Two kinds of diaphragm materials based on polysulfone with impregnated particles of a hydrophilic filler for alkaline water electrolyzers are suggested: nonwoven diaphragm materials produced by the ...electrospinning method and film diaphragms fabricated by the phase-inversion method. Their physicochemical characteristics were compared. It was found that film diaphragms are preferable for water electrolyzers operating under high pressure, for which high requirements are imposed on the purity of the gases being generated.
In the present work the activity and stability of the IrOx/TiOx catalyst obtained by the polyol approach in the oxygen evolution reaction (OER) were studied in comparison with the commercial analogue ...IrOx. Electrochemical studies were provided, including accelerated stress testing. The synthesized IrOx/TiOx catalyst demonstrated higher OER activity and stability than the commercial IrOx, and the obtained results allow to suggest and discuss possible mechanisms of the studied catalysts degradation. Tests of membrane-electrode assemblies based on synthesized IrOx/TiOx catalysts in SPE water electrolyzer demonstrate the possibility to significantly reduce the noble metal content on the anode..
In high energy experiments such as active beam dump searches for rare decays and missing energy events, the beam purity is a crucial parameter. In this paper we present a technique to reject heavy ...charged particle contamination in the 100 GeV electron beam of the H4 beam line at CERN SPS. The method is based on the detection with BGO scintillators of the synchrotron radiation emitted by the electrons passing through a bending dipole magnet. A 100 GeV π− beam is used to test the method in the NA64 experiment resulting in a suppression factor of 10−5 while the efficiency for electron detection is ∼95%. The spectra and the rejection factors are in very good agreement with the Monte Carlo simulation. The reported suppression factors are significantly better than previously achieved.
The influence of the dispersity and morphology of ceramic powders on the characteristics of green bodies and the optical transmittance of YAG:Yb (20 at%) ceramics was considered. The effect of the ...specific surface area on the relative density of compacts was studied. An increase in the specific surface area from 1.45 to 12.38 m2/g led to a decrease in the relative density of green body compacts from 52% to 38% under the fixed uniaxial pressure of 50 MPa. An increase in the uniaxial pressing value up to 150 MPa provided a maximum increase of the optical transmission of ceramics. However, an increase in the specific surface area and uniaxial pressure led to the appearance of macrodefects in ceramic samples. Cold isostatic pressing at 200 MPa after uniaxial pressing at 50 MPa resulted in an increase of optical transparency and the elimination of the macrodefect formation in ceramics. Dispersity and morphology of ceramic powders have a significant effect on the optical transparency of ceramics. Forming conditions had insignificant influence on optical characteristics. Highly transparent YAG:Yb ceramics with 80% transmittance were developed.
The spontaneous YAl3(BO3)4 (YAB) and GdAl3(BO3)4 (GdAB) crystals (of nominal composition and co-doped with Er and Yb) up to 4–5mm in length were grown from high-temperature solutions using K2Mo3O10 ...based fluxes in the temperature range of 1120–900°C. Glass–ceramic composites based on the YAB and GdAB micro-crystals have been prepared by quenching YAB–B2O3 and GdAB–B2O3 melts and characterized by X-ray diffraction and spectroscopic methods. The vitrified melt was shown to contain micro- and nano-crystalline rare-earth borate phases. Their distribution over the composites has been investigated by electron microscopy and three-dimensional X-ray tomography. The absorption spectra of these materials co-doped with erbium and ytterbium as well as luminescence spectrum were demonstrated.
•GdAB- and YAB-based glass–ceramics of different compositions have been prepared.•Optimal temperatures for the synthesis were found.•The absorption and luminescence spectra of these materials were demonstrated.
This work is devoted to the numerical research of free convection by a Newtonian anomalous thermoviscous fluid in a flat cell. The cell is heated from below, cooled from above; and the lateral ...boundaries are heat insulated. The viscosity anomaly of the fluid is modeled by the Gaussian function of temperature and is characterized by two parameters. A flow regime with isolated convective cells separated by a region of high viscosity, the so-called viscous barrier, was detected at a certain set of control parameters. For these flow regimes, current lines, heat fluxes, temperature fields, and contours of the components of the velocity vector of the fluid are given.
The analysis of the safety management method - the Bradley Curve method, as one of the effective tools in improving safety culture in the engineering industry, was carried out. The stages of the ..."Bradley's Curve" method are considered: natural instincts, supervision, one's own consciousness and one team. A study was conducted to assess the effectiveness of the implementation of the "Curve Bradley" method. The level of safety culture at the enterprises of the engineering industry has been determined. It has been confirmed that microtraumas are used as indicators (predecessors) when identifying sources of occupational risks. Substantiated the consideration of microtraumas to improve efficiency in the fight against injuries.
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A new species for the Black Sea, a representative of the Far Eastern fauna, the Korean (dark) rockfish
Sebastes schlegelii
Hilgendorf, 1880, was found in the coastal zone of Crimea and the ...Caucasus. The first find of the Korean rockfish took place in 2013; presently, the findings of this species have become more frequent, which suggests a successful introduction. This paper presents the detailed morphological characteristics of the Black Sea individuals and the features of their biotopic distribution. Random introduction of
Sebastes schlegelii
with ship ballast waters or during the acclimatization of the giant oyster
Crassostrea gigas
is assumed to be the most probable result of the appearance of the species in the Black Sea.
We present the performance of multiplexed XY resistive Micromegas detectors tested in the CERN SPS 100 GeV/c electron beam at intensities up to 3.3×105e−∕(s⋅cm2). So far, all studies with multiplexed ...Micromegas have only been reported for tests with radioactive sources and cosmic rays. The use of multiplexed modules in high intensity environments was not explored due to the effect of ambiguities in the reconstruction of the hit point caused by the multiplexing feature. For the specific mapping and beam intensities analyzed in this work with a multiplexing factor of five, more than 50% level of ambiguity is introduced due to particle pile-up as well as fake clusters due to the mapping feature. Our results prove that by using the additional information of cluster size and integrated charge from the signal clusters induced on the XY strips, the ambiguities can be reduced to a level below 2%. The tested detectors are used in the CERN NA64 experiment for tracking the incoming particles bending in a magnetic field in order to reconstruct their momentum. The average hit detection efficiency of each module was found to be ∼96% at the highest beam intensities. By using four modules a tracking resolution of 1.1% was obtained with ∼85% combined tracking efficiency.
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