The restrictions on carbon dioxide emissions introduced by the European Union encourage experimental work on new-generation materials containing smaller amounts of clinker. At present, silica fly ashes from the combustion of hard coal are widely used in the technology of cement and concrete in Europe and Poland. This research aims to assess the physical and chemical properties of fly ashes from the thermal treatment of sewage sludge for use in concrete technology in relation to applicable standards and determine their impact on the natural environment. The established concentrations of heavy metals are below the maximum values required when discharging sewage into the ground or waters and also meet the necessary leaching limits when inert waste is allowed to be landfilled and on substances particularly harmful to the aquatic environment. On this basis, it was found that the migration of heavy metals from concrete with the addition of ashes to the water environment is insignificant and should not be a major problem. In addition, the tests showed that the activity index did not exceed the limit value.

The main interest in introducing maritime autonomous surface ships (MASS) is centered on communication, autonomous navigation, and collision avoidance systems. This paper presents a more comprehensive approach, accounting for selected issues relating to navigation safety, ship operation, maritime rescue, and decision support systems for the MASS remote managing operator. The technical solutions for improving the safety of MASS operation are described, and the decision support system (DSS) for the MASS operator, based on the stochastic model of the process describing the safety of MASS operation, is proposed. The presented analysis can be used to build a computer program and an integrated decision support system that increases the safety and reliability of the MASS operator’s decision-making process.

This work is devoted to a computational investigation of the position and volume of the cavitation cloud in a cavitation tunnel. The position of the cavitation cloud and its volume in the cavitation tunnel, determined by numerical analysis with respect to the inlet velocity, allows for the determination of the lower or higher intensity of cavitation erosion within the tunnel of the sample material. A numerical analysis is carried out on a model of a typical cavitation tunnel used to investigate the resistance of structural materials to cavitation erosion. The tunnel under study consists of barricade (upper) and counter-barricade (lower) systems. The numerical analysis is carried out with the following five different values of the velocity in the tunnel inlet: 6 m/s, 9 m/s, 12 m/s, 15 m/s, and 18 m/s in the commercial CFD software – Ansys Fluent 2019 R3. The Schnerr and Sauer cavitation model and shear stress transport (SST) viscous model k-omega are used. The paper analyzes the distribution of velocity, pressure, and volume of the cavitation cloud. On the basis of the performed numerical analyses, the optimal velocity at the inlet to the tunnel of 15 m/s is determined, for which the volume of the cavitation cloud is the largest and the phenomenon of cavitation is the most intense. The determination of the position and maximum volume of the cavitation cloud relative to the inlet velocity to the tunnel will, in future, allow us to shorten the resistance tests for cavitation erosion of different materials under real fluid flow conditions.

The COVID-19 pandemic is undoubtedly a global crisis that has forced the world economy to a standstill. Subsequent lockdowns have caused downtime in all industries and all transportation sectors. The removal of the restrictions has made it possible to begin a slow return to pre-pandemic conditions, but research indicates that this will be a long process. Therefore, an indication of the development trends of passenger maritime transport in Poland, considering the impact of the COVID-19 pandemic, is the purpose of the article. Two specific objectives are identified: (1) To visualize the impact of the COVID-19 pandemic on passenger maritime transport in Poland; (2) To make long-term forecasts of passenger maritime traffic in Poland. The analyses showed that the COVID-19 pandemic had a very negative impact on passenger streams. It may take several more years to recover from the pre-pandemic state.

District heating networks are key components of efficient heat supply systems for municipal and industrial consumers. The purpose of the research presented in this article was to analyze the thermo-hydraulic parameters of the operation of a transmission main in a district heating network to improve the heat transfer efficiency. Based on a literature review of existing studies, the basic issues of the heat supply process were discussed, and selected methods and tools for simulating district heating networks were characterized. A detailed mathematical description of the phenomena occurring during heat transport in a district heating network pipeline was also presented. Then, analytical calculations and simulations were carried out for the selected district heating system using Termis software. Operational parameters collected in the actual district heating system were used as output data for analytical modeling. Pressure drops, power losses, and heat transfer efficiencies in the main buses at different outdoor temperatures during the heating season were determined. Selected results of the study were included, and possibilities for improving the efficiency of heat transfer in the studied district heating network were indicated.

