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In this article, the results of modeling a new technology for processing stainless steel wire in the Deform software package are compared with the results of a laboratory experiment. The new technology consists in preheat treatment to obtain an austenitic microstructure and traditional drawing, followed by cryogenic cooling in nitrogen. The analysis of the microstructure evolution during modeling showed that as a result of such processing, an ultrafine-grained microstructure in a wire can be obtained. Moreover, the level of martensite formation is directly dependent on the presence of metal cryogenic cooling. Thus, when processing a thin billet from 6 to 5 mm, the most effective conditions under which martensite is formed in almost the entire section are a reduced drawing speed and the absence of intermediate heating. In this case, the level of martensite in the cross section is 88%. The results of the laboratory experiment confirm the simulation results. As a result of deformation of stainless steel wire using a new technology, an ultrafine-grained microstructure consisting of a mixture of austenite and α—martensite was obtained.

Sodium ion battery (SIB) technology offers an attractive alternative to rechargeable batteries in large-scale applications. To meet the practical demands, it is essential to develop stable electrode materials with a high capacity and high energy density. Herein, we demonstrate a successful activation of the Nb5+/Nb4+, Nb4+/Nb3+, and Cr3+/Cr2+redox couples in NASICON-structured NaCrNb(PO4)3, thus introducing a novel three-electron reaction anode for sodium ion batteries with a high specific capacity. Carbon-coated NaCrNb(PO4)3synthesized using the Pechini sol–gel method demonstrates the reversible capacity of 162 mA h·g–1at the 1C rate and good cycling stability. This is the first example of NASICON-type anode material with the Cr3+/Cr2+reversible transition confirmed by Cr K-edge XANES measurements. Operandopowder X-ray diffraction showed that sodium insertion–extraction in NaCrNb(PO4)3proceeds through a combination of single-phase and biphasic processes. A differential scanning calorimetry study revealed the excellent thermal stability of NaCrNb(PO4)3, exceeding that of hard carbon anodes. Attractive electrochemical properties of NaCrNb(PO4)3, its high thermal and cyclic stability, and the scalable synthesis of this material demonstrate its potential as an anode for use in sodium ion batteries.

The modification of photocathodes based on copper(I) oxide (COPC) by coating with ZnO nanoparticles or graphene oxide (GO) with different compositions and morphologies is considered. To cover the catalyst surface with graphene oxide, a technique was proposed via freezing of a sprayed aqueous suspension of graphene oxide followed by sublimation drying under vacuum conditions. This method improves the uniformity of the GO layer in comparison with the traditional drop-casting method and, as a result, improves the photocatalytic properties of the COPC. The influence of the composition and morphology of graphene oxide on the photocatalytic activity and stability of COPC has been established. ZnO nanoparticles and GO particles in contact with copper(I) oxide increase the photocurrent density by the more efficient separation of light-generated charge carriers, providing higher photocathode stability required in photocatalytic water splitting.

Subjecting a physical system to extreme conditions is one of the means often used to obtain a better understanding and deeper insight into its organization and structure. In the case of the atomic nucleus, one such approach is to investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich isotopes exhibit the most asymmetric N/Zratios and those lying beyond the limits of binding, which undergo spontaneous neutron emission and exist only as very short-lived resonances (about 10−21s), provide the most stringent tests of modern nuclear-structure theories. Here we report on the first observation of 28O and 27O through their decay into 24O and four and three neutrons, respectively. The 28O nucleus is of particular interest as, with the Z= 8 and N= 20 magic numbers1,2, it is expected in the standard shell-model picture of nuclear structure to be one of a relatively small number of so-called ‘doubly magic’ nuclei. Both 27O and 28O were found to exist as narrow, low-lying resonances and their decay energies are compared here to the results of sophisticated theoretical modelling, including a large-scale shell-model calculation and a newly developed statistical approach. In both cases, the underlying nuclear interactions were derived from effective field theories of quantum chromodynamics. Finally, it is shown that the cross-section for the production of 28O from a 29F beam is consistent with it not exhibiting a closed N= 20 shell structure.

