially low-cost transmission experiments using 1310 nm directly modulated distributed feedback lasers (DMLs) in the very-short- to medium-range distances. This paper will recommend operating conditions for error-free transmission at these bit rates

  15. Electronic structure of disordered alloys - I: self-consistent cluster CPA incorporating off-diagonal disorder and short-range order

    International Nuclear Information System (INIS)

    Kumar, V.; Mookerjee, A.; Srivastava, V.K.

    1980-09-01

    We have developed here a self-consistent coherent potential approximation generalized to take into account effect of clusters. Off-diagonal disorder and short-range order are taken into account. A graphical method married to the recursion technique, enables us to work on realistic three-dimensional lattices. Calculations are shown for a binary alloy on a diamond lattice. (author)

  16. Structure Factor of a Hard-core Fluid with Short-range Yukawa Attraction: Analytical FMSA Theory against Monte Carlo Simulations.

    Czech Academy of Sciences Publication Activity Database

    Melnyk, R.; Nezbeda, Ivo; Trokhymchuk, A.

    2016-01-01

    Roč. 114, 16-17 (2016), s. 2523-2529 ISSN 0026-8976 Institutional support: RVO:67985858 Keywords : hard-core fluid * reference system * short-range Yukawa attraction Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.870, year: 2016

  17. Short and long range gain monitoring of photomultipliers by means of a light pulser and an optical fibers bunch

    International Nuclear Information System (INIS)

    Besson, P.

    1989-01-01

    The gain monitoring of 8 XP3462 photomultipliers has been studied during a period of 3 months with a spark gap as a light pulser, an optical fibres bunch and 3 reference detectors. One of the reference PM is monitored thanks to a cristal of NaI irradiated by an 241 Am radioactive source, whereas the photodiode and its associated electronic is monitored thanks to a 57 Co source directly coupled to the junction. Two experimental methods have been tested. First the short term method consists in estimating several means of charge distributions and supposes the stability of different optical parameters like quantum efficiency or photoelectrons collection efficiency. The long term method consists in estimating several variances of charge distributions and supposes the validity, at first order, of photomultipliers' equations. In spite of unpropitious experimental conditions (tension switch off, no climatisation..), our results indicate that the short term method provides a precision of about 0.5% for the relative gain value but only during a short period which has been of 20 days. The long term method provides a precision of about 1.5% but is remained available during the 3 months of our experiment. This study has been developed for the new Neutrino oscillation program taking place near the Bugey nuclear plant and using 600 photomultipliers. The conclusions mentioned above are nevertheless valid for any particle detectors using photomultipliers [fr

  18. Columnar aerosol characteristics and radiative forcing over the Doon Valley in the Shivalik range of northwestern Himalayas.

    Science.gov (United States)

    Dumka, U C; Saheb, Shaik Darga; Kaskaoutis, D G; Kant, Yogesh; Mitra, D

    2016-12-01

    Spectral aerosol optical depth (AOD) measurements obtained from multi-wavelength radiometer under cloudless conditions over Doon Valley, in the foothills of the western Himalayas, are analysed during the period January 2007 to December 2012. High AOD values of 0.46 ± 0.08 and 0.52 ± 0.1 at 500 nm, along with low values of Ångström exponent (0.49 ± 0.01 and 0.44 ± 0.03) during spring (March-May) and summer (June-August), respectively, suggest a flat AOD spectrum indicative of coarse-mode aerosol abundance compared with winter (December-February) and autumn (September-November), which are mostly dominated by fine aerosols from urban/industrial emissions and biomass burning. The columnar size distributions (CSD) retrieved from the King's inversion of spectral AOD exhibit bimodal size patterns during spring and autumn, while combinations of the power-law and unimodal distributions better simulate the retrieved CSDs during winter and summer. High values of extinction coefficient near the surface (∼0.8-1.0 km -1 at 532 nm) and a steep decreasing gradient above are observed via CALIPSO profiles in autumn and winter, while spring and summer exhibit elevated aerosol layers between ∼1.5 and 3.5 km due to the presence of dust. The particle depolarisation ratio shows a slight increasing trend with altitude, with higher values in spring and summer indicative of non-spherical particles of dust origin. The aerosol-climate implications are evaluated via the aerosol radiative forcing (ARF), which is estimated via the synergy of OPAC and SBDART models. On the monthly basis, the ARF values range from ∼ -30 to -90 W m -2 at the surface, while aerosols cause an overall cooling effect at the top of atmosphere (approx. -5 to -15 W m -2 ). The atmospheric heating via aerosol absorption results in heating rates of 1.2-1.6 K day -1 during March-June, which may contribute to changes in monsoon circulation over northern India and the Himalayas.

  19. The Politics of NATO Short-Range Nuclear Modernization 1983-1990: The Follow-On-to-Lance Missile Decisions

    Science.gov (United States)

    1991-06-01

    sequential terms with discussions on SNF given a very low priority. 31 COMPENSATORY MEASURES DEBATED Everyone agrees that If we accept the zero...role and came out in support of the concept. According to insiders who worked with the Air Force in the early days of the TASM program, the lineup of...the lineup for the FY 92 debate has not changed much since that of the 133BASIC Report 90.5/2, December 1990, p. 4; "Defense Spending Bills Differ

  20. Altered Long- and Short-Range Functional Connectivity in Patients with Betel Quid Dependence: A Resting-State Functional MRI Study

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2016-12-01

    Full Text Available Objective: Addiction is a chronic relapsing brain disease. Brain structural abnormalities may constitute an abnormal neural network that underlies the risk of drug dependence. We hypothesized that individuals with Betel Quid Dependence (BQD have functional connectivity alterations that can be described by long- and short-range functional connectivity density(FCD maps. Methods: We tested this hypothesis using functional magnetic resonance imaging (fMRI data from subjects of the Han ethnic group in Hainan, China. Here, we examined BQD individuals (n = 33 and age-, sex-, and education-matched healthy controls (HCs (n = 32 in a rs-fMRI study to observe FCD alterations associated with the severity of BQD. Results: Compared with HCs, long-range FCD was decreased in the right anterior cingulate cortex (ACC and increased in the left cerebellum posterior lobe (CPL and bilateral inferior parietal lobule (IPL in the BQD group. Short-range FCD was reduced in the right ACC and left dorsolateral prefrontal cortex (dlPFC, and increased in the left CPL. The short-range FCD alteration in the right ACC displayed a negative correlation with the Betel Quid Dependence Scale (BQDS (r=-0.432, P=0.012, and the long-range FCD alteration of left IPL showed a positive correlation with the duration of BQD(r=0.519, P=0.002 in BQD individuals. Conclusions: fMRI revealed differences in long- and short- range FCD in BQD individuals, and these alterations might be due to BQ chewing, BQ dependency, or risk factors for developing BQD.

  1. Investigation of the range of validity of the pairwise summation method applied to the calculation of the surface roughness correction to the van der Waals force

    Science.gov (United States)

    Gusso, André; Burnham, Nancy A.

    2016-09-01

    It has long been recognized that stochastic surface roughness can considerably change the van der Waals (vdW) force between interacting surfaces and particles. However, few analytical expressions for the vdW force between rough surfaces have been presented in the literature. Because they have been derived using perturbative methods or the proximity force approximation the expressions are valid when the roughness correction is small and for a limited range of roughness parameters and surface separation. In this work, a nonperturbative approach, the effective density method (EDM) is proposed to circumvent some of these limitations. The method simplifies the calculations of the roughness correction based on pairwise summation (PWS), and allows us to derive simple expressions for the vdW force and energy between two semispaces covered with stochastic rough surfaces. Because the range of applicability of PWS and, therefore, of our results, are not known a priori, we compare the predictions based on the EDM with those based on the multilayer effective medium model, whose range of validity can be defined more properly and which is valid when the roughness correction is comparatively large. We conclude that the PWS can be used for roughness characterized by a correlation length of the order of its rms amplitude, when this amplitude is of the order of or smaller than a few nanometers, and only for typically insulating materials such as silicon dioxide, silicon nitride, diamond, and certain glasses, polymers and ceramics. The results are relevant for the correct modeling of systems where the vdW force can play a significant role such as micro and nanodevices, for the calculation of the tip-sample force in atomic force microscopy, and in problems involving adhesion.

  2. Microscopic nucleon spectral function for finite nuclei featuring two- and three-nucleon short-range correlations: The model versus ab initio calculations for three-nucleon systems

    Science.gov (United States)

    Ciofi degli Atti, Claudio; Mezzetti, Chiara Benedetta; Morita, Hiko

    2017-04-01

    Background: Two-nucleon (2 N ) short-range correlations (SRC) in nuclei have been recently thoroughly investigated, both theoretically and experimentally and the study of three-nucleon (3 N ) SRC, which could provide important information on short-range hadronic structure, is underway. Novel theoretical ideas concerning 2 N and 3 N SRC are put forward in the present paper. Purpose: The general features of a microscopic one-nucleon spectral function which includes the effects of both 2 N and 3 N SRC and its comparison with ab initio spectral functions of the three-nucleon systems are illustrated. Methods: A microscopic and parameter-free one-nucleon spectral function expressed in terms of a convolution integral involving ab initio relative and center-of-mass (c.m.) momentum distributions of a 2 N pair and aimed at describing two- and three-nucleon short-range correlations, is obtained by using: (i) the two-nucleon momentum distributions obtained within ab initio approaches based upon nucleon-nucleon interactions of the Argonne family; (ii) the exact relation between one- and two-nucleon momentum distributions; (iii) the fundamental property of factorization of the nuclear wave function at short internucleon ranges. Results: The comparison between the ab initio spectral function of 3He and the one based upon the convolution integral shows that when the latter contains only two-nucleon short-range correlations the removal energy location of the peaks and the region around them exhibited by the ab initio spectral function are correctly predicted, unlike the case of the high and low removal energy tails; the inclusion of the effects of three-nucleon correlations brings the convolution model spectral function in much better agreement with the ab initio one; it is also found that whereas the three-nucleon short-range correlations dominate the high energy removal energy tail of the spectral function, their effects on the one-nucleon momentum distribution are almost one

  3. Radio Engineering System of Short-Range Navigation. RSBN-2. Part I. (Radioteknicheskaya Sistema Blizhney Navigatsii RSBN-2)

    Science.gov (United States)

    1977-02-09

    RANGE NAVIGATION. RSBN-2 By: Ye. M. Yakovlev, A. N. Kleplkov, et al. English pages: 706 source: Radlotekhnlcheskaya Sistema Bllzhney Navigatsli...L4 and the grid of tube L5 (6N8S) limits grid m^^mammm^m^^^f.^^ rn .„ | -.,, ..S^JTv i tOC = 77050017 PAGE ^ I current©. |: *■ «a—m

  4. Short range attraction of Ceratitis capitata (Diptera: Tephritidae) sterile males to six commercially available plant essential oils

    Science.gov (United States)

    Plant essential oils have a number of roles in insect pest management. For male Ceratitis capitata, this includes use of angelica seed oil as long range attractants and ginger root oil as aromatherapy, which is exposure to sterile males to increase mating success. Neither of these plants are hosts f...

