bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical simulation of caco3 fouling formation in double pipe heat exchanger
Authors: qinqiao Zhou , yangyan Zheng , hancheng Tang
Published: December 2019

Fouling of heat exchangers in the industry is a common problem. This paper studies the fouling formation of CaCO3 in double pipe heat exchanger, and a numerical simulation of CaCO3 fouling formation in double pipe heat exchanger has been established from the perspective of heat and mass transfer. This study uses a fouling model with the CFD framework by a discrete phase model in commercial software (Ansys Fluent). According to the simulation, the change of the rate of fouling formation with Sediment particle diameter, particle mass flow, inlet velocity has been discussed here. The results indicate that smaller particles display a higher deposition rate, and the faster the inlet velocity, the smaller the deposition rate. Also, a higher mass flow rate results in a high deposition rate.
Research on Characteristics and Laws of Fracturing Dust Production in Deep Coking Coal with Similar Material Structure
Authors: Wenbin Zhao , Lei Song , Qing Liu , Shancheng Qiao , Jiyu Lu , Jinfeng Wang
Published: December 2019

The coking coal under the influence of the earth stress is easily broken in the mining process, the dust production is large, the particle size is small, and the dust is serious. Considering the characteristics of primary coal dust, the ratio of similar materials is determined by experiment of single axial compressive strength. By means of acoustic emission detection device, uniaxial compression test is carried out for the coking coal similar materials in different structural forms, and the characteristics of fracture development and dust production of the primary dust are studied. The experimental results show that: pulverized coal: gypsum: cement is 0.81:1:1 and 0.2:1:1 the compressive strength of similar materials is 3.5 mpa and 1.5mpa, which meets the test requirements. The regularity of structural pressure of similar material is shown, similar materials with smaller strength and heavy loading deformation, however, the fracture and fracture development, the primary dust production is large. When the axial pressure is low, the low-intensity similar coal test block is vulnerable to crushing deformation at the upper part, the lower high strength coal needs to be damaged when the force is larger.
Research on Numerical Simulation of Laminated Rubber Bearing
Authors: Gao Xiaoni , Qi Hongxue
Published: December 2019

Based on the test of laminated rubber bearing GYZ250*77 in the literature, the finite element analysis model of the bearing is established by using ANSYS analysis software. The bearing force can be calculated by considering different modeling methods and different load application methods, and the analysis results are compared with the test results. The results show that when the laminated rubber bearing performance is simulated and analyzed under vertical loads, the rigid zone loading method or the steel plate loading method should be selected according to the specific conditions, rather than the direct loading method; Both solid model analysis and plane model analysis can simulate the effect of vertical load on the laminated rubber bearing. The research results provide a reference for the numerical simulation analysis of the laminated rubber bearing.
Analysis of China’s New Energy Development in New Period of Renewable Energy Subsidy
Authors: Zhang Jinfang , Liu Jun , Mi Zhe , Zhao Qiuli
Published: December 2019

With the rapid decline in costs, China’s new energy development has entered a new period of subsidies. In order to achieve energy transition, new energy will keep playing a greater role, reflected in the installed power capacity and power generation electricity. How to improve the new energy carrying capacity of power system and promote the healthy development of new energy are still important problems, on which should be paid more attention in the future. Firstly, the changing trend of new energy generation cost has been analyzed in this paper. Then the development of new energy in the future has been pointed out. Thirdly, the comprehensive measures have been proposed to improve the accommodation capacity, and the relevant policy recommendations also have been figured out finally.
Research on the Performance of Private Pharmaceutical Logistics Enterprises by Statistical Data Analysis
Authors: Liping Xiao , yafang Huang , Yubo
Published: December 2019

This paper uses statistical data analysis method to compare the financial report data of Jiuzhou Tong Pharmaceutical Group Co., Ltd. (hereinafter referred to as Jiuzhoutong) for the past five years, analyzes its operation status, and puts forward the prospect of pharmaceutical logistics industry.
PM2.5 Analysis and Prediction Based on Seasonal Time Series Model
Authors: Ao Xiqin , Yuan Hongwu , Zhang Dianya
Published: December 2019

The PM2.5 data in Hefei area from 2014 to 2018 were collected through the website of meteorological bureau, and the data were analyzed and modeled with the help of statistical analysis software SPSS and EVIEWS. Firstly, the annual and seasonal distribution characteristics and trend of PM2.5 data in Hefei area during the past five years were analyzed. It was concluded that the distribution of PM2.5 had periodic characteristics, and the air quality in summer was the best and that in winter was the worst. According to the results of statistical analysis, PM2.5 data had seasonal characteristics. On this basis, the Holt-Winters additive model and SARIMA model in seasonal time series model were selected to model and predict. The prediction values of the two models were compared with the real values. The results showed that the prediction accuracy of the Holt-Winters additive model was slightly higher than that of the SARIMA model.
Input data analysis for the thermal rating prediction of the overhead conductor
Authors: Wenbo Li , Luhua Xing , Shanqiang Fu , Huadong Li , Zhe Jiang , Bo Chen
Published: December 2019