NASICON-type NaNbV(PO4)3electrode material synthesized by the Pechini sol–gel technique undergoes a reversible three-electron reaction in a Na-ion cell which corresponds to the Nb5+/Nb4+, Nb4+/Nb3+, and V3+/V2+redox processes and provides a reversible capacity of 180 mAh·g–1. The sodium insertion/extraction takes place in a narrow potential range at an average potential of 1.55 V versus Na+/Na. Structural characterization by operandoand ex situX-ray diffraction disclosed the reversible evolution of the NaNbV(PO4)3polyhedron framework during cycling, while XANES measurements in the operandoregime confirmed the multielectron transfer upon sodium intercalation/extraction into NaNbV(PO4)3. This electrode material demonstrates extended cycling stability and excellent rate capability maintaining the capacity value of 144 mAh·g–1at 10 C current rates. It can be regarded as a superior anode material suitable for application in high-power and long-life sodium-ion batteries.

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We present the results of simulations and experimental studies of a W-band surface-wave oscillator powered by a ribbon high-current relativistic electron beam produced by SINUKI accelerator (IAP RAS, Nizhny Novgorod, 1 kA / 650 keV / 17 ns). Planar geometry of the interaction space facilitates efficient mode selection over wide transverse coordinate by using open waveguide at fairly large oversize factor (the width of the waveguide is ~8 wavelengths). Stable oscillation regime is obtained at frequency of 75 GHz with a pulse duration of about 5 ns. The output power measured by the calorimetric method reaches 25 MW.

Hospital wards are noisy environments, and this has been recognised as a global healthcare challenge. Excessive noise can reduce staff performance and disrupt patients' sleep, delaying their recovery and leading to a prolonged stay. Research has suggested that digital noise display devices can alert ward staff and prompt them to reduce noise levels, but the literature on this topic varies. This systematic review summarises the evidence regarding the use of digital noise display devices as the primary intervention to reduce noise levels in hospital wards. The authors searched CINAHL, MEDLINE and PubMed databases, as well as manually harvesting through the references. A total of 1110 articles were identified, of which eight were eligible for inclusion. Thematic analysis was used to synthesise the findings. The evidence demonstrated that digital noise display interventions could reduce noise levels in wards by 2–3 decibels and raise staff awareness of noise. However, there was a lack of evidence that this intervention changed staff behaviour regarding noise levels. Further research is required to explore the experiences of patients and staff to understand if and how these devices changed behaviour towards noise.

ZnO nanorods codoped with Fe, Li (ZnO:Fe,Li) with a diameter of 50–100 nm and a length of 0.5–5 μm were obtained by thermal growth from salt mixtures. The HAADF-STEM, EDX, and AAS analysis showed that the nanorods grew in the [001] direction as single crystals with a wurtzite structure and contain 2.05% Fe and 1.95% Li. A detailed study of ZnO:Fe,Li nanorods using X-ray diffraction, X-ray absorption, Mössbauer spectroscopy, and cathodoluminescence spectroscopy revealed the incorporation of Fe and Li atoms into the nanocrystal lattice, which can lead to ferroelectric behavior of ZnO multiferroic structures, usually fabricated by codoping with transition metals and lithium.

A long-standing question in nuclear physics is whether chargeless nuclear systems can exist. To our knowledge, only neutron stars represent near-pure neutron systems, where neutrons are squeezed together by the gravitational force to very high densities. The experimental search for isolated multi-neutron systems has been an ongoing quest for several decades1, with a particular focus on the four-neutron system called the tetraneutron, resulting in only a few indications of its existence so far2–4, leaving the tetraneutron an elusive nuclear system for six decades. Here we report on the observation of a resonance-like structure near threshold in the four-neutron system that is consistent with a quasi-bound tetraneutron state existing for a very short time. The measured energy and width of this state provide a key benchmark for our understanding of the nuclear force. The use of an experimental approach based on a knockout reaction at large momentum transfer with a radioactive high-energy 8He beam was key.

