bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of information support for innovation development
Authors: Barykina Yuliya
Published: November 2019

The article studies the concept and methods of information support for innovation development. The disadvantages and problems of information support were identified. Monitoring of information support stages, cycles, and directions was carried out. The importance of information support for innovation development was emphasized. Innovation activities as any other activities need information flows. Information support for innovation development includes experimental, technical and scientific information for innovation development. At present, innovation activities are risky activities since they are based on new ideas, new methods, new scientific knowledge, production of new products and improvement of the old ones. They require application of information technology. The information support is data required for regulating economic processes. These data are included into the databases of information systems. It is necessary to identify the following components required for implementing new technologies: safety, project relevance, project purpose, and probability of frequent use. Information that minimizes ambiguity of innovation activities is required.
Problems and prospects of import substitution in the construction industry of the region
Authors: Beregova Galina , Klipin Alexey , Shupletsov Alexander
Published: November 2019

The article provides an in-depth analysis of the construction industry in Russia, and in particular the Irkutsk region. Discloses the tools to support import substitution in the construction industry. As a research tool used economic-statistical, methods of analysis, synthesis and analogy. The statistical data that reflects the effectiveness of state mechanisms to support Russian manufacturers of building materials are presented. A number of proposals for improving the existing mechanism were proposed. The advantages of developing the production of heat-insulating materials, innovative constructions of reinforced concrete structures and ready-made house sets on the territory of the Irkutsk region are revealed. The conclusions are presented, which reflect the effectiveness of the application of the policy of import substitution as a mechanism for the development of the construction industry of the Irkutsk region.
Analysis of the development of small innovative enterprises in the construction industry
Authors: Bovkun Aleksandr , Korodyuk Igor
Published: November 2019

The activity of small innovative enterprises in the construction industry of universities and scientific institutions was analyzed. The main two problems of low growth of these companies are identified. Various mechanisms for raising funds in the implementation of innovative projects of a small enterprise have been identified and considered. After analyzing the functioning of a small innovative business, it can be said that most enterprises cannot compete with other market participants, and their technologies become unclaimed. To make a big leap in innovation development, the government needs to force business structures to invest in innovation.
Optimization of developing district water supply systems taking into account variability of perspective water consumption
Authors: Chupin Victor , Pham Ngoc Minh , Chupin Roman
Published: November 2019

The issues of development and reconstruction of district water supply systems are considered and new techniques and methods for optimizing their structure and parameters are proposed, which allow the complex to optimize installation sites and performance of water intake and treatment facilities from surface and underground water sources, methods of transporting water from sources to consumers, including the selection optimal use of road and pipeline transport. The developed methods are based on the construction of redundant design schemes of possible options for the intake, water treatment and transportation of water and the search for the maximum flow of the minimum cost. This takes into account the capacity of existing systems and structures, optimized methods for the reconstruction of existing pipeline systems. Separately, the issues of increasing seismic resistance and the influence of seismic effects on the structure of structures and on the choice of the method of transporting water are considered. The technique and method allowed to substantiate the scheme and logistics of water providing to three districts of the Irkutsk region.
Study of the regimes planning problem for pipeline systems tests
Authors: Grebneva Oksana
Published: November 2019

When determining the actual characteristics of pipeline systems based on the measurement results, the solution of two problems is required: optimal placement of measuring instruments; planning conditions in which this measure placement will be the most informative. This article presents the results of research for problem of planning test conditions of pipeline systems. The mathematical formulation of the problem under study is presented, methods for its solution are proposed, namely, genetic algorithms. The results of numerical studies that show their potential performance are presented.
Renovation of residential areas for benefit of builders, state and citizens
Authors: Grushina Olga , Torgashina Irina
Published: November 2019

The paper deals with the problem of residential housing renovation projects for benefit of builders, citizens and state. The numerous interpretations of the “renovation” term we understand here as a complete renovation of the housing stock, i.e. demolition of old buildings and construction of new ones in contrast to their reconstruction and modernization. In other words, the renovation is considered as an urgent city-planning challenge involving changes in the field of territorial planning. On the example of the classic “Khrushchev” quarter of Irkutsk city, the authors propose a pilot renovation project with the distribution of roles and expenditures of all participants. The analysis conducted allows drawing a conclusion that renovation will be beneficial to the builder only if budget funds are invested in these projects in order to compensate the costs related to temporary resettlement of citizens from demolished dwellings. Another prerequisite is the governmental repurchase of apartments intended for resettlement of citizens from demolished housing at the prices not lower than those set by the authorities in the region. Citizens are ready to support renovation projects in case of their returning to their former place of residence in conditions improved from the point of view of the living environment comfort. To ensure the profit of the builder, the living area of the newly commissioned housing should exceed the area of the demolished housing by no less than one and a half times, provided that cheap technologies of modern prefabricated housing are used.
Extensibility of fibre reinforced concrete
Authors: Korneeva Inna
Published: November 2019

