Transition from disordered to long-range ordered nanoparticles on Al2O3/Ni3Al(111)

NASA Astrophysics Data System (ADS)

Alyabyeva, N.; Ouvrard, A.; Zakaria, A.-M.; Charra, F.; Bourguignon, B.

2018-06-01

Application of preparation recipes of the literature failed to produce an ordered array of NPs on our particular Ni3Al sample. This has motivated a systematic survey of Pd NP nucleation as a function of experimental parameters. We have shown that the increase of oxidation temperature during the preparation of Al2O3 ultra-thin film on Ni3Al(111) leads to a transition from disordered to long-range ordered Pd nanoparticle (NP) nucleation. Alumina films were prepared at different temperatures ranging from 990 to 1140 K. Crystallinity, electronic structure of the alumina film and Pd nucleation and growth have been investigated using Low Energy Electron Diffraction and Scanning Tunnelling Microscopy. NP density and long-range order nucleation along the so-called "dot structure" of 4.2 nm periodicity, strongly increase for temperatures higher than a threshold value of 1070 ± 20 K. This transition relies on the alumina film improvement and suggests that the modulation of Pd adsorption energy at nucleation centres which is necessary to nucleate NPs at ordered sites, requires higher preparation temperature. Long-range ordered NPs with a high density were obtained 140 K above reported recipes in the literature. This optimized temperature has been tested on a fresh sample (issued from the same supplier) for which just a few cleanings were enough to obtain long-range ordered NPs. Presumably the variability of the optimal oxidation temperature for our samples with respect to the literature is related to fluctuations of the stoichiometry from sample to sample.

Surface and finite size effect on fluctuations dynamics in nanoparticles with long-range order

NASA Astrophysics Data System (ADS)

Morozovska, A. N.; Eliseev, E. A.

2010-02-01

The influence of surface and finite size on the dynamics of the order parameter fluctuations and critical phenomena in the three-dimensional (3D)-confined systems with long-range order was not considered theoretically. In this paper, we study the influence of surface and finite size on the dynamics of the order parameter fluctuations in the particles of arbitrary shape. We consider concrete examples of the spherical and cylindrical ferroic nanoparticles within Landau-Ginzburg-Devonshire phenomenological approach. Allowing for the strong surface energy contribution in micro and nanoparticles, the analytical expressions derived for the Ornstein-Zernike correlator of the long-range order parameter spatial-temporal fluctuations, dynamic generalized susceptibility, relaxation times, and correlation radii discrete spectra are different from those known for bulk systems. Obtained analytical expressions for the correlation function of the order parameter spatial-temporal fluctuations in micro and nanosized systems can be useful for the quantitative analysis of the dynamical structural factors determined from magnetic resonance diffraction and scattering spectra. Besides the practical importance of the correlation function for the analysis of the experimental data, derived expressions for the fluctuations strength determine the fundamental limits of phenomenological theories applicability for 3D-confined systems.

Long-Range Anti-ferromagnetic Order in Sm2Ti2O7

NASA Astrophysics Data System (ADS)

Mauws, Cole; Sarte, Paul; Hallas, Alannah; Wildes, Andrew; Quilliam, Jeffrey; Luke, Graeme; Gaulin, Bruce; Wiebe, Christopher

The spin ice state has been a key topic in frustrated magnetism for decades. Largely due to the presence of monopole-like excitations, leading to interesting physics. There has been a consistent effort in the field at synthesising new spin ice phases that possess smaller moments in the hopes of increasing the density of magnetic monopoles. As well as investigating the phase when quantum fluctuations dominate over dipolar interactions. Initially Sm2Ti2O7 was thought to be a candidate for a quantum spin ice, possessing a low moment of 1.5 μB in the high-spin case and crystal fields may reduce it to a true spin-1/2 system. However anti-ferromagnetic interactions as well as a lambda-like heat capacity anomaly pointed towards long-range antiferromagnetic order. An isotopically enriched samarium-154 single crystal was taken to the D7 polarized diffuse scattering spectrometer at the ILL. Long-range antiferromagnetic order was observed and indexed onto the all-in all-out structure. This agrees with theoretical predictions of Ising pyrochlore systems with sufficiently large anti-ferromagnetic coupling. NSERC, CFI, CIFAR, CRC.

Ductile long range ordered alloys with high critical ordering temperature and wrought articles fabricated therefrom

DOEpatents

Liu, Chain T.; Inouye, Henry

1979-01-01

Malleable long range ordered alloys having high critical ordering temperatures exist in the V(Fe, Co).sub.3 and V(Fe, Co, Ni).sub.3 systems. These alloys have the following compositions comprising by weight: 22-23% V, 14-30% Fe, and the remainder Co or Co and Ni with an electron density no more than 7.85. The maximum combination of high temperature strength, ductility and creep resistance are manifested in the alloy comprising by weight 22-23% V, 14-20% Fe and the remainder Co and having an atomic composition of V(Fe .sub.0.20-0.26 C Co.sub.0.74-0.80).sub.3. The alloy comprising by weight 22-23% V, 16-17% Fe and 60-62% Co has excellent high temperature properties. The alloys are fabricable into wrought articles by casting, deforming, and annealing for sufficient time to provide ordered structure.

Long range order and two-fluid behavior in heavy electron materials

DOE PAGES

Shirer, Kent R.; Shockley, Abigail C.; Dioguardi, Adam P.; ...

2012-09-24

The heavy electron Kondo liquid is an emergent state of condensed matter that displays universal behavior independent of material details. Properties of the heavy electron liquid are best probed by NMR Knight shift measurements, which provide a direct measure of the behavior of the heavy electron liquid that emerges below the Kondo lattice coherence temperature as the lattice of local moments hybridizes with the background conduction electrons. Because the transfer of spectral weight between the localized and itinerant electronic degrees of freedom is gradual, the Kondo liquid typically coexists with the local moment component until the material orders at lowmore » temperatures. The two-fluid formula captures this behavior in a broad range of materials in the paramagnetic state. In order to investigate two-fluid behavior and the onset and physical origin of different long range ordered ground states in heavy electron materials, we have extended Knight shift measurements to URu 2Si 2, CeIrIn 5, and CeRhIn 5. In CeRhIn 5 we find that the antiferromagnetic order is preceded by a relocalization of the Kondo liquid, providing independent evidence for a local moment origin of antiferromagnetism. In URu 2Si 2 the hidden order is shown to emerge directly from the Kondo liquid and so is not associated with local moment physics. Lastly, our results imply that the nature of the ground state is strongly coupled with the hybridization in the Kondo lattice in agreement with phase diagram proposed by Yang and Pines.« less

Interplay between Long-Range Crystal Order and Short-Range Molecular Interactions Tunes Carrier Mobility in Liquid Crystal Dyes

PubMed Central

2017-01-01

We investigated the influence of molecular packing on the optical and electrical properties of the liquid crystalline dye 4,7-bis[5-(2-fluoro-4-pentyl-phenyl)-2-thienyl]-2,1,3-benzothiadiazole (FPPTB). FPPTB is crystalline at room temperature, exhibits a nematic phase at temperatures above 149 °C and is in an isotropic melt at temperatures above 230 °C. Solution processed FPPTB films were subject to thermal annealing through these phase transition temperatures and characterized with X-ray diffraction and polarized optical microscopy. Cooling FPPTB films from the nematic and isotropic phases increased crystal domain size, but also induced local structural variations in the molecular packing of crystalline FPPTB. The decrease in long-range order was correlated with an increase in short-range π–π interactions, leading to changes in molecular aggregation which persisted even when the FPPTB films were cooled to room temperature. Annealing-induced changes in molecular aggregation were confirmed with optical spectroscopy. The carrier mobility in FPPTB films increased over 2 orders of magnitude from (2.2 ± 0.4) × 10–5 cm2 V–1 s–1 in as-spun films to μ = (5.0 ± 0.8) × 10–3 cm2 V–1 s–1 in films cooled from the isotropic melt. We discuss the relationship between thermal stability and high carrier mobility values in terms of the interplay between long-range molecular order and increased π–π interactions between molecular pairs in the FPPTB film. PMID:28139915

Long-range order in InAsSb

NASA Astrophysics Data System (ADS)

Jen, H. R.; Ma, K. Y.; Stringfellow, G. B.

1989-03-01

Results are presented of transmission electron diffraction (TED) observations, demonstrating, for the first time, a CuPt-type ordering in InAs(1-x)Sb(x) alloys, over a wide range of x values (from x = 0.22 to 0.88). The InAsSb alloys were prepared by OMVPE on (001) oriented undoped InSb or InAs substrates. The ordering-induced spots on the TED patterns show the highest intensity for x of about 0.5 and the lowest intensity toward each binary end compound. Only two of the four variants are formed during growth. In some areas, the degree of order for these two variants, 1/2(-1 1 1) and 1/2(1 -1 1), is equal, and in other areas, one variant dominates.

Application of long-range order to predict unfolding rates of two-state proteins.

PubMed

Harihar, B; Selvaraj, S

2011-03-01

Predicting the experimental unfolding rates of two-state proteins and models describing the unfolding rates of these proteins is quite limited because of the complexity present in the unfolding mechanism and the lack of experimental unfolding data compared with folding data. In this work, 25 two-state proteins characterized by Maxwell et al. (Protein Sci 2005;14:602–616) using a consensus set of experimental conditions were taken, and the parameter long-range order (LRO) derived from their three-dimensional structures were related with their experimental unfolding rates ln(k(u)). From the total data set of 30 proteins used by Maxwell et al. (Protein Sci 2005;14:602–616), five slow-unfolding proteins with very low unfolding rates were considered to be outliers and were not included in our data set. Except all beta structural class, LRO of both the all-alpha and mixed-class proteins showed a strong inverse correlation of r = -0.99 and -0.88, respectively, with experimental ln(k(u)). LRO shows a correlation of -0.62 with experimental ln(k(u)) for all-beta proteins. For predicting the unfolding rates, a simple statistical method has been used and linear regression equations were developed for individual structural classes of proteins using LRO, and the results obtained showed a better agreement with experimental results. Copyright © 2010 Wiley-Liss, Inc.

Polariton Chimeras: Bose-Einstein Condensates with Intrinsic Chaoticity and Spontaneous Long-Range Ordering

NASA Astrophysics Data System (ADS)

Gavrilov, S. S.

2018-01-01

The system of cavity polaritons driven by a plane electromagnetic wave is found to undergo the spontaneous breaking of spatial symmetry, which results in a lifted phase locking with respect to the driving field and, consequently, in the possibility of internal ordering. In particular, periodic spin and intensity patterns arise in polariton wires; they exhibit strong long-range order and can serve as media for signal transmission. Such patterns have the properties of dynamical chimeras: they are formed spontaneously in perfectly homogeneous media and can be partially chaotic. The reported new mechanism of chimera formation requires neither time-delayed feedback loops nor nonlocal interactions.

Magnetic quasi-long-range ordering in nematic systems due to competition between higher-order couplings

NASA Astrophysics Data System (ADS)

Žukovič, Milan; Kalagov, Georgii

2018-05-01

Critical properties of the two-dimensional X Y model involving solely nematic-like terms of the second and third orders are investigated by spin-wave analysis and Monte Carlo simulation. It is found that, even though neither of the nematic-like terms alone can induce magnetic ordering, their coexistence and competition leads to an extended phase of the magnetic quasi-long-range-order phase, wedged between the two nematic-like phases induced by the respective couplings. Thus, except for the multicritical point, at which all the phases meet, for any finite value of the coupling parameters ratio there are two phase transition: one from the paramagnetic phase to one of the two nematic-like phases followed by another one at lower temperatures to the magnetic phase. The finite-size scaling analysis indicates that the phase transitions between the magnetic and nematic-like phases belong to the Ising and three-state Potts universality classes. Inside the competition-induced algebraic magnetic phase, the spin-pair correlation function is found to decay even much more slowly than in the standard X Y model with purely magnetic interactions. Such a magnetic phase is characterized by an extremely low vortex-antivortex pair density attaining a minimum close to the point at which the two couplings are of about equal strength.

Long-range ferromagnetic order in LaCoO3 -δ epitaxial films due to the interplay of epitaxial strain and oxygen vacancy ordering

NASA Astrophysics Data System (ADS)

Mehta, V. V.; Biskup, N.; Jenkins, C.; Arenholz, E.; Varela, M.; Suzuki, Y.

2015-04-01

We demonstrate that a combination of electronic structure modification and oxygen vacancy ordering can stabilize a long-range ferromagnetic ground state in epitaxial LaCoO3 thin films. Highest saturation magnetization values are found in the thin films in tension on SrTiO3 and (La ,Sr )(Al ,Ta )O3 substrates and the lowest values are found in thin films in compression on LaAlO3. Electron microscopy reveals oxygen vacancy ordering to varying degrees in all samples, although samples with the highest magnetization are the most defective. Element-specific x-ray absorption techniques reveal the presence of high spin Co2 + and Co3 + as well as low spin Co3 + in different proportions depending on the strain state. The interactions among the high spin Co ions and the oxygen vacancy superstructure are correlated with the stabilization of the long-range ferromagnetic order.

Coexistence of long-range cycloidal order and spin-cluster glass state in the multiferroic BaYFeO4.

PubMed

Ghara, Somnath; Sundaresan, A

2018-06-20

We report the presence of spin glass state below the cycloidal spin ordering in the multiferroic BaYFeO 4 . This compound is known to crystallize in an orthorhombic structure with a centrosymmetric space group Pnma and exhibits two successive antiferromagnetic phase transitions. Upon cooling, it undergoes a spin density wave (SDW)-like antiferromagnetic ordering at T N1 ~ 48 K and a cycloidal ordering at T N2 ~ 35 K. Using dc magnetic memory effect and magnetization relaxation studies, we have shown that this oxide undergoes a reentrant spin glass transition below T * ~ 17 K. Our analysis suggests the presence of spin clusters in the glassy state. The coexistence of spin-cluster glass and long-range cycloidal ordered states results in an exchange bias effect at 2 K. The origin of the glassy state has been attributed to freezing of some Fe 3+ moments, which do not participate in the long-range ordering.

Coexistence of long-range cycloidal order and spin-cluster glass state in the multiferroic BaYFeO4

NASA Astrophysics Data System (ADS)

Ghara, Somnath; Sundaresan, A.

2018-06-01

We report the presence of spin glass state below the cycloidal spin ordering in the multiferroic BaYFeO4. This compound is known to crystallize in an orthorhombic structure with a centrosymmetric space group Pnma and exhibits two successive antiferromagnetic phase transitions. Upon cooling, it undergoes a spin density wave (SDW)-like antiferromagnetic ordering at T N1 ~ 48 K and a cycloidal ordering at T N2 ~ 35 K. Using dc magnetic memory effect and magnetization relaxation studies, we have shown that this oxide undergoes a reentrant spin glass transition below T * ~ 17 K. Our analysis suggests the presence of spin clusters in the glassy state. The coexistence of spin-cluster glass and long-range cycloidal ordered states results in an exchange bias effect at 2 K. The origin of the glassy state has been attributed to freezing of some Fe3+ moments, which do not participate in the long-range ordering.

Off-diagonal long-range order, cycle probabilities, and condensate fraction in the ideal Bose gas.

PubMed

Chevallier, Maguelonne; Krauth, Werner

2007-11-01

We discuss the relationship between the cycle probabilities in the path-integral representation of the ideal Bose gas, off-diagonal long-range order, and Bose-Einstein condensation. Starting from the Landsberg recursion relation for the canonic partition function, we use elementary considerations to show that in a box of size L3 the sum of the cycle probabilities of length k>L2 equals the off-diagonal long-range order parameter in the thermodynamic limit. For arbitrary systems of ideal bosons, the integer derivative of the cycle probabilities is related to the probability of condensing k bosons. We use this relation to derive the precise form of the pik in the thermodynamic limit. We also determine the function pik for arbitrary systems. Furthermore, we use the cycle probabilities to compute the probability distribution of the maximum-length cycles both at T=0, where the ideal Bose gas reduces to the study of random permutations, and at finite temperature. We close with comments on the cycle probabilities in interacting Bose gases.

Long Range Ferromagnetic Order in LaCoO 3-δ epitaxial films due to the interplay of epitaxial strain and oxygen vacancy ordering

DOE PAGES

Mehta, Virat; Biskup, Nevenko; Arenholz, E; ...

2015-04-23

We demonstrate that a combination of electronic structure modification and oxygen vacancy ordering can stabilize a long-range ferromagnetic ground state in epitaxial LaCoO 3 thin films. Highest saturation magnetization values are found in the thin films in tension on SrTiO 3 and (La,Sr)(Al,Ta)O 3 substrates and the lowest values are found in thin films in compression on LaAlO 3. Electron microscopy reveals oxygen vacancy ordering to varying degrees in all samples, although samples with the highest magnetization are the most defective. Element-specific x-ray absorption techniques reveal the presence of high spin Co 2+ and Co 3+ as well as lowmore » spin Co 3+ in different proportions depending on the strain state. The interactions among the high spin Co ions and the oxygen vacancy superstructure are correlated with the stabilization of the long-range ferromagnetic order.« less

Absence of long-range order in the frustrated magnet SrDy2O4 due to trapped defects from a dimensionality crossover

NASA Astrophysics Data System (ADS)

Gauthier, N.; Fennell, A.; Prévost, B.; Uldry, A.-C.; Delley, B.; Sibille, R.; Désilets-Benoit, A.; Dabkowska, H. A.; Nilsen, G. J.; Regnault, L.-P.; White, J. S.; Niedermayer, C.; Pomjakushin, V.; Bianchi, A. D.; Kenzelmann, M.

2017-04-01

Magnetic frustration and low dimensionality can prevent long-range magnetic order and lead to exotic correlated ground states. SrDy2O4 consists of magnetic Dy3 + ions forming magnetically frustrated zigzag chains along the c axis and shows no long-range order to temperatures as low as T =60 mK. We carried out neutron scattering and ac magnetic susceptibility measurements using powder and single crystals of SrDy2O4 . Diffuse neutron scattering indicates strong one-dimensional (1D) magnetic correlations along the chain direction that can be qualitatively accounted for by the axial next-nearest-neighbor Ising model with nearest-neighbor and next-nearest-neighbor exchange J1=0.3 meV and J2=0.2 meV, respectively. Three-dimensional (3D) correlations become important below T*≈0.7 K. At T =60 mK, the short-range correlations are characterized by a putative propagation vector k1 /2=(0 ,1/2 ,1/2 ) . We argue that the absence of long-range order arises from the presence of slowly decaying 1D domain walls that are trapped due to 3D correlations. This stabilizes a low-temperature phase without long-range magnetic order, but with well-ordered chain segments separated by slowly moving domain walls.

Superfluidity or supersolidity as a consequence of off-diagonal long-range order

NASA Astrophysics Data System (ADS)

Shi, Yu

2005-07-01

We present a general derivation of Hess-Fairbank effect or nonclassical rotational inertial (NCRI), i.e., the refusal to rotate with its container, as well as the quantization of angular momentum, as consequences of off-diagonal long-range order (ODLRO) in an interacting Bose system. Afterwards, the path integral formulation of superfluid density is rederived without ignoring the centrifugal potential. Finally and in particular, for a class of variational wave functions used for solid helium, treating the constraint of single-valuedness boundary condition carefully, we show that there is no ODLRO and, especially, demonstrate explicitly that NCRI cannot be possessed in absence of defects, even though there exist zero-point motion and exchange effect.

Vivid structural colors with low angle dependence from long-range ordered photonic crystal films.

PubMed

Su, Xin; Xia, Hongbo; Zhang, Shufen; Tang, Bingtao; Wu, Suli

2017-03-02

Structural colored materials have attracted increasing attention due to their vivid color effects and non-photobleaching characteristics. However, the angle dependence of these structural colors severely restricts their practical applications, for example, in display and sensing devices. Here, a new strategy for obtaining low angle dependent structural colors is demonstrated by fabricating long-range ordered photonic crystal films. By using spheres with high refractive indices as building blocks, the angle dependence of the obtained colors has been strongly suppressed. Green, golden yellow and red structural colored films with low angle dependence were obtained by using 145 nm, 165 nm and 187 nm Cu 2 O spheres as building blocks, respectively. SEM images confirmed the long-range highly ordered arrays of the Cu 2 O photonic crystal films. Reflectance spectra and digital photographs clearly demonstrate the low angle dependence of these structural colors, which is in sharp comparison with the case of polystyrene (PS) and SiO 2 photonic crystal films. Furthermore, these structural colors are vivid with high color saturation, not only under black background, but also under white background and natural light without adding any light-absorbing agents. These low angle dependent structural colors endow Cu 2 O photonic crystal films with great potential in practical applications. Our findings may broaden the strategies for the design and fabrication of angle independent structural colored materials.

Long range magnetic ordering of ultracold fermions in an optical lattice

NASA Astrophysics Data System (ADS)

Duarte, P. M.; Hart, R. A.; Yang, T.-L.; Hulet, R. G.

2013-05-01

We present progress towards the observation of long range antiferromagnetic (AFM) ordering of fermionic 6Li atoms in an optical lattice. We prepare a two spin state mixture of 106 atoms at T /TF = 0 . 1 by evaporatively cooling in an optical dipole trap. The sample is then transferred to a dimple trap formed by three retroreflected laser beams at 1064 nm that propagate in orthogonal directions. The polarization of the retroreflected light is controlled using liquid crystal retarders, which allow us to adiabatically transform the dimple trap into a 3D lattice. Overlapped with each of the three dimple/lattice beams is a beam at 532 nm, which can cancel the harmonic confinement and flatten the band structure in the lattice. This setup offers the possibility of implementing proposed schemes which enlarge the size of the AFM phase in the trap. As a probe for AFM we use Bragg scattering of light. We have observed Bragg scattering off of the (100) lattice planes, and using an off-angle probe we can see the diffuse scattering from the sample which serves as background for the small signals expected before the onset of AFM ordering. Supported by NSF, ONR, DARPA, and the Welch Foundation.

Orientational order as the origin of the long-range hydrophobic effect.

PubMed

Banerjee, Saikat; Singh, Rakesh S; Bagchi, Biman

2015-04-07

The long range attractive force between two hydrophobic surfaces immersed in water is observed to decrease exponentially with their separation-this distance-dependence of effective force is known as the hydrophobic force law (HFL). We explore the microscopic origin of HFL by studying distance-dependent attraction between two parallel rods immersed in 2D Mercedes Benz model of water. This model is found to exhibit a well-defined HFL. Although the phenomenon is conventionally explained by density-dependent theories, we identify orientation, rather than density, as the relevant order parameter. The range of density variation is noticeably shorter than that of orientational heterogeneity. The latter is comparable to the observed distances of hydrophobic force. At large separation, attraction between the rods arises primarily from a destructive interference among the inwardly propagating oppositely oriented heterogeneity generated in water by the two rods. As the rods are brought closer, the interference increases leading to a decrease in heterogeneity and concomitant decrease in free energy of the system, giving rise to the effective attraction. We notice formation of hexagonal ice-like structures at the onset of attractive region which suggests that metastable free energy minimum may play a role in the origin of HFL.

Orientational order as the origin of the long-range hydrophobic effect

NASA Astrophysics Data System (ADS)

Banerjee, Saikat; Singh, Rakesh S.; Bagchi, Biman

2015-04-01

The long range attractive force between two hydrophobic surfaces immersed in water is observed to decrease exponentially with their separation—this distance-dependence of effective force is known as the hydrophobic force law (HFL). We explore the microscopic origin of HFL by studying distance-dependent attraction between two parallel rods immersed in 2D Mercedes Benz model of water. This model is found to exhibit a well-defined HFL. Although the phenomenon is conventionally explained by density-dependent theories, we identify orientation, rather than density, as the relevant order parameter. The range of density variation is noticeably shorter than that of orientational heterogeneity. The latter is comparable to the observed distances of hydrophobic force. At large separation, attraction between the rods arises primarily from a destructive interference among the inwardly propagating oppositely oriented heterogeneity generated in water by the two rods. As the rods are brought closer, the interference increases leading to a decrease in heterogeneity and concomitant decrease in free energy of the system, giving rise to the effective attraction. We notice formation of hexagonal ice-like structures at the onset of attractive region which suggests that metastable free energy minimum may play a role in the origin of HFL.

Viability of long range dragonfly migration across the Indian Ocean: An energetics perspective

NASA Astrophysics Data System (ADS)

Saha, Sandeep; Nirwal, Satvik

2016-11-01

Recently Pantala flavescens (dragonflies) have been reported to migrate in millions from India to Eastern Africa on a multigenerational migratory circuit of length 14000-18000 kms. We attempt to understand the ability of dragonflies to perform long range migration by examining the energetics using computer simulations. In absence of a theory for long range insect migrations, we resort to the extensive literature on long range bird migration from the energetics perspective. The flight energetics depends upon instantaneous power and velocity. The mechanical flight power is computed from the power curve which is then converted to mass depletion using Brequet's equation. However, the mechanical flight power itself depends upon the instantaneous velocity which can vary depending upon the current mass. In order to predict the range in our simulations, we assume that the insect progressively tries to achieve the maximum range velocity. The results indicate that the migration range is approximately 1260 kms in 70 hours based on the true airspeed. However, our analysis is restricted by the lack of data and certain caveats in drag prediction and basal metabolism rate.

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

NASA Astrophysics Data System (ADS)

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.

Long-range Prethermal Time Crystals

NASA Astrophysics Data System (ADS)

Machado, Francisco; Meyer, Gregory D.; Else, Dominic; Olund, Christopher; Nayak, Chetan; Yao, Norman Y.

2017-04-01

Driven quantum systems have recently enabled the realization of a discrete time crystal - an intrinsically out-of-equilibrium phase of matter. One strategy to prevent the drive-induced, runaway heating of the time crystal is the presence of strong disorder leading to many-body localization (MBL). A more elegant, disorder-less approach is simply to work in the prethermal regime where time crystalline order can persist to exponentially long times. One key difference between prethermal and MBL time crystals is that the former is prohibited from existing in one dimensional systems with short-range interactions. In this work, we demonstrate that long-range interactions can stabilize a one dimensional prethermal time crystal. By numerically studying the pre-thermal regime, we find evidence for a phase transition out of the time crystal as a function of increasing energy density. Finally, generalizations of previous analytical bounds for the heating time-scale of driven quantum systems to long-range interactions will also be discussed.

A low-order model for long-range infrasound propagation in random atmospheric waveguides

NASA Astrophysics Data System (ADS)

Millet, C.; Lott, F.

2014-12-01

In numerical modeling of long-range infrasound propagation in the atmosphere, the wind and temperature profiles are usually obtained as a result of matching atmospheric models to empirical data. The atmospheric models are classically obtained from operational numerical weather prediction centers (NOAA Global Forecast System or ECMWF Integrated Forecast system) as well as atmospheric climate reanalysis activities and thus, do not explicitly resolve atmospheric gravity waves (GWs). The GWs are generally too small to be represented in Global Circulation Models, and their effects on the resolved scales need to be parameterized in order to account for fine-scale atmospheric inhomogeneities (for length scales less than 100 km). In the present approach, the sound speed profiles are considered as random functions, obtained by superimposing a stochastic GW field on the ECMWF reanalysis ERA-Interim. The spectral domain is binned by a large number of monochromatic GWs, and the breaking of each GW is treated independently from the others. The wave equation is solved using a reduced-order model, starting from the classical normal mode technique. We focus on the asymptotic behavior of the transmitted waves in the weakly heterogeneous regime (for which the coupling between the wave and the medium is weak), with a fixed number of propagating modes that can be obtained by rearranging the eigenvalues by decreasing Sobol indices. The most important feature of the stochastic approach lies in the fact that the model order (i.e. the number of relevant eigenvalues) can be computed to satisfy a given statistical accuracy whatever the frequency. As the low-order model preserves the overall structure of waveforms under sufficiently small perturbations of the profile, it can be applied to sensitivity analysis and uncertainty quantification. The gain in CPU cost provided by the low-order model is essential for extracting statistical information from simulations. The statistics of a

Long-Range Pre-Thermal Time Crystals

NASA Astrophysics Data System (ADS)

Machado, Francisco; Else, Dominic V.; Nayak, Chetan; Yao, Norman

Driven quantum systems have recently enabled the realization of a discrete time crystal - an intrinsically out-of-equilibrium phase of matter that spontaneously breaks time translation symmetry. One strategy to prevent the drive-induced, runaway heating of the time crystal phase is the presence of strong disorder leading to many-body localization. A simpler disorder-less approach is to work in the pre-thermal regime where time crystalline order can persist to long times, before ultimately being destroyed by thermalization. In this talk, we will consider the interplay between long-range interactions, dimensionality, and pre-thermal time-translation symmetry breaking. As an example, we will consider the phase diagram of a 1D long-range pre-thermal time crystal.

Political Mechanisms for Long-Range Survival and Development

NASA Astrophysics Data System (ADS)

Marshall, W.

As the first species aware of extinction and capable of proactively ensuring our long-term survival and development, it is striking that we do not do so with the rigor, formality, and foresight it requires. Only from a reactive posture have we responded to the challenges of global warfare, human rights, environmental concerns, and sustainable development. Despite our awareness of the possibility for extinction and apocalyptic set-backs to our evolution, and despite the existence of long-range studies-which must still be dramatically increased-proactive global policy implementation regarding our long-term survival and development is arguably non-existent. This lack of long-term policy making can be attributed in part to the lack of formal political mechanisms to facilitate longer-range policy making that extends 30 years or more into the future. Political mechanisms for infusing long-range thinking, research, and strategic planning into the policy-making process can help correct this shortcoming and provide the motivation needed to adequately address long-term challenges with the political rigor required to effectively establish and implement long-term policies. There are some efforts that attempt to address longer-range issues, but those efforts often do not connect to the political process, do not extend 30 or more years into the future, are not well-funded, and are not sufficiently systemic. Political mechanisms for long-range survival and prosperity could correct these inadequacies by raising awareness, providing funding, and most importantly, leveraging political rigor to establish and enforce long-range strategic planning and policies. The feasibility of such mechanisms should first be rigorously studied and assessed in a feasibility study, which could then inform implementation. This paper will present the case for such a study and suggest some possible political mechanisms that should be investigated further in the proposed study. This work is being further

Probing Long-Range Neutrino-Mediated Forces with Atomic and Nuclear Spectroscopy.

PubMed

Stadnik, Yevgeny V

2018-06-01

The exchange of a pair of low-mass neutrinos between electrons, protons, and neutrons produces a "long-range" 1/r^{5} potential, which can be sought for in phenomena originating on the atomic and subatomic length scales. We calculate the effects of neutrino-pair exchange on transition and binding energies in atoms and nuclei. In the case of atomic s-wave states, there is a large enhancement of the induced energy shifts due to the lack of a centrifugal barrier and the highly singular nature of the neutrino-mediated potential. We derive limits on neutrino-mediated forces from measurements of the deuteron binding energy and transition energies in positronium, muonium, hydrogen, and deuterium, as well as isotope-shift measurements in calcium ions. Our limits improve on existing constraints on neutrino-mediated forces from experiments that search for new macroscopic forces by 18 orders of magnitude. Future spectroscopy experiments have the potential to probe long-range forces mediated by the exchange of pairs of standard-model neutrinos and other weakly charged particles.

Probing Long-Range Neutrino-Mediated Forces with Atomic and Nuclear Spectroscopy

NASA Astrophysics Data System (ADS)

Stadnik, Yevgeny V.

2018-06-01

The exchange of a pair of low-mass neutrinos between electrons, protons, and neutrons produces a "long-range" 1 /r5 potential, which can be sought for in phenomena originating on the atomic and subatomic length scales. We calculate the effects of neutrino-pair exchange on transition and binding energies in atoms and nuclei. In the case of atomic s -wave states, there is a large enhancement of the induced energy shifts due to the lack of a centrifugal barrier and the highly singular nature of the neutrino-mediated potential. We derive limits on neutrino-mediated forces from measurements of the deuteron binding energy and transition energies in positronium, muonium, hydrogen, and deuterium, as well as isotope-shift measurements in calcium ions. Our limits improve on existing constraints on neutrino-mediated forces from experiments that search for new macroscopic forces by 18 orders of magnitude. Future spectroscopy experiments have the potential to probe long-range forces mediated by the exchange of pairs of standard-model neutrinos and other weakly charged particles.

Amorphous photonic crystals with only short-range order.

PubMed

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.

Entanglement entropy for the long-range Ising chain in a transverse field.

PubMed

Koffel, Thomas; Lewenstein, M; Tagliacozzo, Luca

2012-12-28

We consider the Ising model in a transverse field with long-range antiferromagnetic interactions that decay as a power law with their distance. We study both the phase diagram and the entanglement properties as a function of the exponent of the interaction. The phase diagram can be used as a guide for future experiments with trapped ions. We find two gapped phases, one dominated by the transverse field, exhibiting quasi-long-range order, and one dominated by the long-range interaction, with long-range Néel ordered ground states. We determine the location of the quantum critical points separating those two phases. We determine their critical exponents and central charges. In the phase with quasi-long-range order the ground states exhibit exotic corrections to the area law for the entanglement entropy coexisting with gapped entanglement spectra.

Long-Range Interactions Restrict Water Transport in Pyrophyllite Interlayers

PubMed Central

Zarzycki, Piotr; Gilbert, Benjamin

2016-01-01

Water diffusion within smectite clay interlayers is reduced by confinement and hence is highly determined by the interlayer spacings that are adopted during swelling. However, a molecular understanding of the short- and long-range forces governing interlayer water structure and dynamics is lacking. Using molecular dynamics simulations of water intercalated between pyrophyllite (smectite prototype) layers we provide a detailed picture of the variation of interlayered water mobility accompanying smectite expansion. Subtle changes in hydrogen bond network structure cause significant changes in water mobility that is greater for stable hydration states and reduced for intermediate separations. By studying pyrophyllite with and without external water we reveal that long-range electrostatic forces apply a restraining effect upon interlayer water mobility. Our findings are relevant for broad range of confining nanostructures with walls thin enough to permit long-range interactions that could affect the mobility of confined solvent molecules and solute species. PMID:27118164

Study of long-range orders of hard-core bosons coupled to cooperative normal modes in two-dimensional lattices

NASA Astrophysics Data System (ADS)

Ghosh, A.; Yarlagadda, S.

2017-09-01

Understanding the microscopic mechanism of coexisting long-range orders (such as lattice supersolidity) in strongly correlated systems is a subject of immense interest. We study the possible manifestations of long-range orders, including lattice-supersolid phases with differently broken symmetry, in a two-dimensional square lattice system of hard-core bosons (HCBs) coupled to archetypal cooperative/coherent normal-mode distortions such as those in perovskites. At strong HCB-phonon coupling, using a duality transformation to map the strong-coupling problem to a weak-coupling one, we obtain an effective Hamiltonian involving nearest-neighbor, next-nearest-neighbor, and next-to-next-nearest-neighbor hoppings and repulsions. Using stochastic series expansion quantum Monte Carlo, we construct the phase diagram of the system. As coupling strength is increased, we find that the system undergoes a first-order quantum phase transition from a superfluid to a checkerboard solid at half-filling and from a superfluid to a diagonal striped solid [with crystalline ordering wave vector Q ⃗=(2 π /3 ,2 π /3 ) or (2 π /3 ,4 π /3 )] at one-third filling without showing any evidence of supersolidity. On tuning the system away from these commensurate fillings, checkerboard supersolid is generated near half-filling whereas a rare diagonal striped supersolid is realized near one-third filling. Interestingly, there is an asymmetry in the extent of supersolidity about one-third filling. Within our framework, we also provide an explanation for the observed checkerboard and stripe formations in La2 -xSrxNiO4 at x =1 /2 and x =1 /3 .

The influence of the long-range order on the vibrational spectra of structures based on sodalite cage.

PubMed

Mikuła, A; Król, M; Koleżyński, A

2015-06-05

Zeolites are a group of tecto-aluminosilicates with numerous practical applications, e.g. gas separators, molecular sieves and sorbents. The unique properties result from porous structure of channels and cages which are built from smaller units - the so-called Secondary Building Units (SBU), and sometimes also larger groups (Breck, 1974; Ciciszwili et al., 1974; Mozgawa, 2008; Čejka and van Bekkum, 2005). The aim of this study was the examination of the influence of long-range order on vibrational spectra of sodalite and zeolite A. Ab initio calculations (geometry optimizations and vibrational spectra calculations) of sodalite cage and selected SBU were carried out by means of Gaussian09 (Frisch et al., 2009) (in the case of isolated clusters) and Crystal09 (Dovesi et al., 2005, 2009) (for periodic structures). The obtained results were compared with the experimental spectra of sodalite and zeolite A crystal structures, synthesized under hydrothermal conditions. These results allowed analyzing of the long-range ordering influence on the vibrational spectra, as well as the identification of the characteristic vibrations in β cage based frameworks. It has been found, that based on small structural fragment (SBU) models a characteristic vibrations can be identify. However, full spectra analysis and especially the interpretation of far-infrared region of the spectra require using periodic models under the influence of translational crystal lattice. Copyright © 2015 Elsevier B.V. All rights reserved.

Isolation of a new two-dimensional honeycomb carbonato-bridged copper(II) complex exhibiting long-range ferromagnetic ordering.

PubMed

Majumder, Arpi; Choudhury, Chirantan Roy; Mitra, Samiran; Rosair, Georgina M; El Fallah, M Salah; Ribas, Joan

2005-04-28

Atmospheric CO2 fixation by an aqueous solution containing Cu(ClO4)2.6H2O and 4-aminopyridine (4-apy) yields a novel example of a two-dimensional mu3-CO3 bridged copper(II) complex {[Cu(4-apy)2]3(mu3-CO3)2(ClO4)2.(1/2)CH3OH}n that has been characterized by IR, UV and X-ray crystallography; preliminary magnetic measurements show that complex exhibits long-range ordered ferromagnetic coupling.

Long-Range Interactions Restrict Water Transport in Pyrophyllite Interlayers

DOE PAGES

Zarzycki, Piotr; Gilbert, Benjamin

2016-04-27

Water diffusion within smectite clay interlayers is reduced by confinement and hence is highly determined by the interlayer spacings that are adopted during swelling. However, a molecular understanding of the short-and long-range forces governing interlayer water structure and dynamics is lacking. Using molecular dynamics simulations of water intercalated between pyrophyllite (smectite prototype) layers we provide a detailed picture of the variation of interlayered water mobility accompanying smectite expansion. Subtle changes in hydrogen bond network structure cause significant changes in water mobility that is greater for stable hydration states and reduced for intermediate separations. By studying pyrophyllite with and without externalmore » water we reveal that long-range electrostatic forces apply a restraining effect upon interlayer water mobility. Our findings are relevant for broad range of confining nanostructures with walls thin enough to permit long-range interactions that could affect the mobility of confined solvent molecules and solute species.« less

Absence of long range order in SrDy2O4 frustrated magnet due to trapped defects from a dimensionality crossover

NASA Astrophysics Data System (ADS)

Gauthier, Nicolas; Fennell, Amy; Uldry, Anne-Christine; Delley, Bernard; Sibille, Romain; White, Jonathan; Niedermayer, Christof; Pomjakushin, Vladimir; Kenzelmann, Michel; Prevost, Bobby; Desilets-Benoit, Alexandre; Bianchi, Andrea D.; Dabkowska, Hanna A.; Nilsen, Goran; Regnault, Louis-Pierre

The simultaneous occurence of geometrical frustration and low dimensionality can lead to strongly correlated fluctuating ground states. In the SrLn2O4 compounds, the Ln magnetic ions form one-dimensional (1D) zig-zag chains that have both of these characteristics, offering a playground to study novel states of matter. In SrDy2O4, the two inequivalent Dy3+ sites are Ising-like with perpendicular easy-axes, favouring the decoupling of neighbouring zig-zag chains. No long range order is observed down to T = 60 mK in zero field but diffuse neutron scattering indicates short range correlations that are consistent with those of the 1D Ising zig-zag chain model. AC susceptibility measurements indicate a slowing down of the fluctuations at low temperatures. We attribute this behaviour to the domain walls in the zig-zag chains. Experimental evidence of a dimensionality crossover at low temperatures in SrDy2O4 suggest that the domains walls are trapped because of interchain interactions, precluding long-range order to the lowest temperatures.

Long Range Technology Planning.

ERIC Educational Resources Information Center

Ambron, Sueann, Ed.

1986-01-01

This summary of a meeting of the Apple Education Advisory Council, on long range technology plans at the state, county, district, and school levels, includes highlights from group discussions on future planning, staff development, and curriculum. Three long range technology plans at the state level are provided: Long Range Educational Technology…

Long-Range Rapidity Correlations in Heavy-Light Ion Collisions

NASA Astrophysics Data System (ADS)

Kovchegov, Yuri; Wertepny, Douglas

2013-04-01

We study two-particle long-range rapidity correlations arising in the early stages of heavy ion collisions in the saturation/Color Glass Condensate framework, assuming for simplicity that one colliding nucleus is much larger than the other. We calculate the two-gluon production cross section while including all-order saturation effects in the heavy nucleus with the lowest-order rescattering in the lighter nucleus. We find four types of correlations in the two-gluon production cross section: (i) geometric correlations, (ii) HBT correlations, (iii) back-to-back correlations, and (iv) near-side azimuthal correlations which are long-range in rapidity. The geometric correlations (i) are due to the fact that nucleons are correlated by simply being confined within the same nucleus and may lead to long-range rapidity correlations for the produced particles without strong azimuthal angle dependence. Somewhat surprisingly, long-range rapidity correlations (iii) and (iv) have exactly the same amplitudes along with azimuthal and rapidity shapes: one centered around δφ=π with the other one centered around δφ=0 (here δφ is the azimuthal angle between the two produced gluons). This prediction is in agreement with the recent ALICE p+Pb data.

Memory and long-range correlations in chess games

NASA Astrophysics Data System (ADS)

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

2014-01-01

In this paper we report the existence of long-range memory in the opening moves of a chronologically ordered set of chess games using an extensive chess database. We used two mapping rules to build discrete time series and analyzed them using two methods for detecting long-range correlations; rescaled range analysis and detrended fluctuation analysis. We found that long-range memory is related to the level of the players. When the database is filtered according to player levels we found differences in the persistence of the different subsets. For high level players, correlations are stronger at long time scales; whereas in intermediate and low level players they reach the maximum value at shorter time scales. This can be interpreted as a signature of the different strategies used by players with different levels of expertise. These results are robust against the assignation rules and the method employed in the analysis of the time series.

Look Ahead: Long-Range Learning Plans

ERIC Educational Resources Information Center

Weinstein, Margery

2010-01-01

Faced with an unsteady economy and fluctuating learning needs, planning a learning strategy designed to last longer than the next six months can be a tall order. But a long-range learning plan can provide a road map for success. In this article, four companies (KPMG LLP, CarMax, DPR Construction, and EMC Corp.) describe their learning plans, and…

One-dimensional long-range percolation: A numerical study

NASA Astrophysics Data System (ADS)

Gori, G.; Michelangeli, M.; Defenu, N.; Trombettoni, A.

2017-07-01

In this paper we study bond percolation on a one-dimensional chain with power-law bond probability C /rd +σ , where r is the distance length between distinct sites and d =1 . We introduce and test an order-N Monte Carlo algorithm and we determine as a function of σ the critical value Cc at which percolation occurs. The critical exponents in the range 0 <σ <1 are reported. Our analysis is in agreement, up to a numerical precision ≈10-3 , with the mean-field result for the anomalous dimension η =2 -σ , showing that there is no correction to η due to correlation effects. The obtained values for Cc are compared with a known exact bound, while the critical exponent ν is compared with results from mean-field theory, from an expansion around the point σ =1 and from the ɛ -expansion used with the introduction of a suitably defined effective dimension deff relating the long-range model with a short-range one in dimension deff. We finally present a formulation of our algorithm for bond percolation on general graphs, with order N efficiency on a large class of graphs including short-range percolation and translationally invariant long-range models in any spatial dimension d with σ >0 .

Towards Long-Range RNA Structure Prediction in Eukaryotic Genes.

PubMed

Pervouchine, Dmitri D

2018-06-15

The ability to form an intramolecular structure plays a fundamental role in eukaryotic RNA biogenesis. Proximate regions in the primary transcripts fold into a local secondary structure, which is then hierarchically assembled into a tertiary structure that is stabilized by RNA-binding proteins and long-range intramolecular base pairings. While the local RNA structure can be predicted reasonably well for short sequences, long-range structure at the scale of eukaryotic genes remains problematic from the computational standpoint. The aim of this review is to list functional examples of long-range RNA structures, to summarize current comparative methods of structure prediction, and to highlight their advances and limitations in the context of long-range RNA structures. Most comparative methods implement the “first-align-then-fold” principle, i.e., they operate on multiple sequence alignments, while functional RNA structures often reside in non-conserved parts of the primary transcripts. The opposite “first-fold-then-align” approach is currently explored to a much lesser extent. Developing novel methods in both directions will improve the performance of comparative RNA structure analysis and help discover novel long-range structures, their higher-order organization, and RNA⁻RNA interactions across the transcriptome.

Long-range electron tunneling.

PubMed

Winkler, Jay R; Gray, Harry B

2014-02-26

Electrons have so little mass that in less than a second they can tunnel through potential energy barriers that are several electron-volts high and several nanometers wide. Electron tunneling is a critical functional element in a broad spectrum of applications, ranging from semiconductor diodes to the photosynthetic and respiratory charge transport chains. Prior to the 1970s, chemists generally believed that reactants had to collide in order to effect a transformation. Experimental demonstrations that electrons can transfer between reactants separated by several nanometers led to a revision of the chemical reaction paradigm. Experimental investigations of electron exchange between redox partners separated by molecular bridges have elucidated many fundamental properties of these reactions, particularly the variation of rate constants with distance. Theoretical work has provided critical insights into the superexchange mechanism of electronic coupling between distant redox centers. Kinetics measurements have shown that electrons can tunnel about 2.5 nm through proteins on biologically relevant time scales. Longer-distance biological charge flow requires multiple electron tunneling steps through chains of redox cofactors. The range of phenomena that depends on long-range electron tunneling continues to expand, providing new challenges for both theory and experiment.

Copulas and time series with long-ranged dependencies.

PubMed

Chicheportiche, Rémy; Chakraborti, Anirban

2014-04-01

We review ideas on temporal dependencies and recurrences in discrete time series from several areas of natural and social sciences. We revisit existing studies and redefine the relevant observables in the language of copulas (joint laws of the ranks). We propose that copulas provide an appropriate mathematical framework to study nonlinear time dependencies and related concepts-like aftershocks, Omori law, recurrences, and waiting times. We also critically argue, using this global approach, that previous phenomenological attempts involving only a long-ranged autocorrelation function lacked complexity in that they were essentially monoscale.

Long-Range Big Quantum-Data Transmission.

PubMed

Zwerger, M; Pirker, A; Dunjko, V; Briegel, H J; Dür, W

2018-01-19

We introduce an alternative type of quantum repeater for long-range quantum communication with improved scaling with the distance. We show that by employing hashing, a deterministic entanglement distillation protocol with one-way communication, one obtains a scalable scheme that allows one to reach arbitrary distances, with constant overhead in resources per repeater station, and ultrahigh rates. In practical terms, we show that, also with moderate resources of a few hundred qubits at each repeater station, one can reach intercontinental distances. At the same time, a measurement-based implementation allows one to tolerate high loss but also operational and memory errors of the order of several percent per qubit. This opens the way for long-distance communication of big quantum data.

Long-Range Big Quantum-Data Transmission

NASA Astrophysics Data System (ADS)

Zwerger, M.; Pirker, A.; Dunjko, V.; Briegel, H. J.; Dür, W.

2018-01-01

We introduce an alternative type of quantum repeater for long-range quantum communication with improved scaling with the distance. We show that by employing hashing, a deterministic entanglement distillation protocol with one-way communication, one obtains a scalable scheme that allows one to reach arbitrary distances, with constant overhead in resources per repeater station, and ultrahigh rates. In practical terms, we show that, also with moderate resources of a few hundred qubits at each repeater station, one can reach intercontinental distances. At the same time, a measurement-based implementation allows one to tolerate high loss but also operational and memory errors of the order of several percent per qubit. This opens the way for long-distance communication of big quantum data.

Two-Step Cycle for Producing Multiple Anodic Aluminum Oxide (AAO) Films with Increasing Long-Range Order

PubMed Central

2017-01-01

Nanoporous anodic aluminum oxide (AAO) membranes are being used for an increasing number of applications. However, the original two-step anodization method in which the first anodization is sacrificial to pre-pattern the second is still widely used to produce them. This method provides relatively low throughput and material utilization as half of the films are discarded. An alternative scheme that relies on alternating anodization and cathodic delamination is demonstrated that allows for the fabrication of several AAO films with only one sacrificial layer thus greatly improving total aluminum to alumina yield. The thickness for which the cathodic delamination performs best to yield full, unbroken AAO sheets is around 85 μm. Additionally, an image analysis method is used to quantify the degree of long-range ordering of the unit cells in the AAO films which was found to increase with each successive iteration of the fabrication cycle. PMID:28630684

Two-Step Cycle for Producing Multiple Anodic Aluminum Oxide (AAO) Films with Increasing Long-Range Order.

PubMed

Choudhary, Eric; Szalai, Veronika

2016-01-01

Nanoporous anodic aluminum oxide (AAO) membranes are being used for an increasing number of applications. However, the original two-step anodization method in which the first anodization is sacrificial to pre-pattern the second is still widely used to produce them. This method provides relatively low throughput and material utilization as half of the films are discarded. An alternative scheme that relies on alternating anodization and cathodic delamination is demonstrated that allows for the fabrication of several AAO films with only one sacrificial layer thus greatly improving total aluminum to alumina yield. The thickness for which the cathodic delamination performs best to yield full, unbroken AAO sheets is around 85 μm. Additionally, an image analysis method is used to quantify the degree of long-range ordering of the unit cells in the AAO films which was found to increase with each successive iteration of the fabrication cycle.

Absence of magnetic long-range order in Y2CrSbO7 : Bond-disorder-induced magnetic frustration in a ferromagnetic pyrochlore

NASA Astrophysics Data System (ADS)

Shen, L.; Greaves, C.; Riyat, R.; Hansen, T. C.; Blackburn, E.

2017-09-01

The consequences of random nonmagnetic-ion dilution for the pyrochlore family Y2(M 1 -xN x)2O7 (M = magnetic ion, N = nonmagnetic ion) have been investigated. As a first step, we experimentally examine the magnetic properties of Y2CrSbO7 (x =0.5 ), in which the magnetic sites (Cr3 +) are percolative. Although the effective Cr-Cr spin exchange is ferromagnetic, as evidenced by a positive Curie-Weiss temperature, ΘCW ≃19.5 K , our high-resolution neutron powder diffraction measurements detect no sign of magnetic long-range order down to 2 K. In order to understand our observations, we construct a lattice model to numerically study the bond disorder introduced by the ionic size mismatch between M and N , which reveals that the bond disorder percolates at xb ≃0.23 , explaining the absence of magnetic long-range order. This model could be applied to a series of frustrated magnets with a pyrochlore sublattice, for example, the spinel compound Zn (Cr1 -xGax )2O4 , wherein a Néel to spin glass phase transition occurs between x =0.2 and 0.25 [Lee et al., Phys. Rev. B 77, 014405 (2008), 10.1103/PhysRevB.77.014405]. Our study stresses the non-negligible role of bond disorder on magnetic frustration, even in ferromagnets.

Optically Tunable Chiral Plasmonic Guest-Host Cellulose Films Weaved with Long-range Ordered Silver Nanowires.

PubMed

Chu, Guang; Wang, Xuesi; Chen, Tianrui; Gao, Jianxiong; Gai, Fangyuan; Wang, Yu; Xu, Yan

2015-06-10

Plasmonic materials with large chiroptical activity at visible wavelength have attracted considerable attention due to their potential applications in metamaterials. Here we demonstrate a novel guest-host chiral nematic liquid crystal film composed of bulk self-co-assembly of the dispersed plasmonic silver nanowires (AgNWs) and cellulose nanocrystals (CNCs). The AgNWs-CNCs composite films show strong plasmonic optical activities, that are dependent on the chiral photonic properties of the CNCs host medium and orientation of the guest AgNWs. Tunable chiral distribution of the aligned anisotropic AgNWs with long-range order is obtained through the CNCs liquid crystal mediated realignment. The chiral plasmonic optical activity of the AgNWs-CNCs composite films can be tuned by changing the interparticle electrostatic repulsion between the CNCs nanorods and AgNWs. We also observe an electromagnetic energy transfer phenomena among the plasmonic bands of AgNWs, due to the modulation of the photonic band gap of the CNCs host matrix. This facile approach for fabricating chiral macrostructured plasmonic materials with optically tunable property is of interest for a variety of advanced optics applications.

Medium range order in aluminum-based metallic glasses

NASA Astrophysics Data System (ADS)

Yi, Feng

2011-12-01

Medium range order (MRO) is the structure order existing between the short range order and long range order in amorphous materials. Fluctuation electron microscopy (FEM) is an effective method to quantify MRO. The FEM signal depends on several effects. In this thesis, I will show how the probe coherence, sample thickness and energy filter affect the FEM signal. We have found that microalloying in Al-based glass has dramatic effect on the primary crystallization temperature and nanocrystal density after annealing treatment. FEM alone cannot uncover the details of MRO in these alloys. Therefore, I resort to modeling to solve the relationship between the variance signal and MRO structure. I improved Stratton and Voyles's analytical model. I also did computer simulation. I explored the effects of thermal disorder and hydrostatic strain on the variance. The extracted size d and volume fraction phi in Al88Y7Fe5, Al88Y6Fe 5Cu1 and Al87Y7Fe5Cu 1 as-spun samples reveals the relationship between MRO in as-quenched sample and thermal behaviors in these alloys. I also did FEM experiments in relaxed Al88Y7Fe 5 samples at various annealing times. MRO structure in these samples does not change. FEM was also done on Al87Y7Fe5Cu 1 to check MRO variation during transient nucleation period. The extracted (d, phi) based on combination of experimental data and simulation shows how MRO changes during this period.

