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Date submitted2024-06-17
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Date accepted2024-07-17
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Date published2025-04-25
Justification on the safe exploitation of closed coal warehouse by gas factor
The annual increase of coal production and its demand lead to the necessity in temporary storage places (warehouses) organization to accommodate raw coal materials before the shipment. It is noted that at the open method of coal storing the dust emission from loading/unloading operations and from the pile surface effects negatively the health of the warehouse workers and adjacent territories. An alternative solution is closed-type warehouses. One of the main hazards of such coal storage can be the release of residual methane from coal segregates into the air after degassing processes during mining and extraction to the surface, as well as transportation to the place of temporary storage. The study carries the analysis of methane content change in coal during the processes of extraction, transportation and storage. Physical and chemical bases of mass transfer during the interaction between gas-saturated coal mass and air are studied. It is determined that the intensity of methane emission depends on: the coal seam natural gas content, parameters of mass transfer between coal, and air and the ambient temperature. The dynamics of coal mass gas exchange with atmospheric air is evaluated by approximate approach, which is based on two interrelated iterations. The first one considers the formation of methane concentration fields in the air space of the bulk volume and the second accounts the methane emission from the pile surface to the outside air. It is determined that safety of closed coal warehouses exploitation by gas factor can be ensured by means of artificial ventilation providing volumetric methane concentration in the air less than 1 %. The flow rate sufficient to achieve this methane concentration was obtained as a result of computer modeling of methane concentration fields formation in the air medium at theoretically calculated methane emission from the pile surface.
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Date submitted2024-05-17
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Date accepted2025-01-28
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Date published2025-04-25
Determination of impact hazard potential of rocks in the Norilsk Industrial Region
The deeper the mineral deposits developments are, the worse the mining and geological conditions become. Significant growth of stress level in the rock mass contributes to possible manifestation of rock pressure in dynamic form. The resulting task of assessment of rock impact hazard is closely related to the task of obtaining more accurate results of compression tests of samples in rigid or servohydraulic test presses using graphs of their full deformation. This approach requires special expensive equipment, considerable time resources, and sufficient core material. Therefore, it is important to have an approach that allows to assess the propensity of rocks to brittle fracture with research methods simple enough not to result in the loss of quality and reliability of the obtained results. This paper presents the results of laboratory tests of rocks from the Norilsk Industrial Region to determine their tensile and compressive strengths. Test methods involved both domestic and foreign standards for determining the value of the brittleness coefficient. The impact hazard potential of rocks was determined using the Kaiser criterion. It is found that the tested lithological types (rich sulfide ores, hornblende, disseminated ores, and gabbro-dolerite rocks), with the exception of anhydrite, have a low impact hazard potential.
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Date submitted2023-03-16
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Date accepted2023-06-20
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Date published2023-07-19
Energy efficiency of the linear rack drive for sucker rod pumping units
- Authors:
- Oksana Yu. Ganzulenko
- Ani P. Petkova
At present, in order to increase oil production and reduce economic costs in the development of marginal fields, the development of a cluster method using compact mobile drives of sucker rod pumping units (SRPU) is relevant. The aim of the work is to analyze the ways to improve the energy efficiency of the SRPU by reducing the loss of mechanical and electrical energy, to select the most energy-efficient compact drive for the development of marginal fields in the cluster method, to carry out the kinematic and strength calculations of the drive of the selected size, to develop an adaptive control system for a group of drives in the cluster development of drillings. According to the results of the performed calculations, the linear rack-and-gear drive has the highest efficiency of the drive mechanism. The kinematic and strength calculations of a linear rack-and-gear drive with a stroke length of 1120 mm and a load of up to 8 tons are presented. It was shown that the usage of a direct torque control system and a kinetic energy storage system for the SRPU drive elements and a rod string is an effective means of reducing energy costs in oil production from marginal fields. The use of the developed system for storing and redistributing the potential energy of the rods between the SRPUs that lift oil made it possible to eliminate fluctuations in the power consumption, reduce the power peak value by three times, the peak value of the current consumed from the electric network by two times, and reduce losses in the input converter and cables by three times.
