bluuebunny/crossref_metadata_2025 huggingface dataset:
Boring a Discontinuous Surface: the Choice of Technological Modes
Authors: Firsov Alexander , Qvcharenko Alexander , Romashev Alexander , Smirnov Vitaly , Kamardin Aleksey
Published: November 2019

The article deals with issues related to ensuring the quality of machining of a discontinuous surface. The subject of research is the technology of boring holes. Machining holes with intermittent areas on the surface is difficult due to the occurrence of dynamic effects. As a rule, regulatory and technical documentation does not give specific recommendations for such cases. The authors of the article describe the introduction of additional conditions, which allow determining the modes of boring holes with intermittent areas on the surface at the design stage of the technological process. This solution ensures that the part meets the specified quality requirements and allows you to verify the correctness of the technological decisions. The algorithm for selecting boring modes of holes with discontinuous surfaces implements the proposed technical solution in practice.
Research of High-Speed Machining With Disk Cutters
Authors: Markov Andrey , Andreev Mikhail , Shityuk Aleksey , Sczygiol Norbert
Published: November 2019

At present, both preliminary and final HSM is recommended to be carried out according to the scheme of cut-down milling. Processing of reinforced and unreinforced polymers is also recommended to be carried out at cut-down travel. The main problem associated with cutdown milling is caused with insufficient dynamic stiffness or the presence of backlash in the feeder table. The proposed concept of machining allows eliminating fundamentally the influence of dynamic stiffness and the presence of backlash in the table feeding mechanism on the quality of machining with GUS makes it possible while retaining the advantages of cutdown milling. Some kinematic schemes for high-speed machining by milling and turnmilling are given in the paper. The schemes for forming geometrical roughness components in such machining and calculation formulas are presented. The results of experimental studies of roughness formation with disc cutters made of fiberglass composite material in high-speed machining are presented. The results obtained are compared with the calculated data.
Development of Innovative Methods for the Assessment of the Technical Condition of the Gearboxes of the Mine Belt Conveyors in the Parameters of the Lubricating Oil
Authors: Mamaeva Mariya , Kuzin Evgeniy
Published: November 2019

This article shows that a significant part of the cost of coal is the cost of transporting it from the long wall to the mine surface, which makes it important to search for reserves in order to increase the efficiency of using mine vehicles, in particular, belt conveyors. This article proposes a method for diagnosing the state of gears of mine belt conveyors based on the actual condition of the lubricating oil. The advantages of combining the study of oil parameters by spectroscopic and microscopic methods are shown. The results of testing lubricating oil of the mine gearboxes located on belt conveyors installed in a single transport and process chain. In order to determine the concentration of wear products the oil was examined with an optical emission spectrometer. For lubricating oil, in which excess wear was observed, a microscopic examination was carried out to clarify the types of wear. Micrographs of wear particles in lubricating oil are given. It characterizes one or another type of wear or their combination. This particular combination of methods increases the probability of identifying possible malfunctions of gearboxes at an early stage of defect development. Thus, the introduction of this technique will reduce the duration of unplanned emergency downtime of belt conveyors and improve the safety of mine transport.
Selection of Non-Magnetic Fraction from the Slime Wastes of Metal Production in the Electromagnetic Field
Authors: Vernigorov Yuri , Lebedev Valery , Chunakhova Lidianna
Published: November 2019

It is proved that the use of a variable inhomogeneous magnetic field, created by the superposition of constant and variable, strongly inhomogeneous fields, is considered to be very promising for the separation of non-magnetic fraction from powders of magnetic materials. This article introduces the effective technology of separation of non-magnetic fraction from the sludge wastes of metal production in the electromagnetic field, which allows to destroy the aggregates, to separate the abrasive and to get products of high purity. A complex on processing of grinding sludge includes the following blocks: the loading block with dispenser; block of preliminary squeezing and washing of DRC; the block of drying; the block of a refinement; the block of division of sludge fractions. Experimental approbation of the proposed technological scheme of sludge separation, which had been carried out on iron ore concentrate of class 63 microns with silica content of 4.57% of the mass, showed that with the field parameters close to the calculated, the magnetic vibrating layer of iron powder PZh-4M has the maximum development; increasing the separation time leads to more efficient separation in the interval of field induction gradient from 550 mT/ m to 610 mT/m.
The Study of Multiradius Roller Running Process
Authors: Krechetov Andrey , Mitrofanova Kristina
Published: November 2019

The results of theoretical and experimental studies of the surface of the sample of steel 45 after surface plastic deformation (SPD) with multi-radius roller (MR-roller) is shown. The goal of this study is to expand the technological capabilities of the method of SPD through the use of a new design of the deforming tool developed at the Department of Engineering Technology of KuzSTU. The advantage of the MR-roller (Patent RU № 2557377) over the traditional tool for SPD (single-radius roller) is the possibility of creating a large hydrostatic pressure in the deformation zone, without destroying the surface layer of the processed material. The research technique included finite element modeling (FEM), microhardness measurement, metallographic studies of the sample structure. As a result of the study, some regularities of the process of hardening by a multi-radius tool with high hydrostatic pressure and a large number of quasi-monotonic deformation sites were revealed. The results indicate a significant hardening without metal destruction and the formation of nanoscale grains, which allows to improve the properties of rolled products in the application of high operating loads.
Features of Creation of Surface Layer Mechanical Condition Parameters in Orthogonal Cutting
Authors: Blumenstein Valeriy , Petrenko Konstantin
Published: November 2019

