bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical principles of work and basic features of Universal Software Radio Peripheral
Authors: Ryabov I V , Nikitin P V , Bazhenov R I , Melnikova A I , Gorokhova R I
Published: January 2021

The current stage in the development of info communication systems is characterized by an active search for a solution to the problem of signal processing in dynamically changing conditions. Growing requirements for bandwidth implemented in practice lead researchers to search for new solutions that can work under restrictions previously considered fundamental, such as a high level of intersymbol distortions [1]. There are many useful signal recognition techniques that use a statistical apparatus, an apparatus for predicting dynamic processes, and means combining the features of different principles. Ensuring the reception of signals transmitted over the meteor channel of a radio communication requires, in addition to modern analog-to-digital conversion devices, the ability to directly synthesize precision signals for heterodyning systems, correlation analysis and statistical processing of a signal-noise complex. Similar problems arise in more traditional applications, such as radar and radio navigation. The most preferred tools of the developer and designer in all cases are devices that implement the technology of software-defined radio (SDR). The article describes the physical principles of Universal Software Radio Peripheral operating using software-defined radio (SDR) technology. It shows the implementation of the technology of software-defined radio system according to the concept of USRP for various tasks, architecture and generalized structure.
Equipment and technology for wastewater post-treatment for returning it to production cycle
Authors: Levin E V , Balgynova A M , Kyzy Ardak M , Korotkov V G , Kolotvin A V , Voloshin E V , Dudorov V E , Arstanaliev E U , Kh Galieva L , Akhmadiyeva Z R , Tsyrkaeva E A
Published: January 2021

Given there is development of state-of-the art technologies in the field of water treatment and the demanding requirements for environmental control, as well as trends in the cost increase of chemicals and usage costs of primary resources, it deemed necessary to modernize the water treatment and water purification systems in such a way as: firstly, to minimize discharges as such; secondly, to increase the degree of use of circulating water; thirdly, using modern non-reagent cleaning technologies to minimize the consumption of necessary chemical agents, which has a complex effect – both in merely economic terms (procurement, transportation, storage, movement and control), and from a practical perspective – increasing the environmental safety of production, area release, etc.
A Revised Particle Swarm Optimization Model of Airplane Evacuations
Authors: Luo Yuandan
Published: January 2021

Aircraft accidents such as the Sukhoi Superjet 100 aircraft crash on May 5, 2019 at Sheremetyevo airport recently have drawn the public attention, requiring a safer evacuation plan and aircraft designs. In this paper, we conduct an evacuation model based on Particle Swarm Optimization (PSO) algorithm. Also, we learn from the PSO with emotion factor algorithm which shows that increasing the emotion raises the average velocity and decreases the repulsion force exerted by neighbour passengers. Our simulations also suggest that adding reaction time and blocking the exits increase the evacuation time significantly. In addition, we conduct simulations that incorporate passengers carrying luggage, according to the real-life scenarios, which has longer evacuation time.
Cyclic Modulation Spectrum Based Bearing Defect Recognition
Authors: Li Hui , Deng Sanpeng
Published: January 2021

A novel practical technique for bearing defect detection and recognition based on cyclic modulation spectrum (CMS) is presented. Cyclic modulation spectrum stands as a much faster method to detect periodic modulation feature and has a lower complexity. CMS has a very fast calculation speed, but it can provide similar results with spectral correlation density. This advantage enables the cyclic modulation spectrum to extract useful information from the noisy environment in rotating machine. The validity of this technique is exhibited on bearing defect vibration data from an industrial gearbox. The results show the advantage of cyclic modulation spectrum. CMS can correctly pick up the transient features from interference signals and can accurately recognize the rolling element bearing defect.
Functionalized zeolitic imidazolate framework-8 as a drug carrier for bioimaging
Authors: Han Xu , Wen Lili , Su Zhongmin , Shan Guogang
Published: January 2021

There has been a surging interest in the synthesis of multifunctional nano platform for drug delivery and bioimaging. ZIF-8 of the zeolitic imidazolate series is widely used in the biological field as the leader of metal-organic frameworks (MOFs). Herein, we processed ZIF-8 nanoparticles (ZIF-8 NPs) by pyrolysis with high temperature, while ensuring that it does not destroy itself. The strategy of calcination ZIF-8 NPs at 600? for 5 min has a higher loading rate for doxorubicin hydrochloride (DOX). Moreover, through bioimaging of ZIF-8@C in A549 lung cancer cell, the red fluorescence was produced, indicating that ZC-6005@DOX successfully entered the cancer cell.
Research development of polymer modified asphalt
Authors: Liu X , Wei X
Published: January 2021

