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Beltek, M., e O. Frolov. "Determination of the influence of the degree of fracturing of the rock mass on the index of reduction of its strength". Collection of Research Papers of the National Mining University 74 (setembro de 2023): 7–18. http://dx.doi.org/10.33271/crpnmu/74.007.
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Purpose. The purpose of research of the presented scientific publication is to establish the regularity of changes in the generalized coefficient of strength reduction of disturbed rock massif depending on the degree of rock fracturing. Research methodology. To solve the set tasks we applied a complex approach, which consists in the analysis and generalization of previous studies on the study of the change in the strength of the rock massif depending on the degree of fracturing, scientific and technical justification of the possibility of generalizing the studied strength indicators of the disturbed massif, approximation of graphs of the change in the structural weakening coefficient, RQD and RMR depending on the fracture modulus. Research results. Scientific data of domestic scientists on determining the value of the structural weakening coefficient depending on the factors affecting the overall strength of the rock massif, and foreign scientists on establishing indicators of the state of disturbed rock massifs have been analyzed. To summarize the results of the presented assessment methods, the changes in the structural weakening coefficient, RQD and RMR indices depending on the fracture modulus of the rock massif are combined in one graph. Alignment of the mentioned graphical dependences showed the identical character of their changes. The curve of approximation (trend) for graphical dependences of the structural weakening coefficient, RQD and RMR on the fracture modulus, which can be described by a polynomial of the 3rd degree, has been obtained and the value of approximation reliability R²= 0.8975 has been established. Scientific novelty. The idea of methods and indicators for assessing the state of disturbance of rock massifs depending on various factors has been developed. The analytical dependence of the change of the generalized coefficient of strength reduction of a rocky rock massif on the fracture modulus has been obtained. Practical significance. The established influence of rock fracture modulus on the degree of strength reduction of rock massif allows to determine reliable data on the condition of ledges and sides of the quarry and to develop organizational and technical measures for further development of technology of their mining.
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Dmitrienko, Vladimir, Nadejda Dmitrienko e Аleksandr Bogomazov. "Impact of “wet conservation” of mining enterprises on constructing buildings of lightweight materials". E3S Web of Conferences 284 (2021): 05013. http://dx.doi.org/10.1051/e3sconf/202128405013.
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The analysis of the influence of flooding of the developed areas of closed mining enterprises on the mechanical characteristics of clay rocks is given. The deformation characteristics of clay shale under prolonged moistening conditions have been experimentally established and proved. Simulation of stress-strain state of soil massifs and building structures by method of finite elements is considered and the influence of power of developed spaces on settlement of building foundations of buildings of light materials is established. The distribution of vertical displacements in the rock massif is presented, the graphs of the dependence of the foundation settlement on the excavation power are plotted, the excess of the standard values of settlement is noted when buildings are located directly above the preparing workings.
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Dongak, Dzhamil Aiyr-Sanaaevich, Artysh Valerievich Mongush, Chinchi Buyanovna Mongush e Shydar Orlanovich Chuldum. "A distance study of seasonal dynamics of the vegetation index (NVDI) of the Mongun-Taiga massif vegetation cover". Samara Journal of Science 11, n.º 4 (1 de dezembro de 2022): 22–29. http://dx.doi.org/10.55355/snv2022114103.
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This paper analyzes seasonal dynamics of the Mongun-Taiga massif vegetation cover from February to October 2022 based on the application of the NDVI vegetation index using Sentinel-2 satellite imagery data. To analyze the seasonal dynamics of the vegetation index of the Mongun-Taiga massif, 15 points on the valleys of five rivers were selected they are the Tolaity River (south side), the Holash River (west side), the Balyktyg River (north side), the Right-Mugur River (north-east side) and the Shara-Khoragai river (east side). The graphs of the vegetation cover of different exposures of the massif slopes show that the highest values are represented at the western side of the massif (the Holash River), then on the southern side (the Tolaity River) and then on the northern side of the massif (the Balyktyg River). The valleys of the Shara-Khoragai River (east side) and the Right-Mugur River (north-east side) have the lowest indicators of vegetation cover. Different curves of the vegetation cover graphs for different exposures of the massif explain that the climate in this area is very complex. Terrain, slope exposures, humidity, strength and direction of winds, sunlight, temperature, slopes of selected points, as well as watercourses affect vegetation cover differently. For a more thorough study, it is necessary to obtain higher-resolution images and conduct ground-based measurement work to assess the state of the vegetation cover of the massif and obtain accurate meteorological data.
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Ter-Martirosyan, Zaven G., Armen Z. Ter-Martirosyan e Yuliya V. Vanina. "Long-term settlement and bearing capacity of foundations adjacent to vertical excavation at various parameters of soil viscosity". Vestnik MGSU, n.º 12 (dezembro de 2022): 1664–76. http://dx.doi.org/10.22227/1997-0935.2022.12.1664-1676.
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Introduction. When the underground part of a high-rise building interacts with the surrounding soil massif behind the excavation pit, a complex heterogeneous stress-strain state occurs, transforming in space and time — during construction and during the exploitation of the building. Special issues arise when the soil massif is heterogeneous and has rheological properties, and an additional load acts near the pit excavation at the same time.
Materials and methods. For the problem of the stress strain statement of soil with a weight behind the enclosure of a pit with a depth h, taking into account the influence of a distributed load q = const with a width b = 2a at a distance c from the edge of the enclosing structure of the pit, the stress components were obtained using a solution based on the Ribier – Filon trigonometric series. To determine the settlement over time of the foundation near the pit, the A.Z. Ter-Martirosyan’s model was used. To describe shear deformations and the Kelvin – Foigt’s model was used to describe volume deformations, assuming that ε.z(t) = ε.v(t) + ε.γ(t), according to the Henky’s system of physical equations.
Results. An analytical method has been developed for quantifying the settlement of soil bases and foundations of nearby buildings behind the pit over the time. The graphs of the settlement-time with double curvature, as well as the graph of the long-term stability of the base are obtained.
Conclusions. The solutions obtained can be used to determine the long-term settlements and bearing capacity of the foundations of buildings and structures with rheological properties near the pits. The selected geomechanical model of the foundation (its geometric parameters, initial and boundary conditions), as well as the computational model of the soil (linear, nonlinear and rheological) and the type of physical equations (Hooke system or Henky system), significantly affect the type of the settlement-time curve (S–t), as well as the bearing capacity of the soils. Collaborative using of A.Z. Ter-Martirosyan’s rheological model and Kelvin – Foigt’s rheological model makes it possible to obtain settlement-time graphs with double curvature, as well as a graph of the long-term stability of the soil base.
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Kuzmenko, Eduard, Sergiy Bagriy, Inna Artym e Volodymyr Artym. "GEODYNAMICS". GEODYNAMICS 2(33)2022, n.º 2(33) (2022): 64–74. http://dx.doi.org/10.23939/jgd2022.02.065.
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The purpose of the research is to substantiate the theoretical prerequisites for the interpretation of the geophysical method of the Earth's natural pulsed electromagnetic field (ENPEMF). The justification will be performed by quantifying the stress state of the rock massif, modeling of the obtained analytical dependencies for disturbed massifs. The basis for the interpretation is the coordination of the obtained distributions of intensity with the intensity of the electromagnetic field. The initial data are classical formulas of theoretical mechanics, modified to the conditions of the geological structure of the object of research and long-term research by the method of ENPEMF at the object – Kalush-Golynsky potassium salt deposit in the Pre-Carpathian. The research methodology included the development and presentation of models of the stress-strain state of the mining area, followed by the calculation of specific distributions of stress and analysis of their relationship with the dynamics of ENPEMF for specific areas of regime observations. The results of the research are given in the following sequence: 1) an example of calculating model stresses; 2) practical results of ENPEMF; 3) comparison of theoretical model calculations and real observations' data. Examples of calculations are given for a rock massif including a rectangular-shaped mining operation located in a salt formation. The distribution of stresses is calculated for the 2D model, taking into account the actual physical parameters. The series of graphs shows the change in tension both along the profile and with depth. The model is complicated for a variant of two chambers located at different depths. Observation of ENPEMF is demonstrated for a complex section of rocks. Actual plots of the field intensity with a high degree of correlation correspond to the calculated plots at a certain depth. The complication of the section and the presence of different stages of the postoperative period, which is reflected in the regime observations, leads to the deviation of the form of the graphs from the "ideal-model", but at the qualitative level this form corresponds to the theoretical one. The novelty lies in the development of the principles of quantitative assessment of the stress-strain state of the disturbed rock mass as the basis for the theoretical assessment of the distribution of the natural pulsed electromagnetic field of the Earth. In particular, the identity of the results of practical geophysical observations and computational models of the stress-strain state is demonstrated. The results obtained should be considered as a contribution to the theoretical basis of the quantitative interpretation principles of the geophysical method of ENPEMF. At the same time, the ways of further research for the full implementation of this research area are indicated.
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Sokornov, Anton, Aleksandr Kon'kov, Anatoliy Novikov e Andrey Benin. "Factors Affecting Additional Pressure Distribution from Ground Construction on Subway Tunnels". Proceedings of Petersburg Transport University 19, n.º 2 (22 de junho de 2022): 367–77. http://dx.doi.org/10.20295/1815-588x-2022-19-2-367-377.
