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Vacuum heat treatment of mechanically alloyed powders of boron and aluminium leads to the formation of a metastable Al-rich phase, which can be quenched. Its structure, composition and thermal stability are established. With the chemical formula Al1.28B the rhombohedral phase is unusually rich in Al. The parameters of the unit cell determined from X-ray powder diffraction are a = 18.3464 (19), c = 8.9241 (9) Å, V = 2601.3 (6) Å3, space group R 3. It is stable on heating to 630°C. It is suggested that this phase is an important intermediate step in the formation of AlB2 and, eventually, of other borides; its nucleation and thermal stability are explained by high elastic energy hindering the formation of equilibrium phases at low temperatures.
Alexander I. Malkin; Vladimir V. Chernyshev; Alena A. Ryazantseva; Alexander L. Vasiliev; Maximilian S. Nickolsky; Andrei A. Shiryaev. Formation and characterization of an Al-rich metastable phase in the Al–B phase diagram. Journal of Applied Crystallography 2021, 54, 1121 -1126.
AMA StyleAlexander I. Malkin, Vladimir V. Chernyshev, Alena A. Ryazantseva, Alexander L. Vasiliev, Maximilian S. Nickolsky, Andrei A. Shiryaev. Formation and characterization of an Al-rich metastable phase in the Al–B phase diagram. Journal of Applied Crystallography. 2021; 54 (4):1121-1126.
Chicago/Turabian StyleAlexander I. Malkin; Vladimir V. Chernyshev; Alena A. Ryazantseva; Alexander L. Vasiliev; Maximilian S. Nickolsky; Andrei A. Shiryaev. 2021. "Formation and characterization of an Al-rich metastable phase in the Al–B phase diagram." Journal of Applied Crystallography 54, no. 4: 1121-1126.
The interest in magnesium-based materials is promoted by their biocompatibility, their bioresorbability, and their recently discovered antibacterial potential. Until now, the widespread use of magnesium alloys in different corrosive environments was inhibited by their weakly controllable degradation rate and poorly understood microbiologically induced corrosion behavior. To better understand the degradation and usability of magnesium-based alloys, in this study we have fabricated superhydrophobic coatings on a magnesium-based alloy, and analyzed the behavior of this alloy in bacterial dispersions of Pseudomonas aeruginosa and Klebsiella pneumoniae cells in phosphate-buffered saline. It was shown that the immersion of such coatings in bacterial dispersions causes notable changes in the morphology of the samples, dependent on the bacterial dispersion composition and the type of bacterial strain. The interaction of the superhydrophobic coatings with the bacterial dispersion caused the formation of biofilms and sodium polyphosphate films, which provided enhanced barrier properties in magnesium dissolution and hence in dispersion medium alkalization, eventually leading to the inhibition of magnesium substrate degradation. The electrochemical data obtained for superhydrophobic samples in continuous contact with corrosive bacterial dispersions for 48 h indicated a high level of anticorrosion protection.
Alexandre Emelyanenko; Valery Kaminsky; Ivan Pytskii; Kirill Emelyanenko; Alexander Domantovsky; Elizaveta Chulkova; Andrei Shiryaev; Andrei Aleshkin; Ludmila Boinovich. Antimicrobial Activity and Degradation of Superhydrophobic Magnesium Substrates in Bacterial Media. Metals 2021, 11, 1100 .
AMA StyleAlexandre Emelyanenko, Valery Kaminsky, Ivan Pytskii, Kirill Emelyanenko, Alexander Domantovsky, Elizaveta Chulkova, Andrei Shiryaev, Andrei Aleshkin, Ludmila Boinovich. Antimicrobial Activity and Degradation of Superhydrophobic Magnesium Substrates in Bacterial Media. Metals. 2021; 11 (7):1100.
Chicago/Turabian StyleAlexandre Emelyanenko; Valery Kaminsky; Ivan Pytskii; Kirill Emelyanenko; Alexander Domantovsky; Elizaveta Chulkova; Andrei Shiryaev; Andrei Aleshkin; Ludmila Boinovich. 2021. "Antimicrobial Activity and Degradation of Superhydrophobic Magnesium Substrates in Bacterial Media." Metals 11, no. 7: 1100.