Since the reform and opening up policy, modified asphalt has achieved a qualitative leap from nothing to being, from small to large, from less to more, and has made great contributions to road construction in China. The good quality of modified asphalt is directly related to the safety and service life of road. Based on the research of modified asphalt at home and abroad, this paper briefly introduces the classification of modified asphalt, and according to the types of polymer modifiers in modified asphalt, the research status and progress of modified asphalt are described. At the same time, the development direction and application prospect of modified asphalt are put forward.
Monometallic phosphide catalyst of Ni2P for Hydrogen production in acidic Solution
Authors: Li Jiao , Xu Chunyan , Li Xiao , Su Zhongmin
Published: January 2021

Nowadays, it is particularly important to develop efficient hydrogen evolution catalyst in the process of water electrolysis. In this paper, a monometallic phosphide (Ni2P@C) was synthesized through a simple one-step calcination and phosphorization process, which was a high efficient catalyst for hydrogen evolution reaction. Ni2P@C exhibits satisfactory activity with a low overpotential of 215 mV and small Tafel slope of 105 mV dec−1 at the current density of 10 mA cm−2. In addition, the catalyst displayed favorable stability for 16 h when current density maintained at 10 mA cm−2. This work provides reference for monometallic phosphates as catalyst for hydrogen evolution.
Enhanced Optical Antennas with Fractal Metasurface
Authors: Fan Yizhe
Published: January 2021

Plasmonic is now a quickly expanding area of research for its versatile in a lot of areas with its perfect ability of confining EM waves and trapping light. Periodic metallic structures are excellent to manipulate the properties of the SPPs by modifying the geometry of the pattern. In this project, we demonstrate a kind of fractal metasurface based on Sierpinsky Nanocarpet to simulate a higher absorption peak and electric field enhancement. We experimentally change the dimension level, size, thickness and separation distance in order to study the geometry dependency of the photosensor. Compared to several different fractal metasurface, the optimized structure proposes an approximately 30% enhancement in light absorption compared to a commom log38 Sierpinsky Nanocarpet structure.
Finite element simulations of rail milling based on the modified Johnson-Cook constitutive model
Authors: Liu Peijie , Quan Yanming , Wan Junjie
Published: January 2021

Rail milling plays an indispensable role to remove surface defects and irregularity in the railway maintenance industry. In this paper, an appropriate 2D orthogonal cutting model of rail milling process was established. Finite element simulations of rail milling were conducted in detail based on a modified Johnson-Cook constitutive model. The simulation results show that a large amount of cutting heat is generated in the tool-chip contact region, and the highest temperature of the milling insert appears somewhere on the rake face with a certain distance away from the cutting edge. With the increase of cutting thickness and milling speed, the milling temperature displays an upward trend.
The Application of Perovskite Quantum Dots in Photodetectors
Authors: XiaoYang
Published: January 2021

Perovskite quantum dots (PQDs) can adsorb visible light and give out fluorescence or excited electron to the surroundings. Therefore, some kinds of PQDs can be used for light detection. Due to the appropriate band gap, cesium bromide and iodide-based perovskite PQDs (i.e. CsPbX3) are especially suitable for visible light detection. Some other kinds of PQDs with different photoluminescence spectrum can be used to detect ultra-violet light or infrared light. In this paper, PQD-based photodetectors are divided into three categories: photoresistors, photodiodes and field effect transistors. Herein, the device structures, characteristics and mechanism of these three types of PQD-based photodetectors are briefly reviewed. Other applications of PQDs are also briefly introduced, including selective ion detection and organic molecular detection associated with molecular imprinted polymers.
Thermo-electro-mechanical vibration of piezoelectric nanobeams resting on a viscoelastic foundation
Authors: Zhang Dapeng , Liu Mingwei , Wang Zhixiang , Lei Yongjun
Published: January 2021

Taking a piezoelectric nanobeam resting on a viscoelastic foundation as the research object, the free vibration of the nanobeam are studied by considering the thermo-electro-mechanical loadings. The vibration governing equations and boundary conditions are first derived using Hamilton’s principle and then the transfer function method are applied to calculate the natural frequencies under general boundary conditions. And then the influences of nonlocal parameter and material parameters of viscoelastic foundation on the vibration characteristics are also studied in detail. The results show that both nonlocal parameter and viscoelastic foundation have significant influence on the vibration of nanobeams. The conclusions of this study could provide important theoretical basis for the research and application of nanostructures in nanosensors, nanodrivers, nanoresonators and other intelligent devices.
Dactyls and inward gripping stance for amphibious crab-like robots on sand
Authors: Graf Nicole M , Behr Alexander M , Daltorio Kathryn A
Published: January 2021