Short-range order in the quantum XXZ honeycomb lattice material BaCo2(PO4)2

NASA Astrophysics Data System (ADS)

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.

Vermont long range transportation plan

DOT National Transportation Integrated Search

2002-01-01

Vermont Agency of Transportation (VTrans) conducted this update of the Long-Range Transportation Plan to review and revise the recommendations of the Long-Range Transportation Plan of 1995. The three objectives from the previous plan were further ref...

Long-range interactions in magnetic bilayer above the critical temperature

NASA Astrophysics Data System (ADS)

de Souza, R. M. V.; Pereira, T. A. S.; Godoy, M.; de Arruda, A. S.

2018-01-01

In this paper we have studied the stabilization of the long-range order in (z ; x) -plane of two isotropic Heisenberg ferromagnetic monolayers coupled by a short-range exchange interaction (J⊥), by a long range dipole-dipole interactions and a magnetic field. We have applied a magnetic field along of the z-direction to study the thermodynamic properties above the critical temperature. The dispersion relation ω and the magnetization are given as function of dipolar anisotropy parameter defined as Ed =(gμ) 2 S /a3J∥ and for other Hamiltonian parameters, and they are calculated by the double-time Zubarev-Tyablikov Green's functions in the random-phase approximation (RPA). The results show that the system is unstable for values of Ed ≥ 0.012 with external magnetic field ranging between H /J∥ = 0 and 10-3. The instability appears for Ed larger then Edc = 0.0158 with H /J∥ = 10-5, Edc = 0.02885 with H /J∥ = 10-4, and Edc = 0.115 with H /J∥ = 10-3, i.e., a small magnetic field is sufficient to maintain the magnetic order in a greater range of the dipolar interaction.

Simultaneous occurrence of multiferroism and short-range magnetic order in DyFeO 3

DOE PAGES

Wang, Jinchen; Liu, Juanjuan; Sheng, Jieming; ...

2016-04-06

In this paper, we present a combined neutron scattering and magnetization study on the multiferroic DyFeO 3, which shows a very strong magnetoelectric effect. Applying magnetic field along the c axis, the weak ferromagnetic order of the Fe ions is quickly recovered from a spin reorientation transition, and the long-range antiferromagnetic order of Dy becomes a short-range one. We found that the short-range order concurs with the multiferroic phase and is responsible for its sizable hysteresis. In conclusion, our H-T phase diagram suggests that the strong magnetoelectric effect in DyFeO 3 has to be understood with not only the weakmore » ferromagnetism of Fe but also the short-range antiferromagnetic order of Dy.« less

First Test of Long-Range Collisional Drag via Plasma Wave Damping

NASA Astrophysics Data System (ADS)

Affolter, Matthew

2017-10-01

In magnetized plasmas, the rate of particle collisions is enhanced over classical predictions when the cyclotron radius rc is less than the Debye length λD. Classical theories describe local velocity scattering collisions with impact parameters ρ long-range collisions exchange energy and momentum over the range rc < ρ <λD with negligible parallel-perpendicular velocity scattering. Previous experiments and theory have shown that these long-range collisions enhance cross-field diffusion, heat transport, and viscosity by orders of magnitude over classical predictions. Here, we present the first experimental confirmation of a new theory, which predicts enhanced parallel velocity slowing due to these long-range collisions. These experiments measure the damping of Trivelpiece-Gould waves in a multispecies pure ion plasma. The damping is dominated by interspecies collisional drag when Landau damping is weak. In this ``drag damping'' regime, the measured damping rates exceed classical predictions of collisional drag damping by as much as an order of magnitude, but agree with the new long-range enhanced collision theory. The enhanced slowing is most significant for strong magnetization and low temperatures. For example, the slowing of anti-protons at a density of 107 cm-3 and a temperature of 10 K in a 6 T trap is enhanced by a factor of 30. Supported by NSF Grant PHY-1414570 and DOE Grant DE-SC0002451. In collaboration with F. Anderegg, D.H.E. Dubin, and C.F. Driscoll.

The effect of long-range order on the elastic properties of Cu3Au

NASA Astrophysics Data System (ADS)

Wang, Gui-Sheng; Krisztina Delczeg-Czirjak, Erna; Hu, Qing-Miao; Kokko, Kalevi; Johansson, Börje; Vitos, Levente

2013-02-01

Ab initio calculations, based on the exact muffin-tin orbitals method are used to determine the elastic properties of Cu-Au alloys with Au/Cu ratio 1/3. The compositional disorder is treated within the coherent potential approximation. The lattice parameters and single-crystal elastic constants are calculated for different partially ordered structures ranging from the fully ordered L12 to the random face centered cubic lattice. It is shown that the theoretical elastic constants follow a clear trend with the degree of chemical order: namely, C11 and C12 decrease, whereas C44 remains nearly constant with increasing disorder. The present results are in line with the experimental findings that the impact of the chemical ordering on the fundamental elastic parameters is close to the resolution of the available experimental and theoretical tools.

Long Range Plan, 1991-1994.

ERIC Educational Resources Information Center

Pennsylvania Coll. of Technology, Williamsport.

This long-range plan for the Pennsylvania College of Technology (PCT) is divided into three main sections. Part I provides an overview of planning at PCT, including a definition of long-range planning, the college philosophy, mission, and vision statements, major institutional initiatives for 1991-92, and accreditation agency recommendations…

Long Range Plan, 1997-2000.

ERIC Educational Resources Information Center

Pennsylvania Coll. of Technology, Williamsport. Office of Strategic Planning and Research.

At Pennsylvania College of Technology (PCT), long range planning is used to define institutional philosophy and mission and determine strategies to make the best use of available resources and implement actions to fulfill institutional mission. This document presents PCT's long-range plan for 1997-2000 in three parts. The first part describes long…

Long-range magnetic order and interchain interactions in the S = 2 chain system MnCl 3 (bpy)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fishman, Randy S.; Shinozaki, Shin-ichi; Okutani, Akira

Here,more » a compound with very weakly interacting chains, MnCl 3(bpy), has attracted a great deal of attention as a possible S = 2 Haldane chain. However, long-range magnetic order of the chains prevents the Haldane gap from developing below 11.5 K. Based on a four-sublattice model, a description of the antiferromagnetic resonance (AFMR) spectrum up to frequencies of 1.5 THz and magnetic fields up to 50 T indicates that the interchain coupling is indeed quite small but that the Dzaloshinskii-Moriya interaction produced by broken inversion symmetry is substantial (0.12 meV). In addition, the antiferromagnetic, nearest-neighbor interaction within each chain (3.3 meV) is significantly stronger than previously reported. The excitation spectrum of this S = 2 compound is well described by a 1/S expansion about the classical limit.« less

Long-range magnetic order and interchain interactions in the S = 2 chain system MnCl 3 (bpy)

DOE PAGES

Fishman, Randy S.; Shinozaki, Shin-ichi; Okutani, Akira; ...

2016-09-28

Here,more » a compound with very weakly interacting chains, MnCl 3(bpy), has attracted a great deal of attention as a possible S = 2 Haldane chain. However, long-range magnetic order of the chains prevents the Haldane gap from developing below 11.5 K. Based on a four-sublattice model, a description of the antiferromagnetic resonance (AFMR) spectrum up to frequencies of 1.5 THz and magnetic fields up to 50 T indicates that the interchain coupling is indeed quite small but that the Dzaloshinskii-Moriya interaction produced by broken inversion symmetry is substantial (0.12 meV). In addition, the antiferromagnetic, nearest-neighbor interaction within each chain (3.3 meV) is significantly stronger than previously reported. The excitation spectrum of this S = 2 compound is well described by a 1/S expansion about the classical limit.« less

Short-range order in the quantum XXZ honeycomb lattice material BaCo 2 ( PO 4 ) 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nair, Harikrishnan S.; Brown, J; Coldren, E.

In this paper, we present observations of highly frustrated quasi-two-dimensional (2D) magnetic correlations in the honeycomb lattice layers of the S eff =1/2 compound γ-BaCo 2(PO 4) 2 (γ-BCPO). Specific heat shows a broad peak comprised of two weak kink features at T N1~6 K and T N2~3.5 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 T N1 and T N2, at which two separate, incompatible, short range magnetic orders onset: commensurate antiferromagnetic correlations with correlation length ξ c=60±2 Å (T N1) andmore » in quasi-2D helical domains with ξ h=350±11 Å (T N2). 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 J 1-J 2-J 3 model with ferromagnetic nearest-neighbor exchange J 1 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. Finally, these data show that γ-BCPO is a rare highly frustrated, quasi-2D S eff =1/2 honeycomb lattice material which resists long range magnetic order and spin freezing.« less

Short-range order in the quantum XXZ honeycomb lattice material BaCo 2 ( PO 4 ) 2

DOE PAGES

Nair, Harikrishnan S.; Brown, J; Coldren, E.; ...

2018-04-12

In this paper, we present observations of highly frustrated quasi-two-dimensional (2D) magnetic correlations in the honeycomb lattice layers of the S eff =1/2 compound γ-BaCo 2(PO 4) 2 (γ-BCPO). Specific heat shows a broad peak comprised of two weak kink features at T N1~6 K and T N2~3.5 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 T N1 and T N2, at which two separate, incompatible, short range magnetic orders onset: commensurate antiferromagnetic correlations with correlation length ξ c=60±2 Å (T N1) andmore » in quasi-2D helical domains with ξ h=350±11 Å (T N2). 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 J 1-J 2-J 3 model with ferromagnetic nearest-neighbor exchange J 1 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. Finally, these data show that γ-BCPO is a rare highly frustrated, quasi-2D S eff =1/2 honeycomb lattice material which resists long range magnetic order and spin freezing.« less

Order-splitting and long-memory in an order-driven market

NASA Astrophysics Data System (ADS)

Yamamoto, R.; LeBaron, B.

2010-01-01

Recent empirical research has documented long-memories of trading volume, volatility, and order-signs in stock markets. We conjecture that traders' order-splitting is related to these empirical features. This study conducts simulations on an order-driven economy where agents split their orders into small pieces and execute piece by piece to reduce price impact. We demonstrate that we can replicate the long-memories in our order-splitting economy and conclude that order-splitting can be a possible cause for these empirical properties.

Quantum-state transfer through long-range correlated disordered channels

NASA Astrophysics Data System (ADS)

Almeida, Guilherme M. A.; de Moura, Francisco A. B. F.; Lyra, Marcelo L.

2018-05-01

We study quantum-state transfer in XX spin-1/2 chains where both communicating spins are weakly coupled to a channel featuring disordered on-site magnetic fields. Fluctuations are modeled by long-range correlated sequences with self-similar profile obeying a power-law spectrum. We show that the channel is able to perform almost perfect quantum-state transmissions even in the presence of significant amounts of disorder provided the degree of those correlations is strong enough, with the cost of having long transfer times and unavoidable timing errors. Still, we show that the lack of mirror symmetry in the channel does not affect much the likelihood of having high-quality outcomes. Our results suggest that coexistence between localized and delocalized states can diminish effects of static perturbations in solid-state devices for quantum communication.

Long Range Plan: 1992-1995.

ERIC Educational Resources Information Center

Pennsylvania Coll. of Technology, Williamsport.

Intended to enhance strategic planning and enable staff to work as a team toward a shared vision and common goals, this report presents the 1992-95 long-range plan of the Pennsylvania College of Technology (PCT). Part I defines long-range planning; describes the structure and use of the plan at PCT; presents PCT's philosophy, mission, and vision…

The interplay of long-range magnetic order and single-ion anisotropy in rare earth nickel germanides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Islam, Z.

1999-05-10

This dissertation is concerned with the interplay of long-range order and anisotropy in the tetragonal RNi{sub 2}Ge{sub 2} (R = rare earth) family of compounds. Microscopic magnetic structures were studied using both neutron and x-ray resonant exchange scattering (XRES) techniques. The magnetic structures of Tb, Dy, Eu and Gd members have been determined using high-quality single-crystal samples. This work has correlated a strong Fermi surface nesting to the magnetic ordering in the RNi{sub 2}Ge{sub 2} compounds. Generalized susceptibility, {chi}{sub 0}(q), calculations found nesting to be responsible for both incommensurate ordering wave vector in GdNi{sub 2}Ge{sub 2}, and the commensurate structuremore » in EuNi{sub 2}Ge{sub 2}. A continuous transition from incommensurate to commensurate magnetic structures via band filling is predicted. The surprisingly higher T{sub N} in EuNi{sub 2}Ge{sub 2} than that in GdNi{sub 2}Ge{sub 2} is also explained. Next, all the metamagnetic phases in TbNi{sub 2}Ge{sub 2} with an applied field along the c axis have been characterized with neutron diffraction measurements. A mixed phase model for the first metamagnetic structure consisting of fully-saturated as well as reduced-moment Tb ions is presented. The moment reduction may be due to moment instability which is possible if the exchange is comparable to the low-lying CEF level splitting and the ground state is a singlet. In such a case, certain Tb sites may experience a local field below the critical value needed to reach saturation.« less

Optimizing long-range order, band gap, and group velocities for graphene on close-packed metal surfaces.

PubMed

Natterer, F D; Rusponi, S; Papagno, M; Carbone, C; Brune, H

2012-08-08

We compare different growth methods with the aim of optimizing the long-range order of a graphene layer grown on Ru(0001). Combining chemical vapor deposition with carbon loading and segregation of the surface layer leads to autocorrelation lengths of 240 Å. We present several routes to band gap and charge carrier mobility engineering for the example of graphene on Ir(111). Ir cluster superlattices self-assembled onto the graphene moiré pattern produce a strong renormalization of the electron group velocity close to the Dirac point, leading to highly anisotropic Dirac cones and the enlargement of the gap from 140 to 340 meV. This gap can further be enhanced to 740 meV by Na co-adsorption onto the Ir cluster superlattice at room temperature. This value is close to that of Ge, and the high group velocity of the charge carriers is fully preserved. We also present data for Na adsorbed without the Ir clusters. In both cases we find that the Na is on top of the graphene layer.

Two modes of longe-range orientation of DNA bases realized upon compaction.

PubMed Central

Yevdokimov YuM; Salyanov, V I; Berg, H

1981-01-01

Formation of compact particles from linear DNA-anthracycline complexes is accompanied by appearance of intense bands in the CD spectra in the region of absorption of DNA bases (UV-region) and in the region of absorption of anthracycline chromophores (visible region). The intense (positive or negative) bands in the region of anthracycline absorption demonstrate an ordered helical location of anthracycline molecules on the DNA template. This fact, in its turn, is related to formation of the DNA superstructure in PEG-containing water-salt solutions with a long-range orientation of nitrogen bases. Possible types of DNA superstructures and the relation between the local- and the long-range order of bases in the DNA superstructure are discussed. PMID:6938929

Improving Limits on Exotic Spin Dependent Long Range Forces using Double Boson Exchange

NASA Astrophysics Data System (ADS)

Aldaihan, Sheakha; Snow, William Michael; Krause, Dennis; Long, Joshua

2016-03-01

The existence of very light weakly interacting particles that mediate new long range forces has been suggested in many extensions of the Standard Model. Such particles span a length scale between a μm and a few meters and include axions, familons, Majorons,and arions. Parameterizations of forces in this range show that they are composite-dependent, have a Yukawa shape, and have both spin-dependent as well as spin independent components. Very stringent limits on spin-independent couplings exist. For long range spin dependent forces, limits are weaker by 20 orders of magnitude compared to their spin independent analogs. The disparity in the limits raises the question of whether interesting limits on spin dependent couplings can be inferred from spin independent searches for long range forces. We show that this is possible using higher order contributions corresponding to double boson exchange and report the limits placed on spin dependent couplings using this method. We gratefully acknowledge the support of Indiana University and the National Science Foundation. The first author also acknowdges King Abdullah scholarship program.

The evolution from long-range magnetic order to spin-glass behaviour in PrAu2(Si1- xGex)2

NASA Astrophysics Data System (ADS)

Krimmel, A.; Hemberger, J.; Kegler, C.; Nicklas, M.; Engelmayer, A.; Knebel, G.; Fritsch, V.; Reehuis, M.; Brando, M.; Loidl, A.

1999-09-01

We have studied the magnetic behaviour of PrAu2(Si1-xGex)2 by means of magnetic susceptibility, resistivity, and heat capacity measurements, and x-ray and neutron powder diffraction. All compounds are isostructural and crystallize in the well known ThCr2Si2-type structure. PrAu2Si2 shows the characteristic features of a canonical spin glass with a freezing temperature of TF = 3 K. Completely unexpectedly, on introducing/increasing the atomic disorder by alloying with Ge, the spin-glass transition is suppressed as is first evident from a slight decrease of the freezing temperature TF up to x = 0.10. Long-range magnetic order sets in for xicons/Journals/Common/ge" ALT="ge" ALIGN="TOP"/>0.12. Within the range 0.15icons/Journals/Common/le" ALT="le" ALIGN="TOP"/> xicons/Journals/Common/le" ALT="le" ALIGN="TOP"/>1, all compounds show the same simple AF-I-type antiferromagnetic structure with a monotonic increase of both the Néel temperature and the ordered magnetic moment for increasing Ge concentration. The magnetic phase diagram of PrAu2(Si1-xGex)2 is explained by the presence of weak disorder at a constant level at the Au sites. Clear indications of crystal-field effects have been observed.

Temperature-modulated annealing of c-plane sapphire for long-range-ordered atomic steps

NASA Astrophysics Data System (ADS)

Yatsui, Takashi; Kuribara, Kazunori; Sekitani, Tsuyoshi; Someya, Takao; Yoshimoto, Mamoru

2016-03-01

High-quality single-crystalline sapphire is used to prepare various semiconductors because of its thermal stability. Here, we applied the tempering technique, which is well known in the production of chocolate, to prepare a sapphire substrate. Surprisingly, we successfully realised millimetre-range ordering of the atomic step of the sapphire substrate. We also obtained a sapphire atomic step with nanometre-scale uniformity in the terrace width and atomic-step height. Such sapphire substrates will find applications in the preparation of various semiconductors and devices.

Probing the role of long-range interactions in the dynamics of a long-range Kitaev chain

NASA Astrophysics Data System (ADS)

Dutta, Anirban; Dutta, Amit

2017-09-01

We study the role of long-range interactions (more precisely, the long-range superconducting gap term) on the nonequilibrium dynamics considering a long-range p -wave superconducting chain in which the superconducting term decays with distance between two sites in a power-law fashion characterized by an exponent α . We show that the Kibble-Zurek scaling exponent, dictating the power-law decay of the defect density in the final state reached following a slow (in comparison to the time scale associated with the minimum gap in the spectrum of the Hamiltonian) quenching of the chemical potential μ across a quantum critical point, depends nontrivially on the exponent α as long as α <2 ; on the other hand, for α >2 , we find that the exponent saturates to the corresponding well-known value of 1 /2 expected for the short-range model. Furthermore, studying the dynamical quantum phase transitions manifested in the nonanalyticities in the rate function of the return possibility I (t ) in subsequent temporal evolution following a sudden change in μ , we show the existence of a new region; in this region, we find three instants of cusp singularities in I (t ) associated with a single sector of Fisher zeros. Notably, the width of this region shrinks as α increases and vanishes in the limit α →2 , indicating that this special region is an artifact of the long-range nature of the Hamiltonian.

Two-dimensional melting of colloids with long-range attractive interactions.

PubMed

Du, Di; Doxastakis, Manolis; Hilou, Elaa; Biswal, Sibani Lisa

2017-02-22

The solid-liquid melting transition in a two-dimensional (2-D) attractive colloidal system is visualized using superparamagnetic colloids that interact through a long-range isotropic attractive interaction potential, which is induced using a high-frequency rotating magnetic field. Various experiments, supported by Monte Carlo simulations, are carried out over a range of interaction potentials and densities to determine structure factors, Lindermann parameters, and translational and orientational order parameters. The system shows a first-order solid-liquid melting transition. Simulations and experiments suggest that dislocations and disclinations simultaneously unbind during melting. This is in direct contrast with reports of 2-D melting of paramagnetic particles that interact with a repulsive interaction potential.

Heart rate, multiple body temperature, long-range and long-life telemetry system for free-ranging animals

NASA Technical Reports Server (NTRS)

Lund, G. F.; Westbrook, R. M.; Fryer, T. B.

1980-01-01

The design details and rationale for a versatile, long-range, long-life telemetry data acquisition system for heart rates and body temperatures at multiple locations from free-ranging animals are presented. The design comprises an implantable transmitter for short to medium range transmission, a receiver retransmitter collar to be worn for long-range transmission, and a signal conditioner interface circuit to assist in signal discrimination and demodulation of receiver or tape-recorded audio outputs. Implanted electrodes are used to obtain an ECG, from which R-wave characteristics are selected to trigger a short RF pulse. Pulses carrying heart rate information are interrupted periodically by a series of pulse interval modulated RF pulses conveying temperature information sensed at desired locations by thermistors. Pulse duration and pulse sequencing are used to discriminate between heart rate and temperature pulses as well as radio frequency interference. The implanted transmitter may be used alone for medium and short-range tracking, or with a receiver-transmitter collar that employs commercial tracking equipment for transmissions of up to 12 km. A system prototype has been tested on a dog.

The Long-Range Impact of Television.

ERIC Educational Resources Information Center

Comstock, George

Long range effects may be of three varieties: those which are observable in the immediate period subsequent to exposure but are long range because of their continuing repetitive accumulation with each exposure; those which represent the cumulative or delayed impact on individuals of exposure to television; or those which represent the immediate…

Long-range synchrony and emergence of neural reentry

NASA Astrophysics Data System (ADS)

Keren, Hanna; Marom, Shimon

2016-11-01

Neural synchronization across long distances is a functionally important phenomenon in health and disease. In order to access the basis of different modes of long-range synchrony, we monitor spiking activities over centimetre scale in cortical networks and show that the mode of synchrony depends upon a length scale, λ, which is the minimal path that activity should propagate through to find its point of origin ready for reactivation. When λ is larger than the physical dimension of the network, distant neuronal populations operate synchronously, giving rise to irregularly occurring network-wide events that last hundreds of milliseconds to several seconds. In contrast, when λ approaches the dimension of the network, a continuous self-sustained reentry propagation emerges, a regular seizure-like mode that is marked by precise spatiotemporal patterns (‘synfire chains’) and may last many minutes. Termination of a reentry phase is preceded by a decrease of propagation speed to a halt. Stimulation decreases both propagation speed and λ values, which modifies the synchrony mode respectively. The results contribute to the understanding of the origin and termination of different modes of neural synchrony as well as their long-range spatial patterns, while hopefully catering to manipulation of the phenomena in pathological conditions.

Absence of a long-range ordered magnetic ground state in Pr3Rh4Sn13 studied through specific heat and inelastic neutron scattering

NASA Astrophysics Data System (ADS)

Nair, Harikrishnan S.; Ogunbunmi, Michael O.; Ghosh, S. K.; Adroja, D. T.; Koza, M. M.; Guidi, T.; Strydom, A. M.

2018-04-01

Signatures of absence of a long-range ordered magnetic ground state down to 0.36 K are observed in magnetic susceptibility, specific heat, thermal/electrical transport and inelastic neutron scattering data of the quasi-skutterudite compound Pr3Rh4Sn13 which crystallizes in the Yb3Rh4Sn13-type structure with a cage-like network of Sn atoms. In this structure, Pr3+ occupies a lattice site with D 2d point symmetry having a ninefold degeneracy corresponding to J  =  4. The magnetic susceptibility of Pr3Rh4Sn13 shows only a weak temperature dependence below 10 K otherwise remaining paramagnetic-like in the range, 10 K-300 K. From the inelastic neutron scattering intensity of Pr3Rh4Sn13 recorded at different temperatures, we identify excitations at 4.5(7) K, 5.42(6) K, 10.77(5) K, 27.27(5) K, 192.28(4) K and 308.33(3) K through a careful peak analysis. However, no signatures of long-range magnetic order are observed in the neutron data down to 1.5 K, which is also confirmed by the specific heat data down to 0.36 K. A broad Schottky-like peak is recovered for the magnetic part of the specific heat, C 4f, which suggests the role of crystal electric fields of Pr3+ . A crystalline electric field model consisting of 7 levels was applied to C 4f which leads to the estimation of energy levels at 4.48(2) K, 6.94(4) K, 11.23(8) K, 27.01(5) K, 193.12(6) K and 367.30(2) K. The CEF energy levels estimated from the heat capacity analysis are in close agreement with the excitation energies seen in the neutron data. The Sommerfeld coefficient estimated from the analysis of magnetic specific heat is γ = 761(6) mJ K-2 mol-Pr which suggests the formation of heavy itinerant quasi-particles in Pr3Rh4Sn13. Combining inelastic neutron scattering results, analysis of the specific heat data down to 0.36 K, magnetic susceptibility and, electrical and thermal transport, we establish the absence of long-range ordered magnetic ground state in Pr3Rh4Sn13.

An Avoidance Model for Short-Range Order Induced by Soft Repulsions in Systems of Rigid Rods

NASA Astrophysics Data System (ADS)

Han, Jining; Herzfeld, Judith

1996-03-01

The effects of soft repulsions on hard particle systems are calculated using an avoidance model which improves upon the simple mean field approximation. Avoidance reduces, but does not eliminate, the energy due to soft repulsions. On the other hand, it also reduces the configurational entropy. Under suitable conditions, this simple trade-off yields a free energy that is lower than the mean field value. In these cases, the variationally determined avoidance gives an estimate for the short-range positional order induced by soft repulsions. The results indicate little short-range order for isotropically oriented rods. However, for parallel rods, short-range order increases to significant levels as the particle axial ratio increases. The implications for long- range positional ordering are also discussed. In particular, avoidance may explain the smectic ordering of tobacco mosaic virus at volume fractions lower than those necessary for smectic ordering of hard particles.

Work probability distribution for a ferromagnet with long-ranged and short-ranged correlations

NASA Astrophysics Data System (ADS)

Bhattacharjee, J. K.; Kirkpatrick, T. R.; Sengers, J. V.

2018-04-01

Work fluctuations and work probability distributions are fundamentally different in systems with short-ranged versus long-ranged correlations. Specifically, in systems with long-ranged correlations the work distribution is extraordinarily broad compared to systems with short-ranged correlations. This difference profoundly affects the possible applicability of fluctuation theorems like the Jarzynski fluctuation theorem. The Heisenberg ferromagnet, well below its Curie temperature, is a system with long-ranged correlations in very low magnetic fields due to the presence of Goldstone modes. As the magnetic field is increased the correlations gradually become short ranged. Hence, such a ferromagnet is an ideal system for elucidating the changes of the work probability distribution as one goes from a domain with long-ranged correlations to a domain with short-ranged correlations by tuning the magnetic field. A quantitative analysis of this crossover behavior of the work probability distribution and the associated fluctuations is presented.

Thermal conductivity of ternary III-V semiconductor alloys: The role of mass difference and long-range order

NASA Astrophysics Data System (ADS)

Mei, S.; Knezevic, I.

2018-03-01

Thermal transport in bulk ternary III-V arsenide (III-As) semiconductor alloys was investigated using equilibrium molecular dynamics with optimized Albe-Tersoff empirical interatomic potentials. Existing potentials for binary AlAs, GaAs, and InAs were optimized to match experimentally obtained acoustic-phonon dispersions and temperature-dependent thermal conductivity. Calculations of thermal transport in ternary III-Vs commonly employ the virtual-crystal approximation (VCA), where the structure is assumed to be a random alloy and all group-III atoms (cations) are treated as if they have an effective weighted-average mass. Here, we showed that it is critical to treat atomic masses explicitly and that the thermal conductivity obtained with explicit atomic masses differs considerably from the value obtained with the average VCA cation mass. The larger the difference between the cation masses, the poorer the VCA prediction for thermal conductivity. The random-alloy assumption in the VCA is also challenged because X-ray diffraction and transmission electron microscopy show order in InGaAs, InAlAs, and GaAlAs epilayers. We calculated thermal conductivity for three common types of order (CuPt-B, CuAu-I, and triple-period-A) and showed that the experimental results for In0.53Ga0.47As and In0.52Al0.48As, which are lattice matched to the InP substrate, can be reproduced in molecular dynamics simulation with 2% and 8% of random disorder, respectively. Based on our results, thermal transport in ternary III-As alloys appears to be governed by the competition between mass-difference scattering, which is much more pronounced than the VCA suggests, and the long-range order that these alloys support.

Long range transport of colloids in aqueous solutions

NASA Astrophysics Data System (ADS)

Florea, Daniel; Musa, Sami; Huyghe, Jacques M. R. J.; Wyss, Hans M.

2013-03-01

Colloids in aqueous suspensions can experience strong, extremely long range repulsive forces near interfaces such as biological tissues, gels, ion exchange resins or metals. As a result exclusion zones extending over several millimeters can be formed. While this phenomenon has been previously described, a physical understanding of this process is still lacking. This exclusion zone formation is puzzling because the typical forces acting on colloidal particles are limited to much shorter distances and external fields that could drive the particles are absent. Here we study the exclusion zone formation in detail by following the time and distance-dependent forces acting on the particles. We present a simple model that accounts for our experimental data and directly links the exclusion zone formation to an already known physical transport phenomenon. We show that the effect can be tuned by changing the zeta potential of the particles or by varying the species present in the aqueous solution. We thus provide a direct physical explanation for the intriguing exclusion zone formation and we illustrate how this effect can be exploited in a range of industrial applications.

Truncated Long-Range Percolation on Oriented Graphs

NASA Astrophysics Data System (ADS)

van Enter, A. C. D.; de Lima, B. N. B.; Valesin, D.

2016-07-01

We consider different problems within the general theme of long-range percolation on oriented graphs. Our aim is to settle the so-called truncation question, described as follows. We are given probabilities that certain long-range oriented bonds are open; assuming that the sum of these probabilities is infinite, we ask if the probability of percolation is positive when we truncate the graph, disallowing bonds of range above a possibly large but finite threshold. We give some conditions in which the answer is affirmative. We also translate some of our results on oriented percolation to the context of a long-range contact process.

Transient versus long-term strength of the "dry" lower continental crust (Musgrave Ranges, Central Australia)

NASA Astrophysics Data System (ADS)

Mancktelow, Neil; Hawemann, Friedrich; Wex, Sebastian; Pennacchioni, Giorgio; Camacho, Alfredo

2017-04-01

One-dimensional yield strength envelope or "Christmas tree" models for the strength of the continental lithosphere assume homogeneous deformation at constant strain-rate and generally predict that felsic lower crust should be viscous and relatively weak. Over the longer term, distributed flow of this supposedly weak lower crust should tend to flatten any irregularities in the Moho. However, these model predictions are in direct contradiction to observations from the well-exposed lower-crustal Fregon Subdomain in the Musgrave Ranges, Central Australia. This unit underwent dehydrating granulite facies metamorphism during the ca. 1200 Ma Musgravian Orogeny. During the subsequent Petermann Orogeny (ca. 550 Ma), these effectively "dry" rocks were very heterogeneously deformed under sub-eclogitic, lower-crustal conditions (ca. 650°C, 1.2 GPa). Shear zones localized over a wide range of thickness and length scales, from mm to km. Widespread and repeated fracturing and pseudotachylyte generation also occurred during the same deformation event, providing weak and approximately planar precursors on which viscous shear zones subsequently localized. On the lithospheric scale, the present day Moho still preserves an offset on the order of 20 km that was caused by the Petermann Orogeny. Brittle fracturing of dry rocks and related pseudotachylyte formation at pressures of ca. 1.2 GPa imply high differential stresses on the order of 1 GPa, if the Mohr-Coulomb yield criterion is still approximately correct at such high confining pressure. High stresses, at least transiently, are also implied by the observed local fracturing of granulite-facies garnets in the vicinity of pseudotachylytes. However, the stress associated with slower crystal-plastic flow appears to be much less, on the order of 10's of MPa, as indicated by the dynamically recrystallized grain size of quartz. Several other observations also indicate that the long-term viscous strength could not have been maintained at

Singular dynamics and emergence of nonlocality in long-range quantum models

NASA Astrophysics Data System (ADS)

Lepori, L.; Trombettoni, A.; Vodola, D.

2017-03-01

We discuss how nonlocality originates in long-range quantum systems and how it affects their dynamics at and out of equilibrium. We focus in particular on the Kitaev chains with long-range pairings and on the quantum Ising chain with long-range antiferromagnetic coupling (both having a power-law decay with exponent α). By studying the dynamic correlation functions, we find that for every finite α two different behaviours can be identified, one typical of short-range systems and the other connected with locality violation. The latter behaviour is shown related also with the known power-law decay tails previously observed in the static correlation functions, and originated by modes—having in general energies far from the minima of the spectrum—where particular singularities develop as a consequence of the long-rangedness of the system. We refer to these modes as to ‘singular’ modes, and as to ‘singular dynamics’ to their dynamics. For the Kitaev model they are manifest, at finite α, in derivatives of the quasiparticle energy, the order of the derivatives at which the singularity occurs is increasing with α. The features of the singular modes and their physical consequences are clarified by studying an effective theory for them and by a critical comparison of the results from this theory with the lattice ones. Moreover, a numerical study of the effects of the singular modes on the time evolution after various types of global quenches is performed. We finally present and discuss the presence of singular modes and their consequences in interacting long-range systems by investigating in the long-range Ising quantum chain, both in the deep paramagnetic regime and at criticality, where they also play a central role for the breakdown of conformal invariance.

Passive long range acousto-optic sensor

NASA Astrophysics Data System (ADS)

Slater, Dan

2006-08-01

Alexander Graham Bell's photophone of 1880 was a simple free space optical communication device that used the sun to illuminate a reflective acoustic diaphragm. A selenium photocell located 213 m (700 ft) away converted the acoustically modulated light beam back into sound. A variation of the photophone is presented here that uses naturally formed free space acousto-optic communications links to provide passive multichannel long range acoustic sensing. This system, called RAS (remote acoustic sensor), functions as a long range microphone with a demonstrated range in excess of 40 km (25 miles).

Long-range correlation and market segmentation in bond market

NASA Astrophysics Data System (ADS)

Wang, Zhongxing; Yan, Yan; Chen, Xiaosong

2017-09-01

This paper investigates the long-range auto-correlations and cross-correlations in bond market. Based on Detrended Moving Average (DMA) method, empirical results present a clear evidence of long-range persistence that exists in one year scale. The degree of long-range correlation related to maturities has an upward tendency with a peak in short term. These findings confirm the expectations of fractal market hypothesis (FMH). Furthermore, we have developed a method based on a complex network to study the long-range cross-correlation structure and applied it to our data, and found a clear pattern of market segmentation in the long run. We also detected the nature of long-range correlation in the sub-period 2007-2012 and 2011-2016. The result from our research shows that long-range auto-correlations are decreasing in the recent years while long-range cross-correlations are strengthening.

Institutional Long Range Planning.

ERIC Educational Resources Information Center

Caldwell Community Coll. and Technical Inst., Lenoir, NC.

Long-range institutional planning has been in effect at Caldwell Community College and Technical Institute since 1973. The first step in the process was the identification of planning areas: administration, organization, educational programs, learning resources, student services, faculty, facilities, maintenance/operation, and finances. The major…

Nucleation in the presence of long-range interactions. [performed on ferroelectric barium titanate

NASA Technical Reports Server (NTRS)

Chandra, P.

1989-01-01

Unlike droplet nucleation near a liquid-gas critical point, the decay of metastable phases in crystalline materials is strongly affected by the presence of long-range forces. Field quench experiments performed on the ferroelectric barium titanate indicate that nucleation in this material is markedly different from that observed in liquids. In this paper, a theory for nucleation at a first-order phase transition in which the mediating forces are long range is presented. It is found that the long-range force induces cooperative nucleation and growth processes, and that this feedback mechanism produces a well-defined delay time with a sharp onset in the transformation to the stable phase. Closed-form expressions for the characteristic onset time and width of the transition are developed, in good agreement with numerical and experimental results.

Multibin long-range correlations

NASA Astrophysics Data System (ADS)

Bialas, A.; Zalewski, K.

2011-06-01

A new method to study the long-range correlations in multiparticle production is developed. It is proposed to measure the joint factorial moments or cumulants of multiplicity distribution in several (more than two) bins. It is shown that this step dramatically increases the discriminative power of data.

Long-range interaction between heterogeneously charged membranes.

PubMed

Jho, Y S; Brewster, R; Safran, S A; Pincus, P A

2011-04-19

Despite their neutrality, surfaces or membranes with equal amounts of positive and negative charge can exhibit long-range electrostatic interactions if the surface charge is heterogeneous; this can happen when the surface charges form finite-size domain structures. These domains can be formed in lipid membranes where the balance of the different ranges of strong but short-ranged hydrophobic interactions and longer-ranged electrostatic repulsion result in a finite, stable domain size. If the domain size is large enough, oppositely charged domains in two opposing surfaces or membranes can be strongly correlated by the electrostatic interactions; these correlations give rise to an attractive interaction of the two membranes or surfaces over separations on the order of the domain size. We use numerical simulations to demonstrate the existence of strong attractions at separations of tens of nanometers. Large line tensions result in larger domains but also increase the charge density within the domain. This promotes correlations and, as a result, increases the intermembrane attraction. On the other hand, increasing the salt concentration increases both the domain size and degree of domain anticorrelation, but the interactions are ultimately reduced due to increased screening. The result is a decrease in the net attraction as salt concentration is increased. © 2011 American Chemical Society

Entropy and long-range memory in random symbolic additive Markov chains.

PubMed

Melnik, S S; Usatenko, O V

2016-06-01

The goal of this paper is to develop an estimate for the entropy of random symbolic sequences with elements belonging to a finite alphabet. As a plausible model, we use the high-order additive stationary ergodic Markov chain with long-range memory. Supposing that the correlations between random elements of the chain are weak, we express the conditional entropy of the sequence by means of the symbolic pair correlation function. We also examine an algorithm for estimating the conditional entropy of finite symbolic sequences. We show that the entropy contains two contributions, i.e., the correlation and the fluctuation. The obtained analytical results are used for numerical evaluation of the entropy of written English texts and DNA nucleotide sequences. The developed theory opens the way for constructing a more consistent and sophisticated approach to describe the systems with strong short-range and weak long-range memory.

Entropy and long-range memory in random symbolic additive Markov chains

NASA Astrophysics Data System (ADS)

Melnik, S. S.; Usatenko, O. V.

2016-06-01

The goal of this paper is to develop an estimate for the entropy of random symbolic sequences with elements belonging to a finite alphabet. As a plausible model, we use the high-order additive stationary ergodic Markov chain with long-range memory. Supposing that the correlations between random elements of the chain are weak, we express the conditional entropy of the sequence by means of the symbolic pair correlation function. We also examine an algorithm for estimating the conditional entropy of finite symbolic sequences. We show that the entropy contains two contributions, i.e., the correlation and the fluctuation. The obtained analytical results are used for numerical evaluation of the entropy of written English texts and DNA nucleotide sequences. The developed theory opens the way for constructing a more consistent and sophisticated approach to describe the systems with strong short-range and weak long-range memory.

Classical investigation of long-range coherence in biological systems

NASA Astrophysics Data System (ADS)

Preto, Jordane

2016-12-01

Almost five decades ago, H. Fröhlich [H. Fröhlich, "Long-range coherence and energy storage in biological systems," Int. J. Quantum Chem. 2(5), 641-649 (1968)] reported, on a theoretical basis, that the excitation of quantum modes of vibration in contact with a thermal reservoir may lead to steady states, where under high enough rate of energy supply, only specific low-frequency modes of vibration are strongly excited. This nonlinear phenomenon was predicted to occur in biomolecular systems, which are known to exhibit complex vibrational spectral properties, especially in the terahertz frequency domain. However, since the effects of terahertz or lower-frequency modes are mainly classical at physiological temperatures, there are serious doubts that Fröhlich's quantum description can be applied to predict such a coherent behavior in a biological environment, as suggested by the author. In addition, a quantum formalism makes the phenomenon hard to investigate using realistic molecular dynamics simulations (MD) as they are usually based on the classical principles. In the current paper, we provide a general classical Hamiltonian description of a nonlinear open system composed of many degrees of freedom (biomolecular structure) excited by an external energy source. It is shown that a coherent behaviour similar to Fröhlich's effect is to be expected in the classical case for a given range of parameter values. Thus, the supplied energy is not completely thermalized but stored in a highly ordered fashion. The connection between our Hamiltonian description, carried out in the space of normal modes, and a more standard treatment in the physical space is emphasized in order to facilitate the prediction of the effect from MD simulations. It is shown how such a coherent phenomenon may induce long-range resonance effects that could be of critical importance at the biomolecular level. The present work is motivated by recent experimental evidences of long-lived excited low

Arkansas statewide long-range intermodal transportation plan 2007 update

DOT National Transportation Integrated Search

2007-01-01

This Arkansas Statewide Long-Range Intermodal Transportation Plan (2007 Long- Range Plan) is the third long-range plan approved by the Arkansas Highway Commission. The first plan was approved in February 1995 followed by the second document in May 20...

Williamsport Area Community College Long Range Planning: The Long Range Plan, Update 1987.

ERIC Educational Resources Information Center

Williamsport Area Community Coll., PA.

This update to Williamsport Area Community College's (WACC's) 1984-89 long-range plan offers a status report on each of the plan's 78 objectives, reassigns responsibility for specific objectives to make the plan responsive to the current organizational structure of the college, and offers 11 new objectives for the 1986-87 academic year. After…

Spectral long-range interaction of temporal incoherent solitons.

PubMed

Xu, Gang; Garnier, Josselin; Picozzi, Antonio

2014-02-01

We study the interaction of temporal incoherent solitons sustained by a highly noninstantaneous (Raman-like) nonlinear response. The incoherent solitons exhibit a nonmutual interaction, which can be either attractive or repulsive depending on their relative initial distance. The analysis reveals that incoherent solitons exhibit a long-range interaction in frequency space, which is in contrast with the expected spectral short-range interaction described by the usual approach based on the Raman-like spectral gain curve. Both phenomena of anomalous interaction and spectral long-range behavior of incoherent solitons are described in detail by a long-range Vlasov equation.

Absence of Long-Range Order in a Triangular Spin System with Dipolar Interactions

NASA Astrophysics Data System (ADS)

Keleş, Ahmet; Zhao, Erhai

2018-05-01

The antiferromagnetic Heisenberg model on the triangular lattice is perhaps the best known example of frustrated magnets, but it orders at low temperatures. Recent density matrix renormalization group (DMRG) calculations find that the next nearest neighbor interaction J2 enhances the frustration, and it leads to a spin liquid for J2/J1∈(0.08 ,0.15 ). In addition, a DMRG study of a dipolar Heisenberg model with longer range interactions gives evidence for a spin liquid at a small dipole tilting angle θ ∈[0 ,1 0 ° ). In both cases, the putative spin liquid region appears to be small. Here, we show that for the triangular lattice dipolar Heisenberg model, a robust quantum paramagnetic phase exists in a surprisingly wide region, θ ∈[0 ,5 4 ° ) , for dipoles tilted along the lattice diagonal direction. We obtain the phase diagram of the model by functional renormalization group (RG), which treats all magnetic instabilities on equal footing. The quantum paramagnetic phase is characterized by a smooth continuous flow of vertex functions and spin susceptibility down to the lowest RG scale, in contrast to the apparent breakdown of RG flow in phases with stripe or spiral order. Our finding points to a promising direction to search for quantum spin liquids in ultracold dipolar molecules.

Entanglement entropy in the long-range Kitaev chain

NASA Astrophysics Data System (ADS)

Ares, Filiberto; Esteve, José G.; Falceto, Fernando; de Queiroz, Amilcar R.

2018-06-01

In this paper we complete the study on the asymptotic behavior of the entanglement entropy for Kitaev chains with long-range pairing. We discover that when the couplings decay with the distance with a critical exponent new properties for the asymptotic growth of the entropy appear. The coefficient of the leading term is not universal any more and the connection with conformal field theories is lost. We perform a numerical and analytical approach to the problem showing a perfect agreement. In order to carry out the analytical study, a technique for computing the asymptotic behavior of block Toeplitz determinants with discontinuous symbols has been developed.

Long-range energy transport in single supramolecular nanofibres at room temperature

NASA Astrophysics Data System (ADS)

Haedler, Andreas T.; Kreger, Klaus; Issac, Abey; Wittmann, Bernd; Kivala, Milan; Hammer, Natalie; Köhler, Jürgen; Schmidt, Hans-Werner; Hildner, Richard

2015-07-01

Efficient transport of excitation energy over long distances is a key process in light-harvesting systems, as well as in molecular electronics. However, in synthetic disordered organic materials, the exciton diffusion length is typically only around 10 nanometres (refs 4, 5), or about 50 nanometres in exceptional cases, a distance that is largely determined by the probability laws of incoherent exciton hopping. Only for highly ordered organic systems has the transport of excitation energy over macroscopic distances been reported--for example, for triplet excitons in anthracene single crystals at room temperature, as well as along single polydiacetylene chains embedded in their monomer crystalline matrix at cryogenic temperatures (at 10 kelvin, or -263 degrees Celsius). For supramolecular nanostructures, uniaxial long-range transport has not been demonstrated at room temperature. Here we show that individual self-assembled nanofibres with molecular-scale diameter efficiently transport singlet excitons at ambient conditions over more than four micrometres, a distance that is limited only by the fibre length. Our data suggest that this remarkable long-range transport is predominantly coherent. Such coherent long-range transport is achieved by one-dimensional self-assembly of supramolecular building blocks, based on carbonyl-bridged triarylamines, into well defined H-type aggregates (in which individual monomers are aligned cofacially) with substantial electronic interactions. These findings may facilitate the development of organic nanophotonic devices and quantum information technology.

Performance of PHOTONIS' low light level CMOS imaging sensor for long range observation

NASA Astrophysics Data System (ADS)

Bourree, Loig E.

2014-05-01

Identification of potential threats in low-light conditions through imaging is commonly achieved through closed-circuit television (CCTV) and surveillance cameras by combining the extended near infrared (NIR) response (800-10000nm wavelengths) of the imaging sensor with NIR LED or laser illuminators. Consequently, camera systems typically used for purposes of long-range observation often require high-power lasers in order to generate sufficient photons on targets to acquire detailed images at night. While these systems may adequately identify targets at long-range, the NIR illumination needed to achieve such functionality can easily be detected and therefore may not be suitable for covert applications. In order to reduce dependency on supplemental illumination in low-light conditions, the frame rate of the imaging sensors may be reduced to increase the photon integration time and thus improve the signal to noise ratio of the image. However, this may hinder the camera's ability to image moving objects with high fidelity. In order to address these particular drawbacks, PHOTONIS has developed a CMOS imaging sensor (CIS) with a pixel architecture and geometry designed specifically to overcome these issues in low-light level imaging. By combining this CIS with field programmable gate array (FPGA)-based image processing electronics, PHOTONIS has achieved low-read noise imaging with enhanced signal-to-noise ratio at quarter moon illumination, all at standard video frame rates. The performance of this CIS is discussed herein and compared to other commercially available CMOS and CCD for long-range observation applications.

Europium mixed-valence, long-range magnetic order, and dynamic magnetic response in EuCu 2 ( Si x Ge 1 - x ) 2

DOE PAGES

Nemkovski, Krill S.; Kozlenko, D. P.; Alekseev, Pavel A.; ...

2016-11-01

In mixed-valence or heavy-fermion systems, the hybridization between local f orbitals and conduction band states can cause the suppression of long-range magnetic order, which competes with strong spin uctuations. Ce- and Yb-based systems have been found to exhibit fascinating physical properties (heavy-fermion superconductivity, non-Fermi-liquid states, etc.) when tuned to the vicinity of magnetic quantum critical points by use of various external control parameters (temperature, magnetic eld, chemical composition). Recently, similar effects (mixed-valence, Kondo uctuations, heavy Fermi liquid) have been reported to exist in some Eu-based compounds. Unlike Ce (Yb), Eu has a multiple electron (hole) occupancy of its 4f shell,more » and the magnetic Eu 2+ state (4f 7) has no orbital component in the usual LS coupling scheme, which can lead to a quite different and interesting physics. In the EuCu 2(Si xGe 1-x) 2 series, where the valence can be tuned by varying the Si/Ge ratio, it has been reported that a significant valence uctuation can exist even in the magnetic order regime. This paper presents a detailed study of the latter material using different microscopic probes (XANES, Mossbauer spectroscopy, elastic and inelastic neutron scattering), in which the composition dependence of the magnetic order and dynamics across the series is traced back to the change in the Eu valence state. In particular, the results support the persistence of valence uctuations into the antiferromagnetic state over a sizable composition range below the critical Si concentration x c ≈ 0:65. In conclusion, the sequence of magnetic ground states in the series is shown to re ect the evolution of the magnetic spectral response.« less

Nanoporous anodic aluminum oxide with a long-range order and tunable cell sizes by phosphoric acid anodization on pre-patterned substrates

PubMed Central

Surawathanawises, Krissada; Cheng, Xuanhong

2014-01-01

Nanoporous anodic aluminum oxide (AAO) has been explored for various applications due to its regular cell arrangement and relatively easy fabrication processes. However, conventional two-step anodization based on self-organization only allows the fabrication of a few discrete cell sizes and formation of small domains of hexagonally packed pores. Recent efforts to pre-pattern aluminum followed with anodization significantly improve the regularity and available pore geometries in AAO, while systematic study of the anodization condition, especially the impact of acid composition on pore formation guided by nanoindentation is still lacking. In this work, we pre-patterned aluminium thin films using ordered monolayers of silica beads and formed porous AAO in a single-step anodization in phosphoric acid. Controllable cell sizes ranging from 280 nm to 760 nm were obtained, matching the diameters of the silica nanobead molds used. This range of cell size is significantly greater than what has been reported for AAO formed in phosphoric acid in the literature. In addition, the relationships between the acid concentration, cell size, pore size, anodization voltage and film growth rate were studied quantitatively. The results are consistent with the theory of oxide formation through an electrochemical reaction. Not only does this study provide useful operational conditions of nanoindentation induced anodization in phosphoric acid, it also generates significant information for fundamental understanding of AAO formation. PMID:24535886

National long range transportation plan

DOT National Transportation Integrated Search

2017-07-01

The NPS National Long Range Transportation Plan (LRTP) establishes a strategic framework for transportation investment service-wide over the next 20 years. It provides guidance to regional and park unit staff who make transportation investment and ma...

Long-range eye tracking: A feasibility study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jayaweera, S.K.; Lu, Shin-yee

1994-08-24

The design considerations for a long-range Purkinje effects based video tracking system using current technology is presented. Past work, current experiments, and future directions are thoroughly discussed, with an emphasis on digital signal processing techniques and obstacles. It has been determined that while a robust, efficient, long-range, and non-invasive eye tracking system will be difficult to develop, such as a project is indeed feasible.

Position-insensitive long range inductive power transfer

NASA Astrophysics Data System (ADS)

Kwan, Christopher H.; Lawson, James; Yates, David C.; Mitcheson, Paul D.

2014-11-01

This paper presents results of an improved inductive wireless power transfer system for reliable long range powering of sensors with milliwatt-level consumption. An ultra-low power flyback impedance emulator operating in open loop is used to present the optimal load to the receiver's resonant tank. Transmitter power modulation is implemented in order to maintain constant receiver power and to prevent damage to the receiver electronics caused by excessive received voltage. Received power is steady up to 3 m at around 30 mW. The receiver electronics and feedback system consumes 3.1 mW and so with a transmitter input power of 163.3 W the receiver becomes power neutral at 4.75 m. Such an IPT system can provide a reliable alternative to energy harvesters for supplying power concurrently to multiple remote sensors.

Probing New Long-Range Interactions by Isotope Shift Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berengut, Julian C.; Budker, Dmitry; Delaunay, Cédric

We explore a method to probe new long- and intermediate-range interactions using precision atomic isotope shift spectroscopy. We develop a formalism to interpret linear King plots as bounds on new physics with minimal theory inputs. We focus only on bounding the new physics contributions that can be calculated independently of the standard model nuclear effects. We apply our method to existing Ca + data and project its sensitivity to conjectured new bosons with spin-independent couplings to the electron and the neutron using narrow transitions in other atoms and ions, specifically, Sr and Yb. Future measurements are expected to improve themore » relative precision by 5 orders of magnitude, and they can potentially lead to an unprecedented sensitivity for bosons within the 0.3 to 10 MeV mass range.« less

Probing New Long-Range Interactions by Isotope Shift Spectroscopy.

PubMed

Berengut, Julian C; Budker, Dmitry; Delaunay, Cédric; Flambaum, Victor V; Frugiuele, Claudia; Fuchs, Elina; Grojean, Christophe; Harnik, Roni; Ozeri, Roee; Perez, Gilad; Soreq, Yotam

2018-03-02

We explore a method to probe new long- and intermediate-range interactions using precision atomic isotope shift spectroscopy. We develop a formalism to interpret linear King plots as bounds on new physics with minimal theory inputs. We focus only on bounding the new physics contributions that can be calculated independently of the standard model nuclear effects. We apply our method to existing Ca^{+} data and project its sensitivity to conjectured new bosons with spin-independent couplings to the electron and the neutron using narrow transitions in other atoms and ions, specifically, Sr and Yb. Future measurements are expected to improve the relative precision by 5 orders of magnitude, and they can potentially lead to an unprecedented sensitivity for bosons within the 0.3 to 10 MeV mass range.

Probing New Long-Range Interactions by Isotope Shift Spectroscopy

DOE PAGES

Berengut, Julian C.; Budker, Dmitry; Delaunay, Cédric; ...

