English Polish
Akademia Morska w Szczecinie

DSpace Home

DSpace/Manakin Repository

Browsing by Title:

  • Mousavi, Seyed Mohamadreza; Khoogar, Ahmad Reza; Ghassemi, Hassan (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    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.
  • Popczyk, Marcin (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    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.
  • Pastierovičová, Lucia; Kuchariková, Lenka; Tillová, Eva; Chalupová, Mária (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    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.
  • Tabor, Joanna (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    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.
  • Raszeja, Magdalena; Hejmlich, Andrzej; Nowicki, Jacek; Jaworski, Tomasz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    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.
  • Bruska, Anna; Boichuk, Nataliia (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    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.
  • Pawelski, Jan (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    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.
  • Sokoła-Szewioła, Violetta; Poniewiera, Marian (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This article presents results for the development of new methods of inserting discontinuity lines into the numerical model of the deposit in CAD systems. The main problem in creating a numerical model of the deposit is usually a very small number, as well as low reliability of the source data. Hence, the authors developed new algorithms for inputting discontinuities, which can be used in particular for conditions when a large number of discontinuities are present. The article offers algorithms for inputting discontinuities into the entire deposit model. The method of transferring faults from the higher seam to subsequent seams and determining the course of the fault in the entire rock mass has been described. The fault can be represented as a spatial mesh of triangles, just like the seam floor. Then the fault can be extended until it intersects with the next seam (with the next triangle mesh) using geostatistical methods. As a result, we determine the exact position of the discontinuity line in the next seam. The paper also presents several algorithms for checking the deposit model made using the methods developed by the authors, including the analysis of outliers (in terms of elevation and inclination), testing the variability of the fault throw, checking the distance between adjacent seams, and verifying the position of the deposit in relation to the existing workings and boreholes. It should be noted that the key issue while building a deposit model is a checking of the model, removal of the assumptions and, obviously, incorrect data in order to obtain the highest possible accuracy.
  • Ignac-Nowicka, Jolanta (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This article presents an analysis of the static loads on the human body during selected manual unloading tasks carried out by warehouse workers in a logistics company. The aim of the presented analyses is to minimize static loads in the work process and thus make the employees’ work more comfortable. A tool in the form of 3D SSPP software for ergonomic workload assessment was used to carry out static load analyses. For the two selected activities, the values of the developed forces of statically working muscles and the forces acting on the vertebrae of the spine were determined. For the values of static loads identified, based on the simulation of the 3D SSPP program, modifications in work posture and a change in the manner of performing the tested activities were devised. Moreover, the proposed reorganization of the tasks examined was verified by the reassessment of the static loads on the muscles using the 3D SSPP tool. The analyses carried out after the reorganization of work confirmed the reduction in static loads and the improvement in work comfort for the analyzed manual tasks.
  • Barczak, Agnieszka (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The Covid-19 pandemic has affected all aspects of human life. Its negative effects have also hit the transport industry, largely as a result of staff contracting the virus and the restrictions imposed on human mobility. Therefore, the purpose of this study is to establish how the situation of rail freight transport in select EU countries has evolved in the post-pandemic era. The trend of rail freight transport is presented for the years 2015–2021, and forecasts are made for the years 2020–2021 using the method of seasonality indices. The study results show that most of the investigated countries show adverse differences in the actual and forecast quantity of freight handled, an effect clearly attributable to the pandemic.
  • Depczyński, Radosław (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Manufacturing, as one of the main pillars of a civilized lifestyle, will be strongly affected by sustainability issues, and it will play an important role in establishing a sustainable future. Within the area of sustainability issues, some specific issues are pointed out, such as the energy and labor intensity of manufacturing processes. The main aims of this paper are a systematic literature review and the evaluation of the energy and labor intensity of manufacturing processes in an industrial enterprise while proposing changes toward sustainable development. In the research, 163 scientific publications (77 related to China) were taken from the Web of Science (WoS) database based on selected keywords describing the studied phenomenon. The analyzed publications were divided into five areas (clusters). In terms of evaluating the energy and labor intensity of manufacturing processes, twelve production processes were selected, which were then grouped according to their most important areas of similarity (automation, ergonomics, and discomfort). The systematic literature review was carried out using the VOSviewer software, version 1.6.14. This article also uses the methodology of a case study with a simplified SWOT analysis based on interviews with employees and expert panels. The subject of the research is an industrial enterprise representing the steel manufacturing sector in Poland.
  • Dembińska, Izabela (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Dear Readers, We are pleased to present you the next issue of our journal, Scientific Journals of the Maritime University of Szczecin. Fourteen articles are presented in this issue, the problems of which fall under the following subject areas: Civil Engineering and Transport, Material and Mechanical Engineering, Environmental Engineering, Mining and Power Engineering, Information and Communication Technology, Economics, Management and Quality Science, Sustainability Management. We are pleased that the manuscripts submitted to us cover a wide field of research, thus giving our readers the opportunity to analyze and give their opinion on a variety of research problems. In the Civil Engineering and Transport section, we present two studies. The first study investigated the effects of buoys and solid mass on mooring lines and the dynamic response of the floating platform. The results of the analysis show that increasing the number of buoys at constant volume contributes to a decrease in the amplitude of wave and tilt motion, while lifting motion increases slightly. On the other hand, adding a buoy and clump weight to the mooring line reduces the tension of the vibration amplitude. The second study characterizes the distribution chain of liquefied natural gas in Poland, paying particular attention to the possibilities of road transport. It has been noted that during transportation and storage, LNG vaporization, known