Abstract: The structure and stressed state of AMg6 alloy have been studied after laser shock processing without protective coating. The method of layer-by-layer X-ray structural analysis has revealed a correlation between the parameters of crystalline structure and the profile of residual stresses of the processed samples. After laser processing, the sizes of coherent scattering regions on the material surface decrease to 50 nm, the value of microstrains increases to 0.0019, and the average dislocation density increases to 4.7 × 1014m–2. The profile and the depth of the residual compressive stresses depend on the power density, coefficient of overlapping of laser spots, and multiplicity of processing, reaching 2 mm.

A special design of the die was developed, which allows to implement the process of severe plastic deformation by high pressure torsion to deform ring blanks, which will be the starting material for creating high-strength piston rings. A special feature of the die design is the provision of torsion of the deforming tool with constant rectilinear movement of the press punch due to the composite deforming tool, which includes both displacement and rotation blocks. Using the obtained geometry, computer simulation of this process in the Deform program was performed in order to assess the possibility of a stable process flow. AISI-316 austenitic stainless steel was chosen as the material of the billet. The resulting strain force on the first two cycles was considered. On the first cycle, the force was equal to 464 kN, on the second cycle the force value was about 1200 kN. The obtained values are quite adequate, which indicates the possibility of multi-cycle deformation.

The paper analyzes the influence of various geometric factors on the destruction possibility of aluminum alloys during pressing in an equal-channel step matrix, which allows to obtain an ultrafine-grained structure. It is found that the angle of the junction of the matrix channels has a significant effect on the Cockroft-Latham damage criterion, in contrast to the length of the inclined channel of the matrix. The most optimal value of the joint angle is 135° - in this case, the metal is processed with a sufficiently high intensity at a low level of the fracture criterion. The length of the inclined channel of the matrix is recommended to use no more than 15 mm to reduce the level of damage.

Recycling of waste, both ferrous and non-ferrous metals is a useful process for the economy of any country. In this paper, a new technology for recycling bar scrap of ferrous metals by rolling on radial-shear rolling mills was proposed to obtain a marketable product in the form of bars with an ultrafine-grained gradient structure. Studies have shown that the deformation of the rod of scrap pieces of rebar from steel 18G2S mill of radial-shear rolling can significantly dispersed structure with obtaining the gradient ultrafine-grained structure, and this in turn leads to an increase of the mechanical characteristics of this steel grade. Thus, the tensile strength of steel grade 18G2S deformed at the radial-shear rolling mill was 620 MPa (at the initial value of 365 MPa).

The functional diversities of two-dimensional (2D) material devices with simple architectures are ultimately limited by immature doping techniques. An alternative strategy is to use geometry-asymmetric metal–semiconductor–metal (GA-MSM) structures, which enable the basic functions of semiconductor junctions such as rectification and photovoltaics. Here, the mixed-dimensional van der Waals heterostructures (MDvdWHs) based on the separation and self-assembly of p-type SnS layered nanosheets (NSs) and n-type SnS2nanoparticles (NPs) are obtained using an aqueous phase exfoliation (APE) method. Due to the surface charge transfer doping, the carrier transport mechanism of devices based on MDvdWHs turns from thermionic field emission (TFE) to thermionic emission (TE), with the rectification factor (Iforward/Ireverse) changing from 0.7 to 3. To further illustrate the experimental results, the generic current transport models of GA-MSM devices have been established based on the TE and TFE mechanisms in which the TE and TFE mechanisms lead to opposite rectification phenomena in good agreement with the experimental results. The GA-MSM devices show a photovoltaic effect with a high responsivity of 35 A W−1and detectivity of 3.4 × 1011cm Hz1/2W−1. This study not only provides a novel strategy to design photovoltaic devices with MDvdWHs, but more importantly, we have established fundamental models for the rectification behavior of GA-MSM devices.

