bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sol-gel synthesis of oxide protective coatings of carbon fibers to increase heat resistance in aggressive oxidizing environments
Authors: Tselovalnikova A A , Trubin D A , Karandashev A N 
Published: December 2019

AbstractCeramic coatings of the Al2O3/SiO2 composition by the sol-gel method on carbon fibers were obtained in order to prevent oxidation and destruction of the fiber at temperatures above 450°C. Various combinations and ratios of aluminum and silicon oxides were used. The results of scanning electron microscopy and X-ray diffraction showed a change in the topographic properties of carbon fiber during the deposition of coatings thereon. Thermal analysis showed that oxidative stability improved significantly due to coverage, increased to 1100°C.
Optimization of curing mode of epoxy resin based composites
Authors: Chen Yangyang , Malysheva G 
Published: December 2019

Abstract
In this article the techniques for determining the thermos-physical properties of epoxy binders depending on their different state of aggregation are presented. The epoxy composition based on epoxy resin and modified aliphatic polyamine was used as an object of research. Experimental studies were carried out to determine heat capacity and thermal conductivity of epoxy binders, depending on their degree of conversion. Mathematical modeling of the curing process of epoxy binder at different heating rates by the finite element method was carried out. When using the results of mathematical modeling, the kinetics of the curing process was optimized depending on different heating rates by the ideal point method. Moreover, a study was conducted on the effect of limit condition on optimization results.
Hybrid composites in reusable space vehicles wing structures
Authors: Ashikhmina E R , Ageyeva T G , Prosuntsov P V 
Published: December 2019

Abstract
The study is dedicated to the solution of a complex problem – development of an optimal thermal design of the tourist class reusable space vehicle (RSV TC) wing structure. The complexity of the problem resides in the necessity to consider critical factors of the suborbital flight and in a number of nesting tasks,that need to be solved. The authors implemented a multiscale modeling approach covering design of hybrid composite material thermal properties (i.e. mesoscale level), determination of thermal loads and thermal state analysis of a composite wing (i.e. macroscale and structural scale levels). Analysis of thermal fields demonstrated the necessity of thermal protection (TP) application for the wing structure. Consequently, optimal from the weight efficiency point of view TP thicknesses were determined. Summing up, the results of a RSV TC wing structure development are presented in the current paper.
Development of branched aromatic maleimides as components of self-healing binders for polymer composites
Authors: Karelina N.V. , Solodilov V I , Polezhaev A.V. 
Published: December 2019

Abstract
Various modifications of epoxy resins with maleimides and polyimide fragments results in the formation of heat-resistant materials with excellent mechanical and electrical properties together with high chemical, corrosion, and radiation resistance. Such materials can be used in the aerospace industry, electronics, instrument making, and other industries. The ability of some epoxy-maleimide resins to react with furanic groups through thermo-reversible Diels-Alder reaction open a new area in composite material science - self-healing binders. Selfhealing materials can restore their structure and mechanical properties after a damage that results in an increase of the service life several times and, therefore, reduce their cost. In this paper, maleimides were modified by diglycidyl ethers to obtain not previously described polyethers, capable of self-healing of mechanical properties after damage. All compounds were characterized by 1H NMR.
Related problems of designing heat-loaded structures from ceramic matrix
Authors: Ezhov A D , Bykov L V , Artemchuk N V 
Published: December 2019

Abstract
The paper presents a method of mathematical modeling of the mechanical and thermal state of the contact pairs on the example of contact between two composites. The algorithm of the study including the preparation of profilograms roughness of the contacting surfaces of the samples (identification roughness parameters), construction of a three-dimensional model of the surface roughness, mechanical interaction analysis microroughness contacting surfaces, determining the thermal contact resistance and the calculation of thermal fields in the contact zone. The technique was tested on a contact pair of ceramic-matrix composites for various values of mechanical and thermal loading. The obtained calculated data are verified according to the experimental study.
Development of carbon/epoxy composite bracket for housing sensitive element of spacecraft
Authors: Komarov V A , Pavlov A A , Pavlova S A 
Published: December 2019