The thermal rating of the overhead conductor is closely related to meteorological factors such as wind speed, wind direction, ambient temperature and solar radiation. Therefore, both the historical thermal ratings and meteorological data are alternative input data to predict the thermal rating of the overhead conductor. It is important to select suitable input data to improve the prediction accuracy of the prediction results. Based on the collection of micro-meteorological data from overhead line monitoring system, this paper presents a method to determine the input data for the thermal rating prediction by analysing the autocorrelation of overhead thermal ratings and the cross-correlation between thermal rating and historical micrometeorological data. The results show that the proposed method can provide reference information for the selection of predictive input quantities and prediction time domain.
CO2 huff and puff pilot with staged-fracturing horizontal well in tight oil reservoirs
Authors: Yu Zhang
Published: December 2019

CO2 huff and puff has been considered as one of the most successful processes to increase oil recovery, however, this stimulation technology is yet to be widely used in tight oil reservoirs. In this paper, a production model is developed to describe the CO2-soak process in tight oil reservoirs, providing a guidance to optimize the production parameters for CO2-soak pilot in the staged-fracturing horizontal well. The result shows that the CO2 huff and puff process helps to improve the reservoir energy, the fluid mobility, and thus the reserves-to-production ratio. To be specific, the recovery factor of tight oil reservoirs stimulated with CO2 huff and puff technology is 2.0% higher than that produced with natural energy. The success in CO2 soak pilot is of importance significance to the effective development of tight oil reservoirs.
Evaluation Of Jiamusi Landfill Site Selection Based on Analytic Hierarchy Process
Authors: Zhang Huanhuan , Wang Xue , Zhang Yuehua , Sun Yanbin , Wang Changbao
Published: December 2019

Analysis of the appropriateness of existing landfills in Jiamusi City by Analytic Hierarchy Process, combining the natural and social conditions of the Jiamusi area, the environmental protection, environmental geology, social influence and other influencing factors are used as the criterion layer of the hierarchical model. The weighting method is used to determine the weight of each influencing factor, thus the comprehensive score of the landfill site is calculated. The result indicates that the landfill in Jiamusi City is a suitable site, which provides a theoretical basis for future site selection.
A review on voltage control for distribution systems with large-scale distributed photovoltaic power integration
Authors: Xu Zhicheng , Wang Xiaochen , Yang Jie , Zhang Fuqiang
Published: December 2019

In order to solve the problems of voltage wide-range fluctuations and over-limitation after large-scale distributed photovoltaic (DPV) integrated into distribution networks, this paper conducts a comprehensive and detailed analysis of voltage control strategy by summarizing existing voltage control technology and experience at home and abroad. The technical points and a comprehensive comparison from the perspectives of active power curtailment (APC), reactive power control (RPC) and active-reactive power coordination control (A/RC) are made. Through comparative analysis, it is found that adopting active-reactive power coordination control is a key measure to effectively improve voltage quality and increase the PV hosting capacity of distribution networks. The optimization of the control strategy can effectively improve the friendliness of large-scale PV system integration. The method and control strategy can provide a theoretical basis and practical reference for voltage management of distribution networks with high penetration PV integration.
Design of driving power supply with high isolation and small coupling capacitance based on current transformere
Authors: Zhang Daojian , Xiong Lan
Published: December 2019

General drive power supply can not meet the requirements of high-voltage isolation under high-voltage and high-frequency (HV-HF) conditions, and the larger coupling capacitance of general power supply will bring common-mode noise. In this paper, a 10kV isolation power supply with 1.55pF low coupling capacitance and multiple output is designed. The power supply adopts LCL-T resonant circuit to produce a 100kHz current source. The current transformer is used to isolate the power supply, which realizes high voltage isolation and small coupling capacitance. The number of output circuits is changed by increasing or decreasing the magnetic core.
The fault analysis for low pressure last stage blade of the deep load changing gas-steam combined cycle steam turbine unit
Authors: Wu Maosong , Zhao Yuzhu , Qi Junfeng
Published: December 2019

In this paper, the causes of the abrasion at the fir-tree type blade root of low pressure last stage which are loosely assembled and the axial movement of the blade root to the intake side of gas-steam combined cycle steam turbine unit are deeply analyzed, which are caused by the special operating conditions of long-term turning and the high-speed setting of turning gear of the deep peak load changing units. At the same time, through the analysis of the fracture of the broken blade, the damage of the top shroud and the vibration data of the accident process, it is concluded that the abrasion at the blade root results in loosening of the blade, the violent striking between the loose blades during the high-speed turning process, results in the damage of the top shroud and the blade. Under the action of centrifugal force of rated speed condition, a break first occurs, and the broken debris falls between the last rotor blade and the static blade, which causes severe impact damage to the blade body, thereby causing secondary tearing of the blade.
Research on High Precision Lithium Battery Management System
Authors: Pengcheng Wang , Zhigang Chen
Published: December 2019

