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Date submitted2023-07-07
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Date accepted2023-12-27
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Date published2024-08-26
Landslide hazard assessment in Tinh Tuc town, Cao Bang province, Vietnam using Frequency ratio method and the combined Fractal-frequency ratio method
Landslides are one of the most frequent natural disasters that cause significant damage to property in Vietnam, which is characterized by mountainous terrain covering three-quarters of the territory. In 17 northern mountainous provinces of the country, over 500 communes are at a high to very high landslide hazard. The main goal of this study was to establish landslide hazard maps and conduct a comparative evaluation of the efficiency of the methods employed in Tinh Tuc town, Cao Bang province. The landslide hazard assessment was carried out in this study using the combined Fractal-frequency ratio (FFR) and the Frequency ratio (FR) methods. The FR method is based on the actualist principle, which assumes that future landslides may be caused by the same factors that contributed to slope failure in the past and present. The FFR method is based on the determination of the fractal dimension, which serves as a measure of the landslide filling density in the study area. Eight landslide-related factors were considered and presented in cartographic format: elevation, distance to roads, slope, geology, distance to faults, land use, slope aspect, and distance to drainage. Determining the area under the receiver operating characteristic curve (ROC-AUC) and verification index (LRclass) was performed to assess the performance of prediction models and the accuracy of the obtained maps. As a result, five zones were identified for the study area, characterized by very low, low, moderate, high, and very high landslide hazards. The analysis of the reliability of the obtained landslide hazard maps using the AUC and LRclass indices revealed that the FFR model has a higher degree of reliability (AUC = 86 %, LRclass = 86 %) compared to the FR model (AUC = 72 %, LRclass = 73 %); therefore, its use is more effective.
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Date submitted2023-11-08
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Date accepted2024-05-02
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Date published2024-12-25
Trace element composition of silicate minerals from Kunashak Meteorite (L6)
- Authors:
- Kristina G. Sukhanova
- Olga L. Galankina
Major (EPMA) and trace (SIMS) element geochemistry in the silicate minerals (olivine, pyroxene and plagioclase) of Kunashak equilibrated ordinary chondrite (L6) is described. No variations in the major element concentrations of the silicate minerals have been found, which is characteristic of equilibrated chondrites of petrological type VI. Low-Са pyroxene and plagioclase from the radiated olivine-pyroxene chondrule of Kunashak Meteorite contain an abundance of trace elements (Yb, Cr, Nb and Ti – pyroxene; Sr, Y, Ti and Zr – plagioclase), which is not characteristic of minerals from the porphyritic olivine and olivine-pyroxene chondrules of the meteorite. The porphyritic olivine-pyroxene chondrule of the Kunashak Meteorite has high trace element concentrations in olivine, in particular, the highest Yb concentration (0.12 ppm on the average) relative to porphyritic and radiated olivine-pyroxene chondrules (0.02 ppm). High trace element concentrations indicate rapid crystallization of a radiated chondrule in a nebula and show no traces of trace element homogenization upon thermal metamorphism. The trace element composition of silicate minerals from Kunashak Meteorite has retained the individual melting pattern of the chondrules and remained unaffected by thermal metamorphism on the parent bodies of the chondrules. Similar results, obtained in the study of Bushkhov Meteorite (L6), indicate that trace elements in olivine and low-Са pyroxene are resistant to thermal metamorphism. The persistence of the individual pattern of the chondrules enables us to use equilibrated ordinary chondrites for the study of processes at early stages in the formation of the Solar System and to better understand chondrule and planet formation mechanisms.