Sandy beaches are areas that challenge robots of all sizes, especially smaller scale robots. Sand can hinder locomotion and waves apply hydrodynamic forces which can displace, reorient, or even invert the robot. Crab-like legs and gaits are well suited for this environment and could be used as inspiration for an improved design of robots operating in this terrain. Tapered, curved feet (similar to crab dactyl shape) paired with a distributed inward gripping method are hypothesized to enable better anchoring in sand to resist hydrodynamic forces. This work demonstrates that crab-like legs can withstand vertical forces that are larger than the body weight (e.g. in submerged sand, the force required to lift the robot can be up to 138% of the robot weight). Such legs help the robot hold its place against hydrodynamic forces imparted by waves (e.g. compared to displacement of 42.7 mm with the original feet, crab-like feet reduced displacement to 1.6 mm in lab wave tests). These feet are compatible with walking on sandy and rocky terrain (tested at three speeds: slow, medium, and fast), albeit at reduced speeds from traditional feet. This work shows potential for future robots to utilize tapered and curved feet to traverse challenging surf zone terrain where biological crabs thrive.
Model coupling biomechanics and fluid dynamics for the simulation of controlled flapping flight
Authors: Colognesi Victor , Ronsse Renaud , Chatelain Philippe
Published: January 2021

This paper proposes a multiphysics computational framework coupling biomechanics and aerodynamics for the simulation of bird flight. It features a biomechanical model based on the anatomy of a bird, which models the bones and feathers of the wing. The aerodynamic solver relies on a vortex particle-mesh method and represents the wing through an immersed lifting line, acting as a source of vorticity in the flow. An application of the numerical tool is presented in the modeling of the flight of a northern bald ibis (Geronticus eremita). The wing kinematics are imposed based on biological observations and controllers are developed to enable stable flight in a closed loop. Their design is based on a linearized model of flapping flight dynamics. The controller solves an underdetermination in the control parameters through minimization. The tool and the controllers are used in two simulations: one where the bird has to trim itself at a given flight speed, and another where it has to accelerate from a trimmed state to another at a higher speed. The bird wake is accurately represented. It is analyzed and compared to the widespread frozen-wake assumption, highlighting phenomena that the latter cannot capture. The method also allows the computation of the aerodynamic forces experienced by the flier, either through the lifting line method or through control-volume analysis. The computed power requirements at several flight speeds exhibit an order of magnitude and dependency on velocity in agreement with the literature.
Recent advances in development of nanomedicines for multiple sclerosis diagnosis
Authors: Zhang Qin , Dai Xinghang , Zhang Hu , Zeng Yujun , Luo Kui , Li Weimin
Published: January 2021

Multiple sclerosis (MS) is a neurodegenerative disease with a high morbidity and disease burden. It is characterized by the loss of the myelin sheath, resulting in the disruption of neuron electrical signal transmissions and sensory and motor ability deficits. The diagnosis of MS is crucial to its management, but the diagnostic sensitivity and specificity are always a challenge. To overcome this challenge, nanomedicines have recently been employed to aid the diagnosis of MS with an improved diagnostic efficacy. Advances in nanomedicine-based contrast agents in magnetic resonance imaging scanning of MS lesions, and nanomedicine-derived sensors for detecting biomarkers in the cerebrospinal fluid biopsy, or analyzing the composition of exhaled breath gas, have demonstrated the potential of using nanomedicines in the accurate diagnosis of MS. This review aims to provide an overview of recent advances in the application of nanomedicines for the diagnosis of MS and concludes with perspectives of using nanomedicines for the development of safe and effective MS diagnostic nanotools.
Previous Atlantic Multidecadal Oscillation (AMO) modulates the lightning-ignited fire regime in the boreal forest of Northeast China
Authors: Gao Cong , Zhao Fengjun , Shi Chunming , Liu Kezhen , Wu Xiaoxu , Wu Guocan , Liang Ying , Shu Lifu
Published: January 2021

Lightning-ignited fire is sensitive to climatic change and responsible for large fires in boreal forests. In addition to global-warming caused fire increase, large-scale climate oscillations have significantly contributed to fire variability. However, the leading climate oscillation driving lightning-ignited fire and the mechanisms connecting regional and large-scale climate in the boreal forest of Northeast China, the most fire-prone biome of China, are still unclear. By compositing fire, climate, and atmospheric data, we found that the previous Atlantic Multidecadal Oscillation (AMO) was significantly coherent with the May to August temperature–evapotranspiration variability and lightning-ignited fire occurrence. These connections were valid at both the interannual and multidecadal time scales. Different from previous viewpoints, we found no connection of fire occurrence with the El Niño-Southern Oscillation and Pacific Decadal Oscillation. A warm AMO was followed by high sea level pressure and geopotential height over the study region. We assume these atmospheric anomalies are associated with descending atmospheric motion, producing adiabatic warming and less precipitation on the land surface, both of which favour high fuel aridity and lightning ignition. Therefore, we believe that the winter AMO could be a promising predictor for lightning-ignited fire occurrences in the following summer.
Nullspaces of entanglement breaking channels and applications
Authors: Kribs David W , Levick Jeremy , Olfert Katrina , Pereira Rajesh , Rahaman Mizanur
Published: January 2021

