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Date submitted2023-09-05
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Date accepted2024-11-07
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Date published2025-02-25
Investigation of the accuracy of constructing digital elevation models of technogenic massifs based on satellite coordinate determinations
At all stages of the life cycle of buildings and structures, geodetic support is provided by electronic measuring instruments – a laser scanning system, unmanned aerial vehicles, and satellite equipment. In this context, a set of geospatial data is obtained that can be presented as a digital model. The relevance of this work is practical recommendations for constructing a local quasigeoid model and a digital elevation model (DEM) of a certain accuracy. A local quasigeoid model and a DEM were selected as the study objects. It is noted that a DEM is often produced for vast areas, and, therefore, it is necessary to build a local quasigeoid model for such models. The task of assessing the accuracy of constructing such models is considered; its solution will allow obtaining a better approximation to real data on preassigned sets of field materials. A general algorithm for creating both DEM and local quasigeoid models in the Golden Software Surfer is presented. The constructions were accomplished using spatial interpolation methods. When building a local quasigeoid model for an area project, the following methods were used: triangulation with linear interpolation (the least value of the root mean square error (RMSE) of interpolation was 0.003 m) and kriging (0.003 m). The least RMSE value for determining the heights by control points for an area project was obtained using the natural neighbour (0.004 m) and kriging (0.004 m) methods. To construct a local quasigeoid model for a linear project, the following methods were applied: kriging (0.006 m) and triangulation with linear interpolation (0.006 m). Construction of the digital elevation model resulted in the least aggregate value of the estimated parameters: on a flat plot of the earth’s surface – the natural neighbour method, for a mountainous plot with anthropogenic topography – the quadric kriging method, for a mountainous plot – quadric kriging.
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Date submitted2023-04-14
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Date accepted2023-08-02
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Date published2023-08-28
A method of determining the errors of segmented GRID models of open-pit mines constructed with the results of unmanned aerial photogrammetric survey
The methodology of building a digital elevation model based on the results of aerial photogrammetric survey from an unmanned aircraft is proposed, which is based on the division of the initial point cloud into equal segments. This allows, having made an assumption of the linear character of change of height of points in a separate segment, to approximate them by separate planes. RMS errors of the models from the survey data were calculated according to the scattering of the points in relation to the approximating surfaces, which made it possible to reveal the dependence of the model construction error relative to the sizes of their constituent segments, as well as to propose a method for filtering the cells containing outliers with respect to the expected model error. The proposed method was tested on the models of three mining objects – limestone quarry, phosphogypsum dump, and peat cut. The experimental results showed a multiple reduction in model error compared to standard DEM models providing the required accuracy for mining documentation.
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Date submitted2022-05-25
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Date accepted2023-02-02
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Date published2023-08-28
Evaluation of the shear strength of rocks by cracks based on the results of testing samples with spherical indentors
Experimental data on the relationship of the residual shear strength of rocks in closed cracks with the functional characteristics of intact rocks – the tensile and compressive components of adhesion, the roughness of the crack surfaces, and the level of normal stresses are presented. A unified integrated approach determines the shear strength of intact and destroyed rocks, the residual shear strength of closed rough cracks has been developed. The approach provides for the selection of stress intervals corresponding to different types of fracture, for each of which a strength criterion is proposed, expressed in terms of functional characteristics of intact rock. An express method for estimating the residual shear strength of rocks by cracks with a rough surface has been developed, in which an improved method of loading samples with spherical indentors is used as a basic test method. The express method implements the transition from the data of mechanical tests of samples with spherical indentors to the shear strength indicators for cracks in the rock mass, taking into account the level of normal stresses and the roughness of the crack surfaces measured in field conditions. In this case the roughness scale developed by Barton is used. The express method is informative and available in the fieldwork.
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Date submitted2022-06-20
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Date accepted2022-09-06
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Date published2022-11-03
Adaptive approach formation using machine vision technology to determine the parameters of enrichment products deposition
In this paper, an adaptive approach has been developed for automatic initialization of the thickening curve using machine vision technology, which makes it possible to determine with high accuracy the material parameters necessary for the design of thickening and clarification apparatuses. Software has been developed that made it possible to search for the coordinates of the condensation critical point in automatic mode. Studies on two samples of materials (tailings of apatite-containing ores and gold-bearing concentrate) were carried out and made it possible to statistically prove the reproducibility of the results obtained using the parametric criteria of Fisher and Bartlett. It has been established that the deposition curves are approximated with high accuracy by the Weibull model, which, together with the piecewise linear approximation, makes it possible to formalize the method for determining the critical point coordinates. The empirical coefficients of the Weibull model for two samples are found, and the final liquefaction and settling rates of the studied materials are determined.