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Purpose: To analyze the factors affecting pressure distribution from ground construction on subway tunnel linings. Method: Mathematical modeling by finite element method of a system that includes a soil massif, an interstation tunnel lining and a load from ground building foundation. Results: The type of additional pressure distribution graph from ground construction inviolate massif and in the massif, which stress-strain state is distorted by tunneling, is established. It is found that the change of additional pressure is directly proportional to load change as by depth as well as by distance from foundation axis; this law is preserved at any other parameter change (in inviolate soil massif and in the massif which stress-strain state is changed by tunneling, at various ways of tunneling modeling, at the use of various geomechanical soil models). It is established that the value of additional pressure from ground construction practically doesn’t depend on tunneling modeling method. The difference between the results at soil description via Mohr-Coulomb model and via its modification is substantiated. Practical importance: It is shown the possibility to determine accurately the amount of additional pressure from ground construction on tunnel lining without having information on tunneling method.
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Alkhdour, Ahmad, Anatolii Radkevych, Oleksii Tiutkin e Nataliia Bondarenko. "Prediction of the stress-strain state of circular workings in a layered massif by scaling". E3S Web of Conferences 168 (2020): 00020. http://dx.doi.org/10.1051/e3sconf/202016800020.
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The scientific and technical task for determining the stress-strain state of mine workings is complicated by the presence of a layered massif. This task assumes particular importance in the case of circular tunneling. During its operation, it is important to predict the change of the stressstrain state for the massif or to carry out the prompt determination in the change of stresses and displacements for the unsupported working. The solution of this geomechanical task allows performing geometrical matching of the working, ensuring its strength and stability in the layered massif. A numerical finite element method based on StructureCAD (SCAD) software package was used to solve it. Four geomechanical systems were calculated: “unsupported working – layered massif”. Owing to the obtained results, graphs of stresses and displacements were constructed, which allow to determine these parameters for workings with different geometric parameters and X-parameter characterizing the ratio of the elasticity modulus of the matrix and the layer. Obtained regularities of change of stresses and displacements for the unsupported working when zooming made it possible to introduce scaling-parameters, which are a dimensionless ratio of the radii for a real system and a system with a unit diameter.
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Vidal, Muriel, Daniel Goujet, Philippe Janvier e Hubert Lardeux. "Micro-restes de Vertébrés du Calcaire de La Grange, Dévonien inférieur (Emsien) du Sud-Est du Massif Armoricain [Fish remains from the La Grange Limestone, Lower Devonian (Emsian), South-Eastern Armorican Massif". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 194, n.º 2-3 (21 de dezembro de 1994): 321–41. http://dx.doi.org/10.1127/njgpa/194/1994/321.
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Atrassi, Fatima E. L., Fabrice Brunet, Mohamed Bouybaouene, Christian Chopin e Gilles Chazot. "Melting textures and microdiamonds preserved in graphite pseudomorphs from the Beni Bousera peridotite massif, Morocco". European Journal of Mineralogy 23, n.º 2 (3 de maio de 2011): 157–68. http://dx.doi.org/10.1127/0935-1221/2011/0023-2094.
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Subbotin, Ignat. "Discrete and continuous models in calculating the bearing capacity of soil massifs reinforced with geosynthetics". Construction and Architecture 8, n.º 4 (15 de outubro de 2020): 28–36. http://dx.doi.org/10.29039/2308-0191-2020-8-4-28-36.
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The article discusses continuous and discrete models of the soil environment on the examples of calculations under the action of a strip load with surcharge on a plane. The options for calculating both slopes and soil base for foundations in natural, artificial and composite environments are considered. A theoretical method for calculating the bearing capacity of a composite medium of a subsoil that is anisotropic in shear resistance is presented. Formulas and graphs of the results of calculating the compared soil conditions are given and their quantitative assessment of strength in comparison with the natural environment is given.
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V. P. KUPRIY, O. L. TIUTKIN e P. YE. ZAKHARCHENKO. "ANALYSIS OF FEATURES OF APPLIED SOFTWARE “LIRA” IN CALCULATIONS OF NON-CIRCULAR TUNNEL LININGS". Bridges and tunnels: Theory, Research, Practice, n.º 12 (21 de maio de 2019): 41–50. http://dx.doi.org/10.15802/bttrp2017/167404.
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Purpose. The article examines the effect on the stress-strain state of the parameters of the finite-element model created in the “Lira” software package in a numerical analysis of non-circular outlined tunnels. Methodology To achieve this goal, the authors developed finite element models of the calotte part of the mine during the construction of a double track railway tunnel using “Lira” software. In each of the models in the “Lira” software package, the interaction zone with temporary fastening was sampled in a specific way. After creation of models, their numerical analysis with the detailed research of his results was conducted. Findings. In the finite element models, the values of deformations and stresses in the horizontal and vertical axes, as well as the maximum values of the moments and longitudinal forces in the temporary fastening were obtained. A comparative analysis of the obtained values of the components of the stress-strain state with a change in the parameters of the finite element model was carried out. The graphs of the laws of these results from the discretization features of the two models were plotted. The third finite element model with a radial meshing in the zone of interaction of temporary support with the surrounding soil massif was investigated. Originality It has been established that in the numerical analysis of the SSS of a tunnel lining of a non-circular outline, its results substantially depend on the shape, size and configuration of the applied finite elements, on the size of the computational area of the soil massif, and also on the conditions for taking into account the actual (elastic or plastic) behavior of the soil massif. Practical value. The features of discretization and the required dimensions of the computational area of the soil massif were determined when modeling the “lining – soil massif” system, which provide sufficient accuracy for calculating the parameters of the stress-strain state of the lining.
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Pidlutskyi, Vasyl, e Vasyl Behan. "Identification of soil parameters in the calcu-lation of high-rise buildings on pile foundation". Bases and Foundations, n.º 44 (27 de junho de 2022): 19–26. http://dx.doi.org/10.32347/0475-1132.44.2022.19-26.
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The results of numerical modeling of the interaction of bored piles with the soil environment are presented. The process of identifying soil parameters according to static tests of piles was studied. The parameters of the soil, which have the greatest influence on the change in the graph of the dependence of the pile settlement on the load, are singled out.
The research process can be divided into the following stages: creation of a numerical model of the interaction of the pile with the volumetric soil array in the PC «LIRA-Sapr». The size of the array is 30x30x40 m, based on the research of scientists [1]. The pile is defined be a rod finite element (pile length 30 m, diameter 0.82 m). The array is defined by non linear finite elements with characteristics according to data from engineering and geological studies. The load is applied step by step (10 steps) with a maximum value of 600 ton-forces. 4 variants of the volumetric soil massif with different values of the modulus of elasticity were considered. In the first variant, the modulus of elasticity is unchanged, in the second it is increased by 2 times, in the third by 3 times and in the fourth variant by 4 times. The modulus of elasticity increased simultaneously in all elements of the soil massif. According to the calculation, it was established that when the elasticity modulus is increased by 4 times, the graph of the dependence of the settlement on the load is close to the graph of field tests. Further, the identification of the angle of internal friction was carried out, with an increased modulus of elasticity by 4 times. It was established that in the soil model with the angle of internal friction taken with a factor of 0.5, the settlement graph of the test pile is very close to the test graph. Therefore, for the calculation of the «base – foundation – above-ground structures» system, it is customary to increase the elasticity modulus by 4 times and take the angle of internal friction with a factor 0.5.
The calculation of the «base – foundation – above-ground structures» system for a high-rise building with identified soil parameters and with parameters that were before identification was performed. The stress- strain state of foundation structures for two variants of soil conditions was investigated. Redistribution of forces in foundation structures with both variants of soil parameters is given
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Polishchuk, M., M. Tkach, O. Zhuchenko e Y. Kornaga. "Mobile robot for monitoring park trees: Design and modeling". FME Transactions 51, n.º 3 (2023): 423–31. http://dx.doi.org/10.5937/fme2303423p.
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One of the modern problems in the field of ecology is the creation of environmentally friendly equipment for monitoring and maintaining trees in parks and forests. The traditional use of forest machines and self-propelled tractors with internal combustion engines has a negative impact on the environment as a result of pollutant emissions, i.e., combustion products and fuel residues. An alternative to this tradition can be the use of mobile robots with remote control of their electric drives when performing such technological operations as pruning bacterial growths of trees and diagnosing the state of tree massifs. The article proposes a fundamentally new mobile robot design for monitoring park trees. The main differences between the robot are the new designs of the body and the walking mechanisms of the mobile robot. These design differences provide the robot with high maneuverability when choosing the path of movement along the tree trunk and reliable holding of the robot body on the tree at a sufficient movement speed to perform diagnostics of the state of tree massifs. The article also describes the dynamic models of the movement of a mobile robot along a tree trunk. It presents the simulation results in the form of graph-analytical dependencies of the robot parameters, which constitutes the scientific aspect of the problem. The main motivation of the conducted research is the creation of environmentally friendly equipment in the form of a mobile robot with a reliable system of retention on the surface moving and sufficient performance to perform park tree monitoring operations.
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Spaeth, Gerhard, Werner Fielitz e Bernard Frank. "Caledonian Deformation and Very Low-Grade Metamorphism in the Northeastern Part of the Stavelot-Venn Massif". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 171, n.º 1-3 (26 de setembro de 1985): 297–310. http://dx.doi.org/10.1127/njgpa/171/1985/297.
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V. P. KUPRIY, O. L. TIUTKIN e P. YE. ZAKHARCHENKO. "GROUND OF PARAMETERS OF DISCRETISATION AT THE NUMERICAL ANALYSIS OF NON-CIRCULAR OUTLINE TUNNELS". Bridges and tunnels: Theory, Research, Practice, n.º 11 (10 de dezembro de 2017): 20–29. http://dx.doi.org/10.15802/bttrp2017/158445.