Lithium battery has been used more and more in recent years due to its excellent performance such as high energy, high voltage, long service life, low self-discharge rate, environmental protection and so on. However, lithium battery also has the disadvantages of poor safety performance, complex protection circuit, high cost, etc. The high-precision lithium ion battery management system (BMS) is proposed to solve the charging and discharging protection problem of multiple lithium batteries. In order to solve this problem, we have designed a set of high-precision lithium battery management system by pulse width modulation based on previous studies.
Multi-objective coordinated scheduling of anomalous control domain with electric/thermal energy storage and translatable load
Authors: Su Anlong , Yu Fengjiao , Wang ShunJiang , Ning Liaoyi , Pan Chao
Published: December 2019

Difficulties in the consumption of new energy such as wind and light are one of the main reasons for the low penetration rate of distributed power. The multi-objective coordinated scheduling model of anomalous control domain with electric/thermal energy storage and translatable load is constructed from the aspects of energy utilization, system network loss and environmental pollution cost. A hybrid random black hole algorithm is proposed to improve the algorithm by using global search mechanism. Optimization ability. The example analysis is carried out by IEEE30 node power distribution system. The simulation results show that the coordinated optimization of energy storage and translatable load can effectively improve energy efficiency, reduce system network loss and environmental pollution cost, and verify the rationality of the proposed model
Design of Long-term and Medium-term Trading Model under Multi-energy Coupling
Authors: Yang Dongmei , Sun Yong , Li Baoju , Zhang Xiaochen , Li Pengfei , Zhang Tingting
Published: December 2019

Integrated energy service is a new industry with broad prospects in China. It is the energy industry from the vertical extension of the industrial chain to the horizontal interconnection. However, there are few studies on the domestic market trading mode. In view of this, this paper proposes a multi-energy coupled trading mode of cold, heat, electricity and gas in the medium and long-term multi-energy flow market.
The effect of Kalimantan Institute of Technology on land use change in Karang Joang
Authors: Rahajeng A S , Pratama M R
Published: December 2019

Placement of a university in an area can be one of the attractions for people in the city and also for people outside the area. This activity will certainly trigger the development of other activities as a form of support for educational activities and it will be affected the numerous changes in land use. This study aims to determine the effect of the presence of the university to land-use changes in surrounding Kalimantan Institute of Technology. This research is a quantitative approach with a descriptive analysis, that used to analysis activity system that supports educational activities and land use change. From 2015 until 2018 there are 512 new buildings that change from cultivated land to residential, industrial, transportation and also trade and service, only 19% of them that appear to meet the needs of students, such as a boarding house, rent houses, stationery stores, restaurants, and grocery stores. In order to anticipated the effect of uncontrolled development for the community, it needs to increase the public awareness to build with the proper conditions and based on the regulation, and for the government is the existence of government regulations especially on building permits.
Evaluation of suitable landuse for existing condition in South Coastal of Sampang Regency
Authors: Budisusanto Yanto , Pribadi Cherie Bhekti , Kunny Latifa Annisa’
Published: December 2019

The detailed and systematic guidelines and direction of development and urban planning are regulated in Regional Spatial Plan (RTRW) under the Law Number 24 of 1992 concerning Spatial Planning, defined that a structural form and pattern of spatial use, whether planned or not. Because the influence of population growth is relatively high and the level of urbanization is not controlled, eventually resulting in the conversion of land use to other uses. The identified problems occurred in the South Coast of Sampang Regency, namely the utilization transition that occurred in the mainland area around the coast, that related to economic interests which affected the availability of land. With these conditions, it is necessary to map and analyze the suitability of existing conditions with the plan documents. This study identified the suitability of 9 coastal land cover classes using the interpretation method in Pleiades satellite images, by digitizing on screen. From the analysis conducted, the dominating land cover class is rice field, which are 5147.656 Ha. The total suitability of land cover with RTRW is 77%, with the most suitable class being ponds, which is equal to 96.75%. Meanwhile, the most inappropriate class is farm class with an area of around 5.09%.
The improvement of ultrasonic sensor-based device for direct ocean wave measurement program at Western Java Sea – Indonesia
Authors: Adrianto D , Djatmiko E B , Suntoyo
Published: December 2019

Sea wave measurement program in the Western Java Sea has been carried out comprehensively over a full one-year period. This activity requires tools that can work robustly and accurately in the long run in the open ocean environment; one of which is the result of modified tidal gauges based on ultrasonic sensors. Testing of modified device has been carried out simultaneously with the RBRduo wave recorder which is installed close to one another. The test was conducted at Ancol beach, Jakarta Bay, with a sampling frequency of 6 Hz, and the measurement time was carried out for 15 days. Measurement data were analyzed by applying the harmonic sea level elevation method, single wave evaluation, and statistical correlation methods. The results of the harmonic analysis show similar types of daily sea level elevations, as well as 9 (nine) daily elevation constituents that are mutually compatible with each other. Results of the wave analysis from the modified device show Hav = 11.9 cm, Hs = 15.4 cm, and Hmax = 41.1 cm, while the RBRduo instrument shows Hav = 11.8 cm, Hs = 18.1 cm, and Hmax = 39.9 cm. Statistical analysis of the wave data shows that the values produced indicate the results of measurements with the two devices have a high correlation. Therefore, it can be concluded that the modified instrument will be ready and reliable to be used for long-term wave measurements. A sample of measurements from the wave station at the Western Java Sea is shown by the end of this paper.
Obtaining low water line contour value for enclave claim regime 12 nautical miles on Hatohobei Island Republic of Palau against the Republic of Indonesia in according with UNCLOS 1982 using satellite-derived bathymetry
Authors: Kurniawan A , Santoso A I
Published: December 2019