In this article, the technique and research results on creation of surface layer mechanical conditions parameters at orthogonal cutting are presented. Stress tensor, strain rate tensor and general mechanical condition factors distribution along flow lines were obtained. Distributions of stresses, strain rates, mean normal stress and stress state index along flow lines consist of three steps of quasi-monotonous deformation. On every step there is a monotonous increasing or decreasing of these parameters. It is demonstrated that creation of surface layer mechanical condition parameters in metal cutting and surface plastic deformation methods follow common patterns. Experimental research results confirmed the validity of proposed analytical models for stressing programs in orthogonal metal cutting.
Automation of Operations Design for Complex-Shaped Surfaces Processing
Authors: Markova Margarita , Markov Andrey , Balashov Aleksandr , Sczygiol Norbert
Published: November 2019

Research work is aimed at modeling the process of milling surfaces of complex shape in automated CAD/CAM systems. To reduce labour input of this process, an algorithm for designing milling operations is proposed. The algorithm is implemented in the form of software written in the VBA programming language from Office Excel. The software allows to select cutting tools and cutting modes for roughing, semi-finishing and finishing milling. The initial data for this are: processed material, part configuration, profile depth, technical requirements on the surface. The work of the algorithm was tested on the parts of the mold type. It is found that the set of cutting tools for all types of milling surfaces of complex shape is selected taking into account the overall dimensions of the treated surface, its curvature and radii of surfaces rounding. The results of simulation of mold processing in Sprut CAM system according to the assigned set of cutting tools and cutting modes allowed to choose the tool path with minimal processing time.
Factors for Development of the Educational and Professional Qualification Profile of the Human Resources in the Machine Building Sector in Bulgaria
Authors: Petrova Mariana , Tepavicharova Milena , Dikova Lyudmila
Published: November 2019

Along with cost optimization, the main reserve is the use of the workforce. Development opportunities depend not only on the level of equipment and technology, but also on the added value of the participants -managers, specialists, workers. The fundamental understanding should be that the workforce is not only a basic production factor, but also an important source of income for the enterprise. The purpose of this article is to analyse the main factors of the management of professional development and human resources qualification, influencing the production and economic results in the machine-building sector. The article is structured into two main sections. The first includes an analysis of the factors of the management of professional development and the qualification of the human resources, by examining their interrelations and links with the economic results by types of enterprises in the machine-building sector. The second section presents a model of the factors which are particularly important for achieving high economic results.
Professional Identification of a Specialist According to the Factor of His Psychological Type of Personality
Authors: Morozova Anna
Published: November 2019

One of the factors determining the psychological comfort of the social and professional interaction of a specialist is his personality type. Modern psychology of personality considers sixteen basic types to identify a person. An individual personality type of a specialist largely either contributes to or hinders the achievement of the optimal level of his competitiveness in the professional environment. The method developed by the author, “The choice of the priority type of professional activity of a specialist on the factor of the psychological type of his personality” allows us to draw conclusions for each specialist: on the priority influence of the components of the psychological type of his personality on the formation of individual social and professional competitiveness; on the choice of this type of professional activity that would allow optimal use of the capabilities of the psychological type of his personality to increase competitiveness in the professional environment. Practical use of the technique is considered on the example of young specialists of machine-building profile who graduated from a professional college.
Integrating the Innovation Management Methodology Into the Existing Quality Management System of a Machine-Building Enterprise
Authors: Miroshnikov Vyacheslav , Morozova Anna , Svetlichnaya Tatyana
Published: November 2019

The problem of integrating European standards in the field of innovation management (SIM) into the existing quality management systems (QMS) of organizations is considered. The authors analyze the most relevant developments of the methodological foundations of innovation management, as a promising direction of scientific knowledge, and research aimed at summarizing the practical experience of its implementation in various sectors of the economy and the service sector. Particular attention is paid to analyzing scientific publications in the field of industrial innovation. The main directions of integrating innovation management methodologies into the systems of quality management of products and services operating at enterprises and organizations are proposed. The conceptual model of the innovation management system is presented, which contains its key elements. It is shown that for industrial enterprises and manufacturing firms it is inappropriate to have two different systems (QMS and SIM), which tend to the same goal namely to improve the product quality. A process model of innovation management that implements the principle of quality management called “Improvement” is proposed, and the description of the model is given. The specificity of implementing QMS and SIM integration processes at Russian enterprises of the machine-building complex is revealed.
Economic and management analysis of the impact of human capital on the development of machinery-building in Bulgaria
Authors: Petrova Mariana , Tepavicharova Milena , Dikova Lyudmila
Published: November 2019

