Acta Montanistica Slovaca最新文献

{"title":"Dynamic model of a longwall shearer with a chain haulage system","authors":"","doi":"10.46544/ams.v27i3.03","DOIUrl":"https://doi.org/10.46544/ams.v27i3.03","url":null,"abstract":"Despite the pro-ecological policy, hard coal still is and for a long time will remain a valuable major source of energy in the world. It is usually found in the form of seams in underground mines. For many years, thin coal seams have been exploited on an increasingly large scale, therefore mines and machine manufacturers are looking for new, effective and safe methods of extraction. One of such methods is the use of a longwall system with a single-head shearer. This solution has been briefly described in the article, with special focus placed on the proprietary dynamic model of a longwall shearer with a chain haulage system. The model concerns a chain-hauled single-head shearer, but can be used to simulate coal ploughs, and to a certain extent, scraper and belt conveyors. There are models in the literature in which the chain is replaced by point masses. In the discussed model, the chain segments have been described as a continuously distributed mass, the value of which changes as the shearer travels along the wall. The shearer has been modelled as a rigid body with six degrees of freedom, placed on elastic skids. The load from cutting, loading and movement resistance has been taken into account in the model. The mathematical model has been saved in the form of scripts in Matlab. The set of scripts allows obtaining information about the behaviour of the shearer and the load on important structural nodes such as skids, chain and loaders fasteners or the driving shaft of the cutting head. The results also enable determining the power demand of the motors as well as calculating the required initial tension of the chain. The fully parametric model makes it possible to analyse the influence of a change in the values of significant parameters of the longwall working, drive units and shearer. This information is crucial at the stage of design construction and verification, which allows avoiding many errors in the prototype.","PeriodicalId":50889,"journal":{"name":"Acta Montanistica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41991730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Vibration and Ground Deformation on Historic Structures: Case Study","authors":"","doi":"10.46544/ams.v27i3.17","DOIUrl":"https://doi.org/10.46544/ams.v27i3.17","url":null,"abstract":"When discussing historic structures, a significant problem is how to preserve and protect these structures. The presented paper deals with some issues of the unfavourable impact of industrial activity on some historic structures. Long-term influences from the industrial activity are one of the common sources of damage observed in these structures. Due to the size and volume of such structures, they are characterized by very low resistance to vibration and ground deformations. At the same time, the high cultural and material value of historic structures necessitates their costly protection and repair. Knowing the origin of problems, one may take proper actions to protect them. This paper discusses two important types of impact typical for industrial areas, especially affected by mining, seismically induced vibrations and continuous ground deformations from underground extraction. The presented discussion is based on the case study examples of historical sites located in some industrial areas in the Czech Republic and Poland. They point to different sources of damage to those structures that may arise as well as a combined effect of mining-induced seismic events and land subsidence. The medieval Jeroným Mine represents an underground structure loaded with natural and technical seismicity. The paper also includes a short overview of the process of seismic loading evaluation and basic information about historic structures with respect to seismic standards and land surface subsidence caused by underground mining.","PeriodicalId":50889,"journal":{"name":"Acta Montanistica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44593706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of sea waves energy resources in the Baltic Sea and technical possibilities of their usage for energy generation in Poland","authors":"","doi":"10.46544/ams.v27i3.20","DOIUrl":"https://doi.org/10.46544/ams.v27i3.20","url":null,"abstract":"Due to the current ecological situation in the world, the demand for renewable energy is growing. Its use does not burden the environment because resources are renewed in a short time, unlike traditional fuels - coal or oil. It can be concluded that the main task of humanity is to choose the appropriate technology for obtaining renewable energy and adapt it to local conditions. The aim of the work is to present the technical, economic and environmental potential of using the wave energy of the Baltic Sea and the possibility of converting this energy into electricity. The theoretical and technical potential of sea wave energy that Poland could use was estimated. The most advanced methods of converting wave energy into electricity were presented, and the most promising technical solutions were selected for use in the Polish Exclusive Economic Zone and off the coast of our country. The selection of the most promising technologies - single and combined wave energy converters was based on reports on the operation of the first experimental wave power plants and wave converters operating in other waters. In terms of technology and economics, obtaining energy from sea waves is much more difficult than using solar or wind energy. However, along with the development of offshore wind farms and access to the infrastructure of the National Power System and the need to give up traditional, emission-related energy sources, wave power plants may have a chance for development in the Polish energy sector. It is an untapped source of renewable energy with great energy potential.","PeriodicalId":50889,"journal":{"name":"Acta Montanistica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42607388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of karstic zones using RS & GIS method, Fuzzy logic and AHP in Neka catchment, Mazandaran, Iran","authors":"","doi":"10.46544/ams.v27i3.10","DOIUrl":"https://doi.org/10.46544/ams.v27i3.10","url":null,"abstract":"This study focuses on identifying zones and karstic phenomena using the RS & GIS method along with Fuzzy logic