This study compares the bending strengths of conventional fine-aggregated concrete and continuously reinforced concrete. It presents reliable statistical data based on testing mode under load conditions with constant strain rate. These prove that polypropylene reinforcing fibres should be in volumes that are able to provide compatibility of their deformation with the concrete matrix. The study establishes qualitative (in terms of structure) and statistical deformation patterns of fibre reinforced concrete that can significantly
Analysis of economic efficiency of the internal air temperature control
Authors: Kuzmin Sergey , Vasilevskaja Tatyana
Published: November 2019

In this paper, analysis of economic efficiency of energysaving activities of the internal air temperature regulation during the daily period by means of individual regulators.
Construction in post-war Siberia: Participation of German and Japan prisoners of War
Authors: Kuznetsov Sergey , Karasev Sergey , Drobotushenko Evgeniy , Chapigin Ugor
Published: November 2019

The most important attribute of the existence of the totalitarian regime in the USSR was the repressive policy that influenced almost all spheres of life of Soviet society. The GULAG and GUPVI CAMPS, which spread throughout the country and absorbed millions of innocent human victims, became an integral part of the Soviet repressions. Siberia, which became a place of hard labor and exile in tsarist times, became in Soviet times a huge concentration camp for both Soviet citizens and foreigners. Why Siberia? There are several explanations for this: the extremely harsh climate of the region, which together with hard work had to «re-educate» the lost; huge deserted spaces that had to be mastered; large construction sites, for example, BAM, which is very profitable to use slave, almost free labor of prisoners or prisoners of war.
Improvement of the energy saving management system in the housing and utilities sector
Authors: Litvinova Olga , Doroshenko Tatiana
Published: November 2019

The article aims to analyze the issues of energy-saving policies in the housing and utilities sector. The article studies the nature of energy saving measures. In the housing and utilities sector, energy savingdepends on the efficiency of the energy saving management system. The article is aimed at 1) systematization of legal acts regulating energy saving at the federal, regional and municipal levels; 2) analysis of factors, principles, directions, objectives, mechanisms of energy saving policies. The control mechanism is an impact of the control subject on the control object. Energy saving subjects, objects and factors were identified. Energy saving factors were classified. Technological improvement of production, investing in production facilities should be a basis for energy saving policies. To search for new ways of rational use of energy resources and implement energy saving solutions, it is necessary to take into account capabilities of each participant in the energy saving management system of the housing and utilities sector. Energy saving is an interrelated set of scientific, methodological, technological, engineering, organizational, and economic measures.The energy saving program is a result of joint efforts of regional and local governments, businesses, experts engaged in solving ecological, housing and utilities problems.
Innovation incentive mechanism in the construction industry
Authors: Nikityuk Lyubov
Published: November 2019

The construction industry carries out effective innovation activities and is characterized by dynamic creation and implementation of construction technologies. In current economic conditions, the most acute problem is intensification of innovation activities of enterprises and restoration of the investment potential of the construction industry. The author developed an organizational economic mechanism for implementing innovative technologies into the construction industry. The mechanism covers the full cycle of the innovation process, determines the list of its main participants, their functions, and is based on the principles of consistency and integrity. This integral approach makes it possible to plan the innovation process due to the shared information space which has to be created by the government. The article describes a method for assessing the economic efficiency of the innovation process in the construction industry, calculating the economic effect of an economic entity for a certain period and identifying the level of innovation activities of enterprises. Innovation activity indicators are used to evaluate achievements of development and implementation of advanced construction technologies.
The «New Angrarstroy» as a project of non-primary-based integration of Russian and Chinese economies: opportunities and challenges
Authors: Nikolskiy Aleksey , Shupletsov Alexander , Beregova Galina
Published: November 2019

In the context of non-primary-based cooperation of Russia and China the innovation Project «New Angarstroy»: Baikal-Amur metallurgical super-combine, is being considered. It was developed as a key part of the new stage of industrialization in Russia, including of large scale Trans-Siberian and Baikal-Amur railway reconstruction. The project serves as an alternative to further increasing the exploitation of forest resources in the Baikal region, creating here new environmentally harmful cellulose and chemical plants and tourist hotels on Baikal. The project assumes the development of the largest metallurgy production of national and international scale, which will includes high-quality ferrous metallurgy of the full cycle and titanium-magnesium industry. The development of the Baikal ecological territory is assumed within the framework of the Lake-Temple subproject.
The experience of state and especially military construction in the Civil war in Easten Siberia territory
Authors: Novikov Pavel , Borisov Igor
Published: November 2019