At present, foreign markets and, above all, the EU market are decisive for the development of the Bulgarian machine-building sector. In the majority of cases, the presence of European and other foreign markets remains at the level of inter-company trading relationships. One reason for this is the absence of strong national scientific, technical and production structures (science-technology-production) which are able to integrate themselves into large production chains. The lack of adequate human capital management, as well as the low level of professional knowledge, skills and competencies, have a negative impact on the economic performance of the sector. Therefore, it is necessary to carry out an economic and managerial analysis of the state of human capital, revealing the possibilities for its effective utilization and management. The purpose of this article is to examine the state of the human capital by analyzing its impact on the development of the machine building sector in Bulgaria.
Best Practices Application in the Development of Industry in Russia
Authors: Demidenko Alexander , Kramar Anastasia , Demidenko Igor , Demidenko Alexander
Published: November 2019

This article is devoted to the analysis of the problems of the Russian economy in modern conditions, in particular, the technical and technological backwardness of Russia from the developed countries. The analysis of the reasons for the low level of competitiveness of the national economy has been carried out, and ways of its possible improvement have been investigated. The necessity of changing the export-raw model of economic development, based on the accelerated increase of fuel and raw materials exports, on the model based on the production of high-tech competitive products is shown. A study of the world’s best practices in the development of industry and the agro-industrial complex has been conducted, and statistics of economic indicators of other countries is given. This article analyses the results obtained by these countries. Also, the most effective principles of economic management, which could be applied in Russia are identified. It is substantiated that the Russian Federation needs to intensify innovation. It is revealed that the strategy of innovative development of the agri-food and industrial complex should be determined on the basis of the state innovation policy, the main task of which remains to mobilize the potential of the scientific and technological potential of the industry for the technical and technological renewal of domestic industry and agro-industrial complex.
Das Hautschutzprogramm in den Schulungs- und Beratungszentren der Berufsgenossenschaft für Gesundheitsdienst und Wohlfahrtspflege
Authors: Hamm K. , Drechsel-Schlund C.
Published: November 2019

Im Rahmen der Individualprävention bietet die Berufsgenossenschaft für Gesundheitsdienst und Wohlfahrtspflege in speziellen Schulungszentren ein Hautschutzprogramm für Versicherte mit arbeitsbedingten Hauterkrankungen an. Das Konzept der Schulungs- und Beratungszentren mit ihren einzelnen Angeboten wird vorgestellt. Die Maßnahmen der Individualprävention sind in das § 3 BKV-Verfahren Haut eingebettet, das ein gestuftes Vorgehen bei Verdachtsfällen einer arbeitsbedingten Hauterkrankung definiert. Dadurch konnte in den vergangenen Jahrzehnten den meisten Betroffenen der Berufsverbleib ermöglicht und ein deutlicher Rückgang anerkannter Berufskrankheiten erreicht werden.
Halogen-Radical-Promoted Dearomative Aza-Spirocyclization of Alkynylimines: An Efficient Approach to 3-Halo-Spirocyclohexadienones
Authors: Chen Dianpeng , Li Jianming , Shan Yingying , Cui Peiying , Zhao Yutong , Tian Laijin , Qiu Guanyinsheng
Published: November 2019

A novel halogen-radical-promoted dearomative aza-spiro­cyclization of alkynylimines for the synthesis of 3-halo-spirocyclohexadienones is described. In this process, it is believed that a radical addition, 5-exo-trig cyclization, and dearomative aza-spirocyclization are involved. Easily available starting materials, mild conditions, and a wide substrate scope make this approach potentially useful.
Adaptive willingness resolves social dilemma in network populations
Authors: Zhu Peican , Song Zhao , Guo Hao , Wang Zhen , Zhao Tianyun
Published: November 2019

Cooperation is an effective manner to enable different elements of complex networks to work well. In this work, we propose a coevolution mechanism of learning willingness in the network population: an agent will be more likely to imitate a given neighbor’s strategy if her payoff is not less than the average performance of all her neighbors. Interestingly, increase of learning willingness will greatly promote cooperation even under the environment of extremely beneficial temptation to defectors. Through a microscopic analysis, it is unveiled that cooperators are protected due to the appearance of large-size clusters. Pair approximation theory also validates all these findings. Such an adaptive mechanism thus provides a feasible solution to relieve social dilemmas and will inspire further studies.
Clamping effects on mechanical stability and energy dissipation in nanoresonators based on carbon nanotubes
Authors: Kumar Lalit , Jenni Laura V. , Haluska Miroslav , Roman Cosmin , Hierold Christofer
Published: November 2019

