Correlating Gas Transport Parameters and X-ray Computed Tomography Measurements in Porous Media
DEFF Research Database (Denmark)
Naveed, Muhammad; Hamamoto, Shoichiro; Kawamoto, Ken
2013-01-01
-dried and partially saturated conditions. Gas transport parameters including gas dispersivity (α), diffusivity (DP/D0), and permeability (ka) were measured using a unified measurement system (UMS). The 3DMA-Rock computational package was used for analysis of three-dimensional CT data. A strong linear relationship...... was found between α and tortuosity calculated from gas transport parameters (Equation (Uncited) Image Tools), indicating that gas dispersivity has a linear and inverse relationship with gas diffusivity. A linear relationship was also found between ka and d50/TUMS2, indicating a strong dependency of ka...... on mean particle size and direct correlation with gas diffusivity. Tortuosity (TMFX) and equivalent pore diameter (deq.MFX) analyzed from microfocus X-ray CT increased linearly with increasing d50 for both Granusil and Accusand and further showing no effect of particle shape. The TUMS values showed...
GIS measured environmental correlates of active school transport: A systematic review of 14 studies
Directory of Open Access Journals (Sweden)
Faulkner Guy
2011-05-01
Full Text Available Abstract Background Emerging frameworks to examine active school transportation (AST commonly emphasize the built environment (BE as having an influence on travel mode decisions. Objective measures of BE attributes have been recommended for advancing knowledge about the influence of the BE on school travel mode choice. An updated systematic review on the relationships between GIS-measured BE attributes and AST is required to inform future research in this area. The objectives of this review are: i to examine and summarize the relationships between objectively measured BE features and AST in children and adolescents and ii to critically discuss GIS methodologies used in this context. Methods Six electronic databases, and websites were systematically searched, and reference lists were searched and screened to identify studies examining AST in students aged five to 18 and reporting GIS as an environmental measurement tool. Fourteen cross-sectional studies were identified. The analyses were classified in terms of density, diversity, and design and further differentiated by the measures used or environmental condition examined. Results Only distance was consistently found to be negatively associated with AST. Consistent findings of positive or negative associations were not found for land use mix, residential density, and intersection density. Potential modifiers of any relationship between these attributes and AST included age, school travel mode, route direction (e.g., to/from school, and trip-end (home or school. Methodological limitations included inconsistencies in geocoding, selection of study sites, buffer methods and the shape of zones (Modifiable Areal Unit Problem [MAUP], the quality of road and pedestrian infrastructure data, and school route estimation. Conclusions The inconsistent use of spatial concepts limits the ability to draw conclusions about the relationship between objectively measured environmental attributes and AST. Future
Energy Technology Data Exchange (ETDEWEB)
Mclean, Jeffrey S.; Ona, Ositadinma; Majors, Paul D.
2008-02-18
Bacterial biofilms are complex, three-dimensional, communities that are found nearly everywhere in nature1 and are being recognized as the cause of treatment-resistant infections1 2. Advanced methods are required to characterize their collective and spatial patterns of metabolism however most techniques are invasive or destructive. Here we describe the use of a combined confocal laser scanning microscopy (CLSM) and nuclear magnetic resonance (NMR) microscopy system to monitor structure, mass transport, and metabolism in active biofilms. Non-invasive NMR methods provide macroscopic structure along with spatially-resolved metabolite profiles and diffusion measurements. CLSM enables monitoring of cells by fluorescent protein reporters to investigate biofilm structure and gene expression concurrently. A planar sample chamber design facilitates depth-resolved measurements on 140 nL sample volumes under laminar flow conditions. The techniques and approaches described here are applicable to environmental and medically relevant microbial communities, thus providing key metabolic information for promoting beneficial biofilms and treating associated diseases.
Energy Technology Data Exchange (ETDEWEB)
Steckel, Frank
2015-10-27
In this work electrical and thermal transport measurements of a antiferromagnetically ordered iridate and of superconducting FeAs-based high-temperature superconductors are presented and analyzed. The iridates are compounds with strong spin-orbit coupling. In the two-dimensional representative Sr{sub 2}IrO{sub 4} this yields isolating behavior with simultaneous antiferromagnetically ordered spin-orbit moments. Thus, Sr{sub 2}IrO{sub 4} is a model system for studying magnetic excitations in iridates. The analysis of the heat transport yields for the first time clear-cut evidence for magnetic heat conductivity in iridates. The extracted magnetic mean free path uncovers scattering processes of the magnons contributing to the heat transport and draws conclusions about the excitations of the spin-orbit coupled system. The FeAs-superconductors have mainly two-dimensional transport of carriers due to their layered crystal structure. The phase diagrams of these materials consist of ordering phenomena of magnetism, superconductivity and structural distortion. The main focus is on the reaction of the transport coefficients to the developed phases in representatives of the 111- and 122-families upon chemical doping in and out of the two-dimensional plane. With the help of resistivity and magnetic susceptibility phase diagrams are constructed. In selected cases, the Hall coefficient as well as electro-thermal transport coefficients are used to study the phase diagram in detail. The majority of these investigations yield omnipresent electrical ordering phenomena, which are named nematic phase. The measurement of the heat conductivity and the Nernst coefficient in doped BaFe{sub 2}As{sub 2} show that these transport coefficients are dominantly influenced by fluctuations which are preceeding the nematic phase. From the Nernst data conclusions are deduced about the driving mechanisms of the correlated electron system yielding the phase transitions.
Energy Technology Data Exchange (ETDEWEB)
Thomas, Edward V. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stork, Christopher L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mattingly, John K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2015-07-01
Inverse radiation transport focuses on identifying the configuration of an unknown radiation source given its observed radiation signatures. The inverse problem is traditionally solved by finding the set of transport model parameter values that minimizes a weighted sum of the squared differences by channel between the observed signature and the signature pre dicted by the hypothesized model parameters. The weights are inversely proportional to the sum of the variances of the measurement and model errors at a given channel. The traditional implicit (often inaccurate) assumption is that the errors (differences between the modeled and observed radiation signatures) are independent across channels. Here, an alternative method that accounts for correlated errors between channels is described and illustrated using an inverse problem based on the combination of gam ma and neutron multiplicity counting measurements.
Measurements of strong correlations in the transport of light through strongly scattering materials
Akbulut, D.
2013-01-01
In this thesis, we study light transport through multiple scattering random photonic materials. Light incident on such materials undergoes many scattering events before exiting the material. The relation between the incident and the transmitted fields is determined by the optical transmission matrix
Measurements of strong correlations in the transport of light through strongly scattering materials
Akbulut, D.
2013-01-01
In this thesis, we study light transport through multiple scattering random photonic materials. Light incident on such materials undergoes many scattering events before exiting the material. The relation between the incident and the transmitted fields is determined by the optical transmission matrix
DEFF Research Database (Denmark)
Durisic, Nela; Bachir, Alexia I; Kolin, David L;
2007-01-01
Semiconductor nanocrystals or quantum dots (QDs) are becoming widely used as fluorescent labels for biological applications. Here we demonstrate that fluorescence fluctuation analysis of their diffusional mobility using temporal image correlation spectroscopy is highly susceptible to systematic e...
Quantum correlations and measurements
Energy Technology Data Exchange (ETDEWEB)
Sperling, Jan
2015-07-16
The present thesis is a state of the art report on the characterization techniques and measurement strategies to verify quantum correlations. I mainly focus on research which has been performed in the theoretical quantum optics group at the University of Rostock during the last few years. The results include theoretical findings and analysis of experimental studies of radiation fields. We investigate the verification of quantum properties, the quantification of these quantum effects, and the characterization of quantum optical detector systems.
EARLINET Correlative Measurements For CALIPSO
Pappalardo, G.
2006-12-01
each station in coincidence with CALIPSO overpasses. Each observation lasts for a minimum of 1 hour centered around the overpass time, longer record of measurements are performed for special case studies (Saharan dust layers, forest fires, long range transport, etc.). Backtrajectory analysis will be also used to quantitatively study comparisons between CALIPSO and EARLINET observations. EARLINET correlative measurements plan for CALIPSO, and first results will be presented. ACKNOWLEDGMENTS The financial support for the improvement of the EARLINET infrastructure by the European Commission under grant RICA-025991 is gratefully acknowledged. The authors also thank the German Weather Service for the air mass backtrajectory analysis.
Transport phenomena in strongly correlated Fermi liquids
Energy Technology Data Exchange (ETDEWEB)
Kontani, Hiroshi [Nagoya Univ., Aichi (Japan). Dept. of Physics
2013-03-01
Comprehensive overview. Written by an expert of this topic. Provides the reader with current developments in the field. In conventional metals, various transport coefficients are scaled according to the quasiparticle relaxation time, {tau}, which implies that the relaxation time approximation (RTA) holds well. However, such a simple scaling does not hold in many strongly correlated electron systems, reflecting their unique electronic states. The most famous example would be cuprate high-Tc superconductors (HTSCs), where almost all the transport coefficients exhibit a significant deviation from the RTA results. To better understand the origin of this discrepancy, we develop a method for calculating various transport coefficients beyond the RTA by employing field theoretical techniques. Near the magnetic quantum critical point, the current vertex correction (CVC), which describes the electron-electron scattering beyond the relaxation time approximation, gives rise to various anomalous transport phenomena. We explain anomalous transport phenomena in cuprate HTSCs and other metals near their magnetic or orbital quantum critical point using a uniform approach. We also discuss spin related transport phenomena in strongly correlated systems. In many d- and f-electron systems, the spin current induced by the spin Hall effect is considerably greater because of the orbital degrees of freedom. This fact attracts much attention due to its potential application in spintronics. We discuss various novel charge, spin and heat transport phenomena in strongly correlated metals.
Blache, Ulrich; Jakob, Torsten; Su, Wanwen; Wilhelm, Christian
2011-08-01
Photosynthesis-irradiance (P-E)-curves describe the photosynthetic performance of autotrophic organisms. From these P-E-curves the photosynthetic parameters α-slope, P(max), and E(k) can be deduced which are often used to characterize and to compare different organisms or organisms in acclimation to different environmental conditions. Particularly, for in situ-measurements of P-E curves of phytoplankton the analysis of variable chlorophyll fluorescence proved its potential as a sensitive and rapid method. By using Chlorella vulgaris (Trebouxiophyceae), Nannochloropsis salina (Eustigmatophyceae), Skeletonema costatum and Cyclotella meneghiniana (Bacillariophyceae), the present study investigated the influence of cellular bio-optical properties on the correlation of the photosynthetic parameters derived from fluorescence-based P-E-curves with photosynthetic parameters obtained from the measurement of oxygen evolution. It is demonstrated that small planktonic algae show a wide range of cellular absorptivity which was subject to species-specifity, growth stage and environmental conditions, e.g. nutrient limitation. This variability in bio-optical properties resulted in a great deviation of relative electron transport rates (rETRs) from oxygen-based photosynthesis rates. Thus, the photosynthetic parameters α-slope and P(max) derived from rETRs strongly depend on the specific cellular absorptivity and cannot be used to compare the photosynthetic performance of cells with different optical properties. However, it was shown that E(k) is independent of cellular absorptivity and could be used to compare samples with unknown optical properties.
Eddy Correlation Flux Measurement System
Oak Ridge National Laboratory — The eddy correlation (ECOR) flux measurement system provides in situ, half-hour measurements of the surface turbulent fluxes of momentum, sensible heat, latent heat,...
Transport phenomena in strongly correlated Fermi liquids
Kontani, Hiroshi
2013-01-01
In conventional metals, various transport coefficients are scaled according to the quasiparticle relaxation time, \\tau, which implies that the relaxation time approximation (RTA) holds well. However, such a simple scaling does not hold in many strongly correlated electron systems, reflecting their unique electronic states. The most famous example would be cuprate high-Tc superconductors (HTSCs), where almost all the transport coefficients exhibit a significant deviation from the RTA results. To better understand the origin of this discrepancy, we develop a method for calculating various transport coefficients beyond the RTA by employing field theoretical techniques. Near the magnetic quantum critical point, the current vertex correction (CVC), which describes the electron-electron scattering beyond the relaxation time approximation, gives rise to various anomalous transport phenomena. We explain anomalous transport phenomena in cuprate HTSCs and other metals near their magnetic or orbital quantum critical poi...
Correlation measurement of squeezed light
DEFF Research Database (Denmark)
Krivitsky, Leonid; Andersen, Ulrik Lund; Dong, R.;
2009-01-01
We study the implementation of a correlation measurement technique for the characterization of squeezed light which is nearly free of electronic noise. With two different sources of squeezed light, we show that the sign of the covariance coefficient, revealed from the time-resolved correlation data...
Electronic transport and dynamics in correlated heterostructures
Mazza, G.; Amaricci, A.; Capone, M.; Fabrizio, M.
2015-05-01
We investigate by means of the time-dependent Gutzwiller approximation the transport properties of a strongly correlated slab subject to Hubbard repulsion and connected with to two metallic leads kept at a different electrochemical potential. We focus on the real-time evolution of the electronic properties after the slab is connected to the leads and consider both metallic and Mott insulating slabs. When the correlated slab is metallic, the system relaxes to a steady state that sustains a finite current. The zero-bias conductance is finite and independent of the degree of correlations within the slab as long as the system remains metallic. On the other hand, when the slab is in a Mott insulating state, the external bias leads to currents that are exponentially activated by charge tunneling across the Mott-Hubbard gap, consistent with the Landau-Zener dielectric breakdown scenario.
TRANSPORT PROPERTIES OF THE STRONGLY CORRELATED SYSTEMS
Directory of Open Access Journals (Sweden)
T.Domanski
2004-01-01
Full Text Available The transport properties of various systems are studied here in the context of three different models. These are: - the disordered Hubbard model applicable to correlated binary alloys with a general disorder, - the Anderson model used in describing the Kondo physics of a quantum dot connected to the external superconducting leads, and - the Ranninger-Robaszkiewicz model applied to the study of optical properties of the system with preformed electron pairs above the temperature of transition to the superconducting state. We calculate the density of states, specific heat, the Wilson ratio and conductivity of the correlated binary alloy with off-diagonal disorder. We investigate the conditions under which the Kondo peak appears in the density of states and in the conductance of a dot coupled to the external superconducting leads. We analyze the effect of the pseudogap on the optical spectra in the high temperature superconductors described by the boson-fermion model.
Quantum Transport in Strongly Correlated Systems
DEFF Research Database (Denmark)
Bohr, Dan
2007-01-01
describes the leads in momentum-space. We benchmark each of these schemes against exact Greens function results for the conductance in the non-interacting limit, thus demonstrating the accuracy of the lead descriptions. We first use the DMRG implementations to calculate the conductance of an interacting...... suppression when having the interaction inside the chain, and conjecture that the enhancement by interacting contacts is universal. This result challenges the commonly used division between interacting transport region and non-interacting leads, and shows that care should be taken when making....... Thus both coherence and correlation effects are important in this model, and the methods applied should be able to handle both these effects rigorously. We present the DMRG setup for this model and benchmark against existing Greens function results for the model. Then we present initial DMRG results...
Optimal measurements for nonlocal correlations
Schwarz, Sacha; Stefanov, André; Wolf, Stefan; Montina, Alberto
2016-08-01
A problem in quantum information theory is to find the experimental setup that maximizes the nonlocality of correlations with respect to some suitable measure such as the violation of Bell inequalities. There are however some complications with Bell inequalities. First and foremost it is unfeasible to determine the whole set of Bell inequalities already for a few measurements and thus unfeasible to find the experimental setup maximizing their violation. Second, the Bell violation suffers from an ambiguity stemming from the choice of the normalization of the Bell coefficients. An alternative measure of nonlocality with a direct information-theoretic interpretation is the minimal amount of classical communication required for simulating nonlocal correlations. In the case of many instances simulated in parallel, the minimal communication cost per instance is called nonlocal capacity, and its computation can be reduced to a convex-optimization problem. This quantity can be computed for a higher number of measurements and turns out to be useful for finding the optimal experimental setup. Focusing on the bipartite case, we present a simple method for maximizing the nonlocal capacity over a given configuration space and, in particular, over a set of possible measurements, yielding the corresponding optimal setup. Furthermore, we show that there is a functional relationship between Bell violation and nonlocal capacity. The method is illustrated with numerical tests and compared with the maximization of the violation of CGLMP-type Bell inequalities on the basis of entangled two-qubit as well as two-qutrit states. Remarkably, the anomaly of nonlocality displayed by qutrits turns out to be even stronger if the nonlocal capacity is employed as a measure of nonlocality.
WenJun Zhang; Xin Li
2015-01-01
Between-taxon interactions can be detected by calculating the sampling data of taxon sample type. In present study, Spearman rank correlation and proportion correlation are chosen as the general correlation measures, and their partial correlations are calculated and compared. The results show that for Spearman rank correlation measure, in all predicted candidate direct interactions by partial correlation, about 16.77% (x, 0-45.4%) of them are not successfully detected by Spearman rank correla...
Sediment transport measurements: Chapter 5
Diplas, P.; Kuhnle, R.; Gray, J.; Glysson, D.; Edwards, T.; García, Marcelo H.
2008-01-01
Sediment erosion, transport, and deposition in fluvial systems are complex processes that are treated in detail in other sections of this book. Development of methods suitable for the collection of data that contribute to understanding these processes is a still-evolving science. Sediment and ancillary data are fundamental requirements for the proper management of river systems, including the design of structures, the determination of aspects of stream behavior, ascertaining the probable effect of removing an existing structure, estimation of bulk erosion, transport, and sediment delivery to the oceans, ascertaining the long-term usefulness of reservoirs and other public works, tracking movement of solid-phase contaminants, restoration of degraded or otherwise modified streams, and assistance in the calibration and validation of numerical models. This chapter presents techniques for measuring bed-material properties and suspended and bed-load discharges. Well-established and relatively recent, yet adequately tested, sampling equipment and methodologies, with designs that are guided by sound physical and statistical principles, are described. Where appropriate, the theory behind the development of the equipment and guidelines for its use are presented.
Eddy correlation measurements of submarine groundwater discharge
Crusius, J.; Berg, P.; Koopmans, D.J.; Erban, L.
2008-01-01
This paper presents a new, non-invasive means of quantifying groundwater discharge into marine waters using an eddy correlation approach. The method takes advantage of the fact that, in virtually all aquatic environments, the dominant mode of vertical transport near the sediment-water interface is turbulent mixing. The technique thus relies on measuring simultaneously the fluctuating vertical velocity using an acoustic Doppler velocimeter and the fluctuating salinity and/or temperature using rapid-response conductivity and/or temperature sensors. The measurements are typically done at a height of 5-15??cm above the sediment surface, at a frequency of 16 to 64??Hz, and for a period of 15 to 60??min. If the groundwater salinity and/or temperature differ from that of the water column, the groundwater specific discharge (cm d- 1) can be quantified from either a heat or salt balance. Groundwater discharge was estimated with this new approach in Salt Pond, a small estuary on Cape Cod (MA, USA). Estimates agreed well with previous estimates of discharge measured using seepage meters and 222Rn as a tracer. The eddy correlation technique has several desirable characteristics: 1) discharge is quantified under in-situ hydrodynamic conditions; 2) salinity and temperature can serve as two semi-independent tracers of discharge; 3) discharge can be quantified at high temporal resolution, and 4) long-term records of discharge may be possible, due to the low power requirements of the instrumentation. ?? 2007 Elsevier B.V. All rights reserved.
Correlation Measurements on Small Mobile Devices
DEFF Research Database (Denmark)
Yanakiev, Boyan Radkov; Nielsen, Jesper Ødum; Christensen, Morten
2012-01-01
Here, analysis of the antenna correlation at the design stage is done, with focus on measurement techniques. Various theoretical definitions of correlations are used with the corresponding measured data required. The problems related to the coaxial measurement cables, when calculating correlation...
Correlated measurement error hampers association network inference.
Kaduk, Mateusz; Hoefsloot, Huub C J; Vis, Daniel J; Reijmers, Theo; van der Greef, Jan; Smilde, Age K; Hendriks, Margriet M W B
2014-09-01
Modern chromatography-based metabolomics measurements generate large amounts of data in the form of abundances of metabolites. An increasingly popular way of representing and analyzing such data is by means of association networks. Ideally, such a network can be interpreted in terms of the underlying biology. A property of chromatography-based metabolomics data is that the measurement error structure is complex: apart from the usual (random) instrumental error there is also correlated measurement error. This is intrinsic to the way the samples are prepared and the analyses are performed and cannot be avoided. The impact of correlated measurement errors on (partial) correlation networks can be large and is not always predictable. The interplay between relative amounts of uncorrelated measurement error, correlated measurement error and biological variation defines this impact. Using chromatography-based time-resolved lipidomics data obtained from a human intervention study we show how partial correlation based association networks are influenced by correlated measurement error. We show how the effect of correlated measurement error on partial correlations is different for direct and indirect associations. For direct associations the correlated measurement error usually has no negative effect on the results, while for indirect associations, depending on the relative size of the correlated measurement error, results can become unreliable. The aim of this paper is to generate awareness of the existence of correlated measurement errors and their influence on association networks. Time series lipidomics data is used for this purpose, as it makes it possible to visually distinguish the correlated measurement error from a biological response. Underestimating the phenomenon of correlated measurement error will result in the suggestion of biologically meaningful results that in reality rest solely on complicated error structures. Using proper experimental designs that allow
Criteria for measures of quantum correlations
Brodutch, Aharon
2011-01-01
Entanglement does not describe all quantum correlations and several authors have shown the need to go beyond entanglement when dealing with mixed states. Several different measures have sprung up in the literature, for a variety of reasons, To describe quantum correlations; some are known under the collective name quantum discord. Yet, in the same sprit as the criteria for entanglement measures, there is no general mechanism that determines whether a measure of quantum and classical correlations is a proper measure of correlations. This is partially due to the fact that the answer is a bit muddy. In this article we attempt tackle this muddy topic by writing down several criteria for a "good" measure of correlations. We breakup our list into necessary, reasonable, and debatable conditions. We then proceed to prove several of these conditions for generalized measures of quantum correlations. However, not all conditions are met by all measures; we show this via several examples. The reasonable conditions are rel...
Transportation inequalities: From Poisson to Gibbs measures
Ma, Yutao; Wang, Xinyu; Wu, Liming; 10.3150/00-BEJ268
2011-01-01
We establish an optimal transportation inequality for the Poisson measure on the configuration space. Furthermore, under the Dobrushin uniqueness condition, we obtain a sharp transportation inequality for the Gibbs measure on $\\mathbb{N}^{\\Lambda}$ or the continuum Gibbs measure on the configuration space.
Collisional broadening of angular correlations in a multiphase transport model
Edmonds, Terrence; Wang, Fuqiang
2016-01-01
Systematic comparisons of jetlike correlation data to radiative and collisional energy loss model calculations are essential to extract transport properties of the quark-gluon medium created in relativistic heavy ion collisions. This paper presents a transport study of collisional broadening of jetlike correlations, by following parton-parton collision history in a multiphase transport (AMPT) model. The correlation shape is studied as a function of the number of parton-parton collisions suffered by a high transverse momentum probe parton ($N_{\\rm coll}$) and the azimuth of the probe relative to the reaction plane ($\\phi_{\\rm fin.}^{\\rm probe}$). Correlation is found to broaden with increasing $N_{\\rm coll}$ and $\\phi_{\\rm fin.}^{\\rm probe}$ from in- to out-of-plane direction. This study provides a transport model benchmark for future jet-medium interaction studies.
Mixed-state quantum transport in correlated spin networks
Ajoy, Ashok; 10.1103/PhysRevA.85.042305
2012-01-01
Quantum spin networks can be used to transport information between separated registers in a quantum information processor. To find a practical implementation, the strict requirements of ideal models for perfect state transfer need to be relaxed, allowing for complex coupling topologies and general initial states. Here we analyze transport in complex quantum spin networks in the maximally mixed state and derive explicit conditions that should be satisfied by propagators for perfect state transport. Using a description of the transport process as a quantum walk over the network, we show that it is necessary to phase correlate the transport processes occurring along all the possible paths in the network. We provide a Hamiltonian that achieves this correlation, and use it in a constructive method to derive engineered couplings for perfect transport in complicated network topologies.
Correlations and anomalous transport effects related to stochastic instability
Energy Technology Data Exchange (ETDEWEB)
Bakunin, O G [Department of Physics and Astronomy, University of Kansas, Malott Hall, 1251 Wescoe Hall Drive, Lawrence, KS 66044 (United States); Nuclear Fusion Institute, RRC ' Kurchatov Institute' , pl. Kurchatova 1, Moscow, 123182 (Russian Federation); FOM Instituut voor Plasmafysica ' Rijnhuizen' , Associate Euroatom-FOM, 3430 BE Nieuwegein (Netherlands)
2005-11-15
In this paper, we analyse turbulent transport in the framework of the correlation approach to obtain the effective diffusion coefficient and characteristic increment in the scaling form. Such factors as anisotropy, seed diffusion mechanisms and reconstruction of flow topology significantly have an impact on the effective diffusivity. We consider the different aspects of stochastic instability such as the decorrelation mechanism to estimate characteristic correlation times and correlation scales in the framework of the scaling approach. The topics to be discussed include the Rechester-Rosenbluth correlation scalings, percolation transport in time dependent flows, anisotropic MHD spectra and a multi-scale approach to the analysis of anomalous transport. To treat long-range correlation effects, the percolation renormalization is analysed in time-dependent regimes. In the framework of the multiscale approach, a scaling for an increment of the stochastic instability in two-dimensional random flow is suggested.
Surface Wear Measurement Using Optical Correlation Technique
Acinger, Kresimir
1983-12-01
The coherent optical correlation technique was applied for measuring the surface wear of a tappet (part of car engine), worn by friction with the camshaft. It was found that maximum correlation intensity decays exponentially with the number of wear cycles (i.e. camshaft revolutions). Tappets of the same make have an identical rate of correlation decay. Tappets of different makes have different rates of correlation decay which are in agreement with observed long term wear.
Integral correlation measures for multiparticle physics
Eggers, H C; Carruthers, Peter A; Buschbeck, Brigitte
1993-01-01
We report on a considerable improvement in the technique of measuring multiparticle correlations via integrals over correlation functions. A modification of measures used in the characterization of chaotic dynamical sytems permits fast and flexible calculation of factorial moments and cumulants as well as their differential versions. Higher order correlation integral measurements even of large multiplicity events such as encountered in heavy ion collisons are now feasible. The change from ``ordinary'' to ``factorial'' powers may have important consequences in other fields such as the study of galaxy correlations and Bose-Einstein interferometry.
Quantum Transport in Strongly Correlated Systems
DEFF Research Database (Denmark)
Bohr, Dan
2007-01-01
the density matrix renormalization group (DMRG) method. We present two DMRG setups for calculating the linear conductance of strongly correlated nanostructures in the infinitesimal source-drain voltage regime. The first setup describes the leads by modified real-space tight-binding chains, whereas the second...... describes the leads in momentum-space. We benchmark each of these schemes against exact Greens function results for the conductance in the non-interacting limit, thus demonstrating the accuracy of the lead descriptions. We first use the DMRG implementations to calculate the conductance of an interacting...... spinless resonant 7 site chain, studying the effect of repulsive interaction inside the chain. We demonstrate that both weak and strong interactions inside the chain lead to Coulomb blockade renormalization of the resonances in the conductance spectrum. Additionally the strongly interacting case sharpens...
Coherent and correlated spin transport in nanoscale superconductors
Energy Technology Data Exchange (ETDEWEB)
Morten, Jan Petter
2008-03-15
Motivated by the desire for better understanding of nano electronic systems, we theoretically study the conductance and noise characteristics of current flow between superconductors, ferromagnets, and normal-metals. Such nano structures can reveal information about superconductor proximity effects, spin-relaxation processes, and spintronic effects with potential applications for different areas of mesoscopic physics. We employ the quasiclassical theory of superconductivity in the Keldysh formalism, and calculate the nonequilibrium transport of spin and charge using various approaches like the circuit theory of quantum transport and full counting statistics. For two of the studied structures, we have been able to compare our theory to experimental data and obtain good agreement. Transport and relaxation of spin polarized current in superconductors is governed by energy-dependent transport coefficients and spin-flip rates which are determined by quantum interference effects. We calculate the resulting temperature-dependent spin flow in ferromagnet-superconductor devices. Experimental data for spin accumulation and spin relaxation in a superconducting nano wire is in agreement with the theory, and allows for a spin-flip spectroscopy that determines the dominant mechanism for spin-flip relaxation in the studied samples. A ferromagnet precessing under resonance conditions can give rise to pure spin current injection into superconductors. We find that the absorbed spin current is measurable as a temperature dependent Gilbert damping, which we calculate and compare to experimental data. Crossed Andreev reflection denotes superconducting pairing of electrons flowing from different normal-metal or ferromagnet terminals into a superconductor. We calculate the nonlocal currents resulting from this process in competition with direct electron transport between the normal-metal terminals. We take dephasing into account, and study the nonlocal current when the types of contact in
Light transport and localization in two-dimensional correlated disorder
Conley, Gaurasundar M; Pratesi, Filippo; Vynck, Kevin; Wiersma, Diederik S
2013-01-01
Structural correlations in disordered media are known to affect significantly the propagation of waves. In this article, we theoretically investigate the transport and localization of light in two-dimensional photonic structures with short-range correlated disorder. The problem is tackled semi-analytically using the Baus-Colot model for the structure factor of correlated media and a modified independent scattering approximation. We find that short-range correlations make it possible to easily tune the transport mean free path by more than a factor of 2 and the related localization length over several orders of magnitude. This trend is confirmed by numerical finite-difference time-domain calculations. This study therefore shows that disorder engineering can offer fine control over light transport and localization in planar geometries, which may open new opportunities in both fundamental and applied photonics research.
Correlation and Sequential Filtering with Doppler Measurements
Institute of Scientific and Technical Information of China (English)
WANGJianguo; HEPeikun; HANYueqiu; WUSiliang
2004-01-01
Two sequential filters are developed for Doppler radar measurements in the presence of correlation between range and range rate measurement errors. Two ideal linear measurement equations with the pseudo measurements are constructed via block-partitioned Cholesky factorization and the practical measurement equationswith the pseudo measurements are obtained through the direction cosine estimation and error compensation. The resulting sequential filters make the position measurement be possibly processed before the pseudo measurement and hence the more accurate direction cosine estimate can be obtained from the filtered position estimate rather than the predicted state estimate. The numerical simulations with different rangerange rate correlation coefficients show thatthe proposed two sequential filters are almost equivalent in performance but both superior to the conventional extended Kalman filter for different correlation coefficients.
Unified entropic measures of quantum correlations induced by local measurements
Bosyk, G. M.; Bellomo, G.; Zozor, S.; Portesi, M.; Lamberti, P. W.
2016-11-01
We introduce quantum correlation measures based on the minimal change in unified entropies induced by local rank-one projective measurements, divided by a factor that depends on the generalized purity of the system in the case of nonadditive entropies. In this way, we overcome the issue of the artificial increasing of the value of quantum correlation measures based on nonadditive entropies when an uncorrelated ancilla is appended to the system, without changing the computability of our entropic correlation measures with respect to the previous ones. Moreover, we recover as limiting cases the quantum correlation measures based on von Neumann and Rényi entropies (i.e., additive entropies), for which the adjustment factor becomes trivial. In addition, we distinguish between total and semiquantum correlations and obtain some inequalities between them. Finally, we obtain analytical expressions of the entropic correlation measures for typical quantum bipartite systems.
On the measurability of quantum correlation functions
Energy Technology Data Exchange (ETDEWEB)
Lima Bernardo, Bertúlio de, E-mail: bertulio.fisica@gmail.com; Azevedo, Sérgio; Rosas, Alexandre
2015-05-15
The concept of correlation function is widely used in classical statistical mechanics to characterize how two or more variables depend on each other. In quantum mechanics, on the other hand, there are observables that cannot be measured at the same time; the so-called incompatible observables. This prospect imposes a limitation on the definition of a quantum analog for the correlation function in terms of a sequence of measurements. Here, based on the notion of sequential weak measurements, we circumvent this limitation by introducing a framework to measure general quantum correlation functions, in principle, independently of the state of the system and the operators involved. To illustrate, we propose an experimental configuration to obtain explicitly the quantum correlation function between two Pauli operators, in which the input state is an arbitrary mixed qubit state encoded on the polarization of photons.
Anomalous transport in low-dimensional systems with correlated disorder
Energy Technology Data Exchange (ETDEWEB)
Izrailev, F M [Instituto de Fisica, Universidad Autonoma de Puebla, Apartado Postal J-48, Puebla, Pue., 72570 (Mexico); Makarov, N M [Instituto de Ciencias, Universidad Autonoma de Puebla, Priv. 17 Norte No 3417, Col. San Miguel Hueyotlipan, Puebla, Pue., 72050 (Mexico)
2005-12-09
We review recent results on the anomalous transport in one-dimensional and quasi-one-dimensional systems with bulk and surface disorder. Principal attention is paid to the role of long-range correlations in random potentials for the bulk scattering and in corrugated profiles for the surface scattering. It is shown that with the proper type of correlations one can construct such a disorder that results in a selective transport with given properties. Of particular interest is the possibility to arrange windows of a complete transparency (or reflection) with dependence on the wave number of incoming classical waves or electrons.
Measurements of Correlation-Enhanced Collision Rates
Anderegg, F.; Dubin, D. H. E.; O'Neil, T. M.; Driscoll, C. F.
2008-11-01
We measure the perp-to-parallel collision rate ν| in laser-cooled Magnesium ion plasmas in the strongly-magnetized and correlated regime; and obtain close agreement with the ``Salpeter correlation enhancement'' first studied for fusion in dense plasmas such as stars. The cyclotron energy, like nuclear energy, is released only through rare close-range collisions. These close collisions are suppressed by strong magnetization, because collisional impact distances are rarely as small as a cyclotron radius rc. However, theory predicts that particle correlations reduce this suppression of collisionality, enhancing the rare close collisions by e^γ, where γ≡e^2 / aT is the correlation parameter. We control the plasma temperature over the range 4 0-6 < T < 1eV, giving correlation parameters up to γ 0, with measured collision rates 2 < ν| 2 10^4 sec-1. At low temperatures, the measured ν| are enhanced by up to 10^9 compared to uncorrelated theory, consistent with the predicted correlation enhancement. When the plasma density is reduced from 2 to 0.12 x10^7cm-3, the correlations are eliminated and the measured ν| agree with uncorrelated theory. E.E. Salpeter and H.M. Van Horn, Astrophys. J. 155, 183 (1969). D.H.E. Dubin, Phys. Rev. Lett. 94, 025002 (2005).
Correlation Measure Equivalence in Dynamic Causal Structures
Gyongyosi, Laszlo
2016-01-01
We prove an equivalence transformation between the correlation measure functions of the causally-unbiased quantum gravity space and the causally-biased standard space. The theory of quantum gravity fuses the dynamic (nonfixed) causal structure of general relativity and the quantum uncertainty of quantum mechanics. In a quantum gravity space, the events are causally nonseparable and all time bias vanishes, which makes it no possible to use the standard causally-biased entropy and the correlation measure functions. Since a corrected causally-unbiased entropy function leads to an undefined, obscure mathematical structure, in our approach the correction is made in the data representation of the causally-unbiased space. We prove that the standard causally-biased entropy function with a data correction can be used to identify correlations in dynamic causal structures. As a corollary, all mathematical properties of the causally-biased correlation measure functions are preserved in the causally-unbiased space. The eq...
Graphene antidot lattice transport measurements
DEFF Research Database (Denmark)
Mackenzie, David; Cagliani, Alberto; Gammelgaard, Lene
2017-01-01
for antidot arrays devices. Graphene devices were fabricated using 100 keV electron beam lithography (EBL) for nanopatterning as well as for defining electrical contacts. Patterns with hole diameter and neck widths of order 30 nm were produced, which is the highest reported pattern density of antidot lattices...... in graphene reported defined by EBL. Electrical measurements showed that devices with one and five rows exhibited field effect mobility of ∼100 cm2/Vs, while a larger number of rows, around 40, led to a significant reduction of field effect mobility (
Eddy Correlation Flux Measurement System (ECOR) Handbook
Energy Technology Data Exchange (ETDEWEB)
Cook, DR
2011-01-31
The eddy correlation (ECOR) flux measurement system provides in situ, half-hour measurements of the surface turbulent fluxes of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The fluxes are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the air temperature, the water vapor density, and the CO2 concentration.
Correlation-driven transport asymmetries through coupled spins in a tunnel junction
Muenks, Matthias; Jacobson, Peter; Ternes, Markus; Kern, Klaus
2017-01-01
Spin-spin correlations can be the driving force that favours certain ground states and are key in numerous models that describe the behaviour of strongly correlated materials. While the sum of collective correlations usually lead to a macroscopically measurable change in properties, a direct quantification of correlations in atomic scale systems is difficult. Here we determine the correlations between a strongly hybridized spin impurity on the tip of a scanning tunnelling microscope and its electron bath by varying the coupling to a second spin impurity weakly hybridized to the sample surface. Electronic transport through these coupled spins reveals an asymmetry in the differential conductance reminiscent of spin-polarized transport in a magnetic field. We show that at zero field, this asymmetry can be controlled by the coupling strength and is related to either ferromagnetic or antiferromagnetic spin-spin correlations in the tip.
Subnanosecond spectral diffusion measurement using photon correlation
Sallen, Gregory; Aichele, Thomas; André, Régis; Besombes, Lucien; Bougerol, Catherine; Richard, Maxime; Tatarenko, Serge; Kheng, Kuntheak; Poizat, Jean-Philippe; 10.1038/nphoton.2010.174
2012-01-01
Spectral diffusion is a result of random spectral jumps of a narrow line as a result of a fluctuating environment. It is an important issue in spectroscopy, because the observed spectral broadening prevents access to the intrinsic line properties. However, its characteristic parameters provide local information on the environment of a light emitter embedded in a solid matrix, or moving within a fluid, leading to numerous applications in physics and biology. We present a new experimental technique for measuring spectral diffusion based on photon correlations within a spectral line. Autocorrelation on half of the line and cross-correlation between the two halves give a quantitative value of the spectral diffusion time, with a resolution only limited by the correlation set-up. We have measured spectral diffusion of the photoluminescence of a single light emitter with a time resolution of 90 ps, exceeding by four orders of magnitude the best resolution reported to date.
γ - γ Angular Correlation Measurements With GRIFFIN
Maclean, Andrew; Griffin Collaboration
2015-10-01
When an excited nuclear state emits successive γ-rays causing a γ - γ cascade an anisotropy is found in the spatial distribution of γ2 with respect to γ1. Defining the direction of γ1 as the z-axis, the intermediate level, in general will have an uneven distribution of m-states. This causes an anisotropy in the angular correlation of the second γ-ray with respect to the first. These angular correlations are expressed by the W (θ) that depends on numerical coefficients described by the sequence of spin-parity values for the nuclear states involved, the multipolarities and mixing ratios. Angular correlations can be used for the assignment of spins and parities for the nuclear states, and thus provide a powerful means to elucidate the structure of nuclei far from stability through β - γ - γ coincidence measurements. In order to explore the sensitivity of the new 16 clover-detector GRIFFIN γ-ray spectrometer at TRIUMF-ISAC to such γ - γ angular correlations, and to optimize its performance for these measurements we have studied a well known γ - γ cascade from 60Co decay through both experimental measurements and Geant4 simulation. Results will be shown in this talk. Work supported by the Canada Foundation for Innovation, the Natural Sciences and Engineering Research Council of Canada and the National Research Council of Canada.
Measuring magnetic correlations in nanoparticle assemblies
DEFF Research Database (Denmark)
Beleggia, Marco; Frandsen, Cathrine
2014-01-01
We illustrate how to extract correlations between magnetic moments in assemblies of nanoparticles from, e.g., electron holography data providing the combined knowledge of particle size distribution, inter-particle distances, and magnitude and orientation of each magnetic moment within...... a nanoparticle superstructure, We show, based on simulated data, how to build a radial/angular pair distribution function f(r,θ) encoding the spatial and angular difference between every pair of magnetic moments. A scatter-plot of f(r,θ) reveals the degree of structural and magnetic order present, and hence...... provides a measure of the strength and range of magnetic correlations....
Energy Technology Data Exchange (ETDEWEB)
Reimus, Paul W [Los Alamos National Laboratory
2011-01-03
Transport parameter cross correlations are rarely considered in models used to predict radionuclide transport in natural systems. In this paper, it is shown that parameter cross correlations could have a significant impact on radionuclide transport predictions in saturated media. In fractured rock, the positive correlation between fracture apertures and groundwater residence times is shown to result in significantly less retardation due to matrix diffusion than is predicted without the correlation. The suppression of matrix diffusion is further amplified by a tendency toward larger apertures, smaller matrix diffusion coefficients, and less sorption capacity in rocks of lower matrix porosity. In a hypothetical example, strong cross correlations between these parameters result in a decrease in predicted radionuclide travel times of an order of magnitude or more relative to travel times calculated with uncorrelated parameters. In porous media, expected correlations between permeability, porosity, and sorption capacity also result in shorter predicted travel times than when the parameters are assumed to be uncorrelated. Individual parameter standard deviations can also have a significant influence on predicted radionuclide travel times, particularly when cross correlations are considered.
Constraining the Correlation Distance in Quantum Measurements
Schneider, Jean
2010-01-01
Standard Quantum Physics states that the outcome of measurements for some distant entangled subsystems are instantaneously statistically correlated, whatever their mutual distance. This correlation presents itself as if there were a correlation at a distance with infinite speed. It is expressed by the Bell Theorem. It has been experimentally verified over distances up to 18 km with a time resolution of a few picosecond, which can be translated into an apparent effective correlation speed larger than 10^7 c. The purpose of the present White Paper is to discuss the scientific interest and the feasibility to extend the correlation distance up to the Earth-Moon distance, i.e. 2 10^4 times larger than in present experiments. We are thus led to propose to install on the Moon a polarimter and a high performance photon detector with a high temporal resolution. Such an exploratory experiment would provide new tests of Quantum Physics and could perhaps discriminate between standard Quantum Physics and for instance the ...
Cosmological Measurements with General Relativistic Galaxy Correlations
Raccanelli, Alvise; Bertacca, Daniele; Doré, Olivier; Durrer, Ruth
2015-01-01
We investigate the cosmological dependence and the constraining power of large-scale galaxy correlations, including all redshift-distortions, wide-angle, lensing and gravitational potential effects on linear scales. We analyze the cosmological information present in the lensing convergence and in the gravitational potential terms describing the so-called "relativistic effects," and we find that, while smaller than the information contained in intrinsic galaxy clustering, it is not negligible. We investigate how neglecting them does bias cosmological measurements performed by future spectroscopic and photometric large-scale surveys such as SKA and Euclid. We perform a Fisher analysis using the CLASS code, modified to include scale-dependent galaxy bias and redshift-dependent magnification and evolution bias. Our results show that neglecting relativistic terms introduces an error in the forecasted precision in measuring cosmological parameters of the order of a few tens of percent, in particular when measuring ...
Eddy Correlation Flux Measurement System Handbook
Energy Technology Data Exchange (ETDEWEB)
Cook, D. R. [Argonne National Lab. (ANL), Argonne, IL (United States)
2016-01-01
The eddy correlation (ECOR) flux measurement system provides in situ, half-hour measurements of the surface turbulent fluxes of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The fluxes are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the air temperature, the water vapor density, and the CO2 concentration. The instruments used are: • a fast-response, three-dimensional (3D) wind sensor (sonic anemometer) to obtain the orthogonal wind components and the speed of sound (SOS) (used to derive the air temperature) • an open-path infrared gas analyzer (IRGA) to obtain the water vapor density and the CO2 concentration, and • an open-path infrared gas analyzer (IRGA) to obtain methane density and methane flux at one SGP EF and at the NSA CF. The ECOR systems are deployed at the locations where other methods for surface flux measurements (e.g., energy balance Bowen ratio [EBBR] systems) are difficult to employ, primarily at the north edge of a field of crops. A Surface Energy Balance System (SEBS) has been installed collocated with each deployed ECOR system in SGP, NSA, Tropical Western Pacific (TWP), ARM Mobile Facility 1 (AMF1), and ARM Mobile Facility 2 (AMF2). The surface energy balance system consists of upwelling and downwelling solar and infrared radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat fluxes with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes. The SEBS at one SGP and one NSA site also support upwelling and downwelling PAR measurements to qualify those two locations as Ameriflux sites.
Transport Experiments on 2D Correlated Electron Physics in Semiconductors
Energy Technology Data Exchange (ETDEWEB)
Tsui, Daniel
2014-03-24
This research project was designed to investigate experimentally the transport properties of the 2D electrons in Si and GaAs, two prototype semiconductors, in several new physical regimes that were previously inaccessible to experiments. The research focused on the strongly correlated electron physics in the dilute density limit, where the electron potential energy to kinetic energy ratio rs>>1, and on the fractional quantum Hall effect related physics in nuclear demagnetization refrigerator temperature range on samples with new levels of purity and controlled random disorder.
Sample selection and taste correlation in discrete choice transport modelling
DEFF Research Database (Denmark)
Mabit, Stefan Lindhard
2008-01-01
the question for a broader class of models. It is shown that the original result may be somewhat generalised. Another question investigated is whether mode choice operates as a self-selection mechanism in the estimation of the value of travel time. The results show that self-selection can at least partly...... explain counterintuitive results in value of travel time estimation. However, the results also point at the difficulty of finding suitable instruments for the selection mechanism. Taste heterogeneity is another important aspect of discrete choice modelling. Mixed logit models are designed to capture...... of taste correlation in willingness-to-pay estimation are presented. The first contribution addresses how to incorporate taste correlation in the estimation of the value of travel time for public transport. Given a limited dataset the approach taken is to use theory on the value of travel time as guidance...
Spatial correlations in bed load transport: evidence, importance, and modelling
Heyman, J; Mettra, F; Ancey, C
2016-01-01
This article examines the spatial {dynamics of bed load particles} in water. We focus particularly on the fluctuations of particle activity, which is defined as the number of moving particles per unit bed {length}. Based on a stochastic model recently proposed by \\citet{Ancey2013}, we derive the second moment of particle activity analytically; that is the spatial correlation functions of particle activity. From these expressions, we show that large moving particle clusters can develop spatially. Also, we provide evidence that fluctuations of particle activity are scale-dependent. Two characteristic lengths emerge from the model: a saturation length $\\ell_{sat}$ describing the length needed for a perturbation in particle activity to relax to the homogeneous solution, and a correlation length $\\ell_c$ describing the typical size of moving particle clusters. A dimensionless P\\'eclet number can also be defined according to the transport model. Three different experimental data sets are used to test the theoretica...
Microscopic theory on charge transports of a correlated multiorbital system
Arakawa, Naoya
2016-07-01
Current vertex correction (CVC), the backflowlike correction to the current, comes from conservation laws, and the CVC due to electron correlation contains information about many-body effects. However, it has been little understood how the CVC due to electron correlation affects the charge transports of a correlated multiorbital system. To improve this situation, I studied the in-plane resistivity ρa b and the Hall coefficient in the weak-field limit RH, in addition to the magnetic properties and the electronic structure, for a t2 g-orbital Hubbard model on a square lattice in a paramagnetic state away from or near an antiferromagnetic (AF) quantum-critical point (QCP) in the fluctuation-exchange (FLEX) approximation with the CVCs arising from the self-energy (Σ ), the Maki-Thompson (MT) irreducible four-point vertex function, and the main terms of the Aslamasov-Larkin (AL) one. Then, I found three main results about the CVCs. First, the main terms of the AL CVC do not qualitatively change the results obtained in the FLEX approximation with the Σ CVC and the MT CVC. Second, ρa b and RH near the AF QCP have a high-temperature region, governed mainly by the Σ CVC, and a low-temperature region, governed mainly by the Σ CVC and the MT CVC. Third, in case away from the AF QCP, the MT CVC leads to a considerable effect on only RH at low temperatures, although RH at high temperatures and ρa b at all temperatures considered are sufficiently described by including only the Σ CVC. Those findings reveal several aspects of many-body effects on the charge transports of a correlated multiorbital system. I also achieved the qualitative agreement with several experiments of Sr2RuO4 or Sr2Ru0.975Ti0.025O4 . Moreover, I showed several better points of this theory than other theories.
Evaluation of urban freight transport management measures
Directory of Open Access Journals (Sweden)
Daniel Kaszubowski
2012-09-01
Full Text Available Background: Problems with urban freight traffic in downtown areas emerge in parallel with the growth of motorization and changes in consumption patterns. Supply chains become more and more dependent on small and frequent deliveries. It is a problem common for most modern cities and one that requires tailor-made solutions which meet local requirements and can be extended, if necessary. Methods: An extensive literature review was conducted to obtain a comprehensive overview of existing urban freight related problems and possible solutions. The specificity of the problem required a broad approach including an analysis of many case studies from European cities and gathering the theoretical background. On this basis a general set of freight related measures was selected for evaluation. Because of the complexity of both the problem and its solutions an adequate method of evaluation was needed. The method had to be flexible and offer an understandable and manageable structure. The analytic network process (ANP was selected for this task. It is a multi-criteria decision making method used in complex decisions, which can measure tangible and intangible factors. The author's aim was to build a sufficiently detailed model that ensures reliable results and accomplishes the goals of the main actors and of sustainable city transport policy. Results and Conclusions: The analysis showed that given the current state of development of urban freight traffic in Gdansk, the situation can be rationalised with regulatory measures. Only well balanced and carefully implemented measures have the potential to rationalize urban freight transport without disturbing the city's economic growth. They have to be prepared in advance on the basis of a continuous analysis of the urban transport system. It is important to involve all actors in the development of more advanced measures in a bottom-up planning process. Otherwise, the risk is that overly complicated solutions without
Strongly Correlated Transport in the Falicov Kimball Model
Boyd, Greg; Freericks, Jim; Zlatic, Veljko
2013-03-01
Many materials like the cuprates, heavy fermions, and strongly correlated oxides, are non-Fermi liquid ``bad metals'', with linear or quasi-linear resistivity as a function of temperature. The low-energy excitations are quasiparticle-like near the Fermi surface, but their lifetimes are short, so they are not coherent or free-particle-like, as in conventional Fermi-liquids (whose quasi-particle lifetimes diverge at the Fermi energy). It turns out that this kind of behavior is ubiquitous in a wide range of different strongly correlated models, as long as the temperature is above the Fermi-liquid scale. To illustrate this, we investigate the strongly correlated transport in the Falicov-Kimball model using dynamical mean-field theory (DMFT) - which is exactly solvable in the limit of infinite coordination number. We show results for the resistivity as a function of temperature, the quasiparticle lifetime, and the spectral function. These results are quite similar to those recently found for the Hubbard model, illustrating that this high temperature behavior is seen in many different models of strong electron correlations.
Measures and applications of quantum correlations
Adesso, Gerardo; Bromley, Thomas R.; Cianciaruso, Marco
2016-11-01
Quantum information theory is built upon the realisation that quantum resources like coherence and entanglement can be exploited for novel or enhanced ways of transmitting and manipulating information, such as quantum cryptography, teleportation, and quantum computing. We now know that there is potentially much more than entanglement behind the power of quantum information processing. There exist more general forms of non-classical correlations, stemming from fundamental principles such as the necessary disturbance induced by a local measurement, or the persistence of quantum coherence in all possible local bases. These signatures can be identified and are resilient in almost all quantum states, and have been linked to the enhanced performance of certain quantum protocols over classical ones in noisy conditions. Their presence represents, among other things, one of the most essential manifestations of quantumness in cooperative systems, from the subatomic to the macroscopic domain. In this work we give an overview of the current quest for a proper understanding and characterisation of the frontier between classical and quantum correlations (QCs) in composite states. We focus on various approaches to define and quantify general QCs, based on different yet interlinked physical perspectives, and comment on the operational significance of the ensuing measures for quantum technology tasks such as information encoding, distribution, discrimination and metrology. We then provide a broader outlook of a few applications in which quantumness beyond entanglement looks fit to play a key role.
Transport through correlated systems with density functional theory
Kurth, S.; Stefanucci, G.
2017-10-01
We present recent advances in density functional theory (DFT) for applications in the field of quantum transport, with particular emphasis on transport through strongly correlated systems. We review the foundations of the popular Landauer–Büttiker(LB) + DFT approach. This formalism, when using approximations to the exchange-correlation (xc) potential with steps at integer occupation, correctly captures the Kondo plateau in the zero bias conductance at zero temperature but completely fails to capture the transition to the Coulomb blockade (CB) regime as the temperature increases. To overcome the limitations of LB + DFT, the quantum transport problem is treated from a time-dependent (TD) perspective using TDDFT, an exact framework to deal with nonequilibrium situations. The steady-state limit of TDDFT shows that in addition to an xc potential in the junction, there also exists an xc correction to the applied bias. Open shell molecules in the CB regime provide the most striking examples of the importance of the xc bias correction. Using the Anderson model as guidance we estimate these corrections in the limit of zero bias. For the general case we put forward a steady-state DFT which is based on one-to-one correspondence between the pair of basic variables, steady density on and steady current across the junction and the pair local potential on and bias across the junction. Like TDDFT, this framework also leads to both an xc potential in the junction and an xc correction to the bias. Unlike TDDFT, these potentials are independent of history. We highlight the universal features of both xc potential and xc bias corrections for junctions in the CB regime and provide an accurate parametrization for the Anderson model at arbitrary temperatures and interaction strengths, thus providing a unified DFT description for both Kondo and CB regimes and the transition between them.
Correlation measurements of fission-fragment properties
Oberstedt, S.; Belgya, T.; Billnert, R.; Borcea, R.; Cano-Ott, D.; Göök, A.; Hambsch, F.-J.; Karlsson, J.; Kis, Z.; Martinez, T.; Oberstedt, A.; Szentmiklosi, L.; Takác, K.
2010-10-01
For the development of future nuclear fission applications and for a responsible handling of nuclear waste the a-priori assessment of the fission-fragments' heat production and toxicity is a fundamental necessity. The success of an indispensable modelling of the fission process strongly depends on a good understanding of the particular mechanism of scission, the mass fragmentation and partition of excitation energy. Experimental observables are fission-fragment properties like mass- and energy-distributions, and the prompt neutron as well as γ-ray multiplicities and emission spectra. The latter quantities should preferably be known as a function of fragment mass and excitation energy. Those data are highly demanded as published by the OECD-NEA in its high priority data request list. With the construction of the double (v, E) spectrometer VERDI we aim at measuring pre- and post-neutron masses directly and simultaneously to avoid prompt neutron corrections. From the simultaneous measurement of pre- and post-neutron fission-fragment data the prompt neutron multiplicity may then be inferred fully correlated with fragment mass yield and total kinetic energy. Using an ultra-fast fission event trigger spectral prompt fission γ-ray measurements may be performed. For that purpose recently developed lanthanum-halide detectors, with excellent timing characteristics, were coupled to the VERDI spectrometer allowing for a very good discrimination of fission γ-rays and prompt neutrons due to their different time-of-flight.
Correlation measurements of fission-fragment properties
Directory of Open Access Journals (Sweden)
Oberstedt A.
2010-10-01
Full Text Available For the development of future nuclear fission applications and for a responsible handling of nuclear waste the a-priori assessment of the fission-fragments’ heat production and toxicity is a fundamental necessity. The success of an indispensable modelling of the fission process strongly depends on a good understanding of the particular mechanism of scission, the mass fragmentation and partition of excitation energy. Experimental observables are fission-fragment properties like mass- and energy-distributions, and the prompt neutron as well as γ-ray multiplicities and emission spectra. The latter quantities should preferably be known as a function of fragment mass and excitation energy. Those data are highly demanded as published by the OECD-NEA in its high priority data request list. With the construction of the double (v, E spectrometer VERDI we aim at measuring pre- and post-neutron masses directly and simultaneously to avoid prompt neutron corrections. From the simultaneous measurement of pre- and post-neutron fission-fragment data the prompt neutron multiplicity may then be inferred fully correlated with fragment mass yield and total kinetic energy. Using an ultra-fast fission event trigger spectral prompt fission γ-ray measurements may be performed. For that purpose recently developed lanthanum-halide detectors, with excellent timing characteristics, were coupled to the VERDI spectrometer allowing for a very good discrimination of fission γ-rays and prompt neutrons due to their different time-of-flight.
Measures and applications of quantum correlations
Adesso, Gerardo; Cianciaruso, Marco
2016-01-01
Quantum information theory is built upon the realisation that quantum resources like coherence and entanglement can be exploited for novel or enhanced ways of transmitting and manipulating information, such as quantum cryptography, teleportation, and quantum computing. We now know that there is potentially much more than entanglement behind the power of quantum information processing. There exist more general forms of non-classical correlations, stemming from fundamental principles such as the necessary disturbance induced by a local measurement, or the persistence of quantum coherence in all possible local bases. These signatures can be identified and are resilient in almost all quantum states, and have been linked to the enhanced performance of certain quantum protocols over classical ones in noisy conditions. Their presence represents, among other things, one of the most essential manifestations of quantumness in cooperative systems, from the subatomic to the macroscopic domain. In this work we give an ove...
Correlation and symmetry effects in transport through an artificial molecule
Energy Technology Data Exchange (ETDEWEB)
Ramirez, F. [Posgrado en Fisica de Materiales, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Ensenada, Baja California (Mexico); Cota, E. [Centro de Ciencias de la Materia Condensada-UNAM, Ensenada, Baja California (Mexico); Ulloa, S.E. [Department of Physics and Astronomy and Condensed Matter and Surface Sciences Program, Ohio University, Athens, Ohio 45701-2979 (United States)
1999-02-01
Spectral weights and current-voltage characteristics of an artificial diatomic molecule are calculated, considering cases where the dots connected in series are in general different. The spectral weights allow us to understand the effects of correlations, their connection with selection rules for transport, and the role of excited states in the experimental conductance spectra of these coupled double dot systems (DDS). An extended Hubbard Hamiltonian with varying interdot tunneling strength is used as a model, incorporating quantum confinement in the DDS, interdot tunneling as well as intra- and interdot Coulomb interactions. We find that interdot tunneling values determine to a great extent the resulting eigenstates and corresponding spectral weights. Details of the state correlations strongly suppress most of the possible conduction channels, giving rise to effective selection rules for conductance through the molecule. Most states are found to make insignificant contributions to the total current for finite biases. We find also that the symmetry of the structure is reflected in the I-V characteristics, and is in qualitative agreement with experiment. {copyright} {ital 1999} {ital The American Physical Society}
Measurement and correlates of physicians' lifelong learning.
Hojat, Mohammadreza; Veloski, J Jon; Gonnella, Joseph S
2009-08-01
To examine the psychometric properties and correlates of an instrument to measure physicians' orientation toward lifelong learning with attention to differences between full-time and academic clinicians. The authors mailed a survey in 2006 to a national sample of 5,349 alumni of Jefferson Medical College who graduated between 1975 and 2000; 3,195 (60%) responded. The respondents were classified as full-time clinicians (n = 1,127) and academic clinicians (n = 1,612). The other 456 respondents were involved in administration or research. The revised Jefferson Scale of Physician Lifelong Learning (JeffSPLL) was included in the survey. Factor analysis, regression analysis, and analysis of variance were used to examine the construct- and criterion-related validities of the scale. Factor analysis of the JeffSPLL items resulted in three factors designated as "learning beliefs and motivation," "attention to learning opportunities," and "skills in seeking information," which supported its construct validity. Alpha reliability coefficients were 0.85 and 0.86, and test-retest reliability coefficients were 0.72 and 0.77 for full-time clinicians and academic clinicians, respectively. For full-time clinicians and academic clinicians, scores on the JeffSPLL were significantly (P satisfaction, and commitment to lifelong learning, which supported the criterion-related validity of the scale. The findings indicate that the JeffSPLL is a psychometrically sound instrument that measures physicians' orientation toward lifelong learning among full-time clinicians and academic clinicians. The instrument can be used to monitor educational programs, assess educational outcomes, and examine group differences.
Transport measurement of Li doped monolayer graphene
Khademi, Ali; Sajadi, Ebrahim; Dosanjh, Pinder; Folk, Joshua; Stöhr, Alexander; Forti, Stiven; Starke, Ulrich
Lithium adatoms on monolayer graphene have been predicted to induce superconductivity with a critical temperature near 8 K, and recent experimental evidence by ARPES indicates a critical temperature nearly that high. Encouraged by these results, we investigated the effects of lithium deposited at cryogenic temperatures on the electronic transport properties of epitaxial and CVD monolayer graphene down to 3 K. The change of charge carrier density due to Li deposition was monitored both by the gate voltage shift of the Dirac point and by Hall measurements, in low and high doping regimes. In the high doping regime, a saturation density of 2×1013 cm-2 was observed independent of sample type, initial carrier density and deposition conditions. No signatures of superconductivity were observed down to 3 K.
Channel cross correlations in transport through complex media
Gehler, Stefan; Köber, Bernd; Celardo, Giuseppe Luca; Kuhl, Ulrich
2016-10-01
Measuring transmission between four antennas in microwave cavities, we investigate directly the channel cross correlations C of the cross sections σa b from antenna at r⃗a to antenna r⃗b. Specifically we look for the CΣ and CΛ, where the only difference is that CΛ has none of the four channels in common, whereas CΣ has exactly one channel in common. We find experimentally that these two channel cross correlations are antiphased as a function of the channel coupling strength, as predicted by theory. This anticorrelation is essential to obtain the correct values for the universal conductance fluctuations. To obtain good agreement between experiment and predictions from random matrix theory the effect of absorption has to be included.
