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Kozhevnikov A.A.,National Mining University | Sudakov A.K.,National Mining University | Dreus A.Yu.,nchar Dnepropetrovsk National University | Lysenko Ye.Ye.,nchar Dnepropetrovsk National University
Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu | Year: 2014

Purpose. To examine the process of heat transmission in the porous coarse environment of cryogenic gravel filters element of block construction, manufactured by low-temperature technology, during its transportation along the drillhole. Methodology. We have applied the mathematical simulation of the heat transmission process. We have carried out the comparative analysis of the results of the simulation and test-bed experimental research of the process of heating the cryogenic gravel element in the aqueous environment. Findings. We have created the mathematical model of the process of heat transmission in the porous coarse environment of cryogenic gravel filters element during its transportation along the drillhole. According to the conditions of heat transmission (physical-mechanical properties of the composite in cryogenic gravel filter element, temperature of cryogenic gravel element heating, and temperature of environment, etc.) we have substantiated the technological conditions of the cryogenic-gravel filter transportation along the drillhole. Originality. For the first time we have obtained the dependence of phase transition time of composite on its thermal and physical characteristics during the heat transmission in porous coarse environment during its transportation along the drillhole. This composite was the experimental example of cryogenic gravel element. Practical value. The results of numeral investigations contributed to development of the methods of designing the manufacturing technologies of the cryogenicgravel elements and equipment for the productive horizons of boreholes.


Pevzner A.O.,nchar Dnepropetrovsk National University | Pevzner M.S.,National Mining University
Russian Physics Journal | Year: 2011

Motion of a charged particle in the field of a grounded conductive sphere is investigated. It is assumed that the field created by the sphere is quasi-static that implies limitation on particle velocities by nonrelativistic values and the possibility of neglecting magnetic interaction and heat losses. A classification is provided and possible particle trajectories are constructed in the examined case. © 2011 Springer Science+Business Media, Inc.


Bulat A.F.,Ukrainian Academy of Sciences | Kiseleva E.M.,nchar Dnepropetrovsk National University | Pichugov S.A.,Dnepropetrovsk State Technical University of Railway Transport | Blyuss O.B.,nchar Dnepropetrovsk National University
Journal of Automation and Information Sciences | Year: 2010

The proposed new vector criterion improves the results obtained based on the fuzzy c-means method. The possibility to apply the proposed vector criterion to fuzzy clustering problems is substantiated. The appropriate algorithm is constructed to allow one to perform clustering of rocks based on a predictive estimate of outburst hazard degree. © 2010 by Begell House Inc.


Nesterova O.U.,nchar Dnepropetrovsk National University | Pugachova A.S.,nchar Dnepropetrovsk National University | Voevudsky M.V.,Ukrainian State University of Chemical Technology | Krischik O.V.,Ukrainian State University of Chemical Technology | Musatov V.I.,Ukrainian Academy of Sciences
Chemistry of Heterocyclic Compounds | Year: 2011

Cyclization of the hydrazide of 5-ethoxycarbonyl-2,6-dimethylpyridine-3- carboxylic acid by acylation with aromatic or aliphatic acid chlorides with subsequent boiling in POCl 3 or heating in orthoformic acid gave the corresponding ethyl 2,6-dimethyl-5-(5-R-1,3,4-oxadiazol-2-yl)pyridine-3- carboxylate. The cyclization of the reaction products with hydrazine hydrate has been studied. Cyclization of the dihydrazide of 2,6-dimethyl-3,5- pyridinedicarboxylic acid under analogous conditions gave only 3,5-bis-(5-R-1,3,4-oxadiazol-2-yl)-2,6-dimethylpyridines, containing R = 2-FC 6H 4, H. © 2011 Springer Science+Business Media, Inc.


Ruzova T.A.,nchar Dnepropetrovsk National University | Tolstopyat A.P.,nchar Dnepropetrovsk National University | Yeliseyev V.I.,nchar Dnepropetrovsk National University | Fleyer L.A.,nchar Dnepropetrovsk National University
Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu | Year: 2014

The presence of aggregated structures is one of the main problems arising in determining dispersion degree of emulsions and other fine-grained materials.Purpose. To create a method for segmentation of aggregated structures of spherical particles in dispersive formations, allowing us to process aggregates including internal objects, which contours are located entirely within the aggregate; without restrictions on components number; and without using the concept of aggregate convexity deficit; it makes it possible to process units of complex configuration.Methodology. The new method includes several steps: filtering the image and converting it to monochrome mode; evaluating coordinates of aggregate's boundary points; contour correcting to eliminate possible contour discontinuities at image binarization; particles markers setting according to glares on particles surfaces; and aggregate's area distribution between the forming particles according to the Voronoy diagram. Particles centers and radii are determined by the area of corresponding diagram cell. Method operation was illustrated on model aggregates. We presented the graphic of dependence of aggregate separation accuracy on components overlap degree. The processing of aggregates in case of internal objects was also illustrated. We showed an example of processing of the image fragment of real emulsion type II (water in oil).Findings. The method allows segmentation of aggregated structures of spherical particles (emulsion drops) in dispersive formations.Originality. We have designed the method for aggregated elements of dispersed formations decomposition by means of investigated objects marking.Practical value. The method may be used to design systems for measuring dispersion degree of emulsions and other fine-grained mediums.


