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Purpose. To develop and substantiate an effective methodology for determining the technological parameters for the use of hydraulic mining giants in the extraction of amber-bearing rocks, and to demonstrate the necessity of applying hydromechanical extraction methods for developing amber deposits in the Polissia region. Methodology. A comprehensive approach was used to determine the technological parameters for hydromechanical amber extraction, involving a systematic analysis and generalization of the experience in amber extraction from amber-bearing rocks. The research focused on the classical scheme of hydromechanical extraction, with an emphasis on establishing an auxiliary pumping station to restore water levels lost during operations. Findings. Based on the conducted calculations, the productivity parameters for the auxiliary pumping station were determined to be Q = 72 m³/hour. The optimal pipeline diameter was selected as D = 0.3 m, and the optimal slurry velocity was determined to be v0 = 2.75 m/s. The methodology for determining the technological parameters of hydromechanical amber extraction from amberbearing rocks was substantiated, including the theoretical foundations for their calculation and the selection of extraction equipment. Originality. For the first time, based on the analysis of the conducted research on the technological parameters for amber extraction from amber-bearing rocks in the Polissia region of Ukraine, a methodology has been theoretically substantiated and developed. This methodology determines the sequence of technological operations for the intensity of the process of destroying and washing out amber-bearing rocks by hydromechanical means. Practical value. The research results propose the most efficient method for amber extraction. These results allow for the determination of optimal parameters for hydraulic mining giants in the hydromechanical extraction of amber-bearing rocks and overburden, thus improving extraction efficiency with minimal costs. [ABSTRACT FROM AUTHOR]

Purpose. To develop a mathematical model for a system of amber extraction based upon physical cumulation and deflation effects under the conditions of turbulent flows. Methodology. Theoretical simulation of the extraction processes took into consideration use of a basic aggregate, converting processes, compounding processes, modification processes, aggregating processes, processes of rotation series development involving practices of design and operation of the available similar facilities, design solutions, and widespread unification of both components and assembly units. Analysis of the gained theoretical and practical experiences helped simulate processes of amber extraction from sandy and clay rocks with stope filling. Findings. Rock mass loosening by means of hydromonitor jets, operating tangentially in a casing while developing swirling pulp flows, has been simulated mathematically. A procedure to prepare filling material from mine tailing by means of a preparator, located within a settling pond, has been substantiated. The research, concerning mineral disintegration, has helped identify that the average value of the maximum deflector radius, shaped as a result of counter jetting action, is Rmax  0.3–0.5 m; at the same time, the average value of the maximum radius of a hole, shaped resulting from helical jetting action around suction pipe, is Rmax  0.3 m. Originality. For the first time, a mathematical model to use cumulation and deflation effects for a mineral disintegration has been developed as well as for preparation of filling material from mine tailing. The model reflects twists of helical 65–85º jetting action with the maximum 0.5 m deflector radius and development of turbulence improving stope filling efficiency. Practical value. The proposed procedure is the theoretical background to develop automated system of amber extraction from sandy and clay rocks, which will improve productive capacity of the mining process substantially. [ABSTRACT FROM AUTHOR]

Background: Matrix metalloproteinase (MMP)-2 and MMP-9 are gelatinases involved in many physiological and pathological processes including inflammation and angiogenesis, which make up the basis for tissue remodeling and repair. Prolonged inflammation and delay in healing of traumatic wounds result in postoperative cicatricial deformities. MMP-2 and MMP-9 activity monitoring might be a biomarker for healing of traumatic ocular adnexal wounds. Purpose: The purpose of the study was to assess MMP-2 and -9 levels in tissues in traumatic ocular adnexal wounds at various times after trauma. Material and Methods: We examined 60 patients presenting with traumatic ocular adnexal wounds one hour to three months after trauma. Tissue biopsy was obtained during surgical debridement of wounds and frozen. The main study group included samples of traumatized ocular adnexal tissue, and the control group, samples of healthy ocular adnexal tissue obtained during blepharoplasty. The levels of MMP-2 and MMP-9 were assessed by enzyme-linked immunoassay (ELISA). The absorbance of each well was read at a wavelength of 450 nm with a Multiskan FC plate reader, and the mean absorbance was calculated for each reference standard and sample. Samples of patients presenting with traumatic ocular adnexal wounds one hour to three months after trauma were compared with controls with regard to optical density. Results: MMP-2 and MMP-9 levels were higher in biopsy samples from traumatic wounds than in control samples. ELISA analysis found that the peak MMP-2 expression was observed at day 3 after trauma, and was 85% above the level in control samples. From day 7 to day 15, this early peak fell to a level close to (15% higher than) that of day 1. From day 15 to day 21, there was a 35 percent increase in MMP-2 expression. MMP-9 expression levels were significantly higher than MMP-2 expression levels. The peak MMP-9 expression was observed at day 4 after trauma, and was 155% above the level in control samples. From day 4 to day 7, MMP-9 expression decreased to a level 85% above the level in control samples. Thereafter, MMP-9 expression increased again to a level 100% above the level in control samples from day 8 to day 15, and gradually decreased from day 15 to day 21. Conclusion: Our study of MMP-2 and -9 levels in tissues in traumatic ocular adnexal wounds at various times after trauma demonstrated that the peak MMP-2 expression was observed at day 3, and the peak MMP-9 expression, at day 4 after trauma. The levels of both enzymes decreased at day 7, and varied thereafter. By day 21, MMP-2 and MMP-9 levels in samples taken from the wound were as low as the levels in control samples. [ABSTRACT FROM AUTHOR]

