bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling and Analysis of Heat transfer of Resolder Furnace based on Thermodynamics
Authors: Liu Yunge 
Published: May 2021

Abstract
In the production process, the printed circuit board with all kinds of electronic components is placed in the rewelding furnace and the electronic components are automatically welded to the circuit board by heating. In this production process, the temperature control of the resolder furnace is very important to ensure the product quality. In this paper, by analyzing the heat transfer characteristics of rewelding furnace, the three-dimensional problem is transformed into one-dimensional problem, and the transient heat transfer process is studied and analyzed. Considering the two heat transfer modes of heat conduction and heat convection, the partial differential equation model of one-dimensional double-layer heat conduction is constructed, and the classical mathematical and physical method is used to model and simulate the heat conduction in the welding process of printed circuit board. the variation diagram of the furnace temperature curve and the temperature in the center of the welding zone at different positions in the small temperature zone are obtained.
Improved Method of Pasting and Fixing Metal Conduit Heating Tape
Authors: He Yun , Du Ruizhao , Zhang Qiang 
Published: May 2021

Abstract
In the development process of my country’s spacecraft, the heating of the working medium in the metal conduit primarily adopts the method of winding a heating tape on the outer wall of the metal conduit. Silicone rubber is usually used as the filling medium to reach good heat transfer between the heating tape and the metal conduit. The heating tape winding and fixing method of the cotton thread used at this stage has disadvantages such as time-consuming, labor-intensive, and low work efficiency. Based on the experience of the spacecraft’s final assembly, a method of winding and fixing the heating tape with a fixing clip is proposed in this paper. This method is simple and convenient, improving the efficiency of pasting and winding the heating tape of the metal conduit.
Research on a New Type of Electronic Audio Communication system
Authors: Wang Guimin , Wang Linfeng , Wang Zihao 
Published: May 2021

Abstract
Bluetooth technology realizes the wireless data transmission between modern communication equipment and the Internet, which greatly improves the efficiency of office and communication. This research is based on matlab/simulink as the development platform to realize the simulation of Bluetooth voice transmission system. The system is composed of master transmitter, slave receiver and transmission, interference, signal source, error table and signal display unit. through simulation, the frequency spectrum of frequency hopping signal, Bluetooth signal, 802.11 and slotting signal time domain diagram are obtained. The system improves students’ understanding and design ability of data wireless transmission technology.
Evaluation of Intelligent Air Defense algorithm based on Machine Learning
Authors: Guo Jiayuan , Zhao Zirui , Zhou Jinghao 
Published: May 2021

Abstract
In the complex and rapidly changing combat environment, the enemy interference and sensor performance limitations and other factors lead to insufficient battlefield information. In order to make the UAV have the ability to carry out threat assessment under the condition of insufficient information, a Bayesian network (BN) threat assessment modeling method based on small data sets is proposed in this paper. Starting with the two problems of BN structure learning and parameter learning under the condition of small data set, using the constraint matrix obtained by Bootstrap method as the constraint item added to the score function, a BN structure learning algorithm based on small data set is proposed, and the BN parameter learning algorithm based on interval prior constraint is adopted. The simulation results show that, compared with the traditional BN learning algorithm, the BN learning algorithm proposed in this paper has higher accuracy and availability in UAV threat assessment modeling under the condition of small data set.
Physical modeling of rocks on the basis of rock–gas–moisture composites
Authors: Kurlenya MV , Rostovtsev VI , Kulagin RA , Kulagin OR , Sivolap BB 
Published: May 2021

Abstract
The issues of obtaining and investigating composites consisting of coal and rock solid particles, gases (methane, hydrogen) and moisture, as well as approaches to mechanisms initiating catastrophic dynamic phenomena in mining are discussed. On the samples of different materials (coal, limestone, graphite, etc.) using the developed test bench, the dependences of physico-mechanical properties of cores on pressure are established. For longflame coal of various size, the features are shown for changing the temperature of briquette mass in increasing pressure up to 200 MPa. The composites imitating natural coal and other rocks are created.
Development of static and kinematic approaches in geomechanical problems
Authors: Mirenkov VE 
Published: May 2021