  5. Effect of Short-Crestedness and Obliquity on Non-Breaking and Breaking Wave Forces Applied to Vertical Caisson Breakwaters

    DEFF Research Database (Denmark)

    Martinelli, Luca; Lamberti, Alberto; Frigaard, Peter

    2007-01-01

    This paper addresses wave forces applied to vertical caisson breakwaters. Design diagrams are proposed to evaluate the reduction of the breaker wave force with increasing horizontal length of the units. A model in 1:100 scale of a typical Italian vertical breakwater was tested under multidirectio......This paper addresses wave forces applied to vertical caisson breakwaters. Design diagrams are proposed to evaluate the reduction of the breaker wave force with increasing horizontal length of the units. A model in 1:100 scale of a typical Italian vertical breakwater was tested under...

  6. Short-Range Correlated Magnetic Core-Shell CrO2/Cr2O3 Nanorods: Experimental Observations and Theoretical Considerations

    Directory of Open Access Journals (Sweden)

    Ashish C. Gandhi

    2018-05-01

    Full Text Available With the evolution of synthesis and the critical characterization of core-shell nanostructures, short-range magnetic correlation is of prime interest in employing their properties to develop novel devices and widespread applications. In this regard, a novel approach of the magnetic core-shell saturated magnetization (CSSM cylinder model solely based on the contribution of saturated magnetization in one-dimensional CrO2/Cr2O3 core-shell nanorods (NRs has been developed and applied for the determination of core-diameter and shell-thickness. The nanosized effect leads to a short-range magnetic correlation of ferromagnetic core-CrO2 extracted from CSSM, which can be explained using finite size scaling method. The outcome of this study is important in terms of utilizing magnetic properties for the critical characterization of core-shell nanomagnetic materials.

  7. Three-dimensional short-range MR angiography and multiplanar reconstruction images in the evaluation of neurovascular compression in hemifacial spasm

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Woo Suk; Kim, Eui Jong; Lee, Jae Gue; Rhee, Bong Arm [Kyunghee Univ. Hospital, Seoul (Korea, Republic of)

    1998-08-01

    To evaluate the diagnostic efficacy of three-dimensional(3D) short-range MR angiography(MRA) and multiplanar reconstruction(MPR) imaging in hemifacial spasm(HS). Materials and Methods : Two hundreds patients with HS were studied using a 1.5T MRI system with a 3D time-of-flight(TOF) MRA sequence. To reconstruct short-range MRA, 6-10 source images near the 7-8th cranial nerve complex were processed using a maximum-intensity projection technique. In addition, an MPR technique was used to investigate neurovascular compression. We observed the relationship between the root-exit zone(REZ) of the 7th cranial nerve and compressive vessel, and identified the compressive vessels on symptomatic sides. To investigate neurovascular contact, asymptomatic contralateral sides were also evaluated. Results : MRI showed that in 197 of 200 patients there was vascular compression or contact with the facial nerve REZ on symptomatic sides. One of the three remaining patients was suffering from acoustic neurinoma on the symptomatic side, while in two patients there were no definite abnormal findings.Compressive vessels were demonstrated in all 197 patients; 80 cases involved the anterior inferior cerebellar artery(AICA), 74 the posterior cerebellar artery(PICA), 13 the vertebral artery(VA), 16 the VA and AICA, eight the VA and PICA, and six the AICA and PICA. In all 197 patients, compressive vessels were reconstructed on one 3D short-range MRA image without discontinuation from vertebral or basilar arteries. 3D MPR studies provided additional information such as the direction of compression and course of the compressive vessel. In 31 patients there was neurovascular contact on the contralateral side at the 7-8th cranial nerve complex. Conclusion : Inpatients with HS, 3D short-range MRA and MPR images are excellent and very helpful for the investigation of neurovascular compression and the identification of compressive vessels.

  8. Mixed hyperfine interaction - a tool to investigate the short range order and the strange magnetic behaviour of amorphous Fe-based binary alloys

    International Nuclear Information System (INIS)

    Fries, S.M.; Crummenauer, J.; Gonser, U.; Schaaf, P.; Chien, C.L.

    1989-01-01

    The Moessbauer study of the mixed magnetic dipole and electric quadrupole interaction in the paramagnetic state of amorphous Fe-Zr and Fe-Hf alloys is presented. Strong evidence for chemical short range order of the iron-pure alloys is found. The hyperfine parameters of the iron-rich alloys are marked by a complex applied field and temperature dependence, suggesting a not negligible spin-correlation well above Tc. (orig.)

  9. Deuterium short-range order in Pd0.975Ag0.025D0.685 by diffuse neutron scattering

    DEFF Research Database (Denmark)

    Blaschko, O.; Klemencic, R.; Fratzl, P.

    1983-01-01

    By diffuse neutron scattering the D short-range order in a Pd0.975Ag0.025D0.685 crystal was investigated at 50 and 70K. The results are compared with the D ordering in the PdDx system previously investigated, and it is shown that the isointensity contours around the (1/2,1,0) point are similar...

  10. Three-dimensional short-range MR angiography and multiplanar reconstruction images in the evaluation of neurovascular compression in hemifacial spasm

    International Nuclear Information System (INIS)

    Choi, Woo Suk; Kim, Eui Jong; Lee, Jae Gue; Rhee, Bong Arm

    1998-01-01

    To evaluate the diagnostic efficacy of three-dimensional(3D) short-range MR angiography(MRA) and multiplanar reconstruction(MPR) imaging in hemifacial spasm(HS). Materials and Methods : Two hundreds patients with HS were studied using a 1.5T MRI system with a 3D time-of-flight(TOF) MRA sequence. To reconstruct short-range MRA, 6-10 source images near the 7-8th cranial nerve complex were processed using a maximum-intensity projection technique. In addition, an MPR technique was used to investigate neurovascular compression. We observed the relationship between the root-exit zone(REZ) of the 7th cranial nerve and compressive vessel, and identified the compressive vessels on symptomatic sides. To investigate neurovascular contact, asymptomatic contralateral sides were also evaluated. Results : MRI showed that in 197 of 200 patients there was vascular compression or contact with the facial nerve REZ on symptomatic sides. One of the three remaining patients was suffering from acoustic neurinoma on the symptomatic side, while in two patients there were no definite abnormal findings.Compressive vessels were demonstrated in all 197 patients; 80 cases involved the anterior inferior cerebellar artery(AICA), 74 the posterior cerebellar artery(PICA), 13 the vertebral artery(VA), 16 the VA and AICA, eight the VA and PICA, and six the AICA and PICA. In all 197 patients, compressive vessels were reconstructed on one 3D short-range MRA image without discontinuation from vertebral or basilar arteries. 3D MPR studies provided additional information such as the direction of compression and course of the compressive vessel. In 31 patients there was neurovascular contact on the contralateral side at the 7-8th cranial nerve complex. Conclusion : Inpatients with HS, 3D short-range MRA and MPR images are excellent and very helpful for the investigation of neurovascular compression and the identification of compressive vessels

  11. Short range photoinduced electron transfer in proteins: QM-MM simulations of tryptophan and flavin fluorescence quenching in proteins

    International Nuclear Information System (INIS)

    Callis, Patrik R.; Liu Tiqing

    2006-01-01

    Hybrid quantum mechanical-molecular mechanics (dynamics) were performed on flavin reductase (Fre) and flavodoxin reductase (Fdr), both from Escherichia coli. Each was complexed with riboflavin (Rbf) or flavin mononucleotide (FMN). During 50 ps trajectories, the relative energies of the fluorescing state (S 1 ) of the isoalloxazine ring and the lowest charge transfer state (CT) were assessed to aid prediction of fluorescence lifetimes that are shortened due to quenching by electron transfer from tyrosine. The simulations for the four cases display a wide range in CT-S 1 energy gap caused by the presence of phosphate, other charged and polar residues, water, and by intermolecular separation between donor and acceptor. This suggests that the Gibbs energy change (ΔG 0 ) and reorganization energy (λ) for the electron transfer may differ in different flavoproteins

  12. Performance Analysis of Ultra-Wideband Channel for Short-Range Monopulse Radar at Ka-Band

    Directory of Open Access Journals (Sweden)

    Naohiko Iwakiri

    2012-01-01

    Full Text Available High-range resolution is inherently provided with Ka-band ultra-wideband (UWB vehicular radars. The authors have developed a prototype UWB monopulse radar equipped with a two-element receiving antenna array and reported its measurement results. In this paper, a more detailed verification using these measurements is presented. The measurements were analyzed employing matched filtering and eigendecomposition, and then multipath components were extracted to examine the behavior of received UWB monopulse signals. Next, conventional direction finding algorithms based on narrowband assumption were evaluated using the extracted multipath components, resulting in acceptable angle-of-arrival (AOA from the UWB monopulse signal regardless of wideband signals. Performance degradation due to a number of averaging the received monopulses was also examined to design suitable radar's waveforms.

  13. Combining short- and long-range fluorescence reporters with simulations to explore the intramolecular dynamics of an intrinsically disordered protein

    Science.gov (United States)

    Zosel, Franziska; Haenni, Dominik; Soranno, Andrea; Nettels, Daniel; Schuler, Benjamin

    2017-10-01

    Intrinsically disordered proteins (IDPs) are increasingly recognized as a class of molecules that can exert essential biological functions even in the absence of a well-defined three-dimensional structure. Understanding the conformational distributions and dynamics of these highly flexible proteins is thus essential for explaining the molecular mechanisms underlying their function. Single-molecule fluorescence spectroscopy in combination with Förster resonance energy transfer (FRET) is a powerful tool for probing intramolecular distances and the rapid long-range distance dynamics in IDPs. To complement the information from FRET, we combine it with photoinduced electron transfer (PET) quenching to monitor local loop-closure kinetics at the same time and in the same molecule. Here we employed this combination to investigate the intrinsically disordered N-terminal domain of HIV-1 integrase. The results show that both long-range dynamics and loop closure kinetics on the sub-microsecond time scale can be obtained reliably from a single set of measurements by the analysis with a comprehensive model of the underlying photon statistics including both FRET and PET. A more detailed molecular interpretation of the results is enabled by direct comparison with a recent extensive atomistic molecular dynamics simulation of integrase. The simulations are in good agreement with experiment and can explain the deviation from simple models of chain dynamics by the formation of persistent local secondary structure. The results illustrate the power of a close combination of single-molecule spectroscopy and simulations for advancing our understanding of the dynamics and detailed mechanisms in unfolded and intrinsically disordered proteins.

