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The author studies stress concentration in wellbore zones during operation of underground gas storages. Numerical modeling yields that at the early stage of high-pressure injection of gas in underground gas storages, near the roof of a productive stratum, in rocks and in the cement lining, destructive shearing stresses arise, comparable with the injection pressure, which can induce the loss of tightness in the annular space. For preventing the loss of gas, it is proposed to ream the wells in the roof of a productive stratum and to install a spring centralizer at a certain place in the casing string. The nominal diameter of the centralizer should exceed the wellbore diameter. This can stop propagation of cement destruction. For decreasing the destructive stress intensity, it is advisable to round off corner zones while reaming within the interval of a productive strata.

Physical modeling of hydraulic fracturing is carried out in cubic blocks with an edge length of 200 mm, made of sand concrete mixed with coal fraction, in the nonuniform stress field. A fracture was created in a vertical branched hole. Computer tomography enabled studying the stress raiser at the mother and daughter hole juncture, the actual diameter of the borehole, the drilling-induced fracturing, the sizes of pores formed in consolidation of the manmade blocks, and the trajectories of the created fractures. It is found how the problem geometry and the compressive stresses affect the direction of the created fracture growth.

A series of laboratory pull-out tests were performed on several types of bolts to investigate the effect of profile geometry of resin grouted bolts on load transfer mechanism. Therefore, three different types of bolts were used to prepare twelve series of specimens with different profiles. To evaluate the effect of bond length, the specimens were made using rebar bolts with two embedment lengths of 75 mm and 150 mm. The results showed that load transfer capacity and displacement at peak load were effectively related to the profile configuration and annulus thickness of resin. The bolt types T1 and G2 had higher peak share stress levels and the bolts with a rib spacing of 12.5, 16, 25 and 8 mm had the highest peak shear strength, respectively. By decreasing the rib spacing and embedment length, the system stiffness increased. In the bolt types T1 and G2, by increasing the embedment length from 75 mm to 150 mm, the shear stress decreased by 7.8% and 10.5% and their stiffness decreased by 60.8% and 75.6%, respectively. As the thickness of the resin annulus increased, the peak load decreased.

This article presents an artificial neural network (ANN)-based mathematical model for the prediction of the intensity of ground vibration at the Veliki Krivelj copper mine. The starting points for the development of the model are the model of ground vibration, the software package Peltarion Synapse, as a basis, using artificial neural networks ANN and input-output data set of blasted patterns at the Veliki Krivelj open pit. The input-output set contains the values of the blasting parameters of individual blasting patterns and the measured peak particle velocities when blasting those patterns. The advantage of the ANN method was confirmed by comparing the results of predicting the particle velocity obtained by different methods.

The behavior of a pillar is examined in the course of mining of a blind ore body in the Southeast site of Tashtagol field. The geomechanics and geodynamics of the field is analyzed. The article gives calculations of stresses and inelastic strains, as well as the possible failure zones nearby the mined-out space during actual mining in the Southeast site and in the period of ground surface sink. The authors present the geophysical survey data on the thickness of the crown pillar between the mined-out area roof and ground surface. The area and parameters of the sink are determined from gravimetric measurements and aerial photography.

The article describes the integrated analytical studies and geotechnical assaying of blasted ore samples with size classification at a gold deposit. The parameters of mixed fractions for processing using different technologies are determined. The ore mining and processing flowsheet is developed for a structurally complex extraction block. An improved technology is proposed for the structurally complex ore deposit. Selective ore extraction is followed with screening and size classification into fractions with high and low contents of useful component. The fractions are blended, the blend with the high content of useful component is subjected to flotation, and the blend with the low content of useful component goes to heap leaching. The fraction with the increased content of useful component from rich ore is treated by two-stage sorption and leaching pre-oxidation, which ensures high metal recovery.

The present article describes the extensive characterization and stabilization of concentrated iron ore suspension having size ≤ 75 µm by various bench-scale tests. The rheological characteristics of iron ore in the concentration range of 60-80% (by wt.) have been investigated with and without the addition of Sapindus Mmukorossi dispersant. The stability of iron ore suspension with saponin is established through rheological properties, dispersant concentration and stabilization mechanism. The nature of experimental rheological data at different shear rates is accomplished by regression analysis and found to be a good fit with Herschel-Bulkley model. The Critical Micellar Concentration of the aqueous extracted dispersant is 0.018 g/cc. The presence of Sapindus Mukorossi saponin greatly improved the slurryability and stability of iron ore suspension. The head loss and specific energy consumption analysis successfully evidence the economic relevance of the surfactants in transporting the slurry through the pipelines.

Crushed rock shear tests are carried out to determine stability of a tailings pond dam. The tests allow finding the rock strength at different grain composition and density of rocks, as well as at different shear ring diameters and normal pressures. It is found that the internal friction angle and cohesion range as 35-40° and 0.0256-0.0293 MPa, respectively, in compacted rocks, and as 25-30° and 0.0163-0.0184 MPa, respectively, in uncompacted rocks.

The article identifies and examines four main directions in the development of corpuscular optics: those of Democritus-Gassendi, Anaxagoras-Hobbes, Philolaus-Descartes and Newton. It provides an epistemological assessment of the cognitive capabilities of corpuscular theories of light.

The article analyzes the shift that science is currently experiencing as a field of activity and an institution. It is concluded that there is a shift from science to technoscience or, more precisely, to biotechnoscience. This shift means a change in the basic setting. In the scientific paradigm, it was allowed to set on the knowledge of the world and the immutability of man as the subject of knowledge. In the techno-scientific paradigm, it is assumed that the world and man should be designed and changed to suit the engineering tasks of transformation. Man, as the main subject of change, should in principle be transformed and enhanced. The principle of human enhancement with the help of modern smart technologies is introduced. During shifting from science to technoscience, the boundary between science, culture, power and society becomes blurred and hybrid forms emerge, in which the production of new forms of life, including a new human project, becomes the basic process. In these hybrid forms, scientific knowledge ceases to be a purely epistemological unit, but integrates into large engineering projects.