bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Geopolymers in the Treatment of Water Contaminated by Industrial Waste
Authors: Bernaudo I , Tagarelli A , Elliani R , Candamano S , Macario A , De Luca P
Published: February 2020

The present research aimed to study the use of geopolymers in the removal of heavy metals in water contaminated by an industrial waste. The geopolymer was synthesized and characterized beforehand in the laboratory while the industrial waste is the so-called zinc ferrite that comes from a zinc processing industry in southern Italy. It is known that this waste contains within it a variety of elements that over time can be released if in contact with water. The study was carried out preparing different aqueous systems containing predetermined quantities of zinc ferrite and geopolymer. The systems were stirred for different reaction times and at room temperature. Subsequently, after the established time the systems were filtered and the resulting solution was analyzed by a mass spectrometer (ICP-Ms). The variation in the concentration of various elements (such as Fe, Zn, Pb, Mn, Ca, Mg, Na and K) was followed as a function of contact times. The obtained data allowed to evaluate the effectiveness of geopolymers in the removal of metals released by zinc ferrite in water. In particular, the geopolymers, in the systems studied, have shown particular propensity in the abatement of iron and zinc which has reached 100%, followed by an abatement of about 95% for Mn and Pb after a 1.5-hour contact time.
Theoretical Analysis of Supersonic Low Reynolds Number Flow Control Technique Based on Flow Mixing
Authors: Dachuan Xu , Zebin Ren , Zhiqiang Chen , Haifeng Wang , Longde Guo
Published: February 2020

The thickness of boundary layer increases rapidly in supersonic low Reynolds number flows. As a result, there will be shock wave-boundary layer interference. The disturbances of downstream can spread upstream through in boundary layer because the flow in boundary layer is subsonic, which may decrease flow field uniformity and stability. The pressure of this type of flow is always very low. For the sake of flow continuity, the increase of flow pressure is necessary. A kind of supersonic low Reynolds number flow control technique was proposed. The high pressure supersonic flow jet-ted from plates which located in the flow channel blew away boundary layer, cut off the disturbances spread from downstream to upstream, and eliminated the shock wave-boundary layer interference. The pressure of primary flow was also increased by mixing with the high pressure jetting flow. The calculation model of this flow control technique was established. A group of standard inputs were selected to calculate the parameters of flow and the preliminary law of flow was also obtained.
Rapid Aerodynamic Calculation Method for Hypersonic Gliding Vehicle
Authors: Zhang Bin , Feng Zhiwei , Xu Boting , Yang Tao , Peng Wuyu
Published: February 2020

The accuracy and efficiency are always conflict in the process of aerodynamic shape design, especially for hypersonic gliding vehicle (HGV). In this work, a rapid aerodynamic calculation method for hypersonic gliding vehicle is conducted, including shape parametric modelling, automatic mesh generation and rapid computational fluid dynamics (CFD) method. In details, the aerodynamic shapes of HGV are modelled by multi-section solids, which parameterized by class function/shape function transformation (CST) method and exponential function. Then, the computational meshes are generated automatically in two steps: one is generating surface mesh by Delaunay method, and another is generating volume mesh by adaptive Cartesian method. In order to minor the computational cost, the hypersonic aerodynamic are analysed by combining the Euler equation and the viscosity force. We have tested the accuracy and efficiency of this rapid aerodynamic calculation method in two flight states for a typical HGV. Compared with Navier Stokes (NS) equations, the results shown the errors of axial aerodynamic force are all less than 6%, but time costs are reduced in hundreds of times.
Study on LabVIEW-based Aviation BLDCM Control System
Authors: Zhang Linhai , Yao Yeming , Xu Lilin
Published: February 2020

with the increasing market demand and rapid development of aircraft technology, more electric concept has become an important trend for the future development of aircraft. Therefore, motors are widely applied in the aviation field increasingly. This paper mainly introduces the hardware environment and LabVIEW implementation process in the development of aviation high speed and high voltage BLDCM control system based on NI hardware and software platform. The test shows the control system is able to realize effective control over aviation BLDCM. This system is highly flexible and can lay a foundation for the algorithms used in subsequent related research efforts.
Experimental Analysis on Combined Vibration and Acoustics Test of a Satellite
Authors: Tingfei Yan , Haiyang Gao , Shuhong Xiang
Published: February 2020