2018-02-26

We explore a method to probe new long- and intermediate-range interactions using precision atomic isotope shift spectroscopy. We develop a formalism to interpret linear King plots as bounds on new physics with minimal theory inputs. We focus only on bounding the new physics contributions that can be calculated independently of the standard model nuclear effects. We apply our method to existing Ca + data and project its sensitivity to conjectured new bosons with spin-independent couplings to the electron and the neutron using narrow transitions in other atoms and ions, specifically, Sr and Yb. Future measurements are expected to improve themore » relative precision by 5 orders of magnitude, and they can potentially lead to an unprecedented sensitivity for bosons within the 0.3 to 10 MeV mass range.« less

Nonequilibrium Tricritical Point in a System with Long-Range Interactions

NASA Astrophysics Data System (ADS)

Antoniazzi, Andrea; Fanelli, Duccio; Ruffo, Stefano; Yamaguchi, Yoshiyuki Y.

2007-07-01

Systems with long-range interactions display a short-time relaxation towards quasistationary states whose lifetime increases with system size. With reference to the Hamiltonian mean field model, we here show that a maximum entropy principle, based on Lynden-Bell’s pioneering idea of “violent relaxation,” predicts the presence of out-of-equilibrium phase transitions separating the relaxation towards homogeneous (zero magnetization) or inhomogeneous (nonzero magnetization) quasistationary states. When varying the initial condition within a family of “water bags” with different initial magnetization and energy, first- and second-order phase transition lines are found that merge at an out-of-equilibrium tricritical point. Metastability is theoretically predicted and numerically checked around the first-order phase transition line.

The Characteristics of Long-range Transboundary Inorganic Secondary Aerosols in Northeast Asia

NASA Astrophysics Data System (ADS)

Kim, Y. J.; Carmichael, G. R.; Woo, J. H.; Qiang, Z.

2014-12-01

Recurrent particle matter episodes greatly influence air quality in Northeast Asia. According to many studies, a major reason is long-range transport of air pollutant. Large amount of emission of chemical compounds aggravate air pollution in the region. Emitted air pollutants mainly come from industrialized regions along the East China coast. It can be transported over downwind region by the prevailing westerlies. The long-rang transported fine particle certainly attributes to air quality in downwind region, but there are many unknowns on the quantity, transport pattern, and secondary aerosol production mechanism despite the fact with many studies have been performed. Major contributors of PM2.5 are inorganic secondary aerosols, sulfate, nitrate and ammonium, in Korea. Especially high relative contributions of inorganic secondary aerosols appear for westerly wind cases. The main pathway of production of inorganic secondary aerosols is produced by converting from SO2 and NOx during the long-range transport but the contribution varies dramatically depending on season and wind pattern. Sulfate is consistently the primary contributor of PM2.5 still now but we should more concern nitrate because that NOx emissions of China is increasing steeply since 2000 by leading powerplant, industry, and transport, despite downward trend of SO2. In order to better understand regional air quality modeling of the long-range transport, international study, MICS-Asia phase III, has been initiated with many researchers. We will present chemical characteristics of PM2.5 long-range transport during westerly wind cases focused on secondary aerosol, tracking their transport pattern, and production pathway. Results using CMAQ with the modeling domain covering Northeast and Southeast China, Korea, and Japan with 15km resolution will be discussed.

Long-ranged contributions to solvation free energies from theory and short-ranged models

PubMed Central

Remsing, Richard C.; Liu, Shule; Weeks, John D.

2016-01-01

Long-standing problems associated with long-ranged electrostatic interactions have plagued theory and simulation alike. Traditional lattice sum (Ewald-like) treatments of Coulomb interactions add significant overhead to computer simulations and can produce artifacts from spurious interactions between simulation cell images. These subtle issues become particularly apparent when estimating thermodynamic quantities, such as free energies of solvation in charged and polar systems, to which long-ranged Coulomb interactions typically make a large contribution. In this paper, we develop a framework for determining very accurate solvation free energies of systems with long-ranged interactions from models that interact with purely short-ranged potentials. Our approach is generally applicable and can be combined with existing computational and theoretical techniques for estimating solvation thermodynamics. We demonstrate the utility of our approach by examining the hydration thermodynamics of hydrophobic and ionic solutes and the solvation of a large, highly charged colloid that exhibits overcharging, a complex nonlinear electrostatic phenomenon whereby counterions from the solvent effectively overscreen and locally invert the integrated charge of the solvated object. PMID:26929375

On the origin of long-range correlations in texts.

PubMed

Altmann, Eduardo G; Cristadoro, Giampaolo; Esposti, Mirko Degli

2012-07-17

The complexity of human interactions with social and natural phenomena is mirrored in the way we describe our experiences through natural language. In order to retain and convey such a high dimensional information, the statistical properties of our linguistic output has to be highly correlated in time. An example are the robust observations, still largely not understood, of correlations on arbitrary long scales in literary texts. In this paper we explain how long-range correlations flow from highly structured linguistic levels down to the building blocks of a text (words, letters, etc..). By combining calculations and data analysis we show that correlations take form of a bursty sequence of events once we approach the semantically relevant topics of the text. The mechanisms we identify are fairly general and can be equally applied to other hierarchical settings.

The long-range shelling of Paris and physical chemistry problems of extremely long-range firing

NASA Astrophysics Data System (ADS)

Stettbacher, A.

1986-04-01

The 128-km long-range artillery shelling of Paris is discussed considering its physical and chemical make-up from the vantage point of the technology in 1919. It compares this shelling with a hypothetical 240-km shelling and concludes that the most important influence on shelling range distance to be air resistance. The amount of air resistance and the resulting velocity deceleration depend on the air's density and the shell's velocity and configuration.

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

NASA Astrophysics Data System (ADS)

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.

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

PubMed

Beuerle, Matthias; Ochsenfeld, Christian

2017-11-28

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.

Hydrodynamics and long range correlations

NASA Astrophysics Data System (ADS)

Bialas, A.; Zalewski, K.

2011-04-01

It is shown that the recently proposed method of studying the long-range correlations in multiparticle production can be effectively used to verify the hydrodynamic nature of the longitudinal expansion of the partonic system created in the collision. The case of ALICE detector is explicitly considered.

Functional importance of short-range binding and long-range solvent interactions in helical antifreeze peptides.

PubMed

Ebbinghaus, Simon; Meister, Konrad; Prigozhin, Maxim B; Devries, Arthur L; Havenith, Martina; Dzubiella, Joachim; Gruebele, Martin

2012-07-18

Short-range ice binding and long-range solvent perturbation both have been implicated in the activity of antifreeze proteins and antifreeze glycoproteins. We study these two mechanisms for activity of winter flounder antifreeze peptide. Four mutants are characterized by freezing point hysteresis (activity), circular dichroism (secondary structure), Förster resonance energy transfer (end-to-end rigidity), molecular dynamics simulation (structure), and terahertz spectroscopy (long-range solvent perturbation). Our results show that the short-range model is sufficient to explain the activity of our mutants, but the long-range model provides a necessary condition for activity: the most active peptides in our data set all have an extended dynamical hydration shell. It appears that antifreeze proteins and antifreeze glycoproteins have reached different evolutionary solutions to the antifreeze problem, utilizing either a few precisely positioned OH groups or a large quantity of OH groups for ice binding, assisted by long-range solvent perturbation. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Resources and Long-Range Forecasts

ERIC Educational Resources Information Center

Smith, Waldo E.

1973-01-01

The author argues that forecasts of quick depletion of resources in the environment as a result of overpopulation and increased usage may not be free from error. Ignorance still exists in understanding the recovery mechanisms of nature. Long-range forecasts are likely to be wrong in such situations. (PS)

Tennessee long-range transportation plan : modal needs

DOT National Transportation Integrated Search

2005-12-01

This report documents one of several major steps in the long-range planning process. This report examines each component of the states transportation network to identify the long-term needs of the transportation modes to 2030. The determination of...

Down the Road...Long Range Planning for Automation.

ERIC Educational Resources Information Center

Texas State Library, Austin. Dept. of Library Development.

The materials in this manual/workbook were prepared to assist participants in a workshop on long-range planning for library automation. Chapters cover the following topics: (1) "What Is Long-Range Planning?" (2) "Why Plan?" (3) "Who Needs to Participate?" (4) "Planning to Plan"; (5) "Determining Needs"; (6) "Description and Introduction"; (7)…

Resident Characteristics Related to the Lack of Morning Care Provision in Long-Term Care

ERIC Educational Resources Information Center

Simmons, Sandra F.; Durkin, Daniel W.; Rahman, Anna N.; Choi, Leena; Beuscher, Linda; Schnelle, John F.

2013-01-01

Purpose: The purpose of this study was to examine usual long-term care (LTC) practices related to 3 aspects of morning care and determine if there were resident characteristics related to the lack of care. Design and Methods: Participants were 169 long-stay residents in 4 community LTC facilities who required staff assistance with either transfer…

Long-Range Facilities - Plan

DTIC Science & Technology

1981-07-31

3. DATES COVERED 00-00-1981 to 00-00-1981 4. TITLE AND SUBTITLE Long-Range Facilities - Plan 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...sternwheeler “Mark Twain” for Disneyland and fabrication of eight 52 foot submarines for the Disneyland “Navy.” This was followed by fabrication of the masts...converting the PRESIDENT GRANT , PRESIDENT McKINLEY and PRESIDENT FILLMORE to container ships for American President Lines, Ltd. These ships were designed to

The generalization of the Mermin-Wagner theorem and the possibility of long-range order in the isotropic discrete one-dimensional quantum Heisenberg model

NASA Astrophysics Data System (ADS)

Rudoy, Yu. G.; Kotelnikova, O. A.

2012-10-01

The problem of existence of long-range order in the isotropic quantum Heisenberg model on the D=1 lattice is reconsidered in view of the possibility of sufficiently slow decaying exchange interaction with infinite effective radius. It is shown that the macrosopic arguments given by Landau and Lifshitz and then supported microscopically by Mermin and Wagner fail for this case so that the non-zero spontaneous magnetization may yet exist. This result was anticipated by Thouless on the grounds of phenomenological analysis, and we give its microscopic foundation, which amounts to the generalization of Mermin-Wagner theorem for the case of the infinite second moment of the exchange interaction. Two well known in lattice statistics models - i.e., Kac-I and Kac-II - illustrate our results.

Fourth International Symposium on Long-Range Sound Propagation

NASA Technical Reports Server (NTRS)

Willshire, William L., Jr. (Compiler)

1990-01-01

Long range sound propagation is an aspect of many acoustical problems ranging from en route aircraft noise to the acoustic detection of aircraft. Over the past decade, the University of Mississippi and the Open University of England, together with a third institution, have held a symposium approx. every 2 years so that experts in the field of long range propagation could exchange information on current research, identify areas needing additional work, and coordinate activities as much as possible. The Fourth International Symposium on Long Range Sound Propagation was jointly sponsored by the University of Mississippi, the Open University of England, and NASA. Papers were given in the following areas: ground effects on propagation; infrasound propagation; and meteorological effects on sound propagation. A compilation of the presentations made at the symposium is presented along with a list of attendees, and the agenda.

Structural properties of medium-range order in CuNiZr alloy

NASA Astrophysics Data System (ADS)

Gao, Tinghong; Hu, Xuechen; Xie, Quan; Li, Yidan; Ren, Lei

2017-10-01

The evolution characteristics of icosahedral clusters during the rapid solidification of Cu50Ni10Zr40 alloy at cooling rate of 1011 K s-1 are investigated based on molecular dynamics simulations. The structural properties of the short-range order and medium-range order of Cu50Ni10Zr40 alloy are analyzed by several structural characterization methods. The results reveal that the icosahedral clusters are the dominant short-range order structure, and that they assemble themselves into medium-range order by interpenetrating connections. The different morphologies of medium-range order are found in the system and include chain, triangle, tetrahedral, and their combination structures. The tetrahedral morphologies of medium-range order have excellent structural stability with decreasing temperature. The Zr atoms are favorable to form longer chains, while the Cu atoms are favorable to form shorter chains in the system. Those chains interlocked with each other to improve the structural stability.

Coexistence of short- and long-range ferromagnetic order in nanocrystalline Fe2Mn1-xCuxAl (x=0.0, 0.1 and 0.3) synthesized by high-energy ball milling

NASA Astrophysics Data System (ADS)

Thanh, Tran Dang; Nanto, Dwi; Tuyen, Ngo Thi Uyen; Nan, Wen-Zhe; Yu, YiKyung; Tartakovsky, Daniel M.; Yu, S. C.

2015-11-01

In this work, we prepared nanocrystalline Fe2Mn1-xCuxAl (x=0.0, 0.1 and 0.3) powders by the high energy ball milling technique, and then studied their critical properties. Our analysis reveals that the increase of Cu-doping concentration (up to x=0.3) in these powders leads to a gradual increase of the ferromagnetic-paramagnetic transition temperature from 406 to 452 K. The Banerjee criterion suggests that all the samples considered undergo a second-order phase transition. A modified Arrott plot and scaling analysis indicate that the critical exponents (β=0.419 and 0.442, γ=1.082 and 1.116 for x=0.0 and 0.1, respectively) are located in between those expected for the 3D-Heisenberg and the mean-field models; the values of β=0.495 and γ=1.046 for x=0.3 sample are very close to those of the mean-field model. These features reveal the coexistence of the short- and long-range ferromagnetic order in the nanocrystalline Fe2Mn1-xCuxAl powders. Particularly, as the concentration of Cu increases, values of the critical exponent shift towards those of the mean-field model. Such results prove the Cu doping favors establishing a long-range ferromagnetic order.

Sensor Control And Film Annotation For Long Range, Standoff Reconnaissance

NASA Astrophysics Data System (ADS)

Schmidt, Thomas G.; Peters, Owen L.; Post, Lawrence H.

1984-12-01

This paper describes a Reconnaissance Data Annotation System that incorporates off-the-shelf technology and system designs providing a high degree of adaptability and interoperability to satisfy future reconnaissance data requirements. The history of data annotation for reconnaissance is reviewed in order to provide the base from which future developments can be assessed and technical risks minimized. The system described will accommodate new developments in recording head assemblies and the incorporation of advanced cameras of both the film and electro-optical type. Use of microprocessor control and digital bus inter-face form the central design philosophy. For long range, high altitude, standoff missions, the Data Annotation System computes the projected latitude and longitude of central target position from aircraft position and attitude. This complements the use of longer ranges and high altitudes for reconnaissance missions.

Multi-scale variability and long-range memory in indoor Radon concentrations from Coimbra, Portugal

NASA Astrophysics Data System (ADS)

Donner, Reik V.; Potirakis, Stelios; Barbosa, Susana

2014-05-01

The presence or absence of long-range correlations in the variations of indoor Radon concentrations has recently attracted considerable interest. As a radioactive gas naturally emitted from the ground in certain geological settings, understanding environmental factors controlling Radon concentrations and their dynamics is important for estimating its effect on human health and the efficiency of possible measures for reducing the corresponding exposition. In this work, we re-analyze two high-resolution records of indoor Radon concentrations from Coimbra, Portugal, each of which spans several months of continuous measurements. In order to evaluate the presence of long-range correlations and fractal scaling, we utilize a multiplicity of complementary methods, including power spectral analysis, ARFIMA modeling, classical and multi-fractal detrended fluctuation analysis, and two different estimators of the signals' fractal dimensions. Power spectra and fluctuation functions reveal some complex behavior with qualitatively different properties on different time-scales: white noise in the high-frequency part, indications of some long-range correlated process dominating time scales of several hours to days, and pronounced low-frequency variability associated with tidal and/or meteorological forcing. In order to further decompose these different scales of variability, we apply two different approaches. On the one hand, applying multi-resolution analysis based on the discrete wavelet transform allows separately studying contributions on different time scales and characterize their specific correlation and scaling properties. On the other hand, singular system analysis (SSA) provides a reconstruction of the essential modes of variability. Specifically, by considering only the first leading SSA modes, we achieve an efficient de-noising of our environmental signals, highlighting the low-frequency variations together with some distinct scaling on sub-daily time-scales resembling

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

NASA Technical Reports Server (NTRS)

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,

Long-Range Correlations Between Transmitted and Reected Fluxes of Electromagnetic Waves

NASA Astrophysics Data System (ADS)

Gorodnichev, E. E.; Kuzovlev, A. I.; Rogozkin, D. B.

2017-12-01

We study the long-range spatial correlations between intensity fluctuations in speckles formed by multiply scattered light. The correlation function between intensity fluctuations at the opposite boundaries of the slab are analyzed under the conditions of circular polarization memory. It shown that, until the scattered light is depolarized completely, the polarization and scalar contributions to the correlation function are of the same order of magnitude. As the slab thickness increases, their ratio falls off in inverse proportion to the thickness.

Long-range correlation in cosmic microwave background radiation.

PubMed

Movahed, M Sadegh; Ghasemi, F; Rahvar, Sohrab; Tabar, M Reza Rahimi

2011-08-01

We investigate the statistical anisotropy and gaussianity of temperature fluctuations of Cosmic Microwave Background (CMB) radiation data from the Wilkinson Microwave Anisotropy Probe survey, using the Multifractal Detrended Fluctuation Analysis, Rescaled Range, and Scaled Windowed Variance methods. Multifractal Detrended Fluctuation Analysis shows that CMB fluctuations has a long-range correlation function with a multifractal behavior. By comparing the shuffled and surrogate series of CMB data, we conclude that the multifractality nature of the temperature fluctuation of CMB radiation is mainly due to the long-range correlations, and the map is consistent with a gaussian distribution.

Modeling of UV laser-induced patterning of ultrathin Co films on bulk SiO2: verification of short- and long-range ordering mechanisms

NASA Astrophysics Data System (ADS)

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.

Role of short-range correlation in facilitation of wave propagation in a long-range ladder chain

NASA Astrophysics Data System (ADS)

Farzadian, O.; Niry, M. D.

2018-09-01

We extend a new method for generating a random chain, which has a kind of short-range correlation induced by a repeated sequence while retaining long-range correlation. Three distinct methods are considered to study the localization-delocalization transition of mechanical waves in one-dimensional disordered media with simultaneous existence of short and long-range correlation. First, a transfer-matrix method was used to calculate numerically the localization length of a wave in a binary chain. We found that the existence of short-range correlation in a long-range correlated chain can increase the localization length at the resonance frequency Ωc. Then, we carried out an analytical study of the delocalization properties of the waves in correlated disordered media around Ωc. Finally, we apply a dynamical method based on the direct numerical simulation of the wave equation to study the propagation of waves in the correlated chain. Imposing short-range correlation on the long-range background will lead the propagation to super-diffusive transport. The results obtained with all three methods are in agreement with each other.

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

NASA Astrophysics Data System (ADS)

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.

Quantum gases. Observation of many-body dynamics in long-range tunneling after a quantum quench.

PubMed

Meinert, Florian; Mark, Manfred J; Kirilov, Emil; Lauber, Katharina; Weinmann, Philipp; Gröbner, Michael; Daley, Andrew J; Nägerl, Hanns-Christoph

2014-06-13

Quantum tunneling is at the heart of many low-temperature phenomena. In strongly correlated lattice systems, tunneling is responsible for inducing effective interactions, and long-range tunneling substantially alters many-body properties in and out of equilibrium. We observe resonantly enhanced long-range quantum tunneling in one-dimensional Mott-insulating Hubbard chains that are suddenly quenched into a tilted configuration. Higher-order tunneling processes over up to five lattice sites are observed as resonances in the number of doubly occupied sites when the tilt per site is tuned to integer fractions of the Mott gap. This forms a basis for a controlled study of many-body dynamics driven by higher-order tunneling and demonstrates that when some degrees of freedom are frozen out, phenomena that are driven by small-amplitude tunneling terms can still be observed. Copyright © 2014, American Association for the Advancement of Science.

Octacyanoniobate(IV)-based molecular magnets revealing 3D long-range order

NASA Astrophysics Data System (ADS)

Pełka, R.; Pinkowicz, D.; Drath, O.; Bałanda, M.; Rams, M.; Majcher, A.; Nitek, W.; Sieklucka, B.

2011-07-01

Isostructural series of chemical formula {[MII(pirazol)4]2[NbIV(CN)8]· 4H2O}n (MII = Mn (1), Fe (2), Co (3), Ni (4)) has been obtained by the self-assembly technique. Its unique crystallographic structure consists in the formation of a 3D extended network of magnetic centers braced by geometrically identical cyanido bridges. Magnetic measurements reveal the transitions to the 3D order at temperatures 23.7, 8.3, 5.9, 13.4 K for 1, 2, 3, and 4, respectively. The character of order is demonstrated to be ferrimagnetic for 1 and 2 and ferromagnetic for 3 and 4. The mean-field approach is used to determine the corresponding exchange coupling constants. The observed interactions are discussed within the magnetic orbital model.

A Long Range Planning Study for the El Paso Community College, El Paso, Texas.

ERIC Educational Resources Information Center

Colvert, C. C.

This planning study was undertaken in order to determine the long-range financial needs of El Paso Community College (Texas) and present them to the Board of Trustees. The document outlines a budget of income and expenditures, projects student enrollment by academic and vocational-technical program areas, and projects total educational costs per…

Constructing high-accuracy intermolecular potential energy surface with multi-dimension Morse/Long-Range model

NASA Astrophysics Data System (ADS)

Zhai, Yu; Li, Hui; Le Roy, Robert J.

2018-04-01

Spectroscopically accurate Potential Energy Surfaces (PESs) are fundamental for explaining and making predictions of the infrared and microwave spectra of van der Waals (vdW) complexes, and the model used for the potential energy function is critically important for providing accurate, robust and portable analytical PESs. The Morse/Long-Range (MLR) model has proved to be one of the most general, flexible and accurate one-dimensional (1D) model potentials, as it has physically meaningful parameters, is flexible, smooth and differentiable everywhere, to all orders and extrapolates sensibly at both long and short ranges. The Multi-Dimensional Morse/Long-Range (mdMLR) potential energy model described herein is based on that 1D MLR model, and has proved to be effective and accurate in the potentiology of various types of vdW complexes. In this paper, we review the current status of development of the mdMLR model and its application to vdW complexes. The future of the mdMLR model is also discussed. This review can serve as a tutorial for the construction of an mdMLR PES.

Formation of the long range Dpp morphogen gradient.

PubMed

Schwank, Gerald; Dalessi, Sascha; Yang, Schu-Fee; Yagi, Ryohei; de Lachapelle, Aitana Morton; Affolter, Markus; Bergmann, Sven; Basler, Konrad

2011-07-01

The TGF-β homolog Decapentaplegic (Dpp) acts as a secreted morphogen in the Drosophila wing disc, and spreads through the target tissue in order to form a long range concentration gradient. Despite extensive studies, the mechanism by which the Dpp gradient is formed remains controversial. Two opposing mechanisms have been proposed: receptor-mediated transcytosis (RMT) and restricted extracellular diffusion (RED). In these scenarios the receptor for Dpp plays different roles. In the RMT model it is essential for endocytosis, re-secretion, and thus transport of Dpp, whereas in the RED model it merely modulates Dpp distribution by binding it at the cell surface for internalization and subsequent degradation. Here we analyzed the effect of receptor mutant clones on the Dpp profile in quantitative mathematical models representing transport by either RMT or RED. We then, using novel genetic tools, experimentally monitored the actual Dpp gradient in wing discs containing receptor gain-of-function and loss-of-function clones. Gain-of-function clones reveal that Dpp binds in vivo strongly to the type I receptor Thick veins, but not to the type II receptor Punt. Importantly, results with the loss-of-function clones then refute the RMT model for Dpp gradient formation, while supporting the RED model in which the majority of Dpp is not bound to Thick veins. Together our results show that receptor-mediated transcytosis cannot account for Dpp gradient formation, and support restricted extracellular diffusion as the main mechanism for Dpp dispersal. The properties of this mechanism, in which only a minority of Dpp is receptor-bound, may facilitate long-range distribution.

Long-range intercellular Ca2+ wave patterns

NASA Astrophysics Data System (ADS)

Tabi, C. B.; Maïna, I.; Mohamadou, A.; Ekobena, H. P. F.; Kofané, T. C.

2015-10-01

Modulational instability is utilized to investigate intercellular Ca2+ wave propagation in an array of diffusively coupled cells. Cells are supposed to be connected via paracrine signaling, where long-range effects, due to the presence of extracellular messengers, are included. The multiple-scale expansion is used to show that the whole dynamics of Ca2+ waves, from the endoplasmic reticulum to the cytosol, can be reduced to a single differential-difference nonlinear equation whose solutions are assumed to be plane waves. Their linear stability analysis is studied, with emphasis on the impact of long-range coupling, via the range parameter s. It is shown that s, as well as the number of interacting cells, importantly modifies the features of modulational instability, as small values of s imply a strong coupling, and increasing its value rather reduces the problem to a first-neighbor one. Our theoretical findings are numerically tested, as the generic equations are fully integrated, leading to the emergence of nonlinear patterns of Ca2+ waves. Strong long-range coupling is pictured by extended trains of breather-like structures whose frequency decreases with increasing s. We also show numerically that the number of interacting cells plays on the spatio-temporal formation of Ca2+ patterns, whilst the quasi-perfect intercellular communication depends on the paracrine coupling parameter.

Order information is used to guide recall of long lists: Further evidence for the item-order account.

PubMed

Forrin, Noah D; MacLeod, Colin M

2016-06-01

Differences in memory for item order have been used to explain the absence of between-subjects (i.e., pure-list) effects in free recall for several encoding techniques, including the production effect, the finding that reading aloud benefits memory compared with reading silently. Notably, however, evidence in support of the item-order account (Nairne, Riegler, & Serra, 1991) has derived primarily from short-list paradigms. We provide novel evidence that the item-order account also applies when recalling long lists. In Experiment 1, participants studied and then free recalled 3 different long lists of words: pure aloud, pure silent, and mixed (half aloud, half silent). A Bayesian analysis supported a null pure-list production effect, and subsequent order analyses were largely consistent with the item-order account. These findings indicate that order information is retained in long-term memory and is useful in guiding subsequent free recall. In Experiment 2, a distractor task was inserted between the study and test phases, ensuring that only long-term memory processes were involved in recall: The pattern of results remained consistent with the item-order account. Order information can be retained in long-term memory for long lists, and is useful in guiding subsequent free recall, extending the domain of the item-order account. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The Effects of Face Inversion on the Perception of Long-Range and Local Spatial Relations in Eye and Mouth Configuration

ERIC Educational Resources Information Center

Sekunova, Alla; Barton, Jason J. S.

2008-01-01

A recent study hypothesized a configurational anisotropy in the face inversion effect, with vertical relations more difficult to process. However, another difference in the stimuli of that report was that the vertical but not horizontal shifts lacked local spatial references. Difficulty processing long-range spatial relations might also be…

Bacterial genomes lacking long-range correlations may not be modeled by low-order Markov chains: the role of mixing statistics and frame shift of neighboring genes.

PubMed

Cocho, Germinal; Miramontes, Pedro; Mansilla, Ricardo; Li, Wentian

2014-12-01

We examine the relationship between exponential correlation functions and Markov models in a bacterial genome in detail. Despite the well known fact that Markov models generate sequences with correlation function that decays exponentially, simply constructed Markov models based on nearest-neighbor dimer (first-order), trimer (second-order), up to hexamer (fifth-order), and treating the DNA sequence as being homogeneous all fail to predict the value of exponential decay rate. Even reading-frame-specific Markov models (both first- and fifth-order) could not explain the fact that the exponential decay is very slow. Starting with the in-phase coding-DNA-sequence (CDS), we investigated correlation within a fixed-codon-position subsequence, and in artificially constructed sequences by packing CDSs with out-of-phase spacers, as well as altering CDS length distribution by imposing an upper limit. From these targeted analyses, we conclude that the correlation in the bacterial genomic sequence is mainly due to a mixing of heterogeneous statistics at different codon positions, and the decay of correlation is due to the possible out-of-phase between neighboring CDSs. There are also small contributions to the correlation from bases at the same codon position, as well as by non-coding sequences. These show that the seemingly simple exponential correlation functions in bacterial genome hide a complexity in correlation structure which is not suitable for a modeling by Markov chain in a homogeneous sequence. Other results include: use of the (absolute value) second largest eigenvalue to represent the 16 correlation functions and the prediction of a 10-11 base periodicity from the hexamer frequencies. Copyright © 2014 Elsevier Ltd. All rights reserved.

Gemini: A long-range cargo transport

NASA Technical Reports Server (NTRS)

1994-01-01

The proposed Gemini, a long-range cargo transport, is designed as a high capacity, dedicated cargo transporter of 8'x8'x20' inter-modal containers, and long-range design. These requirements will result in a design that is larger than any existing aircraft. Due to the size, a conventional configuration would result in an aircraft unable to operate economically at existing airports. It is necessary to design for a minimum possible empty weight, wingspan, and landing gear track. After considering both a single fuselage biplane and a double fuselage biplane configuration, the design team choose the double fuselage biplane configuration. Both of these configuration choices result in a reduced wing root bending moment and subsequently in substantial savings in the wing weight. An overall decrease in the weight of the airplane, its systems, and fuel will be a direct result of the wing weight savings.

Rapid cloning of genes in hexaploid wheat using cultivar-specific long-range chromosome assembly.

PubMed

Thind, Anupriya Kaur; Wicker, Thomas; Šimková, Hana; Fossati, Dario; Moullet, Odile; Brabant, Cécile; Vrána, Jan; Doležel, Jaroslav; Krattinger, Simon G

2017-08-01

Cereal crops such as wheat and maize have large repeat-rich genomes that make cloning of individual genes challenging. Moreover, gene order and gene sequences often differ substantially between cultivars of the same crop species. A major bottleneck for gene cloning in cereals is the generation of high-quality sequence information from a cultivar of interest. In order to accelerate gene cloning from any cropping line, we report 'targeted chromosome-based cloning via long-range assembly' (TACCA). TACCA combines lossless genome-complexity reduction via chromosome flow sorting with Chicago long-range linkage to assemble complex genomes. We applied TACCA to produce a high-quality (N50 of 9.76 Mb) de novo chromosome assembly of the wheat line CH Campala Lr22a in only 4 months. Using this assembly we cloned the broad-spectrum Lr22a leaf-rust resistance gene, using molecular marker information and ethyl methanesulfonate (EMS) mutants, and found that Lr22a encodes an intracellular immune receptor homologous to the Arabidopsis thaliana RPM1 protein.

Effect of simple solutes on the long range dipolar correlations in liquid water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baul, Upayan, E-mail: upayanb@imsc.res.in; Anishetty, Ramesh, E-mail: ramesha@imsc.res.in; Vemparala, Satyavani, E-mail: vani@imsc.res.in

2016-03-14

Intermolecular correlations in liquid water at ambient conditions have generally been characterized through short range density fluctuations described through the atomic pair distribution functions. Recent numerical and experimental results have suggested that such a description of order or structure in liquid water is incomplete and there exist considerably longer ranged orientational correlations in water that can be studied through dipolar correlations. In this study, using large scale classical, atomistic molecular dynamics simulations using TIP4P-Ew and TIP3P models of water, we show that salts such as sodium chloride (NaCl), potassium chloride (KCl), caesium chloride (CsCl), and magnesium chloride (MgCl{sub 2}) havemore » a long range effect on the dipolar correlations, which cannot be explained by the notion of structure making and breaking by dissolved ions. Observed effects are explained through orientational stratification of water molecules around ions and their long range coupling to the global hydrogen bond network by virtue of the sum rule for water. The observations for single hydrophilic solutes are contrasted with the same for a single methane (CH{sub 4}) molecule. We observe that even a single small hydrophobe can result in enhancement of long range orientational correlations in liquid water, contrary to the case of dissolved ions, which have been observed to have a reducing effect. The observations from this study are discussed in the context of hydrophobic effect.« less

Long-Range Adiabatic Corrections to the Ground Molecular State of Alkali-Metal Dimers.

NASA Astrophysics Data System (ADS)

Marinescu, M.; Dalgarno, A.

1997-04-01

The structure of the long-range limit of the diagonal adiabatic corrections to the ground molecular state of diatomic molecules, may be expressed as a series of inverse powers of internuclear distance, R. The coefficients of this expansion are proportional to the inverse of the nuclear mass. Thus, they may be interpreted as a nuclear mass-dependent corrections to the dispersion coefficients. Using perturbation theory we have calculated the long-range coefficients of the diagonal adiabatic corrections up to the order of R-10. The final expressions are in terms of integrals over imaginary frequencies of products of atomic matrix elements involving Green's functions of complex energy. Thus, in our approach the molecular problem is reduced to an atomic one. Numerical evaluations have been done for all alkali-metal dimers. We acknowledge the support of the U.S. Dept. of Energy.

Long Valley caldera and the UCERF depiction of Sierra Nevada range-front faults

USGS Publications Warehouse

Hill, David P.; Montgomery-Brown, Emily K.

2015-01-01

Long Valley caldera lies within a left-stepping offset in the north-northwest-striking Sierra Nevada range-front normal faults with the Hilton Creek fault to the south and Hartley Springs fault to the north. Both Uniform California Earthquake Rupture Forecast (UCERF) 2 and its update, UCERF3, depict slip on these major range-front normal faults as extending well into the caldera, with significant normal slip on overlapping, subparallel segments separated by ∼10  km. This depiction is countered by (1) geologic evidence that normal faulting within the caldera consists of a series of graben structures associated with postcaldera magmatism (intrusion and tumescence) and not systematic down-to-the-east displacements consistent with distributed range-front faulting and (2) the lack of kinematic evidence for an evolving, postcaldera relay ramp structure between overlapping strands of the two range-front normal faults. The modifications to the UCERF depiction described here reduce the predicted shaking intensity within the caldera, and they are in accord with the tectonic influence that underlapped offset range-front faults have on seismicity patterns within the caldera associated with ongoing volcanic unrest.

Laser long-range remote-sensing program experimental results

NASA Astrophysics Data System (ADS)

Highland, Ronald G.; Shilko, Michael L.; Fox, Marsha J.; Gonglewski, John D.; Czyzak, Stanley R.; Dowling, James A.; Kelly, Brian; Pierrottet, Diego F.; Ruffatto, Donald; Loando, Sharon; Matsuura, Chris; Senft, Daniel C.; Finkner, Lyle; Rae, Joe; Gallegos, Joe

1995-12-01

A laser long range remote sensing (LRS) program is being conducted by the United States Air Force Phillips Laboratory (AF/PL). As part of this program, AF/PL is testing the feasibility of developing a long path CO(subscript 2) laser-based DIAL system for remote sensing. In support of this program, the AF/PL has recently completed an experimental series using a 21 km slant- range path (3.05 km ASL transceiver height to 0.067 km ASL target height) at its Phillips Laboratory Air Force Maui Optical Station (AMOS) facility located on Maui, Hawaii. The dial system uses a 3-joule, (superscript 13)C isotope laser coupled into a 0.6 m diameter telescope. The atmospheric optical characterization incorporates information from an infrared scintillometer co-aligned to the laser path, atmospheric profiles from weather balloons launched from the target site, and meteorological data from ground stations at AMOS and the target site. In this paper, we report a description of the experiment configuration, a summary of the results, a summary of the atmospheric conditions and their implications to the LRS program. The capability of such a system for long-range, low-angle, slant-path remote sensing is discussed. System performance issues relating to both coherent and incoherent detection methods, atmospheric limitations, as well as, the development of advanced models to predict performance of long range scenarios are presented.

Random walks with long-range steps generated by functions of Laplacian matrices

NASA Astrophysics Data System (ADS)

Riascos, A. P.; Michelitsch, T. M.; Collet, B. A.; Nowakowski, A. F.; Nicolleau, F. C. G. A.

2018-04-01

In this paper, we explore different Markovian random walk strategies on networks with transition probabilities between nodes defined in terms of functions of the Laplacian matrix. We generalize random walk strategies with local information in the Laplacian matrix, that describes the connections of a network, to a dynamic determined by functions of this matrix. The resulting processes are non-local allowing transitions of the random walker from one node to nodes beyond its nearest neighbors. We find that only two types of Laplacian functions are admissible with distinct behaviors for long-range steps in the infinite network limit: type (i) functions generate Brownian motions, type (ii) functions Lévy flights. For this asymptotic long-range step behavior only the lowest non-vanishing order of the Laplacian function is relevant, namely first order for type (i), and fractional order for type (ii) functions. In the first part, we discuss spectral properties of the Laplacian matrix and a series of relations that are maintained by a particular type of functions that allow to define random walks on any type of undirected connected networks. Once described general properties, we explore characteristics of random walk strategies that emerge from particular cases with functions defined in terms of exponentials, logarithms and powers of the Laplacian as well as relations of these dynamics with non-local strategies like Lévy flights and fractional transport. Finally, we analyze the global capacity of these random walk strategies to explore networks like lattices and trees and different types of random and complex networks.

Long-range electrostatic screening in ionic liquids

PubMed Central

Gebbie, Matthew A.; Dobbs, Howard A.; Valtiner, Markus; Israelachvili, Jacob N.

2015-01-01

Electrolyte solutions with high concentrations of ions are prevalent in biological systems and energy storage technologies. Nevertheless, the high interaction free energy and long-range nature of electrostatic interactions makes the development of a general conceptual picture of concentrated electrolytes a significant challenge. In this work, we study ionic liquids, single-component liquids composed solely of ions, in an attempt to provide a novel perspective on electrostatic screening in very high concentration (nonideal) electrolytes. We use temperature-dependent surface force measurements to demonstrate that the long-range, exponentially decaying diffuse double-layer forces observed across ionic liquids exhibit a pronounced temperature dependence: Increasing the temperature decreases the measured exponential (Debye) decay length, implying an increase in the thermally driven effective free-ion concentration in the bulk ionic liquids. We use our quantitative results to propose a general model of long-range electrostatic screening in ionic liquids, where thermally activated charge fluctuations, either free ions or correlated domains (quasiparticles), take on the role of ions in traditional dilute electrolyte solutions. This picture represents a crucial step toward resolving several inconsistencies surrounding electrostatic screening and charge transport in ionic liquids that have impeded progress within the interdisciplinary ionic liquids community. More broadly, our work provides a previously unidentified way of envisioning highly concentrated electrolytes, with implications for diverse areas of inquiry, ranging from designing electrochemical devices to rationalizing electrostatic interactions in biological systems. PMID:26040001

Quantum Spin Dynamics with Pairwise-Tunable, Long-Range Interactions

DTIC Science & Technology

2016-08-05

rection of the arrows. Dashed (dotted) lines mark the NNN hopping terms (coefficients ±t2). NNNN long -range hopping along curved lines are included to...Quantum spin dynamics with pairwise-tunable, long -range interactions C.-L. Hunga,b,1,2, Alejandro González-Tudelac,1,2, J. Ignacio Ciracc, and H. J...atoms) that interact by way of a variety of processes, such as atomic collisions. Such pro- cesses typically lead to short -range, nearest-neighbor

Holographic thermalization with initial long range correlation

DOE PAGES

Lin, Shu

2016-01-19

Here, we studied the evolution of the Wightman correlator in a thermalizing state modeled by AdS 3-Vaidya background. A prescription was given for calculating the Wightman correlator in coordinate space without using any approximation. For equal-time correlator , we obtained an enhancement factor v 2 due to long range correlation present in the initial state. This was missed by previous studies based on geodesic approximation. Moreover, we found that the long range correlation in initial state does not lead to significant modification to thermalization time as compared to known results with generic initial state. We also studied the spatially integratedmore » Wightman correlator and showed evidence on the distinction between long distance and small momentum physics for an out-of-equilibrium state. We also calculated the radiation spectrum of particles weakly coupled to O and found that lower frequency mode approaches thermal spectrum faster than high frequency mode.« less

Engineered long-range interactions on a 2D array of trapped ions

NASA Astrophysics Data System (ADS)

Britton, Joseph W.; Sawyer, Brian C.; Bollinger, John J.; Freericks, James K.

2014-03-01

Ising interactions are one paradigm used to model quantum magnetism in condensed matter systems. At NIST Boulder we confine and Doppler laser cool hundreds of 9Be+ ions in a Penning trap. The valence electron of each ion behaves as an ideal spin-1/2 particle and, in the limit of weak radial confinement relative to axial confinement, the ions naturally form a two-dimensional triangular lattice. A variable-range anti-ferromagnetic Ising interaction is engineered with a spin-dependent optical dipole force (ODF) through spin-dependent excitation of collective modes of ion motion. We have also exploited this spin-dependent force to perform spectroscopy and thermometry of the normal modes of the trapped ion crystal. The high spin-count and long-range spin-spin couplings achievable in the NIST Penning trap brings within reach simulation of computationally intractable problems in quantum magnetism. Examples include modeling quantum magnetic phase transitions and propagation of spin correlations resulting from a quantum quench. The Penning system may also be amenable to observation of spin-liquid behavior thought to arise in systems where the underlying lattice structure can frustrate long-range ordering. Supported by DARPA OLE and NIST.

Entanglement Generation and Area Law with Long-Range Interactions

NASA Astrophysics Data System (ADS)

Gorshkov, Alexey

In short-range interacting systems, the speed at which entanglement can be established between two separated points is limited by a constant Lieb-Robinson velocity. This same limit also leads to the so-called area-law bound on entanglement in one-dimensional gapped short-range interacting systems. In this talk, we will show that long-range interactions that decay with distance as a power law allow for faster entanglement generation and state transfer. We will also present sufficient conditions for the area law in gapped systems to hold even in the presence of long-range interactions.

Muskegon Community College Long-Range Plan.

ERIC Educational Resources Information Center

Turner, Peter M.; And Others

Long-range planning assumptions and goals are presented for Muskegon Community College (MCC) as they were submitted by a committee of area citizens. After introductory material summarizing the committee's mandate and activities, the report discusses the fiscal, demographic, curricular, and administrative changes likely to affect MCC during the…

Context and meter enhance long-range planning in music performance

PubMed Central

Mathias, Brian; Pfordresher, Peter Q.; Palmer, Caroline

2015-01-01

Neural responses demonstrate evidence of resonance, or oscillation, during the production of periodic auditory events. Music contains periodic auditory events that give rise to a sense of beat, which in turn generates a sense of meter on the basis of multiple periodicities. Metrical hierarchies may aid memory for music by facilitating similarity-based associations among sequence events at different periodic distances that unfold in longer contexts. A fundamental question is how metrical associations arising from a musical context influence memory during music performance. Longer contexts may facilitate metrical associations at higher hierarchical levels more than shorter contexts, a prediction of the range model, a formal model of planning processes in music performance (Palmer and Pfordresher, 2003; Pfordresher et al., 2007). Serial ordering errors, in which intended sequence events are produced in incorrect sequence positions, were measured as skilled pianists performed musical pieces that contained excerpts embedded in long or short musical contexts. Pitch errors arose from metrically similar positions and further sequential distances more often when the excerpt was embedded in long contexts compared to short contexts. Musicians’ keystroke intensities and error rates also revealed influences of metrical hierarchies, which differed for performances in long and short contexts. The range model accounted for contextual effects and provided better fits to empirical findings when metrical associations between sequence events were included. Longer sequence contexts may facilitate planning during sequence production by increasing conceptual similarity between hierarchically associated events. These findings are consistent with the notion that neural oscillations at multiple periodicities may strengthen metrical associations across sequence events during planning. PMID:25628550

Effective theory and breakdown of conformal symmetry in a long-range quantum chain

NASA Astrophysics Data System (ADS)

Lepori, L.; Vodola, D.; Pupillo, G.; Gori, G.; Trombettoni, A.

2016-11-01

We deal with the problem of studying the symmetries and the effective theories of long-range models around their critical points. A prominent issue is to determine whether they possess (or not) conformal symmetry (CS) at criticality and how the presence of CS depends on the range of the interactions. To have a model, both simple to treat and interesting, where to investigate these questions, we focus on the Kitaev chain with long-range pairings decaying with distance as power-law with exponent α. This is a quadratic solvable model, yet displaying non-trivial quantum phase transitions. Two critical lines are found, occurring respectively at a positive and a negative chemical potential. Focusing first on the critical line at positive chemical potential, by means of a renormalization group approach we derive its effective theory close to criticality. Our main result is that the effective action is the sum of two terms: a Dirac action SD, found in the short-range Ising universality class, and an "anomalous" CS breaking term SAN. While SD originates from low-energy excitations in the spectrum, SAN originates from the higher energy modes where singularities develop, due to the long-range nature of the model. At criticality SAN flows to zero for α > 2, while for α < 2 it dominates and determines the breakdown of the CS. Out of criticality SAN breaks, in the considered approximation, the effective Lorentz invariance (ELI) for every finite α. As α increases such ELI breakdown becomes less and less pronounced and in the short-range limit α → ∞ the ELI is restored. In order to test the validity of the determined effective theory, we compared the two-fermion static correlation functions and the von Neumann entropy obtained from them with the ones calculated on the lattice, finding agreement. These results explain two observed features characteristic of long-range models, the hybrid decay of static correlation functions within gapped phases and the area-law violation

Long-Range Coulomb Effect in Intense Laser-Driven Photoelectron Dynamics.

PubMed

Quan, Wei; Hao, XiaoLei; Chen, YongJu; Yu, ShaoGang; Xu, SongPo; Wang, YanLan; Sun, RenPing; Lai, XuanYang; Wu, ChengYin; Gong, QiHuang; He, XianTu; Liu, XiaoJun; Chen, Jing

2016-06-03

In strong field atomic physics community, long-range Coulomb interaction has for a long time been overlooked and its significant role in intense laser-driven photoelectron dynamics eluded experimental observations. Here we report an experimental investigation of the effect of long-range Coulomb potential on the dynamics of near-zero-momentum photoelectrons produced in photo-ionization process of noble gas atoms in intense midinfrared laser pulses. By exploring the dependence of photoelectron distributions near zero momentum on laser intensity and wavelength, we unambiguously demonstrate that the long-range tail of the Coulomb potential (i.e., up to several hundreds atomic units) plays an important role in determining the photoelectron dynamics after the pulse ends.

Long-Range Coulomb Effect in Intense Laser-Driven Photoelectron Dynamics

PubMed Central

Quan, Wei; Hao, XiaoLei; Chen, YongJu; Yu, ShaoGang; Xu, SongPo; Wang, YanLan; Sun, RenPing; Lai, XuanYang; Wu, ChengYin; Gong, QiHuang; He, XianTu; Liu, XiaoJun; Chen, Jing

2016-01-01

In strong field atomic physics community, long-range Coulomb interaction has for a long time been overlooked and its significant role in intense laser-driven photoelectron dynamics eluded experimental observations. Here we report an experimental investigation of the effect of long-range Coulomb potential on the dynamics of near-zero-momentum photoelectrons produced in photo-ionization process of noble gas atoms in intense midinfrared laser pulses. By exploring the dependence of photoelectron distributions near zero momentum on laser intensity and wavelength, we unambiguously demonstrate that the long-range tail of the Coulomb potential (i.e., up to several hundreds atomic units) plays an important role in determining the photoelectron dynamics after the pulse ends. PMID:27256904

The design of a long-range megatransport aircraft

NASA Technical Reports Server (NTRS)

Weisshaar, Terrence A.; Allen, Carl L.

1992-01-01

Aircraft manufacturers are examining the market and feasibility of long-range passenger aircraft carrying more than 600 passengers. These aircraft would carry travelers at reduced cost and, at the same time, reduce congestion around major airports. The design of a large, long-range transport involves broad issues such as: the integration of airport terminal facilities; passenger loading and unloading; trade-offs between aircraft size and the cost to reconfigure these existing facilities; and, defeating the 'square-cube' law. Thirteen Purdue design teams generated RFP's that defined passenger capability and range, based upon team perception of market needs and infrastructure constraints. Turbofan engines were designed by each group to power these aircraft. The design problem and the variety of solutions developed are reviewed.

Angular-momentum couplings in ultra-long-range giant dipole molecules

NASA Astrophysics Data System (ADS)

Stielow, Thomas; Scheel, Stefan; Kurz, Markus

2018-02-01

In this article we extend the theory of ultra-long-range giant dipole molecules, formed by an atom in a giant dipole state and a ground-state alkali-metal atom, by angular-momentum couplings known from recent works on Rydberg molecules. In addition to s -wave scattering, the next higher order of p -wave scattering in the Fermi pseudopotential describing the binding mechanism is considered. Furthermore, the singlet and triplet channels of the scattering interaction as well as angular-momentum couplings such as hyperfine interaction and Zeeman interactions are included. Within the framework of Born-Oppenheimer theory, potential energy surfaces are calculated in both first-order perturbation theory and exact diagonalization. Besides the known pure triplet states, mixed-spin character states are obtained, opening up a whole new landscape of molecular potentials. We determine exact binding energies and wave functions of the nuclear rotational and vibrational motion numerically from the various potential energy surfaces.

Travel: a long-range goal of retired women.

PubMed

Staats, Sara; Pierfelice, Loretta

2003-09-01

The authors surveyed retired persons (predominately women) with regard to their immediate, intermediate, and long-range activities following retirement. As predicted, leisure travel emerged as a frequent long-range goal for persons retired more than 5 years. The travel activity preferences of long-retired older women present challenges and opportunities to both researchers and marketers. Length of trips and frequency of trips have been predicted from regression models, with trip length in particular being well predicted by the problem of daily life hassles. A theoretical model of continued post-retirement travel is presented as a variant of Solomon's opponent process theory of affect (R. L. Solomon, 1980). The authors suggest that to the degree that places traveled to are varied and different, older people may remain stimulated and continue to enjoy retirement.

Long-distance dispersal via ocean currents connects Omani clownfish populations throughout entire species range.

PubMed

Simpson, Stephen D; Harrison, Hugo B; Claereboudt, Michel R; Planes, Serge

2014-01-01

Dispersal is a crucial ecological process, driving population dynamics and defining the structure and persistence of populations. Measuring demographic connectivity between discreet populations remains a long-standing challenge for most marine organisms because it involves tracking the movement of pelagic larvae. Recent studies demonstrate local connectivity of reef fish populations via the dispersal of planktonic larvae, while biogeography indicates some larvae must disperse 100-1000 s kilometres. To date, empirical measures of long-distance dispersal are lacking and the full scale of dispersal is unknown. Here we provide the first measure of long-distance dispersal in a coral reef fish, the Omani clownfish Amphiprion omanensis, throughout its entire species range. Using genetic assignment tests we demonstrate bidirectional exchange of first generation migrants, with subsequent social and reproductive integration, between two populations separated by over 400 km. Immigration was 5.4% and 0.7% in each region, suggesting a biased southward exchange, and matched predictions from a physically-coupled dispersal model. This rare opportunity to measure long-distance dispersal demonstrates connectivity of isolated marine populations over distances of 100 s of kilometres and provides a unique insight into the processes of biogeography, speciation and adaptation.

Long-Distance Dispersal via Ocean Currents Connects Omani Clownfish Populations throughout Entire Species Range

PubMed Central

Claereboudt, Michel R.; Planes, Serge

2014-01-01

Dispersal is a crucial ecological process, driving population dynamics and defining the structure and persistence of populations. Measuring demographic connectivity between discreet populations remains a long-standing challenge for most marine organisms because it involves tracking the movement of pelagic larvae. Recent studies demonstrate local connectivity of reef fish populations via the dispersal of planktonic larvae, while biogeography indicates some larvae must disperse 100–1000 s kilometres. To date, empirical measures of long-distance dispersal are lacking and the full scale of dispersal is unknown. Here we provide the first measure of long-distance dispersal in a coral reef fish, the Omani clownfish Amphiprion omanensis, throughout its entire species range. Using genetic assignment tests we demonstrate bidirectional exchange of first generation migrants, with subsequent social and reproductive integration, between two populations separated by over 400 km. Immigration was 5.4% and 0.7% in each region, suggesting a biased southward exchange, and matched predictions from a physically-coupled dispersal model. This rare opportunity to measure long-distance dispersal demonstrates connectivity of isolated marine populations over distances of 100 s of kilometres and provides a unique insight into the processes of biogeography, speciation and adaptation. PMID:25229550

Vapor-Deposited Glasses with Long-Range Columnar Liquid Crystalline Order

DOE PAGES

Gujral, Ankit; Gomez, Jaritza; Ruan, Shigang; ...

2017-10-04

Anisotropic molecular packing, particularly in highly ordered liquid crystalline arrangements, has the potential for optimizing performance in organic electronic and optoelectronic applications. Here we show that physical vapor deposition can be used to prepare highly organized glassy solids of discotic liquid crystalline systems. Using grazing incidence X-ray scattering, atomic force microscopy, and UV–vis spectroscopy, we compare three systems: a rectangular columnar liquid crystal, a hexagonal columnar liquid crystal, and a nonmesogen. The packing motifs accessible by vapor deposition are highly organized for the liquid crystalline systems with columns propagating either in-plane or out-of-plane depending upon the substrate temperature during deposition.more » As a result, the structures formed at a given substrate temperature can be understood as resulting from partial equilibration toward the structure of the equilibrium liquid crystal surface during the deposition process.« less

Vapor-Deposited Glasses with Long-Range Columnar Liquid Crystalline Order

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gujral, Ankit; Gomez, Jaritza; Ruan, Shigang

Anisotropic molecular packing, particularly in highly ordered liquid crystalline arrangements, has the potential for optimizing performance in organic electronic and optoelectronic applications. Here we show that physical vapor deposition can be used to prepare highly organized glassy solids of discotic liquid crystalline systems. Using grazing incidence X-ray scattering, atomic force microscopy, and UV–vis spectroscopy, we compare three systems: a rectangular columnar liquid crystal, a hexagonal columnar liquid crystal, and a nonmesogen. The packing motifs accessible by vapor deposition are highly organized for the liquid crystalline systems with columns propagating either in-plane or out-of-plane depending upon the substrate temperature during deposition.more » As a result, the structures formed at a given substrate temperature can be understood as resulting from partial equilibration toward the structure of the equilibrium liquid crystal surface during the deposition process.« less

Relationships Between Long-Range Lightning Networks and TRMM/LIS Observations

NASA Technical Reports Server (NTRS)

Rudlosky, Scott D.; Holzworth, Robert H.; Carey, Lawrence D.; Schultz, Chris J.; Bateman, Monte; Cummins, Kenneth L.; Cummins, Kenneth L.; Blakeslee, Richard J.; Goodman, Steven J.