Abstract
The article considers the challenge of using layered carbon/epoxy composite materials in a high-loaded airframe structures. It is demonstrated by a redesign of the bracket for housing a sensitive element of the spacecraft. The new design approach considering simultaneously structural and technological features of composite constructions. It can also be applied to other design tasks to develop a structure of minimum weight.
In situ supported VOx on carbon nanotubes for the low-temperature selective catalytic reduction of NO with NH3
Authors: Jin W , Jiao B Q , Chen W , Li M Y , Zhao J , Zhang X W 
Published: December 2019

Abstract
The vanadium oxide/carbon nanotube (VOx/CNTs) composite catalyst was prepared by in-situ growth of VOx nanoparticles on CNTs with a cetylpyridinium chloride (CPC) assisted reflux route. The in-situ prepared catalysts exhibit better NH3-SCR activity in a broader temperature window at low temperature than those prepared by impregnation or a mechanically mixed method. The structural characterizations show that vanadium oxide nanoparticles have a good dispersion on the CNTs surface, with much lower valence vanadium species and chemisorbed oxygen species. The physics-chemistry properties indicate that there is a strong interaction between the VOx and CNTs, and the catalysts present a larger amount of stronger acid. The abovementioned reasons have eventually led to the enhancement of NH3-SCR activity.
Tailoring quasi-two-dimensional high conductivity and superconductivity areas at the interfaces of ferroelectric/dielectric heterostructures
Authors: Mamin R F , Pavlov D P , Piyanzina I I , Lysogorskiy Yu V , Mukhortov V M , Adachi T , Kawamata T , Koike Y , Balbashev A M , Tayurskii D A , Kabanov V V 
Published: December 2019

Abstract
The results of the investigations of high conducting and superconducting areas at the interfaces between ferroelectric oxide and insulating oxide are presented. The numerical simulations of BaTiO3/LaMnO3 and BaTiO3/La2CuO4 heterostructures have been performed. It is found that in the samples of the Ba0.8Sr0.2TiO3/LaMnO3 heterostructure the electrical resistance decreases significantly and exhibits metallic behaviour at low temperatures for the case when the c axis of ferroelectric film is directed along the normal to the surface of the single crystal. The superconducting behaviour with transition temperature Tc about 30K has been found at the interface of the Ba0.8Sr0.2TiO3/La2CuO4 heterostructure. The proposed concept promises the ferroelectrically controlled interface conductivity and superconductivity.
Thromboresistant properties of nanostructured tantalum coatings on the stainless steel surfaces
Authors: Melnikova G B , Kuznetsova T A , Petrovskaya A S , Tolstaya T N , Lapitskaya V A , Chizhik S A , Zykova A , Safonov V 
Published: December 2019

Abstract
The nanostructured coatings of tantalum and its compounds on the stainless steel surfaces were investigated by atomic force microscopy. Their hydrophilic properties were studied by sessile drop and atomic force spectroscopy methods. The thromboresistant properties of samples were analysed in vitro by incubation of the samples in the rich platelets plasma of patients with acute coronary syndrome. The effect of surface properties on the thromboresistant properties was analysed.
Features of combining scanning probe microscope with optical and scanning electron microscopes
Authors: Sapozhnikov I D , Gorbenko O M , Felshtyn M L , Zhukov M V , Golubok A O 
Published: December 2019

Abstract
The designs of combining a scanning probe microscope (SPM) with an optical microscope (OM) or scanning electron microscope (SEM) have been presented. To reduce the size of the SPM units the self-sensing probes and a piezo-inertial displacement system are proposed to use. The peculiarities of working of such SPM units are discussed. The examples of visualization of different nature objects in combined systems SPM-OM and SPM-SEM have been presented.
Studying surface Fermi level pinning in GaP nanowires with gradient Kelvin probe microscopy
Authors: Sharov V A , Alekseev P A , Fedorov V V , Bolshakov A D , Mukhin I S 
Published: December 2019