Infra-red maps and profiles with high spatial resolution were obtained for two single crystal diamonds with pronounced CO2 IR absorption peaks. Detailed examination allows unambiguous assignment of the spectral features to solid CO2-I phase. It is shown that the distribution of IR band positions, intensities and widths in the sample follows regular patterns and is not chaotic as was suggested in previous works where spectra of a few individual spots were analysed. Consequently, pressure effects alone fail to explain all observed features and shifts of the CO2 bands. Experimental data can be explained by presence of impurities (such as water, N2, etc.) in the trapped CO2. This implies that spectroscopic barometry of CO2 microinclusions in diamond may be subject to poorly controlled bias. However, barometry is still possible if Davydov splitting of the CO2-I ν2 band is unequivocally observed, as this indicates high purity of the CO2 ice.
Evgenii P. Barannik; Andrey A. Shiryaev; Thomas Hainschwang. Shift of CO2-I absorption bands in diamond: A pressure or compositional effect? A FTIR mapping study. Diamond and Related Materials 2021, 113, 108280 .
AMA StyleEvgenii P. Barannik, Andrey A. Shiryaev, Thomas Hainschwang. Shift of CO2-I absorption bands in diamond: A pressure or compositional effect? A FTIR mapping study. Diamond and Related Materials. 2021; 113 ():108280.
Chicago/Turabian StyleEvgenii P. Barannik; Andrey A. Shiryaev; Thomas Hainschwang. 2021. "Shift of CO2-I absorption bands in diamond: A pressure or compositional effect? A FTIR mapping study." Diamond and Related Materials 113, no. : 108280.
The paper consists of two main parts: a microscopic and spectroscopic investigation of the single crystal of 17-year-old 238Pu-doped Eu-monazite, and a theoretical calculation of the properties of several structural types of orthophosphates. It is shown that actinide-doped monazite is prone to the formation of mechanically weak, poorly crystalline crust, presumably consisting of rhabdophane. Its formation is likely promoted by the formation of peroxides and, potentially, acidic compounds, due to the radiolysis of atmospheric moisture. The calculations of mixing the enthalpies and Gibbs energies of binary solid solutions of Pu and rare earth element (REE) phosphates that were performed for the principal structural types—monazite, xenotime, rhabdophane—show that, in the case of light REEs, the plutonium admixture is preferentially redistributed into the rhabdophane. This process strongly affects the behavior of actinides, leached from a monazite-based waste form. The applications of these results for the development of actinide waste forms are discussed. The current data on the behavior of real actinide-doped monazite suggest that this type of ceramic waste form is not very resistant, even in relatively short time periods.
Polina Mikhailova; Boris Burakov; Nikolai Eremin; Alexei Averin; Andrey Shiryaev. Plutonium-Doped Monazite and Other Orthophosphates—Thermodynamics and Experimental Data on Long-Term Behavior. Sustainability 2021, 13, 1203 .
AMA StylePolina Mikhailova, Boris Burakov, Nikolai Eremin, Alexei Averin, Andrey Shiryaev. Plutonium-Doped Monazite and Other Orthophosphates—Thermodynamics and Experimental Data on Long-Term Behavior. Sustainability. 2021; 13 (3):1203.
Chicago/Turabian StylePolina Mikhailova; Boris Burakov; Nikolai Eremin; Alexei Averin; Andrey Shiryaev. 2021. "Plutonium-Doped Monazite and Other Orthophosphates—Thermodynamics and Experimental Data on Long-Term Behavior." Sustainability 13, no. 3: 1203.
Structure, defects and inclusions in natural polycrystalline ballas-type diamonds are studied by complementary techniques: Scanning Electron microscopy, cathodo- and photoluminescence, X-ray diffraction, radiography and fluorescence, infra-red spectroscopy and carbon isotope analyses. Peculiarities of internal structure of some of the samples are explained by growth of the diamonds as volume-filling dendrites. Similarities of structure and mineralogy of trapped inclusions between ballas-type diamonds with fibrous and cuboid diamonds are established. However, significant differences between growth mechanisms of all these varieties exist and are possibly explained by variations in carbon supersaturation and diamond wettability by growth medium.
A. A. Shiryaev; A. F. Khokhryakov; V. N. Reutsky; T. I. Golovanova. Structure and Defects in Natural Ballas-Type Diamonds: a Case Study. Geochemistry International 2020, 58, 1299 -1312.
AMA StyleA. A. Shiryaev, A. F. Khokhryakov, V. N. Reutsky, T. I. Golovanova. Structure and Defects in Natural Ballas-Type Diamonds: a Case Study. Geochemistry International. 2020; 58 (12):1299-1312.
Chicago/Turabian StyleA. A. Shiryaev; A. F. Khokhryakov; V. N. Reutsky; T. I. Golovanova. 2020. "Structure and Defects in Natural Ballas-Type Diamonds: a Case Study." Geochemistry International 58, no. 12: 1299-1312.
