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The article investigates the issues of metrological support of acoustic emission means of nondestructive testing and diagnostics designed to improve the accuracy and veracity of control results to ensure safe and accident-free equipment operation at hazardous production facilities and structures. The composition of the State Primary Standard of the units of the amplitude of ultrasonic displacement, the vibrational velocity of the solid media surface, and the electroacoustic conversion coefficient, GET 194-2022 is presented. The reference installation "Coefficient," developed according to the laser interferometric measurement method and included in GET 194-2022 for reproducing units of electroacoustic conversion coefficient, is described, along with its operation principle. The metrological characteristics of GET 194-2022 are presented. The scope of the standard application is indicated, including the scientific and technical support for the uniformity and required accuracy of acoustic measurements in solid media, thus increasing the veracity of the results, reducing the risk of technogenic accidents, metrological assurance of hygienic requirements when working with sources of "contact ultrasound" on surfaces in contact with the operator's hands. [ABSTRACT FROM AUTHOR]

This work describes a silicon tracker system developed for experiments with proton-rich radioactive ion beams at the SAMURAI superconducting spectrometer of RIBF at RIKEN. The system is designed for accurate angular reconstruction and atomic number identification of relativistic heavy ions and protons which are simultaneously produced in reactions motivated by studies of proton capture reactions of interest for nuclear astrophysics. The technical characteristics of the tracking array are described in detail as are its performance in two pilot experiments. The physics justification for such a system is also presented. [ABSTRACT FROM AUTHOR]

Quasi-free scattering of electrons and protons has been extensively utilized in the past to study the single-particle structure of nuclei, clustering in light nuclei, and short-range correlated nucleon–nucleon pairs in nuclei. Recently, this approach has been applied in inverse kinematics using hydrogen targets. The characteristic features of this reaction and the experimental challenges and advantages of inverse-kinematics experiments are summarized. The applicability to radioactive beams opens a large research potential to study a variety of properties of neutron-to-proton asymmetric nuclei. Applications of quasi-free scattering in inverse kinematics and its potential are reviewed based on recent and ongoing research programs at different accelerator facilities worldwide. [ABSTRACT FROM AUTHOR]

The quasi-free scattering reactions 11C (p , 2 p) and 10,11,12C (p , p n) have been studied in inverse kinematics at beam energies of 300–400 MeV/u at the R3B-LAND setup. The outgoing proton-proton and proton-neutron pairs were detected in coincidence with the reaction fragments in kinematically complete measurements. The efficiency to detect these pairs has been obtained from GEANT4 simulations which were tested using the 12C(p , 2 p) and 12C(p , p n) reactions. Experimental cross sections and momentum distributions have been obtained and compared to DWIA calculations based on eikonal theory. The new results reported here are combined with previously published cross sections for quasi-free scattering from oxygen and nitrogen isotopes and together they enable a systematic study of the reduction of single-particle strength compared to predictions of the shell model over a wide neutron-to-proton asymmetry range. The combined reduction factors show a weak or no dependence on isospin asymmetry, in contrast to the strong dependency reported in nucleon-removal reactions induced by nuclear targets at lower energies. However, the reduction factors for (p , 2 p) are found to be 'significantly smaller than for (p , p n) reactions for all investigated nuclei. [ABSTRACT FROM AUTHOR]

The nuclear structure of 66Se, nucleus beyond the N = Z line on the proton-rich side of the valley of stability, was investigated by the neutron knock-out reaction 67Se(12C,X)66Se using a 12C target. The analysis of the singles spectrum of the γ -rays emitted during the de-excitation of the populated low-lying excited states revealed two previously detected (927(4) keV, 1460(32) keV) and three new (744(6) keV, 1210(17) keV, 1661(23) keV) transitions. The 744-keV, the 1210-keV, and the 1460-keV transitions were found to be in coincidence with the one at 927 keV. The spectrum coincident with the 927-keV transition showed a further possible transition at 299(35) keV, which was obscured by significant atomic background in the singles spectrum. This transition might correspond to a peak previously reported at 273(5) keV that could not be assigned to 66Se unambiguously. Based on a comparison of the experimental data to theoretical calculations, four new excited states are proposed which suggest that 66Se exhibits shape coexistence. [ABSTRACT FROM AUTHOR]

