Thermoelastic equation of state of boron subphosphide B<Subscript>12</Subscript>P<Subscript>2</Subscript>

Compressibility of boron subphosphide B₁₂P₂ has been studied under quasi-hydrostatic conditions up to 26 GPa and 2600 K using laser-heated diamond anvil cell and angle-dispersive synchrotron X-ray diffraction. 300-K data fit yields the values of bulk modulus B ₀ = 192(11) GPa and its first pressure derivative B ₀′ = 5.5(12). It has been found that at ambient pressure the thermal expansion is quasi-linear up to 1300 K with average volume expansion coefficient α = 17.4(1) × 10^?6 K^?1. The whole set of experimental p–V–T data is well described by the Anderson-Grüneisen model with δ_T = 6.     

Wetting and interfacial behavior of Fe-based self-fluxing alloy–refractory compound systems

In this study the wettability and interfacial behaviour of the TiC–FeNiCrBSiC and TiB₂–FeNiCrBSiC systems were investigated. The wetting experiments were performed by the sessile drop method at 1150°C under a vacuum. The contact angles of TiC and TiB₂ wetting by melted Fe-based self-fluxing alloy were 51° and 36°, respectively. Thermodynamic calculations were carried out to understand the metal–ceramic interaction mechanism in the TiC–FeNiCrBSiC and TiB₂–FeNiCrBSiC systems. The structure of the interface region in the TiB₂–FeNiCrBSiC system was characterized by the optical microscopy and SEM-EDS analysis. The formation of Fe, Ni, Cr and Mo complex borides was revealed within the interface region of the TiB₂–FeNiCrBSiC system.     

The Influence of the Shape of Model Hydrometeors on the Formation of Discharge between an Artificial-Thunderstorm Cell and the Ground

We have experimentally studied how arrays of model coarse hydrometeors influence the initiation and propagation of discharge between an artificial-thunderstorm cell of negative or positive polarity and the ground. It is established for the first time that the probability of initiation and stimulation of a channeled discharge between negatively or positively charged cloud and the ground significantly depends on the shape and size of coarse hydrometeors occurring near the thunderstorm cell boundaries. The obtained results can be used in developing methods for the artificial initiation of the cloud–ground type lightning of both polarities and targeted discharge of thunderstorm clouds.     

The efficiency of backward magnetic-pulse processing

The dependence of the efficiency of magnetic-pulse processing of materials on the pulsed magnetic-field shape has been studied. It is shown that, by using a pulse train instead of a single pulse in the fast-rising component of a magnetic field applied during the backward forming process, it is possible to increase the specific mechanical impulse transferred to a workpiece and, thus, improve the efficiency of processing. Possible applications of the proposed method to removing dents from car chassis and aircraft parts are considered

     

A new carbon structure in annealed film coatings of the carbon–lead system

Carbon–lead solid solutions coexisting with amorphous carbon have been obtained for the first time in a film coating deposited by ion-plasma sputtering. During subsequent vacuum annealing of carbon–lead films containing more than 68.5 at % Pb, this element almost completely evaporates to leave an amorphous carbon coating on a substrate. During annealing at 1100°C, this amorphous carbon crystallizes into a new hexagonal lattice with unit cell parameters a = 0.7603 nm and c = 0.8168 nm. Characteristic X-ray diffraction data for the identification of this phase are determined.

     

The structural state of epitaxial GaP films of different polarities grown on misoriented Si(001) substrates

The structure of GaP films grown by molecular-beam epitaxy on vicinal Si(1113) substrates has been studied by X-ray diffraction. It is established that the crystalline lattice of a pseudomorphic film rotates about the <110> axis toward increasing deviation from the singular orientation, while the subsequent relaxation leads to rotation in the opposite direction. This is valid for the films of both (001) and (001̄) polarities. Differences between the surface morphologies of relaxed and pseudomorphic GaP films are revealed.

     

Surface plasmon resonance in a bent single-mode fiber with a metallized cladding experimental research

The processes of surface plasmon resonance excitation in a bent single-mode optical fiber with a metallized cladding have been studied experimentally. It is shown that, for a certain combination of the bending radius of an optical fiber and the thickness of a metal film, a strong coupling between the fundamental and plasmon–polariton mode is achieved through a whispering gallery mode supported by the fiber cladding, which leads to the formation of a resonance dip with a depth of ~30 dB or more in the transmission spectrum of an optical fiber loop. The position of the dip depends strongly on the ambient refractive index, which provides the possibility of refractometric measurements with a spectral sensitivity of ~5 μm/RIU and a resolution of ~4 × 10^–6. Limits of measurement of the refractive index are determined by the operating spectral range and the bending radius of the optical fiber and are 1.42–1.44 for the setup used.     

Sorption of cesium and strontium radionuclides onto crystalline alkali metal titanosilicates

Sorption of tracer amounts of ¹³⁷Cs and ⁹⁰Sr radionuclides from model solutions of various compositions onto synthetic titanosilicates, framework ivanyukite and layered SL3, both synthesized at the Center for Nanomaterials Science, Kola Scientific Center, Russian Academy of Sciences, was studied. Synthetic ivanyukite and titanosilicate SL3 well compete with Termoxid-25 ferrocyanide sorbent in the ability to take up cesium from neutral NaNO₃ solutions and from a simulated solution of bottom residue from a nuclear power plant with RBMK reactors. The maximal sorption of ¹³⁷Cs onto ivanyukite is observed at pH 6–7. The dependence of the ¹³⁷Cs distribution coefficient (K _d) on ivanyukite on the concentration of sodium and potassium ions in the solution was studied. Potassium ions affect the cesium sorption more strongly than sodium ions do. In the ability to take up ⁹⁰Sr, synthetic ivanyukite well competes with synthetic zeolite of type A and with the sorbent based on modified manganese dioxide. The dependences of K _d of ⁹⁰Sr on the concentrations of the Na⁺ and Ca²⁺ ions in the solution were determined. Calcium ions affect the strontium sorption more strongly than sodium ions do. Ivanyukite and SL3 show promise as sorbents for removing cesium and strontium radionuclides from multicomponent salt solutions.     

Beyond-design-basis regimes of uranium stripping and of carbonate regeneration of the solvent

Beyond-design-basis regimes of centrifugal contactors for U stripping and of mixer–settlers for carbonate regeneration of the solvent, 30% TBP in Isopar M, were studied from the viewpoint of the influence of incomplete uranium stripping on the phase stability of the extraction system in the step of the carbonate scrubbing of the solvent. Dynamic relationship between these two operations was determined. A mathematical model of uranium stripping at stepwise–20% deviation from the nominal value was developed and verified; it was shown that the beyond-design-basis regime develops in such apparatuses within 4 h at the total trial time longer than 8 h. The mathematical relationships obtained were used in the development of software for calculating transient processes that occur when the stream parameters in the course of carbonate regeneration of the solvent change. The beyond-design-basis regime of the solvent regeneration was found to have two regions: region of stoichiometric excess of carbonate ions over uranyl ions with the risk of precipitation and region of excess of uranyl ions over carbonate ions with acidification of the unit and uranium breakthrough with the recycled solvent. The conditions of the tests performed correspond to the second region.