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Date submitted2023-04-04
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Date accepted2023-06-20
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Date published2024-02-29
Trace elements in the silicate minerals of the Borodino Meteorite (Н5)
- Authors:
- Kristina G. Sukhanova
Major (EPMA) and trace (SIMS) element geochemistry in olivine, low-Са pyroxene and mesostasis from porphyritic and barred chondrules, as well as the pyroxene-olivine aggregate and matrix of equilibrated ordinary Borodino chondrite (Н5) is discussed. No differences in major element concentrations in the silicate minerals of the chondrules and matrix of the meteorite were found. The minerals of porphyritic olivine-pyroxene and barred chondrules display elevated trace element concentrations, indicating the rapid cooling of chondrule melt in a nebula, and are consistent with experimental data. The trace element composition of low-Са pyroxene is dependent on the position of a pyroxene grain inside a chondrule (centre, rim, matrix) and the composition of mesostasis is controlled by the type of the object (porphyritic and barred chondrules, pyroxene-olivine aggregate). The depletion in trace elements of low-Са pyroxene from the rims of chondrules in comparison with those from the centre and matrix of the meteorite was revealed. The chondrule rim is affected by interaction with surrounding gas in a nebula, possibly resulting in the exchange of moderately volatile trace elements in low-Са pyroxene and depletion in these elements relative to pyroxene from the centre of the chondrule or matrix of the meteorite. The mesostasis of barred and porphyritic olivine-pyroxene chondrules contains more trace elements than that of porphyritic olivine chondrule and pyroxene-olivine aggregate, suggesting the rapid cooling of these objects or their high liability to thermal metamorphism, which results in the recrystallization of chondrule glass into plagioclase. However, no traces of the elevated effect of thermal metamorphism on the above objects have been revealed. The results obtained indicate no traces of the equilibration of the trace element composition of silicate minerals in equilibrated chondrites.
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Date submitted2021-11-10
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Date accepted2022-05-25
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Date published2022-12-29
Predicting the permeability of the near-bottomhole zone during wave impact
The research reveals that during selection of a method to increase oil recovery it is necessary to take into account rheological features of fluid movement through the formation, effect of capillary forces and heterogeneity of reservoir properties of the productive formation in thickness and along the bedding. Low-frequency wave impact, which is used to increase production in oil fields, is considered. At low-frequency impact new fractures appear and existing fractures in rocks increase in size. The greatest increase in porosity and permeability of rocks occurs at an impact frequency up to 10 Hz. Dynamics of oscillation amplitude during wave's movement in saturated porous medium is studied in the paper: essential attenuation of amplitude occurs at distance up to 1 m from borehole axis. With increase of frequency from 1 to 10 Hz the intensity of amplitude's attenuation decreases. The technology was tested on a well in Perm region (Russia). The actual permeability value was 50 % higher than the predicted value. According to the results of hydrodynamic investigations processing, it was noted that the greatest increase of permeability took place near the wellbore, while away from the wellbore axis permeability remained almost unchanged. In order to refine the mathematical model for prediction of wave impact on rock permeability it is necessary to take into account interconnection of pore space structure, change of adhesion layer, as well as to study transfer of particles during vibration.
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Date submitted2022-05-02
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Date accepted2022-05-25
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Date published2022-07-13
Features of olivine crystallization in ordinary chondrites (Saratov meteorite): geochemistry of trace and rare earth elements
The paper discusses the geochemistry of major (EPMA) and trace (SIMS) elements in olivine of porphyritic, nonporphyritic chondrules, and the matrix of equilibrated ordinary chondrite Saratov (L4). Olivine corresponds to forsterite and is rather heterogeneous (Fo 73-77). No differences in the content of the major elements in the olivine of the chondrule and the matrix of the meteorite were found. However, the content of major and trace elements in olivine within chondrules varies considerably; high values found in olivine from barred chondrules. Olivine from porphyritic chondrules and the matrix of the Saratov meteorite have similar concentrations of trace elements. High concentrations of refractory (Zr, Y, Al) and moderately volatile (Sr and Ba) trace elements in barred olivine chondrule indicate the chondrule melt formation due to the melting of precursor minerals and its rapid cooling in the protoplanetary disk, which is consistent with the experimental data. The olivine of the chondrules center of the Saratov meteorite differs from the olivine of the chondrules rims and meteorite matrix by the increased values of the Yb/La ratio. No relict grains and magnesian cores of olivine were found in meteorite chondrules. Individual grains in the chondrules are distinguished by their enrichment in trace elements relative to the rest of the olivine grains in the chondrule.