  14. Application of Short-Range LIDAR in Early Alerting for Low-Level Windshear and Turbulence at Hong Kong International Airport

    Directory of Open Access Journals (Sweden)

    K. K. Hon

    2014-01-01

    Full Text Available Hong Kong Observatory currently uses a series of meteorological instruments, including long-range LIDAR (light detection and ranging systems, to provide alerting services of low-level windshear and turbulence for Hong Kong International Airport. For some events that are smaller in spatial dimensions and are rapidly changing, such as low altitude windshear and turbulence associated with buildings or man-made structures, it would be necessary to involve meteorological instruments that offer greater spatial resolution. Therefore, the Observatory has set up a short-range LIDAR on the roof of the AsiaWorld-Expo during the summers over the past several years, conducting field research on the feasibility of strengthening early alerting for windshear and turbulence over the north runway’s eastern arrival runway (Runway 25RA and developing an automated early alerting algorithm. This paper takes the pilot reports for Runway 25RA during the 2013 field research as verification samples, using different thresholds for radial wind velocity spatial and temporal changes detected by the short-range LIDAR to calculate the relative operating characteristic (ROC curve, and analyzes its early alerting performance.

  15. High-energy X-ray diffraction studies of short- and intermediate-range structure in oxide glasses

    International Nuclear Information System (INIS)

    Suzuya, Kentaro

    2002-01-01

    The feature of high-energy X-ray diffraction method is explained. The oxide glasses studies by using BL04B2, high-energy X-ray diffraction beam line of SPring-8, and the random system materials by high-energy monochromatic X-ray diffraction are introduced. An advantage of third generation synchrotron radiation is summarized. On SPring-8, the high-energy X-ray diffraction experiments of random system are carried out by BL04B2 and BL14B1 beam line. BL04B2 can select Si (111)(E=37.8 keV, λ=0.033 nm) and Si(220)(E=61.7 keV, λ=0.020 nm) as Si monochromator. The intermediate-range structure of (MgO) x (P 2 O 5 ) 1-x glass ,MgP 2 O 6 glass, B 2 O 3 glass, SiO 2 and GeO 2 are explained in detail. The future and application of high-energy X-ray diffraction are stated. (S.Y.)

  16. Concerning the evidence for the formation of dicentric chromosomal aberrations by single tracks of very short-ranged radiations

    International Nuclear Information System (INIS)

    Brenner, D.J.; Zaider, M.

    1987-01-01

    A recent communication by Thacker et al. reported yields of chromosomal exchange aberrations in V79 hamster cells after irradiation by either 250-kVp x rays or carbon characteristic K x rays of energy 270 eV. These latter produce photoelectrons with ranges of less than 10 nm. Such a distance makes it prima facie unlikely that two chromosomes could be damaged by a single track with a significant frequency. Thacker et al., however, discuss the observed effective linear component of induction of chromosome exchanges by ultrasoft carbon x-rays, and are thus led to consider the possibility that only one chromosome needs to be damaged by radiation to lead to an exchange event. In this paper, the authors analyze the data of Thacker et al. using a simple model. For carbon x rays they take advantage of the fact that the cell nuclei are not subject to a distribution of specific energies, but will each undergo essentially the same number of photon absorption events (each consisting of an energy deposition of 270 eV) for a given dose. They define the probability that a given chromosome will be broken as a result of an energy deposition event. They further define the probability that two chromosomes will be broken as a result of a single energy deposition event

  17. Quantum-optical magnets with competing short- and long-range interactions: Rydberg-dressed spin lattice in an optical cavity

    Directory of Open Access Journals (Sweden)

    Jan Gelhausen, Michael Buchhold, Achim Rosch, Philipp Strack

    2016-10-01

    Full Text Available The fields of quantum simulation with cold atoms [1] and quantum optics [2] are currently being merged. In a set of recent pathbreaking experiments with atoms in optical cavities [3,4] lattice quantum many-body systems with both, a short-range interaction and a strong interaction potential of infinite range -mediated by a quantized optical light field- were realized. A theoretical modelling of these systems faces considerable complexity at the interface of: (i spontaneous symmetry-breaking and emergent phases of interacting many-body systems with a large number of atoms $N\\rightarrow\\infty$, (ii quantum optics and the dynamics of fluctuating light fields, and (iii non-equilibrium physics of driven, open quantum systems. Here we propose what is possibly the simplest, quantum-optical magnet with competing short- and long-range interactions, in which all three elements can be analyzed comprehensively: a Rydberg-dressed spin lattice [5] coherently coupled to a single photon mode. Solving a set of coupled even-odd sublattice Master equations for atomic spin and photon mean-field amplitudes, we find three key results. (R1: Superradiance and a coherent photon field can coexist with spontaneously broken magnetic translation symmetry. The latter is induced by the short-range nearest-neighbor interaction from weakly admixed Rydberg levels. (R2: This broken even-odd sublattice symmetry leaves its imprint in the light via a novel peak in the cavity spectrum beyond the conventional polariton modes. (R3: The combined effect of atomic spontaneous emission, drive, and interactions can lead to phases with anomalous photon number oscillations. Extensions of our work include nano-photonic crystals coupled to interacting atoms and multi-mode photon dynamics in Rydberg systems.

  18. Clicking in shallow rivers: short-range echolocation of Irrawaddy and Ganges River dolphins in a shallow, acoustically complex habitat.

    Directory of Open Access Journals (Sweden)

    Frants H Jensen

    Full Text Available Toothed whales (Cetacea, odontoceti use biosonar to navigate their environment and to find and catch prey. All studied toothed whale species have evolved highly directional, high-amplitude ultrasonic clicks suited for long-range echolocation of prey in open water. Little is known about the biosonar signals of toothed whale species inhabiting freshwater habitats such as endangered river dolphins. To address the evolutionary pressures shaping the echolocation signal parameters of non-marine toothed whales, we investigated the biosonar source parameters of Ganges river dolphins (Platanista gangetica gangetica and Irrawaddy dolphins (Orcaella brevirostris within the river systems of the Sundarban mangrove forest. Both Ganges and Irrawaddy dolphins produced echolocation clicks with a high repetition rate and low source level compared to marine species. Irrawaddy dolphins, inhabiting coastal and riverine habitats, produced a mean source level of 195 dB (max 203 dB re 1 µPapp whereas Ganges river dolphins, living exclusively upriver, produced a mean source level of 184 dB (max 191 re 1 µPapp. These source levels are 1-2 orders of magnitude lower than those of similar sized marine delphinids and may reflect an adaptation to a shallow, acoustically complex freshwater habitat with high reverberation and acoustic clutter. The centroid frequency of Ganges river dolphin clicks are an octave lower than predicted from scaling, but with an estimated beamwidth comparable to that of porpoises. The unique bony maxillary crests found in the Platanista forehead may help achieve a higher directionality than expected using clicks nearly an octave lower than similar sized odontocetes.

  19. Modeling of UV laser-induced patterning of ultrathin Co films on bulk SiO2: verification of short- and long-range ordering mechanisms

    Science.gov (United States)

    Trice, Justin; Favazza, Christopher; Kalyanaraman, Ramki; Sureshkumar, R.

    2006-03-01

    Irradiating ultrathin Co films (1 to 10 nm) by a short-pulsed UV laser leads to pattern formation with both short- and long-range order (SRO, LRO). Single beam irradiation produces SRO, while two-beam interference irradiation produces a quasi-2D arrangement of nanoparticles with LRO and SRO. The pattern formation primarily occurs in the molten phase. An estimate of the thermal behavior of the film/substrate composite following a laser pulse is presented. The thermal behavior includes the lifetime of the liquid phase and the thermal gradient during interference heating. Based on this evidence, the SRO is attributed to spinodal dewetting of the film while surface tension gradients induced by the laser interference pattern appear to influence LRO [1]. [1] C.Favazza, J.Trice, H.Krishna, R.Sureshkumar, and R.Kalyanaraman, unpublished.

  20. Hyperinsulinemia in the physiologic range is not superior to short-term fasting in suppressing insulin secretion in obese men.

    Science.gov (United States)

    Pincelli, A I; Brunani, A; Caumo, A; Scacchi, M; Pasqualinotto, L; Tibaldi, A; Dubini, A; Bonadonna, S; Cavagnini, F

    2001-01-01

    The negative-feedback control exerted by plasma insulin on beta-cell insulin release in normal-weight and obese subjects is still a matter of debate. Subjects submitted to a euglycemic insulin clamp undergo a suppression of insulin secretion that is due to both the infused insulin and the 2- to 3-hour fast during the procedure. We elected to elucidate the role of physiologic hyperinsulinemia per se in the insulin negative autofeedback in obese men. Ten men with massive uncomplicated obesity (age, 18 to 37 years; body mass index [BMI], 41 +/- 1.15 kg/m2) and 6 normal-weight healthy men (age, 22 to 30 years; BMI, 22 +/- 0.28 kg/m2) underwent 2 studies in random order: (1) a euglycemic-hyperinsulinemic glucose clamp with an insulin infusion rate of 1 mU/kg/min and (2) a control study with saline infusion. Serum C-peptide concentrations were significantly higher in obese versus control subjects at baseline (2.54 +/- 0.178 v 1.63 +/- 0.256 ng/mL, P < .05). Exogenous insulin infusion significantly suppressed serum C-peptide at steady state ([SS] last 30 minutes of insulin or saline infusion) in controls (mean of the last 4 measurements from 120 minutes to 150 minutes, 0.86 +/- 0.306 ng/mL, P < .05 vbaseline) but not in obese patients (2.03 +/- 0.26 ng/mL, nonsignificant [NS] v baseline). During the saline infusion studies, C-peptide levels slightly and similarly declined over time in both groups (2.71 +/- 0.350 at baseline v 2.31 +/- 0.300 ng/mL at SS in obese patients, NS, and 1.96 +/- 0.189 v 1.62 +/- 0.150 ng/mL in controls, NS). This study shows that in obese men hyperinsulinemia within the postprandial range is not superior to a 2.5-hour fast for the suppression of beta-cell activity, suggesting an impairment of the insulin negative autofeedback in this clinical condition.

  1. Final Environmental Assessment for the Bridge Replacement and Scour Protection Measures at Avon Park Air Force Range, Florida

    Science.gov (United States)

    2012-03-01

    stipulated in the permit. Potential indigo snake refugia: gopher tortoise burrows , active or inactive, other holes, ground cavities, and root hollows...holes, cavities, and snake refugia other than gopher tortoise burrows will be inspected each morning before planned site manipulation of a particular...University 1999 Years Experience: 12 Larry McLain Operational Transportation Manager and Range Maintenance Manager Clarence Morgan Rangeland

  2. Occurrence, bioaccumulation and long-range transport of short-chain chlorinated paraffins on the Fildes Peninsula at King George Island, Antarctica.