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Purpose. Influence on the strain-stress state of discretization of finite element model in the numerical analysis of non-circular outline tunnels is explored in the article. Methodology. For achievement of the put purpose, authors developed three finite element models of callote part at building of two-line railway tunnel. In each of models in a programmatic complex «Lira» was a concrete method of discretization area of cooperation with the temporal fastening. After creation of models, their numerical analysis with the detailed research of his results was conducted. Findings. The values of deformations and tensions of finite element models on horizontal and vertical axes, and also maximal values of moments and longitudinal forces in the temporal support are got. The comparative analysis of the got values is conducted. The graphs of conformities to the law of the indicated results from the features of discretization of two models are built. The third finite element model with the radial laying out of knots in the area of co-operation of the temporal fastening with the surrounding ground array is explored. Originality. It is set that at the numerical analysis of SSS of tunnel support of non-circular outline his results substantially depend on a form, sizes and configuration of the applied finite elements, from the sizes of calculation area of the ground massif, and also from the terms of his fixing (maximum terms). Practical value. The features of discretization and necessary sizes of calculation area of the ground massif at the design of the system are certain «support – ground massif », which provide sufficient exactness of calculation of parameters of the strain-stress state of support.
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Nunes, João Paulo Avelãs. "The First World War, the emergence of the masses and the (in)adaptation of political systems". Revista Portuguesa de História, n.º 45 (2014): 39–52. http://dx.doi.org/10.14195/0870-4147_45_2.
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Sizov, Dmitrii, e Elvira Egereva. "Calculation of the wave field in a layered soil foundation using the grid method". E3S Web of Conferences 515 (2024): 02001. http://dx.doi.org/10.1051/e3sconf/202451502001.
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The article contains a solution to the problem of propagation of waves in a soil massif arising from the movement of subway trains. This problem often arises when predicting vibration levels in buildings located near metro lines. The problem is considered in a two-dimensional formulation, taking into account the actual location of soil layers with different physical and mechanical properties. The soil is modeled using the assumption of its linear deformability, which, to a first approximation, is acceptable due to small vibration displacements. To solve the problem, the finite difference method is used, which allows taking into account the various physical properties of individual soil layers and the structure of subway tunnels and at the same time is one of the simplest numerical methods. To obtain a solution, the direct integration method is used using an explicit scheme, which requires setting sufficiently small time steps. The results are presented as graphs of vibration displacements obtained at various points in time. The graphs illustrate the different nature of the wave field at different load frequencies. The dynamic load is specified in the form of vibrations of the walls of the subway tunnel.
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Boyko, Igor, Liudmyla Skochko e Maksym Khoronzhevskyi. "Identification of soil parameters based on the results of field tests of piles". Bases and Foundations, n.º 42 (24 de junho de 2021): 9–18. http://dx.doi.org/10.32347/0475-1132.42.2021.9-18.
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The work is devoted to the peculiarities of pile works in the soil under the action of static load. The data obtained from the results of in situ tests piles during the construction of a high-rise building were used for research. The calculations were performed by numerical modeling with using different models of soil environment and problem statements.
To increase the convergence of numerical modeling results with in situ tests, the parameters of engineering geological elements were identified.
Several variants of the methods of modeling the calculation scheme of systems "pile-soil massif" are analyzed. Different approaches to modeling the structures of the pile foundation and soil massif, finding the size of the soil massif and its finite elements, input parameters of soils are considered. The influence of the construction of a finite-element model on the results of calculations is obtained. For the analysis of the data, graphs of pile displacements under load were constructed. The dependence of the mechanical characteristics of the soil on the nature of the curve «load-subsidence» is determined.
Based on the comparison of the results of the in situ test and computer modeling of the pile test with static load, an iterative process of identifying the deformation characteristics of soils was carried out.
The influence of the use of the identified parameters of the soil environment on the formation of the stress-strain state of the «base – foundation – superstructure» system in the calculation of a high-rise building has been studied.
The calculation scheme is created in accordance with the real geometry and features of the soil conditions of the construction site.
The results of identification are included in the FEM for the analysis of the stress-strain state of the structures of building and base.
The results are compared with the calculations of high-rise buildings, which were conducted in previous studies by scientists in the field of geotechnics.
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Breiter, Karel, Nina Gardenová, Viktor Kanický e Tomáš Vaculovič. "Gallium and germanium geochemistry during magmatic fractionation and post-magmatic alteration in different types of granitoids: a case study from the Bohemian Massif (Czech Republic)". Geologica Carpathica 64, n.º 3 (1 de junho de 2013): 171–80. http://dx.doi.org/10.2478/geoca-2013-0018.
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Abstract Contents of Ga and Ge in granites, rhyolites, orthogneisses and greisens of different geochemical types from the Bohemian Massif were studied using inductively coupled plasma mass spectrometry analysis of typical whole-rock samples. The contents of both elements generally increase during fractionation of granitic melts: Ga from 16 to 77 ppm and Ge from 1 to 5 ppm. The differences in Ge and Ga contents between strongly peraluminous (S-type) and slightly peraluminous (A-type) granites were negligible. The elemental ratios of Si/1000Ge and Al/1000Ga significantly decreased during magmatic fraction: from ca. 320 to 62 and from 4.6 to 1.2, respectively. During greisenization, Ge is enriched and hosted in newly formed hydrothermal topaz, while Ga is dispersed into fluid. The graph Al/Ga vs. Y/Ho seems to be useful tool for geochemical interpretation of highly evolved granitoids.
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Rebrov, Anton Nikolaevich, Ekaterina Viktorovna Lopatkina e Maria Viktorovna Fatakhetdinova. "DEVELOPMENT OF BASIC GRAPE PLANTS IN CONDITIONS OF HETEROGENEITY OF THE SOIL COVER OF NIZHNEKUNDRYUCHENSKY SANDY MASSIF". Fruit growing and viticulture of South Russia 1, n.º 79 (26 de janeiro de 2023): 154–70. http://dx.doi.org/10.30679/2219-5335-2023-1-79-154-170.
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Feijóo García, Pedro Guillermo, Deiby Fabian Medina Cortés, Maria Catalina Ramírez Cajiao e Edier Ernesto Espinosa Díaz. "Cooperative Learning Web Application for Water Care in Colombia – Manglar: Actor-Network Theory Software Solution". International Journal of Emerging Technologies in Learning (iJET) 12, n.º 04 (28 de abril de 2017): 208. http://dx.doi.org/10.3991/ijet.v12i04.6733.
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One of the major challenges related to water care in Colombia, is to teach and massify good practices along its territory and population, looking forward to promote the preservation of this valuable resource. This paper presents details corresponding to the design, development and implementation of the Web Application Manglar, born within the project Liga del Agua, proposed for cooperative learning towards water care in the department of Cundinamarca, Colombia. The designed Application uses a graph approach, focused on actors and relations, exposing how the participant organizations and communities cooperate, share resources and interact, letting any user to know what has been elaborated and constructed throughout the project Liga del Agua. In this document, we focus on the architecture corresponding to the designed Application, exposing the requirements and functionalities, developed and implemented, looking forward to guarantee a technological scenario for cooperative learning within this context.
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Rebrov, Anton, e Ekaterina Lopatkina. "Influence of variety of soil-ground conditions of sandy soils (by the example of the Ust-Donetsk sandy massif) on the quality of the grape vine". BIO Web of Conferences 53 (2022): 01002. http://dx.doi.org/10.1051/bioconf/20225301002.
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The paper reveals the influence exerted on the development of post vitro grape mother plants and various microzones found on the Ust-Donetsk sand massif. The differences in the microzones were in the fertility level and a number of soil properties. The considerable influence provided by the growing conditions not only on the development of plants but also on the survival rate and life expectancy of mother bushes observed during the use of mother plants for 17 years has been noted. To ensure effective land management, a detailed site study and, depending on the differences identified, the use of precision farming techniques is required before laying out the parent plants. The reason for this is that sandy soils, in general, have a high degree of heterogeneity due to physical and chemical characteristics such as flowability, susceptibility to wind transport, low organic substance content, and cation exchange capacity.
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Tajčmanová, Lucie, Jiří Konopásek e Jan Košler. "Distribution of zinc and its role in the stabilization of spinel in high-grade felsic rocks of the Moldanubian domain (Bohemian Massif)". European Journal of Mineralogy 21, n.º 2 (22 de abril de 2009): 407–18. http://dx.doi.org/10.1127/0935-1221/2009/0021-1899.
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Serhiienko, Alexander, Iaroslav Liashok, Liana Serhiienko, Serhii Podkopaiev e Olha Kohtieva. "PREDICTION OF THE PARAMETERS OF THE CAVE-IN ROCK FORMATION IN ROOF OF THE LONGWALL OF COAL MINES". Journal of Donetsk Mining Institute 51, n.º 2 (2022): 108–21. http://dx.doi.org/10.31474/1999-981x-2022-2-108-121.
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Purpose. Process research of the parameters of the cave-in rock formation in roof of the 9th northern longwall of block #10 “Mines Control Pokrovske” Method. Numerical modeling of the volumetric stress-strain state (finite element method), the method of continuous media, the method of contact interaction of surfaces, analytical studies of the process of the formation of rock cave-in of the immediate roof. Results. The article presents the results of numerical modeling of the three-dimensional stress-strain state of a layered rock massif, with boundary conditions of contact interaction between rock layers and with the load of gravitational forces. The results of the grapho-analytical method of modeling the volume formation of fallout formation are presented on the example of working out the 9th northern bench of block No. 10 “PRAT Mine Management Pokrovske”. Calculated collapse parameters of the direct and main roof. The obtained parameters of fallout and their location. Scientific novelty The results of predicting the formation of cave-in rock the immediate roof of cleaning potholes using the volumetric stress-deformed state of a layered massif with the gravitational load of rock layers are presented. The results of predicting the formation of cave-in rock using the rock crack resistance criterion are presented. Practical significance. The practical significance lies in the method of predicting the processes of cave-in rock formation in the immediate roof during the working of coal seams and determining their parameters. The calculation process of numerical modeling of the step-by-step increase of the produced space gives a general picture of the state of rock layers above the produced space and their destruction zones, and determines the following measures to strengthen the roof in the coal face.