UNCLOS (United Nations Convention on the Law of The Sea) 1982 gives the authority to coastal state to make claims on their sea regime. An island that is more than 125 nautical miles from the mainland where the baseline to draw a territorial line is drawn is given the right to claim the maritime regime by enclave method 12 nautical miles maximum. In determining enclave claims, Low water line contour points are needed through satellite-derived bathymetry using the Lyzenga bathymetry algorithm. The data used in this study is a multispectral planet scope imagery with 3 meters resolution, where the imagery was acquired at the 07th April 2019 and depth sample from NGA nautical chart of the Hatohobei Island and Hellen reef region. To normalize the depth value, tidal correction is done by extrapolating from BIG tides data during 29 days of tides data prediction. The Lyzenga bathymetry is applied using intercept (24.422094) and the coefficient for each band result by Ordinary Least Square regression, where the R2 value obtained is 0.194075. That variable is applied in Lyzenga Bathymetry Formula. The results of the Lyzenga bathymetry algorithm are converted into contour lines to obtain low water line contour, and buffer 12 nautical miles is carried out. The result of this study shows the areas which can be claimed by Hatohobei Island (Republic of Palau). The claim of the maritime space that can be given to Tobi Island is 1634.39 km2.
Analysis of deriving control points from LiDAR intensity image for orthophoto production
Authors: Cahyono A B , Tridasakti D A
Published: December 2019

In aerial photogrammetry need control points and has a reference to the land coordinates where the measurement location is carried out. This control point would be used in aerial photo georeferenced. But in practice it often finds severe field conditions that can affect the process of measuring control points, such a forest, mountains area and even conflict areas, which could make the process of measurement at that location impossible. LiDAR Intensity Image is one product of processing LiDAR data that can be used to produce coordinates of ground control points. So that it can reduce or eliminate the use of coordinates from GCP point measurements in the field of georeferenced in aerial photographs. This research is calculating the accuracy orthophoto produced of control points from LiDAR Intensity Image. The data used are LiDAR data and aerial photography using the Bundle Block Adjustment method. The result is orthophoto which tested for accuracy based on PERKA BIG No. 15 of 2014. The results from the CE90 and LE90 tests for orthophoto that use control points from the Premark Intensity Image are 0.433 m and 0.479 m which means fulfilling the scale 1:2500 class 1 for horizontal and vertical accuracy. For the CE90 and LE90 tests that use control points from a combination of intensity image and GCP points from GPS measurements, produce better accuracy of 0.314 m and 0.301 m so that fulfilling the scale 1:2500 class 1 for horizontal and vertical accuracy.
Financial Aspect and Practicability of Converting Existing Buildings to nZEB Case Study in Cairo, Egypt
Authors: Ahmed Somaya Albadry
Published: December 2019

Financial feasibility of a project is a strong indicator of whether the project will be accepted by different stakeholders of the building or not. This research aims at analysing the financials of converting an existing residential building to net zero energy building. On a case study building, specific retrofit actions are selected, specific PV system is considered and a complete cost analysis is performed based on market available materials in actual prices in the Egyptian market. The research utilizes energy simulation to compare the amount of energy saving between the current and retrofitted cases of the case study building. Actual electricity bills are used to calculate the electricity usage of the building. Similarly, actual solar energy pricing is considered in order to evaluate the feasibility of the conversion. The pricing of the retrofit actions using market available materials is calculated as well. The return on investment study shows how applicable the conversion is.
Towards a Sustainable Touristic Buildings in Egypt Using Innovative Wall Materials
Authors: Ouf Mahmoud Yasser , Mahdy Mohamed M. , Ibrahim Sheriff , ashry Nabil
Published: December 2019

By the unprecedented development witnessed by the world in the field of construction, especially in the tourism sector in Egypt, as well as the efforts of the engineering department of the Egyptian armed forces to make a boom in all standards in the fields of construction. Therefore, it is necessary to search for building materials that are both environment and economy efficient to raise the standard of occupants' life of these facilities, which represented in thermal comfort and all necessities to enjoy the accommodation and the convenience of the intended future operation and maintenance. The objectives of the research are: 1) to evaluate the materials used in the construction of the walls in touristic buildings in the coastal areas of Egypt; 2) to choose the suitable and the economic materials, which is compatible with the surrounding environment, whereas maintaining the level of indoor environmental quality (IEQ) in the buildings; and 3) to proof of this compatibility computationally and geometrically by comparing simulation results with experimental results of these new materials. The Methodology of this research followed the comparative analysis of the simulation results of using traditional Egyptian building materials and innovative ones used in the construction of walls (red bricks and light bricks). Pros and cons were identified according to: savings in construction’s initial cost, providing internal thermal comfort, and reducing electric loads. The study showed the advantages of each type of brick and the benefits gained from it in the near term and the revelation in 2080 (based on the projected climate changes) and calculate the amount of reduction in thermal loads and savings of running costs and other advantages acquired. Moreover, the research showed that light bricks needed to use less reinforcing steel in construction, which was founded to be a fair compromise to compensate its high price.
Synthesis of self-healing polymers precursors from available bio-renewable raw materials.
Authors: Zakharova D V , Pavlov A A , Polezhaev A V
Published: December 2019