Measuring and modelling correlations in multiplex networks
Nicosia, Vincenzo
2014-01-01
In many complex systems the interactions among the elementary components can be of qualitatively different nature. Such systems are therefore naturally described and represented in terms of multiplex or multi-layer networks, i.e. networks where each layer stands for a different type of interaction between the same set of nodes. There is today a growing interest in understanding when and why a description in terms of a multiplex network is necessary and more informative than a single-layer projection. Here, we contribute to this debate by presenting a comprehensive study of correlations in multiplex networks. Correlations in node properties, especially degree-degree correlations, have been thoroughly studied in single-layer networks. Here we extend this idea to investigate and characterize correlations between the different layers of a multiplex network. These correlations are intrinsically multiplex, and we first study them empirically by constructing and analyzing various multiplex networks from the real-wor...
Measurement and modeling of oil slick transport
Jones, Cathleen E.; Dagestad, Knut-Frode; Breivik, Åyvind; Holt, Benjamin; Röhrs, Johannes; Christensen, Kai Hâkon; Espeseth, Martine; Brekke, Camilla; Skrunes, Stine
2016-10-01
Transport characteristics of oil slicks are reported from a controlled release experiment conducted in the North Sea in June 2015, during which mineral oil emulsions of different volumetric oil fractions and a look-alike biogenic oil were released and allowed to develop naturally. The experiment used the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) to track slick location, size, and shape for ˜8 h following release. Wind conditions during the exercise were at the high end of the range considered suitable for radar-based slick detection, but the slicks were easily detectable in all images acquired by the low noise, L-band imaging radar. The measurements are used to constrain the entrainment length and representative droplet radii for oil elements in simulations generated using the OpenOil advanced oil drift model. Simultaneously released drifters provide near-surface current estimates for the single biogenic release and one emulsion release, and are used to test model sensitivity to upper ocean currents and mixing. Results of the modeling reveal a distinct difference between the transport of the biogenic oil and the mineral oil emulsion, in particular in the vertical direction, with faster and deeper entrainment of significantly smaller droplets of the biogenic oil. The difference in depth profiles for the two types of oils is substantial, with most of the biogenic oil residing below depths of 10 m, compared to the majority of the emulsion remaining above 10 m depth. This difference was key to fitting the observed evolution of the two different types of slicks.
Correlations between outcomes of random measurements
Tran, Minh Cong; Dakić, Borivoje; Laskowski, Wiesław; Paterek, Tomasz
2016-10-01
We recently showed that multipartite correlations between outcomes of random observables detect quantum entanglement in all pure and some mixed states. In this followup article we further develop this approach, derive a maximal amount of such correlations, and show that they are not monotonous under local operations and classical communication. Nevertheless, we demonstrate their usefulness in entanglement detection with a single random observable per party. Finally we study convex-roof extension of the correlations and provide a closed-form necessary and sufficient condition for entanglement in rank-2 mixed states and a witness in general.
Accurate measurement of curvilinear shapes by Virtual Image Correlation
Semin, B.; Auradou, H.; François, M. L. M.
2011-10-01
The proposed method allows the detection and the measurement, in the sense of metrology, of smooth elongated curvilinear shapes. Such measurements are required in many fields of physics, for example: mechanical engineering, biology or medicine (deflection of beams, fibers or filaments), fluid mechanics or chemistry (detection of fronts). Contrary to actual methods, the result is given in an analytical form of class C∞ (and not a finite set of locations or pixels) thus curvatures and slopes, often of great interest in science, are given with good confidence. The proposed Virtual Image Correlation (VIC) method uses a virtual beam, an image which consists in a lateral expansion of the curve with a bell-shaped gray level. This figure is deformed until it fits the best the physical image with a method issued from the Digital Image Correlation method in use in solid mechanics. The precision of the identification is studied in a benchmark and successfully compared to two state-of-the-art methods. Three practical examples are given: a bar bending under its own weight, a thin fiber transported by a flow within a fracture and a thermal front. The first allows a comparison with theoretical solution, the second shows the ability of the method to deal with complex shapes and crossings and the third deals with ill-defined image.
Meta-Analysis of Correlations Among Usability Measures
DEFF Research Database (Denmark)
Hornbæk, Kasper Anders Søren; Effie Lai Chong, Law
2007-01-01
are generally low: effectiveness measures (e.g., errors) and efficiency measures (e.g., time) has a correlation of .247 ± .059 (Pearson's product-moment correlation with 95% confidence interval), efficiency and satisfaction (e.g., preference) one of .196 ± .064, and effectiveness and satisfaction one of .164......Understanding the relation between usability measures seems crucial to deepen our conception of usability and to select the right measures for usability studies. We present a meta-analysis of correlations among usability measures calculated from the raw data of 73 studies. Correlations...... ± .062. Changes in task complexity do not influence these correlations, but use of more complex measures attenuates them. Standard questionnaires for measuring satisfaction appear more reliable than homegrown ones. Measures of users' perceptions of phenomena are generally not correlated with objective...
Filtering with perfectly correlated measurement noise.
Reasenberg, R.
1972-01-01
Examination of (radar) Doppler data which are formed by mi1ing the returning microwave signal with a replica of the transmitted signal, counting the cycles of the beat, and sampling the counter at evenly spaced intervals t sub i. It is shown that the amount of information which can be extracted from a set of data may be larger if the associated noise is perfectly correlated than if it is white, and that the use of the white noise assumption in the filter may result in the loss of some of this information.
Correlates of mode of transportation work among Norwegian parents
DEFF Research Database (Denmark)
Bjørkelund, Oline Anita; Dengerud, Hanna; Bere, Elling
Background: Cycling and brisk-walking to work represents an opportunity to incorporate sustainable transport related moderate- to- vigorous physical activity (MVPA) into daily routine among adults, and thus, may make an important contributing to health. Despite the fact that walking and cycling...... is an option for many commuters and also brings a number of benefits, a considerable proportion of commuters choose to use other means of transport when cycling and walking would be a highly appropriate transport mode. The object of this study was to assess the associations between modes of commuting...... and Telemark. Commuting behavior, socio- demographic determinants, personal and environmental factors were ascertained using questionnaire data from the Fruit and Vegetables Makes the Marks project (FVMM) and The Active Transportation in Norway project (ATN). Multivariate logistic regressions were applied...
d + Au hadron correlation measurements at PHENIX
Energy Technology Data Exchange (ETDEWEB)
Sickles, Anne M., E-mail: anne@bnl.gov
2014-06-15
In these proceedings, we discuss recent results from d + Au collisions in PHENIX ridge related measurements and their possible hydrodynamic origin. We present the v{sub 2} at midrapidity and measurements of the pseudorapidity dependence of the ridge, distinguishing between the d-going and Au-going directions. We investigate the possible geometrical origin by comparing v{sub 2} in d + Au to that in p + Pb, Au + Au and Pb + Pb collisions. Future plans to clarify the role of geometry in small collision systems at RHIC are discussed.
Correlating atomic structure and transport in suspended graphene nanoribbons.
Qi, Zhengqing John; Rodríguez-Manzo, Julio A; Botello-Méndez, Andrés R; Hong, Sung Ju; Stach, Eric A; Park, Yung Woo; Charlier, Jean-Christophe; Drndić, Marija; Johnson, A T Charlie
2014-08-13
Graphene nanoribbons (GNRs) are promising candidates for next generation integrated circuit (IC) components; this fact motivates exploration of the relationship between crystallographic structure and transport of graphene patterned at IC-relevant length scales (edges after current annealing, presenting a pathway for the controlled fabrication of semiconducting GNRs with known edge geometry. Finally, we report on simulations of quantum transport in GNRs that are in qualitative agreement with the observations.
Correlated measurement error hampers association network inference
Kaduk, M.; Hoefsloot, H.C.J.; Vis, D.J.; Reijmers, T.; van der Greef, J.; Smilde, A.K.; Hendriks, M.M.W.B.
2014-01-01
Modern chromatography-based metabolomics measurements generate large amounts of data in the form of abundances of metabolites. An increasingly popular way of representing and analyzing such data is by means of association networks. Ideally, such a network can be interpreted in terms of the underlyin
Reflexivity in Teams: A Measure and Correlates
M.C. Schippers (Michaéla); D.N. den Hartog (Deanne); P.L. Koopman (Paul)
2005-01-01
textabstractReflexivity -the extent to which teams reflect upon and modify their functioning- has been identified as a possible key factor in the effectiveness of work teams. The aim of the present study was to develop a questionnaire to measure (aspects of) reflexivity, with a focus on team reflect
Bin-bin correlation measurement by bunching-parameter method
Energy Technology Data Exchange (ETDEWEB)
Chekanov, S.V.; Kittel, W. [High Energy Physics Inst. Nijmegen, Univ. of Nijmegen/NIKHEF, Nijmegen (Netherlands); Kuvshinov, V.I. [Inst. of Physics, Academy of Sciences of Belarus, Minsk (Belgium)
1996-08-01
A new method for the experimental study of bin-bin correlations is proposed. It is shown that this method is able to reveal important additional information on bin-bin correlations, beyond that of factorial-correlator measurements. (author) 15 refs, 1 fig
Quantum discord and other measures of quantum correlation
Modi, Kavan; Cable, Hugo; Paterek, Tomasz; Vedral, Vlatko
2011-01-01
One of the best signatures of nonclassicality in a quantum system is the existence of correlations that have no classical counterpart. Different methods for quantifying the quantum and classical parts of the correlations are amongst the most actively-studied topics of quantum information theory in the past decade. Entanglement is the most prominent of these correlations, but in many cases unentangled states exhibit nonclassical behavior. Thus distinguishing quantum correlation other than entanglement provides a better division between the quantum and classical worlds, especially when considering mixed states. Here we review different notions of classical and quantum correlations quantified by quantum discord and other related measures. In the first half we review the mathematical properties of the measures of quantum correlation, relate them to each other, and discuss the classical-quantum division that is common among them. In the second half, we show that the measures quantum correlation identify and quanti...
Overview of mitigation policies and measures in transportation
Energy Technology Data Exchange (ETDEWEB)
Ernst, J. [IIEC-ASIA, Bangkok (Thailand)
1996-12-31
In this paper the author looks at the general question of what can be done in the transportation sector to address the problem of greenhouse gas emissions. Obviously, fewer vehicles is less emission. But on a global scale he reviews the population growth in major cities, the type of transport employed, the correlation of vehicle ownership and gross national product, as well as the costs, direct and indirect of letting more personal wealth drive one to personal vehicles as a way to transport oneself to work. The increased speed comes with many costs for the individual and for society. The development of mass transportation systems provides a number of benefits, in the form of urban development, less reliance on imported fuels, transport system health, general health and productivity of work force, and reduced costs to government to support transportation systems.
Unification of quantum and classical correlations and quantumness measures
Modi, Kavan
2011-01-01
We give a pedagogical introduction to quantum discord. We the discuss the problem of separation of total correlations in a given quantum state into entanglement, dissonance, and classical correlations using the concept of relative entropy as a distance measure of correlations. This allows us to put all correlations on an equal footing. Entanglement and dissonance, whose definition is introduced here, jointly belong to what is known as quantum discord. Our methods are completely applicable for multipartite systems of arbitrary dimensions. We finally show, using relative entropy, how different notions of quantum correlations are related to each other. This gives a single theory that incorporates all correlations, quantum, classical, etc.
van Milligen, B Ph; Garcia, L; Bruna, D Lopez; Carreras, B A; Xu, Y; Ochando, M; Hidalgo, C; Reynolds-Barredo, J M; Fraguas, A Lopez
2016-01-01
This work explores the relation between magnetic islands, long range temporal correlations and heat transport. A low order rational surface ($\\iota/2\\pi = 3/2$) was purposely scanned outward through an Electron Cyclotron Resonance Heated (ECRH) plasma in the TJ-II stellarator. Density turbulence and the poloidal flow velocity (or radial electric field) were characterized using a two channel Doppler Reflectometer. Simultaneously, the ECRH power was modulated to characterize heat transport, using measurements from a 12 channel Electron Cyclotron Emission diagnostic. A systematic variation of the poloidal velocity was found to be associated with the stationary $\\iota/2\\pi = 3/2$ magnetic island. Inside from the rational surface, the Hurst coefficient, quantifying the nature of long-range correlations, was found to be significantly enhanced. Simultaneously, heat transport was enhanced as well, establishing a clear link between density fluctuations and anomalous heat transport. The variation of the Hurst coefficie...
Correlating substituent parameter values to electron transport properties of molecules
Vedova-Brook, Natalie; Matsunaga, Nikita; Sohlberg, Karl
2004-03-01
There are a vast number of organic compounds that could be considered for use in molecular electronics. Because of this, the need for efficient and economical screening tools has emerged. We demonstrate that the substituent parameter values ( σ), commonly found in advanced organic chemistry textbooks, correlate strongly with features of the charge migration process, establishing them as useful indicators of electronic properties. Specifically, we report that ab initio derived electronic charge transfer values for 16 different substituted aromatic molecules for molecular junctions correlate to the σ values with a correlation coefficient squared ( R2) of 0.863.
Lynch, J. F.; Gross, T. F.; Sherwood, C. R.; Irish, J. D.; Brumley, B. H.
1997-04-01
During the 1988-1989 Sediment Transport Events on Shelves and Slopes (STRESS) experiment, a 1-MHz acoustic backscatter system (ABSS), deployed in 90 m of water off the California coast measured vertical profiles of suspended sediment concentration from 1.5 to (nominally) 26 meters above bottom (m.a.b.). An 8-week-long time series was obtained, showing major sediment transport events (storms) in late December and early January. Comparison of the acoustics measurements from 1.5 m.a.b. are made with optical backscatter system (OBS) concentration estimates lower in the boundary layer (0.25 m.a.b.). Correlations between ABSS and OBS concentration measurements and the boundary layer forcing functions (waves, currents, and their non-linear interaction) provided a variety of insights into the nature of the sediment transport of the STRESS site. Transport rates and integrated transport are seen to be dominated by the largest storm events.
Overview of recent azimuthal correlation measurements from ALICE
INSPIRE-00290856
2016-01-01
Azimuthal correlations are a powerful tool to probe the properties and the evolution of the collision system. In this proceedings, we will review the recent azimuthal correlation measurements from ALICE at the LHC. The comparison to other experimental measurements and various theoretical calculations will be discussed as well.
Eddy-correlation measurements above a maize crop using a simple cruciform hot-wire anemometer
Bottemanne, F.A.
1979-01-01
For measurements of the vertical transport of heat and momentum in the turbulent and slightly unstable boundary layer above a maize crop eddy-correlation techniques were applied. In addition to a vertical Gill-propellor anemometer and a Gill-propellor bivane, a cruciform hot-wire probe, mounted on a
Packwood, Daniel M; Oniwa, Kazuaki; Jin, Tienan; Asao, Naoki
2015-04-14
Organic crystals have unique charge transport properties that lie somewhere between delocalised band-type transport and localised hopping transport. In this paper, we use a stochastic tight-binding model to explore how dynamical disorder in organic crystals affects charge transport. By analysing the model in terms of Feynman diagrams (virtual processes), we expose the crucial role of correlated dynamical disorder to the charge transport dynamics in the model at short times in the order of a few hundred femtoseconds. Under correlated dynamical disorder, the random motions of molecules in the crystal allow for low-energy "bonding"-type interactions between neighboring molecular orbitals can persist over long periods of time. On the other hand, the dependence of charge transport on correlated dynamical disorder also tends to localize the charge, as correlated disorder cannot persist far in space. This concept of correlation may be the "missing link" for describing the intermediate regime between band transport and hopping transport that occurs in organic crystals.
The role of clustering effects in interpreting nondiffusive transport measurements in tokamaks
Graves, J. P.; Dendy, R. O.; Hopcraft, K. I.; Jakeman, E.
2002-05-01
Recent measurements in tokamak plasmas provide clear evidence for rapid nondiffusive transport and non-Gaussian fluctuations, and have been widely interpreted in terms of the sandpile and self-organized criticality (SOC) paradigms. Many of the statistical physics inferences that can be drawn from observations of, for example, avalanching transport remain to be explored. This paper will show that the statistical characterization of both experimentally observed and simulated avalanching transport phenomena reveals several points of contact with existing stochastic process models that have seldom been deployed in a plasma physics context. It will be shown that statistical physics techniques developed to model clustering of events can be used to characterize microscopic fluctuations in both local density and flux, as well as the global transport properties to which they give rise. This provides a fresh interpretation for some of the key aspects of observed critical gradient-driven transport phenomenology in tokamaks. In particular it provides new evidence for scale-free correlations in the fluctuations which drive the transport, and quantifies their distribution in terms of few-parameter non-Gaussian models. The correlation properties of density fluctuations can be interpreted in terms of random walk models, whereas flux fluctuations cannot: instead they can be described by the discrete negative binomial distribution, which again indicates clustering. Some of the spatio-temporal correlations considered emulate multichannel measurements in tokamaks, and it is shown how these can be used to characterize the transport of naturally arising coherent structures.
Scalings of field correlations and heat transport in turbulent convection.
Verma, Mahendra K; Mishra, Pankaj K; Pandey, Ambrish; Paul, Supriyo
2012-01-01
Using direct numerical simulations of Rayleigh-Bénard convection under free-slip boundary condition, we show that the normalized correlation function between the vertical velocity field and the temperature field, as well as the normalized viscous dissipation rate, scales as Ra-0.22 for moderately large Rayleigh number Ra. This scaling accounts for the Nusselt number Nu exponent of approximately 0.3, as observed in experiments. Numerical simulations also reveal that the aforementioned normalized correlation functions are constants for the convection simulation under periodic boundary conditions.
Shielding Performance Measurements of Spent Fuel Transportation Container
Directory of Open Access Journals (Sweden)
SUN Hong-chao
2015-11-01
Full Text Available The safety supervision of radioactive material transportation package has been further stressed and implemented. The shielding performance measurements of spent fuel transport container is the important content of supervision. However, some of the problems and difficulties reflected in practice need to be solved, such as the neutron dose rate on the surface of package is too difficult to measure exactly, the monitoring results are not always reliable, etc. The monitoring results using different spectrometers were compared and the simulation results of MCNP runs were considered. An improvement was provided to the shielding performance measurements technique and management of spent fuel transport.
Criterion distances and correlates of active transportation to school in Belgian older adolescents
Directory of Open Access Journals (Sweden)
De Bourdeaudhuij Ilse
2010-12-01
Full Text Available Abstract Background Since physical activity levels in older adolescents have the potential to be increased by stimulating active transportation to school (ATS, the most important correlates of ATS should be determined before developing interventions, especially in those adolescents for whom the distance to school is feasible for active commuting. The main aims of this study were to determine criterion distances for ATS in Belgian older adolescents, to examine multidimensional correlates of ATS in adolescents living within a feasible distance from school and to investigate the associations of ATS with total physical activity and with other physical activities besides ATS. Methods In total, 1281 older adolescents (17-18 years from 20 general secondary schools in East- and West-Flanders completed a questionnaire on physical activity behaviors, demographic factors and psychosocial and physical environmental correlates of physical activity. Distance to school was objectively measured using Routenet online route planner. Results In total, 58.4% of the participants commuted actively to school. The criterion distance for ATS could be set at eight kilometers for cycling and two kilometers for walking. For those adolescents living within a feasible distance for ATS, gender, smoking status, walkability of the neighborhood and social modeling were associated with transportation mode choice. ATS was positively associated with total physical activity, but not significantly related to min/week of other physical activities. Conclusions For older adolescents living within eight kilometers of their school, interventions taking into account the correlates found to be related to ATS could possibly be effective to enhance ATS and to increase total physical activity levels. In the context of the overall physical activity decline in adolescence, also interventions targeting physical activity behaviors of adolescents living further away from school might be needed, but
Directory of Open Access Journals (Sweden)
Dardo Tomasi
Full Text Available BACKGROUND: Dopamine and dopamine transporters (DAT, which regulate extracellular dopamine in the brain are implicated in the modulation of attention but their specific roles are not well understood. Here we hypothesized that dopamine modulates attention by facilitation of brain deactivation in the default mode network (DMN. Thus, higher striatal DAT levels, which would result in an enhanced clearance of dopamine and hence weaker dopamine signals, would be associated to lower deactivation in the DMN during an attention task. METHODOLOGY/PRINCIPAL FINDINGS: For this purpose we assessed the relationship between DAT in striatum (measured with positron emission tomography and [(11C]cocaine used as DAT radiotracer and brain activation and deactivation during a parametric visual attention task (measured with blood oxygenation level dependent functional magnetic resonance imaging in healthy controls. We show that DAT availability in caudate and putamen had a negative correlation with deactivation in ventral parietal regions of the DMN (precuneus, BA 7 and a positive correlation with deactivation in a small region in the ventral anterior cingulate gyrus (BA 24/32. With increasing attentional load, DAT in caudate showed a negative correlation with load-related deactivation increases in precuneus. CONCLUSIONS/SIGNIFICANCE: These findings provide evidence that dopamine transporters modulate neural activity in the DMN and anterior cingulate gyrus during visuospatial attention. Our findings suggest that dopamine modulates attention in part by regulating neuronal activity in posterior parietal cortex including precuneus (region involved in alertness and cingulate gyrus (region deactivated in proportion to emotional interference. These findings suggest that the beneficial effects of stimulant medications (increase dopamine by blocking DAT in inattention reflect in part their ability to facilitate the deactivation of the DMN.
Energy Technology Data Exchange (ETDEWEB)
Tomasi, D.; Fowler, J.; Tomasi, D.; Volkow, N.D.; Wang, R.L.; Telang, F.; Wang, Chang, L.; Ernst, T.; /Fowler, J.S.
2009-06-01
Dopamine and dopamine transporters (DAT, which regulate extracellular dopamine in the brain) are implicated in the modulation of attention but their specific roles are not well understood. Here we hypothesized that dopamine modulates attention by facilitation of brain deactivation in the default mode network (DMN). Thus, higher striatal DAT levels, which would result in an enhanced clearance of dopamine and hence weaker dopamine signals, would be associated to lower deactivation in the DMN during an attention task. For this purpose we assessed the relationship between DAT in striatum (measured with positron emission tomography and [{sup 11}C]cocaine used as DAT radiotracer) and brain activation and deactivation during a parametric visual attention task (measured with blood oxygenation level dependent functional magnetic resonance imaging) in healthy controls. We show that DAT availability in caudate and putamen had a negative correlation with deactivation in ventral parietal regions of the DMN (precuneus, BA 7) and a positive correlation with deactivation in a small region in the ventral anterior cingulate gyrus (BA 24/32). With increasing attentional load, DAT in caudate showed a negative correlation with load-related deactivation increases in precuneus. These findings provide evidence that dopamine transporters modulate neural activity in the DMN and anterior cingulate gyrus during visuospatial attention. Our findings suggest that dopamine modulates attention in part by regulating neuronal activity in posterior parietal cortex including precuneus (region involved in alertness) and cingulate gyrus (region deactivated in proportion to emotional interference). These findings suggest that the beneficial effects of stimulant medications (increase dopamine by blocking DAT) in inattention reflect in part their ability to facilitate the deactivation of the DMN.
Measuring spin correlations in optical lattices using superlattice potentials
DEFF Research Database (Denmark)
Pedersen, Kim Georg Lind; Andersen, Brian Møller; Bruun, Georg Morten;
2011-01-01
We suggest two experimental methods for probing both short- and long-range spin correlations of atoms in optical lattices using superlattice potentials. The first method involves an adiabatic doubling of the periodicity of the underlying lattice to probe neighboring singlet (triplet) correlations...... for fermions (bosons) by the occupation of the resulting vibrational ground state. The second method utilizes a time-dependent superlattice potential to generate spin-dependent transport by any number of prescribed lattice sites, and probes correlations by the resulting number of doubly occupied sites....... For experimentally relevant parameters, we demonstrate how both methods yield large signatures of antiferromagnetic correlations of strongly repulsive fermionic atoms in a single shot of the experiment. Lastly, we show how this method may also be applied to probe d-wave pairing, a possible ground-state candidate...
Relating quantum coherence and correlations with entropy-based measures.
Wang, Xiao-Li; Yue, Qiu-Ling; Yu, Chao-Hua; Gao, Fei; Qin, Su-Juan
2017-09-21
Quantum coherence and quantum correlations are important quantum resources for quantum computation and quantum information. In this paper, using entropy-based measures, we investigate the relationships between quantum correlated coherence, which is the coherence between subsystems, and two main kinds of quantum correlations as defined by quantum discord as well as quantum entanglement. In particular, we show that quantum discord and quantum entanglement can be well characterized by quantum correlated coherence. Moreover, we prove that the entanglement measure formulated by quantum correlated coherence is lower and upper bounded by the relative entropy of entanglement and the entanglement of formation, respectively, and equal to the relative entropy of entanglement for all the maximally correlated states.
Multifunctional optical correlator for picosecond ultraviolet laser pulse measurement.
Rakhman, Abdurahim; Wang, Yang; Garcia, Frances; Long, Cary; Huang, Chunning; Takeda, Yasuhiro; Liu, Yun
2014-11-01
A compact multifunctional optical correlator system for pulse width measurement of ultrashort ultraviolet (UV) pulses has been designed and experimentally demonstrated. Both autocorrelation and cross-correlation functions are measured using a single nonlinear crystal, and the switching between two measurements requires no adjustment of phase matching and detector. The system can measure UV pulse widths from sub-picoseconds to 100 ps, and it involves no auxiliary pulse in the measurement. The measurement results on a burst-mode picosecond UV laser show a high-quality performance on speed, accuracy, resolution, and dynamic range. The proposed correlator can be applied to measure any ultrashort UV pulses produced through sum-frequency generation or second-harmonic generation.
Correlation and Prediction of the Transport Properties of Ionic Liquids
Hossain, Mohammad Z.; Teja, Amyn S.
2016-01-01
A modified version of the rough hard sphere (RHS) scheme of Gaciño et al. has been used to correlate the viscosity and thermal conductivity of ILs. A total of 661 viscosity data at 0.1 MPa for 48 ILs, and 159 thermal conductivity data at 0.1 MPa for 26 ILs were correlated, with average absolute deviations between calculated and experimental values (AAD) of 1.15 % in the case of the viscosity and 2.32 % in the case of the thermal conductivity. In addition, a total of 453 viscosity data for 10 ILs and 95 thermal conductivity data for 9 ILs over a pressure range of 0.1 MPa to 35.6 MPa were correlated with AADs of 3.46 % in the case of the viscosity and 2.89 % in the case of the thermal conductivity. More importantly, the three parameters of the modified RHS scheme were found to exhibit regular trends with the molecular weight of ILs with a common anion. Finally, IL mixture viscosities were predicted within their experimental uncertainties using a simple mixing rule. Mixtures of water and ILs could also be accommodated within the RHS scheme, although errors were higher in this case.
Methods, measures and indicators for evaluating benefits of transportation research
CSIR Research Space (South Africa)
Du Plessis, Louw
2016-04-01
Full Text Available The purpose of this article is to provide updated information by identifying and discussing methods, measures and indicators for evaluating benefits appropriate for transportation-related research facilities/programmes. The information has been...
Intestinal cholesterol transport: Measuring cholesterol absorption and its reverse
Jakulj, L.
2013-01-01
Intestinal cholesterol transport might serve as an attractive future target for cardiovascular disease reduction, provided that underlying molecular mechanisms are more extensively elucidated, combined with improved techniques to measure changes in cholesterol fluxes and their possible anti-atherosc
Enhancing robustness of multiparty quantum correlations using weak measurement
Energy Technology Data Exchange (ETDEWEB)
Singh, Uttam, E-mail: uttamsingh@hri.res.in [Quantum Information and Computation Group, Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Mishra, Utkarsh, E-mail: utkarsh@hri.res.in [Quantum Information and Computation Group, Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Dhar, Himadri Shekhar, E-mail: dhar.himadri@gmail.com [School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067 (India)
2014-11-15
Multipartite quantum correlations are important resources for the development of quantum information and computation protocols. However, the resourcefulness of multipartite quantum correlations in practical settings is limited by its fragility under decoherence due to environmental interactions. Though there exist protocols to protect bipartite entanglement under decoherence, the implementation of such protocols for multipartite quantum correlations has not been sufficiently explored. Here, we study the effect of local amplitude damping channel on the generalized Greenberger–Horne–Zeilinger state, and use a protocol of optimal reversal quantum weak measurement to protect the multipartite quantum correlations. We observe that the weak measurement reversal protocol enhances the robustness of multipartite quantum correlations. Further it increases the critical damping value that corresponds to entanglement sudden death. To emphasize the efficacy of the technique in protection of multipartite quantum correlation, we investigate two proximately related quantum communication tasks, namely, quantum teleportation in a one sender, many receivers setting and multiparty quantum information splitting, through a local amplitude damping channel. We observe an increase in the average fidelity of both the quantum communication tasks under the weak measurement reversal protocol. The method may prove beneficial, for combating external interactions, in other quantum information tasks using multipartite resources. - Highlights: • Extension of weak measurement reversal scheme to protect multiparty quantum correlations. • Protection of multiparty quantum correlation under local amplitude damping noise. • Enhanced fidelity of quantum teleportation in one sender and many receivers setting. • Enhanced fidelity of quantum information splitting protocol.
Green maritime transportation: Market based measures
DEFF Research Database (Denmark)
Psaraftis, Harilaos N.
2016-01-01
The purpose of this chapter is to introduce the concept of Market Based Measures (MBMs) to reduce Green House Gas (GHG) emissions from ships, and review several distinct MBM proposals that have been under consideration by the International Maritime Organization (IMO). The chapter discusses...
A Review of the Correlates and Measurements of Career Indecision.
Sepich, Robert T.
1987-01-01
Reviews the literature to enhance practitioner understanding of career indecision. Attempts to answer two questions: (1) What are correlates of career indecision? and (2) How is it measured? Summarizes findings; suggests research areas. (CH)
Transport phenomena in correlated quantum liquids: Ultracold Fermi gases and F/N junctions
Li, Hua
Landau Fermi-liquid theory was first introduced by L. D. Landau in the effort of understanding the normal state of Fermi systems, where the application of the concept of elementary excitations to the Fermi systems has proved very fruitful in clarifying the physics of strongly correlated quantum systems at low temperatures. In this thesis, I use Landau Fermi-liquid theory to study the transport phenomena of two different correlated quantum liquids: the strongly interacting ultracold Fermi gases and the ferromagnet/normal-metal (F/N) junctions. The detailed work is presented in chapter II and chapter III of this thesis, respectively. Chapter I holds the introductory part and the background knowledge of this thesis. In chapter II, I study the transport properties of a Fermi gas with strong attractive interactions close to the unitary limit. In particular, I compute the transport lifetimes of the Fermi gas due to superfluid fluctuations above the BCS transition temperature Tc. To calculate the transport lifetimes I need the scattering amplitudes. The scattering amplitudes are dominated by the superfluid fluctuations at temperatures just above Tc. The normal scattering amplitudes are calculated from the Landau parameters. These Landau parameters are obtained from the local version of the induced interaction model for computing Landau parameters. I also calculate the leading order finite temperature corrections to the various transport lifetimes. A calculation of the spin diffusion coefficient is presented in comparison to the experimental findings. Upon choosing a proper value of F0a, I am able to present a good match between the theoretical result and the experimental measurement, which indicates the presence of the superfluid fluctuations near Tc. Calculations of the viscosity, the viscosity/entropy ratio and the thermal conductivity are also shown in support of the appearance of the superfluid fluctuations. In chapter III, I study the spin transport in the low
Cross-correlation Aided Transport in Stochastically Driven Accretion Flows
Nath, Sujit Kumar
2014-01-01
Origin of linear instability resulting in rotating sheared accretion flows has remained a controversial subject for long. While some explanations of such non-normal transient growth of disturbances in the Rayleigh stable limit were available for magnetized accretion flows, similar instabilities in absence of magnetic perturbations remained unexplained. This dichotomy was resolved in two recent publications by Chattopadhyay, {\\it et al} where it was shown that such instabilities, especially for non-magnetized accretion flows, were introduced through interaction of the inherent stochastic noise in the system (even a \\enquote{cold} accretion flow at 3000K is too \\enquote{hot} in the statistical parlance and is capable of inducing strong thermal modes) with the underlying Taylor-Couette flow profiles. Both studies, however, excluded the additional energy influx (or efflux) that could result from nonzero cross-correlation of a noise perturbing the velocity flow, say, with the noise that is driving the vorticity fl...
Gasificaton Transport: A Multiphase CFD Approach & Measurements
Energy Technology Data Exchange (ETDEWEB)
Dimitri Gidaspow; Veeraya Jiradilok; Mayank Kashyap; Benjapon Chalermsinsuwan
2009-02-14
The objective of this project was to develop predictive theories for the dispersion and mass transfer coefficients and to measure them in the turbulent fluidization regime, using existing facilities. A second objective was to use our multiphase CFD tools to suggest optimized gasifier designs consistent with aims of Future Gen. We have shown that the kinetic theory based CFD codes correctly compute: (1) Dispersion coefficients; and (2) Mass transfer coefficients. Hence, the kinetic theory based CFD codes can be used for fluidized bed reactor design without any such inputs. We have also suggested a new energy efficient method of gasifying coal and producing electricity using a molten carbonate fuel cell. The principal product of this new scheme is carbon dioxide which can be converted into useful products such as marble, as is done very slowly in nature. We believe this scheme is a lot better than the canceled FutureGen, since the carbon dioxide is safely sequestered.
Improved position measurement of nanoelectromechanical systems using cross correlations
Doiron, C. B.; Trauzettel, B.; Bruder, C.
2007-11-01
We consider position measurements using the cross-correlated output of two tunnel-junction position detectors. Using a fully quantum treatment, we calculate the equation of motion for the density matrix of the coupled detector detector mechanical-oscillator system. After discussing the presence of a bound on the peak-to-background ratio in a position measurement using a single detector, we show how one can use detector cross correlations to overcome this bound. We analyze two different possible experimental realizations of the cross-correlation measurement and show that in both cases, the maximum cross-correlated output is obtained when using twin detectors and applying equal bias to each tunnel junction. Furthermore, we show how the double-detector setup can be exploited to drastically reduce the added displacement noise of the oscillator.
Individual, Social, and Environmental Correlates of Active Transportation Patterns in French Women
Directory of Open Access Journals (Sweden)
Camille Perchoux
2017-01-01
Full Text Available The objectives were (1 to define physical activity (PA and sedentary behaviors (SB patterns in daily life contexts (work, leisure, and transportation in French working women from NutriNet-Santé web-cohort and (2 to identify pattern(s of active transportation and their individual, social, and environmental correlates. 23,432 participants completed two questionnaires to evaluate PA and SB in daily life contexts and individual representations of residential neighborhood and transportation modes. Hierarchical cluster analysis was performed which identified 6 distinct movement behavior patterns: (i active occupation, high sedentary leisure, (ii sedentary occupation, low leisure, (iii sedentary transportation, (iv sedentary occupation and leisure, (v active transportation, and (vi active leisure. Multinomial logistic regressions were performed to identify correlates of the “active transportation” cluster. The perceived environmental characteristics positively associated with “active transportation” included “high availability of destinations around home,” “presence of bicycle paths,” and “low traffic.” A “positive image of walking/cycling,” the “individual feeling of being physically active,” and a “high use of active transport modes by relatives/friends” were positively related to “active transportation,” identified as a unique pattern regarding individual and environmental correlates. Identification of PA and SB context-specific patterns will help to understand movement behaviors’ complexity and to design interventions to promote active transportation in specific subgroups.
Correlation between Land Use and Urban Public Transport: Case Study of Zagreb
Directory of Open Access Journals (Sweden)
Gordana Štefančić
2014-04-01
Full Text Available Investment in the transport system with the aim of fostering attractiveness and land use in urban structures is of great interest for planners and investors. Investment in urban public transport would especially contribute to revitalising distinct city areas. The samples of high population density and diversified area use are organised around accessible means of urban public transport.The main objective of this case study was to find an adequate model for the solution of urban public transport on the location Novi Jelkovec in Zagreb after the construction of a new urban settlement, with the aim to revitalise the peripheral parts of the city. The theoretical assumption on the influence of better organised transport on land use is hereby researched through the example of correction of timetables and reduction of travelling time between nodes on the line in the Novi Jelkovec settlement. In preparing this paper the following methods were used: analysis and synthesis, mathematical and statistical methods, methods of interviewing. The theory of correlation of land use and urban public transport is based on models that develop the “compact city”. The obtained research results confirm the significance of the correlation between urban land use and urban public transport. It can be concluded that this paper proves the influence of the correlation between land use and urban public transport on the concrete example of Novi Jelkovec. Its implementation could result in solving the concrete traffic problem and along with it a faster urbanisation of the new settlement.
Kleinmann, Matthias; Cabello, Adán
2016-10-07
We show that, for any n, there are m-outcome quantum correlations, with m>n, which are stronger than any nonsignaling correlation produced from selecting among n-outcome measurements. As a consequence, for any n, there are m-outcome quantum measurements that cannot be constructed by selecting locally from the set of n-outcome measurements. This is a property of the set of measurements in quantum theory that is not mandatory for general probabilistic theories. We also show that this prediction can be tested through high-precision Bell-type experiments and identify past experiments providing evidence that some of these strong correlations exist in nature. Finally, we provide a modified version of quantum theory restricted to having at most n-outcome quantum measurements.
Automated measurement of fast mitochondrial transport in neurons.
Miller, Kyle E; Liu, Xin-An; Puthanveettil, Sathyanarayanan V
2015-01-01
There is growing recognition that fast mitochondrial transport in neurons is disrupted in multiple neurological diseases and psychiatric disorders. However, a major constraint in identifying novel therapeutics based on mitochondrial transport is that the large-scale analysis of fast transport is time consuming. Here we describe methodologies for the automated analysis of fast mitochondrial transport from data acquired using a robotic microscope. We focused on addressing questions of measurement precision, speed, reliably, workflow ease, statistical processing, and presentation. We used optical flow and particle tracking algorithms, implemented in ImageJ, to measure mitochondrial movement in primary cultured cortical and hippocampal neurons. With it, we are able to generate complete descriptions of movement profiles in an automated fashion of hundreds of thousands of mitochondria with a processing time of approximately one hour. We describe the calibration of the parameters of the tracking algorithms and demonstrate that they are capable of measuring the fast transport of a single mitochondrion. We then show that the methods are capable of reliably measuring the inhibition of fast mitochondria transport induced by the disruption of microtubules with the drug nocodazole in both hippocampal and cortical neurons. This work lays the foundation for future large-scale screens designed to identify compounds that modulate mitochondrial motility.
Automated Measurement of Fast Mitochondrial Transport in Neurons
Directory of Open Access Journals (Sweden)
Kyle eMiller
2015-11-01
Full Text Available There is a growing recognition that fast mitochondrial transport in neurons is disrupted in multiple neurological diseases and psychiatric disorders. However a major constraint in identifying novel therapeutics based on mitochondrial transport is that the large-scale analysis of fast transport is time consuming. Here we describe methodologies for the automated analysis of fast mitochondrial transport from data acquired using a robotic microscope. We focused on addressing questions of measurement precision, speed, reliably, workflow ease, statistical processing and presentation. We used optical flow and particle tracking algorithms, implemented in ImageJ, to measure mitochondrial movement in primary cultured cortical and hippocampal neurons. With it, we are able to generate complete descriptions of movement profiles in an automated fashion of hundred of thousands of mitochondria with a processing time of approximately one hour. We describe the calibration of the parameters of the tracking algorithms and demonstrate that they are capable of measuring the fast transport of a single mitochondrion. We then show that the methods are capable of reliably measuring the inhibition of fast mitochondria transport induced by the disruption of microtubules with the drug nocodazole in both hippocampal and cortical neurons. This work lays the foundation for future large-scale screens designed to identify compounds that modulate mitochondrial motility.
Molecular transport in collagenous tissues measured by gel electrophoresis.
Hunckler, Michael D; Tilley, Jennifer M R; Roeder, Ryan K
2015-11-26
Molecular transport in tissues is important for drug delivery, nutrient supply, waste removal, cell signaling, and detecting tissue degeneration. Therefore, the objective of this study was to investigate gel electrophoresis as a simple method to measure molecular transport in collagenous tissues. The electrophoretic mobility of charged molecules in tissue samples was measured from relative differences in the velocity of a cationic dye passing through an agarose gel in the absence and presence of a tissue section embedded within the gel. Differences in electrophoretic mobility were measured for the transport of a molecule through different tissues and tissue anisotropy, or the transport of different sized molecules through the same tissue. Tissue samples included tendon and fibrocartilage from the proximal (tensile) and distal (compressive) regions of the bovine flexor tendon, respectively, and bovine articular cartilage. The measured electrophoretic mobility was greatest in the compressive region of the tendon (fibrocartilage), followed by the tensile region of tendon, and lowest in articular cartilage, reflecting differences in the composition and organization of the tissues. The anisotropy of tendon was measured by greater electrophoretic mobility parallel compared with perpendicular to the predominate collagen fiber orientation. Electrophoretic mobility also decreased with increased molecular size, as expected. Therefore, the results of this study suggest that gel electrophoresis may be a useful method to measure differences in molecular transport within various tissues, including the effects of tissue type, tissue anisotropy, and molecular size. Copyright © 2015 Elsevier Ltd. All rights reserved.
MEASURING CUSTOMER’S SATISFACTION ON BUS TRANSPORTATION
Directory of Open Access Journals (Sweden)
Rabiul Islam
2014-01-01
Full Text Available The purpose of the study is to examine the factors measuring customers’ satisfaction, especially the impact of service quality on customers’ satisfaction in public transportation industry in the university town of Sintok located in Kedah province of Malaysia. In order to assess the relationships between service quality and customer satisfaction survey http://www.scientificjournals.org/journals2007/articles/1003.htmdata were collected from 300 Bus commuters. All hypotheses were tested using Pearson correlations, controlling for the background variables of gender, marital status, ethnicity and education. The results indicate that hypotheses 1 through 5 were supported. Using multiple regressions as a basis for causal paths, a model was developed that examined the influence of all five dimensions of service quality on customers’ satisfaction. The model explained 26.9% of the variance which indicates that 26.9% of the changes in the dependent variable are explained by the independent variables. Altogether, independent variables explained 26.9% of the variations.
Measurements of the vertical correlation in turbulence under broken waves
DEFF Research Database (Denmark)
Pedersen, Claus; Deigaard, Rolf; Sutherland, James
1998-01-01
Turbulence measurements have been carried out in the surf zone of a wave flume. The purpose of the measurements is to determine the length scale of the turbulence generated by the wave breaking. The length scale of the turbulence is estimated on basis of the correlation between simultaneous measu...
Internalized Heterosexism: Measurement, Psychosocial Correlates, and Research Directions
Szymanski, Dawn M.; Kashubeck-West, Susan; Meyer, Jill
2008-01-01
This article provides an integrated critical review of the literature on internalized heterosexism/internalized homophobia (IH), its measurement, and its psychosocial correlates. It describes the psychometric properties of six published measures used to operationalize the construct of IH. It also critically reviews empirical studies on correlates…
Statistical measures of Planck scale signal correlations in interferometers
Energy Technology Data Exchange (ETDEWEB)
Hogan, Craig J. [Univ. of Chicago, Chicago, IL (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Kwon, Ohkyung [Univ. of Chicago, Chicago, IL (United States)
2015-06-22
A model-independent statistical framework is presented to interpret data from systems where the mean time derivative of positional cross correlation between world lines, a measure of spreading in a quantum geometrical wave function, is measured with a precision smaller than the Planck time. The framework provides a general way to constrain possible departures from perfect independence of classical world lines, associated with Planck scale bounds on positional information. A parametrized candidate set of possible correlation functions is shown to be consistent with the known causal structure of the classical geometry measured by an apparatus, and the holographic scaling of information suggested by gravity. Frequency-domain power spectra are derived that can be compared with interferometer data. As a result, simple projections of sensitivity for specific experimental set-ups suggests that measurements will directly yield constraints on a universal time derivative of the correlation function, and thereby confirm or rule out a class of Planck scale departures from classical geometry.
Local measurement of transport parameters for laser injected trace impurities
Energy Technology Data Exchange (ETDEWEB)
Giannella, R.; Lauro-Taroni, L. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking
1994-07-01
A procedure has been developed that determines local measurements of transport parameters`s profiles for injected impurities. The measured profiles extend from the plasma centre up to a certain radial position (usually {rho} = 0.6-0.7). In the outer region of the plasma the procedure supplies ``most suitable extensions`` up to the plasma edge of the measured transport profiles. The procedure intrinsically assures consistency and excellent agreement between the simulated and experimental data of local broad band soft X-ray emissivity and intensities of individual emission lines from different ion states of the injected impurities. 4 refs., 3 figs.
Mascaro, Aaron; Wang, Zi; Hovington, Pierre; Miyahara, Yoichi; Paolella, Andrea; Gariepy, Vincent; Feng, Zimin; Enright, Tyler; Aiken, Connor; Zaghib, Karim; Bevan, Kirk H; Grutter, Peter
2017-07-12
One of the main challenges in improving fast charging lithium-ion batteries is the development of suitable active materials for cathodes and anodes. Many materials suffer from unacceptable structural changes under high currents and/or low intrinsic conductivities. Experimental measurements are required to optimize these properties, but few techniques are able to spatially resolve ionic transport properties at small length scales. Here we demonstrate an atomic force microscope (AFM)-based technique to measure local ionic transport on LiFePO4 to correlate with the structural and compositional analysis of the same region. By comparing the measured values with density functional theory (DFT) calculations, we demonstrate that Coulomb interactions between ions give rise to a collective activation energy for ionic transport that is dominated by large phase boundary hopping barriers. We successfully measure both the collective activation energy and the smaller single-ion bulk hopping barrier and obtain excellent agreement with values obtained from our DFT calculations.
Gamma-Gamma Angular Correlation Measurements With GRIFFIN
Maclean, Andrew; Griffin Collaboration
2016-09-01
The goal of this work was to explore the sensitivity of the Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei (GRIFFIN) 16 clover-detector γ-ray spectrometer at TRIUMF-ISAC to such γ - γ angular correlations. The methodology was established using both experimental measurements and Geant4 simulations that were used to create angular correlation templates for the GRIFFIN geometry. Direct comparisons were made between experimental data sets and the simulated angular correlation templates. A first in-beam test of the γ - γ angular correlation measurements with GRIFFIN was performed with a radioactive beam of 66Ga. Mixing ratios of δ = - 2 . 1(2) and δ = - 0 . 08(3) were measured for the 2+ ->2+ ->0+ 833-1039 keV and 1+ ->2+ ->0+ 2752-1039 keV cascades in the daughter nucleus 66Zn. These results are in good agreement with pervious literature values and the mixing ratio for the 833-1039 keV cascade has a higher precision. Also, the sensitivity to the 1333-1039 keV cascade, with its pronounced 0+ ->2+ ->0+ angular correlation, was measured.A test measurement of the superallowed Fermi β emitter 62Ga will also be discussed. Canada Foundation of Innovation, Natural Sciences and Engineering Research Council of Canada, National Research Council of Canada and Canadian Research Chairs Program.
Measurements of Bose-Einstein correlations with the ATLAS detector
Sykora, Ivan; The ATLAS collaboration
2015-01-01
The Bose-Einstein correlations provide a unique opportunity for detailed understanding of space-time characteristics of the hadronization region, for determining the size and shape of the source from which particles are emitted and for interpreting quark confinement effects. The correlations lead to enhancement in production of identical bosons that are close in phase space. The ATLAS collaboration has performed a measurement of Bose-Einstein correlations of pairs of charged particles with transverse momentum greater than 100 MeV in p-p collisions at 900 GeV and 7 TeV. Bose-Einstein correlation parameters are investigated up to very high charged-particle multiplicities. The dependence of the Bose-Einstein correlation parameters on the average transverse momentum per pair is also investigated.
First Measurements of Pion Correlations by the PHENIX Experiment
Energy Technology Data Exchange (ETDEWEB)
Johnson, S C
2001-04-11
First identical-pion correlations measured at RHIC energies by PHENIX are presented. Two analyses with separate detectors, systematics, and statistics provide consistent results. The resulting HBT radii are moderately larger than those measured at lower energies. The k{sub t} dependence of the Bertsch-Pratt HBT radii is also similar to previous measures and is consistent with the conjecture of an expanding source.
Application of Laser Correlation Spectroscopy for Measuring Virus Size.
Nikiforov, V N; Vinogradov, S E; Ivanov, A V; Efremova, E V; Kalnina, L B; Bychenko, A B; Tentsov, Yu Yu; Manykin, A A
2016-05-01
Dynamic light scattering method or laser correlation spectroscopy was applied to evaluation of the size of viruses. We measured correlation functions of the light scattered by human immunodeficiency viruses (HIV) and hepatitis A viruses (HAV) and found that size of HIV-1 (subtype A and B) and HAV virions were 104 nm and 28 nm, respectively. Comparison of these findings with electron microscopy data for fixed samples of the same viruses showed good agreement of the results.
Measurement of pd , pt , and dd correlation functions
Energy Technology Data Exchange (ETDEWEB)
Vlasov, A.V.; Degtyarenko, P.V.; Doroshkevich, E.A.; Kosov, M.V.; Leksin, G.A.; Stavinskii, A.V.; Khasanov, F.M.; Shvartsman, B.B. (Institute of Theoretical and Experimental Physics, State Commission on Use of Atomic Energy (SU))
1989-09-01
Binary correlation functions have been measured for cumulative baryons emitted from nuclei of C, Ti, and Pb bombarded by 7.5-GeV/{ital c} protons. Secondary particles (protons, deuterons, and tritium nuclei) were detected at polar angles close to 90{degree}. It was found that for a fixed value of the product of the momenta of two particles the correlation function does not depend on what kind of particles make up the pair. The data are consistent with the idea that the sizes of the sources determined from correlations of different particles are the same.
Compressed Sensing with Linear Correlation Between Signal and Measurement Noise
DEFF Research Database (Denmark)
Arildsen, Thomas; Larsen, Torben
2014-01-01
Existing convex relaxation-based approaches to reconstruction in compressed sensing assume that noise in the measurements is independent of the signal of interest. We consider the case of noise being linearly correlated with the signal and introduce a simple technique for improving compressed...... sensing reconstruction from such measurements. The technique is based on a linear model of the correlation of additive noise with the signal. The modification of the reconstruction algorithm based on this model is very simple and has negligible additional computational cost compared to standard...... reconstruction algorithms, but is not known in existing literature. The proposed technique reduces reconstruction error considerably in the case of linearly correlated measurements and noise. Numerical experiments confirm the efficacy of the technique. The technique is demonstrated with application to low...
Sawai, Akiho; Ito, Yasuhiko; Mizuno, Masashi; Suzuki, Yasuhiro; Toda, Susumu; Ito, Isao; Hattori, Ryohei; Matsukawa, Yoshihisa; Gotoh, Momokazu; Takei, Yoshifumi; Yuzawa, Yukio; Matsuo, Seiichi
2011-07-01
High baseline peritoneal solute transport rate is reportedly associated with reduced patient and technique survival in continuous peritoneal dialysis (PD) patients. However, the determinants of baseline peritoneal solute transport rate remain uncertain. The aim of this study was to investigate the relationship between peritoneal local inflammation, angiogenesis and systemic inflammation and baseline peritoneal permeability. Peritoneal biopsy specimens from 42 pre-dialysis uraemic patients and 11 control individuals were investigated. Immunohistochemistry for CD68-positive macrophages, chymase- and tryptase-positive mast cells, interleukin-6 (IL-6)-positive cells, CD3-positive T cells, CD20-positive B cells, neutrophils and CD31- and pathologische anatomie Leiden-endothelium (PAL-E)-positive blood vessels in the peritoneum was performed. Baseline dialysate-to-plasma ratio for creatinine (D/P Cr) was determined within 6 months of PD induction. Clinical and laboratory parameters were measured at the time of peritoneal biopsy. Factors associated with peritoneal permeability were assessed by multiple linear regression analysis. Pre-dialysis uraemic peritoneum showed infiltration by CD68-positive macrophages, and mast cells, as compared with controls. Baseline D/P Cr was correlated with density of CD68-positive macrophages (P permeability was not correlated with infiltration by mast cells, B cells, T cells, neutrophils, serum C-reactive protein or other clinical factors. On multiple linear regression analysis, the number of CD68-positive macrophages in peritoneum was an independent predictor for baseline peritoneal permeability (P = 0.009). Peritoneal macrophage infiltration is predominant in uraemic patients and is an important factor in predicting baseline peritoneal permeability.
Influence of Multiple Scattering on Two-Pion Correlation Measurements
Institute of Scientific and Technical Information of China (English)
TANG Gui-Xin; ZHANG Wei-Ning; LIU Yi-Ming; HUO Lei; ZHANG Jing-Bo
2004-01-01
@@ Using the relativistic quantum molecular dynamics model, we study the influence of multiple scattering on the result of two-pion correlation measurements. The scales of pion spatial distribution are larger at thermal freezeout than at chemical freeze-out. By varying the value of the parameter of cross section from 0 to 90mb, we find that the sizes of pion source measured by two-particle correlation functions are almost independent of the parameter of cross section. However, λ parameters are sensitive to the parameter of cross section.
Entanglement Measures for Single- and Multi-Reference Correlation Effects
Boguslawski, Katharina; Legeza, Örs; Reiher, Markus
2012-01-01
Electron correlation effects are essential for an accurate ab initio description of molecules. A quantitative a priori knowledge of the single- or multi-reference nature of electronic structures as well as of the dominant contributions to the correlation energy can facilitate the decision regarding the optimum quantum chemical method of choice. We propose concepts from quantum information theory as orbital entanglement measures that allow us to evaluate the single- and multi-reference character of any molecular structure in a given orbital basis set. By studying these measures we can detect possible artifacts of small active spaces.
McClure, Mark W
2016-01-01
Bed load transport is the movement of particles along the top of a bed through rolling, saltation, and suspension created by turbulent lift above the bed surface. In recent years, there has been a resurgence of interest in the idea that bed load transport is significant for proppant transport during hydraulic fracturing. However, scaling arguments suggest that bed load transport is only dominant in the laboratory and is negligible at the field scale. I review laboratory experiments that have been used to develop concepts of bed load transport in hydraulic fracturing. I also review the scaling arguments and laboratory results that have been used to argue that viscous drag, not bed load transport, is dominant at the field scale. I compare literature correlations for fluvial sediment transport and for pipeline slurry transport with published laboratory data on proppant transport in slot flow. The comparisons indicate that fluvial transport correlations are suitable for predicting the rate of sediment erosion due...
In situ electrical transport measurement of superconductive ultrathin films
Institute of Scientific and Technical Information of China (English)
刘灿华; 贾金锋
2015-01-01
The discovery of an extraordinarily superconductive large energy gap in SrTiO3 supported single-layer FeSe films has recently initiated a great deal of research interests in surface-enhanced superconductivity and superconductive ultrathin films fabricated on crystal surfaces. On account of the instability of ultra-thin films in air, it is desirable to perform elec-trical transport measurement in ultra-high vaccum (UHV). Here we review the experimental techniques of in situ electrical transport measurement and their applications on superconductive ultrathin films.
Measurement of particle transport coefficients on Alcator C-Mod
Energy Technology Data Exchange (ETDEWEB)
Luke, T.C.T.
1994-10-01
The goal of this thesis was to study the behavior of the plasma transport during the divertor detachment in order to explain the central electron density rise. The measurement of particle transport coefficients requires sophisticated diagnostic tools. A two color interferometer system was developed and installed on Alcator C-Mod to measure the electron density with high spatial ({approx} 2 cm) and high temporal ({le} 1.0 ms) resolution. The system consists of 10 CO{sub 2} (10.6 {mu}m) and 4 HeNe (.6328 {mu}m) chords that are used to measure the line integrated density to within 0.08 CO{sub 2} degrees or 2.3 {times} 10{sup 16}m{sup {minus}2} theoretically. Using the two color interferometer, a series of gas puffing experiments were conducted. The density was varied above and below the threshold density for detachment at a constant magnetic field and plasma current. Using a gas modulation technique, the particle diffusion, D, and the convective velocity, V, were determined. Profiles were inverted using a SVD inversion and the transport coefficients were extracted with a time regression analysis and a transport simulation analysis. Results from each analysis were in good agreement. Measured profiles of the coefficients increased with the radius and the values were consistent with measurements from other experiments. The values exceeded neoclassical predictions by a factor of 10. The profiles also exhibited an inverse dependence with plasma density. The scaling of both attached and detached plasmas agreed well with this inverse scaling. This result and the lack of change in the energy and impurity transport indicate that there was no change in the underlying transport processes after detachment.
Accuracy of two points correlation length measurement and its applications in H-1NF heliac
Kim, Jaewook; Michael, C. A.; Nam, Y. U.; Lampert, M.; Ghim, Y. C.
2016-10-01
Anomalous transport observed in fusion-grade plasmas is widely accepted to be correlated with spatial and temporal correlation characteristics of the turbulent eddies. While temporal and 2D spatial (radial and poloidal) correlation characteristics have been studied in detail, the lack of such information in the parallel direction, with respect to the background magnetic field, of hot core plasmas precludes us from full understanding and controlling plasma turbulence. KSTAR is equipped with a couple of 2D diagnostic systems measuring ion-scale density fluctuations, namely the BES and MIR systems, at two different toroidal locations. These systems provide a possibility to measure a parallel correlation length. As it is necessary to identify how reliably one can measure correlation length with only two spatial positions, there has been such a study [Jaewook Kim et al., Nucl. Fusion accepted] recently. Based on this recent study, we experimentally obtained 3D correlation functions from H-1NF heliac using the data from a set of Langmuir probes. One probe is spatially fixed, while the second one is scanned radially and poloidally at a different toroidal location. H1-NF heliac plasmas are highly reproducible, therefore we construct the 3D correlation functions with multi-discharges.
A four-probe thermal transport measurement method for nanostructures.
Kim, Jaehyun; Ou, Eric; Sellan, Daniel P; Shi, Li
2015-04-01
Several experimental techniques reported in recent years have enabled the measurement of thermal transport properties of nanostructures. However, eliminating the contact thermal resistance error from the measurement results has remained a critical challenge. Here, we report a different four-probe measurement method that can separately obtain both the intrinsic thermal conductance and the contact thermal resistance of individual nanostructures. The measurement device consists of four microfabricated, suspended metal lines that act as resistive heaters and thermometers, across which the nanostructure sample is assembled. The method takes advantage of the variation in the heat flow along the suspended nanostructure and across its contacts to the four suspended heater and thermometer lines, and uses sixteen sets of temperature and heat flow measurements to obtain nine of the thermal resistances in the measurement device and the nanostructure sample, including the intrinsic thermal resistance and the two contact thermal resistances to the middle suspended segment of the nanostructure. Two single crystalline Si nanowires with different cross sections are measured in this work to demonstrate the effectiveness of the method. This four-probe thermal transport measurement method can lead to future discoveries of unique size-dependent thermal transport phenomena in nanostructures and low-dimensional materials, in addition to providing reliable experimental data for calibrating theoretical models.
A four-probe thermal transport measurement method for nanostructures
Energy Technology Data Exchange (ETDEWEB)
Kim, Jaehyun; Ou, Eric; Sellan, Daniel P.; Shi, Li, E-mail: lishi@mail.utexas.edu [Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States)
2015-04-15
Several experimental techniques reported in recent years have enabled the measurement of thermal transport properties of nanostructures. However, eliminating the contact thermal resistance error from the measurement results has remained a critical challenge. Here, we report a different four-probe measurement method that can separately obtain both the intrinsic thermal conductance and the contact thermal resistance of individual nanostructures. The measurement device consists of four microfabricated, suspended metal lines that act as resistive heaters and thermometers, across which the nanostructure sample is assembled. The method takes advantage of the variation in the heat flow along the suspended nanostructure and across its contacts to the four suspended heater and thermometer lines, and uses sixteen sets of temperature and heat flow measurements to obtain nine of the thermal resistances in the measurement device and the nanostructure sample, including the intrinsic thermal resistance and the two contact thermal resistances to the middle suspended segment of the nanostructure. Two single crystalline Si nanowires with different cross sections are measured in this work to demonstrate the effectiveness of the method. This four-probe thermal transport measurement method can lead to future discoveries of unique size-dependent thermal transport phenomena in nanostructures and low-dimensional materials, in addition to providing reliable experimental data for calibrating theoretical models.
Measurement-induced disturbances and nonclassical correlations of Gaussian states
Mišta, Ladislav; Tatham, Richard; Girolami, Davide; Korolkova, Natalia; Adesso, Gerardo
2010-01-01
We study quantum correlations beyond entanglement in two--mode Gaussian states of continuous variable systems, by means of the measurement-induced disturbance (MID) and its ameliorated version (AMID). In analogy with the recent studies of the Gaussian quantum discord, we define a Gaussian AMID by constraining the optimization to all bi-local Gaussian positive operator valued measurements. We solve the optimization explicitly for relevant families of states, including squeezed thermal states. Remarkably, we find that there is a finite subset of two--mode Gaussian states, comprising pure states, where non-Gaussian measurements such as photon counting are globally optimal for the AMID and realize a strictly smaller state disturbance compared to the best Gaussian measurements. However, for the majority of two--mode Gaussian states the unoptimized MID provides a loose overestimation of the actual content of quantum correlations, as evidenced by its comparison with Gaussian discord. This feature displays strong sim...
