The migration of hydrogen in a homogeneously hydrogen-saturated commercial titanium VT1-0 has been studied using a high-frequency electromagnetic field and an accelerated electron beam. The use of a high-frequency 50–1000 kHz electromagnetic field, which generates eddy currents in the material, made it possible to observe the process of hydrogen migration near the surface and in the depth of the sample. To accelerate the migration of hydrogen in the volume of the sample electron irradiation with an energy of 30–45 keV was used. The migration process was studied in an inhomogeneously hydrogen-saturated commercial titanium sample with a titanium nitride film deposited on its surface by magnetron sputtering. VT1-0 flat samples were saturated with hydrogen using the Sieverts method. The diffusion coefficient of hydrogen in titanium was determined from the change in the magnitude of the signal from the eddy current sensor along the depth of the sample and along the sample, as hydrogen migrated in the sample. The values of the diffusion coefficients of hydrogen along the surface and in the depth of the sample under equilibrium conditions and under stimulation by an accelerated electron beam were obtained.

In this work, to obtain layered materials with the inclusion of hydrogen, Nb/Zr films with different numbers of layers from 50 to 100 were used. The films were sputtered onto a silicon substrate using the vacuum-magnetron method in a specialized installation. The film thickness was varied from 10 to 50 nm. The resulting material was hydrogenated with protons on a TPU electrostatic generator with an energy of up to 1,2 MeV. The optimal modes for deposition of nano-sized metal multilayer Zr/Nb systems have been determined: for a Zr target, the specific power of the sputtering system is 37,9 W/cm2, for a Nb target — 26,4 W/cm2. A coating with clear boundaries between the individual layers of zirconium and niobium was obtained. It is shown that the optimal modes for studying nano-sized Zr/Nb layers are pressure 700 Pa, power 40 W, frequency 2 kHz, plasma fill factor 12,5 % for coatings with a thickness of individual layers of 100 nm. For coatings with individual layer thicknesses from 10 to 50 nm, the optimal pressure is 650 Pa, power 40 W, frequency 1 kHz. To control properties, the thermopower method is used. It was revealed that after proton irradiation there is an intensive accumulation of hydrogen atoms near the interfaces, which entails a change in the thermopower up to an inversion of its sign. The hydrogen distribution is predominantly bimodal, with local maxima in hydrogen concentration observed at the Nb/Zr interface, and the accumulation at the Zr/Nb interface is significantly lower. Hydrogen localization near the interfaces occurs predominantly in the vicinity of zirconium.

Layered materials incorporating hydrogen were obtained using Nb/Zr films with varying numbers of layers from 50 to 100. The films were deposited on a silicon substrate using a vacuum magnetron sputtering method on a dedicated setup. The film thickness varied from 10 to 50 nm. The resulting material was hydrogenated with protons on a TPU electrostatic generator with an energy of up to 1.2 MeV. The deposition modes for nanoscale metallic multilayer Zr/Nb systems were determined: for a Zr target the specific power of the sputtering system was 37.9 W/cm2, and for a Nb target it was 26.4 W/cm2. A coating with clear boundaries between individual layers of zirconium and niobium was obtained. It was shown that the optimal conditions for studying nanoscale Zr/Nb layers are a pressure of 700 Pa, a power of 40 W, a frequency of 2 kHz, and a plasma filling factor of 12.5

The paper describes the results of a complex study of phytoplankton carried out at the end of August to the first half of September 2020 in the southeastern part of the Barents Sea and the southwestern part of the Kara Sea simultaneously with the determination of hydrological and hydrochemical characteristics. The taxonomic list of microalgae found in the studied area included 35 representatives identified to species. Of these, 14 (40

