Quantum tomography of mesoscopic superpositions of radiation states

We show the feasibility of a tomographic reconstruction of Schr\"{o}dinger cat states generated according to the scheme proposed by S. Song, C.M. Caves and B. Yurke [Phys. Rev. A 41, 5261 (1990)]. We present a technique that tolerates realistic values for quantum efficiency at photodetectors. The measurement can be achieved by a standard experimental setup.Comment: Submitted to Phys. Rev. Lett.; 4 pages including 6 ps figure

A step towards testing general relativity using weak gravitational lensing and redshift surveys

Using the linear theory of perturbations in General Relativity, we express a set of consistency relations that can be observationally tested with current and future large scale structure surveys. We then outline a stringent model-independent program to test gravity on cosmological scales. We illustrate the feasibility of such a program by jointly using several observables like peculiar velocities, galaxy clustering and weak gravitational lensing. After addressing possible observational or astrophysical caveats like galaxy bias and redshift uncertainties, we forecast in particular how well one can predict the lensing signal from a cosmic shear survey using an over-lapping galaxy survey. We finally discuss the specific physics probed this way and illustrate how $f(R)$ gravity models would fail such a test.Comment: 12 pages, 10 figure

Hopping motion of lattice gases through nonsymmetric potentials under strong bias conditions

The hopping motion of lattice gases through potentials without mirror-reflection symmetry is investigated under various bias conditions. The model of 2 particles on a ring with 4 sites is solved explicitly; the resulting current in a sawtooth potential is discussed. The current of lattice gases in extended systems consisting of periodic repetitions of segments with sawtooth potentials is studied for different concentrations and values of the bias. Rectification effects are observed, similar to the single-particle case. A mean-field approximation for the current in the case of strong bias acting against the highest barriers in the system is made and compared with numerical simulations. The particle-vacancy symmetry of the model is discussed.Comment: 8 pages (incl. 6 eps figures); RevTeX 3.

Fundamentals of the adhesion of physical vapor deposited ZnMg-Zn bilayer coatings to steel substrates

In the present study, ZnMg-Zn bilayer coatings with different Mg concentrations and layer thicknesses are deposited on steel substrates by a thermal evaporation process. Thermodynamic calculations reveal that the work of adhesion at the ZnMg/Zn interface (~1.6 J/m2) is lower than that at the Zn/Steel interface (~3 J/m2). This indicates that the ZnMg/Zn interface is inherently weaker than the interface between Zn and steel substrate. The interfacial adhesion strength quantified by the scratch test shows that the adhesion strength at the ZnMg/Zn interface decreases with increasing the Mg content and reaches 66 MPa at 16.5 wt% Mg. It is found that the presence of interfacial defects largely decreases the adhesion strength compared to a defect-free coating. Meanwhile, it is also concluded that the interfacial adhesion strength at the ZnMg/Zn interface does not depend on the thickness of Zn interlayer. The results of the present investigation show that the interfacial adhesion strength is not the only governing parameter for the adhesion performance of the ZnMg-Zn bilayer coatings in forming process, but the thickness of the layers as well as interfacial defect density also play important roles in the adhesion performance

Model of a fluid at small and large length scales and the hydrophobic effect

We present a statistical field theory to describe large length scale effects induced by solutes in a cold and otherwise placid liquid. The theory divides space into a cubic grid of cells. The side length of each cell is of the order of the bulk correlation length of the bulk liquid. Large length scale states of the cells are specified with an Ising variable. Finer length scale effects are described with a Gaussian field, with mean and variance affected by both the large length scale field and by the constraints imposed by solutes. In the absence of solutes and corresponding constraints, integration over the Gaussian field yields an effective lattice gas Hamiltonian for the large length scale field. In the presence of solutes, the integration adds additional terms to this Hamiltonian. We identify these terms analytically. They can provoke large length scale effects, such as the formation of interfaces and depletion layers. We apply our theory to compute the reversible work to form a bubble in liquid water, as a function of the bubble radius. Comparison with molecular simulation results for the same function indicates that the theory is reasonably accurate. Importantly, simulating the large length scale field involves binary arithmetic only. It thus provides a computationally convenient scheme to incorporate explicit solvent dynamics and structure in simulation studies of large molecular assemblies