Random vibration tests and acoustics tests are typical environmental testing approaches for verifying the dynamic environmental adaptability of a satellite, which should be selectively carried out on the ground before launch. Existing test criteria suggests that large spacecraft should be excited in a reverberation chamber, while a shaker should be used for a small spacecraft. With the development of experimental technique of environment simulation, the combined vibration and acoustics (vibro-acoustic) test are increasingly investigated for reproducing a more realistic environment and avoiding an over test or an under test. However, few studies have been published on coupling effect of combined vibration and acoustic test of a full scale prototype satellite. This paper discusses the equivalence between random vibration and acoustics excitation for satellite ground testing. The experiment results have shown advantages of the combined test in reproducing flight environment. And the coupling effect and distributions of high frequency response attenuation during the combined vertical vibro-acoustic test is observed and analyzed in detail.
Comparative Research on Early Warning Determination Methods of Spacecraft Collision
Authors: Hongqiang Sun , Zhanyue Zhang , Ewen Hu
Published: February 2020

With the development of space science, more and more spacecraft have entered into the space, and the operating environment of spacecraft in space has become more complex. Various signs show that the future space field will face congestion, collision and other safety problems, so the collision warning in space is becoming more and more important. It is the primary guarantee for the spacecraft to carry out its mission in space in the future to obtain the early warning information and complete the avoidance within the early time to ensure the environmental safety. In this paper, based on the perspective of collision warning and determination methods, two kinds of warning and determination methods are introduced, including BOX region method and probability method. In addition, by comparing the warning efficiency of these two methods, the results show that, under the same constraint, the probability method is more accurate and saves more space resources than the BOX region method. Considering that the spacecraft is limited in fuel and other resources when working in orbit, it is more scientific to adopt to avoid unnecessary maneuver and waste of resources.
Application and Research of Air Cushion Transportation in Flexible Assembly for Spacecraft
Authors: Yahong Zhu , Chengli Zhang , Shuai Xing , Xiaohuan Li
Published: February 2020

With the development of spacecraft, the problem of flexible transfer between large weight and large size spacecraft stations needs to be solved urgently. Air-cushion transporter is a special transporting platform for heavy load. It can effectively solve the transfer problem of large spacecraft. This paper introduces a parallel air-cushion vehicle for large cargo transportation. In this way, there may be a certain height difference on the road surface where the air cushion vehicle moves, which will affect the transfer. The air volume adjustment of the air cushion vehicle is introduced to ensure the smooth transportation method. Through test, it summarizes the key indicators of air-cushion transporting, which can provide reference for the research of large spacecraft transporting methods.
Simulation of Space Flexible webs on Capture Process Based on Nonlinear Finite Element Method
Authors: Xu Boting , Yang Yueneng , Zhang Bin , Yan Ye
Published: February 2020

Aiming at the problem of the space flexible webs collision during the space capture process, the general method of collision detection was given based on the nonlinear finite element method, and the collision dynamic model of the space flexible webs and target was established. In order to verify the versatility of the space flexible webs structure in different capture scenarios, the target capture position and attitude were changed respectively, and different capture scenarios were established to simulate and analyze the working conditions by using the finite element software. The results showed that the target position and attitude during the collision impact process is the key of the results of the flexible webs capture mission, which can provide some reference for the structural design and on-orbit task planning of the space flexible webs system.
Accuracy Control of Big-scale Space 3D Measurement System in Aircraft Digital Assembly
Authors: Cheng Yan , Xu Yuan-heng , Huang Xue-liang , Wang Lei
Published: February 2020

Large scale space measurement technology is one of the key technologies of aircraft assembly. The accuracy of measurement system affects the efficiency and quality of aircraft assembly directly. However, the accuracy of the measurement system depends on the process of constructing the measurement system. Therefore, this paper explores three principles of constructing high-precision large-scale space measurement system, through a large number of experiments and simulations.
Research on the Construction Technology of Knowledge Graph in Aviation
Authors: Wang Xue , Yang Xizhong , Fu Jiapan , Qiu Xuyi
Published: February 2020

In order to alleviate the overload of airspace information under the network environment and integrate the scattered and useful airspace information, the technical architecture of knowledge graph in the aviation field is proposed. This paper describes the technical architecture of aviation knowledge graph construction, including knowledge extraction, knowledge fusion, knowledge processing, knowledge update and other key technologies and applications. Finally, an instance of knowledge graph for air combat is constructed. The knowledge graph discovers the hidden relationship between task and maneuver through resource sharing and information mining, which can be used for mission optimization and maneuver prediction to assist air combat decision-making.
Analysis of the Influence of On-Board Temperature and Pressure Control System on Inert Gas Generating Performance of Hollow Fiber Membrane
Authors: Zhang Jing-yang , Luo Bi-tai , Hu Wen-chao , Shen Ping
Published: February 2020