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Date submitted2022-04-04
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Date accepted2022-05-13
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Date published2022-07-13
Distribution of trace elements controlled by sector and growth zonings in zircon from a miaskite pegmatite of the Vishnegorsky massif, the Southern Urals
Data on the content and distribution of trace and rare-earth elements (SIMS method) in sectors and growth zones of a large zircon crystal from miaskite pegmatites of the Vishnegogorsky massif are presented. The morphology of the zircon crystal is a combination of a dipyramid {111} and prism {010}. It has been established that the growth sector of dipyramid {111} is characterized by almost one order of magnitude higher contents of Y, Nb, REE, Th; higher Th/U and Eu/Eu* values; REE distribution spectra are flatter compared to prism {010} growth sector. A regular decrease in the content of trace and rare-earth elements in the direction from the central zone to the marginal zone of crystal growth was revealed. A smooth regression of zircon crystallization temperature of zircon from 960 °C in the central zone to 740 °C in the marginal zone of the dipyramid sector and 700-650 °C in the prism sector has been revealed, which may be a reflection of thermal evolution of the crystallization process. It is assumed that crystallization of the central zone of zircon occurred at early stages from a relatively trace-еlement-rich melt. The crystallization was completed at lower temperatures, probably, simultaneously with the formation of REE-concentrating minerals, which resulted in natural decrease of content of trace and rare-earth elements in the melt and, consequently, in zircon crystallizing from it.
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Date submitted2019-03-31
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Date accepted2019-08-25
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Date published2020-02-25
Cascade frequency converters control features
The structures of systems with high-voltage cascade frequency converters containing multi-winding transformers and low-voltage low-power converters connected in series at each output phase of the load are considered. Low-voltage blocks contain three-phase diode or active rectifiers, DC capacitor filters, single-phase stand-alone voltage inverters and block disconnecting devices in partial modes (in case of failure when part of the blocks are disconnected). The possibilities of operation of cascade converters are determined, equations for correcting tasks to units in partial modes are given, tables of correction of tasks with estimates of achievable load characteristics are proposed. The results of experiments on the model of a powerful installation with a cascade frequency converter are presented, confirming the possibility of ensuring the symmetry of the load currents when disconnecting part of the blocks and the asymmetry of the circuit.
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Date submitted2019-05-05
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Date accepted2019-07-03
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Date published2019-10-23
Scraper Face Conveyors Dynamic Load Control
- Authors:
- E. K. Eshchin
The task of controlling the dynamic loading of scraper face conveyors (SC) is considered and the unsatisfactory state of loading of mechanical and electrical components of the SC is recorded. The possibility of the appearance of a self-oscillatory nature of the entire system load due to the peculiarities of the movement of the traction chain along the lattice frame of the SC is indicated. The property of the system is noted – the cyclic nature of the loading of the circuit during movement, which causes energy exchange processes between the mechanical and electromotive components of the conveyor (when using the head and tail electric drives) through the common cable network of the power supply system of the SC. A high level of dynamic loading of the electromechanical system causes the problem of eliminating the self-oscillating operating mode of the SC that generates it which is proposed to be solved by changing the angular rotation speeds of the SC drive sprockets. Angular speeds can be changed by applying frequency control of asynchronous electric motors. The efficiency of setting the frequency of electric motor stator currents of the head and tail drives of the conveyor is established in proportion to the frequency of rotors rotation to eliminate self- oscillating modes of operation in the main operating mode. The possibility of reducing the starting shock values of the electromagnetic moments of electric motors is considered. The results of the calculation of the start-up and liquidation of the self-oscillating operating mode are presented on the example of the scraper face conveyor Anzhera-34. The results of calculations of the start-up modes and the main operational transportation of coal in an uncontrolled mode of operation and after the introduction of control are compared, based on which it is concluded that it is advisable to use active control of the dynamic loading ofSC.