Evaluation of interface adhesion of hot-dipped zinc coating on TRIP steel with tensile testing and finite element calculation

In this work, a methodology for the determination of the interface adhesion strength of zinc coating on TRIP steel is present. This method consists of a conventional tensile test in combination with finite element calculation. The relation between the average interface crack length and the applied tensile stress is determined on the partially delaminated coating with in-situ tensile test. The delamination process of zinc coating on steel substrate is simulated by using a two-grain finite element model with different interface adhesion strengths. By comparing the experimental observation with the finite element calculations, the interface adhesion strength is estimated. The interface adhesion strength of the zinc coating on transformation induced plasticity (TRIP) steel is found as high as 160 MPa. The influences of microstructural parameters of zinc coating including zinc grain orientation and grain size on the delamination behavior of the zinc coating are also analyzed with the finite element model

Conditional generation of sub-Poissonian light from two-mode squeezed vacuum via balanced homodyne detection on idler mode

A simple scheme for conditional generation of nonclassical light with sub-Poissonian photon-number statistics is proposed. The method utilizes entanglement of signal and idler modes in two-mode squeezed vacuum state generated in optical parametric amplifier. A quadrature component of the idler mode is measured in balanced homodyne detector and only those experimental runs where the absolute value of the measured quadrature is higher than certain threshold are accepted. If the threshold is large enough then the conditional output state of signal mode exhibits reduction of photon-number fluctuations below the coherent-state level.Comment: 7 pages, 6 figures, REVTe

Rural Hospital Mergers Increased Between 2005 and 2016—What Did Those Hospitals Look Like?

The objective of this study is to determine whether key hospital-level financial and market characteristics are associated with whether rural hospitals merge. Hospital merger status was derived from proprietary Irving Levin Associates data for 2005 through 2016 and hospital-level characteristics from HCRIS, CMS Impact File Hospital Inpatient Prospective Payment System, Hospital MSA file, AHRF, and U.S. Census data for 2004 through 2016. A discrete-time hazard analysis using generalized estimating equations was used to determine whether factors were associated with merging between 2005 and 2016. Factors included measures of profitability, operational efficiency, capital structure, utilization, and market competitiveness. Between 2005 and 2016, 11% (n = 326) of rural hospitals were involved in at least one merger. Rural hospital mergers have increased in recent years, with more than two-thirds (n = 261) occurring after 2011. The types of rural hospitals that merged during the sample period differed from nonmerged rural hospitals. Rural hospitals with higher odds of merging were less profitable, for-profit, larger, and were less likely to be able to cover current debt. Additional factors associated with higher odds of merging were reporting older plant age, not providing obstetrics, being closer to the nearest large hospital, and not being in the West region. By quantifying the hazard of characteristics associated with whether rural hospitals merged between 2005 and 2016, these findings suggest it is possible to determine leading indicators of rural mergers. This work may serve as a foundation for future research to determine the impact of mergers on rural hospitals

Optical and transport properties in doped two-leg ladder antiferromagnet

Within the t-J model, the optical and transport properties of the doped two-leg ladder antiferromagnet are studied based on the fermion-spin theory. It is shown that the optical and transport properties of the doped two-leg ladder antiferromagnet are mainly governed by the holon scattering. The low energy peak in the optical conductivity is located at a finite energy, while the resistivity exhibits a crossover from the high temperature metallic-like behavior to the low temperature insulating-like behavior, which are consistent with the experiments.Comment: 13 pages, 5 figures, accepted for publication in Phys. Rev. B65 (2002) (April 15 issue

Geomagnetic storm dependence on the solar flare class

Content. Solar flares are often used as precursors of geomagnetic storms. In particular, Howard and Tappin (2005) recently published in A&A a dependence between X-ray class of solar flares and Ap and Dst indexes of geomagnetic storms which contradicts to early published results. Aims. We compare published results on flare-storm dependences and discuss possible sources of the discrepancy. Methods. We analyze following sources of difference: (1) different intervals of observations, (2) different statistics and (3) different methods of event identification and comparison. Results. Our analysis shows that magnitude of geomagnetic storms is likely to be independent on X-ray class of solar flares.Comment: 3 pages, 1 tabl