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Siraziev, Lenar, e Danil Sergeev. "Experimental studies of the various soils bedding influence on the stress-strain state of a layered subsoil base of the slab foundation". E3S Web of Conferences 274 (2021): 03021. http://dx.doi.org/10.1051/e3sconf/202127403021.
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The purpose of the study is to reveal the effect of the stress-strain state of the three-layer soil base of the slab foundation with a rigid underlying layer, which is heterogeneous along the depth of the ground. The main results of the study are obtaining relative deformations in the soil massif and the settlement of ground values of each layer. The results of experimental studies are obtained in the form of a deformation pattern of a layered base, distribution graphs of compressive stresses in the soil in depth and in a horizontal plane. The significance of the results achieved for the construction area is to establish the mutual influence of various soils on the stress-strain state of the laminate basement of the slab foundation. The presence of a dense top layer in a laminate base significantly increases its distribution ability. The stress distribution is proportional to the load-carrying capacity of the individual base layers. On the boundary between the layers, a jump in the compressive stresses may occur, which indicates the presence of shear deformations in the contact layer.
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Nafigin, I. O., V. T. Ishmuhametova, S. A. Ustinov, V. A. Minaev e V. A. Petrov. "Territory Suitability Assessment for Conducting Detailed Geological and Mineralogical Mapping Based on Statistical Methods of Remote Sensing Data Processing Landsat-8: A Case Study in the Southeastern Transbaikalia, Russia". Исследования Земли из космоса 2023, n.º 2 (1 de março de 2023): 61–83. http://dx.doi.org/10.31857/s0205961423010086.
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The work considers the suitability of using multispectral satellite remote sensing data Landsat-8 for conducting regional geological and mineralogical mapping of the territory of south-eastern Transbaikalia (Russia) in conditions of medium- low-mountain relief and continental climate. The territory was chosen as the object of study due to its diverse metallogenic specialization (Au, U, Mo, Pb-Zn, Sn, W, Ta, Nb, Li, fluorite). Diversity in composition and age of ore-bearing massifs of intrusive, volcanogenic and sedimentary rocks are also of interest. Statistical processing algorithms to increase spectral information content of satellite data Landsat-8 were used; they include: principal component analysis (PCA); minimum noise fraction (MNF) and independent component analysis (ICA). Eigenvector matrices analysed on the basis of statistical processing results and two-dimensional correlation graphs were built to compare thematic layers with geological material classes: oxide/hydroxide group minerals containing transition iron ions (Fe3+ and Fe3+/Fe2+); a group of clay minerals containing A1–OH and Fe, Mg–OH; minerals containing Fe2+ and vegetation cover. Pseudo-coloured RGB composites representing the distribution and multiplication of geological materials classes was generated and interpreted. Integration of informative thematic layers with using fuzzy logic model was carried out to construct a prospectivity map. Received map was compared with geological information, and positive conclusions about territory suitability for further remote mapping research of hydrothermally altered zones and hypergenesis products in order to localize areas promising for identifying hydrothermal-metasomatic mineralization were made.
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Kovbyk, K. "Determination of yield of fractional material bydestruction of martiteore by water jets depending on the direction of their cutting". Collection of Research Papers of the National Mining University 69 (junho de 2022): 35–42. http://dx.doi.org/10.33271/crpnmu/69.035.
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Purpose. Highlight the main results of the experiments performed on the destruction of martite ores by the method of borehole hydraulic destruction by their layering. Since, as a result of the analysis of literary sources, it was established that some of the deposits of the Kryvyi Rihiron ore basin are suitable for hydro monitor excavation.Consideration of the method of introducing technologies for hydromechanization of mining operations in the conditions of the Kryvyi Rihiron ore basin is a topical issue. The methods. Using experimental installations conduct experiments on the destruction of layers of martite ores, gradually increasing the water pressure and determine the qualitative fractional yield of raw materials. Mathematical processing of the results obtained and the construction of dependencies based on experiments. Findings. Showing of the sequence of the experiment, the creation of summary tables with the results and the construction of illustrated graphs is the result of a study of determining the yield of fractional material during the destruction of ores by water jets. The originality. Experiments have shown that the yield of the ore fraction during their destruction using the hydro fracture method depends both on the water pressure and on the stratification of the ores. Ores that break down along the layer are more prone to overgrinding, and ores that break into a cross are less likely to. Therefore, the output of fractions during the destruction of layers of martite ores in some values can be controlled. Practical implementation. The development of floodingdeposits of rich iron ores by classical, unsuitable methods is accompanied by a large number of losses of ore raw materials or the impossibility of developing the deposit, because an alternative to the classical drilling and blasting method of destruction of a massif of rock is proposed technology of hydromechanization.The use of borehole hydraulic mining technology will allow the use of water flows from drainage wells or a sump for the safe, non-explosive destruction of the massif. This will increase the safety of mining operations, as well as reduce the seismic impact on the workings before the start of stope extraction.
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Nafigin, Igor Olegovich, Venera Talgatovna Ishmukhametova, Stepan Andreevich Ustinov, Vasily Alexandrovich Minaev e Vladislav Alexandrovich Petrov. "Geological and Mineralogical Mapping Based on Statistical Methods of Remote Sensing Data Processing of Landsat-8: A Case Study in the Southeastern Transbaikalia, Russia". Sustainability 14, n.º 15 (28 de julho de 2022): 9242. http://dx.doi.org/10.3390/su14159242.
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The work considers the suitability of using multispectral satellite remote sensing data Landsat-8 for conducting regional geological and mineralogical mapping of the territory of south-eastern Transbaikalia (Russia) based on statistical methods for processing remote sensing data in conditions of medium–low-mountain relief and continental climate. The territory was chosen as the object of study due to its diverse metallogenic specialization (Au, U, Mo, Pb-Zn, Sn, W, Ta, Nb, Li, fluorite). Diversity in composition and age of ore-bearing massifs of intrusive, volcanogenic, and sedimentary rocks are also of interest. The work describes the initial data and considers the procedure for their pre-processing, including radiometric and atmospheric correction. Statistical processing algorithms to increase spectral information content of satellite data Landsat-8 were used. They include: principal component analysis, minimum noise fraction, and independent component analysis. Eigenvector matrices analyzed on the basis of statistical processing results and two-dimensional correlation graphs were built to compare thematic layers with geological material classes: oxide/hydroxide group minerals containing transition iron ions (Fe3+ and Fe3+/Fe2+); a group of clay minerals containing A1-OH and Fe, Mg-OH; and minerals containing Fe2+ and vegetation cover. Pseudo-colored RGB composites representing the distribution and multiplication of geological material classes are generated and interpreted according to the results of statistical methods. Integration of informative thematic layers using a fuzzy logic model was carried out to construct a prediction scheme for detecting hydrothermal mineralization. The received schema was compared with geological information, and positive conclusions about territory suitability for further remote mapping research of hydrothermally altered zones and hypergenesis products in order to localize areas promising for identifying hydrothermal metasomatic mineralization were made.
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Amralinova, B. B., O. V. Frolova, I. E. Mataibaeva, B. B. Agaliyeva e S. V. Khromykh. "Mineralization of rare metals in the lakes of East Kazakhstan". Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, n.º 5 (2020): 16–21. http://dx.doi.org/10.33271/nvngu/2021-5/016.
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Purpose. Study on the chemical composition of lake waters, salt brines, brine and bottom sediments to identify the mineralization of rare metals and other types of minerals. Methodology. Mass spectrometric studies (mass spectrometer with inductively coupled plasma ICP-MS 7500cx from AgilentTechnologies) for the purpose of high-precision analytical studies on the chemical composition of salt lake water in order to assess the content of rare elements. The use of unmanned aerial vehicles for linking and geometrizing lakes. Findings. Field surveys on the geometrization and linking of lakes were carried out. From the materials obtained with the help of the drone, orthophotoplans were created (with a measurement accuracy of up to 1 centimeter), as well as a digital terrain model and a digital terrain model. A complex of analytical works was carried out using inductively coupled plasma spectrometry. When analyzing the distribution graphs of the absolute content of micro-components in the waters of the lakes of the Delbegeteysky massif, it was found that all samples were enriched with sodium, phosphorus, iron, magnesium and barium. The results of the analyses revealed the predominance of sulfates and chlorides in the composition of the surface waters of most of the water bodies of the Delbegeteysky massif. At the Burabai site, lake waters are characterized by an alkaline reaction of the environment (on average = 8.71). At the same time, the salinity of water bodies varies from 05 to 9 g/dm3. Originality. Large-scale outcrops of granites of the Kalba complex (P1), with which a rare-metal type of mineralization is genetically associated, are known to be on the selected study sites. Quartz-wire-greisen and quartz-wire tin, tin-tungsten and tungsten formations are also widely developed. Considering the large geochemical migration ability of rare alkaline elements in the thickness of loose sediments as a result of intensive geodynamic processes in the East Kazakhstan region, it is possible to assume the possibility of their migration to the upper horizons and accumulation in salt lakes localized within the area of development of granite intrusions of Permian age and associated deep tectonic faults. Practical value. The results of the research can serve as a revival of the rare metal industry in the region, which will allow developing new high-tech industries and creating new jobs in this area. The obtained results can be used for setting up further exploration and operational work on the selected promising areas.
