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It is believed that optical fibers can be used to detect quench in superconducting magnets. In real magnets quench strains has to be separated from operational strains, which may be quite large, spatially inhomogeneous and time dependent. In order to detect quench, it is important to separate quench strains from operational strains. We present an approach to compute strains on optical fibers during normal operation and during quench. Strains are characterized by their variation in space and time. This model will be useful to separate operational strains from quench strains.

Similarity and discrepancy of dispersion properties of Lamb wave propagation in both functionally graded (FG) and stratified composite plates is analyzed and compared with homogeneous plates. The comparison analysis indicates some peculiarities in dispersion properties of Lamb waves in FG and stratified plates comparing with homogeneous ones, especially at large and intermediate frequencies, while at vanishing frequencies all the dispersion curves converge.

The SPARC Toroidal Field Model Coil (TFMC) Program was a three-year effort between 2018 and 2021 that developed novel rare earth barium copper oxide (REBCO) superconductor technologies and then successfully utilized these technologies to design, build, and test a first-in-class, high-field (∼20 T), representative-scale (∼3 m) superconducting toroidal field (TF) coil. The program was executed jointly by the MIT Plasma Science and Fusion Center (PSFC) and Commonwealth Fusion Systems (CFS) as a technology enabler of the superconducting high-field pathway to fusion energy, and, in particular, as a risk retirement program for the no insulation (NI) TF magnet in the SPARC net-energy fusion tokamak. The TFMC achieved its programmatic goal of experimentally demonstrating a large-scale high-field REBCO magnet, achieving 20.1 T peak field-on-conductor with 40.5 kA of terminal current, 815 kN/m of Lorentz loading on the REBCO stacks, and almost 1 GPa of mechanical stress accommodated by the structural case. Fifteen internal demountable pancake-to-pancake joints operated in the 0.5 to 2.0 nΩ range at 20 K and in magnetic fields up to 12 T. The dc and ac electromagnetic performance of the magnet predicted by new advances in high-fidelity computational models was confirmed in two test campaigns while the parallel, single-pass, pressure-vessel style coolant scheme capable of large heat removal was validated. In the test facility, a feeder system composed of REBCO current leads and cables was experimentally qualified up to 50 kA, and a liquid-free cryocooler-based helium cryogenic system provided 600 W of cooling power at 20 K with mass flow rates up to 70 g/s at a maximum design pressure of 2 MPa for the test campaigns. Finally, the feasibility of using passive, self-protection against a quench in a fusion-scale NI TF coil was experimentally assessed. While the TFMC was intentionally not optimized for quench resiliency—and suffered localized thermal damage in response to an intentional open-circuit quench at 31.5 kA terminal current—the extensive data and validated models that it produced represent a critical step towards this important objective.

The SPARC Toroidal Field Model Coil (TFMC) is the first large-scale (∼3 m), high-field (∼20 T) superconducting fusion magnet based on Rare Earth Yttrium Barium Copper Oxide (REBCO). Weighing 10,058 kg and utilizing 270 km of REBCO, the TFMC is a non-insulated, stack-in-plate style superconducting magnet. It has three main components: (1) the winding pack; (2) the structural case; and (3) the case extensions, or plena. The winding pack is composed of sixteen single pancakes with two termination plates top and bottom. The pancakes are Nitronic 40 radial plates machined with spiral channels on one side for the REBCO tape stack and single-pass channels on the opposite side for supercritical helium coolant. After assembly, each pancake undergoes a vacuum-pressure impregnation solder process to provide good mechanical protection of the REBCO tape stack and efficient thermal and electrical connectivity within each pancake. The pancakes are bolted along the inner and outer perimeter to provide mechanical and thermal connectivity while inter-pancake joints provide low resistance current transfer between pancakes. The top and bottom termination plates facilitate electrical connection to a superconducting feeder system. Embedded throughout the winding pack are 211 voltage taps, 34 temperature sensors, 34 helium flow monitors, 4 Hall probes, and 4 resistive surface heaters. The winding pack is contained within a structural case, a “trough and lid” style design composed of two Nitronic 50 forgings machined to shape and bolted together. The case reacts the large electromechanical stresses approaching 1 GPa during operation and serves as a pressure vessel that enables 20 bar supercritical helium flow that cools the winding pack and case. Two case extensions are attached to the case with unique high-pressure feedthroughs to provide winding pack access for current, cooling, and instrumentation, completing the magnet assembly.