Based on the typical on-board membrane separation system for fuel inerting, the mathematical models of temperature and pressure control subsystem and hollow fiber membrane were built with the coupled iterative numerical solution methods. While the temperature and pressure were controlled, the design area, nitrogen production effect of hollow fiber membranes were analyzed and compared with the situation of no temperature and pressure control in the full flight envelope by numerical simulation. Moreover, the root causes for those changes were found out. It shows that the method used in temperature and pressure control can increase the bleed air pressure and enhance the stability of temperature and pressure effectively. Compared with the situation of no temperature and pressure control, the temperature and pressure control method are able to decrease the demanded area of membrane by 42.3%∼51.7%. And there is no need to adjust the membrane area for condition of low nitrogen production efficiency. But it also decreases the highest nitrogen production efficiency by 9.4% and increase the minimum oxygen concentration by 0.65%. The rate of flow has the most significant effect on nitrogen production. These phenomena are caused by the effects of the rate of flow, pressure, temperature and membrane area.
Application of Kalman Filter in Satellite Propellant Remaining Prediction Technology
Authors: Yin Wenjuan , Cao Zhiwei , Wang Mengjie
Published: February 2020

The prediction of the propellant remaining is related to the use efficiency of the propellant, it is of great significance for the estimation of the remaining life of the spacecraft. The gauging uncertainty of the commonly used propellant remaining prediction method is high, and the single gauging method can not meet the higher requirements of long life satellites on-orbit management. In order to further improve the accuracy of the spacecraft propellant remaining prediction, combined with the characteristics of the existing propellant remaining estimation method, a real-time estimation method of propellant remaining is proposed. The algorithm combines two gauging methods to further improve the reliability of propellant consumption estimation. The practical application shows that the algorithm can effectively reduce the disadvantages of the BK method and the PVT method, and provide a more reasonable estimation of the real-time propellant remaining.
Characterization and Uncertainty Analysis of the Interlaminar Inelastic Properties of Unidirectional Fibre-reinforced Composites
Authors: He Tiren , Liu Liu , Xu Jifeng
Published: February 2020

The compression failure mode has been achieved through changing the SBS (Short Beam Shear) experiment parameters, and the nonlinear constitutive relationship along thickness direction for the typical specimens loaded in 1-3 principal material plane has been computed iterative by FEMU with the reconstruction strain field and the numerical simulated stress data of FEM model. The uncertainly of the constitutive parameters is induced by the measurement system noise in the DIC technique and the approximation error in the displacements and strains smoothing algorithm. The covariance matrix of the extracted material constitutive parameters has been given explicitly. Three material constitutive parameters were identified from a customized short-shear experiment simultaneously using an estimated optimal reconstruction mesh size as an illustration. Sensitivity of measurement noise and reconstruction parameter on extracted material properties has been investigated. The effects of region of interest (ROI) and DIC image number on uncertainties of extracted material properties have been addressed. It is suggested that there exist an appropriate ROI and the number of images, from which reliable material parameters can be identified, but much more data used in identification process always lead to smaller standard deviation and COV. It is observed that the material constants used to characterize the interlaminar stress-strain behavior show strong robustness to the measurement noise. Another key finding is that the reconstruction parameter in the global finite-element based approximation approach is critical for reliable material properties identification. Its value has to stay close to optimum for guaranteeing reliable identification of material properties.
Design and Experimental Research of Rope Missle
Authors: Wu Haoting , Zhao Lei , Wu Pingjun , Xiao Feng , Guo Yongxiu , Jiang Ming , Geng Junlei , Yang Lei
Published: February 2020

The UAV (unmanned aerial vehicle) unfolding guide rope is the construction process adopted in the tension stringing of overhead power transmission line. At present, due to the limit of UAV control precision, the function of threading the guide rope into the paying-off sheave groove directly cannot be realized, and we can only unfold the guide rope of UAV to the cross arm of iron tower, and then, make the operation personnel at height transfer the guide rope into the steel wire groove of paying-off sheave. Therefore, the construction efficiency of this process is relatively, and there is operation at height, with a certain safety risk. In this project, it is planned to develop a launching device carried by UAV, and this device uses the compressed carbon dioxide (CO2) which is relatively safe as power source, which realizes the instantaneous release of compressed air through electromechanical servo control, and then generate the power which promotes the “rope missle” to fly. The tail of “rope missle” is connected with guide rope, and when it flies forward, the traction guide rope will move forward synchronously. After the “rope missle” threads into the sheave, the compressed air will be released completely, and then, the “rope missle” will transfer into the motion of a free falling body, thus further driving the falling of guide rope, so as to realize the function of “rope missle” tracts the guide rope to realize threading into the paying-off sheave.
Investigation on Application of Closed Cavity Inductively Coupled Plasma in Inlet Stealth
Authors: Xinmin Han , Wenyuan Zhang , Xiaolong Wei , Haojun Xu , Junlin Chen
Published: February 2020