Abstract
In this work, we use scanning Kelvin probe gradient force microscopy to study surface Fermi level pinning in horizontal undoped nanowires with axial GaP/GaPAs heterojunction. The nanowires were separated from the growth substrate and dispersed on smooth surface of Ni/Si substrate. Then longitudinal and transverse surface potential profiles of several nanowires were captured. The study revealed a distinction between the work function of GaP and GaPAs regions. It was shown that the Fermi level in undoped GaP nanowires was pinned in the middle of the energy gap.
Magnetron sputtering deposition of ultra-thin tungsten coatings onto amorphous graphite for enhancement of horseradish peroxidase adsorption
Authors: Shumov I D , Kanashenko S L , Ziborov V S , Ivanov Y D , Archakov A I , Enikeev D V , Potoldykova N V , O Pleshakova T 
Published: December 2019

AbstractIn the present study, atomic force microscopy (AFM) has been used to investigate the adsorption of horseradish peroxidase (HRP) protein onto the surface of amorphous carbon (graphite). It has been experimentally demonstrated that modification of amorphous carbon surface by magnetron sputtering deposition of ultra-thin (1.3 nm) tungsten coatings allows one to enhance significantly the adsorption of HRP macromolecules onto this surface, as compared with bare carbon.
Synthesis and spectral-optical properties of composite materials based on high-silica porous glasses doped by iodides of silver and erbium
Authors: Girsova M A , Antropova T V , Golovina G F , Anfimova I N , Kurilenko L N , Arsent’ev M Yu 
Published: December 2019

Abstract
Composite materials (CMs) doped by iodides of silver and erbium were synthesized on the base of the thermally modified high-silica porous glasses (PGs) with small additions of P2O5 and fluoride ions. CMs were manufactured by two-stage impregnation of the PGs first with AgNO3 aqueous solution (with or without Er(NO3)3), next in the halide salt (0.6 M KI) aqueous solution. Then the samples of composites were heat treated at the temperatures from 120 to 870°C up to their sintering and closing of the pores. The structure of composites was studied by X-ray powder diffraction (XRD) technique. According to XRD data the CMs doped by iodides of silver and erbium contain the AgI phase. Spectral-optical properties of CMs were investigated by UV-VIS-NIR spectroscopy. Optical density spectra in UV-VIS region have the bands corresponded with the absorption of silver molecular clusters. Peaks at 377, 448, 450–453, 485, 611–622, 647, 668–684 nm answered to the absorption of erbium ions were found. According to NIR transmission spectra, bands caused by the absorption of Si–OH, B–OH and Na–OH groups are found.
Preparation and Properties of Nanocomposites in the Systems S-AgI and S-Ag2S-AgI in Dimethyl Sulfoxide
Authors: Khan N V , Burkitbayev M M , Urakaev F Kh 
Published: December 2019

Abstract
In this research work described synthesis of nanocomposites in the systems S–AgI and S–Ag2S–AgI in dimethyl sulfoxide (DMSO, (CH3)2SO) medium, and its some properties. Nanocomposites were obtained through the solvothermal synthesis at temperature range (T) 25÷160°C. The initial solutions were prepared by dissolution of sulfur (S), silver nitrate (AgNO3
) and ammonium iodine (NH4I) in DMSO. The final products were obtained through the simple exchange reactions between initial solutions. Using the X-ray phase analysis (XRD), energy dispersive X-ray analysis (EDAX) and scanning electron microscopy (SEM) the samples were tested on phase and elemental composition, particle size and morphology, respectively. The results of XRD revealed that nanocomposites represented by S and AgI for system S–AgI, and by S, AgI and Ag2S for S–Ag2S–AgI system. The EDAX analysis showed the presence in composition of the investigated samples such elements like S, Ag and I for both systems. The SEM images demonstrated that both systems have a heterogeneus structure, the particles represented by flat and irregular shape. The size of the particles for S–AgI is fluctuated from 100 to 50000 nm and for S–Ag2S–AgI – from 90 to 4000 nm.
Surface roughness analysis in the drilling of carbon fiber/epoxy composite laminates using hybrid Taguchi-Response experimental design
Authors: Shahabaz S M , Shetty Nagaraja , Shetty S Divakara , Sharma S S 
Published: December 2019