Marinas are of key importance in the development of sustainable marine tourism, whereas requirements posed by certification organizations can have a motivating effect and contribute to the implementation of environmentally and socially friendly solutions. The aim of this study is to analyze two world-leading marina categorization systems: the Gold Anchor Scheme and the IMCI Blue Star Marina Certification System. A special focus is made on the criteria relating to sustainable development, such as requirements concerning services, equipment, and management, posed to marinas by the accreditation bodies. The following research question has been defined: Do certification and categorization contribute to the development of sustainable sailing tourism? The results of the conducted analyses show that part of the requirements set by the accreditation organizations running two of the most popular marina categorization schemes worldwide relate to the achievement of sustainable development goals. The requirements motivate the management at marinas applying for a category to implement solutions that are friendly to the environment and society, and contribute to the growth of local economies. The research results indicate that the categorization of marinas is not only of some marketing value but is also a useful tool in the development of sustainable marine tourism.

This paper substantiates the method of polarization selection of navigation objects located in the zone of atmospheric formations (i.e., precipitation of different intensity and phase state), based on polarization differences in the parameters of their echo signals in a partially polarized electromagnetic wave arriving at the input of the all-polarized antenna of the ship radar polarization complex (SRPC). The partially polarized wave is represented as consisting of two polarized streams with polarization degrees m1 and m2 corresponding to the echo signals of the navigation object and atmospheric formation. The property of the partially polarized electromagnetic wave reflected from a complex object (i.e., navigation object located in the zone of atmospheric formation) is represented by real energy polarization Stokes parameters having intensity dimension. The scattering ability of the complex object is represented by the Mueller scattering matrix, the elements of which are measured by SRPC when it is sequentially irradiated with electromagnetic waves of four fixed polarizations. Polarization selection of navigation objects located in the zone of atmospheric formations uses the difference of polarization degrees of echo signals of the navigation object and atmospheric formation. The process of selection of the navigation object echo signal from the echo signal of the complex object and its observation on the screen of the SRPC indicator or computer display is based on the relationship between the degree of polarization of the electromagnetic wave and the polarization parameters of the navigation object echo signal and the atmospheric formation. The aim of this research is to develop polarization criteria of optimality of radar parameters of echo signals of partially polarized electromagnetic waves, represented by polarization degrees m1 and m2 corresponding to the navigational object and atmospheric formation observed by SRPC. As a result of the performed research, the problem of polarization selection of navigation objects located in the zone of atmospheric formations along the ship’s trajectory according to the values of the polarization degree of the navigation object echo signal is solved.

The search for opportunities to save and use energy efficiently should primarily focus on sectors of the economy with the highest energy consumption. One such sector is construction. Buildings built in Poland in different periods according to the introduced and successively tightened thermal protection requirements have different energy characteristics, which differ from contemporary standards and future expectations in this respect. This article presents guidelines for the energy transformation of building resources towards climate neutrality and the condition of these resources in Poland to an extent relevant for estimating the energy savings potential as a result of their thermal modernization. The economic aspect relating to the implementation of the energy policy is also presented. Over the last twenty years, there has been a nearly 37% increase in final energy consumption and a close to 34% decrease in final energy intensity of gross domestic product (GDP) recorded in Poland, which proves that energy efficiency is growing virtually without increasing energy demand. Significant potential for rationalizing energy consumption is found, as well as the need to incur high costs relating to the construction sector transformation. The problem is the lack of databases on the technical condition, age, and energy performance of various groups of buildings, which means it is difficult to determine the thermal modernization needs and the achievable effects of energy savings for the entire building stock. Some inconveniences relating to the implementation of zero-emission guidelines are also pointed out due to the fact that the Polish energy system is largely based on fossil fuels.