Quantum entanglement breaking channels are a fundamental class of quantum operations; originally investigated for quantum information theoretic reasons, their study has since grown to touch on many aspects of quantum information science. Here we investigate the nullspace structures of entanglement breaking channels and we derive a pair of related applications. We show that every operator space of trace zero matrices is the nullspace of an entanglement breaking channel. We derive a test for mixed unitarity of quantum channels based on complementary channel behaviour and entanglement breaking channel nullspaces. We identify conditions that guarantee the existence of private algebras for certain classes of entanglement breaking channels.
Design and closed-loop control of a piezoelectric actuator
Authors: Rusu C , Besoiu S , Tatar M O
Published: January 2021

Piezoelectric elements can produce a high displacement resolution with high force outputs but exhibits large hysteresis nonlinearities. An efficient way to compensate for nonlinearities is using a closed loop control technique. Another limitation for many applications is their relatively short displacement ranges. One method to avoid the above-mentioned shortcoming is to integrate a piezoelectric element with a mechanical displacement amplifier based on a compliant mechanism. This paper presents the design and closed-loop control of such a piezoelectric actuator. Using the integrated strain gauge sensors, a PI controller was designed and tested.
Manufacturing of SiO2-ZnO materials with optical properties
Authors: Mocioiu O C , Băilă D I , Atkinson I , Brătan V , Mocioiu A M
Published: January 2021

Antireflection coatings have been widely used to increase the absorption of solar collectors and to reduce surface reflection. Many techniques have been explored to prepare thin coatings, such as sputtering, chemical etching, chemical vapour deposition, and sol-gel method. SiO2-ZnO coatings were prepared on the surface of glass substrates via the sol-gel dip-coating process. The structural, morphological and optical properties of the coatings were characterized. The vitreous structure was identified by infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Morphology of materials was observed by scanning electron microscopy (SEM). The reflectance spectra were investigated and the optical performance of the structure was determined.
The role of the friction process in abrasive grain micro cutting technology
Authors: Mazuru S , Scaticailov S
Published: January 2021

The process of micro-cutting with abrasive grain - complicated tribological phenomenon. The removal of the chip-shaped material from the surface of the semi-finished product is accompanied by elastic and plastic deformations of the surface, with heat releases and phase changes. One of the features of the grinding process and other types of abrasive processing, is that the removal of the chip especially takes place with negative front angles. According to [1] the average value of the front cutting angle values is within the limits -(46.6… 56.9). To the geometric parameters of the distant layer that characterizes the cutting process can be attributed: the thickness and width of the cut and the shrinkage of the chip. A series of scientific and manual works on cutting materials can be objected to the fact that in the process of deformation at cutting which is characterized by the coefficient of shrinkage of the chip a physical-mechanical influence has the characteristic of the processed material, the value of advance, depth of cutting and other parameters.
FEM simulation of C45 steel and Cu-ETP billet shaping at hot upsetting between convex conical dies
Authors: Kukhar V V , Yu Balalayeva E , Korenko M G , Prysiazhnyi A H , Anishchenko O S
Published: January 2021

On the basis of finite element analysis (FEA), geometric differences in the shaping during hot upsetting of cylindrical billets with a height-to-diameter ratio of 1.0 and 2.0 made of C45 (1.0503) steel and copper (Cu-ETP) between pointed convex conical dies with a cone slant angle of 12.5°, 15.0° and 17.5° are considered. The stroke velocity of the upper die is 0.5 m/s; process temperature (t) and accepted surface friction coefficient (|μ): for steel - t = 1100 °C, μ = 0.32, for copper - t = 850 °C, μ = 0.34. An equation is obtained for the relation between values of reduction in height ratio and engineering strain on height of workpiece during upsetting between conical dies, taking into account the initial billet dimensions and unevenness of forming due to the geometry of tool. The presence of qualitative and quantitative differences in shaping along the height of upset steel and copper billets was revealed, i.e. influence on unevenness of forming the rheological properties of materials under process conditions. It is advisable to use the results obtained to design and improve of technological processes of open die and closed die forging with preforming of billets.
Study on grinding mode effect on external conical thread quality
Authors: Ya Ropyak L , Vytvytskyi V S , Velychkovych A S , Pryhorovska T O , Shovkoplias M V
Published: January 2021

The article has grounded the necessity to develop an empirical power dependence of cutting modes influence on part surface roughness obtained during thread grinding. The calculations were carried out for grinding of parts made of steel and hard alloy. There have been developed a relation of part material properties, grinding wheel options, lubricating and cooling liquid (constant for concrete conditions of thread grinding), depth of cutting (thickness of a grinded layer per path), revolutions of a part and a wheel, longitudinal feed refer to obtained roughness. It has been stated that components of the grinding mode contribute in roughness values in different way, in particular they are arranged in the ascending order as follows: grinding depth, rotation speed, and detail’s diameter.
Research of fuzzy logic application on surfaces roughness prediction under finishing milling process
Authors: Ghencea D. P. , Anania F. D. , Zapciu M.
Published: January 2021