Abstract: New biocompatible two-dimensional (2D) materials (e.g., graphene, graphene oxide, etc.) exhibit immense potential in the formation of innovative broadband information sensor systems for the real-time monitoring and processing of visual data. Synapse-like memristor heterostructures are considered a new type of electronic gate with extremely low power consumption and small footprints, which can be used to overcome the limitations of modern digital electronics. The results of studying photomemristor structures, based on 2D materials, for efficient information processing in neural networks are reviewed. The photocatalytic oxidation of graphene makes it possible to form high-density memristor elements with resistive switching. Particular attention is paid to the concept of forming self-organizing photomemristor nanostructures and biocompatible sensor elements for obtaining and processing visual data. The 2D photomemristor structures exhibit multilevel states, which can be controlled in a wide wavelength range and can be used in neurohybrid sensor information systems to detect neural signals from the visual cortex and in synthetic-vision systems for pattern recognition and image processing.

In this paper, the structure and surface properties of a mechanically activated filler based on rice processing products were studied. The particles of the natural filler were mechanically activated on a vibrating and planetary ball mill with different impact times and abrasion forces. The particles of the filler were characterized by laser diffraction, scanning electron microscopy and X-ray phase analysis. To study the possibility of using rice production waste in rubber products, model elastomeric compositions were made on laboratory rollers according to a standardized method with a complete replacement of industrial low-strength carbon black. It was determined that the mechanical activation of a natural filler in a planetary mill leads to an improvement in the physical-chemical parameters of the particle surface (the average size of the aggregates decreases by 2.2 times, the specific external surface increases by 3.1 times), increases the interfacial interaction of the filler with rubber (up to 33.9%), increases the Mooney viscosity values of rubber mixtures, increases resistance rubber to premature vulcanization (by 23.1%–61.5%) and leads to the production of vulcanizates with higher elastic strength indicators.

The paper presents the study of the martensitic transformation in AISI-316 austenitic steel during high-pressure torsion in a new design tool at ambient and cryogenic temperatures. It was found that intensive cooling with nitrogen leads to significant structure refinement and martensitic structure with a high number of high-angle boundaries. 8 HPT cycles at cryogenic temperature allows to obtain the content of martensite up to 93%.

One of ways to increase the strength of a structural material is to grind its microstructure to an ultra-fine-grained state. But with the simultaneous increase in strength properties in ultrafine materials, there is an inevitable decrease in its plastic properties. The use of metal materials with a gradient structure is an effective way to solve the problem of increasing the plasticity of metal products in general. This work is devoted to the study of the possibility of a gradient structure forming in austenitic stainless steel AISI-321 using radial-shear rolling. The results of the studies showed that the UFG-structure extends in the bar from its surface to a depth of at least a quarter of the radius of the bar. The transition zone is in the region between 0.5 R and 0.25 R of the bar section. Anything deeper is rolling texture. Due to the structural heterogeneity of the cross-section of the bar, there is a smooth drop in the micro-hardness of the central zone of the bar by 10.2 %. All this testifies to the gradient character of the structure formed in bars of AISI-321 steel deformed on the radial-shear rolling mill.

In this paper the methods of mechanical testing of metal and the possibility of their implementation, using mathematical modeling by the finite element method in Deform software package, are considered. As the studied parameters, both the strength indicators (yield strength, tensile strength, Brinel micro-hardness), and the plasticity indicator (the number of kinks before the crack is formed), were studied. The values obtained in the simulation have a very high convergence with the real data.

Palaeoseismology studies the footprints of ancient earthquakes to improve the knowledge about the modern seismicity of the territory. A ground‐penetrating radar (GPR), among other geophysical methods, is used for quick determination of shallow stratigraphy – displaced, oblique layers within the fault zone. GPR data interpretation from diverse and complex reflection patterns of the fault zone heavily depends on the interpreter's experience. The range of different fault zone parameters in which this method can be successfully applied has not yet been investigated. We used a numerical simulation of GPR data to determine how GPR images the elements of faults (fault plane, hanging wall, footwall) in comparison with other reflections. Furthermore, we studied which parameters have the most significant impact on GPR wave patterns. We performed a series of numerical models of a fault, changing its geometry with increasing complexity from elementary models to realistic ones. The resulting synthetic profiles allowed finding specific GPR signatures from the fault plane, the hanging wall and the footwall. We collected field GPR data from two different fault zones and examined them for verification.

We consider the Cauchy problem for a model partial differential equation of order three with a non-linearity of the form . We prove that when the Cauchy problem in has no local-in-time weak solution for a large class of initial functions, while when there is a local weak solution.