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Date submitted2022-05-25
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Date accepted2023-02-02
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Date published2023-08-28
Evaluation of the shear strength of rocks by cracks based on the results of testing samples with spherical indentors
Experimental data on the relationship of the residual shear strength of rocks in closed cracks with the functional characteristics of intact rocks – the tensile and compressive components of adhesion, the roughness of the crack surfaces, and the level of normal stresses are presented. A unified integrated approach determines the shear strength of intact and destroyed rocks, the residual shear strength of closed rough cracks has been developed. The approach provides for the selection of stress intervals corresponding to different types of fracture, for each of which a strength criterion is proposed, expressed in terms of functional characteristics of intact rock. An express method for estimating the residual shear strength of rocks by cracks with a rough surface has been developed, in which an improved method of loading samples with spherical indentors is used as a basic test method. The express method implements the transition from the data of mechanical tests of samples with spherical indentors to the shear strength indicators for cracks in the rock mass, taking into account the level of normal stresses and the roughness of the crack surfaces measured in field conditions. In this case the roughness scale developed by Barton is used. The express method is informative and available in the fieldwork.
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Date submitted2023-01-27
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Date accepted2023-03-04
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Date published2023-04-25
Use of the UNIFAC model in the calculation of physicochemical properties of ecotoxicants for technological and ecoanalytical purposes
- Authors:
- Vladimir G. Povarov
- Ignatyi I. Efimov
Modern development vector of environmental monitoring leads to elaboration of analytical methods for qualitative and quantitative analysis of different ecotoxicants. Many studies face the lack of information on isomers and homologues of already studied compounds. This problem cannot always be solved experimentally due to the difficulty of separating or synthesizing certain compounds; the use of group theories of solutions will help partly; using them, solubility in water or partition coefficient between two immiscible solvents is calculated for ecotoxicants. These parameters are important for solving the analytical and ecological problems. The partition coefficient in the octanol – water system is associated with a possibility of accumulation of different compounds in living organisms; the partition coefficient in the hexane – acetonitrile system can be used in gas chromatographic analysis. Solubility in water is closely associated with accumulation of ecotoxicants in water bodies, as well as with their ability to be transferred. This paper presents the capabilities of the UNIFAC model for solving physicochemical problems using the example of calculating the properties of real ecotoxicants on the basis of the available thermodynamic data. All the obtained calculated values were compared with those determined experimentally. In the case of pyrene derivatives, solubility data were obtained for the first time using a correlation group model to calculate the heat of fusion and melting temperature.
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Date submitted2022-05-06
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Date accepted2022-11-17
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Date published2023-02-27
Comprehensive study of filtration properties of pelletized sandy clay ores and filtration modes in the heap leaching stack
There are the results of a study of the factors determining the formation and changes in the filtration properties of a heap leaching stack formed from pelletized poor sandy-clay ores. An analysis of methods of investigation of filtration properties of ore material for different stages of heap leaching plots functioning is carried out. Influence of segregation process during stack dumping on formation of zones with very different permeability parameters of ore has been established by experimental and filtration works. The construction and application of a numerical model of filtration processes in pelletized ores based on laboratory experiments is shown. By means of solution percolation simulation at different irrigation intensities the justification of optimal stack parameters is provided in terms of the geomechanical stability and prevention of solution level rise above the drainage layer.
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Date submitted2021-05-13
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Date accepted2022-11-28
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Date published2022-12-29
Reproduction of reservoir pressure by machine learning methods and study of its influence on the cracks formation process in hydraulic fracturing
Hydraulic fracturing is an effective way to stimulate oil production, which is currently widely used in various conditions, including complex carbonate reservoirs. In the conditions of the considered field, hydraulic fracturing leads to a significant differentiation of technological efficiency indicators, which makes it expedient to study in detail the crack formation patterns. For all affected wells, the assessment of the resulting fractures spatial orientation was performed using the developed indirect technique, the reliability of which was confirmed by geophysical methods. In the course of the analysis, it was found that in all cases the fracture is oriented in the direction of the development system element area, which is characterized by the maximum reservoir pressure. At the same time, reservoir pressure values for all wells were determined at one point in time (at the beginning of hydraulic fracturing) using machine learning methods. The reliability of the used machine learning methods is confirmed by high convergence with the actual (historical) reservoir pressures obtained during hydrodynamic studies of wells. The obtained conclusion about the influence of the formation pressure on the patterns of fracturing should be taken into account when planning hydraulic fracturing in the considered conditions.