The design of inlet into S-shaped is a stealth method with limited effect. The ICP generated in closed quartz chamber is an effective solution to improve the stealth effect. In this paper, an inductively coupled plasma (ICP) generator with the size of 30cm×30cm×2cm which could be conformal with S-shaped inlet was designed, the discharge experiment was carried out to study the discharge configuration of air ICP and the distribution of the electron density in the core area of ICP under 100Pa and different discharge power was diagnosed with microwave interference method. On this basis, the three-dimensional electromagnetic model of inlet and the plasma generator were established and the finite-difference time-domain method was used to calculate the broad-band scattering parameter of the inlet with and without the ICP generator. The variation of radar cross section area (RCS) with the azimuth angle, electromagnetic wave frequency and discharge power of ICP was studied. The result indicated that the ICP generator could effectively improve the stealth effect of S-shaped inlet in the head direction.
The Numerical Simulation of Temperature Field in Friction Stir Welding of 7075 Aluminium Alloy
Authors: Ma F J , Fu D Y , Liu Y , Yang D P , Zhang S F , Sha Z H
Published: February 2020

Considering friction heat generation between rotating tool and workpiece and plastic deformation heat generation of material, a numerical simulation model of friction stir welding of 7075 aluminium alloy sheet was established. In this study, the temperature field of the welding process was analysed, and the effects of different stirring speeds and welding speeds on the temperature field were compared. The results show that the high temperature region is located below the shoulder and diffuses outward in a ring shape. After the welding is completed, the workpiece center temperature is high and the ambient temperature is low. The stirring speed of the tool has a large effect on the peak temperature during the welding process. The effect of the welding speed on the peak temperature is less than the stirring speed. The comparison shows that the welding temperature is about 478°C at a stirring speed of 800r/min and a welding speed of 120mm/min, which is a suitable welding parameter.
Study of Different Micro Milling Blades on Milling Titanium Alloy TC4
Authors: Zou ZiChuan , Zhao XianFeng , He Lin , Jiang XueTing
Published: February 2020

With the development of micro-miniature, micro-milling technology has been widely used. Due to the difference in workpiece materials and processing technology, the selection of the edge structure of the micro-milling cutter during processing is particularly important. This paper analyzes the influence of micro-milling of titanium alloy TC4 on cutting force, cutting heat and tool stress distribution for micro-milling cutters with a diameter of 0.1mm based on Definite-3D, ANSYS and other finite element simulation software.The results show that the spiral-edge micro-milling cutter can effectively reduce the cutting force and cutting heat compared with the straight-blade micro-milling cutter. Considering the rigidity, strength, cutting performance and practicability of the tool, the traditional double-edged spiral-edge micro-milling is still the best choice. The research results of this paper can provide a theoretical basis for the design of micro-milling tools.
Construction Process of Continuous Unreeling and Setting of Leading String Based on Trajectory Theory
Authors: Wu Haoting , Zhu Yong , Wang Qinghao , Wang Haichao , Zhao Lei , Wu Pingjun , Jiang Ming , Yang Lei
Published: February 2020

The increasing construction of power transmission line promotes the development of construction technology of overhead power transmission line in our country into a brand-new era; while the paving of leading string of traditional overhead power transmission line is still to be completed by climbing the iron tower and manual operation of construction personnel. Therefore, it has been extremely urgent to implement research on the construction process of the power transmission line’s leading string threading into pulley, thus reducing the frequency of operation at height of construction personnel. This paper aims to introduce the ejection construction technology of UAV based on trajectory theory to reconstruct the line tackle device, states the construction process flow of multi-rotor UAV utilizing ejection technology to conduct continuous unreeling and setting of leading string with ejection technology in detail, summarizes the full process of construction, conducts contrastive analysis with traditional construction process, and summarizes the social benefit and economic benefit of new type of construction process.
Experimental Study of the Cells Interaction on Linear and Nonlinear Operating Modes
Authors: Pisarev P V , Akhunzianova K A
Published: February 2020

In this article, the results of SAS samples laboratory research on an interferometer with a normal sound wave incidence at sound pressure levels of 100 and 130 dB are presented. The mutual influence of prismatic resonators was revealed, which leads to a decrease in the resonators group acoustic efficiency.
Threshold characteristics of non-resonator laser generation in dye solutions with ZnO nanoparticles
Authors: Zemlyanov Al A , Trifonova A V , Ryambov R V
Published: February 2020

An experiment was carried out to determine the generation thresholds in solutions of the Rhodamine 6G dye with Au nanoparticles having a plasmon resonance at the pump wavelength and ZnO nanoparticles not having a plasmon resonance. It was shown that solutions with ZnO nanoparticles have lower lasing thresholds in comparison with solutions with Au nanoparticles.
Electrical discharge machining of polymer composite materials
Authors: Ablyaz T , Muratov K , Shlykov E , Morozov E , Karmanov V , Shakirzianov T , Sarabjeet S S , Sahil D
Published: February 2020