Direct reconstruction of positron emission tomography (PET) data using deep neural networks is a growing field of research. Initial results are promising, but often the networks are complex, memory utilization inefficient, produce relatively small 2-D image slices (e.g., $128 \times 128$ ), and low count rate reconstructions are of varying quality. This article proposes FastPET, a novel direct reconstruction convolutional neural network that is architecturally simple, memory space efficient, works for nontrivial 3-D image volumes and is capable of processing a wide spectrum of PET data including low-dose and multitracer applications. FastPET uniquely operates on a histo-image (i.e., image-space) representation of the raw data enabling it to reconstruct 3-D image volumes $67\times $ faster than ordered subsets expectation maximization (OSEM). We detail the FastPET method trained on whole-body and low-dose whole-body data sets and explore qualitative and quantitative aspects of reconstructed images from clinical and phantom studies. Additionally, we explore the application of FastPET on a neurology data set containing multiple different tracers. The results show that not only are the reconstructions very fast, but the images are high quality and have lower noise than iterative reconstructions.

Particle knockout scattering experiments1,2are fundamental for mapping the structure of atomic nuclei2–6, but their interpretation is often complicated by initial- and final-state interactions of the incoming and scattered particles1,2,7–9. Such interactions lead to reduction in the scattered particle flux and distort their kinematics. Here we overcome this limitation by measuring the quasi-free scattering of 48 GeV c–112C ions from hydrogen. The distribution of single protons is studied by detecting two protons at large angles in coincidence with an intact 11B nucleus. The 11B detection suppresses the otherwise large distortions of reconstructed single-proton distributions induced by initial- and final-state interactions. By further detecting residual 10B and 10Be nuclei, we also identified short-range correlated nucleon–nucleon pairs9–13and provide direct experimental evidence for separation of the pair wavefunction from that of the residual many-body nuclear system9,14. All measured reactions are well described by theoretical calculations that include no distortions from the initial- and final-state interactions. Our results showcase the ability to study the short-distance structure of short-lived radioactive nuclei at the forthcoming Facility for Antiproton and Ion Research (FAIR)15and Facility for Rare Isotope Beams (FRIB)16facilities, which is relevant for understanding the structure and properties of nuclei far from stability and the formation of visible matter in the Universe.

In the context of infrastructure resources deficiency, there is an increasing need to develop consistent approaches to the rational management of car traffic with a target level of reliability in providing consignors’ demand with cargo resources based on comprehensive interaction principle for all transportation process participants. Freight transportation simulation together with forecasting of its economic indicators, overcoming of difficulties arisen due to deficiency of infrastructure resources, and its prevention in further work is possible by using a hybrid intelligent system of cooperative transportation business planning. The key directions in this system are actualization of assessment criteria of car traffic volume management options in order to improve accuracy and promptness of their modification under operational conditions changes, establishment of train admission to port railway stations in automatic mode, discovery of conflicts and limiting elements based on cooperative planning. Implementation of this system will allow to make comprehensive decisions on transportation management based on the differentiated assessment of risks and economic efficiency, business activity.

We described workflows and methodologies for fully automated parametric imaging using clinical positron emission tomography (PET) systems with continuous bed motion (CBM) which aim to enable physicians to practice parametric PET routinely. The key components of our implemented methods include automatic generation of image-derived blood input functions, accurate tracking of slice imaging time during CBM acquisitions, and parametric image formation with advanced algorithms. Locations of the left ventricle and the descending aorta were automatically detected from high resolution anatomical images and registered to dynamic PET images to generate blood input functions. A method to accurately track dynamic scans and calculate time information for whole body CBM parametric PET was implemented based on bed position tags. This approach of calculating time information based on finely sampled bed position tags can be applied to flexible scan modes with various scan speeds over different body regions. We applied the calculated slice time information for whole body parametric imaging using a linear Patlak model. Parametric images were reconstructed with a nested expectation maximization (EM) algorithm. We demonstrated that parametric images generated by our automated workflow can provide quantitative parameters in addition to standardized uptake value images. We presented results for a uni-direction dynamic scan from a Biograph mCT system and a bi-direction dynamic scan from a Biograph Vision system.