The experience of especially military construction accumulated by the sides in the conditions of the Civil war can not be ignored. These actions only in modern Russian historiography were objectively evaluated. Author reconstructs the combat performance of military units and stressed the attention o the chronology and geography. During the June - August, 1918 struggle anti-Bolshevik force occupied East Siberia territory. The mobilisation of the population in the region was carried out on ьthe same principles, as in other territories controlled by the Provisional Siberian government. As the territory was occupied, all officers and military officials were called up, and the volunteers were also enlisted. Since the end of August, 1918 the mobilisation of persons, born in 1898-1899, began. A nucleus of the Whites was the officers, the studying youth and a part of bureaucrats and administrators, whose example carried away the representatives of other social groups.They were defeated, partly killed, partly driven out of Russia, but did not change their beliefs and once made choice.
Dilapidated and dilapidated housing in the aspect of the Federal project “Ensuring sustainable reduction of uninhabitable housing”
Authors: Peshkov VV , Gertsekovich DA , Gorbachevskaya Li
Published: November 2019

In Russia, a fairly high level of dilapidated and dilapidated housing, this problem is closely linkedto housing and communal services for housing funds, with inaction of municipal authorities for emergency anddilapidated housing, with the absence of certain by-laws in the field of overhaul, is high. Clearing blocks of dilapidated housing, resettlement of citizens, creation of favorable conditions for investors in order to effectively integrated development of built-up areas are urgent tasks facing the government of Russian cities. In this article, these problems are disclosed in the example of the national program. According to the results of this study revealed that government should use an individual approach to the development of builtup areas, which should be based on a deep town-planning analysis and integrated approach to their development with comprehensive discussion platforms of both architects, urbanists, developers, and with economist, sociologists and marketers.
Factors separating the initial (maximum) price of the state construction contract
Authors: Pinchuk T O , Maizel I V , Bezrukikh O A
Published: November 2019

The problem of increasing transparency and excluding the corruption component in procurement is the most acute in the modern community. The methodological bases of the formation of the initial maximum contract price are considered. The considered approach is a new approach, since this separation will allow manipulating the controlled part in the composition of the initial maximum contract price and, thereby, optimizing costs. The application of the approach will allow you to follow a scientifically based strategy to control the cost of all phases of construction, a detailed comprehensive study of investment and construction programs.
Formation of the assessment method of the living environment comfortability in cities
Authors: Polyakova Nina , Zaleshin Vitalii , Polyakov Vladimir
Published: November 2019

A brief characteristic of the problem of urgent researches of living environment comfortability in Russian cities is presented in this article. The authors’ method of urban environment comfortability diagnostics on the basis of integrated approach is given. It is proved that living environment comfortability assessment should be based not only on the analysis of the official statistics, the data of Russian government and technical observations, but also on the city residents’ interview results. The sequence of method development of urban environment comfortability assessment is stated. This sequence includes such components as: the formation of the complex of factors defining urban comfortability state; the development of the set of criteria (aggregated into five groups), which render the content of factors and reflect a wide range of residents’ requirements; the defining of assessment intervals for each criterion. The formed method reflects the following groups of residents’ requirements to the urban environment comfortability: a) to the general living conditions in the city; b) to the conditions for labor / education / other productive work; c) to the conditions for leisure and creative activities; d) to social conditions; e) to psychological conditions. The results of approbation of the developed method are presented. The pilot study was held in Irkutsk, a Siberian city, and resulted in urban comfortability assessment. The results of this approbation allow to say about this method usefulness for getting quantitative assessment of the urban comfortability state in general and also in its isolated aspects.
Author’s approach to selection of municipal property management forms and methods
Authors: Prigozhin Vyacheslav
Published: November 2019

Municipal property is one of the economic components of local self-government. It is an important factor of the sustainable socio-economic development of the city. The population evaluates results of municipal property management. Municipal property has to satisfy needs of residents which requires the effective use of methods and forms of municipal property management. The lack of effective management forms causes a budget gap. Therefore, it is necessary to choose effective forms of municipal property management. To solve this problem, the author carried out a comparative analysis of the existing municipal property management forms and methods. The article suggests mechanisms aimed at improving the efficiency of municipal property management. The mechanisms account for modern municipality development priorities, can increase business efficiency in the local real estate market, improve the quality of municipal management, contribute to the rational use of municipal property objects.
Strengthening of a node of connection of floor slabs with racks in structural systems with without a crossbar framework
Authors: Shcherbin Sergey , Gorbach Pavel , Savenkov Andrey
Published: November 2019

The article deals with different options for strengthening node of connection of floor slabs with racks in systems with without a crossbar framework. Modeling of the strengthened nodes in the environment of SCAD has been made, the analysis and comparison of numerical calculation data to select the most rational option of strengthening is carried out.
Evaluation of new possibilities of using thermoelectric generators in systems of renewable energy sources (RES)
Authors: Shelekhov Igor , Dorofeeva Natalia , Smirnov Evgenij , Shelekhov Maximilian
Published: November 2019