With continuous downscaling of resonators, clamping is expected to significantly impact the mechanical stability as well as the energy dissipation mechanisms, especially at the nanoscale. To understand the clamping effects at the nanoscale, we here report on an experimental investigation of a same nanotube based resonator subjected to two different clamping configurations. We investigate clamping associated stability and damping mechanisms by pushing the resonator into the nonlinear regime. The nanotube was first dry-transferred and suspended between source-drain palladium electrodes resulting in a bottom clamped configuration. A selective top-metallization process by platinum atomic layer deposition applied later resulted in a top-bottom clamped configuration. Large nanotube motional amplitude leading to a nonlinear Duffing response initiated small slippage of the nanotube. This instability in clamping was seen in both clamping configurations and was measured as an irreversible resonance frequency downshift. For the measured resonator devices, a gate induced nanotube tension in the range of 58–71 pN was estimated to overcome clamping forces and initiate slipping. In terms of energy dissipation, the top-metallization process was accompanied by a reduction in amplitude dependent nonlinear damping and Q-factor enhancement. Subjecting the same nanotube to both clamping configurations allowed for a direct comparison of clamping and quantification of nonlinear damping. In the present case, nonlinear damping was observed at an estimated nanotube motional amplitude of 11 nm (and higher), being dominant in bottom clamped configuration, suggesting the origin of this nonlinear damping to partially stem from external mechanisms in addition to other possible internal dissipation paths reported such as viscoelastic effects.
Anisotropic plasmons due to carrier electrons in Cs-doped hexagonal WO3 studied by momentum transfer resolved electron energy-loss spectroscopy
Authors: Sato Yohei K. , Terauchi Masami , Adachi Kenji
Published: November 2019

Cs-doped hexagonal WO3 (CWO) is used as a solar heat-shielding material for windows, in which plasma oscillation due to carrier electrons (carrier plasmon) plays an important role for near infrared scattering. Despite the hexagonal crystal structure of CWO, the anisotropic properties of the carrier plasmons have not been investigated. This study reports the momentum transfer resolved electron energy-loss spectroscopic measurements of CWO to investigate the anisotropic properties of carrier plasmons. The experimental results clarified that the two plasma oscillation modes at 1.2 and 1.8 eV have different excitation properties in CWO. One plasma oscillation at 1.2 eV was excited for q along the ab plane with a large damping effect, which indicated that electron excitations occur for the q//ab plane. Another mode at 1.8 eV was an oscillation excited for q along the c-axis with a small damping effect, i.e., a long plasmon relaxation time. These two modes can be interpreted by the anisotropic energy dispersion of the electronic states around the Fermi level of CWO. Such anisotropic properties of the carrier plasmons led to an accurate understanding of the heat-shielding mechanism.
The overdamped transmission coefficient: Recovering the true mean first passage time from an inaccurate reaction coordinate
Authors: Yappert Ryan , Kamat Kartik , Peters Baron
Published: November 2019

For inertial reaction dynamics, a transition state theory rate constant obtained from an inaccurate reaction coordinate can be a posteriori corrected with reactive flux methods. In contrast, reaction coordinate errors in overdamped mean first passage time calculations cannot be a posteriori corrected. This work develops an overdamped version of the transmission coefficient. The calculation requires information from committor analyses and an estimate of the diffusivity along the committor coordinate. We illustrate the calculation for a simple two-dimensional potential that admits exact solutions.
Selective terahertz emission due to electrically excited 2D plasmons in AlGaN/GaN heterostructure
Authors: Shalygin V. A. , Moldavskaya M. D. , Vinnichenko M. Ya. , Maremyanin K. V. , Artemyev A. A. , Panevin V. Yu. , Vorobjev L. E. , Firsov D. A. , Korotyeyev V. V. , Sakharov A. V. , Zavarin E. E. , Arteev D. S. , Lundin W. V. , Tsatsulnikov A. F. , Suihkonen S. , Kauppinen C.
Published: November 2019

Terahertz radiation emission from an electrically excited AlGaN/GaN heterostructure with a surface metal grating was studied under conditions of two-dimensional (2D) electron heating by the lateral electric field. Intensive peaks related to nonequilibrium 2D plasmons were revealed in the terahertz emission spectra with up to 4 times selective amplification of the radiation emission in the vicinity of 2D plasmon resonance. This selective emission was shown to be frequency-controllable by the grating period. Exact spectral positions of the 2D plasmon resonances were preliminarily experimentally detected with the help of equilibrium transmission spectra measured at various temperatures. The resonance positions are in a satisfactory agreement with the results of theoretical simulation of the transmission spectra performed using a rigorous solution of Maxwell’s equations. The effective temperature of hot 2D electrons was determined by means of I–V characteristics and their analysis using the power balance equation. It was shown that for a given electric field, the effective temperature of nonequilibrium 2D plasmons is close to the hot 2D electron temperature. The work may have applications in GaN-based electrically pumped emitters of terahertz radiation.
Calibration of thermocouple-based scanning thermal microscope in active mode (2ω method)
Authors: Nguyen T. P. , Thiery L. , Euphrasie S. , Gomès S. , Hay B. , Vairac P.
Published: November 2019