    Science.gov (United States)

    Li, Huijuan; Fu, Jianjie; Zhang, Aiqian; Zhang, Qinghua; Wang, Yawei

    2016-09-01

    As a candidate persistent organic pollutant of the Stockholm Convention, short-chain chlorinated paraffins (SCCPs) have recently received particular attention. In this study, we investigated, for the first time, the concentrations of SCCPs in biota samples collected from the Fildes Peninsula at King George Island and Ardley Island, Antarctica. The concentrations of SCCPs ranged from 3.5 to 256.6ng/g (dry weight, dw), with a mean of 76.6±61.8ng/g dw, which was lower than those detected in mid- and low-latitude regions. The long-range transport behaviour of SCCPs was confirmed by both the detection of SCCPs in Antarctic remote areas and their special congener profiles. Short carbon chain (C10) congeners predominated in the Antarctic samples, which accounted for 56.1% of the total SCCP contamination. Such enrichment of C10 congeners indicated the high potential for the long-range transport of shorter chain congeners. In addition, SCCPs tended to be enriched in the species with high lipid contents. The biomagnification potential of SCCPs was found between Archeogastropoda (Agas) and Neogastropoda (Ngas), and the biomagnification factors of shorter chain congeners of SCCPs were higher than that of the longer chain ones. Considering that the endemic species in polar regions may be sensitive and vulnerable to the adverse effects of environmental contaminants, more attention should be paid on the bioaccumulation and toxicological risks of SCCPs in polar environments. Copyright © 2016. Published by Elsevier Ltd.

  3. Short range charge/orbital ordering in La1-xSrxMn1-zBzO3 (B Cu,Zn) manganites

    International Nuclear Information System (INIS)

    Popovic, Z V; Cantarero, A; Thijssen, W H A; Paunovic, N; Dohcevic-Mitrovic, Z; Sapina, F

    2005-01-01

    We have measured the reflectivity spectra of La 1-x Sr x Mn 1-z B z O 3 (B = Cu, Zn; 0.17 ≤ x ≤ 0.30; 0 ≤ z ≤ 0.10) manganites over wide frequency (100-4000 cm -1 ) and temperature (80-300 K) ranges. Besides the previously observed infrared active modes or mode pairs at about 160 cm -1 (external mode), 350 cm -1 (bond bending mode) and 590 cm -1 (bond stretching mode), we have clearly observed two additional phonon modes at about 645 and 720 cm -1 below the temperature T 1 (T 1 C ), which coincides with the phase transition temperature when the system transforms from ferromagnetic metallic into a ferromagnetic insulator state. This transition is related to the formation of short range charge/orbitally ordered domains. The temperature T 1 of the phase transition is dependent on the doping concentration and for optimally doped samples we have found that T 1 ∼(0.93 ± 0.02) T C . Electrical resistivity and magnetization measurements versus temperature and magnetic field support the short range charge/orbital ordering scenario

  4. Improving the scanning speed of atomic force microscopy at the scanning range of several tens of micrometers

    International Nuclear Information System (INIS)

    Wang, Yanyan; Hu, Xiaodong; Xu, Linyan; Hu, Xiaotang

    2013-01-01

    The atomic force microscope (AFM) is a powerful instrument which can measure the surface of samples at the nanoscale. The resonance of the scanner in xy directions, and the feedback control in the z direction are two major sources of image distortion at high scan speed. In order to improve the scanning speed of the AFM, a low-cost and easy method, which includes sinusoidal scans in the fast scan direction, and an intelligent fuzzy controller in the z direction, is proposed in this paper. The use of a single-frequency driving signal in the fast scan direction allows the scanner to move at a higher speed without exciting its mechanical resonance. The intelligent fuzzy controller automatically selects appropriate PI parameters through the analysis of the tracking errors, thus improving the dynamic tracking performance of the z scanner. The development and functioning of the sinusoidal fast scans and the intelligent fuzzy controller are demonstrated, as well as how this approach significantly achieves faster scans and a higher resolution AFM imaging. -- Highlights: ► The sinusoidal scan and the intelligent controller are used to improve AFM's rate. ► A new method is raised to overcome the nonlinearity caused by the sinusoidal scan. ► A new controller is proposed to improve the performance of the vertical direction.

  5. Casimir force, excess free energy and C-function in O(n) systems with long-range interactions in the n → ∞ limit

    International Nuclear Information System (INIS)

    Chamati, H.; Dantchev, D.M.

    2004-06-01

    We present exact results on the behavior of the thermodynamic Casimir force and the excess free energy and the C-function in the framework of the d-dimensional spherical model with a power law long-range interaction decaying at large distances r as r -d- σ, where σ c , as well as for T > Tc and T c . The universal finite-size scaling function governing the behavior of the force in the critical region is derived and its asymptotics are investigated. While in the critical and under -d -d-, critical region the force is of the order of L -d , for T > T c it decays as L -dσ , where L is the thickness of the film. We consider both the case of a finite system that has no phase transition of its own, when d - σ when one observes a dimensional crossover from d to a d - 1 dimensional critical behavior. The behavior of the force along the phase coexistence line for a magnetic field H = 0 and T c . is also derived. We have proven analytically that the excess free energy is always negative ad monotonically increasing function of T and H, while the C-function is always non-negative and monotonically decreasing function of T and H. For the Casimir force we have demonstrated that for any σ > it is everywhere negative, i.e. an attraction between the surfaces bounding the system is to be observed. At T = T c the force is an increasing function of T for σ > 1 and a decreasing one for σ c is always achieved at some H ≠ 0 . (author)

  6. Final Range Environmental Assessment for Test Areas C-87 and D-51 at Eglin Air Force Base, Florida

    Science.gov (United States)

    2015-05-01

    TA C-87 consists of one septic tank and associated leach field. There are nine septic tanks and associated leach fields on TA D-51. Under...storage tank , and septic systems, and connecting the test area to the Okaloosa County water and wastewater utility lines. The existing utility systems on T...8840E Water Treatment Plan 8840F Biological/Chemical Training Area 13 (acres) 8840ST Septic Tank at 8840 8840W Well at 8840 8841 Range Support

  7. Comparison of short-range rapidity correlations in anti pp and pp interactions at √S = 53 GeV

    International Nuclear Information System (INIS)

    Breakstone, A.; Crawley, H.B.; Firestone, A.; Gorbics, M.; Lamsa, J.W.; Meyer, W.T.

    1982-01-01

    Measurements are presented of two-particle rapidity correlations in anti pp and pp at √S = 53 GeV. The data were recorded at the CERN-ISR using the Split Field Magnet spectrometer with a minimum bias trigger. Short range correlations in normal inelastic events with measured charged multiplicities nsub(ch) >= 4 are observed for pairs of charged particles in all charge combinations. Within the experimental errors no differences are observed between the analogous correlations in pp and anti pp interactions. (orig.)

  8. Associations between rate of force development metrics and throwing velocity in elite team handball players: a short research report.

    Science.gov (United States)

    Marques, Mário C; Saavedra, Francisco J; Abrantes, Catarina; Aidar, Felipe J

    2011-09-01

    Performance assessment has become an invaluable component of monitoring participant's development in distinct sports, yet limited and contradictory data are available in trained subjects. The purpose of this study was to examine the relationship between ball throwing velocity during a 3-step running throw in elite team handball players and selected measures of rate of force development like force, power, velocity, and bar displacement during a concentric only bench press exercise in elite male handball players. Fitteen elite senior male team handball players volunteered to participate. Each volunteer had power and bar velocity measured during a concentric only bench press test with 25, 35, and 45 kg as well as having one-repetition maximum strength determined. Ball throwing velocity was evaluated with a standard 3-step running throw using a radar gun. The results of this study indicated significant associations between ball velocity and time at maximum rate of force development (0, 66; pvelocity was only median associated with maximum rate of force development with light loads. A training regimen designed to improve ball-throwing velocity in elite male team handball players should emphasize bench press movement using light loads.

  9. Impact of ice particle shape on short-wave radiative forcing: A case study for an arctic ice cloud

    International Nuclear Information System (INIS)

    Kahnert, Michael; Sandvik, Anne Dagrun; Biryulina, Marina; Stamnes, Jakob J.; Stamnes, Knut

    2008-01-01

    We used four different non-spherical particle models to compute optical properties of an arctic ice cloud and to simulate corresponding cloud radiative forcings and fluxes. One important finding is that differences in cloud forcing, downward flux at the surface, and absorbed flux in the atmosphere resulting from the use of the four different ice cloud particle models are comparable to differences in these quantities resulting from changing the surface albedo from 0.4 to 0.8, or by varying the ice water content (IWC) by a factor of 2. These findings show that the use of a suitable non-spherical ice cloud particle model is very important for a realistic assessment of the radiative impact of arctic ice clouds. The differences in radiative broadband fluxes predicted by the four different particle models were found to be caused mainly by differences in the optical depth and the asymmetry parameter. These two parameters were found to have nearly the same impact on the predicted cloud forcing. Computations were performed first by assuming a given vertical profile of the particle number density, then by assuming a given profile of the IWC. In both cases, the differences between the cloud radiative forcings computed with the four different non-spherical particle models were found to be of comparable magnitude. This finding shows that precise knowledge of ice particle number density or particle mass is not sufficient for accurate prediction of ice cloud radiative forcing. It is equally important to employ a non-spherical shape model that accurately reproduces the ice particle's dimension-to-volume ratio and its asymmetry parameter. The hexagonal column/plate model with air-bubble inclusions seems to offer the highest degree of flexibility

  10. Acute heart failure with mid-range left ventricular ejection fraction: clinical profile, in-hospital management, and short-term outcome.

    Science.gov (United States)

    Farmakis, Dimitrios; Simitsis, Panagiotis; Bistola, Vasiliki; Triposkiadis, Filippos; Ikonomidis, Ignatios; Katsanos, Spyridon; Bakosis, George; Hatziagelaki, Erifili; Lekakis, John; Mebazaa, Alexandre; Parissis, John

    2017-05-01

    Heart failure with mid-range left ventricular ejection fraction (HFmrEF) is a poorly characterized population as it has been studied either in the context of HF with reduced (HFrEF) or preserved (HFpEF) left ventricular ejection fraction (LVEF) depending on applied LVEF cutoffs. We sought to investigate the clinical profile, in-hospital management, and short-term outcome of HFmrEF patients in comparison with those with HFrEF or HFpEF in a large acute HF cohort. The Acute Heart Failure Global Registry of Standard Treatment (ALARM-HF) included 4953 patients hospitalized for HF in nine countries in Europe, Latin America, and Australia. Baseline characteristics, clinical presentation, in-hospital therapies, and short-term mortality (all-cause in-hospital or 30-day mortality, whichever first) were compared among HFrEF (LVEF chronic renal disease (p = 0.003), more hospitalizations for acute coronary syndrome (p < 0.001), or infection (p = 0.003), and were more frequently treated with intravenous vasodilators compared to HFrEF or HFpEF. Adjusted short-term mortality in HFmrEF was lower than HFrEF [hazard ratio (HR) = 0.635 (0.419, 0.963), p = 0.033] but similar to HFpEF [HR = 1.026 (0.605, 1.741), p = 0.923]. Hospitalized HFmrEF patients represent a demographically and clinically diverse group with many intermediate features compared to HFrEF and HFpEF and carry a lower risk of short-term mortality than HFrEF but a similar risk with HFpEF.

  11. SIRAH: a structurally unbiased coarse-grained force field for proteins with aqueous solvation and long-range electrostatics.