This paper presents an analysis of the application of new technologies in the design of thermoelectric cooling systems, presented the results of the comparative analysis of classical thermoelectric system and the thermoelectric system with the spatial orientation of the heat transfer sides. New thermoelectric systems are beginning to compete with traditional ways of energy transformation up to several hundred watts. To extend the range of applications of thermoelectric systems, it is necessary to use new design methods and new design solutions that will more effectively convert heat losses into useful energy for future use. This paper presents the results of a comparative analysis of conventional thermoelectric module and the thermoelectric module with the spatial orientation of the parties. It is shown that the efficiency of the thermoelectric module with the spatial orientation of the parties in the current in 4A 36% higher compared to the classic thermoelectric module and 43% higher when the current is 8A. The results of the research have shown that the efficiency of the thermoelectric modules to a greater extent influence not electrophysical characteristics of thermoelectric junctions, and the technical decisions when designing and designing. Studies have shown that further work to increase the efficiency of thermoelectric systems should be conducted in the field of improvement of structure of the thermoelectric modules. Using the known topology emitted or absorbed heat from the thermoelectric module can be moved to side to distribute it over a larger area or concentrate on a smaller area. With the increase of its efficiency, thermoelectric modules can compete with traditional heat pumps in the field of higher capacity and will be able to expand your range of applications.
The multifunctional power container. Water treatment
Authors: Tolstoy Mikhail , Belookaya Nina , Tolstoy Vasily , Leontyev Anton , Tunik Alexander
Published: November 2019

The results of studies of a multifunctional energy container are given. Investigated mixing of the fluid due to the rotation of the pneumatic-hydraulic aerator. The possibility of combining various technologies for wastewater treatment in one combined mobile structure is shown. Based on the conducted research, a wastewater treatment plant was proposed.
Development of digital economy in Irkutsk region
Authors: Turkova Valentina , Arkhi Anastasia
Published: November 2019

For several years, the digital economy has been implemented into the economic system of Russia. The group of promising digitalization areas are as follows: transport, housing and utilities, banking, education, healthcare, etc. Currently, the digital economy is a project aimed at improving the efficiency of the regional policies. Implementation of new nanotechnologies makes it possible to implement the “smart city” or “digital region” system. The regional authorities are solving the problems of implementation of new and unknown technologies that can reduce costs without increasing the unemployment level. The government is ready to support all projects aimed at changing social spheres. For successful implementation of digital technology projects, it is necessary to analyze all sectors that need special attention. The development of the region will depend on the solution of these tasks. Today, Irkutsk region is ready to perform priority tasks set by the President of the Russian Federation in the economic and social spheres (industry, agriculture, construction, urban economy, transport and energy infrastructure, financial services). For this purpose, they are implementing digital technologies and platform solutions.
Machine-Learning-Assisted the Design of Resin Matrix Composites Coating with Ablation Resistance
Authors: An D , Ma Z , Li C Y , Ma C , Li W Z
Published: November 2019

Traditional experimental methods always cost a lot but produce little when designing and developing new kinds of materials, especially for coating materials. However, with the assistance of machine learning, it is possible to predict the performance of a specific coating without preparation or simulation, which makes the design of material more efficient. In this study, machine learning was introduced to assist the design of resin matrix composites coating with ablation resistance. A structured method for engineering data in the material field was approved. Based on this method, the data from laboratory records and Lange’s Chemistry Handbook were collated into one operational database. All the 190 sets of data were used to train the artificial neural network (ANN) regression model to predict the back-surface temperature of the substrate for specific coating under given ablation condition. The mean absolutely percentage error (MAPE) of the model is 7%. Concerning the characteristics of the material database, a feature engineering method, which combines the Pearson correlation coefficient and random forest (RF) algorithm was performed to identify the main controlling factors of the service performance of the coatings.
Isothermal Oxidation Behavior of CrSiN Coating Deposited by Magnetron Sputtering at 700°C
Authors: Ou Tianxiong , Chang Weijie , Zhang Hao , Xu Xiangmin , Xie Shengliang , Duo Shuwang
Published: November 2019

CrSiN coatings have been successfully deposited on the surface of GH169 alloy by closed filed unbalanced magnetron sputtering (CFUBMS). The microstructure, chemical and phase composition of the coatings were characterized by SEM, EDS and XRD, respectively. The mechanical properties of the coatings such as microhardness and adhesion strength were measured by indentation method and scratch method, respectively. The isothermal oxidation behavior of CrSiN coating at 700°C was investigated using thermogravimetric analysis. Results show that Cr, Cr2N and CrN coexisted in the dense as-deposited CrSiN coating without Si-containing phases; the coating surface was rough and a small amount of oxide (Cr2O3 and SiO2) was formed on the surface after oxidation at 700°C for 24 hours. The isothermal oxidation result suggested that CrSiN coating possesses excellent oxidation resistance at 700°C. It is considered that the good oxidation resistance of CrSiN coating itself and the formation of dense protectiveCr2O3 and SiO2 films are primarily responsible for the good service performance during the oxidation process at 700°C.
Silicon Carbide Films Prepared by Silicon Nitride Evaporation
Authors: Liang Xin , Chen Changlian , Zhou Shicong , Xu Man , Ji Jiayou , Huang Zhiliang , Ding Gangqiang , Zhang Hongliang
Published: November 2019