We present a procedure dedicated to the calibration of a scanning thermal microscopy probe operated in an active mode and a modulated regime especially for the measurement of solid material thermal conductivities. The probe used is a microthermocouple wire mounted on a quartz tuning fork. Measurements on reference samples are performed successively in vacuum and ambient air conditions revealing a clear difference in the dependence of the thermal interaction between the probe and the sample on the sample properties. Analytical modeling based on the resolution of the heat equation in the wire probe and a description of the thermal interaction using a network of thermal conductances are used to fit experimental data and analyze this difference. We have experimentally verified that the effective thermal contact radius of the probe tip depends on the sample thermal conductivity in ambient conditions, whereas it remains constant in vacuum. We have defined the measurement range of the technique based on the decrease in the probe sensitivity at high thermal conductivities. Considering the experimental noise of our electrical device, it is shown that the maximum measurable value of thermal conductivity is near 23 W m−1 K−1 in vacuum and 37 W m−1 K−1 in ambient air conditions. Moreover, the lowest uncertainties are obtained for thermal conductivities below 5 W m−1 K−1 typically.
Cross-stream migration and coalescence of droplets in a microchannel co-flow using magnetophoresis
Authors: Banerjee U. , Mandal C. , Jain S. K. , Sen A. K.
Published: November 2019

Manipulation of aqueous droplets in microchannels has great significance in various emerging applications such as biological and chemical assays. Magnetic-field based droplet manipulation that offers unique advantages is consequently gaining attention. However, the physics of magnetic field-driven cross-stream migration and the coalescence of aqueous droplets with an aqueous stream are not well understood. Here, we unravel the mechanism of cross-stream migration and the coalescence of aqueous droplets flowing in an oil based ferrofluid with a coflowing aqueous stream in the presence of a magnetic field. Our study reveals that the migration phenomenon is governed by the advection (τa) and magnetophoretic (τm) time scales. Experimental data show that the dimensionless equilibrium cross-stream migration distance δ* and the length Lδ* required to attain equilibrium cross-stream migration depend on the Strouhal number, St = (τa/τm), as δ* = 1.1 St0.33 and Lδ*=5.3 St−0.50, respectively. We find that the droplet-stream coalescence phenomenon is underpinned by the ratio of the sum of magnetophoretic (τm) and film-drainage time scales (τfd) and the advection time scale (τa), expressed in terms of the Strouhal number (St) and the film-drainage Reynolds number (Refd) as ξ = (τm + τfd)/τa = (St−1 + Refd). Irrespective of the flow rates of the coflowing streams, droplet size, and magnetic field, our study shows that droplet-stream coalescence is achieved for ξ ≤ 50 and ferrofluid stream width ratio w* < 0.7. We utilize the phenomenon and demonstrated the extraction of microparticles and HeLa cells from aqueous droplets to an aqueous stream.
Universalities among natural orbitals and occupation numbers pertaining to ground states of two electrons in central potentials
Authors: Cioslowski Jerzy , Prątnicki Filip
Published: November 2019

Although both the natural orbitals (NOs) {ψnlm(r→)} and their occupation numbers {νnl} pertaining to the ground state of two electrons confined by a central potential are completely determined by the spatial component Ψ(r→1,r→2) of the underlying wavefunction through a homogeneous Fredholm equation of the second kind in which Ψ(r→1,r→2) plays the role of the kernel, for the species with a single positive-valued natural amplitude that corresponds to the strongly occupied NO (“the normal sign pattern”), these quantities turn out to depend almost entirely on the “on-top” wavefunction Ψ(r→,r→). For such species, for which the occupation numbers are found to have the large-n asymptotics of n−8, a universal expression involving only Ψ(r→,r→) that reproduces the weakly occupied NOs with remarkable accuracy is inferred from the electron-electron coalescence cusp in Ψ(r→1,r→2). These theoretical predictions are fully confirmed by comparisons among the benchmark-quality NOs computed for the helium atom, the isoelectronic cations with the nuclear charges ranging from 3 to 5, and the two-electron harmonium atom at the limit of an infinitely strong confinement.
Understanding supported noble metal catalysts using first-principles calculations
Authors: Rice Peter S. , Hu P.
Published: November 2019

Heterogeneous catalysis on supported and nonsupported nanoparticles is of fundamental importance in the energy and chemical conversion industries. Rather than laboratory analysis, first-principles calculations give us an atomic-level understanding of the structure and reactivity of nanoparticles and supports, greatly reducing the efforts of screening and design. However, unlike catalysis on low index single crystalline surfaces, nanoparticle catalysis relies on the tandem properties of a support material as well as the metal cluster itself, often with charge transfer processes being of key importance. In this perspective, we examine current state-of-the-art quantum-chemical research for the modeling of reactions that utilize small transition metal clusters on metal oxide supports. This should provide readers with useful insights when dealing with chemical reactions on such systems, before discussing the possibilities and challenges in the field.
Millimeter-wave spectroscopy of HDC=CH
Authors: Hayashi Masato , Matsubayashi Hiromu , Ichiyama Tomohiro , Harada Kensuke , Tanaka Keiichi
Published: November 2019