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Date submitted2021-02-05
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Date accepted2021-03-30
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Date published2021-04-26
Assessment of negative infrastructural externalities when determining the land value
- Authors:
- Elena N. Bykova
The work forms and substantiates the concept of land value, based on a new institutional theory. The infrastructural component of the cost of land in the presented concept determines, on the one hand, the efficiency of the use of natural resources, properties, demand for land on the market, on the other hand, the costs, which are determined not only by capital investments in construction of engineering infrastructure, but also by losses associated with restrictions on activities within zones with special conditions for territory use, creation of unfavorable conditions for economic activity, small contours, irregularities and others on a specific land plot, which are external negative infrastructural externalities that create losses of rights holders of land plots that are not compensated by the market, falling within the boundaries of these zones. Methods for assessing the impact of such negative infrastructural externalities on the cost of land encumbered by zones in different conditions of land market activity have been developed and tested, based on an expert-analytical approach (depressed market); the ratio of market values of land plots encumbered and unencumbered by a specific zone, and qualimetric modeling (inactive market); modeling by introducing into the model the factor of presence of zones with special conditions for territory use, based on the grouping of zones according to similar regulations for use, or by introducing the parameters of this factor (active market). Methods for taking into account spatial deficiencies and compensating for restrictions and prohibitions on activities on the territory of land plots with an individual market assessment are proposed.
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Date submitted2021-01-25
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Date accepted2021-02-22
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Date published2021-04-26
Conducting industrial explosions near gas pipelines
The problem to ensure the safety of objects which are in the area of blasting operations, ensuring the destruction of hard rocks, remains relevant. The article presents the results of a large-scale experiment to determine the safe conditions for conducting drilling and blasting operations near the active gas pipeline. The simplest and most reliable way to ensure the safety of the protected object from seismic impact is to reduce the intensity of the seismic wave, which is achieved by changing the parameters of drilling and blasting operations. This requires research to determine the impact of blasting operations on the parameters of seismic waves and the development of methods for measuring these parameters. The paper presents a detailed analysis of the seismic blast wave impact on the displacement of the ground and the model gas pipeline. The features of seismic monitoring during blasting operations near the active gas pipeline are shown. The seismic coefficients and attenuation coefficient of seismic waves are determined. It is proved that the readings of the seismic receivers on the surface and in the depth of the massive differ by two or more times.
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Date submitted2020-05-18
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Date accepted2020-06-16
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Date published2021-04-26
Traction asynchronous electric drive of mine electric locomotivesimulation model structure improvement
The article discusses the solution to the problem of underground railway transport slipping in dynamic modes, which occurs when there is a significant difference in the speeds of the driving and driven pairs of wheels. The state of the rail surfaces largely determines the coefficient of adhesion, therefore, using a mathematical model, the condition for the dependence of the magnitude of slipping and tractive effort is selected. For effective acceleration and deceleration of an electric locomotive, it is necessary to control the coefficient of adhesion at a certain level. A simulation model of rolling stock has been created, which for the first time takes into account a mechanical system with distributed parameters. In the structural diagram of the automatic control system of traction electric drives with frequency regulation, such factors as the volume of goods being moved, rolling friction, slope (rise) levels and the state of the rail track are taken into account. The simulation results show the features of the movement and stops of the freight train not only by the diagrams of speed and forces in the modes of acceleration-deceleration and uniform movement, but also the positions of the plungers and tractive forces on the couplings of the electric locomotive and all trolleys involved in the movement of goods. The practical application of the proposed method lies in the possibility of starting a heavily laden train from its place on the ascent section in conditions of insufficient adhesion coefficient with contaminated roads.