Silicon carbide (SiC) films were synthesized on graphite substrates using silicon nitride (Si3N4) as silicon source at 1850°C, 1950°C, 2050°C and 2150°C, respectively. The characteristics of the synthesized films were analyzed by X-ray diffraction and scanning electron microscopy. The results show that the synthesis reaction can take place above 1850°C, and the SiC films were β-SiC. With the increase of temperature, the size of SiC particles increases, and when the soaking time is too short, the SiC particles are connected in a large area. Through the analysis of the films synthesis process, it is inferred that the growth of the SiC films belongs to the gas-solid growth mechanism.
Thermal behavior of chitosan as a carbon material precursor under IR radiation
Authors: Vasilev A , Efimov M , Bondarenko G , Kozlov V , Dzidziguri E , Karpacheva G
Published: November 2019

An effective accelerated synthesis procedure of a carbon material based on chitosan via infrared pyrolysis was developed. Infrared radiation heating allows to shorten preparation time significantly. It takes only 2 min of the residence time at 800 °C for complete carbonization of the polymer. The chemical transformations in chitosan during infrared pyrolysis depended on temperature were studied. The formation of C=C–C=N and C=C–C=C conjugated bonds at a low-temperature stage of the carbonization process was demonstrated. It was revealed that the main product of the chitosan pyrolysis at 600-800 °C represents a graphite-like carbon material in the form of carbocyclic structures.
Method of modeling the heat exchange process in the synthesis of carbon nanostructures in arc discharge plasma
Authors: Abramov G V , Avcinov I A , Gavrilov A N , Sukhanova N V
Published: November 2019

The method for calculating the temperature field during the synthesis of carbon nanostructures by plasma of electric arc discharge is proposed. The calculation scheme of heat exchange process is given. An algorithm for constructing a discrete model of the numerical solution of the heat transfer problem by the finite-element method in the environment of multiphysical modeling COMSOL Multiphysics is considered. The research of influence of parameters of different types of finite element grids on the convergence rate, calculations time and simulation accuracy is carried out. The rational parameters of the discretization of the computational domain of the considered system are determined. The results of correspondence of the constructed model of heat exchange process to the physical process are presented.
Evaluation of the efficiency of lightweight concrete modified with additives based on nanostructures
Authors: Sldozian R J , Mikhaleva Z , Tkachev A
Published: November 2019

The paper presents the results of studies on assessing the effectiveness of the modification of lightweight concrete with nanostructures. The results of these experimental studies show that the introduction of additives based on nanostructures, such as dispersions of carbon nanotubes and silica nanoparticles, improves the physical-mechanical characteristics of lightweight foam concrete (LWFC), even at low additive concentrations. As a result of chemical and physical interactions, nanosilica (NS) accelerates the pozzolanic reaction between cement and nanosilicate in the concrete mixture, filling the gaps. CNTs affect the hydration process and effectively increase the grain growth of calcium silicate hydrate (C-S-H). The presented experimental studies not only demonstrate the possibility of modifying construction materials with nanostructures in order to improve the physical and mechanical properties of the LWFC but also provide potential modification mechanisms that help in designing and manufacturing high-tech lightweight concrete of various compositions.
Polymer composites based on functionalized carbon nanotubes
Authors: Dyachkova T P , Tarov D V , Burakova E A , Tugolukov E N , Blokhin A N , Galunin E V , Rosenblum L V , Kobzev D E
Published: November 2019

The present paper considers the efficiency of using carbon nanotubes (CNTs) functionalized by titanium stearate groups for modifying of polyethylene and polypropylene. For this purpose, the strength characteristics, Shore hardness, thermal diffusivity and conductivity of the obtained nanocomposites were determined. The weak effect of the CNTs (0.01-1.5 wt.%) on the values of thermal conductivity coefficients and thermal diffusivity was revealed. It was found that compared to the unmodified matrix, nanocomposites containing 0.01-0.1 wt.% of the titanium stearatefunctionalized CNTs demonstrate, an increase in the Shore hardness by 12.5-14.5%, a decrease in the weight wear by 54.2%, and the daily water absorption - to the values below the threshold of sensitivity of the standardized method of determination. The functionalization by the titanium stearate groups made it possible to reduce the CNTs mass fraction in the composition of polyethylene and polypropylene composites by more than 10 times compared with the pristine nanotubes.
Flat electric heaters with the effect of self-regulation based on nanomodified polymer composite
Authors: Yagubov V , Shchegolkov Alexander , Shchegolkov Alexey , Tkachev A , Sukhorukov A
Published: November 2019