2012-01-01

Recent advances in long-range lightning detection technologies have improved our understanding of thunderstorm evolution in the data sparse oceanic regions. Although the expansion and improvement of long-range lightning datasets have increased their applicability, these applications (e.g., data assimilation, atmospheric chemistry, and aviation weather hazards) require knowledge of the network detection capabilities. The present study intercompares long-range lightning data with observations from the Lightning Imaging Sensor (LIS) aboard the Tropical Rainfall Measurement Mission (TRMM) satellite. The study examines network detection efficiency and location accuracy relative to LIS observations, describes spatial variability in these performance metrics, and documents the characteristics of LIS flashes that are detected by the long-range networks. Improved knowledge of relationships between these datasets will allow researchers, algorithm developers, and operational users to better prepare for the spatial and temporal coverage of the upcoming GOES-R Geostationary Lightning Mapper (GLM).

Beam-based measurements of long-range transverse wakefields in the Compact Linear Collider main-linac accelerating structure

DOE PAGES

Zha, Hao; Latina, Andrea; Grudiev, Alexej; ...

2016-01-20

The baseline design of CLIC (Compact Linear Collider) uses X-band accelerating structures for its main linacs. In order to maintain beam stability in multibunch operation, long-range transverse wakefields must be suppressed by 2 orders of magnitude between successive bunches, which are separated in time by 0.5 ns. Such strong wakefield suppression is achieved by equipping every accelerating structure cell with four damping waveguides terminated with individual rf loads. A beam-based experiment to directly measure the effectiveness of this long-range transverse wakefield and benchmark simulations was made in the FACET test facility at SLAC using a prototype CLIC accelerating structure. Furthermore,more » the experiment showed good agreement with the simulations and a strong suppression of the wakefields with an unprecedented minimum resolution of 0.1 V/(pC mm m).« less

Long-range Coulomb interaction effects on the topological phase transitions between semimetals and insulators

NASA Astrophysics Data System (ADS)

Han, SangEun; Moon, Eun-Gook

2018-06-01

Topological states may be protected by a lattice symmetry in a class of topological semimetals. In three spatial dimensions, the Berry flux around gapless excitations in momentum space concretely defines a chirality, so a protecting symmetry may be referred to as a chiral symmetry. Prime examples include a Dirac semimetal (DSM) in a distorted spinel, BiZnSiO4, protected by a mirror symmetry, and a DSM in Na3Bi , protected by a rotational symmetry. In these states, topology and chiral symmetry are intrinsically tied. In this Rapid Communication, the characteristic interplay between a chiral symmetry order parameter and an instantaneous long-range Coulomb interaction is investigated with the standard renormalization group method. We show that a topological transition associated with chiral symmetry is stable under the presence of a Coulomb interaction and the electron velocity always becomes faster than the one of a chiral symmetry order parameter. Thus, the transition must not be relativistic, which implies that supersymmetry is intrinsically forbidden by the long-range Coulomb interaction. Asymptotically exact universal ratios of physical quantities such as the energy gap ratio are obtained, and connections with experiments and recent theoretical proposals are also discussed.

Long-Range Planning: A Case Study.

ERIC Educational Resources Information Center

Vance, Carmen L.; And Others

1987-01-01

Describes the use of one model to guide the long-range planning process of the Department of Residential Life, within the Division of Student Affairs and Services, at the University of Connecticut. Suggestions derived from the use of the model over a three-year planning cycle are presented for other housing officers to consider. (NB)

Long-range-corrected Rung 3.5 density functional approximations

NASA Astrophysics Data System (ADS)

Janesko, Benjamin G.; Proynov, Emil; Scalmani, Giovanni; Frisch, Michael J.

2018-03-01

Rung 3.5 functionals are a new class of approximations for density functional theory. They provide a flexible intermediate between exact (Hartree-Fock, HF) exchange and semilocal approximations for exchange. Existing Rung 3.5 functionals inherit semilocal functionals' limitations in atomic cores and density tails. Here we address those limitations using range-separated admixture of HF exchange. We present three new functionals. LRC-ωΠLDA combines long-range HF exchange with short-range Rung 3.5 ΠLDA exchange. SLC-ΠLDA combines short- and long-range HF exchange with middle-range ΠLDA exchange. LRC-ωΠLDA-AC incorporates a combination of HF, semilocal, and Rung 3.5 exchange in the short range, based on an adiabatic connection. We test these in a new Rung 3.5 implementation including up to analytic fourth derivatives. LRC-ωΠLDA and SLC-ΠLDA improve atomization energies and reaction barriers by a factor of 8 compared to the full-range ΠLDA. LRC-ωΠLDA-AC brings further improvement approaching the accuracy of standard long-range corrected schemes LC-ωPBE and SLC-PBE. The new functionals yield highest occupied orbital energies closer to experimental ionization potentials and describe correctly the weak charge-transfer complex of ethylene and dichlorine and the hole-spin distribution created by an Al defect in quartz. This study provides a framework for more flexible range-separated Rung 3.5 approximations.

Topological footprints of the Kitaev chain with long-range superconducting pairings at a finite temperature

NASA Astrophysics Data System (ADS)

Bhattacharya, Utso; Dutta, Amit

2018-06-01

We study the one-dimensional Kitaev chain with long-range superconductive pairing terms at a finite temperature where the system is prepared in a mixed state in equilibrium with a heat reservoir maintained at a constant temperature T . In order to probe the footprint of the ground-state topological behavior of the model at finite temperature, we look at two global quantities extracted out of two geometrical constructions: the Uhlmann and the interferometric phase. Interestingly, when the long-range effect dominates, the Uhlmann phase approach fails to reproduce the topological aspects of the model in the pure-state limit; on the other hand, the interferometric phase which has a proper pure state reduction, shows a behavior independent of the ambient temperature.

Order-disorder effects in structure and color relation of photonic-crystal-type nanostructures in butterfly wing scales.

PubMed

Márk, Géza I; Vértesy, Zofia; Kertész, Krisztián; Bálint, Zsolt; Biró, László P

2009-11-01

In order to study local and global order in butterfly wing scales possessing structural colors, we have developed a direct space algorithm, based on averaging the local environment of the repetitive units building up the structure. The method provides the statistical distribution of the local environments, including the histogram of the nearest-neighbor distance and the number of nearest neighbors. We have analyzed how the different kinds of randomness present in the direct space structure influence the reciprocal space structure. It was found that the Fourier method is useful in the case of a structure randomly deviating from an ordered lattice. The direct space averaging method remains applicable even for structures lacking long-range order. Based on the first Born approximation, a link is established between the reciprocal space image and the optical reflectance spectrum. Results calculated within this framework agree well with measured reflectance spectra because of the small width and moderate refractive index contrast of butterfly scales. By the analysis of the wing scales of Cyanophrys remus and Albulina metallica butterflies, we tested the methods for structures having long-range order, medium-range order, and short-range order.

Order-disorder effects in structure and color relation of photonic-crystal-type nanostructures in butterfly wing scales

NASA Astrophysics Data System (ADS)

Márk, Géza I.; Vértesy, Zofia; Kertész, Krisztián; Bálint, Zsolt; Biró, László P.

2009-11-01

In order to study local and global order in butterfly wing scales possessing structural colors, we have developed a direct space algorithm, based on averaging the local environment of the repetitive units building up the structure. The method provides the statistical distribution of the local environments, including the histogram of the nearest-neighbor distance and the number of nearest neighbors. We have analyzed how the different kinds of randomness present in the direct space structure influence the reciprocal space structure. It was found that the Fourier method is useful in the case of a structure randomly deviating from an ordered lattice. The direct space averaging method remains applicable even for structures lacking long-range order. Based on the first Born approximation, a link is established between the reciprocal space image and the optical reflectance spectrum. Results calculated within this framework agree well with measured reflectance spectra because of the small width and moderate refractive index contrast of butterfly scales. By the analysis of the wing scales of Cyanophrys remus and Albulina metallica butterflies, we tested the methods for structures having long-range order, medium-range order, and short-range order.

Long-range, noncoherent laser Doppler velocimeter.

PubMed

Bloom, S H; Kremer, R; Searcy, P A; Rivers, M; Menders, J; Korevaar, E

1991-11-15

An experimental demonstration of a long-range, noncoherent laser Doppler velocimeter (LDV) is presented. The LDV detects incoming Doppler-shifted signal photons by using the sharp spectral absorption features in atomic or molecular vapors. The edge of the absorption feature is used to convert changes in frequency to large changes in transmission. Preliminary measurements of wind velocity using seeded aerosols showed that the LDV results agreed with mechanical anemometer measurements to within the accuracy of the LDV measurements. With optimization the LDV will provide accurate range-resolved and vibration-tolerant wind-speed measurements at large distances.

Long-Range Planning--Finances. Higher Education.

ERIC Educational Resources Information Center

Ward, Robert C.

This paper presents views on long-range financial planning for public and private higher education. Emphasis is placed on a mix of revenue sources for future support and on key budgetary considerations such as faculty and non-academic wages, the rising cost of graduate education, and the community and junior college movement. A triple crisis is…

Griffiths phase and long-range correlations in a biologically motivated visual cortex model

NASA Astrophysics Data System (ADS)

Girardi-Schappo, M.; Bortolotto, G. S.; Gonsalves, J. J.; Pinto, L. T.; Tragtenberg, M. H. R.

2016-07-01

Activity in the brain propagates as waves of firing neurons, namely avalanches. These waves’ size and duration distributions have been experimentally shown to display a stable power-law profile, long-range correlations and 1/f b power spectrum in vivo and in vitro. We study an avalanching biologically motivated model of mammals visual cortex and find an extended critical-like region - a Griffiths phase - characterized by divergent susceptibility and zero order parameter. This phase lies close to the expected experimental value of the excitatory postsynaptic potential in the cortex suggesting that critical be-havior may be found in the visual system. Avalanches are not perfectly power-law distributed, but it is possible to collapse the distributions and define a cutoff avalanche size that diverges as the network size is increased inside the critical region. The avalanches present long-range correlations and 1/f b power spectrum, matching experiments. The phase transition is analytically determined by a mean-field approximation.

Long-range looping of a locus control region drives tissue-specific chromatin packing within a multigene cluster

PubMed Central

Tsai, Yu-Cheng; Cooke, Nancy E.; Liebhaber, Stephen A.

2016-01-01

Abstract The relationships of higher order chromatin organization to mammalian gene expression remain incompletely defined. The human Growth Hormone (hGH) multigene cluster contains five gene paralogs. These genes are selectively activated in either the pituitary or the placenta by distinct components of a remote locus control region (LCR). Prior studies have revealed that appropriate activation of the placental genes is dependent not only on the actions of the LCR, but also on the multigene composition of the cluster itself. Here, we demonstrate that the hGH LCR ‘loops’ over a distance of 28 kb in primary placental nuclei to make specific contacts with the promoters of the two GH genes in the cluster. This long-range interaction sequesters the GH genes from the three hCS genes which co-assemble into a tightly packed ‘hCS chromatin hub’. Elimination of the long-range looping, via specific deletion of the placental LCR components, triggers a dramatic disruption of the hCS chromatin hub. These data reveal a higher-order structural pathway by which long-range looping from an LCR impacts on local chromatin architecture that is linked to tissue-specific gene regulation within a multigene cluster. PMID:26893355

Disordered Kitaev chains with long-range pairing.

PubMed

Cai, Xiaoming

2017-03-22

We study the competition of disorder and superconductivity for a generalized Kitaev model in incommensurate potentials. The generalized Kitaev model describes one dimensional spinless fermions with long-range p-wave superconducting pairing, which decays with distance l as a power law  ∼[Formula: see text]. We focus on the transition from the topological superconducting phase to the topologically trivial Anderson localized phase, and effects of the exponent α on this phase transition. In the topological superconducting phase, for a system under open boundary condition the amplitude of zero-mode Majorana fermion has a hybrid exponential-algebraic decay as the distance increases from the edge. In the Anderson localized phase, some single-particle states remain critical for very strong disorders and the number of critical states increases as α decreases. In addition, except for critical disorders, the correlation function always has an exponential decay at the short range and an algebraic decay at the long range. Phase transition points are also numerically determined and the topological phase transition happens earlier at a smaller disorder strength for a system with smaller α.

Dolphin "packet" use during long-range echolocation tasks.

PubMed

Finneran, James J

2013-03-01

When echolocating, dolphins typically emit a single broadband "click," then wait to receive the echo before emitting another click. However, previous studies have shown that during long-range echolocation tasks, they may instead emit a burst, or "packet," of several clicks, then wait for the packet of echoes to return before emitting another packet of clicks. The reasons for the use of packets are unknown. In this study, packet use was examined by having trained bottlenose dolphins perform long-range echolocation tasks. The tasks featured "phantom" echoes produced by capturing the dolphin's outgoing echolocation clicks, convolving the clicks with an impulse response to create an echo waveform, and then broadcasting the delayed, scaled echo to the dolphin. Dolphins were trained to report the presence of phantom echoes or a change in phantom echoes. Target range varied from 25 to 800 m. At ranges below 75 m, the dolphins rarely used packets. As the range increased beyond 75 m, two of the three dolphins increasingly produced packets, while the third dolphin instead utilized very high click repetition rates. The use of click packets appeared to be governed more by echo delay (target range) than echo amplitude.

Long-range, full-duplex, modulated-reflector cell phone for voice/data transmission

DOEpatents

Neagley, Daniel L.; Briles, Scott D.; Coates, Don M.; Freund, Samuel M.

2002-01-01

A long-range communications apparatus utilizing modulated-reflector technology is described. The apparatus includes an energy-transmitting base station and remote units that do not emit radiation in order to communicate with the base station since modulated-reflector technology is used whereby information is attached to an RF carrier wave originating from the base station which is reflected by the remote unit back to the base station. Since the remote unit does not emit radiation, only a low-power power source is required for its operation. Information from the base station is transmitted to the remote unit using a transmitter and receiver, respectively. The range of such a communications system is determined by the properties of a modulated-reflector half-duplex link.

Advanced Tactical Booster Technologies: Applications for Long-Range Rocket Systems

DTIC Science & Technology

2016-09-07

Applications for Long-Range Rocket Systems 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Matthew McKinna, Jason Mossman 5d...technology advantages currently under development for tactical rocket motors which have direct application to land-based long-range rocket systems...increased rocket payload capacity, improved rocket range or increased rocket loadout from the volumetrically constrained environment of a land-based

Target recognition of ladar range images using even-order Zernike moments.

PubMed

Liu, Zheng-Jun; Li, Qi; Xia, Zhi-Wei; Wang, Qi

2012-11-01

Ladar range images have attracted considerable attention in automatic target recognition fields. In this paper, Zernike moments (ZMs) are applied to classify the target of the range image from an arbitrary azimuth angle. However, ZMs suffer from high computational costs. To improve the performance of target recognition based on small samples, even-order ZMs with serial-parallel backpropagation neural networks (BPNNs) are applied to recognize the target of the range image. It is found that the rotation invariance and classified performance of the even-order ZMs are both better than for odd-order moments and for moments compressed by principal component analysis. The experimental results demonstrate that combining the even-order ZMs with serial-parallel BPNNs can significantly improve the recognition rate for small samples.

Maturational trajectories of local and long-range functional connectivity in autism during face processing.

PubMed

Mamashli, Fahimeh; Khan, Sheraz; Bharadwaj, Hari; Losh, Ainsley; Pawlyszyn, Stephanie M; Hämäläinen, Matti S; Kenet, Tal

2018-06-26

Autism spectrum disorder (ASD) is characterized neurophysiologically by, among other things, functional connectivity abnormalities in the brain. Recent evidence suggests that the nature of these functional connectivity abnormalities might not be uniform throughout maturation. Comparing between adolescents and young adults (ages 14-21) with ASD and age- and IQ-matched typically developing (TD) individuals, we previously documented, using magnetoencephalography (MEG) data, that local functional connectivity in the fusiform face areas (FFA) and long-range functional connectivity between FFA and three higher order cortical areas were all reduced in ASD. Given the findings on abnormal maturation trajectories in ASD, we tested whether these results extend to preadolescent children (ages 7-13). We found that both local and long-range functional connectivity were in fact normal in this younger age group in ASD. Combining the two age groups, we found that local and long-range functional connectivity measures were positively correlated with age in TD, but negatively correlated with age in ASD. Last, we showed that local functional connectivity was the primary feature in predicting age in ASD group, but not in the TD group. Furthermore, local functional connectivity was only correlated with ASD severity in the older group. These results suggest that the direction of maturation of functional connectivity for processing of faces from childhood to young adulthood is itself abnormal in ASD, and that during the processing of faces, these trajectory abnormalities are more pronounced for local functional connectivity measures than they are for long-range functional connectivity measures. © 2018 Wiley Periodicals, Inc.

Spread of Correlations in Long-Range Interacting Quantum Systems

NASA Astrophysics Data System (ADS)

Hauke, P.; Tagliacozzo, L.

2013-11-01

The nonequilibrium response of a quantum many-body system defines its fundamental transport properties and how initially localized quantum information spreads. However, for long-range-interacting quantum systems little is known. We address this issue by analyzing a local quantum quench in the long-range Ising model in a transverse field, where interactions decay as a variable power law with distance ∝r-α, α>0. Using complementary numerical and analytical techniques, we identify three dynamical regimes: short-range-like with an emerging light cone for α>2, weakly long range for 1<α<2 without a clear light cone but with a finite propagation speed of almost all excitations, and fully nonlocal for α<1 with instantaneous transmission of correlations. This last regime breaks generalized Lieb-Robinson bounds and thus locality. Numerical calculation of the entanglement spectrum demonstrates that the usual picture of propagating quasiparticles remains valid, allowing an intuitive interpretation of our findings via divergences of quasiparticle velocities. Our results may be tested in state-of-the-art trapped-ion experiments.

7 CFR 1717.604 - Long-range engineering plans and construction work plans.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false Long-range engineering plans and construction work... AND GUARANTEED ELECTRIC LOANS Operational Controls § 1717.604 Long-range engineering plans and construction work plans. (a) All borrowers are required to maintain up-to-date long-range engineering plans and...

7 CFR 1717.604 - Long-range engineering plans and construction work plans.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 11 2013-01-01 2013-01-01 false Long-range engineering plans and construction work... AND GUARANTEED ELECTRIC LOANS Operational Controls § 1717.604 Long-range engineering plans and construction work plans. (a) All borrowers are required to maintain up-to-date long-range engineering plans and...

7 CFR 1717.604 - Long-range engineering plans and construction work plans.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 11 2014-01-01 2014-01-01 false Long-range engineering plans and construction work... AND GUARANTEED ELECTRIC LOANS Operational Controls § 1717.604 Long-range engineering plans and construction work plans. (a) All borrowers are required to maintain up-to-date long-range engineering plans and...

7 CFR 1717.604 - Long-range engineering plans and construction work plans.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 11 2012-01-01 2012-01-01 false Long-range engineering plans and construction work... AND GUARANTEED ELECTRIC LOANS Operational Controls § 1717.604 Long-range engineering plans and construction work plans. (a) All borrowers are required to maintain up-to-date long-range engineering plans and...

7 CFR 1717.604 - Long-range engineering plans and construction work plans.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 11 2011-01-01 2011-01-01 false Long-range engineering plans and construction work... AND GUARANTEED ELECTRIC LOANS Operational Controls § 1717.604 Long-range engineering plans and construction work plans. (a) All borrowers are required to maintain up-to-date long-range engineering plans and...

Predicting long-range transport: a systematic evaluation of two multimedia transport models.

PubMed

Bennett, D H; Scheringer, M; McKone, T E; Hungerbühler, K

2001-03-15

The United Nations Environment Program has recently developed criteria to identify and restrict chemicals with a potential for persistence and long-range transport (persistent organic pollutants or POPs). There are many stakeholders involved, and the issues are not only scientific but also include social, economic, and political factors. This work focuses on one aspect of the POPs debate, the criteria for determining the potential for long-range transport (LRT). Our goal is to determine if current models are reliable enough to support decisions that classify a chemical based on the LRT potential. We examine the robustness of two multimedia fate models for determining the relative ranking and absolute spatial range of various chemicals in the environment. We also consider the effect of parameter uncertainties and the model uncertainty associated with the selection of an algorithm for gas-particle partitioning on the model results. Given the same chemical properties, both models give virtually the same ranking. However, when chemical parameter uncertainties and model uncertainties such as particle partitioning are considered, the spatial range distributions obtained for the individual chemicals overlap, preventing a distinct rank order. The absolute values obtained for the predicted spatial range or travel distance differ significantly between the two models for the uncertainties evaluated. We find that to evaluate a chemical when large and unresolved uncertainties exist, it is more informative to use two or more models and include multiple types of uncertainty. Model differences and uncertainties must be explicitly confronted to determine how the limitations of scientific knowledge impact predictions in the decision-making process.

Is walking a random walk? Evidence for long-range correlations in stride interval of human gait

NASA Technical Reports Server (NTRS)

Hausdorff, Jeffrey M.; Peng, C.-K.; Ladin, Zvi; Wei, Jeanne Y.; Goldberger, Ary L.

1995-01-01

Complex fluctuation of unknown origin appear in the normal gait pattern. These fluctuations might be described as being (1) uncorrelated white noise, (2) short-range correlations, or (3) long-range correlations with power-law scaling. To test these possibilities, the stride interval of 10 healthy young men was measured as they walked for 9 min at their usual rate. From these time series we calculated scaling indexes by using a modified random walk analysis and power spectral analysis. Both indexes indicated the presence of long-range self-similar correlations extending over hundreds of steps; the stride interval at any time depended on the stride interval at remote previous times, and this dependence decayed in a scale-free (fractallike) power-law fashion. These scaling indexes were significantly different from those obtained after random shuffling of the original time series, indicating the importance of the sequential ordering of the stride interval. We demonstrate that conventional models of gait generation fail to reproduce the observed scaling behavior and introduce a new type of central pattern generator model that sucessfully accounts for the experimentally observed long-range correlations.

A criterion autoscheduler for long range planning

NASA Technical Reports Server (NTRS)

Sponsler, Jeffrey L.

1994-01-01

A constraint-based scheduling system called SPIKE is used to create long-term schedules for the Hubble Space Telescope. A meta-level scheduler called the Criterion Autoscheduler for Long range planning (CASL) was created to guide SPIKE's schedule generation according to the agenda of the planning scientists. It is proposed that sufficient flexibility exists in a schedule to allow high level planning heuristics to be applied without adversely affected crucial constraints such as spacecraft efficiency. This hypothesis is supported by test data which is described.

A Model for Long Range Planning for Seminole Community College.

ERIC Educational Resources Information Center

Miner, Norris

A model for long-range planning designed to maximize involvement of college personnel, to improve communication among various areas of the college, to provide a process for evaluation of long-range plans and the planning process, to adjust to changing conditions, to utilize data developed at a level useful for actual operations, and to have…

The Alabama Long Range Program for Library Development, 1995-1999.

ERIC Educational Resources Information Center

Alabama Public Library Service, Montgomery.

This document contains the long range plan of the Alabama public libraries. The purpose of presenting this long range program is to meet the requirements of the Library Services and Construction Act (LSCA) and to assess, prioritize, and communicate library needs to librarians, officials, and the public to provide adequate library service to the…

Long-range effect of ion implantation of Raex and Hardox steels

NASA Astrophysics Data System (ADS)

Budzyński, P.; Kamiński, M.; Droździel, A.; Wiertel, M.

2016-09-01

Ion implantation involves introduction of ionized atoms of any element (nitrogen) to metals thanks to the high kinetic energy that they acquired in the electric field. The distribution of nitrogen ions implanted at E = 65 keV energy and D = 1.1017 N+ /cm2 fluence in the steel sample and vacancies produced by them was calculated using the SRIM program. This result was confirmed by RBS measurements. The initial maximum range of the implanted nitrogen ions is ∼⃒0.17 μm. This value is relatively small compared to the influence of nitriding on the thickness surface layer of modified steel piston rings. Measurements of the friction coefficient during the pin-on-disc tribological test were performed under dry friction conditions. The friction coefficient of the implanted sample increased to values characteristic of an unimplanted sample after ca. 1500 measurement cycles. The depth of wear trace is ca. 2.4 μm. This implies that the thickness of the layer modified by the implantation process is ∼⃒2.4 μm and exceeds the initial range of the implanted ions by an order of magnitude. This effect, referred to as a long-range implantation effect, is caused by migration of vacancies and nitrogen atoms into the sample. This phenomenon makes ion implantation a legitimate process of modification of the surface layer in order to enhance the tribological properties of critical components of internal combustion engines such as steel piston rings.

Long-distance dispersal suppresses introgression of local alleles during range expansions

PubMed Central

Amorim, C E G; Hofer, T; Ray, N; Foll, M; Ruiz-Linares, A; Excoffier, L

2017-01-01

During range expansions, even low levels of interbreeding can lead to massive introgression of local alleles into an invader's genome. Nonetheless, this pattern is not always observed in human populations. For instance, European Americans in North America are barely introgressed by Amerindian genes in spite of known contact and admixture. With coalescent spatially explicit simulations, we examined the impact of long-distance dispersal (LDD) events on introgression of local alleles into the invading population using a set of different demographic scenarios applicable to a diverse range of natural populations and species. More specifically, we consider two distinct LDD models: one where LDD events originate in the range core and targets only the expansion front and a second one where LDD events can occur from any area to any other. We find that LDD generally prevents introgression, but that LDD events specifically targeting the expansion front are most efficient in suppressing introgression. This is likely due to the fact that LDD allows for the presence of a larger number of invader alleles at the wave front, where effective population size is thus increased and local introgressed alleles are rapidly outnumbered. We postulate that the documented settlement of pioneers directly on the wave front in North America has contributed to low levels of Amerindian admixture observed in European Americans and that this phenomenon may well explain the lack of introgression after a range expansion in natural populations without the need to evoke other mechanisms such as natural selection. PMID:27577693

Large, long range tensile forces drive convergence during Xenopus blastopore closure and body axis elongation

PubMed Central

Kasprowicz, Eric M; Davidson, Lance A; Keller, Raymond

2018-01-01

Indirect evidence suggests that blastopore closure during gastrulation of anamniotes, including amphibians such as Xenopus laevis, depends on circumblastoporal convergence forces generated by the marginal zone (MZ), but direct evidence is lacking. We show that explanted MZs generate tensile convergence forces up to 1.5 μN during gastrulation and over 4 μN thereafter. These forces are generated by convergent thickening (CT) until the midgastrula and increasingly by convergent extension (CE) thereafter. Explants from ventralized embryos, which lack tissues expressing CE but close their blastopores, produce up to 2 μN of tensile force, showing that CT alone generates forces sufficient to close the blastopore. Uniaxial tensile stress relaxation assays show stiffening of mesodermal and ectodermal tissues around the onset of neurulation, potentially enhancing long-range transmission of convergence forces. These results illuminate the mechanobiology of early vertebrate morphogenic mechanisms, aid interpretation of phenotypes, and give insight into the evolution of blastopore closure mechanisms. PMID:29533180

Stepping Stone Mechanism: Carrier-Free Long-Range Magnetism Mediated by Magnetized Cation States in Quintuple Layer

NASA Astrophysics Data System (ADS)

Chan, Chunkai; Zhang, Xiaodong; Zhang, Yiou; Tse, Kinfai; Deng, Bei; Zhang, Jingzhao; Zhu, Junyi

2018-01-01

The long-range magnetism observed in group-V tellurides quintuple layers is the only working example of carrier-free dilute magnetic semiconductors (DMS), whereas the physical mechanism is unclear, except the speculation on the band topology enhanced van Vleck paramagnetism. Based on DFT calculations, we find a stable long-range ferromagnetic order in a single quintuple layer of Cr-doped Bi2Te3 or Sb2Te3, with the dopant separation more than 9 Å. This configuration is the global energy minimum among all configurations. Different from the conventional super exchange theory, the magnetism is facilitated by the lone pair derived anti-bonding states near the cations. Such anti-bonding states work as stepping stones merged in the electron sea and conduct magnetism. Further, spin orbit coupling induced band inversion is found to be insignificant in the magnetism. Therefore, our findings directly dismiss the common misbelief that band topology is the only factor that enhances the magnetism. We further demonstrate that removal of the lone pair derived states destroys the long-range magnetism. This novel mechanism sheds light on the fundamental understanding of long-range magnetism and may lead to discoveries of new classes of DMS. Supported by Chinese University of Hong Kong (CUHK) under Grant No 4053084, University Grants Committee of Hong Kong under Grant No 24300814, and the Start-up Funding of CUHK.

Laser-ranging long-baseline differential atom interferometers for space

NASA Astrophysics Data System (ADS)

Chiow, Sheng-wey; Williams, Jason; Yu, Nan

2015-12-01

High-sensitivity differential atom interferometers (AIs) are promising for precision measurements in science frontiers in space, including gravity-field mapping for Earth science studies and gravitational wave detection. Difficulties associated with implementing long-baseline differential AIs have previously included the need for a high optical power, large differential Doppler shifts, and narrow dynamic range. We propose a configuration of twin AIs connected by a laser-ranging interferometer (LRI-AI) to provide precise information of the displacements between the two AI reference mirrors and also to phase-lock the two independent interferometer lasers over long distances, thereby drastically improving the practical feasibility of long-baseline differential AI measurements. We show that a properly implemented LRI-AI can achieve equivalent functionality to the conventional differential AI measurement configuration.

NASA's Long-range Technology Goals

NASA Technical Reports Server (NTRS)

1990-01-01

This document is part of the Final Report performed under contract NASW-3864, titled "NASA's Long-Range Technology Goals". The objectives of the effort were: To identify technologies whose development falls within NASA's capability and purview, and which have high potential for leapfrog advances in the national industrial posture in the 2005-2010 era. To define which of these technologies can also enable quantum jumps in the national space program. To assess mechanisms of interaction between NASA and industry constituencies for realizing the leapfrog technologies. This Volume details the findings pertaining to the advanced space-enabling technologies.

Local and long-range circuit elements for cerebellar function.

PubMed

Xiao, Le; Scheiffele, Peter

2018-02-01

The view of cerebellar functions has been extended from controlling sensorimotor processes to processing 'contextual' information and generating predictions for a diverse range of behaviors. These functions rely on the computation of the local cerebellar microcircuits and long-range connectivity that relays cerebellar output to various brain areas. In this review, we discuss recent work on two of the circuit elements, which are thought to be fundamental for a wide range of non-sensorimotor behaviors: The role for cerebellar granule cells in multimodal integration in the cerebellar cortex and the long-range connectivity between the deep cerebellar nuclei and the basal ganglia. Lastly, we discuss how studies on synapses and circuits of the cerebellum in rodent models of autism-spectrum disorders might contribute to our understanding of the pathophysiology of this class of neurodevelopmental disorders. Copyright © 2017. Published by Elsevier Ltd.

Long-Range Self-Assembly via the Mutual Lorentz Force of Plasmon Radiation.

PubMed

Ji, Haojie; Trevino, Jacob; Tu, Raymond; Knapp, Ellen; McQuade, James; Yurkiv, Vitaliy; Mashayek, Farzad; Vuong, Luat T

2018-04-11

Long-range interactions often proceed as a sequence of hopping through intermediate, statistically favored events. Here, we demonstrate predictable mechanical dynamics of particles that arise from the Lorentz force between plasmons. Even if the radiation is weak, the nonconservative Lorentz force produces stable locations perpendicular to the plasmon oscillation; over time, distinct patterns emerge. Experimentally, linearly polarized light illumination leads to the formation of 80 nm diameter Au nanoparticle chains, perpendicularly aligned, with lengths that are orders of magnitude greater than their plasmon near-field interaction. There is a critical intensity threshold and optimal concentration for observing self-assembly.

Quantum transport with long-range steps on Watts-Strogatz networks

NASA Astrophysics Data System (ADS)

Wang, Yan; Xu, Xin-Jian

2016-07-01

We study transport dynamics of quantum systems with long-range steps on the Watts-Strogatz network (WSN) which is generated by rewiring links of the regular ring. First, we probe physical systems modeled by the discrete nonlinear schrödinger (DNLS) equation. Using the localized initial condition, we compute the time-averaged occupation probability of the initial site, which is related to the nonlinearity, the long-range steps and rewiring links. Self-trapping transitions occur at large (small) nonlinear parameters for coupling ɛ=-1 (1), as long-range interactions are intensified. The structure disorder induced by random rewiring, however, has dual effects for ɛ=-1 and inhibits the self-trapping behavior for ɛ=1. Second, we investigate continuous-time quantum walks (CTQW) on the regular ring ruled by the discrete linear schrödinger (DLS) equation. It is found that only the presence of the long-range steps does not affect the efficiency of the coherent exciton transport, while only the allowance of random rewiring enhances the partial localization. If both factors are considered simultaneously, localization is greatly strengthened, and the transport becomes worse.

Long-Range Strategic Planning: The Rochester Experience.

ERIC Educational Resources Information Center

Schultz, John M.; Anthony, Deborah L.

The administration of Rochester Community Schools (Michigan) initiated a process for long-range strategic planning in 1984, described in this synopsis. Strategic planning is an ongoing, evolutionary process of defining the business one is in or should be in; establishing organizational goals and objectives; and developing and implementing…

A Long-Range Approach to Instructional Leadership.

ERIC Educational Resources Information Center

McDermott, Donald F.

1984-01-01

In Anchorage, Alaska, aspiring principals are getting on-the-job experience through a two-year intern program that facilitates long range planning by enabling the district to test and mold its future administrators. Interns serve as administrative assistants, troubleshooters, and participates in instructional supervision and policy decision. (TE)

Segmentation of time series with long-range fractal correlations

PubMed Central

Bernaola-Galván, P.; Oliver, J.L.; Hackenberg, M.; Coronado, A.V.; Ivanov, P.Ch.; Carpena, P.

2012-01-01

Segmentation is a standard method of data analysis to identify change-points dividing a nonstationary time series into homogeneous segments. However, for long-range fractal correlated series, most of the segmentation techniques detect spurious change-points which are simply due to the heterogeneities induced by the correlations and not to real nonstationarities. To avoid this oversegmentation, we present a segmentation algorithm which takes as a reference for homogeneity, instead of a random i.i.d. series, a correlated series modeled by a fractional noise with the same degree of correlations as the series to be segmented. We apply our algorithm to artificial series with long-range correlations and show that it systematically detects only the change-points produced by real nonstationarities and not those created by the correlations of the signal. Further, we apply the method to the sequence of the long arm of human chromosome 21, which is known to have long-range fractal correlations. We obtain only three segments that clearly correspond to the three regions of different G + C composition revealed by means of a multi-scale wavelet plot. Similar results have been obtained when segmenting all human chromosome sequences, showing the existence of previously unknown huge compositional superstructures in the human genome. PMID:23645997

Segmentation of time series with long-range fractal correlations.

PubMed

Bernaola-Galván, P; Oliver, J L; Hackenberg, M; Coronado, A V; Ivanov, P Ch; Carpena, P

2012-06-01

Segmentation is a standard method of data analysis to identify change-points dividing a nonstationary time series into homogeneous segments. However, for long-range fractal correlated series, most of the segmentation techniques detect spurious change-points which are simply due to the heterogeneities induced by the correlations and not to real nonstationarities. To avoid this oversegmentation, we present a segmentation algorithm which takes as a reference for homogeneity, instead of a random i.i.d. series, a correlated series modeled by a fractional noise with the same degree of correlations as the series to be segmented. We apply our algorithm to artificial series with long-range correlations and show that it systematically detects only the change-points produced by real nonstationarities and not those created by the correlations of the signal. Further, we apply the method to the sequence of the long arm of human chromosome 21, which is known to have long-range fractal correlations. We obtain only three segments that clearly correspond to the three regions of different G + C composition revealed by means of a multi-scale wavelet plot. Similar results have been obtained when segmenting all human chromosome sequences, showing the existence of previously unknown huge compositional superstructures in the human genome.

Individual differences in long-range time representation.

PubMed

Agostino, Camila S; Caetano, Marcelo S; Balci, Fuat; Claessens, Peter M E; Zana, Yossi

2017-04-01

On the basis of experimental data, long-range time representation has been proposed to follow a highly compressed power function, which has been hypothesized to explain the time inconsistency found in financial discount rate preferences. The aim of this study was to evaluate how well linear and power function models explain empirical data from individual participants tested in different procedural settings. The line paradigm was used in five different procedural variations with 35 adult participants. Data aggregated over the participants showed that fitted linear functions explained more than 98% of the variance in all procedures. A linear regression fit also outperformed a power model fit for the aggregated data. An individual-participant-based analysis showed better fits of a linear model to the data of 14 participants; better fits of a power function with an exponent β > 1 to the data of 12 participants; and better fits of a power function with β < 1 to the data of the remaining nine participants. Of the 35 volunteers, the null hypothesis β = 1 was rejected for 20. The dispersion of the individual β values was approximated well by a normal distribution. These results suggest that, on average, humans perceive long-range time intervals not in a highly compressed, biased manner, but rather in a linear pattern. However, individuals differ considerably in their subjective time scales. This contribution sheds new light on the average and individual psychophysical functions of long-range time representation, and suggests that any attribution of deviation from exponential discount rates in intertemporal choice to the compressed nature of subjective time must entail the characterization of subjective time on an individual-participant basis.

Efficient Long-Range Hole Transport Through G-Quadruplexes.

PubMed

Wu, Jingyuan; Meng, Zhenyu; Lu, Yunpeng; Shao, Fangwei

2017-10-09

DNA offers a means of long-range charge transport for biology and electric nanodevices. Here, a series of tetra-stranded G-quadruplexes were assembled within a dendritic DNA architecture to explore oxidative charge transport (hole transport) through the G-quadruplex. Efficient charge transport was achieved over 28 Å upon UV irradiation. Over a longer G-quadruplex bridge, hole transport was escalated to a higher efficiency, which resulted in a higher yield than that of the optimal duplex DNA for charge transport, that is, the adenine tract. Efficient long-range hole transport suggests tetra-stranded G-quadruplexes, instead of an oxidation hotspot, hold better potential as an electron conduit than duplex DNA. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Long-range Kitaev chains via planar Josephson junctions

NASA Astrophysics Data System (ADS)

Liu, Dillon T.; Shabani, Javad; Mitra, Aditi

2018-06-01

We show how a recently proposed solid-state Majorana platform comprising a planar Josephson junction proximitized to a 2D electron gas (2DEG) with Rashba spin-orbit coupling and Zeeman field can be viewed as an effectively one-dimensional (1D) Kitaev chain with long-range pairing and hopping terms. We highlight how the couplings of the 1D system may be tuned by changing experimentally realistic parameters. We also show that the mapping is robust to disorder by computing the Clifford pseudospectrum index in real space for the long-range Kitaev chain across several topological phases. This mapping opens up the possibility of using current experimental setups to explore 1D topological superconductors with nonstandard and tunable couplings.

Long-range electron transfer in a model for DNA

NASA Astrophysics Data System (ADS)

Endres, R. G.; Cox, D. L.

2001-03-01

Long-range electron transfer (ET) between well separated donor (D) and acceptor (A) sites through quantum mechanical tunneling is essential to many biological processes like respiration, photosynthesis and possibly DNA repair and damage. We are investigating the distance dependence of the electronic transition matrix element H_DA and hence of the electron transfer rate in a model for DNA. Fluorescence quenching in DNA at D-A distances of 40 Åand more suggests ET with an unusually high decay length β-1 of order 10 Å (S.O.Kelley and J.K.Barton, in:Metal Ions in Biological Systems), A.Sigel and H.Sigel, Eds., Marcel Dekker, New York, Vol.36, 1999. Assuming strong electron interactions on the D complex and suitable energetics, this could be explained by formation of a many electron Kondo boundstate. We obtain H_DA from the splitting between the two lowest adiabatic electronic eigenenergies, which constitute the potential energy surfaces (PES) of the nuclear motion in lowest order Born-Oppenheimer approximation. The PES are constructed by coupling D and A to local breathing modes and by making a semi-analytical variational ansatz for the adiabatic eigenstates. The results from the PES are compared with results from the Mulliken-Hush algorithm.

Thermal ageing and short-range ordering of Alloy 690 between 350 and 550 °C

NASA Astrophysics Data System (ADS)

Mouginot, Roman; Sarikka, Teemu; Heikkilä, Mikko; Ivanchenko, Mykola; Ehrnstén, Ulla; Kim, Young Suk; Kim, Sung Soo; Hänninen, Hannu

2017-03-01

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 M23C6 carbides increased with increasing ageing temperature in all conditions, as well as diffusion-induced grain boundary migration (DIGM).

Using short-range and long-range functional connectivity to identify schizophrenia with a family-based case-control design.

PubMed

Guo, Wenbin; Liu, Feng; Chen, Jindong; Wu, Renrong; Li, Lehua; Zhang, Zhikun; Chen, Huafu; Zhao, Jingping

2017-06-30

Abnormal short-range and long-range functional connectivities (FCs) have been implicated in the neurophysiology of schizophrenia. This study was conducted to examine the potential of short-range and long-range FCs for differentiating the patients from the controls with a family-based case-control design. Twenty-eight first-episode, drug-naive patients with schizophrenia, 28 unaffected siblings of the patients (family-based controls, FBCs), and 40 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging (fMRI) scans. The data were analyzed by short-range and long-range FC analyses, receiver operating characteristic curve (ROC) and support vector machine (SVM). Compared with the FBCs/HCs, the patients exhibit increased short-range positive FC strength (spFCS) and/or long-range positive FC strength (lpFCS) in the default-mode network (DMN) and decreased spFCS and lpFCS in the sensorimotor circuits. Furthermore, a combination of the spFCS values in the right superior parietal lobule and the lpFCS values in the left fusiform gyrus/cerebellum VI can differentiate the patients from the FBCs with high sensitivity and specificity. The findings highlight the importance of the DMN and sensorimotor circuits in the pathogenesis of schizophrenia. Combining with family-based case-control design may be a viable option to limit the confounding effects of environmental risk factors in neuroimaging studies of schizophrenia. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Pressure effect on the long-range order in CeB6

NASA Astrophysics Data System (ADS)

Sera, M.; Ikeda, S.; Iwakubo, H.; Uwatoko, Y.; Hane, S.; Kosaka, M.; Kunii, S.

2006-08-01

The pressure effect of CeB6 was investigated. The pressure dependence of the Néel temperature, TN and the critical field from the antiferro-magnetic phase III to antiferro-quadrupolar phase II, HcIII-II of CeB6 exhibits the unusual pressure dependence that the suppression rate of HcIII-II is much larger than that of TN. In order to explain this unusual result, we have performed the mean field calculation for the 4-sublattice model assuming that the pressure dependence of TN, the antiferro-octupolar and quadrupolar temperatures, Toct and TQ as follows; dTN/dP<0, dToct/dP>dTQ/dP>0 and could explain the unusual pressure dependence of TN and HcIII-II.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bytchkov, Aleksei; Hennet, Louis; Price, David L.

2011-04-01

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{sub x}Se{sub 1-x} glasses spanning two glass regions, x 0.025-0.54 and 0.64-0.84. Liquid P{sub 4}Se{sub 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 {approx}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 {sup -1}, identified in earlier numerical simulations,more » 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.« less

Long-range correlation of the membrane potential in neocortical neurons during slow oscillation

PubMed Central

Volgushev, Maxim; Chauvette, Sylvain; Timofeev, Igor

2012-01-01

Large amplitude slow waves are characteristic for the summary brain activity, recorded as electroencephalogram (EEG) or local field potentials (LFP), during deep stages of sleep and some types of anesthesia. Slow rhythm of the synchronized EEG reflects an alternation of active (depolarized, UP) and silent (hyperpolarized, DOWN) states of neocortical neurons. In neurons, involvement in the generalized slow oscillation results in a long-range synchronization of changes of their membrane potential as well as their firing. Here, we aimed at intracellular analysis of details of this synchronization. We asked which components of neuronal activity exhibit long-range correlations during the synchronized EEG? To answer this question, we made simultaneous intracellular recordings from two to four neocortical neurons in cat neocortex. We studied how correlated is the occurrence of active and silent states, and how correlated are fluctuations of the membrane potential in pairs of neurons located close one to the other or separated by up to 13 mm. We show that strong long-range correlation of the membrane potential was observed only (i) during the slow oscillation but not during periods without the oscillation, (ii) during periods which included transitions between the states but not during within-the-state periods, and (iii) for the low-frequency (<5 Hz) components of membrane potential fluctuations but not for the higher-frequency components (>10 Hz). In contrast to the neurons located several millimeters one from the other, membrane potential fluctuations in neighboring neurons remain strongly correlated during periods without slow oscillation. We conclude that membrane potential correlation in distant neurons is brought about by synchronous transitions between the states, while activity within the states is largely uncorrelated. The lack of the generalized fine-scale synchronization of membrane potential changes in neurons during the active states of slow oscillation may

Local Structure and Short-Range Order in a NiCoCr Solid Solution Alloy

DOE PAGES

Zhang, F. X.; Zhao, Shijun; Jin, Ke; ...

2017-05-19

Multi-element solid solution alloys are intrinsically disordered on the atomic scale, and many of their advanced properties originate from the unique local structural characteristics. We measured the local structure of a NiCoCr solid solution alloy with X-ray/neutron total scattering and extended X-ray absorption fine structure (EXAFS) techniques. The atomic pair distribution function analysis (PDF) did not exhibit distinct structural distortion. But, EXAFS analysis suggested that the Cr atoms are favorably bonded with Ni and Co in the solid solution alloys. This short-range order (SRO) plays a role in the distinct low values of electrical and thermal conductivities in Ni-based solidmore » solution alloys when Cr is incorporated. Both the long-range and local structures of the NiCoCr alloy upon Ni ion irradiation were studied and an irradiation-induced enhancement of SRO was found.« less

Long-range forecasts for the energy market - a case study

NASA Astrophysics Data System (ADS)

Hyvärinen, Otto; Mäkelä, Antti; Kämäräinen, Matti; Gregow, Hilppa

2017-04-01

We examined the feasibility of long-range forecasts of temperature for needs of the energy sector in Helsinki, Finland. The work was done jointly by Finnish Meteorological Institute (FMI) and Helen Ltd, the main Helsinki metropolitan area energy provider, and especially provider of district heating and cooling. Because temperatures govern the need of heating and cooling and, therefore, the energy demand, better long-range forecasts of temperature would be highly useful for Helen Ltd. Heating degree day (HDD) is a parameter that indicates the demand of energy to heat a building. We examined the forecasted monthly HDD values for Helsinki using UK Met Office seasonal forecasts with the lead time up to two months. The long-range forecasts of monthly HDD showed some skill in Helsinki in winter 2015-2016, especially if the very cold January is excluded.

Mechanobiological induction of long-range contractility by diffusing biomolecules and size scaling in cell assemblies

NASA Astrophysics Data System (ADS)

Dasbiswas, K.; Alster, E.; Safran, S. A.

2016-06-01

Mechanobiological studies of cell assemblies have generally focused on cells that are, in principle, identical. Here we predict theoretically the effect on cells in culture of locally introduced biochemical signals that diffuse and locally induce cytoskeletal contractility which is initially small. In steady-state, both the concentration profile of the signaling molecule as well as the contractility profile of the cell assembly are inhomogeneous, with a characteristic length that can be of the order of the system size. The long-range nature of this state originates in the elastic interactions of contractile cells (similar to long-range “macroscopic modes” in non-living elastic inclusions) and the non-linear diffusion of the signaling molecules, here termed mechanogens. We suggest model experiments on cell assemblies on substrates that can test the theory as a prelude to its applicability in embryo development where spatial gradients of morphogens initiate cellular development.

Fit Point-Wise AB Initio Calculation Potential Energies to a Multi-Dimension Long-Range Model

NASA Astrophysics Data System (ADS)

Zhai, Yu; Li, Hui; Le Roy, Robert J.

2016-06-01

A potential energy surface (PES) is a fundamental tool and source of understanding for theoretical spectroscopy and for dynamical simulations. Making correct assignments for high-resolution rovibrational spectra of floppy polyatomic and van der Waals molecules often relies heavily on predictions generated from a high quality ab initio potential energy surface. Moreover, having an effective analytic model to represent such surfaces can be as important as the ab initio results themselves. For the one-dimensional potentials of diatomic molecules, the most successful such model to date is arguably the ``Morse/Long-Range'' (MLR) function developed by R. J. Le Roy and coworkers. It is very flexible, is everywhere differentiable to all orders. It incorporates correct predicted long-range behaviour, extrapolates sensibly at both large and small distances, and two of its defining parameters are always the physically meaningful well depth {D}_e and equilibrium distance r_e. Extensions of this model, called the Multi-Dimension Morse/Long-Range (MD-MLR) function, linear molecule-linear molecule systems and atom-non-linear molecule system. have been applied successfully to atom-plus-linear molecule, linear molecule-linear molecule and atom-non-linear molecule systems. However, there are several technical challenges faced in modelling the interactions of general molecule-molecule systems, such as the absence of radial minima for some relative alignments, difficulties in fitting short-range potential energies, and challenges in determining relative-orientation dependent long-range coefficients. This talk will illustrate some of these challenges and describe our ongoing work in addressing them. Mol. Phys. 105, 663 (2007); J. Chem. Phys. 131, 204309 (2009); Mol. Phys. 109, 435 (2011). Phys. Chem. Chem. Phys. 10, 4128 (2008); J. Chem. Phys. 130, 144305 (2009) J. Chem. Phys. 132, 214309 (2010) J. Chem. Phys. 140, 214309 (2010)

Methane Hydrate Formation in Thick Sand Reservoirs: Long-range Gas Transport or Short-range Methane Diffusion?

NASA Astrophysics Data System (ADS)

You, K.; Flemings, P. B.

2016-12-01

We developed two 2-D numerical models to simulate hydrate formation by long range methane gas transport and short-range methane diffusion. We interpret that methane hydrates in thick sands are most likely formed by long range gas transport where methane gas is transported upward into the hydrate stability zone (HSZ) under buoyancy and locally forms hydrate to its stability limit. In short-range methane diffusion, methane is generated locally by biodegradation of organic matter in mud and diffused into bounding sands where it forms hydrate. We could not simulate enough methane transport by diffusion to account for its observed concentration in thick sands. In our models, we include the capillary effect on dissolved methane solubility and on the hydrate phase boundary, sedimentation and different compaction in sand and mud, fracture generation as well as the fully coupled multiphase flow and multicomponent transport. We apply our models to a 12 meter-thick hydrate-bearing sand layer at Walker Ridge 313, Northern Gulf of Mexico. With the long-range gas transport, hydrate saturation is greater than 90% and salinity is increased from seawater to about 8 wt.% through the entire sand. With short-range diffusion, hydrate saturation is more than 90% at the sand base and is less than 10% in the overlying section; salinity is close to seawater when sand is deposited to 800 meter below seafloor by short-range methane diffusion. With short-range diffusion, the amount of hydrate formed is much less than that interpreted from the well log data. Two transient gas layers separated by a hydrate layer are formed from short-range diffusion caused by capillary effect. This could be interpreted as a double bottom simulating reflector. This study provides further insights into different hydrate formation mechanisms, and could serve as a base to confirm the hydrate formation mechanism in fields.

Observation of prethermalization in long-range interacting spin chains

PubMed Central

Neyenhuis, Brian; Zhang, Jiehang; Hess, Paul W.; Smith, Jacob; Lee, Aaron C.; Richerme, Phil; Gong, Zhe-Xuan; Gorshkov, Alexey V.; Monroe, Christopher

2017-01-01

Although statistical mechanics describes thermal equilibrium states, these states may or may not emerge dynamically for a subsystem of an isolated quantum many-body system. For instance, quantum systems that are near-integrable usually fail to thermalize in an experimentally realistic time scale, and instead relax to quasi-stationary prethermal states that can be described by statistical mechanics, when approximately conserved quantities are included in a generalized Gibbs ensemble (GGE). We experimentally study the relaxation dynamics of a chain of up to 22 spins evolving under a long-range transverse-field Ising Hamiltonian following a sudden quench. For sufficiently long-range interactions, the system relaxes to a new type of prethermal state that retains a strong memory of the initial conditions. However, the prethermal state in this case cannot be described by a standard GGE; it rather arises from an emergent double-well potential felt by the spin excitations. This result shows that prethermalization occurs in a broader context than previously thought, and reveals new challenges for a generic understanding of the thermalization of quantum systems, particularly in the presence of long-range interactions. PMID:28875166

Long-range correlations and asymmetry in the Bitcoin market

NASA Astrophysics Data System (ADS)

Alvarez-Ramirez, J.; Rodriguez, E.; Ibarra-Valdez, C.

2018-02-01

This work studies long-range correlations and informational efficiency of the Bitcoin market for the period from June 30, 2013 to June 3rd, 2017. To this end, the detrended fluctuation analysis (DFA) was implemented over sliding windows to estimate long-range correlations for price returns. It was found that the Bitcoin market exhibits periods of efficiency alternating with periods where the price dynamics are driven by anti-persistence. The pattern is replicated by prices samples at day, hour and second frequencies. The Bitcoin market also presents asymmetric correlations with respect to increasing and decreasing price trending, with the former trend linked to anti-persistence of returns dynamics.

Long-range analysis of density fitting in extended systems

NASA Astrophysics Data System (ADS)

Varga, Scarontefan

Density fitting scheme is analyzed for the Coulomb problem in extended systems from the correctness of long-range behavior point of view. We show that for the correct cancellation of divergent long-range Coulomb terms it is crucial for the density fitting scheme to reproduce the overlap matrix exactly. It is demonstrated that from all possible fitting metric choices the Coulomb metric is the only one which inherently preserves the overlap matrix for infinite systems with translational periodicity. Moreover, we show that by a small additional effort any non-Coulomb metric fit can be made overlap-preserving as well. The problem is analyzed for both ordinary and Poisson basis set choices.