Rotational transitions of the mono(β)-deuterated vinyl radical, HDC=CH, produced in a supersonic jet expansion by the ArF excimer laser photolysis, were observed by millimeter-wave spectroscopy. The b-type rotational transitions together with the weak a-type transitions were observed only for the lower component of the tunneling doublet, and no tunneling-rotation transitions connecting the lower and upper components were observed, suggesting that state mixing between the two components is negligibly small. The derived molecular constants such as the A rotational constant, Fermi contact interaction constants, and magnetic dipolar interaction constants indicate that the carrier of the observed spectrum is the trans-form of HDC=CH isomers, where the α-proton is located on the opposite side of the β-deuteron. The present conclusion of the trans-form of HDC=CH was also supported by the ab initio calculation in the CCSD(T)/cc-pVTZ level since the trans-form is calculated to be located by 30.04 cm−1 lower than the cis-form due to the difference in the zero point energy. As a result, the tunneling components in the ground state of HDC=CH behave as two different isomers localized at the trans- and cis-wells of the asymmetric double minimum potential. Observed hyperfine constants for HDC=CH were compared with those for H2C=CH to be consistent with each other.
Negative thermal expansion of Cu2O studied by quasi-harmonic approximation and cubic force-constant method
Authors: Linnera Jarno , Erba Alessandro , Karttunen Antti J.
Published: November 2019

Cubic cuprous oxide, Cu2O, is characterized by a peculiar structural response to temperature: it shows a relatively large negative thermal expansion below 250 K, then followed by a positive thermal expansion at higher temperatures. The two branches of its thermal expansion (negative and positive) are almost perfectly symmetric at low temperatures, with the minimum of its lattice parameter at about 250 K and with the lattice parameter at 500 K almost coinciding with that at 0 K. We perform lattice-dynamical quantum-mechanical calculations to investigate the thermal expansion of Cu2O. Phonon mode-specific Grüneisen parameters are computed, which allows us to identify different spectral regions of atomic vibrations responsible for the two distinct regimes of thermal expansion. Two different computational approaches are explored, their results compared, and their numerical aspects critically assessed: a well-established method based on the quasiharmonic approximation, where harmonic frequencies are computed at different lattice volumes, and an alternative approach, where quadratic and cubic interatomic force-constants are computed at a single volume. The latter scheme has only recently become computationally feasible in the context of lattice thermal conductivity simulations. When proper numerical parameters are used (phonon sampling, tolerances, etc.), the two approaches are here shown to provide a very consistent description, yet at a rather different computational cost. All of the experimentally observed features of the complex thermal expansion of Cu2O are correctly reproduced up to 500 K, with a slight overall underestimation of the volume contraction.
Existence and uniqueness of a weak solution of an integro-differential aggregation equation on a Riemannian manifold
Authors: Vil’danova V. F.
Published: November 2019

A class of integro-differential aggregation equations with nonlinear parabolic term

is considered on a compact Riemannian manifold

. The divergence term in the equations can degenerate with loss of coercivity and may contain nonlinearities of variable order. The impermeability boundary condition on the boundary

of the cylinder

is satisfied if there are no external sources of ‘mass’ conservation,

. In a cylinder

for a sufficiently small

, the mixed problem for the aggregation equation is shown to have a bounded solution. The existence of a bounded solution of the problem in the cylinder

is proved under additional conditions.

For equations of the form

with the Laplace-Beltrami operator

and an integral operator

, the mixed problem is shown to have a unique bounded solution.

Bibliography: 26 titles.
A connected compact locally Chebyshev set in a finite-dimensional space is a Chebyshev set
Authors: Shklyaev K. S.
Published: November 2019

Let

be a Banach space. A set

is a Chebyshev set if, for each

, there exists a unique best approximation to

in

. A set

is locally Chebyshev if, for any point

, there exists a Chebyshev set

such that some neighbourhood of

in

lies in

. It is shown that each connected compact locally Chebyshev set in a finite-dimensional normed space is a Chebyshev set.

Bibliography: 11 titles.
The wave model of a metric space with measure and an application
Authors: Belishev M. I. , Simonov S. A.
Published: November 2019

Let

be a complete metric space and let

be a Borel measure on

. Under certain fairly general assumptions about the metric and the measure, we use lattice theory to construct an isometric copy

of the space

, which is called its wave model. The construction is motivated by applications to inverse problems of mathematical physics. We show how the wave model solves the problem of reconstructing a Riemannian manifold with boundary from its spectral data.

Bibliography: 13 titles.
Oxidation of isomaltose, gentiobiose, and melibiose by membrane-bound quinoprotein glucose dehydrogenase from acetic acid bacteria
Authors: Kiryu Takaaki , Kiso Taro , Sato Hirofumi , Murakami Hiromi
Published: November 2019

Membrane-bound quinoprotein glucose dehydrogenase from acetic acid bacteria produces lactobionic acid by the oxidation of lactose. Its enzymatic activity on lactose and maltose is much lower than that on d-glucose. For that reason, the activity of the enzyme on disaccharides has been considered low. In this study, we show that the isomaltose-oxidizing activity of acetic acid bacteria is much higher than their lactose-oxidizing activity. In addition to isomaltose, the enzyme oxidized gentiobiose and melibiose to the same extent. According to the characteristics of the isomaltose-oxidizing activity and investigations using dehydrogenase-deficient mutant bacteria, we identified the responsible enzyme as membrane-bound quinoprotein glucose dehydrogenase.