The evolution/degradation of the structure and phase composition of rail head material of 100-meter differentially quenched rails after extremely long-term operation is analyzed. It is shown that similar conditions of loading result in different structural transformations on the rail head surface. The formation of lattice curvature in crystal interstitial sites and initiation of highly mobile interstitial structural states there cause a dissolution of pearlite. It occurs at a depth of ≈10 mm. It is superimposed by the formation of a nanoscale substructure in the tread surface in a layer ≈2 mm thick. The nanoparticles of the carbide phase precipitate on the boundaries of the substructure. The failure of the rail metal will proceed, in the first place, in the surface layer where a critical level of the crystal lattice curvature is formed and the concentration of interstitial vacancies is maximum. [ABSTRACT FROM AUTHOR]

It is shown that, under an electroexplosive spraying of coatings of various systems, the dynamic rotation of the particles deposited is the basis for forming a vortex hierarchically organized structure in both the coating and upper layers of the substrate, including their interface. This causes dispersion of all the structural elements of the cover, their mutual penetration into each other, and the absence of a sharp interface between the coating and the substrate. The impact of multiple shocks on the deposited coating by a highenergy plasma jet from the discharge of a plasma accelerator creates the forged structure in the material, which is characterized by high strength, wear resistance, and relaxation capability. [ABSTRACT FROM AUTHOR]

Quasi-free scattering reactions of the type ( p , 2 p ) were measured for the first time exclusively in complete and inverse kinematics, using a 12 C beam at an energy of ∼ 400 MeV / u as a benchmark. This new technique has been developed to study the single-particle structure of exotic nuclei in experiments with radioactive-ion beams. The outgoing pair of protons and the fragments were measured simultaneously, enabling an unambiguous identification of the reaction channels and a redundant measurement of the kinematic observables. Both valence and deeply-bound nucleon orbits are probed, including those leading to unbound states of the daughter nucleus. Exclusive ( p , 2 p ) cross sections of 15.8(18) mb, 1.9(2) mb and 1.5(2) mb to the low-lying 0 p -hole states overlapping with the ground state ( 3 / 2 − ) and with the bound excited states of 11 B at 2.125 MeV ( 1 / 2 − ) and 5.02 MeV ( 3 / 2 − ), respectively, were determined via γ -ray spectroscopy. Particle-unstable deep-hole states, corresponding to proton removal from the 0 s -orbital, were studied via the invariant-mass technique. Cross sections and momentum distributions were extracted and compared to theoretical calculations employing the eikonal formalism. The obtained results are in a good agreement with this theory and with direct-kinematics experiments. The dependence of the proton–proton scattering kinematics on the internal momentum of the struck proton and on its separation energy was investigated for the first time in inverse kinematics employing a large-acceptance measurement. [ABSTRACT FROM AUTHOR]

A theoretical and experimental analysis of the influence of the dispersed transition layer between a coating and a substrate on the development of deformation structures near the interface has been performed as part of an interdisciplinary study of the deformation and fracture of coating-substrate compositions under contact interaction. Elastic energy transfer from an indenter was simulated using excitable cellular automata taking into account the self-organization of translations and rotations of the structure near the interface. The effect of the transition layer between the coating and the substrate on the development of deformation structures during contact interaction with the indenter in three-point bending was studied experimentally using a TOMSC television-optical measuring complex. [ABSTRACT FROM AUTHOR]

The multiscale mechanism of fatigue fracture of titanium with the surface layer hydrogenated under alternating bending at room temperature is studied. It is shown that the generation of the fatigue fracture occurs in the surface layer subjected to plastic deformation in conjunction with an elastically loaded substrate. The latter causes the appearance of a strong curvature of the material and the appearance of micropores in these areas along with any fatigue cracks. The emergence of the local curvature of the crystal structure plays a central role in the origin and the development of the fatigue fracture as the structural phase decomposition of the material under cyclic loading. [ABSTRACT FROM AUTHOR]