The article focuses on determining the impact of the consequences of the russian invasion of Ukraine on macroeconomic stability and the exchange rate of the national currency. The relevance of the chosen topic is substantiated. The problems of assessing the negative consequences of the russian invasion of Ukraine are outlined, including: violation of general macroeconomic stability, significant fluctuations in foreign exchange markets and destabilization of the national currency. The study considers the theoretical and methodological foundations of the study of foreign exchange markets and analyzes global trends in the development of the global currency market. The structure of world currency reserves is analyzed according to the assessment of the currency composition of the official currency reserve (COFER) of the IMF. The analysis of the dynamics of average spreads of purchase and sale of reserve currencies against the US dollar for traditional and non-traditional reserve currencies is carried out. As a result of studying world trends, the main factors that affect fluctuations in the exchange rate of currencies are identified. The main problems regarding the functioning of the national currency market in the context of the hostilities in Ukraine are outlined, in particular, the existing inflationary processes are analyzed. The dynamics of currency interventions of the NBU for 2021-2022 is considered. The features (advantages) of the application and the results of using the singular spectral analysis (SSA) method for predicting fluctuations in the US dollar and Euro in the national foreign exchange market are presented. The practical implementation of this method was carried out using the CaterpillarSSA software product. Evaluation of the accuracy of the forecast is performed using the MAPE method. The obtained forecast errors (less than 6%) suggest that the constructed models are adequate and can be used for further research and recommendations. Thus, it can be concluded that for Ukraine the most important factors affecting the exchange rate are seasonality and successful trade policy of the government, which, in turn, largely depends on resource prices. The carried out research allowed to highlight the features and main aspects of the functioning of the foreign exchange market of Ukraine during the period of ongoing military aggression

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Copyright of Radio Electronics, Computer Science, Control is the property of Zaporizhzhia National Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose. To increase the accuracy of dynamic models of difficult nonlinear processes for solving tasks to control these processes. Methodology. Complex estimation of characteristics, the choice of model structure and parametric identification of difficult nonlinear processes on the example of technological processes of mining and metallurgical production and processes in information networks. Findings. We have developed the prediction models of process indices of the ore ragging and the thermal state of blast-furnace process as well as traffic fractal models in information networks. The relative errors of approximation and prediction on the models range from 3 to 4,6%. The adequacy of experimental and model data has been proved. Originality. We have proposed the complex method of estimation and identification of difficult nonlinear processes comprising the estimation of characteristics based on the complex use of time-frequency, statistical and fractal analyses, the choice of model structure in accordance with received qualitative and numerical values of the process characteristics and its parametric identification based on the methods of local or global optimization allowing to get adequate models of the processes having increased accuracy. Practical value. The results can be applied to design management algorithms of complex nonlinear processes based on their comprehensive evaluation and identification. [ABSTRACT FROM AUTHOR]

This paper studies the rock mass stress state of deposits under highland conditions, depending on the geological structure of a particular rock mass area, the tectonic field of stresses and the region relief. This study is aimed to develop an experimental method for assessing and monitoring the properties and state of the rock mass adjacent to mine workings. Experimental studies are performed through stresses measurements in-situ. Based on research results, it has been revealed that the geological structures, tectonic fields of stresses and the earth’s surface relief of the deposit normally reflect the values and direction of the main stresses acting in the rock mass. These patterns can be used to predict and assess the stress state of the rock mass. During the rock mass stress state assessment, quantitative dependences have been obtained for determining the stress tensors conditioned by the overlying rocks weight, tectonics and fracturing, and the deposit surface relief The research results make possible to assess the nature of the stresses distribution, to identify the areas of reduced, equal, increased and maximum stresses concentration of the virgin rock mass, as well as to increase the efficiency of the geoacoustic control developed by the authors for the state of the rock mass adjacent to mine working.

Industrial use of hydromechanical method and equipment made it possible to represent quantitative assessment of parameters for efficient amber extraction from amber-bearing deposits. Mined-out deposits with non-commercial reserves, being technogenic ones, may become potential source of amber mining; however, it should involve technological development. Due to imperfection of available methods, losses of the mineral in pillars and mine dumps excess 50%. Taking into consideration positive vibration effect in the process of amber extraction from sandy deposits, special structure of vibration classifier has been designed making it possible to extract maximally even fine-size amber with the least technological losses. The studies have helped determine that the use of the vibration classifier to extract amber makes it possible to mine up to 95% of the mineral; in this context, both medium density and vibration effect amber-bearing sand dilution. Maximum velocity of amber buoying up achieves depending upon changes in water and air consumption for certain amber-bearing rock masses. Laboratory tests and full-scale experiments have determined that velocity values of amber buying up to the surface are 0.1 m/s – 0.21 m/s. The research has proved possibility of efficient use of integrated effect on rock mass of enhancing density of amber-bearing medium, vibration, and air flows in the form of bubbles. In this context, closed cycle on the liquid phase of the effect is implemented making it possible to substantiate the developed method for amber extraction.

New devices were developed to increase the extraction of amber, especially with the size less than 5 mm, which can not be extracted at the present time. They are made on the basis of a hydraulic spiral classifier using vibration and bubbling with air bubbles. Analytical formulas are needed to calculate such devices, in first, for free motion of particles, then the constrained motion, and then to determine the effect of vibration and bubbling on the speed. This article discussed the first part of the problem – hydrodynamics of free movement of amber and quartz particles in a mixture of amber sand-clay rocks with water. The technique and formulas of calculation of kinematic viscosity and speed of movement are given. The dependences of the kinematic viscosity and the speed of free deposition of quartz and free ascent of amber on the density of the suspension for particles size less than 5 mm are obtained. The non-linear character of the dependence of the speed of ascent of amber from the density of the suspension is set. The results obtained are the basis for the calculation constructional parameters and technological characteristics of the hydraulic classifiers of new construction.