Artificial intelligence systems are usefully tools for estimation of different parameters for industrial and non-industrial applications. In this paper is presented a fuzzy logic application for surface roughness prediction for two material type for a CAM milling process. A minimum number of measurements have been made on a specific material (Al 6061) and were used for prediction of a roughness of another material (Al 7075). The link parameters between these materials, used in Fuzzy logic system, is the Rockwell hardness. In this way many correction parameters of cutting regime can be calculated in a short time with minimum resource (less experiments and tests needed).
Correlation between market segmentation, industrial product features and context in design assessment
Authors: Craciun A E
Published: January 2021

When referring to product design assessment, even with a standard evaluation format, the perspective from which the criteria are approached differs strongly from one market category to another, this having a direct impact on the accuracy of the method. In order to achieve an objective assessment, the product must relate to a frame of reference in accordance with the product’s destination, taking into account the user specifications and the actual experience of use. This paper represents the study of correlations between the market segment, product features and context and their degree of interdependence. Thus, analysing the relations between sections, the representative influence formulas for each considered feature were deduced, highlighting the extent to which the user’s typology and context relate to the product features.
A brief review of the methods and techniques used in the innovative internal logistics processes and systems
Authors: Pascu I G , Neacsu G C , Nitu E L , Gavriluta A C
Published: January 2021

In the last period, logistics knew a strong technological evolution that has changed the way it operates and determined its transformation into innovative logistics, especially in the case of internal logistics. Innovation in internal logistics processes and systems consists in the use of different Industry 4.0 and digitization technologies. So, it is necessary to use modern methods and techniques to support the transformation of internal logistics processes and systems into innovative ones. This paper presents an analysis of recent studies, briefly presenting the evolution of the concept of logistics, the concepts of process and logistics system and Industry 4.0. Also, the most common methods and techniques used in the realization of innovative internal logistics systems are presented and some conclusions are presented regarding their use.
New design of precise deployable reflector. Technologies for manufacturing of physical model
Authors: Bujakas V I , Glotov M D
Published: January 2021

The new design of petal space antenna is considered in the paper. Various versions of solid petal-type mirrors have been considered and investigated in a number of articles and space projects. The classical scheme of petal type deployable space reflector was proposed and developed by Dornier Corporation within FIRST space project and was used in the Radioastron project to create a 10-meter antenna of space radio telescope. However, the classical petal mirror design has two significant drawbacks. Firstly, in the open state, the petals are cantilevered on the central mirror, what leads to low rigidity of the structure in open state. Secondly, in the classical design, the accuracy of the reflecting surface of the open mirror strongly depends on small errors in the operation of the deployment system. To overcome these drawbacks a new design of petal type mirror and a new system for precise opening of the mirror were proposed and studied. To test a new technical solution, a physical model of a deployable reflector was developed. The model contains a central mirror, a set of petals, hinges, locks and actuators for opening the mirror. 3D printing technology, CNC (computer numerical control) milling, plastic injection molding and carbon fiber technologies have been tested for central mirror and petals of the model fabrication. The results of computer and physical simulation are presented in the paper.
Determination of the regularities of the covered wagon supporting structure dynamic loading when conducting fire from it in the horizontal plane
Authors: Fomin O , Lovska A , Gerlici J , Fomina Yu , Fedosov-Nikonov D , Prokopenko P
Published: January 2021

A study of the supporting structure dynamic loading of a covered wagon for the military equipment transportation and for firing has been carried out. A mathematical model has been drawn for this purpose, taking into account the vertical and angular displacements relative to the longitudinal axis (side rolling) of the wagon supporting structure when firing. Accelerations as the components of the dynamic load acting on the wagon supporting structure have been determined. It was found that the accelerations acting on the wagon supporting structure in the vertical plane were about 6.0 m/s2 (0.6 g). In the horizontal plane, the accelerations were 2.6 m/s2 (0.26 g). That is, the wagon movement can be assessed as “satisfactory”. To reduce the wagon dynamic loading during the conduct of fire, it is proposed to install elastic vibration dampers under the support sectors. In this case, the horizontal acceleration was about 2 m/s2 (0.2 g). Taking into account the proposed technical solutions, the wagon dynamic load is reduced by about 25% in comparison with the case of the rigid interaction of the sector with the frame. The strength analysis of the covered wagon bearing structure has been carried out. It was found that the maximum equivalent stresses are concentrated in the area of the front stops and are about 315 MPa. The conducted research will contribute to the creation of recommendations for the design of covered wagons for the military equipment transport and for firing, as well as to increase the efficiency of the railway transport operation..
Determination of residual resource of flat wagons load-bearing structures with a 25-year service life
Authors: Fomin O , Vatulia G , Horbunov M , Lovska A , Píštěk V. , Kučera P.
Published: January 2021