Abbreviations: AAB: acetic acid bacteria; m-GDH: membrane-bound quinoprotein glucose dehydrogenase; DCIP: 2,6-dichlorophenolindophenol; DP: degree of polymerization; HPAEC-PAD: high-performance anion-exchange chromatography with pulsed amperometric detection; NMR: nuclear magnetic resonance; TLC: thin layer chromatography; COSY: correlation spectroscopy
Effect of dietary cellulose nanofiber and exercise on obesity and gut microbiota in mice fed a high-fat-diet
Authors: Nagano Takao , Yano Hiromi
Published: November 2019

Cellulose nanofiber (CN) consumption with exercise could be a potential strategy to control obesity. Here, we studied the effects of CN supplementation and voluntary exercise on obesity and gut microbiota in high-fat diet (HFD)-fed mice. Consumption of CN increased voluntary wheel running activity. CN intake and exercise together suppressed the increase in body weight and fat mass, and improved glucose tolerance. The fecal gut microbiota was analyzed by sequencing 16S ribosomal RNA genes. Principal component analysis revealed a shift in the microbiota composition resulting from exercise, but not from CN supplementation. Erysipelotrichaceae and Rikenellaceae decreased with exercise. Exercise also increased Ruminococcaceae, whereas exercise and CN intake together increased Eubacteriaceae. These two families are butyrate producers. Exercise increased the amount of acetate in the cecum. These results suggest that CN consumption improves exercise performance and exerts anti-obesity effects by modulating the balance of the gut microbiota.
Getting under the skin: Cuticle damage elicits systemic autophagy response in C. elegans
Authors: Kumsta Caroline , Hansen Malene
Published: November 2019

In this issue, Zhang et al. (2019. J. Cell. Biol. https://doi.org/10.1083/jcb.201907196) describe a molecular mechanism by which cuticular damage in the nematode C. elegans leads to systemic induction of autophagy by signals propagated from sensory neurons via the TGF-β signaling pathway.
Rotationally inelastic processes of

C2−

(

2Σg+

) colliding with He (1
S) at low
temperatures: ab initio interaction potential, state changing
rates and kinetic modelling
Authors: Mant B P , Gianturco F A , González-Sánchez L , Yurtsever E , Wester R
Published: November 2019

We discuss in detail the quantum rotationally inelastic dynamics of an important
anion often discussed as a possible constituent of the interstellar medium (ISM)
and in different environments of circumstellar envelopes: the

C

2

−

molecular ion. Its interaction forces with one of the most
abundant atoms of the ISM, the neutral helium atom, are obtained for the first
time using ab initio quantum chemistry methods. The overall
angular anisotropy of the potential energy surface is analysed in order to link
its features with the efficiency of transferring energy from the abundant He
atoms to the internal rotational levels of this molecular anion. Calculations of
the corresponding rotational state-to-state inelastic cross sections, for both
excitation and de-excitation paths are obtained by using a multichannel quantum
method. The corresponding inelastic rates at the temperatures of interest are
determined and their role in distributing molecular states over the different
populations of the rotational levels at the temperatures of that environment is
discussed. These computed rates are also linked to the dynamical behaviour of
the title molecule when confined in cold ion traps and made to interact with He
as the common buffer gas, in preparation for state-selective photo-detachment
experiments.
Study on attenuation characteristics of electromagnetic waves in plasma-superimposed artificial wave vector metasurface structure
Authors: Zhang Wenyuan , Xu Haojun , Song Zhijie , Han Xinmin , Wei Xiaolong , Wu Xin , Li Yiwen
Published: November 2019

Because of the limitations of thin-layer plasma for electromagnetic wave attenuation, a new PS-AWV (plasma-superimposed artificial wave vector) metasurface structure is proposed. We also introduced the design principle of increasing the propagation distance of electromagnetic waves in plasma using artificial wave vector metasurface. We designed a X band artificial wave vector metasurface by geometric phase dispersion control such that the incident electromagnetic wave abnormally reflected, and the reflection angle reached 55° when measured at normal incidence. Using an electromagnetic finite element method, we established a coupling model of the PS-AWV metasurface structure attenuated electromagnetic wave using CST (Computer Simulation Technology). We analyzed the variation law of reflectivity under different plasma parameter distribution, and the experiment was performed in a microwave darkroom. We also measured the reflectivity of the wave-vector metasurface structure. Both simulation and experimental results show that the artificial wave vector metasurface can effectively increase the attenuation effect of plasma on electromagnetic waves and improve the attenuation effect of electromagnetic waves because of thickness reduction; thus, it can reduce the plasma thickness required for plasma stealth and improve its application in practical scenarios.
Cryogenic 9Be+ Penning trap for precision measurements with (anti-)protons
Authors: Niemann M , Meiners T , Mielke J , Borchert M J , Cornejo J M , Ulmer S , Ospelkaus C
Published: November 2019