Abstract
The hypothesis of a linear stress field of a rock mass undisturbed by driving workings underlies the solution to many problems of rock mechanics. The problem of rock pressure control requires knowledge of the stress-strain state of the rock mass in the vicinity of workings, which causes the development of analytical and numerical methods for calculating the deformation. When the methods of numerical calculation were not sufficiently developed, the analytical capabilities of the selection of stress functions were used, which satisfied the conditions of small strain elasticity theory. The greatest success in this direction was achieved for the areas with angular points. The development of numerical methods shifted the point of influence of investigations to calculating the deformation of specific cases arising in a rock mass with workings. It is established in the work that analytical solutions for the areas with angular points are incorrect, and numerical solutions of Cauchy problems are also incorrect if an additional problem is not considered.
Solution of three basic problems of elasticity for half-plane
Authors: Mirenkov VE 
Published: May 2021

Abstract
Solution of elastic problem for half-plane is of the highest concern in almost every field of engineering. However, there are no relations binding the values of all components of the stress-strain state at the half-plane boundary This paper shows that arbitrary formulation of the boundary conditions considerably simplifies integral equations and transfers them to the class of Fredholm’s first kind equations. Considering symmetry, the problem for half-plane with mathematical cut is reduced to the problem on half-plane boundary. Regardless of the method, any solution is reduced to ill-posed problem.
Development of experimental plant for investigation of coal adsorptive capacity using methane
Authors: Rybalkin LA , Shilova TV 
Published: May 2021

Abstract
A thermostatic plant for studying the adsorptive capacity and permeability of coal core was developed. The plant design allows to saturate coal with methane and to filter gas at various values of axial and lateral compression of the sample. The use of an automated system for recording differential pressure and gas volumes in the inlet and outlet tanks eliminates the need for manual control, which is especially important during long-term testing of low-permeable coals.
Analysis of coal seam degassing efficiency using boreholes and hydraulic fracturing
Authors: Serdyukov SV , Kurlenya MV 
Published: May 2021

Abstract
The effect produced by hydraulic fracturing on the filtration resistance of coal seam zone subject to drainage by parallel boreholes is considered. The resistances to the gas inflow depending on the orientation of fractures, thickness of seam, and distance between the boreholes are analyzed. The efficiency of single and multistage hydraulic fracturing in forming multiple transverse and main longitudinal cracks is compared.
New methods for signal digital processing to determine the parameters of seismic wave propagation models
Authors: Serdyukov AS , Yablokov AV , Chernyshov GS 
Published: May 2021

AbstractThe methods based on the use of time-frequency representations are proposed. The useful signal is reconstructed from the amplitude peaks of time-frequency spectrograms obtained by S-transform. As a result of numerical experiments, it is shown that using narrow time-frequency intervals (about 10–20 time reports), it is possible to determine the parameters of a pulsed-type signal with substantially longer duration.
Effect of confining pressure on pendulum wave spectra recoded in block media under seismic loading
Authors: Sher EN , Chernikov AG 
Published: May 2021

Abstract
Effect of external compression on seismic waves in rock mass was tested on one-dimensional models of block media subjected to impulsive loading. It is shown that a low-frequency pendulum wave appears at the shock wave head as a result of dispersion. The pendulum wave parameters are governed by the mass of blocks and by the yielding properties of block interfaces. External compression increases stiffness of block interfaces, which leads to an increase of the wave velocities and to a change of the wave spectra. The model experiments tested the possibility of external compression assessment from the parameters of pendulum wave spectra.
Features of seismic wave travel along a coal pit wall
Authors: Yushkin VF 
Published: May 2021