The convergence of hydrometallurgical waste management and the principles of the circular economy holds immense potential for addressing the challenges posed by metal-enriched waste. By turning waste into valuable resources through efficient metal extraction, this approach not only aligns with sustainable development goals but also contributes to the conservation of resources, reduction of waste, and the promotion of economic and environmental well-being. This article deals with the further possibilities of processing metal-bearing wastes in the form of steel drifts via hydrometallurgy. The main part of this research focuses on the development of suitable technology for the leaching of steel flakes to obtain selected non-ferrous metals, mainly zinc and lead, for economic and environmental reasons. Laboratory experiments are carried out to verify a suitable leaching agent in the form of high-temperature acid leaching, neutralizing leaching, and magnetic separation verified in lead seals. From the results of the experiments, a suitable technology for processing steel fumes is proposed.

Ice phenomena in watercourses and channels pose a threat to flow continuity and hydrotechnical devices. The organoleptic method, relying on human observation, has limitations such as a narrow range, subjective assessment, and high effort, leading to its decline in use. This article presents a number of modern techniques, i.e., the interpretation of RGB images, using unmanned aerial vehicles. Drone imagery offers a bird’s-eye view of areas that would otherwise be difficult to survey. It can improve the detection of frazil ice jams and, thus, contribute to the monitoring and spread of frazil ice. The authors performed research in the area of the Wrocław Water Junction on the Odra River in the area of the inlet near the fish pass at the Opatowice Weir during the flow of frazil ice on the water surface. To observe the phenomenon, a UAV with an RGB camera was used to record video in an orthogonal perspective in order to reduce geometric distortions of the optical system. The center of the frame was used for the analysis. The presented research results and the recognition of the literature indicate the possibility of using the presented technique for early detection of a potential threat from emerging ice phenomena. The results of the conducted analyses are objectively compared to the observational technique used at observation stations and allow for a reliable comparison of the intensity of ice phenomena in selected periods.

Parcel lockers seem to be a very interesting and innovative solution for any type of city, beneficial to both customers and online stores. Accounting for the growing number of B2C e-commerce customers, this measure significantly meets their needs. Moreover, this solution solves the challenges of last-mile deliveries, which are one of the major effects of heavy traffic of commercial vehicles in the whole city area. Recipients and senders of parcels through parcel lockers are the main generators of demand for this service. Hence, assessing their satisfaction and requirements is a key indicator of the development of this area. This work focuses on the efficiency of user parcel lockers and compares the situation in Italy, Poland, and Ukraine. This paper also presents an analysis of the already existing data on the satisfaction of parcel locker users, as well as the results of a study conducted among Ukrainian consumers for this work.

Since the 1970s, ships in the Kattegat area and the Baltic Sea entrances have been advised to use one of the routes established by the Danish Maritime Safety Administration. As time passed, traffic increased significantly, demanding adjustments to the introduced solutions to accommodate new volumes of ships passing through the entrances to the Baltic Sea. It is estimated that about 70,000 vessels are passaged via Kattegat yearly. Additionally, an increase in the traffic of fishing vessels and small pleasure crafts of different types has been observed, necessitating regulation to ensure the safety of navigation for everyone involved. Therefore, on the 1st of July 2020, a new routing system was introduced in the area of Kattegat by the decision of the International Maritime Organization (IMO). This paper focuses on the exact changes made and how those changes may influence the safety of navigation in Kattegat and the Sound, considering the COLREG rules and human factors in planning and executing passage via this area. A short presentation of recent accidents, and a study of difficulties arising from the new traffic organization, will be given. Brief traffic analysis is conducted using IWRAP MK II software, and historical AIS data from research will advance a more detailed examination and simulations. Finally, the introduced routing system’s effectiveness is compared using density plots from chosen periods. Furthermore, the analysis of the influence on the safety of navigation, as the introduced solution, is observed to be unusual. New routings have been in force for over two years and are accepted and used by most merchant vessels operating in Kattegat. Even so, this period is too short to clearly state that it is completely safe.