    Science.gov (United States)

    Darré, Leonardo; Machado, Matías Rodrigo; Brandner, Astrid Febe; González, Humberto Carlos; Ferreira, Sebastián; Pantano, Sergio

    2015-02-10

    Modeling of macromolecular structures and interactions represents an important challenge for computational biology, involving different time and length scales. However, this task can be facilitated through the use of coarse-grained (CG) models, which reduce the number of degrees of freedom and allow efficient exploration of complex conformational spaces. This article presents a new CG protein model named SIRAH, developed to work with explicit solvent and to capture sequence, temperature, and ionic strength effects in a topologically unbiased manner. SIRAH is implemented in GROMACS, and interactions are calculated using a standard pairwise Hamiltonian for classical molecular dynamics simulations. We present a set of simulations that test the capability of SIRAH to produce a qualitatively correct solvation on different amino acids, hydrophilic/hydrophobic interactions, and long-range electrostatic recognition leading to spontaneous association of unstructured peptides and stable structures of single polypeptides and protein-protein complexes.

  12. Radiophysical methods of diagnostics the Earth's ionosphere and the underlying earth's surface by remote sensing in the short-wave range of radio waves

    Science.gov (United States)

    Belov, S. Yu.; Belova, I. N.

    2017-11-01

    Monitoring of the earth's surface by remote sensing in the short-wave band can provide quick identification of some characteristics of natural systems. This band range allows one to diagnose subsurface aspects of the earth, as the scattering parameter is affected by irregularities in the dielectric permittivity of subsurface structures. This method based on the organization of the monitoring probe may detect changes in these environments, for example, to assess seismic hazard, hazardous natural phenomena such as earthquakes, as well as some man-made hazards and etc. The problem of measuring and accounting for the scattering power of the earth's surface in the short-range of radio waves is important for a number of purposes, such as diagnosing properties of the medium, which is of interest for geological, environmental studies. In this paper, we propose a new method for estimating the parameters of incoherent signal/noise ratio. The paper presents the results of comparison of the measurement method from the point of view of their admissible relative analytical errors. The new method is suggested. Analysis of analytical error of estimation of this parameter allowed to recommend new method instead of standard method. A comparative analysis and shows that the analytical (relative) accuracy of the determination of this parameter new method on the order exceeds the widely-used standard method.

  13. Adaptive Blending of Model and Observations for Automated Short-Range Forecasting: Examples from the Vancouver 2010 Olympic and Paralympic Winter Games

    Science.gov (United States)

    Bailey, Monika E.; Isaac, George A.; Gultepe, Ismail; Heckman, Ivan; Reid, Janti

    2014-01-01

    An automated short-range forecasting system, adaptive blending of observations and model (ABOM), was tested in real time during the 2010 Vancouver Olympic and Paralympic Winter Games in British Columbia. Data at 1-min time resolution were available from a newly established, dense network of surface observation stations. Climatological data were not available at these new stations. This, combined with output from new high-resolution numerical models, provided a unique and exciting setting to test nowcasting systems in mountainous terrain during winter weather conditions. The ABOM method blends extrapolations in time of recent local observations with numerical weather predictions (NWP) model predictions to generate short-range point forecasts of surface variables out to 6 h. The relative weights of the model forecast and the observation extrapolation are based on performance over recent history. The average performance of ABOM nowcasts during February and March 2010 was evaluated using standard scores and thresholds important for Olympic events. Significant improvements over the model forecasts alone were obtained for continuous variables such as temperature, relative humidity and wind speed. The small improvements to forecasts of variables such as visibility and ceiling, subject to discontinuous changes, are attributed to the persistence component of ABOM.

  14. HATS-43b, HATS-44b, HATS-45b, and HATS-46b: Four Short-period Transiting Giant Planets in the Neptune–Jupiter Mass Range

    Science.gov (United States)

    Brahm, R.; Hartman, J. D.; Jordán, A.; Bakos, G. Á.; Espinoza, N.; Rabus, M.; Bhatti, W.; Penev, K.; Sarkis, P.; Suc, V.; Csubry, Z.; Bayliss, D.; Bento, J.; Zhou, G.; Mancini, L.; Henning, T.; Ciceri, S.; de Val-Borro, M.; Shectman, S.; Crane, J. D.; Arriagada, P.; Butler, P.; Teske, J.; Thompson, I.; Osip, D.; Díaz, M.; Schmidt, B.; Lázár, J.; Papp, I.; Sári, P.

    2018-03-01

    We report the discovery of four short-period extrasolar planets transiting moderately bright stars from photometric measurements of the HATSouth network coupled to additional spectroscopic and photometric follow-up observations. While the planet masses range from 0.26 to 0.90 {M}{{J}}, the radii are all approximately a Jupiter radii, resulting in a wide range of bulk densities. The orbital period of the planets ranges from 2.7 days to 4.7 days, with HATS-43b having an orbit that appears to be marginally non-circular (e = 0.173 ± 0.089). HATS-44 is notable for having a high metallicity ([{Fe}/{{H}}] = 0.320 ± 0.071). The host stars spectral types range from late F to early K, and all of them are moderately bright (13.3 Carnegie Institute is operated by PU in conjunction with PUC, the station at the High Energy Spectroscopic Survey (H.E.S.S.) site is operated in conjunction with MPIA, and the station at Siding Spring Observatory (SSO) is operated jointly with ANU. This paper includes data gathered with the MPG 2.2 m and ESO 3.6 m telescopes at the ESO Observatory in La Silla. This paper includes data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile.

  15. Comparison of the Tritium permeated from ITER Blanket in normal operation and its short range impact of HT over France, Swiss or Spain

    Energy Technology Data Exchange (ETDEWEB)

    Castro, P.; Velarde, M.; Ardao, J.; Perlado, J.; Sedano, L.; Xiberta, J.

    2015-07-01

    In this paper we assumes the hydrogen isotopes permeation from a liquid metal ITER breeder blanket (assuming normal operation and a LM as DCLL or HCLL blanket) as one of the possible sources of a leak and tritium release,mainly but not only. The paper presents a short range low impact of HT gas activity over France, Swiss or Spain from same cases in 2014 and 2015 releases from ITER. The permeation of hydrogen isotopes is an important experimental issue to take into account into the development of a Tritium Breeder Module for ITER [1]. Tritium cannot be confined -without an uncertainty of 5% in the flux permeation- and therefore HT can be detected (e.g. by ionization chamber) as permeates though the structure of RAFM steel towards the coolant [1]. HT from Pb15.7Li and permeated in Eurofer97 can contaminate the other parts of the system and may be delivered though the normal-vent detritiation system (NVDS). Real time forecast of transport of tritium in air from the fusion reactor towards off-site far downwind though extended tritium clouds into the low levels of the atmosphere is calculated for the short range (up to 24 hours) by the coupling of 2 models the European Centre for Medium Range Weather Forecast (ECMWF) [2] model and the FLEXPART lagrangian dispersion model [3] verified with NORMTRI simulation [4] and implemented in many different cases and scenarios [5, 6, 7]. As a function of daily weather conditions the release will affect just France or already can be delivered towards Swiss when cyclonic circulation, or towards the Iberian Peninsula or Balearic Islands (Spain) when high produce anticyclonic circulation of the air over the Mediterranean Sea. (Author)

  16. Range of motion exercise of temporo-mandibular joint with hot pack increases occlusal force in patients with Duchenne muscular dystrophy.

    Science.gov (United States)

    Nozaki, S; Kawai, M; Shimoyama, R; Futamura, N; Matsumura, T; Adachi, K; Kikuchi, Y

    2010-12-01

    The purpose of this study is to evaluate whether the range of motion exercise of the temporo-mandibular joint (jaw ROM exercise) with a hot pack and massage of the masseter muscle improve biting disorder in Duchenne muscular dystrophy (DMD). The subjects were 18 DMD patients (21.3+/- 4.1 years old). The jaw ROM exercise consisted of therapist-assisted training (2 times a week) and self-training (before each meal every day). The therapist-assisted training consisted of the application of a hot pack on the cheek of the masseter muscle region (15 minutes), the massage of the masseter (10 minutes), and jaw ROM exercise (5 minutes). The self-training involved jaw ROM exercise by opening the mouth to the maximum degree, ten times. These trainings continued for six months. Outcomes were evaluated by measuring the greatest occlusal force and the distance at the maximum degree of mouth opening between an incisor of the top and that of the bottom. Six months later, the greatest occlusal force had increased significantly compared with that at the start of jaw ROM exercise (intermediate values: from 73.8N to 97.3N) (p = 0.005) as determined by the Friedman test and Scheffi's nonparametric test. The patients' satisfaction with meals increased. However, the maximum degree of mouth opening did not change after six months of jaw ROM exercise. Jaw ROM exercise in DMD is effective for increasing the greatest occlusal force.

  17. Effects of short-range order on electronic properties of Zr-Ni glasses as seen from low-temperature specific heat

    International Nuclear Information System (INIS)

    Kroeger, D.M.; Koch, C.C.; Scarbrough, J.O.; McKamey, C.G.

    1984-01-01

    Measurements of the low-temperature specific heat C/sub p/ of liquid-quenched Zr-Ni glasses for a large number of compositions in the range from 55 to 74 at. % Zr revealed an unusual composition dependence of the density of states at the Fermi level, N(E/sub F/). Furthermore, for some compositions the variation of C/sub p/ near the superconducting transition temperature T/sub c/ indicated the presence of two superconducting phases, i.e., two superconducting transitions were detected. Comparison of the individual T/sub c/'s in phase-separated samples to the composition dependence of T/sub c/ for all of the samples suggests that amorphous phases with compositions near 60 and 66.7 at. % Zr occur. We discuss these results in terms of an ''association model'' for liquid alloys (due to Sommer), in which associations of unlike atoms with definite stoichiometries are assumed to exist in equilibrium with unassociated atoms. We conclude that in the composition range studied, associate clusters with the compositions Zr 3 Ni 2 and Zr 2 Ni occur. In only a few cases are the clusters sufficiently large, compared with the superconducting coherence length, for separate superconducting transitions to be observed. The variation of N(E/sub F/) with composition is discussed, as well as the effects of this chemical short-range ordering on the crystallization behavior and glass-forming tendency

  18. Effects of short-range order on electronic properties of Zr-Ni glasses as seen from low-temperature specific heat

    Science.gov (United States)

    Kroeger, D. M.; Koch, C. C.; Scarbrough, J. O.; McKamey, C. G.

    1984-02-01

    Measurements of the low-temperature specific heat Cp of liquid-quenched Zr-Ni glasses for a large number of compositions in the range from 55 to 74 at.% Zr revealed an unusual composition dependence of the density of states at the Fermi level, N(EF). Furthermore, for some compositions the variation of Cp near the superconducting transition temperature Tc indicated the presence of two superconducting phases, i.e., two superconducting transitions were detected. Comparison of the individual Tc's in phase-separated samples to the composition dependence of Tc for all of the samples suggests that amorphous phases with compositions near 60 and 66.7 at.% Zr occur. We discuss these results in terms of an "association model" for liquid alloys (due to Sommer), in which associations of unlike atoms with definite stoichiometries are assumed to exist in equilibrium with unassociated atoms. We conclude that in the composition range studied, associate clusters with the compositions Zr3Ni2 and Zr2Ni occur. In only a few cases are the clusters sufficiently large, compared with the superconducting coherence length, for separate superconducting transitions to be observed. The variation of N(EF) with composition is discussed, as well as the effects of this chemical short-range ordering on the crystallization behavior and glass-forming tendency.