Abstract
Triple gain of the maximum amplitudes or massif vibrations in a final phase of the consecutive blasting of groups of borehole charges during the propagation of a seismic blast wave outside the mined block in the Quarternary deposits of a coal mine slope has been experimentally established. The effect of “rocking” the massif occurs stepwise, and it is synchronized according to the selected delay intervals at detonation.
A method for calculating loads on roof support in mines
Authors: Seryakov VM 
Published: May 2021

Abstract
The author proposes an approach to the stress–strain analysis of mine support with regard to all displacements of the stope boundary until it makes contact with the support using the stiffness matrix of intact rock mass. Modeling of the void formation and of the joint deformation of the support and adjacent rock mass uses iterative procedures from the methods of initial stresses and initial strains. The support load algorithm and software package are developed.
Assessment of natural horizontal stresses and deformation characteristics of load-bearing elements in room-and-pillar mining by inverse problem solution using mine survey data
Authors: Panov AV , Miroshnichenko NA 
Published: May 2021

Abstract
The authors discuss assessment of deformation characteristics of load-bearing elements in room-and-pillar mining system and natural horizontal stresses. This method is based on solution of mixed-type inverse problems using a two-dimensional elastic model. Numerical calculations for a typical mine geometry using synthetic input data (relative displacements of mine void boundary points, recorded using mine survey techniques) have found the required data amount sufficient to ensure unambiguous solvability of inverse problem.
Safe and ecological performance of mining and processing industry
Authors: Kovalenko KA 
Published: May 2021

Abstract
Mineral mining and processing activities result in highly toxic arsenic-bearing waste water discharged in natural water bodies. The promising methods of arsenic removal from waste water use adsorption at natural sorbents and oxidizers. The tests of arsenic removal by adsorption at magnesium- and manganese-bearing minerals show that the use of these natural raw materials can greatly enhance efficiency of the environmental activities in the mining and processing industry.
Test bench to study drying of geomaterials in vibratory conveying
Authors: Kulikova EG , Dudina AM 
Published: May 2021

Abstract
The authors review vibrating machines used to convey and dry different geomaterials. The article describes the structural layout of a vibrating device with an elastic operating component designed at the Institute of Mining, SB RAS for the simultaneous conveying and drying of loose materials. The experimental test bench is applicable to studying influence of dynamic parameters of the elastic conveying component on the efficiency of drying of granular materials.
Justification of layout diagrams hydraulic percussion mechanisms by the comparative analysis of dynamic parameters
Authors: Cheshchin DO , Rechkin AA , Danilov BB 
Published: May 2021

Abstract
The simulation models are used to compare achievable dynamic parameters of layout diagrams of hydraulic percussion mechanisms having similar size and weight. The comparison results prove application feasibility of these layouts in engineering hydraulically driven percussion machines. The optimization methods are used to find the optimal values of design variables to meet the criterion of maximal blow energy.
Physical modeling of ring-shaped elastic valve operation in hydraulic percussion mechanism
Authors: Plokhikh VV , Danilov BB 
Published: May 2021

Abstract
The paper proves usability of elastic lock-and-control valves in hydraulic percussion mechanisms. The requirements imposed on positive-displacement impact machines for rock drilling are substantiated. The dedicated test bench for determination of actuation conditions of the elastic valve is described. The experimentation procedure, sequence and data are presented.
Tensile strength test and fracture toughness test of cores with axial hole
Authors: Efimov VP 
Published: May 2021

Abstract
This studies approves the the tensile stress tests of rock specimens with axial holes of different diameters under loading along the diameter. The test results are presented for core specimens of rocks and some equivalent materials. The test data are processed using the criterion of fracture gradient and the integral criterion of fracture. The values of tensile strength and fracture toughness obtained using this approach and by the standard technique are compared.
Heat losses in train movement in transportation tunnels in different operating conditions
Authors: Lugin IV , Alferova EL 
Published: May 2021