The simultaneous PET data reconstruction of emission activity and attenuation coefficient distribution is presented, where the attenuation image is constrained by exploiting an external transmission source. Data are acquired in timeof- flight (TOF) mode, allowing in principle for separation of emission and transmission data. Nevertheless, here all data are reconstructed at once, eliminating the need to trace the position of the transmission source in sinogram space. Contamination of emission data by the transmission source and vice versa is naturally modeled. Attenuated emission activity data also provide additional information about object attenuation coefficient values. The algorithm alternates between attenuation and emission activity image updates. We also proposed a method of estimation of spatial scatter distribution from the transmission source by incorporating knowledge about the expected range of attenuation map values. The reconstruction of experimental data from the Siemens mCT scanner suggests that simultaneous reconstruction improves attenuation map image quality, as compared to when data are separated. In the presented example, the attenuation map image noise was reduced and nonuniformity artifacts that occurred due to scatter estimation were suppressed. On the other hand, the use of transmission data stabilizes attenuation coefficient distribution reconstruction from TOF emission data alone. The example of improving emission images by refining a CT-based patient attenuation map is presented, revealing potential benefits of simultaneous CT and PET data reconstruction [ABSTRACT FROM AUTHOR]

The authors discuss the acceleration of fatigue failure in cracks of cyclic loading for mesomechanics of a two-layer composite material. They state that polycrystalline foils have been glued to rigid massive plates to prepare two-layer composites for alternate bending. The authors note that zigzag mesobands of localized strain have yielded well-defined back surfaces of unstuck foil.

The authors emphasize advisability of the geomechanical laws and rules to be included in the geotechnical decision-making in terms of the Khibiny rock mass state assessment using numerical modeling. A procedure of finding seismic-hazardous sites in rocks by the seismicity parameters is described. The geomechanical control methods are presented for the surface and underground mining systems to achieve higher safety and efficiency mineral extraction. [ABSTRACT FROM AUTHOR]

The nonlinear dynamics of the instability developed upon the interaction between a relativistic electron beam and a dense plasma as a function of the beam density is numerically modeled. The appropriate solutions are obtained and analyzed. [ABSTRACT FROM AUTHOR]

The article discusses the analysis of processes of neck formation and viscous fracture with the multilevel relation between the plastic flow and structure. The study aims to investigate the laws of plastic flow at the macroscale and mesascale levels through local characteristics of strain measurement and constructing the distribution patterns. The author concludes that the central neck volume is the most favorable for the development of cracks because of high intensity in both symmetric.

By simultaneously using approaches of mesomechanics and nonequilibrium thermodynamics, it is shown that any nanoinclusions, including those with a low elastic modulus, and nanopores cause material strengthening. [ABSTRACT FROM AUTHOR]

new flotation machine of the reactor-separator type has been designed based on the creation of compatible hydrodynamic conditions for control of the main stages of the flotation process in spatially separated zones of the machine. The dependence of the efficiency of the flotation process on the time of residence of the pulp in the reactor is shown to be of an extreme nature and is determined by the ratio of the rates of formation and destruction of flotation complexes and the rate of coalescence of the bubbles. The manner in which the zones in reactor-separators are organized and connected to one another for the selective flotation of mineral particles should be significantly different than for the treatment of waste water. The application of external vibrations (ultrasound) to mineralized air bubbles in the reactor zone makes it possible to independently regulate the process of particle separation and enhances selectivity in the division of copper sulfides from nickel sulfides. [ABSTRACT FROM AUTHOR]

The paper deals with an analysis of two kinds of multiple cracking in a loaded solid with a brittle coating. First is the front-wise development of opening mode cracks, while the second is the formation of a system of sliding mode cracks along conjugate directions of maximum tangential stresses τ max. The mesomechanics of each kind of multiple cracking is discussed. The conditions which provide an increase in both the strength and the ductility of a loaded solid experiencing multiple cracking are formulated; the essence of the model is the growth of cracks in the sliding mode along conjugate directions of maximum tangential stresses [ABSTRACT FROM AUTHOR]

Theoretical and experimental investigation is performed into the relation between plastic strain localizations of different scale in solids and the respective stress concentrators arising in the surface layer and at internal interfaces. It is found that localized plastic flow of any kind may form and propagate only under strongly nonequilibrium conditions in the zones of normal tensile stress. In the presence of excessive atomic volume, virtual nodes of a structure with higher energy emerge in the space of interstitials and a local structural transformation occurs via collective atom-vacancy configuration excitations. It is concluded that the nature of the plastic flow localization should be described on the basis of representation of strained solid as a multilevel system. [ABSTRACT FROM AUTHOR]

A conceptual substantiation of the necessity to consider the nanoscale structural level of plastic strain in the physics of plasticity and strength of solids is presented. It is inferred that the fundamental mechanism of plastic strain is represented by local structural transformations (of the type of rearrangement of atomic clusters of various configurations) that occur in a loaded solid in local zones of tensile normal stresses. This mechanism determines generality of the nature of all possible kinds of plastic deformation of solids. [ABSTRACT FROM AUTHOR]

The article reports on a study that analyzes the chess-board effect for the surface layer of quasi-periodic stress-strain distribution at their interfaces of a deformed solid. Structural studies based on alternating bending of commercial pure titanium were performed to experimentally verify the chess-board shape of the strain distribution.