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Date submitted2019-05-30
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Date accepted2019-09-03
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Date published2020-02-25
Study on influence of two-phase filtration transformation on formation of zones of undeveloped oil reserves
- Authors:
- S. I. Grachev
- V. A. Korotenko
- N. P. Kushakova
In order to study the process of fluid filtration during flooding of an oil field, article uses Rapoport – Lis model of non-piston oil displacement by water. During plane-radial filtration in a homogeneous formation, radii of disturbance zones are determined with and without taking into account the end effect. Influence of changes in value of capillary pressure gradient on distribution of water saturation coefficient in the non-piston displacement zone for high and low permeability reservoirs is revealed. Application of an element model for a five-point injection and production well placement system showed that, using traditional flooding technology, flat-radial fluid filtration is transformed into rectilinear-parallel. At solving equation of water saturation, Barenblatt method of integral relations was used, which allows determining the transformation time. By solving the saturation equation for rectilinear-parallel filtration, change in the value of water saturation coefficient at bottomhole of production well for an unlimited and closed deposit is determined. It is shown that an increase in water cut coefficient of a production well is possible only for a closed formation. To determine coefficient of water saturation in a closed deposit, a differential equation with variable coefficients is obtained, an iterative solution method is proposed. In the element of the five-point system, oil-saturated zones not covered by development were identified. For channels of low filtration resistance, conditions for their location in horizontal and vertical planes are established. It is shown that, at maintaining formation pressure, there is an isobar line in formation, corresponding to initial formation pressure, location of which determines direction of fluid crossflow rates. Intensity of crossflows affects application efficiency of hydrodynamic, physical and chemical, thermal and other methods of enhanced oil recovery.
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Date submitted2019-01-31
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Date accepted2022-12-02
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Date published2020-02-25
The relationship of fracture toughness coefficients and geophysical characteristics of rocks of hydrocarbon deposits
This paper contains the results of laboratory tests to determine the fracture toughness coefficient K IC of rocks for terrigenous and carbonate objects by three methods. The tests were carried out by different methods due to the lack of a standard method for determining the fracture toughness characteristics of rocks in Russia. We used the following methods for determining the K IC coefficient: the extension of core specimens with an annular fracture, the action of a concentrated load on a beam specimen with a fracture and the method of bending semi-circular samples with a fracture according to ISRM recommendations. The paper presents the relationship of the fracture toughness coefficients with the P-wave velocity and porosity. The obtained dependencies characterize the general trend of changing for the studied parameter and can be used in the design of hydraulic fracturing in the fields for which tests were conducted.
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Date submitted2019-04-27
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Date accepted2019-07-10
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Date published2019-10-23
Estimation of Rock Mass Strength in Open-Pit Mining
The paper presents results of an experimental study on strength characteristics of the rock mass as applied to the assessment of open-pit slope stability. Formulas have been obtained that describe a correlation between ultimate and residual strength of rock samples and residual shear strength along the weakening surface. A new method has been developed to calculate residual interface strength of the rock mass basing on data from the examination of small-scale monolith samples with opposing spherical indentors. A method has been proposed to estimate strength characteristics (structural weakening coefficients and internal friction angles) of the fractured near-slope rock mass. The method relies on test data from shattering small-scale monolith samples with spherical indentors, taking into ac- count contact conditions along the weakening surface, and can be applied in the field conditions. It is acceptable to use irregular-shaped samples in thetests.