Improving the technical capabilities of manufacturing processes and creating new parts that surpass existing quality benchmarks is a need of modern engineering. Polymer Composite Materials (PCM) are commonly used in the manufacturing of advanced aerospace components. The aim of this work is to study the process of Electrical Discharge Machining (EDM) of PCM VKU-29. To study the process performance, three different types of Electrode Tools (ET) of different materials were used. EDM was performed on three modes viz. maximum, medium, and minimum. The influence of process parameters and the electrode type on the formation of spark gap was investigated. The visual and the microscopic inspection revealed the absence of hairiness and traces of fiber rupture in case of composite ET. Thus, it can be concluded that the combination of smallest value of spark gap and the composite ET leads to the best quality of surface amongst all the other combinations. Moreover, while processing the PCM VKU-29 using composite ET, it is advisable to maintain a spark gap of 0.14 mm for the best results.
Investigation of the influence of radiation on the optical biomaterials characteristics of the storage lake Sorbulak
Authors: Voronova N A , Kupchishin A I , Niyazov M N , Esyrev O V , Abdukhairova A T
Published: February 2020

The authors carried out the study on the effects of radiation on the optical characteristics of water solutions of Lake Sorbulak during the passage of laser radiation through them. The experimental data are well consistent with the theoretical calculations of the exponential model.
Effects of laser treatment modes on the parameters of the hardening zones and the wear resistance of steel 40Cr
Authors: Biryukov V P , Petrovsky V N , Panov D V , Ushakov D V
Published: February 2020

The paper presents the results of metallographic and tribological studies of laser hardening zones of steel samples. A full factorial experiment on laser hardening with a change in the distance from the focal plane, radiation power and processing speed was carried out. The regularities of changes in the depth and width of the quenching zones are obtained from the regression equations. With low-frequency transverse scanning of the laser beam up to 100 Hz, the hardening zones with a width of 20 mm and a depth of 1.4-2.0 mm in one pass were obtained. The wear resistance of the hardened zones is 3.68 times higher than the base material.
Control of electron beam wielding parameters based on the gap scanning system data during the welding process
Authors: Kasitsyn A N , Yu Agafonov R , Leonov A V , Grigoriev G V
Published: February 2020

Influence of the gap between the welded edges when sealing the case of electronic devices on the magnitude of the electron emission sensor signal in the process of electron beam welding (EBW) is studied. The impact of electron beam current variation at a constant value of the focusing system current on the penetration depth with the increasing gap between the welded edges is determined. The dependence of the length of the weld at different electron beam currents on samples with an increasing gap between the welded edges is studied. The possibility of controlling the process of electron beam welding by electronic emission from the weld pool is presented. A sensor for electronic emission registration is proposed, which includes an electron collector and an electron current data record system as a part of the EBW installation. The efficiency of the electronic emission sensor directly in the process of sealing under precision welding modes is shown.
Analysis of the amplitude-time parameters of current pulses in a plasma during laser beam welding
Authors: Yu Letyagin I , Ya Belenkiy V , Trushnikov D N , Pang S
Published: February 2020

The share of application of laser processing of materials in technological processes of mechanical engineering has increased over the past few years. In this regard, there is a need for reliable control of the technological parameters of the laser welding process. In deep penetration laser welding, part of the beam power is absorbed by the plasma cloud. As a result, a significant decrease in the penetration depth is observed. Using amplitude-time pulse of current in the plasma in the zone of impact of the laser beam on the metal is one of the directions of the work necessary for the control of the processes in the melting channel. The study of the processes of secondary emission in the plasma in the zone of impact of the laser beam on the metal allowed carrying out numerical simulation of the processes during laser welding. The models took into account the dependence on the focusing of the laser beam and other technological parameters of laser welding. The registration of the secondary emission current was also carried out in order to control the geometric parameters of penetration during laser welding. This technique can be used to build methods for the operational control of the welding process.
Development of methods for forecasting the microstructure of the welded joint with reference to the temperature-time modes of electron-beam welding
Authors: Olshanskaya T V , Fedoseeva E M
Published: February 2020

The research is devoted to the development of methods for forecasting microstructure of a welded joint in relation to the temperature-time modes of an electron-beam welding (EBW). The analysis of the simulation models and methods existing in the practice of thermal treatment and relating to austenite decomposition kinetics during cooling was carried out to choose methods for forecasting the forming microstructure in a welded joint at EBW. On the basis of these models one method for forecasting the microstructure of welded joints at EBW is offered in this work.
Evaluation of the strain-stress condition of rails
Authors: Abdurashitov A.Y. , Sychev V.P.
Published: February 2020