Cooling and detection schemes using laser cooling and methods of quantum logic can contribute to high precision CPT symmetry tests in the baryonic sector. This work introduces an experiment to sympathetically cool protons and antiprotons using the Coulomb interaction with a

ion trapped in a nearby but separate potential well. We have designed and set up an apparatus to show such coupling between two identical ions for the first time in a Penning trap. In this paper, we present evidence for successful loading and Doppler cooling of clouds and single ions. Our coupling scheme has applications in a range of high-precision measurements in Penning traps and has the potential to substantially improve motional control in these experiments.
Experimental proof of quantum Zeno-assisted noise sensing
Authors: Do Hoang-Van , Lovecchio Cosimo , Mastroserio Ivana , Fabbri Nicole , Cataliotti Francesco S , Gherardini Stefano , Müller Matthias M , Dalla Pozza Nicola , Caruso Filippo
Published: November 2019

In the ideal quantum Zeno (QZ) effect, repeated quantum projective measurements can freeze the coherent dynamics of a quantum system. However, in the weak QZ regime, measurement back-actions can allow the sensing of semi-classical field fluctuations. In this regard, we theoretically show how to combine the controlled manipulation of a quantum two-level system, used as a probe, with a sequence of projective measurements to have direct access to the noise correlation function. We experimentally test the effectiveness of the proposed noise sensing method on a properly engineered Bose–Einstein condensate of

87

Rb

atoms realized on an atom chip. We believe that our QZ-based approach can open a new path towards novel quantum sensing devices.
A priori ranking and an analysis of factors affecting tire wear
Authors: Abdulaev E K , Makharatkin P N , Pumpur E V
Published: November 2019

The aim of the paper is to analyze factors affecting tire life and to rank them using experimental data in order to determine how influential each of them is. The issue of tire wear is an important concern for many different companies because tires account for a major part of the operating costs of rubber-tired equipment.
Influence of the bottom relief on the formation of the navigable routes network in the water area of the Northern Sea Route
Authors: Afonin A B , Ol’khovik E O , Tezikov A L
Published: November 2019

The paper is devoted to the study of the influence of the bottom relief on the formation of the navigable routes network in the water area of the Northern Sea Route. A brief historical overview of the main stages of mapping the bottom relief of the Arctic seas in the interests of the Arctic shipping development is given. The results of the bottom relief survey are summarized. A high degree of hydrographic knowledge of the coastal routes, intended for use by vessels with a draft of 6-7 meters in summer, is noted. The navigation and hydrographic conditions for the development of the navigable routes network intended for large-capacity vessels with a large draft are determined. Data on the cartographic study of the water area of the Northern Sea Route, basic information on the depths distribution over the Arctic seas area, as well as information on areas with insufficient hydrographic study, are given. The principles of formation of the shipping routes network of large-tonnage vessels in the water area of the Northern Sea Route are formulated. Recommendations on aligning the level of hydrographic knowledge into line with the requirements of navigation safety of large-tonnage shipping at promising projects implementation are presented. The results of research can be used for planning the hydrographic works and the development of a promising network of shipping routes in the Arctic basin.
About the use of 110G13L steel as a material for the excavator bucket teeth
Authors: Bolobov V I , Chupin S A
Published: November 2019

The causes of failure of the bucket teeth of the excavator during excavations in rocks are analyzed in the article. It is shown that the most typical cause of failure of bucket teeth is wear of teeth. The wear with soft rocks (less than 1100 HV) which hardness is lower than the hardness of steel in the cold-work hardened state, a preliminary cold-work hardening can essentially (up to 10 times) increase the material wear resistance. The wear with rocks, having greater hardness with hardness of ~1250 HV, the cold-work hardening do not lead to increase of the Hadfield steel wear resistance.
The algorithm for vehicle fleet creation
Authors: Borodina Yu V , Menukhova T A
Published: November 2019

The article deals with the problem of creating the structure of a vehicle fleet. Today when specialists solve this problem, they rather use their experience and intuition, based on one criterion, which is the most important in their opinion. The most usual criterion, in this case, is the cost of a vehicle and the level of vehicle safety is often neglected. Meanwhile, the increase in this level is one of the World Health Organization’s activities aimed at decreasing the number of road traffic injuries within the Decade of Action for Road Safety. This article analyzes different quality indicators of goods transportation by automobile transport. As a result, it establishes a list of indicators that can be important when solving the task of creating a rational vehicle fleet to satisfy the requirements for goods transportation in the mineral resources sector. The article also describes the validation scheme for weighting factors used for the indicators in the list. As a consequence, the algorithm for vehicle fleet creation is developed.
Current challenges and innovations in environmental safety of vehicles
Authors: Avramov D , Dobromirov V , Martynov N
Published: November 2019

The automobile is one of the mass industrial products. The article analyzes its environmentally harmful effects on the environment. The current environmental safety of vehicles is analyzed and changes in the structure and volumes of harmful emissions caused by innovative design changes are justified. The destructive effect of the wheel propulsion on the soil cover in natural landscapes is described. The current state of the car recycling system is analyzed and some promising technologies for its implementation are described.