integration and the Hierarchical Analysis Process (AHP) in part of Neka catchment in Mazandaran province in the north of Iran. In this research, eight lithological factors, density and distance from the fractured lineaments, density and distance from the drainages, topographic slope, precipitation and vegetation status, were extracted from satellite and archival data as well as field data. Then these factors which affect karst formation and development are fuzzy and are weighted by the AHP method and integrated with T-norm, T-conorm (S-norm) and Compromise Operators. The results were processed by using software such as ArcGIS, ENVI, RockWorks, IDRISI, Expert Choice and PCI Geomatica, which were evaluated based on fieldwork. The results of this study show that most karst developments occurred in Lar Formation with the upper Jurassic. According to field visits, the best and most appropriate output for fuzzy layers integration are the use of a compromise operator in the range of 0.9 to 0.95. In spite of the suitable ability of Landsat 8 bands to extract lineaments due to vegetation status and other environmental conditions, the use of DEM was also necessary. This study shows that the use of new remote sensing and GIS technology, combined with Fuzzy logic and AHP, increases accuracy and speed and reduces cost in karst studies.","PeriodicalId":50889,"journal":{"name":"Acta Montanistica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48173751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Autoregressive Model in the Construction Management of Tunnels","authors":"A. Mahmoodzadeh, H. H. Ali, H. Ibrahim, Adil, H. Mohammed, S. Rashidi, M. Majeed, Mohammed Sardar","doi":"10.46544/ams.v27i3.02","DOIUrl":"https://doi.org/10.46544/ams.v27i3.02","url":null,"abstract":"The unknown subsurface conditions in tunnelling projects have led to their management with many uncertainties. From these uncertainties, we can mention the geological condition of the tunnel route and the time and costs required for construction. In order to significantly reduce these uncertainties, techniques that have a high predictive power must be used. For this purpose, in this study, an autoregressive model was used to reduce the uncertainties related to geology and construction time and cost in tunnelling projects. A comparison between the predicted results and the actual values through several statistical indices showed the high-performance prediction of the autoregressive model in the prediction of tunnel resources. Also, three input parameters affecting tunnel construction time and costs, such as RQD, groundwater, and RMR, were considered. The sensitivity analysis of these parameters on the time and cost of tunnelling projects was investigated through mutual information test (MIT). The groundwater was the most effective parameter on the tunnel's time and cost.","PeriodicalId":50889,"journal":{"name":"Acta Montanistica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44316616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of different clay minerals on the flotation kinetics of chalcopyrite","authors":"","doi":"10.46544/ams.v27i3.19","DOIUrl":"https://doi.org/10.46544/ams.v27i3.19","url":null,"abstract":"This study investigated the effects of clay minerals (montmorillonite, illite, and kaolinite) on chalcopyrite recovery and flotation kinetic parameters. Classical first-order flotation kinetic model was applied as a function of froth height and amount of clay minerals to fit overall flotation results on chalcopyrite recovery against flotation time. Clay minerals enhanced chalcopyrite recovery by mechanical entrainment and slime coating of valuable chalcopyrite particles. Flotation tests have shown that the deleterious impact of clay minerals on the chalcopyrite flotation is enhanced as follows: montmorillonite>kaolinite>illite. Montmorillonite significantly raised viscosity and also considerably diminished chalcopyrite grade. Recovery and selectivity were lower for montmorillonite than kaolinite and illite. The adjunct of illite was of little effect on chalcopyrite flotation kinetics. The obtained flotation rate constants indicate that clay minerals are carried to the concentrate together with the chalcopyrite. The flotation rate constants increased with increasing the amount of all clay minerals. Slime minerals easily entered to concentrate by mechanical entrainment, and the inhibition effect of clay particles on chalcopyrite became more obvious with increasing flotation time. However, the negative effect of clay minerals is reduced with high froth height.","PeriodicalId":50889,"journal":{"name":"Acta Montanistica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44659465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the functionality of bankruptcy models in mining companies","authors":"","doi":"10.46544/ams.v27i3.15","DOIUrl":"https://doi.org/10.46544/ams.v27i3.15","url":null,"abstract":"Mining companies are an important part of the national industry of the Czech Republic. Since mining companies are important for the industry, it is necessary to predict their economic development. Moreover, forecasting the economic development of an enterprise in terms of the risk of bankruptcy is an important activity for the financial management of any enterprise. One of the ways to predict economic development and assess the risk of possible bankruptcy is to use bankruptcy models. The aim of this paper is to determine the most appropriate model for predicting the bankruptcy risk of a mining company. The subject of the article is to identify the most suitable bankruptcy models applicable for bankruptcy risk prediction in Czech conditions of mining enterprises and to verify their functionality on real data of mining enterprises. On the basis of a search of expert sources and comparative analysis, it was found that the most suitable models for predicting the development of the enterprise in terms of bankruptcy risk are modified versions of traditional bankruptcy models. The analysis showed that the bankruptcy models are the IN05 Index, Altman's analysis for Czech companies and the modified Taffler's index. The authors' team conducted a thorough analysis during which they verified the functionality of the selected bankruptcy models on real data of mining companies. After a thorough analysis to test the functionality of bankruptcy models on real data from mining companies, the most appropriate model for estimating the evolution of bankruptcy probability risk