The present work focused on the experimental study of the performance of a scaled system of adsorbed natural gas (ANG) storage and transportation based on carbon adsorbents. For this purpose, three different samples of activated carbons (AC) were prepared by varying the size of coconut shell char granules and steam activation conditions. The parameters of their porous structure, morphology, and chemical composition were determined from the nitrogen adsorption at 77 K, X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), and scanning electron microscopy (SEM) measurements. The methane adsorption data measured within the temperature range from 178 to 360 K and at pressures up to 25 MPa enabled us to identify the most efficient adsorbent among the studied materials: AC-90S. The differential heats of methane adsorption on AC-90S were determined in order to simulate the gas charge/discharge processes in the ANG system using a mathematical model with consideration for thermal effects. The results of simulating the charge/discharge processes under two different conditions of heat exchange are consistent with the experimentally determined temperature distribution over a scaled ANG storage tank filled with the compacted AC-90S adsorbent and equipped with temperature sensors and heat-exchanger devices. The amounts of methane delivered from the ANG storage system employing AC-90S as an adsorbent differ from the model predictions by 4–6%. Both the experiments and mathematical modeling showed that the thermal regulation of the ANG storage tank ensured the higher rates of charge/discharge processes compared to the thermal insulation.
Ilya E. Men’Shchikov; Andrey V. Shkolin; Evgeny M. Strizhenov; Elena V. Khozina; Sergey S. Chugaev; Andrey A. Shiryaev; Anatoly A. Fomkin; Anatoly A. Zherdev. Thermodynamic Behaviors of Adsorbed Methane Storage Systems Based on Nanoporous Carbon Adsorbents Prepared from Coconut Shells. Nanomaterials 2020, 10, 2243 .
AMA StyleIlya E. Men’Shchikov, Andrey V. Shkolin, Evgeny M. Strizhenov, Elena V. Khozina, Sergey S. Chugaev, Andrey A. Shiryaev, Anatoly A. Fomkin, Anatoly A. Zherdev. Thermodynamic Behaviors of Adsorbed Methane Storage Systems Based on Nanoporous Carbon Adsorbents Prepared from Coconut Shells. Nanomaterials. 2020; 10 (11):2243.
Chicago/Turabian StyleIlya E. Men’Shchikov; Andrey V. Shkolin; Evgeny M. Strizhenov; Elena V. Khozina; Sergey S. Chugaev; Andrey A. Shiryaev; Anatoly A. Fomkin; Anatoly A. Zherdev. 2020. "Thermodynamic Behaviors of Adsorbed Methane Storage Systems Based on Nanoporous Carbon Adsorbents Prepared from Coconut Shells." Nanomaterials 10, no. 11: 2243.
A nanoscale bimetallic alloy catalyst PtFe/C is prepared by pyrolysis of the heterometallic platinum-iron carboxylate complex [PtFe(OAc)4]2O⋅4CH2Cl2 on Vulcan XC-72 carbon black. It is characterized by X-ray powder diffraction analysis, X-ray fluorescence spectroscopy, transmission electron microscopy, and electrochemical methods. Its activity in the oxygen reduction reaction (ORR) is tested in an aqueous H2SO4 electrolyte in model conditions, using a rotating disc electrode (RDE) technique, and in the membrane electrode assembly of the hydrogen-air single fuel cell. The synthesized catalyst is a tetragonal PtFe intermetallic compound with Pt:Fe = 1:1 atomic ratio. It is uniformly distributed over the carbon support with a predominant metal particle size between 3 and 6 nm. The ORR specific activity of the prepared alloy catalyst is superior to that of a commercial Pt/C E-Tek catalyst and, thus, the PtFe/C catalyst may be a promising cathode material for hydrogen-air fuel cells.
Natalia A. Mayorova; Alexandr D. Modestov; Vitali A. Grinberg; Andrey A. Shiryaev; Sergey S. Shapovalov; Maximillian S. Nickolsky; Igor P. Stolyarov. Nanoscale catalyst based on a heterometallic carboxylate complex of platinum and iron for hydrogen-air fuel cells. Materials Chemistry and Physics 2020, 259, 123968 .
AMA StyleNatalia A. Mayorova, Alexandr D. Modestov, Vitali A. Grinberg, Andrey A. Shiryaev, Sergey S. Shapovalov, Maximillian S. Nickolsky, Igor P. Stolyarov. Nanoscale catalyst based on a heterometallic carboxylate complex of platinum and iron for hydrogen-air fuel cells. Materials Chemistry and Physics. 2020; 259 ():123968.