Ruzova T.A.,nchar Dnepropetrovsk National University | Tolstopyat T.A.,nchar Dnepropetrovsk National University | Yeliseyev V.I.,nchar Dnepropetrovsk National University | Fleer L.A.,nchar Dnepropetrovsk National University
Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu | Year: 2014

The main problems of the micro objects measuring by their video images are: low contrast, lack of lighting, background noisiness, and the presence of aggregated structures. The incorrect processing leads to substantial distortion of the measuring results. Purpose. To create the method for segmentation of aggregated structures of spherical particles (emulsion drops) in dispersive formations. The method is to be resistant to image noises and to allow processing aggregates of complex shape. Methodology. The method includes several steps: source image filtering, converting it to monochrome mode, evaluating coordinates of aggregate's boundary points, and making skeleton on the base of Zhang-Suen algorithm. The connecting points are defined as the narrowest places of examined aggregate (necks). To find connecting points, we propose to work in special function on each skeleton branch. This function characterizes the width of aggregate area corresponding to the examined branch in given point. The particles connecting points are defined as points of local minimum for mentioned function. Low-frequency filter have been used for smoothing function and decrease boundary noises influence. We have developed the method for correcting this function in order to smooth errors of object's boundary raster representation. The effect of the method is illustrated at model images as well as at the images of real emulsion fragments (type II emulsions, water in oil). Findings. The developed method allows realizing decomposition of complex structured aggregates, consisting of many spherical particles. Originality. We have proposed the method for aggregates segmentation based on information of their structure and aggregates contours. Practical value. Method may be used to design systems for emulsions (and other micro objects) measuring and analyzing.


Tolstopyat A.P.,nchar Dnepropetrovsk National University | Yeliseyev V.I.,nchar Dnepropetrovsk National University | Ruzova T.A.,nchar Dnepropetrovsk National University | Fleyer L.A.,nchar Dnepropetrovsk National University
Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu | Year: 2012

Purpose. To study hydro-gas-dynamic interaction, determine the most efficient blowing modes, and find the ways to increase the process efficiency. Methodology. Experimental investigation of liquidgas interaction in transparent model of technological device has been carried out. Water was used as liquid and air was used as gas in the model (gas consumption is 0,5-3,5 m3/h). The pipe (tuyere) with external diameter of 3 mm has been installed along the vessel axis. Pipe penetration into liquid was 200 mm. Three types of tuyers have been tested. The difference between them consisted in the configuration of the submersible part and nozzle. Two tips were extension of the pipe and differ by internal diameter, and the third one was V-shaped nozzle, made of two pipes. Injected medium was polystyrene (consumption of 30-100 g/min). Process recording was realized by camcorder (shutter is ~ 1/2000 c, 25 fps) in transmitted light. Video material was processed by computer. On the basis of the results optical heterogeneities, including both gas phase and conglomerates (condensed areas) of solid dispersive phase particles has been selected and digitized. Irregularity ratios for distribution of these parameters in diametric section of the vessel have been evaluated. Originality. We have investigated experimentally the submersible jet injection into liquid in the ladle by blowing devices of different construction of and blowing modes of gas and dispersive phases. On the base of statistical treatment analysis of videoimages the efficient dispergation modes have been determined. Findings. We have determined that double change in gas speed at the nozzle output makes no effect on heterogeneities value and their distribution uniformity. Dispergation of the system by V-shaped pipe is 2 times higher, and the distribution irregularity is 3 times less than dispergation by single-nozzle pipe, and this corresponds to more efficient and quiet process. The dependency in dimensionless complexes for calculating the length of immersed two phase jet has been obtained. Practical value. The results are used for design the plan of out-of-furnace metal treatment in hot-metal ladle cars.


Korkina M.P.,nchar Dnepropetrovsk National University | Kazemir V.S.,nchar Dnepropetrovsk National University
Russian Physics Journal | Year: 2011

Different types of T-solutions are investigated. The conditions at which one region of space-time can be described only by a statistic R-solution and another region can be described only by a T-solution are obtained. The common metric for R- and T-solutions is obtained where the spatial and temporal variables are interchanged. The T-solution which has the same mass function as for the internal static Schwarzschild solution is obtained. © 2011 Springer Science+Business Media, Inc.

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