Evidence for superconductivity in fluorinated La2CuO4 at 35 K: Microwave investigations

In the fluorinated La₂CuO_4−x prepared using a solid state reaction with NH₄HF₂ as a fluorinating agent at 550 K at ambient pressure, superconductivity was detected by microwave and EPR techniques with aT _c of 35 K.     

The nuclear response and the imaginary potential for nucleus-nucleus collisions

The Fermi-gas model is used in this paper to study the nucleus-nucleus collision. The field produced by one of the nuclei is considered to act on nucleons in the other nucleus, which is treated as a Fermi gas of radius R. The imaginary part of the (non-local) nucleus-nucleus potential is then computed by evaluating the energy-conserving second-order term in which the intermediate states are particle-hole excitations produced in the Fermi gas. The equivalent local potential, obtained by using the Perey-Saxon method, is compared with phenomenological imaginary potentials. Later it is shown that, in the limit of small range of non-locality, the imaginary potential can be related to the nuclear response function. With this, one can write the nuclear friction coefficient that is used in phenomenological analyses of heavy-ion collisions in terms of the imaginary potential.     

Exact probability propagators for motion with arbitrary degree of transport coherence

We present an explicit expression for porbability propagators for the motion of a quasiparticle in a one-dimensional crystal with arbitrary degree of transport coherence. The expression is exact, simple, and convenient for pratical computations, analytical as well as numerical.     

Synthesis,antimicrobial activity,and molecular docking study of formylnaphthalenyloxymethyl‐triazolyl‐N‐phenylacetamides

In the present study, substituted formylnaphthalenyloxymethyl‐triazolyl‐N‐phenylacetamide derivatives ( 6a – k ) have been designed and synthesized employing click chemistry approach and evaluated for their in vitro antifungal and antibacterial activities. All the newly synthesized compounds were thoroughly characterized by ¹H NMR, ¹³C NMR, and HRMS spectral techniques. Among the screened compounds, 6d , 6e , 6j , and 6k have shown good antifungal and antibacterial activities. Compound 6k has shown very effective antimicrobial activity. We further performed exploratory docking studies on microbial DNA gyrase to rationalize the in vitro biological data and to demonstrate the mechanism of antimicrobial activity. This is the first report to demonstrate the formylnaphthalenyloxymethyl, triazole, and N‐phenylacetamide hybrids as potential antimicrobial agents.     

A convolutional neural network approach to calibrating the rotation axis for X‐ray computed tomography

This paper presents an algorithm to calibrate the center‐of‐rotation for X‐ray tomography by using a machine learning approach, the Convolutional Neural Network (CNN). The algorithm shows excellent accuracy from the evaluation of synthetic data with various noise ratios. It is further validated with experimental data of four different shale samples measured at the Advanced Photon Source and at the Swiss Light Source. The results are as good as those determined by visual inspection and show better robustness than conventional methods. CNN has also great potential for reducing or removing other artifacts caused by instrument instability, detector non‐linearity, etc. An open‐source toolbox, which integrates the CNN methods described in this paper, is freely available through GitHub at tomography/xlearn and can be easily integrated into existing computational pipelines available at various synchrotron facilities. Source code, documentation and information on how to contribute are also provided.     

Quark matter formation in dense stellar objects

It is expected that at very large densities and/or temperatures a quark-hadron phase transition takes place. Lattice QCD calculations at zero baryon density indicate that the transition occurs at T _c ∼ 150–170 MeV. The transition is likely to be second order or a cross over phenomenon. Although not much is known about the density at which the phase transition takes place at small temperatures, it is expected to occur around the nuclear densities of few times nuclear matter density. Also, there is a strong reason to believe that the quark matter formed after the phase transition is in colour superconducting phase. The matter densities in the interior of neutron stars being larger than the nuclear matter density, the neutron star cores may possibly consist of quark matter which may be formed during the collapse of supernova. Starting with the assumption that the quark matter, when formed consists of predominantly u and d quarks, we consider the evolution of s quarks by weak interactions in the present work. The reaction rates and time required to reach the chemical equilibrium are computed here. Our calculations show that the chemical equilibrium is reached in about 10⁻⁷ seconds. Further more during the equilibration process enormous amont of energy is released and copious numbers of neutrinos are produced. Implications of these on the evolution of supernovae will be discussed.     

Non-intrinsic superconductivity in InN epilayers: Role of Indium Oxide

In recent years there have been reports of anomalous electrical resistivity and the presence of superconductivity in semiconducting InN layers. By a careful correlation of the temperature dependence of resistivity and magnetic susceptibility with structural information from high-resolution x-ray diffraction measurements, we show that superconductivity is not intrinsic to InN and is seen only in samples that show traces of oxygen impurity. We hence believe that InN is not intrinsically a superconducting semiconductor.     

Elliptic flow in a hadron-string cascade model at 130 GeV energy

We present the analysis of elliptic flow at =130 A GeV energy in a hadron-string cascade model. We find that the final hadronic yields are qualitatively described. The elliptic flow v ₂ is reasonably well-described at low transverse momentum (p t<1 GeV/c) in mid-central collisions. On the other hand, this model does not explain v ₂ at high p t or in peripheral collisions and thus generally, it underestimates the elliptic flow at RHIC energy.     

ICE: a new method for the multivariate curve resolution of hyperspectral images

The iterated constrained endmembers (ICE) algorithm is a new method of unmixing hyperspectral images that combines aspects of multivariate curve resolution (MCR) methods in chemometrics and unmixing algorithms in remote sensing. Like many MCR methods, ICE also estimates pure components, or endmembers, via alternating least squares; however, it is explicitly based on a convex geometry model and estimation is carried out in a subspace of reduced dimensionality defined by the minimum noise fraction (MNF) transform. In this paper, we describe the ICE algorithm and its properties. We also illustrate its use on a hyperspectral image of cervical tissue. The unmixing of hyperspectral images presents some unique challenges, and we also outline where further development is required. © 2008 John Wiley & Sons, Ltd.     

Impulse-approximation correction in pion-nucleus optical potential

The local density approximation is used in this paper to calculate the first-order pion-nucleus optical potential. TheπN scattering matrix in nuclear medium is computed by employing separableπN scattering matrix. This nuclear-mediumπN scattering matrix, which includes impulse-approximation correction is then used to construct the pion-nucleus optical potential.π-¹²C elastic scattering results obtained by using this potential are compared with the impulse-approximation potential results.