Chicago/Turabian StyleNatalia A. Mayorova; Alexandr D. Modestov; Vitali A. Grinberg; Andrey A. Shiryaev; Sergey S. Shapovalov; Maximillian S. Nickolsky; Igor P. Stolyarov. 2020. "Nanoscale catalyst based on a heterometallic carboxylate complex of platinum and iron for hydrogen-air fuel cells." Materials Chemistry and Physics 259, no. : 123968.
Specific features of the porous structure of irradiated and virgin reactor graphite of Russian brands have been analyzed. The porosity parameters affecting the leaching of radionuclides from graphite radioactive waste (RAW) were determined: fraction of open porosity, distribution of pore throat cross-sections, surface of open pores. The volume of open pores accessible for leaching aqueous media in the irradiated graphite was estimated. A model describing the leaching of radionuclides from irradiated graphite accounting for the porosity contribution is proposed. The parameters that numerically characterize the resistance of graphite RAW against leaching and are independent of the geometric shapes of separate fragments (samples) were determined.
A. O. Pavlyuk; S. G. Kotlyarevskii; R. I. Kan; A. G. Volkova; D. A. Zolotov; A. V. Pakhnevich; E. V. Zakharova; A. A. Shiryaev. Determination of Parameters of Porous Structure Affecting the Release Mechanisms of Long-Lived Radionuclides from Irradiated Graphite in Contact with Liquid Media. Radiochemistry 2020, 62, 759 -768.
AMA StyleA. O. Pavlyuk, S. G. Kotlyarevskii, R. I. Kan, A. G. Volkova, D. A. Zolotov, A. V. Pakhnevich, E. V. Zakharova, A. A. Shiryaev. Determination of Parameters of Porous Structure Affecting the Release Mechanisms of Long-Lived Radionuclides from Irradiated Graphite in Contact with Liquid Media. Radiochemistry. 2020; 62 (6):759-768.
Chicago/Turabian StyleA. O. Pavlyuk; S. G. Kotlyarevskii; R. I. Kan; A. G. Volkova; D. A. Zolotov; A. V. Pakhnevich; E. V. Zakharova; A. A. Shiryaev. 2020. "Determination of Parameters of Porous Structure Affecting the Release Mechanisms of Long-Lived Radionuclides from Irradiated Graphite in Contact with Liquid Media." Radiochemistry 62, no. 6: 759-768.
Structural properties and water dissolution of six sodium–aluminum–phosphate (NAP) glasses have been investigated before and after irradiation by a gamma-ray source based on 60Co. Two of these samples were of simple composition, and four samples had a complex composition with radionuclide simulants representing actinides, fission, and activated corrosion products. Samples of the simple composition are fully vitreous, whereas samples of the complex composition contained up to 10 vol.% of aluminum–phosphate, AlPO4, and traces of ruthenium dioxide, RuO2. Based on the study of pristine and irradiated glasses, it was established that the radiation dose of 62 million Gray had practically no effect on the phase composition and structure of samples. At the same time, the rate of leaching of elements from the irradiated samples by water was decreased by about two times.
Alexey V. Luzhetsky; Vladislav A. Petrov; Sergey V. Yudintsev; Viktor I. Malkovsky; Michael I. Ojovan; Maximilian S. Nickolsky; Andrey A. Shiryaev; Sergey S. Danilov; Elizaveta E. Ostashkina. Effect of Gamma Irradiation on Structural Features and Dissolution of Nuclear Waste Na–Al–P Glasses in Water. Sustainability 2020, 12, 4137 .
AMA StyleAlexey V. Luzhetsky, Vladislav A. Petrov, Sergey V. Yudintsev, Viktor I. Malkovsky, Michael I. Ojovan, Maximilian S. Nickolsky, Andrey A. Shiryaev, Sergey S. Danilov, Elizaveta E. Ostashkina. Effect of Gamma Irradiation on Structural Features and Dissolution of Nuclear Waste Na–Al–P Glasses in Water. Sustainability. 2020; 12 (10):4137.
Chicago/Turabian StyleAlexey V. Luzhetsky; Vladislav A. Petrov; Sergey V. Yudintsev; Viktor I. Malkovsky; Michael I. Ojovan; Maximilian S. Nickolsky; Andrey A. Shiryaev; Sergey S. Danilov; Elizaveta E. Ostashkina. 2020. "Effect of Gamma Irradiation on Structural Features and Dissolution of Nuclear Waste Na–Al–P Glasses in Water." Sustainability 12, no. 10: 4137.
Inelastic neutron scattering is a novel method for determination of thermodynamic and isotopic properties of nanoparticles. Influence of surface can be evaluated. The Cv of nanodiamonds is higher and the β-factor is lower than those of bulk diamond.