Abstract
The carbon fiber reinforced polymer composite has made a substantial impact on the manufacturing sectors owing to its excellent mechanical, thermal and corrosion resisting properties. The surface roughness mainly depends on the machining parameters while drilling of carbon fiber reinforced polymer composite laminates. The study concentrates on the impact of uncoated and titanium nitride coated solid carbide drills on minimizing the roughness that is generated while making holes in bi-directional carbon fiber reinforced polymer composite by optimizing the drilling constraints [spindle speed (A), feed rate (B), point angle (C) and drill diameter (D)]. Experimental studies are carried out using Taguchi L

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orthogonal array. The investigation discloses that the drill diameter is one of the most influencing cutting parameters followed by spindle speed and feed rate. The response surface methodology is chosen as a tool for predicting and optimizing the process parameters. The investigation also discloses that the experimental and the predicted results of surface roughness are closely matching with each other. The surface morphology illustrates that titanium nitride coated solid carbide drills minimize the surface roughness compare to that of uncoated solid carbide drills.
Enhanced emission from CH3NH3PbBr3 perovskite films by graphene quantum dot modification
Authors: Guo Xi , Han Bingquan , Gao Yu , Liu Dan , Chen Jiayao , Chen Pengyun , Xu Lingbo , Cui Can 
Published: December 2019

Abstract
Organic-inorganic hybrid perovskites have emerged as promising emitters with the benefits of low cost and high color purity, but their low luminescence efficiency is a drawback for practical application on light emitting devices. Here we show that by incorporating proper amount of graphene quantum dots (GQDs) into perovskite precursor, dense CH3NH3PbBr3 films with reduced grain size and well passivated grain boundaries could be obtained. This gives rise to enhanced emission from GQD modified perovskite films. Our work thus provides a viable way to prepare highly luminescent perovskite films for optoelectronic applications.
Effect of two-step ausforming on bainite transformation and retained austenite in a medium-carbon bainitic steel
Authors: Chen Guanghui , Xu Guang , Hu Haijiang , Tian Junyu , Yuan Qing , Wang Jun 
Published: December 2019

Abstract
It is commonly accepted that single ausforming with small strain at low temperature promotes isothermal bainite transformation and leads to more retained austenite. In the present study, the effects of two-step ausforming on the bainite transformation and retained austenite in a Fe-C-Mn-Si medium-carbon bainitic steel were investigated by thermo-mechanical simulator, x-ray diffraction, scanning electron microscope and transmission electron microscope. The results show that the two-step ausforming cannot further promote the bainite transformation compared with single ausforming. However, the two-step ausforming enhances the mechanical stability of residual austenite due to more dislocations induced by the second deformation and therefore leads to more retained austenite. In addition, when the total strain is constant, the fraction of retained austenite increases with the increasing second strain. Moreover, the thickness of bainite plates treated with two-step ausforming is larger compared with single-step ausforming when the total strain is the same.
A photocatalytic and electrochemical study of gold nanoparticles synthesized by a green approach
Authors: Herrero-Calvillo R , Santoveña-Uribe A , Esparza R , Rosas G 
Published: December 2019

Abstract
Quasi-spherical gold nanoparticles mixed with a controlled amount of gold nano triangles were obtained through a green chemical method using leaf extract of Loeselia mexicana. Moreover, the influence of the extract and HAuCl4 solution concentration in the morphology of the nanoparticles was studied. The nanoparticle preparation was performed by varying the concentration of the extract and precursor salt. The catalytic activity of the as-prepared nanoparticles was studied by the reduction of methylene blue, rhodamine B, and gentian violet organic dyes. Also, cyclic voltammetry profiles were obtained in order to analyze the electrochemical response of the nanoparticles. The morphology and structural characterization were analyzed by UV–vis, SEM, TEM, FTIR, and XRD. The SEM analysis reveals gold nanoparticles with spherical and triangular morphologies. The UV–vis spectra revealed that the extract concentration influenced the morphology and amount of the obtained gold nanoparticles. The XRD and TEM analysis showed that gold nanoparticles presented a face-centered cubic lattice structure. The cyclic voltammetry analysis confirms a high-sensitivity electrochemical response and stability corresponding to the gold nano triangles. Finally, the presence of gold nano triangles shapes influenced the efficiency of the degradation of the dyes due to their high specific surface area.
A study on machinability of nickel based superalloy using micro-textured tungsten carbide cutting tools
Authors: Khan M Adam , Gupta Kapil 
Published: December 2019