Design of a high capacity long range cargo aircraft

NASA Technical Reports Server (NTRS)

Weisshaar, Terrence A.

1994-01-01

This report examines the design of a long range cargo transport to attempt to reduce ton-mile shipping costs and to stimulate the air cargo market. This design effort involves the usual issues but must also include consideration of: airport terminal facilities; cargo loading and unloading; and defeating the 'square-cube' law to design large structures. This report reviews the long range transport design problem and several solutions developed by senior student design teams at Purdue University. The results show that it will be difficult to build large transports unless the infrastructure is changed and unless the basic form of the airplane changes so that aerodynamic and structural efficiencies are employed.

Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues

DTIC Science & Technology

2013-01-10

and Long-Range Ballistic Missiles Congressional Research Service Forward-Based Global Strike ( FBGS ...they may address the nuclear ambiguity issues raised by long-range ballistic missiles in the CPGS program. Forward-Based Global Strike ( FBGS

Space - The long range future

NASA Technical Reports Server (NTRS)

Von Puttkamer, J.

1985-01-01

Space exploration goals for NASA in the year 2000 time frame are examined. A lunar base would offer the opportunity for continuous earth viewing, further cosmogeochemical exploration and rudimentary steps at self-sufficiency in space. The latter two factors are also compelling reasons to plan a manned Mars base. Furthermore, competition and cooperation in a Mars mission and further interplanetary exploration is an attractive substitute for war. The hardware requirements for various configurations of Mars missions are briefly addressed, along with other, unmanned missions to the asteroid belt, Mercury, Venus, Jupiter and the moons of Jupiter and Saturn. Finally, long-range technological requirements for providing adequate living/working facilities for larger human populations in Space Station environments are summarized.

Repeated or long-duration TASER electronic control device exposures: acidemia and lack of respiration.

PubMed

Jauchem, James R

2010-03-01

Conducted energy weapons (CEWs), such as TASER devices, may be applied to subjects in repeated or long-duration modes. Such applications may result in more potentially harmful effects (as reflected in blood factor changes) than shorter exposures. In this review, results from a number of studies of repeated and long-duration CEW exposures in an animal model are examined. Additionally, a few limited investigations of shorter CEW applications to human subjects are considered. Specifically, in anesthetized swine, increased blood acidity (acidemia) and lack of effective respiration were found to be common during or immediately after CEW exposure. The acidemia could have been due to both metabolic and respiratory acidosis. A relatively rapid recovery toward baseline pH levels occurred. The lack of effective respiration has not been verified in experiments of CEW applications to human subjects; however, in some incidents of human deaths after CEW exposures subjects have been reported to stop breathing immediately after the exposure. It is not known if all human subjects exposed to CEW applications in the field (often "on drugs" or "in excited delirium") would be able to maintain adequate breathing. Since a limited number of short CEW applications would be less likely to cause adverse effects, however, CEWs can still be a valuable tool for law enforcement activities.

Aggregation of heteropolyanions in aqueous solutions exhibiting short-range attractions and long-range repulsions

DOE PAGES

Bera, Mrinal K.; Qiao, Baofu; Seifert, Soenke; ...

2015-12-15

Charged colloids and proteins in aqueous solutions interact via short-range attractions and long-range repulsions (SALR) and exhibit complex structural phases. These include homogeneously dispersed monomers, percolated monomers, clusters, and percolated clusters. We report the structural architectures of simple charged systems in the form of spherical, Keggin-type heteropolyanions (HPAs) by small-angle X-ray scattering (SAXS) and molecular dynamics (MD) simulations. Structure factors obtained from the SAXS measurements show that the HPAs interact via SALR. Concentration and temperature dependences of the structure factors for HPAs with –3e (e is the charge of an electron) charge are consistent with a mixture of nonassociated monomersmore » and associated randomly percolated monomers, whereas those for HPAs with –4e and –5e charges exhibit only nonassociated monomers in aqueous solutions. Our experiments show that the increase in magnitude of the charge of the HPAs increases their repulsive interactions and inhibits their aggregation in aqueous solutions. MD simulations were done to reveal the atomistic scale origins of SALR between HPAs. As a result, the short-range attractions result from water or proton-mediated hydrogen bonds between neighboring HPAs, whereas the long-range repulsions are due to the distributions of ions surrounding the HPAs.« less

Long-range magnetic interactions and proximity effects in an amorphous exchange-spring magnet

DOE PAGES

Magnus, F.; Brooks-Bartlett, M. E.; Moubah, R.; ...

2016-06-13

Low-dimensional magnetic heterostructures are a key element of spintronics, where magnetic interactions between different materials often define the functionality of devices. Although some interlayer exchange coupling mechanisms are by now well established, the possibility of direct exchange coupling via proximity-induced magnetization through non-magnetic layers is typically ignored due to the presumed short range of such proximity effects. Here we show that magnetic order can be induced throughout a 40-nm-thick amorphous paramagnetic layer through proximity to ferromagnets, mediating both exchange-spring magnet behaviour and exchange bias. Furthermore, Monte Carlo simulations show that nearest-neighbour magnetic interactions fall short in describing the observed effectsmore » and long-range magnetic interactions are needed to capture the extent of the induced magnetization. Lastly, the results highlight the importance of considering the range of interactions in low-dimensional heterostructures and how magnetic proximity effects can be used to obtain new functionality.« less

Long-Term Phonological Knowledge Supports Serial Ordering in Working Memory

ERIC Educational Resources Information Center

Nakayama, Masataka; Tanida, Yuki; Saito, Satoru

2015-01-01

Serial ordering mechanisms have been investigated extensively in psychology and psycholinguistics. It has also been demonstrated repeatedly that long-term phonological knowledge contributes to serial ordering. However, the mechanisms that contribute to serial ordering have yet to be fully understood. To understand these mechanisms, we demonstrate…

Revisiting long-range dependence in annual precipitation

NASA Astrophysics Data System (ADS)

Iliopoulou, Theano; Papalexiou, Simon Michael; Markonis, Yannis; Koutsoyiannis, Demetris

2018-01-01

Long-range dependence (LRD), the so-called Hurst-Kolmogorov behaviour, is considered to be an intrinsic characteristic of most natural processes. This behaviour manifests itself by the prevalence of slowly decaying autocorrelation function and questions the Markov assumption, often habitually employed in time series analysis. Herein, we investigate the dependence structure of annual rainfall using a large set, comprising more than a thousand stations worldwide of length 100 years or more, as well as a smaller number of paleoclimatic reconstructions covering the last 12,000 years. Our findings suggest weak long-term persistence for instrumental data (average H = 0.59), which becomes stronger with scale, i.e. in the paleoclimatic reconstructions (average H = 0.75).

The design of a long range megatransport aircraft

NASA Technical Reports Server (NTRS)

Weisshaar, Terrence A.; Allen, Carl L.

1992-01-01

During the period from August 1991 - June 1992 two design classes at Purdue University participated in the design of a long range, high capacity transport aircraft, dubbed the megatransport. Thirteen Purdue design teams generated RFP's that defined passenger capability and range, based upon team perception of market needs and infrastructure constraints. Turbofan engines were designed by each group to power these aircraft. The design problem and the variety of solutions developed are described in an attached paper.

Long-Range Correlations in Stride Intervals May Emerge from Non-Chaotic Walking Dynamics

PubMed Central

Ahn, Jooeun; Hogan, Neville

2013-01-01

Stride intervals of normal human walking exhibit long-range temporal correlations. Similar to the fractal-like behaviors observed in brain and heart activity, long-range correlations in walking have commonly been interpreted to result from chaotic dynamics and be a signature of health. Several mathematical models have reproduced this behavior by assuming a dominant role of neural central pattern generators (CPGs) and/or nonlinear biomechanics to evoke chaos. In this study, we show that a simple walking model without a CPG or biomechanics capable of chaos can reproduce long-range correlations. Stride intervals of the model revealed long-range correlations observed in human walking when the model had moderate orbital stability, which enabled the current stride to affect a future stride even after many steps. This provides a clear counterexample to the common hypothesis that a CPG and/or chaotic dynamics is required to explain the long-range correlations in healthy human walking. Instead, our results suggest that the long-range correlation may result from a combination of noise that is ubiquitous in biological systems and orbital stability that is essential in general rhythmic movements. PMID:24086274

Modelling control of epidemics spreading by long-range interactions.

PubMed

Dybiec, Bartłomiej; Kleczkowski, Adam; Gilligan, Christopher A

2009-10-06

We have studied the spread of epidemics characterized by a mixture of local and non-local interactions. The infection spreads on a two-dimensional lattice with the fixed nearest neighbour connections. In addition, long-range dynamical links are formed by moving agents (vectors). Vectors perform random walks, with step length distributed according to a thick-tail distribution. Two distributions are considered in this paper, an alpha-stable distribution describing self-similar vector movement, yet characterized by an infinite variance and an exponential power characterized by a large but finite variance. Such long-range interactions are hard to track and make control of epidemics very difficult. We also allowed for cryptic infection, whereby an infected individual on the lattice can be infectious prior to showing any symptoms of infection or disease. To account for such cryptic spread, we considered a control strategy in which not only detected, i.e. symptomatic, individuals but also all individuals within a certain control neighbourhood are treated upon the detection of disease. We show that it is possible to eradicate the disease by using such purely local control measures, even in the presence of long-range jumps. In particular, we show that the success of local control and the choice of the optimal strategy depend in a non-trivial way on the dispersal patterns of the vectors. By characterizing these patterns using the stability index of the alpha-stable distribution to change the power-law behaviour or the exponent characterizing the decay of an exponential power distribution, we show that infection can be successfully contained using relatively small control neighbourhoods for two limiting cases for long-distance dispersal and for vectors that are much more limited in their dispersal range.

Simulations of sheared dense noncolloidal suspensions: Evaluation of the role of long-range hydrodynamics

NASA Astrophysics Data System (ADS)

Gallier, Stany; Peters, François; Lobry, Laurent

2018-04-01

This work intends to evaluate the role of many-body long-range hydrodynamics by simulations of sheared neutrally buoyant non-Brownian, noncolloidal suspensions. Three-dimensional simulations of sheared suspensions are conducted with and without long-range hydrodynamics, for a volume fraction range between 0.1-0.62 (frictionless) and 0.1-0.56 (frictional). Discarding long-range hydrodynamics has only a moderate effect on viscosity for the range of volume fractions investigated and viscosities diverge with similar scaling laws; the critical fraction is found to be approximately 0.64 (frictionless) and 0.58 (frictional). Conversely, many-body hydrodynamics are found to affect diffusion and particle velocities, which are correlated on a longer range when long-range interactions are included, even in dense suspensions. This means that long-range hydrodynamics may not be significantly screened by crowding. Assuming only short-range lubrication interactions is therefore suitable for predicting viscosity in noncolloidal suspensions but becomes questionable when flow details (e.g., diffusion or velocity correlations) are needed.

Relative phase asynchrony and long-range correlation of long-term solar magnetic activity

NASA Astrophysics Data System (ADS)

Deng, Linhua

2017-07-01

Statistical signal processing is one of the most important tasks in a large amount of areas of scientific studies, such as astrophysics, geophysics, and space physics. Phase recurrence analysis and long-range persistence are the two dynamical structures of the underlying processes for the given natural phenomenon. Linear and nonlinear time series analysis approaches (cross-correlation analysis, cross-recurrence plot, wavelet coherent transform, and Hurst analysis) are combined to investigate the relative phase interconnection and long-range correlation between solar activity and geomagnetic activity for the time interval from 1932 January to 2017 January. The following prominent results are found: (1) geomagnetic activity lags behind sunspot numbers with a phase shift of 21 months, and they have a high level of asynchronous behavior; (2) their relative phase interconnections are in phase for the periodic scales during 8-16 years, but have a mixing behavior for the periodic belts below 8 years; (3) both sunspot numbers and geomagnetic activity can not be regarded as a stochastic phenomenon because their dynamical behaviors display a long-term correlation and a fractal nature. We believe that the presented conclusions could provide further information on understanding the dynamical coupling of solar dynamo process with geomagnetic activity variation, and the crucial role of solar and geomagnetic activity in the long-term climate change.

Dark matter, long-range forces, and large-scale structure

NASA Technical Reports Server (NTRS)

Gradwohl, Ben-Ami; Frieman, Joshua A.

1992-01-01

If the dark matter in galaxies and clusters is nonbaryonic, it can interact with additional long-range fields that are invisible to experimental tests of the equivalence principle. We discuss the astrophysical and cosmological implications of a long-range force coupled only to the dark matter and find rather tight constraints on its strength. If the force is repulsive (attractive), the masses of galaxy groups and clusters (and the mean density of the universe inferred from them) have been systematically underestimated (overestimated). We explore the consequent effects on the two-point correlation function, large-scale velocity flows, and microwave background anisotropies, for models with initial scale-invariant adiabatic perturbations and cold dark matter.

Parametrization and Benchmark of Long-Range Corrected DFTB2 for Organic Molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vuong, Van Quan; Akkarapattiakal Kuriappan, Jissy; Kubillus, Maximilian

In this paper, we present the parametrization and benchmark of long-range corrected second-order density functional tight binding (DFTB), LC-DFTB2, for organic and biological molecules. The LC-DFTB2 model not only improves fundamental orbital energy gaps but also ameliorates the DFT self-interaction error and overpolarization problem, and further improves charge-transfer excited states significantly. Electronic parameters for the construction of the DFTB2 Hamiltonian as well as repulsive potentials were optimized for molecules containing C, H, N, and O chemical elements. We use a semiautomatic parametrization scheme based on a genetic algorithm. With the new parameters, LC-DFTB2 describes geometries and vibrational frequencies of organicmore » molecules similarly well as third-order DFTB3/3OB, the de facto standard parametrization based on a GGA functional. Finally, LC-DFTB2 performs well also for atomization and reaction energies, however, slightly less satisfactorily than DFTB3/3OB.« less

Parametrization and Benchmark of Long-Range Corrected DFTB2 for Organic Molecules

DOE PAGES

Vuong, Van Quan; Akkarapattiakal Kuriappan, Jissy; Kubillus, Maximilian; ...

2017-12-12

In this paper, we present the parametrization and benchmark of long-range corrected second-order density functional tight binding (DFTB), LC-DFTB2, for organic and biological molecules. The LC-DFTB2 model not only improves fundamental orbital energy gaps but also ameliorates the DFT self-interaction error and overpolarization problem, and further improves charge-transfer excited states significantly. Electronic parameters for the construction of the DFTB2 Hamiltonian as well as repulsive potentials were optimized for molecules containing C, H, N, and O chemical elements. We use a semiautomatic parametrization scheme based on a genetic algorithm. With the new parameters, LC-DFTB2 describes geometries and vibrational frequencies of organicmore » molecules similarly well as third-order DFTB3/3OB, the de facto standard parametrization based on a GGA functional. Finally, LC-DFTB2 performs well also for atomization and reaction energies, however, slightly less satisfactorily than DFTB3/3OB.« less

Density of states and magnetotransport in Weyl semimetals with long-range disorder

NASA Astrophysics Data System (ADS)

Pesin, D. A.; Mishchenko, E. G.; Levchenko, A.

2015-11-01

We study the density of states and magnetotransport properties of disordered Weyl semimetals, focusing on the case of a strong long-range disorder. To calculate the disorder-averaged density of states close to nodal points, we treat exactly the long-range random potential fluctuations produced by charged impurities, while the short-range component of disorder potential is included systematically and controllably with the help of a diagram technique. We find that, for energies close to the degeneracy point, long-range potential fluctuations lead to a finite density of states. In the context of transport, we discuss that a self-consistent theory of screening in magnetic field may conceivably lead to nonmonotonic low-field magnetoresistance.

Fan-less long range alpha detector

DOEpatents

MacArthur, D.W.; Bounds, J.A.

1994-05-10

A fan-less long range alpha detector is disclosed which operates by using an electrical field between a signal plane and the surface or substance to be monitored for air ions created by collisions with alpha radiation. Without a fan, the detector can operate without the possibility of spreading dust and potential contamination into the atmosphere. A guard plane between the signal plane and the electrically conductive enclosure and maintained at the same voltage as the signal plane, reduces leakage currents. The detector can easily monitor soil, or other solid or liquid surfaces. 2 figures.

Fan-less long range alpha detector

DOEpatents

MacArthur, Duncan W.; Bounds, John A.

1994-01-01

A fan-less long range alpha detector which operates by using an electrical field between a signal plane and the surface or substance to be monitored for air ions created by collisions with alpha radiation. Without a fan, the detector can operate without the possibility of spreading dust and potential contamination into the atmosphere. A guard plane between the signal plane and the electrically conductive enclosure and maintained at the same voltage as the signal plane, reduces leakage currents. The detector can easily monitor soil, or other solid or liquid surfaces.

Ising-like chain magnetism, Arrhenius magnetic relaxation, and case against 3D magnetic ordering in β-manganese phthalocyanine (C₃₂H₁₆MnN₈).

PubMed

Wang, Zhengjun; Seehra, Mohindar S

2016-04-06

Previous magnetic studies in the organic semiconductor β-manganese phthalocyanine (β-MnPc) have reported it to be a canted ferromagnet below T(C)  ≈  8.6 K. However, the recent result of the lack of a λ-type anomaly in the specific heat versus temperature data near the quoted T(C) has questioned the presence of long-range 3-dimensional (3D) magnetic ordering in this system. In this paper, detailed measurements and analysis of the temperature (2 K-300 K) and magnetic field (up to 90 kOe) dependence of the dc and ac magnetic susceptibilities in a powder sample of β-MnPc leads us to conclude that 3D long-range magnetic ordering is absent in this material. This is supported by the Arrott plots and the lack of a peak in the ac susceptibilities, χ' and χ″, near the quoted T(C). Instead, the system can be best described as an Ising-like chain magnet with Arrhenius relaxation of the magnetization governed by an intra-layer ferromagnetic exchange constant J/k(B)  =  2.6 K and the single ion anisotropy energy parameter |D|/k(B)  =  8.3 K. The absence of 3D long range order is consistent with the measured |D|/  >  J.

Long-range anticorrelations and non-Gaussian behavior of the heartbeat

NASA Technical Reports Server (NTRS)

Peng, C.-K.; Mietus, J.; Hausdorff, J. M.; Havlin, S.; Stanley, H. E.; Goldberger, A. L.

1993-01-01

We find that the successive increments in the cardiac beat-to-beat intervals of healthy subjects display scale-invariant, long-range anticorrelations (up to 10 exp 4 heart beats). Furthermore, we find that the histogram for the heartbeat intervals increments is well described by a Levy (1991) stable distribution. For a group of subjects with severe heart disease, we find that the distribution is unchanged, but the long-range correlations vanish. Therefore, the different scaling behavior in health and disease must relate to the underlying dynamics of the heartbeat.

Generic Long-Range Interactions Between Passive Bodies in an Active Fluid.

PubMed

Baek, Yongjoo; Solon, Alexandre P; Xu, Xinpeng; Nikola, Nikolai; Kafri, Yariv

2018-02-02

A single nonspherical body placed in an active fluid generates currents via breaking of time-reversal symmetry. We show that, when two or more passive bodies are placed in an active fluid, these currents lead to long-range interactions. Using a multipole expansion, we characterize their leading-order behaviors in terms of single-body properties and show that they decay as a power law with the distance between the bodies, are anisotropic, and do not obey an action-reaction principle. The interactions lead to rich dynamics of the bodies, illustrated by the spontaneous synchronized rotation of pinned nonchiral bodies and the formation of traveling bound pairs. The occurrence of these phenomena depends on tunable properties of the bodies, thus opening new possibilities for self-assembly mediated by active fluids.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noh, Heeso; Liew, Seng Fatt; Saranathan, Vinodkumar

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.

Long-range correlations and patterns of recurrence in children and adults' attention to hierarchical displays

PubMed Central

Castillo, Ramon D.; Kloos, Heidi; Holden, John G.; Richardson, Michael J.

2015-01-01

In order to make sense of a scene, a person must pay attention to several levels of nested order, ranging from the most differentiated details of the display to the integrated whole. In adults, research shows that the processes of integration and differentiation have the signature of self-organization. Does the same hold for children? The current study addresses this question with children between 6 and 9 years of age, using two tasks that require attention to hierarchical displays. A group of adults were tested as well, for control purposes. To get at the question of self-organization, reaction times were submitted to a detrended fluctuation analysis and a recurrence quantification analysis. H exponents show a long-range correlations (1/f noise), and recurrence measures (percent determinism, maximum line, entropy, and trend), show a deterministic structure of variability being characteristic of self-organizing systems. Findings are discussed in terms of organism-environment coupling that gives rise to fluid attention to hierarchical displays. PMID:25999862

Ising universality describes emergent long-range synchronization of coupled ecological oscillators

NASA Astrophysics Data System (ADS)

Noble, Andrew

Understanding the synchronization of oscillations across space is fundamentally important to many scientific disciplines. In ecology, long-range synchronization of oscillations in spatial populations may elevate extinction risk and signal an impending catastrophe. The prevailing assumption is that synchronization on distances longer than the dispersal scale can only be due to environmental correlation. By contrast, recent work shows how scale-invariant synchronization can emerge from locally coupled population dynamics. In particular, we have found that the transition from incoherence to long-range synchronization of coupled ecological two-cycles is described by the Ising universality class. I will discuss evidence that an Ising critical point describes long-range correlations found in data on the individual yields of female pistachio trees in a large orchard. NSF INSPIRE Grant No. 1344187.

A better understanding of long-range temporal dependence of traffic flow time series

NASA Astrophysics Data System (ADS)

Feng, Shuo; Wang, Xingmin; Sun, Haowei; Zhang, Yi; Li, Li

2018-02-01

Long-range temporal dependence is an important research perspective for modelling of traffic flow time series. Various methods have been proposed to depict the long-range temporal dependence, including autocorrelation function analysis, spectral analysis and fractal analysis. However, few researches have studied the daily temporal dependence (i.e. the similarity between different daily traffic flow time series), which can help us better understand the long-range temporal dependence, such as the origin of crossover phenomenon. Moreover, considering both types of dependence contributes to establishing more accurate model and depicting the properties of traffic flow time series. In this paper, we study the properties of daily temporal dependence by simple average method and Principal Component Analysis (PCA) based method. Meanwhile, we also study the long-range temporal dependence by Detrended Fluctuation Analysis (DFA) and Multifractal Detrended Fluctuation Analysis (MFDFA). The results show that both the daily and long-range temporal dependence exert considerable influence on the traffic flow series. The DFA results reveal that the daily temporal dependence creates crossover phenomenon when estimating the Hurst exponent which depicts the long-range temporal dependence. Furthermore, through the comparison of the DFA test, PCA-based method turns out to be a better method to extract the daily temporal dependence especially when the difference between days is significant.

Improving the Lieb-Robinson Bound for Long-Range Interactions

NASA Astrophysics Data System (ADS)

Matsuta, Takuro; Koma, Tohru; Nakamura, Shu

2017-02-01

We improve the Lieb-Robinson bound for a wide class of quantum many-body systems with long-range interactions decaying by power law. As an application, we show that the group velocity of information propagation grows by power law in time for such systems, whereas systems with short-range interactions exhibit a finite group velocity as shown by Lieb and Robinson.

Long-range memory and multifractality in gold markets

NASA Astrophysics Data System (ADS)

Mali, Provash; Mukhopadhyay, Amitabha

2015-03-01

Long-range correlation and fluctuation in the gold market time series of the world's two leading gold consuming countries, namely China and India, are studied. For both the market series during the period 1985-2013 we observe a long-range persistence of memory in the sequences of maxima (minima) of returns in successive time windows of fixed length, but the series, as a whole, are found to be uncorrelated. Multifractal analysis for these series as well as for the sequences of maxima (minima) is carried out in terms of the multifractal detrended fluctuation analysis (MF-DFA) method. We observe a weak multifractal structure for the original series that mainly originates from the fat-tailed probability distribution function of the values, and the multifractal nature of the original time series is enriched into their sequences of maximal (minimal) returns. A quantitative measure of multifractality is provided by using a set of ‘complexity parameters’.

Atomic Scale Medium Range Order and Relaxation Dynamics in Metallic Glass

NASA Astrophysics Data System (ADS)

Zhang, Pei

We studied the atomic scale structure of bulk metallic glass (BMG) with the combination of fluctuation electron microscopy (FEM) and hybrid reverse Monte Carlo (HRMC) simulation. Medium range order (MRO), which occupies the length scale between short range order (SRO) and long-range order, plays an important role on the properties of metallic glass, but the characterization of MRO in experiment is difficult because conventional techniques are not sensitive to the structure at MRO scale. Compared with the X-ray and neutron which can measure SRO by two-body correlation functions, FEM is an effective way to detect MRO structure through three and four-body correlation functions, providing information about the size, distribution, and internal structure of MRO combing HRMC modeling. Thickness estimation is necessary in FEM experiment and HRMC calculation, so in Chapter 3, we measured the elastic and inelastic mean free paths of metallic glass alloys based on focused ion beam prepared thin samples with measured thickness gradients. We developed a model based on the Wentzel atomic model to predict the elastic mean free path for other amorphous materials. In Chapter 4, we studied the correlation of MRO and glass forming ability ZrCuAl alloy. Results from Variable resolution fluctuation microscopy show that in Zr50Cu35Al15 the crystal-like clusters shrink but become more ordered, while icosahedral-like clusters grow. Compared with Zr50Cu45Al5, Zr50Cu35Al15 with poorer glass forming ability exhibits more stable crystal-like structure under annealing, indicating that destabilizing crystal-like structures is important to achieve better glass forming ability in this alloy. In Chapter 5, we studied the crystallization and MRO structural in deformed and quenched Ni60Nb40 metallic glass. The deformed Ni60Nb40 contains fewer icosahedral-like Voronoi clusters and more crystal-like and bcc-like Voronoi clusters. The crystal-like and bcc-like medium range order clusters may be the

Edge Singularities and Quasilong-Range Order in Nonequilibrium Steady States.

PubMed

De Nardis, Jacopo; Panfil, Miłosz

2018-05-25

The singularities of the dynamical response function are one of the most remarkable effects in many-body interacting systems. However in one dimension these divergences only exist strictly at zero temperature, making their observation very difficult in most cold atomic experimental settings. Moreover the presence of a finite temperature destroys another feature of one-dimensional quantum liquids: the real space quasilong-range order in which the spatial correlation functions exhibit power-law decay. We consider a nonequilibrium protocol where two interacting Bose gases are prepared either at different temperatures or chemical potentials and then joined. We show that the nonequilibrium steady state emerging at large times around the junction displays edge singularities in the response function and quasilong-range order.

Edge Singularities and Quasilong-Range Order in Nonequilibrium Steady States

NASA Astrophysics Data System (ADS)

De Nardis, Jacopo; Panfil, Miłosz

2018-05-01

The singularities of the dynamical response function are one of the most remarkable effects in many-body interacting systems. However in one dimension these divergences only exist strictly at zero temperature, making their observation very difficult in most cold atomic experimental settings. Moreover the presence of a finite temperature destroys another feature of one-dimensional quantum liquids: the real space quasilong-range order in which the spatial correlation functions exhibit power-law decay. We consider a nonequilibrium protocol where two interacting Bose gases are prepared either at different temperatures or chemical potentials and then joined. We show that the nonequilibrium steady state emerging at large times around the junction displays edge singularities in the response function and quasilong-range order.

Bottom Interaction in Long Range Acoustic Propagation

DTIC Science & Technology

2006-09-30

Pacific Ocean utilizing controlled sources and vertical and horizontal receiver arrays . Broadband sources are considered with typical center...The LOAPEX (Long-range Ocean Acoustic Propagation Experiment) vertical line arrays (VLA) are described on page 1 of the LOAPEX cruise report: " The...hydrophone arrays on the two combined VLAs covered most of the 5-km water column. We refer to one of the VLAs as the deep VLA (DVLA), located at

Long-range stripe nanodomains in epitaxial (110) BiFeO 3 thin films on (100) NdGaO 3 substrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Yogesh; Agarwal, Radhe; Phatak, Charudatta

Here, we report the observation of ferroelectric and ferroelastic nanodomains in (110)-oriented BiFeO 3 (BFO) thin films epitaxially grown on low symmetric (100) NdGaO 3 (NGO) substrate. We observed long range ordering of ferroelectric 109° stripe nanodomains separated by periodic vertical domain walls in as-grown 130 nm thick BFO films. The effect of La 0.67Sr 0.33CoO 3 (LSCO) conducting interlayer on domain configurations in BFO/NGO film was also observed with relatively short range-ordering of stripe domains due to the modified electrostatic boundary conditions in BFO/LSCO/NGO film. Additional studies on B-site doping of Nb ions in BFO films showed change inmore » the domain structures due to doping induced change in lattice anisotropy while maintaining the stripe domain morphology with 109° domain wall. Finally, this long-range array of ferroelectric and ferroelastic domains can be useful for optoelectronic devices and ferroelastic templates for strain coupled artificial magnetoelectric heterostructures.« less

Long-range stripe nanodomains in epitaxial (110) BiFeO 3 thin films on (100) NdGaO 3 substrate

DOE PAGES

Sharma, Yogesh; Agarwal, Radhe; Phatak, Charudatta; ...

2017-07-07

Here, we report the observation of ferroelectric and ferroelastic nanodomains in (110)-oriented BiFeO 3 (BFO) thin films epitaxially grown on low symmetric (100) NdGaO 3 (NGO) substrate. We observed long range ordering of ferroelectric 109° stripe nanodomains separated by periodic vertical domain walls in as-grown 130 nm thick BFO films. The effect of La 0.67Sr 0.33CoO 3 (LSCO) conducting interlayer on domain configurations in BFO/NGO film was also observed with relatively short range-ordering of stripe domains due to the modified electrostatic boundary conditions in BFO/LSCO/NGO film. Additional studies on B-site doping of Nb ions in BFO films showed change inmore » the domain structures due to doping induced change in lattice anisotropy while maintaining the stripe domain morphology with 109° domain wall. Finally, this long-range array of ferroelectric and ferroelastic domains can be useful for optoelectronic devices and ferroelastic templates for strain coupled artificial magnetoelectric heterostructures.« less

Long-Range Near-Side Angular Correlations in Proton-Proton Interactions in CMS.

ScienceCinema

None

2017-12-09

The CMS Collaboration Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center of mass energies of 0.9, 2.36 and 7TeV over a broad range of pseudorapidity (?) and azimuthal angle (f) are presented using data collected with the CMS detector at the LHC. Short-range correlations in ??, which are studied in minimum bias events, are characterized using a simple independent cluster parameterization in order to quantify their strength (cluster size) and their extent in ? (cluster decay width). Long-range azimuthal correlations are studied more differentially as a function of charged particle multiplicity and particle transverse momentum using a 980nb-1 data set at 7TeV. In high multiplicity events, a pronounced structure emerges in the two-dimensional correlation function for particles in intermediate pT’s of 1-3GeV/c, 2.0< |??|<4.8 and ?f˜0. This is the ?rst observation of such a ridge-like feature in two-particle correlation functions in pp or p-pbar collisions. EVO Universe, password "seminar"; Phone Bridge ID: 2330444 Password: 5142

Long Range Plan for Information Systems from the State Board of Education.

ERIC Educational Resources Information Center

Texas Education Agency, Austin.

The Information Systems Long Range Plan specifically addresses Goal four of the Texas State Board of Education's (SBOE's) "Long-Range Plan for Public School Education" dealing with efficient management and organization of the educational system. To facilitate this goal, the SBOE in 1986 approved and directed the Texas Education Agency to…

Many-Body Physics in Long-Range Interacting Quantum Systems

NASA Astrophysics Data System (ADS)

Zhu, Bihui

Ultracold atomic and molecular systems provide a useful platform for understanding quantum many-body physics. Recent progresses in AMO experiments enable access to systems exhibiting long-range interactions, opening a window for exploring the interplay between long-range interactions and dissipation. In this thesis, I develop theoretical approaches to study non-equilibrium dynamics in systems where such interplay is crucial. I first focus on a system of KRb molecules, where dipolar interactions and fast chemical reactions coexist. Using a classical kinetic theory and Monte Carlo methods, I study the evaporative cooling in a quasi-two-dimensional trap, and develop a protocol to reach quantum degeneracy. I also study the case where molecules are loaded into an optical lattice, and show that the strong dissipation induces a quantum Zeno effect, which suppresses the molecule loss. The analysis requires including multiple bands to explain recent experimental measurements, and can be used to determine the molecular filling fraction. I also investigate a system of radiating atoms, which experience long-range elastic and dissipative interactions. I explore the collective behavior of atoms and the role of atomic motion. The model is validated by comparison with a recent light scattering experiment using Sr atoms. I also show that incoherently pumped dipoles can undergo a dynamical phase transition to synchronization, and study its signature in the quantum regime.

Long-range airplane study: The consumer looks at SST travel

NASA Technical Reports Server (NTRS)

Landes, K. H.; Matter, J. A.

1980-01-01

The attitudes of long-range air travelers toward several basic air travel decisions, were surveyed. Of interest were tradeoffs involving time versus comfort and time versus cost as they pertain to supersonic versus conventional wide-body aircraft on overseas routes. The market focused upon was the segment of air travelers most likely to make that type of tradeoff decision: those having flown overseas routes for business or personal reasons in the recent past. The information generated is intended to provide quantifiable insight into consumer demand for supersonic as compared to wide-body aircraft alternatives for long-range overseas air travel.

Long range wetting transparency on top of layered metal dielectric substrates

DTIC Science & Technology

2015-11-20

multi-layered stacks were deposited onto glass substrates ( silica -based Micro cover glass , 22mmx22mm from VWR (48366-067), index of refraction n...necessarily endorsed by the United States Government. Long-range wetting transparency on top of layered metal-dielectric substrates M. A...as far as ~100 nm beneath the water/MgF2 interface. We refer to this phenomenon as long range wetting transparency . The latter effect cannot be

Long-range sound-mediated dark-soliton interactions in trapped atomic condensates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, A. J.; Jackson, D. P.; Barenghi, C. F.

2011-01-15

A long-range soliton interaction is discussed whereby two or more dark solitons interact in an inhomogeneous atomic condensate, modifying their respective dynamics via the exchange of sound waves without ever coming into direct contact. An idealized double-well geometry is shown to yield perfect energy transfer and complete periodic identity reversal of the two solitons. Two experimentally relevant geometries are analyzed which should enable the observation of this long-range interaction.

Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues

DTIC Science & Technology

2014-08-26

13 The FALCON Study...that would mate a rocket booster with a hypersonic glide vehicle. Congress has generally supported the rationale for the PGS mission, but it has...General: Precise Long-Range Missiles may Enable Big Nuclear Cuts,” Inside the Pentagon, April 28, 2005. Conventional Prompt Global Strike and Long-Range

Phase diagrams and free-energy landscapes for model spin-crossover materials with antiferromagnetic-like nearest-neighbor and ferromagnetic-like long-range interactions

NASA Astrophysics Data System (ADS)

Chan, C. H.; Brown, G.; Rikvold, P. A.

2017-11-01

We present phase diagrams, free-energy landscapes, and order-parameter distributions for a model spin-crossover material with a two-step transition between the high-spin and low-spin states (a square-lattice Ising model with antiferromagnetic-like nearest-neighbor and ferromagnetic-like long-range interactions) [P. A. Rikvold et al., Phys. Rev. B 93, 064109 (2016), 10.1103/PhysRevB.93.064109]. The results are obtained by a recently introduced, macroscopically constrained Wang-Landau Monte Carlo simulation method [Phys. Rev. E 95, 053302 (2017), 10.1103/PhysRevE.95.053302]. The method's computational efficiency enables calculation of thermodynamic quantities for a wide range of temperatures, applied fields, and long-range interaction strengths. For long-range interactions of intermediate strength, tricritical points in the phase diagrams are replaced by pairs of critical end points and mean-field critical points that give rise to horn-shaped regions of metastability. The corresponding free-energy landscapes offer insights into the nature of asymmetric, multiple hysteresis loops that have been experimentally observed in spin-crossover materials characterized by competing short-range interactions and long-range elastic interactions.

Long-Range Plan, Phase II: Implementation Plan, 1994-1999. Holyoke Community College.

ERIC Educational Resources Information Center

Holyoke Community Coll., MA.

The Long-Range Planning Committee at Holyoke Community College (HCC) in Massachusetts has devised a 5-year plan to help the college focus on its most important priorities as it seeks to grow and accommodate change. This planning document identifies seven major institutional goals, objectives comprised by each goal, long-range strategies to achieve…

Frequency multiplexed long range swept source optical coherence tomography

PubMed Central

Zurauskas, Mantas; Bradu, Adrian; Podoleanu, Adrian Gh.

2013-01-01

We present a novel swept source optical coherence tomography configuration, equipped with acousto-optic deflectors that can be used to simultaneously acquire multiple B-scans originating from different depths. The sensitivity range of the configuration is evaluated while acquiring five simultaneous B-scans. Then the configuration is employed to demonstrate long range B-scan imaging by combining two simultaneous B-scans from a mouse head sample. PMID:23760762

Long-range exciton transport in conjugated polymer nanofibers prepared by seeded growth

NASA Astrophysics Data System (ADS)

Jin, Xu-Hui; Price, Michael B.; Finnegan, John R.; Boott, Charlotte E.; Richter, Johannes M.; Rao, Akshay; Menke, S. Matthew; Friend, Richard H.; Whittell, George R.; Manners, Ian

2018-05-01

Easily processed materials with the ability to transport excitons over length scales of more than 100 nanometers are highly desirable for a range of light-harvesting and optoelectronic devices. We describe the preparation of organic semiconducting nanofibers comprising a crystalline poly(di-n-hexylfluorene) core and a solvated, segmented corona consisting of polyethylene glycol in the center and polythiophene at the ends. These nanofibers exhibit exciton transfer from the core to the lower-energy polythiophene coronas in the end blocks, which occurs in the direction of the interchain π-π stacking with very long diffusion lengths (>200 nanometers) and a large diffusion coefficient (0.5 square centimeters per second). This is made possible by the uniform exciton energetic landscape created by the well-ordered, crystalline nanofiber core.

Integrated optical gyroscope using active Long-range surface plasmon-polariton waveguide resonator

PubMed Central

Zhang, Tong; Qian, Guang; Wang, Yang-Yang; Xue, Xiao-Jun; Shan, Feng; Li, Ruo-Zhou; Wu, Jing-Yuan; Zhang, Xiao-Yang

2014-01-01

Optical gyroscopes with high sensitivity are important rotation sensors for inertial navigation systems. Here, we present the concept of integrated resonant optical gyroscope constructed by active long-range surface plasmon-polariton (LRSPP) waveguide resonator. In this gyroscope, LRSPP waveguide doped gain medium is pumped to compensate the propagation loss, which has lower pump noise than that of conventional optical waveguide. Peculiar properties of single-polarization of LRSPP waveguide have been found to significantly reduce the polarization error. The metal layer of LRSPP waveguide is electro-optical multiplexed for suppression of reciprocal noises. It shows a limited sensitivity of ~10−4 deg/h, and a maximum zero drift which is 4 orders of magnitude lower than that constructed by conventional single-mode waveguide. PMID:24458281

Stochastic Simulations of Long-Range Forecasting Models for Less Developed Regions

DTIC Science & Technology

1975-06-01

descriptors—nation national alignment, internal insl; less developed regions of Africa, report describes (1) the regions’ (2) the strategic importance of...imr.T.ARSTFTi?n SPI unty ( I,is*iif it at i 3200.0 (Att ] to End l) Mar 7, 66 *. ( * y. o 1 < n i Forecasting for Planning Strategic Importance...the long range. The forecasts that have been produced so far have been direct inputs into the Joint Long-Range Strategic Study (JLRSS), prepared by

Damage assessment of long-range rocket system by electromagnetic pulse weapon

NASA Astrophysics Data System (ADS)

Cao, Lingyu; Liu, Guoqing; Li, Jinming

2017-08-01

This paper analyzes the damage mechanism and characteristics of electromagnetic pulse weapon, establishes the index system of survivability of long-range rocket launcher system, and uses AHP method to establish the combat effectiveness model of long-range rocket missile system. According to the damage mechanism and characteristics of electromagnetic pulse weapon, the damage effect of the remote rocket system is established by using the exponential method to realize the damage efficiency of the remote rocket system.

Bounds on Energy Absorption and Prethermalization in Quantum Systems with Long-Range Interactions

NASA Astrophysics Data System (ADS)

Ho, Wen Wei; Protopopov, Ivan; Abanin, Dmitry A.

2018-05-01

Long-range interacting systems such as nitrogen vacancy centers in diamond and trapped ions serve as experimental setups to probe a range of nonequilibrium many-body phenomena. In particular, via driving, various effective Hamiltonians with physics potentially quite distinct from short-range systems can be realized. In this Letter, we derive general rigorous bounds on the linear response energy absorption rates of periodically driven systems of spins or fermions with long-range interactions that are sign changing and fall off as 1 /rα with α >d /2 . We show that the disorder averaged energy absorption rate at high temperatures decays exponentially with the driving frequency. This strongly suggests the presence of a prethermal plateau in which dynamics is governed by an effective, static Hamiltonian for long times, and we provide numerical evidence to support such a statement. Our results are relevant for understanding timescales of heating and new dynamical regimes described by effective Hamiltonians in such long-range systems.

Probabilistic approach to long range planning of manpower

NASA Technical Reports Server (NTRS)

Lejk, R. A.

1967-01-01

Publication presents a total long range planning model for project oriented organizations. The total model consists of planning systems which originate - /1/ at the project level and consolidate into an overall plan, and /2/ from a budetary ceiling and allocate to the individual projects. Analysis of /1/ and /2/ is provided for management decision making.

Hidden asymmetry and long range rapidity correlations

NASA Astrophysics Data System (ADS)

Bialas, A.; Bzdak, A.; Zalewski, K.

2012-04-01

Interpretation of long-range rapidity correlations in terms of the fluctuating rapidity density distribution of the system created in high-energy collisions is proposed. When applied to recent data of the STAR Collaboration, it shows a substantial asymmetric component in the shape of this system in central Au-Au collisions, implying that boost invariance is violated on the event-by-event basis even at central rapidity. This effect may seriously influence the hydrodynamic expansion of the system.

Amylose Phase Composition As Analyzed By FTIR In A Temperature Ramp: Influence Of Short Range Order On The Thermodynamic Properties

NASA Astrophysics Data System (ADS)

Bernazzani, Paul; Delmas, Genevieve

1998-03-01

Amylose, a major component of starch, is one of the most important biopolymers, being mainly associated with the pharmacological and food industries. Although widely studied, a complete control and understanding of the physical properties of amylose is still lacking. It is well known that structure and phase transition are important aspects of the functionality of biopolymers since they influence physical attributes such as appearance, digestibility, water holding capacity, etc. In the past, we have studied polyethylene phase composition by DSC in a very slow temperature (T) ramp (1K/h) and have demonstrated the presence and importance of short-range order on the polymer and its characteristics. In this study, we evaluated the phase composition of potato amylose and associated the thermodynamic properties with the presence of short-range order. Two methods were correlated, DSC (in a 1K/h T-ramp) and FTIR as a function of temperature, also in a 1K/h T-ramp. The effects of the various phases on thermodynamic properties such as gelation and enzyme or chemical resistance are discussed.

Formula for the Transition Probability Induced by Long-range Potential Terms Varying as R-8 and R-10 for Atom-dimer Collisions

NASA Astrophysics Data System (ADS)

Matthews, N. F.; Robson, D.; Grant, M. A.

1990-12-01

An explicit formula is derived for the transition probability between two different states of the atom-dimer collisional system governed by second-order long-range interaction potential terms varying as R-8 and R-10.

Long-range dynamical magnetic order and spin tunneling in the cooperative paramagnetic states of the pyrochlore analogous spinel antiferromagnets CdYb2X4 (X =S or Se)

NASA Astrophysics Data System (ADS)

Dalmas de Réotier, P.; Marin, C.; Yaouanc, A.; Ritter, C.; Maisuradze, A.; Roessli, B.; Bertin, A.; Baker, P. J.; Amato, A.

2017-10-01

Magnetic systems with spins sitting on a lattice of corner sharing regular tetrahedra have been particularly prolific for the discovery of new magnetic states for the last two decades. The pyrochlore compounds have offered the playground for these studies, while little attention has been comparatively devoted to other compounds where the rare earth R occupies the same sublattice, e.g., the spinel chalcogenides Cd R2X4 (X =S or Se ). Here, we report measurements performed on powder samples of this series with R =Yb using specific heat, magnetic susceptibility, neutron diffraction, and muon-spin-relaxation measurements. The two compounds are found to be magnetically similar. They long-range order into structures described by the Γ5 irreducible representation. The magnitude of the magnetic moment at low temperature is 0.77 (1) and 0.62 (1) μB for X =S and Se , respectively. Persistent spin dynamics is present in the ordered states. The spontaneous field at the muon site is anomalously small, suggesting magnetic moment fragmentation. A double spin-flip tunneling relaxation mechanism is suggested in the cooperative paramagnetic state up to 10 K. The magnetic space groups into which magnetic moments of systems of corner-sharing regular tetrahedra order are provided for a number of insulating compounds characterized by null propagation wave vectors.

Wide-range narrowband multilayer mirror for selecting a single-order harmonic in the photon energy range of 40-70 eV.

PubMed

Hatayama, Masatoshi; Ichimaru, Satoshi; Ohcni, Tadayuki; Takahashi, Eiji J; Midorikawa, Katsumi; Oku, Satoshi

2016-06-27

An experimental demonstration of a wide-range narrowband multilayer mirror for selecting a single-order high-harmonic (HH) beam from multiple-order harmonics in the photon energy range between 40 eV and 70 eV was carried out. This extreme ultraviolet (XUV) mirror, based on a pair of Zr and Al_0.7Si_0.3 multilayers, has a reflectivity of 20-35% and contrast of more than 7 with respect to neighboring HHs at angles of incidence from 10 to 56.9 degrees, assuming HHs pumped at 1.55 eV. Thus, specific single-order harmonic beams can be arbitrarily selected from multiple-order harmonics in this photo energy range. In addition, the dispersion for input pulses of the order of 1 fs is negligible. This simple-to-align optical component is useful for the many various applications in physics, chemistry and biology that use ultrafast monochromatic HH beams.

Conventional Prompt Global Strike and Long Range Ballistic Missiles: Background and Issues

DTIC Science & Technology

2017-02-03

Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues Amy F. Woolf Specialist in Nuclear Weapons Policy...February 3, 2017 Congressional Research Service 7-5700 www.crs.gov R41464 Conventional Prompt Global Strike and Long-Range Ballistic Missiles...Congressional Research Service Summary Conventional prompt global strike (CPGS) weapons would allow the United States to strike targets anywhere

Soil pyrogenic carbon lacks long-term persistence

NASA Astrophysics Data System (ADS)

Lutfalla, Suzanne; Abiven, Samuel; Barré, Pierre; Wiedemeier, Daniel; Christensen, Bent; Houot, Sabine; Kätterer, Thomas; Macdonald, Andy; van Oort, Fok; Chenu, Claire

2015-04-01

In the context of climate change, one mitigation technique currently investigated is the use of pyrogenic organic carbon (PyOC) -which is biomass turned into charcoal- to sequester carbon in soils with the hypothesis that PyOC is persistent and will not be biodegraded (or mineralized). In this study, we use the unique opportunity offered by five long term bare fallow (LTBF) experiments across Europe (Askov in Denmark, Grignon and Versailles in France, Ultuna in Sweden and Rothamsted in the United Kingdom) to compare the dynamics of PyOC and soil organic carbon (SOC) in the same plots at the decadal time scale (from 25 to 80 years of bare fallow depending on the site). Bare fallow plots were regularly sampled throughout the bare fallow duration and these samples were carefully archived. In bare fallow plots, with negligible external carbon input and with continuing biodegradation, SOC is depleting. Using the Benzene Polycarboxylic Acid (BPCA) technique to estimate the PyOC quantity and quality in the soils at different sampling dates, we investigated if PyOC content was also decreasing and compared the rates of depletion of PyOC and SOC. We found that PyOC contents decreased rapidly in soils at all sites. The loss of PyOC between the first and the last soil sampling ranged from 19.8 to 57.3% of the initial PyOC content. Furthermore, PyOC quality exhibited a similar evolution at all sites, becoming more enriched in condensed material with time. We applied a one pool model with mono-exponential decay to our data and found an average mean residence time of native PyOC of 116 years across the different sites, with a standard deviation of 15 years, just 1.6 times longer than that of SOC. Our results show that, though having a longer residence time than total SOC, PyOC content can decrease rapidly in soils suggesting that the potential for long-term C storage in soil by PyOC amendments is less than currently anticipated. Our results therefore question the concept of

Tennessee long-range transportation plan : bicycle and pedestrian element

DOT National Transportation Integrated Search

2005-12-01

The Bicycle and Pedestrian Element of the Long-Range Transportation Plan aims to position Tennessee as one of the most progressive states for bicycling and walking for the next 25 years. This Plan provides a clear directive that emphasizes the contin...

Anomalous dynamical phase in quantum spin chains with long-range interactions

NASA Astrophysics Data System (ADS)

Homrighausen, Ingo; Abeling, Nils O.; Zauner-Stauber, Valentin; Halimeh, Jad C.

2017-09-01

The existence or absence of nonanalytic cusps in the Loschmidt-echo return rate is traditionally employed to distinguish between a regular dynamical phase (regular cusps) and a trivial phase (no cusps) in quantum spin chains after a global quench. However, numerical evidence in a recent study (J. C. Halimeh and V. Zauner-Stauber, arXiv:1610.02019) suggests that instead of the trivial phase, a distinct anomalous dynamical phase characterized by a novel type of nonanalytic cusps occurs in the one-dimensional transverse-field Ising model when interactions are sufficiently long range. Using an analytic semiclassical approach and exact diagonalization, we show that this anomalous phase also arises in the fully connected case of infinite-range interactions, and we discuss its defining signature. Our results show that the transition from the regular to the anomalous dynamical phase coincides with Z2-symmetry breaking in the infinite-time limit, thereby showing a connection between two different concepts of dynamical criticality. Our work further expands the dynamical phase diagram of long-range interacting quantum spin chains, and can be tested experimentally in ion-trap setups and ultracold atoms in optical cavities, where interactions are inherently long range.

Direct solution of the H(1s)-H + long-range interaction problem in momentum space

NASA Astrophysics Data System (ADS)

Koga, Toshikatsu

1985-02-01

Perturbation equations for the H(1s)-H+ long-range interaction are solved directly in momentum space up to the fourth order with respect to the reciprocal of the internuclear distance. As in the hydrogen atom problem, the Fock transformation is used which projects the momentum vector of an electron from the three-dimensional hyperplane onto the four-dimensional hypersphere. Solutions are given as linear combinations of several four-dimensional spherical harmonics. The present results add an example to the momentum-space solution of the nonspherical potential problem.

N-scaling of timescales in long-range N-body quantum systems

NASA Astrophysics Data System (ADS)

Kastner, Michael

2017-01-01

Long-range interacting many-body systems exhibit a number of peculiar and intriguing properties. One of those is the scaling of relaxation times with the number N of particles in a system. In this paper I give a survey of results on long-range quantum spin models that illustrate this scaling behaviour, and provide indications for its common occurrence by making use of Lieb-Robinson bounds. I argue that these findings may help in understanding the extraordinarily short equilibration timescales predicted by typicality techniques.

Long-Range Correlations in Sentence Series from A Story of the Stone.

PubMed

Yang, Tianguang; Gu, Changgui; Yang, Huijie

2016-01-01

A sentence is the natural unit of language. Patterns embedded in series of sentences can be used to model the formation and evolution of languages, and to solve practical problems such as evaluating linguistic ability. In this paper, we apply de-trended fluctuation analysis to detect long-range correlations embedded in sentence series from A Story of the Stone, one of the greatest masterpieces of Chinese literature. We identified a weak long-range correlation, with a Hurst exponent of 0.575±0.002 up to a scale of 104. We used the structural stability to confirm the behavior of the long-range correlation, and found that different parts of the series had almost identical Hurst exponents. We found that noisy records can lead to false results and conclusions, even if the noise covers a limited proportion of the total records (e.g., less than 1%). Thus, the structural stability test is an essential procedure for confirming the existence of long-range correlations, which has been widely neglected in previous studies. Furthermore, a combination of de-trended fluctuation analysis and diffusion entropy analysis demonstrated that the sentence series was generated by a fractional Brownian motion.

Long-Range Correlations in Sentence Series from A Story of the Stone

PubMed Central

Yang, Tianguang; Gu, Changgui; Yang, Huijie

2016-01-01

A sentence is the natural unit of language. Patterns embedded in series of sentences can be used to model the formation and evolution of languages, and to solve practical problems such as evaluating linguistic ability. In this paper, we apply de-trended fluctuation analysis to detect long-range correlations embedded in sentence series from A Story of the Stone, one of the greatest masterpieces of Chinese literature. We identified a weak long-range correlation, with a Hurst exponent of 0.575±0.002 up to a scale of 104. We used the structural stability to confirm the behavior of the long-range correlation, and found that different parts of the series had almost identical Hurst exponents. We found that noisy records can lead to false results and conclusions, even if the noise covers a limited proportion of the total records (e.g., less than 1%). Thus, the structural stability test is an essential procedure for confirming the existence of long-range correlations, which has been widely neglected in previous studies. Furthermore, a combination of de-trended fluctuation analysis and diffusion entropy analysis demonstrated that the sentence series was generated by a fractional Brownian motion. PMID:27648941

Tricritical and Critical Exponents in Microcanonical Ensemble of Systems with Long-Range Interactions

NASA Astrophysics Data System (ADS)

Li, Liang-Sheng

2016-12-01

We explore the tricritical points and the critical lines of both Blume-Emery-Grifnths and Ising model within long-range interactions in the microcanonical ensemble. For K = K MTP , the tricritical exponents take the values β = 1/4, 1 = γ- ≠ γ+ = 1/2 and 0 = α- ≠ α+ = -1/2, which disagree with classical (mean held) values. When K > K MTP , the phase transition becomes second order and the critical exponents have classical values except close to the canonical tricritical parameters (K CTP ), where the values of the critical expoents become β = 1/2, 1 = γ- ≠ γ+ = 2 and 0 = α- ≠ α+ = 1. Supported by the National Natural Science Foundation of China under Grant No. 11104032

Results of the long range position-determining system tests. [Field Army system

NASA Technical Reports Server (NTRS)

Rhode, F. W.