This paper describes the comprehensive studies of phytoplankton carried out in April 2018 in the northwestern Barents Sea, in the Polar Front region (74.8°–76.2° N), at a distance of 10–100 km from the ice edge at depths ranging from 0 to 50 m. The hydrological, hydrochemical, and microbiological parameters of the seawater are determined simultaneously. An early-spring species complex is observed on both sides of the front; 90% of the biomass of which is formed by the diatoms Pauliella taeniata, Fragilariopsis oceanica, and Thalassiosira antarctica var. borealis. The taxonomic composition of microalgae communities in water masses of different origin has an 83% similarity. The average abundance and biomass of microalgae and chlorophyll-a content per m2 in Atlantic waters reaches 37 170 cells/L, 0.12 μg/L, and 0.5 mg/m3, respectively. In Arctic waters, these values are about 30 times higher, 0.87 million cells/L, 2.59 μg/L, and 3.13 mg/m3, respectively. The results obtained suggest that the Polar Front is not a boundary between various algal communities, but separates highly productive Arctic waters from Atlantic waters with low phytoplankton abundance.

Automation is a topical issue in the development of methods and equipment for ultrasonic nondestructive testing. The conditions of modern industrial production require the development of ultrasonic testing equipment that would be sufficiently flexible for a wide and changing range of manufactured products, which, as a rule, have a complex shape. This paper proposes a technology for ultrasonic flaw detection of complex shaped objects. Within the framework of this technology, it is proposed to use six-axis robotic manipulators to ensure the required angle of input of ultrasonic waves into the test object at each measuring position. The correct trajectory of robot’s movement during scanning is ensured by reconstructing the surface profile of the test object using optical profilometry and determining the location of the test object relative to the robotic manipulator using an electric probe. The effectiveness of the developed technology is verified experimentally within the framework of this work.

Nowadays, automation is an actual issue in the development of methods and equipment for ultrasonic non-destructive testing. The conditions of modern industrial production require the development and application the automated testing equipment which is versatile to a wide range of manufactured products, which can have a complex shape. In this paper, we propose a technique for ultrasonic testing of complex-shaped objects. Such technique implies the application of six degrees of freedom robotic manipulators to ensure the required refraction angle of ultrasonic waves into the test object at each measuring position. The trajectory of the robot movement during scanning is provided by restoring the surface profile of the test object using optical profilometry and determining the location of the test object relative to the robotic manipulator using a probe tip. Within the framework of this work, the effectiveness of the developed technology is verified experimentally.

Shupeng Xu, V.V. Larionov, A.M. Lider The dielectric losses tgδ in hydrogenated titanium in the range of hydrogen concentration in titanium VT1-0 from 190 to 2900 ppm in the range of frequencies of eddy currents of 200-1000 kHz are investigated. The dependence of tgδ on the frequency has two well-defined peaks, which indicates an uneven distribution of hydrogen in the titanium in the depth of the sample. It is assumed that this method can determine the hydrogen concentration in the hydrogenated metal.

This paper presents some research results of the plankton laboratory MMBI RAS over the past 5 years. One of the main directions was the study of the structure of zooplankton communities and an assessment of their productivity off the coast of the Kola Peninsula and in the coastal waters of the Svalbard archipelago.Analysis of the vast perennial material revealed the main features of the spatial distribution of phytoplankton in the water area of the Pechora Sea. In the ice edge zone for nano-, micro-and zooplankton, the presence of ice edge effect in different seasons of the year is shown. It has been shown that in the Barents Sea, the Polar Front is not the boundary between various pelagic phytocenoses. During the polar night, virio-, bacterio-, phyto-and zooplankton were studied. When studyingthe deep-sea Barents Sea shelf, an autochthonous community of microalgae was found, the lower distribution limit of which is 300 m isobath.

Dielectric loss tangent tanδ in hydrogen-saturated VT1-0 titanium has been studied in the hydrogen concentration range 190–2000 ppm and eddy current frequency interval 200–1000 kHz. The frequency dependence of tanδ has two distinct peaks indicating that hydrogen is nonuniformly distributed along the depth of the titanium sample. It is supposed that this approach can be used to determine the hydrogen concentration in hydrogen-saturated VT1-0 metal.