was identified.","PeriodicalId":50889,"journal":{"name":"Acta Montanistica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49665405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The hybrid mathematical model for the evaluation and selection of iron ore raw materials in the context of the European Green Deal","authors":"","doi":"10.46544/ams.v27i3.01","DOIUrl":"https://doi.org/10.46544/ams.v27i3.01","url":null,"abstract":"The actual scientific research on the development of the hybrid mathematical model for evaluating and selecting iron ore raw materials in the context of the EU Green Deal is carried out. The necessity of developing decision support systems within the framework of the EU Green Deal concept is substantiated, in order to increase the degree of validity of decision-making in the evaluation space, regarding the green course and achieving the goals of the green agreement. For the first time, a systematic theoretical-multiple model of the problem of evaluation and selection of iron ore raw materials, according to the proposed factors of chemical composition, cost, and environmental policy of the manufacturer. The problem of multi-criteria selection of alternatives based on the imaginary alternative of the \"satisfaction point\" of the decision-makers (DM) requirements using the information model of criteria for evaluating the properties of the object of study on the chemical composition of iron ore raw materials. For the first time, a hybrid mathematical model of multi-criteria evaluation of iron ore raw materials with target needs was developed: quality of chemical composition of iron ore raw materials; the cost of iron ore; environmental policy and environmental impact in the extraction and/or enrichment of iron ore raw materials. The results of a study on a real example of evaluation and selection of iron ore concentrate for six alternatives implemented by Metinvest (Ukraine) were tested. The general step-by-step algorithm of the evaluation concept is described, which can be quickly implemented in the software product for the application. The developed model will be a useful tool for various programs of state support/business assistance in the procurement of iron ore raw materials by reasonably choosing a supplier using targeted needs in the context of synchronization with the EU Green Deal initiative. Raw material extraction and subsequent transport logistics are especially important for the engineering industry, the electrical engineering industry, and the automotive industry, with strong potential for the aeronautics and aerospace industry.","PeriodicalId":50889,"journal":{"name":"Acta Montanistica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45311062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The development of the blast furnace metallurgy of the iron in Slovakia","authors":"","doi":"10.46544/ams.v27i3.06","DOIUrl":"https://doi.org/10.46544/ams.v27i3.06","url":null,"abstract":"Easily available sources of iron ore, the abundance of hydropower, and wood for charcoal were the prerequisites for the development of iron metallurgy in Slovakia. Since the 16th century, the bloomery process used in iron metallurgy has been gradually replaced by the blast furnace process. This new process was more economical, but it required extremely high investments. The steam engine replaced the unreliable water power in the blowing process, and coke replaced charcoal. Especially due to economic problems, the first blast furnaces in Slovakia started to be built about two hundred years later than in Western Europe. Despite the promising start, the installation of steam engines was lagging. A major drawback was the lack of road and rail networks combined with the absence of local coking coal. The introductory part of the paper compares chronologically the individual stages of the development of blast furnace production in Slovakia and abroad. Next, the paper presents comprehensive results of the analysis of samples of the slag found at 59 sites of extinct ironworks with a blast furnace, localised until now. The samples were analysed by metallographic, chemical, spectral (secondary and trace elements), and X-ray methods. In the past, these data were published with territorial restrictions and mostly in a language other than Slovak. The contents of secondary and trace elements in slag from individual sites using cluster analysis and also metallic iron content in slags categorised according to owners of the blast furnaces and the slag basicity are compared.","PeriodicalId":50889,"journal":{"name":"Acta Montanistica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44063681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An analysis of groundwater drought in combination with meteorological droughts. Case study of the Gwda River catchment (northern Poland)","authors":"","doi":"10.46544/ams.v27i3.08","DOIUrl":"https://doi.org/10.46544/ams.v27i3.08","url":null,"abstract":"The article presents the research results aimed at determining the impact of meteorological droughts on groundwater droughts in the Gwda River catchment (northern Poland). The analysis was based on the Standardised Precipitation Index (SPI) and Standardised Groundwater Index (SGI) in various cumulation periods (1, 6, 12, 18, 24, 30 and 36 months) from 1986–2015. Monthly groundwater levels measured in wells and monthly sums of precipitation from meteorological stations in the vicinity of those wells were used to assess the relationships between droughts. During the study period from 1986–2015, three to 43 meteorological droughts and one to five groundwater droughts were identified. Meteorological droughts were most numerous for the shortest cumulation period (1 month), while droughts for the longer accumulation of 24 to 36 months were less numerous. The SPI and SGI indices were most strongly correlated over the annual cycle in the upper part of the catchment (between the Sępólno Wielkie station and well I-33_1). The correlation coefficient r was highest (0.69) between SPI-18 and SGI-1. Correlations were much lower in the middle of the catchment, where the maximum annual r coefficient was 0.39. There was no correlation between droughts in the lower catchment (r=0.14). The correlations presented for the Gwda catchment indicate that the relationship between droughts is not clear.","PeriodicalId":50889,"journal":{"name":"Acta Montanistica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42726164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}