A series of a new diglycidyl derivatives of aromatic amines containing a furan fragment was obtained. The synthetic scheme consists of two stages: reductive amination and epoxidation. We used industrially produced inexpensive amines and furfural as starting material. Diepoxides obtained are key components for development of epoxy binders capable of intrinsic self-healing based on the reversible Diels-Alder reaction between furan and maleimide. To demonstrate the possibility of self-healing, the Diels-Alder reaction adduct of one of the products with N-phenyl maleimide was isolated and characterized by 2D NMR spectroscopy. The reversibility of the reaction was confirmed by DSC experiment.
Distribution of electromagnetic fields in heterogeneous composite structures when exposed to direct current.
Authors: Dimitrienko Yu I , Krasnov I K , Zubarev K M
Published: December 2019

In this paper, we study the electromagnetic fields in composite structures that occur when exposed to an external source of direct current, located on the surface of the composite. The article proposes an algorithm for solving the direct problem, based on the application of the finite element method, and a method for solving the inverse problem, which is described as an optimization problem. To search for the extremum of the target functional, an empirically developed method is used. The task is considered in a quasistatic approximation. The developed software was tested on a three-layer composite. The developed algorithms made it possible to solve a given problem with high accuracy.
Research of temperature and stress-strain state of mirror space antenna reflector with fins based on nonbraided polyester material
Authors: Azhevsky Y A , Novikov D
Published: December 2019

A number of designs of reflectors of a mirror space antenna in the form of a thin-walled shell made of high-modulus carbon fiber reinforced with a developed finning system in the form of three-layer panels with a filler made of nonwoven polyester material is considered. Within the framework of the finite element modeling, a comparative analysis of serviceability under operating conditions (radiative heat transfer in open space conditions) has been carried out. Patterns of temperature distribution and thermal displacements along the reflector surface have been obtained. According to the results of the research, MSA reflector’s design layout with the best indicators has been chosen.
C/C composites developed from phthalonitrile based composites
Authors: Aleshkevich V V , Babkin A V , Avdeev V V
Published: December 2019

Carbonization of carbon fabric reinforced plastics (CFRPs) with phthalonitrile matrices at 1000°C was investigated. Four different carbonization modes were tested. It was explored, that a mode with step heat rate is most beneficial. Two different phthalonitrile resins were investigated. Elemental analysis of final carbon-carbon composite (C/C) matrix was carried out and the results showed up to 88.5 mass% carbon presence. Final C/C density reached 1.5991 after only one cycle of impregnation-carbonization. Final porosity of samples reached 9.2%. These results allow to consider phthalonitriles as a prospective carbon precursor for C/Cs manufacturing. Mechanical testing of the C/C samples was performed (Compressive strength P = 72.2MPa, E = 11.8 GPa). Tribological data was received (coefficient of friction = 0.31, wear rate = 30 μ/min). Thermal analysis was carried out (η = 72.94 W/m*K, α = 85.8 cm2/s).
Modelling of composite energy absorbing structures for automotive load-bearing systems
Authors: Harutyunyan G A , Kartashov A B
Published: December 2019

Due to the increasing demands for environmental friendliness and fuel economy of cars, the task of reducing their weight is becoming topical. One of the promising ways to solve this problem is the use of composite materials for the manufacture of automotive body. The body of the car is subjected not only to static and slowly changing dynamic loads, but also can be subjected to impact loading. Therefore, it is necessary to assess the effectiveness of the use of composite materials for the manufacture of elements responsible for energy absorption. The paper analyzes the features of energy absorption during the destruction of composite structures, describes the ongoing processes and gives recommendations on the design of composite front rails. To assess the effectiveness of the composite front rail, a simulation of process of its crushing is carried out. To confirm the performance of the design, a crash test of a car with a composite energy absorbing structure is simulated. The applicability and high efficiency of composite energy absorber are confirmed
Thermophysical processes models in composite workpieces processed by microwave radiation
Authors: Belenkov E S , Prosuntsov P V , Reznik S V
Published: December 2019

The solution that improves energy effectiveness and polymer composite materials parts quality by means of microwave heating with polymer matrix curing is proposed. Thermal state analysis of workpiece for various layout configurations of microwave heating equipment was conducted. It was found that the most uniform heating is obtained inside the rectangular chamber while workpiece is rotating around the transverse axis.
The method of reinforcement of holes of mechanical fasteners with composite liners
Authors: Nasonov F A , Morozov B B , Bukharov S V , Zinin AV , Kharchenko K D , Piskunov G S
Published: December 2019

