CeOx/Al2O3 thin films on stainless steel substrate - Dynamical X-ray photoelectron spectroscopy investigations

Cataloged from PDF version of article.The CeOx/Al2O3 thin films on stainless steel with different ceria loading were subjected to a. c. ( square wave) pulses at various frequencies in the range 10(-3) to 100 kHz while recording X-ray photoelectron spectra. The resulting binding energy differences were derived from the frequency dependence of the corresponding Al2p, Ce3d and O1s peaks. At low ceria loadings the main constituent on the surface is CeAlO3 phase, while for high ceria loading the film is constructed from CeO2 and CeAlO3 phases spread over the Al2O3. Accordingly, it was observed that the ceria loading determines the conductivities of the investigated thin oxide films. (C) 2013 Elsevier B.V. All rights reserved

Measurement of crack opening stresses and crack closure stress profiles from heat generation in vibrating cracks

A method is described to measure crack opening stresses and closure stress profiles of a surface-breaking crack. Vibration is used to generate frictional heat by rubbing crack face asperities. Heat is generated at regions of contacting crack asperities under low, but nonzero, closure stress. Increasing force is applied to incrementally open the crack and measure the locations of crack heating as a function of applied load. Surface crack closure stresses are approximated from the heating locations as the load is varied and the crack opening stress is measured from the load required to fully open the crack and terminate heat generatio

Intensity distribution for waves in disordered media: deviations from Rayleigh statistics

We study the intensity distribution function, P(I), for monochromatic waves propagating in quasi one-dimensional disordered medium, assuming that a point source and a point detector are embedded in the bulk of the medium. We find deviations from the Rayleigh statistics at moderately large I and a logarithmically-normal asymptotic behavior of P(I). When the radiation source and the detector are located close to the opposite edges of the sample (on a distance much less then the sample length), an intermediate regime with a stretched-exponential behavior of P(I) emerges.Comment: 4 pages Revtex, 3 figures included as eps file

Steps towards the hyperfine splitting measurement of the muonic hydrogen ground state: pulsed muon beam and detection system characterization

The high precision measurement of the hyperfine splitting of the muonic-hydrogen atom ground state with pulsed and intense muon beam requires careful technological choices both in the construction of a gas target and of the detectors. In June 2014, the pressurized gas target of the FAMU experiment was exposed to the low energy pulsed muon beam at the RIKEN RAL muon facility. The objectives of the test were the characterization of the target, the hodoscope and the X-ray detectors. The apparatus consisted of a beam hodoscope and X-rays detectors made with high purity Germanium and Lanthanum Bromide crystals. In this paper the experimental setup is described and the results of the detector characterization are presented.Comment: 22 pages, 14 figures, published and open access on JINS

Characterization of Electrochemically Deposited Ce1-xZrxO2 Layers Modified with Cobalt Oxide for Electrocatalytic Conversion of NOx and CO

A method for electrochemical deposition of a two-component Ce1−xZrxO2 system on stainless steel substrate that is attractive from catalytic point of view is proposed. As reported in the literature, it is a promising carrier layer for the production of catalytic converters for purification of exhaust gases containing NOx and CO. This system is modified by electrodeposition of a thin film of cobalt oxide over it. A series of samples of the Ce1−xZrxO2/СоxОy system was produced with various concentrations and proportions of the components. These samples are characterized by XRD, SEM, EDS, XPS and РCС (partial electrocatalytic curves) of CO oxidation and of NОx reduction. Based on the obtained results, it has been concluded that the electrodeposited two-component Ce1−xZrxO2 system is a solid solution with composition, structure, and physicochemical properties that make it suitable for use as active phase carrier for catalytic oxidation of CO and reduction of NOx