Malfunction diagnosis of sensors based on correlation of measurements
Lu, Wei; Teng, Jun; Wen, Runfa; Zhu, Jiayi; Li, Chao
2017-02-01
Structural health monitoring (SHM) is a type of on-site characterization of a real-world full-scale structure that is subjected to the real-world load cases. The fundamental element of SHM is the structural response measurements by sensors, the reliability of which is significant for safety assessment and other SHM applications. The paper proposed a method to diagnosis the fault in sensors using the correlation of measurements. The correlation of the variations of the measurements is examined using the sliding time windows, which is the principle to determine the fault in the sensors. The strain measurements from the SHM system of a real world structure, Shenzhen Bay Stadium, are performed to simulate the faults in sensors and to verify the effectiveness of the proposed method.
Sub-Rayleigh limit imaging via intensity correlation measurements
Institute of Scientific and Technical Information of China (English)
姚旭日; 李龙珍; 刘雪峰; 俞文凯; 翟光杰
2015-01-01
We demonstrate sub-Rayleigh limit imaging of an object via intensity correlation measurements. The image com-pletely unaffected by the disturbance of diffraction-limit is achieved under the condition that the imaging system has an appropriate field of view. The resolution of this sub-Rayleigh limit imaging system is only tied to the lateral resolution of the illumination light.
Purification and correlated measurements of bipartite mixed states
Bouda, J; Bouda, Jan; Buzek, Vladimir
2001-01-01
We prove that all purifications of a non-factorable state (i.e., the state which cannot be expressed in a form $\\rho_{AB}=\\rho_A\\otimes\\rho_B$) are entangled. We also show that for any bipartite state there exists a pair of measurements which are correlated on this state if and only if the state is non-factorable.
Positive-operator-valued measure optimization of classical correlations
Hamieh, S; Kobes, R; Zaraket, H
2004-01-01
We study the problem of optimization over positive-operator-valued measures to extract classical correlation in a bipartite quantum system. The proposed method is applied to binary states only. Moreover, to illustrate this method, an explicit example is studied in detail.
Rapid Measurement of Spectral Characteristics by Correlation Matching Method
Kim, Chol-Sun; Im, Song-Jin
2015-01-01
In this paper, we have established the couple system of a spectroscope, CCD and computer and proposed a method of the rapid measurement on spectral characteristics such as central wavelengths, relative intensities, sensitivity lines and the wavelength range and image pixel of the spectral images of a material by using the correlation matching method for the image discernment of digital spectra.
Khirevich, Siarhei; Höltzel, Alexandra; Daneyko, Anton; Seidel-Morgenstern, Andreas; Tallarek, Ulrich
2011-09-16
The mass transport properties of bulk random sphere packings depend primarily on the bed (external) porosity ε, but also on the packing microstructure. We investigate the influence of the packing microstructure on the diffusive tortuosity τ=D(m)/D(eff), which relates the bulk diffusion coefficient (D(m)) to the effective (asymptotic) diffusion coefficient in a porous medium (D(eff)), by numerical simulations of diffusion in a set of computer-generated, monodisperse, hard-sphere packings. Variation of packing generation algorithm and protocol yielded four Jodrey-Tory and two Monte Carlo packing types with systematically varied degrees of microstructural heterogeneity in the range between the random-close and the random-loose packing limit (ε=0.366-0.46). The distinctive tortuosity-porosity scaling of the packing types is influenced by the extent to which the structural environment of individual pores varies in a packing, and to quantify this influence we propose a measure based on Delaunay tessellation. We demonstrate that the ratio of the minimum to the maximum void face area of a Delaunay tetrahedron around a pore between four adjacent spheres, (A(min)/A(max))(D), is a measure for the structural heterogeneity in the direct environment of this pore, and that the standard deviation σ of the (A(min)/A(max))(D)-distribution considering all pores in a packing mimics the tortuosity-porosity scaling of the generated packing types. Thus, σ(A(min)/A(max))(D) provides a structure-transport correlation for diffusion in bulk, monodisperse, random sphere packings. Copyright © 2011 Elsevier B.V. All rights reserved.
Tang, Man; He, Tao; Meng, Qing-yan; Broussard, John Isaac; Yao, Lan; Diao, Yao; Sang, Xiu-bo; Liu, Qing-peng; Liao, Ying-jun; Li, Yuge; Zhao, Shulei
2014-11-01
Mouse strain differences in immobility and in sensitivity to antidepressants have been observed in the forced swimming test (FST) and the tail suspension test (TST). However, the neurotransmitter systems and neural substrates that contribute to these differences remain unknown. To investigate the role of the hippocampal serotonin transporter (5-HTT), we measured baseline immobility and the immobility responses to fluoxetine (FLX) in the FST and the TST in male CD-1, C57BL/6, DBA and BALB/c mice. We observed strain differences in baseline immobility time, with CD-1 mice showing the longest and DBA mice showing the shortest. In contrast, DBA and BALB/c mice showed the highest sensitivity to FLX, whereas CD-1 and C57BL/6 mice showed the lowest sensitivity. Also we found strain differences in both the total 5-HTT protein level and the membrane-bound 5-HTT level (estimated by V max) as follows: DBA>BALB/c>CD-1=C57BL/6. The uptake efficiency of the membrane-bound 5-HTT (estimated by 1/K m) was highest in DBA and BALB/c mice and lowest in CD-1 and C57BL/6 mice. A correlation analysis of subregions within the hippocampus revealed that immobility time was negatively correlated with V max and positively correlated with K m in the hippocampus. Therefore a higher uptake capacity of the membrane-bound 5-HTT in the hippocampus was associated with lower baseline immobility and greater sensitivity to FLX. These results suggest that alterations in hippocampal 5-HTT activity may contribute to mouse strain differences in the FST and the TST.
Measurements of the transport efficiency of the fragment mass analyzer
Energy Technology Data Exchange (ETDEWEB)
Back, B.B.; Blumenthal, D.J.; Davids, C.N. [and others
1995-08-01
Extensive calculations of the transport of reaction products were carried out during the design phase of the instrument using the computer code GIOS. These show that the energy acceptance depends strongly on the angular deviation from the optical axis of the instrument. In order to reliably measure cross sections using this instrument it is therefore necessary to verify these calculations empirically.
Heat transport measurements in turbulent rotating Rayleigh-Benard convection
Energy Technology Data Exchange (ETDEWEB)
Ecke, Robert E [Los Alamos National Laboratory; Liu, Yuanming [Los Alamos National Laboratory
2008-01-01
We present experimental heat transport measurements of turbulent Rayleigh-Benard convection with rotation about a vertical axis. The fluid, water with Prandtl number ({sigma}) about 6, was confined in a cell which had a square cross section of 7.3 cm x 7.3 cm and a height of 9.4 cm. Heat transport was measured for Rayleigh numbers 2 x 10{sup 5} < Ra < 5 x 10{sup 8} and Taylor numbers 0 < Ta < 5 x 10{sup 9}. We show the variation of normalized heat transport, the Nusselt number, at fixed dimensional rotation rate {Omega}{sub D}, at fixed Ra varying Ta, at fixed Ta varying Ra, and at fixed Rossby number Ro. The scaling of heat transport in the range 10{sup 7} to about 10{sup 9} is roughly 0.29 with a Ro dependent coefficient or equivalently is also well fit by a combination of power laws of the form a Ra{sup 1/5} + b Ra{sup 1/3} . The range of Ra is not sufficient to differentiate single power law or combined power law scaling. The overall impact of rotation on heat transport in turbulent convection is assessed.
Measuring weak lensing correlations of Type Ia supernovae
Scovacricchi, D.; Nichol, R. C.; Macaulay, E.; Bacon, D.
2017-03-01
We study the feasibility of detecting weak lensing spatial correlations between supernova (SN) Type Ia magnitudes with present (Dark Energy Survey, DES) and future (Large Synoptic Survey Telescope, LSST) surveys. We investigate the angular auto-correlation function of SN magnitudes (once the background cosmology has been subtracted) and cross-correlation with galaxy catalogues. We examine both analytical and numerical predictions, the latter using simulated galaxy catalogues from the MICE Grand Challenge Simulation. We predict that we will be unable to detect the SN auto-correlation in DES, while it should be detectable with the LSST SN deep fields (15 000 SNe on 70 deg2) at ≃6σ level of confidence (assuming 0.15 mag of intrinsic dispersion). The SN-galaxy cross-correlation function will deliver much higher signal to noise, being detectable in both surveys with an integrated signal to noise of ∼100 (up to 30 arcmin separations). We predict joint constraints on the matter density parameter (Ωm) and the clustering amplitude (σ8) by fitting the auto-correlation function of our mock LSST deep fields. When assuming a Gaussian prior for Ωm, we can achieve a 25 per cent measurement of σ8 from just these LSST supernovae (assuming 0.15 mag of intrinsic dispersion). These constraints will improve significantly if the intrinsic dispersion of SNe Ia can be reduced.
Cost benefit analysis of policy measures in the transport sector
Energy Technology Data Exchange (ETDEWEB)
Buus Kristensen, N. [COWI (Denmark)
1996-12-01
The Government has introduced a national target for the reduction of CO{sub 2} emissions from the transport sector, which aims to stabilize emissions at the 1988 level, by the year 2005. This target was first formalized in the Government`s 1990 transport action plan, and later repeated in `Traffic 2005`, published in December 1993. The latter document also makes reference to six strategies, which the Government proposed in order to attain the national target. The majority of the transport policy measures will impact on CO{sub 2} emissions from the sector, even if they are targeted at different objectives, e.g. road safety, air pollution, time savings, etc. A long-list of potential measures, which might be adopted with the primary purpose is to reduce CO{sub 2} emissions, has been identified from the six overall strategies. The measures identified have been subjected to detailed analyses, to ascertain all the potential impacts. The main emphasis has been on clarifying the potential efficacy of each of the measures in reducing CO{sub 2} emissions, and the social costs in a wide sense. The analysis assumes that each policy measure is implemented separately. A methodology is developed that presents the respective consequences in commensurate terms. Similar calculations are undertaken for two different combinations of policy measures. (EG)
Correlation techniques and measurements of wave-height statistics
Guthart, H.; Taylor, W. C.; Graf, K. A.; Douglas, D. G.
1972-01-01
Statistical measurements of wave height fluctuations have been made in a wind wave tank. The power spectral density function of temporal wave height fluctuations evidenced second-harmonic components and an f to the minus 5th power law decay beyond the second harmonic. The observations of second harmonic effects agreed very well with a theoretical prediction. From the wave statistics, surface drift currents were inferred and compared to experimental measurements with satisfactory agreement. Measurements were made of the two dimensional correlation coefficient at 15 deg increments in angle with respect to the wind vector. An estimate of the two-dimensional spatial power spectral density function was also made.
Temporal correlations and structural memory effects in break junction measurements
DEFF Research Database (Denmark)
Magyarkuti, A.; Lauritzen, Kasper Primdal; Balogh, Zoltan Imre
2017-01-01
that correlations between the opening and subsequent closing traces may indicate structural memory effects in atomic-sized metallic and molecular junctions. Applying these methods on measured and simulated gold metallic contacts as a test system, we show that the surface diffusion induced flattening of the broken......-molecule junctions, we demonstrate pronounced contact memory effects and recovery of the molecule for junctions breaking before atomic chains are formed. However, if chains are pulled the random relaxation of the chain and molecule after rupture prevents opening-closing correlations....
Magnetic noise measurements using cross-correlated Hall sensor arrays
Jung, G.; Ocio, M.; Paltiel, Y.; Shtrikman, H.; Zeldov, E.
2001-01-01
An experimental technique for measuring magnetic fluctuations by means of a double-layer Hall sensor array is described. The technique relies on cross-correlating Hall signals from two independent sensors positioned one above the other in two separate two-dimensional-electron-gas layers of a GaAs/AlGaAs heterostructure. The effectiveness of the technique is demonstrated by a reduction of the magnitude of the background noise floor of the correlated sensors with respect to the noise level of the best single sensor.
A Generalized Linear Transport Model for Spatially-Correlated Stochastic Media
Davis, Anthony B
2014-01-01
We formulate a new model for transport in stochastic media with long-range spatial correlations where exponential attenuation (controlling the propagation part of the transport) becomes power law. Direct transmission over optical distance $\\tau(s)$, for fixed physical distance $s$, thus becomes $(1+\\tau(s)/a)^{-a}$, with standard exponential decay recovered when $a\\to\\infty$. Atmospheric turbulence phenomenology for fluctuating optical properties rationalizes this switch. Foundational equations for this generalized transport model are stated in integral form for $d=1,2,3$ spatial dimensions. A deterministic numerical solution is developed in $d=1$ using Markov Chain formalism, verified with Monte Carlo, and used to investigate internal radiation fields. Standard two-stream theory, where diffusion is exact, is recovered when $a=\\infty$. Differential diffusion equations are not presently known when $a<\\infty$, nor is the integro-differential form of the generalized transport equation. Monte Carlo simulations...
Correlating Function and Imaging Measures of the Medial Longitudinal Fasciculus.
Directory of Open Access Journals (Sweden)
Ken Sakaie
Full Text Available To test the validity of diffusion tensor imaging (DTI measures of tissue injury by examining such measures in a white matter structure with well-defined function, the medial longitudinal fasciculus (MLF. Injury to the MLF underlies internuclear ophthalmoparesis (INO.40 MS patients with chronic INO and 15 healthy controls were examined under an IRB-approved protocol. Tissue integrity of the MLF was characterized by DTI parameters: longitudinal diffusivity (LD, transverse diffusivity (TD, mean diffusivity (MD and fractional anisotropy (FA. Severity of INO was quantified by infrared oculography to measure versional disconjugacy index (VDI.LD was significantly lower in patients than in controls in the medulla-pons region of the MLF (p < 0.03. FA was also lower in patients in the same region (p < 0.0004. LD of the medulla-pons region correlated with VDI (R = -0.28, p < 0.05 as did FA in the midbrain section (R = 0.31, p < 0.02.This study demonstrates that DTI measures of brain tissue injury can detect injury to a functionally relevant white matter pathway, and that such measures correlate with clinically accepted evaluation indices for INO. The results validate DTI as a useful imaging measure of tissue integrity.
Long-range correlations in a simple stochastic model of coupled transport
Energy Technology Data Exchange (ETDEWEB)
Larralde, Hernan [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62551 Cuernavaca, Morelos (Mexico); Sanders, David P [Departamento de Fisica, Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, 04510 Mexico DF (Mexico)], E-mail: hernan@fis.unam.mx, E-mail: dps@fciencias.unam.mx
2009-08-21
We study coupled transport in the nonequilibrium stationary state of a model consisting of independent random walkers, moving along a one-dimensional channel, which carry a conserved energy-like quantity, with density and temperature gradients imposed by reservoirs at the ends of the channel. In our model, walkers interact with other walkers at the same site by sharing energy at each time step, but the amount of energy carried does not affect the motion of the walkers. We find that already in this simple model long-range correlations arise in the nonequilibrium stationary state which are similar to those observed in more realistic models of coupled transport. We derive an analytical expression for the source of these correlations, which we use to obtain semi-analytical results for the correlations themselves assuming a local-equilibrium hypothesis. These are in very good agreement with results from direct numerical simulations.
Longterm Measurements of Bedload-Transport in alpine Catchments
Achleitner, Stefan; Kammerlander, Johannes; Eichner, Bernhard; Schöber, Johannes; Chiari, Michael
2016-04-01
In recent years the necessity of predicting the long-term behavior of sediment transport has increased. On the one hand, the effects of technical measures (e.g. retaining measures, hydropower, etc.) in the natural system are to be evaluated. On the other hand long term ecological studies that are strongly linked to the sediment budgets and its variation are more and more evolving. The ACRP Project DevoBeta-CC addresses the dynamics of long term sediment transport dynamics and its temporal altering. The focus is put on smaller tributary catchments enabling the model development. In total the data from ten catchments connected to the hydropower station Kaunertal (Tyrol/Austria) and eleven catchments linked to the power plant group Sellrain-Silz (Tyrol/Austria) are available. The considered catchments vary regarding their characteristics such as size (3 km³ to 27 km²), glaciation (0 % to 53 %), mean catchment slope (53 % to 92 %) and mean channel gradient (4 % to 49 %). The main data basis are records from the water intake structures operated (partly since 1965) by the TIWAG (Tiroler Wasserkraft AG). The sedimentation dynamics and operational flushings of the connected settling basins are used to measure the transported sediments. Since 1985 even high resolution data (15min intervals) are available. At selected catchments, the operationally recorded data (flushings, load membrane measurements,...) are verified within measuring campaigns using bed load traps upstream. Further, the sedimentation dynamics and grain size distributions in the settling basins are evaluated. Therefor two water intakes were put temporally out of operation, allowing an improved measurement of settled volumes by means of terrestrial surveying. Uncertainty assessments reveal an overall accuracy of estimated annual bed load volumes lower than a factor of two. Additionally, the data set enables to address sediment transport at a sub-annual basis, hence, the presented data set is unique regarding
Chen, Yong-Zhou; Fu, Chun-Hua; Chang, Hui; Li, Nan; He, Da-Ren
2008-10-01
In this paper, an empirical investigation is presented, which focuses on unveiling the universality of connectivity correlations in three spaces (the route space, the stop geographical space and bus-transferring space) of urban bus-transport networks (BTNs) in four major cities of China. The underlying features of the connectivity correlations are shown in two statistical ways. One is the correlation between the (weighted) average degree of all the nearest neighbouring vertices with degree k, (Knnw (k)) Knn(k), and k, and the other is the correlations between the assortativity coefficient r and, respectively, the network size N, the network diameter D, the averaged clustering coefficient C, and the averaged distance . The obtained results show qualitatively the same connectivity correlations of all the considered cities under all the three spaces.
Measurements and models of reactive transport in geological media
Berkowitz, Brian; Dror, Ishai; Hansen, Scott K.; Scher, Harvey
2016-12-01
Reactive chemical transport plays a key role in geological media across scales, from pore scale to aquifer scale. Systems can be altered by changes in solution chemistry and a wide variety of chemical transformations, including precipitation/dissolution reactions that cause feedbacks that directly affect the flow and transport regime. The combination of these processes with advective-dispersive-diffusive transport in heterogeneous media leads to a rich spectrum of complex dynamics. The principal challenge in modeling reactive transport is to account for the subtle effects of fluctuations in the flow field and species concentrations; spatial or temporal averaging generally suppresses these effects. Moreover, it is critical to ground model conceptualizations and test model outputs against laboratory experiments and field measurements. This review emphasizes the integration of these aspects, considering carefully designed and controlled experiments at both laboratory and field scales, in the context of development and solution of reactive transport models based on continuum-scale and particle tracking approaches. We first discuss laboratory experiments and field measurements that define the scope of the phenomena and provide data for model comparison. We continue by surveying models involving advection-dispersion-reaction equation and continuous time random walk formulations. The integration of measurements and models is then examined, considering a series of case studies in different frameworks. We delineate the underlying assumptions, and strengths and weaknesses, of these analyses, and the role of probabilistic effects. We also show the key importance of quantifying the spreading and mixing of reactive species, recognizing the role of small-scale physical and chemical fluctuations that control the initiation of reactions.
Resolution of ambiguous radar measurements using a floating bin correlator
Addison, E. R.; Frost, E. L.
It is pointed out that the Chinese Remainder Theorem (Mooney and Skillman, 1970) can be used to yield unambiguous measurements by comparing outputs allocated to fixed integer number bins using integer arithmetic to modulo to the correct bin number. In general, targets straddling two or more bins or the assignment of an incorrect bin number will yield incorrect parameter values. An ambiguity resolution technique using multiple pulse repetition frequency (PRF) data and a sliding floating point window or 'floating bin' to correlate ambiguous centroided Doppler measurements is proposed. An advantage of the technique is that false targets are much less prevalent than in classical techniques. What is more, the same technique may be employed to resolve ambiguous range wherein centroided range measurements are moduloed with the pulse repetition interval associated with each PRF. Results demonstrate that this method is better than conventional approaches in that the number of false targets produced is significantly lower while simultaneoulsy providing a high probability of correlation. In addition, the correlation can be effected in real time.
Bunch Length Measurements With Laser/SR Cross-Correlation
Energy Technology Data Exchange (ETDEWEB)
Miller, Timothy; /Stanford U., Phys. Dept.; Daranciang, Dan; /Stanford U., Phys. Dept.; Lindenberg, Aaron; /Stanford U., Phys. Dept.; Corbett, Jeff; /SLAC; Fisher, Alan; /SLAC; Goodfellow, John; /SLAC; Huang, Xiaobiao; /SLAC; Mok, Walter; /SLAC; Safranek, James; /SLAC; Wen, Haidan; /SLAC
2012-07-06
By operating SPEAR3 in low-{alpha} mode the storage ring can generate synchrotron radiation pulses of order 1ps. Applications include pump-probe x-ray science and the production of THz radiation in the CSR regime. Measurements of the bunch length are difficult, however, because the light intensity is low and streak cameras typically provide resolution of only a few ps. Tests are now underway to resolve the short bunch length using cross-correlation between a 60-fs Ti:Sapphire laser and the visible SR beam in a BBO crystal. In this paper we report on the experimental setup, preliminary measurements and prospects for further improvement.
Bunch Length Measurements With Laser/SR Cross-Correlation
Energy Technology Data Exchange (ETDEWEB)
Miller, Timothy; /Stanford U., Phys. Dept.; Daranciang, Dan; /Stanford U., Phys. Dept.; Lindenberg, Aaron; /Stanford U., Phys. Dept.; Corbett, Jeff; /SLAC; Fisher, Alan; /SLAC; Goodfellow, John; /SLAC; Huang, Xiaobiao; /SLAC; Mok, Walter; /SLAC; Safranek, James; /SLAC; Wen, Haidan; /SLAC
2012-07-06
By operating SPEAR3 in low-{alpha} mode the storage ring can generate synchrotron radiation pulses of order 1ps. Applications include pump-probe x-ray science and the production of THz radiation in the CSR regime. Measurements of the bunch length are difficult, however, because the light intensity is low and streak cameras typically provide resolution of only a few ps. Tests are now underway to resolve the short bunch length using cross-correlation between a 60-fs Ti:Sapphire laser and the visible SR beam in a BBO crystal. In this paper we report on the experimental setup, preliminary measurements and prospects for further improvement.
3D shape measurement with phase correlation based fringe projection
Kühmstedt, Peter; Munckelt, Christoph; Heinze, Matthias; Bräuer-Burchardt, Christian; Notni, Gunther
2007-06-01
Here we propose a method for 3D shape measurement by means of phase correlation based fringe projection in a stereo arrangement. The novelty in the approach is characterized by following features. Correlation between phase values of the images of two cameras is used for the co-ordinate calculation. This work stands in contrast to the sole usage of phase values (phasogrammetry) or classical triangulation (phase values and image co-ordinates - camera raster values) for the determination of the co-ordinates. The method's main advantage is the insensitivity of the 3D-coordinates from the absolute phase values. Thus it prevents errors in the determination of the co-ordinates and improves robustness in areas with interreflections artefacts and inhomogeneous regions of intensity. A technical advantage is the fact that the accuracy of the 3D co-ordinates does not depend on the projection resolution. Thus the achievable quality of the 3D co-ordinates can be selectively improved by the use of high quality camera lenses and can participate in improvements in modern camera technologies. The presented new solution of the stereo based fringe projection with phase correlation makes a flexible, errortolerant realization of measuring systems within different applications like quality control, rapid prototyping, design and CAD/CAM possible. In the paper the phase correlation method will be described in detail. Furthermore, different realizations will be shown, i.e. a mobile system for the measurement of large objects and an endoscopic like system for CAD/CAM in dental industry.
MEASURING CUSTOMER’S SATISFACTION ON BUS TRANSPORTATION
Rabiul Islam; Mohammed S. Chowdhury; Mohammad Sumann Sarker; Salauddin Ahmed
2014-01-01
The purpose of the study is to examine the factors measuring customers’ satisfaction, especially the impact of service quality on customers’ satisfaction in public transportation industry in the university town of Sintok located in Kedah province of Malaysia. In order to assess the relationships between service quality and customer satisfaction survey http://www.scientificjournals.org/journals2007/articles/1003.htmdata were collected from 300 Bus commuters. All hypotheses were tes...
The Effect of Correlations on the Heat Transport in a Magnetized Plasma
Ott, Torben; Donko, Zoltan
2015-01-01
In a classical ideal plasma, a magnetic field is known to reduce the heat conductivity perpendicular to the field whereas it does not alter the one along the field. Here we show that, in strongly correlated plasmas that are observed at high pressure or/and low temperature, a magnetic field reduces the perpendicular heat transport much less and even {\\it enhances} the parallel transport. These surprising observations are explained by the competition of kinetic, potential and collisional contributions to the heat conductivity. Our results are based on first principle molecular dynamics simulations of a one-component plasma.
Transport measurements under pressure in III-IV layered semiconductors
Energy Technology Data Exchange (ETDEWEB)
Segura, A.; Errandonea, D.; Martinez-Garcia, D. [ICMUV, Universitat de Valencia, Ed. Investigacio, 46100 Burjassot (Spain); Manjon, F.J. [Dpto. de Fisica Aplicada, Univ. Politecnica de Valencia, Cno. de Vera s/n, 46022 Valencia (Spain); Chevy, A. [Physique des Milieux Condenses, Universite Pierre et Marie Curie, 75252 Paris Cedex 05 (France); Tobias, G.; Ordejon, P.; Canadell, E. [Institut de Ciencia dels Materials de Barcelona, CSIC, Campus de la UAB, 08193 Bellaterra (Barcelona) (Spain)
2007-01-15
This paper reports on Hall effect, resistivity and thermopower effect measurements under high pressure up to 12 GPa in p-type {gamma}-indium selenide (InSe) and {epsilon}-gallium selenide (GaSe). The paper focuses on two applications of transport measurements under pressure: electronic structure and phase transition studies. As concerns the electronic structure, we investigate the origin of the striking differences between the pressure behaviour of transport parameters in both layered compounds. While the hole concentration and mobility increase moderately and monotonously in {epsilon}-GaSe up to 10 GPa, a large increase of the hole concentration at near 0.8 GPa and a large continuous increase of the hole mobility, which doubled its ambient pressure value by 3.2 GPa, is observed in {gamma}-InSe. Based on electronic structure calculations the difference is found to arise from the pressure evolution of the valence band maximum. While the shape of the valence band maximum is virtually pressure-insensitive in {epsilon}-GaSe, it changes dramatically in {gamma}-InSe, with the emergence of a ring-shaped subsidiary maximum that becomes the absolute valence-band maximum as pressure increases. Transport measurements as a function of pressure and temperature are also used to investigate the phase diagram of InSe and, in particular, the transition to the rock-salt polymorph. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
LIF Diagnostic for Measuring Beam-Transport Magnetic Fields
Jones, T. G.; Hinshelwood, D. D.; Neri, J. M.; Ottinger, P. F.; Noonan, W. A.
1997-11-01
A novel, spatially-resolved diagnostic is being developed to measure magnetic fields associated with intense ion beam propagation through a low-pressure gas, as is envisioned for light ion-driven ICF. The diagnostic technique uses laser-induced fluorescence (LIF) spectroscopy, and can be varied to measure either small or large fields. Small fields, as expected in ballistic transport with solenoidal lens focusing using ~ 1 Torr gas, produce Zeeman shifts, Δ λ_Z, smaller than the transition linewidth, Δ λ. High sensitivity to measure these shifts is achieved by a variation on the Babcock technique.^1 Large fields, as expected in self-pinched transport using 1--100 mTorr gas, produce Δ λZ larger than Δ λ. These Δ λZ will be resolved using an etalon as a narrowband, high-throughput optical filter. Available results from benchtop experiments using calibrated B-fields for both the small- and large-field techniques, and progress in fielding this diagnostic on the Gamble-II accelerator for beam-transport studies will be presented. Work supported by DOE through Sandia National Laboratories. ^ National Research Council Research Associate. ^ Present address University of Maryland, College Park, MD. ^1 W.A. Noonan, et al., Rev. Sci. Instrum. 68, 1032 (1997).
Development of Methods Precision Length Measurement Using Transported Laser Interferometer
Lavrov, E. A.; Epikhin, V. M.; Mazur, M. M.; Suddenok, Y. A.; Shorin, V. N.
The paper shows the results of a comparison of a developed transported laser interferometer (TLI) with a measurement interferometer XL-80 Renishaw at the distance 0-60 meters. Testings of a breadboard model of the TLI showed that a difference between the travel measurements of the two interferometers does not exceed 6 μm. The mean value of the difference of indications between the TLI and a Renishaw travel measurer at the distance near 58 m approximately equals to 0,5 μm. Root-mean square deviation of the indications of the interferometers approximately equals to 3 μm. At comparison of the sections with the same name between the TLI and the Renishaw travel measurer, measured at different days, a repeatability of the results for the sections with the same name is noted.
Nonlinear ultrasonic measurements based on cross-correlation filtering techniques
Yee, Andrew; Stewart, Dylan; Bunget, Gheorghe; Kramer, Patrick; Farinholt, Kevin; Friedersdorf, Fritz; Pepi, Marc; Ghoshal, Anindya
2017-02-01
Cyclic loading of mechanical components promotes the formation of dislocation dipoles in metals, which can serve as precursors to crack nucleation and ultimately lead to failure. In the laboratory setting, an acoustic nonlinearity parameter has been assessed as an effective indicator for characterizing the progression of fatigue damage precursors. However, the need to use monochromatic waves of medium-to-high acoustic energy has presented a constraint, making it problematic for use in field applications. This paper presents a potential approach for field measurement of acoustic nonlinearity by using general purpose ultrasonic pulser-receivers. Nonlinear ultrasonic measurements during fatigue testing were analyzed by the using contact and immersion pulse-through method. A novel cross-correlation filtering technique was developed to extract the fundamental and higher harmonic waves from the signals. As in the case of the classic harmonic generation, the nonlinearity parameters of the second and third harmonics indicate a strong correlation with fatigue cycles. Consideration was given to potential nonlinearities in the measurement system, and tests have confirmed that measured second harmonic signals exhibit a linear dependence on the input signal strength, further affirming the conclusion that this parameter relates to damage precursor formation from cyclic loading.
Matrix-based concordance correlation coefficient for repeated measures.
Hiriote, Sasiprapa; Chinchilli, Vernon M
2011-09-01
In many clinical studies, Lin's concordance correlation coefficient (CCC) is a common tool to assess the agreement of a continuous response measured by two raters or methods. However, the need for measures of agreement may arise for more complex situations, such as when the responses are measured on more than one occasion by each rater or method. In this work, we propose a new CCC in the presence of repeated measurements, called the matrix-based concordance correlation coefficient (MCCC) based on a matrix norm that possesses the properties needed to characterize the level of agreement between two p× 1 vectors of random variables. It can be shown that the MCCC reduces to Lin's CCC when p= 1. For inference, we propose an estimator for the MCCC based on U-statistics. Furthermore, we derive the asymptotic distribution of the estimator of the MCCC, which is proven to be normal. The simulation studies confirm that overall in terms of accuracy, precision, and coverage probability, the estimator of the MCCC works very well in general cases especially when n is greater than 40. Finally, we use real data from an Asthma Clinical Research Network (ACRN) study and the Penn State Young Women's Health Study for demonstration.
Measuring Fisher information accurately in correlated neural populations.
Kanitscheider, Ingmar; Coen-Cagli, Ruben; Kohn, Adam; Pouget, Alexandre
2015-06-01
Neural responses are known to be variable. In order to understand how this neural variability constrains behavioral performance, we need to be able to measure the reliability with which a sensory stimulus is encoded in a given population. However, such measures are challenging for two reasons: First, they must take into account noise correlations which can have a large influence on reliability. Second, they need to be as efficient as possible, since the number of trials available in a set of neural recording is usually limited by experimental constraints. Traditionally, cross-validated decoding has been used as a reliability measure, but it only provides a lower bound on reliability and underestimates reliability substantially in small datasets. We show that, if the number of trials per condition is larger than the number of neurons, there is an alternative, direct estimate of reliability which consistently leads to smaller errors and is much faster to compute. The superior performance of the direct estimator is evident both for simulated data and for neuronal population recordings from macaque primary visual cortex. Furthermore we propose generalizations of the direct estimator which measure changes in stimulus encoding across conditions and the impact of correlations on encoding and decoding, typically denoted by Ishuffle and Idiag respectively.
Theoretical model of blood flow measurement by diffuse correlation spectroscopy
Sakadžić, Sava; Boas, David A.; Carp, Stefan
2017-02-01
Diffuse correlation spectroscopy (DCS) is a noninvasive method to quantify tissue perfusion from measurements of the intensity temporal autocorrelation function of diffusely scattered light. However, DCS autocorrelation function measurements in tissue better match theoretical predictions based on the diffusive motion of the scatterers than those based on a model where the advective nature of blood flow dominates the stochastic properties of the scattered light. We have recently shown using Monte Carlo (MC) simulations and assuming a simplistic vascular geometry and laminar flow profile that the diffusive nature of the DCS autocorrelation function decay is likely a result of the shear-induced diffusion of the red blood cells. Here, we provide theoretical derivations supporting and generalizing the previous MC results. Based on the theory of diffusing-wave spectroscopy, we derive an expression for the autocorrelation function along the photon path through a vessel that takes into account both diffusive and advective scatterer motion, and we provide the solution for the DCS autocorrelation function in a semi-infinite geometry. We also derive the correlation diffusion and correlation transfer equation, which can be applied for an arbitrary sample geometry. Further, we propose a method to take into account realistic vascular morphology and flow profile.
Xiao, Xing; Yao, Yao; Xie, Ying-Mao; Wang, Xing-Hua; Li, Yan-Ling
2016-09-01
Based on the quantum technique of weak measurement, we propose a scheme to protect the entanglement from correlated amplitude damping decoherence. In contrast to the results of memoryless amplitude damping channel, we show that the memory effects play a significant role in the suppression of entanglement sudden death and protection of entanglement under severe decoherence. Moreover, we find that the initial entanglement could be drastically amplified by the combination of weak measurement and quantum measurement reversal even under the correlated amplitude damping channel. The underlying mechanism can be attributed to the probabilistic nature of weak measurements.
Measuring capital market efficiency: Global and local correlations structure
Kristoufek, Ladislav; Vosvrda, Miloslav
2013-01-01
We introduce a new measure for capital market efficiency. The measure takes into consideration the correlation structure of the returns (long-term and short-term memory) and local herding behavior (fractal dimension). The efficiency measure is taken as a distance from an ideal efficient market situation. The proposed methodology is applied to a portfolio of 41 stock indices. We find that the Japanese NIKKEI is the most efficient market. From a geographical point of view, the more efficient markets are dominated by the European stock indices and the less efficient markets cover mainly Latin America, Asia and Oceania. The inefficiency is mainly driven by a local herding, i.e. a low fractal dimension.
Estimating correlation for a real-time measure of connectivity.
Arunkumar, Akhil; Panday, Ashish; Joshi, Bharat; Ravindran, Arun; Zaveri, Hitten P
2012-01-01
There has recently been considerable interest in connectivity analysis of fMRI and scalp and intracranial EEG time-series. The computational requirements of the pair-wise correlation (PWC), the core time-series measure used to estimate connectivity, presents a challenge to the real-time estimation of the PWC between all pairs of multiple time-series. We describe a parallel algorithm for computing PWC in real-time for streaming data from multiple channels. The algorithm was implemented on the Intel Xeon™ and IBM Cell Broadband Engine™ platforms. We evaluated time to estimate correlation for signals recorded with different acquisition parameters as a comparison to real-time constraints. We demonstrate that the execution time of these efficient implementations meet real-time constraints in most instances.
Offset balancing in pseudo-correlation radiometers for CMB measurements
Mennella, A.; Bersanelli, M.; Seiffert, M.; Kettle, D.; Roddis, N.; Wilkinson, A.; Meinhold, P.
2003-11-01
Radiometeric CMB measurements need to be highly stable and this stability is best obtained with differential receivers. The residual 1/f noise in the differential output is strongly dependent on the radiometer input offset which can be cancelled using various balancing strategies. In this paper we discuss a software method implemented in the PLANCK-LFI pseudo-correlation receivers which uses a tunable gain modulation factor, r, in the sky-load difference. Numerical simulations and experimental data show how proper tuning of the parameter r ensures a very stable differential output with knee frequencies of the order of few mHz. Various approaches to calculate r using the radiometer total power data are discussed with some examples relevant to PLANCK-LFI. Although the paper focuses on pseudo-correlation receivers and the examples are relative to PLANCK-LFI, the proposed method and its analysis is general and can be applied to a large class of differential radiometric receivers.
Offset balancing in pseudo-correlation radiometers for CMB measurements
Mennella, A; Seiffert, M; Kettle, D; Roddis, N; Wilkinson, A; Meinhold, P; Mennella, Aniello; Bersanelli, Marco; Seiffert, Michael; Kettle, Danielle; Roddis, Neil; Wilkinson, Althea; Meinhold, Peter
2003-01-01
Radiometeric CMB measurements need to be highly stable and this stability is best obtained with differential receivers. The residual 1/f noise in the differential output is strongly dependent on the radiometer input offset which can be cancelled using various balancing strategies. In this paper we discuss a software method implemented in the Planck-LFI pseudo-correlation receivers which uses a tunable "gain modulation factor, r, in the sky-load difference. Numerical simulations and experimental data show how proper tuning of the parameter r ensures a very stable differential output with knee frequencies of the order of few mHz. Various approaches to calculate r using the radiometer total power data are discussed with some examples relevant to Planck-LFI. Although the paper focuses on pseudo-correlation receivers and the examples are relative to Planck-LFI, the proposed method and its analysis is general and can be applied to a large class of differential radiometric receivers.
da Silva, L. D.; Sales, M. O.; Ranciaro Neto, A.; Lyra, M. L.; de Moura, F. A. B. F.
2016-12-01
We investigate electronic transport in a one-dimensional model with four different types of atoms and long-ranged correlated disorder. The latter was attained by choosing an adequate distribution of on-site energies. The wave-packet dynamics is followed by taking into account effects due to a static electric field and electron-phonon coupling. In the absence of electron-phonon coupling, the competition between correlated disorder and the static electric field promotes the occurrence of wave-packet oscillations in the regime of strong correlations. When the electron-lattice coupling is switched on, phonon scattering degrades the Bloch oscillations. For weak electron-phonon couplings, a coherent oscillatory-like dynamics of the wave-packet centroid persists for short periods of time. For strong couplings the wave-packet acquires a diffusive-like displacement and spreading. A slower sub-diffusive spreading takes place in the regime of weak correlations.
Correlation between AC and DC transport properties of Mn substituted cobalt ferrite
Supriya, Sweety; Kumar, Sunil; Kar, Manoranjan
2016-12-01
The CoFe2-xMnxO4 compound is prepared by following the sol gel technique. The structural analysis through XRD and Rietveld has been confirmed for the single cubic phase having F d 3 ¯ m space group for CoFe2-xMnxO4 and also verified it through Raman spectroscopy measurements. The tetrahedral site observed to be red shifted with increase in Mn concentration in cobalt ferrite. All the XRD patterns have been analyzed by employing the Rietveld refinement technique. The particle size was found to be in the range of 30-40 nm. The electrical properties of polycrystalline CoFe2-xMnxO4 for x = 0.00, 0.10, 0.15, and 0.2, spinel ferrite was investigated by impedance spectroscopy. The influence of doping, frequency and temperature on the electrical transport properties of the CoFe2-xMnxO4 for x = 0.00, 0.10, 0.15, and 0.20 were investigated. The magnitude of Z' and Z″ decreases with increase in temperature. Only one semicircle is observed in each Cole Cole plot which reveals that ac conductivity is dominated by grains. The grain resistance and grain boundary resistance both were found to decrease as a function of temperature. Temperature variation of DC electrical conductivity follows the Arrhenius relationship. A detailed analysis of electrical parameters provides assistance in connecting information regarding the conduction mechanism as well as determination of both dielectric and magnetic transition temperatures in the substituted cobalt ferrite. Detailed analysis of ac impedance and DC resistivity measurement reveals that, the magnetic ordering temperature in the Mn substituted cobalt ferrite does not respond to the frequency of ac electrical signal; however, it responds to the DC resistivity. The correlation between ac impedance and DC resistivity has been established.
CppTransport: a platform to automate calculation of inflationary correlation functions
Seery, David
2016-01-01
CppTransport is a numerical platform that can automatically generate and solve the evolution equations for the 2- and 3-point correlation functions (in field space and for the curvature perturbation) for any inflationary model with canonical kinetic terms. It makes no approximations beyond the applicability of tree-level perturbation theory. Given an input Lagrangian, CppTransport performs symbolic calculations to determine the 'Feynman rules' of the model and generates efficient C++ to integrate the correlation functions of interest. It includes a visualization suite that automates extraction of observable quantities from the raw n-point functions and generates high quality plots with minimal manual intervention. It is intended to be used as a collaborative platform, promoting the rapid investigation of models and systematizing their comparison with observation. This guide describes how to install and use the system, and illustrates its use through some simple examples.
Exploiting Spatio-Temporal Correlation for Reliable Information Transport in WSNs
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Faisal Karim Shaikh
2011-01-01
Full Text Available Delivering reliable services in service oriented architectures entails the underlying basis of having communication network models and well structured systems. With the rapid proliferation of ad-hoc mode of communication the reliable delivery of services increasingly encounter new communication and network perturbations. Empirically the core of service delivery in WSNs (Wireless Sensor Networks is information transport from the sensor nodes to the sink node where the service resides. In this work we provide a reliable information transport for enhanced service delivery by using spatio-temporal correlation in WSN. The classification for different types of information required by the services is also presented. To overcome dynamic network conditions and evolving service requirements an adaptive retransmission mechanism based on spatial correlation is utilized. Simulation results show that the proposed solutions provide service specific reliability and save expensive retransmissions and thus provide energy efficient solution.
Dynamic defect correlations dominate activated electronic transport in SrTiO3
Snijders, Paul C.; Şen, Cengiz; McConnell, Michael P.; Ma, Ying-Zhong; May, Andrew F.; Herklotz, Andreas; Wong, Anthony T.; Ward, T. Zac
2016-07-01
Strontium titanate (SrTiO3, STO) is a critically important material for the study of emergent electronic phases in complex oxides, as well as for the development of applications based on their heterostructures. Despite the large body of knowledge on STO, there are still many uncertainties regarding the role of defects in the properties of STO, including their influence on ferroelectricity in bulk STO and ferromagnetism in STO-based heterostructures. We present a detailed analysis of the decay of persistent photoconductivity in STO single crystals with defect concentrations that are relatively low but significantly affect their electronic properties. The results show that photo-activated electron transport cannot be described by a superposition of the properties due to independent point defects as current models suggest but is, instead, governed by defect complexes that interact through dynamic correlations. These results emphasize the importance of defect correlations for activated electronic transport properties of semiconducting and insulating perovskite oxides.
Measuring peptide mass spectrum correlation using the quantum Grover algorithm.
Choo, Keng Wah
2007-03-01
We investigated the use of the quantum Grover algorithm in the mass-spectrometry-based protein identification process. The approach coded the mass spectra on a quantum register and uses the Grover search algorithm for searching multiple solutions to find matches from a database. Measurement of the fidelity between the input and final states was used to quantify the similarity between the experimental and theoretical spectra. The optimal number of iteration is proven to be pi/4sqrt[N/k] , where k refers to the number of marked states. We found that one iteration is sufficient for the search if we let more that 62% of the N states be marked states. By measuring the fidelity after only one iteration of Grover search, we discovered that it resembles that of the correlation-based measurement used in the existing protein identification software. We concluded that the quantum Grover algorithm can be adapted for a correlation-based mass spectra database search, provided that decoherence can be kept to a minimum.
Directory of Open Access Journals (Sweden)
Arcady Zhukov
2017-02-01
Full Text Available We overviewed the correlation between the structure, magnetic and transport properties of magnetic microwires prepared by the Taylor-Ulitovsky method involving rapid quenching from the melt and drawing of the composite (metallic core, glass coated wire. We showed that this method can be useful for the preparation of different families of magnetic microwires: soft magnetic microwires displaying Giant magnetoimpedance (GMI effect, semi-hard magnetic microwires, microwires with granular structure exhibiting Giant Magnetoresistance (GMR effect and Heusler-type microwires. Magnetic and transport properties of magnetic microwires depend on the chemical composition of metallic nucleus and on the structural features (grain size, precipitating phases of prepared microwires. In all families of crystalline microwires, their structure, magnetic and transport properties are affected by internal stresses induced by the glass coating, depending on the quenching rate. Therefore, properties of glass-coated microwires are considerably different from conventional bulk crystalline alloys.
Transportable IOT measurement station for direct-broadcast satellites
Ulbricht, Michael
A transportable 11.7-12.5-GHz flux-density measurement facility for use in the in-orbit testing (IOT) of the FRG TV-Sat direct-broadcast satellites is described. Major components include a 1.2-m-diameter antenna, the fluxmeter, a radiometer to determine atmospheric attenuation, a weather station, and a control and data-processing computer; all of the components are mounted on a 5.10 x 2.35 x 2.70-m trailer. IOT performance parameters include gain/temperature ratio 15.9 dB/K, measurement range -97 to -117 dBW/sq m, measurement accuracy less than 0.5 dB rms, and measurement rate 250-650 msec. Photographs and a block diagram are provided.
Kim, Howon; Lin, Shi-Zeng; Graf, Matthias J.; Miyata, Yoshinori; Nagai, Yuki; Kato, Takeo; Hasegawa, Yukio
2016-09-01
Local disordered nanostructures in an atomically thick metallic layer on a semiconducting substrate play significant and decisive roles in transport properties of two-dimensional (2D) conductive systems. We measured the electrical conductivity through a step of monoatomic height in a truly microscopic manner by using as a signal the superconducting pair correlation induced by the proximity effect. The transport property across a step of a one-monolayer Pb surface metallic phase, formed on a Si(111) substrate, was evaluated by inducing the pair correlation around the local defect and measuring its response, i.e., the reduced density of states at the Fermi energy using scanning tunneling microscopy. We found that the step resistance has a significant contribution to the total resistance on a nominally flat surface. Our study also revealed that steps in the 2D metallic layer terminate the propagation of the pair correlation. Superconductivity is enhanced between the first surface step and the superconductor-normal-metal interface by reflectionless tunneling when the step is located within a coherence length.
BRAŠIĆ, JAMES ROBERT; BIBAT, GENILA; KUMAR, ANIL; ZHOU, YUN; HILTON, JOHN; YABLONSKI, MARYBETH E.; DOGAN, AHMET SEMIH; GUEVARA, MARIA RITA; STEPHANE, MASSOUD; JOHNSTON, MICHAEL; WONG, DEAN FOSTER; NAIDU, SAKKUBAI
2012-01-01
Rett syndrome (RTT) is a neurodevelopmental disability characterized by mutations in the X-linked methyl-CpG-binding protein 2 (MeCP2) located at the Xq28 region. The severity is modified in part by X chromosomal inactivation resulting in wide clinical variability. We hypothesized that the ability to perform the activities of daily living (ADL) is correlated with the density of vesicular acetylcholine transporters in the striata of women with RTT. The density of the vesicular acetylcholine transporters in the living human brain can be estimated by single-photon emission-computed tomography (SPECT) after the administration of (−)-5-[123I]iodobenzovesamicol ([123I]IBVM). Twenty-four (24) hours following the intravenous injection of approximately 333 MBq (9 mCi) [123I]IBVM, four women with RTT and nine healthy adult volunteer control participants underwent SPECT brain scans for sixty (60) minutes. The Vesicular Acetylcholine Transporter Binding Site Index (VATBSI) (Kuhl et al., 1994), a measurement of the density of vesicular acetylcholine transporters, was estimated in the striatum and the reference structure, the cerebellum. The women with RTT were assessed for certain activities of daily living (ADL). Although striatal VATSBI was not significantly lower in RTT (5.2 ± 0.9) than in healthy adults (5.7 ± 1.6), RTT striatal VATSBI and ADL scores were linearly associated (ADL = 0.89*VATSBI + 4.5; R2=0.93; p<0.01), suggesting a correlation between the ability to perform ADL and the density of vesicular acetylcholine transporters in the striata of women with RTT. [123I]IBVM is a promising tool to characterize the pathophysiological mechanisms of RTT and other neurodevelopmental disabilities. PMID:22223404
Turbulent correlation measurements in a two-stream mixing layer.
Jones, B. G.; Planchon, H. P.; Hammersley, R. J.
1973-01-01
Two point space-time measurements of the axial component of fluctuating velocity were made using linearized hot-wire anemometry. Space scales, convected frame correlations and time scales, and convection velocities in the shear layer were evaluated. Both filtered narrow and broad band convected frame autocorrelations were determined. Differences between axial broad band convection velocities and both mean turbulence and mean entrained fluid velocities were observed. Scaled broad band convection velocities for the mixing layer and simple round jets were found to collapse to a common curve. Axial narrow band convection velocities showed strong frequency and transverse position dependence.
Discontinuous membrane helices in transport proteins and their correlation with function.
Screpanti, Emanuela; Hunte, Carola
2007-08-01
Alpha-helical bundles and beta-barrel proteins represent the two basic types of architecture known for integral membrane proteins. Irregular structural motifs have been revealed with the growing number of structures determined. "Discontinuous" helices are present in membrane proteins that actively transport ions. In the Ca(2+)-ATPase, a primary active transporter, and in the secondary transporters NhaA, LeuT(Aa), ClC H(+)/Cl(-) exchanger and Glt(Ph), the helical structure of two membrane segments is interrupted and the interjacent polypeptide chain forms an extended peptide. The discontinuous helices are integrated in the membrane either as transmembrane-spanning or hairpin-type segments. In addition, the secondary transporters have inverted internal duplication domains, which are only weakly correlated with their amino acid sequence. The symmetry comprises either parts of or the complete molecule, but always includes the discontinuous helices. The helix-peptide-helix motif is correlated with the ion translocation function. The extended peptides with their backbone atoms, the helix termini and the polar/charged amino acid residues in close vicinity provide the basis for ion recognition, binding and translocation.
Bayesian Concordance Correlation Coefficient with Application to Repeatedly Measured Data
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Atanu BHATTACHARJEE
2015-10-01
Full Text Available Objective: In medical research, Lin's classical concordance correlation coefficient (CCC is frequently applied to evaluate the similarity of the measurements produced by different raters or methods on the same subjects. It is particularly useful for continuous data. The objective of this paper is to propose the Bayesian counterpart to compute CCC for continuous data. Material and Methods: A total of 33 patients of astrocytoma brain treated in the Department of Radiation Oncology at Malabar Cancer Centre is enrolled in this work. It is a continuous data of tumor volume and tumor size repeatedly measured during baseline pretreatment workup and post surgery follow-ups for all patients. The tumor volume and tumor size are measured separately by MRI and CT scan. The agreement of measurement between MRI and CT scan is calculated through CCC. The statistical inference is performed through Markov Chain Monte Carlo (MCMC technique. Results: Bayesian CCC is found suitable to get prominent evidence for test statistics to explore the relation between concordance measurements. The posterior mean estimates and 95% credible interval of CCC on tumor size and tumor volume are observed with 0.96(0.87,0.99 and 0.98(0.95,0.99 respectively. Conclusion: The Bayesian inference is adopted for development of the computational algorithm. The approach illustrated in this work provides the researchers an opportunity to find out the most appropriate model for specific data and apply CCC to fulfill the desired hypothesis.
Oxygen measurement by multimode diode lasers employing gas correlation spectroscopy.
Lou, Xiutao; Somesfalean, Gabriel; Chen, Bin; Zhang, Zhiguo
2009-02-10
Multimode diode laser (MDL)-based correlation spectroscopy (COSPEC) was used to measure oxygen in ambient air, thereby employing a diode laser (DL) having an emission spectrum that overlaps the oxygen absorption lines of the A band. A sensitivity of 700 ppm m was achieved with good accuracy (2%) and linearity (R(2)=0.999). For comparison, measurements of ambient oxygen were also performed by tunable DL absorption spectroscopy (TDLAS) technique employing a vertical cavity surface emitting laser. We demonstrate that, despite slightly degraded sensitivity, the MDL-based COSPEC-based oxygen sensor has the advantages of high stability, low cost, ease-of-use, and relaxed requirements in component selection and instrument buildup compared with the TDLAS-based instrument.
APPLICATION OF NOVEL NEUTRON CORRELATION TECHNIQUES TO NUCLEAR MATERIAL MEASUREMENTS
Energy Technology Data Exchange (ETDEWEB)
Sale, K
2006-06-09
Confirmation of the fissile mass of a system containing plutonium can be done using neutron multiplicity techniques. This can be accomplished with a detector system that is smaller and less costly than a standard neutron multiplicity counter (NMC). Also the fissile mass of a uranium containing system can be confirmed by passive means. Recent work at Lawrence Livermore National Laboratory has demonstrated that simple slab neutron detectors and a novel approach to data acquisition and analysis can be used to make an accurate measurement of the mass of fissile materials. Purely passive measurement of kilogram quantities of highly enriched uranium (HEU) have also been shown to be feasible. In this paper we discuss calculational tools for assessing the application of these techniques to fissile material transparency regimes. The tools required to adequately model the correlations and their application will be discussed.
Strongly correlated two-dimensional plasma explored from entropy measurements.
Kuntsevich, A Y; Tupikov, Y V; Pudalov, V M; Burmistrov, I S
2015-06-23
Charged plasma and Fermi liquid are two distinct states of electronic matter intrinsic to dilute two-dimensional electron systems at elevated and low temperatures, respectively. Probing their thermodynamics represents challenge because of lack of an adequate technique. Here, we report a thermodynamic method to measure the entropy per electron in gated structures. Our technique appears to be three orders of magnitude superior in sensitivity to a.c. calorimetry, allowing entropy measurements with only 10(8) electrons. This enables us to investigate the correlated plasma regime, previously inaccessible experimentally in two-dimensional electron systems in semiconductors. In experiments with clean two-dimensional electron system in silicon-based structures, we traced entropy evolution from the plasma to Fermi liquid regime by varying electron density. We reveal that the correlated plasma regime can be mapped onto the ordinary non-degenerate Fermi gas with an interaction-enhanced temperature-dependent effective mass. Our method opens up new horizons in studies of low-dimensional electron systems.
Correlating Atom Probe Crystallographic Measurements with Transmission Kikuchi Diffraction Data.
Breen, Andrew J; Babinsky, Katharina; Day, Alec C; Eder, K; Oakman, Connor J; Trimby, Patrick W; Primig, Sophie; Cairney, Julie M; Ringer, Simon P
2017-03-14
Correlative microscopy approaches offer synergistic solutions to many research problems. One such combination, that has been studied in limited detail, is the use of atom probe tomography (APT) and transmission Kikuchi diffraction (TKD) on the same tip specimen. By combining these two powerful microscopy techniques, the microstructure of important engineering alloys can be studied in greater detail. For the first time, the accuracy of crystallographic measurements made using APT will be independently verified using TKD. Experimental data from two atom probe tips, one a nanocrystalline Al-0.5Ag alloy specimen collected on a straight flight-path atom probe and the other a high purity Mo specimen collected on a reflectron-fitted instrument, will be compared. We find that the average minimum misorientation angle, calculated from calibrated atom probe reconstructions with two different pole combinations, deviate 0.7° and 1.4°, respectively, from the TKD results. The type of atom probe and experimental conditions appear to have some impact on this accuracy and the reconstruction and measurement procedures are likely to contribute further to degradation in angular resolution. The challenges and implications of this correlative approach will also be discussed.
Esmaeli, Farzad; Shirmohammadi, Adileh; Faramarzie, Masoumeh; Abolfazli, Nader; Rasouli, Hossein; Fallahi, Saied
2012-01-01
Background Diagnosis and accuracy in determining the exact location, extent and configuration of bony defects of the jaw are of utmost importance to determine prognosis, treatment planning and long-term preservation of teeth. If relatively accurate diagnosis can be established by radiography, proper treatment planning prior to treatment procedures will be possible. Objectives The aim of the present study was to assess the correlation between indirect digital radiographic measurements and clinical measurements in determining the topography of interproximal bony defects. Patients and Methods Twenty interproximal bony defects, preferably in the mandibular and maxillary 5↔5 area were selected and radiographed using the parallel periapical technique. The radiographs were corrected and digitized on a computer using “Linear Measurement” software; then the three parameters of the base of defect (BD), alveolar crest (AC) and cementoenamel junction (CEJ) were determined using a software. Subsequent to radiographic measurements, clinical measurements were carried out meticulously during flap procedures. Then linear measurements were carried out using a periodontal probe to determine the defect depth and its mesiodistal width. Then the amount of correlation between these two measurements was assessed by Pearson's correlation coefficient. Results The correlation between clinical and radiographic measurements in defect depth determination, in the evaluation of defect angle and in determination of defect width were 88%, 98% and 90%, respectively. Conclusions Indirect digital radiographic technique can be used to diagnose intra-osseous defects, providing a better opportunity to treat bony defects. PMID:23329969
Accurate measurement of liquid transport through nanoscale conduits
Alibakhshi, Mohammad Amin; Xie, Quan; Li, Yinxiao; Duan, Chuanhua
2016-01-01
Nanoscale liquid transport governs the behaviour of a wide range of nanofluidic systems, yet remains poorly characterized and understood due to the enormous hydraulic resistance associated with the nanoconfinement and the resulting minuscule flow rates in such systems. To overcome this problem, here we present a new measurement technique based on capillary flow and a novel hybrid nanochannel design and use it to measure water transport through single 2-D hydrophilic silica nanochannels with heights down to 7 nm. Our results show that silica nanochannels exhibit increased mass flow resistance compared to the classical hydrodynamics prediction. This difference increases with decreasing channel height and reaches 45% in the case of 7 nm nanochannels. This resistance increase is attributed to the formation of a 7-angstrom-thick stagnant hydration layer on the hydrophilic surfaces. By avoiding use of any pressure and flow sensors or any theoretical estimations the hybrid nanochannel scheme enables facile and precise flow measurement through single nanochannels, nanotubes, or nanoporous media and opens the prospect for accurate characterization of both hydrophilic and hydrophobic nanofluidic systems. PMID:27112404
The Effect of Error Correlation on Interfactor Correlation in Psychometric Measurement
Westfall, Peter H.; Henning, Kevin S. S.; Howell, Roy D.
2012-01-01
This article shows how interfactor correlation is affected by error correlations. Theoretical and practical justifications for error correlations are given, and a new equivalence class of models is presented to explain the relationship between interfactor correlation and error correlations. The class allows simple, parsimonious modeling of error…
Hinde, Elizabeth; Thammasiraphop, Kitiphume; Duong, Hien T. T.; Yeow, Jonathan; Karagoz, Bunyamin; Boyer, Cyrille; Gooding, J. Justin; Gaus, Katharina
2017-01-01
Nanoparticle size, surface charge and material composition are known to affect the uptake of nanoparticles by cells. However, whether nanoparticle shape affects transport across various barriers inside the cell remains unclear. Here we used pair correlation microscopy to show that polymeric nanoparticles with different shapes but identical surface chemistries moved across the various cellular barriers at different rates, ultimately defining the site of drug release. We measured how micelles, vesicles, rods and worms entered the cell and whether they escaped from the endosomal system and had access to the nucleus via the nuclear pore complex. Rods and worms, but not micelles and vesicles, entered the nucleus by passive diffusion. Improving nuclear access, for example with a nuclear localization signal, resulted in more doxorubicin release inside the nucleus and correlated with greater cytotoxicity. Our results therefore demonstrate that drug delivery across the major cellular barrier, the nuclear envelope, is important for doxorubicin efficiency and can be achieved with appropriately shaped nanoparticles.
Sonographic Measurement of Renal Dimensions in Adults and its Correlates
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Iffat Yazdani
2012-09-01
Full Text Available Background: Unilateral or bilateral changes in kidney size are manifested by many renal diseases and to recognize these anatomical deviations, it is important to have standard sonographic measurements for appropriate comparison. Our primary aim was to determine a normal range of values for renal dimensions in our asymptomatic adult population and to correlate renal length with measures of renal function as a secondary objective. Methods: A cross-sectional population survey was conducted at two spaced-out densely populated areas in the city of Karachi, Pakistan. Ultrasound was preformed and blood samples collected from 225 healthy individuals with no known renal pathology and with normal calculated GFR. Results: Mean kidney lengths were 9.85cm (95% CI: 9.74-9.95 cm on right side and 10.0 cm (9.85-10.1 cm on left. The mean width was 4.61cm (95%CI: 4.53 – 4.68cm, cortical thickness 1.46 cm (CI 1.43-1.49cm with estimated average kidney volume 35.7 cm3 (CI: 34.1-36.5 cm3. Males had larger kidney sizes than females (p < 0.001; age however was only associated with a decrease in renal length after ages 70 and above.(p=0.001 Renal length best correlated with body weight (correlation coefficient 0.384 .eGFR, representative of renal function also positively correlated with renal length (Coefficient 0.415. A multivariate analysis showed male gender (OR 1.60, age (OR 0.89, weight (OR 1.02 and height (OR 7.77 to be significant independent predictors of renal length. Conclusion: We established the normal values for renal dimensions in our adult population. Our study signifies the potential of ultrasound as a useful tool for diagnostic and follow-up purposes of kidney–associated diseases. By extending this research and including data from other parts of the country; we can formulate a gender and age specific nomogram for kidney dimensions for adequate comparison in evaluation of kidney diseases.