The article determines the residual resource of flat wagons load-bearing structures with a 25-year service life. For this purpose, field studies of the technical condition of the load-bearing structures of flat wagons based on the wagon depot of the Foundation of the Southern Railway branch of JSC “Ukrzaliznytsia” were carried out. The flat wagon of model 13-401 was chosen as the subject. It is established that the design service life of the load-bearing structures of the studied flat wagons, taking into account the extension of their operation is not less than 18 years. The strength of the load-bearing structure of the flat wagon in the environment of SolidWorks Simulation (CosmosWorks) software by the finite element method is calculated. It is established that the maximum equivalent stresses occur in the zone of interaction of the spine beam with the pivot be equal to 337.5 MPa. Therefore, the strength of the load-bearing structure of the flat wagons is provided. The estimation of the course of the flat wagons is determined. The research was carried out in the vertical plane during the movement of the butt rail track. The calculation was performed in the MathCad software environment by the Runge-Kutta method. The assessment of the wagon is “excellent”. The conducted researches will promote increase of efficiency of combined transportations in the international communication and strengthening of foreign economic positions of Ukraine in the market of transport services.
Development of a methodology for determining an energy efficient technology for the freight transportation on a singletrack railway line
Authors: Prokhorchenko A. , Malakhova O. , Gurin D. , Sikonenko G. , Prokhorchenko G.
Published: January 2021

In the context of the search for strategies for the development of railway infrastructure, it is important to theoretically substantiate the choice of constructive and organizational measures that will allow the development of promising passenger and freight traffic. This study proposes an approach to determining the rational parameters of energy efficient technology for the transportation of freights on the site in the context of the implementation of one of the reconstruction measures - modern dispatch centralization of train traffic control. The main aim of research is to develop a methodology for determining an energy efficient technology for transporting freights on a single-track railway line. It is proposed to use analytical methods for calculating the average speed of trains with a combination of micromodeling of traction characteristics of freight trains of different mass. Theoretical calculations of the change in the section speed were carried out when the dispatch centralization was introduced, taking into account the choice of various options for the mass of freight trains. The calculations performed for a single-track line and the dependences of the cost change per one shipped carriage and the section speed on the train mass were obtained, which made it possible to determine the optimal parameters of the energy-efficient technology for the transportation of freights by the line. The proposed method for determining the energy efficient technology for the transportation of freights can be used in the technical and economic calculations of projects for the implementation of various systems of train dispatch control on single-track railway lines.
Calculation residual strength of reinforced concrete beams with damages, which occurred during loading
Authors: Blikharskyy Yaroslav , Vashkevych Rostyslav , Kopiika Nadiia , Bobalo Taras , Blikharskyy Zinoviy
Published: January 2021

The article presents the development of a method of experimental study of reinforced concrete beams with damaged steel reinforcement. In addition, the purpose is to conduct experimental tests of undamaged samples with steel reinforcement of 20- and 16-mm diameter. Also, the 20 mm steel bars were damaged to the area equal to 16 mm samples, experimental tests of such samples were performed and corresponding analysis and comparison of the results of both tests was conducted. According to the study program, 6 beam samples were tested. Two of them were undamaged control samples with single load bearing reinforcement of Ø20 mm diameter; 2 samples with Ø20 mm reinforcement had about 36% damages (which corresponds to area of the 16 mm diameter samples) and 2 samples with Ø16 mm single reinforcement, which corresponds to 36% load bearing reinforcement damage of control samples (the area of 36% damages of 20 mm samples corresponds to 16 mm diameter). The experimental study identified the strength and strain parameters of reinforced concrete beams with damages in the load bearing stretched reinforcement due to the action of the bending moment, which causes the exhaustion of the bearing capacity.
Strengthening of the reinforced concrete tank of anaerobic purification plants with the manufacture of biogas, damaged as a result of design and construction errors
Authors: Kramarchuk A , Ilnytskyy B , Hladyshev D , Lytvyniak O
Published: January 2021

The defects and damages of bearing structures (walls, covering) of the solid-cast reinforced concrete tank were identified and detected using visual and instrumental testing. The actual reinforcement of the tank was determined and coordinated with designed reinforcement. Furthermore, the deformations were measured, the cracks opening in the walls and its depth in the concrete were detected and was also the strength quality of concrete was defined. During the year of the operation, the tank developed a considerable system of cracks in all lateral walls from technological loadings. At the same time, the width of the crack opening exceeded the limit values for reinforced capacitive structures (wk), which is equal to 0.1 mm. The walls lost tightness, the use of the structure in the technological process was suspended. Checking calculations of the design solutions was carried out for the elements of the tank on technological loadings in the software package LIRA to find the causes of the cracks opening and water penetration in the walls of the reinforced concrete tank. It was determined that the existing design solutions did not ensure the bearing capacity and the fracture strength of bearing reinforced elements of the tank and its spatial rigidity from technological loadings. Necessary reinforcement was defined by ensuring the strength and possible limitation of the width of the cracks opening. This article presents the technical solutions concerning the strengthening of repair bearing elements of reinforced concrete spatial frame of the existing structure. The external bandages (reinforcing steel 4d32A400C) and inner tension bars (stainless steel round pipes 168 x 5 mm) were used as the strengthening of the reinforced concrete tank.
Methodical approach in determining the reliability and efficiency of urban cargo transportation taking into account the congestion of street networks
Authors: Kutiya O , Kravcov A , Gorodetska T , Voytov O
Published: January 2021