  19. Short-to-Medium-Range Order and Atomic Packing in Zr48Cu36Ag8Al8 Bulk Metallic Glass

    Directory of Open Access Journals (Sweden)

    Yong Xu

    2016-10-01

    Full Text Available Due to its excellent glass-forming ability (GFA, the Zr48Cu36Al8Ag8 bulk metallic glass (BMG is of great importance in glass transition investigations and new materials development. However, due to the lack of detailed structural information, the local structure and atomic packing of this alloy is still unknown. In this work, synchrotron measurement and reverse Monte Carlo simulation are performed on the atomic configuration of a Zr-based bulk metallic glass. The local structure is characterized in terms of bond pairs and Voronoi tessellation. It is found that there are mainly two types of bond pairs in the configuration, as the body-centered cubic (bcc-type and icosahedral (ico-type bond pairs. On the other hand, the main polyhedra in the configuration are icosahedra and the bcc structure. That is, the bcc-type bond pairs, together with the ico-type bond pairs, form the bcc polyhedra, introducing the distortion in bcc clusters in short range. However, in the medium range, the atoms formed linear or planar structures, other than the tridimensional clusters. That is, the medium-range order in glass is of 1D or 2D structure, suggesting the imperfect ordered packing feature.

  20. Altered calcium handling and increased contraction force in human embryonic stem cell derived cardiomyocytes following short term dexamethasone exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kosmidis, Georgios; Bellin, Milena; Ribeiro, Marcelo C.; Meer, Berend van; Ward-van Oostwaard, Dorien [Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (Netherlands); Passier, Robert [Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (Netherlands); MIRA, University of Twente (Netherlands); Tertoolen, Leon G.J.; Mummery, Christine L. [Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (Netherlands); Casini, Simona, E-mail: s.casini@amc.uva.nl [Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (Netherlands)

    2015-11-27

    One limitation in using human pluripotent stem cell derived cardiomyocytes (hPSC-CMs) for disease modeling and cardiac safety pharmacology is their immature functional phenotype compared with adult cardiomyocytes. Here, we report that treatment of human embryonic stem cell derived cardiomyocytes (hESC-CMs) with dexamethasone, a synthetic glucocorticoid, activated glucocorticoid signaling which in turn improved their calcium handling properties and contractility. L-type calcium current and action potential properties were not affected by dexamethasone but significantly faster calcium decay, increased forces of contraction and sarcomeric lengths, were observed in hESC-CMs after dexamethasone exposure. Activating the glucocorticoid pathway can thus contribute to mediating hPSC-CMs maturation. - Highlights: • Dexamethasone accelerates Ca{sup 2+} transient decay in hESC-CMs. • Dexamethasone enhances SERCA and NCX function in hESC-CMs. • Dexamethasone increases force of contraction and sarcomere length in hESC-CMs. • Dexamethasone does not alter I{sub Ca,L} and action potential characteristics in hESC-CMs.

  1. Altered calcium handling and increased contraction force in human embryonic stem cell derived cardiomyocytes following short term dexamethasone exposure

    International Nuclear Information System (INIS)

    Kosmidis, Georgios; Bellin, Milena; Ribeiro, Marcelo C.; Meer, Berend van; Ward-van Oostwaard, Dorien; Passier, Robert; Tertoolen, Leon G.J.; Mummery, Christine L.; Casini, Simona

    2015-01-01

    One limitation in using human pluripotent stem cell derived cardiomyocytes (hPSC-CMs) for disease modeling and cardiac safety pharmacology is their immature functional phenotype compared with adult cardiomyocytes. Here, we report that treatment of human embryonic stem cell derived cardiomyocytes (hESC-CMs) with dexamethasone, a synthetic glucocorticoid, activated glucocorticoid signaling which in turn improved their calcium handling properties and contractility. L-type calcium current and action potential properties were not affected by dexamethasone but significantly faster calcium decay, increased forces of contraction and sarcomeric lengths, were observed in hESC-CMs after dexamethasone exposure. Activating the glucocorticoid pathway can thus contribute to mediating hPSC-CMs maturation. - Highlights: • Dexamethasone accelerates Ca"2"+ transient decay in hESC-CMs. • Dexamethasone enhances SERCA and NCX function in hESC-CMs. • Dexamethasone increases force of contraction and sarcomere length in hESC-CMs. • Dexamethasone does not alter I_C_a_,_L and action potential characteristics in hESC-CMs.

  2. Potential Predictability of the Sea-Surface Temperature Forced Equatorial East Africa Short Rains Interannual Variability in the 20th Century

    Science.gov (United States)

    Bahaga, T. K.; Gizaw, G.; Kucharski, F.; Diro, G. T.

    2014-12-01

    In this article, the predictability of the 20th century sea-surface temperature (SST) forced East African short rains variability is analyzed using observational data and ensembles of long atmospheric general circulation model (AGCM) simulations. To our knowledge, such an analysis for the whole 20th century using a series of AGCM ensemble simulations is carried out here for the first time. The physical mechanisms that govern the influence of SST on East African short rains in the model are also investigated. It is found that there is substantial skill in reproducing the East African short rains variability, given that the SSTs are known. Consistent with previous recent studies, it is found that the Indian Ocean and in particular the western pole of the Indian Ocean dipole (IOD) play a dominant role for the prediction skill, whereas SSTs outside the Indian Ocean play a minor role. The physical mechanism for the influence of the western Indian Ocean on East African rainfall in the model is consistent with previous findings and consists of a gill-type response to a warm (cold) anomaly that induces a westerly(easterly) low-level flow anomaly over equatorial Africa and leads to moisture flux convergence (divergence) over East Africa. On the other hand, a positive El Nino-Southern Oscillation (ENSO) anomaly leads to a spatially non-coherent reducing effect over parts of East Africa, but the relationship is not strong enough to provide any predictive skill in our model. The East African short rains prediction skill is also analyzed within a model-derived potential predictability framework and it is shown that the actual prediction skill is broadly consistent with the model potential prediction skill. Low-frequency variations of the prediction skill are mostly related to SSTs outside the Indian Ocean region and are likely due to an increased interference of ENSO with the Indian Ocean influence on East African short rains after the mid-1970s climate shift.

  3. Hydrologic transport of depleted uranium associated with open air dynamic range testing at Los Alamos National Laboratory, New Mexico, and Eglin Air Force Base, Florida

    Energy Technology Data Exchange (ETDEWEB)

    Becker, N.M. [Los Alamos National Lab., NM (United States); Vanta, E.B. [Wright Laboratory Armament Directorate, Eglin Air Force Base, FL (United States)

    1995-05-01

    Hydrologic investigations on depleted uranium fate and transport associated with dynamic testing activities were instituted in the 1980`s at Los Alamos National Laboratory and Eglin Air Force Base. At Los Alamos, extensive field watershed investigations of soil, sediment, and especially runoff water were conducted. Eglin conducted field investigations and runoff studies similar to those at Los Alamos at former and active test ranges. Laboratory experiments complemented the field investigations at both installations. Mass balance calculations were performed to quantify the mass of expended uranium which had transported away from firing sites. At Los Alamos, it is estimated that more than 90 percent of the uranium still remains in close proximity to firing sites, which has been corroborated by independent calculations. At Eglin, we estimate that 90 to 95 percent of the uranium remains at test ranges. These data demonstrate that uranium moves slowly via surface water, in both semi-arid (Los Alamos) and humid (Eglin) environments.

  4. Hydrologic transport of depleted uranium associated with open air dynamic range testing at Los Alamos National Laboratory, New Mexico, and Eglin Air Force Base, Florida

    International Nuclear Information System (INIS)

    Becker, N.M.; Vanta, E.B.

    1995-01-01

    Hydrologic investigations on depleted uranium fate and transport associated with dynamic testing activities were instituted in the 1980's at Los Alamos National Laboratory and Eglin Air Force Base. At Los Alamos, extensive field watershed investigations of soil, sediment, and especially runoff water were conducted. Eglin conducted field investigations and runoff studies similar to those at Los Alamos at former and active test ranges. Laboratory experiments complemented the field investigations at both installations. Mass balance calculations were performed to quantify the mass of expended uranium which had transported away from firing sites. At Los Alamos, it is estimated that more than 90 percent of the uranium still remains in close proximity to firing sites, which has been corroborated by independent calculations. At Eglin, we estimate that 90 to 95 percent of the uranium remains at test ranges. These data demonstrate that uranium moves slowly via surface water, in both semi-arid (Los Alamos) and humid (Eglin) environments

  5. Concentration and temperature dependence of short-range order in Ni-Ta solid solution using X-ray diffraction method

    International Nuclear Information System (INIS)

    Khwaja, F.A.; Alam, A.

    1980-09-01

    Diffuse X-ray scattering investigations about the existence of short-range order (SRO) have been carried out in the Ni-Ta system for different concentrations and annealing temperatures. It is observed that the values of the SRO parameters for the first co-ordination shell have anomalously large negative values for all the samples studied. These values of the α 1 depend upon the annealing temperatures and the concentration of Ta atoms in the Ni-Ta system. The results of the theoretical predictions of the ordering potential obtained using the formulae of the electronic theory of SRO, confirm the existence of very strong attractive correlation between the atoms of the different species in this system. (author)

  6. Applications of the KKR-DCA: A Finite-Temperature Density Functional Theory to Predict Chemical Short-Range Order Effects in Disordered Metallic Alloys

    Science.gov (United States)

    Biava, D. A.; Johnson, D. D.

    2009-03-01

    Short-range order (SRO) is ubiquitous in metallic alloys, affecting changes in their electronic, thermodynamic, mechanical, magnetic, and structural properties. For example, SRO is responsible for the yield-strength anomalies observed in Cu-Al at high temperatures, i.e., the materials is more resistant to dislocation motion at high temperature than it is at room temperature. Within the Korringa-Kohn-Rostorker (KKR) electronic-structure method, we present results using the dynamical cluster approximations (DCA) to obtain the temperature-dependent SRO in disordered alloys. We obtain the KKR-DCA SRO energetics versus local neighbor SRO parameters and minimize it at fixed temperature to predict the SRO. We show that the calculated SRO at fixed temperature compares well with available experimental results, and then correlate the results to the electronic structure. We discuss how an accurate analytic estimate can be made for the SRO in most metals due to the dependence of the grand potential on SRO.