The paper presents semi-analytical approaches to the method of evaluating strain-stress mode of railway rails when a part of the solution is in the form of ramp functions whose rate of change cannot be adequately considered using the standard method of finite elements. The proposed model of a multipoint boundary value problem allows for effective evaluation of the rail’s work against the changing of its profile, i.e. due to its wear.
Reliability analysis of power equipment of traction rolling stock within the Eastern region
Authors: Khudonogov A M , Khudonogov I A , Dulskiy E Y , Ivanov P Y , Lobytsin I O , Khamnaeva A A
Published: February 2020

Annotation

One of the most loaded structures, and at the same time, the weakest elements of the power equipment of traction rolling stock, is isolation. The analysis of the operation of power equipment of electric locomotives from the negative impact of climatic factors on it has been made. It was revealed that to ensure reliable and safe operation, a system of maintenance and repair of rolling stock is necessary, taking into account the zonal conditions of operational features. The necessity of creating adaptive systems to maintain optimal values for temperature and humidity conditions for the insulation structures of electric locomotives is shown.
Suggestions for improving the efficiency of repair activity
Authors: Gladkih A M , Yu Konyuhov V , Galyautdinov I I , Shchadova E I
Published: February 2020

In order to improve the organization and performance of equipment maintenance, innovative proposals were developed and implemented. The explanations were taken into account when determining the methods for evaluating the maintenance performed for the joint approval of a unified methodology of applying the concept of a standard hour. The planning of performing equipment maintenance by day during the whole month was revised, which, in turn, allowed minimizing significant fluctuations in the scope of work and eliminating peak loads. The works on the maintenance of the mechanical and energy components of a single assembly were revised and combined as much as possible, which ensured the more efficient use of working time. Work has been organized on updating the composition of the operations to be performed, since the scope of maintenance work in the assignment forms is not always representative of the complex of necessary operations. Preventive work with subordinate personnel is organized in the field of improving the industrial standards in the workplace.
Types and methods of application of information technologies in the transport industry of Siberia
Authors: Krasovskaya O A , Chigir A E
Published: February 2020

Transport in Siberia is an integral part of human life. It is one of the important sectors of the national and regional economies. It is necessary to know how transport technologies have evolved. Development of technologies accelerates the economic growth of the region, establishes strong economic ties with developed regions of the country. The regions with a developed transport infrastructure have the most useful conditions for the economic growth. This article aims to describe the development of the transport system in Siberia. It describes the development of information technologies applied in the transport industry of Siberia. Application of the GLONASS navigation system is analyzed by the example of Irkutsk region.
Planning of qualitative indexes of railroad operational work in polygon technologies
Authors: Malovetskaya E V , Bolshakov R S , Dimov A V , Byshlyago A A
Published: February 2020

Increase of transit traffic volume demands application of new technological solutions structured in accordance with the tight schedule of the movement of freight trains. The forms of organizing traffic volumes based on the tight schedule are the intersectional and group trains and technical routes of regular service requiring specially organized reception of groups of wagons at their railroad yard.

Now there are quite a few optimizing models aimed at describing and researching of the uniform object – a freight transportation control system. Many of them give the individual formal description of the system, while being closed to further specification and development.

One of the main goals of transport processes control consists in optimum performance of cargo transportation of the predefined volume determined at a certain time interval, using the existing technical, information and steering complexes.
Investigation of sorption characteristics of modified klinoptilolites by the method of infra-red energy and differential X-ray spectroscopy
Authors: Obuzdina M V , Rush E A
Published: February 2020

The article presents investigations of adsorption of heavy metal ions Ni2+, Zn2+, Cu2+ by modified zeolites. As a modifier of zeolites of the Holinsky deposit, a sulfur polymer is proposed that is obtained from waste during the production of epichlorohydrin, the main components of which is 1,2,3 - trichloropropane. The mechanisms of adsorption and the results of investigations by the methods of infra-red pectroscopy and energy differential X-ray spectroscopy of the initial samples of materials are described in detail. On the IR- spectres new absorption bands are considered. These bands reflect the nature of fixation of modifier on the surface of sorbent.
The effect of asymmetry of the loading cycle on heat dissipation in metal structures
Authors: Yu Solovyov L , Solovyov A L
Published: February 2020

The paper is devoted to the experimental study of heat generation processes in various metallic materials under high-cycle loading with different values of asymmetry and amplitudes of cycles. Tests were performed on flat, smooth specimens subjected to cyclic stretching with increasing amplitude. Change in thermal radiation detected by an infrared detector, by the value of the thermal sensitivity of the device NETD was taken for the beginning of a metal sample self-heating. The stresses corresponding to the beginning of self-heating, are called critical. It has been established that Smith and Haigh diagrams of critical stresses of the onset of self-heating are similar to the same diagrams of ultimate fatigue stresses.
The application of relational interactive logic in control operation problems by the example of monitoring the server equipment of transport systems
Authors: Zakharov D V , Kuzmin O V
Published: February 2020