A methodical approach has been developed in order to assess the reliability and efficiency of urban cargo traffic, taking into account the congestion of street networks. Modelling the transportation process is carried out online and allows one to determine the parameters of the transportation process, which take into account the presence of traffic jams on the city streets. A criterion for assessing the reliability of the logistics system of cargo urban transportation has been proposed – the reliability coefficient and the integral criterion of efficiency. The criteria take into account the travel time of the vehicle along the route and the time of delays in accepting the applications for services at the logistics centre (LC), as well as the time of delays at the transport company. It has been shown that in the absence of delays in the logistic chains, the reliability coefficient is equal to one, and the efficiency criterion tends to a minimum. The role of the LC capacity in the unit costs of transport services has been determined. Insufficient capacity of the LC increases the processing time of one application, which leads to an increase in the total unit costs.
Reconstruction of Shallow Foundations Using Peracetic Silicate Solutions
Authors: Levenko H M , Aleksandrovych V A
Published: January 2021

The modern world is facing the acute issues of environmental pollution. Recently, they have begun to come out on top in the global relations and in the cooperation of various global business entities. The states allocate significant funds both for measures to prevent environmental pollution and to combat their consequences. The operating experience of many enterprises has shown that the issues of reconstruction of the foundations of existing buildings and structures are currently acute and urgent. One of the most effective types of soil consolidation is stabilizing with various binders, such as silication, bituminous grouting, tarring, cementation. As economic exploitation of soils intensively increases, various pollutants, both organic and nonorganic, affect them by deteriorating their composition, structure and properties. Different types of soils react differently to pollutants, some of them are more “sensitive” to them while others are less “sensitive”. Pollution and environmental deterioration of soils due to the uncontrolled accumulation of various industrial wastes in the soils are the main problems. In this regard, under current conditions, along with the elimination of sources of pollution, it is necessary to develop new methods and technologies to prevent pollution. Physiochemical methods can solve these problems.
Determining the Dependence of Fire Parameters in a Cable Tunnel on its Characteristics
Authors: Nuianzin Oleksandr , Sidnei Stanislav , Zayika Petro , Fedchenko Svitlana , Alimov Bogdan
Published: January 2021

In order to study the parameters of fires in cable tunnels both experimental methods and numerical simulations are used. The purpose of this article was to determine the dependences of the maximum temperature inside the cable tunnel during a fire, the duration of the fire in a local area of the cable tunnel and the time of reaching the maximum temperature inside the cable tunnel during a fire on its characteristics (cross-sectional area of the cable tunnel, fire load) inside the tunnel. In the course of the research a complete factorial experiment was developed and conducted. According to its results, the required regressions were obtained. Thus, there are reasons to believe that the obtained results of the study are the basis for the creation of mathematical models that describe fires in cable tunnels and can be used for engineering assessment of fire resistance of cable tunnel structures. In addition, computer simulation of heat and mass transfer in case of fire in cable tunnels was further developed.
Systems and subsystems of track, control and management of high-speed railway
Authors: Shevchenko A A , Matviienko O O , Lyuty V A , Manuylenko V G , Murygina N A
Published: January 2021

The article discusses the following issues: according to the current level of development and equipment of the existing network of railways in Ukraine, it is necessary to state the determination of the gauge of the high-speed line; the main characteristics of the highspeed rail system and the general requirements for laying the line; track systems and subsystems, as well as including their movement and control on free terrain, ensuring the safety of operation and transportation of passengers with the declared conditions of comfort and speed; the distance between the centres of the tracks increases in proportion to the speed of movement of passenger flows, which requires additional arrangement of the roadbed, taking into account the radii of the curves, the elevation of the outer rail, the angle of descent and ascent of the track, the equivalent taper, the slope of the rail, the profile of the rail head, such as rail and sleepers; lateral and vertical forces acting on the track. In order to ensure traffic safety at the maximum permissible speeds, it is necessary that the indicated vertical and lateral forces (static and dynamic) meet the requirements, which in turn depend on the above factors.
Features of assessing the evenness of road surfaces using laser road scanners
Authors: Smolianiuk R V , Smolianiuk N V , Kiashko I V
Published: January 2021