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Date submitted2021-09-17
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Date accepted2022-04-07
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Date published2022-12-29
Technique for calculating technological parameters of non-Newtonian liquids injection into oil well during workover
Technique for automated calculation of technological parameters for non-Newtonian liquids injection into a well during workover is presented. At the first stage the algorithm processes initial flow or viscosity curve in order to determine rheological parameters and coefficients included in equations of rheological models of non-Newtonian fluids. At the second stage, based on data from the previous stage, the program calculates well design and pump operation modes, permissible values of liquid flow rate and viscosity, to prevent possible hydraulic fracturing. Based on the results of calculations and dependencies, a decision is made on the necessity of changing the technological parameters of non-Newtonian liquid injection and/or its composition (components content, chemical base) in order to prevent the violation of the technological operation, such as unintentional formation of fractures due to hydraulic fracturing. Fracturing can lead to catastrophic absorptions and, consequently, to increased consumption of technological liquids pumped into the well during workover. Furthermore, there is an increased risk of uncontrolled gas breakthrough through highly conductive channels.
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Date submitted2020-06-02
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Date accepted2021-05-21
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Date published2021-09-20
Analysis of technological schemes for creating a geodetic control at the industrial site
The article highlights the issues of creating with the necessary accuracy a planned control on the industrial site of the engineering structures under construction using satellite technologies and total stations. Depending on the design features of the engineering structures under construction, as well as the technological scheme for the installation of building constructions and industrial equipment, various schemes for creating such control are considered, based on the application of the inverse linear-angular notch. Errors in the source data are one of the main errors that affect the accuracy of geodetic constructions, including the solution of the inverse linear-angular notch. When creating a geodetic network in several stages, the errors of the initial data of the first stage affect the values of the root-mean-square errors (RMS) of determining the position of the second stage points, the errors of which affect the value of the RMS of the position of the third stage points, etc. The reason for their occurrence is the errors of geodetic measurements that occur at each stage of control creating, as well as the stability violation of the points during the production of excavation, construction and installation works. When determining the coordinates of a separate project point at the stage of its removal in-situ by a total station, the entire network is not equalized in the vast majority of cases, and the coordinates of the starting points to which the total station is oriented are considered error-free. As a result, the RMS determination of the points coordinates of the control network or the removal of the design points of the elements of building structures and equipment will also be considered satisfying the requirements, i.e. the measurement accuracy will be artificially overestimated and will not correspond to the actual one obtained. This is due to the fact that the accumulation of errors in the initial data is not taken into account when the number of steps (stages) of control creating increases. The purpose of this work is to analyze the influence of measurement errors and initial data when creating a geodetic control on an industrial site by several stages of its construction based on inverse linear-angular notches and a priori estimation of the accuracy of the determined points position.
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Date submitted2020-06-11
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Date accepted2021-03-30
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Date published2021-06-24
Crystal morphology of spherical viruses
- Authors:
- Yury L. Voytekhovsky
The article discusses modern views on the structure of spherical virus capsids, which have the shape of icosahedrons (icosahedral viruses). Each face of icosahedron is composed of a single-layer closest packing of protein globules, which can have different orientation relative to the edges of icosahedron. If the lines of globules are parallel to the edges of icosahedron, then the capsid has a point symmetry group I h (with symmetry planes), if they are not parallel – the symmetry group I (without planes). From a mathematical point of view, in both symmetry groups there are series that unite equally (up to similarity) arranged capsids. They are connected pairwise by transitions to dual forms (homologous series). A hypothesis is formulated that the largest spherical viruses can have even more diverse and complex capsid structures. Along with icosahedron, their basic forms can be any simple shapes, allowed in I h and I symmetry groups (8 in total). A suggestion is made that transitions within similarity series and between homologous series have a phylogenetic significance. There are known spherical viruses of both symmetry groups. For example, the SARS-CoV-2 coronavirus has a symmetry group I h and belongs to a well-known series. The crystallographic approach allows to construct a strict morphological classification of spherical viruses. This is important for their early recognition and separate examination. The article demonstrates practical application of crystal morphology in the study of viral systems – an urgent problem of geoecology and life protection.