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Arestova, Natalia, e Irina Ryabchun. "Special aspects of the development of harmful objects on the grape mother plants of the original category in the conditions of the Rostov region". BIO Web of Conferences 25 (2020): 06001. http://dx.doi.org/10.1051/bioconf/20202506001.
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The results of monitoring the distribution of phytopathogens and pests under conditions of maintaining mother plantations, improved and propagated in tissue culture, category original in the conditions of the Nizhne-Kundryuchensky sand massif in Rostov region, are presented. In the basic vineyard, conditions are met that exclude the possibility of secondary infection of healthy plants and make it possible to obtain planting material of the elite category. Vineyards have not been cultivated on these areas for at least 10 years, which reduces the risk of the presence of outbreaks of harmful organisms specific to grapes. Before establishing of the basic vineyard, the soil samples were diagnosed for the presence of harmful organisms in it. The results of the survey showed the absence of such pests in the soil as the larvae of scoops, beetles, click beetles, as well as bacterial diseases and nematodes. According to the results of monitoring observations, it was revealed that the mother plants of the basic plants of the ARRIV&W Branch of FSBSI FRANC are mainly spread by the following fungal diseases: powdery mildew, black spot, downy mildew, the intensity of which, due to regular protective treatments, did not exceed 2.5 points. The harmfulness of the main insects (leafhoppers, ticks, thrips) on the basic vineyard, is economically insignificant. Studies confirm the absence of migration of the leaf form of phylloxera. Pesticides were used during protective measures, guided by the principle of rotation of active substances and with the use of an active substance of one name no more than twice a season.
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Cherdantsev, S. V., P. A. Shlapakov e K. S. Lebedev. "Analysis of a sudden release of a gas-coal mixture from a conical cavity formed during the gas outburst". Mining Industry Journal (Gornay Promishlennost), n.º 6/2023 (25 de dezembro de 2023): 109–15. http://dx.doi.org/10.30686/1609-9192-2023-6-109-115.
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Indispensable attributes in underground coal mining are methane and coal dust of various particle sizes. When they are mixed, coal-gas mixtures are formed, predisposed to various hazardous and extremely hazardous gas-dynamic phenomena, primarily to sudden emissions, accompanied by formation of cavities in the coal massif and intensive release of coal-gas mixtures from these cavities into the mine workings. The article deals with the problem of a one-dimensional stationary flow of a gas-coal mixture in an underground cone-shaped cavity formed during a sudden release. The Euler equation of motion and the continuity equation are used as the basic equations. As a result of their transformation, an ordinary differential equation of the first order is obtained, for which the Cauchy problem is formulated. The solution to the Cauchy problem is a transcendental equation with respect to the desired Mach numbers. The roots of the transcendental equation are calculated using the MathCAD mathematical software suite. Upon finding the Mach numbers, the remaining parameters of the mixture are determined, i.e. the pressure, density and temperature of the gas-coal mixture at any point in the conical region, including their critical values. Graphs are constructed that were used as the basis to establish some regularities of the one-dimensional stationary flow of a gascoal mixture in a conical region. In particular, it was found that with an increase in the Mach number, parameters of the gas-coal mixture decrease non-linearly, and with an increase in the Poisson's adiabatic index, the pressure and temperature decrease, and the density increases.
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Kosenko, Andrii, e Andrii Khorolskyi. "DETERMINATION OF DEPENDENCE OF GEOMETRIC PARAMETERS OF DRAWN STOPES (UNDERCUTS) FOR IMPLEMENTING TECNOLOGIES OF ACTIVE CONTROL OF MOUNTAIN MASSIF STATE". Naukovyi visnyk Donetskoho natsionalnoho tekhnichnoho universytetu, n.º 1-2 (2022): 8–19. http://dx.doi.org/10.31474/2415-7902-2022-1(8)-2(9)-8-19.
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Purpose. Increasing the efficiency of mining of rich iron ores by sublevel caving methods based on the development of the technology of active control of the state of a mountain massif, which will ensure the stability of the outcrops of exposure of drawn stopes (undercuts)and the quality of the mined ore mass. Methodology. To achieve the goal, a complex of modern research methods has been used, which includes the analysis of literary sources, design and construction documentation and practice of developing iron ore deposits at great depths, theoretical generalization of laboratory and industrial experiments, the method of functional characteristics for determining the permissible sizes of structural elements of underground mining methods, systemic economic, graph-analytical and correlation analysis. Results. It has been established that the volumes of drawn stopes (undercuts) with flat inclined and vertical exposures are characterized by a larger volume than those with flat horizontal and vertical exposures. Also, the maximum possible stable parameters are determined for the exposure of the drawn stopes (undercuts), which are formed with the help of smooth blasting. Scientific novelty. Reserves for increasing the efficiency of extraction of rich iron ores by the sublevel caving methods have been determined based on the study of the dependences of geometric parameters of the depth of drawn stopes (undercuts) and the intensity of stoping. Due to substantiation of the above parameters, the intensification of the processes of stoping is carried out, which is an integral part of the active control of the state of a rock massif during underground mining of iron ore deposits. Practical significance. The developed technological solutions allow to increase the volume of pure ore extraction by 5–51%, depending on the mining-geological, mining-technical and geomechanical conditions of the development of rich iron ore deposits and the intensity of stoping and, as a result, to reduce losses by 2.6–4.6% and ore weakening by 2.8–5.2%, to improve absolute quality of the extracted ore mass by 0.8–1.5%, and to increase the economic efficiency of the development of mining units by10.1–27.5%. Conclusions. It has been established that during the development of deposits of rich iron ores with a strength coefficient of f=4–6, an average and below average stability and a thickness of 15–40 m, which are concentrated in the depth range of 1200–1400 m, it becomes possible to form exposure of drawn stopes (undercuts) with a volume of up to 70% of the main stock of the stoping panel, with an increase in the intensity of the technological process of ore drawingup to 8.8 t/m2 per day.
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Saponenko, D. S., e O. Y. Kuleshov. "Interaction of temperature fields in soil massif during abstraction of low-grade heat by U-shaped probes of geothermal heat pump units". Vestnik IGEU, n.º 6 (28 de dezembro de 2022): 5–17. http://dx.doi.org/10.17588/2072-2672.2022.6.005-017.
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Research in the field of alternative energy sources use is of relevance due to the limited reserves of fossil fuels, the constant cost increase and flue gas emissions generated by power plants along with fuel combustion. The use of low-grade ground energy with the help of geothermal heat pump stations makes it possible to save fossil fuel and reduce environmental pollution. Since about 50 % of the one-time capital investment is spent on the construction of ground loop, the issues on improving the efficiency of ground heat abstraction are of particular relevance. However, until now there is no unified normative technique to calculate ground probes and to create ground loops of optimal constructions. The absence of calculation methods and intelligible practical dependencies does not allow one to quantify the influence of various factors on the heat extraction process, the intensity of which varies significantly over time. The authors have applied two analytical methods in the developed mathematical model. The first one is a source-sink method adapted to the non-stationary process of heat abstraction away from the soil mass. And the second one is the superposition method which made it possible to quantify the effect of the interaction of temperature fields in the well. The mathematical model has been developed, and calculated dependences have been obtained. The authors have presented a calculation method and the results of mathematical modeling of the non-stationary process of soil heat abstraction by a vertical U-shaped geothermal probe and the internal interaction of the temperature fields of the downcomer and riser pipes. The results of the computational experiment are presented in the form of graphs. The authors have determined three key particular cases of the operation of a ground probe and formulas to define the maximum allowable increment of the temperature of the heated coolant under the condition of maximum efficient use of the heat-receiving surface applicable to various types of soil. The analysis of the obtained results makes it possible to identify the main factors affecting the heat-absorption efficiency (actual heat transfer coefficients and specific heat inflows) for each of the pipes and for the entire probe, considering the interaction of temperature fields around the downcomer and riser pipes during the heating period.
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Liashenko, Vasilii, Oleg Khomenko, Vladimir Golik e Mikhail Mitsik. "Justifying the parameters of ore fields underground mining with goaf backfilling". Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal 1 (15 de fevereiro de 2022): 58–71. http://dx.doi.org/10.21440/0536-1028-2022-1-58-71.
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Relevance. Manmade deposits have a major impact on environmental ecosystems in mining. Therefore, the priority direction of comprehensive research is the creation of technologies and technical means based on minimizing production waste. Research objective is to justify the parameters of ore fields underground mining with goaf backfilling using mathematical modeling and multi-criteria minimization of mining waste based on the results obtained by the regression analysis and planning of an experiment, ensuring economic efficiency and environmental safety growth, as well as subsoil rational use and protection. Methods of research. The parameters of technogenic deposit formation when extracting ore by traditional and alternative technologies were determined. The earth’s surface and underground working stress-strain state parameters were calculated. The technologies of converting inactive reserves of technogenic deposits into active ones by influencing them by physicochemical processes were studied. Parameters and regression dependences were calculated using the Maple 9.5 mathematical software package. The presented graphs were built in Maple 9.5 or Microsoft Excel using standard and new methods. Results. It is shown that the preservation of the rock mass implies the possibility of controlling the main stresses by limiting their deformations by filling technogenic voids with hardening mixtures of different composition and strength from 1.2 to 6.0 MPa. The structural weakening coefficient increases towards the periphery to 0.15, which means a decrease in strength in comparison with the undisturbed massif from 1.5 to 6.0 times. Conclusions. The regression dependences of profit on the coefficients of losses and dilution, indicators of soil excavation, total processing costs, as well as damage (economic consequences) from dilution of ore in the vicinity of the optimum point are obtained. The profit dependence is a convex monotonically decreasing function, where the profit value is the smaller, the greater the ore dilution coefficient. With an increase in the ore dilution coefficient to 0.6, the profit value will fall to 50.5 rubles/t, i.e. more than 20%. The main directions of modernization of technologies for underground mining of mineral deposits are recommended, taking into account their combination within a single mine field.