1973-01-01

The long range position-determining system (LRPDS) has been developed by the Corps of Engineers to provide the Field Army with a rapid and accurate positioning capability. The LRPDS consists of an airborne reference position set (RPS), up to 30 ground based positioning sets (PS), and a position computing central (PCC). The PCC calculates the position of each PS based on the range change information provided by each Set. The positions can be relayed back to the PS again via RPS. Each PS unit contains a double oven precise crystal oscillator. The RPS contains a Hewlett-Packard cesium beam standard. Frequency drifts and off-sets of the crystal oscillators are taken in account in the data reduction process. A field test program was initiated in November 1972. A total of 54 flights were made which included six flights for equipment testing and 48 flights utilizing the field test data reduction program. The four general types of PS layouts used were: short range; medium range; long range; tactical configuration. The overall RMS radial error of the unknown positions varied from about 2.3 meters for the short range to about 15 meters for the long range. The corresponding elevation RMS errors vary from about 12 meters to 37 meters.

Does the long-range transport of African mineral dust across the Atlantic enhance their hygroscopicity?

NASA Astrophysics Data System (ADS)

Denjean, Cyrielle; Caquineau, Sandrine; Desboeufs, Karine; Laurent, Benoit; Quiñones Rosado, Mariana; Vallejo, Pamela; Mayol-Bracero, Olga; Formenti, Paola

2015-04-01

Influence of mineral dust on radiation balance is largely dependent on their ability to interact with water. While fresh mineral dusts are highly hydrophobic, various transformation processes (coagulation, heterogeneous chemical reaction) can modify the dust physical and chemical properties during long-range transport, which, in turn, can change the dust hygroscopic properties. The model predictions of the radiative effect by mineral dust still suffer of the lack of certainty of dust hygroscopic properties, and their temporal evolution during long-range transport. We present the first direct surface measurements of the hygroscopicity of Saharan dust after long-range transport over the Atlantic Ocean, their relationship with chemical composition, their influence on particle size and shape and implications for optical properties. Particles were collected during the DUST Aging and TransporT from Africa to the Caribbean (Dust-AttaCk) campaign at the Cape San Juan Puerto Rico station in June-July 2012. Environmental scanning electron microscopy (ESEM) was used to analyze the size, shape, chemical composition and hygroscopic properties of individual particles. At different levels of concentrations in summertime, the coarse mode of atmospheric aerosols in Puerto Rico is dominated by Saharan mineral dust. Most of aged dust particles survived atmospheric transport intact with no observed internal mixture with other species and did not show hygroscopic growth up to 94% relative humidity. This is certainly due to the fact that in summertime dust is mostly transported above the marine boundary layer. A minor portion of mineral dust (approximately 19-28% by number) were involved in atmospheric heterogeneous reactions with acidic gases (likely SO2 and HCl) and sea salt aggregation. While sulfate- and chloride-coated dust remained extremely hydrophobic, dust particles in internal mixing with NaCl underwent profound changes in their hygroscopicity, therefore in size and shape. We

Probing Long-Range Configurations of Molecular Hydrogen

NASA Astrophysics Data System (ADS)

McCormack, Elizabeth

2011-05-01

Very long-range molecular configurations are of interest in a variety of contexts, for example, in the astro-chemistry of cold molecular clouds and in planetary atmospheres, including our own. Such states can be more than 10 times the size of the ground state and often possess energies above multiple ionization potentials and dissociation limits resulting in diverse and complex decay dynamics. Many of these configurations possess a double-well character arising from the interaction of molecular Rydberg states, repulsive doubly-excited states, and ionic states. The ion pair in hydrogen, an unusual molecular configuration consisting of one proton shrouded in a cloud of two electrons separated very far from the other proton, is notoriously difficult to create and study. We report results from on our investigation of such states using resonantly enhanced multi-photon ionization via the E,F v = 6, J = 0, 1, and 2 states to probe the H(n = 1) + H(n = 3) dissociation threshold energy region. Both molecular and atomic ion production were detected as a function of wavelength by using a time-of-flight mass spectrometer. Below threshold a series of highly excited vibrational levels of several long range states are observed. Above threshold broad resonances are observed with energies that agree well with the predictions of a mass-scaled Rydberg formula for bound states of the H+ H- ion pair. Measured linewidths, quantum defects, and rotational dependences are reported for ion pair principal quantum numbers in the range of n = 130 to 206. Our new results can be compared to recent experimental work using a different excitation scheme, which was the first spectroscopic observation of heavy Rydberg states in hydrogen, and new ab initio theoretical work. Supported by the National Science Foundation.

Long-range repulsion of colloids driven by ion exchange and diffusiophoresis

PubMed Central

Florea, Daniel; Musa, Sami; Huyghe, Jacques M. R.; Wyss, Hans M.

2014-01-01

Interactions between surfaces and particles in aqueous suspension are usually limited to distances smaller than 1 μm. However, in a range of studies from different disciplines, repulsion of particles has been observed over distances of up to hundreds of micrometers, in the absence of any additional external fields. Although a range of hypotheses have been suggested to account for such behavior, the physical mechanisms responsible for the phenomenon still remain unclear. To identify and isolate these mechanisms, we perform detailed experiments on a well-defined experimental system, using a setup that minimizes the effects of gravity and convection. Our experiments clearly indicate that the observed long-range repulsion is driven by a combination of ion exchange, ion diffusion, and diffusiophoresis. We develop a simple model that accounts for our data; this description is expected to be directly applicable to a wide range of systems exhibiting similar long-range forces. PMID:24748113

Long-Range Planning Can Improve the Efficiency of Agricultural Research and Development.

DTIC Science & Technology

1981-07-24

planning is not done » Conclusions Recommendat ion Agency comments ADVISORY BODIES HAVE HAD MIXED SUCCESS IN AFFECTING LONG-RANGE PLANNING... kfc r Their efforts have more impact on determining priorities for the short-range budgeting cycle rather than influencing development of long...cultural products, (2) developing an efficient marketing and processing system, (3) conserving natural resources, and (4) im- proving the well-being of

Universality and tails of long-range interactions in one dimension

NASA Astrophysics Data System (ADS)

Valiente, Manuel; Öhberg, Patrik

2017-07-01

Long-range interactions and, in particular, two-body potentials with power-law long-distance tails are ubiquitous in nature. For two bosons or fermions in one spatial dimension, the latter case being formally equivalent to three-dimensional s -wave scattering, we show how generic asymptotic interaction tails can be accounted for in the long-distance limit of scattering wave functions. This is made possible by introducing a generalization of the collisional phase shifts to include space dependence. We show that this distance dependence is universal, in that it does not depend on short-distance details of the interaction. The energy dependence is also universal, and is fully determined by the asymptotic tails of the two-body potential. As an important application of our findings, we describe how to eliminate finite-size effects with long-range potentials in the calculation of scattering phase shifts from exact diagonalization. We show that even with moderately small system sizes it is possible to accurately extract phase shifts that would otherwise be plagued with finite-size errors. We also consider multichannel scattering, focusing on the estimation of open channel asymptotic interaction strengths via finite-size analysis.

Experimental evidence of the self-similarity and long-range correlations of the edge fluctuations in HT-6M tokamak

NASA Astrophysics Data System (ADS)

Wang, Wen-hao; Yu, Chang-xuan; Wen, Yi-zhi; Xu, Yu-hong; Ling, Bi-li; Gong, Xian-zu; Liu, Bao-hua; Wan, Bao-nian

2001-02-01

For a better understanding of long timescale transport dynamics, the rescaled range analysis techniques, the autocorrelation function (ACF) and the probability distribution function (PDF) are used to investigate long-range dependences in edge plasma fluctuations in an HT-6M tokamak. The results reveal the self-similar characters of the electrostatic fluctuations with self-similarity parameters (Hurst exponent) ranging from 0.64 to 0.79, taking into consideration the Er×B rotation-sheared effect. Fluctuation ACFs of both the ion saturation current and the floating potential, as well as PDF of the turbulence-induced particle flux, have two distinct timescales. One corresponds to the decorrelation timescale of local fluctuations (µs) and the other lasts to the order of the confinement time (ms). All these experimental results suggest that some of the mechanisms of the underlying turbulence are consistent with plasma transport as characterized by self-organized criticality (SOC).

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

NASA Astrophysics Data System (ADS)

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.

Cape Cod National Seashore alternative transportation systems long range planning study

DOT National Transportation Integrated Search

2003-05-01

This project involves the development of short-range and long-range plans for alternative transportation to, from, and within the Cape Cod National Seashore. The five-year plan notes that improved public transportation services are needed both to mit...

Traveling solitons in long-range oscillator chains

NASA Astrophysics Data System (ADS)

Miloshevich, George; Nguenang, Jean Pierre; Dauxois, Thierry; Khomeriki, Ramaz; Ruffo, Stefano

2017-03-01

We investigate the existence and propagation of solitons in a long-range extension of the quartic Fermi-Pasta-Ulam (FPU) chain of anharmonic oscillators. The coupling in the linear term decays as a power-law with an exponent 1<α ≤slant 3 . We obtain an analytic perturbative expression of traveling envelope solitons by introducing a non linear Schrödinger equation for the slowly varying amplitude of short wavelength modes. Due to the non analytic properties of the dispersion relation, it is crucial to develop the theory using discrete difference operators. Those properties are also the ultimate reason why kink-solitons may exist but are unstable, at variance with the short-range FPU model. We successfully compare these approximate analytic results with numerical simulations for the value α =2 which was chosen as a case study.

A Long Range Science Rover For Future Mars Missions

NASA Technical Reports Server (NTRS)

Hayati, Samad

1997-01-01

This paper describes the design and implementation currently underway at the Jet Propulsion Laboratory of a long range science rover for future missions to Mars. The small rover prototype, called Rocky 7, is capable of long traverse. autonomous navigation. and science instrument control, carries three science instruments, and can be commanded from any computer platform and any location using the World Wide Web. In this paper we describe the mobility system, the sampling system, the sensor suite, navigation and control, onboard science instruments. and the ground command and control system.

Linear response theory for long-range interacting systems in quasistationary states.

PubMed

Patelli, Aurelio; Gupta, Shamik; Nardini, Cesare; Ruffo, Stefano

2012-02-01

Long-range interacting systems, while relaxing to equilibrium, often get trapped in long-lived quasistationary states which have lifetimes that diverge with the system size. In this work, we address the question of how a long-range system in a quasistationary state (QSS) responds to an external perturbation. We consider a long-range system that evolves under deterministic Hamilton dynamics. The perturbation is taken to couple to the canonical coordinates of the individual constituents. Our study is based on analyzing the Vlasov equation for the single-particle phase-space distribution. The QSS represents a stable stationary solution of the Vlasov equation in the absence of the external perturbation. In the presence of small perturbation, we linearize the perturbed Vlasov equation about the QSS to obtain a formal expression for the response observed in a single-particle dynamical quantity. For a QSS that is homogeneous in the coordinate, we obtain an explicit formula for the response. We apply our analysis to a paradigmatic model, the Hamiltonian mean-field model, which involves particles moving on a circle under Hamiltonian dynamics. Our prediction for the response of three representative QSSs in this model (the water-bag QSS, the Fermi-Dirac QSS, and the Gaussian QSS) is found to be in good agreement with N-particle simulations for large N. We also show the long-time relaxation of the water-bag QSS to the Boltzmann-Gibbs equilibrium state. © 2012 American Physical Society

Long-range dependence and multifractality in the term structure of LIBOR interest rates

NASA Astrophysics Data System (ADS)

Cajueiro, Daniel O.; Tabak, Benjamin M.

2007-01-01

In this paper we present evidence of long-range dependence in LIBOR interest rates. We study a data set from 2000 to 2005, for six different currencies and various maturities. Empirical results suggest that the degree of long-range dependence decreases with maturity, with the exception of interest rates on Japanese Yen and on Indonesian Rupiah. Furthermore, interest rates have a multifractal nature and the degree of multifractality is much stronger for Indonesia (emerging market). These findings suggest that interest rates derivatives should take these features into account. Furthermore, fixed income risk and portfolio management should incorporate long-range dependence in the modeling of interest rates.

Long-range multiplicity correlations in proton-proton collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bzdak, Adam

The forward-backward long-range multiplicity correlations in proton-proton collisions are investigated in the model with two independent sources of particles: one left- and one right-moving wounded nucleon. A good agreement with the UA5 Collaboration proton-antiproton data at the c.m. energy of 200 GeV is observed. For comparison the model with only one source of particles is also discussed.

Memory traces of long-range coordinated oscillations in the sleeping human brain.

PubMed

Piantoni, Giovanni; Van Der Werf, Ysbrand D; Jensen, Ole; Van Someren, Eus J W

2015-01-01

Cognition involves coordinated activity across distributed neuronal networks. Neuronal activity during learning triggers cortical plasticity that allows for reorganization of the neuronal network and integration of new information. Animal studies have shown post-learning reactivation of learning-elicited neuronal network activity during subsequent sleep, supporting consolidation of the reorganization. However, no previous studies, to our knowledge, have demonstrated reactivation of specific learning-elicited long-range functional connectivity during sleep in humans. We here show reactivation of learning-induced long-range synchronization of magnetoencephalography power fluctuations in human sleep. Visuomotor learning elicited a specific profile of long-range cortico-cortical synchronization of slow (0.1 Hz) fluctuations in beta band (12-30 Hz) power. The parieto-occipital part of this synchronization profile reappeared in delta band (1-3.5 Hz) power fluctuations during subsequent sleep, but not during the intervening wakefulness period. Individual differences in the reactivated synchronization predicted postsleep performance improvement. The presleep resting-state synchronization profile was not reactivated during sleep. The findings demonstrate reactivation of long-range coordination of neuronal activity in humans, more specifically of reactivation of coupling of infra-slow fluctuations in oscillatory power. The spatiotemporal profile of delta power fluctuations during sleep may subserve memory consolidation by echoing coordinated activation elicited by prior learning. © 2014 Wiley Periodicals, Inc.

Long range surface plasmon resonance (LRSPR) based highly sensitive refractive index sensor using Kretschmann prism coupling arrangement

NASA Astrophysics Data System (ADS)

Paliwal, Ayushi; Sharma, Anjali; Tomar, Monika; Gupta, Vinay

2016-04-01

Long range surface plasmon resonance (LRSPR) when exploited for sensing purpose exhibit less losses in comparison to the sensors based on conventional SPR technique leading to the development of highly sensitive refractive index sensor. In order to excite long range surface plasmon (LRSP) mode, a high refractive index prism is used as coupler and a thin metal layer is sandwiched between a dielectric having similar refractive index with that of another semi-infinite dielectric. LRSP mode has been excited in symmetric configuration where metal (Au) layer is sandwiched between the two similar refractive index dielectrics (LiF thin film and a fixed concentration of sugar solution) for realization of a refractive index sensor. When the concentration of sugar solution is slightly increased from 30% to 40%, the LRSPR angle increases from 64.6° to 67.9° and the sensor is found to be highly sensitive with sensitivity of 0.0911 °/(mg/dl).

Biosensing using long-range surface plasmon waveguides

NASA Astrophysics Data System (ADS)

Krupin, Oleksiy; Khodami, Maryam; Fan, Hui; Wong, Wei Ru; Mahamd Adikan, Faisal Rafiq; Berini, Pierre

2017-05-01

Long-range surface plasmon waveguides, and their application to various transducer architectures for amplitude- or phase-sensitive biosensing, are discussed. Straight and Y-junction waveguides are used for direct intensity-based detection, whereas Bragg gratings and single-, dual- and triple-output Mach Zehnder interferometers are used for phasebased detection. In either case, multiple-output biosensors which provide means for referencing are very useful to eliminate common perturbations and drift. Application of the biosensors to disease detection in complex fluids is discussed. Application to biomolecular interaction analysis and kinetics extraction is also discussed.

Comprehensive Long-Range Program for Library Services in Wisconsin.

ERIC Educational Resources Information Center

Wisconsin State Dept. of Public Instruction, Madison. Div. of Library Services.

The main areas of concern in this long-range development program to meet the requirements of the Library Services and Construction Act are the following: public library development and facilities, public library services for the disadvantaged, library services for the blind, physically handicapped and institutionalized persons, intertype library…

Long-range AIS message analysis based on the TianTuo-3 micro satellite

NASA Astrophysics Data System (ADS)

Li, Shiyou; Chen, Lihu; Chen, Xiaoqian; Zhao, Yong; Bai, Yuzhu

2017-07-01

The "Type-27 AIS message" is the long-range AIS broadcast message, which is primarily intended for the long-range detection of AIS typically by satellite. The TT3-AIS uses a four-frequency receiver scheme which includes two frequency channels conventionally applied by the AIS system and two new frequency channels allocated to the long-range AIS broadcast message. To the end of April 2016, the TT3-AIS has already received more than 11,400 packets of Type-27 AIS messages. In this paper, a detailed analysis of the Type-27 AIS messages is performed. Firstly, an eavesdropper diagram of the space-borne AIS received from the worldwide vessels is obtained. Secondly, the analysis to the trend of the number and the ratio of the new-type vessels is performed based on the Type-27 AIS message. The detection probability of the new-type vessels is also discussed. The result would be helpful on the usage of the long-range AIS message both for data application and for the improvement in designing the next space-based AIS receiver.

Optimized equation of the state of the square-well fluid of variable range based on a fourth-order free-energy expansion.

PubMed

Espíndola-Heredia, Rodolfo; del Río, Fernando; Malijevsky, Anatol

2009-01-14

The free energy of square-well (SW) systems of hard-core diameter sigma with ranges 1 < or = lambda < or = 3 is expanded in a perturbation series. This interval covers most ranges of interest, from short-ranged SW fluids (lambda approximately 1.2) used in modeling colloids to long ranges (lambda approximately 3) where the van der Waals classic approximation holds. The first four terms are evaluated by means of extensive Monte Carlo simulations. The calculations are corrected for the thermodynamic limit and care is taken to evaluate and to control the various sources of error. The results for the first two terms in the series confirm well-known independent results but have an increased estimated accuracy and cover a wider set of well ranges. The results for the third- and fourth-order terms are novel. The free-energy expansion for systems with short and intermediate ranges, 1 < or = lambda < or = 2, is seen to have properties similar to those of systems with longer ranges, 2 < or = lambda < or = 3. An equation of state (EOS) is built to represent the free-energy data. The thermodynamics given by this EOS, confronted against independent computer simulations, is shown to predict accurately the internal energy, pressure, specific heat, and chemical potential of the SW fluids considered and for densities 0 < or = rho sigma(3) < or = 0.9 including subcritical temperatures. This fourth-order theory is estimated to be accurate except for a small region at high density, rho sigma(3) approximately 0.9, and low temperature where terms of still higher order might be needed.

Fractality Evidence and Long-Range Dependence on Capital Markets: a Hurst Exponent Evaluation

NASA Astrophysics Data System (ADS)

Oprean, Camelia; Tănăsescu, Cristina

2014-07-01

Since the existence of market memory could implicate the rejection of the efficient market hypothesis, the aim of this paper is to find any evidence that selected emergent capital markets (eight European and BRIC markets, namely Hungary, Romania, Estonia, Czech Republic, Brazil, Russia, India and China) evince long-range dependence or the random walk hypothesis. In this paper, the Hurst exponent as calculated by R/S fractal analysis and Detrended Fluctuation Analysis is our measure of long-range dependence in the series. The results reinforce our previous findings and suggest that if stock returns present long-range dependence, the random walk hypothesis is not valid anymore and neither is the market efficiency hypothesis.

Tennessee long-range transportation plan : 10-year strategic investments program

DOT National Transportation Integrated Search

2005-12-01

The 10-Year Strategic Investments Program report identifies proposed spending priorities and policy initiatives that will address many of Tennessees transportation needs and help implement the states new Long-Range Transportation Plan (LRTP) ov...

Evaluation of a scale-model experiment to investigate long-range acoustic propagation

NASA Technical Reports Server (NTRS)

Parrott, Tony L.; Mcaninch, Gerry L.; Carlberg, Ingrid A.

1987-01-01

Tests were conducted to evaluate the feasibility of using a scale-model experiment situated in an anechoic facility to investigate long-range sound propagation over ground terrain. For a nominal scale factor of 100:1, attenuations along a linear array of six microphones colinear with a continuous-wave type of sound source were measured over a wavelength range from 10 to 160 for a nominal test frequency of 10 kHz. Most tests were made for a hard model surface (plywood), but limited tests were also made for a soft model surface (plywood with felt). For grazing-incidence propagation over the hard surface, measured and predicted attenuation trends were consistent for microphone locations out to between 40 and 80 wavelengths. Beyond 80 wavelengths, significant variability was observed that was caused by disturbances in the propagation medium. Also, there was evidence of extraneous propagation-path contributions to data irregularities at more remote microphones. Sensitivity studies for the hard-surface and microphone indicated a 2.5 dB change in the relative excess attenuation for a systematic error in source and microphone elevations on the order of 1 mm. For the soft-surface model, no comparable sensitivity was found.

Two general models that generate long range correlation

NASA Astrophysics Data System (ADS)

Gan, Xiaocong; Han, Zhangang

2012-06-01

In this paper we study two models that generate sequences with LRC (long range correlation). For the IFT (inverse Fourier transform) model, our conclusion is the low frequency part leads to LRC, while the high frequency part tends to eliminate it. Therefore, a typical method to generate a sequence with LRC is multiplying the spectrum of a white noise sequence by a decaying function. A special case is analyzed: the linear combination of a smooth curve and a white noise sequence, in which the DFA plot consists of two line segments. For the patch model, our conclusion is long subsequences leads to LRC, while short subsequences tend to eliminate it. Therefore, we can generate a sequence with LRC by using a fat-tailed PDF (probability distribution function) of the length of the subsequences. A special case is also analyzed: if a patch model with long subsequences is mixed with a white noise sequence, the DFA plot will consist of two line segments. We have checked known models and actual data, and found they are all consistent with this study.

Are Long-Range Structural Correlations Behind the Aggregration Phenomena of Polyglutamine Diseases?

PubMed Central

Moradi, Mahmoud; Babin, Volodymyr; Roland, Christopher; Sagui, Celeste

2012-01-01

We have characterized the conformational ensembles of polyglutamine peptides of various lengths (ranging from to ), both with and without the presence of a C-terminal polyproline hexapeptide. For this, we used state-of-the-art molecular dynamics simulations combined with a novel statistical analysis to characterize the various properties of the backbone dihedral angles and secondary structural motifs of the glutamine residues. For (i.e., just above the pathological length for Huntington's disease), the equilibrium conformations of the monomer consist primarily of disordered, compact structures with non-negligible -helical and turn content. We also observed a relatively small population of extended structures suitable for forming aggregates including - and -strands, and - and -hairpins. Most importantly, for we find that there exists a long-range correlation (ranging for at least residues) among the backbone dihedral angles of the Q residues. For polyglutamine peptides below the pathological length, the population of the extended strands and hairpins is considerably smaller, and the correlations are short-range (at most residues apart). Adding a C-terminal hexaproline to suppresses both the population of these rare motifs and the long-range correlation of the dihedral angles. We argue that the long-range correlation of the polyglutamine homopeptide, along with the presence of these rare motifs, could be responsible for its aggregation phenomena. PMID:22577357

Randomly diluted eg orbital-ordered systems.

PubMed

Tanaka, T; Matsumoto, M; Ishihara, S

2005-12-31

Dilution effects on the long-range ordered state of the doubly degenerate e(g) orbital are investigated. Quenched impurities without the orbital degree of freedom are introduced in the orbital model where the long-range order is realized by the order-from-disorder mechanism. It is shown by Monte Carlo simulations and the cluster-expansion method that a decrease in the orbital-ordering temperature by dilution is substantially larger than that in the randomly diluted spin models. Tilting of orbital pseudospins around impurities is the essence of this dilution effect. The present theory provides a new viewpoint for the recent resonant x-ray scattering experiments in KCu(1-x)Zn(x)F(3).

Bias Reduction and Filter Convergence for Long Range Stereo

NASA Technical Reports Server (NTRS)

Sibley, Gabe; Matthies, Larry; Sukhatme, Gaurav

2005-01-01

We are concerned here with improving long range stereo by filtering image sequences. Traditionally, measurement errors from stereo camera systems have been approximated as 3-D Gaussians, where the mean is derived by triangulation and the covariance by linearized error propagation. However, there are two problems that arise when filtering such 3-D measurements. First, stereo triangulation suffers from a range dependent statistical bias; when filtering this leads to over-estimating the true range. Second, filtering 3-D measurements derived via linearized error propagation leads to apparent filter divergence; the estimator is biased to under-estimate range. To address the first issue, we examine the statistical behavior of stereo triangulation and show how to remove the bias by series expansion. The solution to the second problem is to filter with image coordinates as measurements instead of triangulated 3-D coordinates.

Challenges in miniaturized automotive long-range lidar system design

NASA Astrophysics Data System (ADS)

Fersch, Thomas; Weigel, Robert; Koelpin, Alexander

2017-05-01

This paper discusses the current technical limitations posed on endeavors to miniaturize lidar systems for use in automotive applications and how to possibly extend those limits. The focus is set on long-range scanning direct time of flight LiDAR systems using APD photodetectors. Miniaturization evokes severe problems in ensuring absolute laser safety while maintaining the systems' performance in terms of maximum range, signal-to-noise ratio, detection probability, pixel density, or frame rate. Based on hypothetical but realistic specifications for an exemplary system the complete lidar signal path is calculated. The maximum range of the system is used as a general performance indicator. It is determined with the minimum signal-to-noise ratio required to detect an object. Various system parameters are varied to find their impact on the system's range. The reduction of the laser's pulse width and the right choice for the transimpedance amplifier's amplification have shown to be practicable measures to double the system's range.

Fractional-order difference equations for physical lattices and some applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tarasov, Vasily E., E-mail: tarasov@theory.sinp.msu.ru

2015-10-15

Fractional-order operators for physical lattice models based on the Grünwald-Letnikov fractional differences are suggested. We use an approach based on the models of lattices with long-range particle interactions. The fractional-order operators of differentiation and integration on physical lattices are represented by kernels of lattice long-range interactions. In continuum limit, these discrete operators of non-integer orders give the fractional-order derivatives and integrals with respect to coordinates of the Grünwald-Letnikov types. As examples of the fractional-order difference equations for physical lattices, we give difference analogs of the fractional nonlocal Navier-Stokes equations and the fractional nonlocal Maxwell equations for lattices with long-range interactions.more » Continuum limits of these fractional-order difference equations are also suggested.« less

Adiabatic description of long range frequency sweeping

NASA Astrophysics Data System (ADS)

Breizman, Boris; Nyqvist, Robert; Lilley, Matthew

2012-10-01

A theoretical framework is developed to describe long range frequency sweeping events in the 1D electrostatic bump-on-tail model with fast particle sources and collisions. The model includes three collision operators (Krook, drag (dynamical friction) and velocity space diffusion), and allows for a general shape of the fast particle distribution function. The behavior of phase space holes and clumps is analyzed, and the effect of particle trapping due to separatrix expansion is discussed. With a fast particle distribution function whose slope decays above the resonant phase velocity, hooked frequency sweeping is found for holes in the presence of drag collisions alone.

Long Range Transport of War-Related Burn Casualties

DTIC Science & Technology

2008-02-01

Long Range Transport of War-Related Burn Casualties Evan M. Renz, MD, FACS, Leopoldo C . Cancio, MD, FACS, David J. Barillo, MD, FACS, Christopher E...White, MD, FACS, Michael C . Albrecht, MD, Charles K. Thompson, PA- C , Jody L. Ennis, RN, BSN, Sandra M. Wanek, MD, James A. King, MD, FACEP, Kevin K...sched- Submitted for publication October 29, 2007. Accepted for publication October 30, 2007. Copyright © 2008 by Lippincott Williams & Wilkins From the

Possible biomechanical origins of the long-range correlations in stride intervals of walking

NASA Astrophysics Data System (ADS)

Gates, Deanna H.; Su, Jimmy L.; Dingwell, Jonathan B.

2007-07-01

When humans walk, the time duration of each stride varies from one stride to the next. These temporal fluctuations exhibit long-range correlations. It has been suggested that these correlations stem from higher nervous system centers in the brain that control gait cycle timing. Existing proposed models of this phenomenon have focused on neurophysiological mechanisms that might give rise to these long-range correlations, and generally ignored potential alternative mechanical explanations. We hypothesized that a simple mechanical system could also generate similar long-range correlations in stride times. We modified a very simple passive dynamic model of bipedal walking to incorporate forward propulsion through an impulsive force applied to the trailing leg at each push-off. Push-off forces were varied from step to step by incorporating both “sensory” and “motor” noise terms that were regulated by a simple proportional feedback controller. We generated 400 simulations of walking, with different combinations of sensory noise, motor noise, and feedback gain. The stride time data from each simulation were analyzed using detrended fluctuation analysis to compute a scaling exponent, α. This exponent quantified how each stride interval was correlated with previous and subsequent stride intervals over different time scales. For different variations of the noise terms and feedback gain, we obtained short-range correlations (α<0.5), uncorrelated time series (α=0.5), long-range correlations (0.5<α<1.0), or Brownian motion (α>1.0). Our results indicate that a simple biomechanical model of walking can generate long-range correlations and thus perhaps these correlations are not a complex result of higher level neuronal control, as has been previously suggested.

Current transport properties and phase diagram of a Kitaev chain with long-range pairing

NASA Astrophysics Data System (ADS)

Giuliano, Domenico; Paganelli, Simone; Lepori, Luca

2018-04-01

We describe a method to probe the quantum phase transition between the short-range topological phase and the long-range topological phase in the superconducting Kitaev chain with long-range pairing, both exhibiting subgap modes localized at the edges. The method relies on the effects of the finite mass of the subgap edge modes in the long-range regime (which survives in the thermodynamic limit) on the single-particle scattering coefficients through the chain connected to two normal leads. Specifically, we show that, when the leads are biased at a voltage V with respect to the superconducting chain, the Fano factor is either zero (in the short-range correlated phase) or 2 e (in the long-range correlated phase). As a result, we find that the Fano factor works as a directly measurable quantity to probe the quantum phase transition between the two phases. In addition, we note a remarkable "critical fractionalization effect" in the Fano factor, which is exactly equal to e along the quantum critical line. Finally, we note that a dual implementation of our proposed device makes it suitable as a generator of large-distance entangled two-particle states.

What moves you Arizona : long-range transportation plan : 2010-2035.

DOT National Transportation Integrated Search

2011-11-01

"What Moves You Arizona is the Arizona Department of Transportations (ADOT) Long-Range Transportation Plan (LRTP). The LRTP, or Plan, defines visionary, yet pragmatic, investment choices Arizona will make over the next 25 years to maintain a...

Active hydrodynamics of synchronization and ordering in moving oscillators

NASA Astrophysics Data System (ADS)

Banerjee, Tirthankar; Basu, Abhik

2017-08-01

The nature of emergent collective behaviors of moving interacting physical agents is a long-standing open issue in physical and biological systems alike. This calls for studies on the control of synchronization and the degree of order in a collection of diffusively moving noisy oscillators. We address this by constructing a generic hydrodynamic theory for active phase fluctuations in a collection of a large number of nearly-phase-coherent moving oscillators in two dimensions. Our theory describes the general situation where phase fluctuations and oscillator mobility mutually affect each other. We show that the interplay between the active effects and the mobility of the oscillators leads to a variety of phenomena, ranging from synchronization with long-range, nearly-long-range, and quasi-long-range orders to instabilities and desynchronization with short-range order of the oscillator phases. We highlight the complex dependences of synchronization on the active effects. These should be testable in wide-ranging systems, e.g., oscillating chemical reactions in the presence of different reaction inhibitors and facilitators, live oriented cytoskeletal extracts, and vertebrate segmentation clocks.

BKT phase transition in a 2D system with long-range dipole-dipole interaction

NASA Astrophysics Data System (ADS)

Fedichev, P. O.; Men'shikov, L. I.

2012-01-01

We consider phase transitions in 2D XY-like systems with long-range dipole-dipole interactions and demonstrate that BKT-type phase transition always occurs separating the ordered (ferroelectric) and the disordered (paraelectric) phases. The low-temperature phase corresponds to a thermal state with bound vortex-antivortex pairs characterized by linear attraction at large distances. Using the Maier-Schwabl topological charge model, we show that bound vortex pairs polarize and screen the vortex-antivortex interaction, leaving only the logarithmic attraction at sufficiently large separations between the vortices. At higher temperatures the pairs dissociate and the phase transition similar to BKT occurs, though at a larger temperature than in a system without the dipole-dipole interaction.

Many-body localization in a long range XXZ model with random-field

NASA Astrophysics Data System (ADS)

Li, Bo

2016-12-01

Many-body localization (MBL) in a long range interaction XXZ model with random field are investigated. Using the exact diagonal method, the MBL phase diagram with different tuning parameters and interaction range is obtained. It is found that the phase diagram of finite size results supplies strong evidence to confirm that the threshold interaction exponent α = 2. The tuning parameter Δ can efficiently change the MBL edge in high energy density stats, thus the system can be controlled to transfer from thermal phase to MBL phase by changing Δ. The energy level statistics data are consistent with result of the MBL phase diagram. However energy level statistics data cannot detect the thermal phase correctly in extreme long range case.

In-flight sleep, pilot fatigue and Psychomotor Vigilance Task performance on ultra-long range versus long range flights.

PubMed

Gander, Philippa H; Signal, T Leigh; van den Berg, Margo J; Mulrine, Hannah M; Jay, Sarah M; Jim Mangie, Captain

2013-12-01

This study evaluated whether pilot fatigue was greater on ultra-long range (ULR) trips (flights >16 h on 10% of trips in a 90-day period) than on long range (LR) trips. The within-subjects design controlled for crew complement, pattern of in-flight breaks, flight direction and departure time. Thirty male Captains (mean age = 54.5 years) and 40 male First officers (mean age = 48.0 years) were monitored on commercial passenger flights (Boeing 777 aircraft). Sleep was monitored (actigraphy, duty/sleep diaries) from 3 days before the first study trip to 3 days after the second study trip. Karolinska Sleepiness Scale, Samn-Perelli fatigue ratings and a 5-min Psychomotor Vigilance Task were completed before, during and after every flight. Total sleep in the 24 h before outbound flights and before inbound flights after 2-day layovers was comparable for ULR and LR flights. All pilots slept on all flights. For each additional hour of flight time, they obtained an estimated additional 12.3 min of sleep. Estimated mean total sleep was longer on ULR flights (3 h 53 min) than LR flights (3 h 15 min; P(F) = 0.0004). Sleepiness ratings were lower and mean reaction speed was faster at the end of ULR flights. Findings suggest that additional in-flight sleep mitigated fatigue effectively on longer flights. Further research is needed to clarify the contributions to fatigue of in-flight sleep versus time awake at top of descent. The study design was limited to eastward outbound flights with two Captains and two First Officers. Caution must be exercised when extrapolating to different operations. © 2013 European Sleep Research Society.

Development of a Long-Range Gliding Underwater Vehicle Utilizing Java Sun SPOT Technology

DTIC Science & Technology

2008-09-01

release; distribution is unlimited DEVELOPMENT OF A LONG-RANGE GLIDING UNMANNED UNDERWATER VEHICLE UTILIZING JAVA SUN SPOT TECHNOLOGY by...TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE: Development of a Long-Range Gliding Underwater Vehicle Utilizing Java Sun SPOT...vehicle. Further work is needed to demonstrate the efficiency and effectiveness of this design. 15. NUMBER OF PAGES 117 14. SUBJECT TERMS Java

A new variation of the Buckingham exponential-6 potential with a tunable, singularity-free short-range repulsion and an adjustable long-range attraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Werhahn, Jasper C.; Miliordos, Evangelos; Xantheas, Sotiris S.

2015-01-05

We introduce new generalized (reverting to the original) and extended (not reverting to the original) 4-parameter forms of the (B-2) Potential Energy Function (PEF) of Wang etal. (L.-P. Wang, J. Chen and T. van Voorhis, J. Chem. Theor. Comp. 9, 452 (2013)), which is itself a modification of the Buckingham exponential-6 PEF. The new forms have a tunable, singularity-free short-range repulsion and an adjustable long-range attraction. They produce fits to high quality ab initio data for the X–(H2O), X=F, Cl, Br, I and M+(H2O), M=Li, Na, K, Rb, Cs dimers that are between 1 and 2 orders of magnitude bettermore » than the original 3-parameter (B-2) and modified Buckingham exponential-6 PEFs. They are also slightly better than the 4-parameter generalized Buckingham exponential-6(gBe-6) and of comparable quality with the 4-parameter extended Morse (eM) PEFs introduced recently by us.« less

Composition-dependent stability of the medium-range order responsible for metallic glass formation

DOE PAGES

Zhang, Feng; Ji, Min; Fang, Xiao-Wei; ...

2014-09-18

The competition between the characteristic medium-range order corresponding to amorphous alloys and that in ordered crystalline phases is central to phase selection and morphology evolution under various processing conditions. We examine the stability of a model glass system, Cu–Zr, by comparing the energetics of various medium-range structural motifs over a wide range of compositions using first-principles calculations. Furthermore, we focus specifically on motifs that represent possible building blocks for competing glassy and crystalline phases, and we employ a genetic algorithm to efficiently identify the energetically favored decorations of each motif for specific compositions. These results show that a Bergman-type motifmore » with crystallization-resisting icosahedral symmetry is energetically most favorable in the composition range 0.63 < xCu < 0.68, and is the underlying motif for one of the three optimal glass-forming ranges observed experimentally for this binary system (Li et al., 2008). This work establishes an energy-based methodology to evaluate specific medium-range structural motifs which compete with stable crystalline nuclei in deeply undercooled liquids.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reece, Amy E.; Oakey, John, E-mail: joakey@uwyo.edu

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 channelsmore » 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

Long-range effect in nitrogen ion-implanted AISI 316L stainless steel

NASA Astrophysics Data System (ADS)

Budzynski, P.

2015-01-01

The effect of nitrogen ion implantation on AISI 316L stainless steel was investigated. The microstructure and composition of an N implanted layer were studied by RBS, GIXRD, SEM, and EDX measurements. Friction and wear tests were also performed. The discrepancy between the measured and calculated stopped ion maximum range does not exceed 0.03 μm. After nitrogen implantation with a fluence of 5 × 1017 ion/cm2, additional phases of expanded austenite were detected. At a 5-fold larger depth than the maximum ion range, improvement in the coefficient of friction and wear was detected. We have shown, for the first time, the long-range effect in tribological investigations. The long-range effect is caused by movement of not only defects along the depth of the sample, as assumed so far, but also nitrogen atoms.

Immobilization of paracetamol and benzocaine pro-drug derivatives as long-range self-organized monolayers on graphite.

PubMed

Popoff, Alexandre; Fichou, Denis

2008-05-01

We show here by means of scanning tunneling microscopy (STM) at the liquid/solid interface that paracetamol and benzocaine molecules bearing a long aliphatic chain can be immobilized on highly oriented pyrolitic graphite (HOPG) as perfectly ordered two-dimensional domains extending over several hundreds of nanometers. In both cases, high-resolution STM images reveal that compounds 1 and 2 self-assemble into parallel lamellae having a head-to-head arrangement. The paracetamol heads of 1 are in a zigzag position with entangled n-dodecyloxy side chains while benzocaine heads of compound 2 are perfectly aligned as a double row and have their palmitic side chains on either sides of the head alignment. We attribute the very long-range ordering of these two pro-drug derivatives on HOPG to the combined effects of intermolecular H-bonding on one side and Van der Waals interactions between aliphatic side chains and graphite on the other side. The 2D immobilization of pro-drug derivatives via a non-destructive physisorption mechanism could prove to be useful for applications such as drug delivery if it can be realized on a biocompatible substrate.

The production effect in long-list recall: In no particular order?

PubMed

Lambert, Angela M; Bodner, Glen E; Taikh, Alexander

2016-06-01

The production effect reflects a memory advantage for words read aloud versus silently. We investigated how production influences free recall of a single long list of words. In each of 4 experiments, a production effect occurred in a mixed-list group but not across pure-list groups. When compared to the pure-list groups, the mixed-list effects typically reflected a cost to silent words rather than a benefit to aloud words. This cost persisted when participants had to perform a generation or imagery task for the silent items, ruling out a lazy reading explanation. This recall pattern challenges both distinctiveness and strength accounts, but is consistent with an item-order account. By this account, the aloud words in a mixed list disrupt the encoding of item-order information for the silent words, thus impairing silent word recall. However, item-order measures and a forced-choice order test did not provide much evidence that recall was guided by retrieval of item-order information. We discuss our pattern of results in light of another recent study of the effects of production on long-list recall. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Novel Soft-Pion Theorem for Long-Range Nuclear Parity Violation.

PubMed

Feng, Xu; Guo, Feng-Kun; Seng, Chien-Yeah

2018-05-04

The parity-odd effect in the standard model weak neutral current reveals itself in the long-range parity-violating nuclear potential generated by the pion exchanges in the ΔI=1 channel with the parity-odd pion-nucleon coupling constant h_{π}^{1}. Despite decades of experimental and theoretical efforts, the size of this coupling constant is still not well understood. In this Letter, we derive a soft-pion theorem relating h_{π}^{1} and the neutron-proton mass splitting induced by an artificial parity-even counterpart of the ΔI=1 weak Lagrangian and demonstrate that the theorem still holds exact at the next-to-leading order in the chiral perturbation theory. A considerable amount of simplification is expected in the study of h_{π}^{1} by using either lattice or other QCD models following its reduction from a parity-odd proton-neutron-pion matrix element to a simpler spectroscopic quantity. The theorem paves the way to much more precise calculations of h_{π}^{1}, and thus a quantitative test of the strangeness-conserving neutral current interaction of the standard model is foreseen.

Novel Soft-Pion Theorem for Long-Range Nuclear Parity Violation

NASA Astrophysics Data System (ADS)

Feng, Xu; Guo, Feng-Kun; Seng, Chien-Yeah

2018-05-01

The parity-odd effect in the standard model weak neutral current reveals itself in the long-range parity-violating nuclear potential generated by the pion exchanges in the Δ I =1 channel with the parity-odd pion-nucleon coupling constant hπ1 . Despite decades of experimental and theoretical efforts, the size of this coupling constant is still not well understood. In this Letter, we derive a soft-pion theorem relating hπ1 and the neutron-proton mass splitting induced by an artificial parity-even counterpart of the Δ I =1 weak Lagrangian and demonstrate that the theorem still holds exact at the next-to-leading order in the chiral perturbation theory. A considerable amount of simplification is expected in the study of hπ1 by using either lattice or other QCD models following its reduction from a parity-odd proton-neutron-pion matrix element to a simpler spectroscopic quantity. The theorem paves the way to much more precise calculations of hπ1, and thus a quantitative test of the strangeness-conserving neutral current interaction of the standard model is foreseen.

Long and Short Range Correlations in Healthy and Pathologic Human Cardiac Prosses

NASA Astrophysics Data System (ADS)

Bunde, Armin

2001-03-01

Healthy sleep consists of several stages: deep sleep, light sleep and REM sleep. In this talk, recent work on the characterization of heart-rates in the three stages by long-range correlations is presented. Only in REM sleep, long-range correlations reminiscent to the wake phase occur, and the heart-rates show multifractal behaviour. In contrast, in non-REM phases, the heart-rates are uncorrelated above the typical breathing cycle time, pointing to a random regulation of the heartbeat during non-REM sleep. In deep sleep, the heart-rates show simple multifractal behaviour.

Adiabatic description of long range frequency sweeping

NASA Astrophysics Data System (ADS)

Nyqvist, R. M.; Lilley, M. K.; Breizman, B. N.

2012-09-01

A theoretical framework is developed to describe long range frequency sweeping events in the 1D electrostatic bump-on-tail model with fast particle sources and collisions. The model includes three collision operators (Krook, drag (dynamical friction) and velocity space diffusion), and allows for a general shape of the fast particle distribution function. The behaviour of phase space holes and clumps is analysed in the absence of diffusion, and the effect of particle trapping due to separatrix expansion is discussed. With a fast particle distribution function whose slope decays above the resonant phase velocity, hooked frequency sweeping is found for holes in the presence of drag collisions alone.

Describing long-range charge-separation processes with subsystem density-functional theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solovyeva, Alisa; Neugebauer, Johannes, E-mail: j.neugebauer@uni-muenster.de; Pavanello, Michele, E-mail: m.pavanello@rutgers.edu

2014-04-28

Long-range charge-transfer processes in extended systems are difficult to describe with quantum chemical methods. In particular, cost-effective (non-hybrid) approximations within time-dependent density functional theory (DFT) are not applicable unless special precautions are taken. Here, we show that the efficient subsystem DFT can be employed as a constrained DFT variant to describe the energetics of long-range charge-separation processes. A formal analysis of the energy components in subsystem DFT for such excitation energies is presented, which demonstrates that both the distance dependence and the long-range limit are correctly described. In addition, electronic couplings for these processes as needed for rate constants inmore » Marcus theory can be obtained from this method. It is shown that the electronic structure of charge-separated states constructed by a positively charged subsystem interacting with a negatively charged one is difficult to converge — charge leaking from the negative subsystem to the positive one can occur. This problem is related to the delocalization error in DFT and can be overcome with asymptotically correct exchange–correlation (XC) potentials or XC potentials including a sufficiently large amount of exact exchange. We also outline an approximate way to obtain charge-transfer couplings between locally excited and charge-separated states.« less

General formulation of long-range degree correlations in complex networks

NASA Astrophysics Data System (ADS)

Fujiki, Yuka; Takaguchi, Taro; Yakubo, Kousuke

2018-06-01

We provide a general framework for analyzing degree correlations between nodes separated by more than one step (i.e., beyond nearest neighbors) in complex networks. One joint and four conditional probability distributions are introduced to fully describe long-range degree correlations with respect to degrees k and k' of two nodes and shortest path length l between them. We present general relations among these probability distributions and clarify the relevance to nearest-neighbor degree correlations. Unlike nearest-neighbor correlations, some of these probability distributions are meaningful only in finite-size networks. Furthermore, as a baseline to determine the existence of intrinsic long-range degree correlations in a network other than inevitable correlations caused by the finite-size effect, the functional forms of these probability distributions for random networks are analytically evaluated within a mean-field approximation. The utility of our argument is demonstrated by applying it to real-world networks.

Long-range interactions, wobbles, and phase defects in chains of model cilia

NASA Astrophysics Data System (ADS)

Brumley, Douglas R.; Bruot, Nicolas; Kotar, Jurij; Goldstein, Raymond E.; Cicuta, Pietro; Polin, Marco

2016-12-01

Eukaryotic cilia and flagella are chemo-mechanical oscillators capable of generating long-range coordinated motions known as metachronal waves. Pair synchronization is a fundamental requirement for these collective dynamics, but it is generally not sufficient for collective phase-locking, chiefly due to the effect of long-range interactions. Here we explore experimentally and numerically a minimal model for a ciliated surface: hydrodynamically coupled oscillators rotating above a no-slip plane. Increasing their distance from the wall profoundly affects the global dynamics, due to variations in hydrodynamic interaction range. The array undergoes a transition from a traveling wave to either a steady chevron pattern or one punctuated by periodic phase defects. Within the transition between these regimes the system displays behavior reminiscent of chimera states.

Long-term high-fat feeding induces greater fat storage in mice lacking UCP3.

PubMed

Costford, Sheila R; Chaudhry, Shehla N; Crawford, Sean A; Salkhordeh, Mahmoud; Harper, Mary-Ellen

2008-11-01

Uncoupling protein-3 (UCP3) is a mitochondrial inner-membrane protein highly expressed in skeletal muscle. While UCP3's function is still unknown, it has been hypothesized to act as a fatty acid (FA) anion exporter, protecting mitochondria against lipid peroxidation and/or facilitating FA oxidation. The aim of this study was to determine the effects of long-term feeding of a 45% fat diet on whole body indicators of muscle metabolism in congenic C57BL/6 mice that were either lacking UCP3 (Ucp3(-/-)) or had a transgenically induced approximately twofold increase in UCP3 levels (UCP3tg). Mice were fed the high-fat (HF) diet for a period of either 4 or 8 mo immediately following weaning. After long-term HF feeding, UCP3tg mice weighed an average of 15% less than wild-type mice (P < 0.05) and were 20% less metabolically efficient than both wild-type and Ucp3(-/-) mice (P < 0.01). Additionally, wild-type mice had 21% lower, whereas UCP3tg mice had 36% lower, levels of adiposity compared with Ucp3(-/-) mice (P < 0.05 and P < 0.001, respectively), indicating a protective effect of UCP3 against fat gain. No differences in whole body oxygen consumption were detected following long-term HF feeding. Glucose and insulin tolerance tests revealed that both the UCP3tg and Ucp3(-/-) mice were more glucose tolerant and insulin sensitive compared with wild-type mice after short-term HF feeding, but this protection was not maintained in the long term. Findings indicate that UCP3 is involved in protection from fat gain induced by long-term HF feeding, but not in protection from insulin resistance.

Influence of long-range Coulomb interaction in velocity map imaging.

PubMed

Barillot, T; Brédy, R; Celep, G; Cohen, S; Compagnon, I; Concina, B; Constant, E; Danakas, S; Kalaitzis, P; Karras, G; Lépine, F; Loriot, V; Marciniak, A; Predelus-Renois, G; Schindler, B; Bordas, C

2017-07-07

The standard velocity-map imaging (VMI) analysis relies on the simple approximation that the residual Coulomb field experienced by the photoelectron ejected from a neutral or ion system may be neglected. Under this almost universal approximation, the photoelectrons follow ballistic (parabolic) trajectories in the externally applied electric field, and the recorded image may be considered as a 2D projection of the initial photoelectron velocity distribution. There are, however, several circumstances where this approximation is not justified and the influence of long-range forces must absolutely be taken into account for the interpretation and analysis of the recorded images. The aim of this paper is to illustrate this influence by discussing two different situations involving isolated atoms or molecules where the analysis of experimental images cannot be performed without considering long-range Coulomb interactions. The first situation occurs when slow (meV) photoelectrons are photoionized from a neutral system and strongly interact with the attractive Coulomb potential of the residual ion. The result of this interaction is the formation of a more complex structure in the image, as well as the appearance of an intense glory at the center of the image. The second situation, observed also at low energy, occurs in the photodetachment from a multiply charged anion and it is characterized by the presence of a long-range repulsive potential. Then, while the standard VMI approximation is still valid, the very specific features exhibited by the recorded images can be explained only by taking into consideration tunnel detachment through the repulsive Coulomb barrier.

Modified Lippmann--Schwinger equations for two-body scattering theory with long-range interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prugovecki, E.; Zorbas, J.

Two kinds of modified Lippmann-Schwinger equations are derived for the case of long-range potentials. The equations of the first kind are homogeneous and are a direct result of the fact that the standard Lippmann-Schwinger equations do not hold when long-range forces are present. The equations of the second kind depend on the existence of an operator Z such that W/sub plus or minus /=s-lim exp(iHt)Z exp-(-iHot). A general recipe for constructing Z is given and ita computation is carried through for the case of asymptotically Coulombic potentials. The resulting equations are used to compare the long-range theory with the theorymore » with a space cutoff (i.e., screened potential) in the limit in which that cutoff is being removed. (auth)« less

Two-Dimensional SIR Epidemics with Long Range Infection

NASA Astrophysics Data System (ADS)

Grassberger, Peter

2013-10-01

We extend a recent study of susceptible-infected-removed epidemic processes with long range infection (referred to as I in the following) from 1-dimensional lattices to lattices in two dimensions. As in I we use hashing to simulate very large lattices for which finite size effects can be neglected, in spite of the assumed power law p( x)˜| x|- σ-2 for the probability that a site can infect another site a distance vector x apart. As in I we present detailed results for the critical case, for the supercritical case with σ=2, and for the supercritical case with 0< σ<2. For the latter we verify the stretched exponential growth of the infected cluster with time predicted by M. Biskup. For σ=2 we find generic power laws with σ-dependent exponents in the supercritical phase, but no Kosterlitz-Thouless (KT) like critical point as in 1-d. Instead of diverging exponentially with the distance from the critical point, the correlation length increases with an inverse power, as in an ordinary critical point. Finally we study the dependence of the critical exponents on σ in the regime 0< σ<2, and compare with field theoretic predictions. In particular we discuss in detail whether the critical behavior for σ slightly less than 2 is in the short range universality class, as conjectured recently by F. Linder et al. As in I we also consider a modified version of the model where only some of the contacts are long range, the others being between nearest neighbors. If the number of the latter reaches the percolation threshold, the critical behavior is changed but the supercritical behavior stays qualitatively the same.

Enhanced SO2 Concentrations Observed over Northern India: Role of Long-range Transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mallik, C.; Lal, S.; Naja, M.