Exploring Interatomic Coulombic Decay by Free Electron Lasers

To exploit the high intensity of laser radiation, we propose to select frequencies at which single-photon absorption is of too low energy and two or more photons are needed to produce states of an atom that can undergo interatomic Coulombic decay (ICD) with its neighbors. For Ne dimer it is explicitly demonstrated that the proposed scheme to investigate interatomic processes by multiphoton absorption is much more efficient than with single-photon absorption of sufficiently large frequency as used until now. Extensive calculations on Ne dimer including all the involved nuclear dynamics and the losses by ionization of the participating states show how the low-energy ICD electrons and Ne$^+$ pairs are produced for different laser intensities and pulse durations. At higher intensities the production of Ne$^+$ pairs by successive ionization of the two atoms becomes competitive and the respective emitted electrons interfere coherently with the ICD electrons. It is also demonstrated that a measurement after a time delay can be used to determine the contribution of ICD even at high laser intensity.Comment: 5 figures, Supplemental material fil

Party system closure and openness: conceptualization, operationalization and validation

The degree of closure of the governmental arena is a central aspect of the stabilization of party systems, and yet little systematic effort has been devoted to its operationalization. The article proposes a new index, examines its reliability and validity, and reports the ranking of 60 party systems. By redefining the units of measurement we suggest new indicators that are uniform and transparent in their logic of construction, can be applied both to specific government-changes and to time periods, and are sensitive to the degree of change. The article finds a hierarchy among the components of party system closure, dominated by coalition formula. While new and established democracies can both produced closed patterns, the analysis of inter-war European party systems shows that closed systems are less prone to authoritarian takeover. The article demonstrates the power of inertia: the completely closed configurations stand out as the most durable ones

First FAMU observation of muon transfer from \u3bcp atoms to higher-Z elements

Abstract: The FAMU experiment aims to accurately measure the hyperfine splitting of the ground state of the muonic hydrogen atom. A measurement of the transfer rate of muons from hydrogen to heavier gases is necessary for this purpose. In June 2014, within a preliminary experiment, a pressurized gas-target was exposed to the pulsed low-energy muon beam at the RIKEN RAL muon facility (Rutherford Appleton Laboratory, U.K.). The main goal of the test was the characterization of both the noise induced by the pulsed beam and the X-ray detectors. The apparatus, to some extent rudimental, has served admirably to this task. Technical results have been published that prove the validity of the choices made and pave the way for the next steps. This paper presents the results of physical relevance of measurements of the muon transfer rate to carbon dioxide, oxygen, and argon from non-thermalized excited \u3bcp atoms. The analysis methodology and the approach to the systematics errors are useful for the subsequent study of the transfer rate as function of the kinetic energy of the \u3bcp currently under way

Pine cone scale-inspired motile origami

Stimuli-sensitive hydrogels have received attention because of their potential applications in various fields. Stimuli-directed motion offers many practical applications, such as in drug delivery systems and actuators. Directed motion of asymmetric hydrogels has long been designed; however, few studies have investigated the motion control of symmetric hydrogels. We designed a pine cone scale-inspired movable temperature-sensitive symmetric hydrogel that contains Fe3O4. Alignment of Fe3O4 along the magnetic force is key in motion control in which Fe3O4 acts like fibers in a pine cone scale. Although a homogeneous temperature-sensitive hydrogel cannot respond to a temperature gradient, the Fe3O4-containing hydrogel demonstrates considerable bending motion. Varying degrees and directions of motion are easily facilitated by controlling the amount and alignment angle of the Fe3O4. The shape of the hydrogel layer also influences the morphological structure. This study introduced facile and low-cost methods to control various bending motions. These results can be applied to many fields of engineering, including industrial engineering.111Ysciescopu

CeOx/Al2O3 thin films on stainless steel substrate - Dynamical X-ray photoelectron spectroscopy investigations

The CeOx/Al2O3 thin films on stainless steel with different ceria loading were subjected to a.c. (square wave) pulses at various frequencies in the range 10- 3 to 100 kHz while recording X-ray photoelectron spectra. The resulting binding energy differences were derived from the frequency dependence of the corresponding Al2p, Ce3d and O1s peaks. At low ceria loadings the main constituent on the surface is CeAlO 3 phase, while for high ceria loading the film is constructed from CeO2 and CeAlO3 phases spread over the Al 2O3. Accordingly, it was observed that the ceria loading determines the conductivities of the investigated thin oxide films. © 2013 Elsevier B.V. All Rights Reserved