The present paper considers the effect of multi-walled carbon nanotubes (acting as a part of a silicon-organic composite) on the properties of a self-regulating electric heater. Flat electric heaters were manufactured with a heat exchange area of 1600 m2. The heater operating parameters were studied in the temperature range from -60°C to +70°C. The dynamics of the electric current consumed was investigated under self-regulation in the same temperature range It was revealed that when cutting the self-regulating heater into separate parts, the properties of self-regulation and power are maintained in proportion to the size.
Structure and electrical conductivity of heat treated iodine-doped multi-walled carbon nanotubes
Authors: Stolyarov R , Blohin A , Gorshkov N , Tkachev A , Kulnitskiy B , Pasko T , Sukhorukov A , Burmistrov I
Published: November 2019

The present paper discusses the possibility of simultaneously using two methods for the modification of multi-walled carbon nanotubes - high-temperature annealing and halogen-assisted modification. The nanotube modification was carried out during the high-temperature annealing in the presence of iodine. A change in the structure and an increase in the electrical conductivity of the modified multi-walled carbon nanotubes was observed.
Impedance spectroscopy of electrochromic films of nanocrystalline tungsten (VI) oxide
Authors: Shchegolkov A V , Tugolukov E N , Shchegolkov A V , Yagubov V S
Published: November 2019

The present paper study electrochromic films of nanocrystalline tungsten oxide (VI) by electrochemical impedance spectroscopy. Electrochromic films were obtained using the simplified technique of deposition of tungsten (VI) oxide from an aqueous dispersion on surface of transparent electrode In2O3. To obtain a uniform composition, the aqueous dispersion was treated with ultrasonic radiation, while the average particle size of tungsten oxide in the dispersion volume was from 30 to 70 nm. The prepared films had an amorphous structure and a crystalline structure was obtained by pyrolysis at a temperature of 250, 300, and 400 °C corresponding to different samples. The obtained nanocrystalline films were studied by electrochemical impedance spectroscopy in the frequency range from 1 to 106 Hz with an amplitude of an alternating voltage of 10 mV to determine the effect of temperature on the impedance of the films. The analysis data allowed us to determine the dependence of electrical conductivity on the volume of grains and the boundaries between crystals on the influence of temperatures on the structure properties of electrochromic films of nanocrystalline tungsten (VI) oxide.
Analysis of the structural characteristics of graphene materials obtained by electrochemical exfoliation of graphite
Authors: Khan Yu A , Dyachkova T P , Burakova E A , Bakunin E S , Rukhov A V , Orlova N V , Yu Obraztsova E
Published: November 2019

The aim of the research is to study the structural characteristics of graphene materials obtained by electrochemical exfoliation of graphite. The objects of study are prepared in electrochemical cells using alkaline and acid electrolytes with various applied voltages. Scanning electron microscopy, Raman spectroscopy, and X-ray diffraction have been used as research methods. The possibility of a theoretical calculation of the structural characteristics of nanomaterials (the defectiveness parameter, the density of the defects, the average distance between defects and average crystallite size) obtained by electrochemical exfoliation, according to Raman spectroscopy, is discovered. The results of these calculations satisfactorily correlate with the data of X-ray analysis.
Removal of Cu2+, Zn2+ and Pb2+ ions using a graphene-containing nanocomposite: a kinetic study
Authors: Babkin A , Burakova I , Burakov A , Kurnosov D , Galunin E , Tkachev A , Ali I
Published: November 2019

In the present paper, the urgent issue of removing heavy metal ions from aqueous solutions is considered by the example of extraction of Cu2+, Zn2+ and Pb2+ ions using an innovative sorbent - polyhydroquinone/graphene nanocomposite. Kinetics of the metal sorption on this material was studied. Moreover, the effect of solution pH on the sorption capacity of the nanocomposite was estimated. Besides, to elucidate mechanisms of kinetic removal and determine process parameters, experimental data were fitted to kinetic (pseudo-first- and pseudo-second-order, and Elovich) and diffusion (intraparticle and Boyd) models. The kinetic experiments showed that equilibrium is reached within 60 min. The effective diffusion coefficient values calculated according to the Boyd model were found to increase in the following sequence: Pb2+ (1.26 10-13 m2 s-1) < Zn2+ (3.74 10-13m2 s-1) < Cu2+ (4.24 10-13 m2 s-1). Finally, it was established that the metal sorption process is controlled by the internal diffusion of the sorbate into the bulk (volume) of the sorbent.
Rheological properties of “Vaseline – Carbon nanoparticles” model systems under conditions of non-destructive deformations”
Authors: Shilov M , Smirnova A , Gvozdev A , Rozhkova N , Dyachkova T , Burkov A , Stolbov D , Savilov S , Usol’tseva N
Published: November 2019

