In the article is given a review on production and application nonisocyanate polyurethanes based on cyclic carbonate oligomers. Nonisocyanate polyurethane (NIPU) networks are obtained by reaction between the polycyclic carbonate oligomers and aliphatic or cycloaliphatic polyamines with primary amino groups. This forms a crosslinked polymer with β-hydroxyurethane groups of different structure – polyhydroxyurethane polymer. Considered as a proper NIPU and hybrid polymers, involving various other oligomeric systems (HNIPU). Significant attention was paid to the materials based on renewable raw materials.The authors give an overview of recent publications in the field with a more detailed description of the Polymate Ltd. achievements.
Keywords: nonisocyanate polyurethanes, cyclic carbonates, polyhydroxyurethane polymer.
This article describes a method for producing two-component nonisocyanate insulating foams and technology of its spraying on the insulated surface. It describes the device, which, along with standard equipment, includes principally new design of components pre-mixing chamber. Constructive solutions described in the article will allow using the compositions which have different time and temperature of curing than conventional PU foams.
Keywords: Keywords: spray foams, insulating foams, nonisocyanate urethanes, pre-mixing chamber.
The paper describes the method for determining the position of the contact wire of electrified railways using microwaves. The method is based on the triangulation system of two georadars and allows to determine a contact wire zigzag and height from the rail head. The proposed method is all-weather with the possibility of continuous monitoring of the overhead contact wire in plan and profile with the opportunity to automate the processing and signaling abnormalities.
Keywords: railroad contact line, contact wire location, GPR, automatic control systems
The main issues of competitiveness, assess the quality of services, pricing strategy, especially sales service, new services, cost accounting and auditing in the tourist and recreation industry
Keywords: competitiveness, quality of services, audit, pricing strategy, marketing, tourist and recreational industry.
The article depicts test results of ballastless track system roadbed stressed state. In-situ tests of roadbed vertical stresses were held considering rolling stock type and speed. Roadbed vertical stress distribution dependence was carried out.
Keywords: Roadbed, ballastless track system, RHEDA 2000, vertical stress damping, stress distribution
The solid solution of LiMn1/3Cr1/3Fe1/3O2 with the structure of α-NaFeO2 isostructural with the widely used LiCoO2 has been synthesized and investigated as a cathode material. Rated voltage of LiMn1/3Cr1/3Fe1/3O2 relative to the lithium is 4 V. The possibility of charging − discharging the material to a specific capacity of 220-250 mAh/g at currents of C/15-C/50 without phase transformations has been experimentally demonstrated.
Keywords: lithium-ion batteries, cathode materials, Delafosse, solid solution, X-ray structural analysis, electrochemical properties
In this paper we study of the local atomic and electronic structure of nanostructured condensed material for rechargeable current sources on the basis of 15mas.%V2O5/Fe/LiF nanocomposite within charge-discharge cycle. Principle component analysis (PCA) of the series of Fe K-edge spectra collected during 1 st charge showing the concentrations of the components Fe, FeF2 and V[FeV]O4. We found the changes in the V oxidation state from the analysis of the experimental Fe K- and V K- XANES spectra. Total and partial density of states of components are presented.
Keywords: nanostructured materials for rechargeable current sources, dynamics of local atomic and electronic structures, XANES, DFT
The work is devoted to the study of algorithms of control subsystem as part of the integrated onboard control system of the aircraft and used in the final part of the trajectory. Algorithms of control subsystems are synthesized on the basis of the theory of optimized delta-transformations of the second order using the principle of the inverted pendulum on a cart. The studies based on the simulation using the developed software model, allowed to estimate as the impact dispersion, and the contribution to it of various subsystems.
Keywords: terminal control, aircraft, on-board integrated control system, optimized delta transformation of the second order, autonomous short range radionavigation system, simulation, software model
The article is devoted to the problem of the identification of the Black Sea – Caspian region as a special segment of the World Space in the postbypolar system. The Great Limitrophe conception developed by V.L. Tsymbursky and S.V. Khatuntsev is used as «the structural frame» for understanding modern peculiarities of this region. The author outlines two aspects of its identification: geopolitical and geocivilozational. He also introduces the key concept «limitroph territory» adapting it to the specific region. The key concept involves two other concepts – «shatterbelt» and «(inter)civilizational split zone». The article contains brand new facts on the Black Sea – Caspian region problem.
Keywords: «big political space», geopolitics, Black Sea – Caspian region, Great Limitrophe conception, limitrophe-territory, «shatterbellt», civilizational layer, «(inter)civilizational split zone».