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Kvitsiani, Tariel, e Liana Kvatskhava. "Impact of Underground Waters on the Stability of the Mountain Rock Slope. Depression Surface Equation". Works of Georgian Technical University, n.º 1(523) (25 de março de 2022): 217–30. http://dx.doi.org/10.36073/1512-0996-2022-1-217-230.
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The underground waters move in the slope massif of a homogeneous mountain rocks. It is demonstrated that the filtration forces are the main cause for the decreased soil strength and slope deformation that further causes landslides. It was found that calculating the variability of groundwater levels and the location of the depressive curve plays an important role in the slope sustainability analysis. To solve this problem, the movement of the filtration water flow is considered within the slope of a homogeneous soil, which relies on the water-permeable cliffy bed sloping at an angle to the horizon. A common differential equation for the motion of the filtration water flow is deduced and reduced to the first-order linear equation, which is satisfied by the equation of the depression line. The method to draft a theoretical depression curve by using the solution of the differential equation is discussed. Based on this method, several typical points on the depression curve were selected. By using different values of geometrical parameters and ground characteristics of the slope, the coordinates of the typical points were determined. Auxiliary graphs were construed based on the results obtained by the numerical method to determine the coordinates of the outcrop of the depression curve on the slope surface and midpoint. The solution of a test example is given for illustration purposes. As the filtration water moves through the ground of the mountain rock slope, the impact of filtration forces or hydrodynamic pressure on the reduction of the slope ground stability is substantiated. Additional shear forces are taken into account in the calculation of the slope stability: hydrostatic and hydrodynamic pressures. The impact of the sums of these two forces results in the decreased ground mass strength, landslides and avalanches. For the slope stability analysis, the condition of the stability of the unit volume of the ground particle on the slope surface is considered. The formula to calculate the shear strength coefficient is deduced.
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Soroka, Pavlo. "Comparison of the bearing capacities of a small-diameter bored pile obtained from the results of field tests and numerical modeling". Bases and Foundations, n.º 47 (22 de dezembro de 2023): 38–48. http://dx.doi.org/10.32347/0475-1132.47.2023.38-48.
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Abstract. The paper compares the results of modeling static soil tests with a small-diameter drill pile with the data obtained from field tests. The calculations were performed by numerical modeling using the PC software "Plaxis", which is based on the finite element method. This problem was solved in a flat (2D) formulation for an axisymmetric model, which makes it possible to analyze the stress-strain state (SSS) and the interaction of elements of the pile-soil environment system.
Separate computational models were created for two types of piles made using different technologies: a bored- CFA pile and a drilled pile with partial soil displacement. In order to take into account the preload history in order to maximize the models' approximation to real conditions, the calculations were performed in 4 stages in accordance with the construction sequence: Stage 1 - initial stage (determination of the initial stresses in the soil massif in the natural state), Stage 2 - excavation to the design mark of the pit bottom, Stage 3 - testing of the soils with a pile by static load. Stage 4 - pile unloading. Based on the results of the calculations, the SSS and the interaction of the elements of the "pile-soil environment" system have been analyzed and compared the settlement graphs obtained from the results of the calculations with the data of field tests.
It is shown that the use of a plane axisymmetric FEM is a sufficiently effective approach for assessing the stress-strain state and understanding the interaction of elements of the pile-soil system, as well as predicting the bearing capacity of piles for further design of the pile foundation before obtaining the results of field tests. In addition, the labor intensity and time consumption of this approach are relatively low compared to other alternative methods.
With appropriate experience in using this approach in different soil conditions with appropriate comparison with field test data, it can be applied in the feasibility study and final decisions on the choice of a particular type of foundation.
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Rodriguez-Gil, Maria E. "Joan C. Beal, Carmela Nocera & Massimo Sturiale (eds.). Perspectives on prescriptivism (Linguistic Insights 73). Bern: Peter Lang, 2008. Pp. 269 + 9 tables and graphs. ISBN 978-3-03911-632-4." English Language and Linguistics 13, n.º 3 (19 de outubro de 2009): 510–16. http://dx.doi.org/10.1017/s1360674309990244.
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Bondareva, Liudmyla, e Maksym Khoronzhevskyi. "Assessing the impact of the process of constructing foundation pit enclosure structures on surrounding building". Bases and Foundations, n.º 45 (23 de dezembro de 2022): 22–32. http://dx.doi.org/10.32347/0475-1132.45.2022.22-32.
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An important issue in the calculations of retaining structures of pits and their interaction with the foundation and existing structures is taking into account the features of their installation technology. Quite often, during calculations, this factor is ignored or taken into account by introducing correction factors, which are somehow based on the statistical processing of observation data during the construction of similar objects.
The development of numerical methods has enabled designers to use detailed finite-element models in calculations to more accurately predict the behavior of bases and structures, without spending excessive amounts of time.
In this work, numerical modeling methods are used to reproduce the process of installation of the pit enclosure structures using the trench method "wall in soil" to determine its impact on existing buildings. For this, a numerical model of a 9-floor building with a soil massif was created. Modeling of the foundation pit and enclosure structures, which is installed next to the building, was done. At the same time, the use of a three-dimensional formulation of the problem made it possible to take into account the length of the wall panel and the technological sequence of the construction.
The existing methods of trench excavation modeling were analyzed and one of them was implemented in the calculation scheme.
The impact of various factors on the formation of additional deformations of the existing building was investigated, such as: L - distance from the foundation pit to the building; Нст - the depth of laying the sole "wall in the ground"; Lзхв - the length of the wall panel; ρг.р - is the density of the clay slurry.
Within each task, the settlement of the foundation of the building is determined with different input parameters: L={1,2; 3; 5; 10m}, Нст={12; 18; 24m}, Lзхв={3; 4; 5m}, ρг.р={1.05; 1.10; 1.30t/m3}. The results are presented in the form of graphs.
The results of the research show that the most determining factors affecting the «technological settlements» of the slab foundation of the building are the distance from the pit to the building and the depth of laying the sole of the "wall in the soil". With different combinations of these parameters, the values of calculated vertical deformations of the building can differ up to several times.
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Minieiev, S., A. Prusova, O. Yanzhula e O. Minieiev. "DYNAMICS OF CHANGES IN THE VOLMER DIFFUSION COEFFICIENT OF METHANE ADSORBED IN THE MICROSORPTION STRUCTURE OF THE RESISTANT PRESSURE ELASTIC ZONE OF A COAL LAYER". Naukovyi visnyk Donetskoho natsionalnoho tekhnichnoho universytetu, n.º 1 (2023): 105–14. http://dx.doi.org/10.31474/2415-7902-2023-1-105-114.
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Purpose. Set the possible change in the coefficient of Volmer diffusion of methane in the microsorption structure of the elastic zone of the supporting pressure of the coal seam. Methodology. The energy of the sorption bond of methane with the coals, the activation energy of the Volmer diffusion in the porous expanse of coal, as well as the stresses of the elastic zone and its effect on the change of the Volmer porosity, was taken into account. In the calculations, such parameters as the diameter of the Volmer micropores and the length of the descending branch of the support pressure diagram were varied. Results. Approximation of calculations made it possible to establish both the pairwise dependences of the Volmer diffusion coefficient on the listed parameters and its multifactorial relationship with them. It was concluded that the diffuse process of methane in the elastic support pressure zone is not blocked by rock pressure, as previously thought, but is actively developing. In this case, the diffusion of free methane will be determined by the established pattern of change in the Volmer diffusion coefficient in the elastic zone of the coal seam bearing pressure. Calculations showed that as the distance from the maximum reference pressure increases, the Volmer diffusion coefficient of methane in the coal seam increases, which is due to a decrease in rock pressure in the descending branch of the reference pressure graph. However, this growth is not strong due to the weak compressibility of pores. Therefore, for pores of the same diameter, the Volmer diffusion coefficient in the elastic zone of the supporting pressure of the coal seam for the given mining geological conditions can be considered a constant. For depths of, for example, 1000 m and pore diameters of 10 Å, the value of the Volmer diffusion coefficient will be approximately 3.77×10-8 m2/s. Scientific novelty. Calculations of the Volmer diffusion coefficient of methane adsorbed in the micropores of coal in the elastic zone of the supporting pressure of the coal seam, which, of course, is under significant compressive stresses, have been performed. The established phenomenon confirms that methane gas release is determined not only by free gas filtration, but also by Volmer diffusion of adsorbed methane. Practical significance. Since adsorbed methane reserves are known to be the main methane reserves in coal, the regularity established in the article makes it possible to more accurately calculate the volumes of methane that will be released from the coal massif during mining operations for the assessment of safe working conditions for coal deposits and for the development of technologies for the production of shale methane.
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KANTEMIROV, Valeriy Daniilovich, e Roman Sergeevich TITOV. "Optimization of parameters of open-pit screening and dumping stations". NEWS of the Ural State Mining University 59, n.º 3 (15 de setembro de 2020): 107–14. http://dx.doi.org/10.21440/2307-2091-2020-3-107-114.
