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Date submitted2023-04-10
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Date accepted2024-12-27
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Date published2024-04-25
Optimization of specific energy consumption for rock crushing by explosion at deposits with complex geological structure
The selection of efficient drilling and blasting technology to achieve the required particle size distribution of blasted rock mass and reduce ore dilution is directly related to the accurate definition of rock mass properties. The zoning of the rock massif by its hardness, drillability and blastability does not consider the variability of the geological structure of the block for blasting, resulting in an overestimated specific consumption of explosives. The decision of this task is particularly urgent for enterprises developing deposits with a high degree of variability of geological structure, for example, at alluvial deposits. Explosives overconsumption causes non-optimal granulometric composition of the blasted rock mass for the given conditions and mining technology. It is required to define physical and mechanical properties of rocks at deposits with complex geological structure at each block prepared for blasting. The correlation between the physical and mechanical properties of these rocks and drilling parameters should be used for calculation. The relation determined by the developed method was verified in industrial conditions, and the granulometric composition of the blasted rock mass was measured by an indirect method based on excavator productivity. The results demonstrated an increase in excavation productivity, thus indicating the accuracy of given approach to the task of identifying the rocks of the blasted block.
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Date submitted2015-08-20
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Date accepted2015-10-17
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Date published2016-04-22
Increasing the accuracy of the fast laser measurments transparent solid and liquid films thicknesses
- Authors:
- A. B. Fedortsov
Nondestructive optical methods for measuring of the «thick» films thickness of the order of 0,001-1,00 mm are analyzed. It is shown that using the laser beam radiation and modern optical and electronic schemes possible to decrease the time of single measurement to 1ms and less at the measuring frequency of 10-50 Hz. The possibility of measuring thickness and spreading coefficient and evaporation kinetics of liquid films is demonstrated. A new computer method of the data processing aimed to determine the film thickness from the angle dependence of the laser beam reflection coefficient by the film is offered. The offered procedure and the experimental technique realizing it permits to decrease the thickness determination uncertainty to the order of ten.
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Date submitted2009-09-26
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Date accepted2009-11-22
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Date published2010-06-25
Use of mosfet for the control of dielectric characteristics
- Authors:
- N. S. Pshchelko
- A. S. Mustafaev
In this work a device for measurement on a constant voltage of the basic electric characteristics of high-resistance dielectric materials and products from – their electric capacitance and resistance – is developed. The principle of work of the device is based on use of transients in connected in sereies elements having electric capacity and resistance. In the electric circuit of the device the MOSFET with high entrance resistance is used. The device on the basis of the MOSFET for measurement of surface potential of dielectrics is considered also. Use of this device is especially effective at measurement of electret surface potential. Results of research of electrets on a basis of silicon dioxide are discussed.