The paper presents experimental data on the rheological properties of “Vaseline – Carbon Nanoparticles” systems, which were obtained through oscillation tests. The nanoparticles used are multi-layered oxidized graphene (Gr), single- (SWCNTs) and multi-walled (MWCNTs) carbon nanotubes, as well as shungite nanocarbon (Sh). It was demonstrated that when carbon nanoparticles were added to the Vaseline (VM) at concentrations from 0.5 to 1.5 wt.%, the elasticity of the systems increased as compared with the pure VM, wherein the system containing 1.0 wt. % of MWCNTs was characterized by the greatest elasticity. All the studied carbon nanoparticles proved to be rheomodifiers. However, Gr, SWCNTs and MWCNTs acted essentially depending on their concentration in the vaseline system, resulting in both shortening and lengthening of the relaxation time. The natural shungite nanocarbon always led to the decrease of the relaxation time within the studied concentration range. The obtained results form an experimental basis for the development of scientific approaches to the production of lubricants operating in various friction modes
Kinetic of the dyes adsorption on a polyhydroquinone/graphene nanocomposite under dynamic conditions
Authors: Mkrtchyan E , Neskoromnaya E , Burakova I , Kurnosov D , Burakov A , Tkachev A , Ali I
Published: November 2019

Conducting adsorption experiments in a dynamic mode makes it possible to simulate process parameters as close to real conditions as possible. In the present work, the kinetics of the adsorption of some organic dyes (methylene blue, alizarin red S, and malachite green) on a novel polyhydroquinone/graphene nanocomposite, developed by the authors, were studied.It was established that the equilibrium of the adsorption system is achieved within 40, 120 and 57 min for methylene blue, alizarin red S and malachite green, respectively. Data processing using kinetic models showed that chemical interactions take place between the dye molecules and the active sites of the adsorbent during the adsorption. Besides, the contribution of the diffusion through the film on the adsorbent surface was also marked. The maximum adsorption capacity of the adsorbent was found to increase in the following sequence: malachite green (688.1 mg g-1) < methylene blue (2.610 mg g-1) < alizarin red S (2.923 mg g-1).
Impact of plasma treatment in CH4/N2 on the properties of reduced graphene oxide
Authors: Neustroev E P , Prokopiev A R , Timofeev V B , Popov V I , Kurkina I I , Davydova Z Y , Alekseev A A , Semenov S O
Published: November 2019

The effect of the two-step process on the properties of graphene oxide (GO) is studied. At the first stage, CH4 (or CH2+N2) plasma treatment was performed. The second one was heat treated at a temperature of 650° C. The formation of thin polycrystalline carbon films on the surface of graphene oxide was detected. The ratio of carbon to oxygen concentration corresponds to graphene oxide. Smooth surfaces of the films were detected by an atomic force microscope. Films have lower sheet resistance and higher carrier mobility than reduced GO (rGO) during the same heat treatment. An analysis of the Raman spectra shows that the formed films have larger graphene domains than the rGO. The presence of nitrogen in methane plasma leads to a decrease in the resistance and mobility of carriers in the carbon film.
Electromagnetic characteristics of coatings based on graphene oxide- and multi-walled carbon nanotubes Taunit-M in a wide range of frequencies
Authors: Suslyaev V , Tkachev A , Korovin E , Stolyarov R , Dorozhkin K , Chapaksov N , Dyachkova T , Blokhin A , Korshunov A
Published: November 2019

The frequency dependences of the reflection, transmission, and absorption coefficients of samples of materials based on graphene oxide and Taunit-M multi-walled carbon nanotubes were measured. Graphene oxide and carbon nanotubes are glued with acrylic adhesive to a double-sided sheet of plastic. The method of free space is used to measure in the frequency range 35 - 260 GHz. It is shown that the addition of MWCNT of 30 weight percent reduces the transmission coefficient by more than ten times.
Adsorption of Cu2+, Zn2+and Pb2+ ions on a novel graphene-containing nanocomposite: An isotherm study
Authors: Babkin A , Burakova I , Burakov A , Kurnosov D , Galunin E , Tkachev A , Ali I
Published: November 2019

The present research is dedicated to the problem of adsorption purification of aquatic media from toxic heavy metal ions. To extract some of these species (Cu2+, Zn2+, and Pb2+) from aqueous solutions, a novel material - polyhydroquinone/graphene nanocomposite – was used as adsorbent. Its adsorption/desorption performance was assessed through isotherm studies. The following process parameters were determined: equilibrium metal concentrations in solution, metal distribution coefficients, percentage desorption, and adjusted metal distribution coefficients. Besides, based on experimental data, adsorption isotherms were constructed, from which it was possible to determine the maximum adsorption capacity of the nanocomposite regarding each heavy metal ion (Pb2+ - 1350 mg-1; Cu2+ - 800 mg g-1, and Zn2+ -300 mg g-1). In order to elucidate adsorption-desorption mechanisms occurring in the considered adsorbate/adsorbent systems and the process nature, the data were fitted to different isotherm models: empirical (Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich), and combined (single- and dual-site Langmuir-Freundlich). All the models provided satisfactory fits to the data, thereby making it possible to assume heterogeneity of adsorption sites on the adsorption surface, and the irreversibility of the adsorption process.
Enhancing the efficiency of dye-sensitized solar cell by increasing the light trapping and decreasing the electron-hole recombination rate due to Ag@TiO2 core-shell photoanode structure
Authors: Fallah Milad , Maleki Iraj , Zamani-Meymian Mohammad-Reza , Abdi Yaser
Published: November 2019