2013-01-17

Volcanic emissions and coal burning are among the major sources of SO2 over the continental environment. In this study, we show episodes of long-range transport of volcanic SO2 from Africa to Northern India using satellite observations. Monthly averaged SO2 from OMI were of the order of 0.6-0.9 DU during November, 2008 over the Indo-Gangetic Plain (IGP), which far exceeded background values (<0.3 DU) retrieved from observations across different locations over North India during 2005-2010. The columnar SO2 loadings were much higher on November 6 over most of the IGP and even exceeded 6 DU, a factor of 10 higher thanmore » background levels at some places. These enhanced SO2 levels were, however, not reciprocated in satellite derived NO2 or CO columns, indicating transport from a non-anthropogenic source of SO2. Backward trajectory analysis revealed strong winds in the free troposphere, which originated from the Dalaffilla volcanic eruption over the Afar region of Ethiopia during November 4-6, 2008. Wind streams and stable atmospheric conditions were conducive to the long-range transport of volcanic plume into the IGP. As most of the local aerosols over IGP region are below 3 km, a well separated layer at 4-5 km is observed from CALIPSO, most likely as a result of this transport. Apart from known anthropogenic sources, the additional transport of volcanic SO2 over the IGP region would have implications to air quality and radiation balance over this region.« less

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

NASA Astrophysics Data System (ADS)

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.

The long range voice coil atomic force microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnard, H.; Randall, C.; Bridges, D.

2012-02-15

Most current atomic force microscopes (AFMs) use piezoelectric ceramics for scan actuation. Piezoelectric ceramics provide precision motion with fast response to applied voltage potential. A drawback to piezoelectric ceramics is their inherently limited ranges. For many samples this is a nonissue, as imaging the nanoscale details is the goal. However, a key advantage of AFM over other microscopy techniques is its ability to image biological samples in aqueous buffer. Many biological specimens have topography for which the range of piezoactuated stages is limiting, a notable example of which is bone. In this article, we present the use of voice coilsmore » in scan actuation for an actuation range in the Z-axis an order of magnitude larger than any AFM commercially available today. The increased scan size will allow for imaging an important new variety of samples, including bone fractures.« less

Real-Time Quantum Dynamics of Long-Range Electronic Excitation Transfer in Plasmonic Nanoantennas.

PubMed

Ilawe, Niranjan V; Oviedo, M Belén; Wong, Bryan M

2017-08-08

Using large-scale, real-time, quantum dynamics calculations, we present a detailed analysis of electronic excitation transfer (EET) mechanisms in a multiparticle plasmonic nanoantenna system. Specifically, we utilize real-time, time-dependent, density functional tight binding (RT-TDDFTB) to provide a quantum-mechanical description (at an electronic/atomistic level of detail) for characterizing and analyzing these systems, without recourse to classical approximations. We also demonstrate highly long-range electronic couplings in these complex systems and find that the range of these couplings is more than twice the conventional cutoff limit considered by Förster resonance energy transfer (FRET)-based approaches. Furthermore, we attribute these unusually long-ranged electronic couplings to the coherent oscillations of conduction electrons in plasmonic nanoparticles. This long-range nature of plasmonic interactions has important ramifications for EET; in particular, we show that the commonly used "nearest-neighbor" FRET model is inadequate for accurately characterizing EET even in simple plasmonic antenna systems. These findings provide a real-time, quantum-mechanical perspective for understanding EET mechanisms and provide guidance in enhancing plasmonic properties in artificial light-harvesting systems.

Experimental Demonstration of Long-Range Underwater Acoustic Communication Using a Vertical Sensor Array

PubMed Central

Zhao, Anbang; Zeng, Caigao; Hui, Juan; Ma, Lin; Bi, Xuejie

2017-01-01

This paper proposes a composite channel virtual time reversal mirror (CCVTRM) for vertical sensor array (VSA) processing and applies it to long-range underwater acoustic (UWA) communication in shallow water. Because of weak signal-to-noise ratio (SNR), it is unable to accurately estimate the channel impulse response of each sensor of the VSA, thus the traditional passive time reversal mirror (PTRM) cannot perform well in long-range UWA communication in shallow water. However, CCVTRM only needs to estimate the composite channel of the VSA to accomplish time reversal mirror (TRM), which can effectively mitigate the inter-symbol interference (ISI) and reduce the bit error rate (BER). In addition, the calculation of CCVTRM is simpler than traditional PTRM. An UWA communication experiment using a VSA of 12 sensors was conducted in the South China Sea. The experiment achieves a very low BER communication at communication rate of 66.7 bit/s over an 80 km range. The results of the sea trial demonstrate that CCVTRM is feasible and can be applied to long-range UWA communication in shallow water. PMID:28653976

The long-range correlation and evolution law of centennial-scale temperatures in Northeast China.

PubMed

Zheng, Xiaohui; Lian, Yi; Wang, Qiguang

2018-01-01

This paper applies the detrended fluctuation analysis (DFA) method to investigate the long-range correlation of monthly mean temperatures from three typical measurement stations at Harbin, Changchun, and Shenyang in Northeast China from 1909 to 2014. The results reveal the memory characteristics of the climate system in this region. By comparing the temperatures from different time periods and investigating the variations of its scaling exponents at the three stations during these different time periods, we found that the monthly mean temperature has long-range correlation, which indicates that the temperature in Northeast China has long-term memory and good predictability. The monthly time series of temperatures over the past 106 years also shows good long-range correlation characteristics. These characteristics are also obviously observed in the annual mean temperature time series. Finally, we separated the centennial-length temperature time series into two time periods. These results reveal that the long-range correlations at the Harbin station over these two time periods have large variations, whereas no obvious variations are observed at the other two stations. This indicates that warming affects the regional climate system's predictability differently at different time periods. The research results can provide a quantitative reference point for regional climate predictability assessment and future climate model evaluation.

Phase diagram of the quantum Ising model with long-range interactions on an infinite-cylinder triangular lattice

NASA Astrophysics Data System (ADS)

Saadatmand, S. N.; Bartlett, S. D.; McCulloch, I. P.

2018-04-01

Obtaining quantitative ground-state behavior for geometrically-frustrated quantum magnets with long-range interactions is challenging for numerical methods. Here, we demonstrate that the ground states of these systems on two-dimensional lattices can be efficiently obtained using state-of-the-art translation-invariant variants of matrix product states and density-matrix renormalization-group algorithms. We use these methods to calculate the fully-quantitative ground-state phase diagram of the long-range interacting triangular Ising model with a transverse field on six-leg infinite-length cylinders and scrutinize the properties of the detected phases. We compare these results with those of the corresponding nearest neighbor model. Our results suggest that, for such long-range Hamiltonians, the long-range quantum fluctuations always lead to long-range correlations, where correlators exhibit power-law decays instead of the conventional exponential drops observed for short-range correlated gapped phases. Our results are relevant for comparisons with recent ion-trap quantum simulator experiments that demonstrate highly-controllable long-range spin couplings for several hundred ions.

Reaching for the Horizon: The 2015 NSAC Long Range Plan

NASA Astrophysics Data System (ADS)

Geesaman, Donald

2015-10-01

In April 2014, the Nuclear Science Advisory Committee was charged to conduct a new study of the opportunities and priorities for United States nuclear physics research and to recommend a long range plan for the coordinated advancement of the Nation's nuclear science program over the next decade. The entire community actively contributed to developing this plan. Ideas and goals, new and old, were examined and community priorities were established. The Long Range Plan Working Group gathered at Kitty Hawk, NC to converge on the recommendations. In this talk I will discuss the vision for the future that has emerged from this process. The new plan, ``Reaching for the Horizon,'' offers the promise of great leaps forward in our understanding of nuclear science and new opportunities for nuclear science to serve society. This work was supported by the U. S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.

Long-Range Repulsion Between Spatially Confined van der Waals Dimers

NASA Astrophysics Data System (ADS)

Sadhukhan, Mainak; Tkatchenko, Alexandre

2017-05-01

It is an undisputed textbook fact that nonretarded van der Waals (vdW) interactions between isotropic dimers are attractive, regardless of the polarizability of the interacting systems or spatial dimensionality. The universality of vdW attraction is attributed to the dipolar coupling between fluctuating electron charge densities. Here, we demonstrate that the long-range interaction between spatially confined vdW dimers becomes repulsive when accounting for the full Coulomb interaction between charge fluctuations. Our analytic results are obtained by using the Coulomb potential as a perturbation over dipole-correlated states for two quantum harmonic oscillators embedded in spaces with reduced dimensionality; however, the long-range repulsion is expected to be a general phenomenon for spatially confined quantum systems. We suggest optical experiments to test our predictions, analyze their relevance in the context of intermolecular interactions in nanoscale environments, and rationalize the recent observation of anomalously strong screening of the lateral vdW interactions between aromatic hydrocarbons adsorbed on metal surfaces.

Cell type-specific long-range connections of basal forebrain circuit.

PubMed

Do, Johnny Phong; Xu, Min; Lee, Seung-Hee; Chang, Wei-Cheng; Zhang, Siyu; Chung, Shinjae; Yung, Tyler J; Fan, Jiang Lan; Miyamichi, Kazunari; Luo, Liqun; Dan, Yang

2016-09-19

The basal forebrain (BF) plays key roles in multiple brain functions, including sleep-wake regulation, attention, and learning/memory, but the long-range connections mediating these functions remain poorly characterized. Here we performed whole-brain mapping of both inputs and outputs of four BF cell types - cholinergic, glutamatergic, and parvalbumin-positive (PV+) and somatostatin-positive (SOM+) GABAergic neurons - in the mouse brain. Using rabies virus -mediated monosynaptic retrograde tracing to label the inputs and adeno-associated virus to trace axonal projections, we identified numerous brain areas connected to the BF. The inputs to different cell types were qualitatively similar, but the output projections showed marked differences. The connections to glutamatergic and SOM+ neurons were strongly reciprocal, while those to cholinergic and PV+ neurons were more unidirectional. These results reveal the long-range wiring diagram of the BF circuit with highly convergent inputs and divergent outputs and point to both functional commonality and specialization of different BF cell types.

R-matrix-valued Lax pairs and long-range spin chains

NASA Astrophysics Data System (ADS)

Sechin, I.; Zotov, A.

2018-06-01

In this paper we discuss R-matrix-valued Lax pairs for slN Calogero-Moser model and their relation to integrable quantum long-range spin chains of the Haldane-Shastry-Inozemtsev type. First, we construct the R-matrix-valued Lax pairs for the third flow of the classical Calogero-Moser model. Then we notice that the scalar parts (in the auxiliary space) of the M-matrices corresponding to the second and third flows have form of special spin exchange operators. The freezing trick restricts them to quantum Hamiltonians of long-range spin chains. We show that for a special choice of the R-matrix these Hamiltonians reproduce those for the Inozemtsev chain. In the general case related to the Baxter's elliptic R-matrix we obtain a natural anisotropic extension of the Inozemtsev chain. Commutativity of the Hamiltonians is verified numerically. Trigonometric limits lead to the Haldane-Shastry chains and their anisotropic generalizations.

Evidence for short-range magnetic order in the nematic phase of FeSe from anisotropic in-plane magnetostriction and susceptibility measurements

NASA Astrophysics Data System (ADS)

He, Mingquan; Wang, Liran; Hardy, Frédéric; Xu, Liping; Wolf, Thomas; Adelmann, Peter; Meingast, Christoph

2018-03-01

The nature of the nematic state in FeSe remains one of the major unsolved mysteries in Fe-based superconductors. Both spin and orbital physics have been invoked to explain the origin of this phase. Here we present experimental evidence for frustrated, short-range magnetic order, as suggested by several recent theoretical works, in the nematic state of FeSe. We use a combination of magnetostriction, susceptibility, and resistivity measurements to probe the in-plane anisotropies of the nematic state and its associated fluctuations. Despite the absence of long-range magnetic order in FeSe, we observe a sizable in-plane magnetic susceptibility anisotropy, which is responsible for the field-induced in-plane distortion inferred from magnetostriction measurements. Further we demonstrate that all three anisotropies in FeSe are very similar to those of BaFe2As2 , which strongly suggests that the nematic phase in FeSe is also of magnetic origin.

Measurements of long-range enhanced collisional velocity drag through plasma wave damping

NASA Astrophysics Data System (ADS)

Affolter, M.; Anderegg, F.; Dubin, D. H. E.; Driscoll, C. F.

2018-05-01

We present damping measurements of axial plasma waves in magnetized, multispecies ion plasmas. At high temperatures T ≳ 10-2 eV, collisionless Landau damping dominates, whereas, at lower temperatures T ≲ 10-2 eV, the damping arises from interspecies collisional drag, which is dependent on the plasma composition and scales roughly as T-3 /2 . This drag damping is proportional to the rate of parallel collisional slowing, and is found to exceed classical predictions of collisional drag damping by as much as an order of magnitude, but agrees with a new collision theory that includes long-range collisions. Centrifugal mass separation and collisional locking of the species occur at ultra-low temperatures T ≲ 10-3 eV, which reduce the drag damping from the T-3 /2 collisional scaling. These mechanisms are investigated by measuring the damping of higher frequency axial modes, and by measuring the damping in plasmas with a non-equilibrium species profile.

Long-range strategic planning: a case study.

PubMed

Moller-Tiger, D

1999-05-01

In highly competitive healthcare markets, integrated delivery systems (IDSs) that have exhausted traditional means of maintaining market competitiveness are challenged to identify effective new strategies that will ensure market success in an uncertain future. Finding itself facing this challenge, Legacy Health System, a Portland, Oregon-based IDS, undertook an innovative, long-range, strategic-planning initiative based on an evaluation of key market trends. Legacy discovered that it might benefit from making some changes in the way it approached its mission. These changes included focusing on specific customer segments, developing products and services aimed at those customers, and broadening physician and insurer relationships to enhance service and improve customers' access to health care.

The Nucleus Reuniens Controls Long-Range Hippocampo-Prefrontal Gamma Synchronization during Slow Oscillations.

PubMed

Ferraris, Maëva; Ghestem, Antoine; Vicente, Ana F; Nallet-Khosrofian, Lauriane; Bernard, Christophe; Quilichini, Pascale P

2018-03-21

Gamma oscillations are involved in long-range coupling of distant regions that support various cognitive operations. Here we show in adult male rats that synchronized bursts of gamma oscillations bind the hippocampus (HPC) and prefrontal cortex (mPFC) during slow oscillations and slow-wave sleep, a brain state that is central for consolidation of memory traces. These gamma bursts entrained the firing of the local HPC and mPFC neuronal populations. Neurons of the nucleus reuniens (NR), which is a structural and functional hub between HPC and mPFC, demonstrated a specific increase in their firing before gamma burst onset, suggesting their involvement in HPC-mPFC binding. Chemical inactivation of NR disrupted the temporal pattern of gamma bursts and their synchronization, as well as mPFC neuronal firing. We propose that the NR drives long-range hippocampo-prefrontal coupling via gamma bursts providing temporal windows for information exchange between the HPC and mPFC during slow-wave sleep. SIGNIFICANCE STATEMENT Long-range coupling between hippocampus (HPC) and prefrontal cortex (mPFC) is believed to support numerous cognitive functions, including memory consolidation occurring during sleep. Gamma-band synchronization is a fundamental process in many neuronal operations and is instrumental in long-range coupling. Recent evidence highlights the role of nucleus reuniens (NR) in consolidation; however, how it influences hippocampo-prefrontal coupling is unknown. In this study, we show that HPC and mPFC are synchronized by gamma bursts during slow oscillations in anesthesia and natural sleep. By manipulating and recording the NR-HPC-mPFC network, we provide evidence that the NR actively promotes this long-range gamma coupling. This coupling provides the hippocampo-prefrontal circuit with a novel mechanism to exchange information during slow-wave sleep. Copyright © 2018 the authors 0270-6474/18/383026-13$15.00/0.

Long-range correction for tight-binding TD-DFT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Humeniuk, Alexander; Mitrić, Roland, E-mail: roland.mitric@uni-wuerzburg.de

2015-10-07

We present two improvements to the tight-binding approximation of time-dependent density functional theory (TD-DFTB): First, we add an exact Hartree-Fock exchange term, which is switched on at large distances, to the ground state Hamiltonian and similarly to the coupling matrix that enters the linear response equations for the calculation of excited electronic states. We show that the excitation energies of charge transfer states are improved relative to the standard approach without the long-range correction by testing the method on a set of molecules from the database in Peach et al. [J. Chem. Phys. 128, 044118 (2008)] which are known tomore » exhibit problematic charge transfer states. The degree of spatial overlap between occupied and virtual orbitals indicates where TD-DFTB and long-range corrected TD-DFTB (lc-TD-DFTB) can be expected to produce large errors. Second, we improve the calculation of oscillator strengths. The transition dipoles are obtained from Slater Koster files for the dipole matrix elements between valence orbitals. In particular, excitations localized on a single atom, which appear dark when using Mulliken transition charges, acquire a more realistic oscillator strength in this way. These extensions pave the way for using lc-TD-DFTB to describe the electronic structure of large chromophoric polymers, where uncorrected TD-DFTB fails to describe the high degree of conjugation and produces spurious low-lying charge transfer states.« less

Flash Detection Efficiencies of Long Range Lightning Detection Networks During GRIP

NASA Technical Reports Server (NTRS)

Mach, Douglas M.; Bateman, Monte G.; Blakeslee, Richard J.

2012-01-01

We flew our Lightning Instrument Package (LIP) on the NASA Global Hawk as a part of the Genesis and Rapid Intensification Processes (GRIP) field program. The GRIP program was a NASA Earth science field experiment during the months of August and September, 2010. During the program, the LIP detected lighting from 48 of the 213 of the storms overflown by the Global Hawk. The time and location of tagged LIP flashes can be used as a "ground truth" dataset for checking the detection efficiency of the various long or extended range ground-based lightning detection systems available during the GRIP program. The systems analyzed included Vaisala Long Range (LR), Vaisala GLD360, the World Wide Lightning Location Network (WWLLN), and the Earth Networks Total Lightning Network (ENTLN). The long term goal of our research is to help understand the advantages and limitations of these systems so that we can utilize them for both proxy data applications and cross sensor validation of the GOES-R Geostationary Lightning Mapper (GLM) sensor when it is launched in the 2015 timeframe.

Empirical mode decomposition and long-range correlation analysis of sunspot time series

NASA Astrophysics Data System (ADS)

Zhou, Yu; Leung, Yee

2010-12-01

Sunspots, which are the best known and most variable features of the solar surface, affect our planet in many ways. The number of sunspots during a period of time is highly variable and arouses strong research interest. When multifractal detrended fluctuation analysis (MF-DFA) is employed to study the fractal properties and long-range correlation of the sunspot series, some spurious crossover points might appear because of the periodic and quasi-periodic trends in the series. However many cycles of solar activities can be reflected by the sunspot time series. The 11-year cycle is perhaps the most famous cycle of the sunspot activity. These cycles pose problems for the investigation of the scaling behavior of sunspot time series. Using different methods to handle the 11-year cycle generally creates totally different results. Using MF-DFA, Movahed and co-workers employed Fourier truncation to deal with the 11-year cycle and found that the series is long-range anti-correlated with a Hurst exponent, H, of about 0.12. However, Hu and co-workers proposed an adaptive detrending method for the MF-DFA and discovered long-range correlation characterized by H≈0.74. In an attempt to get to the bottom of the problem in the present paper, empirical mode decomposition (EMD), a data-driven adaptive method, is applied to first extract the components with different dominant frequencies. MF-DFA is then employed to study the long-range correlation of the sunspot time series under the influence of these components. On removing the effects of these periods, the natural long-range correlation of the sunspot time series can be revealed. With the removal of the 11-year cycle, a crossover point located at around 60 months is discovered to be a reasonable point separating two different time scale ranges, H≈0.72 and H≈1.49. And on removing all cycles longer than 11 years, we have H≈0.69 and H≈0.28. The three cycle-removing methods—Fourier truncation, adaptive detrending and the

Surprises from quenches in long-range-interacting systems: temperature inversion and cooling

NASA Astrophysics Data System (ADS)

Gupta, Shamik; Casetti, Lapo

2016-10-01

What happens when one of the parameters governing the dynamics of a long-range interacting system of particles in thermal equilibrium is abruptly changed (quenched) to a different value? While a short-range system, under the same conditions, will relax in time to a new thermal equilibrium with a uniform temperature across the system, a long-range system shows a fast relaxation to a non-equilibrium quasistationary state (QSS). The lifetime of such an off-equilibrium state diverges with the system size, and the temperature is non-uniform across the system. Quite surprisingly, the density profile in the QSS obtained after the quench is anticorrelated with the temperature profile in space, thus exhibiting the phenomenon of temperature inversion: denser regions are colder than sparser ones. We illustrate with extensive molecular dynamics simulations the ubiquity of this scenario in a prototypical long-range interacting system subject to a variety of quenching protocols, and in a model that mimics an experimental setup of atoms interacting with light in an optical cavity. We further demonstrate how a procedure of iterative quenching combined with filtering out the high-energy particles in the system may be employed to cool the system. Temperature inversion is observed in nature in some astrophysical settings; our results imply that such a phenomenon should be observable, and could even be exploitable to advantage, also in controlled laboratory experiments.

Long range intermolecular interactions between the alkali diatomics Na2, K2, and NaK

NASA Astrophysics Data System (ADS)

Zemke, Warren T.; Byrd, Jason N.; Michels, H. Harvey; Montgomery, John A.; Stwalley, William C.

2010-06-01

Long range interactions between the ground state alkali diatomics Na2-Na2, K2-K2, Na2-K2, and NaK-NaK are examined. Interaction energies are first determined from ab initio calculations at the coupled-cluster with singles, doubles, and perturbative triples [CCSD(T)] level of theory, including counterpoise corrections. Long range energies calculated from diatomic molecular properties (polarizabilities and dipole and quadrupole moments) are then compared with the ab initio energies. A simple asymptotic model potential ELR=Eelec+Edisp+Eind is shown to accurately represent the intermolecular interactions for these systems at long range.

Strategic Long Range Planning for Universities. AIR Forum 1980 Paper.

ERIC Educational Resources Information Center

Baker, Michael E.

The use of strategic long-range planning at Carnegie-Mellon University (CMU) is discussed. A structure for strategic planning analysis that integrates existing techniques is presented, and examples of planning activities at CMU are included. The key concept in strategic planning is competitive advantage: if a university has a competitive…

Long-Range Spin-Qubit Interaction Mediated by Microcavity Polaritons

NASA Astrophysics Data System (ADS)

Quinteiro, G. F.; Fernández-Rossier, J.; Piermarocchi, C.

2006-09-01

We study the optically induced coupling between spins mediated by polaritons in a planar microcavity. In the strong-coupling regime, the vacuum Rabi splitting introduces anisotropies in the spin coupling. Moreover, due to their photonlike mass, polaritons provide an extremely long spin coupling range. This suggests the realization of two-qubit all-optical quantum operations within tens of picoseconds with spins localized as far as hundreds of nanometers apart.

The 2002 review of Florida's twenty-five long range transportation plans

DOT National Transportation Integrated Search

2002-08-01

Florida's 25 metropolitan planning organization (MPO) long range transportation plans (LRTPs) were reviewed. Each MPO had completed at least one update cycle since the initial review in 1997. Additionally, federal transportation legislation added a f...

Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues

DTIC Science & Technology

2016-02-24

13 The FALCON Study...range strike capabilities. These include bombers, cruise missiles, ballistic missiles, and boost-glide technologies that would mate a rocket booster...Command, Hearing, April 4, 2005. 23 Grossman, Elaine M., “U.S. General: Precise Long-Range Missiles may Enable Big Nuclear Cuts,” Inside the Pentagon

Contribution of long-range interactions to the secondary structure of an unfolded globin.

PubMed

Fedyukina, Daria V; Rajagopalan, Senapathy; Sekhar, Ashok; Fulmer, Eric C; Eun, Ye-Jin; Cavagnero, Silvia

2010-09-08

This work explores the effect of long-range tertiary contacts on the distribution of residual secondary structure in the unfolded state of an alpha-helical protein. N-terminal fragments of increasing length, in conjunction with multidimensional nuclear magnetic resonance, were employed. A protein representative of the ubiquitous globin fold was chosen as the model system. We found that, while most of the detectable alpha-helical population in the unfolded ensemble does not depend on the presence of the C-terminal region (corresponding to the native G and H helices), specific N-to-C long-range contacts between the H and A-B-C regions enhance the helical secondary structure content of the N terminus (A-B-C regions). The simple approach introduced here, based on the evaluation of N-terminal polypeptide fragments of increasing length, is of general applicability to identify the influence of long-range interactions in unfolded proteins. Copyright 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Contribution of Long-Range Interactions to the Secondary Structure of an Unfolded Globin

PubMed Central

Fedyukina, Daria V.; Rajagopalan, Senapathy; Sekhar, Ashok; Fulmer, Eric C.; Eun, Ye-Jin; Cavagnero, Silvia

2010-01-01

This work explores the effect of long-range tertiary contacts on the distribution of residual secondary structure in the unfolded state of an α-helical protein. N-terminal fragments of increasing length, in conjunction with multidimensional nuclear magnetic resonance, were employed. A protein representative of the ubiquitous globin fold was chosen as the model system. We found that, while most of the detectable α-helical population in the unfolded ensemble does not depend on the presence of the C-terminal region (corresponding to the native G and H helices), specific N-to-C long-range contacts between the H and A-B-C regions enhance the helical secondary structure content of the N terminus (A-B-C regions). The simple approach introduced here, based on the evaluation of N-terminal polypeptide fragments of increasing length, is of general applicability to identify the influence of long-range interactions in unfolded proteins. PMID:20816043

Long Range Planning for Computer Use--A Task Force Model.

ERIC Educational Resources Information Center

Raucher, S. M.; Koehler, T. J.

A Management Operations Review and Evaluation (MORE) study of the Department of Management Information and Computer Services, which was completed in the fall of 1980, strongly recommended that the Montgomery County Public Schools (MCPS) develop a long-range plan to meet the computer needs of schools and central offices. In response to this…

Long-range Self-interacting Dark Matter in the Sun

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Jing; State Key Laboratory of Theoretical Physics, Kavli Institute for Theoretical Physics China,Institute of Theoretical Physics, Chinese Academy of Science,Zhong Guan Cun East Street 55#, Beijing, 100190; Liang, Zheng-Liang

2015-12-10

We investigate the implications of the long-rang self-interaction on both the self-capture and the annihilation of the self-interacting dark matter (SIDM) trapped in the Sun. Our discussion is based on a specific SIDM model in which DM particles self-interact via a light scalar mediator, or Yukawa potential, in the context of quantum mechanics. Within this framework, we calculate the self-capture rate across a broad region of parameter space. While the self-capture rate can be obtained separately in the Born regime with perturbative method, and in the classical limits with the Rutherford formula, our calculation covers the gap between in amore » non-perturbative fashion. Besides, the phenomenology of both the Sommerfeld-enhanced s- and p-wave annihilation of the solar SIDM is also involved in our discussion. Moreover, by combining the analysis of the Super-Kamiokande (SK) data and the observed DM relic density, we constrain the nuclear capture rate of the DM particles in the presence of the dark Yukawa potential. The consequence of the long-range dark force on probing the solar SIDM turns out to be significant if the force-carrier is much lighter than the DM particle, and a quantitative analysis is provided.« less

Long-range Self-interacting Dark Matter in the Sun

NASA Astrophysics Data System (ADS)

Chen, Jing; Liang, Zheng-Liang; Wu, Yue-Liang; Zhou, Yu-Feng

2015-12-01

We investigate the implications of the long-rang self-interaction on both the self-capture and the annihilation of the self-interacting dark matter (SIDM) trapped in the Sun. Our discussion is based on a specific SIDM model in which DM particles self-interact via a light scalar mediator, or Yukawa potential, in the context of quantum mechanics. Within this framework, we calculate the self-capture rate across a broad region of parameter space. While the self-capture rate can be obtained separately in the Born regime with perturbative method, and in the classical limits with the Rutherford formula, our calculation covers the gap between in a non-perturbative fashion. Besides, the phenomenology of both the Sommerfeld-enhanced s- and p-wave annihilation of the solar SIDM is also involved in our discussion. Moreover, by combining the analysis of the Super-Kamiokande (SK) data and the observed DM relic density, we constrain the nuclear capture rate of the DM particles in the presence of the dark Yukawa potential. The consequence of the long-range dark force on probing the solar SIDM turns out to be significant if the force-carrier is much lighter than the DM particle, and a quantitative analysis is provided.

Many-body localization in Ising models with random long-range interactions

NASA Astrophysics Data System (ADS)

Li, Haoyuan; Wang, Jia; Liu, Xia-Ji; Hu, Hui

2016-12-01

We theoretically investigate the many-body localization phase transition in a one-dimensional Ising spin chain with random long-range spin-spin interactions, Vi j∝|i-j |-α , where the exponent of the interaction range α can be tuned from zero to infinitely large. By using exact diagonalization, we calculate the half-chain entanglement entropy and the energy spectral statistics and use them to characterize the phase transition towards the many-body localization phase at infinite temperature and at sufficiently large disorder strength. We perform finite-size scaling to extract the critical disorder strength and the critical exponent of the divergent localization length. With increasing α , the critical exponent experiences a sharp increase at about αc≃1.2 and then gradually decreases to a value found earlier in a disordered short-ranged interacting spin chain. For α <αc , we find that the system is mostly localized and the increase in the disorder strength may drive a transition between two many-body localized phases. In contrast, for α >αc , the transition is from a thermalized phase to the many-body localization phase. Our predictions could be experimentally tested with an ion-trap quantum emulator with programmable random long-range interactions, or with randomly distributed Rydberg atoms or polar molecules in lattices.

Long-range synchrony of gamma oscillations and auditory hallucination symptoms in schizophrenia

PubMed Central

Mulert, C.; Kirsch; Pascual-Marqui, Roberto; McCarley, Robert W.; Spencer, Kevin M.

2010-01-01

Phase locking in the gamma-band range has been shown to be diminished in patients with schizophrenia. Moreover, there have been reports of positive correlations between phase locking in the gamma-band range and positive symptoms, especially hallucinations. The aim of the present study was to use a new methodological approach in order to investigate gamma-band phase synchronization between the left and right auditory cortex in patients with schizophrenia and its relationship to auditory hallucinations. Subjects were 18 patients with chronic schizophrenia (SZ) and 16 healthy control (HC) subjects. Auditory hallucination symptom scores were obtained using the Scale for the Assessment of Positive Symptoms. Stimuli were 40-Hz binaural click trains. The generators of the 40 Hz-ASSR were localized using eLORETA and based on the computed intracranial signals lagged interhemispheric phase locking between primary and secondary auditory cortices was analyzed. Current source density of the 40 ASSR response was significantly diminished in SZ in comparison to HC in the right superior and middle temporal gyrus (p<0.05). Interhemispheric phase locking was reduced in SZ in comparison to HC for the primary auditory cortices (p<0.05) but not in the secondary auditory cortices. A significant positive correlation was found between auditory hallucination symptom scores and phase synchronization between the primary auditory cortices (p<0.05, corrected for multiple testing) but not for the secondary auditory cortices. These results suggest that long-range synchrony of gamma oscillations is disturbed in schizophrenia and that this deficit is related to clinical symptoms such as auditory hallucinations. PMID:20713096

Long-range memory and non-Markov statistical effects in human sensorimotor coordination

NASA Astrophysics Data System (ADS)

M. Yulmetyev, Renat; Emelyanova, Natalya; Hänggi, Peter; Gafarov, Fail; Prokhorov, Alexander

2002-12-01

In this paper, the non-Markov statistical processes and long-range memory effects in human sensorimotor coordination are investigated. The theoretical basis of this study is the statistical theory of non-stationary discrete non-Markov processes in complex systems (Phys. Rev. E 62, 6178 (2000)). The human sensorimotor coordination was experimentally studied by means of standard dynamical tapping test on the group of 32 young peoples with tap numbers up to 400. This test was carried out separately for the right and the left hand according to the degree of domination of each brain hemisphere. The numerical analysis of the experimental results was made with the help of power spectra of the initial time correlation function, the memory functions of low orders and the first three points of the statistical spectrum of non-Markovity parameter. Our observations demonstrate, that with the regard to results of the standard dynamic tapping-test it is possible to divide all examinees into five different dynamic types. We have introduced the conflict coefficient to estimate quantitatively the order-disorder effects underlying life systems. The last one reflects the existence of disbalance between the nervous and the motor human coordination. The suggested classification of the neurophysiological activity represents the dynamic generalization of the well-known neuropsychological types and provides the new approach in a modern neuropsychology.

Long range science scheduling for the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Miller, Glenn; Johnston, Mark

1991-01-01

Observations with NASA's Hubble Space Telescope (HST) are scheduled with the assistance of a long-range scheduling system (SPIKE) that was developed using artificial intelligence techniques. In earlier papers, the system architecture and the constraint representation and propagation mechanisms were described. The development of high-level automated scheduling tools, including tools based on constraint satisfaction techniques and neural networks is described. The performance of these tools in scheduling HST observations is discussed.

Long range intermolecular interactions between the alkali diatomics Na(2), K(2), and NaK.

PubMed

Zemke, Warren T; Byrd, Jason N; Michels, H Harvey; Montgomery, John A; Stwalley, William C

2010-06-28

Long range interactions between the ground state alkali diatomics Na(2)-Na(2), K(2)-K(2), Na(2)-K(2), and NaK-NaK are examined. Interaction energies are first determined from ab initio calculations at the coupled-cluster with singles, doubles, and perturbative triples [CCSD(T)] level of theory, including counterpoise corrections. Long range energies calculated from diatomic molecular properties (polarizabilities and dipole and quadrupole moments) are then compared with the ab initio energies. A simple asymptotic model potential E(LR)=E(elec)+E(disp)+E(ind) is shown to accurately represent the intermolecular interactions for these systems at long range.

Stable distribution and long-range correlation of Brent crude oil market

NASA Astrophysics Data System (ADS)

Yuan, Ying; Zhuang, Xin-tian; Jin, Xiu; Huang, Wei-qiang

2014-11-01

An empirical study of stable distribution and long-range correlation in Brent crude oil market was presented. First, it is found that the empirical distribution of Brent crude oil returns can be fitted well by a stable distribution, which is significantly different from a normal distribution. Second, the detrended fluctuation analysis for the Brent crude oil returns shows that there are long-range correlation in returns. It implies that there are patterns or trends in returns that persist over time. Third, the detrended fluctuation analysis for the Brent crude oil returns shows that after the financial crisis 2008, the Brent crude oil market becomes more persistence. It implies that the financial crisis 2008 could increase the frequency and strength of the interdependence and correlations between the financial time series. All of these findings may be used to improve the current fractal theories.

The Alabama Long Range Program for Library Development 1994-1998.

ERIC Educational Resources Information Center

Alabama Public Library Service, Montgomery.

This document contains the long range plan of the Alabama public libraries. The purpose of presenting this program is to meet the requirements of the Library Services and Construction Act (LSCA) and to assess, prioritize, and communicate library needs to librarians, officials, and the public to provide adequate library service to the citizens of…

Space: The Long-Range Future: An Interview with Jesco von Puttkamer.

ERIC Educational Resources Information Center

Lawler, Andrew

1985-01-01

Jesco von Puttkamer manages long-range planning in NASA's Office of Space Flight. He believes that space offers the opportunity to ease global tensions, help the developing world, and create a new global culture off the planet. (Author/RM)

The design of a long range megatransport aircraft

NASA Technical Reports Server (NTRS)

Weisshaar, T. A.; Layton, J. B.; Allen, C. L.

1993-01-01

Megatransport objectives and constraints are briefly reviewed, and certain solutions developed by student design teams at Perdue University are summarized. Particular attention is given to the market needs and the economic risks involved in such a project; and the different approaches taken to solve the problem and difficulties faced by the design teams. A long range megatransport aircraft is aimed at carrying more than 600 passengers at reduced cost, and at the same time, reducing airport and airway congestion. The design effort must take into account airport terminal facilities; passenger loading and unloading; and defeating the 'square-cube' law to design large structures.

Long-range transport and universality classes in in vitro viral infection spread

NASA Astrophysics Data System (ADS)

Manrubia, S. C.; García-Arriaza, J.; Domingo, E.; Escarmís, C.

2006-05-01

Dispersal mechanisms play a main role in the dynamics of infection spread. Recent experimental results with in vitro infections of foot-and-mouth disease virus reveal that the time needed for the virus to kill a cellular monolayer depends qualitatively on the number of viral particles required to initiate infection in a susceptible cell. A two-dimensional susceptible-infected-removed (SIR) model based on the experimental setting agrees with the observations only when viral particles are subject to long-range transport. Numerical and analytical results show that this long-range transport plays a role when a single particle causes infection, while it is inefficient when complementation between two or more particles is necessary.

Dynamics of correlations in long-range quantum systems follwing a quantum quench

NASA Astrophysics Data System (ADS)

Cevolani, Lorenzo; Carleo, Giuseppe; Sanchez-Palencia, Laurent

We study how and how fast correlations can spread in a quantum system abruptly driven out of equilibrium by a quantum quench. This protocol can be experimentally realized and it allow to address fundamental questions concerning the quasi-locality principle in isolated quantum systems with both short- and long-range interactions. We focus on two different models describing, respectively, lattice bosons, and spins. Our study is based on a combined approach, based on one hand on accurate many-body numerical calculations and on the other hand on a quasi-particle microscopic theory. We find that, for sufficiently fast decaying interaction potential the propagation is ballistic and the Lieb-Robinson bounds for long-range interactions are never attained. When the interactions are really long-range, the scenario is completely different in the two cases. In the bosonic system the locality is preserved and a ballistic propagation is still present while in the spin system an instantaneous propagation of correlations completely destroys locality. Using the microscopic point of view we can quantitatively describe all the different regimes, from instantaneous to ballistic, found in the spin model and we explain how locality is protected in the bosonic model leading to a ballistic propagation. ERC (FP7/2007-2013 No. 256294), QUIC (H2020 No. 641122).

Negative mood and mind wandering increase long-range temporal correlations in attention fluctuations.

PubMed

Irrmischer, Mona; van der Wal, C Natalie; Mansvelder, Huibert D; Linkenkaer-Hansen, Klaus

2018-01-01

There is growing evidence that the intermittent nature of mind wandering episodes and mood have a pronounced influence on trial-to-trial variability in performance. Nevertheless, the temporal dynamics and significance of such lapses in attention remains inadequately understood. Here, we hypothesize that the dynamics of fluctuations in sustained attention between external and internal sources of information obey so-called critical-state dynamics, characterized by trial-to-trial dependencies with long-range temporal correlations. To test this, we performed behavioral investigations measuring reaction times in a visual sustained attention task and cued introspection in probe-caught reports of mind wandering. We show that trial-to-trial variability in reaction times exhibit long-range temporal correlations in agreement with the criticality hypothesis. Interestingly, we observed the fastest responses in subjects with the weakest long-range temporal correlations and show the vital effect of mind wandering and bad mood on this response variability. The implications of these results stress the importance of future research to increase focus on behavioral variability.

Negative mood and mind wandering increase long-range temporal correlations in attention fluctuations

PubMed Central

van der Wal, C. Natalie; Mansvelder, Huibert D.; Linkenkaer-Hansen, Klaus

2018-01-01

There is growing evidence that the intermittent nature of mind wandering episodes and mood have a pronounced influence on trial-to-trial variability in performance. Nevertheless, the temporal dynamics and significance of such lapses in attention remains inadequately understood. Here, we hypothesize that the dynamics of fluctuations in sustained attention between external and internal sources of information obey so-called critical-state dynamics, characterized by trial-to-trial dependencies with long-range temporal correlations. To test this, we performed behavioral investigations measuring reaction times in a visual sustained attention task and cued introspection in probe-caught reports of mind wandering. We show that trial-to-trial variability in reaction times exhibit long-range temporal correlations in agreement with the criticality hypothesis. Interestingly, we observed the fastest responses in subjects with the weakest long-range temporal correlations and show the vital effect of mind wandering and bad mood on this response variability. The implications of these results stress the importance of future research to increase focus on behavioral variability. PMID:29746529

Imputation of Missing Genotypes From Sparse to High Density Using Long-Range Phasing

USDA-ARS?s Scientific Manuscript database

Related individuals in a population share long chromosome segments which trace to a common ancestor. We describe a long-range phasing algorithm that makes use of this property to phase whole chromosomes and simultaneously impute a large number of missing markers. We test our method by imputing marke...

Monitoring long-range electron transfer pathways in proteins by stimulated attosecond broadband X-ray Raman spectroscopy

DOE PAGES

Zhang, Yu; Biggs, Jason D.; Govind, Niranjan; ...

2014-10-09

In this study, long-range electron transfer (ET) plays a key role in many biological energy conversion and synthesis processes. We show that nonlinear spectroscopy with attosecond X-ray pulses provides a real time movie of the evolving oxidation states and electron densities around atoms, and can probe these processes with high spatial and temporal resolution. This is demonstrated in a simulation study of the stimulated X-ray Raman (SXRS) signals in Re-modified azurin, which had long served as a benchmark for long-range ET in proteins. Nonlinear SXRS signals are sensitive to the local electronic structure and should offer a novel window formore » long-range ET.« less

Breakdown of long-range temporal correlations in brain oscillations during general anesthesia.

PubMed

Krzemiński, Dominik; Kamiński, Maciej; Marchewka, Artur; Bola, Michał

2017-10-01

Consciousness has been hypothesized to emerge from complex neuronal dynamics, which prevails when brain operates in a critical state. Evidence supporting this hypothesis comes mainly from studies investigating neuronal activity on a short time-scale of seconds. However, a key aspect of criticality is presence of scale-free temporal dependencies occurring across a wide range of time-scales. Indeed, robust long-range temporal correlations (LRTCs) are found in neuronal oscillations during conscious states, but it is not known how LRTCs are affected by loss of consciousness. To further test a relation between critical dynamics and consciousness, we investigated LRTCs in electrocorticography signals recorded from four macaque monkeys during resting wakefulness and general anesthesia induced by various anesthetics (ketamine, medetomidine, or propofol). Detrended Fluctuation Analysis was used to estimate LRTCs in amplitude fluctuations (envelopes) of band-pass filtered signals. We demonstrate two main findings. First, during conscious states all lateral cortical regions are characterized by significant LRTCs of alpha-band activity (7-14 Hz). LRTCs are stronger in the eyes-open than eyes-closed state, but in both states they form a spatial gradient, with anterior brain regions exhibiting stronger LRTCs than posterior regions. Second, we observed a substantial decrease of LRTCs during loss of consciousness, the magnitude of which was associated with the baseline (i.e. pre-anesthesia) state of the brain. Specifically, brain regions characterized by strongest LRTCs during a wakeful baseline exhibited greatest decreases during anesthesia (i.e. "the rich got poorer"), which consequently disturbed the posterior-anterior gradient. Therefore, our results suggest that general anesthesia affects mainly brain areas characterized by strongest LRTCs during wakefulness, which might account for lack of capacities for extensive temporal integration during loss of consciousness. Copyright

Bayesian Analysis of Non-Gaussian Long-Range Dependent Processes

NASA Astrophysics Data System (ADS)

Graves, T.; Franzke, C.; Gramacy, R. B.; Watkins, N. W.

2012-12-01

Recent studies have strongly suggested that surface temperatures exhibit long-range dependence (LRD). The presence of LRD would hamper the identification of deterministic trends and the quantification of their significance. It is well established that LRD processes exhibit stochastic trends over rather long periods of time. Thus, accurate methods for discriminating between physical processes that possess long memory and those that do not are an important adjunct to climate modeling. We have used Markov Chain Monte Carlo algorithms to perform a Bayesian analysis of Auto-Regressive Fractionally-Integrated Moving-Average (ARFIMA) processes, which are capable of modeling LRD. Our principal aim is to obtain inference about the long memory parameter, d,with secondary interest in the scale and location parameters. We have developed a reversible-jump method enabling us to integrate over different model forms for the short memory component. We initially assume Gaussianity, and have tested the method on both synthetic and physical time series such as the Central England Temperature. Many physical processes, for example the Faraday time series from Antarctica, are highly non-Gaussian. We have therefore extended this work by weakening the Gaussianity assumption. Specifically, we assume a symmetric α -stable distribution for the innovations. Such processes provide good, flexible, initial models for non-Gaussian processes with long memory. We will present a study of the dependence of the posterior variance σ d of the memory parameter d on the length of the time series considered. This will be compared with equivalent error diagnostics for other measures of d.

Mitigating and monitoring flight crew fatigue on a westward ultra-long-range flight.

PubMed

Signal, T Leigh; Mulrine, Hannah M; van den Berg, Margo J; Smith, Alexander A T; Gander, Philippa H; Serfontein, Wynand

2014-12-01

This study examined the uptake and effectiveness of fatigue mitigation guidance material including sleep recommendations for a trip with a westward ultra-long-range flight and return long-range flight. There were 52 flight crew (4-pilot crews, mean age 55 yr) who completed a sleep/duty diary and wore an actigraph prior to, during, and after the trip. Primary crew flew the takeoff and landing, while relief crew flew the aircraft during the Primary crew's breaks. At key times in flight, crewmembers rated their fatigue (Samn-Perelli fatigue scale) and sleepiness (Karolinska Sleepiness Scale) and completed a 5-min Psychomotor Vigilance Task. Napping was common prior to the outbound flight (54%) and did not affect the quantity or quality of in-flight sleep (mean 4.3 h). Primary crew obtained a similar amount on the inbound flight (mean 4.0 h), but Secondary crew had less sleep (mean 2.9 h). Subjective fatigue and sleepiness increased and performance slowed across flights. Performance was faster on the outbound than inbound flight. On both flights, Primary crew were less fatigued and sleepy than Secondary crew, particularly at top of descent and after landing. Crewmembers slept more frequently and had more sleep in the first 24 h of the layover than the last, and had shifted their main sleep to the local night by the second night. The suggested sleep mitigations were employed by the majority of crewmembers. Fatigue levels were no worse on the outbound ultra-long-range flight than on the return long-range flight.

Surface tension and long range corrections of cylindrical interfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourasseau, E.; Malfreyt, P.; Ghoufi, A., E-mail: aziz.ghoufi@univ-rennes1.fr

2015-12-21

The calculation of the surface tension of curved interfaces has been deeply investigated from molecular simulation during this last past decade. Recently, the thermodynamic Test-Area (TA) approach has been extended to the calculation of surface tension of curved interfaces. In the case of the cylindrical vapour-liquid interfaces of water and Lennard-Jones fluids, it was shown that the surface tension was independent of the curvature of the interface. In addition, the surface tension of the cylindrical interface is higher than that of the planar interface. Molecular simulations of cylindrical interfaces have been so far performed (i) by using a shifted potential,more » (ii) by means of large cutoff without periodic boundary conditions, or (iii) by ignoring the long range corrections to the surface tension due to the difficulty to estimate them. Indeed, unlike the planar interfaces there are no available operational expressions to consider the tail corrections to the surface tension of cylindrical interfaces. We propose here to develop the long range corrections of the surface tension for cylindrical interfaces by using the non-exponential TA (TA2) method. We also extend the formulation of the Mecke-Winkelmann corrections initially developed for planar surfaces to cylindrical interfaces. We complete this study by the calculation of the surface tension of cylindrical surfaces of liquid tin and copper using the embedded atom model potentials.« less

A class of circadian long non-coding RNAs mark enhancers modulating long-range circadian gene regulation

PubMed Central

Fan, Zenghua; Zhao, Meng; Joshi, Parth D.; Li, Ping; Zhang, Yan; Guo, Weimin; Xu, Yichi; Wang, Haifang; Zhao, Zhihu

2017-01-01

Abstract Circadian rhythm exerts its influence on animal physiology and behavior by regulating gene expression at various levels. Here we systematically explored circadian long non-coding RNAs (lncRNAs) in mouse liver and examined their circadian regulation. We found that a significant proportion of circadian lncRNAs are expressed at enhancer regions, mostly bound by two key circadian transcription factors, BMAL1 and REV-ERBα. These circadian lncRNAs showed similar circadian phases with their nearby genes. The extent of their nuclear localization is higher than protein coding genes but less than enhancer RNAs. The association between enhancer and circadian lncRNAs is also observed in tissues other than liver. Comparative analysis between mouse and rat circadian liver transcriptomes showed that circadian transcription at lncRNA loci tends to be conserved despite of low sequence conservation of lncRNAs. One such circadian lncRNA termed lnc-Crot led us to identify a super-enhancer region interacting with a cluster of genes involved in circadian regulation of metabolism through long-range interactions. Further experiments showed that lnc-Crot locus has enhancer function independent of lnc-Crot's transcription. Our results suggest that the enhancer-associated circadian lncRNAs mark the genomic loci modulating long-range circadian gene regulation and shed new lights on the evolutionary origin of lncRNAs. PMID:28335007

Prediction of protein long-range contacts using an ensemble of genetic algorithm classifiers with sequence profile centers.

PubMed

Chen, Peng; Li, Jinyan

2010-05-17

Prediction of long-range inter-residue contacts is an important topic in bioinformatics research. It is helpful for determining protein structures, understanding protein foldings, and therefore advancing the annotation of protein functions. In this paper, we propose a novel ensemble of genetic algorithm classifiers (GaCs) to address the long-range contact prediction problem. Our method is based on the key idea called sequence profile centers (SPCs). Each SPC is the average sequence profiles of residue pairs belonging to the same contact class or non-contact class. GaCs train on multiple but different pairs of long-range contact data (positive data) and long-range non-contact data (negative data). The negative data sets, having roughly the same sizes as the positive ones, are constructed by random sampling over the original imbalanced negative data. As a result, about 21.5% long-range contacts are correctly predicted. We also found that the ensemble of GaCs indeed makes an accuracy improvement by around 5.6% over the single GaC. Classifiers with the use of sequence profile centers may advance the long-range contact prediction. In line with this approach, key structural features in proteins would be determined with high efficiency and accuracy.

Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues

DTIC Science & Technology

2012-07-06

Missiles Congressional Research Service Forward-Based Global Strike ( FBGS ...Congressional Research Service 36 Forward-Based Global Strike ( FBGS ) Analysts have also explored the option of deploying long-range land-based

75 FR 1799 - Terminate Long Range Aids to Navigation (Loran-C) Signal

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-13

... to Navigation (Loran-C) Signal AGENCY: U.S. Coast Guard, DHS. ACTION: Notice; correction. SUMMARY... 998). The document announced termination of the Long Range Aids to Navigation (Loran-C) Signal...

Scalar relativistic computations of nuclear magnetic shielding and g-shifts with the zeroth-order regular approximation and range-separated hybrid density functionals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aquino, Fredy W.; Govind, Niranjan; Autschbach, Jochen

2011-10-01

Density functional theory (DFT) calculations of NMR chemical shifts and molecular g-tensors with Gaussian-type orbitals are implemented via second-order energy derivatives within the scalar relativistic zeroth order regular approximation (ZORA) framework. Nonhybrid functionals, standard (global) hybrids, and range-separated (Coulomb-attenuated, long-range corrected) hybrid functionals are tested. Origin invariance of the results is ensured by use of gauge-including atomic orbital (GIAO) basis functions. The new implementation in the NWChem quantum chemistry package is verified by calculations of nuclear shielding constants for the heavy atoms in HX (X=F, Cl, Br, I, At) and H2X (X = O, S, Se, Te, Po), and Temore » chemical shifts in a number of tellurium compounds. The basis set and functional dependence of g-shifts is investigated for 14 radicals with light and heavy atoms. The problem of accurately predicting F NMR shielding in UF6-nCln, n = 1 to 6, is revisited. The results are sensitive to approximations in the density functionals, indicating a delicate balance of DFT self-interaction vs. correlation. For the uranium halides, the results with the range-separated functionals are mixed.« less

Compensation of the long-range beam-beam interactions as a path towards new configurations for the high luminosity LHC

DOE PAGES

Fartoukh, Stéphane; Valishev, Alexander; Papaphilippou, Yannis; ...

2015-12-01

Colliding bunch trains in a circular collider demands a certain crossing angle in order to separate the two beams transversely after the collision. The magnitude of this crossing angle is a complicated function of the bunch charge, the number of long-range beam-beam interactions, of β* and type of optics (flat or round), and possible compensation or additive effects between several low-β insertions in the ring depending on the orientation of the crossing plane at each interaction point. About 15 years ago, the use of current bearing wires was proposed at CERN in order to mitigate the long-range beam-beam effects [J.P. Koutchouk,more » CERN Report No. LHC-Project-Note 223, 2000], therefore offering the possibility to minimize the crossing angle with all the beneficial effects this might have: on the luminosity performance by reducing the need for crab-cavities or lowering their voltage, on the required aperture of the final focus magnets, on the strength of the orbit corrector involved in the crossing bumps, and finally on the heat load and radiation dose deposited in the final focus quadrupoles. In this paper, a semianalytical approach is developed for the compensation of the long-range beam-beam interactions with current wires. This reveals the possibility of achieving optimal correction through a careful adjustment of the aspect ratio of the β functions at the wire position. We consider the baseline luminosity upgrade plan of the Large Hadron Collider (HL-LHC project), and compare it to alternative scenarios, or so-called ''configurations,'' where modifications are applied to optics, crossing angle, or orientation of the crossing plane in the two low-β insertions of the ring. Furthermore, for all these configurations, the beneficial impact of beam-beam compensation devices is then demonstrated on the tune footprint, the dynamical aperture, and/or the frequency map analysis of the nonlinear beam dynamics as the main figures of merit.« less

Cs 62 DJ Rydberg-atom macrodimers formed by long-range multipole interaction

NASA Astrophysics Data System (ADS)

Han, Xiaoxuan; Bai, Suying; Jiao, Yuechun; Hao, Liping; Xue, Yongmei; Zhao, Jianming; Jia, Suotang; Raithel, Georg

2018-03-01

Long-range macrodimers formed by D -state cesium Rydberg atoms are studied in experiments and calculations. Cesium [62DJ]2 Rydberg-atom macrodimers, bonded via long-range multipole interaction, are prepared by two-color photoassociation in a cesium atom trap. The first color (pulse A) resonantly excites seed Rydberg atoms, while the second (pulse B, detuned by the molecular binding energy) resonantly excites the Rydberg-atom macrodimers below the [62DJ]2 asymptotes. The molecules are measured by extraction of autoionization products and Rydberg-atom electric-field ionization, and ion detection. Molecular spectra are compared with calculations of adiabatic molecular potentials. From the dependence of the molecular signal on the detection delay time, the lifetime of the molecules is estimated to be 3 -6 μ s .