Abstract—The processes of hydrogen migration in a titanium plate and inhomogeneous hydrogen saturation are studied by measuring the thermopower and eddy currents. The processes of inhomogeneous hydrogen saturation of commercial-purity VT1-0 titanium are developed, tested, and investigated using these methods of nondestructive testing. To achieve an inhomogeneous hydrogen concentration in a titanium plate, a TiN film 1–2.6 μm thick is deposited onto it by magnetron sputtering, and the parts of the plate free of the film are hydrogenated. The thermo-emf and eddy currents are measured at various probe coordinates before and after hydrogen saturation of the plate. Eddy current testing demonstrates that, after the plate is hydrogen saturated for 1.5 h, the thermo-emf on the side of hydrogen sorption is significantly lower than on the coated side. After 144 h, a uniform thermo-emf ​​ distribution is obtained, as follows from eddy current measurements. The thermo-emf study is performed upon heating at a constant rate. The thermo-emf of each part of the titanium alloy surface (including the uncoated part) is approximately equal to the value obtained before hydrogenation. The electrical resistivity of the coated titanium plate at room temperature is approximately 0.315 mΩ cm. After hydrogenation, the hydrogen content in the uncoated part decreases slowly. The thermo-emf also decreases gradually. A hydrogen content distribution can be formed via a thermo-emf distribution ​​in the titanium plate. After holding for a sufficiently long time, a uniform thermo-emf distribution forms in the plate.

Hydrogen saturation of titanium-based materials exposed to irradiation with resonance neutrons with an energy of 0.1 MeV is considered. Radioactive scandium Sc-22(46), gamma-quanta with energy of 889 and 1120 keV, and hydrogen form during nuclear reactions in titanium. The intensity of the gamma radiation depends on the concentration of hydrogen in titanium pre-saturated with hydrogen. The gamma field likely effects the excitation of the hydrogen subsystem of titanium. Irradiated materials in the presence of gamma radiation are controlled by measuring the thermo-emf. Hydrogenation of titanium exposed to neutron irradiation increases by 10-12%, which changes the thermo-emf by 20%. The temperature of components required to obtain the most hydrogen-saturated titanium corresponds to room temperature. Using this method, the hydrogen saturation time of material decreases and its amount of hydrogen increases. The effective conductivity energy is 0.17/0.5 mV K for unirradiated titanium and 0.122/0.5 mV K for irradiated titanium, change of 30%. The effect of gamma radiation must be considered when producing neutron shields based on titanium borides. Intermetallic compounds used for the accumulation and transportation of hydrogen and exposed to irradiation lose titanium atoms, negating the composition stoichiometry. The quality of commercial titanium saturated with hydrogen under these conditions improves. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Nickel films formed on the surface of zirconium alloys are often used to protect materials against hydrogen penetration. Hydrogen adsorption on nickel is faster since the latter actively interacts with hydrogen, oxidizes and forms a protective film. The goal of the study is to develop a method providing control of hydrogen absorption by nickel films during vacuum-magnetron sputtering and hydrogenation via measuring thermoEMF. Zirconium alloy E110 was saturated from the gas phase with hydrogen at a temperature of 350°C and a pressure of 2 atm. A specialized Rainbow Spectrum unit was used for coating. It is shown that a nickel film present on the surface significantly affects the hydrogen penetration into the alloy. A coating with a thickness of more than 2 μm deposited by magnetron sputtering on the surface of a zirconium alloy with 1% Nb, almost completely protects the alloy against hydrogen penetration. The magnitude of thermoemf depends on the hydrogen concentration in the zirconium alloy and film thickness. An analysis of the hysteresis width of the thermoEMF temperature loop and a method for determining the effective activation energy of the conductivity of a hydrogenated material coated with a nickel film are presented. The results of the study can be used in assessing the hydrogen concentration and, hence, corrosion protection of the material.