Reimus, P. W.
2010-12-01
A process-oriented modeling approach is implemented to examine the importance of parameter variances, correlation lengths, and especially cross-correlations in contaminant transport predictions over large scales. It is shown that the most important consideration is the correlation between flow rates and retardation processes (e.g., sorption, matrix diffusion) in the system. If flow rates are negatively correlated with retardation factors in systems containing multiple flow pathways, then characterizing these negative correlation(s) may have more impact on reactive transport modeling than microscale information. Such negative correlations are expected in porous-media systems where permeability is negatively correlated with clay content and rock alteration (which are usually associated with increased sorption). Likewise, negative correlations are expected in fractured rocks where permeability is positively correlated with fracture apertures, which in turn are negatively correlated with sorption and matrix diffusion. Parameter variances and correlation lengths are also shown to have important effects on reactive transport predictions, but they are less important than parameter cross-correlations. Microscale information pertaining to contaminant transport has become more readily available as characterization methods and spectroscopic instrumentation have achieved lower detection limits, greater resolution, and better precision. Obtaining detailed mechanistic insights into contaminant-rock-water interactions is becoming a routine practice in characterizing reactive transport processes in groundwater systems (almost necessary for high-profile publications). Unfortunately, a quantitative link between microscale information and flow and transport parameter distributions or cross-correlations has not yet been established. One reason for this is that quantitative microscale information is difficult to obtain in complex, heterogeneous systems, so simple systems that lack the
Measuring correlations in non-separable vector beams using projective measurements
Subramanian, Keerthan
2016-01-01
In quantum mechanics, two particles are said to be entangled if the composite wavefunction is non-separable. Separating the two particles and measuring their coincidences as was done in the Aspect experiment leads to a modulated correlation between the polarization states of the two particles. In this article we demonstrate a similar experiment to look at a system whose two degrees of freedom (DoF)- polarization and mode - are entangled, ie the system can be modelled as a non-separable function in the Hilbert space. We propose an interferometric method to perform projective measurements that leads to correlations as seen for entangled quantum particles.
Transport measurements on individual CuO 2 double layers
Mößle, M.; Kleiner, R.; Gatt, R.; Onellion, M.; Müller, P.
2000-11-01
Oxygen loss at the surface of Bi 2Sr 2CaCu 2O 8+ x single crystals provides CuO 2 layers with different critical temperatures. Particularly for overdoped crystals this allows to achieve a T c maximum near the surface. We performed transport measurements of this oxygen depleted layer. Samples were prepared by evaporating four Pb or Ag electrodes on top of freshly cleaved Bi 2Sr 2CaCu 2O 8+ x single crystals. Using overdoped crystals with a bulk T c of 55 to 60 K, the outermost layer was found to be underdoped with T c down to 30 K while the adjacent one was near optimal doping with T c between 80 and 90 K. The T c of the third layer was close to the bulk value. For temperatures above the bulk T c often only one CuO 2 double layer was found to be superconducting. We discuss current transport measurements with current flow along the CuO 2 layers.
Spam Source Clustering by Constructing Spammer Network with Correlation Measure
Shin, Jeongkyu; Kim, Seunghwan
Spam filtering is one of the most challenging problems in electric message systems. In general, recent studies on specifying real spam source are based on content filtering because spammers usually falsify their origin. We propose a method to specify spam source based on structural analysis with complex network. We assume that each spam sources either has the same victim list or uses the same spam-hosting program. We treat spam source - target relationship as a bipartite network and construct weighted spam source network by network projection using correlation measure. We find that community clustering methods are inappropriate with spammer network. We group spammers with gradient-based grouping, which uses correlations between nodes as gradient between nodes. We convert them into local minima, which helps to cluster spammers into a few spam source groups. We investigate the weblog spam data with the proposed method and validate it. The method that we propose can be applied to diverse categorization problems, such as multiple text categorization and network subunit clustering.
Nonlocal spin-transport measurement of superconductor-ferromagnet nanostructures
Energy Technology Data Exchange (ETDEWEB)
Kolenda, Stefan; Wolf, Michael J.; Huebler, Florian; Beckmann, Detlef [Institut fuer Nanotechnologie, Karlsruher Institut fuer Technologie (Germany)
2015-07-01
We present measurements of the nonlocal conductance of nanostructures with several ferromagnetic electrodes lying perpendicular on a superconducting wire. In these structures nonlocal conductance is mostly given by diffusion of quasiparticles, which are injected by one of the electrodes and detected by an other one. Applying a magnetic field induces a Zeeman splitting in the quasiparticles density of states, which suppresses the relaxation of injected spin imbalance, thus spin transport over distances of several micrometers is found. While in the previous experiments the magnetic field was aligned parallel to the ferromagnetic electrodes, we also show measurements applying the magnetic field noncollinear with the magnetization of the ferromagnetic electrodes. We compare our results to the previous case.
Dhital, Chetan
The work performed within this thesis is divided into two parts, each focusing primarily on the study of magnetic phase behavior using neutron scattering techniques. In first part, I present transport, magnetization, and neutron scattering studies of materials within the iridium oxide-based Ruddelsden-Popper series [Srn+1IrnO3n+1] compounds Sr 3Ir2O7 (n=2) and Sr2IrO4 (n=1). This includes a comprehensive study of the doped bilayer system Sr 3(Ir1-xRux )2O7. In second part, I present my studies of the effect of uniaxial pressure on magnetic and structural phase behavior of the iron-based high temperature superconductor Ba(Fe1-xCox)2As2. Iridium-based 5d transition metal oxides host rather unusual electronic/magnetic ground states due to strong interplay between electronic correlation, lattice structure and spin-orbit effects. Out of the many oxides containing iridium, the Ruddelsden-Popper series [Srn+1IrnO 3n+1] oxides are some of the most interesting systems to study both from the point of view of physics as well as from potential applications. My work is focused on two members of this series Sr3Ir2O 7 (n=2) and Sr2IrO4 (n=1). In particular, our combined transport, magnetization and neutron scattering studies of Sr 3Ir2O7 (n=2) showed that this system exhibits a complex coupling between charge transport and magnetism. The spin magnetic moments form a G-type antiferromagnetic structure with moments oriented along the c-axis, with an ordered moment of 0.35+/-0.06 muB/Ir. I also performed experiments doping holes in this bilayer Sr3(Ir1-xRu x)2O7 system in order to study the role of electronic correlation in these materials. Our results show that the ruthenium-doped holes remain localized within the Jeff=1/2 Mott insulating background of Sr3Ir2O7, suggestive of 'Mott blocking' and the presence of strong electronic correlation in these materials. Antiferromagnetic order however survives deep into the metallic regime with the same ordering q-vector, suggesting an
Viscosity Measurements and Correlation of the Squalane + CO2 Mixture
Tomida, D.; Kumagai, A.; Yokoyama, C.
2007-02-01
Experimental results for the viscosity of squalane + CO2 mixtures are reported. The viscosities were measured using a rolling ball viscometer. The experimental temperatures were 293.15, 313.15, 333.15, and 353.15 K, and pressures were 10.0, 15.0, and 20.0 MPa. The CO2 mole fraction of the mixtures varied from 0 to 0.417. The experimental uncertainties in viscosity were estimated to be within ±3.0%. The viscosity of the mixtures decreased with an increase in the CO2 mole fraction. The experimental data were compared with predictions from the Grunberg-Nissan and McAllister equations, which correlated the experimental data with maximum deviations of 10 and 8.7%, respectively.
Influence of the surface hydrophobicity on fluorescence correlation spectroscopy measurements
Boutin, Céline; Jaffiol, Rodolphe; Plain, Jérome; Royer, Pascal
2007-02-01
Fluorescence correlation spectroscopy (FCS) is a powerful experimental technique used to analyze the diffusion at the single molecule level in solution. FCS is based on the temporal autocorrelation of fluorescent signal generated by dye molecules diffusing through a small confocal volume. These measurements are mostly carried out in a chambered coverglass, close to the glass substrate. In this report, we discuss how the chemical nature of the glass-water interface may interact with the free diffusion of molecules. Our results reveal a strong influence, up to a few Î¼m from the interface, of the surface hydrophobicity degree. This influence is assessed through the relative weight of the two dimension diffusion process observed at the vicinity of the surface.
Liu, Mengmeng; Li, Qian; Liang, Le; Li, Jiang; Wang, Kun; Li, Jiajun; Lv, Min; Chen, Nan; Song, Haiyun; Lee, Joon; Shi, Jiye; Wang, Lihua; Lal, Ratnesh; Fan, Chunhai
2017-05-01
Mechanistic understanding of the endocytosis and intracellular trafficking of nanoparticles is essential for designing smart theranostic carriers. Physico-chemical properties, including size, clustering and surface chemistry of nanoparticles regulate their cellular uptake and transport. Significantly, even single nanoparticles could cluster intracellularly, yet their clustering state and subsequent trafficking are not well understood. Here, we used DNA-decorated gold (fPlas-gold) nanoparticles as a dually emissive fluorescent and plasmonic probe to examine their clustering states and intracellular transport. Evidence from correlative fluorescence and plasmonic imaging shows that endocytosis of fPlas-gold follows multiple pathways. In the early stages of endocytosis, fPlas-gold nanoparticles appear mostly as single particles and they cluster during the vesicular transport and maturation. The speed of encapsulated fPlas-gold transport was critically dependent on the size of clusters but not on the types of organelle such as endosomes and lysosomes. Our results provide key strategies for engineering theranostic nanocarriers for efficient health management.
Measurement of the Critical Deposition Velocity in Slurry Transport through a Horizontal Pipe
Energy Technology Data Exchange (ETDEWEB)
Erian, Fadel F.; Furfari, Daniel J.; Kellogg, Michael I.; Park, Walter R.
2001-03-01
Critical Deposition Velocity (CDV) is an important design and operational parameter in slurry transport. Almost all existing correlations that are used to predict this parameter have been obtained experimentally from slurry transport tests featuring single solid species in the slurry mixture. No correlations have been obtained to describe this parameter when the slurry mixture contains more than one solid species having a wide range of specific gravities, particle size distributions, and volume concentrations within the overall slurry mixture. There are no physical or empirical bases that can justify the extrapolation or modification of the existing single species correlations to include all these effects. New experiments must be carried out to obtain new correlations that would be suited for these types of slurries, and that would clarify the mechanics of solids deposition as a function of the properties of the various solid species. Our goal in this paper is to describe a robust experimental technique for the accurate determination of the critical deposition velocity associated with the transport of slurries in horizontal or slightly inclined pipes. Because of the relative difficulty encountered during the precise determination of this useful operational parameter, it has been the practice to connect it with some transitional behavior of more easily measurable flow parameters such as the pressure drop along the slurry pipeline. In doing so, the critical deposition velocity loses its unique and precise definition due to the multitude of factors that influence such transitional behaviors. Here, data has been obtained for single species slurries made up of washed garnet and water and flowing through a 1- inch clear pipe. The selected garnet had a narrow particle size distribution with a mean diameter of 100 mm, approximately. The critical deposition velocity was measured for garnet/water slurries of 10, 20, and 30 percent solids concentration by volume.
Directory of Open Access Journals (Sweden)
Farzad Esmaeli
2012-01-01
Full Text Available Background: Diagnosis and accuracy in determining the exact location, extent and configurationof bony defects of the jaw are of utmost importance to determine prognosis,treatment planning and long-term preservation of teeth. If relatively accurate diagnosiscan be established by radiography, proper treatment planning prior to treatment procedureswill be possible.Objectives: The aim of the present study was to assess the correlation between indirectdigital radiographic measurements and clinical measurements in determining the topographyof interproximal bony defects.Patients and Methods: Twenty interproximal bony defects, preferably in the mandibularand maxillary 5↔5 area were selected and radiographed using the parallel periapical technique.The radiographs were corrected and digitized on a computer using “Linear Measurement”software; then the three parameters of the base of defect (BD, alveolar crest(AC and cementoenamel junction (CEJ were determined using a software. Subsequentto radiographic measurements, clinical measurements were carried out meticulouslyduring flap procedures. Then linear measurements were carried out using a periodontalprobe to determine the defect depth and its mesiodistal width. Then the amount of correlationbetween these two measurements was assessed by Pearson's correlation coefficient.Results: The correlation between clinical and radiographic measurements in defect depthdetermination, in the evaluation of defect angle and in determination of defect widthwere 88%, 98% and 90%, respectively.Conclusions: Indirect digital radiographic technique can be used to diagnose intra-osseousdefects, providing a better opportunity to treat bony defects.
Karolak, M.; Jacob, D.
2016-11-01
We study the impact of the valence and the geometry on the electronic structure and transport properties of different transition metal-benzene sandwich molecules bridging the tips of a Cu nanocontact. Our density-functional calculations show that the electronic transport properties of the molecules depend strongly on the molecular geometry which can be controlled by the nanocontact tips. Depending on the valence of the transition metal center certain molecules can be tuned in and out of half-metallic behaviour facilitating potential spintronics applications. We also discuss our results in the framework of an Anderson impurity model, indicating cases where the inclusion of local correlations alters the ground state qualitatively. For Co and V centered molecules we find indications of an orbital Kondo effect.
Energy Technology Data Exchange (ETDEWEB)
He, Qinggang; Kusoglu, Ahmet; Lucas, Ivan T.; Clark, Kyle; Weber, Adam Z.; Kostecki, Robert
2011-08-01
The objective of this effort was to correlate the local surface ionic conductance of a Nafion? 212 proton-exchange membrane with its bulk and interfacial transport properties as a function of water content. Both macroscopic and microscopic proton conductivities were investigated at different relative humidity levels, using electrochemical impedance spectroscopy and current-sensing atomic force microscopy (CSAFM). We were able to identify small ion-conducting domains that grew with humidity at the surface of the membrane. Numerical analysis of the surface ionic conductance images recorded at various relative humidity levels helped determine the fractional area of ion-conducting active sites. A simple square-root relationship between the fractional conducting area and observed interfacial mass-transport resistance was established. Furthermore, the relationship between the bulk ionic conductivity and surface ionic conductance pattern of the Nafion? membrane was examined.
Measurement and correlates of empathy among female Japanese physicians.
Kataoka, Hitomi U; Koide, Norio; Hojat, Mohammadreza; Gonnella, Joseph S
2012-06-22
The measurement of empathy is important in the assessment of physician competence and patient outcomes. The prevailing view is that female physicians have higher empathy scores compared with male physicians. In Japan, the number of female physicians has increased rapidly in the past ten years. In this study, we focused on female Japanese physicians and addressed factors that were associated with their empathic engagement in patient care. The Jefferson Scale of Empathy (JSE) was translated into Japanese by using the back-translation procedure, and was administered to 285 female Japanese physicians. We designed this study to examine the psychometrics of the JSE and group differences among female Japanese physicians. The item-total score correlations of the JSE were all positive and statistically significant, ranging from .20 to .54, with a median of .41. The Cronbach's coefficient alpha was .81. Female physicians who were practicing in "people-oriented" specialties obtained a significantly higher mean empathy score than their counterparts in "procedure-" or "technology-oriented" specialties. In addition, physicians who reported living with their parents in an extended family or living close to their parents, scored higher on the JSE than those who were living alone or in a nuclear family. Our results provide support for the measurement property and reliability of the JSE in a sample of female Japanese physicians. The observed group differences associated with specialties and living arrangement may have implications for sustaining empathy. In addition, recognizing these factors that reinforce physicians' empathy may help physicians to avoid career burnout.
A fast digital image correlation method for deformation measurement
Pan, Bing; Li, Kai
2011-07-01
Fast and high-accuracy deformation analysis using digital image correlation (DIC) has been increasingly important and highly demanded in recent years. In literature, the DIC method using the Newton-Rapshon (NR) algorithm has been considered as a gold standard for accurate sub-pixel displacement tracking, as it is insensitive to the relative deformation and rotation of the target subset and thus provides highest sub-pixel registration accuracy and widest applicability. A significant drawback of conventional NR-algorithm-based DIC method, however, is its extremely huge computational expense. In this paper, a fast DIC method is proposed deformation measurement by effectively eliminating the repeating redundant calculations involved in the conventional NR-algorithm-based DIC method. Specifically, a reliability-guided displacement scanning strategy is employed to avoid time-consuming integer-pixel displacement searching for each calculation point, and a pre-computed global interpolation coefficient look-up table is utilized to entirely eliminate repetitive interpolation calculation at sub-pixel locations. With these two approaches, the proposed fast DIC method substantially increases the calculation efficiency of the traditional NR-algorithm-based DIC method. The performance of proposed fast DIC method is carefully tested on real experimental images using various calculation parameters. Results reveal that the computational speed of the present fast DIC is about 120-200 times faster than that of the traditional method, without any loss of its measurement accuracy
Deformation-phase measurement by digital speckle correlation method
Zhao, Ran; Sun, Ping
2016-10-01
A novel algorithm which extracts the out-of-plane component of deformation phase from two continuous fringe patterns is proposed. The velocity field between two consecutive frames is estimated by digital speckle correlation method (DSCM). After that, according to the optical flow constrained equation, the whole-field deformation-phase map is obtained by the estimations of the velocity field and the local frequency of the original image. The operation of the proposed method is simple compared with other phase demodulation methods. Moreover, the new method works perfectly at the areas with dense fringes. In this paper, the proposed algorithm is introduced. Meanwhile, in order to verify the effectiveness, the new algorithm is applied to simulated interferogram and real fringe pattern with a centrally loaded and edge-clamped plate. The results of simulation and experiment show that the new method can demodulate the out-of-plane component of deformation phase from the visible in-plane velocity field without unwrapping process. Further, dynamic deformation-phase extraction will be realized when we know the time interval of two continuous images. The proposed algorithm provides a new approach for whole-field deformation-phase measurement and dynamic deformation measurement.
DEFF Research Database (Denmark)
Ziebell, Morten; Andersen, Birgitte B; Pinborg, Lars H;
2013-01-01
Patients who have dementia with Lewy bodies (DLB) show both clinical and histopathologic overlap with Alzheimer disease patients and Parkinson disease patients. In this study, we correlated the core features of DLB (dementia, parkinsonism, hallucinations, and fluctuations) with striatal dopamine...... transporter (DAT) availability as assessed with SPECT and (123)I-N-(3-iodoprop-2E-enyl)-2-β-carbomethoxy-3β-(4-methylphenyl) nortropane ((123)I-PE2I) in patients with newly diagnosed DLB. METHODS: Two hundred eighty-eight patients were consecutively included in the study as they were referred for diagnostic...
Energy Technology Data Exchange (ETDEWEB)
Masutomi, Ryuichi, E-mail: masutomi@phys.s.u-tokyo.ac.jp; Okamoto, Tohru [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)
2015-06-22
An adsorbate-induced quantum Hall system at the cleaved InSb surfaces is investigated in magnetic fields up to 14 T using low-temperature scanning tunneling microscopy and spectroscopy combined with transport measurements. We show that an enhanced Zeeman splitting in the Shubnikov-de Haas oscillations is explained by an exchange enhancement of spin splitting and potential disorder, both of which are obtained from the spatially averaged density of states (DOS). Moreover, the Altshuler–Aronov correlation gap is observed in the spatially averaged DOS at 0 T.
Saadatfar, M; Sahimi, Muhammad
2002-03-01
We present the results of extensive Monte Carlo simulation of diffusion in disordered media with long-range correlations, a problem which is relevant to transport of contaminants in field-scale porous media, such as aquifers, gas transport in soils, and transport in composite materials. The correlations are generated by a fractional Brownian motion characterized by a Hurst exponent H. For H>1/2 the correlations appear to have no effect, and the transport process is diffusive. However, for Hpower-law growth of the mean square displacements with the time in which the effective exponents characterizing the power-law oscillates log periodically with the time. This result cannot be predicted by any of the currently available continuum theories of transport in disordered media.
Mass transport measurements and modeling for chemical vapor infiltration
Energy Technology Data Exchange (ETDEWEB)
Starr, T.L.; Chiang, D.Y.; Fiadzo, O.G.; Hablutzel, N. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Materials Science and Engineering
1997-12-01
This project involves experimental and modeling investigation of densification behavior and mass transport in fiber preforms and partially densified composites, and application of these results to chemical vapor infiltration (CVI) process modeling. This supports work on-going at ORNL in process development for fabrication of ceramic matrix composite (CMC) tubes. Tube-shaped composite preforms are fabricated at ORNL with Nextel{trademark} 312 fiber (3M Corporation, St. Paul, MN) by placing and compressing several layers of braided sleeve on a tubular mandrel. In terms of fiber architecture these preforms are significantly different than those made previously with Nicalon{trademark} fiber (Nippon Carbon Corp., Tokyo, Japan) square weave cloth. The authors have made microstructure and permeability measurements on several of these preforms and a few partially densified composites so as to better understand their densification behavior during CVI.
Transport measurements on monolayer and few-layer WSe2
Palomaki, Tauno; Zhao, Wenjin; Finney, Joe; Fei, Zaiyao; Nguyen, Paul; McKay, Frank; Cobden, David
The behavior of the electrical contacts often dominates transport measurements in mono and few-layer transition metal dichalcogenide (TMD) devices. Creating good contacts for some TMDs is particularly challenging since the fabrication procedure should prevent the TMD from oxidizing or chemically interacting with the contacts. In this talk, we discuss our progress on creating mono and few-layer WSe2 devices with both good electrical contacts and minimal effects from the substrate, polymer contamination, oxidation and other chemistry. For example, we have developed a technique for encapsulating metallic contacts and WSe2 flakes together in hexagonal boron nitride with multiple gates to separate and control the contributions from the channel and the Schottky barriers at the contacts. Research supported in part by Samsung GRO grant US 040814
Jones, M; Aptaker, P S; Cox, J; Gardiner, B A; McDonald, P J
2012-05-01
This paper presents the design of the 'Tree Hugger', an open access, transportable, 1.1 MHz (1)H nuclear magnetic resonance imaging system for the in situ analysis of living trees in the forest. A unique construction employing NdFeB blocks embedded in a reinforced carbon fibre frame is used to achieve access up to 210 mm and to allow the magnet to be transported. The magnet weighs 55 kg. The feasibility of imaging living trees in situ using the 'Tree Hugger' is demonstrated. Correlations are drawn between NMR/MRI measurements and other indicators such as relative humidity, soil moisture and net solar radiation. Copyright © 2012 Elsevier Inc. All rights reserved.
Roach, William; Beringer, Douglas; Skuza, Jonathan; Clavero, Cesar; Lukaszew, Rosa Alejandra
2009-11-01
Interest in graphene, a single layer of carbon atoms arranged in a hexagonal lattice, has increased in recent years due to exciting characteristics such as its predicted high mobility [1]. However, developing a method to produce graphene that is easily integrated into existing fabrication processes has proved difficult thus far. One promising method is high temperature annealing of 6H-SiC such that Si desorption occurs [2], although this method leads to graphene that exhibits lower mobility than predicted [3]. Thus, we have investigated the relationship between different growth conditions (i.e. annealing time and temperature), the resulting surface morphology and the transport properties of graphene films produced using this method. Raman spectroscopy, atomic force microscopy, and Van der Pauw Hall mobility measurements have been used to correlate the surface morphology to transport properties of graphene formed on SiC. Understanding the effect of growth conditions on the resulting transport properties will help optimize the fabrication of graphene for use in the next generation of electronic devices and other applications. [1] Novoselov et al., Science 306, 666 (2004). [2] C. Berger et al., J. Phys. Chem. B 108, 19912 (2004). [3] G. Gu et al., Appl. Phys. Lett. 90, 253507 (2007).
Polysulfide transport through separators measured by a linear voltage sweep method
Cui, Yi; Fu, Yongzhu
2015-07-01
Shuttle of polysulfide from the sulfur cathode to lithium metal anode in rechargeable lithium-sulfur batteries is a critical issue hindering cycling efficiency and life. Several approaches have been developed to minimize it including polysulfide-blocking separators; there is a need for measuring polysulfide transport through separators. We here show a linear voltage sweep method to measure anodic (oxidization) current of polysulfide crossed separators, which can be used as a quantitative measurement of the polysulfide transport. The electrochemical oxidation of polysulfide is diffusion controlled. The electrical charge in Coulombs produced by the oxidation of polysulfide is linearly related to the concentration of polysulfide within a certain range (≤0.5 M). Separators with a high porosity (large pore size) show high anodic currents, resulting in fast capacity degradation and low Coulombic efficiencies in Li-S cells. These results demonstrate this method can be used to correlate the polysulfide transport through separators with the separator structure and battery performance, therefore provide guidance for developing new separators for lithium-sulfur batteries.
Rapidity bin multiplicity correlations from a multi-phase transport model
Energy Technology Data Exchange (ETDEWEB)
Wang, Mei-Juan; Chen, Gang [China University of Geoscience, School of Mathematics and Physics, Wuhan (China); Wu, Yuan-Fang [Central China Normal University, Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Wuhan (China); Ma, Guo-Liang [Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Shanghai (China)
2016-03-15
The central-arbitrary bin and forward-backward bin multiplicity correlation patterns for Au+Au collisions at √(s{sub NN}) = 7.7-62.4 GeV are investigated within a multi-phase transport (AMPT) model. An interesting observation is that for √(s{sub NN}) < 19.6 GeV Au+Au collisions, these two correlation patterns both have an increase with the pseudorapidity gap, while for √(s{sub NN}) > 19.6 GeV Au+Au collisions, they decrease. We mainly discuss the influence of different evolution stages of collision system on the central-arbitrary bin correlations, such as the initial conditions, partonic scatterings, hadronization scheme and hadronic scatterings. Our results show that the central-arbitrary bin multiplicity correlations have different responses to partonic phase and hadronic phase, which can be suggested as a good probe to explore the dynamical evolution mechanism of the hot dense matter in high-energy heavy-ion collisions. (orig.)
Estimation of Apollo lunar dust transport using optical extinction measurements
Lane, John E
2015-01-01
A technique to estimate mass erosion rate of surface soil during landing of the Apollo Lunar Module (LM) and total mass ejected due to the rocket plume interaction is proposed and tested. The erosion rate is proportional to the product of the second moment of the lofted particle size distribution N(D), and third moment of the normalized soil size distribution S(D), divided by the integral of S(D)D^2/v(D), where D is particle diameter and v(D) is the vertical component of particle velocity. The second moment of N(D) is estimated by optical extinction analysis of the Apollo cockpit video. Because of the similarity between mass erosion rate of soil as measured by optical extinction and rainfall rate as measured by radar reflectivity, traditional NWS radar/rainfall correlation methodology can be applied to the lunar soil case where various S(D) models are assumed corresponding to specific lunar sites.
Turbulent transport measurements in a model of GT-combustor
Chikishev, L. M.; Gobyzov, O. A.; Sharaborin, D. K.; Lobasov, A. S.; Dulin, V. M.; Markovich, D. M.; Tsatiashvili, V. V.
2016-10-01
To reduce NOx formation modern industrial power gas-turbines utilizes lean premixed combustion of natural gas. The uniform distribution of local fuel/air ratio in the combustion chamber plays one of the key roles in the field of lean combustion to prevent thermo-acoustic pulsations. Present paper reports on simultaneous Particle Image Velocimetry and acetone Planar Laser Induced Fluorescence measurements in a cold model of GT-combustor to investigate mixing processes which are relevant to the organization of lean premixed combustion. Velocity and passive admixture pulsations correlations were measured to verify gradient closer model, which is often used in Reynolds-Averaged Navier-Stokes (RANS) simulation of turbulent mixing.
Alizadeh, S. M.; Latham, S.; Middleton, J.; Limaye, A.; Senden, T. J.; Arns, C. H.
2017-02-01
Assessing the mechanisms of micro-structural change and their effect on transport properties using digital core analysis requires balancing field of view and resolution. This typically leads to the compromise of working with relatively small samples, where boundary effects can be substantial. A direct comparison with experiment, as e.g. desirable to eliminate unknown parameters and integrate numerical and physical experiments, needs to consider these boundary effects. Here we develop a workflow to define measuring windows within a sample where these boundary effects are minimised allowing the integration of physical and numerical experiment. We consider in particular sleeve leakage and use a radial partitioning of the solutions to various transport equations to derive relevant regional measures, which may be used for the development of cross-correlations between physical properties. Samples of Bentheimer and Castlegate sandstone as well as Mt. Gambier limestone and a sucrosic dolomite are considered. The sample plugs are encased in rubber sleeves and micro-CT images acquired at ambient conditions. Using these high-resolution images we calculate transport properties, namely permeability and electrical conductivity, and analyse the resulting field solutions with regard to flux across different regions of interest. The latter are selected on the basis of distance to the sample sleeve inner surface. Clear bypassing at the sleeve-sample interface in terms of elevated fluxes is observed for all samples, although to different extent. We consider different sleeve boundary conditions to define a measuring window minimising these effects, use the procedure to compare flux averages defined over these measuring windows with conventional choices of simulation domains, and compare resulting physical cross-correlations.
Wallmann-Sperlich, Birgit; Froboese, Ingo
2014-01-01
Background This study aimed 1) to provide data estimates concerning overall moderate- and vigorous-intensity physical activity (MVPA) as well as MVPA during work, transport and leisure in Germany and 2) to investigate MVPA and possible associations with socio-demographic correlates. Methods A cross-sectional telephone survey interviewed 2248 representative participants in the age of 18–65 years (1077 men; 42.4±13.4 years; body mass index: 25.3±4.5kg•m−2) regarding their self-reported physical activity across Germany. The Global Physical Activity Questionnaire was applied to investigate MVPA during work, transport and leisure and questions were answered concerning their demographics. MVPA was stratified by gender, age, body mass index, residential setting, educational and income level. To identify socio-demographic correlates of overall MVPA as well as in the domains, we used a series of linear regressions. Results 52.8% of the sample achieved physical activity recommendations (53.7% men/52.1% women). Overall MVPA was highest in the age group 18–29 years (psocio-demographic variables, residential setting as well as the physical activity domain in Germany. PMID:25390071
Measurement and correlates of empathy among female Japanese physicians
Directory of Open Access Journals (Sweden)
Kataoka Hitomi U
2012-06-01
Full Text Available Abstract Background The measurement of empathy is important in the assessment of physician competence and patient outcomes. The prevailing view is that female physicians have higher empathy scores compared with male physicians. In Japan, the number of female physicians has increased rapidly in the past ten years. In this study, we focused on female Japanese physicians and addressed factors that were associated with their empathic engagement in patient care. Methods The Jefferson Scale of Empathy (JSE was translated into Japanese by using the back-translation procedure, and was administered to 285 female Japanese physicians. We designed this study to examine the psychometrics of the JSE and group differences among female Japanese physicians. Results The item-total score correlations of the JSE were all positive and statistically significant, ranging from .20 to .54, with a median of .41. The Cronbach’s coefficient alpha was .81. Female physicians who were practicing in “people-oriented” specialties obtained a significantly higher mean empathy score than their counterparts in “procedure-” or “technology-oriented” specialties. In addition, physicians who reported living with their parents in an extended family or living close to their parents, scored higher on the JSE than those who were living alone or in a nuclear family. Conclusions Our results provide support for the measurement property and reliability of the JSE in a sample of female Japanese physicians. The observed group differences associated with specialties and living arrangement may have implications for sustaining empathy. In addition, recognizing these factors that reinforce physicians’ empathy may help physicians to avoid career burnout.
Kasteel, R.; Pütz, Th.; Vereecken, H.
2003-04-01
Lysimeter studies are one step within the registration procedure of pesticides. Flow and transport in these free-draining lysimeters do not reflect the field situation mainly because of the occurence of a zone of local saturation at the lower boundary (seepage face). The objective of this study is to evaluate the impact of flow and transport behaviour of bromide detected with different measuring devices (lysimeters, suction plates, and soil coring) by comparing experimental results with numerical simulations in heterogeneous flow domains. We applied bromide as a small pulse to the bare soil surface (Orthic Luvisol) of the three devices and the displacement of bromide was regurlarly sampled for three years under natural wheather conditions. Based on the mean breakthrough curves we observe experimentally that lysimeters have a lower effective pore-water velocity and exhibit more solute spreading resulting in a larger dispersivity than the suction plates. This can be ascribed to the artefact of the lower boundary. We performed numerical transport simulations in 2-D heterogeneous flow fields (scaling approach) choosing appropriate boundary conditions for the various devices. The simulations allow to follow the temporal evolution of flow and transport processes in the various devices and to gain additional process understanding. We conclude that the model is essentially capable to reproduce the main experimental findings only if we account for the spatial correlation structure of the hydraulic properties, i.e. soil heterogeneity.
Energy Technology Data Exchange (ETDEWEB)
DePaolo, Donald J.; Maher, Kate; Christensen, John N.; McManus,Jerry
2006-06-05
High precision uranium isotope measurements of marineclastic sediments are used to measure the transport and storage time ofsediment from source to site of deposition. The approach is demonstratedon fine-grained, late Pleistocene deep-sea sediments from Ocean DrillingProgram Site 984A on the Bjorn Drift in the North Atlantic. The sedimentsare siliciclastic with up to 30 percent carbonate, and dated by sigma 18Oof benthic foraminifera. Nd and Sr isotopes indicate that provenance hasoscillated between a proximal source during the last three interglacialperiods volcanic rocks from Iceland and a distal continental sourceduring glacial periods. An unexpected finding is that the 234U/238Uratios of the silicate portion of the sediment, isolated by leaching withhydrochloric acid, are significantly less than the secular equilibriumvalue and show large and systematic variations that are correlated withglacial cycles and sediment provenance. The 234U depletions are inferredto be due to alpha-recoil loss of234Th, and are used to calculate"comminution ages" of the sediment -- the time elapsed between thegeneration of the small (<_ 50 mu-m) sediment grains in the sourceareas by comminution of bedrock, and the time of deposition on theseafloor. Transport times, the difference between comminution ages anddepositional ages, vary from less than 10 ky to about 300 to 400 ky forthe Site 984A sediments. Long transport times may reflect prior storagein soils, on continental shelves, or elsewhere on the seafloor. Transporttime may also be a measure of bottom current strength. During the mostrecent interglacial periods the detritus from distal continental sourcesis diluted with sediment from Iceland that is rapidly transported to thesite of deposition. The comminution age approach could be used to dateQuaternary non-marine sediments, soils, and atmospheric dust, and may beenhanced by concomitant measurement of 226Ra/230Th, 230Th/234U, andcosmogenic nuclides.
Directory of Open Access Journals (Sweden)
Hannah Verhoeven
Full Text Available Active transport is a convenient way to incorporate physical activity in adolescents' daily life. The present study aimed to investigate which psychosocial and environmental factors are associated with walking, cycling, public transport (train, tram, bus, metro and passive transport (car, motorcycle, moped over short distances (maximum eight kilometres among older adolescents (17-18 years, to school and to other destinations.562 older adolescents completed an online questionnaire assessing socio-demographic variables, psychosocial variables, environmental variables and transport to school/other destinations. Zero-inflated negative binomial regression models were performed.More social modelling and a higher residential density were positively associated with walking to school and walking to other destinations, respectively. Regarding cycling, higher self-efficacy and a higher social norm were positively associated with cycling to school and to other destinations. Regarding public transport, a higher social norm, more social modelling of siblings and/or friends, more social support and a higher land use mix access were positively related to public transport to school and to other destinations, whereas a greater distance to school only related positively to public transport to school. Regarding passive transport, more social support and more perceived benefits were positively associated with passive transport to school and to other destinations. Perceiving less walking and cycling facilities at school was positively related to passive transport to school only, and more social modelling was positively related to passive transport to other destinations.Overall, psychosocial variables seemed to be more important than environmental variables across the four transport modes. Social norm, social modelling and social support were the most consistent psychosocial factors which indicates that it is important to target both older adolescents and their social
Verhoeven, Hannah; Simons, Dorien; Van Dyck, Delfien; Van Cauwenberg, Jelle; Clarys, Peter; De Bourdeaudhuij, Ilse; de Geus, Bas; Vandelanotte, Corneel; Deforche, Benedicte
2016-01-01
Active transport is a convenient way to incorporate physical activity in adolescents' daily life. The present study aimed to investigate which psychosocial and environmental factors are associated with walking, cycling, public transport (train, tram, bus, metro) and passive transport (car, motorcycle, moped) over short distances (maximum eight kilometres) among older adolescents (17-18 years), to school and to other destinations. 562 older adolescents completed an online questionnaire assessing socio-demographic variables, psychosocial variables, environmental variables and transport to school/other destinations. Zero-inflated negative binomial regression models were performed. More social modelling and a higher residential density were positively associated with walking to school and walking to other destinations, respectively. Regarding cycling, higher self-efficacy and a higher social norm were positively associated with cycling to school and to other destinations. Regarding public transport, a higher social norm, more social modelling of siblings and/or friends, more social support and a higher land use mix access were positively related to public transport to school and to other destinations, whereas a greater distance to school only related positively to public transport to school. Regarding passive transport, more social support and more perceived benefits were positively associated with passive transport to school and to other destinations. Perceiving less walking and cycling facilities at school was positively related to passive transport to school only, and more social modelling was positively related to passive transport to other destinations. Overall, psychosocial variables seemed to be more important than environmental variables across the four transport modes. Social norm, social modelling and social support were the most consistent psychosocial factors which indicates that it is important to target both older adolescents and their social environment
Stasyszyn, F; Dolag, K; Beck, R; Donnert, J
2010-01-01
Using cosmological MHD simulations of the magnetic field in galaxy clusters and filaments we evaluate the possibility to infer the magnetic field strength in filaments by measuring cross-correlation functions between Faraday Rotation Measures (RM) and the galaxy density field. We also test the reliability of recent estimates considering the problem of data quality and Galactic foreground (GF) removal in current datasets. Besides the two self-consistent simulations of cosmological magnetic fields based on primordial seed fields and galactic outflows analyzed here, we also explore a larger range of models scaling up the resulting magnetic fields of one of the simulations. We find that, if an unnormalized estimator for the cross-correlation functions and a GF removal procedure is used, the detectability of the cosmological signal is only possible for future instruments (e.g. SKA and ASKAP). However, mapping of the observed RM signal to the underlying magnetization of the Universe (both in space and time) is an e...
Someswara Rao, Chinta; Viswanadha Raju, S
2016-03-01
In this paper, we consider correlation coefficient, rank correlation coefficient and cosine similarity measures for evaluating similarity between Homo sapiens and monkeys. We used DNA chromosomes of genome wide genes to determine the correlation between the chromosomal content and evolutionary relationship. The similarity among the H. sapiens and monkeys is measured for a total of 210 chromosomes related to 10 species. The similarity measures of these different species show the relationship between the H. sapiens and monkey. This similarity will be helpful at theft identification, maternity identification, disease identification, etc.
Entropy measure of credit risk in highly correlated markets
Gottschalk, Sylvia
2017-07-01
We compare the single and multi-factor structural models of corporate default by calculating the Jeffreys-Kullback-Leibler divergence between their predicted default probabilities when asset correlations are either high or low. Single-factor structural models assume that the stochastic process driving the value of a firm is independent of that of other companies. A multi-factor structural model, on the contrary, is built on the assumption that a single firm's value follows a stochastic process correlated with that of other companies. Our main results show that the divergence between the two models increases in highly correlated, volatile, and large markets, but that it is closer to zero in small markets, when asset correlations are low and firms are highly leveraged. These findings suggest that during periods of financial instability, when asset volatility and correlations increase, one of the models misreports actual default risk.
Cottaar, J.; Coehoorn, R.; Bobbert, P. A.
2012-06-01
We recently introduced a scaling theory for charge transport in molecular semiconductors with uncorrelated Gaussian energetic disorder, considering Miller-Abrahams as well as Marcus hopping and different lattice structures [Cottaar , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.107.136601 107, 136601 (2011)]. A compact expression was derived for the dependence of the charge-carrier mobility on temperature and carrier concentration. We show here that for Miller-Abrahams hopping the theory can also be applied to non-Gaussian energetic disorder, without parameter changes. Moreover, we show how it can be applied to correlated energetic disorder as obtained from randomly oriented molecular dipoles, which experiments suggest to be often more suitable. The same compact expression still describes the charge-carrier mobility, with new parameter values as determined from numerically exact results. The critical scaling exponent for correlated disorder is about twice as large as for uncorrelated disorder, which is caused by a different topology of the percolating network. The temperature dependence of the mobility for correlated disorder is significantly weaker than for uncorrelated disorder, while the carrier-concentration dependence is slightly weaker, due to small deviations of the density of states from a Gaussian. We indicate how comparison with experiments could distinguish between the different models.
Farzam, Parisa; Sutin, Jason; Wu, Kuan-Cheng; Zimmermann, Bernhard B.; Tamborini, Davide; Dubb, Jay; Boas, David A.; Franceschini, Maria Angela
2017-02-01
Intracranial pressure (ICP) monitoring has a key role in the management of neurosurgical and neurological injuries. Currently, the standard clinical monitoring of ICP requires an invasive transducer into the parenchymal tissue or the brain ventricle, with possibility of complications such as hemorrhage and infection. A non-invasive method for measuring ICP, would be highly preferable, as it would allow clinicians to promptly monitor ICP during transport and allow for monitoring in a larger number of patients. We have introduced diffuse correlation spectroscopy (DCS) as a non-invasive ICP monitor by fast measurement of pulsatile cerebral blood flow (CBF). The method is similar to Transcranial Doppler ultrasound (TCD), which derives ICP from the amplitude of the pulsatile cerebral blood flow velocity, with respect to the amplitude of the pulsatile arterial blood pressure. We believe DCS measurement is superior indicator of ICP than TCD estimation because DCS directly measures blood flow, not blood flow velocity, and the small cortical vessels measured by DCS are more susceptible to transmural pressure changes than the large vessels. For fast DCS measurements to recover pulsatile CBF we have developed a custom high-power long-coherent laser and a strategy for delivering it to the tissue within ANSI standards. We have also developed a custom FPGA-based correlator board, which facilitates DCS data acquisitions at 50-100 Hz. We have tested the feasibility of measuring pulsatile CBF and deriving ICP in two challenging scenarios: humans and rats. SNR is low in human adults due to large optode distances. It is similarly low in rats because the fast heart rate in this setting requires a high repetition rate.
Runge, Jakob
2013-01-01
The dependencies of the lagged (Pearson) correlation function on the coefficients of multivariate autoregressive models are interpreted in the framework of time series graphs. Time series graphs are related to the concept of Granger causality and encode the conditional independence structure of a multivariate process. The authors show that the complex dependencies of the Pearson correlation coefficient complicate an interpretation and propose a novel partial correlation measure with a straigh...
Measurements and simulations of water transport in maize plants
Heinlein, Florian; Klein, Christian; Thieme, Christoph; Priesack, Eckart
2017-04-01
In Central Europe climate change will become manifest in the increase of extreme weather events like flash floods, heat waves and summer droughts, and in a shift of precipitation towards winter months. Therefore, regional water availability will alter which has an effect on future crop growth, water use efficiency and yields. To better estimate these effects accurate model descriptions of transpiration and other parts of the water balance are important. In this study, we determined transpiration of four maize plants on a field of the research station Scheyern (about 40km North of Munich) by means of sap flow measurement devices (ICQ International Pty Ltd, Australia) using the Heat-Ratio-Method: two temperature probes, 0.5 cm above and below a heater, detect a heat pulse and its speed which facilitates the calculation of sap flow. Additionally, high resolution changes of stem diameters were measured with dendrometers (DD-S, Ecomatik). The field was also situated next to an eddy covariance station which provided latent heat fluxes from the soil-plant system. We also performed terrestrial laser scans of the respective plants to extract the plant architectures. These structures serve as input for our mechanistic transpiration model simulating the water transport within the plant. This model, which has already been successfully applied to single Fagus sylvatica L. trees, was adapted to agricultural plants such as maize. The basic principle of this model is to solve a 1-D Richards equation along the graph of the single plants. A comparison between the simulations and the measurements is presented and discussed.
Directory of Open Access Journals (Sweden)
Benjamin Siegert
2015-12-01
Full Text Available The interplay of exchange correlations and spin–orbit interaction (SOI on the many-body spectrum of a copper phtalocyanine (CuPc molecule and their signatures in transport are investigated. We first derive a minimal model Hamiltonian in a basis of frontier orbitals that is able to reproduce experimentally observed singlet–triplet splittings. In a second step SOI effects are included perturbatively. Major consequences of the SOI are the splitting of former degenerate levels and a magnetic anisotropy, which can be captured by an effective low-energy spin Hamiltonian. We show that scanning tunneling microscopy-based magnetoconductance measurements can yield clear signatures of both these SOI-induced effects.
Geometric measures of quantum correlations with Bures and Hellinger distances
2016-01-01
Comment: to be published as a chapter of the book "Lectures on general quantum correlations and their applications" edited by F. Fanchini, D. Soares-Pinto, and G. Adesso (Springer, 2017); 43 pages, 3 figures
Correlation function as a measure of the structure
Buryak, O E
1995-01-01
Geometrical model of structure of the universe is examined to obtain analytical expression for the two points nonlinear correlation function. According to the model the objects (galaxies) are concentrated into two types of structure elements - filaments and sheets. We considered the filaments ( similar to galaxy filaments ) simply as straight lines and the sheets ( similar to superclusters of galaxies ) simply as planes. The homogeneously distributed objects are also taken into consideration. The spatial distribution of lines, planes and points is uncorrelated. The nonlinear correlation function depends on four parameters and is similar to the observed and simulated ones for different samples. It describes quite well the correlation of galaxies, clusters of galaxies and dark matter distribution. Possible interpretation of the parameters of nonlinear correlation function is discussed.
Measurement of Angular Correlations in the Decay of Polarized Neutrons
DEFF Research Database (Denmark)
Christensen, Carl Jørgen; Krohn, V.E.; Ringo, G.R.
1970-01-01
The electron-momentum-neutron-spin correlation coefficient was found to be A=-0.115±0.008, and the antineutrino-momentum-neutron-spin correlation coefficient was found to be B=1.00±0.05. The value of A leads to |GA/GV|=1.26±0.02 for the ratio of Gamow-Teller-to-Fermi coupling constants in β decay...
THE CORRELATION EFFECT ON THE CHAIN MOTION CONTRIBUTION TO IONIC TRANSPORT IN POLYMER ELECTROLYTES
Institute of Scientific and Technical Information of China (English)
XU Gu
1994-01-01
The ionic transport process in polymer electrolytes (such as polyethylene oxide) was simulated numerically on a two dimensional square lattice where charge carriers are accommodated by the lattice sites connected randomly with available bonds to represent the amorphous chain configuration. Following the dynamic bond percolation theory(DBPT),the chain motion contribution to the ionic conduction was incorporated via periodical renewal of the random bond configuration. To check and extend the prediction made by DBPT employing global abrupt bond renewal,spatial correlation of the bond reassignment was introduced to the system by:1)regional bond renewal and 2) organized bond motion. It is found that the difference between the diffusivities simulated involving regional bond renewal and those of DBPT becomes negligible when the bond renewal rate approaches the carrier hopping rate.
Effects of electron correlations on transport properties of iron at Earth's core conditions.
Zhang, Peng; Cohen, R E; Haule, K
2015-01-29
Earth's magnetic field has been thought to arise from thermal convection of molten iron alloy in the outer core, but recent density functional theory calculations have suggested that the conductivity of iron is too high to support thermal convection, resulting in the investigation of chemically driven convection. These calculations for resistivity were based on electron-phonon scattering. Here we apply self-consistent density functional theory plus dynamical mean-field theory (DFT + DMFT) to iron and find that at high temperatures electron-electron scattering is comparable to the electron-phonon scattering, bringing theory into agreement with experiments and solving the transport problem in Earth's core. The conventional thermal dynamo picture is safe. We find that electron-electron scattering of d electrons is important at high temperatures in transition metals, in contrast to textbook analyses since Mott, and that 4s electron contributions to transport are negligible, in contrast to numerous models used for over fifty years. The DFT+DMFT method should be applicable to other high-temperature systems where electron correlations are important.
Dynamical and transport properties in plasmas including three-particle spatial correlations
Ababsa, Hakima; Meftah, Med Tayeb; Chohra, Thouria
2017-03-01
In this work, we study the two and triplet static correlation functions in plasma when the ions interact via the Debye screened potential and via the Deutsch screened potential. The latter takes into consideration the possible quantum effects at short distances. The ratio of the mean distance between two ions and the thermal De Broglie wavelength ri/λT gives the measure of these effects. Our investigation is developed in the conditions of weak coupling parameter (Γ <1 ). The pair and the triplet correlation functions are calculated numerically and compared to the correlation functions due to the Kirkwood superposition approximation (KSA). Some applications to the ion velocity auto-correlation function D(t) and the electric field auto-correlation function C(t) at an ion (assumed to be an impurity) and the diffusion coefficient D are calculated for the two kinds of potentials in different plasma conditions. The comparison with other results found in the literature shows a well satisfactory agreement, for the static as well as the dynamic properties.
Protocal for the measurement of hydrocarbon transport in bacteria
Due to the hydrophobic, volatility, and relatively low aqueous solubility of aliphatic and aromatic hydrocarbons, transport of these chemicals by bacteria has not been extensively studied. These issues make transport assays difficult to carry out, and as a result, strong evidence for the active tran...
Fluctuations and correlations in nucleus-nucleus collisions within transport approaches
Energy Technology Data Exchange (ETDEWEB)
Konchakovski, Volodymyr P.
2009-10-01
The current thesis is devoted to a systematic study of fluctuations and correlations in heavy-ion collisions, which might be considered as probes for the phase transition and the critical point in the phase diagram, within the Hadron-String- Dynamics (HSD) microscopic transport approach. This is a powerful tool to study nucleus-nucleus collisions and allows to completely simulate experimental collisions on an event-by-event basis. Thus, the transport model has been used to study fluctuations and correlations including the influence of experimental acceptance as well as centrality, system size and collision energy. The comparison to experimental data can separate the effects induced by a phase transition since there is no phase transition in the HSD version used here. Firstly the centrality dependence of multiplicity fluctuations has been studied. Different centrality selections have been performed in the analysis in correspondence to the experimental situation. For the fixed target experiment NA49 events with fixed numbers of the projectile participants have been studied while in the collider experiment PHENIX centrality classes of events have been defined by the multiplicity in certain phase space region. A decrease of participant number fluctuations (and thus volume fluctuations) in more central collisions for both experiments has been obtained. Another area of this work addresses to transport model calculations of multiplicity fluctuations in nucleus-nucleus collisions as a function of colliding energy and system size. This study is in full correspondence to the experimental program of the NA61 Collaboration at the SPS. Central C+C, S+S, In+In, and Pb+Pb nuclear collisions at Elab = 10, 20, 30, 40, 80, 158 AGeV have been investigated. The expected enhanced fluctuations - attributed to the critical point and phase transition - can be observed experimentally on top of a monotonic and smooth 'hadronic background'. These findings should be helpful for the
Electrostatic and magnetic measurements of turbulence and transport in Extrap T2
Möller, Anders; Sallander, Eva
1999-10-01
Langmuir probe and magnetic pick-up coil measurements are used to study edge turbulence in the Extrap T2 reversed field pinch. Magnetic fluctuations resonant outside the toroidal field reversal surface are observed where previously only fluctuations in the spectra of potential and electron density and temperature have been measured. Results are presented which imply that these fluctuations are coupled to and also correlated to the internally resonant tearing mode fluctuations. Evidence of coupling between low-frequency (<100 kHz) and high-frequency fluctuations is also presented. The normalized floating potential fluctuations are seen to increase with the edge electron temperature. This causes an increase of the potential and density fluctuation driven transport with the temperature which is faster than linear. These results, in combination, are consistent with a picture where internally resonant fluctuations couple to edge fluctuations through radial heat conduction from the stochastic core to the edge.
Measuring weak lensing correlations of Type Ia Supernovae
Scovacricchi, D; Macaulay, E; Bacon, D
2016-01-01
We study the feasibility of detecting weak lensing spatial correlations between Supernova (SN) Type Ia magnitudes with present (Dark Energy Survey, DES) and future (Large Synoptic Survey Telescope, LSST) surveys. We investigate the angular auto-correlation function of SN magnitudes (once the background cosmology has been subtracted) and cross-correlation with galaxy catalogues. We examine both analytical and numerical predictions, the latter using simulated galaxy catalogues from the MICE Grand Challenge Simulation. We predict that we will be unable to detect the SN auto-correlation in DES, while it should be detectable with the LSST SN deep fields (15,000 SNe on 70 deg^2) at ~6sigma level of confidence (assuming 0.15 magnitudes of intrinsic dispersion). The SN-galaxy cross-correlation function will deliver much higher signal-to-noise, being detectable in both surveys with an integrated signal-to-noise of ~100 (up to 30 arcmin separations). We predict joint constraints on the matter density parameter (Omega_m...
Measures of galaxy environment -- II. Rank-ordered mark correlations
Skibba, Ramin A; Croton, Darren J; Muldrew, Stuart I; Abbas, Ummi; Pearce, Frazer R; Shattow, Genevieve M
2012-01-01
We analyze environmental correlations using mark clustering statistics with the mock galaxy catalogue constructed by Muldrew et al. (Paper I). We find that mark correlation functions are able to detect even a small dependence of galaxy properties on the environment, quantified by the overdensity $1+\\delta$, while such a small dependence would be difficult to detect by traditional methods. We then show that rank ordering the marks and using the rank as a weight is a simple way of comparing the correlation signals for different marks. With this we quantify to what extent fixed-aperture overdensities are sensitive to large-scale halo environments, nearest-neighbor overdensities are sensitive to small-scale environments within haloes, and colour is a better tracer of overdensity than is luminosity.
Zhang, Yongjun
A key part of the FutureGen concept is to support the production of hydrogen to fuel a "hydrogen economy," with the use of clean burning hydrogen in power-producing fuel cells, as well as for use as a transportation fuel. One of the key technical barriers to FutureGen deployment is reliable and efficient hydrogen separation technology. Most Hydrogen Transport Membrane (HTM) research currently focuses on separation technology and hydrogen flux characterization. No significant work has been performed on thermo-mechanical properties of HTMs. The objective of the thesis is to understand the structure-property correlation of HTM and to characterize (1) thermo mechanical properties under different reducing environments and thermal cycles (thermal shock), and (2) evaluate the stability of the novel HTM material. A novel HTM cermet bulk sample was characterized for its physical and mechanical properties at both room temperature and at elevated temperature up to 1000°C. Micro-structural properties and residual stresses were evaluated in order to understand the changing mechanism of the microstructure and its effects on the mechanical properties of materials. A correlation of the microstructural and thermo mechanical properties of the HTM system was established for both HTM and the substrate material. Mechanical properties of both selected structural ceramics and the novel HTM cermet bulk sample are affected mainly by porosity and microstructural features, such as grain size and pore size-distribution. The Young's Modulus (E-value) is positively correlated to the flexural strength for materials with similar crystallographic structure. However, for different crystallographic materials, physical properties are independent of mechanical properties. Microstructural properties, particularly, grain size and crystallographic structure, and thermodynamic properties are the main factors affecting the mechanical properties at both room and high temperatures. The HTM cermet behaves
An inventory of measures for internalising external costs in transport
Energy Technology Data Exchange (ETDEWEB)
Van Essen, H.; Nelissen, D.; Smit, M.; Van Grinsven, A.; Aarnink, S. [CE Delft, Delft (Netherlands); Breemersch, T. [Transport and Mobility Leuven TML, Leuven (Belgium); Martino, A.; Rosa, C.; Parolin, R. [Trasporti e Territorio TRT, Brussels (Belgium); Harmsen, J. [Sustainable Transport and Logistics TNO, Rotterdam (Netherlands)
2012-11-15
This study provides an overview of all existing and close to implementation pricing policies in transport. It supported the European Commission with the evaluation of existing pricing policies in the light of Article 11.4 of the revised Eurovignette Directive. The study covers all existing pricing instruments in all transport modes in all EU Member States. In addition it includes data on revenues and administrative costs and some comparisons across Member States and transport modes. The most recent data have been gathered: data for 2010 and where possible 2011. Also the link with external and infrastructure costs is discussed, and where possible, high level comparisons have been made.
Magnetization Measurements of Hard Superconductors under Dissipative Transport
Energy Technology Data Exchange (ETDEWEB)
Giordano, J L [Departamento de Ciencias de la IngenierIa, Universidad de Talca (Chile); Luzuriaga, J [Centro Atomico Bariloche, CNEA, Instituto Balseiro, UNC (Argentina); RuIz-Tagle, I A [Instituto de QuImica de Recursos Naturales, Universidad de Talca (Chile); Nieva, G [Centro Atomico Bariloche, CNEA, Instituto Balseiro, UNC (Argentina); BadIa-Majos, A [Departamento de Fisica de la Materia Condensada-I.C.M.A., Universidad de Zaragoza (Spain)
2006-06-01
The hysteretic magnetic flux dynamics of ceramic type-II superconductors under superimposed transport current cycles has been investigated. Field cooled and zero field cooled experiments were carried-out on polycrystalline YBa{sub 2}Cu{sub 3}O{sub 7-x} cylinders by using both temperature and applied field control, to drive the sample into the semi-reversible granular regime. The transport current magnitude was near and above the dissipative threshold. The interplay between shielding and transport due to vortex-pinning interactions, equilibrium magnetization effects, and diamagnetic/paramagnetic relaxation phenomena are shown to play an important role in the range of practical applications.
Eddy correlation measurements of oxygen uptake in deep ocean sediments
DEFF Research Database (Denmark)
Berg, P.; Glud, Ronnie Nøhr; Hume, A.
2010-01-01
Abstract: We present and compare small sediment-water fluxes of O-2 determined with the eddy correlation technique, with in situ chambers, and from vertical sediment microprofiles at a 1450 m deep-ocean site in Sagami Bay, Japan. The average O-2 uptake for the three approaches, respectively, was ...
Benefits of Time Correlation Measurements for Passive Screening
Murer, David; Blackie, Douglas; Peerani, Paolo
2014-02-01
The “FLASH Portals Project” is a collaboration between Arktis Radiation Detectors Ltd (CH), the Atomic Weapons Establishment (UK), and the Joint Research Centre (European Commission), supported by the Technical Support Working Group (TSWG). The program's goal was to develop and demonstrate a technology to detect shielded special nuclear materials (SNM) more efficiently and less ambiguously by exploiting time correlation. This study presents experimental results of a two-sided portal monitor equipped with in total 16 4He fast neutron detectors as well as four polyvinyltoluene (PVT) plastic scintillators. All detectors have been synchronized to nanosecond precision, thereby allowing the resolution of time correlations from timescales of tens of microseconds (such as (n, γ) reactions) down to prompt fission correlations directly. Our results demonstrate that such correlations can be detected in a typical radiation portal monitor (RPM) geometry and within operationally acceptable time scales, and that exploiting these signatures significantly improves the performance of the RPM compared to neutron counting. Furthermore, the results show that some time structure remains even in the presence of heavy shielding, thus significantly improving the sensitivity of the detection system to shielded SNM.
Fission fragment energy correlation measurements for Cf-252(SF)
Energy Technology Data Exchange (ETDEWEB)
Barreau, G.; Sicre, A.; Caitucoli, F.; Doan, T.P.; Leroux, B.; Martinez, G.; Asghar, M.; Benfoughal, T.
1986-01-01
The mean total kinetic energy, its variance and to a lesser extent the mass yield show strong and correlated fluctuations. These structures are discussed in terms of the static macro-microscopic potential energy calculations. The cold fission mass yield distribution exhibits a fine structure which results from an odd-even effect on nuclear charge.
Measuring Two-Event Structural Correlations on Graphs
2012-08-01
Morgan Kaufmann , 2006. [13] T. Hesterberg. Weighted average importance sampling and defensive mixture distributions. Technometrics, 37(2):185–194, 1995...15] M. Kendall and J. Gibbons. Rank correlation methods. Edward Arnold , 1990. [16] A. Khan, X. Yan, and K. Wu. Towards proximity pattern mining in
2005-01-01
In 2001, the Washington State Legislature established the Transportation Permit Efficiency and Accountability Committee (TPEAC) to identify measures to streamline permit procedures for transportation activities and improve environmental outcomes. A programmatic subcommittee was created to develop a multi-agency approach for developing programmatic permits that would cover 60 to 70 percent of Washington State Department of Transportation (WSDOT) activities (mostly maintenance and preservation ...
Identifying fire plumes in the Arctic with tropospheric FTIR measurements and transport models
Viatte, C.; Strong, K.; Hannigan, J.; Nussbaumer, E.; Emmons, L. K.; Conway, S.; Paton-Walsh, C.; Hartley, J.; Benmergui, J.; Lin, J.