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Date submitted2019-05-07
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Date accepted2019-07-25
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Date published2019-10-23
Intensification of Bacterial-Chemical Leaching of Nickel, Copper and Cobalt from Sulfide Ores Using Microwave Radiation
- Authors:
- A. V. Kioresku
Currently, Russia and other countries display a steady tendency to decrease the amount of high grade and free- milling ore reserves. In this regard, the attention is being paid to the technology of bacterial-chemical leaching (BCL), which, unlike traditional pyrometallurgical enrichment methods, is well applicable for processing low-grade mineral raw materials. However, this technology has a significant drawback, which is the inability of microorganisms to create sufficiently aggressive conditions for the effective destruction of mineral complexes, which negatively affects the duration of the processes. The article presents the results of an experiment, the purpose of which was to study the multiple short-term effects of microwave radiation on the efficiency of extraction of nickel, copper, and cobalt in the process of bacterial-chemical leaching of sulfide ore. A microwave oven with a power of 900 W and a radiation frequency of 2.45 GHz was used as a source of microwave radiation. Irradiation was carried out every day throughout the experiment. The exposure time was 5 and 10 s; the flux density was 0.7 W/cm 2 . It was found that for all the studied microwave irradiation modes, a significant increase in the efficiency of biomass accumulation and the oxidizing ability of the medium was observed in comparison with the control that was not exposed to microwave radiation. Irradiation for 5 s twice a day increased the reduction of nickel by 16 %, cobalt by 15 % and copper by 6 %. The results of the study allow us to assess the prospects for the application of new biotechnology methods in the industrial practice of ore processing with an improvement in qualityindicators.
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Date submitted2019-03-13
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Date accepted2019-05-18
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Date published2019-08-23
Improving the Operation of Pump-ejector Systems at Varying Flow Rates of Associated Petroleum Gas
- Authors:
- A. N. Drozdov
- Ya. A. Gorbyleva
Application of pump-ejector systems for the utilization of associated petroleum gas reduces the negative environmental impact of its flaring, and also allows the implementation of a promising method of water-gas stimulation of the formation, which effectively increases oil recovery. Equally feasible is the use of pump-ejector systems in the operation of oil wells with a high gas factor, low bottomhole pressures to increase production rates and increase the turnaround period. A significant change in the flow rate of associated petroleum gas over time is a serious problem for the efficient operation of pump-ejector systems for the utilization of associated petroleum gas. To ensure the rational operation of the pump-ejector system under the condition of a variable flow rate of associated petroleum gas, experimental studies of a liquid-gas ejector characteristics were carried out. The article presents the results of the research, obtained pressure-energy characteristics of the investigated jet apparatus at various values of the working stream pressure before the ejector nozzle. The possibility of adapting the operation of pump-ejector systems to changes in the flow rate of the pumped gas, regulated by the working pressure and fluid flow rate through the nozzle is revealed. To successfully change the operation of the pump-ejector system, the possibility of frequency regulation of the pump shaft's rotation at changing gas flow rates in a small range of values is considered. With a large difference in the values of the possible flow rate of associated petroleum gas, it is recommended that frequency regulation should be supplemented by periodic short-term operation. The possibility of increasing the efficiency of the pump-ejector system when using salt solutions with a concentration that contributes to the suppression of bubble coalescence is noted.
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Date submitted2017-10-27
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Date accepted2018-01-01
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Date published2018-04-24
Method of induction control of iron weight fraction in magnetite ore
- Authors:
- I. N. Bazhenov
- O. O. Basov
This paper analyzes the peculiarities of existing methods and means of induction control of magnetic susceptibility of the medium are analyzed. It is concluded that these means have a common drawback due to the low measurement accuracy caused by the wave-like dependence of the instrument sensitivity on the gap between the probe and the medium surface. The ways of increasing the instrument sensitivity and measurement accuracy of controlled parameters by means of inductive measuring transducers are revealed. A method for induction resonance control of iron weight fraction in magnetite ore has been developed, and its effectiveness has been estimated using simulation modeling. Practical recommendations for the development of quality control instruments for magnetite ores have been developed. A variant of the quality control unit layout for working with magnetite ores is proposed.
