The transition from the linear model to the circular economy (CE) model is not an easy task and it requires constant monitoring of the achieved effects. Taking this fact into consideration, in January 2018 the European Union (EU) set 10 indicators to monitor and evaluate the main elements of the circular economy in the EU and its Member States. The list of indicators is short and it is based on the use of current available data. The monitoring results are intended to constitute the basis for setting new priorities towards the long-term goal of the circular economy. In case of companies there is still no framework for monitoring the effects of circular economy at micro level. In practice, various indicators for circularity assessment at micro level are available, but each of the indicators evaluates the complexity of circular economy to different extent. For this reason, there is a need to create a framework for monitoring the circular economy at company level, which would also be based on information already collected by the companies for the preparation of various environmental reports. Therefore, this article presents the results of review 66 environmental statements, which are prepared and updated annually by organizations participating in the Eco-Management and Audit Scheme (EMAS) system in Poland. On this basis, it was determined what circular economy information are already collected and reported by the companies and which information can be included in the framework of circular economy monitoring at company level in the future.
The aim of this article is to investigate the fiscal policy changes in six Central and Eastern European countries outside the Eurozone: Bulgaria, the Czech Republic, Croatia, Hungary, Poland and Romania. The analysis covers the period from 2004 to 2017. The study uses changes in the cyclically-adjusted primary balance as a main indicator to assess the fiscal policy stance. The results indicate that, in general, over the period from 2004 to 2017, the fiscal stance in these countries was somewhat contractionary.
Mining of longwalls ventilated by the „U” method is willingly applied in Polish coal-mines due to low costs of workings maintenance, low costs of ventilation and a lower fire threat because of a limited flow of air through goafs. However, such a way of ventilation may pose an increased risk of methane explosion. For this reason, the “U” ventilation has been limited in longwalls with methane risk. The mining regulations in force provide that ventilation methane-bearing capacity, i.e. the intensity of methane flow into the ventilation air cannot exceed 20 m3 CH4/min. The regulations also provide that in the event the absolute methane-bearing capacity, i.e. a sum of methane released to the ventilation air and captured by the methane drainage system is higher than 25 m3 CH4/min and the “U” method of ventilation is applied, the effectiveness of methane drainage should be minimum 50% in relation to the forecast absolute methane-bearing capacity. To streamline the process of ventilation near the junction of the longwall and the gallery carrying off the used air, auxiliary ventilation means are applied, such as a ventilation partition, a ventube – which supplies air without methane or with a low concentration of methane, injectors etc. Application of these means is limited by the cross-section of the heading carrying off the air from the longwall. Deformations of the ventilating roadway, which is usually located in the one-sided vicinity of goafs, may prevent the use of a ventilation partition, which has a negative influence on the conditions of ventilating the junction of the longwall and ventilating roadway. The author of the article also refers to such conditions, presenting average values and maximum concentrations of methane concentrations recorded with four methane concentration sensors, located in the vicinity of the junction of the longwall and ventilating roadway.
Soil contamination with rare earth metals (REE) can have both direct and indirect connection with industrial activity and ore-exploration. In the studies conducted so far, the presence of rare earth elements in coal seams, coal combustion waste as well as fly ash was found. It is important that detailed studies of the REE content in soil were not carried out in Poland. Until now, in a few studies, a high content of cerium and lanthanum was found in relation to the average content of the torn ones in the world. This work focuses on the areas under the influence of the industry associated with the extraction and combustion of hard coal, but also with other types of industry. Analyzes of REE content in soil were conducted in selected areas of the Upper Silesian Industrial Region and Norway, located near the Bjornevatn mine. In study areas, soil samples were collected and used for chemical and magnetometric measurements. Firstly, concentrations of REE were determined, and after that soil samples were used to measure soil magnetic susceptibility. Finally, statistical analyses were performed in order to check the correlation between REE concentrations in soil and soil magnetic susceptibility.