The quality of images reconstructed by statistical iterative methods depends on an accurate model of the relationship between image space and projection space through the system matrix. The elements of a system matrix on the HiRez scanner from CPS Innovations were acquired by positioning a point source at different positions in the scanner field of view. Then, a whole system matrix was derived by processing the responses in projection space. Such responses included both geometrical and detection physics components of the system matrix. The response was parameterized to correct for point source location, smooth projection noise and the whole system matrix was derived. The model accounts for axial compression (span) used on the scanner. The projection operator for iterative reconstruction was constructed using the estimated response parameters. Computer-generated and acquired data were used to compare reconstruction obtained by the HiRez standard software and that produced by better modeling. Results showed that better resolution and noise property can be achieved with the modeled system matrix. [ABSTRACT FROM AUTHOR]

Analyzes the role of mesoscopic mechanisms of cyclic deformation in the surface layers of polycrystals with strongly varied parameters in the presence of fatigue failure. Study of the polycrystals of titanium, aluminum, and lead and its alloys; Different homological temperatures of the polycrystals; Composition and parameters of the materials under investigation.

Analysis of experimental results obtained in recent years is used for concluding that surface layers of loaded solid bodies are an independent subsystem in which wave mechanisms of plastic yielding develop and determine the nucleation of primary strain-induced defects of all kinds. These processes play the role of synergetic activator of plastic yielding in the bulk of deformed solids. [ABSTRACT FROM AUTHOR]

The results of the investigations performed in collaboration with our co-workers are reviewed and used to formulate a conceptual framework of the physical mesomechanics of nanostructured materials. Low plasticity of materials of this kind is associated with suppression of the microscale deformation due to the motion of dislocations and with development of meso- and macroscale localized-deformation bands. For an optimum combination of strains at the micro- and mesoscale levels, formation of a nanocrystalline structure provides high strength and plastic properties of the materials. Strain localization at the macroscale level impairs the strength and plasticity of nanostructured materials. [ABSTRACT FROM AUTHOR]

ABSTRACT Electron-beam deposition (EBD) is an advanced technique intended for the formation of protective coatings that exhibit high strength and wear, and fatigue resistance. The investigation of the structure of coated materials and the development of mesoscale plastic deformation shows that these properties depend heavily on EBD modes. It is proposed that the latter can be optimized by: (i) choosing the electron-beam parameters that ensure a uniform structure of the coating, appropriate width and proper structure of the transient zone, (ii) the trial-and-error method of selecting such deposited powder composition that ensure high strength properties, and (iii) mechanical test aimed at distinguishing the coatings whose performance has been advantageously increased by EBD. [ABSTRACT FROM AUTHOR]

Using a television optical TOMSC system, regular features of localization of macroplastic deformation are studied in composite aluminum-based materials with hard inclusions of Al[SUB2]O[SUB3] under tension. Before investigation, the specimens are subjected to cold rolling, tempering for 30 min at 500 °C with subsequent cooling in air, and annealing at 550 °C during 2 h with subsequent cooling in furnace. It is shown that the tempered and annealed alloys exhibit mobile centers of active macrolocalization long before the formation of a stationary neck preceding material fracture. Physical mesomechanics, relying on the concepts of the leading role of different-scale stress concentrators that relax and develop in a loaded heterogeneous material, is capable of providing a qualitative description of macrolocalization development. [ABSTRACT FROM AUTHOR]

Investigates the mesomechanics of failure in cold-rolled metal polycrystals subjected to tension. Evolution of the deformation mesostructures; Curves of plastic flow in polycrystals of armco iron; Level of deforming stresses.

Studies the mechanism for developing fatigue fracture in surface layers of aluminum polycrystals under cyclic loading. Patterns of the strain mechanism in surface layers; Nucleation of surface cracks in coarse grains; Directions of displacement vectors.