2015-03-01
their transport. Good agreement in winter confirms that transport is well implemented in the model. For C2H6, however, the lower wintertime concentration estimated by the model as compared to the FTIR observations highlights an underestimation of its emission. Results show that modeled and measured total columns are correlated (linear correlation coefficient r > 0.6 for all gases except for H2CO at Eureka and HCOOH at Thule), but suggest a general underestimation of the concentrations in the model for all seven tropospheric species in the high Arctic.
Identifying fire plumes in the Arctic with tropospheric FTIR measurements and transport models
Directory of Open Access Journals (Sweden)
C. Viatte
2014-10-01
agreement in winter confirms that transport is well implemented in the model. For C2H6, however, the lower wintertime concentration estimated by the model as compared to the FTIR observations highlight an underestimation of its emission. Results show that modelled and measured total columns are correlated (linear correlation coefficient r > 0.6 for all gases except for H2CO at Eureka and HCOOH at Thule, but suggest a~general underestimation of the concentrations in the model for all seven tropospheric species in the high Arctic.
Correlation measure to detect time series distances, whence economy globalization
Miśkiewicz, Janusz; Ausloos, Marcel
2008-11-01
An instantaneous time series distance is defined through the equal time correlation coefficient. The idea is applied to the Gross Domestic Product (GDP) yearly increments of 21 rich countries between 1950 and 2005 in order to test the process of economic globalisation. Some data discussion is first presented to decide what (EKS, GK, or derived) GDP series should be studied. Distances are then calculated from the correlation coefficient values between pairs of series. The role of time averaging of the distances over finite size windows is discussed. Three network structures are next constructed based on the hierarchy of distances. It is shown that the mean distance between the most developed countries on several networks actually decreases in time, -which we consider as a proof of globalization. An empirical law is found for the evolution after 1990, similar to that found in flux creep. The optimal observation time window size is found ≃15 years.
BENEFITS OF TIME CORRELATION MEASUREMENTS FOR PASSIVE SCREENING
2014-01-01
The “FLASH Portals Project” is a collaboration between Arktis Radiation Detectors Ltd (CH), the Atomic Weapons Establishment (UK), and the Joint Research Centre (European Commission), supported by the Technical Support Working Group (TSWG). The program’s goal was to develop and demonstrate a technology to detect shielded special nuclear materials (SNM) more efficiently and less ambiguously by exploiting time correlation. This study presents experimental results of a two-sided portal monitor e...
Parallax Measurement Using an Image Matched Filter Correlator
1975-04-01
was also necessary to isolate the laser by installing rubber pads under it and by suspending the umbilical cord in order to eliminate vibrations...mirror. This assembly tended to vibrate and it proved necessary to remove it and replace the small mirror by a larger mirror clamped directly to...where a ^ b. Consider the situation in Figure A-l where a hologram is re- corded in plane H. The correlations are formed by lens Lj in
Correlation function as a measure of the structure
Buryak, O.; Doroshkevich, A.
1995-01-01
Geometrical model of structure of the universe is examined to obtain analytical expression for the two points nonlinear correlation function. According to the model the objects (galaxies) are concentrated into two types of structure elements - filaments and sheets. We considered the filaments ( similar to galaxy filaments ) simply as straight lines and the sheets ( similar to superclusters of galaxies ) simply as planes. The homogeneously distributed objects are also taken into consideration....
A new measure-correlate-predict approach for resource assessment
Energy Technology Data Exchange (ETDEWEB)
Joensen, A.; Landberg, L. [Risoe National Lab., Dept. of Wind Energy and Atmospheric Physics, Roskilde (Denmark); Madsen, H. [The Technical Univ. of Denmark, Dept. of Mathematical Modelling, Lyngby (Denmark)
1999-03-01
In order to find reasonable candidate site for wind farms, it is of great importance to be able to calculate the wind resource at potential sites. One way to solve this problem is to measure wind speed and direction at the site, and use these measurements to predict the resource. If the measurements at the potential site cover less than e.g. one year, which most likely will be the case, it is not possible to get a reliable estimate of the long-term resource, using this approach. If long-term measurements from e.g. some nearby meteorological station are available, however, then statistical methods can be used to find a relation between the measurements at the site and at the meteorological station. This relation can then be used to transform the long-term measurements to the potential site, and the resource can be calculated using the transformed measurements. Here, a varying-coefficient model, estimated using local regression, is applied in order to establish a relation between the measurements. The approach is evaluated using measurements from two sites, located approximately two kilometres apart, and the results show that the resource in this case can be predicted accurately, although this approach has serious shortcomings. (au)
Energy Technology Data Exchange (ETDEWEB)
McGraw, Robert [Atmospheric Sciences Division, Environmental Sciences Department Brookhaven National Laboratory, Upton, NY 11973 (United States)
2007-07-15
Nonlinear transport algorithms designed to reduce numerical diffusion fail to preserve correlations between moments, isotope abundances, etc. when these scalar densities are transported in models as separate tracers. In case of the particle size/composition coordinates of an aerosol, such loss can give rise to unphysical moment sets. New statistical approaches to aerosol dynamics, which involve tracking moments directly, offer highly efficient alternatives to sectional and modal methods for representing aerosols in climate models, but it is essential that moment set integrity be preserved throughout a simulation. In this paper we review the problem and weaknesses of previous attempts at solution, including vector transport - a scheme in which the moments, as internal aerosol coordinates, are transported together with a single lead tracer such as number or mass. A non-negative least squares (NNLS) solution that finally eliminates the problem without requiring modification of the transport algorithm itself is presented. Following each transport step, new moment sets are resolved into sums of previously validated sets with non-negative coefficients using NNLS Transport errors are removed and the now guaranteed-to-be-valid moment sets are ready for passage to the aerosol dynamics module. In addition to moment set validation, the new scheme reduces numerical diffusion during transport and provides greater accuracy for the source apportionment of aerosol mixtures. The method is not limited to moment transport - similar improvements in accuracy are expected using NNLS in conjunction with modal and sectional methods.
Measurement of q ˆ in Relativistic Heavy Ion Collisions using di-hadron correlations
Tannenbaum, M. J.
2017-08-01
The propagation of partons from hard scattering through the Quark Gluon Plasma produced in A+A collisions at RHIC and the LHC is represented in theoretical analyses by the transport coefficient q ˆ and predicted to cause both energy loss of the outgoing partons, observed as suppression of particles or jets with large transverse momentum pT, and broadening of the azimuthal correlations of the outgoing di-jets or di-hadrons from the outgoing parton-pair, which has not been observed. The widths of azimuthal correlations of di-hadrons with the same trigger particle pTt and associated pTa transverse momenta in p+p and Au+Au are so-far statistically indistinguishable as shown in recent as well as older di-hadron measurements and also with jet-hadron and hadron-jet measurements. The azimuthal width of the di-hadron correlations in p+p collisions, beyond the fragmentation transverse momentum, jT, is dominated by kT, the so-called intrinsic transverse momentum of a parton in a nucleon, which can be measured. The broadening should produce a larger kT in A+A than in p+p collisions. The present work introduces the observation that the kT measured in p+p collisions for di-hadrons with pTt and pTa must be reduced to compensate for the energy loss of both the trigger and away parent partons when comparing to the kT measured with the same di-hadron pTt and pTa in Au+Au collisions. This idea is applied to a recent STAR di-hadron measurement, with result = 2.1 ± 0.6 GeV2. This is more precise but in agreement with a theoretical calculation of =14-14+42 GeV2 using the same data. Assuming a length ≈ 7 fm for central Au+Au collisions the present result gives q ˆ ≈ 0.30 ± 0.09 GeV2/fm, in fair agreement with the JET collaboration result from single hadron suppression of q ˆ ≈ 1.2 ± 0.3 GeV2/fm at an initial time τ0 = 0.6 fm/c in Au+Au collisions at √{sNN} = 200 GeV.
Directory of Open Access Journals (Sweden)
Natalia A Iutaka
2017-01-01
Conclusion: VFI showed a strong correlation with MD and PSD but demonstrated a weak correlation with structural measures. It can possibly be used as a marker for functional impairment severity in patients with glaucoma.
Wickramarachchi, P. N.; Kawamoto, K.; Hamamoto, S.; Nagamori, M.; Moldrup, P.; Komatsu, T.
2011-12-01
for ka than Dp for both fractions. We suggest this is because of compaction effects caused to create well-aligned macropore networks that are available for gas transport through the porous material. Then, the famous predictive models, the water induced linear reduction (WLR) model for Dp and the reference point law (RPL) model for ka were modified with reference point measurements (dry conditions) and model parameters and they correlated linearly to dry bulk density values for both fractions of landfill final cover soil.
Monte Carlo analysis of radiative transport in oceanographic lidar measurements
Energy Technology Data Exchange (ETDEWEB)
Cupini, E.; Ferro, G. [ENEA, Divisione Fisica Applicata, Centro Ricerche Ezio Clementel, Bologna (Italy); Ferrari, N. [Bologna Univ., Bologna (Italy). Dipt. Ingegneria Energetica, Nucleare e del Controllo Ambientale
2001-07-01
The analysis of oceanographic lidar systems measurements is often carried out with semi-empirical methods, since there is only a rough understanding of the effects of many environmental variables. The development of techniques for interpreting the accuracy of lidar measurements is needed to evaluate the effects of various environmental situations, as well as of different experimental geometric configurations and boundary conditions. A Monte Carlo simulation model represents a tool that is particularly well suited for answering these important questions. The PREMAR-2F Monte Carlo code has been developed taking into account the main molecular and non-molecular components of the marine environment. The laser radiation interaction processes of diffusion, re-emission, refraction and absorption are treated. In particular are considered: the Rayleigh elastic scattering, produced by atoms and molecules with small dimensions with respect to the laser emission wavelength (i.e. water molecules), the Mie elastic scattering, arising from atoms or molecules with dimensions comparable to the laser wavelength (hydrosols), the Raman inelastic scattering, typical of water, the absorption of water, inorganic (sediments) and organic (phytoplankton and CDOM) hydrosols, the fluorescence re-emission of chlorophyll and yellow substances. PREMAR-2F is an extension of a code for the simulation of the radiative transport in atmospheric environments (PREMAR-2). The approach followed in PREMAR-2 was to combine conventional Monte Carlo techniques with analytical estimates of the probability of the receiver to have a contribution from photons coming back after an interaction in the field of view of the lidar fluorosensor collecting apparatus. This offers an effective mean for modelling a lidar system with realistic geometric constraints. The retrieved semianalytic Monte Carlo radiative transfer model has been developed in the frame of the Italian Research Program for Antarctica (PNRA) and it is
Electrical conductivity measurements of nanofluids and development of new correlations.
Konakanchi, Hanumantharao; Vajjha, Ravikanth; Misra, Debasmita; Das, Debendra
2011-08-01
In this study the electrical conductivity of aluminum oxide (Al2O3), silicon dioxide (SiO2) and zinc oxide (ZnO) nanoparticles dispersed in propylene glycol and water mixture were measured in the temperature range of 0 degrees C to 90 degrees C. The volumetric concentration of nanoparticles in these fluids ranged from 0 to 10% for different nanofluids. The particle sizes considered were from 20 nm to 70 nm. The electrical conductivity measuring apparatus and the measurement procedure were validated by measuring the electrical conductivity of a calibration fluid, whose properties are known accurately. The measured electrical conductivity values agreed within +/- 1% with the published data reported by the manufacturer. Following the validation, the electrical conductivities of different nanofluids were measured. The measurements showed that electrical conductivity of nanofluids increased with an increase in temperature and also with an increase in particle volumetric concentration. For the same nanofluid at a fixed volumetric concentration, the electrical conductivity was found to be higher for smaller particle sizes. From the experimental data, empirical models were developed for three nanofluids to express the electrical conductivity as functions of temperature, volumetric concentration and the size of the nanoparticles.
Physical meaning of two-particle HBT measurements in case of correlated emission
Bialas, A.; Zalewski, K.
2004-01-01
It is shown that, in the presence of correlations in particle emission, the measured HBT radii are related to the correlation range rather than to the size of the interaction volume. Only in the case of weak correlations the standard interpretation may be applicable, The earlier discussion [1] of short-range correlations in configuration space is generalized to include also the correlations of particle momenta.
Directory of Open Access Journals (Sweden)
Linda J Gahan
2010-12-01
Full Text Available Transgenic crops producing insecticidal toxins from Bacillus thuringiensis (Bt are commercially successful in reducing pest damage, yet knowledge of resistance mechanisms that threaten their sustainability is incomplete. Insect resistance to the pore-forming Cry1Ac toxin is correlated with the loss of high-affinity, irreversible binding to the mid-gut membrane, but the genetic factors responsible for this change have been elusive. Mutations in a 12-cadherin-domain protein confer some Cry1Ac resistance but do not block this toxin binding in in vitro assays. We sought to identify mutations in other genes that might be responsible for the loss of binding. We employed a map-based cloning approach using a series of backcrosses with 1,060 progeny to identify a resistance gene in the cotton pest Heliothis virescens that segregated independently from the cadherin mutation. We found an inactivating mutation of the ABC transporter ABCC2 that is genetically linked to Cry1Ac resistance and is correlated with loss of Cry1Ac binding to membrane vesicles. ABC proteins are integral membrane proteins with many functions, including export of toxic molecules from the cell, but have not been implicated in the mode of action of Bt toxins before. The reduction in toxin binding due to the inactivating mutation suggests that ABCC2 is involved in membrane integration of the toxin pore. Our findings suggest that ABC proteins may play a key role in the mode of action of Bt toxins and that ABC protein mutations can confer high levels of resistance that could threaten the continued utilization of Bt-expressing crops. However, such mutations may impose a physiological cost on resistant insects, by reducing export of other toxins such as plant secondary compounds from the cell. This weakness could be exploited to manage this mechanism of Bt resistance in the field.
Gahan, Linda J; Pauchet, Yannick; Vogel, Heiko; Heckel, David G
2010-12-16
Transgenic crops producing insecticidal toxins from Bacillus thuringiensis (Bt) are commercially successful in reducing pest damage, yet knowledge of resistance mechanisms that threaten their sustainability is incomplete. Insect resistance to the pore-forming Cry1Ac toxin is correlated with the loss of high-affinity, irreversible binding to the mid-gut membrane, but the genetic factors responsible for this change have been elusive. Mutations in a 12-cadherin-domain protein confer some Cry1Ac resistance but do not block this toxin binding in in vitro assays. We sought to identify mutations in other genes that might be responsible for the loss of binding. We employed a map-based cloning approach using a series of backcrosses with 1,060 progeny to identify a resistance gene in the cotton pest Heliothis virescens that segregated independently from the cadherin mutation. We found an inactivating mutation of the ABC transporter ABCC2 that is genetically linked to Cry1Ac resistance and is correlated with loss of Cry1Ac binding to membrane vesicles. ABC proteins are integral membrane proteins with many functions, including export of toxic molecules from the cell, but have not been implicated in the mode of action of Bt toxins before. The reduction in toxin binding due to the inactivating mutation suggests that ABCC2 is involved in membrane integration of the toxin pore. Our findings suggest that ABC proteins may play a key role in the mode of action of Bt toxins and that ABC protein mutations can confer high levels of resistance that could threaten the continued utilization of Bt-expressing crops. However, such mutations may impose a physiological cost on resistant insects, by reducing export of other toxins such as plant secondary compounds from the cell. This weakness could be exploited to manage this mechanism of Bt resistance in the field.
Accurate measurement of curvilinear shapes by Virtual Image Correlation
Semin, B; Auradou, H.; François, M.L.M.
2011-01-01
Abstract The proposed method allows the detection and the measurement, in the sense of metrology, of smooth elongated curvilinear shapes. Such measurements are required in many fields of physics, for example: mechanical engineering, biology or medicine (deflection of beams, fibers or filaments), fluid mechanics or chemistry (detection of fronts). Contrary to actual methods, the result is given in an analytical form of class C? (and not a finite set of locations or pixels) thus curv...
Electrophysiological correlates of listening effort: neurodynamical modeling and measurement.
Strauss, Daniel J; Corona-Strauss, Farah I; Trenado, Carlos; Bernarding, Corinna; Reith, Wolfgang; Latzel, Matthias; Froehlich, Matthias
2010-06-01
An increased listing effort represents a major problem in humans with hearing impairment. Neurodiagnostic methods for an objective listening effort estimation might support hearing instrument fitting procedures. However the cognitive neurodynamics of listening effort is far from being understood and its neural correlates have not been identified yet. In this paper we analyze the cognitive neurodynamics of listening effort by using methods of forward neurophysical modeling and time-scale electroencephalographic neurodiagnostics. In particular, we present a forward neurophysical model for auditory late responses (ALRs) as large-scale listening effort correlates. Here endogenously driven top-down projections related to listening effort are mapped to corticothalamic feedback pathways which were analyzed for the selective attention neurodynamics before. We show that this model represents well the time-scale phase stability analysis of experimental electroencephalographic data from auditory discrimination paradigms. It is concluded that the proposed neurophysical and neuropsychological framework is appropriate for the analysis of listening effort and might help to develop objective electroencephalographic methods for its estimation in future.
Correlation measurements of light transmittance in polymer dispersed liquid crystals
Maksimyak, P. P.; Nehrych, A. L.
2015-11-01
The methods of correlation optics are for the first time applied to study structure of liquid crystal (LC) - polymer (P) composites at various concentrations of LC and P. Their phase correlation function (PCF) was obtained considering LC-P composite as a random phase screen. The amplitude of PCF contains information about number of LC domains and structure of LC director inside of them, while a half-width of this function is connected with a size of these domains. We studied unpowered and powered composite layers with a thickness of 5 μm. As liquid crystal and polymer were used nematic LC E7 from Merck and photopolymer composition NOA65 from Norland. Concentration of polymer φP was varied in a range 10-55 vol. %. In good agreement with previous studies by SEM technique we detected monotone decrease of LC domains with concentration of polymer. With application of electric field, amplitude of PCF behaves differently for the samples with different polymer content. For the samples with φP>35 vol. % (samples having morphology of polymer dispersed LC), this dependence is monotonic. In turn, if φPLC morphology), the amplitude of PCF non-monotonically depends on the applied voltage going through a maximum. The latter fact is explained by transformation of orientational defects of LC phase with the applied voltage.
Choi, Hyun-Deok; Liu, Hongyu; Crawford, James H.; Considine, David B.; Allen, Dale J.; Duncan, Bryan N.; Horowitz, Larry W.; Rodriguez, Jose M.; Strahan, Susan E.; Zhang, Lin; Liu, Xiong; Damon, Megan R.; Steenrod, Stephen D.
2017-07-01
We examine the capability of the Global Modeling Initiative (GMI) chemistry and transport model to reproduce global mid-tropospheric (618 hPa) ozone-carbon monoxide (O3-CO) correlations determined by the measurements from the Tropospheric Emission Spectrometer (TES) aboard NASA's Aura satellite during boreal summer (July-August). The model is driven by three meteorological data sets (finite-volume General Circulation Model (fvGCM) with sea surface temperature for 1995, Goddard Earth Observing System Data Assimilation System Version 4 (GEOS-4 DAS) for 2005, and Modern-Era Retrospective Analysis for Research and Applications (MERRA) for 2005), allowing us to examine the sensitivity of model O3-CO correlations to input meteorological data. Model simulations of radionuclide tracers (222Rn, 210Pb, and 7Be) are used to illustrate the differences in transport-related processes among the meteorological data sets. Simulated O3 values are evaluated with climatological profiles from ozonesonde measurements and satellite tropospheric O3 columns. Despite the fact that the three simulations show significantly different global and regional distributions of O3 and CO concentrations, they show similar patterns of O3-CO correlations on a global scale. All model simulations sampled along the TES orbit track capture the observed positive O3-CO correlations in the Northern Hemisphere midlatitude continental outflow and the Southern Hemisphere subtropics. While all simulations show strong negative correlations over the Tibetan Plateau, northern Africa, the subtropical eastern North Pacific, and the Caribbean, TES O3 and CO concentrations at 618 hPa only show weak negative correlations over much narrower areas (i.e., the Tibetan Plateau and northern Africa). Discrepancies in regional O3-CO correlation patterns in the three simulations may be attributed to differences in convective transport, stratospheric influence, and subsidence, among other processes. To understand how various
Hayden, Elizabeth P; Hanna, Brigitte; Sheikh, Haroon I; Laptook, Rebecca S; Kim, Jiyon; Singh, Shiva M; Klein, Daniel N
2013-02-01
The dopamine active transporter 1 (DAT1) gene is implicated in psychopathology risk. Although the processes by which this gene exerts its effects on risk are poorly understood, a small body of research suggests that the DAT1 gene influences early emerging negative emotionality, a marker of children's psychopathology risk. As child negative emotionality evokes negative parenting practices, the DAT1 gene may also play a role in gene-environment correlations. To test this model, children (N = 365) were genotyped for the DAT1 gene and participated in standardized parent-child interaction tasks with their primary caregiver. The DAT1 gene 9-repeat variant was associated with child negative affect expressed toward the parent during parent-child interactions, and parents of children with a 9-repeat allele exhibited more hostility and lower guidance/engagement than parents of children without a 9-repeat allele. These gene-environment associations were partially mediated by child negative affect toward the parent. The findings implicate a specific polymorphism in eliciting negative parenting, suggesting that evocative associations play a role in elevating children's risk for emotional trajectories toward psychopathology risk.
Measured Gradients in Alongshore Sediment Transport Along the Dutch Coast
De Vries, S.; De Schipper, M.A.; Stive, M.J.F.
2014-01-01
In this paper it is aimed to quantify bulk (surf-zone integrated) alongshore sediment transport using morphological data collected along the Dutch coast. The collected morphological data covers a domain of 18 km alongshore including the beach, the foreshore and the intertidal zone in the cross shore
Konkova, Elizaveta S.; Burtseva, Larisa V.; Gromov, Sergey A.; Gromov, Sergey S.
2017-04-01
Increasing trends of airborne lead and cadmium at background station within the central region of European Russia have been identified previously (e.g., Gromov & Konkova, 2016). In order to reveal the possible drivers of these trends, a deeper investigation of correlation among these heavy metals (HM) and other co-measured pollutants is done in this study. Based on the data for the 2001-2012 period, calculations have been carried out for the period from 2006 onwards, when the growth of HM concentrations is observed. Pairwise correlations of individual species abundances were derived for the entire time series and subsets for each calendar year, including warm (April to September) and cold seasons (October to March). The calculated values for the seasons and the whole years vary substantially, suggesting that that variable ratios of atmospheric HM emission sources could affect the final air concentrations at measurement site in these periods. To distinguish the events of predominant influence of natural and anthropogenic sources, we assume that correlation between lead and cadmium levels must be greater in the case of natural sources being in effect. High values of the correlation coefficient are expected in cases when HM air abundances are induced by the long-range transport from the regions of anthropogenic sources (co-emission of these metals results from a number of same sources, and both of them are also present on same matrix aerosols). The results demonstrate a substantial correlation between Pb and Cd, with higher values for individual seasons (70% of 0.5 and higher) than for whole years. Higher mass concentrations of airborne dust (TSP) in remote areas are to large extent promoted by large particles blown away from the surface at local surroundings. Captured better by filters, such events could be a particular indicator of local (mostly natural) sources. Low or insignificant correlation with HM indicates prevalence of long-range transport of them and could
Symplectic invariants, entropic measures and correlations of Gaussian states
Energy Technology Data Exchange (ETDEWEB)
Serafini, Alessio; Illuminati, Fabrizio; Siena, Silvio De [Dipartimento di Fisica ' E R Caianiello' , Universita di Salerno, INFM UdR Salerno, INFN Sezione di Napoli, Gruppo Collegato di Salerno, Via S Allende, 84081 Baronissi, SA (Italy)
2004-01-28
We present a derivation of the Von Neumann entropy and mutual information of arbitrary two-mode Gaussian states, based on the explicit determination of the symplectic eigenvalues of a generic covariance matrix. The key role of the symplectic invariants in such a determination is pointed out. We show that the Von Neumann entropy depends on two symplectic invariants, while the purity (or the linear entropy) is determined by only one invariant, so that the two quantities provide two different hierarchies of mixed Gaussian states. A comparison between mutual information and entanglement of formation for symmetric states is considered, taking note of the crucial role of the symplectic eigenvalues in qualifying and quantifying the correlations present in a generic state. (letter to the editor)
Longshore sediment transport rate-measurement and estimation, central west coast of India
Digital Repository Service at National Institute of Oceanography (India)
SanilKumar, V.; Anand, N.M.; Chandramohan, P.; Naik, G.N.
transport rate were measured with traps deployed on a line spanning the surf zone. Sediment transport in the swash zone was not considered in the present study. The longshore current was measured at each trap location. The breaking wave parameters were...
An experimental setup for measuring generation and transport of radon in building materials
van der Pal, M.; Hendriks, N.A.; de Meijer, R.J.; van der Graaf, E.R.; de Wit, M.H.
2001-01-01
This study describes an approach for measuring and modelling diffusive and advective transport of radon through building materials. The goal of these measurements and model calculations is to improve our understanding concerning the factors influencing the transport of radon through building
Toelle, V D; Robison, O W
1985-01-01
Data from 528 male and 645 female progeny of 63 sires were used to estimate genetic correlations between female and male reproductive traits. Data were from two Hereford herds involved in a long-term selection program of the North Carolina Agricultural Experiment Service. Testicular measurements of circumference, diameter, length and volume were obtained on bulls at 205 and 365 d. Testicular growth measures were defined as differences between 205-and 365-d measurements. Heifers were placed in the breeding herd as yearlings and given two breeding seasons to produce a calf. Traits utilized from females were three age-at-first-breeding traits, two age-at-first-calving traits, two pregnancy rate traits, rebreeding interval and calving interval. Genetic correlations were estimated from half-sib and from sire-daughter analyses. Seventy-five percent or more of the correlations of testicular measurements with pregnancy rats, age at first breeding and age at first calving were in the favorable direction. Average correlations were .62, -.55 and -.66, respectively. For each of the remaining female traits, approximately 50% of the correlations were favorable and the average correlations were small. Correlations were summarized by testicular measurement with favorable correlations given a negative sign. Testicular diameter had more favorable correlations (80%) than length, volume or circumference (70%). However, average correlations were similar (-.31, -.30, -.34 and -.26, respectively). Testicular measurements taken at either 205 or 365 d had the same percentage of favorable correlations (72%), while testicular growth measurements had a slightly higher percentage of favorable correlations (78%). Average correlations of 365-d measures were higher (-.38) than either 205-d or growth measures (-.25 and -.28, respectively). Heritabilities for testicular measurements tended to be moderate to high, while those for female reproduction tended to be low to moderate. These results
Xue, Zhenyu; Vlachos, Pavlos P
2014-01-01
In particle image velocimetry (PIV) the measurement signal is contained in the recorded intensity of the particle image pattern superimposed on a variety of noise sources. The signal-to-noise-ratio (SNR) strength governs the resulting PIV cross correlation and ultimately the accuracy and uncertainty of the resulting PIV measurement. Hence we posit that correlation SNR metrics calculated from the correlation plane can be used to quantify the quality of the correlation and the resulting uncertainty of an individual measurement. In this paper we present a framework for evaluating the correlation SNR using a set of different metrics, which in turn are used to develop models for uncertainty estimation. The SNR metrics and corresponding models presented herein are expanded to be applicable to both standard and filtered correlations. In addition, the notion of a valid measurement is redefined with respect to the correlation peak width in order to be consistent with uncertainty quantification principles and distinct ...
GHz measurements of correlated electron systems in high magnetic fields
Edwards, R S
2002-01-01
This Thesis presents experiments performed on the high-frequency conductivity of materials in high magnetic fields. The angle dependence of resonances measured in the millimetre-wave absorption is studied using a rotating resonant cavity system, and the frequency dependence is measured using transmission techniques and a tuneable resonant cavity. Chapter 1 introduces the materials. These include the crystalline organic metals, the layered superconductor Sr sub 2 RUO sub 4 and the quantum Ising ferromagnet LiHoF sub 4. In Chapters 2 and 3, the necessary physics and experimental techniques for their investigation are outlined. Chapters 4 to 6 present measurements of cyclotron resonance in layered materials. Chapter 4 describes several models for the origin of cyclotron resonance harmonics, and describes the first definite measurement of the harmonics of a cyclotron resonance in an organic molecular metal, namely beta sup - (BEDT-TTF) sub 2 SF sub 5 CH sub 2 CF sub 2 SO sub 3. The angle dependence of the field p...
Correlation between precision gravity and subsidence measurements at Cerro Prieto
Energy Technology Data Exchange (ETDEWEB)
Zelwer, R.; Grannell, R.B.
1982-10-01
Precision gravity measurements were made in the region of the Cerro Prieto geothermal field at yearly intervals from 1977 to 1981 to assess the feasibility of using gravity to determine subsurface reservoir changes with time. The extent of mass recharge in response to the continued production of fluids from this field was studied. Changes in gravity and ground elevation were observed throughout the region for the period of observation. Results indicate that the largest changes observed were the result of the Magnitude 6.1 (Caltech) Victoria earthquake of 8 June 1980. The epicenter of this earthquake was located 25 km southeast of the field on the Cerro Prieto Fault, which bounds the field on the southwest. Subsidence of up to 55 cm was measured east of the power plant, in the region between the northern end of the Cerro Prieto Fault and the southern end of the Imperial Fault. This area has been postulated to be the site of an active spreading center or pull-apart basin, and has been characterized by a high level of seismic activity during the last 10 years. Minor subsidence and small related gravity changes for the period preceeding the Victoria earthquake suggest that in spite of large fluid production rates, the reservoir is being almost completely recharged and that a measurable increase in subsurface density may be taking place. The results of measurements of horizontal ground motions made in this area are discussed in relation to the gravity and subsidence observations.
Yagdiran, Yagmur; Tallkvist, Jonas; Artursson, Karin
2016-01-01
Inflammation in the mammary gland (mastitis) is the most common disease in dairy herds worldwide, often caused by the pathogens Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Little is known about the effects of mastitis on drug transporters and the impact on transporter-mediated excretion of drugs into milk. We used murine mammary epithelial HC11 cells, after lactogenic differentiation into a secreting phenotype, and studied gene expressions of ABC- and SLC- transporters after treatment of cells with S. aureus and lipopolysaccharide, an endotoxin secreted by E. coli. The studied transporters were Bcrp, Mdr1, Mrp1, Oatp1a5, Octn1 and Oct1. In addition, Csn2, the gene encoding β-casein, was analyzed. As biomarkers of the inflammatory response, gene expressions of the cytokines Il6 and Tnfα and the chemokine Cxcl2 were determined. Our results show that S. aureus and LPS treatment of cells, at non-cytotoxic concentrations, induced an up-regulation of Mdr1 and of the inflammatory biomarkers, except that Tnfα was not affected by lipopolysaccharide. By simple regression analysis we could demonstrate statistically significant positive correlations between each of the transporters with each of the inflammatory biomarkers in cells treated with S. aureus. The coefficients of determination (R2) were 0.7–0.9 for all but one correlation. After treatment of cells with lipopolysaccharide, statistically significant correlations were only found between Mdr1 and the two parameters Cxcl2 and Il6. The expression of Csn2 was up-regulated in cells treated with S. aureus, indicating that the secretory function of the cells was not impaired. The strong correlation in gene expressions between transporters and inflammatory biomarkers may suggest a co-regulation and that the transporters have a role in the transport of cytokines and chemokines. Our results demonstrate that transporters in mammary cells can be affected by infection, which may have an impact on
Measurement and modeling of phosphorous transport in shallow groundwater environments.
Hendricks, G S; Shukla, S; Obreza, T A; Harris, W G
2014-08-01
Leaching of phosphorus (P) from agricultural soils, especially those that are sandy, is adversely impacting P-limited ecosystems like Florida's Everglades. A more developed understanding of P and water management strategies and their effects on P leaching is needed to achieve reductions in subsurface P losses, especially from intensively managed dual cropping systems under plastic mulch in shallow water regions. We compared the effects of conservation P and water management strategies with traditional practices on P transport to groundwater. A 3-year experiment was conducted on hydrologically isolated plots with plastic-mulched successive cropping systems to compare high (HEI) and soil test based recommended (REI) external input (water and fertilizer P) systems with traditional sub-irrigation (seepage), and REI with a potential water conservation subsurface drip irrigation system (REI-SD) with regard to groundwater P concentrations above and below the low conductivity spodic horizon (Bh). The REI treatments had higher available storage for rainfall and P than HEI. Use of both REI systems (REI=2098μg/L and REI-SD=2048μg/L) reduced groundwater P concentrations above the Bh horizon by 33% compared to HEI (3090μg/L), and results were significant at the 0.05 level. Although the subsurface drip system saved water, it did not offer any groundwater quality (P) benefit. Mixing and dilution of influent P below the low conductivity Bh horizon between treatments and with the regional groundwater system resulted in no significant differences in groundwater P concentration below the Bh horizon. Groundwater P concentrations from this study were higher than reported elsewhere due to low soil P storage capacity (SPSC), high hydraulic conductivity of sandy soils, and a high water table beneath crop beds. The HEI system leached more P due to ferilizer P in excess of SPSC and used higher irrigation volumes compared with REI systems. Despite a 40% difference in the average amount of
Garg, S; Porcar, L; Woodka, A C; Butler, P D; Perez-Salas, U
2011-07-20
Proper cholesterol transport is essential to healthy cellular activity and any abnormality can lead to several fatal diseases. However, complete understandings of cholesterol homeostasis in the cell remains elusive, partly due to the wide variability in reported values for intra- and intermembrane cholesterol transport rates. Here, we used time-resolved small-angle neutron scattering to measure cholesterol intermembrane exchange and intramembrane flipping rates, in situ, without recourse to any external fields or compounds. We found significantly slower transport kinetics than reported by previous studies, particularly for intramembrane flipping where our measured rates are several orders of magnitude slower. We unambiguously demonstrate that the presence of chemical tags and extraneous compounds employed in traditional kinetic measurements dramatically affect the system thermodynamics, accelerating cholesterol transport rates by an order of magnitude. To our knowledge, this work provides new insights into cholesterol transport process disorders, and challenges many of the underlying assumptions used in most cholesterol transport studies to date.
Correlation of subjective and objective measures of speech intelligibility
Bowden, Erica E.; Wang, Lily M.; Palahanska, Milena S.
2003-10-01
Currently there are a number of objective evaluation methods used to quantify the speech intelligibility in a built environment, including the Speech Transmission Index (STI), Rapid Speech Transmission Index (RASTI), Articulation Index (AI), and the Percentage Articulation Loss of Consonants (%ALcons). Many of these have been used for years; however, questions remain about their accuracy in predicting the acoustics of a space. Current widely used software programs can quickly evaluate STI, RASTI, and %ALcons from a measured impulse response. This project compares subjective human performance on modified rhyme and phonetically balanced word tests with objective results calculated from impulse response measurements in four different spaces. The results of these tests aid in understanding performance of various methods of speech intelligibility evaluation. [Work supported by the Univ. of Nebraska Center for Building Integration.] For Speech Communication Best Student Paper Award.
The Belt voice: Acoustical measurements and esthetic correlates
Bounous, Barry Urban
This dissertation explores the esthetic attributes of the Belt voice through spectral acoustical analysis. The process of understanding the nature and safe practice of Belt is just beginning, whereas the understanding of classical singing is well established. The unique nature of the Belt sound provides difficulties for voice teachers attempting to evaluate the quality and appropriateness of a particular sound or performance. This study attempts to provide answers to the question "does Belt conform to a set of measurable esthetic standards?" In answering this question, this paper expands on a previous study of the esthetic attributes of the classical baritone voice (see "Vocal Beauty", NATS Journal 51,1) which also drew some tentative conclusions about the Belt voice but which had an inadequate sample pool of subjects from which to draw. Further, this study demonstrates that it is possible to scientifically investigate the realm of musical esthetics in the singing voice. It is possible to go beyond the "a trained voice compared to an untrained voice" paradigm when evaluating quantitative vocal parameters and actually investigate what truly beautiful voices do. There are functions of sound energy (measured in dB) transference which may affect the nervous system in predictable ways and which can be measured and associated with esthetics. This study does not show consistency in measurements for absolute beauty (taste) even among belt teachers and researchers but does show some markers with varying degrees of importance which may point to a difference between our cognitive learned response to singing and our emotional, more visceral response to sounds. The markers which are significant in determining vocal beauty are: (1) Vibrancy-Characteristics of vibrato including speed, width, and consistency (low variability). (2) Spectral makeup-Ratio of partial strength above the fundamental to the fundamental. (3) Activity of the voice-The quantity of energy being produced. (4
Resolving Dynamics Structure in the Mlt: Correlative Measurements with Tidi and Hrdi
Niciejewski, R.; Skinner, W. R.; Marshall, A.; Cooper, M.
2011-12-01
Undoubtedly, line of sight Doppler measurements of the terrestrial limb have and continue to provide the longest sequence of routine synoptic wind data of the mesosphere and lower thermosphere. To provide the community with basic information about global MLT winds, UARS/HRDI was launched in 1991 and later joined by TIMED/TIDI in 2001. Correlative observations of the MLT with the two instruments began in February 2002 and continued until April 2005 when battery problems aboard UARS forced the final turn-off of HRDI. TIDI continues observing the MLT to the present day with nearly a 100% duty cycle. On short time intervals (a few days), tidal frequencies are difficult to unambiguously identify from orbit by either HRDI or TIDI due to aliasing issues with single satellite observations. Combining measurements from the two platforms provides a significant improvement in understanding two-dimensional frequency wavenumber spectra for short data sets. This paper will describe the progress that has been made in characterizing migrating and non-migrating diurnal tides in the MLT. Short data sets of several days' length are necessary to identify planetary waves, such as the two-day wave, and its effect on MLT dynamics. These waves can transport water vapour exhaust from rocket launches over large distances providing a seed for enhancing noctilucent cloud formation at high latitudes.
This study aimed to explore the associations among psychological correlates and physical activity (PA) in Chinese children and to further examine whether these associations varied by different PA measures. PA self-efficacy, motivation, and preference were reported in 449 8–13-year-old Chinese childr...
Gerra, G; Garofano, L; Santoro, G; Bosari, S; Pellegrini, C; Zaimovic, A; Moi, G; Bussandri, M; Moi, A; Brambilla, F; Donnini, C
2004-04-01
In previous studies, serotonin (5-HT) system disturbance was found involved in a variety of behavioral disorders, psychopathologies, and substance use disorders. A functional polymorphism in the promoter region of the human serotonin transporter gene (5-HTTLPR) was recently identified and the presence of the short (S) allele found to be associated with a lower level of expression of the gene, lower levels of 5-HT uptake, type 2 alcoholism, violence and suicidal behavior. In the present study, 101 heroin addicts (males, West European, Caucasians) and 101 healthy control subjects matched for race and gender, with no history of substance use disorder, have been genotyped. Aggressiveness levels were measured in both heroin addicts and controls utilizing Buss-Durkee-Hostility-Inventory (BDHI). Data about suicide attempt and violent criminal behavior in subject history have been collected. The short-short (SS) genotype frequency was significantly higher among heroin dependent individuals compared with control subjects (P = 0.025). The odds ratio for the SS genotype versus the long-long (LL) genotype frequency was 0.69, 95% Cl (0.49-0.97), when heroin addicts were compared with healthy controls. The SS genotype frequency was significantly higher among violent heroin dependent individuals compared with addicted individuals without aggressive behavior (P = 0.02). BDHI mean total scores and suspiciousness and negativism subscales scores were significantly higher in SS individuals, in comparison with LL subjects, among heroin addicts. No association was found between SS genotype and suicide history. Our data suggest that a decreased expression of the gene encoding the 5-HTT transporter, due to "S" promoter polymorphism, may be associated with an increased risk for substance use disorders, particularly in the subjects with more consistent aggressiveness and impulsiveness.
Measurement of Genuine Three-Particle Bose-Einstein Correlations in Hadronic Z decay
Achard, P; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Baldew, S V; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; de la Cruz, B; Cucciarelli, S; van Dalen, J A; De Asmundis, R; Déglon, P L; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Dionisi, C; Dittmar, Michael; Doria, A; Dova, M T; Duchesneau, D; Echenard, B; Eline, A; El-Mamouni, H; Engler, A; Eppling, F J; Ewers, A; Extermann, Pierre; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisher, W; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hakobyan, R S; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, G; Hou, S R; Hu, Y; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Likhoded, S A; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lübelsmeyer, K; Luci, C; Luminari, L; Lustermann, W; Ma Wen Gan; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Nagy, S; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Ofierzynski, R A; Organtini, G; Palomares, C; Pandoulas, D; Paolucci, P; Paramatti, R; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofiev, D O; Prokofev, D; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Roux, B; Rubio, Juan Antonio; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S V; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Ulbricht, J; Valente, E; Van de Walle, R T; Vásquez, R P; Veszpremi, V; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wallraff, W; Wang, X L; Wang, Z M; Weber, M; Wienemann, P; Wilkens, H; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhao, J; Zhu, G Y; Zhu, R Y; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M
2002-01-01
We measure three-particle Bose-Einstein correlations in hadronic Z decay with the L3 detector at LEP. Genuine three-particle Bose-Einstein correlations are observed. By comparing two- and three-particle correlations we find that the data are consistent with fully incoherent pion production.
Navarrete-Reyes, Ana Patricia; Medina-Rimoldi, Carlos Tonatiuh; Avila-Funes, José Alberto
2017-02-11
Older adults frequently report problems of transportation. Little is known about the correlates of transportation deficiency in Latin America. Therefore, the aim of the present study was to determine the correlates of subjective transportation deficiency (STD) among community-dwelling older adults attending a tertiary care hospital in Mexico City. Cross-sectional study of 228 participants aged ≥70 years being followed in any of the outpatient clinics of a tertiary care hospital in Mexico City. Data were obtained through a structured questionnaire. Univariate and multivariate logistic regression analyses were carried out in order to identify the correlates of STD. The mean age of the participants was 79.8 years (SD 6.4) and 67.1% were women. STD was present in 46% of participants. The multivariate logistic regression model showed that female sex, illiteracy, mobility disability and the use of an assistive walking device had an independent and statistically significant association with STD. Female sex, illiteracy, mobility disability and the use of an assistive walking device were independent correlates of STD in the present study. Identifying the frequency and correlates of transportation deficiency in vulnerable populations will allow for the identification and implementation of useful public policies, as well as for the optimization of prevention and treatment strategies in an attempt to preserve mobility and autonomy, especially in low- and middle-income countries where previous work on transportation deficiency is lacking. Geriatr Gerontol Int 2016; ••: ••-••. © 2017 Japan Geriatrics Society.
Imaging of adult flatfoot: correlation of radiographic measurements with MRI.
Lin, Yu-Ching; Mhuircheartaigh, Jennifer Ni; Lamb, Joshua; Kung, Justin W; Yablon, Corrie M; Wu, Jim S
2015-02-01
OBJECTIVE. The purpose of this study is to determine whether radiographic foot measurements can predict injury of the posterior tibial tendon (PTT) and the supporting structures of the medial longitudinal arch as diagnosed on MRI. MATERIALS AND METHODS. After institutional review board approval, 100 consecutive patients with radiographic and MRI examinations performed within a 2-month period were enrolled. Thirty-one patients had PTT dysfunction clinically, and 69 patients had other causes of ankle pain. Talonavicular uncoverage angle, incongruency angle, calcaneal pitch angle, Meary angle, cuneiform-to-fifth metatarsal height, and talar tilt were calculated on standing foot or ankle radiographs. MRI was used to assess for abnormalities of the PTT (tenosynovitis, tendinosis, and tear) and supporting structures of the medial longitudinal arch (spring ligament, deltoid ligament, and sinus tarsi). Statistical analysis was performed using the chi-square and Fisher exact tests for categoric variables; the Student t test was used for continuous variables. RESULTS. There was a statistically significant association of PTT tear with abnormal talonavicular uncoverage angle, calcaneal pitch angle, Meary angle, and cuneiform-to-fifth metatarsal height. PTT tendinosis and isolated tenosynovitis had a poor association with most radiologic measurements. If both calcaneal pitch and Meary angles were normal, no PTT tear was present. An abnormal calcaneal pitch angle had the best association with injury to the supporting medial longitudinal arch structures. CONCLUSION. Radiographic measurements, especially calcaneal pitch and Meary angles, can be useful in detecting PTT tears. Calcaneal pitch angle provides the best assessment of injury to the supporting structures of the medial longitudinal arch.
Measurement and correlates of internalized homophobia: a factor analytic study.
Ross, M W; Rosser, B R
1996-01-01
We developed a scale to measure internalized homophobia in men who have sex with men, which is comprised of items derived from theoretical and clinical reports of internalized homophobia. Two hundred two men who have sex with men and who attend "Man to Man" sexual health seminars in a midwestern U.S. city completed the scale at baseline. Orthogonal factor analysis revealed four dimensions of internalized homophobia: public identification as gay, perception of stigma associated with being homosexual, social comfort with gay men, and the moral and religious acceptability of being gay. Factor scoring of these dimensions indicated that they were associated significantly with relationship satisfaction, duration of longest relationship, extent of attraction to men and women, proportion of social time with gay people, membership of gay/bisexual groups, HIV serostatus, and disclosure of sexual orientation. Internalized homophobia is measurable and consists of four dimensions that are associated significantly with low disclosure, shorter length of and satisfaction with relationships, lower degree of sexual attraction to men and higher degree of attraction to women, and lower social time with gay people.
Correlation between precision gravity and subsidence measurements at Cerro Prieto
Zelwer, R.; Grannell, R. B.
1982-10-01
Precision gravity measurements were made in the region of the Cerro Prieto geothermal field at yearly intervals from 1977 to 1981 to assess the feasibility of using gravity to determine subsurface reservoir changes with time. The extent of mass recharge in response to the continued production of fluids from this field was studied. Changes in gravity and ground elevation were observed throughout the region for the period of observation. Results indicate that the largest changes observed were the result of the Magnitude 6.1 (Caltech) Victoria earthquake of 8 June 1980. The epicenter of this earthquake was located 25 km southeast of the field on the Cerro Prieto Fault, which bounds the field on the southwest. Subsidence of up to 55 cm was measured east of the power plant, in the region between the northern end of the Cerro Prieto Fault and the southern end of the Imperial Fault. This area has been postulated to be the site of an active spreading center or pull-apart basin, and has been characterized by a high level of seismic activity during the last 10 years.
GONOME: measuring correlations between GO terms and genomic positions
Directory of Open Access Journals (Sweden)
Bailey Timothy L
2006-02-01
Full Text Available Abstract Background: Current methods to find significantly under- and over-represented gene ontology (GO terms in a set of genes consider the genes as equally probable "balls in a bag", as may be appropriate for transcripts in micro-array data. However, due to the varying length of genes and intergenic regions, that approach is inappropriate for deciding if any GO terms are correlated with a set of genomic positions. Results: We present an algorithm – GONOME – that can determine which GO terms are significantly associated with a set of genomic positions given a genome annotated with (at least the starts and ends of genes. We show that certain GO terms may appear to be significantly associated with a set of randomly chosen positions in the human genome if gene lengths are not considered, and that these same terms have been reported as significantly over-represented in a number of recent papers. This apparent over-representation disappears when gene lengths are considered, as GONOME does. For example, we show that, when gene length is taken into account, the term "development" is not significantly enriched in genes associated with human CpG islands, in contradiction to a previous report. We further demonstrate the efficacy of GONOME by showing that occurrences of the proteosome-associated control element (PACE upstream activating sequence in the S. cerevisiae genome associate significantly to appropriate GO terms. An extension of this approach yields a whole-genome motif discovery algorithm that allows identification of many other promoter sequences linked to different types of genes, including a large group of previously unknown motifs significantly associated with the terms 'translation' and 'translational elongation'. Conclusion: GONOME is an algorithm that correctly extracts over-represented GO terms from a set of genomic positions. By explicitly considering gene size, GONOME avoids a systematic bias toward GO terms linked to large genes
Correlates of subjectively and objectively measured physical activity in young adolescents
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Kelly Kavanaugh
2015-09-01
Conclusion: Measuring MVPA via self-report versus accelerometry produces considerably different results in a sample of young adolescents. Future studies should use caution when selecting outcome measures if the intent is to identify modifiable correlates of MVPA in youth.
Measurement of Grit and Correlation to Student Pharmacist Academic Performance.
Pate, Adam N; Payakachat, Nalin; Harrell, T Kristopher; Pate, Kristen A; Caldwell, David J; Franks, Amy M
2017-08-01
Objective. To describe grittiness of students from three pharmacy schools and determine if grit is associated with academic performance measures. Methods. Pharmacy students completed an electronic questionnaire that included the Short Grit Scale (Grit-S). Associations were determined using logistic regression. Results. Grit-S total score was a significant and independent predictor for participants who reported a GPA ≥3.5, and Consistency of Interest (COI) and Perseverance of Effort (POE) domain scores were significantly higher compared to participants with a GPA of 3.0-3.49. Participants reporting a D or F had slightly lower average total Grit-S scores and COI domain scores compared to participants who did not. In addition, the group who reported a GPA GPA of 3.0-3.4. Conclusion. Grittiness may be associated with student pharmacist academic performance and the Grit-S Scale may have substantive implications for use in pharmacy programs.
Surface roughness measurement on a wing aircraft by speckle correlation.
Salazar, Félix; Barrientos, Alberto
2013-09-05
The study of the damage of aeronautical materials is important because it may change the microscopic surface structure profiles. The modification of geometrical surface properties can cause small instabilities and then a displacement of the boundary layer. One of the irregularities we can often find is surface roughness. Due to an increase of roughness and other effects, there may be extra momentum losses in the boundary layer and a modification in the parasite drag. In this paper we present a speckle method for measuring the surface roughness on an actual unmanned aircraft wing. The results show an inhomogeneous roughness distribution on the wing, as expected according to the anisotropic influence of the winds over the entire wing geometry. A calculation of the uncertainty of the technique is given.
Magnetometry and electrical transport measurements of high temperature superconductors
Energy Technology Data Exchange (ETDEWEB)
Chan, Mun Keat [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-02-13
Prior to preparing and performing measurements in pulsed magnetic fields, it is necessary to characterize them. For the cuprates such as HgBa_{2}CuO_{4+δ} (Hg1201), measurements of the superconducting temperature is essential. This experiment comprises just such a characterization of Hg1201 crystals to be used for pulsed magnetic field measurements.
Stollenwerk, K.G.
1998-01-01
A natural-gradient tracer test was conducted in an unconfined sand and gravel aquifer on Cape Cod, Massachusetts. Molybdate was included in the injectate to study the effects of variable groundwater chemistry on its aqueous distribution and to evaluate the reliability of laboratory experiments for identifying and quantifying reactions that control the transport of reactive solutes in groundwater. Transport of molybdate in this aquifer was controlled by adsorption. The amount adsorbed varied with aqueous chemistry that changed with depth as freshwater recharge mixed with a plume of sewage-contaminated groundwater. Molybdate adsorption was strongest near the water table where pH (5.7) and the concentration of the competing solutes phosphate (2.3 micromolar) and sulfate (86 micromolar) were low. Adsorption of molybdate decreased with depth as pH increased to 6.5, phosphate increased to 40 micromolar, and sulfate increased to 340 micromolar. A one-site diffuse-layer surface-complexation model and a two-site diffuse-layer surface-complexation model were used to simulate adsorption. Reactions and equilibrium constants for both models were determined in laboratory experiments and used in the reactive-transport model PHAST to simulate the two-dimensional transport of molybdate during the tracer test. No geochemical parameters were adjusted in the simulation to improve the fit between model and field data. Both models simulated the travel distance of the molybdate cloud to within 10% during the 2-year tracer test; however, the two-site diffuse-layer model more accurately simulated the molybdate concentration distribution within the cloud.
Correlation coefficient measurement of the mode-locked laser tones using four-wave mixing.
Anthur, Aravind P; Panapakkam, Vivek; Vujicic, Vidak; Merghem, Kamel; Lelarge, Francois; Ramdane, Abderrahim; Barry, Liam P
2016-06-01
We use four-wave mixing to measure the correlation coefficient of comb tones in a quantum-dash mode-locked laser under passive and active locked regimes. We study the uncertainty in the measurement of the correlation coefficient of the proposed method.
The concordance correlation coefficient for repeated measures estimated by variance components.
Carrasco, Josep L; King, Tonya S; Chinchilli, Vernon M
2009-01-01
The concordance correlation coefficient (CCC) is an index that is commonly used to assess the degree of agreement between observers on measuring a continuous characteristic. Here, a CCC for longitudinal repeated measurements is developed through the appropriate specification of the intraclass correlation coefficient from a variance components linear mixed model. A case example and the results of a simulation study are provided.
Measurements of fluid transport by controllable vertical migrations of plankton
Houghton, Isabel A.; Dabiri, John O.
2016-11-01
Diel vertical migration of zooplankton has been proposed to be a significant contributor to local and possibly large-scale fluid transport in the ocean. However, studies of this problem to date have been limited to order-of-magnitude estimates based on first principles and a small number of field observations. In this work, we leverage the phototactic behavior of zooplankton to stimulate controllable vertical migrations in the laboratory and to study the associated fluid transport and mixing. Building upon a previous prototype system, a laser guidance system induces vertical swimming of brine shrimp (Artemia salina) in a 2.1 meter tall, density-stratified water tank. The animal swimming speed and spacing during the controlled vertical migration is characterized with video analysis. A schlieren imaging system is utilized to visualize density perturbations to a stable stratification for quantification of fluid displacement length scales and restratification timescales. These experiments can add to our understanding of the dynamics of active particles in stratified flows. NSF and US-Israel Binational Science Foundation.
Longitudinal transport measurements in an energy recovery accelerator with triple bend achromat arcs
Jackson, F.; Angal-Kalinin, D.; Saveliev, Y. M.; Williams, P. H.; Wolski, A.
2016-12-01
Longitudinal properties of electron bunches (energy spread and bunch length) and their manipulation are of importance in free electron lasers (FELs), where magnetic bunch length compression is a common feature of beam transport. Recirculating accelerators and energy recovery linac accelerators (ERLs) have been used as FEL drivers for several decades and control of longitudinal beam transport is particularly important in their magnet lattices. We report on measurements of longitudinal transport properties in an ERL-FEL, the ALICE (Accelerators and Lasers in Combined Experiments) accelerator at Daresbury Laboratory. ALICE is an energy recovery research accelerator that drives an infrared free electron laser. By measuring the time of arrival of electron bunches, the canonical longitudinal transport quantities were measured in the beam transport and bunch compression sections of the lattice. ALICE includes a four-dipole bunch compression chicane providing fixed longitudinal transport, and triple bend achromat arcs including sextupole magnets where the first and second order longitudinal transport can be adjusted. The longitudinal transport properties in these lattice sections were measured and compared with the theoretical model of the lattice. A reasonable level of agreement has been found. The effect of sextupoles in second order, as well as first order, longitudinal correction is considered, with the measurements indicating the level of alignment of the beam to the center of the sextupole.
INVESTIGATION OF ATMOSPHERIC HUMIDITY TRANSPORT ON THE BASIS OF AEROLOGICAL MEASUREMENTS
L. NYITRAI; Tóth, R
2015-01-01
The global upper-air data base over the last 40 years is available by courtesy of College of Engineering and Applied Sciences at the University of Wyoming. Considering the fact, that in the atmospheric moisture transport between the oceans and the continents the humidity flow is much stronger towards the mainland than in the reverse direction, therefore it is reasonable to look for some correlation between the moisture transport and precipitation climate of the continents. For Europe, this is...
Economic evaluation of safety measures for transport companies
Rietveld, Piet; Rienstra, Sytze A.
1998-01-01
Measures to reduce material damage within companies may both increase the business economic performance of the company and traffic safety in general. In this paper the notion of whether such measures are economically feasible is investigated. Results are presented of a series of interviews amongtran
On extracting sediment transport information from measurements of luminescence in river sediment
Gray, Harrison J; Mahan, Shannon A; McGuire, Chris; Rhodes, Edward J
2016-01-01
Accurately quantifying sediment transport rates in rivers remains an important goal for geomorphologists, hydraulic engineers, and environmental scientists. However, current techniques for measuring transport rates are laborious, and formulae to predict transport are notoriously inaccurate. Here, we attempt to estimate sediment transport rates using luminescence, a property of common sedimentary minerals that is used by the geoscience community for geochronology. This method is advantageous because of the ease of measurement on ubiquitous quartz and feldspar sand. We develop a model based on conservation of energy and sediment mass to explain the patterns of luminescence in river channel sediment from a first-principles perspective. We show that the model can accurately reproduce the luminescence observed in previously published field measurements from two rivers with very different sediment transport styles. The parameters from the model can then be used to estimate the time-averaged virtual velocity, charac...
Directory of Open Access Journals (Sweden)
R Chad Webb
Full Text Available Measurements of the thermal transport properties of the skin can reveal changes in physical and chemical states of relevance to dermatological health, skin structure and activity, thermoregulation and other aspects of human physiology. Existing methods for in vivo evaluations demand complex systems for laser heating and infrared thermography, or they require rigid, invasive probes; neither can apply to arbitrary regions of the body, offers modes for rapid spatial mapping, or enables continuous monitoring outside of laboratory settings. Here we describe human clinical studies using mechanically soft arrays of thermal actuators and sensors that laminate onto the skin to provide rapid, quantitative in vivo determination of both the thermal conductivity and thermal diffusivity, in a completely non-invasive manner. Comprehensive analysis of measurements on six different body locations of each of twenty-five human subjects reveal systematic variations and directional anisotropies in the characteristics, with correlations to the thicknesses of the epidermis (EP and stratum corneum (SC determined by optical coherence tomography, and to the water content assessed by electrical impedance based measurements. Multivariate statistical analysis establishes four distinct locations across the body that exhibit different physical properties: heel, cheek, palm, and wrist/volar forearm/dorsal forearm. The data also demonstrate that thermal transport correlates negatively with SC and EP thickness and positively with water content, with a strength of correlation that varies from region to region, e.g., stronger in the palmar than in the follicular regions.
Surface electronic transport measurements: A micro multi-point probe approach
DEFF Research Database (Denmark)
Barreto, Lucas
2014-01-01
This work is mostly focused on the study of electronic transport properties of two-dimensional materials, in particular graphene and topological insulators. To study these, we have improved a unique micro multi-point probe instrument used to perform transport measurements. Not only the experimental...
Cui, Ping
The thesis comprises two major themes of quantum statistical dynamics. One is the development of quantum dissipation theory (QDT). It covers the establishment of some basic relations of quantum statistical dynamics, the construction of several nonequivalent complete second-order formulations, and the development of exact QDT. Another is related to the applications of quantum statistical dynamics to a variety of research fields. In particular, unconventional but novel theories of the electron transfer in Debye solvents, quantum transport, and quantum measurement are developed on the basis of QDT formulations. The thesis is organized as follows. In Chapter 1, we present some background knowledge in relation to the aforementioned two themes of this thesis. The key quantity in QDT is the reduced density operator rho(t) ≡ trBrho T(t); i.e., the partial trace of the total system and bath composite rhoT(t) over the bath degrees of freedom. QDT governs the evolution of reduced density operator, where the effects of bath are treated in a quantum statistical manner. In principle, the reduced density operator contains all dynamics information of interest. However, the conventional quantum transport theory is formulated in terms of nonequilibrium Green's function. The newly emerging field of quantum measurement in relation to quantum information and quantum computing does exploit a sort of QDT formalism. Besides the background of the relevant theoretical development, some representative experiments on molecular nanojunctions are also briefly discussed. In chapter 2, we outline some basic (including new) relations that highlight several important issues on QDT. The content includes the background of nonequilibrium quantum statistical mechanics, the general description of the total composite Hamiltonian with stochastic system-bath interaction, a novel parameterization scheme for bath correlation functions, a newly developed exact theory of driven Brownian oscillator (DBO
Directory of Open Access Journals (Sweden)
Gropp Kathleen M
2012-10-01
Full Text Available Abstract Background Active transportation to school is a method by which youth can build physical activity into their daily routines. We examined correlates of active transportation to school at both individual- (characteristics of the individual and family and area- (school and neighborhood levels amongst youth living within 1 mile (1.6 km of their school. Methods Using the 2009/10 Canadian Health Behaviour in School-Aged Children (HBSC survey, we selected records of students (n = 3 997 from 161 schools that resided in an urban setting and lived within 1 mile from their school. Student records were compiled from: (1 individual-level HBSC student questionnaires; (2 area-level administrator (school questionnaires; and (3 area-level geographic information system data sources. The outcome, active transportation to school, was determined via a questionnaire item describing the method of transportation that individual students normally use to get to school. Analyses focused on factors at multiple levels that potentially contribute to student decisions to engage in active transportation. Multi-level logistic regression analyses were employed. Results Approximately 18% of the variance in active transportation was accounted for at the area-level. Several individual and family characteristics were associated with engagement in active transportation to school including female gender (RR vs. males = 0.86, 95% CI: 0.80-0.91, having ≥2 cars in the household (RR vs. no cars = 0.87, 0.74-0.97, and family socioeconomic status (RR for ‘not well off’ vs. ‘very well off’ = 1.14, 1.01-1.26. Neighborhood characteristics most strongly related to active transportation were: the length of roads in the 1 km buffer (RR in quartile 4 vs. quartile 1 = 1.23, 1.00-1.42, the amount of litter in the neighborhood (RR for ‘major problem’ vs. ‘no problem’ = 1.47, 1.16-1.57, and relatively hot climates (RR in quartile 4 vs. quartile 1
Energy Technology Data Exchange (ETDEWEB)
Artu, X. [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; Collins, J. [Pennsylvania State Univ., University Park, PA (United States). Davey Lab.