Let be a regular local ring containing a field. Let be a reductive group scheme over . We prove that a principal -bundle over is trivial if it is trivial over the field of fractions of . In other words, if is the field of fractions of , then the map of the non-Abelian cohomology pointed sets induced by the inclusion of in has trivial kernel. This result was proved in [1] for regular local rings containing an infinitefield.

There are concerns that recent climate change is altering the frequency and magnitude of river floods in an unprecedented way1. Historical studies have identified flood-rich periods in the past half millennium in various regions of Europe2. However, because of the low temporal resolution of existing datasets and the relatively low number of series, it has remained unclear whether Europe is currently in a flood-rich period from a long-term perspective. Here we analyse how recent decades compare with the flood history of Europe, using a new database composed of more than 100 high-resolution (sub-annual) historical flood series based on documentary evidence covering all major regions of Europe. We show that the past three decades were among the most flood-rich periods in Europe in the past 500 years, and that this period differs from other flood-rich periods in terms of its extent, air temperatures and flood seasonality. We identified nine flood-rich periods and associated regions. Among the periods richest in floods are 1560–1580 (western and central Europe), 1760–1800 (most of Europe), 1840–1870 (western and southern Europe) and 1990–2016 (western and central Europe). In most parts of Europe, previous flood-rich periods occurred during cooler-than-usual phases, but the current flood-rich period has been much warmer. Flood seasonality is also more pronounced in the recent period. For example, during previous flood and interflood periods, 41 per cent and 42 per cent of central European floods occurred in summer, respectively, compared with 55 per cent of floods in the recent period. The exceptional nature of the present-day flood-rich period calls for process-based tools for flood-risk assessment that capture the physical mechanisms involved, and management strategies that can incorporate the recent changes in risk.

Background:Sleep is essential for the physical and psychological restoration of inpatients, and lack of sleep results in sleep deprivation and poor sleep quality, with potentially harmful consequences.Aim:To summarise sleep-promoting interventions in the Intensive care unit (ICU) and acute ward setting.Method and results:Six databases were searched to obtain studies for review and eight studies were selected, appraised, analysed and produced two themes: sleep-disturbing factors and sleep-promoting strategies. Sleep-disturbing factors included environmental factors (such as light and noise), illness-related factors (such as pain, anxiety and discomfort), clinical care and diagnostics. Sleep-promoting strategies included using pharmacological aids (medication) and non-pharmacological aids (reducing noise and disturbances, eye masks, earplugs and educational and behavioural changes).Conclusion:The literature review showed that both ICU and acute ward settings affect patients' sleep and both use similar strategies to improve this. Nevertheless, noise and sleep disturbances remain the most critical sleep-inhibiting factors in both settings. The review recommended future research should focus on behavioural changes among health professionals to reduce noise and improve patients' sleep.

A comparative analysis on structure, mechanical and tribological properties of a multicomponent extrudable polymer composites "UHMWPE + 17 wt. % HDPE-g-SMA + 12 wt. % PP" fabricated by i) FDM (fused deposition modeling) as well as hot pressing of ii) powder mixture, and iii) granules of the same composition has been conducted. It is shown that UHMWPE composites obtained by the 3D–printing over a complex of tribomechanical properties (wear resistance, friction coefficient, elastic modulus, yield point, tensile strength, elongation at break) are comparable with those of composites fabricated by compression sintering of granules (this is associated with formation of more homogeneous permolecular structure, first of all, due to the compounding with the help of a twin-screw extruder) and significantly exceed those for hot pressing of powder mixtures. The obtained results allow one to recommend this composite for manufacturing complex shape products for tribotechnical application at employing 3D-printing technologies.

An initial-boundary value problem for the multidimensional equation of ion-sound waves in a plasma is considered. Its time-local solvability in the classical sense in Hölder spaces is proved. This is a development of results in our previous papers, where the local solvability of one-dimensional analogs of the equation under consideration was established and, in the general case (regardless of the dimension of the space), sufficient conditions for the blow-up of the solution were obtained.