Provides information on a study which proposed an iterative Bayesian image reconstruction algorithm based on the total variation norm constraint. Likelihood distribution of maximum likelihood-expectation maximization algorithm and divergence; Maximum a posteriori estimate; Results and conclusion.

The nucleation and propagation of mesoscopic inelastic deformation bands in the two-level non-equilibrium surface layer-substrate system under uniaxial tension conditions has been studied using the method of stochastic excitable cellular automata. It is demonstrated that mesoscopic inelastic deformation bands are nucleated in the regions of tensile normal stresses at the interface and then propagate in depth of the substrate along the conjugated directions of maximum tangent stresses (τmax). The intersection of mesoscopic inelastic deformation bands propagating in the two adjacent conjugated τmax directions terminates their development. [ABSTRACT FROM AUTHOR]

The Facility for Antiproton and Ion Research (FAIR) is in its final construction stage next to the campus of the Gesellschaft für Schwerionenforschung Helmholtzzentrum for heavy-ion research in Darmstadt, Germany. Once it starts its operation, it will be the main nuclear physics research facility in many basic sciences and their applications in Europe for the coming decades. Owing to the ability of the new fragment separator, Super-FRagment Separator, to produce high-intensity radioactive ion beams in the energy range up to about 2 GeV/nucleon, these can be used in various nuclear reactions. This opens a unique opportunity for various nuclear structure studies across a range of fields and scales: from low-energy physics via the investigation of multi-neutron systems and halos to high-density nuclear matter and the equation of state, following heavy-ion collisions, fission and study of short-range correlations in nuclei and hypernuclei. The newly developed reactions with relativistic radioactive beams (R3B) set up at FAIR would be the most suitable and versatile for such studies. An overview of highlighted physics cases foreseen at R3B is given, along with possible future opportunities, at FAIR. This article is part of the theme issue 'The liminal position of Nuclear Physics: from hadrons to neutron stars'. [ABSTRACT FROM AUTHOR]

The Facility for Antiproton and Ion Research (FAIR) is in its final construction stage next to the campus of the Gesellschaft für Schwerionenforschung Helmholtzzentrum for heavy-ion research in Darmstadt, Germany. Once it starts its operation, it will be the main nuclear physics research facility in many basic sciences and their applications in Europe for the coming decades. Owing to the ability of the new fragment separator, Super-FRagment Separator, to produce high-intensity radioactive ion beams in the energy range up to about 2 GeV/nucleon, these can be used in various nuclear reactions. This opens a unique opportunity for various nuclear structure studies across a range of fields and scales: from low-energy physics via the investigation of multi-neutron systems and halos to high-density nuclear matter and the equation of state, following heavy-ion collisions, fission and study of short-range correlations in nuclei and hypernuclei. The newly developed reactions with relativistic radioactive beams (R3B) set up at FAIR would be the most suitable and versatile for such studies. An overview of highlighted physics cases foreseen at R3B is given, along with possible future opportunities, at FAIR. This article is part of the theme issue 'The liminal position of Nuclear Physics: from hadrons to neutron stars'. [ABSTRACT FROM AUTHOR]

Laws governing the buildup of fatigue fracture under cyclic loading of aluminum alloy polycrystals under conditions of multicycle fatigue have been studied by analyzing the spacetime dynamics of mesoscopic structures. It has been shown that under the periodic action of an external mechanical field, deformation domains form in the material at the mesoscopic level. The evolution of these dynamic mesoscopic domain substructures determines the kinetics of the fatigue fracture of the polycrystals. [ABSTRACT FROM AUTHOR]

The proton-removal mechanism of the 12C → 11 B reaction induced on a carbon target via elementary nucleon-nucleon scattering is investigated in exclusive triple-coincidence measurements. The observed two-nucleon angular correlations are found to be consistent with quasi-free scattering of a projectile-like proton off a target-like nucleon. Exclusive cross sections for one-step pp and pn interactions are determined as σ p p = 17.2 (12) mb and σ p n = 18.2 (18) , respectively. The extracted quasi-free component amounts up to 58(4)% of the total proton-removal cross section. The results are compared to total proton-removal cross sections obtained from the experiment and eikonal reaction theory. [ABSTRACT FROM AUTHOR]