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Date submitted2017-09-03
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Date accepted2017-11-04
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Date published2018-02-22
Development of sensorless vector control system for permanent magnet synchronous motor in Matlab Simulink
- Authors:
- V. Ya. Frolov
- R. I. Zhiligotov
In last 20 years segment of electric drives with permanent magnet synchronous motors has increased. This type of motors has better technical characteristics compared to induction motors, but has problems in actual implementation, one of which is the requirement of rotor position data. It is possible to implement with use of sensors or without them by means of motor state observer. The paper describes problems of sensorless vector control system for permanent magnet synchronous motors. The vector control system with state observer for permanent magnet synchronous motors is described. Synthesis of sliding mode observer for rotor speed and position is presented. The algorithm is implemented by development of model in Matlab Simulink environment with support by Texas Instruments processors support blocks. Experimental comparison of results of rotor angle state calculation and the data obtained by rotor position sensors was conducted. Research objective is a development of control algorithm, which has required precision for calculation of rotor start angle, high range of speed regulation and resistance to drift of motor parameters.
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Date submitted2015-12-17
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Date accepted2016-03-01
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Date published2016-12-23
Anomalous geochemistry of zircon from the Yastrebetskoe rare metal deposit (SIMS- and TOF-study)
- Authors:
- S. G. Skublov
- S.-Kh. Li
A detailed isotopic geochemical study (secondary ions mass-spectrometry – SIMS, time-of-flight mass-spectrometry – TOF) of zircon from ore-bearing syenites of the Yastrebetskoe rare metal-rare earth deposit (the Ukrainian Shield) has yielded proofs of magmatic genesis of the deposit: unaltered central parts of zircon grains typically feature characteristic magmatic spectra of REE distribution, their values of δ 18 O staying somewhat higher than the mantle value (6.5 ‰, on the average). During the final stage of forming the deposit the role of fluorine-water-bearing fluids enriched with Y, REE, Nb, Ве and heavy oxygen had increased, as directly reflected in the anomalous isotopic-geochemical characteristics of zircon rims and zones of zircon alteration (the contents of Y reaches 61874 ppm, that of Nb – 7976 ppm, Be – 1350 ppm, δ 18 O reaches 12.42‰, F – 0.7 % mass, H 2 O – 4% mass).
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Date submitted2015-12-28
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Date accepted2016-02-28
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Date published2016-12-23
Ion distribution function in their own gas plasma
- Authors:
- A. S. Mustafaev
- V. S. Sukhomlinov
Flat one-sided probe was used for the first time to measure the first seven coefficients in the Legendre polynomial expansion of ion energy and angle distribution functions for He + in He and Ar + in Ar under the conditions when the ion velocity gained along its free run distance is comparable to the average thermal energy of atoms. Analytic solution of the Boltzmann kinetic equation is found for ions in their own gas for arbitrary tension of electric field in plasma when the dominating process is resonant charge exchange. The dependence of cross-section of resonant charge exchange on the relative velocity is accounted for. It is demonstrated that the ion velocity distribution function differs significantly from the Maxwell distribution and is defined by two parameters instead of just one. The results of computational and experimental data agree quite well, provided the spread function of measurement technique is taken into account.
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Date submitted2015-08-18
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Date accepted2015-10-06
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Date published2016-04-22
Energy- efficient control of asynchronous motor drive with current refinement of the loss minimum on the basis of fuzzy logic
- Authors:
- O. B. Shonin
- V. S. Pronko
Currently, asynchronous electric drive on the basis of semiconductor frequency converters is widespread because of the relative simplicity and reliability of the design, the use of digital control systems, providing the accuracy and flexibility of process control, which allows for a significant increase in product quality, reduction in energy consumption and improvement of the enterprise profitability. In spite of these advantages, the problem of ensuring high energy efficiency of the drive in wide range of its operational modes is still not solved in full scale. The paper is devoted to the reduction of losses in the asynchronous drive on the basis of en-ergy-saving control algorithms that aim to ensure the desired mode of the driven mechanism while minimizing losses in copper and steel of the motor. On the basis of the motor model, taking into account magnetic losses, dependences of losses in the copper and steel, as well as the total loss from the absolute slip have been derived for different operating points of the drive. The optimal values of the absolute slip for different speeds of the rotor have been obtained for use in the con-trollers ensuring operation of the drive at maximum efficiency, highest power factor and minimum of the stator current. For minimizing the losses in the drive when changing the motor parameters it has been offered the combined method based on the method of loss model and iterative method of searching the minimum of power consumption. The effectiveness of the proposed control system using fuzzy logic is confirmed by comparing the graphs of losses and efficiency, obtained at using a traditional control law and the optimal control law.