  7. Short-range spatial variability of soil δ15N natural abundance – effects on symbiotic N2-fixation estimates in pea

    DEFF Research Database (Denmark)

    Holdensen, Lars; Hauggaard-Nielsen, Henrik; Jensen, Erik Steen

    2007-01-01

    abundance in spring barley and N2-fixing pea was measured within the 0.15-4 m scale at flowering and at maturity. The short-range spatial variability of soil δ15N natural abundance and symbiotic nitrogen fixation were high at both growth stages. Along a 4-m row, the δ15N natural abundance in barley......-abundance are that estimates of symbiotic N2-fixation can be obtained from the natural abundance method if at least half a square meter of crop and reference plants is sampled for the isotopic analysis. In fields with small amounts of representative reference crops (weeds) it might be necessary to sow in reference crop...

  8. Growth of epitaxially oriented Ag nanoislands on air-oxidized Si(1 1 1)-(7 × 7) surfaces: Influence of short-range order on the substrate

    International Nuclear Information System (INIS)

    Roy, Anupam; Bhattacharjee, K.; Ghatak, J.; Dev, B.N.

    2012-01-01

    Clean Si(1 1 1)-(7 × 7) surfaces, followed by air-exposure, have been investigated by reflection high-energy electron diffraction (RHEED) and scanning tunneling microscopy (STM). Fourier transforms (FTs) of STM images show the presence of short-range (7 × 7) order on the air-oxidized surface. Comparison with FTs of STM images from a clean Si(1 1 1)-(7 × 7) surface shows that only the 1/7th order spots are present on the air-oxidized surface. The oxide layer is ∼2-3 nm thick, as revealed by cross-sectional transmission electron microscopy (XTEM). Growth of Ag islands on these air-oxidized Si(1 1 1)-(7 × 7) surfaces has been investigated by in situ RHEED and STM and ex situ XTEM and scanning electron microscopy. Ag deposition at room temperature leads to the growth of randomly oriented Ag islands while preferred orientation evolves when Ag is deposited at higher substrate temperatures. For deposition at 550 °C face centered cubic Ag nanoislands grow with a predominant epitaxial orientation [11 ¯ 0] Ag ||[11 ¯ 0] Si , (1 1 1) Ag || (1 1 1) Si along with its twin [1 ¯ 10] Ag ||[11 ¯ 0] Si , (1 1 1) Ag || (1 1 1) Si , as observed for epitaxial growth of Ag on Si(1 1 1) surfaces. The twins are thus rotated by a 180° rotation of the Ag unit cell about the Si[1 1 1] axis. It is intriguing that Ag nanoislands follow an epitaxial relationship with the Si(1 1 1) substrate in spite of the presence of a 2-3 nm thick oxide layer between Ag and Si. Apparently the short-range order on the oxide surface influences the crystallographic orientation of the Ag nanoislands.

  9. Identification of the same polyomavirus species in different African horseshoe bat species is indicative of short-range host-switching events.

    Science.gov (United States)

    Carr, Michael; Gonzalez, Gabriel; Sasaki, Michihito; Dool, Serena E; Ito, Kimihito; Ishii, Akihiro; Hang'ombe, Bernard M; Mweene, Aaron S; Teeling, Emma C; Hall, William W; Orba, Yasuko; Sawa, Hirofumi

    2017-10-06

    Polyomaviruses (PyVs) are considered to be highly host-specific in different mammalian species, with no well-supported evidence for host-switching events. We examined the species diversity and host specificity of PyVs in horseshoe bats (Rhinolophus spp.), a broadly distributed and highly speciose mammalian genus. We annotated six PyV genomes, comprising four new PyV species, based on pairwise identity within the large T antigen (LTAg) coding region. Phylogenetic comparisons revealed two instances of highly related PyV species, one in each of the Alphapolyomavirus and Betapolyomavirus genera, present in different horseshoe bat host species (Rhinolophus blasii and R. simulator), suggestive of short-range host-switching events. The two pairs of Rhinolophus PyVs in different horseshoe bat host species were 99.9 and 88.8 % identical with each other over their respective LTAg coding sequences and thus constitute the same virus species. To corroborate the species identification of the bat hosts, we analysed mitochondrial cytb and a large nuclear intron dataset derived from six independent and neutrally evolving loci for bat taxa of interest. Bayesian estimates of the ages of the most recent common ancestors suggested that the near-identical and more distantly related PyV species diverged approximately 9.1E4 (5E3-2.8E5) and 9.9E6 (4E6-18E6) years before the present, respectively, in contrast to the divergence times of the bat host species: 12.4E6 (10.4E6-15.4E6). Our findings provide evidence that short-range host-switching of PyVs is possible in horseshoe bats, suggesting that PyV transmission between closely related mammalian species can occur.

  10. Assessment of Sampling Error Associated with Collection and Analysis of Soil Samples at a Firing Range Contaminated with HMX

    National Research Council Canada - National Science Library

    Jenkins, Thomas F

    1997-01-01

    Short-range and mid-range (grid size) spatial heterogeneity in explosives concentrations within surface soils was studied at an active antitank firing range at the Canadian Force Base-Valcartier, Val-Belair, Quebec...

  11. The Effect of Synchronized Forced Running with Chronic Stress on Short, Mid and Long- term Memory in Rats.

    Science.gov (United States)

    Radahmadi, Maryam; Alaei, Hojjatallah; Sharifi, Mohammad-Reza; Hosseini, Nasrin

    2013-03-01

    Impairment of learning and memory processes has been demonstrated by many studies using different stressors. Other reports suggested that exercise has a powerful behavioral intervention to improve cognitive function and brain health. In this research, we investigated protective effects of treadmill running on chronic stress-induced memory deficit in rats. Fifty male Wistar rats were randomly divided into five groups (n=10) as follows: Control (Co), Sham (Sh), Stress (St), Exercise (Ex) and Stress and Exercise (St & Ex) groups. Chronic restraint stress was applied by 6h/day/21days and also treadmill running at a speed 20-21m/min for 1h/day/21days. Memory function was evaluated by the passive avoidance test in different intervals (1, 7 and 21 days) after foot shock. OUR RESULTS SHOWED THAT: 1) Although exercise alone showed beneficial effects especially on short and mid-term memory (Pshort, mid and long-term memory deficit in stressed rats. 2) Short and mid-term memory deficit was significantly (PMemory deficit in synchronized exercise with stress group was nearly similar to stressed rats. 4) Helpful effects of exercise were less than harmful effects of stress when they were associated together. The data correspond to the possibility that although treadmill running alone has helpful effects on learning and memory consolidation, but when it is synchronized with stress there is no significant benefit and protective effects in improvement of memory deficit induced by chronic stress. However, it is has a better effect than no training on memory deficit in stressed rats.

  12. Short-Range Stacking Disorder in Mixed-Layer Compounds: A HAADF STEM Study of Bastnäsite-Parisite Intergrowths

    Directory of Open Access Journals (Sweden)

    Cristiana L. Ciobanu

    2017-11-01

    Full Text Available Atomic-scale high angle annular dark field scanning transmission electron microscopy (HAADF STEM imaging and electron diffractions are used to address the complexity of lattice-scale intergrowths of REE-fluorocarbonates from an occurrence adjacent to the Olympic Dam deposit, South Australia. The aims are to define the species present within the intergrowths and also assess the value of the HAADF STEM technique in resolving stacking sequences within mixed-layer compounds. Results provide insights into the definition of species and crystal-structural modularity. Lattice-scale intergrowths account for the compositional range between bastnäsite and parasite, as measured by electron probe microanalysis (at the µm-scale throughout the entire area of the intergrowths. These comprise rhythmic intervals of parisite and bastnäsite, or stacking sequences with gradational changes in the slab stacking between B, BBS and BS types (B—bastnäsite, S—synchysite. An additional occurrence of an unnamed B2S phase [CaCe3(CO34F3], up to 11 unit cells in width, is identified among sequences of parisite and bastnäsite within the studied lamellar intergrowths. Both B2S and associated parisite show hexagonal lattices, interpreted as 2H polytypes with c = 28 and 38 Å, respectively. 2H parisite is a new, short hexagonal polytype that can be added to the 14 previously reported polytypes (both hexagonal and rhombohedral for this mineral. The correlation between satellite reflections and the number of layers along the stacking direction (c* can be written empirically as: Nsat = [(m × 2 + (n × 4] − 1 for all BmSn compounds with S ≠ 0. The present study shows intergrowths characterised by short-range stacking disorder and coherent changes in stacking along perpendicular directions. Knowing that the same compositional range can be expressed as long-period stacking compounds in the group, the present intergrowths are interpreted as being related to disequilibrium

  13. Effect of regional precursor emission controls on long-range ozone transport – Part 1: Short-term changes in ozone air quality

    Directory of Open Access Journals (Sweden)

    J. J. West

    2009-08-01

    Full Text Available Observations and models demonstrate that ozone and its precursors can be transported between continents and across oceans. We model the influences of 10% reductions in anthropogenic nitrogen oxide (NOx emissions from each of nine world regions on surface ozone air quality in that region and all other regions. In doing so, we quantify the relative importance of long-range transport between all source-receptor pairs, for direct short-term ozone changes. We find that for population-weighted concentrations during the three-month "ozone-season", the strongest inter-regional influences are from Europe to the Former Soviet Union, East Asia to Southeast Asia, and Europe to Africa. The largest influences per unit of NOx reduced, however, are seen for source regions in the tropics and Southern Hemisphere, which we attribute mainly to greater sensitivity to changes in NOx in the lower troposphere, and secondarily to increased vertical convection to the free troposphere in tropical regions, allowing pollutants to be transported further. Results show, for example, that NOx reductions in North America are ~20% as effective per unit NOx in reducing ozone in Europe during summer, as NOx reductions from Europe itself. Reducing anthropogenic emissions of non-methane volatile organic compounds (NMVOCs and carbon monoxide (CO by 10% in selected regions, can have as large an impact on long-range ozone transport as NOx reductions, depending on the source region. We find that for many source-receptor pairs, the season of greatest long-range influence does not coincide with the season when ozone is highest in the receptor region. Reducing NOx emissions in most source regions causes a larger decrease in export of ozone from the source region than in ozone production outside of the source region.

  14. Structure of short-range-ordered iron(III)-precipitates formed by iron(II) oxidation in water containing phosphate, silicate, and calcium

    Science.gov (United States)

    Voegelin, A.; Frommer, J.; Vantelon, D.; Kaegi, R.; Hug, S. J.