This paper outlines the preliminary design of an experimental compact (<2 tons), high-field (∼20 T on tape, ∼17 T at center bore), and conduction-cooled HTS REBCO magnet. An identical pair of these magnets will be manufactured for a magnetic mirror axial fusion device. The magnet consists of eight single pancakes in series, each of which is an interchangeable, dry-wound, partial-insulated winding. Once charged, the magnet is operated with a constant current and will be used in the presence of other magnets. Field-induced mechanical stresses in the winding pack are managed using a novel technique of ‘partitions’ keyed into structural plates. The system is conduction-cooled by cryocoolers to operate at 20 K. The winding pack is mechanically supported and thermally isolated in the cryostat by high-strength, low-thermal conductivity brackets designed to sustain over 60 tons of axial loading during peak device operating conditions.

A pilot post-mortem study identifies a strong correlation between the attenuation coefficient estimated from the OCT data and some morphological features of the sample, namely the number of nuclei in the field of view of the histological image and the fiber structural parameter introduced in the study to quantify the difference in the myelinated fibers arrangements. The morphological features were identified from the histopathological images of the sample taken from the same locations as the OCT images and stained with the immunohistochemical (IHC) staining specific to the myelin. It was shown that the linear regression of the IHC quantitative characteristics allows adequate prediction of the attenuation coefficient of the sample. This discovery opens the opportunity for the usage of the OCT as a neuronavigation tool.

Machine performance is one of the most important technical and economic indicators. Due to the influence of many factors (weather conditions, age and technical condition of machines, qualifications of the operator, etc.), the specific performance in each case will be different, that is, the real performance is a random variable and it is impossible to predict it accurately in advance. However, on the basis of experience, it is possible to establish the proportion of cases where the relevant building codes are met. This share will be an assessment of the probability of meeting the standards. It makes it possible to calculate the required number of machines more reasonably, the energy intensity of the construction process, its cost and labour intensity. In this regard, even at the design stage, it is necessary to use probabilistic ideas about the technological process and machine productivity that will allow taking into account the possible deviations of the actual parameters of work operations from those planned, an increase in the timing of the work and completion of the project. When analyzing the operation of machines, this article will consider only complex reliability indicators: availability factor, operational readiness factor, technical utilization factor, efficiency factor. At the same time, it is desirable to carry out logical and mathematical processing of statistical information for the corresponding coefficients. The article uses software for constructing confidence intervals for statistical models (regression equations) developed at the Siberian Transport University. Taking into account the probability of machines operating in real operating conditions makes it possible to plan their rhythmic work more reasonably, determine the time (terms, duration) of work more accurately, that affects the reduction in the cost of construction products.

The results of full-scale tests of hydro transport systems operation under real production conditions have been collected in Siberian Transport University. Statistical processing of information has been carried out while creating a database for random variables. The following parameters of hydro transport system operation have been studied: availability factor, coefficient of technical use, efficiency factor, operating time to failure, and coefficient of time use. Indices of technical (coefficient of technical use, the coefficient of readiness, the coefficient of efficiency and operating time to failure) and organizational-technological (coefficient of time use) reliability have been determined. Methodical, mathematical and software methods for estimating reliability of construction machines by the example of systems have been worked out. Using the software, the efficiency and reliability of the operation of systems, complexes, sets and individual machines at specific objects have been substantiated. This allowed the most accurate prediction of timing and cost of production at specific sites. A method for taking into account specific production conditions in a comprehensive assessment of the operation of machines, kits, complexes and systems has been proposed. The use of databases based on the results of field tests of machines made it possible to calculate more accurately the indicators of technical organizational and technological reliability of performing a given volume of work. Taking into account the probability of organizational and technological reliability makes it possible to plan the work of the system under specific operating conditions with a greater validity. It is more accurate to predict the main indicators of work production. The method, which allows taking into account the specific working conditions of the performance of works and forecasting the main indices of the reliability of a particular machine, is proposed. The proposed toolkit of indicators of technical and organizational-technological reliability of hydro transport systems for making informed management decisions has real reliability.