Andrey A. Shiryaev; Veniamin B. Polyakov; Stephane Rols; Antonio Rivera; Olga Shenderova. Inelastic neutron scattering: a novel approach towards determination of equilibrium isotopic fractionation factors. Size effects on heat capacity and beta-factor of diamond. Physical Chemistry Chemical Physics 2020, 22, 13261 -13270.
AMA StyleAndrey A. Shiryaev, Veniamin B. Polyakov, Stephane Rols, Antonio Rivera, Olga Shenderova. Inelastic neutron scattering: a novel approach towards determination of equilibrium isotopic fractionation factors. Size effects on heat capacity and beta-factor of diamond. Physical Chemistry Chemical Physics. 2020; 22 (23):13261-13270.
Chicago/Turabian StyleAndrey A. Shiryaev; Veniamin B. Polyakov; Stephane Rols; Antonio Rivera; Olga Shenderova. 2020. "Inelastic neutron scattering: a novel approach towards determination of equilibrium isotopic fractionation factors. Size effects on heat capacity and beta-factor of diamond." Physical Chemistry Chemical Physics 22, no. 23: 13261-13270.
A strategy for rational design of synergetic hybrid materials exploiting stabilization of intercalated layered matrices via coordination bonding is described. A new hybrid material is assembled through subsequent intercalation of the surface‐anchored metal–organic framework (SURMOF) components, zinc acetate and 5,10,15,20‐tetrakis(4‐carboxyphenyl)‐porphyrin‐zinc(II) (ZnTCPP), into the layered europium(III) hydroxychloride (LEuH). The formation of the SURMOF clusters intercalated in LEuH is confirmed by X‐ray diffraction, FTIR and Raman spectroscopy, and BET nitrogen absorption methods. The catalytic function of the SURMOF/LEuH hybrid and its components in the model reaction of hydrolysis of bis(4‐nitrophenyl) phosphate in the acidic solution is studied by UV–vis and MALDI‐TOF spectroscopy. Both the non‐intercalated matrix and the MOF powder are inactive and unstable in the substrate solution. Unlike its components, the SURMOF/LEuH hybrid exhibits synergetic catalytic activity increasing with the amount of the intercalated compounds because of the mutual stabilization of the components through coordination interactions. The results provide a basis for symbimetic (mimicking the symbiotic behavior in biological systems) hybrid materials, in which stabilization of functional units in the intercalated structure translates into a synergy of useful properties.
Maksim R. Sokolov; Yulia Yu. Enakieva; Alexey D. Yapryntsev; Andrey A. Shiryaev; Alexandra I. Zvyagina; Maria A. Kalinina. Intercalation of Porphyrin‐Based SURMOF in Layered Eu(III) Hydroxide: An Approach Toward Symbimetic Hybrid Materials. Advanced Functional Materials 2020, 30, 1 .
AMA StyleMaksim R. Sokolov, Yulia Yu. Enakieva, Alexey D. Yapryntsev, Andrey A. Shiryaev, Alexandra I. Zvyagina, Maria A. Kalinina. Intercalation of Porphyrin‐Based SURMOF in Layered Eu(III) Hydroxide: An Approach Toward Symbimetic Hybrid Materials. Advanced Functional Materials. 2020; 30 (27):1.
Chicago/Turabian StyleMaksim R. Sokolov; Yulia Yu. Enakieva; Alexey D. Yapryntsev; Andrey A. Shiryaev; Alexandra I. Zvyagina; Maria A. Kalinina. 2020. "Intercalation of Porphyrin‐Based SURMOF in Layered Eu(III) Hydroxide: An Approach Toward Symbimetic Hybrid Materials." Advanced Functional Materials 30, no. 27: 1.
New developments of application of X-ray topography in the quasi-forbidden (222) reflection from perfect crystals with diamond lattice to investigate defects are presented. The spatial distribution of intensities of (111) and (222) X-ray reflections is correlated with the distribution of point defects in synthetic diamonds of various types. It is shown that X-ray topography in the quasi-forbidden (222) reflection is a promising tool for investigation of weak stress fields in perfect crystals.
A. A. Shiryaev; D. A. Zolotov; E. M. Suprun; I. G. Dyachkova; S. A. Ivakhnenko; V. E. Asadchikov. Contribution of Lattice Defects to the Intensity of Quasi-Forbidden X-ray Reflections of Diamond: Comparison of X-Ray Topography and Infrared Spectroscopy Data. JETP Letters 2020, 111, 489 -493.
