energetic investigation of organic rankine cycles orcs for the exploitation of low temperature geothermal sources a possible application in slovakia

Abstract: The paper aims at analysing the energetic performances of Organic Rankine Cycles (ORCs) for the exploitation of low temperature heat sources. Specifically, the attention has been focused on low-enthalpy geothermal energy for small-scale applications. To this purpose a thermodynamic model has been developed and a parametric investigation has been performed considering different organic fluids (isobutane, isopentane, and R245ca). Saturated conditions at the expander inlet have been adopted and the effect of the internal regenerator on the system performances has been evaluated. The investigation highlights the large impact of the evaporation temperature on the ORC behaviour and the positive influence of the internal regenerator at the highest temperatures. Conversely, the effect of the internal heat exchanger reduces when the evaporation temperature decreases. Furthermore, a possible application in the Kosice Basin (Slovakia) has been analysed. The investigation demonstrates that the organic Rankine cycle represents an interesting option for efficient valorisation of low-enthalpy geothermal resources and electricity production in small-scale applications

Meranie konkurencieschopnosti viackriteriálnym hodnotením

Príspevok sa zaoberá analýzou konkurencieschopnosti výrobkov, ktorú určuje komplex rôznorodých vlastností. Z tohto dôvodu je pre meranie konkurencieschopnosti výrobkov vhodné použiť štatistické metódy najmä viackriteriálne hodnotenie, ktoré dokáže syntetizovať niekoľko rôznych znakov do jedného integrálneho ukazovateľa. V príspevku uvádzame prípadovú štúdiu hodnotenia konkurencieschopnosti osobných automobilov porovnávaním vybraných parametrov. Výsledkom článku je odvodenie súhrnného kvantifikátora Qi využitím korelačnej analýzy

XXV. mezinárodní kolokvium o regionálních vědách

Title in English: 25th International Colloquium on Regional Sciences: Conference proceedings The conference proceedings consists of papers presented at the 25th International Colloquium on Regional Sciences that was organized by Department of Regional Economics and Administration FEA MU. It contains 57 articles arranged by topic. The individual articles deal with e.g. socioeconomic disparities among regions, regional policy, territory attractiveness, tourism, or regional public administration

Techno-economic assessment of green hydrogen production integrated with hybrid and organic Rankine cycle (ORC) systems

This study aims to determine the most cost-effective approach for production of green hydrogen, a crucial element for global decarbonization efforts despite its high production costs. The primary research question addresses the optimal and economically viable strategy for green hydrogen production considering various scenarios and technologies. Through a comprehensive analysis of eight scenarios, the study employs economic parameters such as net present value, minimum production cost, payback period and sensitivity analysis. The analysis is validated using established economic metrics and real-world considerations to ensure feasibility. The results suggest that a hybrid system combining solar photovoltaic (PV) with storage and onshore wind turbines is a promising approach yielding a minimum cost of $3.01 per kg of green hydrogen, an internal rate of return (IRR) of 5.04% and 8-year payback period. These findings provide a practical solution for cost-effective green hydrogen production supporting the transition to sustainable energy sources. The study also highlights the future potential of integrating solar thermal (CSP) with an organic Rankine cycle (ORC) system for waste heat recovery in hydrogen production. The sensitivity analysis provides the importance of capacity factor, levelized cost of hydrogen, capital expenditure and discount rate in influencing production costs

How can companies actively redound to improve their ratings?: a current bank survey

The article deals with the possibilities of improving companies ́ ratings used for the evaluation of the probability of default of the credits granted by banks. There are two general views mentioned in the article. The view of banks, which can refine their conditions, and, above all, adapt themselves to potential risks, which leads to an improvement of their own risk management and their refinancing conditions. The view of companies, whose good ratings, no matter whether arranged by banks or by external rating agencies, imply appropriate interest terms. The influencing factors for the rating are known by many companies. Hence, in practice it is often a target to influence these factors and key figures positively. A successful implementation of the findings of the conducted survey would help companies to improve their rating. The main part of the article describes the results extracted for this purpose from the survey which was carried out between 28 November .2008 and 28 February 2009. The analysis of the survey identified contemporary allocation of documents, completeness of documents, actual financial + profit planning, disclosure of accounting policy and extensive company documentation as the five best possibilities for companies to improve their ratings. Also we can see a strong weighting of the banks on measures within the ranges of do- cumentation and balance relations. Of course, the conclusion concerning the best possibility for the rating improvement cannot be seen as unambiguous, since it depends on too many variables