A change in the natural composition of titanium subjected to neutron irradiation with energies up to 0.1 MeV is shown. The process is accompanied by the formation of hydrogen and radioactive scandium. Gamma rays with energies of 889 and 1120 keV are observed. The effect of changing the natural composition of the titanium alloy and the presence of gamma studies should be taken into account when creating structural products and when creating a neutron shield based on titanium.

Hydrogen saturated samples of technically pure titanium have been studied by the electron-positron annihilation method (EPA), coupled with the thermoelectric power measurements performed in these samples saturated by different amount of hydrogen. The structure of the hydrogenated samples was additionally investigated by X-ray diffraction. The complete coincidence of the moment of occurrence of a change in the structure of hydrogenated titanium depending on the amount of introduced hydrogen has been established. The intensity of positron annihilation drops with increasing hydrogen concentration in α-titanium to 0.04 wt % and then remains unchanged up to values of 0.05 wt % ($$\alpha + \delta $$) -titanium to increases afterwards. At the same time, a sharp change in the values of the thermoelectric power occurs in this range. In the region of 0.05%, the annihilation rate stabilizes and begins to increase, while the thermoelectric power begins to decrease slowly. The inflection point on the dependence of thermoelectric power on hydrogen concentration corresponds to the onset of the formation of titanium $$\delta $$-hydrides. An increase in the positron lifetime is observed in the concentration range of 0.05–0.08 wt %, then the lifetime stays stable up to concentrations of 0.08–0.12 wt %. A transition from ($$\alpha + \beta $$) to ($$\alpha + \delta $$) phase is formed in this range. Next, the positron lifetime increases, as does the number of defects, while the thermoelectric power gradually drops (to a concentration of 0.24 wt %). This is followed by a stabilization mode of all the above parameters to 0.35 wt %.

The mechanical properties of the hydrogenated zirconium alloy Zr-1Nb are studied under different conditions for hydrogen removal by an electron beam and thermal heating. The mechanical testing of zirconium samples is analyzed during hydrogenation and irradiation with a low energy electron beam. The plasticity of the samples is shown to be increased during the radiation stimulation of hydrogen removal from zirconium by even a weak electron beam. In this case, the tensile strength (ultimate strength) is practically not changed.

We study the procedure of hydrogen removal from welded joints of 12Kh18N10T sheet steel by the irradiation with electrons with the simultaneous monitoring of its temperature. We perform the quantitative evaluation of the duration of hydrogen removal from the weld in the process of its formation and determine the main factors affecting the possibility of application of the proposed procedure.

This paper considers metal hydrogenation and hydrogen release from metals under electron irradiation. The study shows that there are two processes during irradiation: the increase in the hydrogen yield from metal and the increase in the ability of hydrogenated metal to accumulate the energy of a beam of accelerated electrons. The energy introduced into hydrogenated metal is preserved for a longer period when compared to pure metal in time scales of electronic relaxation. Electron irradiation accelerates the saturation of metals with hydrogen and deuterium. Deuterium and hydrogen participate in the collective excitation of the internal hydrogen atmosphere of metals. This effect is explained by the nonequilibrium migration and release of hydrogen from metals. The migration of hydrogen isotopes during irradiation can be used to enhance the light isotope separation.

The paper represents the investigations concerning the geometrical size effect of hydrogenated zirconium alloys (Zr-1Ni-H) during gamma-ray irradiation on the amount of energy absorbed. The results have shown that the less the cross-sectional dimensions of the sample or product is, the less energy is absorbed. The paper provides theoretical calculations. The zirconium sample with a cross-section of 2.8х2.8 cm absorbs 30-35% of the energy of the incident gamma-ray flow. The increase in the cross-section of a product up to 28 cm leads to the increase in the absorbed energy by more than 2 times. At the same time, the thickness of the product is constant. This effect is explained by the multiple scattering of gamma-rays. It leads to the nonuniform distribution of defects which can accumulate hydrogen and should be considered when developing the analysis methods. These edge effects are confirmed by the measurement of the thermal electromotive force for the samples of zirconium alloys before hydrogenation and gamma-ray irradiation, and after irradiation.