Nanoparticles’ environment, in particular pH, can strongly affect their photoluminescence (PL). This can be especially true for the surface PL of nanodiamonds (NDs) known to be dependent on the composition of surface groups. In this paper, the effect of environmental pH in the range from 2 to 12.5 on the surface photoluminescence of oxidized NDs of various syntheses and surface treatments was investigated. For the first time, the varying changes of the NDs’ PL with the pH were shown, having, however, an essential common feature: they were observed in the same pH regions from 2 to 5 and from 9 to 12.5, while in the pH region from 5 to 9, the PL intensity of all samples was almost constant. Obtained dependences of NDs’ ζ-potentials on pH and quantum mechanical modeling showed that all changes of NDs’ PL are due to the (de)protonation of surface groups: carboxyl at pH from 2 to 5 and hydroxyl on sp2-hybridized carbon at pH from 9 to 12.5. The varying response of NDs’ PL to such deprotonation shows the possibility of tuning the surface photoluminescence of NDs for use in industry and biomedicine beyond what is possible by only controlling the nanodiamonds’ surface groups.

Our goal was to study the methodological aspects of avionics reliability at low temperatures during aircraft operation in the Far North and the Arctic. In the course of the study, we systematized data on the actual failures of avionics in modern aircraft with onboard digital complexes when operated at extremely low temperatures. It is shown that low-temperature avionics failures are mainly critical by nature, which requires radical measures for their elimination. It is also noted that, besides critical failures, latent avionics defects, as well as poorly studied failures and failures of undetermined origin, occur.

AbstractCo-simulation strategies using both Abaqus/Explicit and Abaqus/Implicit are investigated for analysing wave propagation in two-dimensional unbounded soil domain. The co-simulation is based on the coupling GC method, allowing for coupling different finite element codes with different time integrators and time-scales depending on the partitions of the domain. Absorbing layers using increasing damping (ALID), based on Rayleigh viscous damping, are considered at the boundary to model the semi-infinite medium. The proposed absorbing region is called hybrid (different time integrators) asynchronous (different time steps) absorbing layers using increasing damping (HA-ALID). Lamb’s test and a wave barrier problem are investigated. First, HA-ALID turns out to be more accurate than non-reflective conditions available in Abaqus/Explicit. Second, the critical time step in the domain of interest remains unaffected by the choice of damping characteristics in the HA-ALID, contrary to the case of a full explicit computation. Third, the time steps for the solid barrier and the HA-ALID are not restrained by the CFL condition imposed by the explicit partition for stability reasons. Because of its good accuracy and ability to be realized using only FE Abaqus package, without a third-party software component, this strategy provides a wide range of applications in soil–structure interaction problems.

Emerging methods of anti-tumor therapies require new approaches to tumor response evaluation, especially enabling label-free diagnostics and in vivo utilization. Here, to assess the tumor early reaction and predict its long-term response, for the first time we apply in combination the recently developed OCT extensions - optical coherence angiography (OCA) and compressional optical coherence elastography (OCE), thus enabling complementary functional/microstructural tumor characterization. We study two vascular-targeted therapies of different types, (1) anti-angiogenic chemotherapy (ChT) and (2) photodynamic therapy (PDT), aimed to indirectly kill tumor cells through blood supply injury. Despite different mechanisms of anti-angiogenic action for ChT and PDT, in both cases OCA demonstrated high sensitivity to blood perfusion cessation. The new method of OCE-based morphological segmentation revealed very similar histological structure alterations. The OCE results showed high correlation with conventional histology in evaluating percentages of necrotic and viable tumor zones. Such possibilities make OCE an attractive tool enabling previously inaccessible in vivo monitoring of individual tumor response to therapies without taking multiple biopsies.

