Dear Readers, We are pleased to present you the last issue of our Scientific Journals of the Maritime University of Szczecin in this year. In this last edition, you will find twenty-two articles addressing topics from a wide variety of research areas. They have been grouped into the following sections: Civil Engineering and Transport, Material and Mechanical Engineering, Environmental Engineering and Mining, Power Engineering, Sustainability and Smart City, Economics, Management and Quality Science. We are pleased that the manuscripts submitted to us cover such a broad research field. This allows us to offer our readers a multi-disciplinary spectrum of research problems.

This study aims to identify a model for building a resilient supply chain in a company testing engine oil samples. Unstructured face-to-face and structured remote interviews were used as the research methods. The proposed contextual research procedure allows for the elucidation of the content of the components of the final resilient supply chain model and may facilitate theory building on the basis of future multiple case studies. As a result of the research, it was found that at the level of the described chain, its strength and continuity of flow are based on the durability of relationships with suppliers, speed, trust, and information sharing, the role of which has been explained in relation to the nature of the supply chain. Due to the nature of the chain, building its resistance on the basis of agility, which is most often indicated in model approaches, has no justification in this case. It was also established that in this process, 4.0 technologies such as the internet of things (IoT), machine learning, artificial intelligence, and cloud technologies are more important for management at the level of the entire corporation than at the level of the tested chain. The analysis covered the supply chain embedded in the industry, which (according to the author’s knowledge) was not discussed in the context of logistics processes in world literature. Therefore, the results of the work undertaken are of great cognitive value.

The modern security environment is marked with significant changes and unpredictability. This is true both for natural threats caused most often by forces of nature and for threats to civilization such as technical disasters or failures. The fact that these threats may be synergistic not only complicates efforts that are mainly intended to mitigate them but also makes it difficult to determine their direct cause. The article presents a hypothetical model of the spread of dangerous substances released during a disaster involving a tanker carrying 20,000 kg of anhydrous ammonia by road, by rail, and by water in the territory of the Municipality of the City of Szczecin. A 2016 rail disaster involving two derailed tankers carrying ammonia is proof of the likelihood of such an event. Great amounts of dangerous substances are transported through Szczecin’s densely populated areas, most often to and from Zakłady Chemiczne Police S.A. (Police Chemical Plant), which causes a risk to the life and health of persons on the premises. The method of situation assessment in chemical, biological, and radiological contaminations (ATP 45 (Delta)) and the Promień IT system were used to forecast the hypothetical development of contamination. The results were compared with those of the ALOHA program. The author assumes that the conclusions from this paper will be used in the assessment of the likelihood of threat categories (KZ-3) and in the crisis response procedure (PRK-15), both included in the Municipal Crisis Management Plan.

This article presents an economic analysis of the exploitation of the main mine drainage according to the condition of machines. The study is based on actual operating data obtained during the operation of an underground hard coal mine. Through the selection of state estimators, appropriate sensory systems, as well as a long-term economic approach, operating procedures were developed that allowed for the introduction of significant financial savings. Operating costs are reduced by lowering energy consumption and reducing the costs of current repairs and spare parts. In addition to the classic approach to monitoring the state of a machine, based on the observation of residual processes, a global coefficient, referred to as unit energy consumption, has been proposed. Thanks to this, the operation of the machine occurs not only on the basis of its current dynamic state, but also due to the control processes of the machine’s operation. Moreover, the article refers to the area related to water safety and the reliability of the pumping station.

The article presents results on the influence range of mining exploitation in a rock mass at the site of dog headings located in an area of intensive mining exploitation. The research is based on geodetic measurements of the subsidence of measurement line points located above the panel of a mined-out longwall. Studies were applied to assess the range of mining influence in a rock mass, which is important for the protection of dog headings against mining damage. If a range of mining influence comprises any protected workings, then the deformations caused by mining operations may result in the loss of their functionality and even in dangerous damage to them. The values of the parameters of the influence theory determined by geodetic measurements of subsidence can be used to determine the permissible length of longwall panels, ensuring the maintenance of the functionality of the protected dog headings and to optimize stress concentration zones in terms of the risk of rock mass tremors.

Statistical data on occupational diseases registered by the Institute of Occupational Medicine in Łódź indicates a renewed increase in the number of pneumoconiosis in Poland in recent years, especially in the section of PKD (Polish Classification of Business Activities) – mining. Simultaneously, in 2018, because of the implementation of Directives of the European Parliament and the Council of the European Union, changes were introduced to Polish legislation in the field of protection of workers against the risk of exposure to carcinogens or mutagens related to the respirable fraction of crystalline silica formed during work. Considering this information, the members of the Department of Safety Engineering of the Silesian University of Technology attempted to assess the dust hazard and the frequency of occurrence of respiratory diseases among the employees of the preparation plant of mine X exposed to the harmful effects of industrial dust produced in the work process. The following methods were used as part of the research: individual dosimetry, infrared spectrometry, directional interview, diagnostic tests, and spirometry. The obtained results made it possible to identify workstations with the highest exposure to the harmful effects of industrial dust and to recognize the impact of this action in the form of pathological changes in the respiratory system in 18.4% of the miners surveyed.