Developed and experimentally justified constructive and technological method of increasing strength and reliability of point mechanical connection of composite panels by thermocompression installation along the contour of the hole of the intermediate element-less rigid composite liner. The effectiveness of the method is provided by reducing the stress concentration in the hole area and confirmed finite element analysis and results of mechanical tests of samples of connection.
Stress-strain state of the interfacial layer in a visco-composite composite with longitudinal shear
Authors: Dudchenko A A , Lurie S A , Makovskij S V , Shramko K K
Published: December 2019

Annotation. In this paper, we propose a three-phase method for determining the effective properties of reinforced by whiskerized fibers composite materials. The model takes into account the presence of a whiskerized interfacial layer between the fiber and the matrix. The calculation of the stress-strain state of the interfacial layer loaded with a longitudinal shear using the Eshelby self-consistent field method is given.
Development of a new experimental method for the determination of inplane shear strength and elastic characteristics of polymer composite materials based on highmodulus carbon fiber-reinforced plastics having the ±45° plies
Authors: Matyushevsky Nikolai , Popov Alexei
Published: December 2019

A new method for the determination of shear strength and modulus of high-modulus CFRP reinforced with ±45°plies was developed. The optimal geometrical parameters of the specimen to determine shear properties of high-modulus CFRP reinforced with the ±45° plies were determined by calculation and experimental methods. A comparative analysis of the results of the experimental determination of shear properties was performed.
Topology optimization of the lattice payload adapter for carrier rocket
Authors: Baldzhiev R S , Alekseyev A A , Azarov A V
Published: December 2019

Current study is dedicated to the evaluation of the topology optimization method for the design of load-bearing aerospace structures. The subject of research was composite spacecraft attach fitting (adapter) which provides the interface between a spacecraft and a commercial launcher. Modelling of stress-strain state of the lattice payload adapter under operation conditions was performed. Compression strengths of structural ribs were defined together with the stiffness and buckling stability taken as the design constrains. By means of the topology optimization procedure optimal material distribution in the payload adapter was obtained. The workability of the adapter was proved by the confirmatory analysis.
Estimation of the effective elastic characteristics of carbon composite materials by testing ring-shaped samples under high temperatures
Authors: Ponomarev K A
Published: December 2019

A computational and experimental method is suggested to determine indirectly the elastic properties of carbon composite materials at room temperature up to 2200°C and more. The method involves loading of ring-shaped test specimens through diametrical compression using non-cooled indenters at three points, within the elastic strain range, with ductility measurements. Based on the measured ductility values, shear moduli, as well as the longitudinal and transversal elasticity moduli in the test specimen cutting plane, can be determined by solving the identification problem. Results of experimental assessment of the permissibility of repetitive mechanical and thermal loading of the carbon-carbon composite material are presented. Method tryout with high-density needle-punched composite material is described.
Furfurylglycidyl ether: a new effective active diluent for epoxy resins from bio-renewable raw materials
Authors: Petrova T V , Solodilov V I , Kabantseva V E , Karelina N V , Polezhaev A V
Published: December 2019

New reactive diluents based on bio-renewable raw materials are widely explored as additives to traditional resins. We investigated the effect of furfurylglycidyl ether on the rheological and thermomechanical properties of a widely used epoxy binder with an anhydride hardener. It was shown that the addition of 5-15% active diluent significantly reduces the viscosity of the composition to the values optimal for RTM and vacuum infusion technologies for fiber-reinforced plastics and does not lead to a significant decrease in heat resistance and Young’s modulus of the cured binder
Active thermography as a contemporary method for ensuring the quality of composite material products
Authors: Kotovshchikov I O
Published: December 2019

This paper examines the current trends in the quality control of composites and the perspectives of application of active thermography method to ensure the quality of products made of composite materials. Using NDTherm™ – system of active thermography, the research has been carried out on composite samples and products with inbuilt artificial defects. Based on research results the author highlights the most promising applications of the active thermography method.
Metal-coated carbon fiber model
Authors: Nelyub V A , Bocharov A A
Published: December 2019

The results of the modeling of the stress-strain state of the filaments from which the carbon unidirectional tape LUP is made, are provided for the latter’s initial state and after applying a grade 12X18H10T stainless steel coating thereon. The results of calculations were compared to experimental data. Magnetron sputtering was used to apply a metallic coating, with pre-cleaning the carbon tape. These models allow to optimize the thickness and choose the type of metallic coating.
Layered nanostructured composites with self-healing effect based on plastic borosiloxane matrices
Authors: Sitnikov N N , Khabibullina I A , Mashchenko V I
Published: December 2019