The article demonstrates the use of relational interactive logic in solving the problem of monitoring the server equipment of the transport control system. An example of such a problem is the problem of analyzing log records of monitoring server hardware. The server is considered as a special case of the physical control system. The conditions for the correctness of the current state of the equipment are defined in the form of systems of logical equations and inequalities. Solving a system of logical equations by executing a SQL query on a set of tables describing the elementary control systems in the server allows us to judge the deviation of the hardware parameters of the equipment. Recording the correctness conditions in the form of systems of logical equations provides the ability to take into account both the peculiarities of the functioning of the server hardware and some external context within which the server operates. The considered solution demonstrates the applicability of relational interactive logic in solving the problem of controlling individual classes of control systems within the scope of the system analysis discipline.
Development of multivariate equivalent cyclic tests of HALT-based aviation radio equipment for assessing reliability
Authors: Trushnikov V E , Komissarov A V , Grishin M V
Published: February 2020

The article studies forced test models for determining reliability of on-board electronic equipment due to the combined effects of broadband random vibration and cyclical changes in temperature. The model of multivariate equivalent cyclic tests based on HALT (High accelerated life / limited test) procedures is described.
South African radio telescope design nears completion
Authors: Makoni Munyaradzi
Published: February 2020

Scientists working on a new R70m ($5m) radio telescope array in South Africa have begun collecting data on two prototype dish designs that will form the Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX).
Winning starts
Authors: McKenzie James
Published: February 2020

The story of Research Instruments and its founder, Mike Lee, is a fascinating lesson in adaptability. It also comes with a wonderful coda, as James McKenzie explains
Dark digits
Authors: Metcalf Michael
Published: February 2020

In April this year, astronomers working on the Event Horizon Telescope captured the first direct images of a black hole and its “shadow”. Inspired by this revolutionary discovery, Michael Metcalf has created a variant of a traditional sudoku.
Planetary motions put limits on graviton mass
Authors: Jarman Sam
Published: February 2020

The motions of the planets have been used to make the best estimate yet of the upper limit of the mass of the graviton – a hypothetical particle that is a quantum of the gravitational field.
Epstein case continues to reverberate around MIT
Authors: Gwynne Peter
Published: February 2020

Women at the Massachusetts Institute of Technology (MIT) feel belittled and marginalized and “star” faculty members bully staff.
Genome editing in the nematode Caenorhabditis briggsae using the CRISPR/Cas9 system
Authors: Culp Elizabeth , Richman Cory , Sharanya Devika , Jhaveri Nikita , van den Berg Wouter , Gupta Bhagwati P
Published: February 2020

The CRISPR/Cas system has recently emerged as a powerful tool to engineer the genome of an organism. The system is adopted from bacteria where it confers immunity against invading foreign DNA. This work reports the first successful use of the CRISPR/Cas system in Caenorhabditis briggsae (a cousin of the well-known nematode C. elegans), to generate mutations via non-homologous end joining. We recovered deletion alleles of several conserved genes by microinjecting plasmids that express Cas9 endonuclease and an engineered CRISPR RNA corresponding to the DNA sequence to be cleaved. Evidence for somatic mutations and off-target mutations are also reported. Our approach allows for the generation of loss-of-function mutations in C. briggsae genes thereby facilitating a comparative study of gene function.
The Data Tags Suite (DATS) model for discovering data access and use requirements
Authors: Alter George , Gonzalez-Beltran Alejandra , Ohno-Machado Lucila , Rocca-Serra Philippe
Published: February 2020

Background

Data reuse is often controlled to protect the privacy of subjects and patients. Data discovery tools need ways to inform researchers about restrictions on data access and re-use.

Results

We present elements in the Data Tags Suite (DATS) metadata schema describing data access, data use conditions, and consent information. DATS metadata are explained in terms of the administrative, legal, and technical systems used to protect confidential data.

Conclusions

The access and use metadata items in DATS are designed from the perspective of a researcher who wants to find and re-use existing data. We call for standard ways of describing informed consent and data use agreements that will enable automated systems for managing research data.
Just Say No…to the Nocebo Effect
Authors: Rossmann Leah , Cross Raymond K
Published: February 2020

Biosimilars are highly similar products of an innovator biologic used to decrease costs. The nocebo effect is an increase in symptoms resulting from a patient’s negative perceptions about a biosimilar. Multistep notification, organized transition, and opt-out ability constitute a framework for switching patients from a reference product to a biosimilar.
Radiation-induced accelerated aging of the brain vasculature in young adult survivors of childhood brain tumors
Authors: Remes Tiina Maria , Suo-Palosaari Maria Helena , Koskenkorva Päivi K T , Sutela Anna K , Toiviainen-Salo Sanna-Maria , Arikoski Pekka M , Arola Mikko O , Heikkilä Vesa-Pekka , Kapanen Mika , Lähteenmäki Päivi Maria , Lönnqvist Tuula R I , Niiniviita Hannele , Pokka Tytti M-L , Porra Liisa , Riikonen V Pekka , Seppälä Jan , Sirkiä Kirsti H , Vanhanen Antti , Rantala Heikki M J , Harila-Saari Arja H , Ojaniemi Marja K
Published: February 2020

Background

Cranial radiotherapy may damage the cerebral vasculature. The aim of this study was to understand the prevalence and risk factors of cerebrovascular disease (CVD) and white matter hyperintensities (WMHs) in childhood brain tumors (CBT) survivors treated with radiotherapy.