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Date submitted2018-08-30
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Date accepted2018-10-26
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Date published2019-02-22
Study of bearing units wear resistance of engines career dump trucks, working in fretting corrosion conditions
- Authors:
- Ju. Olt
- V. V. Maksarov
- V. A. Krasnyy
The occurrence of fretting corrosion on nominally fixed surfaces of high-loaded parts of mining machines and mechanisms is considered. Examples of wear and damage of critical parts, bearing assemblies of engines of dump trucks in fretting conditions are given. The mechanisms of fretting corrosion when using wear-resistant coatings are considered. It is noted that when choosing protective thin-layer coatings that provide an increase in the fretting-resistance of surfaces of tightly contacting parts, it is necessary to take into account both their wear resistance and the ability to resist shear. At the same time, the thickness of such coatings allows preserving, during operation, those provided during the assembly of the tension, without disturbing the maintainability of the nodes. The results of research of fretting wear of a number of coatings on a special installation are given. The mechanisms of wear of a number of thin-layer coatings based on friction-mechanical brazing, polymer fluorocarbon composition, solid lubricant coating using scanning electron microscopy were studied. Recommendations on the use of the studied thin-layer coatings for high-loaded parts of mining machines operating in fretting corrosion conditions have been developed. The aim of the work was to study the effect of a number of thin-layer coatings on the wear of highly loaded connections of the mechanisms of mining machines, in particular bearing assemblies of quarry dump trucks operating under fretting corrosion conditions.
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Date submitted2018-01-19
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Date accepted2018-03-23
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Date published2018-06-22
Topochemical kinetics of external friction during mechanical and thermal activation of the friction contact
The article deals with the process of contact interaction (relative displacement) of surfaces as a chemical reaction, the regularity of which is described by the Arrhenius equation. The kinetic characteristics of Gersi-Striebeck are obtained taking into account the mechanical and temperature conditions of the frictional contact. The process of interaction of materials in friction in the form of regularities of topochemical kinetics, realized due to the processes of formation and growth of adhesion adhesion nuclei, makes it possible to present the experimental characteristics in the form of theoretical dependences. These dependences reflect the entire range of variation of the coefficient of friction from the speed of mutual movement of materials, including at ultra-low sliding speeds. In the framework of this approach, the lubricating action of the medium prevents and blocks the reactions of the transition of nuclei to actively growing nuclei.
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Date submitted2017-12-29
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Date accepted2018-03-06
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Date published2018-06-22
Evaluation of signal properties when searching for cavities in soil under concrete slabs by radio detection stations of subsurface investigation
- Authors:
- G. V. Rudianov
- E. I. Krapivskii
- S. M. Danilev
A method of localization of concealed cavities on the basis of studying of the reflected electromagnetic impulses is considered in the paper. An issue of early detecting of concealed cavities in engineering facilities is a critical one due to a significant influence on further serviceability of a structure. Problems of localization of concealed cavities in the soil body under the concrete slabs of hydropower stations were studied; the results of ground radar detecting investigations of the cavities, physical simulation of a cavity as well as a mathematical modeling of a reflected signal are presented. Modern subsurface radar detection provides methods which allow to reliably detect concealed cavities in the soil. However, it is possible only in case of a clear boundary between the adjacent layers that conditions a jump of dielectric permeability. In the result of an abrupt change of dielectric permeability a reflected wave occurred; the existence of subsurface heterogeneity is conditioned by the properties of this wave. Moreover, the greater is the difference between the values of dielectric permeability in the adjacent layers, the larger amplitude the reflected wave will have. If the cavity is at the stage of forming, i.e. it is filled with the soil of reduced density, then there is no clear boundary at the border of the layers which will condition a gradual change of dielectric permeability with depth. In this case an amplitude of a reflected wave will be minimal and a formation signal will be masked out by jamming signals reflected from various heterogeneities. In such case to determine a cavity at the stage of forming seems to be impossible. To determine poor signals an analysis of a phase of a reflected signal may be used; phase alters in compliance with the reflection coefficient change pattern. The article contains information about signals reflected from the heterogeneities and a conclusion regarding a possibility of detecting cavities in the soil on the basis of a method of coherent processing of signals is made.