    2009-04-01

    The oxidation of Fe(II) in water leads to the formation of Fe(III)-precipitates that strongly affect the fate of nutrients and contaminants in natural and engineered systems. Examples include the cycling of As in rice fields irrigated with As-rich groundwater or the treatment of drinking water for As removal. Knowledge of the types of Fe(III)-precipitates forming in such systems is essential for the quantitative modeling of nutrient and contaminant dynamics and for the optimization of water purification techniques on the basis of a mechanistic understanding of the relevant biogeochemical processes. In this study, we investigated the local coordination of Fe, P, and Ca in Fe(III)-precipitates formed by aeration of synthetic Fe(II)-containing groundwater with variable composition (pH 7, 2-30 mg/L Fe(II), 2-20 mg/L phosphate-P, 2-20 mg/L silicate-Si, 8 mM Na-bicarbonate or 2.5 mM Ca-&1.5 mM Mg-bicarbonate). After 4 hours of oxidation, Fe(III)-precipitates were collected on 0.2 µm nylon filters and dried. The precipitates were analyzed by Fe K-edge EXAFS (XAS beamline, ANKA, Germany) and by P and Ca K-edge XANES spectroscopy (LUCIA beamline, SLS, Switzerland). The Fe K-edge EXAFS spectra indicated that local Fe coordination in the precipitates systematically shifted with water composition. As long as water contained P, mainly short-range-ordered Fe(III)-phosphate formed (with molar P/Fe ~0.5). In the absence of P, Fe(III) precipitated as hydrous ferric oxide at high Si/Fe>0.5, as ferrihydrite at intermediate Si/Fe, and mainly as lepidocrocite at Si/Fe<0.2. Analysis of the EXAFS by shell-fitting indicated that Fe(III)-phosphates mainly contained mono- or oligomeric (edge- or corner-sharing) Fe and that the linkage between neighboring Fe(III)-octahedra changed from predominantly edge-sharing in Si-rich hydrous ferric oxide to edge- and corner-sharing in ferrihydrite. Electron microscopic data showed that changes in local precipitate structure were systematically

  15. Red River flooding, short-term measures : interim report to the International Red River Basin Task Force to the International Joint Commission

    International Nuclear Information System (INIS)

    1997-12-01

    The 1997 flood of the Red River Basin was one of the worst in recorded history. The basin covers 45,000 square miles and includes portions of South Dakota, North Dakota, Minnesota and Manitoba. This report of a special task force provides an overview of the environmental impacts of the 1997 flood and recommends a series of strategies to prevent or reduce future flood damage in the Basin. For example, within Manitoba, more than 550 containers that held hazardous materials were retrieved from the Red River. The contents of the containers which included propane, heating fuel, petroleum products, fire-fighting foam, tar, alcohol, solvents, corrosive liquids, polyester resin, paint, and pesticides, made their way into the floodwaters. Estimates of the amount of fuel oil that spilled in Manitoba are not available, but some 15,000 gallons of gasoline spilled from service stations in Breckenridge, Minnesota. The precursors that lead to the severe flooding in 1997 included heavy precipitation and higher than average temperatures that created less than ideal melt conditions. Since 1989, weekly maps of snow and water in the Canadian prairies have been produced because knowledge of the spatial distribution and amount of snow cover during the winter is important for forecasting spring water supply conditions. The Task Force made 40 recommendations that should be initiated within the short term. One of the recommendations was to remove or secure hazardous materials stored in the flood plain. 3 tabs., 4 figs

  16. Determination of Seed Soundness in Conifers Cryptomeria japonica and Chamaecyparis obtusa Using Narrow-Multiband Spectral Imaging in the Short-Wavelength Infrared Range

    Science.gov (United States)

    Matsuda, Osamu; Hara, Masashi; Tobita, Hiroyuki; Yazaki, Kenichi; Nakagawa, Toshinori; Shimizu, Kuniyoshi; Uemura, Akira; Utsugi, Hajime

    2015-01-01

    Regeneration of planted forests of Cryptomeria japonica (sugi) and Chamaecyparis obtuse (hinoki) is the pressing importance to the forest administration in Japan. Low seed germination rate of these species, however, has hampered low-cost production of their seedlings for reforestation. The primary cause of the low germinability has been attributed to highly frequent formation of anatomically unsound seeds, which are indistinguishable from sound germinable seeds by visible observation and other common criteria such as size and weight. To establish a method for sound seed selection in these species, hyperspectral imaging technique was used to identify a wavelength range where reflectance spectra differ clearly between sound and unsound seeds. In sound seeds of both species, reflectance in a narrow waveband centered at 1,730 nm, corresponding to a lipid absorption band in the short-wavelength infrared (SWIR) range, was greatly depressed relative to that in adjacent wavebands on either side. Such depression was absent or less prominent in unsound seeds. Based on these observations, a reflectance index SQI, abbreviated for seed quality index, was formulated using reflectance at three narrow SWIR wavebands so that it represents the extent of the depression. SQI calculated from seed area-averaged reflectance spectra and spatial distribution patterns of pixelwise SQI within each seed area were both proven as reliable criteria for sound seed selection. Enrichment of sound seeds was accompanied by an increase in germination rate of the seed lot. Thus, the methods described are readily applicable toward low-cost seedling production in combination with single seed sowing technology. PMID:26083366

  17. How Hydroclimate Influences the Effectiveness of Particle Filter Data Assimilation of Streamflow in Initializing Short- to Medium-range Streamflow Forecasts

    Science.gov (United States)

    Clark, E.; Wood, A.; Nijssen, B.; Clark, M. P.

    2017-12-01

    Short- to medium-range (1- to 7-day) streamflow forecasts are important for flood control operations and in issuing potentially life-save flood warnings. In the U.S., the National Weather Service River Forecast Centers (RFCs) issue such forecasts in real time, depending heavily on a manual data assimilation (DA) approach. Forecasters adjust model inputs, states, parameters and outputs based on experience and consideration of a range of supporting real-time information. Achieving high-quality forecasts from new automated, centralized forecast systems will depend critically on the adequacy of automated DA approaches to make analogous corrections to the forecasting system. Such approaches would further enable systematic evaluation of real-time flood forecasting methods and strategies. Toward this goal, we have implemented a real-time Sequential Importance Resampling particle filter (SIR-PF) approach to assimilate observed streamflow into simulated initial hydrologic conditions (states) for initializing ensemble flood forecasts. Assimilating streamflow alone in SIR-PF improves simulated streamflow and soil moisture during the model spin up period prior to a forecast, with consequent benefits for forecasts. Nevertheless, it only consistently limits error in simulated snow water equivalent during the snowmelt season and in basins where precipitation falls primarily as snow. We examine how the simulated initial conditions with and without SIR-PF propagate into 1- to 7-day ensemble streamflow forecasts. Forecasts are evaluated in terms of reliability and skill over a 10-year period from 2005-2015. The focus of this analysis is on how interactions between hydroclimate and SIR-PF performance impact forecast skill. To this end, we examine forecasts for 5 hydroclimatically diverse basins in the western U.S. Some of these basins receive most of their precipitation as snow, others as rain. Some freeze throughout the mid-winter while others experience significant mid-winter melt

  18. Traplining in bumblebees (Bombus impatiens): a foraging strategy's ontogeny and the importance of spatial reference memory in short-range foraging.

    Science.gov (United States)

    Saleh, Nehal; Chittka, Lars

    2007-04-01

    To test the relative importance of long-term and working spatial memories in short-range foraging in bumblebees, we compared the performance of two groups of bees. One group foraged in a stable array of six flowers for 40 foraging bouts, thereby enabling it to establish a long-term memory of the array, and adjust its spatial movements accordingly. The other group was faced with an array that changed between (but not within) foraging bouts, and thus had only access to a working memory of the flowers that had been visited. Bees in the stable array started out sampling a variety of routes, but their tendency to visit flowers in a repeatable, stable order ("traplining") increased drastically with experience. These bees used shorter routes and converged on four popular paths. However, these routes were mainly formed through linking pairs of flowers by near-neighbour movements, rather than attempting to minimize overall travel distance. Individuals had variations to a primary sequence, where some bees used a major sequence most often, followed by a minor less used route, and others used two different routes with equal frequency. Even though bees foraging in the spatially randomized array had access to both spatial working memory and scent marks, this manipulation greatly disrupted foraging efficiency, mainly via an increase in revisitation to previously emptied flowers and substantially longer search times. Hence, a stable reference frame greatly improves foraging even for bees in relatively small arrays of flowers.

  19. The invisible cues that guide king penguin chicks home: use of magnetic and acoustic cues during orientation and short-range navigation.

    Science.gov (United States)

    Nesterova, Anna P; Chiffard, Jules; Couchoux, Charline; Bonadonna, Francesco

    2013-04-15

    King penguins (Aptenodytes patagonicus) live in large and densely populated colonies, where navigation can be challenging because of the presence of many conspecifics that could obstruct locally available cues. Our previous experiments demonstrated that visual cues were important but not essential for king penguin chicks' homing. The main objective of this study was to investigate the importance of non-visual cues, such as magnetic and acoustic cues, for chicks' orientation and short-range navigation. In a series of experiments, the chicks were individually displaced from the colony to an experimental arena where they were released under different conditions. In the magnetic experiments, a strong magnet was attached to the chicks' heads. Trials were conducted in daylight and at night to test the relative importance of visual and magnetic cues. Our results showed that when the geomagnetic field around the chicks was modified, their orientation in the arena and the overall ability to home was not affected. In a low sound experiment we limited the acoustic cues available to the chicks by putting ear pads over their ears, and in a loud sound experiment we provided additional acoustic cues by broadcasting colony sounds on the opposite side of the arena to the real colony. In the low sound experiment, the behavior of the chicks was not affected by the limited sound input. In the loud sound experiment, the chicks reacted strongly to the colony sound. These results suggest that king penguin chicks may use the sound of the colony while orienting towards their home.

  20. Investigations of coal ignition in a short-range flame burner using optical measuring systems; Untersuchungen zur Kohlezuendung am Flachflammenbrenner unter Verwendung optischer Messtechnik

    Energy Technology Data Exchange (ETDEWEB)

    Hackert, G.; Kremer, H.; Wirtz, S. [Bochum Univ. (Germany). Lehrstuhl fuer Energieanlagentechnik

    1999-09-01

    The short-range flame burner and the KOALA reactor of DMT are experimental facilities for realistic simulation of coal conversion processes at high temperatures and pressures in atmospheric conditions. The TOSCA system enable measurements of temperatures, sizes, shapes and velocities of the fuel particles, which serve as a basis for a three-dimensional simulation model of coal combustion. In the future, further parameter studies will deepen the present knowledge of coal dust combustion under pressure and enable optimisation of the numerical models for simulation of industrial-scale systems for coal dust combustion under pressure. [Deutsch] Mit dem Flachflammenbrenner und dem KOALA-Reaktor der DMT stehen Versuchsapparaturen zur Verfuegung, mit deren Hilfe die Kohleumwandlungsprozesse bei hohen Temperaturen unter Druck und unter atmosphaerischen Bedingungen realistisch wiedergegeben werden. Das TOSCA-System erlaubt dabei die Bestimmung von Temperaturen, Groessen, Formen und Geschwindigkeiten der Brennstoffpartikel. Diese Daten liefern die Grundlage fuer die Erstellung eines dreidimensionalen Simulationsmodells zur Modellierung der Kohleverbrennung. In Zukunft werden weitere Parameterstudien das Verstaendnis der Kohlenstaubdruckverbrennung vertiefen und ein Optimierung der numerischen Modelle ermoeglichen, so dass die Simulation grosstechnischer Kohlenstaubdruckverbrennungsanlagen realisiert werden kann. (orig.)