3D problems for plane cracks of arbitrary shape in anisotropic media are considered. The stress intensity factors are determined by the intensity factors of the crack displacement discontinuity field. Strong ellipticity of the constructed pseudodifferential operator is proved. The solution of the pseudodifferential operator of the crack theory is obtained by the specially constructed potentials with densities concentrated at the crack front. Irwin’s relation for the energy release rate is obtained for a plane crack of arbitrary shape in a medium with arbitrary elastic anisotropy.

ABSTRACTWe solve the argument mining problem by investigating discourse and communicative text structure. A new formal graph-based structure called communicative discourse tree (CDT) is defined. It consists of a discourse tree with additional labels on edges, which stand for verbs. These verbs represent communicative actions. Discourse trees are based on rhetoric relations, extracted from a text according to Rhetoric Structure Theory. The problem is tackled as a binary classification task, where the positive class corresponds to texts with arguments and the negative class corresponds to texts with no arguments. The feature engineering for the classification task is conducted, deciding on which syntactic and discourse features are associated with logical argumentation. Text classification framework based on syntactic, discourse and communicative discourse text structures with a number of learning approaches is implemented. Evaluation on a combined data-set is provided.

The electroreduction of HfCl4 in the NaCl-KCl melt was studied in the temperature range 973-1123 K by cyclic voltammetry and impedance spectroscopy methods. It was determined that electrochemical reduction of Hf(IV) in the NaCl-KCl melt occurs via two successive stages involving transfer of two electrons at each stage. The formal standard potentials of E*Hf(II)/Hf, E*Hf(IV)/Hf and the formal standard redox potentials of E*Hf(IV)/Hf(II) were determined from the cyclic voltammetry and the values of the standard rate constants of charge transfer obtained by impedance spectroscopy method. The thermodynamic properties of the dilute solutions of hafnium di - and tetrachloride formation from the elements in an equimolar mixture of molten NaCl-KCl were determined. The free Gibbs energy changes for the reaction HfCl4(sol.) HfCl2(sol.) + Cl2(g.) and the equilibrium constants of the metal-salt reaction Hf(IV) + Hf - 2Hf(II) were calculated.

Interaction regularities of the complex particle [Ti(3)F6]3- with an outer-sphere shell and an external environment were studied by quantum chemistry methods. A direct calculation of the interaction energies of the fragments of the second coordination sphere both with the complex itself and with a fragment of the external environment was performed. In all studied systems, the composition of the most stable particle was nM2+[?][Ti(3)F6]3- (M - Mg, Ca, Sr, Ba). Based on these data and additional calculations pertaining to the fragments of these systems, it was concluded the formation of stable particles "complex-outer-sphere shell".

The standard rate constants of charge transfer (ks) for the redox couple Nb(V)/Nb(IV) in NaCl-KCl(equimol.)-NaF(10 wt.%)-K2NbF7 (I) and NaCl-KCl(equimol.)-K2NbF7 (II) melts with addition of alkaline earth metal cations were determined. It was found that addition of alkaline earth metal cations resulted in increasing of ks to the certain ratio of Me2+/Nb(V) for the all alkaline earth metal cations due to substitution of Na+ and K+ cations by Me2+ in the second coordination sphere of niobium complexes that leads to decreasing of niobium fluoride complexes strength. Further addition brought to some decrease of the standard rate constants because the viscosity of melts increasing which brings to decrease of the diffusion coefficients. It was determined that in the melt (II) ks a little bit increased with increasing scan rate probably due to the secondary electrode process.