1996-01-01
The azimuthal distribution of pairs of particles in a jet is sensitive to the transverse polarization of the quark initiating the jet, but with a sensitivity that involves a nonperturbative analyzing power. We show in detail how to measure the analyzing power from 4-hadron correlations in e{sup +}e{sup -} {yields} 2 jets. We explain the combinations of particle flavor that are likely to give the biggest effect. (orig.)
Valassi, A
2014-01-01
We discuss the effect of large positive correlations in the combinations of several measurements of a single physical quantity using the Best Linear Unbiased Estimate (BLUE) method. We suggest a new approach for comparing the relative weights of the different measurements in their contributions to the combined knowledge about the unknown parameter, using the well-established concept of Fisher information. We argue, in particular, that one contribution to information comes from the collective interplay of the measurements through their correlations and that this contribution cannot be attributed to any of the individual measurements alone. We show that negative coefficients in the BLUE weighted average invariably indicate the presence of a regime of high correlations, where the effect of further increasing some of these correlations is that of reducing the error on the combined estimate. In these regimes, we stress that the correlations provided as input to BLUE combinations need to be assessed with extreme ca...
Photon-correlation measurements of atomic-cloud temperature using an optical nanofiber
Grover, J A; Orozco, L A; Rolston, S L
2015-01-01
We develop a temperature measurement of an atomic cloud based on the temporal correlations of fluorescence photons evanescently coupled into an optical nanofiber. We measure the temporal width of the intensity-intensity correlation function due to atomic transit time and use it to determine the most probable atomic velocity, hence the temperature. This technique agrees well with standard time-of-flight temperature measurements. We confirm our results with trajectory simulations.
High dynamic range multi-channel cross-correlator for single-shot temporal contrast measurement
Kon, A.; Nishiuchi, M.; Kiriyama, H.; Ogura, K.; Mori, M.; Sakaki, H.; Kando, M.; Kondo, K.
2016-05-01
We have developed a multi-channel cross-correlator for high dynamic range (>1010), single-shot temporal contrast measurements. The correlator utilizes a third-order crosscorrelation technique and has a reference channel, to be normalized by the measured peak intensity, and four independent optical delay lines. The measurement results of the shot-to-shot temporal contrast clearly show the intensity fluctuations of short pre-pulses at -4.5 ps and -26 ps before main pulse.
Energy Technology Data Exchange (ETDEWEB)
Ness, H., E-mail: herve.ness@kcl.ac.uk [Department of Physics, School of Natural and Mathematical Sciences, King' s College London, Strand, London WC2R 2LS (United Kingdom); Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); European Theoretical Spectroscopy Facility (ETSF), Liege (Belgium); Dash, L. K. [European Theoretical Spectroscopy Facility (ETSF), Liege (Belgium); Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)
2014-04-14
We study the non-equilibrium (NE) fluctuation-dissipation (FD) relations in the context of quantum thermoelectric transport through a two-terminal nanodevice in the steady-state. The FD relations for the one- and two-particle correlation functions are derived for a model of the central region consisting of a single electron level. Explicit expressions for the FD relations of the Green's functions (one-particle correlations) are provided. The FD relations for the current-current and charge-charge (two-particle) correlations are calculated numerically. We use self-consistent NE Green's functions calculations to treat the system in the absence and in the presence of interaction (electron-phonon) in the central region. We show that, for this model, there is no single universal FD theorem for the NE steady state. There are different FD relations for each different class of problems. We find that the FD relations for the one-particle correlation function are strongly dependent on both the NE conditions and the interactions, while the FD relations of the current-current correlation function are much less dependent on the interaction. The latter property suggests interesting applications for single-molecule and other nanoscale transport experiments.
Ness, H; Dash, L K
2014-04-14
We study the non-equilibrium (NE) fluctuation-dissipation (FD) relations in the context of quantum thermoelectric transport through a two-terminal nanodevice in the steady-state. The FD relations for the one- and two-particle correlation functions are derived for a model of the central region consisting of a single electron level. Explicit expressions for the FD relations of the Green's functions (one-particle correlations) are provided. The FD relations for the current-current and charge-charge (two-particle) correlations are calculated numerically. We use self-consistent NE Green's functions calculations to treat the system in the absence and in the presence of interaction (electron-phonon) in the central region. We show that, for this model, there is no single universal FD theorem for the NE steady state. There are different FD relations for each different class of problems. We find that the FD relations for the one-particle correlation function are strongly dependent on both the NE conditions and the interactions, while the FD relations of the current-current correlation function are much less dependent on the interaction. The latter property suggests interesting applications for single-molecule and other nanoscale transport experiments.
Measures of Transport-Related Social Exclusion: A Critical Review of the Literature
Directory of Open Access Journals (Sweden)
Md. Kamruzzaman
2016-07-01
Full Text Available Quantitative measures of transport disadvantage are reviewed in this paper from the perspective of their effectiveness to investigate social exclusion. The effectiveness is assessed using criteria derived through a review of the concepts of transport disadvantage and social exclusion and their operationalisation. The specified criteria are related to issues of spatial (e.g., urban accessibility, and public transport accessibility, temporal (e.g., public transport availability, and facility opening hours, and social attributes of travel and activity participation (e.g., personal mobility, and disability. Four groups of transport disadvantage measures are identified and evaluated. These include deprivation-based measures, mobility-based measures, accessibility-based measures, and activity-based measures. The review suggests that although the first three categories of measures have traditionally been used to identify transport disadvantage, they do not satisfy issues surrounding activity participation—the key outcome of social exclusion. The activity space concept is a way in which these issues can be incorporated, as it is a measure of the outcomes of activity participation and their associated travel to that activity. Participation in an activity means that an individual has overcome the spatial, temporal and social barriers of travel for that activity. The research using the activity space concept has, however, inadequately identified individual travel and activity participation. This has been due to a separate application of a range of different indicators to assess activity space size. These indicators are by their nature multidimensional—e.g., area visited, distance travelled, and number of activity sites visited. Although each indicator represents a specific qualitative/quantitative aspect of travel and activity participation, researchers have treated these indicators in an isolated manner to identify transport disadvantage and
Directory of Open Access Journals (Sweden)
Piotr Kubica
2015-01-01
Full Text Available The transport properties of the poly(ethylene-co-vinyl acetate (EVA materials to He, N2, O2, and CO2 are correlated with two polymer molecular structure parameters, that is, cohesive energy density (CED and fractional free volume (FFV, determined by the group contribution method. In our preceding paper, the attempt was made to approximate EVA permeability using a linear function of 1/FFV as predicted by the free volume theory. However, the deviations from this relationship appeared to be significant. In this paper, it is shown that permeation of gas molecules is controlled not only by free volume but also by the polymer cohesive energy. Moreover, the behavior of CO2 was found to differ significantly from that of other gases. In this instance, the correlation is much better when diffusivity instead of permeability is taken into account in a modified transport model.
Ohyama, Hirofumi; Kawakami, Shuji; Uchino, Osamu; Sakai, Tetsu; Morino, Isamu; Nagai, Tomohiro; Shiomi, Kei; Sakashita, Masanori; Akaho, Taiga; Okumura, Hiroshi; Arai, Kohei
2016-12-01
We used a lower tropospheric ozone column (LTOC) and column-averaged dry-air mole fraction of carbon monoxide (XCO) data observed in the area around Saga, which is located in western Japan and is close to the Asian continent, with an aim to investigate whether these data can characterize the seasonal variation of the photochemical ozone (O3) formation in the northeast Asian Pacific rim region. The LTOC data after April 2009 were retrieved from thermal infrared spectra measured by the Thermal and Near Infrared Sensor for Carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) onboard the Greenhouse Gases Observing Satellite (GOSAT). The XCO data after July 2011 were obtained from ground-based high-resolution FTS measurements at Saga. The retrieved LTOCs were validated with those derived from a differential absorption lidar for O3 at Saga. The LTOCs showed a distinct seasonal variation that reached a maximum in late spring (May or June) and a local minimum in winter. In addition to the general seasonal pattern, we observed pronounced minimums in July or August. The XCO concentrations showed a maximum in spring and a minimum in summer. These seasonal patterns are consistent with those observed from mountainous sites in Japan. The origins of the air masses reaching Saga were characterized for each season according to backward trajectories, and the factors causing the temporal variations of the LTOCs and the XCO were identified based on the transport paths of the air masses. The enhancement of the LTOC relative to the XCO (ΔO3/ΔCO ratio) reveals significant positive correlations in the spring and summer seasons with slopes of 0.21 and 0.45 ppb/ppb, respectively. The effects of stratospheric air intrusion on the observed ΔO3/ΔCO ratio in spring were investigated using meteorological data (backward trajectory and potential vorticity) and column-averaged hydrogen fluoride data derived from the ground-based FTS measurements. It was found that there was little
Peng, Jiajun; Chen, Yani; Wu, Xiaohan; Zhang, Qian; Kan, Bin; Chen, Xiaoqing; Chen, Yongsheng; Huang, Jia; Liang, Ziqi
2015-06-24
Efficient charge transport is a key step toward high efficiency in small-molecule organic photovoltaics. Here we applied time-of-flight and organic field-effect transistor to complementarily study the influences of molecular structure, trap states, and molecular orientation on charge transport of small-molecule DRCN7T (D1) and its analogue DERHD7T (D2). It is revealed that, despite the subtle difference of the chemical structures, D1 exhibits higher charge mobility, the absence of shallow traps, and better photosensitivity than D2. Moreover, charge transport is favored in the out-of-plane structure within D1-based organic solar cells, while D2 prefers in-plane charge transport.
Iden, Hiroshi; Ohma, Atsushi; Tokunaga, Tomomi; Yokoyama, Kouji; Shinohara, Kazuhiko
2016-05-14
The optimization of the catalyst layers is necessary for obtaining a better fuel cell performance and reducing fuel cell cost. Although the ionomer coverage of the Pt catalyst is said to be a key parameter in this regard, the proportion of Pt either directly or indirectly covered by the ionomer is thought to be an important parameter with regard to gas transport (indirectly covered Pt: its gas transport paths are completely blocked by the ionomer even if it does not directly cover Pt). In this study, a new technique has been developed for evaluating the proportion of Pt covered indirectly or directly by the ionomer, which is defined as the "capped proportion", based on the carbon monoxide (CO) adsorption properties at different temperatures. The validity of the method was thoroughly examined by identifying the CO adsorption properties of the components of the catalyst layers. The capped proportion and oxygen transport resistance in the catalyst layers showed a good correlation, indicating that the capped proportion is a dominant factor of oxygen transport resistance. This technique thus enables the evaluation of the dominant factor of the gas transport properties of the catalyst layers. The method has another significant advantage in that it does not require a membrane electrode assembly, let alone electrochemical measurement, which should be helpful for catalyst layer optimization.
Zhao, J; Goldberg, J; Vaccarino, V
2013-01-01
Epigenetic mechanisms are increasingly being recognized as an important factor for obesity. The serotonin transporter gene (SLC6A4) has a critical role in regulating food intake, body weight and energy balance. This study examines the potential association between SLC6A4 promoter methylation and obesity measures in a monozygotic (MZ) twin sample. We studied 84 MZ twin pairs drawn from the Vietnam Era Twin Registry. Obesity measures include body mass index (BMI), body weight, waist circumference (WC) and waist-hip ratio (WHR). The SLC6A4 promoter methylation profile in peripheral blood leukocytes was quantified by bisulfite pyrosequencing. The association between methylation variation and obesity parameters was examined by mixed-model regression and matched pair analysis, adjusting for age, smoking, alcohol consumption, physical activity and total daily energy intake. Multiple testing was controlled using the adjusted false discovery rate (q-value). Mean methylation level was positively correlated with BMI (r=0.29; P=0.0002), body weight (r=0.31; Pobesity within a MZ twin study.
Huang, Chun Y; Shirley, Neil; Genc, Yusuf; Shi, Bujun; Langridge, Peter
2011-07-01
Genetic variation in phosphorus (P) efficiency exists among wheat (Triticum aestivum) and barley (Hordeum vulgare) genotypes, but the underlying mechanisms for the variation remain elusive. High- and low-affinity phosphate (Pi) PHT1 transporters play an indispensable role in P acquisition and remobilization. However, little is known about genetic variation in PHT1 gene expression and association with P acquisition efficiency (PAE) and P utilization efficiency (PUE). Here, we present quantitative analyses of transcript levels of high- and low-affinity PHT1 Pi transporters in four barley genotypes differing in PAE. The results showed that there was no clear pattern in the expression of four paralogs of the high-affinity Pi transporter HvPHT1;1 among the four barley genotypes, but the expression of a low-affinity Pi transporter, HvPHT1;6, and its close homolog HvHPT1;3 was correlated with the genotypes differing in PUE. Interestingly, the expression of HvPHT1;6 and HvPHT1;3 was correlated with the expression of HvIPS1 (for P starvation inducible; noncoding RNA) but not with HvIPS2, suggesting that HvIPS1 plays a distinct role in the regulation of the low-affinity Pi transporters. In addition, high PUE was found to be associated with high root-shoot ratios in low-P conditions, indicating that high carbohydrate partitioning into roots occurs simultaneously with high PUE. However, high PUE accompanying high carbon partitioning into roots could result in low PAE. Therefore, the optimization of PUE through the modification of low-affinity Pi transporter expression may assist further improvement of PAE for low-input agriculture systems.
Surface electronic transport measurements: A micro multi-point probe approach
DEFF Research Database (Denmark)
Barreto, Lucas
2014-01-01
setup, but the terminology used and data analysis were also ameliorated in order to simplify the interpretation of the results. We used the mentioned technique in the following projects: • The electronic transport dimensionality of epitaxial grahene grown on SiC is detected and important physical......This work is mostly focused on the study of electronic transport properties of two-dimensional materials, in particular graphene and topological insulators. To study these, we have improved a unique micro multi-point probe instrument used to perform transport measurements. Not only the experimental...... a direct measurement of the surface electronic transport on a bulk topological insulator. The surface state conductivity and mobility are obtained. Apart from transport properties, we also investigate the atomic structure of the Bi2Se3(111) surface via surface x-ray diraction and low-energy electron...
Muñoz, Enrique; Bolech, C J; Kirchner, Stefan
2013-01-04
The nonlinear conductance of semiconductor heterostructures and single molecule devices exhibiting Kondo physics has recently attracted attention. We address the observed sample dependence of the measured steady state transport coefficients by considering additional electronic contributions in the effective low-energy model underlying these experiments that are absent in particle-hole symmetric setups. A novel version of the superperturbation theory of Hafermann et al. in terms of dual fermions is developed, which correctly captures the low-temperature behavior. We compare our results with the measured transport coefficients.
Disordered Fermi liquid in epitaxial graphene from quantum transport measurements.
Lara-Avila, Samuel; Tzalenchuk, Alexander; Kubatkin, Sergey; Yakimova, Rositza; Janssen, T J B M; Cedergren, Karin; Bergsten, Tobias; Fal'ko, Vladimir
2011-10-14
We have performed magnetotransport measurements on monolayer epitaxial graphene and analyzed them in the framework of the disordered Fermi liquid theory. We have separated the electron-electron and weak-localization contributions to resistivity and demonstrated the phase coherence over a micrometer length scale, setting the limit of at least 50 ps on the spin relaxation time in this material.
Angular correlations of identified charged particles measured in pp collisions by ALICE at the LHC
Energy Technology Data Exchange (ETDEWEB)
Graczykowski, Łukasz Kamil, E-mail: lgraczyk@if.pw.edu.pl; Janik, Małgorzata Anna, E-mail: majanik@if.pw.edu.pl
2014-06-15
We report on studies of untriggered two-particle angular correlations of identified particles (pions, kaons and protons) measured in proton–proton collisions at center-of-mass energy √(s)=7 TeV recorded by ALICE at the LHC. These type of studies are sensitive to a wide range of correlations which arise from different physics mechanisms, each of them having a unique structure in ΔηΔφ space. The correlations of particles with different quark content and flavor are sensitive to various conservation laws. The study of these correlations is the main goal of this analysis. The results confirm that these laws strongly influence the shape of the correlation functions for different particle types and must be taken into account while analyzing the data. Moreover, we verify their implementation using two Monte Carlo event generators and we found that the analyzed models do not reproduce the measured correlations for protons.
Variance in population firing rate as a measure of slow time-scale correlation
Directory of Open Access Journals (Sweden)
Adam C. Snyder
2013-12-01
Full Text Available Correlated variability in the spiking responses of pairs of neurons, also known as spike count correlation, is a key indicator of functional connectivity and a critical factor in population coding. Underscoring the importance of correlation as a measure for cognitive neuroscience research is the observation that spike count correlations are not fixed, but are rather modulated by perceptual and cognitive context. Yet while this context fluctuates from moment to moment, correlation must be calculated over multiple trials. This property undermines its utility as a dependent measure for investigations of cognitive processes which fluctuate on a trial-to-trial basis, such as selective attention. A measure of functional connectivity that can be assayed on a moment-to-moment basis is needed to investigate the single-trial dynamics of populations of spiking neurons. Here, we introduce the measure of population variance in normalized firing rate for this goal. We show using mathematical analysis, computer simulations and in vivo data how population variance in normalized firing rate is inversely related to the latent correlation in the population, and how this measure can be used to reliably classify trials from different typical correlation conditions, even when firing rate is held constant. We discuss the potential advantages for using population variance in normalized firing rate as a dependent measure for both basic and applied neuroscience research.
Transport currents measured in ring samples: test of superconducting weld
Zheng, H.; Claus, H.; Chen, L.; Paulikas, A. P.; Veal, B. W.; Olsson, B.; Koshelev, A.; Hull, J.; Crabtree, G. W.
2001-02-01
The critical current densities in bulk melt-textured YBa 2Cu 3O x and across superconducting “weld” joints are measured using scanning Hall probe measurements of the trapped magnetic field in ring samples. With this method, critical current densities are obtained without the use of electrical contacts. Large persistent currents are induced in ring samples at 77 K, after cooling in a 3 kG field. These currents can be determined from the magnetic field they produce. At 77 K a supercurrent exceeding 2000 A (about 10 4 A/cm 2) was induced in a 2 cm diameter ring; this current produces a magnetic field exceeding 1.5 kG in the bore of the ring. We demonstrate that when a ring is cut, and the cut is repaired by a superconducting weld, the weld joint can transmit the same high supercurrent as the bulk.
Experimental evidence of interhemispheric transport from airborne carbon monoxide measurements
Newell, R. E.; Gauntner, D. J.
1979-01-01
During the period 28-30 October 1977, a Pan American 747-SP aircraft flew around the world with an automated instrument package that included measurements of atmospheric CO made every 4 sec. The flight path extended from San Francisco, over the North Pole to London, south to Capetown, over the South Pole to Auckland, and back to San Francisco. The data collected show large changes with longitude, which are interpreted as direct evidence of interhemispheric mixing. Possible sources for CO are discussed.
DEFF Research Database (Denmark)
Jacobsen, R. H.; Birkelund, Karen; Holst, T.;
1996-01-01
Photocurrent correlation measurements used for the characterization of ultrafast photoconductive switches based on GaAs and silicon-on-sapphire are demonstrated. The correlation signal arises from the interplay of the photoexcited carriers, the dynamics of the bias field and a subsequent rechargi...
Correlation Attenuation Due to Measurement Error: A New Approach Using the Bootstrap Procedure
Padilla, Miguel A.; Veprinsky, Anna
2012-01-01
Issues with correlation attenuation due to measurement error are well documented. More than a century ago, Spearman proposed a correction for attenuation. However, this correction has seen very little use since it can potentially inflate the true correlation beyond one. In addition, very little confidence interval (CI) research has been done for…
Gordon, David M; Ash, Stephen R
2009-01-01
The purpose of this research project was to determine whether the glucose level of a blood plasma sample from a diabetic patient could be predicted by measuring the density and conductivity of ultrafiltrate of plasma created by a 30,000 m.w. cutoff membrane. Conductivity of the plasma filtrate measures electrolyte concentration and should correct density measurements for changes in electrolytes and water concentration. In vitro studies were performed measuring conductivity and density of solutions of varying glucose and sodium chloride concentrations. Plasma from seven hospitalized patients with diabetes was filtered across a 30,000 m.w. cutoff membrane. The filtrate density and conductivity were measured and correlated to glucose levels. In vitro studies confirmed the ability to predict glucose from density and conductivity measurements, in varying concentrations of glucose and saline. In plasma filtrate, the conductivity and density measurements of ultrafiltrate allowed estimation of glucose in some patients with diabetes but not others. The correlation coefficient for the combined patient data was 0.45 which was significant but only explained 20% of the variability in the glucose levels. Individually, the correlation was significant in only two of the seven patients with correlation coefficients of 0.79 and 0.88. The reasons for lack of correlation are not clear, and cannot be explained by generation of idiogenic osmoles, effects of alcohol dehydrogenase, water intake, etc. This combination of physical methods for glucose measurement is not a feasible approach to measuring glucose in plasma filtrate.
Ding, Wenxin; Žitko, Rok; Shastry, B. Sriram
2017-09-01
Using two approaches to strongly correlated systems, the extremely correlated Fermi liquid theory and the dynamical mean field theory, we compute the transverse transport coefficients, namely, the Hall constants RH and Hall angles θH, and the longitudinal and transverse optical response of the U =∞ Hubbard model in the limit of infinite dimensions. We focus on two successive low-temperature regimes, the Gutzwiller-correlated Fermi liquid (GCFL) and the Gutzwiller-correlated strange metal (GCSM). We find that the Hall angle cotθH is proportional to T2 in the GCFL regime, while upon warming into the GCSM regime it first passes through a downward bend and then continues as T2. Equivalently, RH is weakly temperature dependent in the GCFL regime, but becomes strongly temperature dependent in the GCSM regime. Drude peaks are found for both the longitudinal optical conductivity σx x(ω ) and the optical Hall angles tanθH(ω ) below certain characteristic energy scales. By comparing the relaxation rates extracted from fitting to the Drude formula, we find that in the GCFL regime there is a single relaxation rate controlling both longitudinal and transverse transport, while in the GCSM regime two different relaxation rates emerge. We trace the origin of this behavior to the dynamical particle-hole asymmetry of the Dyson self-energy, arguably a generic feature of doped Mott insulators.
Sensitivity of charge transport measurements to local inhomogeneities
DEFF Research Database (Denmark)
Koon, Daniel; Wang, Fei; Petersen, Dirch Hjorth;
We derive analytic expressions for the sensitivity of resistive and Hall measurements to local variations in a specimen's material properties in the combined linear limit of both small magnetic fields and small perturbations, presenting exact, algebraic expressions both for four-point probe...... in the arbitrary case and of order N2 in the handful of cases that can be solved exactly, putting a powerful tool for inhomogeneity analysis in the hands of the researcher:calculation of the sensitivities requires little more than the solution of Laplace's equation on the specimen geometry....
Real-time deformation measurement using a transportable shearography system
Weijers, A. L.; van Brug, Hedser H.; Frankena, Hans J.
1997-03-01
A new system for deformation visualization has been developed, being a real time phase stepped shearing speckle interferometer. This system provides the possibility to measure quantitatively deformations of diffusely reflecting objects in an industrial environment. The main characteristics of this interferometer are its speed of operation and its reduced sensitivity to external disturbances. Apart from its semiconductor laser source, this system has a shoe-box size and is mounted on a tripod for easy handling during inspection. This paper describes the shearing speckle interferometry set-up, as it is developed at our laboratory and its potential for detecting defects.
Measurements of texture properties related to tenderness at different locations within deboned broiler breast fillets have been used to validate techniques for texture analysis and establish correlations between different texture evaluation methods. However, it has been demonstrated that meat text...
Field methods to measure surface displacement and strain with the Video Image Correlation method
Maddux, Gary A.; Horton, Charles M.; Mcneill, Stephen R.; Lansing, Matthew D.
1994-01-01
The objective of this project was to develop methods and application procedures to measure displacement and strain fields during the structural testing of aerospace components using paint speckle in conjunction with the Video Image Correlation (VIC) system.
PyTransport: A Python package for the calculation of inflationary correlation functions
Mulryne, David J
2016-01-01
PyTransport constitutes a straightforward code written in C++ together with Python scripts which automatically edit, compile and run the C++ code as a Python module. It has been written for Unix-like systems (OS X and Linux). Primarily the module employs the transport approach to inflationary cosmology to calculate the tree-level power-spectrum and bispectrum of user specified models of multi-field inflation, accounting for all sub and super-horizon effects. The transport method we utilise means only coupled differential equations need to be solved, and the implementation presented here combines the speed of C++ with the functionality and convenience of Python. At present the code is restricted to canonical models. This document details the code and illustrates how to use it with a worked example.
Droghetti, Andrea; Rungger, Ivan
2017-02-01
We present a computational method to quantitatively describe the linear-response conductance of nanoscale devices in the Kondo regime. This method relies on a projection scheme to extract an Anderson impurity model from the results of density functional theory and nonequilibrium Green's functions calculations. The Anderson impurity model is then solved by continuous-time quantum Monte Carlo. The developed formalism allows us to separate the different contributions to the transport, including coherent or noncoherent transport channels, and also the quantum interference between impurity and background transmission. We apply the method to a scanning tunneling microscope setup for the 1,3,5-triphenyl-6-oxoverdazyl (TOV) stable radical molecule adsorbed on gold. The TOV molecule has one unpaired electron, which when brought in contact with metal electrodes behaves like a prototypical single Anderson impurity. We evaluate the Kondo temperature, the finite-temperature spectral function, and transport properties, finding good agreement with published experimental results.
Correlation and agreement: overview and clarification of competing concepts and measures.
Liu, Jinyuan; Tang, Wan; Chen, Guanqin; Lu, Yin; Feng, Changyong; Tu, Xin M
2016-04-25
Agreement and correlation are widely-used concepts that assess the association between variables. Although similar and related, they represent completely different notions of association. Assessing agreement between variables assumes that the variables measure the same construct, while correlation of variables can be assessed for variables that measure completely different constructs. This conceptual difference requires the use of different statistical methods, and when assessing agreement or correlation, the statistical method may vary depending on the distribution of the data and the interest of the investigator. For example, the Pearson correlation, a popular measure of correlation between continuous variables, is only informative when applied to variables that have linear relationships; it may be non-informative or even misleading when applied to variables that are not linearly related. Likewise, the intraclass correlation, a popular measure of agreement between continuous variables, may not provide sufficient information for investigators if the nature of poor agreement is of interest. This report reviews the concepts of agreement and correlation and discusses differences in the application of several commonly used measures.
Measurements of air pollution emission factors for marine transportation
Alföldy, B.; Balzani Lööv, J.; Lagler, F.; Mellqvist, J.; Berg, N.; Beecken, J.; Weststrate, H.; Duyzer, J.; Bencs, L.; Horemans, B.; Cavalli, F.; Putaud, J.-P.; Janssens-Maenhout, G.; Pintér Csordás, A.; Van Grieken, R.; Borowiak, A.; Hjorth, J.
2012-12-01
The chemical composition of the plumes of seagoing ships was investigated during a two weeks long measurement campaign in the port of Rotterdam, Hoek van Holland, The Netherlands, in September 2009. Altogether, 497 ships were monitored and a statistical evaluation of emission factors (g kg-1 fuel) was provided. The concerned main atmospheric components were SO2, NO2, NOx and the aerosol particle number. In addition, the elemental and water-soluble ionic composition of the emitted particulate matter was determined. Emission factors were expressed as a function of ship type, power and crankshaft rotational speed. The average SO2 emission factor was found to be roughly half of what is allowed in sulphur emission control areas (16 vs. 30 g kg-1 fuel), and exceedances of this limit were rarely registered. A significant linear relationship was observed between the SO2 and particle number emission factor. The intercept of the regression line, 0.5 × 1016 (kg fuel)-1, gives the average number of particles formed during the burning of 1 kg zero sulphur content fuel, while the slope, 2 × 1018, provides the average number of particles formed with 1 kg sulphur burnt with the fuel. Water-soluble ionic composition analysis of the aerosol samples from the plumes showed that ~144 g of particulate sulphate was emitted from 1 kg sulphur burnt with the fuel. The mass median diameter of sulphate particles estimated from the measurements was ~42 nm.
Impaired axonal transport in motor neurons correlates with clinical prion disease.
Directory of Open Access Journals (Sweden)
Vladimir Ermolayev
2009-08-01
Full Text Available Prion diseases are fatal neurodegenerative disorders causing motor dysfunctions, dementia and neuropathological changes such as spongiosis, astroglyosis and neuronal loss. The chain of events leading to the clinical disease and the role of distinct brain areas are still poorly understood. The role of nervous system integrity and axonal properties in prion pathology are still elusive. There is no evidence of both the functional axonal impairments in vivo and their connection with prion disease. We studied the functional axonal impairments in motor neurons at the onset of clinical prion disease using the combination of tracing as a functional assay for axonal transport with immunohistochemistry experiments. Well-established and novel confocal and ultramicroscopy techniques were used to image and quantify labeled neurons. Despite profound differences in the incubation times, 30% to 45% of neurons in the red nucleus of different mouse lines showed axonal transport impairments at the disease onset bilaterally after intracerebral prion inoculation and unilaterally -- after inoculation into the right sciatic nerve. Up to 94% of motor cortex neurons also demonstrated transport defects upon analysis by alternative imaging methods. Our data connect axonal transport impairments with disease symptoms for different prion strains and inoculation routes and establish further insight on the development of prion pathology in vivo. The alterations in localization of the proteins involved in the retrograde axonal transport allow us to propose a mechanism of transport disruption, which involves Rab7-mediated cargo attachment to the dynein-dynactin pathway. These findings suggest novel targets for therapeutic and diagnostic approaches in the early stages of prion disease.
Xiao, Kai; Yi, Li; Liu, Feng; Wang, Fuqiang
2016-08-01
Momentum-space azimuthal harmonic event planes (EP) are constructed from final-state midrapidity particles binned in transverse momentum (pT) in √{sN N}=200 GeV Au+Au collisions in a multiphase transport (AMPT) model. The EP correlations between pT bins, corrected by EP resolutions, are smaller than unity. This indicates that the EP's decorrelate over pT in AMPT, qualitatively consistent with data and hydrodynamic calculations. It is further found that the EP correlations approximately factorize into single pT-bin EP correlations to a common plane. This common plane appears to be the momentum-space EP integrated over all pT, not the configuration-space participant plane (PP).
Inter-dot coupling effects on transport through correlated parallel coupled quantum dots
Indian Academy of Sciences (India)
Shyam Chand; G Rajput; K C Sharma; P K Ahluwalia
2009-05-01
Transport through symmetric parallel coupled quantum dot system has been studied, using non-equilibrium Green function formalism. The inter-dot tunnelling with on-dot and inter-dot Coulomb repulsion is included. The transmission coefficient and Landaur–Buttiker like current formula are shown in terms of internal states of quantum dots. The effect of inter-dot tunnelling on transport properties has been explored. Results, in intermediate inter-dot coupling regime show signatures of merger of two dots to form a single composite dot and in strong coupling regime the behaviour of the system resembles the two decoupled dots.
Directory of Open Access Journals (Sweden)
Buliung Ron
2011-08-01
Full Text Available Abstract Background Studies examining the correlates of school transport commonly fail to make the distinction between morning and afternoon school trips. The purpose of this study was to examine the prevalence and correlates of mode shift from passive in the morning to active in the afternoon among elementary and secondary school students in Ontario, Canada. Methods Data were derived from the 2009 cycle of the Ontario Student Drug Use and Health Survey (OSDUHS. 3,633 students in grades 7 through 12 completed self-administered questionnaires. Socio-demographic, behavioural, psychological, and environmental predictors of active school transport (AST were assessed using logistic regression. Results Overall, 47% and 38% of elementary school students reported AST to and from school, respectively. The corresponding figures were 23% and 32% for secondary school students. The prevalence of AST varied temporarily and spatially. There was a higher prevalence of walking/biking found for elementary school students than for secondary school students, and there was an approximate 10% increase in AST in the afternoon. Different correlates of active school transport were also found across elementary and secondary school students. For all ages, students living in urban areas, with a shorter travel time between home and school, and having some input to the decision making process, were more likely to walk to and from school. Conclusions Future research examining AST should continue to make the analytic distinction between the morning and afternoon trip, and control for the moderating effect of age and geography in predicting mode choice. In terms of practice, these variations highlight the need for school-specific travel plans rather than 'one size fits all' interventions in promoting active school transport.
One and two dimensional analysis of 3$\\pi$ correlations measured in Pb+Pb interactions
Bearden, I G; Boissevain, J G; Christiansen, P; Conin, L; Dodd, J; Erazmus, B; Esumi, S C; Fabjan, Christian Wolfgang; Ferenc, D; Fields, D E; Franz, A; Gaardhøje, J J; Hansen, A G; Hansen, O; Hardtke, D; van Hecke, H; Holzer, E B; Humanic, T J; Hummel, P; Jacak, B V; Jayanti, R; Kaimi, K; Kaneta, M; Kohama, T; Kopytine, M L; Leltchouk, M; Ljubicic, A; Lörstad, B; Maeda, N; Martin, L; Medvedev, A; Murray, M; Ohnishi, H; Paic, G; Pandey, S U; Piuz, François; Pluta, J; Polychronakos, V; Potekhin, M V; Poulard, G; Reichhold, D M; Sakaguchi, A; Schmidt-Sørensen, J; Simon-Gillo, J; Sondheim, W E; Sugitate, T; Sullivan, J P; Sumi, Y; Willis, W J; Wolf, K L; Xu, N; Zachary, D S
2001-01-01
$\\pi^{-}\\pi^{-}\\pi^{-}$ correlations from Pb+Pb collisions at 158 GeV/c per nucleon are presented as measured by the focusing spectrometer of the NA44 experiment at CERN. The three-body effect is found to be stronger for PbPb than for SPb. The two-dimensional three-particle correlation function is also measured and the longitudinal extension of the source is larger than the transverse extension.
2012-02-01
AFRL-RZ-WP-TP-2012-0100 CORRELATION OF AC LOSS DATA FROM MAGNETIC SUSCEPTIBILITY MEASUREMENTS WITH YBCO FILM QUALITY (POSTPRINT) Paul N...CORRELATION OF AC LOSS DATA FROM MAGNETIC SUSCEPTIBILITY MEASUREMENTS WITH YBCO FILM QUALITY (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT...spreading of the temperature-dependent ac susceptibility curves with increasing applied magnetic field, the quality of the YBCO film generally
MEASUREMENTS AND COMPUTATIONS OF FUEL DROPLET TRANSPORT IN TURBULENT FLOWS
Energy Technology Data Exchange (ETDEWEB)
Joseph Katz and Omar Knio
2007-01-10
The objective of this project is to study the dynamics of fuel droplets in turbulent water flows. The results are essential for development of models capable of predicting the dispersion of slightly light/heavy droplets in isotropic turbulence. Since we presently do not have any experimental data on turbulent diffusion of droplets, existing mixing models have no physical foundations. Such fundamental knowledge is essential for understanding/modeling the environmental problems associated with water-fuel mixing, and/or industrial processes involving mixing of immiscible fluids. The project has had experimental and numerical components: 1. The experimental part of the project has had two components. The first involves measurements of the lift and drag forces acting on a droplet being entrained by a vortex. The experiments and data analysis associated with this phase are still in progress, and the facility, constructed specifically for this project is described in Section 3. In the second and main part, measurements of fuel droplet dispersion rates have been performed in a special facility with controlled isotropic turbulence. As discussed in detail in Section 2, quantifying and modeling the of droplet dispersion rate requires measurements of their three dimensional trajectories in turbulent flows. To obtain the required data, we have introduced a new technique - high-speed, digital Holographic Particle Image Velocimetry (HPIV). The technique, experimental setup and results are presented in Section 2. Further information is available in Gopalan et al. (2005, 2006). 2. The objectives of the numerical part are: (1) to develop a computational code that combines DNS of isotropic turbulence with Lagrangian tracking of particles based on integration of a dynamical equation of motion that accounts for pressure, added mass, lift and drag forces, (2) to perform extensive computations of both buoyant (bubbles) and slightly buoyant (droplets) particles in turbulence conditions
DEFF Research Database (Denmark)
Adkins, Erica; (Vægter), Christian Bjerggaard; van Deurs, Bo;
FCS measurements in transiently transfected N2A neuroblastoma cells were impaired by photobleachning suggesting immobilization of the transporter in the membrane. This was confirmed by the use of fluorescence recovery after photobleaching (FRAP), which showed clear recovery of YFP-DAT fluorescence...
Correlates of subjectively and objectively measured physical activity in young adolescents
Institute of Scientific and Technical Information of China (English)
Kelly Kavanaugh; Justin B. Moore; Leisha Johnson Hibbett; Andrew T. Kaczynski
2015-01-01
Background:Many studies examining individual-level correlates in youth utilize self-report rather than objective measures of physical activity (PA). This utilization of self-report may result in associations that are not present when examining objectively measured PA. The present study investigates the relationship between hypothesized correlates of PA with objectively and subjectively measured PA. Methods: Participating children (n = 232, 101 males, mean age = 12.3 years) provided a minimum of four monitored days of PA (via accelerometer) and completed a survey assessing moderate-to-vigorous physical activity (MVPA), sport competence, appearance, enjoyment, and self-efficacy. Height and weight were measured and body mass index (BMI) was calculated. Results: Hierarchical regression models controlling for sex, race, and BMI Z-score showed that only sex and BMI Z-score were significant correlates of objective MVPA while only sex was a significant correlate of objective total PA. However, in a separate model examining the relationship with subjective MVPA, enjoyment of PA and self-efficacy for PA were the only significant correlates of self-reported PA. Conclusion:Measuring MVPA via self-report versus accelerometry produces considerably different results in a sample of young adolescents. Future studies should use caution when selecting outcome measures if the intent is to identify modifiable correlates of MVPA in youth.
Devillard, P.; Chevallier, D.; Albert, M.
2017-09-01
We compute various current-correlation functions of electrons flowing from a topological nanowire to the tip of a superconducting scanning tunnel microscope and identify fingerprints of a Majorana bound state. In particular, the spin resolved cross correlations are shown to display a clear distinction between the presence of a such an exotic state (negative correlations) and an Andreev bound state (positive correlations). Similarity and differences with measurements with a normal tunnel microscope are also discussed, like the robustness to finite temperature, for instance.
Miettinen, Arttu; Harjupatana, Tero; Kataja, Markku; Fortino, Stefania; Immonen, Kirsi
2016-07-01
Natural fibre composites are prone to absorb moisture from the environment which may lead to dimensional changes, mold growth, degradation of mechanical properties or other adverse effects. In this work we develop a method for direct non-intrusive measurement of local moisture content inside a material sample. The method is based on X-ray microtomography, digital image correlation and image analysis. As a first application of the method we study axial transport of water in a cylindrical polylactic acid/birch pulp composite material sample with one end exposed to water. Based on the results, the method seems to give plausible estimates of water content profiles inside the cylindrical sample. The results may be used, e.g., in developing and validating models of moisture transport in biocomposites.
A robust measure of correlation between two genes on a microarray
Directory of Open Access Journals (Sweden)
Hicks Leanne
2007-06-01
Full Text Available Abstract Background The underlying goal of microarray experiments is to identify gene expression patterns across different experimental conditions. Genes that are contained in a particular pathway or that respond similarly to experimental conditions could be co-expressed and show similar patterns of expression on a microarray. Using any of a variety of clustering methods or gene network analyses we can partition genes of interest into groups, clusters, or modules based on measures of similarity. Typically, Pearson correlation is used to measure distance (or similarity before implementing a clustering algorithm. Pearson correlation is quite susceptible to outliers, however, an unfortunate characteristic when dealing with microarray data (well known to be typically quite noisy. Results We propose a resistant similarity metric based on Tukey's biweight estimate of multivariate scale and location. The resistant metric is simply the correlation obtained from a resistant covariance matrix of scale. We give results which demonstrate that our correlation metric is much more resistant than the Pearson correlation while being more efficient than other nonparametric measures of correlation (e.g., Spearman correlation. Additionally, our method gives a systematic gene flagging procedure which is useful when dealing with large amounts of noisy data. Conclusion When dealing with microarray data, which are known to be quite noisy, robust methods should be used. Specifically, robust distances, including the biweight correlation, should be used in clustering and gene network analysis.
Melconian, D; Fenker, B; Mehlman, M; Shidling, P D; Anholm, M; Ashery, D; Behr, J A; Gorelov, A; Gwinner, G; Olchankski, K; Smale, S
2014-01-01
The correlations of the decay products following the beta decay of nuclei have a long history of providing a low-energy probe of the fundamental symmetries of our universe. Over half a century ago, the correlation of the electrons following the decay of polarized 60Co demonstrated that parity is not conserved in weak interactions. Today, the same basic idea continues to be applied to search for physics beyond the standard model: make precision measurements of correlation parameters and look for deviations compared to their standard model predictions. Efforts to measure these parameters to the 0.1% level utilizing atom and ion trapping techniques are described.
Measurement of Spin Correlation in Top Quark Pair Production in Semi-Leptonic Final State
Baarmand, Marc M; Vodopiyanov, Igor
2006-01-01
The measurement of correlation between spins of top and anti-top quarks, produced in proton-proton collisions at LHC, is described for the semi-leptonic decay of the top quark pair (one top quark decaying leptonically and the other hadronically). The simulated events are reconstructed after full simulation of the CMS detector. The spin correlation coefficient is estimated based on a total integrated luminosity of ten inverse femtobarns. Including systematic uncertainties, the correlation coefficient can be measured with a total relative uncertainty of 17% or 27% depending on the choice of the deay angles used.
Evaluation of cross correlation technique to measure flow in pipes of the oil industry
Energy Technology Data Exchange (ETDEWEB)
Avilan, Eddie J., E-mail: eddieavilan@gmail.com [Universidad Central de Venezuela (UCV), Facultad de Ingenieria, Departamento de Fisica Aplicada, Caracas (Venezuela, Bolivarian Republic of); Reis, Verginia, E-mail: verginia@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Barreira, Luis E.; Salgado, Cesar Marques, E-mail: brandao@ien.gov.br, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (DIRA/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Divisao de Radiofarmacos
2013-07-01
The present work is concerned with the use of the cross correlation technique to measure delay time between two simulated signals displaced with respect to time, in order to develop a cross correlator system that will be used to measure the water and oil pipes flowrate in which the detection system is composed by two external low intensity radiation sources located along the tube and two NaI(Tl) gamma-ray detectors. The final purpose of the correlator system is to use the natural disturbances, as the turbulence in the own flow rather than to inject radioactive tracers to the fluid flow as usually is carried out. In the design of this correlator is evaluated the point-by-point calculation method for the cross correlation function in order to produce a system accurate and fast. This method is divided at the same time in three modes of operation: direct, relay and polarity. (author)
Field-measured drag area is a key correlate of level cycling time trial performance
Directory of Open Access Journals (Sweden)
James E. Peterman
2015-08-01
Full Text Available Drag area (Ad is a primary factor determining aerodynamic resistance during level cycling and is therefore a key determinant of level time trial performance. However, Ad has traditionally been difficult to measure. Our purpose was to determine the value of adding field-measured Ad as a correlate of level cycling time trial performance. In the field, 19 male cyclists performed a level (22.1 km time trial. Separately, field-determined Ad and rolling resistance were calculated for subjects along with projected frontal area assessed directly (AP and indirectly (Est AP. Also, a graded exercise test was performed to determine $\\dot {V}{O}_{2}$V̇O2 peak, lactate threshold (LT, and economy. $\\dot {V}{O}_{2}$V̇O2 peak ($\\mathrm{l}~\\min ^{-1}$lmin−1 and power at LT were significantly correlated to power measured during the time trial (r = 0.83 and 0.69, respectively but were not significantly correlated to performance time (r = − 0.42 and −0.45. The correlation with performance time improved significantly (p < 0.05 when these variables were normalized to Ad. Of note, Ad alone was better correlated to performance time (r = 0.85, p < 0.001 than any combination of non-normalized physiological measure. The best correlate with performance time was field-measured power output during the time trial normalized to Ad (r = − 0.92. AP only accounted for 54% of the variability in Ad. Accordingly, the correlation to performance time was significantly lower using power normalized to AP (r = − 0.75 or Est AP (r = − 0.71. In conclusion, unless normalized to Ad, level time trial performance in the field was not highly correlated to common laboratory measures. Furthermore, our field-measured Ad is easy to determine and was the single best predictor of level time trial performance.
PARALLEL MEASUREMENT AND MODELING OF TRANSPORT IN THE DARHT II BEAMLINE ON ETA II
Energy Technology Data Exchange (ETDEWEB)
Chambers, F W; Raymond, B A; Falabella, S; Lee, B S; Richardson, R A; Weir, J T; Davis, H A; Schultze, M E
2005-05-31
To successfully tune the DARHT II transport beamline requires the close coupling of a model of the beam transport and the measurement of the beam observables as the beam conditions and magnet settings are varied. For the ETA II experiment using the DARHT II beamline components this was achieved using the SUICIDE (Simple User Interface Connecting to an Integrated Data Environment) data analysis environment and the FITS (Fully Integrated Transport Simulation) model. The SUICIDE environment has direct access to the experimental beam transport data at acquisition and the FITS predictions of the transport for immediate comparison. The FITS model is coupled into the control system where it can read magnet current settings for real time modeling. We find this integrated coupling is essential for model verification and the successful development of a tuning aid for the efficient convergence on a useable tune. We show the real time comparisons of simulation and experiment and explore the successes and limitations of this close coupled approach.
Theory and signal processing of acoustic correlation techniques for current velocity measurement
Institute of Scientific and Technical Information of China (English)
ZHU Weiqing; FENG Lei; WANG Changhong; WANG Yuling; QIU Wei
2008-01-01
A theoretical model and signal processing of acoustic correlation measurements to estimate current velocity are discussed. The sonar space-time correlation function of vol-ume reverberations within Fraunhofer zone is derived. The function, which is in exponential forms, is the theoretical model of acoustic correlation measurements. The characteristics of the correlation values around the maximum of the amplitude of the correlation function, where most information about current velocity is contained, are primarily analyzed. Localized Least Mean Squares (LLMS) criterion is put forward for velocity estimation. Sequential Quadratic Programming (SQP) method is adopted as the optimization method. So the systematic sig-nal processing method of acoustic correlation techniques for current velocity measurement is established. A prototype acoustic correlation current profiler (ACCP) underwent several sea trials, the results show that theoretical model approximately coincides with experimental re-sults. Current profiles including the speed and direction from ACCP are compared with those from acoustic Doppler current profiler (ADCP). The current profiles by both instruments agree reasonably well. Also, the standard deviation of velocity measurement by ACCP is statistically calculated and it is a little larger than predicted value.
Thermal transport in suspended silicon membranes measured by laser-induced transient gratings
Directory of Open Access Journals (Sweden)
A. Vega-Flick
2016-12-01
Full Text Available Studying thermal transport at the nanoscale poses formidable experimental challenges due both to the physics of the measurement process and to the issues of accuracy and reproducibility. The laser-induced transient thermal grating (TTG technique permits non-contact measurements on nanostructured samples without a need for metal heaters or any other extraneous structures, offering the advantage of inherently high absolute accuracy. We present a review of recent studies of thermal transport in nanoscale silicon membranes using the TTG technique. An overview of the methodology, including an analysis of measurements errors, is followed by a discussion of new findings obtained from measurements on both “solid” and nanopatterned membranes. The most important results have been a direct observation of non-diffusive phonon-mediated transport at room temperature and measurements of thickness-dependent thermal conductivity of suspended membranes across a wide thickness range, showing good agreement with first-principles-based theory assuming diffuse scattering at the boundaries. Measurements on a membrane with a periodic pattern of nanosized holes (135nm indicated fully diffusive transport and yielded thermal diffusivity values in agreement with Monte Carlo simulations. Based on the results obtained to-date, we conclude that room-temperature thermal transport in membrane-based silicon nanostructures is now reasonably well understood.
Joint Measurement of Lensing-Galaxy Correlations Using SPT and DES SV Data
Baxter, E J; Giannantonio, T; Dodelson, S; Jain, B; Huterer, D; Bleem, L E; Crawford, T M; Efstathiou, G; Fosalba, P; Kirk, D; Kwan, J; Sánchez, C; Story, K T; Troxel, M A; Abbott, T M C; Abdalla, F B; Armstrong, R; Benoit-Lévy, A; Benson, B A; Bernstein, G M; Bernstein, R A; Bertin, E; Brooks, D; Carlstrom, J E; Rosell, A Carnero; Kind, M Carrasco; Carretero, J; Chown, R; Crocce, M; Cunha, C E; D'Andrea, C B; da Costa, L N; Desai, S; Diehl, H T; Dietrich, J P; Doel, P; Evrard, A E; Neto, A Fausti; Flaugher, B; Frieman, J; Gruen, D; Gruendl, R A; Gutierrez, G; de Haan, T; Holder, G P; Honscheid, K; Hou, Z; James, D J; Kuehn, K; Kuropatkin, N; Lima, M; March, M; Marshall, J L; Martini, P; Melchior, P; Miller, C J; Miquel, R; Mohr, J J; Nord, B; Omori, Y; Plazas, A A; Reichardt, C L; Romer, A K; Rykoff, E S; Sanchez, E; Sevilla-Noarbe, I; Sheldon, E; Smith, R C; Soares-Santos, M; Sobreira, F; Suchyta, E; Stark, A A; Swanson, M E C; Tarle, G; Thomas, D; Walker, A R; Wechsler, R H
2016-01-01
We measure the correlation of galaxy lensing and cosmic microwave background lensing with a set of galaxies expected to trace the matter density field. The measurements are performed using pre-survey Dark Energy Survey (DES) Science Verification optical imaging data and millimeter-wave data from the 2500 square degree South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) survey. The two lensing-galaxy correlations are jointly fit to extract constraints on cosmological parameters, constraints on the redshift distribution of the lens galaxies, and constraints on the absolute shear calibration of DES galaxy lensing measurements. We show that an attractive feature of these fits is that they are fairly insensitive to the clustering bias of the galaxies used as matter tracers. The measurement presented in this work confirms that DES and SPT data are consistent with each other and with the currently favored $\\Lambda$CDM cosmological model. It also demonstrates that joint lensing-galaxy correlation measurement considered ...
Tsai, Tracy; Rella, Chris; Crosson, Eric
2013-04-01
Quantification of fugitive methane emissions from unconventional natural gas (i.e. shale gas, tight sand gas, etc.) production, processing, and transport is essential for scientists, policy-makers, and the energy industry, because methane has a global warming potential of at least 21 times that of carbon dioxide over a span of 100 years [1]. Therefore, fugitive emissions reduce any environmental benefits to using natural gas instead of traditional fossil fuels [2]. Current measurement techniques involve first locating all the possible leaks and then measuring the emission of each leak. This technique is a painstaking and slow process that cannot be scaled up to the large size of the natural gas industry in which there are at least half a million natural gas wells in the United States alone [3]. An alternative method is to calculate the emission of a plume through dispersion modeling. This method is a scalable approach since all the individual leaks within a natural gas facility can be aggregated into a single plume measurement. However, plume dispersion modeling requires additional knowledge of the distance to the source, atmospheric turbulence, and local topography, and it is a mathematically intensive process. Therefore, there is a need for an instrument capable of simple, rapid, and accurate measurements of fugitive methane emissions on a per well head scale. We will present the "plume camera" instrument, which simultaneously measures methane at different spatial points or pixels. The spatial correlation between methane measurements provides spatial information of the plume, and in addition to the wind measurement collected with a sonic anemometer, the flux can be determined. Unlike the plume dispersion model, this approach does not require knowledge of the distance to the source and atmospheric conditions. Moreover, the instrument can fit inside a standard car such that emission measurements can be performed on a per well head basis. In a controlled experiment
Directory of Open Access Journals (Sweden)
Chao Si
2015-01-01
Full Text Available Water transport and the corresponding water management strategy in proton exchange membrane (PEM fuel cells are quite critical for the improvement of the cell performance. Accuracy modeling of water transport in porous electrodes strongly depends on the appropriate constitutive relationship for capillary pressure which is referred to as pc-s correlation, where pc is the capillary pressure and s is the fraction of saturation in the pores. In the present PEM fuel cell two-phase models, the Leverett-Udell pc-s correlation is widely utilized which is proposed based on fitting the experimental data for packed sands. However, the size and structure of pores for the commercial porous electrodes used in PEM fuel cells differ from those for the packed sands significantly. As a result, the Leverett-Udell correlation should be improper to characterize the two-phase transport in the porous electrodes. In the recent decade, many efforts were devoted to measuring the capillary pressure data and developing new pc-s correlations. The objective of this review is to review the most significant developments in recent years concerning the capillary pressure measurements and the developed pc-s correlations. It is expected that this review will be beneficial to develop the improved PEM fuel cell two-phase model.
On extracting sediment transport information from measurements of luminescence in river sediment
Gray, Harrison J.; Tucker, Gregory E.; Mahan, Shannon A.; McGuire, Chris; Rhodes, Edward J.
2017-03-01
Accurately quantifying sediment transport rates in rivers remains an important goal for geomorphologists, hydraulic engineers, and environmental scientists. However, current techniques for measuring long-time scale (102-106 years) transport rates are laborious, and formulae to predict transport are notoriously inaccurate. Here we attempt to estimate sediment transport rates by using luminescence, a property of common sedimentary minerals that is used by the geoscience community for geochronology. This method is advantageous because of the ease of measurement on ubiquitous quartz and feldspar sand. We develop a model from first principles by using conservation of energy and sediment mass to explain the downstream pattern of luminescence in river channel sediment. We show that the model can accurately reproduce the luminescence observed in previously published field measurements from two rivers with very different sediment transport styles. The model demonstrates that the downstream pattern of river sand luminescence should show exponential-like decay in the headwaters which asymptotes to a constant value with further downstream distance. The parameters from the model can then be used to estimate the time-averaged virtual velocity, characteristic transport lengthscale, storage time scale, and floodplain exchange rate of fine sand-sized sediment in a fluvial system. The sediment transport values predicted from the luminescence method show a broader range than those reported in the literature, but the results are nonetheless encouraging and suggest that luminescence demonstrates potential as a sediment transport indicator. However, caution is warranted when applying the model as the complex nature of sediment transport can sometimes invalidate underlying simplifications.
On extracting sediment transport information from measurements of luminescence in river sediment
Gray, Harrison J.; Tucker, Gregory E.; Mahan, Shannon; McGuire, Chris; Rhodes, Edward J.
2017-01-01
Accurately quantifying sediment transport rates in rivers remains an important goal for geomorphologists, hydraulic engineers, and environmental scientists. However, current techniques for measuring long-time scale (102–106 years) transport rates are laborious, and formulae to predict transport are notoriously inaccurate. Here we attempt to estimate sediment transport rates by using luminescence, a property of common sedimentary minerals that is used by the geoscience community for geochronology. This method is advantageous because of the ease of measurement on ubiquitous quartz and feldspar sand. We develop a model from first principles by using conservation of energy and sediment mass to explain the downstream pattern of luminescence in river channel sediment. We show that the model can accurately reproduce the luminescence observed in previously published field measurements from two rivers with very different sediment transport styles. The model demonstrates that the downstream pattern of river sand luminescence should show exponential-like decay in the headwaters which asymptotes to a constant value with further downstream distance. The parameters from the model can then be used to estimate the time-averaged virtual velocity, characteristic transport lengthscale, storage time scale, and floodplain exchange rate of fine sand-sized sediment in a fluvial system. The sediment transport values predicted from the luminescence method show a broader range than those reported in the literature, but the results are nonetheless encouraging and suggest that luminescence demonstrates potential as a sediment transport indicator. However, caution is warranted when applying the model as the complex nature of sediment transport can sometimes invalidate underlying simplifications.
Maximum key-profile correlation (MKC) as a measure of tonal structure in music.
Takeuchi, A H
1994-09-01
Tonal structure is musical organization on the basis of pitch, in which pitches vary in importance and rate of occurrence according to their relationship to a tonal center. Experiment 1 evaluated the maximum key-profile correlation (MKC), a product of Krumhansl and Schmuckler's key-finding algorithm (Krumhansl, 1990), as a measure of tonal structure. The MKC is the maximum correlation coefficient between the pitch class distribution in a musical sample and key profiles, which indicate the stability of pitches with respect to particular tonal centers. The MKC values of melodies correlated strongly with listeners' ratings of tonal structure. To measure the influence of the temporal order of pitches on perceived tonal structure, three measures (fifth span, semitone span, and pitch contour) taken from previous studies of melody perception were also correlated with tonal structure ratings. None of the temporal measures correlated as strongly or as consistently with tonal structure ratings as did the MKC, and nor did combining them with the MKC improve prediction of tonal structure ratings. In Experiment 2, the MKC did not correlate with recognition memory of melodies. However, melodies with very low MKC values were recognized less accurately than melodies with very high MKC values. Although it does not incorporate temporal, rhythmic, or harmonic factors that may influence perceived tonal structure, the MKC can be interpreted as a measure of tonal structure, at least for brief melodies.
Kavand, Marzieh; Baird, Douglas; van Schooten, Kipp; Malissa, Hans; Lupton, John M.; Boehme, Christoph
2016-08-01
Spin-dependent processes play a crucial role in organic electronic devices. Spin coherence can give rise to spin mixing due to a number of processes such as hyperfine coupling, and leads to a range of magnetic field effects. However, it is not straightforward to differentiate between pure single-carrier spin-dependent transport processes which control the current and therefore the electroluminescence, and spin-dependent electron-hole recombination which determines the electroluminescence yield and in turn modulates the current. We therefore investigate the correlation between the dynamics of spin-dependent electric current and spin-dependent electroluminescence in two derivatives of the conjugated polymer poly(phenylene-vinylene) using simultaneously measured pulsed electrically detected (pEDMR) and optically detected (pODMR) magnetic resonance spectroscopy. This experimental approach requires careful analysis of the transient response functions under optical and electrical detection. At room temperature and under bipolar charge-carrier injection conditions, a correlation of the pEDMR and the pODMR signals is observed, consistent with the hypothesis that the recombination currents involve spin-dependent electronic transitions. This observation is inconsistent with the hypothesis that these signals are caused by spin-dependent charge-carrier transport. These results therefore provide no evidence that supports earlier claims that spin-dependent transport plays a role for room-temperature magnetoresistance effects. At low temperatures, however, the correlation between pEDMR and pODMR is weakened, demonstrating that more than one spin-dependent process influences the optoelectronic materials' properties. This conclusion is consistent with prior studies of half-field resonances that were attributed to spin-dependent triplet exciton recombination, which becomes significant at low temperatures when the triplet lifetime increases.
Scenarios for measuring station-based impedances in a national transport model
La Paix Puello, Lissy Cesarina; Geurs, Karst Teunis; van Weperen, Sander
2015-01-01
The measures of local and regional accessibility have been developed separately, resulting on a scarcely studied connection between these two. Accessibility evaluation of land-use and transport strategies can be much improved by linkages with more understandable, and local, accessibility measures
Direct measurement of chiral structure and transport in single- and multi-walled carbon nanotubes
Cui, Taoran; Lin, Letian; Qin, Lu-Chang; Washburn, Sean
2016-11-01
Electrical devices based on suspended multi-wall carbon nanotubes were constructed and studied. The chiral structure of each shell in a particular nanotube was determined using nanobeam electron diffraction in a transmission electron microscope. The transport properties of the carbon nanotube were also measured. The nanotube device length was short enough that the transport was nearly ballistic, and multiple subbands contributed to the conductance. Thermal excitation of carriers significantly affected nanotube resistance at room temperature.
Structural correlates of the creatine transporter function regulation: the undiscovered country.
Santacruz, Lucia; Jacobs, Danny O
2016-08-01
Creatine (Cr) and phosphocreatine constitute an energy shuttle that links ATP production in mitochondria to subcellular locations of ATP consumption. Cells in tissues that are reliant on this energy shuttle, such as myocytes and neurons, appear to have very limited ability to synthesize creatine. Therefore, these cells depend on Cr uptake across the cell membrane by a specialized creatine transporter (CrT solute carrier SLC6A8) in order to maintain intracellular creatine levels. Cr supplementation has been shown to have a beneficial effect in numerous in vitro and in vivo models, particularly in cases of oxidative stress, and is also widely used by athletes as a performance enhancement nutraceutical. Intracellular creatine content is maintained within narrow limits. However, the physiological and cellular mechanisms that mediate Cr transport during health and disease (such as cardiac failure) are not understood. In this narrative mini-review, we summarize the last three decades of research on CrT structure, function and regulation.