AMA StyleA. A. Shiryaev, D. A. Zolotov, E. M. Suprun, I. G. Dyachkova, S. A. Ivakhnenko, V. E. Asadchikov. Contribution of Lattice Defects to the Intensity of Quasi-Forbidden X-ray Reflections of Diamond: Comparison of X-Ray Topography and Infrared Spectroscopy Data. JETP Letters. 2020; 111 (9):489-493.
Chicago/Turabian StyleA. A. Shiryaev; D. A. Zolotov; E. M. Suprun; I. G. Dyachkova; S. A. Ivakhnenko; V. E. Asadchikov. 2020. "Contribution of Lattice Defects to the Intensity of Quasi-Forbidden X-ray Reflections of Diamond: Comparison of X-Ray Topography and Infrared Spectroscopy Data." JETP Letters 111, no. 9: 489-493.
Sergey S. Shapovalov; Ivan V. Skabitsky; Natalia A. Mayorova; Andrey A. Shiryaev; Maximillian S. Nickolsky; Vitali A. Grinberg. Synthesis of Cobalt-Iron Chalcogenide Clusters as Precursors for Catalysts of Oxygen Electroreduction in Alkali Media. European Journal of Inorganic Chemistry 2020, 2020, 2055 -2062.
AMA StyleSergey S. Shapovalov, Ivan V. Skabitsky, Natalia A. Mayorova, Andrey A. Shiryaev, Maximillian S. Nickolsky, Vitali A. Grinberg. Synthesis of Cobalt-Iron Chalcogenide Clusters as Precursors for Catalysts of Oxygen Electroreduction in Alkali Media. European Journal of Inorganic Chemistry. 2020; 2020 (21):2055-2062.
Chicago/Turabian StyleSergey S. Shapovalov; Ivan V. Skabitsky; Natalia A. Mayorova; Andrey A. Shiryaev; Maximillian S. Nickolsky; Vitali A. Grinberg. 2020. "Synthesis of Cobalt-Iron Chalcogenide Clusters as Precursors for Catalysts of Oxygen Electroreduction in Alkali Media." European Journal of Inorganic Chemistry 2020, no. 21: 2055-2062.
The paper presents a summary of extensive experiments on diamond resorption rates in presence of various ions performed at Prof. Rudenko lab at Moscow State University. For the first time all experimental data are shown together allowing direct comparison. Surface features of the samples etched in different conditions were studied using optical, scanning electron and atomic force microscopy. It is shown that catalytic theory of diamond resorption, a variant of topochemical adsorption theory of crystal etching, explains dramatic differences between activities of ions from different groups of periodic table on diamond resorption rate at least on qualitative level. Strong variations in surface features on diamonds etched in presence of ions with various catalytic activities are observed.
Valeria L. Skvortsova; Andrey A. Shiryaev; Yana Fedortchouk. Influence of ions on diamond resorption. Diamond and Related Materials 2020, 104, 107764 .
AMA StyleValeria L. Skvortsova, Andrey A. Shiryaev, Yana Fedortchouk. Influence of ions on diamond resorption. Diamond and Related Materials. 2020; 104 ():107764.
Chicago/Turabian StyleValeria L. Skvortsova; Andrey A. Shiryaev; Yana Fedortchouk. 2020. "Influence of ions on diamond resorption." Diamond and Related Materials 104, no. : 107764.
Samples of real irradiated (i-)graphite from bushings of RBMK reactor after several types of decontamination treatments were put in contact with aqueous solutions modelling underground water of Nizhnekansky massif (Russia) equilibrated with bentonite for periods up to 1.5 years. Leach rates of radionuclides and evolution of graphite surface morphology and oxidation state were monitored using nuclear spectroscopy, SEM and XPS. After the experiment, less than one third of surface carbons remains unoxidised. Extensive precipitation of secondary phases (alumosilicates, carbonates) was observed on some samples and is possibly correlated with surface oxidation extent. The leach rates of dose-forming 14C and 36Cl are comparable with the leach rates of radionuclides in glassy waste forms. According to the current study i-graphite could be regarded as a waste form, which is suitable for near-surface disposal.
Andrey A. Shiryaev; Anna G. Volkova; Stanislav Dvoryak; Maximillian S. Nickolsky; Elena V. Zakharova. Influence of long-term aqueous leaching of irradiated graphite on surface properties and behavior of radionuclides. MRS Advances 2020, 5, 177 -184.
AMA StyleAndrey A. Shiryaev, Anna G. Volkova, Stanislav Dvoryak, Maximillian S. Nickolsky, Elena V. Zakharova. Influence of long-term aqueous leaching of irradiated graphite on surface properties and behavior of radionuclides. MRS Advances. 2020; 5 (3-4):177-184.