FAA Long-Range Aviation Forecasts Fiscal Years 2005-2020

DTIC Science & Technology

1993-09-01

assumptions translate into somewhat slower growth of aviation activity and FAA workload measures during the extended 16 -year period (2004 to 2020) than was...OPERATIONS 1.8 1.2 INSTRUMENT OPERATIONS 2.0 1.3 IFR AIRCRAFT HANDLED 2.0 1.3 FLIGHT SERVICE STTIONS (0.2) 0.1 2 II. LONG-RANGE FORECAST ASSUMPTIONS The...product (GDP), adjusted for price changes and expressed in 1987 dollars, will average 1.9 percent annually over the extended 16 -year fore- cast period

Measurement and modeling of short and medium range order in amorphous Ta 2O 5 thin films

DOE PAGES

Shyam, Badri; Stone, Kevin H.; Bassiri, Riccardo; ...

2016-08-26

Here, amorphous films and coatings are rapidly growing in importance. Yet, there is a dearth of high-quality structural data on sub-micron films. Not understanding how these materials assemble at atomic scale limits fundamental insights needed to improve their performance. Here, we use grazing-incidence x-ray total scattering measurements to examine the atomic structure of the top 50–100 nm of Ta 2O 5 films; mirror coatings that show high promise to significantly improve the sensitivity of the next generation of gravitational-wave detectors. Our measurements show noticeable changes well into medium range, not only between crystalline and amorphous, but also between as-deposited, annealedmore » and doped amorphous films. It is a further challenge to quickly translate the structural information into insights into mechanisms of packing and disorder. Here, we illustrate a modeling approach that allows translation of observed structural features to a physically intuitive packing of a primary structural unit based on a kinked Ta-O-Ta backbone. Our modeling illustrates how Ta-O-Ta units link to form longer 1D chains and even 2D ribbons, and how doping and annealing influences formation of 2D order. We also find that all the amorphousTa 2O 5 films studied in here are not just poorly crystalline but appear to lack true 3D order.« less

Near-zero temperature coefficient of resistivity associated with magnetic ordering in antiperovskite Mn{sub 3+x}Ni{sub 1−x}N

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Sihao; Sun, Ying; Wang, Lei

2016-01-25

The near-zero temperature coefficient of resistivity (NZ-TCR) behavior is reported in the antiperovskite compounds Mn{sub 3+x}Ni{sub 1−x}N (0 ≤ x ≤ 0.333). Our results indicate that the broad temperature range (above 275 K extending to above 220 K) of NZ-TCR is obtained by Mn doping at the Ni site. The short-range magnetic ordering is revealed by both neutron powder diffraction and inverse magnetic susceptibility. Further, we find a strong correlation between the anomalous resistivity change of Mn{sub 3+x}Ni{sub 1−x}N from the metal-like to the NZ-TCR behavior and the lack of the long-range magnetic ordering. The possible mechanism of NZ-TCR behavior is discussed using the spin-disorder scatteringmore » model.« less

Deep seafloor arrivals in long range ocean acoustic propagation.

PubMed

Stephen, Ralph A; Bolmer, S Thompson; Udovydchenkov, Ilya A; Worcester, Peter F; Dzieciuch, Matthew A; Andrew, Rex K; Mercer, James A; Colosi, John A; Howe, Bruce M

2013-10-01

Ocean bottom seismometer observations at 5000 m depth during the long-range ocean acoustic propagation experiment in the North Pacific in 2004 show robust, coherent, late arrivals that are not readily explained by ocean acoustic propagation models. These "deep seafloor" arrivals are the largest amplitude arrivals on the vertical particle velocity channel for ranges from 500 to 3200 km. The travel times for six (of 16 observed) deep seafloor arrivals correspond to the sea surface reflection of an out-of-plane diffraction from a seamount that protrudes to about 4100 m depth and is about 18 km from the receivers. This out-of-plane bottom-diffracted surface-reflected energy is observed on the deep vertical line array about 35 dB below the peak amplitude arrivals and was previously misinterpreted as in-plane bottom-reflected surface-reflected energy. The structure of these arrivals from 500 to 3200 km range is remarkably robust. The bottom-diffracted surface-reflected mechanism provides a means for acoustic signals and noise from distant sources to appear with significant strength on the deep seafloor.

A new member of ferrous sulfates, FeSO{sub 4}·2H{sub 2}O with PtS topology showing spin-canted long-range antiferromagnetic ordering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Long; Liu, Wei, E-mail: weiliu@ouc.edu.cn; Cao, Lixin

2015-11-15

A sanderite ferrous sulfate FeSO{sub 4}·2H{sub 2}O has been synthesized by the hydro/solvothermal method. Its crystal structure (Pccn, a=6.3160 Å, b=7.7550 Å, c=8.9880 Å, V=440.2 Å{sup 3}, Z=4) can be regarded as the condensation of alternately corner-shared FeO{sub 4}(H{sub 2}O){sub 2} octahedra and SO{sub 4} tetrahedra with a similar topology of PtS. By structural comparison with the known hydrated ferrous sulfates, the structural relation among them has been noted and discussed in detail. A variable temperature magnetic study shows a spin-canted long-range antiferromagnetic ordering in the low temperature regime, which might result from a possible phase transition during the coolingmore » from the high temperature. - Graphical abstract: As a new number of ferrous sulfates, sanderite FeSO{sub 4}·2H{sub 2}O has been synthesized under hydro/solvothermal conditions, which exhibits a similar topology of PtS. - Highlights: • Sanderite ferrous sulfate has been synthesized. • The topology of its structure is similar to that of PtS. • A structural relation between these hydrated ferrous sulfates is discovered.« less

Policy Negotiations: Simulation as a Tool in Long-Range Library Planning

ERIC Educational Resources Information Center

Townley, Charles T.; And Others

1978-01-01

The development and use of a simulation game designed to facilitate nationwide long-range library planning for American Indian communities is described. The use of simulation outcomes in plan development is analyzed. Implications on the effectiveness of simulation in the library planning process are made. (Author)

Bond-orientational order in liquid Si

NASA Technical Reports Server (NTRS)

Wang, Z. Q.; Stroud, D.

1991-01-01

Bond-orientational order in liquid Si via Monte Carlo simulation in conjuncation with empirical two- and three-body potentials of the form proposed by Stillinger and Weber are studied. Bond-orientational order (BOO) is described in terms of combinations of spherical harmonic functions. Liquid Si is found to have pronounced short-range BOO corresponding to l = 3, as expected for a structure with local tetrahedral order. No long-range BOO is found either in the equilibrium or the supercooled liquid. When the three-body potential is artificially removed, the tetrahedral bond-orientation order disappears and the liquid assumes a close-packed structure.

High sensitivity long-period grating-based temperature monitoring using a wide wavelength range to 2.2 μm

NASA Astrophysics Data System (ADS)

Venugopalan, Thillainathan; Yeo, Teck L.; Sun, Tong; Grattan, Kenneth T. V.

2006-12-01

Temperature effects on the various cladding modes of a long-period grating (LPG) fabricated in B-Ge co-doped fibre have been investigated to create a high sensitivity measurement device. The temperature sensitivities of the attenuation bands of the LPG over the wavelength region 1.2-2.2 μm, for a grating with a 330 μm period, were obtained by monitoring the wavelength shift of each attenuation band, with a temperature increment of 20 °C, over the range from 23 °C to 140 °C. The attenuation band appearing over the 1.8-2.0 μm wavelength range has shown a nearly five times higher temperature sensitivity than that of lower order modes, and thus it shows significant promise for fibre optic temperature sensor applications.

A meta-GGA level screened range-separated hybrid functional by employing short range Hartree-Fock with a long range semilocal functional.

PubMed

Jana, Subrata; Samal, Prasanjit

2018-03-28

The range-separated hybrid density functionals are very successful in describing a wide range of molecular and solid-state properties accurately. In principle, such functionals are designed from spherically averaged or system averaged as well as reverse engineered exchange holes. In the present attempt, the screened range-separated hybrid functional scheme has been applied to the meta-GGA rung by using the density matrix expansion based semilocal exchange hole (or functional). The hybrid functional proposed here utilizes the spherically averaged density matrix expansion based exchange hole in the range separation scheme. For slowly varying density correction the range separation scheme is employed only through the local density approximation based exchange hole coupled with the corresponding fourth order gradient approximate Tao-Mo enhancement factor. The comprehensive testing and performance of the newly constructed functional indicates its applicability in describing several molecular properties. The most appealing feature of this present screened hybrid functional is that it will be practically very useful in describing solid-state properties at the meta-GGA level.

Exploring cavity-mediated long-range interactions in a dilute quantum gas

NASA Astrophysics Data System (ADS)

Landig, Renate; Mottl, Rafael; Brennecke, Ferdinand; Baumann, Kristian; Donner, Tobias; Esslinger, Tilman

2013-05-01

We report on the observation of a characteristic change in the excitation spectrum of a Bose-Einstein condensate and increased density fluctuations due to cavity-mediated atom-atom interactions. Increasing the strength of the interaction leads to a softening of an excitation mode at finite momentum, preceding a superfluid to supersolid phase transition. The observed behavior is reminiscent of a roton minimum, as predicted for quantum gases with long-range interactions. We create long-range interactions in the BEC using a non-resonant transverse pump beam which induces virtual photon exchange via the vacuum field of an optical cavity. The mode softening is spectroscopically studied across the phase transition using a variant of Bragg spectroscopy. At the phase transition a diverging density response is observed which is linked to increased density fluctuations. Using the cavity dissipation channel we monitor these fluctuations in real-time and identify the influence of measurement backaction onto the critical behavior of the system.

Evaluation of Long-Range Lightning Detection Networks Using TRMM/LIS Observations

NASA Technical Reports Server (NTRS)

Rudlosky, Scott D.; Holzworth, Robert H.; Carey, Lawrence D.; Schultz, Chris J.; Bateman, Monte; Cecil, Daniel J.; Cummins, Kenneth L.; Petersen, Walter A.; Blakeslee, Richard J.; Goodman, Steven J.

2011-01-01

Recent advances in long-range lightning detection technologies have improved our understanding of thunderstorm evolution in the data sparse oceanic regions. Although the expansion and improvement of long-range lightning datasets have increased their applicability, these applications (e.g., data assimilation, atmospheric chemistry, and aviation weather hazards) require knowledge of the network detection capabilities. Toward this end, the present study evaluates data from the World Wide Lightning Location Network (WWLLN) using observations from the Lightning Imaging Sensor (LIS) aboard the Tropical Rainfall Measurement Mission (TRMM) satellite. The study documents the WWLLN detection efficiency and location accuracy relative to LIS observations, describes the spatial variability in these performance metrics, and documents the characteristics of LIS flashes that are detected by WWLLN. Improved knowledge of the WWLLN detection capabilities will allow researchers, algorithm developers, and operational users to better prepare for the spatial and temporal coverage of the upcoming GOES-R Geostationary Lightning Mapper (GLM).

Fractional quantum mechanics on networks: Long-range dynamics and quantum transport

NASA Astrophysics Data System (ADS)

Riascos, A. P.; Mateos, José L.

2015-11-01

In this paper we study the quantum transport on networks with a temporal evolution governed by the fractional Schrödinger equation. We generalize the dynamics based on continuous-time quantum walks, with transitions to nearest neighbors on the network, to the fractional case that allows long-range displacements. By using the fractional Laplacian matrix of a network, we establish a formalism that combines a long-range dynamics with the quantum superposition of states; this general approach applies to any type of connected undirected networks, including regular, random, and complex networks, and can be implemented from the spectral properties of the Laplacian matrix. We study the fractional dynamics and its capacity to explore the network by means of the transition probability, the average probability of return, and global quantities that characterize the efficiency of this quantum process. As a particular case, we explore analytically these quantities for circulant networks such as rings, interacting cycles, and complete graphs.

Fractional quantum mechanics on networks: Long-range dynamics and quantum transport.

PubMed

Riascos, A P; Mateos, José L

2015-11-01

In this paper we study the quantum transport on networks with a temporal evolution governed by the fractional Schrödinger equation. We generalize the dynamics based on continuous-time quantum walks, with transitions to nearest neighbors on the network, to the fractional case that allows long-range displacements. By using the fractional Laplacian matrix of a network, we establish a formalism that combines a long-range dynamics with the quantum superposition of states; this general approach applies to any type of connected undirected networks, including regular, random, and complex networks, and can be implemented from the spectral properties of the Laplacian matrix. We study the fractional dynamics and its capacity to explore the network by means of the transition probability, the average probability of return, and global quantities that characterize the efficiency of this quantum process. As a particular case, we explore analytically these quantities for circulant networks such as rings, interacting cycles, and complete graphs.

A preliminary assessment of year long relative loose mineral intake and range cow productivity in Northern Great Plains

USDA-ARS?s Scientific Manuscript database

ssessment of the effectiveness of supplementary mineral nutrition in range cattle to promote important economic traits is lacking due a paucity of methods to measure cause and effect relationships, dynamic dietary mineral concentrations, shifting requirements and a lack of mineral intake quantificat...

A preliminary assessment of year long relative loose mineral intake and range cow productivity in Northern Great Plains

USDA-ARS?s Scientific Manuscript database

Assessment of the effectiveness of supplementary mineral nutrition in range cattle to promote important economic traits is lacking due a paucity of methods to measure cause and effect relationships, dynamic dietary mineral concentrations, shifting requirements and a lack of mineral intake quantifica...

Moths behaving like butterflies. Evolutionary loss of long range attractant pheromones in castniid moths: a Paysandisia archon model.

PubMed

Sarto i Monteys, Víctor; Acín, Patricia; Rosell, Glòria; Quero, Carmen; Jiménez, Miquel A; Guerrero, Angel

2012-01-01

In the course of evolution butterflies and moths developed two different reproductive behaviors. Whereas butterflies rely on visual stimuli for mate location, moths use the 'female calling plus male seduction' system, in which females release long-range sex pheromones to attract conspecific males. There are few exceptions from this pattern but in all cases known female moths possess sex pheromone glands which apparently have been lost in female butterflies. In the day-flying moth family Castniidae ("butterfly-moths"), which includes some important crop pests, no pheromones have been found so far. Using a multidisciplinary approach we described the steps involved in the courtship of P. archon, showing that visual cues are the only ones used for mate location; showed that the morphology and fine structure of the antennae of this moth are strikingly similar to those of butterflies, with male sensilla apparently not suited to detect female-released long range pheromones; showed that its females lack pheromone-producing glands, and identified three compounds as putative male sex pheromone (MSP) components of P. archon, released from the proximal halves of male forewings and hindwings. This study provides evidence for the first time in Lepidoptera that females of a moth do not produce any pheromone to attract males, and that mate location is achieved only visually by patrolling males, which may release a pheromone at short distance, putatively a mixture of Z,E-farnesal, E,E-farnesal, and (E,Z)-2,13-octadecadienol. The outlined behavior, long thought to be unique to butterflies, is likely to be widespread in Castniidae implying a novel, unparalleled butterfly-like reproductive behavior in moths. This will also have practical implications in applied entomology since it signifies that the monitoring/control of castniid pests should not be based on the use of female-produced pheromones, as it is usually done in many moths.

Order of wetting transitions in electrolyte solutions.

PubMed

Ibagon, Ingrid; Bier, Markus; Dietrich, S

2014-05-07

For wetting films in dilute electrolyte solutions close to charged walls we present analytic expressions for their effective interface potentials. The analysis of these expressions renders the conditions under which corresponding wetting transitions can be first- or second-order. Within mean field theory we consider two models, one with short- and one with long-ranged solvent-solvent and solvent-wall interactions. The analytic results reveal in a transparent way that wetting transitions in electrolyte solutions, which occur far away from their critical point (i.e., the bulk correlation length is less than half of the Debye length) are always first-order if the solvent-solvent and solvent-wall interactions are short-ranged. In contrast, wetting transitions close to the bulk critical point of the solvent (i.e., the bulk correlation length is larger than the Debye length) exhibit the same wetting behavior as the pure, i.e., salt-free, solvent. If the salt-free solvent is governed by long-ranged solvent-solvent as well as long-ranged solvent-wall interactions and exhibits critical wetting, adding salt can cause the occurrence of an ion-induced first-order thin-thick transition which precedes the subsequent continuous wetting as for the salt-free solvent.

Long-range interacting systems in the unconstrained ensemble.

PubMed

Latella, Ivan; Pérez-Madrid, Agustín; Campa, Alessandro; Casetti, Lapo; Ruffo, Stefano

2017-01-01

Completely open systems can exchange heat, work, and matter with the environment. While energy, volume, and number of particles fluctuate under completely open conditions, the equilibrium states of the system, if they exist, can be specified using the temperature, pressure, and chemical potential as control parameters. The unconstrained ensemble is the statistical ensemble describing completely open systems and the replica energy is the appropriate free energy for these control parameters from which the thermodynamics must be derived. It turns out that macroscopic systems with short-range interactions cannot attain equilibrium configurations in the unconstrained ensemble, since temperature, pressure, and chemical potential cannot be taken as a set of independent variables in this case. In contrast, we show that systems with long-range interactions can reach states of thermodynamic equilibrium in the unconstrained ensemble. To illustrate this fact, we consider a modification of the Thirring model and compare the unconstrained ensemble with the canonical and grand-canonical ones: The more the ensemble is constrained by fixing the volume or number of particles, the larger the space of parameters defining the equilibrium configurations.

Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues

DTIC Science & Technology

2012-02-13

Ballistic Missiles Congressional Research Service Forward-Based Global Strike ( FBGS ...missiles in the CPGS program. Forward-Based Global Strike ( FBGS ) Analysts have also explored the option of deploying long-range land-based ballistic

Evolution of short range order in Ar: Liquid to glass and solid transitions-A computational study

NASA Astrophysics Data System (ADS)

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.

Surface Roughness Measurements Utilizing Long-Range Surface-Plasma Waves

DTIC Science & Technology

1984-11-01

8217 The theory dealt only with the depen- modes, one symmetric and one antisymmetric, dence of the real wave vector on the real part of that propagate...quantity, while the wave vector is complex. It is shown that for both the supported and unsup- From Eqs. (1) and (2) one obtains the real implic- ported...Opt. Soc. sabbatical leave from the University of Toledo. Am.). Optical feild enhancemeft by long-range surface- I" ouT In O’ in OUT way@, plasma waves

Dynamical Quantum Phase Transitions in Spin Chains with Long-Range Interactions: Merging Different Concepts of Nonequilibrium Criticality

NASA Astrophysics Data System (ADS)

Žunkovič, Bojan; Heyl, Markus; Knap, Michael; Silva, Alessandro

2018-03-01

We theoretically study the dynamics of a transverse-field Ising chain with power-law decaying interactions characterized by an exponent α , which can be experimentally realized in ion traps. We focus on two classes of emergent dynamical critical phenomena following a quantum quench from a ferromagnetic initial state: The first one manifests in the time-averaged order parameter, which vanishes at a critical transverse field. We argue that such a transition occurs only for long-range interactions α ≤2 . The second class corresponds to the emergence of time-periodic singularities in the return probability to the ground-state manifold which is obtained for all values of α and agrees with the order parameter transition for α ≤2 . We characterize how the two classes of nonequilibrium criticality correspond to each other and give a physical interpretation based on the symmetry of the time-evolved quantum states.

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

PubMed

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).

Fractal landscapes in biological systems: long-range correlations in DNA and interbeat heart intervals

NASA Technical Reports Server (NTRS)

Stanley, H. E.; Buldyrev, S. V.; Goldberger, A. L.; Hausdorff, J. M.; Havlin, S.; Mietus, J.; Sciortino, F.; Simons, M.

1992-01-01

Here we discuss recent advances in applying ideas of fractals and disordered systems to two topics of biological interest, both topics having common the appearance of scale-free phenomena, i.e., correlations that have no characteristic length scale, typically exhibited by physical systems near a critical point and dynamical systems far from equilibrium. (i) DNA nucleotide sequences have traditionally been analyzed using models which incorporate the possibility of short-range nucleotide correlations. We found, instead, a remarkably long-range power law correlation. We found such long-range correlations in intron-containing genes and in non-transcribed regulatory DNA sequences as well as intragenomic DNA, but not in cDNA sequences or intron-less genes. We also found that the myosin heavy chain family gene evolution increases the fractal complexity of the DNA landscapes, consistent with the intron-late hypothesis of gene evolution. (ii) The healthy heartbeat is traditionally thought to be regulated according to the classical principle of homeostasis, whereby physiologic systems operate to reduce variability and achieve an equilibrium-like state. We found, however, that under normal conditions, beat-to-beat fluctuations in heart rate display long-range power law correlations.

Tennessee long-range transportation plan : traditionally underserved populations outreach and analysis approach

DOT National Transportation Integrated Search

2006-01-01

This report describes efforts undertaken during the preparation of the Tennessee Long-Range Transportation Plan to engage traditionally underserved populations of the state and to provide opportunities for members of those populations to provide inpu...

Effect of cutoff radius, long range interaction and temperature controller on thermodynamic properties of fluids: Methanol as an example

NASA Astrophysics Data System (ADS)

Obeidat, Abdalla; Jaradat, Adnan; Hamdan, Bushra; Abu-Ghazleh, Hind

2018-04-01

The best spherical cutoff radius, long range interaction and temperature controller were determined using surface tension, density, and diffusion coefficients of van Leeuwen and Smit methanol. A quite good range of cutoff radii from 0.75 to 1.45 nm has been studied on Coulomb cut-off and particle mesh Ewald (PME) long range interaction to determine the best cutoff radius and best long range interaction as well for four sets of temperature: 200, 230, 270 and 300 K. To determine the best temperature controller, the cutoff radius of 1.25 nm was fixed using PME long range interaction on calculating the above properties at low temperature range: 200-300 K.

Long-range synchronization and local desynchronization of alpha oscillations during visual short-term memory retention in children.

PubMed

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.

The Design of an Ultra High Capacity Long Range Transport Aircraft

NASA Technical Reports Server (NTRS)

Weisshaar, Terrence A.; Bucci, Gregory; Hare, Angela; Szolwinski, Matthew

1993-01-01

This paper examines the design of a 650 passenger aircraft with 8000 nautical mile range to reduce seat mile cost and to reduce airport and airway congestion. This design effort involves the usual issues that require trades between technologies, but must also include consideration of: airport terminal facilities; passenger loading and unloading; and, defeating the 'square-cube' law to design large structures. This paper will review the long range ultra high capacity or megatransport design problem and the variety of solutions developed by senior student design teams at Purdue University.

The Use of Principal Components in Long-Range Forecasting

NASA Astrophysics Data System (ADS)

Chern, Jonq-Gong

Large-scale modes of the global sea surface temperatures and the Northern Hemisphere tropospheric circulation are described by principal component analysis. The first and the second SST components well describe the El Nino episodes, and the El Nino index (ENI), suggested in this study, is consistent with the winter Southern Oscillation index (SOI), where this ENI is a composite component of the weighted first and second SST components. The large-scale interactive modes of the coupling ocean-atmosphere system are identified by cross-correlation analysis The result shows that the first SST component is strongly correlated with the first component of geopotential height in lead time of 6 months. In the El Nino-Southern Oscillation (ENSO) evolution, the El Nino mode strongly influences the winter tropospheric circulation in the mid -latitudes for up to three leading seasons. The regional long-range variation of climate is investigated with these major components of the SST and the tropospheric circulation. In the mid-latitude, the climate of the central United States shows a weak linkage with these large-scale circulations, and the climate of the western United States appears to be consistently associated with the ENSO modes. These El Nino modes also show a dominant influence on Eastern Asia as evidenced in Taiwan Mei-Yu patterns. Possible regional long-range forecasting schemes, utilizing the complementary characteristics of the winter El Nino mode and SST anomalies, are examined with the Taiwan Mei-Yu.

Beam-Dynamics Analysis of Long-Range Wakefield Effects on the SCRF Cavities at the Fast Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shin, Young-Min; Bishofberger, Kip; Carlsten, Bruce

Long-range wakefields in superconducting RF (SCRF) cavities create complicated effects on beam dynamics in SCRF-based FEL beamlines. The driving bunch excites effectively an infinite number of structure modes (including HOMs) which oscillate within the SCRF cavity. Couplers with loads are used to damp the HOMs. However, these HOMs can persist for long periods of time in superconducting structures, which leads to long-range wakefields. Clear understanding of the long-range wakefield effects is a critical element for risk mitigation of future SCRF accelerators such as XFEL at DESY, LCLS-II XFEL, and MaRIE XFEL. We are currently developing numerical tools for simulating long-rangemore » wakefields in SCRF accelerators and plan to experimentally verify the tools by measuring these wakefields at the Fermilab Accelerator Science and Technology (FAST) facility. This paper previews the experimental conditions at the FAST 50 MeV beamline based on the simulation results.« less

Optimal Interception of a Maneuvering Long-range Missile

NASA Astrophysics Data System (ADS)

X. Vinh, Nguyen; T. Kabamba, Pierre; Takehira, Tetsuya

2001-01-01

In a Newtonian central force field, the minimum-fuel interception of a satellite, or a ballistic missile, in elliptic trajectory can be obtained via Lawden's theory of primer vector. To secure interception when the target performs evasive maneuvers, a new control law, with explicit solutions, is implemented. It is shown that by a rotation of coordinate system, the problem of three-dimensional interception is reduced to a planar problem. The general case of planar interception of a long-range ballistic missile is then studied. Examples of interception at a specified time, head-on interception and minimum-fuel interception are presented. In each case, the requirement for the thrust acceleration is expressed explicitly as a function of time.

Ferromagnetic Long Range Ordering in Copper(2) Maleate Monohydrate.

DTIC Science & Technology

1988-11-20

thanks the Consejo Nacional de Ciencia y Tecnologia for a partial fellowship. 10 References 1a) SYNTHECO, Inc., 1920 Industrial Pike, Gastonia, N.C...Philadelphia, 1966; Chapter 3. 14) D. B. Losee and W. E. Hatfield, Phs e.i Q 1122 (1974). 15) y . Yamamoto, M. Matsuura, and T. Haseda, J. Phys.-Soc...Mal in the solid state recorded at room temperature. 12 (0 Vj) N 4W +C +~ 13 4P4 CYC CS) (SG) CS + 0 (0 + C, S+ + 06 + + + 3 CC, (( Y ) uo p1 3ubA 00 CL

Long range forecasts of the Northern Hemisphere anomalies with antecedent sea surface temperature patterns

NASA Technical Reports Server (NTRS)

Kung, Ernest C.

1994-01-01

The contract research has been conducted in the following three major areas: analysis of numerical simulations and parallel observations of atmospheric blocking, diagnosis of the lower boundary heating and the response of the atmospheric circulation, and comprehensive assessment of long-range forecasting with numerical and regression methods. The essential scientific and developmental purpose of this contract research is to extend our capability of numerical weather forecasting by the comprehensive general circulation model. The systematic work as listed above is thus geared to developing a technological basis for future NASA long-range forecasting.

Bayesian Analysis of Non-Gaussian Long-Range Dependent Processes

NASA Astrophysics Data System (ADS)

Graves, Timothy; Watkins, Nicholas; Franzke, Christian; Gramacy, Robert

2013-04-01

Recent studies [e.g. the Antarctic study of Franzke, J. Climate, 2010] have strongly suggested that surface temperatures exhibit long-range dependence (LRD). The presence of LRD would hamper the identification of deterministic trends and the quantification of their significance. It is well established that LRD processes exhibit stochastic trends over rather long periods of time. Thus, accurate methods for discriminating between physical processes that possess long memory and those that do not are an important adjunct to climate modeling. As we briefly review, the LRD idea originated at the same time as H-selfsimilarity, so it is often not realised that a model does not have to be H-self similar to show LRD [e.g. Watkins, GRL Frontiers, 2013]. We have used Markov Chain Monte Carlo algorithms to perform a Bayesian analysis of Auto-Regressive Fractionally-Integrated Moving-Average ARFIMA(p,d,q) processes, which are capable of modeling LRD. Our principal aim is to obtain inference about the long memory parameter, d, with secondary interest in the scale and location parameters. We have developed a reversible-jump method enabling us to integrate over different model forms for the short memory component. We initially assume Gaussianity, and have tested the method on both synthetic and physical time series. Many physical processes, for example the Faraday Antarctic time series, are significantly non-Gaussian. We have therefore extended this work by weakening the Gaussianity assumption, assuming an alpha-stable distribution for the innovations, and performing joint inference on d and alpha. Such a modified FARIMA(p,d,q) process is a flexible, initial model for non-Gaussian processes with long memory. We will present a study of the dependence of the posterior variance of the memory parameter d on the length of the time series considered. This will be compared with equivalent error diagnostics for other measures of d.

Magnetic Properties of a Fluvial Chronosequence From the Eastern Wind River Range, Wyoming

NASA Astrophysics Data System (ADS)

Quinton, E. E.; Dahms, D. E.; Geiss, C. E.

2010-12-01

In order to constrain the rate of magnetic enhancement in glacial fluvial sediments, we sampled modern soils from eight fluvial terraces in the East Wind River Range in Wyoming. Soil profiles up to 1.2 meters deep were described in the field and sampled in five cm intervals from a series of hand-dug pits or natural river-bank exposure. The age of the studied profiles are estimated to range from >600 ka to modern. They include Sacagawea Ridge, Bull Lake and Pinedale-age fluvial terraces as well as one Holocene profile. To characterize changes in magnetic properties we measured low-field magnetic susceptibility, anhysteretic remanent magnetization, isothermal remanent magnetization and S-ratios for all, and hysteresis loops for a selected sub-set of samples. Our measurements show no clear trend in magnetic enhancement with estimated soil age. The observed lack of magnetic enhancement in the older soils may be due to long-term deflation, which continuously strips off the magnetically enhanced topsoil. It is also possible that the main pedogenic processes, such as the development of well-expressed calcic horizons destroy or mask the effects of long-term magnetic enhancement.

Emergent long-range synchronization of oscillating ecological populations without external forcing described by Ising universality

PubMed Central

Noble, Andrew E.; Machta, Jonathan; Hastings, Alan

2015-01-01

Understanding the synchronization of oscillations across space is fundamentally important to many scientific disciplines. In ecology, long-range synchronization of oscillations in spatial populations may elevate extinction risk and signal an impending catastrophe. The prevailing assumption is that synchronization on distances longer than the dispersal scale can only be due to environmental correlation (the Moran effect). In contrast, we show how long-range synchronization can emerge over distances much longer than the length scales of either dispersal or environmental correlation. In particular, we demonstrate that the transition from incoherence to long-range synchronization of two-cycle oscillations in noisy spatial population models is described by the Ising universality class of statistical physics. This result shows, in contrast to all previous work, how the Ising critical transition can emerge directly from the dynamics of ecological populations. PMID:25851364

Editors pp iii Effects of long-range magnetic interactions on DLA aggregation [rapid communication

NASA Astrophysics Data System (ADS)

Xu, Xiao-Jun; Cai, Ping-Gen; Ye, Quan-Lin; Xia, A.-Gen; Ye, Gao-Xiang

2005-04-01

An extra degree of freedom is introduced in the well-known diffusion-limited aggregation model, i.e., the growth entities are “spin” taking. The model with long-range magnetic interactions that decay as βC/rα on two-dimensional square lattices is studied for different values of α. This model leads to a wide variety of kinetic processes and morphology distribution with both the coupling energy βC and the range of the interactions, i.e., the exponent α. The simulated result of the model shows that the “quenching” of the degree of freedom on the cluster by the long-range magnetic interactions leads to branching or compactness, but, moreover, to combined geometric and physical “transitions” of the aggregations with the growth parameters.

Long-range sound propagation: A review of some experimental data

NASA Technical Reports Server (NTRS)

Sutherland, Louis C.

1990-01-01

Three experimental studies of long range sound propagation carried out or sponsored in the past by NASA are briefly reviewed to provide a partial prospective for some of the analytical studies presented in this symposium. The three studies reviewed cover (1) a unique test of two large rocket engines conducted in such a way as to provide an indication of possible atmospheric scattering loss from a large low-frequency directive sound source, (2) a year-long measurement of low frequency sound propagation which clearly demonstrated the dominant influence of the vertical gradient in the vector sound velocity towards the receiver in defining excess sound attenuation due to refraction, and (3), a series of excess ground attenuation measurements over grass and asphalt surfaces replicated several times under very similar inversion weather conditions.

Long-Range Master Plan, 1986-1989. Black Hawk College, East Campus.

ERIC Educational Resources Information Center

Black Hawk Coll. Kewanee, IL. East Campus.

This 3-year strategic long-range master plan states the intended direction of Black Hawk College-East Campus (BHC) in Illinois for October 1986 to October 1989. The report begins with a series of graphs offering various service area comparisons between rural Illinois residents and BHE students; enrollment data; and student demographics. Next, the…

Management and Research Applications of Long-range Surveillance Radar Data for Birds, Bats, and Flying Insects

USGS Publications Warehouse

Ruth, Janet M.; Buler, Jeffrey J.; Diehl, Robert H.; Sojda, Richard S.

2008-01-01

There is renewed interest in using long-range surveillance radar as a biological research tool due to substantial improvements in the network of radars within the United States. Technical improvements, the digital nature of the radar data, and the availability of computing power and geographic information systems, enable a broad range of biological applications. This publication provides a summary of long-range surveillance radar technology and applications of these data to questions about movement patterns of birds and other flying wildlife. The intended audience is potential radar-data end users, including natural-resource management and regulatory agencies, conservation organizations, and industry. This summary includes a definition of long-range surveillance radar, descriptions of its strengths and weaknesses, information on applications of the data, cost, methods of calibration, and what end users need to do, and some key references and resources.

Six orders of magnitude dynamic range in capillary electrophoresis with ultrasensitive laser-induced fluorescence detection

PubMed Central

Whitmore, Colin D.; Essaka, David; Dovichi, Norman J.

2009-01-01

An ultrasensitive laser-induced fluorescence detector was used with capillary electrophoresis for the study of 5-carboxy-tetramethylrhodamine. The raw signal from the detector provided roughly three orders of magnitude dynamic range. The signal saturated at high analyte concentrations due to the dead time associated with the single-photon counting avalanche photodiode employed in the detector. The signal can be corrected for the detector dead time, providing an additional order of magnitude dynamic range. To further increase dynamic range, two fiber-optic beam-splitters were cascaded to generate a primary signal and two attenuated signals, each monitored by a single-photon counting avalanche photodiode. The combined signals from the three photodiodes are reasonably linear from the concentration detection limit of 3 pM to 10 μM, the maximum concentration investigated, a range of 3,000,000. Mass detection limits were 150 yoctomoles injected onto the capillary. PMID:19836546

Improved numerical methods for infinite spin chains with long-range interactions

NASA Astrophysics Data System (ADS)

Nebendahl, V.; Dür, W.

2013-02-01

We present several improvements of the infinite matrix product state (iMPS) algorithm for finding ground states of one-dimensional quantum systems with long-range interactions. As a main ingredient, we introduce the superposed multioptimization method, which allows an efficient optimization of exponentially many MPS of different lengths at different sites all in one step. Here, the algorithm becomes protected against position-dependent effects as caused by spontaneously broken translational invariance. So far, these have been a major obstacle to convergence for the iMPS algorithm if no prior knowledge of the system's translational symmetry was accessible. Further, we investigate some more general methods to speed up calculations and improve convergence, which might be partially interesting in a much broader context, too. As a more special problem, we also look into translational invariant states close to an invariance-breaking phase transition and show how to avoid convergence into wrong local minima for such systems. Finally, we apply these methods to polar bosons with long-range interactions. We calculate several detailed Devil's staircases with the corresponding phase diagrams and investigate some supersolid properties.

Criticality and phase diagram of quantum long-range O(N ) models

NASA Astrophysics Data System (ADS)

Defenu, Nicolò; Trombettoni, Andrea; Ruffo, Stefano

2017-09-01

Several recent experiments in atomic, molecular, and optical systems motivated a huge interest in the study of quantum long-range systems. Our goal in this paper is to present a general description of their critical behavior and phases, devising a treatment valid in d dimensions, with an exponent d +σ for the power-law decay of the couplings in the presence of an O(N ) symmetry. By introducing a convenient ansatz for the effective action, we determine the phase diagram for the N -component quantum rotor model with long-range interactions, with N =1 corresponding to the Ising model. The phase diagram in the σ -d plane shows a nontrivial dependence on σ . As a consequence of the fact that the model is quantum, the correlation functions are anisotropic in the spatial and time coordinates for σ smaller than a critical value, and in this region the isotropy is not restored even at criticality. Results for the correlation length exponent ν , the dynamical critical exponent z , and a comparison with numerical findings for them are presented.

Spatial search on a two-dimensional lattice with long-range interactions

NASA Astrophysics Data System (ADS)

Osada, Tomo; Sanaka, Kaoru; Munro, William J.; Nemoto, Kae

2018-06-01

Quantum-walk-based algorithms that search a marked location among N locations on a d -dimensional lattice succeeds in time O (√{N }) for d >2 , while this is not found to be possible when d =2 . In this paper, we consider a spatial search algorithm using continuous-time quantum walk on a two-dimensional square lattice with the existence of additional long-range edges. We examined such a search on a probabilistic graph model where an edge connecting non-nearest-neighbor lattice points i and j apart by a distance |i -j | is added by probability pi j=|i-j | -α(α ≥0 ) . Through numerical analysis, we found that the search succeeds in time O (√{N }) when α ≤αc=2.4 ±0.1 . For α >2 , the expectation value of the additional long-range edges on each node scales as a constant when N →∞ , which means that search time of O (√{N }) is achieved on a graph with average degree scaling as a constant.

Direct Imaging of Long-Range Exciton Transport in Quantum Dot Superlattices by Ultrafast Microscopy.

PubMed

Yoon, Seog Joon; Guo, Zhi; Dos Santos Claro, Paula C; Shevchenko, Elena V; Huang, Libai

2016-07-26

Long-range charge and exciton transport in quantum dot (QD) solids is a crucial challenge in utilizing QDs for optoelectronic applications. Here, we present a direct visualization of exciton diffusion in highly ordered CdSe QDs superlattices by mapping exciton population using ultrafast transient absorption microscopy. A temporal resolution of ∼200 fs and a spatial precision of ∼50 nm of this technique provide a direct assessment of the upper limit for exciton transport in QD solids. An exciton diffusion length of ∼125 nm has been visualized in the 3 ns experimental time window and an exciton diffusion coefficient of (2.5 ± 0.2) × 10(-2) cm(2) s(-1) has been measured for superlattices constructed from 3.6 nm CdSe QDs with center-to-center distance of 6.7 nm. The measured exciton diffusion constant is in good agreement with Förster resonance energy transfer theory. We have found that exciton diffusion is greatly enhanced in the superlattices over the disordered films with an order of magnitude higher diffusion coefficient, pointing toward the role of disorder in limiting transport. This study provides important understandings on energy transport mechanisms in both the spatial and temporal domains in QD solids.

Laser diode stack beam shaping for efficient and compact long-range laser illuminator design

NASA Astrophysics Data System (ADS)

Lutz, Y.; Poyet, J. M.

2014-04-01

Laser diode stacks are interesting laser sources for active imaging illuminators. They allow the accumulation of large amounts of energy in multi-pulse mode, which is best suited for long-range image recording. Even when the laser diode stacks are equipped with fast-axis collimation (FAC) and slow-axis collimation (SAC) micro-lenses, their beam parameter products BPP are not compatible with direct use in highly efficient and compact illuminators. This is particularly true when narrow divergences are required such as for long-range applications. A solution to overcome these difficulties is to enhance the poor slow-axis BPP by virtually restacking the laser diode stack. We present a beam shaping and homogenization method that is low-cost and efficient and has low alignment sensitivity. After conducting simulations, we have realized and characterized the illuminator. A compact long-range laser illuminator has been set up with a divergence of 3.5×2.6 mrad and a global efficiency of 81%. Here, a projection lens with a clear aperture of 62 mm and a focal length of 571 mm was used.

Polarization control of high order harmonics in the EUV photon energy range.

PubMed

Vodungbo, Boris; Barszczak Sardinha, Anna; Gautier, Julien; Lambert, Guillaume; Valentin, Constance; Lozano, Magali; Iaquaniello, Grégory; Delmotte, Franck; Sebban, Stéphane; Lüning, Jan; Zeitoun, Philippe

2011-02-28

We report the generation of circularly polarized high order harmonics in the extreme ultraviolet range (18-27 nm) from a linearly polarized infrared laser (40 fs, 0.25 TW) focused into a neon filled gas cell. To circularly polarize the initially linearly polarized harmonics we have implemented a four-reflector phase-shifter. Fully circularly polarized radiation has been obtained with an efficiency of a few percents, thus being significantly more efficient than currently demonstrated direct generation of elliptically polarized harmonics. This demonstration opens up new experimental capabilities based on high order harmonics, for example, in biology and materials science. The inherent femtosecond time resolution of high order harmonic generating table top laser sources renders these an ideal tool for the investigation of ultrafast magnetization dynamics now that the magnetic circular dichroism at the absorption M-edges of transition metals can be exploited.

ADRPM-VII applied to the long-range acoustic detection problem

NASA Technical Reports Server (NTRS)

Shalis, Edward; Koenig, Gerald

1990-01-01

An acoustic detection range prediction model (ADRPM-VII) has been written for IBM PC/AT machines running on the MS-DOS operating system. The software allows the user to predict detection distances of ground combat vehicles and their associated targets when they are involved in quasi-military settings. The program can also calculate individual attenuation losses due to spherical spreading, atmospheric absorption, ground reflection and atmospheric refraction due to temperature and wind gradients while varying parameters effecting the source-receiver problem. The purpose here is to examine the strengths and limitations of ADRPM-VII by modeling the losses due to atmospheric refraction and ground absorption, commonly known as excess attenuation, when applied to the long range detection problem for distances greater than 3 kilometers.

Active and Inactive Enhancers Cooperate to Exert Localized and Long-Range Control of Gene Regulation.

PubMed

Proudhon, Charlotte; Snetkova, Valentina; Raviram, Ramya; Lobry, Camille; Badri, Sana; Jiang, Tingting; Hao, Bingtao; Trimarchi, Thomas; Kluger, Yuval; Aifantis, Iannis; Bonneau, Richard; Skok, Jane A

2016-06-07

V(D)J recombination relies on the presence of proximal enhancers that activate the antigen receptor (AgR) loci in a lineage- and stage-specific manner. Unexpectedly, we find that both active and inactive AgR enhancers cooperate to disseminate their effects in a localized and long-range manner. Here, we demonstrate the importance of short-range contacts between active enhancers that constitute an Igk super-enhancer in B cells. Deletion of one element reduces the interaction frequency between other enhancers in the hub, which compromises the transcriptional output of each component. Furthermore, we establish that, in T cells, long-range contact and cooperation between the inactive Igk enhancer MiEκ and the active Tcrb enhancer Eβ alters enrichment of CBFβ binding in a manner that impacts Tcrb recombination. These findings underline the complexities of enhancer regulation and point to a role for localized and long-range enhancer-sharing between active and inactive elements in lineage- and stage-specific control. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Effect of long-range interactions on the phase transition of Axelrod's model

NASA Astrophysics Data System (ADS)

Reia, Sandro M.; Fontanari, José F.

2016-11-01

Axelrod's model with F =2 cultural features, where each feature can assume k states drawn from a Poisson distribution of parameter q , exhibits a continuous nonequilibrium phase transition in the square lattice. Here we use extensive Monte Carlo simulations and finite-size scaling to study the critical behavior of the order parameter ρ , which is the fraction of sites that belong to the largest domain of an absorbing configuration averaged over many runs. We find that it vanishes as ρ ˜(qc0-q )β with β ≈0.25 at the critical point qc0≈3.10 and that the exponent that measures the width of the critical region is ν0≈2.1 . In addition, we find that introduction of long-range links by rewiring the nearest-neighbors links of the square lattice with probability p turns the transition discontinuous, with the critical point qcp increasing from 3.1 to 27.17, approximately, as p increases from 0 to 1. The sharpness of the threshold, as measured by the exponent νp≈1 for p >0 , increases with the square root of the number of nodes of the resulting small-world network.

Compensation of long-range process effects on photomasks by design data correction

NASA Astrophysics Data System (ADS)

Schneider, Jens; Bloecker, Martin; Ballhorn, Gerd; Belic, Nikola; Eisenmann, Hans; Keogan, Danny

2002-12-01

CD requirements for advanced photomasks are getting very demanding for the 100 nm-node and below; the ITRS roadmap requires CD uniformities below 10 nm for the most critical layers. To reach this goal, statistical as well as systematic CD contributions must be minimized. Here, we focus on the reduction of systematic CD variations across the masks that may be caused by process effects, e.g. dry etch loading. We address this topic by compensating such effects via design data correction analogous to proximity correction. Dry etch loading is modeled by gaussian convolution of pattern densities. Data correction is done geometrically by edge shifting. As the effect amplitude has an order of magnitude of 10 nm this can only be done on e-beam writers with small address grids to reduce big CD steps in the design data. We present modeling and correction results for special mask patterns with very strong pattern density variations showing that the compensation method is able to reduce CD uniformity by 50-70% depending on pattern details. The data correction itself is done with a new module developed especially to compensate long-range effects and fits nicely into the common data flow environment.

Fast Quantum State Transfer and Entanglement Renormalization Using Long-Range Interactions.

PubMed

Eldredge, Zachary; Gong, Zhe-Xuan; Young, Jeremy T; Moosavian, Ali Hamed; Foss-Feig, Michael; Gorshkov, Alexey V

2017-10-27

In short-range interacting systems, the speed at which entanglement can be established between two separated points is limited by a constant Lieb-Robinson velocity. Long-range interacting systems are capable of faster entanglement generation, but the degree of the speedup possible is an open question. In this Letter, we present a protocol capable of transferring a quantum state across a distance L in d dimensions using long-range interactions with a strength bounded by 1/r^{α}. If α

Fast Quantum State Transfer and Entanglement Renormalization Using Long-Range Interactions

NASA Astrophysics Data System (ADS)

Eldredge, Zachary; Gong, Zhe-Xuan; Young, Jeremy T.; Moosavian, Ali Hamed; Foss-Feig, Michael; Gorshkov, Alexey V.

2017-10-01

In short-range interacting systems, the speed at which entanglement can be established between two separated points is limited by a constant Lieb-Robinson velocity. Long-range interacting systems are capable of faster entanglement generation, but the degree of the speedup possible is an open question. In this Letter, we present a protocol capable of transferring a quantum state across a distance L in d dimensions using long-range interactions with a strength bounded by 1 /rα. If α

Largo hot water system long range thermal performance test report, addendum

NASA Technical Reports Server (NTRS)

1978-01-01

The test procedure used and the test results obtained during the long range thermal performance tests of the LARGO Solar Hot Water System under natural environmental conditions are presented. Objectives of these tests were to determine the amount of energy collected, the amount of power required for system operation, system efficiency, temperature distribution, and system performance degradation.

Stable swarming using adaptive long-range interactions

NASA Astrophysics Data System (ADS)

Gorbonos, Dan; Gov, Nir S.

2017-04-01

Sensory mechanisms in biology, from cells to humans, have the property of adaptivity, whereby the response produced by the sensor is adapted to the overall amplitude of the signal, reducing the sensitivity in the presence of strong stimulus, while increasing it when it is weak. This property is inherently energy consuming and a manifestation of the nonequilibrium nature of living organisms. We explore here how adaptivity affects the effective forces that organisms feel due to others in the context of a uniform swarm, in both two and three dimensions. The interactions between the individuals are taken to be attractive and long-range and of power-law form. We find that the effects of adaptivity inside the swarm are dramatic, where the effective forces decrease (or remain constant) with increasing swarm density. Linear stability analysis demonstrates how this property prevents collapse (Jeans instability), when the forces are adaptive. Adaptivity therefore endows swarms with a natural mechanism for self-stabilization.

Measured long-range repulsive Casimir-Lifshitz forces.

PubMed

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.

Long-range interactions of hydrogen atoms in excited states. III. n S -1 S interactions for n ≥3

NASA Astrophysics Data System (ADS)

Adhikari, C. M.; Debierre, V.; Jentschura, U. D.

2017-09-01

The long-range interaction of excited neutral atoms has a number of interesting and surprising properties such as the prevalence of long-range oscillatory tails and the emergence of numerically large van der Waals C6 coefficients. Furthermore, the energetically quasidegenerate n P states require special attention and lead to mathematical subtleties. Here we analyze the interaction of excited hydrogen atoms in n S states (3 ≤n ≤12 ) with ground-state hydrogen atoms and find that the C6 coefficients roughly grow with the fourth power of the principal quantum number and can reach values in excess of 240 000 (in atomic units) for states with n =12 . The nonretarded van der Waals result is relevant to the distance range R ≪a0/α , where a0 is the Bohr radius and α is the fine-structure constant. The Casimir-Polder range encompasses the interatomic distance range a0/α ≪R ≪ℏ c /L , where L is the Lamb shift energy. In this range, the contribution of quasidegenerate excited n P states remains nonretarded and competes with the 1 /R2 and 1 /R4 tails of the pole terms, which are generated by lower-lying m P states with 2 ≤m ≤n -1 , due to virtual resonant emission. The dominant pole terms are also analyzed in the Lamb shift range R ≫ℏ c /L . The familiar 1 /R7 asymptotics from the usual Casimir-Polder theory is found to be completely irrelevant for the analysis of excited-state interactions. The calculations are carried out to high precision using computer algebra in order to handle a large number of terms in intermediate steps of the calculation for highly excited states.

A nonrecursive 'Order N' preconditioned conjugate gradient/range space formulation of MDOF dynamics

NASA Technical Reports Server (NTRS)

Kurdila, A. J.; Menon, R.; Sunkel, John

1991-01-01

This paper addresses the requirements of present-day mechanical system simulations of algorithms that induce parallelism on a fine scale and of transient simulation methods which must be automatically load balancing for a wide collection of system topologies and hardware configurations. To this end, a combination range space/preconditioned conjugage gradient formulation of multidegree-of-freedon dynamics is developed, which, by employing regular ordering of the system connectivity graph, makes it possible to derive an extremely efficient preconditioner from the range space metric (as opposed to the system coefficient matrix). Because of the effectiveness of the preconditioner, the method can achieve performance rates that depend linearly on the number of substructures. The method, termed 'Order N' does not require the assembly of system mass or stiffness matrices, and is therefore amenable to implementation on work stations. Using this method, a 13-substructure model of the Space Station was constructed.

Critical assessment of pendimethalin in terms of persistence, bioaccumulation, toxicity, and potential for long-range transport.

PubMed

Vighi, Marco; Matthies, Michael; Solomon, Keith R

2017-01-01

Pendimethalin (PND, CAS registry number 40487-42-1) is a dinitroaniline herbicide that selectively controls broad-leaf and grassy weeds in a variety of crops and in noncrop areas. It has been on the market for about 30 yr and is currently under review for properties related to persistence (P), bioaccumulation (B), and toxicity (T) in the European Union (EU). A critical review of these properties as well as potential for long-range transport (LRT) was conducted. Pendimethalin has a geometric mean (GM) half-life of 76-98 d in agriculturally relevant soils under aerobic conditions in the lab. The anaerobic half-life was 12 d. The GM for field half-lives was 72 d. The GM half-life for sediment-water tests in the lab was 20 d and that in field aquatic cosms ranged from 45 to 90 d. From these data PND is not persistent as defined in the Annex II of EC regulation 1107/2009. The GM bioconcentration factor for PND was 1878, less than the criterion value. This was consistent with lack of biomagnification or accumulation in aquatic and terrestrial food chains. The GM no-observed-effect concentration (NOEC) value for fish was 43 µg/L, and 11 µg/L for algae. These do not trigger the criterion value for toxicity. In air, the DT50 of PND was estimated to be 0.35 d, which is well below the criterion of 2 d for LRT under the United Nations Economic Commission for Europe (UNECE) Aarhus protocol. Modeling confirmed lack of LRT. Because of its volatility, PND may be transported over short distances in air and was found in samples in local and semiremote regions; however, these concentrations are not of toxicological concern. Unlike other current-use pesticides, PND has not been found in samples from remote regions since 2000 and there is no apparent evidence that this herbicide accumulates in food chains in the Arctic.

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

NASA Astrophysics Data System (ADS)

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

Thermal transport in the Fermi-Pasta-Ulam model with long-range interactions

NASA Astrophysics Data System (ADS)

Bagchi, Debarshee

2017-03-01

We study the thermal transport properties of the one-dimensional Fermi-Pasta-Ulam model (β type) with long-range interactions. The strength of the long-range interaction decreases with the (shortest) distance between the lattice sites as distance-δ, where δ ≥0 . Two Langevin heat baths at unequal temperatures are connected to the ends of the one-dimensional lattice via short-range harmonic interactions that drive the system away from thermal equilibrium. In the nonequilibrium steady state the heat current, thermal conductivity, and temperature profiles are computed by solving the equations of motion numerically. It is found that the conductivity κ has an interesting nonmonotonic dependence with δ with a maximum at δ =2.0 for this model. Moreover, at δ =2.0 ,κ diverges almost linearly with system size N and the temperature profile has a negligible slope, as one expects in ballistic transport for an integrable system. We demonstrate that the nonmonotonic behavior of the conductivity and the nearly ballistic thermal transport at δ =2.0 obtained under nonequilibrium conditions can be explained consistently by studying the variation of largest Lyapunov exponent λmax with δ , and excess energy diffusion in the equilibrium microcanonical system.

Cell-veto Monte Carlo algorithm for long-range systems.