This paper presents a layered composite material with an internal self-healing matrix based on borosiloxane compounds. The effects of self-healing in materials of various chemical nature (polymers, cements, ceramics, metals and composite materials) are considered and evaluated from the point of view of their practical application and the creation on their basis of self-healing composites. The properties and characteristics of borosiloxane are described. The prospects of using of borosiloxane as an internal self-healing matrix of layered or reinforced composites are shown. The effect of self-healing of the developed layered composite at breakdown and cut is demonstrated.
Transport properties of ceramic composites based on bismuth and indium oxides
Authors: Dergacheva P E , Kulbakin I V , Fedorov S V
Published: December 2019

Solid solutions based on indium oxide In2-xZrxO3+0.5x (x = 0.005, 0.01, 0.015, 0.02, 0.025, 0.05, 0.075, 0.1) were synthesized and temperature dependences of their conductivity at 25-800 °C were investigated. It was found that In1.985Zr0.015O3.0075 solid solution possessed the highest conductivity of about 100 S/cm at 800 °C. Dense In1.985Zr0.015O3.0075 – 50 vol.% Bi2O3 ceramic composite was obtained and investigated, its microstructure was studied, and the formation of fine-grained structure with homogeneous distribution of components by volume was demonstrated. The total conductivity of composite was measured, and oxygen fluxes for composite 1.7 mm thick membrane at 750-800 °C was obtained. The oxygen flux was found to be 2.4 ×~ 10−7 mol⋅cm−2⋅s−1 at 800 °C when oxygen partial pressures on both sides of membrane was 0.21 atm/0.017 atm, while the oxygen selectivity was more than 20. This indicates thepromising of investigated composite to use as an intermediate-temperature (750800 °C) ion transport membrane for obtaining of pure oxygen from air.
Resistive switching phenomena in thin ferroelectric films
Authors: Andreeva N V , Petraru A , Petukhov A E , Batueva A V
Published: December 2019

Switching of the resistance in thin ferroelectric films is a complex phenomenon involving an influence of polarization states, point defects, processes of electron injection from electrodes and peculiarity of polarization charges screening. In order to clarify the mechanism of surface charge screening under ferroelectric polarization switching and its correlation with the local resistive properties in thin ferroelectric films, we studied the changes in the surface potential under dc bias voltage application in SrTiO3/La0.7Sr0.3MnO3/BaTiO3 heterostructures using different modes of atomic force microscopy (Kelvin probe, piezoresponse, and conductive) at ambient conditions. It is found that the peculiarity of surface charge screening under polarization reversal gives a strong electrostatic contribution in the measurements of local resistive properties at the ambient conditions and could completely veil the real current distribution over the film surface. Remarkably, scanning tunnelling microscopy measurements under ultra-high vacuum conditions show evidence of oxygen vacancy formation in thin ferroelectric films after poling, revealing an increase of the film thickness due to the chemical expansion.
Dielectric characterization of erythrocytes by electrostatic force microscopy
Authors: Davletkildeev N A , Sokolov D V , Yu Mosur E , Lopandina A A
Published: December 2019

The method of determination of the dielectric constant of individual erythrocytes, based on a quantitative analysis of the profiles of their images obtained by electrostatic force microscopy, is presented. A model of electrostatic interaction between the atomic force microscope probe and the biological cell is proposed. The obtained values of the permittivity of individual erythrocytes agree well with known literature data.
Microscopic studies of disordered carbon-rich inclusions in ultra-high pressure glasses from impactites of the Kara astrobleme
Authors: Golubev Ye A , Shumilova T G , Isaenko S I , Utkin A A
Published: December 2019

The paper presents the results of study of the carbon-containing phase discovered in the impact glass of the Kara astrobleme. We used the following research methods: optical, scanning electron, and atomic force microscopies, as well as Raman spectroscopy. This phase represents carbon-containing inclusions up to several tens of micrometres in size with an amorphous diamond-like structure. At the nanoscale, the studied phase is characterized mainly by a homogeneous structure.
Charged domain walls in lithium tantalate with compositional gradients produced by partial VTE process
Authors: Greshnyakov E D , Lisjikh B I , Pryakhina V I , Nebogatikov M S , Shur V Ya
Published: December 2019

The morphology of a single charged domain wall, appeared under the action of composition gradients produced by partial VTE procedure by Cherenkov-type second harmonic generation microscopy, was observed in detail. The width of the charged domain wall was estimated as 70 μm. Non-through and through narrow domains, grown from the charged domain wall, were revealed. The maximum length of non-through domains with submicron diameter was about 100 μm. The growth of narrow domains from the charged domain wall was demonstrated and attributed to the action of pyroelectric field. The widening of domains occurred after achieving the polar surface.
Styrene-terminated polyphenylene oxide and polybutadiene low dielectric reactive blend
Authors: Hu W , Shen J , Zhou J , Jin W , Chen W
Published: December 2019

Styrene-terminated polyphenylene oxide (SPPO) and low polar thermosetting polybutadiene (PB) resin were employed to obtain a curing system with excellent electrical properties and enhanced thermal properties. By terminal styrenisation, SPPO is cured with PB, forming a continuous phase in the blend. The SPPO/PB blends have excellent solvent resistance and thermal stability, while the good dielectric performance is retained. Especially, when the mass ratio of PB is 0.5, the curing system has a highTgof 226.5°C and excellent dielectric properties with Dk = 2.46 and Df = 0.0022 at 10 GHz, which is suitable for high frequency electrical applications.
Development and research carbon nanotube-based resistive gas sensor
Authors: Il’in O I , Il’ina M V , Rudyk N N , Guryanov A V , Fedotov A A
Published: December 2019