Implementation of Circular Economy Technologies: An Empirical Study of Slovak and Slovenian Manufacturing Companies

Circular Economy (CE) practices and technologies are essential for increasing sustainability performance in manufacturing. Due to the increasing number of environmental regulations and growing public awareness of environmental issues, especially in the EU, CE is increasingly seen as a valuable factor in improving competitiveness. Therefore, there is a need for a fuller understanding of the ways in which CE technologies can be implemented into the manufacturing industries. The aim of this paper is to contribute to the identification of the characteristics of manufacturing companies and their perceptions of the barriers to the adoption of CE technologies. This survey-based study of 241 manufacturing companies (comprising a sub-sample of Slovak and Slovenian companies from the more extensive European Manufacturing Survey) uses a series of statistical tests to examine the implementation of three CE technologies. The results show that there is significant relationship between the adoption of CE technologies in manufacturing companies and their size, location, R&D activities, company age and product batch size. Finally, the research reveals the surprising finding that there is no apparent link between the perception of CE barriers and the plans of companies to implement selected CE technologies

Implementation of Circular Economy Technologies: An Empirical Study of Slovak and Slovenian Manufacturing Companies

Circular Economy (CE) practices and technologies are essential for increasing sustainability performance in manufacturing. Due to the increasing number of environmental regulations and growing public awareness of environmental issues, especially in the EU, CE is increasingly seen as a valuable factor in improving competitiveness. Therefore, there is a need for a fuller understanding of the ways in which CE technologies can be implemented into the manufacturing industries. The aim of this paper is to contribute to the identification of the characteristics of manufacturing companies and their perceptions of the barriers to the adoption of CE technologies. This survey-based study of 241 manufacturing companies (comprising a sub-sample of Slovak and Slovenian companies from the more extensive European Manufacturing Survey) uses a series of statistical tests to examine the implementation of three CE technologies. The results show that there is significant relationship between the adoption of CE technologies in manufacturing companies and their size, location, R&D activities, company age and product batch size. Finally, the research reveals the surprising finding that there is no apparent link between the perception of CE barriers and the plans of companies to implement selected CE technologies

Investigation of the Industry 4.0 Technologies Adoption Effect on Circular Economy

Industry 4.0 technologies’ adoption became a reality in manufacturing and other industrial companies. The effects of this adoption on several areas including the Circular Economy are interesting in the research field. Deep research and investigation of various Industry 4.0 technologies’ relationships with the Circular Economy are presented in this article. The investigation is based on collected data from 798 companies in five countries, Lithuania, Slovakia, Austria, Croatia, and Slovenia as part of the European Manufacturing Survey project in 2018. After filtering the data, groups’ comparison is used to form potential prospective relationships in connection with the presented literature. A logistics regression test is used by SPSS software to validate the hypotheses and potential relations. Based on the achieved results, it seems that both Industry 4.0 and non-Industry 4.0 technologies can have significant relations with Circular Economy technologies, so they can be potentially influenced or enhanced by both. Similarly, an investigation of the relations between the development of products with improved environmental impact and the use of Industry 4.0 technologies showed no clear dominance of Industry 4.0 technologies over non-Industry 4.0. Finally, there are two of the twelve investigated technologies that have a significant relationship (potential impact) on both the Circular Economy technologies and product development with improved environmental impact

Investigation of the Industry 4.0 Technologies Adoption Effect on Circular Economy

Industry 4.0 technologies’ adoption became a reality in manufacturing and other industrial companies. The effects of this adoption on several areas including the Circular Economy are interesting in the research field. Deep research and investigation of various Industry 4.0 technologies’ relationships with the Circular Economy are presented in this article. The investigation is based on collected data from 798 companies in five countries, Lithuania, Slovakia, Austria, Croatia, and Slovenia as part of the European Manufacturing Survey project in 2018. After filtering the data, groups’ comparison is used to form potential prospective relationships in connection with the presented literature. A logistics regression test is used by SPSS software to validate the hypotheses and potential relations. Based on the achieved results, it seems that both Industry 4.0 and non-Industry 4.0 technologies can have significant relations with Circular Economy technologies, so they can be potentially influenced or enhanced by both. Similarly, an investigation of the relations between the development of products with improved environmental impact and the use of Industry 4.0 technologies showed no clear dominance of Industry 4.0 technologies over non-Industry 4.0. Finally, there are two of the twelve investigated technologies that have a significant relationship (potential impact) on both the Circular Economy technologies and product development with improved environmental impact