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Date submitted2017-09-10
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Date accepted2017-11-10
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Date published2018-02-22
Research of heat generation indicators of gas engines
- Authors:
- O. N. Didmanidze
- A. S. Afanasev
- R. T. Khakimov
A comprehensive strategy for reviving the production of mining industry equipment and ensuring its competitiveness includes the wide use of gas engines for various purposes. Experimental studies of the working cycle of a gas engine are one of the main tasks in determining the heat generation characteristics. To this end, indicator charts were recorded in various modes, which were subjected to analysis in order to determine the key parameters characterizing intra-cylinder processes. According to the experimental program, the maximum cycle pressure, the rate of pressure build-up, the heat generation characteristic, the first heat generation phase, the duration of the second combustion phase, and the effect of the ignition advance angle for the ignition period were determined. The results of an experimental study of the influence of gas engine working process with allowance for the change in the ignition advance angle for the ignition period are described and the parameters of the maximum cycle pressure, the rate of pressure build-up, and the heat generation characteristics are determined. In the processing of data, integral charts are constructed, the working cycle parameters are calculated, and the dynamics of the engine heat generation is determined.
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Date submitted2016-10-28
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Date accepted2017-01-08
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Date published2017-04-14
Problems of mineral tax computation in the oil and gas sector
- Authors:
- N. G. Privalov
- S. G. Privalova
The paper demonstrates the role of mineral tax in the overall sum of tax revenues in the budget. Problems of tax computation and payment have been reviewed; taxpayers and taxation basis of the amount of extracted minerals have been clearly defined. Issues of rental content of natural resource taxes are reviewed, as well as problems of right definition of the rental component in the process of mineral tax calculation for liquid and gaseous hydrocarbons. One of important problems in mineral tax calculation is a conflict between two laws – the Subsoil Law and the Tax Code of Russian Federation (26 th chapter). There is an ambiguity in the mechanism of calculating amounts of extracted mineral resources – from the positions of the Tax Code and the Subsoil Law. The second problem is in the necessity to amend the mineral tax for oil extraction the same way as it has been done for gas extraction, when characteristics of each field are taken into account. This will provide a basis for correct computation of the natural resource rent for liquid and gaseous hydrocarbons. The paper offers recommendations for Russian authorities on this issue.
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Date submitted2015-12-01
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Date accepted2016-02-29
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Date published2016-12-23
Simulation of diesel engine energy conversion processes
- Authors:
- A. S. Afanasev
- A. A. Tretyakov
In order to keep diesel engines in good working order the troubleshooting methods shall be improved. For their further improvement by parameters of associated processes a need has arisen to develop a diesel engine troubleshooting method based on time parameters of operating cycle. For such method to be developed a computational experiment involving simulation of diesel engine energy conversion processes has been carried out. The simulation was based on the basic mathematical model of reciprocating internal combustion engines, representing a closed system of equations and relationships. The said model has been supplemented with the engine torque dynamics taking into account the current values of in-cylinder processes with different amounts of fuel injected, including zero feed. The torque values obtained by the in-cylinder pressure conversion does not account for mechanical losses, which is why the base simulation program has been supplemented with calculations for the friction and pumping forces. In order to determine the indicator diagram of idle cylinder a transition to zero fuel feed mode and exclusion of the combustion process from calculation have been provisioned.
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Date submitted2014-12-20
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Date accepted2015-02-05
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Date published2015-12-25
Synergetic changes of tribochemical properties in the heterogeneous systems containing surface modified metals
- Authors:
- A. G. Syrkov
In the article tribochemical properties and synergetic effects in lubricants with metal addi-tives, characterized by surface modifcations, have been analysed. The priority results of measur-ings friction coefficient (f) and friction force (F fr) are given for heterogeneous systems in the form of И-20 oil with solid Al-additives, contatiing dispersed aluminium, with surface-modified triamon (Т), alkamon (A) and ethylhydridsiloxane according to various programs. It has been educed that with all other things being equal, triamon underlayers introduction into Al-additives with the external chemisorpted ethylhydridsiloxane layer results in the decrease of F fr and f in the system in proportion to the Т-underlayer number reduction from three to one. It has been discovered that the use of low-molecular Т-underlayer in Al-additives is a delicate method of summand value regulation (from 10,8 to 13,2 Н), accountable for intermolecular forces in the boundary fritction equation in the tribological pair applied.