Chicago/Turabian StyleAndrey A. Shiryaev; Anna G. Volkova; Stanislav Dvoryak; Maximillian S. Nickolsky; Elena V. Zakharova. 2020. "Influence of long-term aqueous leaching of irradiated graphite on surface properties and behavior of radionuclides." MRS Advances 5, no. 3-4: 177-184.
New data on microstructure of 16 years old (La, Pu)PO4 monazite ceramics doped with 8.1 wt% of 238Pu are presented. It is shown that the sample consists from at least two phases differing in La/Pu ratio and small precipitates of Pu-phosphate. Possible mechanisms of the compositional heterogeneity are discussed. Formation of Pu-containing rhabdophane after sample storage in air is observed. This phenomenon together with gradual mechanical destruction of the ceramic pellet formation of submicron particles will likely increase rate of radionuclides loss from the monazite-based waste form. X-ray emission lines produced by recoil uranium ions from Pu decay are analysed. It is suggested that careful examination of their relative intensities may provide important information about behaviour of "hot" recoils in nuclear waste forms.
Andrey A. Shiryaev; Boris E. Burakov; Vasily O. Yapaskurt; Alexander V. Egorov; Irina E. Vlasova. Microstructure of Aged 238Pu-doped La-monazite Ceramic and Peculiarities of its X-ray Emission Spectra. MRS Advances 2020, 5, 1 -7.
AMA StyleAndrey A. Shiryaev, Boris E. Burakov, Vasily O. Yapaskurt, Alexander V. Egorov, Irina E. Vlasova. Microstructure of Aged 238Pu-doped La-monazite Ceramic and Peculiarities of its X-ray Emission Spectra. MRS Advances. 2020; 5 (1-2):1-7.
Chicago/Turabian StyleAndrey A. Shiryaev; Boris E. Burakov; Vasily O. Yapaskurt; Alexander V. Egorov; Irina E. Vlasova. 2020. "Microstructure of Aged 238Pu-doped La-monazite Ceramic and Peculiarities of its X-ray Emission Spectra." MRS Advances 5, no. 1-2: 1-7.
X-ray absorption experiments at Ce L3 and M5 edges and theoretical calculations demonstrate that in addition to the nanoceria charge stability, the formation of hydroxyl groups at the surface affects the chemical performance of nanomaterials.
Tatiana V. Plakhova; Anna Yu. Romanchuk; Sergei M. Butorin; Anastasia D. Konyukhova; Alexander V. Egorov; Andrey A. Shiryaev; Alexander E. Baranchikov; Pavel V. Dorovatovskii; Thomas Huthwelker; Evgeny Gerber; Stephen Bauters; Madina M. Sozarukova; Andreas C. Scheinost; Vladimir K. Ivanov; Stepan N. Kalmykov; Kristina O. Kvashnina. Towards the surface hydroxyl species in CeO2 nanoparticles. Nanoscale 2019, 11, 18142 -18149.
AMA StyleTatiana V. Plakhova, Anna Yu. Romanchuk, Sergei M. Butorin, Anastasia D. Konyukhova, Alexander V. Egorov, Andrey A. Shiryaev, Alexander E. Baranchikov, Pavel V. Dorovatovskii, Thomas Huthwelker, Evgeny Gerber, Stephen Bauters, Madina M. Sozarukova, Andreas C. Scheinost, Vladimir K. Ivanov, Stepan N. Kalmykov, Kristina O. Kvashnina. Towards the surface hydroxyl species in CeO2 nanoparticles. Nanoscale. 2019; 11 (39):18142-18149.
Chicago/Turabian StyleTatiana V. Plakhova; Anna Yu. Romanchuk; Sergei M. Butorin; Anastasia D. Konyukhova; Alexander V. Egorov; Andrey A. Shiryaev; Alexander E. Baranchikov; Pavel V. Dorovatovskii; Thomas Huthwelker; Evgeny Gerber; Stephen Bauters; Madina M. Sozarukova; Andreas C. Scheinost; Vladimir K. Ivanov; Stepan N. Kalmykov; Kristina O. Kvashnina. 2019. "Towards the surface hydroxyl species in CeO2 nanoparticles." Nanoscale 11, no. 39: 18142-18149.