In the introduction the relevance of the study of diffusion along grain boundaries in metals. The aim of the work was to develop a method for determining the diffusion coefficient of impurity atoms at the grain boundaries in metals based on the numerical solution of the model by Fisher. The methodology laid plotting the ratio of the depth of bulk diffusion and grain boundary diffusion on the ratio of the diffusion coefficients of impurity atoms in them. In the construction of numerical solutions available to simplify the modeling of the physical nature of the process of diffusion along grain boundaries. The technique may be used in experiments with widely varying parameters diffusion annealing. Examples of the application procedure. The estimation of the coefficient of grain-boundary diffusion of copper in polycrystalline nickel. Also calculated the ratio of maximal depth of diffusion of silver in the grain and the grain boundary in the SMC copper.
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production
In the present work we report on the study of local atomic and electronic structure of gold nanoparticles funnctionalised by thiol and amine containing long-chain ligands. The study of nanoscale atomic structure is performed by means of X-ray absorption spectroscopy (XANES: X-ray Absorption Near-Edge Structure) and computer simulation. In consequence of the experimantally obtained data analysis and computer simulation it was obtained that strong bonding takes place when 11-mercaptoundecanoic acid is bound to the gold nanoparticles surface, forming a chemical bond Au-S 0.25 nm in length. Weaker bonding is observed when forming bond between dodecylamine and gold nanoparticles surface atom resulting in Au-N bond 0.23 nm in length. Supplementary XANES spectra analysis by means of density functional theory reveals the nature of formation of the investigated nanoscale structure.
Keywords: nanoscale structure of matter, X-ray absorption spectroscopy, XANES, density functional theory, nanoparticles functionalisation
The paper studies the possibility of quantitative processing of the GPR data for determining the dielectric permittivity and conductivity of a medium (soil samples). Experimental studies are made using radargrams of soil samples with specified values of moisture and conductivity. New methods of quantitative processing of radargrams are proposed in this work to determine the dielectric permittivity and conductivity of soils. The methods were successfully tested on various sections of Russian railways net.
Keywords: layered road profiling, GPR, soil moisture, soil layers profiling, soil conductivity
The nano-catalyst ceria (CeO2), activated by Pt nanoparticles, is known for being prospective and efficient material widely used in catalysis, fuel elements, and sensors. One of the most up-to-date methods of catalysts' reasearch is X-ray absorption spectroscopy (XAS) that is sensitive to the chemical state of catalyst's active centers [1,2]. Using XAS in the fluorescense detection mode at CeL1 line with high precision we studied electronic structure of Pt-activated nanoparticles of ceria at various redox conditions. In order to detect partial X-ray fluorescence yield the emission line CeLγ3 was used, which allowed us to increase spectral resolution. We researched local atomic and electronic structure of the materials under study. Oxygen vacansies were found to appear on the nanoparticles surface of ceria at 5% CO He atmosphere. Theoretical modeling of the obtained spectra at CeL1-edge demonstrated good agreement with experiment.
Keywords: X-ray absorption spectroscopy, HERFD, XAS, Ce-based catalysts, oxygen vacansies
This paper describes an in-situ experimental technique to study of ceria nanocatalysts by using X-ray absorption near edge spectroscopy XANES. This technique allows us to determine Ce3+ concentration inside ceria nanoparticles in the course of catalytic reaction based on the comparison and divergence minimization of the Ce L3 XANES spectrum of the ceria nanoparticles under catalysts (atmosphere, temperature) with a linear combination of two independent components corresponding to spectra of Ce4+ ion of the CeO2 structure and Ce3+ ion of the theoretical Ce2O3 structure. The calculated weight ratio determines the Ce3 + concentration in the sample during the catalytic reactions.
Keywords: in-situ X-ray absorption spectroscopy, HERFD, XAS, ceria nanoparticles, Ce-based catalysts, Ce3+ concentration
In this paper we study the dynamics of the local atomic structure of new nanostructured condensed material for for rechargeable current sources on the basis of 15mas.%V2O5/Fe/LiF nanocomposite within charge-discharge cycle on the basis of X-ray diffraction (XRD), X-ray absorption spectroscopy (XANES) and of computer simulation. The analysis of the experimental data obtained during the first charge cycle reveals the transformation of iron to more than 50% of iron fluoride (II) , Li ions intercalate into the structure of amorphous V2O5 forming LiVO2 compound.
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production