Maritime and coastal areas are the lifeblood of many countries. They are vital to the prosperity of countries because they provide trade routes, regulate the climate, are a source of organic and inorganic resources and energy, and provide a place for the public to live and relax. Increasingly, however, there are divergences and barriers to the use of marine areas. On the one hand, available and developed technology and knowledge enable increasingly improved use of the sea. On the other hand, the combined effect of these activities leads to conflicts of interest and the deterioration of the marine environment. The purpose of this study is to analyze the feasibility of using automatic identification system (AIS) maritime traffic data, in terms of its suitability, to correctly assess the utilization of the potential of a specific fleet within the offshore shipping industry. In addition, the authors undertake the task of determining to what extent activities relating to the GPS position of the ship, ship type (i.e., cargo or passenger), ship status (i.e., aground, anchored, moored, not under command, restricted maneuverability, underway sailing, or underway using its engine), ship draught, service speed, total engine power, and deadweight constitute areas and methods for optimizing the use of the offshore fleet under all the conditions previously described that limit this optimization. Given the stated goal, this paper uses both a literature review procedure and statistical methods to conduct a comparative analysis.

The aim of this work was to determine the effectiveness of using the FMEA method in the traditional and modern versions for a small company producing plastic toys. It also identified the production process of a plastic instrument toy selected for analysis by dividing operations into adding and not adding value, in accordance with the Lean concept. Through the FMEA sheets constructed and presented in this work in both versions of this method, the causes and effects of defects in the technological operations of the production process of the test subject were presented. A risk analysis was carried out using assessments available for the traditional and new versions, and preventive and detective actions were proposed. The result of the work was a comparison of risk indicators characteristic for both versions of the FMEA method and an assessment of the effectiveness of this method in the analysed enterprise. Emphasis was placed on the human factor in the research. Both the division of operations into adding and not adding value, as well as the FMEA method, were useful for further optimization and process improvement activities.

The main purpose of this article is to prepare an appropriate plan for the development of the infrastructure of the Bieszczady region for the use of electric cars as the primary means of mass and private transport for residents and tourists in the Bieszczady region. Over the next few years, electric cars will be available to an increasing number of people, thanks to more affordable purchase costs. This is made possible due to the dissemination of technology on the market and the emergence of increasing competition in individual segments of the automotive industry. The decisive condition will be the appropriate infrastructural facilities – i.e., chargers for electric cars, both those “fast” for direct current (DC) and “slow” for alternating current (AC). The development of infrastructure directly contributes to the purchasing decisions of electric cars made by residents of a given territory or people traveling through a given country with their own cars in the context of potential supplementation of electricity. In the first part, a review of the literature on the topic of electric cars is introduced. The second part presents the Bieszczady region in the context of electromobility implementation. In the last part, a detailed analysis of the region’s infrastructure (roads and car parks) is prepared, and, as a consequence, places are selected where the construction of a charging station would be justified. During point selection, the key parameters are the current condition of the road and parking infrastructure, the number of residents and tourists in a given zone of the region, and the strategic importance of the region. This article presents a detailed infrastructure analysis of locations where charging stations could be installed, including their amounts and power, in the Bieszczady region. The latter is divided into communes (i.e., Ustrzyki Dolne, Czarna, and Lutowiska), which provide a total of 14 locations, 55 stations, and 113 charging points. Introduction In the face of the challenge of the current climate crisis, it is necessary to accelerate the so-called energy transition to mitigate the harmful effects on the planet caused by the increase in greenhouse gas emissions into its atmosphere over the last few decades (Cook et al., 2013). One of the main pillars of this transition is the decarbonization of the econom