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Introduction. The mining and geological features of a number of deposits lead to the fact that during the development of the massif under the influence of drilling and blasting operations, the degree of crushing of a mineral depends on the content of useful components in it, and the chemical composition of the ore is differentiated by size classes. The determined relationship between the quality of the ore mass and its size can be used to increase the efficiency of the ore preparation technology through the use of screening and dumping stations (SDS) in open pits. The implementation of the ore preparation technology based on the SDS will allow to reduce the costs of enrichment and transportation of the ore mass by separating its substandard part directly in the open pit and excluding it from the traffic flow at the processing plant, where the efficient operation of SDS is possible by optimizing a number of parameters as mining transport equipment serving SDS and a screener itself. Results. To determine the main parameters of SDS the characteristics of the initial movement of the rock mass along the inclined surface of the screen were determined, such as the productivity of unloading the vehicle onto the surface, the initial thickness of the layer for feeding and the speed of movement of the rock mass along the slope of the screener. Based on the presented algorithm, the main characteristics of the screening process are calculated: the size of the material flow layer in the i-th screener section; the speed of movement of the bulk mass along the screener; the average size of a piece in the starting material and the output of the material into screen throughs. The parameters of the screening process were determined on the basis of a given relative content of the size class of the material supplied to the surface of the screener, subject to its uniform distribution within the class. The optimized parameters of SDS were selected: the angle of inclination of the screener and the linear dimensions of the unloading platform, depending on the dimensions of the dump truck. Determination of the optimal parameters of SDS was carried out by constructing a generalized desirability function for two optimized criteria: the material yield to screen throughs and the oversize of the screener. Based on results of the calculation, optimization graphs of the dependence of the optimization function on the angle of inclination of the surface of the screener and the carrying capacity of the dump truck unloaded onto the screener were constructed. Conclusions. The optimal angle of inclination of SDS screen is 40° –42° and does not depend on the grain size distribution of the feedstock supplied to screening.
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Pakula, Hubert, Ryan Carelli, Nicolo Fanelli, Madhavi Jere, Caitlin Unkenholz, Mohamed Omar, Caroline Ribeiro Fidalgo et al. "Abstract 3816: Functional atlas of prostate mesenchyme". Cancer Research 82, n.º 12_Supplement (15 de junho de 2022): 3816. http://dx.doi.org/10.1158/1538-7445.am2022-3816.
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Abstract Prostate cancer has a heterogeneous prognosis, and genetic alterations alone do not fully explain clinical behavior. We previously characterized the stroma of localized human prostates by Laser Capture Microdissection, and found that stroma was substantially different in prostates with and without tumor. Furthermore, a stromal gene signature reflecting bone remodeling was upregulated in high compared to low Gleason grade cases. To determine how stromal cells contribute to carcinogenesis and progression we study whether specific genetic alterations in the epithelium induce unique stromal changes. To do this, we utilized Genetically Engineered Mouse Models (GEMMs) representing common prostate cancer mutations and compared these to their wild-type conterparts: the Tmprss2-ERG fusion knock-in murine model induces histological alterations in the stroma in the absence of an epithelial phenotype; the Pten deletion mouse model (PtenKO) results in prostate intraepithelial neoplasia (PIN) but not invasive cancer; the Hi-Myc GEMM, leads to PIN and subsequently invasion; and the Pb4-Cre +/-;Pten f/f; LSL-MYCN +/+; Rb1 f/f (MNRPDKO) mouse model that leads to neuroendocrine prostate cancer (NEPC). We generated a comprehensive single-cell transcriptomic atlas of the mouse prostate cancer mesenchyme in these models. Using deep generative modeling followed by graph-based clustering and gene regulatory network inference, six (6) distinct subsets of fibroblasts and two (2) subsets of smooth muscle cells (myofibroblasts and pericytes) were identified. Notably, some subsets were common across all GEMMs and WT mice, while others aligned with specific genotypes. Moreover, we found a variable pattern of positive and negative Ar expressing cells between genotypes. Analysis by CellphoneDB of mesenchymal-epithelial communications revealed the complex cross-talk between mutated epithelial cells and the tumor microenvironment. Multiplex immunofluorescence phenotyping of mesenchymal cell confirmed the cluster subtypes by both expression and spatial location. Finally, stromal transcripts defining mesenchymal cluster subtypes associated with Tmprss2-ERG were conserved between mouse and human genotypes.This study lays the groundwork for understanding and ultimately targeting stromal-epithelial interactions in prostate cancer. Citation Format: Hubert Pakula, Ryan Carelli, Nicolo Fanelli, Madhavi Jere, Caitlin Unkenholz, Mohamed Omar, Caroline Ribeiro- Fidalgo, Filippo Pederzoli, Cory Abate-Shen, David S. Rickman, Brian Robinson, Luigi Marchionni, Massimo Loda. Functional atlas of prostate mesenchyme [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3816.
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Kallor, Ashwin Adrian, Michał Waleron, Georges Bedran, Patrícia Eugénio, Catia Pesquita, Daniel Faria, Fabio Massimo Zanzotto, Christophe Battail, Ajitha Rajan e Javier Alfaro. "Abstract 6577: CARMEN: A pan-HLA and pan-cancer proteogenomic database on antigen presentation to support cancer immunotherapy". Cancer Research 83, n.º 7_Supplement (4 de abril de 2023): 6577. http://dx.doi.org/10.1158/1538-7445.am2023-6577.
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Abstract Cancer immunotherapy has greatly improved the quality of life of cancer patients and it hinges on the discovery of novel cancer antigens that could be targeted to improve disease outcomes. The creation of databases such as IEDB, SysteMHC, TANTIGEN, caAtlas, HLA Ligand Atlas, Cancer Antigenic Peptide Database, SPENCER and IEAtlas support the immunopeptidomics community in understanding the landscape of antigen presentation. We have developed a pan-cancer, pan-HLA, and pan-tissue database containing immunopeptidomics data mapped to transcriptomic, genomic, immunological and biochemical data. The database was generated from 80 different publicly available immunopeptidomics mass spectrometry datasets collected between 2015-2022 (76 cancer and 4 normal datasets), covering 15 different types of cancers and 152 different HLA-I alleles. The peptides contained in our database were obtained by a combination of closed, open and de novo searches using an in-house developed computational pipeline. Following rigorous false discovery rate estimation at 1% and a second-round search to eliminate any false signals that may not have been detected in the previous round of FDR estimation, we obtained a list of 11.2 million peptide-HLA combinations comprising both coding and non-coding regions of the genome as well as bacterial peptides. These peptides have been mapped to chromosomal coordinates to facilitate adoption by the genomics community of this useful resource on antigen presentation. Pathway/biochemical analysis of each peptide was performed using the rWikiPathways package. Finally, mutations associated with each peptide were annotated using COSMIC and dbSNP resources. Our database includes a FAIR knowledge graph which contextualizes and enriches the data to enable clinicians to take effective therapeutic decisions on the appropriate form of treatment for cancer immunotherapy with the case study of clear cell renal cell carcinoma (ccRCC). We will continue to expand our database with new data over the next two years and expand the scope of its applications to facilitate uptake by the larger scientific community. Citation Format: Ashwin Adrian Kallor, Michał Waleron, Georges Bedran, Patrícia Eugénio, Catia Pesquita, Daniel Faria, Fabio Massimo Zanzotto, Christophe Battail, Ajitha Rajan, Javier Alfaro. CARMEN: A pan-HLA and pan-cancer proteogenomic database on antigen presentation to support cancer immunotherapy. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6577.
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Peers, Glenn. "Massimo Bernabò, ed., Il Tetravangelo di Rabbula. Firenze, Biblioteca Medicea Laurenziana, plut. 1.56: L'illustrazione del Nuovo Testamento nella Siria del VI secolo. (Folia Picta, 1.) Rome: Edizioni di Storia e Letteratura, 2008. Paper. Pp. ix, 177 plus separate errata sheet, 31 black-and-white and color plates, and 126 black-and-white and color figures; black-and-white figures, tables, and graphs. €75." Speculum 85, n.º 3 (julho de 2010): 635–37. http://dx.doi.org/10.1017/s003871341000134x.
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KAZTAEV, Ermurat, Aiman KOPOBAEVA e Viktor DYAKONOV. "Granitoids Geological and Geochemical Features Study at Akchatau Massif". Trudy Universiteta, 30 de março de 2023. http://dx.doi.org/10.52209/1609-1825_2023_1_138.
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. The aim of the work is to identify the geological and geochemical features of the granitoids of the Akchatau massif. This article discusses the petrochemical data of the first and second phase introduction of the Akchatau massif, as well as the petrogenesis of rocks and the distribution conditions of tungsten and molybdenum. To diagnose the distribution of elements, the data were normalized by UCC. According to the results of the analysis, it was found that the chemical analysis of REE for granites is less than for leukogranites. It was also found that the REE distribution graph in the rocks of the Akchatau massif repeats the line of the upper crust.
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Sarkar, Niladri. "Immature Ovarian Teratoma (Grade 3) Associated ith Massive Gliomatosis Peritonei". journal of medical science and clinical research 5, n.º 7 (30 de julho de 2017). http://dx.doi.org/10.18535/jmscr/v5i7.246.
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Lanchava, Omar, Giorgi Nozadze, Nino Arudashvili e Zaza Khokerashvili. "TO DETERMINATION OF VENTILATION AIR OF THE METRO OF TBILISI BY THERMAL FACTOR". GEORGIAN SCIENTISTS, 10 de junho de 2021. http://dx.doi.org/10.52340/gs.02.21.283.
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It is established that the geothermal field of a massif around underground structures located above the neutral layer is non-stationary because of the influence of solar radiation. Below the above marked layer, the formation of the geothermal field of the subsoil is due to the process of depths and is stationary. The definition of these fields is necessary for the performance of the thermal physical calculation of the ventilation and the specification of the air consumption of the underground facilities of the metro by the thermal factor. The paper gives formulas, tables and graphs with the help of which it is possible to reliably determine the sought-for geothermal fields
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Идармачев, Ш. Г., В. И. Черкашин, И. А. Алиев e И. Ш. Идармачев. "Studying the dynamics of the crack width of a potentially collapsing rock massif with a string sensor on Mount Gunib(Dagestan)". Геология и геофизика Юга России, n.º 2 (27 de junho de 2022). http://dx.doi.org/10.46698/vnc.2022.70.64.006.