Vibration measurement based on the optical cross-correlation technique with femtosecond pulsed laser
Han, Jibo; Wu, Tengfei; Zhao, Chunbo; Li, Shuyi
2016-10-01
Two vibration measurement methods with femtosecond pulsed laser based on the optical cross-correlation technique are presented independently in this paper. The balanced optical cross-correlation technique can reflect the time jitter between the reference pluses and measurement pluses by detecting second harmonic signals using type II phase-matched nonlinear crystal and balanced amplified photo-detectors. In the first method, with the purpose of attaining the vibration displacement, the time difference of the reference pulses relative to the measurement pluses can be measured using single femtosecond pulsed laser. In the second method, there are a couple of femtosecond pulsed lasers with high pulse repetition frequency. Vibration displacement associated with cavity length can be calculated by means of precisely measuring the pulse repetition frequency. The results show that the range of measurement attains ±150μm for a 500fs pulse. These methods will be suited for vibration displacement measurement, including laboratory use, field testing and industrial application.
Massé, Andrea; Friederich, Pascal; Symalla, Franz; Liu, Feilong; Meded, Velimir; Coehoorn, Reinder; Wenzel, Wolfgang; Bobbert, Peter A.
2017-03-01
In this study, we investigate on the basis of ab initio calculations how the morphology, molecular on-site energies, reorganization energies, and charge transfer integral distribution affect the hopping charge transport and the exciton formation process in disordered organic semiconductors. We focus on three materials applied frequently in organic light-emitting diodes: α -NPD , TCTA, and Spiro-DPVBi. Spatially correlated disorder and, more importantly, superexchange contributions to the transfer integrals, are found to give rise to a significant increase of the electric field dependence of the electron and hole mobility. Furthermore, a material-specific correlation is found between the HOMO and LUMO energy on each specific molecular site. For α -NPD and TCTA, we find a positive correlation between the HOMO and LUMO energies, dominated by a Coulombic contribution to the energies. In contrast, Spiro-DPVBi shows a negative correlation, dominated by a conformational contribution. The size and sign of this correlation have a strong influence on the exciton formation rate.
Azimuthal correlations in Pb--Pb and pp collisions measured with the ALICE detector
DEFF Research Database (Denmark)
Zhou, You; Collaboration, for the ALICE
2012-01-01
We present results from the measurements of azimuthal correlations of charged particles in $\\sqrt{s_{_{NN}}}$ = 2.76 TeV Pb--Pb collisions and $\\sqrt{s_{_{NN}}}$ = 7 TeV pp collisions. In addition, the comparison of the experimental measurements in pp collisions with those from Pythia and Phojet...
Principles of azimuthal correlation measurement of J/psi with charged hadrons
Maire, Antonin
2012-01-01
Schematic illustration of measurement variables in the azimuthal J/psi-hadron correlation measurement. The z-axis perpendicular to the x-y-plane corresponds to the beam axis in the experiment. The reconstructed e+e- pairs are only identifiable as J/psi mesons on a statistical basis.
DEFF Research Database (Denmark)
Eldrup, Morten Mostgaard; Lund-Thomsen, E.; Mogensen, O. E.
1972-01-01
The dose dependence of the relative EPR signal intensity and positron lifetime spectrum was measured for γ‐irradiated acetyl methionine in the dose range from 0 to 30 Mrad. Angular correlation measurements were performed for the doses 0 and 30 Mrad. The result of the irradiation was the creation...
A Simple Superresolution Approach of Multipath Delay Profiles Measured by PN Correlation Method
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
Time resolution of multipath delay profiles measured by using autocorrelation of pseudonoise (PN) code sequence is generally limitec by the chip rate of the PN code sequence. In this paper, we propose a simple method to improve the time resolution of delay profiles measured by the PN correlation method. Effectiveness of this method is demonstrated by indoor wireless propagation experiments.
Simulating network throughput by correlating perfSONAR measurements with link utilisation
Babik, Marian; CERN. Geneva. IT Department
2017-01-01
In this report the modeling of the network performance through delay and packet loss measurements is explored. It is shown that correlations exists and different models are proposed to exploit them. In addition, the developed models are then implemented into the existing network measurement platform and made available to general use.
Conditional purity and quantum correlation measures in two qubit mixed states
Rebón, L.; Rossignoli, R.; Varga, J. J. M.; Gigena, N.; Canosa, N.; Iemmi, C.; Ledesma, S.
2016-11-01
We analyze and show experimental results of the conditional purity, the quantum discord and other related measures of quantum correlation in mixed two-qubit states constructed from a pair of photons in identical polarization states. The considered states are relevant for the description of spin pair states in interacting spin chains in a transverse magnetic field. We derive clean analytical expressions for the conditional local purity and other correlation measures obtained as a result of a remote local projective measurement, which are fully verified by the experimental results. A simple exact expression for the quantum discord of these states in terms of the maximum conditional purity is also derived.
Validation of SAGE II aerosol measurements by comparison with correlative sensors
Swissler, T. J.
1986-01-01
The SAGE II limb-scanning radiometer carried on the Earth Radiation Budget Satellite functions at wavelengths of 0.385, 0.45, 0.525, and 1.02 microns to identify vertical profiles of aerosol density by atmospheric extinction measurements from cloud tops upward. The data are being validated by correlating the satellite data with data gathered with, e.g., lidar, sunphotometer, and dustsonde instruments. Work thus far has shown that the 1 micron measurements from the ground and satellite are highly correlated and are therefore accurate to within measurement uncertainty.
Richardson, Norman E., IV
Since the beginning of the nuclear age, there has been a strong demand for the development of efficient technologies for the detection of ionizing radiation. According to the United States' Department of Energy, the accurate assessment of fissile materials is essential in achieving the nonproliferation goals of enhancing safety and security of nuclear fuel cycle and nuclear energy facilities. Nuclear materials can be characterized by the measurement of prompt and delayed neutrons and gamma rays emitted in spontaneous or induced fission reactions and neutrons emitted in fission reactions are the distinctive signatures of nuclear materials. Today, the most widely used neutron detection technologies rely on thermal neutron capture reactions using a moderating material to cause the neutron to lose its energy prior to the detection event. This is necessary because as the fission event occurs, neutrons are emitted carrying high amounts of energy, typically on the order of mega electron volts (MeV). These energetic particles are classified as "fast" neutrons. For detecting the thermal neutrons, the Helium-3 (3He) gas-filled counters are arguably the most widely used technology of neutron detection. 3He counters have been the scientific standard for the nuclear engineering community for several decades, and have earned their place as a reliable technique for the detection of neutrons. However, 3He gas-filled counters have several disadvantages. First, gas-filled counters are not rigid and are sensitive to vibrations. Secondly, gas-filled counters are prone to the count rate limitations due to the physical processes of charge multiplication and transport in the gas medium in the electric field. Lastly, 3He gas-filled counters suffer from a supply shortage of the 3He isotope. As it is stated in [3], this shortage is created by the new demand for Helium-3 due to the deployment of neutron detectors at the borders after the 9/11 attack to help secure the nation against smuggled
Gradl, Paul
2016-01-01
NASA Marshall Space Flight Center (MSFC) has been advancing dynamic optical measurement systems, primarily Digital Image Correlation, for extreme environment rocket engine test applications. The Digital Image Correlation (DIC) technology is used to track local and full field deformations, displacement vectors and local and global strain measurements. This technology has been evaluated at MSFC through lab testing to full scale hotfire engine testing of the J-2X Upper Stage engine at Stennis Space Center. It has been shown to provide reliable measurement data and has replaced many traditional measurement techniques for NASA applications. NASA and AMRDEC have recently signed agreements for NASA to train and transition the technology to applications for missile and helicopter testing. This presentation will provide an overview and progression of the technology, various testing applications at NASA MSFC, overview of Army-NASA test collaborations and application lessons learned about Digital Image Correlation.
Zhuang, H; Savage, E M
2009-01-01
Measurements of texture properties related to tenderness at different locations within deboned broiler breast fillets have been used to validate techniques for texture analysis and establish correlations between different texture evaluation methods. However, it has been demonstrated that meat texture can vary from location to location within individual muscles. The objective of our study was to investigate the intramuscular variation and Pearson correlation coefficients of Warner-Bratzler (WB) shear force measurements within early deboned broiler breast fillets and the effect of deboning time and cold storage on the variation and correlation coefficients. Broiler breast fillets were removed from carcasses early postmortem (2 h) and later postmortem (24 h). Storage treatments of the 2 h samples included 0 d, 7 d at 3 degrees C, 7 d at -20 degrees C, and 6 d at -20 degrees C plus 1 d at 3 degrees C. The WB shears of cooked fillets were measured using a TA-XTPlus Texture Analyzer and a TA-7 WB shear type blade. Our results showed that although the average WB shear force values differed within the 0-d, 2-h fillets, compared with the variation among the fillets within the treatment, the difference within a fillet is still evidently small. The Pearson correlation coefficients were significant between the locations; however, values of the correlation coefficients depended on the paired locations. Location differences in the WB shear values and the correlation coefficient values between them changed with deboning time and cold storage. These results demonstrate that the variation of WB shear force measurements is substantial within early deboned broiler breast fillets and the Pearson correlation coefficient values of the measurements vary among the locations. Both the variation and the Pearson correlation coefficients can be affected by postmortem aging time and storage. The differences in the means between the locations in early deboned breasts are much smaller than the
CORRELATION BETWEEN SOME BODY MEASURES OF LIPPIZANER STALLION PER LINES AT ĐAKOVO STUD
Directory of Open Access Journals (Sweden)
T. Rastija
2002-06-01
Full Text Available Body measures of Lippizaner line stallions and their correlation were processed in Đakovo stud. The measures performed by Lydtin rod and stock band included withers height, chest girth and cannon bone circumference on the total of 75 heads. Neapolitano line was characterized by the fewest number of stallions (4 whereas Tulip by the largest one (20. Data attained by the measuring were processed by the statistical program SPSS/PC (Nie et. al. 1975. Neapolitano line stallions had the lowest withers height (164.00 cm measured by the band whereas Conversano line stallions had the highest one (166.33 cm. Withers height measured by the rod was the lowest in the Maestoso line stallion (156.50 cm and the highest one in the Favory line (159.20 cm. Chest girth ranged between 183.82 cm (Pluto line and 186.89 cm (Conversano line. Cannon bone circumference was uniform with all lines ranged from 20.05 cm (Tulipan line and 20.65 cm (Maestoso lines. Correlation between withers height measured by the band and rod and that one measured by the rod and chest girth was positive and highly significant. However, correlation between others ranged from slight positive to slight negative. Neapolitano line was known for the most pronounced correlation per lines whereas Tulip line for the weakest one. Correlation between withers height measured by the band and rod was in all lines highly significant (except Tulip line whereas other correlation varied from positive to negative.
Tunable spin transport in CrAs : Role of correlation effects
Chioncel, L; Katsnelson, MI; de Wijs, GA; de Groot, RA; Lichtenstein, AI
Correlation effects on the electronic structure of half-metallic CrAs in zinc-blende structure are studied for different substrate lattice constants. Depending on the substrate the spectral weight of the nonquasiparticle states might be tuned from a well-developed value in the case of an InAs
Simultaneous Differential Polarimetric Measurements and Co-Polar Correlation Coefficient Measurement
National Oceanic and Atmospheric Administration, Department of Commerce — A polarimetric Doppler weather radar system which allows measurement of linear orthogonal polarimetric variables without a switch by using simultaneous transmission...
Smith, P.; Beven, K.; Blazkova, S.; Merta, L.
2003-04-01
This poster outlines a methodology for the estimation of parameters in an Aggregated Dead Zone (ADZ) model of pollutant transport, by use of an example reach of the River Elbe. Both tracer and continuous water quality measurements are analysed to investigate the relationship between discharge and advective time delay. This includes a study of the effects of different error distributions being applied to the measurement of both variables using Monte-Carlo Markov Chain (MCMC) techniques. The derived relationships between discharge and advective time delay can then be incorporated into the formulation of the ADZ model to allow prediction of pollutant transport given uncertainty in the parameter values. The calibration is demonstrated in a hierarchical framework, giving the potential for the selection of appropriate model structures for the change in transport characteristics with discharge in the river. The value of different types and numbers of measurements are assessed within this framework.
Reddy, V R; Reddy, T G; Reddy, P Y; Reddy, K R
2003-01-01
An AC modulation technique is described to convert stochastic signal variations into an amplitude variation and its retrieval through Fourier analysis. It is shown that this AC detection of signals of stochastic processes when processed through auto- and cross-correlation techniques improve the signal-to-noise ratio; the correlation techniques serve a similar purpose of frequency and phase filtering as that of phase-sensitive detection. A few model calculations applied to nuclear spectroscopy measurements such as Angular Correlations, Mossbauer spectroscopy and Pulse Height Analysis reveal considerable improvement in the sensitivity of signal detection. Experimental implementation of the technique is presented in terms of amplitude variations of harmonics representing the derivatives of normal spectra. Improved detection sensitivity to spectral variations is shown to be significant. These correlation techniques are general and can be made applicable to all the fields of particle counting where measurements ar...
Evans, G. F.; Haller, R. G.; Wyrick, P. S.; Parkey, R. W.; Fleckenstein, J. L.; Blomqvist, C. G. (Principal Investigator)
1998-01-01
PURPOSE: To assess correlations between muscle edema on magnetic resonance (MR) images and clinical indexes of muscle injury in delayed-onset muscle soreness (DOMS) produced by submaximal exercise protocols. MATERIALS AND METHODS: Sixteen subjects performed 36 elbow flexions ("biceps curls") at one of two submaximal workloads that emphasized eccentric contractions. Changes in MR imaging findings, plasma levels of creatine kinase, and pain scores were correlated. RESULTS: Both exercise protocols produced DOMS in all subjects. The best correlation was between change in creatine kinase level and volume of muscle edema on MR images, regardless of the workload. Correlations tended to be better with the easier exercise protocol. CONCLUSION: Whereas many previous studies of DOMS focused on intense exercise protocols to ensure positive results, the present investigation showed that submaximal workloads are adequate to produce DOMS and that correlations between conventionally measured indexes of injury may be enhanced at lighter exercise intensities.
Institute of Scientific and Technical Information of China (English)
Boulbeba Abdelmoumen; Aref Jeribi; Maher Mnif
2012-01-01
In this paper,we define new measures called respectively graph measure of noncompactness and graph measure of weak noncompactness.Moreover,we apply the obtained results to discuss the incidence of some perturbation results realized in [2] on the behavior of essential spectra of such closed densely defined linear operators on Banach spaces.These results are exploited to investigate the essential spectra of a multidimensional neutron transport operator on L1 spaces.
Correlates of objectively measured sedentary time and self-reported screen time in Canadian children
LeBlanc, Allana G; Stephanie T Broyles; Chaput, Jean-Philippe; Leduc, Geneviève; Boyer, Charles; Borghese, Michael M.; Tremblay, Mark S
2015-01-01
Background Demographic, family, and home characteristics play an important role in determining childhood sedentary behaviour. The objective of this paper was to identify correlates of total sedentary time (SED) and correlates of self-reported screen time (ST) in Canadian children. Methods Child- and parent-reported household, socio-demographic, behavioural, and diet related data were collected; directly measured anthropometric and accelerometer data were also collected for each child. Partici...
Measuring the correlation of two optical frequencies using four-wave mixing.
Anthur, Aravind P; Watts, Regan T; Huynh, Tam N; Venkitesh, Deepa; Barry, Liam P
2014-11-10
We use the physics of four-wave mixing to study the decorrelation of two optical frequencies as they propagate through different fiber delays. The phase noise relationship between the four-wave mixing components is used to quantify and measure the correlation between the two optical frequencies using the correlation coefficient. We show the difference in the evolution of decorrelation between frequency-dependent and frequency-independent components of phase noise.
Walczak, Zbigniew; Wintrowicz, Iwona
2017-03-01
Recently, Brodutch and Modi proposed a general method of constructing meaningful measures of classical and quantum correlations. We systematically apply this method to obtain geometric classical and quantum correlations based on the Bures and the trace distances for two-qubit Bell diagonal states. Moreover, we argue that in general the Brodutch and Modi method may provide non-unique results, and we show how to modify this method to avoid this issue.
Measurement of the Correlation and Coherence Lengths in Boundary Layer Flight Data
Palumbo, Daniel L.
2011-01-01
Wall pressure data acquired during flight tests at several flight conditions are analyzed and the correlation and coherence lengths of the data reported. It is shown how the frequency bandwidth of the analysis biases the correlation length and how the convection of the flow acts to reduce the coherence length. Coherence lengths measured in the streamwise direction appear much longer than would be expected based on classical results for flow over a flat plat.
Energy Technology Data Exchange (ETDEWEB)
NONE
1998-12-01
The scope of the work described in this report was (1) to evaluate methods for risk mapping considering all of the different means of transport, (2) to evaluate the extent to which measures should be taken against various types of accidents, (3) to evaluate cost-benefit assessments of accident-reducing measures irrespective of the different means of transport, (4) to evaluate the preferences of measures/cost effectiveness of different measures within different sectors, and (4) to evaluate the possibility of improving the efficiency of possible measures. It also considers the risk situation for ferry service. In addition to the purely human aspect, traffic accidents constitute an expensive social problem. Yet it would be too costly to meet a potential requirement that traffic accidents should disappear. The resources used by society to combat accidents have to be seen in the light of (1) the profit that can be achieved compared to alternative use of the resources, and (2) the possible negative consequences of different safety measures on, for instance, travel time and the extent of the transport. It is pointed out that when accident risk is compared from one transport means to another, different relative positions are found depending on how risk is quantified. Thus, for instance, on average, per year 5 times as many people die in accidents involving private cars as in motor cycle accidents, while for the number of deaths per billion person kilometers the ratio is almost the opposite,1:6.5. 34 refs., 12 figs., 13 tabs.
OsowskiNeil, Doreen; Yee, Jeng-Hwa; Boldt, John; Edwards, David
2010-01-01
We present the progress toward an analytical performance model of a 2.3 micron infrared correlation radiometer (IRCRg) prototype subsystem for a future geostationary space-borne instrument. The prototype is designed specifically to measure carbon monoxide (CO) from geostationary orbit. NASA's Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission, one of the United States Earth Science and Applications Decadal Survey missions, specifies the use of infrared correlation radiometry to measure CO in two spectral regions for this mission. GEO-CAPE will use the robust IRCR measurement technique at geostationary orbit, nearly 50 times farther away than the Terra/MOPITT orbit, to determine hourly changes in CO across a continental domain. The abundance of CO in Earth's troposphere directly affects the concentration of hydroxyl, which regulates the lifetimes of many tropospheric pollutants. In addition, CO is a precursor to ozone formation; CO is used as a tracer to study the transport of global and regional pollutants; and CO is used as an indicator of both natural and anthropogenic air pollution sources and sinks. We have structured our development project to enable rapid evaluation of future spaceborne instrument designs. The project is part of NASA's Instrument Incubator Program. We describe the architecture of the performance model and the planned evaluation of the performance model using laboratory test data.
The negativity of Wigner function as a measure of quantum correlations
Siyouri, F.; El Baz, M.; Hassouni, Y.
2016-10-01
In this paper, we study comparatively the behaviors of Wigner function and quantum correlations for two quasi-Werner states formed with two general bipartite superposed coherent states. We show that the Wigner function can be used to detect and quantify the quantum correlations. However, we show that it is in fact not sensitive to all kinds of quantum correlations but only to entanglement. Then, we analyze the measure of non-classicality of quantum states based on the volume occupied by the negative part of the Wigner function.
Directory of Open Access Journals (Sweden)
Jennine M Dawicki-McKenna
Full Text Available In adipocytes, vesicles containing glucose transporter-4 (GLUT4 redistribute from intracellular stores to the cell periphery in response to insulin stimulation. Vesicles then fuse with the plasma membrane, facilitating glucose transport into the cell. To gain insight into the details of microtubule involvement, we examined the spatial organization and dynamics of microtubules in relation to GLUT4 vesicle trafficking in living 3T3-L1 adipocytes using total internal reflection fluorescence (TIRF microscopy. Insulin stimulated an increase in microtubule density and curvature within the TIRF-illuminated region of the cell. The high degree of curvature and abrupt displacements of microtubules indicate that substantial forces act on microtubules. The time course of the microtubule density increase precedes that of the increase in intensity of fluorescently-tagged GLUT4 in this same region of the cell. In addition, portions of the microtubules are highly curved and are pulled closer to the cell cortex, as confirmed by Parallax microscopy. Microtubule disruption delayed and modestly reduced GLUT4 accumulation at the plasma membrane. Quantitative analysis revealed that fusions of GLUT4-containing vesicles with the plasma membrane, detected using insulin-regulated aminopeptidase with a pH-sensitive GFP tag (pHluorin, preferentially occur near microtubules. Interestingly, long-distance vesicle movement along microtubules visible at the cell surface prior to fusion does not appear to account for this proximity. We conclude that microtubules may be important in providing spatial information for GLUT4 vesicle fusion.
Aerosol transport of biomass burning to the Bolivian Andean region from remote sensing measurements
Perez-Ramirez, Daniel; Whiteman, David; Andrade, Marcos; Gasso, Santiago; Stein, Ariel; Torres, Omar; Eck, Tom; Velarde, Fernando; Aliaga, Diego
2016-04-01
This work deals with the analysis of columnar aerosol optical and microphysical properties obtained by the AERONET network in the region of Bolivia and its border with Brazil. Through the long record AERONET measurements we focus in the transport of biomass-burning aerosol from the Amazon basin (stations at Rio Branco, Cuiba, Ji Parana and Santa Cruz) to the Andean Altiplano (altitude above 3000 m a.s.l. at the station in the city of La Paz). Also, measurements from the space-sensors MODIS and OMI are used to understand spatial distribution. The main results is the high impact in the aerosol load during the months of August, September and August with mean values of aerosol optical depth at 500 nm (AOD) at the low lands of ≈ 0.60 ± 0.60 and Angstrom exponent (α(440-870)) of ≈ 1.52 ± 0.38. Satellite measurements also follow very similar patterns. Also, that season is characterized by some extreme events that can reach AOD of up to 6.0. Those events are cloud-screened by MODIS but not by OMI sensor, which is attributed to different pixel resolutions. The biomass-burning is clearly transport to the Andean region where higher values of AOD (~ 0.12 ± 0.06 versus 0.09 ± 0.04 in the no biomass-burning season) and α(440-870) (~ 0.95 ± 0.30 versus 0.84 ± 0.3 in the no biomass-burning season). However, the intensity of the biomass-burning season varies between different years. Analysis of precipitation anomalies using TRNM satellites indicates a strong correlation with AOD, which suggest that on dry years there is less vegetation to burn and so less aerosol load. The opposite is found for positive anomalies of precipitation. In the transport of biomass burning larger values of the effective radius (reff) are observed in La Paz (reff = 0.26 ± 0.10 μm) than in the low lands (reff = 0.63 ± 0.24 μm), which has been explained by aerosol aging processes. Moreover, although the spectral dependence is similar, single scattering albedo (SSA) is larger in the low lands
Energy Technology Data Exchange (ETDEWEB)
Bulzacchelli, John F [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Lee, Hae-Seung [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Hong, Merit Y [Motorola, Inc., Semiconductor Products Sector, Tempe, AZ 85284 (United States); Misewich, James A [IBM Research Division, T J Watson Research Center, Yorktown Heights, NY 10598 (United States); Ketchen, Mark B [IBM Research Division, T J Watson Research Center, Yorktown Heights, NY 10598 (United States)
2003-12-01
Segmented correlation is a useful technique for testing a superconducting analogue-to-digital converter, as it allows the output spectrum to be estimated with fine frequency resolution even when data record lengths are limited by small on-chip acquisition memories. Previously, we presented segmented correlation measurements on a superconducting bandpass delta-sigma modulator sampling at 40.2 GHz under idle channel (no input) conditions. This paper compares the modulator output spectra measured by segmented correlation with and without an input tone. Important practical considerations of calculating segmented correlations are discussed in detail. Resolution enhancement by segmented correlation does reduce the spectral width of the input tone in the desired manner, but the signal power due to the input increases the variance of the spectral estimate near the input frequency, hindering accurate calculation of the in-band noise. This increased variance, which is predicted by theory, must be considered carefully in the application of segmented correlation. Methods for obtaining more accurate estimates of the quantization noise spectrum which are closer to those measured with no input are described.
Bulzacchelli, John F.; Lee, Hae-Seung; Hong, Merit Y.; Misewich, James A.; Ketchen, Mark B.
2003-12-01
Segmented correlation is a useful technique for testing a superconducting analogue-to-digital converter, as it allows the output spectrum to be estimated with fine frequency resolution even when data record lengths are limited by small on-chip acquisition memories. Previously, we presented segmented correlation measurements on a superconducting bandpass delta-sigma modulator sampling at 40.2 GHz under idle channel (no input) conditions. This paper compares the modulator output spectra measured by segmented correlation with and without an input tone. Important practical considerations of calculating segmented correlations are discussed in detail. Resolution enhancement by segmented correlation does reduce the spectral width of the input tone in the desired manner, but the signal power due to the input increases the variance of the spectral estimate near the input frequency, hindering accurate calculation of the in-band noise. This increased variance, which is predicted by theory, must be considered carefully in the application of segmented correlation. Methods for obtaining more accurate estimates of the quantization noise spectrum which are closer to those measured with no input are described.
Environmental assessment of the measures increasing the sustainability of motor transport
Magaril, E.; Magaril, R.; Abrzhina, L.
2017-06-01
Ensuring the sustainable development of motor transport, whose emission of greenhouse gases and other contaminants is one of the main sources of air pollution, requires informed decision-making on the implementation of effective environmental protection measures. A simplified methodological approach to a comparative assessment of the effectiveness of these environmental protection measures has been developed. The offered approach has been approved at estimating application for motor fuels of the multipurpose additive, which increases both the energy efficiency and environmental safety of motor transport.
Energy Technology Data Exchange (ETDEWEB)
Sanchez Valdes, C.F. [Superconductivity Laboratory, Magnetism Laboratory, IMRE-Physics Faculty, University of Havana, 10400 Havana (Cuba); Perez-Penichet, C. [Superconductivity Laboratory, Magnetism Laboratory, IMRE-Physics Faculty, University of Havana, 10400 Havana (Cuba); Noda, C. [Superconductivity Laboratory, Magnetism Laboratory, IMRE-Physics Faculty, University of Havana, 10400 Havana (Cuba); Arronte, M. [Laser Technology Laboratory, CICATA-IPN, ALTAMIRA, Altamira 89600, TAMPS (Mexico); Batista-Leyva, A.J. [Department of General Physics and Mathematics, InSTEC, 10400 Havana (Cuba); Haugen, O. [Department of Physics, University of Oslo, Blindern, N-0316 Oslo (Norway); Johansen, T.H. [Department of Physics, University of Oslo, Blindern, N-0316 Oslo (Norway); Han, Z. [Applied Superconductivity Research Center, Department of Physics, Tsinghua University, Beijing 100084 (China); Altshuler, E. [Superconductivity Laboratory, Magnetism Laboratory, IMRE-Physics Faculty, University of Havana, 10400 Havana (Cuba)]. E-mail: ea@infomed.sld.cu
2007-09-15
The determination of inter- and intra-filament characteristics in superconducting composites such as BSCCO-Ag tapes is of great importance for material evaluation towards applications. Most attempts to separate the two contributions have relied on indirect methods based on magnetic measurements such as SQUID or magneto-optic imaging techniques. Here we show that laser patterning of superconducting BSCCO-Ag tapes constitutes a simple approach to measure local transport properties in a direct way, even able to separate inter- and intra-filament contributions to the overall transport behavior of the sample.
Measurements of the production and transport of helium ash on the TFTR Tokamak
Energy Technology Data Exchange (ETDEWEB)
Synakowski, E.J.; Bell, R.E.; Budny, R.V. [and others
1995-03-01
Helium ash production and transport have been measured in TFTR deuterium-tritium plasmas using charge-exchange recombination spectroscopy. The helium ash confinement time, including recycling effects, is 6--10 times the energy confinement time and is compatible with sustained ignition in a reactor. The ash confinement time is dominated by edge pumping rates rather than core transport. The measured evolution of the local thermal ash density agrees with modeling, indicating that alpha particle slowing-down calculations used in the modeling are reasonable.
Shi, Lizheng; Liu, Jinan; Fonseca, Vivian; Walker, Philip; Kalsekar, Anupama; Pawaskar, Manjiri
2010-09-13
It is vital to understand the associations between the medication event monitoring systems (MEMS) and self-reported questionnaires (SRQs) because both are often used to measure medication adherence and can produce different results. In addition, the economic implication of using alternative measures is important as the cost of electronic monitoring devices is not covered by insurance, while self-reports are the most practical and cost-effective method in the clinical settings. This meta-analysis examined the correlations of two measurements of medication adherence: MEMS and SRQs. The literature search (1980-2009) used PubMed, OVID MEDLINE, PsycINFO (EBSCO), CINAHL (EBSCO), OVID HealthStar, EMBASE (Elsevier), and Cochrane Databases. Studies were included if the correlation coefficients [Pearson (rp) or Spearman (rs)] between adherences measured by both MEMS and SRQs were available or could be calculated from other statistics in the articles. Data were independently abstracted in duplicate with standardized protocol and abstraction form including 1) first author's name; 2) year of publication; 3) disease status of participants; 4) sample size; 5) mean age (year); 6) duration of trials (month); 7) SRQ names if available; 8) adherence (%) measured by MEMS; 9) adherence (%) measured by SRQ; 10) correlation coefficient and relative information, including p-value, 95% confidence interval (CI). A meta-analysis was conducted to pool the correlation coefficients using random-effect model. Eleven studies (N = 1,684 patients) met the inclusion criteria. The mean of adherence measured by MEMS was 74.9% (range 53.4%-92.9%), versus 84.0% by SRQ (range 68.35%-95%). The correlation between adherence measured by MEMS and SRQs ranged from 0.24 to 0.87. The pooled correlation coefficient for 11 studies was 0.45 (p = 0.001, 95% confidence interval [95% CI]: 0.34-0.56). The subgroup meta-analysis on the seven studies reporting rp and four studies reporting rs reported the pooled
MEASURING SEA ICE DRIFT VIA CROSS-CORRELATION OF RADAR ICE IMAGES
Institute of Scientific and Technical Information of China (English)
SUN He-quan; SHEN Yong-ming; Qiu Da-hong
2004-01-01
The motion of sea ice has a great effect on winter navigation, and oil field exploration in the Bohai Sea. It is very important to measure the ice drift accurately and efficiently. As a practical technique, radar imagery has been used for sea ice monitoring and forecasting for a long time. Combining with the radar imagery and cross-correlation technique, a new measurement method based on the cross-correlation of radar ice images is specified in this paper to obtain full field measurement of sea ice drift. The theory and fast implementation of cross-correlation are presented briefly in the paper, including the filtering method to modify the invalid vectors. To show deeply the validity of the present method, the velocity maps of sea ice drift are provided in the paper, which are calculated from the radar images grabbed in the Liaodong Gulf. The comparison with the traditional tracing method is also conducted.
DEFF Research Database (Denmark)
Holstein, P; Lassen, N A
1980-01-01
The frequency of healing in subchronic ulcers in 66 feet in 62 patients with arterial occlusive disease was correlated with the systolic digital blood pressure (SDBP) and the systolic ankle blood pressure (SABP), both measured with a strain gauge, and with the skin perfusion pressure on the heel...... of healing correlated significantly with the three distal blood pressure parameters investigated, the closest correlation being with the SDBP measured at the final examination, i.e. just after healing of the ulcer or just before an inevitable major amputation. Of the 22 cases with SDBP below 20 mmHg only two...... (SPPH) as measured with a photocell. Thirty-two patients (35 feet with ulcerations) had diabetes mellitus. The treatment was conservative. In 42 feet the ulcers healed after an average period of 5.8 months; in 24 feet major amputation became necessary after an average of 4.3 months. The frequency...
A problem with the correlation coefficient as a measure of gene expression divergence.
Pereira, Vini; Waxman, David; Eyre-Walker, Adam
2009-12-01
The correlation coefficient is commonly used as a measure of the divergence of gene expression profiles between different species. Here we point out a potential problem with this statistic: if measurement error is large relative to the differences in expression, the correlation coefficient will tend to show high divergence for genes that have relatively uniform levels of expression across tissues or time points. We show that genes with a conserved uniform pattern of expression have significantly higher levels of expression divergence, when measured using the correlation coefficient, than other genes, in a data set from mouse, rat, and human. We also show that the Euclidean distance yields low estimates of expression divergence for genes with a conserved uniform pattern of expression.
Measuring a hidden coordinate: Rate-exchange kinetics from 3D correlation functions
Berg, Mark A.; Darvin, Jason R.
2016-08-01
Nonexponential kinetics imply the existence of at least one slow variable other than the observable, that is, the system has a "hidden" coordinate. We develop a simple, but general, model that allows multidimensional correlation functions to be calculated for these systems. Homogeneous and heterogeneous mechanisms are both included, and slow exchange of the rates is allowed. This model shows that 2D and 3D correlation functions of the observable measure the distribution and kinetics of the hidden coordinate controlling the rate exchange. Both the mean exchange time and the shape of the exchange relaxation are measurable. However, complications arise because higher correlation functions are sums of multiple "pathways," each of which measures different dynamics. Only one 3D pathway involves exchange dynamics. Care must be used to extract exchange dynamics without contamination from other processes.
Measurement of the $t\\bar{t}$ spin correlations and top quark polarization in dileptonic channel
Khatiwada, Ajeeta
2017-01-01
The degree of top polarization and strength of $t\\bar{t}$ correlation are dependent on production dynamics, decay mechanism, and choice of the observables. At the LHC, measurement of the top polarization and spin correlations in $t\\bar{t}$ production is possible through various observables related to the angular distribution of decay leptons. A measurement of differential distribution provides a precision test of the standard model of particle physics and probes for deviations, which could be a sign of new physics. In particular, the phase space for the super-symmetric partner of the top quark can be constrained. Results from the Compact Muon Solenoid (CMS) collaboration for top quark polarization and spin correlation in the dileptonic channel are reviewed briefly in this proceeding. The measurements are obtained using 19.5 fb$^{-1}$ of data collected in pp collisions at the center-of-mass energy of 8 TeV.
Measuring a hidden coordinate: Rate-exchange kinetics from 3D correlation functions.
Berg, Mark A; Darvin, Jason R
2016-08-07
Nonexponential kinetics imply the existence of at least one slow variable other than the observable, that is, the system has a "hidden" coordinate. We develop a simple, but general, model that allows multidimensional correlation functions to be calculated for these systems. Homogeneous and heterogeneous mechanisms are both included, and slow exchange of the rates is allowed. This model shows that 2D and 3D correlation functions of the observable measure the distribution and kinetics of the hidden coordinate controlling the rate exchange. Both the mean exchange time and the shape of the exchange relaxation are measurable. However, complications arise because higher correlation functions are sums of multiple "pathways," each of which measures different dynamics. Only one 3D pathway involves exchange dynamics. Care must be used to extract exchange dynamics without contamination from other processes.
Measurement of b anti b correlations at the CERN p anti p collider
Energy Technology Data Exchange (ETDEWEB)
Albajar, C.; Ankoviak, K.; Bartha, S.; Bezaguet, A.; Boehrer, A.; Bos, K.; Buchanan, C.; Buschbeck, B.; Castilla-Valdez, H.; Cennini, P.; Cittolin, S.; Clayton, E.; Cline, D.; Caughlan, J.A.; Dau, D.; Daum, C.; Della Negra, M.; Demoulin, M.; Denegri, D.; Dibon, H.; Dorenbosch, J.; Dowell, J.D.; Eggert, K.; Eisenhandler, E.; Ellis, N.; Evans, H.; Faissner, H.; Fensome, I.F.; Fortson, L.; Garvey, J.; Geiser, A. Givernaud, A.; Gonidec, A.; Gonzalez, B.; Gronberg, J.; Holthuizen, D.J.; Jank, W.; Jorat, G.; Kalmus, P.I.P.; Karimaeki, V.; Kenyon, I.; Kinnunen, R.; Krammer, M.; Lammel, S.; Landon, M.P.J.; Lemoigne, Y.; Levegruen, S.; Lipa, P.; Markou, C.; Markytan, M.; Maurin, G.; McMahon, S.; Merlo, J.P.; Meyer, T.; Moers, T.; Mohammadi, M.; Morsch, A.; Moulin, A.; Norton, A.; Otwinowski, S.; Pancheri, G.; Pietarinen, E.; Pimiae, M.; Placci, A.; Porte, J.P.; Priem, R.; Prosi, R.; Radermacher, E.; Rauschkolb, M.; Reithler, H.; Revol, J.P.; Robinson, D.; Rubbia, C.; Samyn, D.; Schinzel, D.; Sc; UA1 Collaboration
1994-01-01
We report on measurements of correlated b anti b production in p anti p at [radical]s=630 GeV, using dimuon data to tag both the b and anti b quarks. Starting from an inclusive dimuon sample we obtain improved cross-sections for single inclusive beauty production and confirm our earlier results on B[sup 0]- anti B[sup 0] mixing. From a study of b anti b correlations we derive explicit cross-sections for semi-differential b anti b production. We compare the measured cross-sections and correlations to OMIKRON ([alpha][sub s][sup 3]) QCD predictions and find good quantitative agreement. From the measured angular distributions we establish a sizeable contribution from higher order QCD processes with a significance of about seven standard deviations. A large nonperturbative contribution to these higher order corrections is excluded. (orig.)
Song, John; Chu, Wei; Tong, Mingsi; Soons, Johannes
2014-06-01
Based on three-dimensional (3D) topography measurements on correlation cells, the National Institute of Standards and Technology (NIST) has developed the ‘NIST Ballistics Identification System (NBIS)’ aimed at accurate ballistics identifications and fast ballistics evidence searches. The 3D topographies are divided into arrays of correlation cells to identify ‘valid correlation areas’ and eliminate ‘invalid correlation areas’ from the matching and identification procedure. A ‘congruent matching cells’ (CMC)’ method using three types of identification parameters of the paired correlation cells (cross correlation function maximum CCFmax, spatial registration position in x-y and registration angle θ) is used for high accuracy ballistics identifications. ‘Synchronous processing’ is proposed for correlating multiple cell pairs at the same time to increase the correlation speed. The proposed NBIS can be used for correlations of both geometrical topographies and optical intensity images. All the correlation parameters and algorithms are in the public domain and subject to open tests. An error rate reporting procedure has been developed that can greatly add to the scientific support for the firearm and toolmark identification specialty, and give confidence to the trier of fact in court proceedings. The NBIS is engineered to employ transparent identification parameters and criteria, statistical models and correlation algorithms. In this way, interoperability between different ballistics identification systems can be more easily achieved. This interoperability will make the NBIS suitable for ballistics identifications and evidence searches with large national databases, such as the National Integrated Ballistic Information Network in the United States.
Energy Technology Data Exchange (ETDEWEB)
Yoon, Jung Hyun, E-mail: lvjenny0417@gmail.com [Department of Radiology, CHA Bundang Medical Center, CHA University, School of Medicine (Korea, Republic of); Department of Radiology, Research Institute of Radiological Science, Yonsei University, College of Medicine (Korea, Republic of); Ko, Kyung Hee, E-mail: yourheeya@cha.ac.kr [Department of Radiology, CHA Bundang Medical Center, CHA University, School of Medicine (Korea, Republic of); Jung, Hae Kyoung, E-mail: AA40501@cha.ac.kr [Department of Radiology, CHA Bundang Medical Center, CHA University, School of Medicine (Korea, Republic of); Lee, Jong Tae, E-mail: jtlee@cha.ac.kr [Department of Radiology, CHA Bundang Medical Center, CHA University, School of Medicine (Korea, Republic of)
2013-12-01
Objective: To determine the correlation of qualitative shear wave elastography (SWE) pattern classification to quantitative SWE measurements and whether it is representative of quantitative SWE values with similar performances. Methods: From October 2012 to January 2013, 267 breast masses of 236 women (mean age: 45.12 ± 10.54 years, range: 21–88 years) who had undergone ultrasonography (US), SWE, and subsequent biopsy were included. US BI-RADS final assessment and qualitative and quantitative SWE measurements were recorded. Correlation between pattern classification and mean elasticity, maximum elasticity, elasticity ratio and standard deviation were evaluated. Diagnostic performances of grayscale US, SWE parameters, and US combined to SWE values were calculated and compared. Results: Of the 267 breast masses, 208 (77.9%) were benign and 59 (22.1%) were malignant. Pattern classifications significantly correlated with all quantitative SWE measurements, showing highest correlation with maximum elasticity, r = 0.721 (P < 0.001). Sensitivity was significantly decreased in US combined to SWE measurements to grayscale US: 69.5–89.8% to 100.0%, while specificity was significantly improved: 62.5–81.7% to 13.9% (P < 0.001). Area under the ROC curve (A{sub z}) did not show significant differences between grayscale US to US combined to SWE (P > 0.05). Conclusion: Pattern classification shows high correlation to maximum stiffness and may be representative of quantitative SWE values. When combined to grayscale US, SWE improves specificity of US.
A New Approach to Measuring the Neutron Decay Correlations with Cold Neutrons at LANSCE
Energy Technology Data Exchange (ETDEWEB)
Wilburn, W.S.; Bowman, J.D.; Greene, G.L.; Jones, G.L.; Kapustinsky, J.S.; Penttila, S.I.
1999-06-08
Precision measurements of the neutron beta-decay correlations A, B, a, and b provide important tests of the standard model of electroweak interactions: a test of the unitarity of the first row of the CKM matrix, a search for new weak interactions, a test of the theory of nuclear beta decays, and a test of the conserved-vector-current hypothesis. The authors are designing an experiment at the LANSCE short-pulse spallation source to measure all four correlations to an order of magnitude better accuracy than the existing measurements. The accuracy of the previous measurements was limited by systematics. The design of the proposed experiment makes use of the pulsed nature of the LANSCE source to reduce systematic errors associated with the measurement of the neutron polarization as well as other systematic errors. In addition, the authors are developing silicon strip detectors for detecting both the proton and electron from the neutron decay.
Directory of Open Access Journals (Sweden)
S.M. Badwai
2013-01-01
Full Text Available the key point of super resolution process is the accurate measuring of sub-pixel shift. Any tiny error in measuring such shift leads to an incorrect image focusing. In this paper, methodology of measuring sub-pixel shift using Phase correlation (PC are evaluated using different window functions, then modified version of (PC method using high pass filter (HPF is introduced . Comprehensive analysis and assessment of (PC methods shows that different natural features yield different shift measurements. It is concluded that there is no universal window function for measuring shift; it mainly depends on the features in the satellite images. Even the question of which window is optimal of particular feature is generally remains open. This paper presents the design of a method for obtaining high accuracy sub pixel shift phase correlation using (HPF.The proposed method makes the change in the different locations that lack of edges easy.
Sub-cycle measurement of intensity correlations in the Terahertz range
Benea-Chelmus, Ileana-Cristina; Beck, Mattias; Faist, Jerome
2015-01-01
The Terahertz frequency range bears intriguing opportunities, beyond very advanced applications in spectroscopy and matter control. Peculiar quantum phenomena are predicted to lead to light emission by non-trivial mechanisms. Typically, such emission mechanisms are unraveled by temporal correlation measurements of photon arrival times, as demonstrated in their pioneering work by Hanbury Brown and Twiss. So far, the Terahertz range misses an experimental implementation of such technique with very good temporal properties and high sensitivity. In this paper, we propose a room-temperature scheme to measure photon correlations at THz frequencies based on electro-optic sampling. The temporal resolution of 146 fs is faster than one cycle of oscillation and the sensitivity is so far limited to ~1500 photons. With this technique, we measure the photon statistics of a THz quantum cascade laser. The proposed measurement scheme allows, in principle, the measurement of ultrahigh bandwidth photons and paves the way toward...
Measurements of Correlated Conductances and Noise Fluctuations from 3-Lead Quantum Dots
Toonen, R. C.; Prada, M.; Qin, H.; Huettel, A. K.; Goswami, S.; Eriksson, M. A.; van der Weide, D. W.; Eberl, K.; Blick, R. H.
2005-08-01
We have investigated the conductance properties of a few-electron quantum dot with three terminals. In the regime of strong coupling between the quantum dot and the leads, we have observed the both the integer- and half-integer-spin Kondo effect at zero magnetic field. Within the integer-spin conductance diamond, we find cotunneling spectral lines which correspond to singlet-triplet transitions. We extract the exchange energy from this information and find that the value (J = 320 μeV) agrees remarkably well with the theoretical prediction. We believe that spin dependent transport in a three-terminal quantum dot could yield positive cross-correlations between shot noise events on two output channels. To investigate such phenomena, we have designed an analog continuum cross-correlator to analyze the shot noise spectra of our device in the X- and Ku-bands (8 to 18 GHz).
Lebreton, A; Braive, R; Sagnes, I; Robert-Philip, I; Beveratos, A
2013-01-01
Interferometric photon-correlation measurements, which correspond to the second-order intensity cross-correlations between the two output ports of an unbalanced Michelson interferometer, are sensitive to both amplitude and phase fluctuations of an incoming beam of light. Here, we present the theoretical framework behind these measurements and show that they can be used to unambiguously differentiate a coherent wave undergoing dynamical amplitude and phase fluctuations from a chaotic state of light. This technique may thus be used to characterize the output of nanolasers and monitor the onset of coherent emission.
Nieminen, Teemu; Lähteenmäki, Pasi; Tan, Zhenbing; Cox, Daniel; Hakonen, Pertti J.
2016-11-01
We present a microwave correlation measurement system based on two low-cost USB-connected software defined radio dongles modified to operate as coherent receivers by using a common local oscillator. Existing software is used to obtain I/Q samples from both dongles simultaneously at a software tunable frequency. To achieve low noise, we introduce an easy low-noise solution for cryogenic amplification at 600-900 MHz based on single discrete HEMT with 21 dB gain and 7 K noise temperature. In addition, we discuss the quantization effects in a digital correlation measurement and determination of optimal integration time by applying Allan deviation analysis.
DEFF Research Database (Denmark)
Nørholm, Morten Helge Hauberg; Nour-Eldin, Hussam H; Brodersen, Peter;
2006-01-01
GFP expression only in the vascular tissue in emerging petals under non-stressed conditions. Quantitative PCR and the pSTP13-GFP plants show induction of STP13 in programmed cell death (PCD) obtained by treatments with the fungal toxin fumonisin B1 and the pathogen Pseudomonas syringae. A role for STP......13 in PCD is supported by microarray data from e.g. plants undergoing senescence and a strong correlation between STP13 transcripts and the PCD phenotype in different accelerated cell death (acd11) mutants....
Volatility and correlation-based systemic risk measures in the US market
Civitarese, Jamil
2016-10-01
This paper deals with the problem of how to use simple systemic risk measures to assess portfolio risk characteristics. Using three simple examples taken from previous literature, one based on raw and partial correlations, another based on the eigenvalue decomposition of the covariance matrix and the last one based on an eigenvalue entropy, a Granger-causation analysis revealed some of them are not always a good measure of risk in the S&P 500 and in the VIX. The measures selected do not Granger-cause the VIX index in all windows selected; therefore, in the sense of risk as volatility, the indicators are not always suitable. Nevertheless, their results towards returns are similar to previous works that accept them. A deeper analysis has shown that any symmetric measure based on eigenvalue decomposition of correlation matrices, however, is not useful as a measure of "correlation" risk. The empirical counterpart analysis of this proposition stated that negative correlations are usually small and, therefore, do not heavily distort the behavior of the indicator.
Lin, Tingting; Zhang, Siyuan; Zhang, Yang; Wan, Ling; Lin, Jun
2017-01-01
Compared with the other geophysical approaches, magnetic resonance sounding (MRS) technique is direct and nondestructive in subsurface water exploration. It provides water content distribution and estimates hydrogeological properties. The biggest challenge is that MRS measurement always suffers bad signal-to-noise ratio, and it can be carried out only far from sources of noise. To solve this problem, a series of de-noising methods are developed. However, most of them are post-processing, leading the data quality uncontrolled for in situ measurements. In the present study, a new approach that removal of correlated noise online is found to overcome the restriction. Based on LabVIEW, a method is provided to enable online data quality control by the way of realizing signal acquisition and noise filtering simultaneously. Using one or more reference coils, adaptive noise cancellation based on LabVIEW to eliminate the correlated noise is available for in situ measurements. The approach was examined through numerical simulation and field measurements. The correlated noise is mitigated effectively and the application of MRS measurements is feasible in high-level noise environment. The method shortens the measurement time and improves the measurement efficiency.
DeSouza, Alexander L
2016-01-01
We model the mass accretion rate $\\dot{M}$ to stellar mass $M_*$ correlation that has been inferred from observations of intermediate to upper mass T Tauri stars---that is $\\dot{M} \\propto M_*^{1.3 \\pm 0.3}$. We explain this correlation within the framework of quiescent disk evolution, in which accretion is driven largely by gravitational torques acting in the bulk of the mass and volume of the disk. Stresses within the disk arise from the action of gravitationally driven torques parameterized in our 1D model in terms of Toomre's $Q$ criterion. We do not model the hot inner sub-AU scale region of the disk that is likely stable according to this criterion, and appeal to other mechanisms to remove or redistribute angular momentum and allow accretion onto the star. Our model has the advantage of agreeing with large-scale angle-averaged values from more complex nonaxisymmetric calculations. The model disk transitions from an early phase (dominated by initial conditions inherited from the burst mode of accretion) ...
Measurement of electron spin transport in graphene on 6H-silicon carbide(0001)
Abel, Joseph
The focus of this thesis is to demonstrate the potential of wafer scale graphene spintronics. Graphene is a single atomic layer of sp 2-bonded carbon atoms that has high carrier mobilities, making it a desirable material for future nanoscale electronic devices. The vision of spintronics is to utilize the spin of the electron to produce novel high-speed low power consuming devices. Materials with long spin relaxation times and spin diffusion lengths are needed to realize these goals. Graphene is an ideal material as it meets these requirements and is amenable to planar device geometries. In this thesis, spin transport in wafer scale epitaxial graphene grown on the silicon face of silicon carbide is demonstrated. Non-local Hanle spin precession measurement devices were fabricated using graphene with and without a hafnium oxide interface layer between the ferromagnetic metal and graphene. The structural properties of the devices were investigated with Raman spectroscopy, x-ray photoelectric spectroscopy, Rutherford backscattering spectroscopy, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. The electrical properties of the graphene were measured utilizing Hall transport measurements. The magnetic properties of the contacts were investigated with vibrating sample magnetometery. The processes developed to fabricate the Hanle measurement devices are presented as well. A custom Hanle measurement setup was developed and utilized for the Hanle spin precession measurements. Spin precession is observed in the epitaxial graphene on silicon carbide, with improved spin transport properties with the utilization of a hafnium oxide barrier between the ferromagnetic contacts and graphene. The charge transport and spin transport properties are compared to determine the relevant spin relaxation mechanism in the devices. These results demonstrate that graphene has great potential for wafer scale production of future spintronic devices.
Park, Dae Woo; Kruger, Grant H; Rubin, Jonathan M; Hamilton, James; Gottschalk, Paul; Dodde, Robert E; Shih, Albert J; Weitzel, William F
2013-10-01
This study investigated the use of ultrasound speckle decorrelation- and correlation-based lateral speckle-tracking methods for transverse and longitudinal blood velocity profile measurement, respectively. By studying the blood velocity gradient at the vessel wall, vascular wall shear stress, which is important in vascular physiology as well as the pathophysiologic mechanisms of vascular diseases, can be obtained. Decorrelation-based blood velocity profile measurement transverse to the flow direction is a novel approach, which provides advantages for vascular wall shear stress measurement over longitudinal blood velocity measurement methods. Blood flow velocity profiles are obtained from measurements of frame-to-frame decorrelation. In this research, both decorrelation and lateral speckle-tracking flow estimation methods were compared with Poiseuille theory over physiologic flows ranging from 50 to 1000 mm/s. The decorrelation flow velocity measurement method demonstrated more accurate prediction of the flow velocity gradient at the wall edge than the correlation-based lateral speckle-tracking method. The novelty of this study is that speckle decorrelation-based flow velocity measurements determine the blood velocity across a vessel. In addition, speckle decorrelation-based flow velocity measurements have higher axial spatial resolution than Doppler ultrasound measurements to enable more accurate measurement of blood velocity near a vessel wall and determine the physiologically important wall shear.
McEwen, J D; Hobson, M P; Vandergheynst, P; Lasenby, A N
2007-01-01
Using local morphological measures on the sphere defined through a steerable wavelet analysis, we examine the three-year WMAP and the NVSS data for correlation induced by the integrated Sachs-Wolfe (ISW) effect. The steerable wavelet constructed from the second derivative of a Gaussian allows one to define three local morphological measures, namely the signed-intensity, orientation and elongation of local features. Detections of correlation between the WMAP and NVSS data are made with each of these morphological measures. The most significant detection is obtained in the correlation of the signed-intensity of local features at a significance of 99.9%. By inspecting signed-intensity sky maps, it is possible for the first time to see the correlation between the WMAP and NVSS data by eye. Foreground contamination and instrumental systematics in the WMAP data are ruled out as the source of all significant detections of correlation. Our results provide new insight on the ISW effect by probing the morphological nat...
Correlations between the disintegration of melt and the measured impulses in steam explosions
Energy Technology Data Exchange (ETDEWEB)
Froehlich, G.; Linca, A.; Schindler, M. [Univ. of Stuttgart (Germany)
1995-09-01
To find our correlations in steam explosions (melt water interactions) between the measured impulses and the disintegration of the melt, experiments were performed in three configurations i.e. stratified, entrapment and jet experiments. Linear correlations were detected between the impulse and the total surface of the fragments. Theoretical considerations point out that a linear correlation assumes superheating of a water layer around the fragments of a constant thickness during the fragmentation process to a constant temperature (here the homogeneous nucleation temperature of water was assumed) and a constant expansion velocity of the steam in the main expansion time. The correlation constant does not depend on melt temperature and trigger pressure, but it depends on the configuration of the experiment or of a scenario of an accident. Further research is required concerning the correlation constant. For analysing steam explosion accidents the explosivity is introduced. The explosivity is a mass specific impulse. The explosivity is linear correlated with the degree of fragmentation. Knowing the degree of fragmentation with proper correlation constant the explosivity can be calculated and from the explosivity combined with the total mass of fragments the impulse is obtained which can be used to an estimation of the maximum force.
Zheng, Tianxiang; Cao, Liangcai; Zhao, Tian; He, Qingsheng; Jin, Guofan
2012-10-01
Volume holographic optical correlator can compute the correlation results between images at a super-high speed. In the application of remote imaging processing such as scene matching, 6,000 template images have been angularly multiplexed in the photorefractive crystal and the 6,000 parallel processing channels are achieved. In order to detect the correlation pattern of images precisely and distinguishingly, an on-off pixel inverted technology of images is proposed. It can fully use the CCD's linear range for detection and expand the normalized correlation value differences as the target image rotates. Due to the natural characteristics of the remote sensing images, the statistical formulas between the rotation distortions and the correlation results can be estimated. The rotation distortion components can be estimated by curve fitting method with the data of correlation results. The intensities of the correlation spots are related to the distortion between the two images. The rotation distortion could be derived from the intensities in the post processing procedure. With 18 rotations of the input image and sending them into the volume holographic system, the detection of the rotation variation in the range of 180° can be fulfilled. So the large range rotation distortion detection is firstly realized. It offers a fast, large range rotation measurement method for image distortions.
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
The correlation between ground motion intensity measures (IM) and single-degree-of-freedom (SDOF) deformation demands is described in this study. Peak ground acceleration (APG), peak ground velocity (VPG), peak ground displacement (DPG), spectral acceleration at the first-mode period of vibration [As(T1)] and ratio of VPG to APG are used as IM parameters, and the correlation is characterized by correlation coefficients ρ. The numerical results obtained by nonlinear dynamic analyses have shown good correlation between As(T1) or VPG and deformation demands. Furthermore, the effect of As(T1) and VPG as IM on the dispersion of the mean value of deformation demands is also investigated for SDOF systems with three different periods T=0.3 s, 1.0 s, 3.0 s respectively.
Measurement of 21 cm brightness fluctuations at z ~ 0.8 in cross-correlation
Masui, K W; Banavar, N; Bandura, K; Blake, C; Calin, L -M; Chang, T -C; Chen, X; Li, Y -C; Liao, Y -W; Natarajan, A; Pen, U -L; Peterson, J B; Shaw, J R; Voytek, T C
2012-01-01
In this letter, 21 cm intensity maps acquired at the Green Bank Telescope are cross-correlated with large-scale structure traced by galaxies in the WiggleZ Dark Energy Survey. The data span the redshift range 0.6 < z < 1 over two fields totaling ~41 deg. sq. and 190 hours of radio integration time. The cross-correlation constrains Omega_HI b_HI r = [0.43 \\pm 0.07 (stat.) \\pm 0.04(sys.)] x 10^-3, where Omega_HI is the neutral hydrogen HI fraction, r is the galaxy-hydrogen correlation coefficient, and b_HI is the HI bias parameter. This is the most precise constraint on neutral hydrogen density fluctuations in a challenging redshift range. Our measurement improves the previous 21 cm cross-correlation at z ~ 0.8 both in its precision and in the range of scales probed.
Correlation between the Cogstate computerized measure and WAIS-IV among birth cohort mothers.
Kataja, Eeva-Leena; Karlsson, Linnea; Tolvanen, Mimmi; Parsons, Christine; Schembri, Adrian; Kiiski-Mäki, Hanna; Karlsson, Hasse
2017-03-01
Large studies, with limited resources call for cost-effective cognitive assessment methods. Computerized tests offer viable alternatives but more data are needed on their functioning. Our aim was to evaluate the overlap between a computerized neuropsychological test battery and a traditional test of general intelligence (IQ). Cognitive functioning was assessed in birth cohort mothers (n = 80) with two widely used methods: Cogstate, computerized test battery, and WAIS-IV, a traditional IQ test. Correlational analyses were conducted. We found weak-to-moderate correlations between the measures, except for verbal comprehension. The indices of overall performance showed more consistent correlations than Subtests. The overall correlations were in accordance with earlier studies. Cogstate is relatively independent of verbal comprehension abilities. The choice of the cognitive assessment method should be strongly guided by the research question. More studies are needed to evaluate the applicability of the Cogstate Composite Score in cognitive screening.
Laser particle counter validation for aeolian sand transport measurements using a highspeed camera
Duarte Campos, Leonardo Andres; Wijnberg, Kathelijne Mariken; Oyarte Galvez, Loreto Alejandra; Hulscher, Suzanne J.M.H.
2017-01-01
Measuring aeolian sand transport rates in the field has been a long-standing challenge. In this paper, we present the results of a laboratory experiment to test the ability of a laser particle counter sensor (Wenglor) to accurately count sand grains of various grain size classes and stainless steel
Montagnese, Matteo; Otter, Marian; Zotos, Xenophon; Fishman, Dmitry A.; Hlubek, Nikolai; Mityashkin, Oleg; Hess, Christian; Saint-Martin, Romuald; Singh, Surjeet; Revcolevschi, Alexandre; van Loosdrecht, Paul H. M.
2013-01-01
Thirty-five years ago, Sanders and Walton [Phys. Rev. B 15, 1489 (1977)] proposed a method to measure the phonon-magnon interaction in antiferromagnets through thermal transport which so far has not been verified experimentally. We show that a dynamical variant of this approach allows direct extract
Institute of Scientific and Technical Information of China (English)
Shuo Zhang,Yan Zhao,Min Li,; Jianhui Zhao
2015-01-01
The global y optimal recursive filtering problem is stu-died for a class of systems with random parameter matrices, stochastic nonlinearities, correlated noises and missing measure-ments. The stochastic nonlinearities are presented in the system model to reflect multiplicative random disturbances, and the addi-tive noises, process noise and measurement noise, are assumed to be one-step autocorrelated as wel as two-step cross-correlated. A series of random variables is introduced as the missing rates governing the intermittent measurement losses caused by un-favorable network conditions. The aim of the addressed filtering problem is to design an optimal recursive filter for the uncertain systems based on an innovation approach such that the filtering error is global y minimized at each sampling time. A numerical simulation example is provided to il ustrate the effectiveness and applicability of the proposed algorithm.
A Novel Three-Head Ultrasonic System for Distance Measurements Based on the Correlation Method
Directory of Open Access Journals (Sweden)
Gądek Krzysztof
2014-12-01
Full Text Available A novel double-emitter ultrasonic system for distance measurements based on the correlation method is presented. The proposed distance measurement method may be particularly useful in difficult conditions, e.g. for media parameters undergoing fast changes or in cases when obstacles and mechanical interference produce false reflections. The system is a development of a previously studied single-head idea. The present article covers a comparison of the two systems in terms of efficiency and precision. Experimental research described in this paper indicated that adding the second head improved the measurement exactness – standard deviation decreased by 40%. The correlation method is also described in detail, also giving the criterion for the quality of the measurement signal.
Correlation of Spherical Thermistor for the Measurement of Low Velocity Air Flow
Institute of Scientific and Technical Information of China (English)
Xin－GangLiang; Ying－PingZhang; 等
1998-01-01
A spherical thermistor,an accurate temperature sensor is employed as an air velocity sensor in this work.The measuring principle is derived and the effects of the insulation layer,air temperature,netural convection and thermal radiation are discussed.Two different correlation relations for velocity measurements are proposed based on theoretical analyses and experimental calibrations,Experiments have shown that spherical thermistor is a good velocity sensor for speed between 0.1-2.5m/s at room temperature and the insulation layer hardly influences the accuracy of the thermistor used in the present work,Modification of correlation can even further imporve measurement accuracy.Since the thermistor is small and cheap,it is possible to apply this method to multi-Point velocity measurement with a low disturbance to the flow field.