Abstract
The paper describes the results of numerical modeling of heat exchange between trains and air in transportation tunnels operated in the conditions of dry continental climate in Siberia and Russian Far East in cold seasons. The modeling uses a nonstationary 2D axially symmetrical formulation. The relationships have been obtained for the components of heat balance in transportation tunnels and the outside air temperature and the process conditions of operation of the tunnel entry equipment.
Experimental study of two-way hydraulic percussion device operation in vibro-impact drilling in rocks
Authors: Kudryavtsev VG 
Published: May 2021

Abstract
The authors describe the physical model of a hydraulic percussion device with frequency adjustment using standard flow rate controller and impact energy adjustment using an original throttle control of flow distribution, which allows dragging the hammering piston before its back run. The operating cycle characteristics required for the analysis of this system dynamics are obtained in a series of tests. Recommendations on improvement of operation of the hydraulic percussion device are given.
Review of the placer mining methods with regard to geotechnical conditions and climate in Yakutia
Authors: Silin SA 
Published: May 2021

Abstract
The author reviews the current situation in opencast mining placers in Yakutia and characterizes geotechnical conditions and climate in the major mining regions in the Republic. In the most placers under mining, sands and peat have thickness of 1.5–1.6 and 5.2 m, respectively. Dozer cutting is applicable to peat with maximum thickness of 15.2 m; the combinations of dozer–shovel–dump truck and dozer–loader–dump truck are bet suitable t peat thicknesses f 17.5 and 11.5 m, respectively. Permafrost rocks are widely prepared to mining through natural thawing (71–76% in the Aldan, North and East regions). The common method of stripping is dozers. The most popular method of actual extraction is the combination of dozer–loader–dump truck. The most efficient approach to stripping is the combination of dozer–shovel–dump truck as its cost is lower than in striping with dozers or with the dozer– loader combination.
Rock slope stability assessment toward elimination of accidents
Authors: Zharikov SN , Taranzhin SS , Kutuev VA 
Published: May 2021

Abstract
The authors assess the effect of seismic vibrations induced by blasting in Biyanka gravel quarry and by movement of trains. The research was initiated in view of the accident in summer of 2017, which resulted in off-trip of two cars. The jointing structure of the rock slope is inspected, and the slope stability is assessed in some sites of the slope within the limits of the Asha railway haul. The recorded seismic vibrations in the rockfall-hazardous sites of the slope are less hazardous for the slope stability than the geological features of the slope, which are the cause of all rock falls. The recommendations on prevention of rock falls on the track are given.
Application of probabilistic clustering analysis to rockburst hazard assessment of rock mass
Authors: Gladyr AV , Tereshkin AA , Rasskazov MI , Konstantinov AV 
Published: May 2021

Abstract
The team of researchers from the Institute of Mining, FEB RAS have developed the rockburts hazards assessment procedure which enjoys successful application in Russian mines. The main objective of the procedure is the continuous computer-automated geomechanical monitoring of rock mass behavior, identification of seismically active zone and determination of static and dynamic parameters for rockburst hazard prediction and assessment in the detected zones. This paper co-authors propose an algorithm to identify fracture souse zones in rock mass and to calculate parameters of these zones by geomechanical monitoring data and using the methods and tools of nonparametric density estimate and probabilistic clustering analysis.
Provisions for higher mining efficiency with regard to cluster arrangement of mineral deposits
Authors: Batugina NS , Khoyutanov EA , Andreev YuP 
Published: May 2021

