Countries of the European Union have stated transition to carbon-neutral economy until the year of 2050. Countries with a higher share of coal-fired power generation currently have no solution to end their combustion and use clean, emission-free energy immediately. The solution to this problem in the energy industry appears to be the increased use of natural gas, which significantly reduces CO₂ emissions. In this article, we investigated the possibility of using coal in situ, using UCG (underground coal gasification) technology. We focused on verified geological, hydrogeological, and tectonic information about the selected brown coal deposit in Slovakia. This information has been assessed in research projects in recent years at the Technical University. From the abovementioned information, possible adverse factors were evaluated. These factors affect the rock environment around the underground generator by UCG activity. As part of the process management, measures were proposed to eliminate the occurrence of pollution and adverse effects on the environment. In the final phase of the UCG technology, we proposed to carry out, in the boreholes and in the generator cavity, water flushing and subsequent grouting. The proposed are suitable materials for solidification and stabilization. Results of this article´s solutions are crucial in the case of usage of this so-called clean technology, not only in Slovakia but also worldwide.

The purpose of this article is to determine the environmental impacts of underground gasification on the population and to analyze the risk of underground coal gasification (UCG) activities using selected risk assessment methods. Coal gas is a regular part of coal deposits and its extraction also allows the use of coal deposits that cannot be extracted by traditional methods. These technologies bring both positive and negative aspects. The paper points out the risk analysis, hazard identification and assessment during the operation of UCG technology using a risk graph and a risk matrix. Identified risks to workers that cannot be reduced should be taken into consideration and appropriate safeguard should be used. For each risk, it is necessary to inform employees about regular education and training. From worldwide experience with this technology, it is possible to analyze risks in Slovakia. Actual gasification produces polluting gases such as carbon dioxide, carbon monoxide, hydrogen sulphide, hydrogen sulphide, nitrogen oxides, tar and ash, and creates a risk that may occur on and under the surface of the site depending on the geological and hydrogeological structure of the deposits. Possible measures to mitigate the adverse effects are proposed for the implementation of this technology. Coal is still one of the main domestic primary energy sources. Currently, only 5 out of 19 deposits in the Slovak Republic are used. Underground gasification could increase the use of Slovak coal and brown coal deposits.

The use of geothermal energy (GE) and the green economy in the environment of Slovak municipalities and towns is significant, due to the reduction in the negative influences and impacts of human society’s constant consumer lifestyle. The authors highlight the use of modern scientific knowledge, practical experience, and ever-improving technologies in the field of renewable energy sources RES. The aim of this contribution is to draw attention to the under-utilization of GE’s potential in Slovakia. Given the country’s commitment to meeting emission limits under EU carbon neutrality agreements by 2050, the use of this resource is very pertinent. Slovakia has significant geothermal resources that are not currently sufficiently utilized. The article suggests using GE to heat housing units of the housing estate near the geothermal source. Three scenarios (60 °C (pessimistic), 65 °C (conservative), and 70 °C (optimistic)) were considered in our energy balance and economic advantage calculations. The green economy offers a sustainable way of using the earth’s resources. The financial calculations regarding the amount of investment, the expected financial return and the possible values of the saved emissions confirm the possibility of the further use of GE technology. The information under consideration can be used in other significant territories, which may be a theme for further research in this field.

Implementing quality tools and methods creates a basic foundation for innovations, sustainability, optimization, and competitiveness in the era of Industry 4.0 and Quality 4.0. This paper aimed to investigate the use of quality tools and methods in the 24 divisions of a mother manufacturing company without the influence of external factors such as geographical location (America, Africa, Asia, and Europe). It was important for the mother manufacturing company to implement a uniform process standard for innovation and performance. Research methods focused on using the Kanban card, Ishikawa diagram, affinity diagram, Flowchart, 5S, OPL, layout, and Pareto analysis. It was determined in this research that the synergy (combination) of quality tools and methods in divisions improves the process performance. This hypothesis was confirmed by the results of implementing quality tools in processes within divisions. A top result was the new innovative model of synergy of the quality tools and methods for divisions of the parent company thus filling a gap in the scientific field. This model created the basis for the uniform process standard in all divisions. The results brought improvements in the processes such as material input inspection, spare parts production, production process, and product packaging. This model could be a proactive instrument for process innovation.

Rotary rock drilling generates vibration signals that capture the dynamic behavior of the drilling system, the interaction between the tool and the rock, and the progression of tool wear. These signals, traditionally considered undesirable, have become a key source of information for condition monitoring and predictive maintenance. This study experimentally investigates vibration sources and diagnostic indicators using a laboratory horizontal drilling stand equipped with accelerometers and controlled operating regimes. Six regimes were evaluated, ranging from idle operation of individual aggregates (motor, pump, hydrogenerator) to drilling of concrete and granite under defined process parameters. Vibration data were analyzed in the time, frequency, and time–frequency domains using RMS, variance, spectral centroid, spectral entropy, FFT-based spectra, autocorrelation, cross-correlation, and spectrograms. The results confirm the research hypothesis that selected vibration-based indicators correlate with tool degradation. Increased RMS values, higher variance, reduced correlation symmetry, and a shift of spectral energy above 6 kHz reliably reflect wear progression and changes in the dynamic response of the system. Spectrograms further reveal transient phases and redistribution of vibration energy during drilling. The findings demonstrate that vibration measurements enable the identification and separation of vibration sources related to aggregates and processes. The extracted diagnostic features form a basis for intelligent monitoring and predictive algorithms in rotary drilling, supporting advanced condition monitoring strategies within Industry 4.0.

The article highlights the investigation of the relationships between measured quantities during the atmospheric geochemical survey of contaminated soil and the environmental burden of the industrial establishment in eastern Slovakia. Statistical data processing was undertaken from the measured values of pollutants. The basic statistical characteristics of the monitored indicators were defined here. With the help of regressive and correlative analysis, dependency was confirmed between examined values, further expressed by a mathematical relationship. We analysed variability of the measured variables due to the influence of changed input quantities by the non-parametric Wilcox test. The statistical data processing helps us to identify the dependency between the measured values and improves valorization of the pollution of a given environmental burden. This was due to the handling of organic pollutants and the production of basic organic and inorganic chemicals stated for other industries. Chemical analysis of soil air helps us to determine the extent and amount of soil contamination by pollutants. Individual pollutants have their own characteristic properties and their negative effects on biota, the environment and humans are different.