Several 238Pu-doped Eu monazite single crystals stored at ambient conditions are monitored for 15 years using Scanning and Transmission electron microscopy, spectroscopy, diffraction and optical microscopy. Despite preservation of high crystalline quality, mechanical cracking and formation of small flakes is observed. After several month of aging, a new phase appeared on surfaces of the crystals, which later formed a continuous shell of most crystallographic faces. Electron diffraction indicated that the shell consists of submicron Pu-containing rhabdophanes. Its formation likely occurs due to combined action of atmospheric moisture and recrystallisation of radiation damage in monazite domains adjacent to external and internal surfaces. Extent of the rhabdophane formation appears to be influenced by crystallography and Pu content of corresponding growth sectors of the parent monazite. Whereas macroscopic rhabdophanes and monazites are relatively stable against irradiation, formation of sub-microscopic particles is a point of concern for development of monazite-based ceramic forms for actinide immobilization.
Andrey A. Shiryaev; Boris E. Burakov; Maximillian S. Nickolsky; Vasily O. Yapaskurt; Anton D. Pavlushin; Mikhail S. Grigoriev; Irina E. Vlasova. Surface features on aged 238Pu-doped Eu-monazite. Radiochimica Acta 2019, 108, 353 -360.
AMA StyleAndrey A. Shiryaev, Boris E. Burakov, Maximillian S. Nickolsky, Vasily O. Yapaskurt, Anton D. Pavlushin, Mikhail S. Grigoriev, Irina E. Vlasova. Surface features on aged 238Pu-doped Eu-monazite. Radiochimica Acta. 2019; 108 (5):353-360.
Chicago/Turabian StyleAndrey A. Shiryaev; Boris E. Burakov; Maximillian S. Nickolsky; Vasily O. Yapaskurt; Anton D. Pavlushin; Mikhail S. Grigoriev; Irina E. Vlasova. 2019. "Surface features on aged 238Pu-doped Eu-monazite." Radiochimica Acta 108, no. 5: 353-360.
Structural peculiarities of several types of cryptocrystalline diamond varieties: carbonado, impact-related yakutite and cryptocrystalline diamond aggregates from kimberlite were studied using Infrared spectroscopy, X-ray diffraction contrast (DCT—Diffraction Contrast Tomography) and phase contrast tomography (PCT). It is shown that the porosity of the carbonado and kimberlitic cryptocrystalline aggregates is similar being in range of 5–10 vol %, possibly indicating similar formation mechanism(s), whereas that of yakutite is essentially zero. Crystallographic texture is observed for some carbonado samples. It is suggested that at least partially the texture is explained by deformation-related bands. Infrared spectroscopy reveals presence of hydrous and, probably, of hydrocarbon species in carbonado.
A. A. Shiryaev; F. V. Kaminsky; W. Ludwig; Denis Zolotov; A. V. Buzmakov; S. V. Titkov. Texture and Genesis of Polycrystalline Varieties of Diamond Based on Phase-Contrast and Diffraction Contrast Tomography. Geochemistry International 2019, 57, 1015 -1023.
AMA StyleA. A. Shiryaev, F. V. Kaminsky, W. Ludwig, Denis Zolotov, A. V. Buzmakov, S. V. Titkov. Texture and Genesis of Polycrystalline Varieties of Diamond Based on Phase-Contrast and Diffraction Contrast Tomography. Geochemistry International. 2019; 57 (9):1015-1023.
Chicago/Turabian StyleA. A. Shiryaev; F. V. Kaminsky; W. Ludwig; Denis Zolotov; A. V. Buzmakov; S. V. Titkov. 2019. "Texture and Genesis of Polycrystalline Varieties of Diamond Based on Phase-Contrast and Diffraction Contrast Tomography." Geochemistry International 57, no. 9: 1015-1023.
Based on extensive laboratory characterization of presolar nanodiamonds extracted from mete-orites, we have proposed a novel approach to detect nanodiamonds at astrophysical objects using the 7370 {\AA} emission band arising from lattice defects. Details of laboratory spectroscopic studies and preliminary results of observations are presented.
Andrey Shiryaev; Laurence Sabin; Gennady Valyavin; Gazinur Galazutdinov. On possibility of detection of emission from nanodiamonds in vicinity of stellar objects: laboratory spectroscopy and observational data. 2019, 1 .
AMA StyleAndrey Shiryaev, Laurence Sabin, Gennady Valyavin, Gazinur Galazutdinov. On possibility of detection of emission from nanodiamonds in vicinity of stellar objects: laboratory spectroscopy and observational data. . 2019; ():1.
Chicago/Turabian StyleAndrey Shiryaev; Laurence Sabin; Gennady Valyavin; Gazinur Galazutdinov. 2019. "On possibility of detection of emission from nanodiamonds in vicinity of stellar objects: laboratory spectroscopy and observational data." , no. : 1.