Abstract
In this research, an investigation on machinability of nickel-based superalloy (Inconel 600) under the influence of textured tungsten carbide cutting tools is conducted. Two main machinability indicators, namely, wear and life, have been investigated. Three types of micro-texture patterns i.e. dimples, lines and splines are laser engraved on the flank face of the cutting tool. Experiments are done with different cutting velocities, feed rate and depth of cut considering the texture pattern one among the input parameters. Firstly, while machining Inconel 600 with plain (non-textured) tungsten carbide cutting tool, it is investigated that at low velocity, the cutting nose caused damage due to abrasion and friction between the tool-chip interface. Severity in tool edge has increased along with adhesive wear and built-up edge at the cutting radius with increase in velocity. Thereafter, using textured on the tools, it is observed that the cutting tool wear resistance has tremendously increased with different textured patterns due to significant reduction in friction and heat. At low velocity (50 m min−1) the tool wear measured is in the range of 100–150 μm and maximum of 394 μm at high cutting velocity of 150 m min−1. The tool life was calculated using Taylor’s equation based on Gaussian method. Tool lives for dimple and line textures are found superior. It is concluded that textured tools have potential to machine hard materials like Inconel superalloys with longer tool life.
Numerical analysis of subwavelength field effects in photonic crystal slab cavities
Authors: Mertin Paul , Römer Friedhard , Witzigmann Bernd 
Published: December 2019

Abstract
Surface coupling of single quantum emitters to optical cavities consisting of a photonic crystal slab is a delicate yet crucial task for photonic quantum applications. By coupling through the evanescent surface field only small Purcell factors can be achieved. Here, we propose to introduce a pit in the slab to position the emitter closer to the mode field maximum. Photonic crystal slab L3 cavities are investigated with respect to quality factor and Purcell effect, using finite element calculations in the frequency domain. That way the spatial distribution of the Purcell factor can be calculated. Introducing a small sized pit to the surface of the photonic crystal cavity can evoke subwavelength field effects, confining the field maximum inside the pit. By engineering a pit in the center of the cavity the Purcell factor can be increased from 176 to 1331, albeit reducing the Q factor from 20769 to 16696.
Quantifying the importance of a realistic tomato (Solanum lycopersicum) leaflet shape for 3-D light modelling
Authors: Vermeiren Jonathan , Villers Selwyn L Y , Wittemans Lieve , Vanlommel Wendy , van Roy Jeroen , Marien Herman , Coussement Jonas R , Steppe Kathy 
Published: December 2019

Abstract

Background and Aims
Leaflet shapes of tomato plants (Solanum lycopersicum) have been reduced to simple geometric shapes in previous functional–structural plant models (FSPMs) in order to facilitate measurements and reduce the time required to reconstruct the plant virtually. The level of error that such simplifications introduce remains unaddressed. This study therefore aims to quantify the modelling error associated with simplifying leaflet shapes.

Methods
Realistic shapes were implemented in a static tomato FSPM based on leaflet scans, and simulation results were compared to simple geometric shapes used in previous tomato FSPMs in terms of light absorption and gross photosynthesis, for both a single plant and a glasshouse scenario.

Key Results
The effect of simplifying leaflet shapes in FSPMs leads to small but significant differences in light absorption, alterations of canopy light conditions and differences in photosynthesis. The magnitude of these differences depends on both the type of leaflet shape simplification used and the canopy shape and density. Incorporation of realistic shapes requires a small increase in initial measurement and modelling work to establish a shape database and comes at the cost of a slight increase in computation time.

Conclusions
Our findings indicate that the error associated with leaflet shape simplification is small, but often unpredictable, and is affected by plant structure but also lamp placement, which is often a primary optimization goal of these static models. Assessment of the cost–benefit of realistic shape inclusion shows relatively little drawbacks for a decrease in model uncertainty.