Abstract
Cluster (discrete) arrangement of minerals and their aggregates in different vectors in space is typical of most placers and deposits. Large and small pockets of valuable components in mineral bodies have different shapes, sizes, formation conditions and other geological characteristics. Cluster arrangement exists on all scales: an ore province in a region; an ore zone in an ore province; a deposit in an ore zone; an ore body in a deposit; an ore pillar in an ore body; pay zones in an ore pillar, nest, etc. By analogy with taxonomy and image identification, for differentiation of mineral resources by their processing properties or commercial value, space-detached accumulations of points representing some mineral objects are assumed as clusters with increased or lowered content of useful components. Structural order and clustering are the common features of many mineral deposits. Accurate geometrization of placers with regard to useful component content, inclusion of spatially variable quality conditions of useful components and proper management of mining favors reduction in volume of rock mass to be extracted, hauled and processed by 2 times at the same recovery factor of useful component; make it possible to increase cutoff grade by 2 times, and enables increment in production of useful component within the same production areas and at the same production capacities.
Investigation into the release of gravity-recoverable gold particles in products of a dynamic-impact mill
Authors: Lvov ES 
Published: May 2021

Abstract
The experimental data on assessment of the gravity-recoverable gold release in disintegration of lumpy gold-bearing geomaterials at dynamic-effect crushers DKD-300, designed at the Mineral Processing Laboratory at the Institute of Mining of the North, SB RAS, Yakutsk. The tests on gold-bearing ore originated from Gurbey deposit, made it possible to establish experimentally that the multiple-dynamic-effect facility enabled to release up to 47% gravity-recoverable gold of -1 mm in size.
Ventilation in long blind stopes during operation of load–haul–dumpers with combustion engines
Authors: Nakaryakov EV , Grishin EL 
Published: May 2021

Abstract
The paper describes the in-situ test data and mathematical modeling results on ventilation in long (more than 10 m) blind stopes during operation of load–haul–dumpers with combustion engines. The change in the toxic gas concentration versus the running time of the machinery in the stopes is determined, and the appropriate relations are derived.
Upgrading of qualitative characteristics of Yakutia brown coals
Authors: Popova KS 
Published: May 2021

Abstract
In Yakutia the fuel-and-energy balance involves low-grade brown coals originated from Kangalas, Kirov and Kempendyay deposits. The techniques to improve the efficiency of utilization and conservation of these coals involve classification of coals and burning of coarse-size products, enrichment, and briquetting of fine coal products. The last technique permits to upgrade the poor-grade coals of low demand and to produce the full-value fuel coal, convenient for transportation, long storage and effective combustion. The experimental results are given on the agglomeration of Kirov brown coal by briquetting with the introduction of polyethylene crumbs into the briquetting blend. This addition promotes 20 % increase in combustion heat as compared to this parameter for the original coal. The researchers propose the technological scheme for classification, preparation, follow-on briquetting of brown coals. The urgency of a local classification-and-briquetting plant is pointed out.
Mathematical modeling of heavy particle concentration in a jig bed
Authors: Sleptsova ES , Yakovlev BV 
Published: May 2021

Abstract
The mathematical model for motion of heavy particles surrounded with grains in a jig is proposed in the present paper. The grains are modeled by balls of a certain radius. The statistical approach to the process description is considered. The Brownian particle motion model is used, where the researchers consider and take into account the kinetic energy of grains surrounding the bead of a heavy particle moving under the influence and power of the vibrating jig, rather than the kinetic energy of the random thermal motion of the molecules bombarding the Brownian particle. This force depends on the amplitude and frequency, being, the parameters of the jigging cycles. The mathematical modeling allowed derivation of the Fokker-Planck-type equation for fractions distributed by density in the jig chamber. The dynamic curves for distribution of heavy grains along the height of a jig bed are obtained.
Fracture of quasi-brittle geomaterials with a circular hole under compression
Authors: Suknev SV 
Published: May 2021

Abstract
The new nonlocal fracture criteria are proposed, which are the extension of the average stress criterion and the point stress criterion, and which contain a complex parameter that characterizes the size of the fracture process zone and accounts not only for the material microstructure, but also ductile properties of the material, geometry of the specimen, and its loading conditions. The formulas are obtained for the critical pressure in the problem of tensile fracture initiation in the specimens of geomaterials containing a circular hole and subjected to uniformly or nonuniformly distributed compression. The results of the calculations are in good agreement with the experimental data on failure of gypsum plates with a hole.