Electrochemical studies of the redox couple Sm(III)/Sm(II) were carried out in NaCl-KCl-SmCl3 and NaCl-KCl-SmCl3 melts in a temperature range of 973-1173 K by cyclic voltammetry.Diffusion coefficients (D) of Sm(III) in these melts were determined using Randels-Shevchik equation. It was found that D in the NaCl-KCl-SmF3 melt are less than D in the NaCl-KCl-SmCl3 melt. At the same time activation energies for diffusion (DU) of Sm(III) in the NaCl-KCl-SmF3 melt are higher than DU in the NaCl-KCl-SmCl3 melt that is related to the increased strength of the complexes in transition from SmCl3 to SmF3 molten system. The standard rate constants of charge transfer (ks) for the Sm(III)/Sm(II) redox couple were determined by cyclic voltammetry both in NaCl-KCl-SmCl3 and NaCl-KCl-SmF3 molten salts using the Nicholson's equation. The higher values of ks were obtained in chloride melt than in chloride-fluoride molten system.

It has been demonstrated that the application of the frontier orbital method to the quantum-chemical analysis of possible variants of electron transfer in electrochemical systems makes it possible to sharply narrow the search for the transition state and to reduce computational burden by several orders of magnitude. The high informativity of the method allows us to recommend it as a tool for verifying any hypotheses about the mechanism of charge transfer in electrochemical systems.

Primary hyperparathyroidism (PHPT) is a relatively rare disorder among children, adolescents and young adults. Its development at an early age is suspicious for hereditary causes, though the need for routine genetic testing remains controversial.To identify and describe hereditary forms of PHPT in patients with manifestation of the disease under 40 years of age.We enrolled 65 patients with PHPT diagnosed before 40 years of age. Ten of them had MEN1mutation, and PHPT in them was the first manifestation of multiple endocrine neoplasia type 1 syndrome.The other fifty-five patients underwent next-generation sequencing (NGS) of a custom-designed panel of genes, associated with PHPT (MEN1, CASR, CDC73, CDKN1A, CDKN1B, CDKN1C, CDKN2A, CDKN2C, CDKN2D). In cases suspicious for gross CDC73deletions multiplex ligation-dependent probe amplification was performed.NGS revealed six pathogenic or likely pathogenic germline sequence variants: four in CDC73c.271C>T (p.Arg91*), c.496C>T (p.Gln166*), c.685A>T (p.Arg229*) and c.787C>T (p.Arg263Cys); one in CASRc.3145G>T (p.Glu1049*) and one in MEN1c.784-9G>A. In two patients, MLPA confirmed gross CDC73deletions. In total, 44 sporadic and 21 hereditary PHPT cases were identified. Parathyroid carcinomas and atypical parathyroid adenomas were present in 8/65 of young patients, in whom CDC73mutations were found in 5/8.Hereditary forms of PHPT can be identified in up to 1/3 of young patients with manifestation of the disease at <40 years of age. Parathyroid carcinomas or atypical parathyroid adenomas in young patients are frequently associated with CDC73mutations.

ABSTRACTG-Protein Coupled Receptor (GPCR), Class C, Group 5, Member A (GPRC5A) has been implicated in several malignancies. The underlying mechanisms, however, remain poorly understood. Using a panel of human cell lines, we demonstrate that CRISPR/Cas9-mediated knockout and RNAi-mediated depletion of GPRC5A impairs cell adhesion to integrin substrates: collagens I and IV, fibronectin, as well as to extracellular matrix proteins derived from the Engelbreth-Holm-Swarm (EHS) mouse sarcoma (Matrigel). Consistent with the phenotype, knock-out of GPRC5A correlated with a reduced integrin β1 (ITGB1) protein expression, impaired phosphorylation of the focal adhesion kinase (FAK), and lower activity of small GTPases RhoA and Rac1. Furthermore, we provide the first evidence for a direct interaction between GPRC5A and a receptor tyrosine kinase EphA2, an upstream regulator of FAK, although its contribution to the observed adhesion phenotype is unclear. Our findings reveal an unprecedented role for GPRC5A in regulation of the ITGB1-mediated cell adhesion and it's downstream signaling, thus indicating a potential novel role for GPRC5A in human epithelial cancers.