Road pavement evenness is one of the basic parameters characterizing road quality. Evenness influences car wear, fuel consumption, transportation costs, emotional state and comfort of drivers and passengers, and many other parameters. Assessment of road pavement evenness, which is widely used all over the world, has a number of features that do not allow to correctly assess an evenness at bridges, viaducts and other structures. Moreover, particularities of laser scanners operation do not allow to compare the obtained data with data obtained with the help of three-meter straight-edge. The paper suggests ways to solve problems in question, which enable significantly improving quality of evenness assessment at such important transport infrastructure objects as bridges, overpasses and viaducts. There is also a solution to compare the data of transverse evenness obtained by laser scanners with data obtained with the help of a three-meter straight-edge that will permit to use these data later for comparison with standard values.
Research of the behavioral of the wooden beams with fire protection lining under fire loading
Authors: Zmaha M I , Pozdieiev S V , Zmaha Y V , Nekora O V , Sidnei S O
Published: January 2021

This article highlights the current issues of ensuring the fire resistance of wooden beams as load-bearing structures. Scientists have studied various types of fire protection of wood from the effects of fire. In the existing methods of fire protection, fire-retardant impregnating materials, fire-retardant paint, commercial fire-retardant coverings are presented. In addition, a study on the creation of fire-retardant materials was conducted. Therefore, in the field of our research there are the issues of using fire-protective plywood as a fire-retardant cladding method of protection of wooden structures. This article describes the process of manufacturing fire-retardant plywood made of 2-millimeter sheet of veneer and impregnated with a flame retardant using the method of technological baths and glued in a pressed machine to the appropriate thickness. Then in the experimental setup, fire tests were performed at standard temperature for three intervals of exposure to determine the depth of charring. These studies make it possible to draw conclusions about the effectiveness of the proposed method of fire protection of wooden structures and to determine the calculated class of fire resistance for these structures.
Application of energy efficient materials in reconstruction of buildings and structures of transport infrastructure
Authors: Zolotov S , Pustovoitova O , Firsov P , Orel Y , Rezunenko M
Published: January 2021

The article analyzes in detail the results of the performed reconstruction works with the application of thermosetting polymers. The method of adhesive anchoring of reinforcement rods with fixing them in the concrete body with acrylic glue was carried out on transport infrastructure facilities (railway steam shop and railway itinerary post). It has been determined that strengthening the foundation with application of the thermosetting polymers (adhesive anchor joints) gives a significant reduction in the consumption of concrete, metal and labor costs. The advantage of such acrylic adhesives is the possibility of varying the ratio of monomeric and polymeric part (powder) containing redox system, within acceptable concentrations, without significant changes in adhesion and cohesion parameters. The obtained results are very important in practice, because in the conditions of preparation of the adhesive (especially in construction conditions) it is difficult to determine the exact number of components. The experimental research data can be used for attachment joints projecting and industrial technological lines development, as well as for further polymeric adhesive materials, widely applied in industrial and civil engineering, improvement.
The use of incineration waste to improve the properties of the bases
Authors: Zotsenko M L , Mykhailovska O V , Lartseva I I , Klymenko V V
Published: January 2021

Innovative ways of using furnace dust to improve the strength of soil-cement are analyzed. It is proposed to solve the environmental problem of utilization of this material, when using the addition of furnace dust during the construction of soil-cement elements. The samples were kept immersed in water for 28 days in order to gain strength, until laboratory tests. The removal ash before the experiment was sieved on a 4 mm sieve. Strength of soil-cement samples with the addition of furnace dust and pellet ash (with the main content of sunflower husk with a percentage of 5% by weight of cement) was studied. It is established that the average compressive strength of the samples with the addition of Mykolaiv CHP furnace dust with a fraction of inclusions up to 4 mm in the amount of 5 % increases the compressive strength by 30%. It was found that the content of organic matter (ash from burning sunflower husks) in soil-cement reduces its strength.
Carbon fiber plastics for vehicles manufactured by resource-saving formation technology
Authors: Bilym P , Rogozin A , Firsov P , Zolotov S
Published: January 2021

The advantages of the technology of molding carbon plastics based on pre-pregs with separate application of components (SAC-technology) of epoxy binders cured by the mechanism of migration polymerization of epoxy cycles are presented. Using the methods of linear dilatometry and dynamic mechanical tests, the molecular mobility of the segmental and local types in polymer matrices of carbon fiber reinforced plastics based on traditional mixed pre-pregs and binary pre-pregs with separate application of components has been investigated. The question of the influence of the activation ability of an acid catalyst during the curing of an epoxy binder on the degree of decrease in internal stresses and the realization of an increased packing density of polymer chains in the polymer matrix of the composite is considered. The importance of choosing an acid catalyst for the curing of a polymer binder is shown, which for CFRP composites provides the necessary combination of elastic and dissipative properties. The use of the considered binders makes it possible to improve a number of important operational characteristics, especially in the case of the production of large-sized products: solidity, crack resistance, impact resistance, fracture toughness. These properties are very significant during the composite materials applying in transport engineering.