Nowadays, when we try to automatize all activities, there is a growing demand for energy in all forms. Increasingly we reach for new energy sources that can be problematic to store or to transport, owing to their toxicity or explosive propensity. The article examines the issues of determining danger zones occurring as a result of liquefied natural gas (LNG) release. The range of danger zones caused through LNG release depends on a multitude of factors. The basic parameter that needs to be considered is a type of the released substance as well as the manner of its release. The range of a danger zone is determined by, inter alia, the concentration of a released substance and the atmospheric conditions existing at the time when depressurization occurs. The article analyses the problem of the range of danger zones in a function of wind speed and surface roughness with a defined value of Pasquill stability for various LNG types, starting with pure methane, and ending with the so-called LNG-heavy. The difficulty of the task becomes more complicated when the analysed surface over which a depressurization incident takes place involves water. The problem deepens even further when the analysed substance possesses explosive properties. Then, apart from regular substance concentration, upper and lower flammability limit ought to be considered. Calculations were conducted with DNV-Phast software, version 7.11.
Dariusz Plinta, Martin Krajčovič, Radovan Svitek and Patrik Grznár
This paper presents a possibility of applying modelling and simulation in logistic processes management and design in production enterprises. New functionalities of the modelling software, especially those connected with analysing material and information flow, are already necessary for designing and evaluating complex logistic systems. The possibilities of modelling and simulation with the use of the CET Table system are illustrated by practical example.
Computer systems supporting the management of machines operation and maintenance in companies have been successfully applied in many branches of industry. Over the last few years these systems have been considerably transformed. It also seems that using them for operating mining machines in hard coal mines is inevitable, as maintenance generates high production costs. If implemented, the systems will allow for optimization of stocks, spare parts and materials, supplies, outsourced services as well as maintenance-repair works. Application of a system supporting the management of mining machines/equipment will also enable a better, more effective use of employees. As a result of these actions, the time needed for preparations and repair will be shortened, which will translate directly into the economic effects of mines.
For the Polish economy, hard coal is the basic raw material for the production of electricity and heat, guaranteeing energy security. To ensure safe and effective work in underground mines, the most modern technical solutions are implemented. Innovative achievements of production automation are increasingly being used. Introduction of the Industry 4.0 concept elements is an opportunity for: improvement of coal exploitation processes, use of IT tools supporting decision-making processes and ensuring real-time process management. However, the specificity of the mining environment poses many barriers, for example limitations resulting from geology, extent and volume of excavations, device mobility and telecommunications. The article describes mining threats and limitations as well as the current technical condition of Polish mining. The latest trends in mining development are described in line with the ideas of the fourth industrial revolution. The main goal of the article is to analyze the feasibility of implementing Industry 4.0 concept solutions for underground mining. The analysis was performed with a tabular descriptive method, based on the conducted mining documentation, own observations, surveys and literature research. The indicated limitations and recommendations developed can serve as a guide to further scientific research and implementations in this area.
The article addresses the problem of population aging and the related problem of using and maintenance of technical means by the older persons. Such persons, as participants of the exploitation process, experience various problems. Therefore, the challenge is to adapt technical means to the needs of older people. The response of engineers to this challenge may be the technology assessment, which assumes the adoption of various achievements in the field of philosophy, sociology, psychology or other social sciences as tools for their work. The proposal for such a solution is presented in the article and it is an indicator that allows you to draw conclusions about the real needs of older people. The effect of calculations with its use is the Wi characterization in the function of the human age. This characteristic complements the characteristics obtained on the basis of empirical data about the behavior of a technical mean. The article also presents the possibilities of using the discussed indicator. These include: improving the quality of life of users of technical means at various ages through rational management of company resources, improving the quality of life of users through user-centered design, exclusion from exploitation by the elderly technical means/their components based on social technology assessment, analysis and optimization of needs people of different ages, modeling the movement of older people, elimination of social exclusion of older people, improving the quality of life of people of all ages through appropriate knowledge management.
Shadow economy and corruption are the two harmful activities that do not work in the favour of tax revenue performance. As a result it renders an effective government incapacitated and unable to carry out its social responsibilities. This study considers the effect of the informal economy and graft on tax revenue performance in Nigeria using secondary data that cover a period from 1996 to 2018. This period has been covered by the corruption perception index captured by the Transparency International for Nigeria. Despite the theoretical approaches available in measuring the size of the shadow economy, the ordinary least squares technique is specifically used to perform the multi-regression analysis to arrive at the empirical results which indicate that both the shadow economy and corruption have negative influences on tax revenue performance in Nigeria, although the negative impact of corruption on tax revenue is more robust and significant. Thus, the study suggests among others that the government should step up action against corruption and also address the root causes of shadow economy in order to make the participants of the informal sector willing to formalize their businesses and voluntarily comply with tax payment obligations.