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Date submitted2014-10-09
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Date accepted2014-12-26
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Date published2015-08-25
Improving the precision of manufacturing power hydraulic cylinders of powered roof supports based on a vibration-damping tooling system
- Authors:
- V. V. Maksarov
- Yu. Olt
The article deals with a new system of a vibration-damping tool, the effect of which is achieved by a combination of the multi-layer principle and the use of anisotropic properties of sheet metal. Operation of such tool systems in turning operations can reduce high-frequency vibra-tions arising in the process of cutting due to the ordered disorientation of anisotropic plate texture of a multilayer modular tool holder that allows you to efficiently dissipate oscillatory wave energy at the boundary of transition between the plates of the tool holder. This method allows increasing the resistance of the tool cutting edge significantly and expanding the technological capabilities for the effective selection of cutting modes to ensure compliance with requirements for dimensional and geometric accuracy, quality of processed surfaces of powered roof supports, hydraulic units, mining machinery and equipment.
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Date submitted2014-09-08
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Date accepted2014-11-04
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Date published2015-06-26
Justification of kinematic and power parameters of rack and pinion gear for heavyloaded mining machines
- Authors:
- L. V. Lukienko
- K. V. Galchenko
- I. V. Litvinov
The article contains the research findings on the justification of kinematic and power parameters of a rack and pinion system for heavy-loaded mining machines. The article points out that for a designer to find more reasonable constructive solutions it is advisable to carry out wear assessment of the designed gear at a design stage. Application of additional quality parameters of gearing is proposed, i.e. coefficients of acceleration and sliding velocity and the scoring resistance coefficient. Introduction of these parameters will allow choosing geometrical parameters of the designed gearing, which will possess the best kinematic and power character-istics and will be least inclined to wear.
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Date submitted2014-09-16
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Date accepted2014-11-04
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Date published2015-06-26
The possibility to predict the oil and gas price crisis in the world market on the basis of the correlation analysis
- Authors:
- V. A. Lebedev
- B. I. Spesivtsev
The article is devoted to the search for the formal signs of the onset of crisis phenomena in the global economy related to the financial and oil and gas markets. To predict the crisis in the financial market and, as a consequence, the fuel market, the theory of «Jokers and Channels» is used in this paper. In accordance with the theory, the market is divided into predictable and unpredictable periods. Methods of the correlation analysis are used to analyze time series of exchange rates and oil and gas prices. In this paper, the authors construct the time dependence of the annual Pearson correlation coefficients between the ranks of quotes of the world leading currencies over the period from 1999 to 2013. A strong correlation between oil prices and the dollar exchange rate leads to the suggestion of identifying the crisis phenomena in the oil market, and due to the strong link between oil and gas prices, in the liquefied gas market. According to the results of the correlation analysis, the «Joker» period is determined and the conventional period of crisis enters it with some delay. Thus, based on the research the authors can conclude that, in fact, the global crisis starts earlier than the generally accepted term and is determined by the Joker period.
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Date submitted2013-07-23
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Date accepted2013-09-11
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Date published2014-03-17
Use of coefficient of output at pit delimitation
- Authors:
- G. A. Kholodnyakov
- N. S. Vainonen
In work it is settled an invoice the final depth of a pit of the conditional complex occurrence presented by three minerals. It is shown that when developing complex occurrence it is more expedient to use coefficient of output, instead of overburden ratio.
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Date submitted2010-07-16
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Date accepted2010-09-06
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Date published2011-03-21
The aboveground oil pipeline temperature regimes calculation
- Authors:
- S. Yu. Trapeznikov
The theoretical and experimental investigations of the highviscosity oil transportation temperature regimes to improve the pipeline efficiency are caused by the insufficient knowledge of its heat transfer process. The dependencies for the hydraulic resistance coefficient and the dimensionless heat transfer coefficient of Nusselt are proposed.