Growth and Low Temperature Transport Measurements of Pure and Doped Bismuth Selenide
DEFF Research Database (Denmark)
Mlack, Jerome Thomas
Se3, which is a strong spin orbit material and a topological insulator. I describe a synthesis technique and low-temperature transport measurements of nanostructures of Bi2Se3, that when annealed with palladium show evidence of superconductivity. The growth method is a catalyst-free atmospheric...... pressure vapor-solid growth. The growth method yields a variety of nanostructures, and materials analysis shows ordered structures of bismuth selenide in all cases. Low-temperature measurements of as-grown nanostructures indicate tunable carrier density in all samples. By doping the nanostructures...... and that the absorption of Pd results in evidence of superconductivity, as shown by transport measurements measurements below 1K....
Measurements on, and modelling of diffusive and advective radon transport in soil
DEFF Research Database (Denmark)
Graff, E.R. van der; Witteman, G.A.A.; Spoel, W.H. van der;
1994-01-01
Results are presented of measurements on radon transport in soil under controlled conditions with a laboratory facility consisting of a stainless steel vessel (height and diameter 2 m) filled with a uniform column of sand. At several depths under the sand surface, probes are radially inserted...... into the vessel to measure the radon concentration in the soil gas. To study advective radon transport a perforated circular box is placed in the sand close to the bottom of the vessel. By pressurising this box, an air flow through the sand column is induced. Radon concentration profiles were measured without...... an air flow as a function of time, and for several values of the air flow, equilibrium radon concentration profiles were measured....
Energy Technology Data Exchange (ETDEWEB)
Polster, S. [Chair of Electron Devices, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Cauerstrasse 6, 91058 Erlangen (Germany); Jank, M. P. M. [Fraunhofer Institute for Integrated Systems and Device Technology, Schottkystrasse 10, 91058 Erlangen (Germany); Frey, L. [Chair of Electron Devices, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Cauerstrasse 6, 91058 Erlangen (Germany); Fraunhofer Institute for Integrated Systems and Device Technology, Schottkystrasse 10, 91058 Erlangen (Germany)
2016-01-14
The correlation of defect content and film morphology with the charge-carrier transport in field-effect devices based on zinc oxide nanoparticles was investigated. Changes in the defect content and the morphology were realized by annealing and sintering of the nanoparticle thin films. Temperature-dependent electrical measurements reveal that the carrier transport is thermally activated for both the unsintered and sintered thin films. Reduced energetic barrier heights between the particles have been determined after sintering. Additionally, the energetic barrier heights between the particles can be reduced by increasing the drain-to-source voltage and the gate-to-source voltage. The changes in the barrier height are discussed with respect to information obtained by scanning electron microscopy and photoluminescence measurements. It is found that a reduction of surface states and a lower roughness at the interface between the particle layer and the gate dielectric lead to lower barrier heights. Both surface termination and layer morphology at the interface affect the barrier height and thus are the main criteria for mobility improvement and device optimization.
Kamimura, H.; Gouveia, R. C.; Carrocine, S. C.; Souza, L. D.; Rodrigues, A. D.; Teodoro, M. D.; Marques, G. E.; Leite, E. R.; Chiquito, A. J.
2016-11-01
Indium phosphide nanowires with a single crystalline zinc-blend core and polycrystalline/amorphous shell were grown from a reliable route without the use of hazardous precursors. The nanowires are composed by a crystalline core covered by a polycrystalline shell, presenting typical lengths larger than 10 μm and diameters of 80-90 nm. Raman spectra taken from as-grown nanowires exhibited asymmetric line shapes with broadening towards higher wave numbers which can be attributed to phonon localization effects. It was found that optical phonons in the nanowires are localized in regions with average size of 3 nm, which seems to have the same order of magnitude of grain sizes in the polycrystalline shell. Regardless of the fact that the nanowires exhibit a crystalline core, any considerable degree of disorder can lead to a localized behaviour of carriers. In consequence, the variable range hopping was observed as the main transport instead of the usual thermal excitation mechanisms. Furthermore the hopping length was ten times smaller than nanowire cross-sections, confirming that the nanostructures do behave as a 3D system. Accordingly, the V-shape observed in PL spectra clearly demonstrates a very strong influence of the potential fluctuations on the exciton optical recombination. Such fluctuations can still be observed at low temperature regime, confirming that the amorphous/polycrystalline shell of the nanowires affects the exciton recombination in every laser power regime tested.
Cluster-based statistics for brain connectivity in correlation with behavioral measures.
Directory of Open Access Journals (Sweden)
Cheol E Han
Full Text Available Graph theoretical approaches have successfully revealed abnormality in brain connectivity, in particular, for contrasting patients from healthy controls. Besides the group comparison analysis, a correlational study is also challenging. In studies with patients, for example, finding brain connections that indeed deepen specific symptoms is interesting. The correlational study is also beneficial since it does not require controls, which are often difficult to find, especially for old-age patients with cognitive impairment where controls could also have cognitive deficits due to normal ageing. However, one of the major difficulties in such correlational studies is too conservative multiple comparison correction. In this paper, we propose a novel method for identifying brain connections that are correlated with a specific cognitive behavior by employing cluster-based statistics, which is less conservative than other methods, such as Bonferroni correction, false discovery rate procedure, and extreme statistics. Our method is based on the insight that multiple brain connections, rather than a single connection, are responsible for abnormal behaviors. Given brain connectivity data, we first compute a partial correlation coefficient between every edge and the behavioral measure. Then we group together neighboring connections with strong correlation into clusters and calculate their maximum sizes. This procedure is repeated for randomly permuted assignments of behavioral measures. Significance levels of the identified sub-networks are estimated from the null distribution of the cluster sizes. This method is independent of network construction methods: either structural or functional network can be used in association with any behavioral measures. We further demonstrated the efficacy of our method using patients with subcortical vascular cognitive impairment. We identified sub-networks that are correlated with the disease severity by exploiting diffusion
Sabouri, Shirin; Fazli, Ladan; Chang, Silvia D; Savdie, Richard; Jones, Edward C; Goldenberg, S Larry; Black, Peter C; Kozlowski, Piotr
2017-09-01
To determine the relationship between parameters measured from luminal water imaging (LWI), a new magnetic resonance imaging (MRI) T2 mapping technique, and the corresponding tissue composition in prostate. In all, 17 patients with prostate cancer were examined with a 3D multiecho spin echo sequence at 3T prior to undergoing radical prostatectomy. Maps of seven MR parameters, called N, T2-short , T2-long , Ashort , Along , geometric mean T2 time (gmT2 ), and luminal water fraction (LWF), were generated using nonnegative least squares (NNLS) analysis of the T2 decay curves. MR parametric maps were correlated to digitized whole-mount histology sections. Percentage area of tissue components, including luminal space, nuclei, and cytoplasm plus stroma, was measured on the histology sections by using color-based image segmentation. Spearman's rank correlation test was used to evaluate the correlation between MR parameters and the corresponding tissue components, with particular attention paid to the correlation between LWF and percentage area of luminal space. N, T2-short , Along , gmT2 , and LWF showed significant correlation (P correlation (P correlation was observed between LWF and luminal space (Spearman's coefficient of rank correlation = 0.75, P correlated with the fractional amount of luminal space in prostatic tissue. This result suggests that LWI can potentially be applied for evaluation of prostatic diseases in which the extent of luminal space differs between normal and abnormal tissues. 1 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:861-869. © 2017 International Society for Magnetic Resonance in Medicine.
Cross-Correlation by Single-bit Signal Processing for Ultrasonic Distance Measurement
Hirata, Shinnosuke; Kurosawa, Minoru Kuribayashi; Katagiri, Takashi
Ultrasonic distance measurement using the pulse-echo method is based on the determination of the time of flight of ultrasonic waves. The pulse-compression technique, in which the cross-correlation function of a detected ultrasonic wave and a transmitted ultrasonic wave is obtained, is the conventional method used for improving the resolution of distance measurement. However, the calculation of a cross-correlation operation requires high-cost digital signal processing. This paper presents a new method of sensor signal processing within the pulse-compression technique using a delta-sigma modulated single-bit digital signal. The proposed sensor signal processing method consists of a cross-correlation operation employing single-bit signal processing and a smoothing operation involving a moving average filter. The proposed method reduces the calculation cost of the digital signal processing of the pulse-compression technique.
Velocity Distribution Measurement Using Pixel-Pixel Cross Correlation of Electrical Tomography
Institute of Scientific and Technical Information of China (English)
DENGXiang; PENGLihui; YAODanya; ZHANGBaofen
2004-01-01
Electrical tomography (ET) provides a novel means of visualizing the internal behavior of twophase flow in industrial process. Using a dual-sensingplane Electrical resistance tomography (ERT) or Electrical capacitance tomography (ECT) system, the raw data of two different section images can be acquired synchronously and the two images reflecting the inner medium distribution respectively can also be reconstructed by using imaging algorithm. Further, the analysis of pixel-pixel cross correlation is able to be setup and the measurement of velocity distribution of two-phase flow could be achieved. The principle is described in the paper. The FFT algorithm for gray value computation and cross correlation function calculation is also introduced. Some experimental results of velocity distribution measurement using pixelpixel cross correlation in vertical slug flow are presented.
Measure of Information Content of Remotely Sensed Images Accounting for Spatial Correlation
Directory of Open Access Journals (Sweden)
ZHANG Ying
2015-10-01
Full Text Available A measure is proposed based on the information theory and geostatistics to evaluate information content in remotely sensed images. The method is based on the additive noise model and maximum mutual information.These factors affecting the information content have been taken into account, such as noise, spatial correlation and so on. It is suitable for measuring the information content in optical images that have robust spatial correlation with different land cover types. An experiment was performed on a Landsat TM image with three different kinds of land cover types (city, farmland and mountain. The result shows that city has the most information content. It also proves that there is a log positive correlation between information content and the variance of the images.
Institute of Scientific and Technical Information of China (English)
程传福; 刘曼; 滕树云; 宋洪胜; 陈建平; 徐至展
2003-01-01
A method for the extracting the correlation functions of random surfaces is proposed by using the image speckle intensity. Theoretically, we analyse the integral expression of average intensity of the image speckles, and compare it with the pair of Fourier-Bessel-transform-and-the-inversion of the exponential function of the height-height correlation function of the random surfaces. Then the algorithm is proposed numerically to complement the lacking Bessel function factor in the expression of the average speckle intensity, which changes the intensity data into the pair of the Fourier-Bessel-transform. Experimentally, we measure the average image speckle intensities versus the radius of the filtering aperture in the 4 f system and extract the height-height correlation function by using the proposed algorithm. The results of the practical measurements for three surface samples and the comparison with those by atomic force microscopy validate the feasibility of this method.
DEFF Research Database (Denmark)
Holstein, P; Lassen, N A
1980-01-01
The frequency of healing in subchronic ulcers in 66 feet in 62 patients with arterial occlusive disease was correlated with the systolic digital blood pressure (SDBP) and the systolic ankle blood pressure (SABP), both measured with a strain gauge, and with the skin perfusion pressure on the heel...... of healing correlated significantly with the three distal blood pressure parameters investigated, the closest correlation being with the SDBP measured at the final examination, i.e. just after healing of the ulcer or just before an inevitable major amputation. Of the 22 cases with SDBP below 20 mmHg only two...... and peripheral neuropathy were frequent in the diabetic group. The data show that the systolic digital blood pressure is a particularly valuable prognostic parameter....
Parker, Stephen R; Ivanov, Eugene N; Tobar, Michael E
2015-01-01
Weakly Interacting Slim Particles (WISPs), such as axions, are highly motivated dark matter candidates. The most sensitive experimental searches for these particles exploit WISP-to-photon conversion mechanisms and use resonant cavity structures to enhance the resulting power signal. For WISPs to constitute Cold Dark Matter their required masses correspond to photons in the microwave spectrum. As such, searches for these types of WISPs are primarily limited by the thermal cavity noise and the broadband first-stage amplifier noise. In this work we propose and then verify two cross-correlation measurement techniques for cavity-based WISP searches. These are two channel measurement schemes where the cross-spectrum is computed, rejecting uncorrelated noise sources while still retaining correlated signals such as those generated by WISPs. The first technique allows for the cavity thermal spectrum to be observed with an enhanced resolution. The second technique cross-correlates two individual cavity/amplifier system...
Scambos, Theodore A.; Dutkiewicz, Melanie J.; Wison, Jeremy C.; Bindschadler, Robert A.
1992-01-01
A high-resolution map of the velocity field of the central portion of Ice Stream E in West Antarctica, generated by the displacement-measuring technique, is presented. The use of cross-correlation software is found to be a significant improvement over previous manually based photogrammetric methods for velocity measurement, and is far more cost-effective than in situ methods in remote polar areas. A hue-intensity-saturation image of Ice Stream E and its velocity field is shown.
Measurement of noise and its correlation to performance and geometry of small aircraft propellers
Štorch Vít; Nožička Jiří; Brada Martin; Gemperle Jiří; Suchý Jakub
2016-01-01
A set of small model and UAV propellers is measured both in terms of aerodynamic performance and acoustic noise under static conditions. Apart from obvious correlation of noise to tip speed and propeller diameter the influence of blade pitch, blade pitch distribution, efficiency and shape of the blade is sought. Using the measured performance data a computational model for calculation of aerodynamic noise of propellers will be validated. The range of selected propellers include both propeller...
Norholm, Morten H H; Nour-Eldin, Hussam H; Brodersen, Peter; Mundy, John; Halkier, Barbara A
2006-04-17
We report the biochemical characterization in Xenopus oocytes of the Arabidopsis thaliana membrane protein, STP13, as a high affinity, hexose-specific H(+)-symporter. Studies with kinase activators suggest that it is negatively regulated by phosphorylation. STP13 promoter GFP reporter lines show GFP expression only in the vascular tissue in emerging petals under non-stressed conditions. Quantitative PCR and the pSTP13-GFP plants show induction of STP13 in programmed cell death (PCD) obtained by treatments with the fungal toxin fumonisin B1 and the pathogen Pseudomonas syringae. A role for STP13 in PCD is supported by microarray data from e.g. plants undergoing senescence and a strong correlation between STP13 transcripts and the PCD phenotype in different accelerated cell death (acd11) mutants.
Energy Technology Data Exchange (ETDEWEB)
Guo Aimin [Department of Physics Science and Technology, Central South University, Changsha 410083 (China)]. E-mail: guoaimin1982@163.com; Xu Hui [Department of Physics Science and Technology, Central South University, Changsha 410083 (China)
2007-04-01
Understanding the intrinsic conduction properties in DNA plays a vital role in molecular electronic engineering. We use a tight-binding model to investigate the transmissivity, Lyapunov coefficient and localization length of DNA, including periodic poly(G)-poly(C), quasiperiodic Fibonacci polyGC and random sequences, as a function of sequence length and temperature. Our results show that the periodicity and long-range correlations in DNA can persist high transmittivity, and new transmission peaks can appear for whatever the sequence length or temperature increases, but the mean transmission coefficient decreases. Meanwhile, thermal enhancement of conductance is a generic feature in all these sequences and the asymptotic behaviors of localization length for random DNA are in good agreement with the mobility edge theory.
DeSouza, Alexander L.; Basu, Shantanu
2017-02-01
We model the mass accretion rate M˙ to stellar mass M* correlation that has been inferred from observations of intermediate to upper mass T Tauri stars-that is M˙ ∝ M*1.3±0.3. We explain this correlation within the framework of quiescent disk evolution, in which accretion is driven largely by gravitational torques acting in the bulk of the mass and volume of the disk. Stresses within the disk arise from the action of gravitationally driven torques parameterized in our 1D model in terms of Toomre's Q criterion. We do not model the hot inner sub-AU scale region of the disk that is likely stable according to this criterion, and appeal to other mechanisms to remove or redistribute angular momentum and allow accretion onto the star. Our model has the advantage of agreeing with large-scale angle-averaged values from more complex nonaxisymmetric calculations. The model disk transitions from an early phase (dominated by initial conditions inherited from the burst mode of accretion) into a later self-similar mode characterized by a steeper temporal decline in M˙. The models effectively reproduce the spread in mass accretion rates that have been observed for protostellar objects of 0.2 M⊙ ≤ M* ≤ 3.0 M⊙, such as those found in the ρ Ophiuchus and Taurus star forming regions. We then compare realistically sampled populations of young stellar objects produced by our model to their observational counterparts. We find these populations to be statistically coincident, which we argue is evidence for the role of gravitational torques in the late time evolution of quiescent protostellar disks.
Oxygen optodes as fast sensors for eddy correlation measurements in aquatic systems
DEFF Research Database (Denmark)
Chipman, Lindsay; Huettel, Markus; Berg, Peter
2012-01-01
The aquatic eddy-correlation technique can be used to noninvasively determine the oxygen exchange across the sediment-water interface by analyzing the covariance of vertical flow velocity and oxygen concentration in a small measuring volume above the sea bed. The method requires fast sensors that...
DEFF Research Database (Denmark)
Wu, Shengjun; Poulsen, Uffe Vestergaard; Mølmer, Klaus
2009-01-01
We consider the classical correlations that two observers can extract by measurements on a bipartite quantum state and we discuss how they are related to the quantum mutual information of the state. We show with several examples how complementarity gives rise to a gap between the quantum and the ...... in the deterministic quantum computation with one quantum bit....
The relation between Pearson’s correlation coefficient r and Salton’s cosine measure
Egghe, L.; Leydesdorff, L.
2009-01-01
The relation between Pearson's correlation coefficient and Salton's cosine measure is revealed based on the different possible values of the division of the L1-norm and the L2-norm of a vector. These different values yield a sheaf of increasingly straight lines which together form a cloud of points,
The relation between Pearson’s correlation coefficient r and Salton’s cosine measure
Egghe, L.; Leydesdorff, L.
2009-01-01
The relation between Pearson's correlation coefficient and Salton's cosine measure is revealed based on the different possible values of the division of the L1-norm and the L2-norm of a vector. These different values yield a sheaf of increasingly straight lines which together form a cloud of points,
Top quark pair charge asymmetry and spin correlation measurements [CMS speaker
Chwalek, Thorsten
2016-01-01
We give an overview over charge asymmetry and spin correlation measurements in top quark pair production. The presented analyses use data collected with the ATLAS and CMS detectors at a center-of-mass energy of 8TeV. Events with either dileptonic or semileptonic top quark pair decays are analyzed. All results are comparable with the predictions by the standard model.
Ochoa, Kelly; Nunez, Jeranil; Wang, Vincent J
2015-09-01
Measurement of peak expiratory flow (PEF) is recommended in the assessment of patients with asthma. However, the use of PEF involves multiple barriers, which have limited its use. Phonospirometry, as assessed by a novel Los Angeles phonospirometry technique, has shown good correlation to standard PEF measurements in a pilot study on symptomatic patients with asthma. We sought to develop a normogram for phonospirometry, and to validate the PEF normogram. A convenience sample of asymptomatic children ages 3-17 years old was approached for participation in the Emergency Department. Sample size calculations determined that at least 30 children per age group (n = 450) were needed. Children were asked to perform PEF measurements and phonospirometry, measured as the length of time (in s) the child was able to chant "lalala" in a single breath. 510 children were enrolled. Spearman's rho between PEF and phonospirometry was 0.722. Phonospirometry correlated with both age and height, with a Spearman rho of 0.697 and 0.696, respectively. This was slightly lower than the correlation of PEF with age and height with Spearman rhos of 0.877 and 0.902, respectively. A normogram was developed for phonospirometry based on age and height. This study determined normal value ranges for the Los Angeles phonospirometry technique for age and height, and also showed that the technique has good correlation with PEF. This technique may be used to assess a pediatric patient with an acute asthma exacerbation.
Measurement of carrier transport and recombination parameter in heavily doped silicon
Swanson, Richard M.
1986-01-01
The minority carrier transport and recombination parameters in heavily doped bulk silicon were measured. Both Si:P and Si:B with bulk dopings from 10 to the 17th and 10 to the 20th power/cu cm were studied. It is shown that three parameters characterize transport in bulk heavily doped Si: the minority carrier lifetime tau, the minority carrier mobility mu, and the equilibrium minority carrier density of n sub 0 and p sub 0 (in p-type and n-type Si respectively.) However, dc current-voltage measurements can never measure all three of these parameters, and some ac or time-transient experiment is required to obtain the values of these parameters as a function of dopant density. Using both dc electrical measurements on bipolar transitors with heavily doped base regions and transients optical measurements on heavily doped bulk and epitaxially grown samples, lifetime, mobility, and bandgap narrowing were measured as a function of both p and n type dopant densities. Best fits of minority carrier mobility, bandgap narrowing and lifetime as a function of doping density (in the heavily doped range) were constructed to allow accurate modeling of minority carrier transport in heavily doped Si.
Energy Technology Data Exchange (ETDEWEB)
Joshi, B. [Gautam Buddha University, Department of Applied Sciences, Greater Noida (India); Ghosh, S.; Srivastava, P. [Indian Institute of Technology Delhi, Nanostech Laboratory, New Delhi (India); Kumar, P.; Kanjilal, D. [Aruna Asaf Ali Marg, Inter University Accelerator Centre, New Delhi (India)
2012-05-15
We report variable temperature resistivity measurements and mechanisms related to electrical conduction in 200 keV Ni{sup 2+} ion implanted ZnO thin films deposited by vapor phase transport. The dc electrical resistivity versus temperature curves show that all polycrystalline ZnO films are semiconducting in nature. In the room temperature range they exhibit band conduction and conduction due to thermionic emission of electrons from grain boundaries present in the polycrystalline films. In the low temperature range, nearest neighbor hopping (NNH) and variable range hopping (VRH) conduction are observed. The detailed conduction mechanism of these films and the effects of grain boundary (GB) barriers on the electrical conduction process are discussed. An attempt is made to correlate electrical conduction behavior and previously observed room temperature ferromagnetism of these films. (orig.)
DEFF Research Database (Denmark)
Kupers, Ron; Frokjaer, Vibe G.; Erritzoe, David
2010-01-01
analysis revealed a positive correlation between pain tolerance and SERT binding in the hypothalamus (r = 0.53; p = 0.02) although this was not seen in the parametric analysis. These data extend our earlier observation that cortical 5-HT receptors co-determine responses to tonic but not to phasic pain......There is a large body of evidence that the serotonergic system plays an important role in the transmission and regulation of pain. Here we used positron emission tomography (PET) with the serotonin transporter (SERT) tracer [11C]DASB to study the relationship between SERT binding in the brain...... and responses to noxious heat stimulation in a group of 21 young healthy volunteers. Responses to noxious heat stimuli were assessed in a separate psychophysical experiment and included measurements of pain threshold, pain tolerance, and responses to phasic noxious heat stimuli and to a long lasting (7-minute...
Measurement of the internal magnetic fluctuation by the transport of runaways on J-TEXT
Chen, Z. Y.; Huang, D. W.; Tong, R. H.; Yan, W.; Wei, Y. N.; Ma, T. K.; Jiang, Z. H.; Zhang, X. Q.; Chen, Z. P.; Yang, Z. J.; Zhuang, G.
2016-11-01
The measurement of internal magnetic fluctuation is important for the study of transport in tokamak plasmas. The runaway electron transport induced by the sawtooth crash can be used to obtain the internal magnetic fluctuation. Inversed sawtooth-like activities on hard x-ray (HXR) fluxes following sawtooth activities were observed after the application of electrode biasing on J-TEXT tokamak. The runaway diffusion coefficient Dr is deduced to be about 30 m2/s according to the time delay of HXR flux peaks to the sawtooth crashes. The averaged value of normalized magnetic fluctuation in the discharges with electrode biasing was increased to the order of 1 × 10-4.
Computational Study of Correlated Domain Motions in the AcrB Efflux Transporter
Directory of Open Access Journals (Sweden)
Robert Schulz
2015-01-01
Full Text Available As active part of the major efflux system in E. coli bacteria, AcrB is responsible for the uptake and pumping of toxic substrates from the periplasm toward the extracellular space. In combination with the channel protein TolC and membrane fusion protein AcrA, this efflux pump is able to help the bacterium to survive different kinds of noxious compounds. With the present study we intend to enhance the understanding of the interactions between the domains and monomers, for example, the transduction of mechanical energy from the transmembrane domain into the porter domain, correlated motions of different subdomains within monomers, and cooperative effects between monomers. To this end, targeted molecular dynamics simulations have been employed either steering the whole protein complex or specific parts thereof. By forcing only parts of the complex towards specific conformational states, the risk for transient artificial conformations during the simulations is reduced. Distinct cooperative effects between the monomers in AcrB have been observed. Possible allosteric couplings have been identified providing microscopic insights that might be exploited to design more efficient inhibitors of efflux systems.
Gaspard, Dany; Kass, Jonathan; Akers, Stephen; Hunter, Krystal; Pratter, Melvin
2017-08-08
Patient-reported dyspnea plays a central role in assessing cardiopulmonary disease. There is little evidence, however, that dyspnea correlates with objective exercise capacity measurements. If the correlation is poor, dyspnea as a proxy for objective assessment may be misleading. To compare patient's perception of dyspnea with maximum oxygen uptake (MaxVO2) during cardiopulmonary exercise testing (CPET). Fifty patients undergoing CPET for dyspnea evaluation were studied prospectively. Dyspnea assessment was measured by a metabolic equivalent of task (METs) table, Mahler Dyspnea Index, Borg Index, number of blocks walked, and flights of stairs climbed before stopping due to dyspnea. These descriptors were compared to MaxVO2. MaxVO2 showed low correlation with METs table (r = 0.388, p = 0.005) and no correlation with Mahler Index (r = 0.24, p = 0.093), Borg Index (r = -0.017, p = 0.905), number of blocks walked (r = 0.266, p = 0.077) or flights of stairs climbed (r = 0.188, p = 0.217). When adjusted for weight (maxVO2/kg), there was significant correlation between MaxVO2 and METs table (r = 0.711, p Max VO2 and the assessment methods, while patients with BMI > 30 had moderate correlation between MaxVO2 and METs table (r = 0.568, p = 0.002). Patient-reported dyspnea correlates poorly with MaxVO2 and fails to predict exercise capacity. Reliance on reported dyspnea may result in suboptimal categorization of cardiopulmonary disease severity.
Koor, Behrooz Ebrahimzadeh; Nakhaie, Mohammad Reza; Babaie, Saied
2015-01-01
One of the most important problems in patients on hemodialysis (HD) is chronic malnutrition. This study is aimed to assess the prevalence of malnutrition using a subjective global assessment (SGA) in HD patients referred to the Valie ASR Hospital, Arak, Iran. In this descriptive analysis study, 190 HD patients were selected with random sampling. SGA and anthropometric and biochemical measurements were assessed in all patients. Data were analyzed with the Chi-square and t-tests and Pearson correlation coefficient. P correlation of SGA score with patient's weight (r = -0.147) and patient's body mass index (BMI) (r = -0.238). Also, it correlated significantly with duration of dialysis treatment (years) (r = 0.404). The SGA score showed a significant negative correlation with mid-arm circumference (MAC) (r = - 0.152). No significant correlation was found between SGA score and mid-arm muscle area. Our study showed that >50% of patients on maintenance HD had mild or moderate malnutrition. There was no case of severe malnutrition. Duration of dialysis treatment and some anthropometric indices (weight, BMI and MAC) also showed a significant correlation with SGA score, which are important to determine the nutritional status of HD patients.
The classical correlation limits the ability of the measurement-induced average coherence
Zhang, Jun; Yang, Si-ren; Zhang, Yang; Yu, Chang-shui
2017-01-01
Coherence is the most fundamental quantum feature in quantum mechanics. For a bipartite quantum state, if a measurement is performed on one party, the other party, based on the measurement outcomes, will collapse to a corresponding state with some probability and hence gain the average coherence. It is shown that the average coherence is not less than the coherence of its reduced density matrix. In particular, it is very surprising that the extra average coherence (and the maximal extra average coherence with all the possible measurements taken into account) is upper bounded by the classical correlation of the bipartite state instead of the quantum correlation. We also find the sufficient and necessary condition for the null maximal extra average coherence. Some examples demonstrate the relation and, moreover, show that quantum correlation is neither sufficient nor necessary for the nonzero extra average coherence within a given measurement. In addition, the similar conclusions are drawn for both the basis-dependent and the basis-free coherence measure. PMID:28374756
Speciated Fine Particle Deposition to a Forest Canopy Measured by Eddy-Correlation Mass Spectrometry
Allen, J. O.; Gonzales, D. A.; Delia, A. E.; Jimenez, J. L.; Smith, K. A.; Canagaratna, M.; Jayne, J. T.; Worsnop, D. R.
2002-12-01
Dry deposition serves as an important mechanism for the removal particles from the atmosphere and for the addition of material to ecosystems. Here we report on measurements of aerosol particle deposition using eddy-correlation mass spectrometry data collected during the PROPHET 2001 study which was conducted at the University of Michigan Biological Station in a north Michigan forest. Aerosol composition was measured with fast time response using the recently-developed Aerodyne Aerosol Mass Spectrometer (AMS) (Jayne et~al.,~2000). In the AMS, particles were focused using an aerodynamic lens. The aerosol was then expanded into a vacuum where aerodynamic particle size is determined by particle time-of-flight. The particles were then directed to an oven where semi-volatile components were flash vaporized. Vaporized components were ionized by electron impaction and detected using a quadrupole mass spectrometer. Thus the response of characteristic ions from fine aerosol particles (particle diameter, Dp, = 0.04-1.5 μm) were measured with a frequency of 10 Hz. A sonic anemometer was also deployed to measure wind velocity with a frequency of 10 Hz. Fluxes of aerosol species were then calculated using the well-known eddy-correlation method as the covariance of the vertical wind speed and the species concentration. These results demonstrate the new eddy-correlation mass spectrometry technique for measuring directly speciated fine particle deposition rates.
Nursing workload measurement scales in Intensive Care Units. Correlation between NAS and NEMS
Directory of Open Access Journals (Sweden)
Montserrat Martínez Lareo
2011-11-01
Full Text Available The high costs of intensive care and the importance of patient safety and quality of care highlight the need to develop instrument to measure, as precisely as possible, nursing workload and staffing levels in intensive care. To assess the ideal staff number, we need instruments to measure the real nursing workload. The aim of this research is to compare two nursing workload measurement scales in Intensive Care Units, the Nursing Activities Score (NAS and Nine Equivalents of Nurse Manpower Use Score (NEMS. We also want to assess the staffing needs of our ICU. A descriptive correlational study will be performed in a mixed medical ICU. The sample will be composed of of a minimum of 70 patients. Data regarding individual patients and unit global workload will be recorded, measured both with the NEMS and NAS scales. The required nursing staff will be calculated according to the measured workload. Nursing staffing needs using both scales will be calculated and compared to the actual staff. A descriptive analysis of the variables will be performed, and the existing correlation between both scales will be assessed using the Pearson correlation coefficient. A Student-t test will be performed to determine the differences between the calculated staffing requirements and the actual nursing staff. All data analyses will be done using a statistical software.
Joint measurement of lensing–galaxy correlations using SPT and DES SV data
Energy Technology Data Exchange (ETDEWEB)
Baxter, E.; Clampitt, J.; Giannantonio, T.; Dodelson, S.; Jain, B.; Huterer, D.; Bleem, L.; Crawford, T.; Efstathiou, G.; Fosalba, P.; Kirk, D.; Kwan, J.; Sánchez, C.; Story, K.; Troxel, M. A.; Abbott, T. M. C.; Abdalla, F. B.; Armstrong, R.; Benoit-Lévy, A.; Benson, B.; Bernstein, G. M.; Bernstein, R. A.; Bertin, E.; Brooks, D.; Carlstrom, J.; Rosell, A. Carnero; Carrasco Kind, M.; Carretero, J.; Chown, R.; Crocce, M.; Cunha, C. E.; da Costa, L. N.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Evrard, A. E.; Fausti Neto, A.; Flaugher, B.; Frieman, J.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; de Haan, T.; Holder, G.; Honscheid, K.; Hou, Z.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Lima, M.; March, M.; Marshall, J. L.; Martini, P.; Melchior, P.; Miller, C. J.; Miquel, R.; Mohr, J. J.; Nord, B.; Omori, Y.; Plazas, A. A.; Reichardt, C.; Romer, A. K.; Rykoff, E. S.; Sanchez, E.; Sevilla-Noarbe, I.; Sheldon, E.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Stark, A.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Walker, A. R.; Wechsler, R. H.
2016-07-04
We measure the correlation of galaxy lensing and cosmic microwave background lensing with a set of galaxies expected to trace the matter density field. The measurements are performed using pre-survey Dark Energy Survey (DES) Science Verification optical imaging data and millimetre-wave data from the 2500 sq. deg. South Pole Telescope Sunyaev–Zel'dovich (SPT-SZ) survey. The two lensing–galaxy correlations are jointly fit to extract constraints on cosmological parameters, constraints on the redshift distribution of the lens galaxies, and constraints on the absolute shear calibration of DES galaxy-lensing measurements. We show that an attractive feature of these fits is that they are fairly insensitive to the clustering bias of the galaxies used as matter tracers. The measurement presented in this work confirms that DES and SPT data are consistent with each other and with the currently favoured Λ cold dark matter cosmological model. It also demonstrates that joint lensing–galaxy correlation measurement considered here contains a wealth of information that can be extracted using current and future surveys.
Roga, W.; Spehner, D.; Illuminati, F.
2016-06-01
We investigate and compare three distinguished geometric measures of bipartite quantum correlations that have been recently introduced in the literature: the geometric discord, the measurement-induced geometric discord, and the discord of response, each one defined according to three contractive distances on the set of quantum states, namely the trace, Bures, and Hellinger distances. We establish a set of exact algebraic relations and inequalities between the different measures. In particular, we show that the geometric discord and the discord of response based on the Hellinger distance are easy to compute analytically for all quantum states whenever the reference subsystem is a qubit. These two measures thus provide the first instance of discords that are simultaneously fully computable, reliable (since they satisfy all the basic Axioms that must be obeyed by a proper measure of quantum correlations), and operationally viable (in terms of state distinguishability). We apply the general mathematical structure to determine the closest classical-quantum state of a given state and the maximally quantum-correlated states at fixed global state purity according to the different distances, as well as a necessary condition for a channel to be quantumness breaking.
Measuring Distance Ratios with CMB-Galaxy Lensing Cross-correlations
Das, Sudeep; 10.1103/PhysRevD.79.043509
2009-01-01
We propose a method for cosmographic measurements by combining gravitational lensing of the cosmic microwave background (CMB) with cosmic shear surveys. We cross-correlate the galaxy counts in the lens plane with two different source planes: the CMB at $z \\sim 1100$ and galaxies at an intermediate redshift. The ratio of the galaxy count/CMB lensing cross-correlation to the galaxy count/galaxy lensing cross correlation is shown to be a purely geometric quantity, depending only on the distribution function of the source galaxies. By combining Planck, ADEPT and LSST the ratio can be measured to $\\sim 4%$ accuracy, whereas a future polarization based experiment like CMBPOL can make a more precise ($\\sim 1%$) measurement. For cosmological models where the curvature and the equation of state parameter are allowed to vary, the direction of degeneracy defined by the measurement of this ratio is different from that traced out by Baryon Acoustic Oscillation (BAO) measurements. Combining this method with the stacked clu...
Tsai, Miao-Yu
2017-04-15
The concordance correlation coefficient (CCC) is a commonly accepted measure of agreement between two observers for continuous responses. This paper proposes a generalized estimating equations (GEE) approach allowing dependency between repeated measurements over time to assess intra-agreement for each observer and inter- and total agreement among multiple observers simultaneously. Furthermore, the indices of intra-, inter-, and total agreement through variance components (VC) from an extended three-way linear mixed model (LMM) are also developed with consideration of the correlation structure of longitudinal repeated measurements. Simulation studies are conducted to compare the performance of the GEE and VC approaches for repeated measurements from longitudinal data. An application of optometric conformity study is used for illustration. In conclusion, the GEE approach allowing flexibility in model assumptions and correlation structures of repeated measurements gives satisfactory results with small mean square errors and nominal 95% coverage rates for large data sets, and when the assumption of the relationship between variances and covariances for the extended three-way LMM holds, the VC approach performs outstandingly well for all sample sizes. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
Joint measurement of lensing-galaxy correlations using SPT and DES SV data
Baxter, E.; Clampitt, J.; Giannantonio, T.; Dodelson, S.; Jain, B.; Huterer, D.; Bleem, L.; Crawford, T.; Efstathiou, G.; Fosalba, P.; Kirk, D.; Kwan, J.; Sánchez, C.; Story, K.; Troxel, M. A.; Abbott, T. M. C.; Abdalla, F. B.; Armstrong, R.; Benoit-Lévy, A.; Benson, B.; Bernstein, G. M.; Bernstein, R. A.; Bertin, E.; Brooks, D.; Carlstrom, J.; Rosell, A. Carnero; Carrasco Kind, M.; Carretero, J.; Chown, R.; Crocce, M.; Cunha, C. E.; da Costa, L. N.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Evrard, A. E.; Fausti Neto, A.; Flaugher, B.; Frieman, J.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; de Haan, T.; Holder, G.; Honscheid, K.; Hou, Z.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Lima, M.; March, M.; Marshall, J. L.; Martini, P.; Melchior, P.; Miller, C. J.; Miquel, R.; Mohr, J. J.; Nord, B.; Omori, Y.; Plazas, A. A.; Reichardt, C.; Romer, A. K.; Rykoff, E. S.; Sanchez, E.; Sevilla-Noarbe, I.; Sheldon, E.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Stark, A.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Walker, A. R.; Wechsler, R. H.
2016-10-01
We measure the correlation of galaxy lensing and cosmic microwave background lensing with a set of galaxies expected to trace the matter density field. The measurements are performed using pre-survey Dark Energy Survey (DES) Science Verification optical imaging data and millimetre-wave data from the 2500 sq. deg. South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) survey. The two lensing-galaxy correlations are jointly fit to extract constraints on cosmological parameters, constraints on the redshift distribution of the lens galaxies, and constraints on the absolute shear calibration of DES galaxy-lensing measurements. We show that an attractive feature of these fits is that they are fairly insensitive to the clustering bias of the galaxies used as matter tracers. The measurement presented in this work confirms that DES and SPT data are consistent with each other and with the currently favoured Λ cold dark matter cosmological model. It also demonstrates that joint lensing-galaxy correlation measurement considered here contains a wealth of information that can be extracted using current and future surveys.
Laporte, Catherine; Arbel, Tal
2008-01-01
In freehand 3-D ultrasound (US), the relative positions of US images are usually measured using a position tracking device despite its cumbersome nature. The probe trajectory can instead be estimated from image data, using registration techniques to recover in-plane motion and speckle decorrelation to recover out-of-plane transformations. The relationship between speckle decorrelation and elevational separation is typically represented by a single curve, estimated from calibration data. Distances read off such a curve are corrupted by bias and uncertainty, and only provide an absolute estimate of elevational displacement. This paper presents a probabilistic model of the relationship between correlation measurements and elevational separation. This representation captures the skewed distribution of distance estimates based on high correlations and the uncertainties attached to each measurement. Multiple redundant correlation measurements can then be integrated within a maximum likelihood estimation framework. This paper also introduces a new method based on the traveling salesman problem for resolving sign ambiguities in data sets resulting from nonmonotonic probe motion and frame intersections. Experiments with real and synthetic US data show that by combining these new methods, out-of-plane US probe motion is recovered with improved accuracy over baseline methods using a deterministic model and fewer measurements.
Application of Digital Image Correlation to Measurement of Packaging Material Mechanical Properties
Directory of Open Access Journals (Sweden)
Jian-Wei Zhou
2013-01-01
Full Text Available Among various packaging materials, papers and polymer plastics are the most common due to their light weights, low costs, and other advantages. However, their mechanical properties are difficult to measure precisely because of their softness. To overcome the difficulty, a new measure instrument prototype is proposed based on an optical method known as the digital image correlation (DIC. Experiments are designed to apply the DIC to measure mechanical properties of flexible packaging materials, including the stress-strain relationship, the Poisson ratio, the coefficient of heat expansion, the creep deformation, and the top-pressure deformation of corrugated box. In addition, the low frequency vibration of package is simulated, and the vibration frequencies are measured by DIC. Results obtained in the experiments illustrate the advantages of the DIC over traditional methods: noncontact, no reinforced effect, high precision over entire area, wide measurement range, and good measurement stability.
Jizan, Iman; Xiong, Chunle; Collins, Matthew J; Choi, Duk-Yong; Chae, Chang Joon; Liscidini, Marco; Steel, M J; Eggleton, Benjamin J; Clark, Alex S
2014-01-01
The growing requirement for photon pairs with specific spectral correlations in quantum optics experiments has created a demand for fast, high resolution and accurate source characterization. A promising tool for such characterization uses the classical stimulated process, in which an additional seed laser stimulates photon generation yielding much higher count rates, as recently demonstrated for a $\\chi^{(2)}$ integrated source in A.~Eckstein \\emph{et al.}, Laser Photon. Rev. \\textbf{8}, L76 (2014). In this work we extend these results to $\\chi^{(3)}$ sources, demonstrating spectral correlation measurements via stimulated four-wave mixing for the first time in a integrated optical waveguide, namely a silicon nanowire. We directly confirm the speed-up due to higher count rates and demonstrate that additional resolution can be gained when compared to traditional coincidence measurements. As pump pulse duration can influence the degree of spectral entanglement, all of our measurements are taken for two differen...
Tensor Correlations Measured in 3He(e,e'pp)n
Baghdasaryan, H; Laget, J M; Adhikari, K P; Aghasyan, M; Amarian, M; Anghinolfi, M; Avakian, H; Ball, J; Battaglieri, M; Bedlinskiy, I; Berman, B L; Biselli, A S; Bookwalter, C; Briscoe, W J; Brooks, W K; B?ultmann, S; Burkert, V D; Carman, D S; Crede, V; D'Angelo, A; Daniel, A; Dashyan, N; DeVita, R; DeSanctis, E; Deur, A; Dey, B; Dickson, R; Djalali, C; Dodge, G E; Doughty, D; Dupre, R; Egiyan, H; Alaoui, A El; Fassi, L El; Eugenio, P; Fegan, S; Gabrielyan, M Y; Gilfoyle, G P; Giovanetti, K L; Gohn, W; Gothe, R W; Griffioen, K A; Guidal, M; Guo, L; Gyurjyan, V; Hakobyan, H; Hanretty, C; Hyde, C E; Hicks, K; Holtrop, M; Ilieva, Y; Ireland, D G; Joo, K; Keller, D; Khandaker, M; Khetarpal, P; Kim, A; Kim, W; Klein, A; Klein, F J; Konczykowski, P; Kubarovsky, V; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Kvaltine, N D; Livingston, K; Lu, H Y; MacGregor, I J D; Markov, N; Mayer, M; McAndrew, J; McKinnon, B; Meyer, C A; Mikhailov, K; Mokeev, V; Moreno, B; Moriya, K; Morrison, B; Moutarde, H; Munevar, E; Nadel-Turonski, P; Nepali, C; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Paremuzyan, R; Park, K; Park, S; Pasyuk, E; Pereira, S Anefalos; Pisano, S; Pogorelko, O; Pozdniakov, S; Price, J W; Procureur, S; Protopopescu, D; Ricco, G; Ripani, M; Rosner, G; Rossi, P; Sabati?e, F; Salgado, C; Schumacher, R A; Seraydaryan, H; Smith, G D; Sober, D I; Sokhan, D; Stepanyan, S S; Stepanyan, S; Stoler, P; Strauch, S; Taiuti, M; Tang, W; Taylor, C E; Tedeschi, D J; Ungaro, M; Vineyard, M F; Voutier, E; Watts, D P; Weygand, D P; Wood, M H; Zhao, B; Zhao, Z W
2010-01-01
We have measured the 3He(e,e'pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum, $p_{tot}$. For pair relative momenta between 0.3 and 0.5 GeV/c, the ratio is very small at low $p_{tot}$ and rises to approximately 0.5 at large $p_{tot}$. This shows the dominance of tensor over central correlations at this relative momentum.
Tensor Correlations Measured in 3He(e,e'pp)n
Energy Technology Data Exchange (ETDEWEB)
Baghdasaryan, H; Weinstein, L B; Adhikari, K P; Aghasyan, K P; Amarian, M; Anghinolfi, M; Avakian, H; Ball, J; Battaglieri, M; Bedlinskiy, I; Berman, B L; Biselli, A S; Bookwalter, C; Briscoe, W J; Brooks, W K; Boltmann, S; Burkert, V D; Carman, D S; Crede, V; D& #x27; Angelo, A; Daniel, A; Dashyan, N; DeVita, R; DeSanctis, E; Deur, A; Dey, B; Dickson, R; Djalali, C; Dodge, G E; Doughty, D; Dupre, R; Egiyan, H; El Alaoui, A; El Fassi, L; Eugenio, P; Fegan, S; Gabrielyan, M Y; Gilfoyle, G P; Giovanetti, K L; Gohn, W; Gothe, R W; Griffioen, K A; Guidal, M; Guo, L; Gyurjyan, V; Hakobyan, H; Hanretty, C; Hyde, C E; Hicks, K; Holtrop, M; Ilieva, Y; Ireland, D G; Joo, K; Keller, D; Khandaker, M; Khetarpal, P; Kim, A; Kim, W; Klein, A; Klein, F J; Konczykowski, P; Kubarovsky, V; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Kvaltine, N D; Livingston, K; Lu, H Y; MacGregor, I.J.D.; Markov, N; Mayer, M; McAndrew, J; McKinnon, B; Meyer, C A; Mikhailov, K; Mokeev, V; Moreno, B; Moriya, K; Morrison, B; Moutarde, H; Munevar, E; Nadel-Turonski, P; Nepali, C; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Paremuzyan, R; Park, K; Park, S; Pasyuk, E; Anefalos Pereira, S; Pisano, S; Pogorelko, O; Pozdniakov, S; Price, J W; Procureur, S; Protopopescu, D; Ricco, G; Ripani, M; Rosner, G; Rossi, P; Sabatie, F; Salgado, C; Schumacher, R A; Seraydaryan, H; Smith, G D; Sober, D I; Sokhan, D; Stepanyan, S S; Stepanyan, S; Stoler, P; Strauch, S; Taiuti, M; Tang, W; Taylor, C E; Tedeschi, D J; Ungaro, M; Vineyard, M F; Voutier, E; Watts, D P; Weygand, D P; Wood, M H; Zhao, B; Zhao, Z W
2010-11-01
We have measured the 3He(e,e'pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs by using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum ptot. For pair relative momenta between 0.3 and 0.5 GeV/c, the ratio is very small at low ptot and rises to approximately 0.5 at large ptot. This shows the dominance of tensor over central correlations at this relative momentum.
Validation of MIPAS-ENVISAT by Correlative Measurements of MIPAS-STR
Keim, C.; Blom, C. E.; von der Gathen, P.; Gulde, T.; Höpfner, M.; Liu, G. Y.; Oulanovski, A.; Piesch, C.; Ravegnani, F.; Sartorius, C.; Schlager, H.; Volk, C. M.
2004-08-01
We report on the validation of profiles from the MIPAS-Envisat on-line processor of ESA version 4.61 with correlative measurements derived from MIPASSTR onboard the high-altitude aircraft M55-Geophysica. The validation is made for the July 22, 2002, orbit 2051 in the region of the campaign base in Forlí, Italy [1] and for several orbits in February / March 2003 around Kiruna, northern Sweden. This paper includes a careful comparison of the MIPASSTR data with O3 sondes and with in-situ measurements from the Geophysica obtained during ascent, descent and occasional dives. To obtain accurate N2O and CH4 profiles close to the MIPAS-Envisat tangent points we used the MIPAS-STR measurements of CFC-11 and CFC-12 and correlations [2] obtained by the HAGAR instrument.
Wallman, Joel J
2011-01-01
Quantum theory allows for correlations between the outcomes of distant measurements that are inconsistent with any locally causal theory, as demonstrated by the violation of a Bell inequality. Typical demonstrations of these correlations require careful alignment between the measurements, which requires distant parties to share a reference frame. Here, we prove, following a numerical observation by Shadbolt et al., that if two parties share a Bell state and each party randomly chooses three orthogonal measurements, then the parties will always violate a Bell inequality. Furthermore, we prove that this probability is highly robust against local depolarizing noise, in that small levels of noise only decrease the probability of violating a Bell inequality by a small amount. We also show that generalizing to N parties increases the robustness against noise. These results improve on previous ones that only allowed a high probability of violating a Bell inequality for large numbers of parties.
Measurement of Polarization and Triple-Product Correlations in B -> phi K^* Decays
Abe, K
2004-01-01
We present a measurement of the decay amplitudes and triple-product correlations in B -> phi K^* decays based on 140 fb^-1 of data recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB e^+ e^- storage ring. The decay amplitudes for the different phi K^* helicity states are measured from the angular distributions of final state particles in the transversity basis. The longitudinal and transverse complex amplitude moduli and angles are |A_0|^2 = 0.51 +- 0.06 +- 0.04, |A_perp|^2 = 0.24 +- 0.06 +- 0.03, arg(A_parallel) = -2.21 +- 0.22 +- 0.05 rad, and arg(A_perp) = 0.72 +- 0.21 +- 0.06 rad. The T-violating asymmetries through triple-product correlations are measured to be consistent with zero.
Quantized correlation coefficient for measuring reproducibility of ChIP-chip data.
Peng, Shouyong; Kuroda, Mitzi I; Park, Peter J
2010-07-27
Chromatin immunoprecipitation followed by microarray hybridization (ChIP-chip) is used to study protein-DNA interactions and histone modifications on a genome-scale. To ensure data quality, these experiments are usually performed in replicates, and a correlation coefficient between replicates is used often to assess reproducibility. However, the correlation coefficient can be misleading because it is affected not only by the reproducibility of the signal but also by the amount of binding signal present in the data. We develop the Quantized correlation coefficient (QCC) that is much less dependent on the amount of signal. This involves discretization of data into set of quantiles (quantization), a merging procedure to group the background probes, and recalculation of the Pearson correlation coefficient. This procedure reduces the influence of the background noise on the statistic, which then properly focuses more on the reproducibility of the signal. The performance of this procedure is tested in both simulated and real ChIP-chip data. For replicates with different levels of enrichment over background and coverage, we find that QCC reflects reproducibility more accurately and is more robust than the standard Pearson or Spearman correlation coefficients. The quantization and the merging procedure can also suggest a proper quantile threshold for separating signal from background for further analysis. To measure reproducibility of ChIP-chip data correctly, a correlation coefficient that is robust to the amount of signal present should be used. QCC is one such measure. The QCC statistic can also be applied in a variety of other contexts for measuring reproducibility, including analysis of array CGH data for DNA copy number and gene expression data.
Electron transport parameters in CO$_2$: scanning drift tube measurements and kinetic computations
Vass, M; Loffhagen, D; Pinhao, N; Donko, Z
2016-01-01
This work presents transport coefficients of electrons (bulk drift velocity, longitudinal diffusion coefficient, and effective ionization frequency) in CO2 measured under time-of-flight conditions over a wide range of the reduced electric field, 15Td <= E/N <= 2660Td in a scanning drift tube apparatus. The data obtained in the experiments are also applied to determine the effective steady-state Townsend ionization coefficient. These parameters are compared to the results of previous experimental studies, as well as to results of various kinetic computations: solutions of the electron Boltzmann equation under different approximations (multiterm and density gradient expansions) and Monte Carlo simulations. The experimental data extend the range of E/N compared with previous measurements and are consistent with most of the transport parameters obtained in these earlier studies. The computational results point out the range of applicability of the respective approaches to determine the different measured tr...
Energy Technology Data Exchange (ETDEWEB)
Dorado, B.
2010-09-15
Uranium dioxide UO{sub 2} is the standard nuclear fuel used in pressurized water reactors. During in-reactor operation, the fission of uranium atoms yields a wide variety of fission products (FP) which create numerous point defects while slowing down in the material. Point defects and FP govern in turn the evolution of the fuel physical properties under irradiation. In this study, we use electronic structure calculations in order to better understand the fuel behavior under irradiation. In particular, we investigate point defect behavior, as well as the stability of three volatile FP: iodine, krypton and xenon. In order to take into account the strong correlations of uranium 5f electrons in UO{sub 2}, we use the DFT+U approximation, based on the density functional theory. This approximation, however, creates numerous metastable states which trap the system and induce discrepancies in the results reported in the literature. To solve this issue and to ensure the ground state is systematically approached as much as possible, we use a method based on electronic occupancy control of the correlated orbitals. We show that the DFT+U approximation, when used with electronic occupancy control, can describe accurately point defect and fission product behavior in UO{sub 2} and provide quantitative information regarding point defect transport properties in the oxide fuel. (author)
Studies of the dimensionality, correlates, and meaning of measures of the maximizing tendency
Directory of Open Access Journals (Sweden)
Hye Bin Rim
2011-08-01
Full Text Available This series of four studies was designed to clarify the underlying dimensionality and psychological well-being correlates of the major extant measures of the maximization tendency: the Maximization Scale (MS; Schwarz et al., 2002 and the Maximization Tendency Scale (MTS; Diab et al., 2008. Four studies using psychometric and factor analysis, item response theory (IRT, and an experimental manipulation all supported the following conclusions. The MS does measure three separate factors as postulated by its authors, but only two of them (alternative search and decisional difficulty are correlated with each other and (negatively with indices of well-being as postulated by the scale authors; high standards, the third factor, correlated strongly with the MTS, and both of these were strongly correlated with positive indices of well-being (optimism and happiness and functioning (e.g., self-esteem and self-efficacy. The high standards subscale and MTS were related to analytical decision making style, while alternative search and decision difficulty were related to the regret-based decision making style and to procrastination. The IRT analysis indicated serious weaknesses in the measurement capabilities of existing scales, and the findings of the experimental study confirmed that alternative search and decision difficulty are related to the maximization tendency while high standards and MTS are not. Implications for further research and scale development are discussed.
Measurement of long-range particle correlations in small systems with the ATLAS detector
Milov, Alexander; The ATLAS collaboration
2016-01-01
Study of particle correlations is an important instrument to understand the nature of relativistic heavy ion collisions. Using a wealth of new data available from the recent heavy ion runs of Large Hadron Collider at CERN it becomes possible to study particle correlations in different collisions systems under the same conditions. The results of several recent measurement performed by the ATLAS experiment are reviewed in this proceeding. Measurements are performed in various techniques in $pp$, $p+$Pb and PbPb collisions at the energies $\\sqrt{s_{_{\\rm{NN}}}}$, $\\sqrt{s}$ from 2.76 to 13 TeV. The results are compared between the systems having the same charged particle multiplicities in the final state, but different initial geometries. Results for multiplicity correlations, two-particle and muti-particle correlations measured in different techniques are presented and discussed. The goal of these comparison is to make further steps in understanding the nature of fluctuations observed in the small collisions sy...
Local transport measurements at mesoscopic length scales using scanning tunneling potentiometry.
Wang, Weigang; Munakata, Ko; Rozler, Michael; Beasley, Malcolm R
2013-06-07
Under mesoscopic conditions, the transport potential on a thin film carrying a current is theoretically expected to bear spatial variation due to quantum interference. Scanning tunneling potentiometry is the ideal tool to investigate such variation, by virtue of its high spatial resolution. We report in this Letter the first detailed measurement of transport potential under mesoscopic conditions. Epitaxial graphene at a temperature of 17 K was chosen as the initial system for study because the characteristic transport length scales in this material are relatively large. Tip jumping artifacts are a major possible contribution to systematic errors; and we mitigate such problems by using custom-made slender and sharp tips manufactured by focused ion beam. In our data, we observe residual resistivity dipoles associated with topographical defects, and local peaks and dips in the potential that are not associated with topographical defects.
Charonko, John J.; Vlachos, Pavlos P.
2013-06-01
Numerous studies have established firmly that particle image velocimetry (PIV) is a robust method for non-invasive, quantitative measurements of fluid velocity, and that when carefully conducted, typical measurements can accurately detect displacements in digital images with a resolution well below a single pixel (in some cases well below a hundredth of a pixel). However, to date, these estimates have only been able to provide guidance on the expected error for an average measurement under specific image quality and flow conditions. This paper demonstrates a new method for estimating the uncertainty bounds to within a given confidence interval for a specific, individual measurement. Here, cross-correlation peak ratio, the ratio of primary to secondary peak height, is shown to correlate strongly with the range of observed error values for a given measurement, regardless of flow condition or image quality. This relationship is significantly stronger for phase-only generalized cross-correlation PIV processing, while the standard correlation approach showed weaker performance. Using an analytical model of the relationship derived from synthetic data sets, the uncertainty bounds at a 95% confidence interval are then computed for several artificial and experimental flow fields, and the resulting errors are shown to match closely to the predicted uncertainties. While this method stops short of being able to predict the true error for a given measurement, knowledge of the uncertainty level for a PIV experiment should provide great benefits when applying the results of PIV analysis to engineering design studies and computational fluid dynamics validation efforts. Moreover, this approach is exceptionally simple to implement and requires negligible additional computational cost.
Measurement of ttbar Spin Correlation in ppbar Collisions Using the CDF II Detector at the Tevatron
al., T Aaltonen et
2010-01-01
The ttbar spin correlation at production is a fundamental prediction of QCD and a potentially incisive test of new physics coupled to top quarks. We measure the ttbar spin state in ppbar collisions at sqrt(s) = 1.96 TeV using 1001 candidate events in the lepton plus jets decay channel reconstructed in the CDF II detector. In the helicity basis, for a top-quark mass of 172.5 GeV/c^2, we find a spin correlation coefficient kappa = 0.60 +/- 0.50 (stat) +/- 0.16 (syst), consistent with the QCD prediction, kappa ~= 0.40.
Lebreton, A; Abram, I; Braive, R; Sagnes, I; Robert-Philip, I; Beveratos, A
2013-04-19
We present a novel experimental technique that can differentiate unequivocally between chaotic light and coherent light with amplitude fluctuations, and thus permits us to characterize unambiguously the output of a laser. This technique consists of measuring the second-order intensity cross correlation at the outputs of an unbalanced Michelson interferometer. It is applied to a chaotic light source and to the output of a semiconductor nanolaser whose "standard" intensity correlation function above threshold displays values compatible with a mixture of coherent and chaotic light. Our experimental results demonstrate that the output of such lasers is not partially chaotic but is indeed a coherent state with amplitude fluctuations.
Correlates of objectively measured physical activity in 5-6 year old preschool children
DEFF Research Database (Denmark)
Olesen, L G; Kristensen, P L; Korsholm, L;
2015-01-01
preschools. Percentage of total daily time spent in moderate and vigorously physical activity (MVPA) was measured using ActiGraph accelerometers over 5 preschool days and 2 days off. Thirty--nine potential correlates of child MVPA across 5 domains were tested for associations with gender specific MVPA......The aim of this study was to identify gender specific physical activity correlates in Danish preschool children. METHODS: Cross--sectional study in Odense, Denmark. The gender specific models were based on data from 174 boys and 177 girls, 5--6 years of age and enrolled in 40 randomly selected...
Lebreton, Armand; Braive, Rémy; Sagnes, Isabelle; Robert-Philip, Isabelle; Beveratos, Alexios
2013-01-01
We present a novel experimental technique that can differentiate unequivocally between chaotic light and coherent light with amplitude fluctuations, and thus permits to characterize unambiguously the output of a laser. This technique consists of measuring the second-order intensity cross-correlation at the outputs of an unbalanced Michelson interferometer. It is applied to a chaotic light source and to the output of a semiconductor nanolaser whose "standard" intensity correlation function above-threshold displays values compatible with a mixture of coherent and chaotic light. Our experimental results demonstrate that the output of such lasers is not partially chaotic but is indeed a coherent state with amplitude fluctuations.
Energy Technology Data Exchange (ETDEWEB)
Zhang, J.; Chowdhury, S.; Messac, A.; Hodge, B. M.
2013-08-01
This paper significantly advances the hybrid measure-correlate-predict (MCP) methodology, enabling it to account for variations of both wind speed and direction. The advanced hybrid MCP method uses the recorded data of multiple reference stations to estimate the long-term wind condition at a target wind plant site. The results show that the accuracy of the hybrid MCP method is highly sensitive to the combination of the individual MCP algorithms and reference stations. It was also found that the best combination of MCP algorithms varies based on the length of the correlation period.
Song repertoire size correlates with measures of body size in Eurasian blackbirds
DEFF Research Database (Denmark)
Hesler, Nana; Mundry, Roger; Sacher, Thomas;
2012-01-01
organisation. Here we investigated whether repertoire size in Eurasian blackbirds correlates with measures of body size, namely length of wing, 8th primary, beak and tarsus. So far, very few studies have investigated species with large repertoires and a flexible song organisation in this context. We found...... positive correlations, meaning that larger males had larger repertoires. Larger males may have better fighting abilities and, thus, advantages in territorial defence. Larger structural body size may also reflect better conditions during early development. Therefore, under the assumption that body size...