The paper presents a new approach to the evaluation of human factor (HF) influence on the risk of maritime accidents. This approach is based on a formal human–ship–environment system definition including the relationships between humans, technology, environment, and organization. Social and organizational factors have already been included in the International Maritime Organization regulations; however, the individual factors still need investigation. A combination of psychological studies and technical operations of sea-going ships has given a huge opportunity to use HF assessment in rule-making processes. The main scientific goal of the research presented in the paper was the development of a method to assess the influence of HF on the risk of maneuvering accidents in restricted waters. This method is based on research within the area of technical ship operation and the results of the psychological profile of operators. The proposed model is based on a quantitative HF model developed by an authorized psychologist comprising personality traits, vulnerability to stress, and risk approach. The investigations were carried out with a group of 32 experienced ship masters performing a complex maneuvering task on the Full Mission Ship Handling Simulator. The multidimensional dependencies between variables of the psychological profile and the risk of an accident resulting from maneuvering errors were implemented into the Sugeno fuzzy model. The developed model allows risk assessment to be conducted that depends on the selected personality profile features. These features can be measured using psychological questionnaires, and then the risk of an accident due to maneuvering error can be calculated for a captain or marine pilot in order to improve human resource management.

Flight training is occupied by many hours of theoretical and practical training. Polish universities offer the possibility of conducting the aforementioned training as part of academic training. A young aviation student, implementing himself in this process, takes on the burden of academic training and aviation training. The aviation environment is sensitive to safety issues. These include the occurrence of incidents, events, and aviation accidents. This issue arises directly from the possibility of endangering the health and lives of bystanders as well as aviation personnel and the damage or destruction of aviation equipment. In addition, there are issues related to the immobilization of airports, aviation organizations, excess repairs, or cases settled in court. Despite all the above, it should be mentioned that air transport is described as the safest means of transportation where – although incidents, events, or high-profile crashes are occasionally recorded. It is desirable for personnel to remain as focused as possible during aviation tasks. The multitude of tasks carried out by aviation students, combined with the burden of academic study, can carry a significant impact on maintaining concentration, lowering perception, or at least meticulousness. These topics correlate closely with the human factor. As a research problem, the submitted work was adopted to determine the impact of academic teaching load on the safety of aviation activities performed, in the context of aviation training provided at universities. The research included aviation mechanics and aircraft crews within its scope.

The solution of the nonlinear equation for a ship’s rotational motion around its longitudinal axis, even with simplifying assumptions, is complicated. This oscillatory motion, which is known as the roll motion, is generated when the ship sails in the waves, and the irregular behavior of the waves causes time-varying dynamics. Calculating the ship’s roll response is possible by determining roll equation coefficients. In the current study, the coefficients were determined from the dynamic response of the ship using a training feed-forward neural network. The training was carried out in two modes: as a free swing in calm water and forced oscillation in irregular waves. The DTMB 5415 vessel was selected as the case study ship. The results of the simulation by the neural network were validated by numerical analysis and model test results.

Currently, the Polish power industry is mainly based on solid fuels, such as hard coal and lignite, and there is a problem with the management of significant amounts of combustion waste. One of the directions of recovery of these types of waste is underground hard coal mining operations, where the general problem of their management is the variability of physical and chemical properties resulting from the combustion of fuels of different parameters in power boilers with different exhaust gas cleaning solutions, mainly desulphurization methods. One of the solutions for energy production currently in use is the combustion of coal in fluidized bed boilers, in which the so-called dry desulfurization method is adopted. As a result of this process, a fine-fraction waste with the European code 10 01 82 is created, which is characterized by pozzolanic features, enabling its use wherever specific strength parameters are expected from the material. One such technology is the liquidation of underground workings based on the pouring of a hydro-mixture into the fenced-off space of the workings using a gravity-fed pipeline. The space to be filled is fenced off by closing it on both sides with dams, usually made of brick walls, located at an appropriate distance. It should be taken into account that the hydro-mixture will tend to slow the sedimentation of solid particles on the spreading path, and working may have a variable slope. The paper presents the results of laboratory tests of the physical and mechanical properties of hydro-mixtures made on the basis of selected energy waste from a fluidized bed boiler, along with a practical example of its application for the liquidation of underground workings.