ABSTRACTHigh-rise buildings influence wind characteristics in complex urban areas and can significantly change the natural ventilation in adjacent low- and medium-rise buildings. The results of previous studies show that the windward zones of high-rise buildings can create adverse effects on natural air ventilation because they reverse the flow regime, simultaneously almost double the wind suction of downwind air zones, and increase the heat loss of smaller structures due to the resulting pressure distribution on the facade. In this study, the pressure distribution of low- and medium-rise buildings is measured in wind tunnels and discussed. It focuses on the fundamental understanding of the effects of high-rise building height and distance from adjacent structures on wind flow characteristics and natural ventilation. The study uses a pair of building models tested in a set of parametric experiments, comprising pressure measurements and particle image velocimetry (PIV).

The conditions of electrochemical synthesis of tantalum carbide in the NaCl-KCl-K2TaF7-K2CO3 melt have been determined. These conditions are following: potentiostatic electrolysis at discharge potentials of CO32--ions during 40-50 min after addition of K2CO3 to the melt and the molar ratio of K2CO3/K2TaF7 = 1:1.

The possibility to synthesize TaO using the CsCl-K3TaOF6 melt has been shown. TaO crystallizes at the cathode as nanoneedles together with other tantalum compounds. It was found that TaO can be obtained by electrolysis of molten salts only at temperatures below 810 oC.

The standard rate constants of charge transfer (ks) for the redox couple Ti(IV)/Ti(III) in the (NaCl-KCl)equimol.-NaF(10 wt.%)-K2TiF6 melt were determined. It was shown, that ks increase with temperature increasing. Influence of strongly polarizing cations on the charge transfer kinetics was studied. It was determined the linear dependence of ks on ionic potential of alkaline earth metal cations and the activation energies of charge transfer were calculated.

The refractory metal carbides were deposited on carbon steel and fibers by currentless transfer in molten salts at temperatures 1073-1123 K. The microhardness of refractory metal carbides on carbon steels at the cross section had the values 21 GPa, 29 GPa, 31 GPa for Cr7C3, NbC and TaC, respectively. The corrosion resistance of these carbides was studied in concentrated HCl, H2SO4 and H3PO4 acids. The wear resistance was evaluated by the mass loss of samples. Deposition of NbC coatings on parts of oil pumps increased their lifetime in several times. Coatings of Cr7C3 or TaC on the knifes for cutting rubber, made of St. 3, improve their wear resistance and increase a tool life in 2.0 and 2.5 times respectively.

The interaction of different materials with the niobium containing melt was investigated. As substrate materials the ceramics, beryllium and carbopyroceram were chosen. Several spherical ceramic and beryllium samples were coated with protective molybdenum film by magnetron sputtering. After the experiment (exposition time 10 min) the exfoliation of molybdenum film from ceramic samples was observed due to interaction of the substrate with the melt. The beryllium samples regardless of the shape and the presence of the protective films were dissolved in the niobium containing melt due to more negative electrode potential comparing with niobium one. The carbopyroceram samples were exposed in the melt during 3 and 12 hours. It was found that the carbopyroceram it not corrodes in the niobium containing melt. The optimal regimes for electrodeposition of smooth uniform niobium coatings with the thickness up to 50 um on carbopyroceram spheres were found.

The standard rate constants of charge transfer (ks) for the Nb(V)/Nb(IV) redox couple in KCl-NbCl5 and CsCl-NbCl5 chloride melts are determined. The Nb(V) electrochemical reduction process in the NaCl-KCl-NbCl5 melt was shown being reversible; hence, the determination of ks appeared impossible. Values of ks in the KCl-NbCl5 melt are higher than those in the CsCl-NbCl5 one. Previously, in a quantum-chemical calculations of nM+*[NbCl6] model systems (M = Na, K, Cs), containing a complex anion with cations outer-sphere (OS) shell (nM+) have been done. It was found that compositions with an intermediate number of OS cations n < nlim, where nlim is the limiting number of OS cations bound to a given complex, are thermodynamically most stable. The aim of this quantum-chemical study is an estimation of the temperature effect on the composition of the stable particles in the extended systems M+[?][NbCl6]+18MCl (M = Na, K, Cs).