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Date submitted2015-07-14
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Date accepted2015-09-28
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Date published2016-02-24
Ion velocity distribution function in arbitrary electric field plasma
- Authors:
- A. S. Mustafaev
- V. S. Sukhomlinov
Experimental investigations of the ion velocity distribution function (IVDF) are of great importance to various kinds of application: plasma nanotechnology, surface treatment, nanoelectronics, etching processes et al. In this paper, we propose a new probe method for diagnostics of anisotropic IVDF. The possibilities of the method have been demonstrated in arbitrary electric field plasma under conditions when an ion acquires a velocity on its mean free path comparable with the average thermal velocity of atoms. The energy and angular dependency of seven IVDF Legendre components for He + in He and Ar + in Ar have been measured and polar diagrams of the ion motion have been plotted. In order to verify the reliability and accuracy of the method the analytic solution of the kinetic Boltzmann equation for ions in plasma of their own gas has been found. Conditions under which resonant charge exchange is the dominant process and the ambipolar field is arbitrary have been considered. For the ambipolar field the dependence of resonant charge cross-section on the relative velocity has been taken into account. It is shown that the form of the IVDF is significantly different from the Maxwellian distribution and defined by two parameters. The results of theoretical and experimental data taking into account the instrumental function of the probe method are in good agreement. Calculations of the drift velocity of Hg + ions in Hg, He + in He, Ar + in Ar, and mobility of N 2 + in N 2 are well matched with known experimental data in wide range of electric field values.
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Date submitted2014-12-27
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Date accepted2015-03-01
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Date published2015-12-25
Minimization of energy losse when starting a variable frequency drive through application of a genetic algorithm of optimization
- Authors:
- O. B. Shonin
- V. S. Pronko
In the face of energy lack and rising energy prices one of the priorities of current researches is to improve energy efficiency of electric drives, which are widely used in modern industrial plants. Existing methods of minimizing losses are mainly designed for stationary regimes. At the same time, the development of algorithms for reducing losses in transient and in particular starting conditions is given little attention. Due to the high complexity of the description of the multivari-ate dynamic processes determining the optimal control laws is advantageously to be carried out us-ing stochastic optimization methods. The work seeks to substantiate the optimal starting character-istics of an asynchronous drive based on a genetic algorithm. A feature of the proposed method of optimization is the use of multiple simulation experiments to find start-up characteristics which provide a minimum energy loss. Automation of the search is performed using the developed pro-gram, which includes a module of a genetic algorithm and a module for interfacing with the elec-tric model in the MATLAB/Simulink environment. The program allows choosing the parameters of the genetic algorithm along with controlling the process of optimization. Application of the proposed method allowed obtaining the optimal starting characteristics «voltage – frequency» in a tabular form with consequent linear approximation of the data. Increase in efficiency due to the proposed start up law has been confirmed by comparing the simulation re-sults under conditions of using a traditional linear characteristic and derived optimal law. The es-timation of losses reduction has been carried out at the drive load of different kind in a wide range of its variation.
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Date submitted2010-07-15
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Date accepted2010-09-13
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Date published2011-03-21
Experimental setup for research Influence of vibromechanical treatment on mechanical properties of welded joints
- Authors:
- O. F. Khafizova
- V. I. Bolobov
The description of developed experimental setup for welding product that made of pipeline steels with application of applying vibration with intended frequency approximating to natural-vibration frequency of welded construction unit of pipelines during the welding cycle is presented.