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Date submitted2018-11-03
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Date accepted2019-01-21
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Date published2019-04-23
Estimation of critical depth of deposits by rock bump hazard condition
- Authors:
- V. N. Tyupin
During the development of minerals by the underground method, dynamic manifestations of rock pressure occur at a certain depth, which significantly reduces the safety of mining operations. Regulatory documents prescribe at the exploration and design stages to establish the critical depth for classifying a deposit as liable to rock bumps. Currently, there are a number, mainly instrumental, methods for determining the liability of rock mass to rock bumps and methods based on the determination of physical and technical properties and the stress-strain state of rock massifs. The paper proposes a theoretical method for determining the critical depth for classifying a deposit as liable to rock bumps. A formula for determining the critical depth of the rock bump hazard condition is obtained. A mathematical analysis of the influence of the physical and technical parameters of the formula on the critical depth is carried out. Its physical and mathematical validity is substantiated. The numerical calculations of the critical depth for 17 developed fields were carried out using a simplified formula. It also provides a comparison of calculated and actual critical depth values. It is established that the variation of the actual and calculated critical depth is due to the lack of actual data on the value of the friction coefficient and parameters of fracturing of the rock mass in the simplified formula. A simplified calculation formula can be used to estimate the critical depth of a field at the survey and design stages. More accurate results can be obtained if there are actual data on fracture parameters, friction coefficients and stress concentration near the working areas.
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Date submitted2017-10-31
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Date accepted2018-01-01
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Date published2018-04-24
Peculiarities of formation and growth of nanodispersed intermetallic strengthening inclusions in rapidly-solidified alloys of Al–Mg–Zr–X-system
- Authors:
- D. I. Budelovskii
- S. Yu. Petrovich
- V. A. Lipin
The paper is devoted to the influence of the fourth element on the microstructure of the rapidly-solidified alloys of the Al–Mg–Zr-system. Alloys were additionally doped with high-melting-point metals Ti, Hf, W, and Nb. In the structure of all samples in the immediate area of the cooled surface, uniformly distributed intermetallic inclusions of several nanometers in size were detected. Such a structure can be represented as a dispersion-strengthened composite. A quantitative metallographic analysis was carried out to quantitatively describe the structure of the obtained particles of the cooled melt. The obtained rapidly-solidified alloys can be described as dispersion-strengthened composite materials with the aluminum-magnesium alloy matrix and the intermetallic particles strengthener. Depending on the alloying component, these particles differ in shape (spheres, plates, agglomerates) and in size (from 200 nm when alloying with Hf and W up to 1.2-1.5 μm with Ti and Nb alloying). The X-ray phase analysis (XPA) showed that in the studied alloys of the Al–5Mg–1.2Zr–(0.5÷2.0)X-system, high cooling rates of melts lead to the formation of new intermetallic compounds that are absent in equilibrium systems. The example of an alloy with hafnium additive shows that an increase in the content of the alloying component (from 0.5 to 2 % by mass) leads to an increase in the volume ratio of intermetallic inclusions (from 5 to 12.8 %). At the same time, their shape and average size remain unchanged. The additional alloying component will improve the mechanical characteristics of aluminum alloys by increasing the recrystallization threshold of a rapidly-solidified alloy.
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Date submitted2015-07-14
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Date accepted2015-09-28
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Date published2016-02-24
Selection of rational heating temperature for pipeline pumping high-viscosity and high pour point crude oil
- Authors:
- A. K. Nikolaev
- V. I. Klimko
The article deals with the transportation problems of high-viscosity and high pour point crude oil through pipelines. The possibility of a structural oil movement mode development during transportation below the pour point is analyzed. The results of the experiment for unevenness of the heat flux identification in the underground pipeline are given.
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Date submitted2009-09-03
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Date accepted2009-11-05
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Date published2010-06-25
Multimedia presentations as an element of lecturer work in technical higher school
- Authors:
- N. A. Egorenkova
This article is devoted to methodological aspects of modern computer technologies introduction to liberal arts teaching in technical higher school. Question of reasonability of lectures accompaniment by multimedia presentation is depicted. The experience of Russian Language and Culture of Speech lectures multimedia presentation creation is described in the article, recommendations to blocks of presentation preparation are given, some methods of working with Microsoft PowerPoint program with the help of which studying process could be done more effective, multisided, attractive, dynamic, possible to stimulate students’ creative activity are described.