Methods

Seventy CBT survivors who received radiotherapy were enrolled in a cross-sectional study at a median 20 years after radiotherapy cessation. The prevalence of and risk factors for CVD were investigated using MRI, MRA, and laboratory testing. Tumors, their treatment, and stroke-related data were retrieved from patients’ files.

Results

Forty-four individuals (63%) had CVD at a median age of 27 years (range, 16-43 years). The prevalence rates at 20 years for CVD, small-vessel disease, and large-vessel disease were 52%, 38%, and 16%, respectively. Ischemic infarcts were diagnosed in 6 survivors, and cerebral hemorrhage in 2. Lacunar infarcts were present in 7, periventricular or deep WMHs in 34 (49%), and mineralizing microangiopathy in 21 (30%) survivors. Multiple pathologies were detected in 44% of the participants, and most lesions were located in a high-dose radiation area. Higher blood pressure was associated with CVD and a presence of WMHs. Higher cholesterol levels increased the risk of ischemic infarcts and WMHs, and lower levels of high-density lipoprotein and higher waist circumference increased the risk of lacunar infarcts.

Conclusions

Treating CBTs with radiotherapy increases the risk of early CVD and WMHs in young adult survivors. These results suggest an urgent need for investigating CVD prevention in CBT patients.
Appeals to Authority in Political Rhetoric: Machiavelli in the Italian Parliament 1945–1994
Authors: Casiraghi Matteo Cesare Mario , Testini Francesco
Published: February 2020

Scholarship in rhetorical political analysis and parliamentary studies devoted little attention to study how politicians employ intellectuals’ authority and theories in their discourses. We offer methodological directions to navigate this territory, combining quantitative and qualitative analyses to investigate the employment of Machiavelli’s figure in the Italian Parliament. We show that Machiavelli is regarded as a contested authority and that appeals to his arguments can perform different rhetorical functions, which are countered with different rhetorical tactics. In particular, we show that the right appropriates the realist Machiavelli, especially in foreign policy, both as a national symbol and as a legitimate source of insights on political affairs, while the left and the centre resist these claims with alternative rhetorical tactics. Finally, we provide an original dataset and a new theoretical framework for future explorations of intellectuals and other authoritative figures’ rhetorical influence on politics.
The Merits of Bilateral Application of Bone-Conduction Devices in Children With Bilateral Conductive Hearing Loss
Authors: den Besten Chrisje A. , Vogt Katharina , Bosman Arjan J. , Snik Ad F. M. , Hol Myrthe K. S. , Agterberg Martijn J. H.
Published: February 2020

Objectives:

This study aims to characterize lateralization of sounds and localization of sounds in children with bilateral conductive hearing loss (BCHL) when listening with either one or two percutaneous bone conduction devices (BCDs).

Design:

Sound lateralization was measured with the minimum audible angle test in which children were asked to indicate from which of the two visible speakers the sound originated. Sound localization was measured with a test in which stimuli were presented from speakers that were not visible to the children. In the sound localization test, 150 ms broadband noise bursts were presented, and sound level was roved over a 20-dB range. Because speakers were not visible the localization response was not affected by any visual cue. The sound localization test provides a clear distinction between lateralization and localization of sounds. Ten children with congenital BCHL and one child with acquired BCHL participated.

Results:

Both lateralization and sound localization were better with bilateral BCDs compared with the unilaterally aided conditions. In the bilateral BCD condition, lateralization was close to normal in nearly all the children. The localization test demonstrated lateralization rather than sound localization behavior when listening with bilateral BCDs. Furthermore, in the unilateral aided condition, stimuli presented at different sound levels were mainly perceived at the same location.

Conclusions:

This study demonstrates that, in contrast to listening with two BCDs, children demonstrated difficulties in lateralization of sounds and in sound localization when listening with just one BCD (i.e., one BCD turned off). Because both lateralization and sound localization behavior were tested, it could be demonstrated that these children are more able to lateralize than localize sounds when listening with bilateral BCDs. The present study provides insight in (sub-optimal) sound localization capabilities of children with congenital BCHL in the unilateral-aided and bilateral-aided condition. Despite the sub-optimal results on sound localization, this study underlines the merits of bilateral application of BCDs in such children.