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Date submitted2010-07-06
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Date accepted2010-09-14
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Date published2011-03-21
Electromechanical processes in electric drives of mountain equipment on the basis of the synchronous electric motor
- Authors:
- A. O. Sviridenko
The description is given and the function chart of the bench installation is resulted, allowing to reproduce static and dynamic modes of adjustable electric drives of an alternating current. The modes considered during experimental researches of the electric drive on the basis of the synchronous electric motor, working in a mode of ventilniy electric motor are listed. Conclusions are drawn on character of course of dynamic modes, comparison of the electric drive to the synchronous electric motor and the electric drive of a direct current with the subordinated regulation is given.
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Date submitted2010-07-20
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Date accepted2010-09-14
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Date published2011-03-21
The physical breadboard model of dynamically counterbalanced drilling string with swinging movement with the asynchronous electric drive powered by inverter laboratory experimental researche
- Authors:
- V. V. Ivanik
The laboratory experimental stand for research of the asynchronous resonant electric drive on a physical breadboard model of dynamically counterbalanced drilling string is developed. The asynchronous electric drive with swinging movement the autoresonant oscillation mode is realized.
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Date submitted2010-07-08
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Date accepted2010-09-02
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Date published2011-03-21
The autoresonant asynchronous electric drive of dynamically counterbalanced drilling string on carrying cable with swinging movement fluctuations amplitude stabilization
- Authors:
- E. A. Zagrivnyi
- V. V. Ivanik
The algorithm of resonant fluctuations amplitude stabilization of dynamically counterbalanced drilling string on carrying cable with swinging movement of jackbit is developed. Imitating modeling of the resonant asynchronous electric drive with swinging movement of jackbit with the frequency converter in various operating modes is resulted.
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Date submitted2010-07-26
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Date accepted2010-09-14
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Date published2011-03-21
Algorithm of control of the electric drive with ventilniy electric motor and the converter of frequency with the active rectifier
- Authors:
- A. P. Emelyanov
- A. O. Sviridenko
Advantages of application of the active rectifier as a part of converters of frequency for powerful drives with ventilniy electric motors are considered. The mathematical description of the processes proceeding in a power part of the active rectifier is given. The scheme of a drive with a vector control system with the gage of position of a rotor and the active rectifier is presented, schedules of power consumption and a current by a drive with the active rectifier are resulted.
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Date submitted2009-09-19
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Date accepted2009-11-15
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Date published2010-06-25
Potassium chloride content in ore and products оf recycling automatic control system
- Authors:
- S. S. Galushkin
- B. A. Vishnyak
- V. N. Smirnov
Potassium chloride percentage in continuous transported ore flows and products of potassium plants recycling automatic control system is offered and described. It differs fundamentally from used before ones at bulk solids containing natural radio-activity elements effective constituents producing and recycling plants. Sensing device is used in this information-measuring system (IMS). It allows to realize automatic control in flows for that instantaneous productivity fluidity in wide limits is resided. Using such IMS gives considerable economic effect by measurements error lowering and their quickness increase.
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Date submitted2009-09-26
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Date accepted2009-11-14
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Date published2010-06-25
Automatic bulk solids moisture in stream control system
- Authors:
- S. S. Galushkin
- B. A. Vishniak
- V. N. Smirnov
Automatic moisture in fine-dyspersated stream control system based on microwave frequency method is presented. Minimizing means of interrupting factors peculiar to this method of measurement are produced and systematically proved.
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Date submitted2009-08-17
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Date accepted2009-10-25
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Date published2010-02-01
Compensation of supply station reactive power by means of the mine main fan electric drive
- Authors:
- V. V. Sobolev
- O. B. Shonin
On the basis of comparative analysis of the mine main fan electric drive input voltage-current characteristics, a frequency-variable drive with pulse width modulation (PWM) rectifier and PWM inverter is shown to be the most competitive one because of its capability to independently implement the substation power factor correction and the mine air flow energy-saving control.