Due to the high demand for secondary alloys in the automotive and aerospace industry, this work investigates the effect of higher iron content on the quality of AlSi7Mg0.6 sand castings. Secondary-recycled Al-Si alloys contain an increased amount of impurities due to their remelting of scrap metal. One of the most unwanted impurities found in these alloys is iron. Iron leads to the formation of various Fe-rich intermetallic phases, whose morphology influences the mechanical properties even at low Fe content. It also promotes the formation of casting defects, such as porosity and shrinkage. The formation of porosity in secondary Al-alloys is another major aspect that can affect the final properties of castings. Since these materials are mainly used to produce castings for the automotive industry, such as engine blocks, cylinder heads, and so on, it is necessary to produce castings without any defects. Therefore, the quality of AlSi7Mg0.6 sand casting is investigated at lower iron content (0.128% wt. Fe) and compared to the higher iron content (0.429% wt. Fe), whereby a correlation between iron content and porosity is monitored.

Inland waterway transport (IWT) is currently in focus for EU countries due to a shift in policy towards a more sustainable and green economy. The aim of this article is to analyze the possibility of using a grey incidence analysis (GIA) to identify key factors related to the functioning of the IWT system. GIA is classified as a multi-criteria decision-making method and is one of the key applications of grey systems theory (GTS), i.e., systems with incomplete and uncertain information about structure and behavior. GIA identifies the most favorable (or quasi-preferred) system characteristics and the most favorable (or quasi-preferred) system factors. The identification of such characteristics and factors enables a reduction in the inconsistencies in decision making on the functioning of the system. The application of the GIA to the assessment of the IWT system is an original concept.

For many reasons, ship model interaction tests are performed in experimental towing tanks. This paper presents research on the hydrodynamic forces acting on a ship tied up at the solid berth, which is produced by other ships passing by using free-running ship models with much larger dimensions than those used in towing tanks. A passing ship model was controlled by a human operator – an experienced master. This enabled a study of the influence of the interaction impact on the course of the maneuver. The research was carried out at the Ship Handling Research and Training Centre in Iława. The ship model was moored alongside and equipped with multi-directional force sensors linking the ship model with a solid berth. Forces were measured as a function of the passing ship speed, side distance between both ships, ship sizes, and depth-to-draft ratio (H/T). Forces were measured in two planes: the longitudinal (surge) and the transversal (sway). A numerical database was processed and ordered according to the variables. The fuzzy model was created within a “Matlab” computing environment using a Sugeno-type self-learning neuron network model. The proposed Sugeno model was evaluated with other methods presented by Flory (2002), Seelig (2001), and PASS-MOOR by Wang (1975). The ultimate goal of this study was to simplify the method of predictive calculations for adjusting speed and distance when passing by the moored ship, which ensures compliance with safe port mooring requirements.

Rising awareness of sustainable development challenges, along with the quest for optimization of the everyday functioning of the city, motivate many urban authorities to search for promising concepts and solutions. One of these is the smart city concept, which has gained governors of cities’ attention for little more than ten years. An object of research and development, it is still a distinctive feature for the cities that adopt this concept. City marketers use such distinction towards a large palette of beneficiaries of the city. At the same time, it deploys some traits suggesting synergies between the implementation of smart city solutions and sustainable development goals. The main objective of our work was to verify if the relationship between these aspects (smartness and sustainability of a transportation) in smart city rankings exists and, if that is true, what impact it has on marketing communication of the city comprised in such rankings. To fulfill this goal, we answered such research questions as: what place sustainability criteria in smart city rankings have occurred, how is the transport represented in these criteria, what use graded cities make of their presence in such competition, and which perspective dominates (if any) in daily marketing communication activities of the city. To provide such an analysis, we considered the criteria used to rank the cities to find the places that accorded to sustainable ones. We examined the marketing use of the results of such rankings, referring to the official websites and social media of selected cities (random selection from the total population of 174 cities comprised). The sources used to provide the data in natural language, and their analysis proceeded with methods and tools used in NLP (natural language processing), which are accessible through CLARIN.EU infrastructure. The results determine that cities can be classed into different groups, accordingly to their sustainability/smartness pending, and ability to use accorded ranks in marketing context.

Today’s shipping industry is experiencing a shortage of properly trained and competent deck and engine officers. This problem is becoming more acute with each passing year and traditional methods to resolve it apparently do not work. It has become obvious that cargo vessels must be less dependent on human operators. The solution lies in the replacement of manned vessels with autonomous ones. The introduction of autonomous vessels encounters several barriers, which need to be analyzed to find ways to overcome them. It requires a multipronged analysis of existing regulations, technical limitations, cyber security, and co-existence of manned and unmanned vessels in waters with dense traffic. The most difficult problems lie in international regulations, which were written for manned vessels only. Such rules need to be reworked before the deployment of autonomous vessels can be sanctioned worldwide. Technical issues are being gradually resolved with the introduction of new technologies. Special attention should be given to the cyber security of autonomous shipping as it requires the transfer of very large amounts of data through wireless networks. Accommodation of manned and unmanned vessel traffic may require a new approach for ship routing to separate both kinds of traffic.