In this research, efficiency enhancement of dye-sensitized solar cell (DSSC) with Ag doped TiO2 core-shell (C–S) as plasmonic photoanode structure, abbreviated as Ag@TiO2, was investigated using Sol-Gel- Dr Blade method. Different amount of Ag in two different thick of photoanode were applied to enhance the light absorption for high-performance DSSCs. The localized surface plasmonic resonance (LSPR) effect of Ag@TiO2 showed an improvement in light trapping and power conversion efficiency (PCE) of developed DSSCs. Conforming to the conclusions under AM 1.5 spectrum, the prepared plasmonic solar cells exhibited 21.9% and 41.46% increase in PCE for 13 μm and 8.4 μm thick of photoanode, respectively.
RETRACTED: Green synthesis of Cefadroxil loaded chitosan/PVA nanofibers by freeze drying
Authors: Iqbal Haroon , Mahar Faraz Khan , Razzaq Anam , Kamal Robia , Khan Naveed Ullah , Ullah Kifayat , Iqbal Shahid
Published: November 2019

Freeze drying (lyophilization) is a simple method of nanofibers preparation which has been extensively used in the biological application as well as in pharmaceutical production to improve the mean life of labile drug. Cefadroxil drug loaded chitosan/PVA nanofibers (CFX-CPNFs) were successfully fabricated by freeze drying method. The maximum loading capacity (%) and entrapment efficiency (%) of drug were achieved up to 12.3% and 45% respectively. The release profile of drug was studied within 6 h. The drug release profile was analyzed by Korsmeyer-Peppas and Higuchi’s models, the drug delivery system best fitted to Korsmeyer-Peppas model. The antimicrobial activity of CFX-CPNFs was analyzed against 16 strains of staphylococcus bacteria, which showed excellent results and the zone of inhibition was twice than CFX drug.
Synthesis of SCMNPs@imine/SO3H magnetic nanocatalyst by chlorosulfonic acid as sulfonating agents and their application for the preparation of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one and 1,8-dioxooctahydroxanthene derivatives
Authors: Zhou Ji , Liu Dan , Wu Fengshou , Xiong Yun , Ashraf Muhammad Aqeel
Published: November 2019

In this survey, new recoverable sulfonated magnetic nanocatalysts (SCMNPs@imine/SO3H) was synthesized by covalent attachment of a Schiff base ligand on the surface of SCMNPs@APTES/sucanh through reaction with 4-[(Pyridin-2-ylmethylene)-amino]-phenol and subsequent reaction with chlorosulfonic acid. The synthesized nanocatalyst was characterized by several techniques such as FTIR, TGA, VSM, XRD, UV–vis and EDX analysis. The nanocatalyst was evaluated in the preparation of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one and 1,8-dioxooctahydroxanthene derivatives with pharmacologically and biologically remarkable activity. 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one and 1,8-dioxooctahydroxanthene derivatives were respectively prepared via one-pot, three-component reactions of 2-naphthol, dimedone and aldehydes, as well as the reaction between dimedone and aldehydes in the presence of SCMNPs@imine/SO3H under solvent-free conditions. The merits of this synthesis are high-to-excellent yields, short reaction time, mild basic conditions and high catalytic activity. Also, the SCMNPs@imine/SO3H with suitable magnetic strength can be easily separated from the reaction solution using an external magnetic field.
Effect of Mg addition on microstructure and mechanical properties of Al-Si-Cu-Fe alloy with squeeze casting
Authors: Jiang Bo , Xu Song , Xu Hong-Yu , Hu Mao-Liang , He Ying-Jie , Ji Ze-Sheng
Published: November 2019

In this work, the Al-10Si-2.5Cu-0.8Fe alloy was used as the base alloy to squeeze casting with different content Mg-10Al master alloy addition. The effects of microstructure and mechanical properties were investigated by XRD, OM, SEM, and tensile test analysis. The results show that with the increase of Mg addition, the morphology of eutectic Si in the alloy changes from strip to fiber and the size is obviously reduced. Al8Mg3FeSi6 phase in the microstructure gradually grows, and the splitting effect on the matrix structure is increased. The tensile strength and elongation of the alloy increased first and then decreased with the increase of Mg content. When the Mg content is 1.38%, the tensile strength of the alloy reached a maximum of 289 MPa and the elongation is 2.24%. The hardness of the alloy gradually increases. When the Mg content is 2.51%, the hardness reaches 121.8 HV. The cleavage surface in the fracture becomes fine with the increase of Mg content, the number of dimples increases, and the fracture mode transitions from quasi-cleavage fracture to brittle fracture.