Experimental studies of the processes of formation of catalytic centres (CC) and carbon nanotubes (CNTs) at ITO contacts have been carried out. The regularities of the influence of the annealing temperature on the geometric dimensions of CC have been established. An array of interwoven CNTs with a highly developed surface has been grown. A model of a gas sensor with a sensitive element based on a CNT network has been created. The reaction time and reaction of the sensor, its sensitivity to N2, O2, and Ar have been experimentally investigated. It has been shown that the sensor has a maximum sensitivity of 17.2% to N2, 16.3% to Ar, and 18.7% to O2 in the range of gas concentrations from 30 to 70 ppm. It has been shown that gas detection is possible at room temperature, despite a rather long reaction and reduction time. In this case, an almost complete restoration of the sensitive element of the initial resistance has occurred without additional heating.
Evaluation of mechanical and electrical parameters of individual polyaniline nanoparticles
Authors: Lobov I A , Davletkildeev N A , Sokolov D V , Mosur E Yu
Published: December 2019

The work function, the static dielectric constant, and the elastic modulus of individual polyaniline nanoparticles in the base form deposited on HOPG were determined. Electrostatic force microscopy was used to determine the electrical parameters. The value of the work function is 4.66 eV. The dielectric constant is 2.2. Contact atomic force microscopy was used to determine Young’s modulus. The modulus of elasticity is 4.42 GPa. The obtained values differ from the typical values obtained on bulk samples of the base form polyaniline. In the case of electrical parameters, this is due to contact phenomena between the conductive substrate and the dielectric nanoparticle. The Young’s modulus of a polyaniline nanoparticle depends on the packing density of the macromolecule, while the Young’s modulus of a compressed tablet depends mainly on the intermolecular forces.
Structural, electronic, and magnetic properties of ferroelectric/dielectric heterostructures
Authors: Lysogorskii Yu V , Piyanzina I I , Pavlov D P , Leontyev A V , Mamin R F , Tayurskii D A , Kabanov V V
Published: December 2019

We present the results of structural, electronic, and magnetic properties of BaTiO3/LaMnO3 heterostructure by means of first-principles calculations. We demonstrate the possibility of highly conducting layer formation at the heterostructure composed of perovskite ferroelectric BaTiO3 and antiferromagnet manganite LaMnO3. We also analyse magnetic properties and an impact of ferroelectric polarization onto the conducting properties. Experimental results of magnetic field effect on Ba0.8Sr0.2TiO3/LaMnO3 heterostructure are presented as well. Effect of illumination of the Ba0.8Sr0.2TiO3/LaMnO3 heterostructure is also demonstrated.
The modification of PETF-membranes by Langmuir-Blodgett films of Nafion
Authors: Melnikova G B , Ledvig O G , Chizhik S A , Kozlovskiy A L , Zdorovec M V
Published: December 2019

In this research, the surfaces of track PETF-membranes were modified by Langmuir-Blodgett (LB) films of Nafion. The changes of structure of modified membranes were studied by atomic force microscopy (AFM). The LB-film of Nafion monolayer was found to be 30-100 nm thick. The incorporation of SiO2 nanoparticles in LB-layer in small quantities was structuring the monolayer. The performance of water of PET-200 membranes with a Nafion film was increased to 401.3 ml/(m2·h) from the initial values of 342.1 ml/(m2·h). The air performance was increased for all modified PETF-200 membranes. The maximum performance was achieved by modifying the membranes with pure Nafion; the productivity was 154.3 ml/min compared with 96.4 ml/min for the initial membrane. It was shown that LB-films were stable during monitoring filtration characteristics.
Light polarization and intensity behaviour in aperture cantilevers with carbon tip created by focused ion beam
Authors: Mikhailova T V , Vysokikh Yu E , Krasnoborodko S Yu , Kolomiytsev A S , Fedotov A A
Published: December 2019

Modern atomic force microscopy (AFM) techniques and their combination with other methods give us a possibility to investigate the same samples from the new side at nano-scale. One of very promising combinations is polarization near field microscopy integrated into AFM tool. It allows one to make topography imaging by standard AFM tool and optical magnetic structure imaging by magneto-optical method simultaneously. Moreover, this combination gives synergy effect on both methods by improving their weak sides: elimination of magnetic influence of magnetic force microscopy on the sample, on the one hand, and overcoming the diffraction limit of the magneto-optical microscopy, on another hand. The cantilevers play a very important role in this combination of the methods since they interact with the surface and allow focusing the laser beam to the sample in near field mode. The geometry and other parameters of cantilevers are determined as a result of the combined methods implementation. Authors investigate the new type of carbon-tips aperture cantilevers for AFM and high resolution magneto-optical combination.