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Изучение обвальных геологических процессов на Кавказе является важной проблемой обеспечения безопасности высокогорных населенных пунктов. Для этого применяются различные методы: аэрокосмические, палеогеографические, геоморфологические и др. Отдельным пунктом стоит вопрос геофизического мониторинга неустойчивых массивов в местах расположения населенных пунктов, линий электропередач и других объектов народно-хозяйственного значения. Поэтому целью работы является изучение динамики ширины трещины, связанной с неустойчивым состоянием скального массива, представляющего опасность обрушения на населенный пункт Гуниб с координатами 42.40° с.ш., 46.94° в.д. Данный массив представляет собой вертикальный блок размером 20´50´60 м, отделенный от основной части горы. На вершине массива ширина трещины между целиком и оторванным блоком составляет около 2 м. Для геофизического мониторинга был использован новый метод инструментального измерения ширины трещины. Разработка состоит из датчика линейного изменения длины с циферблатным регистратором, вольфрамовой проволоки, закрепленной на противоположных торцах трещины отрыва неустойчивого скального массива от цельной части. Преимуществом данного инструмента, по сравнению с электронными устройствами, является отсутствие источника питания, дрейфа нуля, простота конструкции. Данная установка может быть рекомендована для практического применения. Результаты работы. На основе мониторинга исследована динамика изменения ширины трещины скального массива в течение полутора лет. Установлена зависимость ширины трещины от сезонной годовой температуры атмосферы с отрицательным коэффициентом корреляции 0,78. Максимальная амплитуда изменения ширины трещины за период 365 сут с 18.08.2020 по 18.08.2021 составила 4570 мкм. Установлено, что атмосферные осадки не оказывают прямого влияния на деформационный процесс скального массива. Однако не исключается возможность их влияния спустя некоторое время, которое необходимо для просачивания дождевой воды в основание исследуемого массива. Увлажнение прослойки глинистых пород, лежащих в основании толщи известняков, может привести к деформации глин, в результате чего возможно оседание массива или подвижка по направлению уклона пласта в сторону обрыва. Обратимый характер изменения ширины трещины за годовой период наблюдений, а также отсутствие тренда в ряде данных измерений за весь период наблюдений позволяет полагать, что скальный массив на данном этапе не испытывает динамику, связанную с наклоном в сторону его предполагаемого падения. Однако на графике в отдельные периоды наблюдаются скачкообразные изменения большой амплитуды 1500–2500 мкм, природу которых предстоит еще выяснить. Это предполагает проведение дальнейших исследований, например, наклонометрических и сейсмометрических. The study of landslide geological processes in the Caucasusis an important problem of ensuring the safety of high-altitude settlements. Various methods are used for this: aerospace, paleogeographic, geomorphological, etc. A separate point is the issue of geophysical monitoring of unstable massifs in the locations of settlements, power lines and other objects of national economic importance. Therefore, the aim of the work is to study the dynamics of the crack width associated with the unstable state of the rock massif, which poses a danger of collapse on the settlement of Gunib with coordinates 42.40° S.W., 46.94° V.D. This massif is a vertical block measuring 20×50×60 m, separated from the main part of the mountain. At the top of the array, the width of the crack between the whole and the detached block is about 2 m. A new method of instrumental measurement of the crack width was used for geophysical monitoring. The development consists of a linear length change sensor with a dial recorder, a tungsten wire fixed at opposite ends of a crack in the separation of an unstable rock mass from a solid part. The advantage of this tool, in comparison with electronic devices, is the absence of a power source, zero drift, and simplicity of design. This installation can be recommended for practical use. Results. On the basis of monitoring, the dynamics of changes in the width of a crack in a rock massif over a year and a half has been studied. The dependence of the crack width on the seasonal annual atmospheric temperature with a negative correlation coefficient of 0.78 has been established. The maximum amplitude of the crack width change over the seasonal period of 365 days from 08/18/2020 to 08/18/2021 was 4570 microns. It is established that atmospheric precipitation does not have a direct effect on the deformation process of the rock mass. However, the possibility of their influence after some time, which is necessary for rainwater to seep into the base of the studied massif, is not excluded. Moistening of the layer of clay rocks underlying the limestone strata can lead to deformation of clays, resulting in possible subsidence of the massif or movement in the direction of the slope of the formation towards the cliff. The reversible nature of the change in the crack width over the annual observation period, as well as the absence of a trend in a number of measurement data for the entire observation period, suggests that the rock mass at this stage does not experience dynamics associated with a slope towards its expected fall. However, in some periods, the graph shows abrupt changes of a large amplitude of 1500-2500 microns, the nature of which remains to be determined. This implies further research, for example, tilt and seismometric.
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Lanchava, Omar, Nino Arudashvili e Zaza Khokerashvili. "NON-STATIONARY TRANSMISSION OF HEAT AND HYGROSCOPIC MASS BETWEEN VENTIIATION FLOW OF METRO AND SURROUNDING MINING MASSIF". GEORGIAN SCIENTISTS, 21 de maio de 2021. http://dx.doi.org/10.52340/gs.2021.305.
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According to modern technologies of construction and operation of transport tunnels, it is assumed in the present work that drainage of water does not occur inside the membrane in the area of reinforced coating of the tunnel and here takes place a non-stationary process of transfer of hygroscopic mass (moisture) together with а similar process of heat transfer between the ventilation stream and the surrounding mining massif. Thus, we have to deal only with the sorption mass content in the pores of the massif and the water in the explicit form in the tunnels can only be in exceptional cases as local sources and therefore, their influence on the ventilation flow should be considered separately. The paper provides results of mathematical modeling of heat and mass transfer processes as well as graphs and nomograms, which can be used to define non-stationary coefficients of the heat and mass transmission required for thermal physics calculation of underground ventilation. The additional flows initiated by the Soret and Dufour effects usually strengthen the main flows, but in practice one can find a case where it is not necessary to take into account the effect of additional flows. Based on the analysis of processes, the criteria that determine the numerical value of these show the case when accounting for additional flows of Soret and Dufour is mandatory. The marked effects can be ignored when 106 Lα=1.
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Bonnafous, Alain, e Yves Crozet. "Evaluation, devaluation or reevaluation of the high speed train lines ?" Les Cahiers Scientifiques du Transport - Scientific Papers in Transportation 32 | 1997 (30 de novembro de 1997). http://dx.doi.org/10.46298/cst.11955.
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Cet article peut être téléchargé sur le site de la revue : http://www.afitl.com/CST/precedents-numeros/N32/BONNAF32.PDF (lien visité le 04/04/2007) The disappointing commercial results of the northern high speed train, associated with a global crisis of railway transport in France at the beginning of the 90', have led to call into question all the projects of new high speed train lines. All of them have been revalued in the Rouvillois report which concluded to the impossibility of building new high speed lines without public finances support. Given the fact that the most profitable lines are already built, private funding alone is not sufficient. But this obviousness must not lead to abandon all the projects. Some of them have indeed a good financial profitability and even a very good social return. But in order not to penalize the whole high speed train system, priority must not be given to the less profitable lines. And it would be better to avoid a zero sum game between the owner of infrastructure and the running company. Les résultats commerciaux et financiers décevants du TGV Nord, associés à une crise générale du transport ferroviaire en France au début des années 90, ont conduit à remettre en cause l'ensemble des projets de lignes à grande vitesse. Ces derniers ont été réexaminés par le rapport Rouvillois, qui a conclu à la quasi impossibilité de réaliser de nouvelles lignes TGV sans un soutien direct, et parfois massif, des fonds publics. Les lignes les plus rentables étant déjà construites, le seul financement privé ne peut suffire pour développer des lignes nouvelles. Cela ne signifie pas que tous les projets doivent être abandonnés puisque certains conservent une bonne rentabilité financière, et même une très bonne rentabilité socio-économique. La grande vitesse ferroviaire a donc un avenir, mais il est important de ne pas pénaliser le système TGV en donnant la priorité aux projets les moins rentables. Et il faut aussi éviter que les relations entre l'exploitant et le propriétaire de l'infrastructure apparaissent comme un jeu à somme nulle.
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Ilyin, A. A., V. S. Shatsky e A. L. Ragozin. "U–Pb Age and Mineral Inclusions in Zircon from Diamondiferous Garnet–Pyroxene Rocks of the Kumdy-Kol Microdiamond Deposit in Northern Kazakhstan". Russian Geology and Geophysics, 29 de janeiro de 2024. http://dx.doi.org/10.2113/rgg20234661.
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Abstract ––This paper describes the results of studying inclusions and determining the U–Pb age in zircon from the diamondiferous garnet–pyroxene rock of the Kumdy-Kol metamorphogenic diamond deposit, located in the Kokchetav subduction-collision zone. The distribution of rare earth elements in garnet and clinopyroxene is used as a basis for estimating the equilibrium pressure (5.5 ± 0.3 GPa) and temperature (993 ± 24 °C), which correspond to the diamond stability field. The composition of mineral inclusions in zircon indicates its formation at both the progressive and the regressive stage of metamorphism. The concordia diagram shows that the figurative points of zircon lie on a discordia with an upper intersection at 1953 ± 139 Ma and a lower intersection at 512 ± 4 Ma. The main peak on the graph of the probability density distribution of zircon ages corresponds to an age of 519 Ma. The presence of grossular–almandine garnet inclusions in zircon confirms the previous assumption that the basement rocks of the Kokchetav massif act as protoliths of garnet–pyroxene rocks.