as boil-off gas, is a significant problem leading to an increase in tank pressure. Hence, one solution to this problem is to compress it to high pressure, which produces compressed gaseous fuels. In the Material and Mechanical Engineering Section, we have six manuscripts. As the authors write in the first study, one of the primary hazards associated with the operation of marine and deep-sea vessels-particularly ship power plants-are fires and explosions, which cause accidents and incidents with an average frequency of up to every 60 days. The article discusses the explosion hazard status of the crankcase of main propulsion engines of various types of vessels. The evaluation was based on the results of statistical analysis of historical data from 1972–2018. Based on the analysis, it was generally shown that the risk of a crankcase explosion affects ships of all ages and that the number of serious incidents remains constant over the period studied. It is interesting to note that half of all incidents occurred on vessels younger than 15 years. The second article describes the prospects for ultrasonic cleaning of shell-and-tube heat exchangers used, among others, on ships. This is because the main problem of seawater heat exchangers is their clogging – as a result of the operation, over time a process of overgrowth begins (e.g., algae), leading to reduced efficiency. In order to obtain information about the distribution of ultrasonic power inside the reactor, the authors conducted a finite element simulation using a designed test reactor represented by a shell-and-tube heat exchanger with ultrasonic-assisted cleaning. The simulation results are presented in the article. The authors 6 Scientific Journals of the Maritime University of Szczecin 71 (143) of the next article in this section point out that concrete is currently the most widely used man-made composite material and is second only to water across the range of materials used. This paper presents the results of a study of the effect of partial replacement of Portland cement with fly ash on the strength parameters, frost resistance and carbonation of concrete in comparison with a reference concrete and concrete containing a conventional additive – silica fly ash. The results obtained confirmed the feasibility of producing plain concrete modified with fly ash from thermal treatment of sewage sludge, while demonstrating the compliance of concrete parameters with environmental requirements for the leaching of heavy metals. Concrete was also analyzed in the following article. It presents the effects of the addition of steel and propylene fibres on the mechanical properties of floor concretes, such as compressive and tensile strengths in the flexural test. It was shown that the amount of steel fibres dosed in the study, regardless of their shape, does not adversely affect the consistency and workability of the concrete mixture. On the other hand, the addition of polypropylene fibres has a significant impact on the properties of the concrete mix. In the introduction of the following article, the authors explain that a digital twin is a digital replica, a mathematical model of a given object, product, process, system or service. It enables the acquisition of a significant amount of data and can be used to obtain comprehensive knowledge about a given object, its behaviour and reactions. The authors analyzed the operation of a rotating bearing in a wind turbine structure using a digital twin model, and more specifically, analyzed the distribution of loads prevailing in the rotor blade bearings at wind turbine limit loads. The basic types of the most commonly used rim bearings for wind turbine applications are analyzed. In doing so, a methodology for building computational models of rim bearings using the finite element method was developed, as well as an original method of simulating rolling elements with rod elements (for rollers and super elements) for load-bearing balls was proposed. The subject of research in the last article of this section is stainless steels widely used in various automotive parts. Knowing that some of them are exposed to the external environment, the pitting corrosion resistance of two austenitic stainless steels was analyzed, i.e., AISI 304 and AISI 316L in road salt solutions of 5% wt. and 10% wt. Experimental results confirmed the lower pitting corrosion resistance of AISI 304 stainless steel in a 10% wt. road salt solution. We present one article in the Environmental Engineering, Mining and Power Engineering section. It notes that the biggest problem of creating a numerical model of a coal seam is the insertion of discontinuity lines: faults, seam connection lines, wedging, etc. Therefore, proprietary methods were developed to determine the spatial location of faults, implemented in Geolisp in CAD. A method is presented for calculating the spatial position of a fault based on existing contours reaching it from both sides, a method based on the assumption that the slope of the deck upstream and downstream of the fault is constant, a method based on making independent surfaces of the updip and downdip sides with kriging extrapolation, a method based on transferring the fault from the deck above it or the Carboniferous roof. It was assumed that the correct introduction of the fault course is important for the accuracy of forecasting the impact of mining operations on the rock mass and surface. Two studies make up the Information and Communication Technology section. The Automatic Identification System (AIS) device is mandatory on ships that comply with the International Convention for the Safety of Life at Sea (SOLAS), the first study reads. AIS is designed to monitor vessel traffic in order to improve shipping safety. In their study, the authors compare the execution speed of geospatial queries in the relational database engine PostgreSQL and the non-relational database engine MongoDB. Four AIS datasets, four test polygons with different numbers of vertices, and a reference point on the fairway were defined for the study. The tests were used to evaluate the execution of queries in the database, which shows the number of ships in a given area and the number of ships within a given distance from a defined point. Test results say that test queries are executed faster, and data stored in the database takes up less disk space in MongoDB compared to PostgreSQL. Justifying the need for the research, the authors say that faster geospatial analysis of AIS messages can improve navigation safety by detecting dangerous situations earlier. The second article in this section highlights the use of satellite tracking during an environmental disaster at sea and evaluates the feasibility of using remote sensing images captured by satellites using multispectral cameras and Synthetic Aperture Radar (SAR). The purpose of the analysis is to evaluate selected remote sensing methods for detecting and tracking marine debris. The research value of the analysis is determined by the fact that the study was conducted in real-time at the time of the incident. The Economics, Management and Quality Science section is filled with one article. The object of research inquiry in this case was the pallet. The purpose of the article was to present the issues of pallet pool players’ Zeszyty Naukowe Akademii Morskiej w Szczecinie 71 (143) 7 strategies and the organizational, operational and market challenges they face in such a way that they are better understood by all supply chain players. The author proposes adopting a value-added synergy perspective as an alternative, understood as different and complementary, rather than excluding opportunities for other approaches to supply chain value. The final section, Sustainability Management, begins with a study highlighting the impact of increasing container throughput in the northern Adriatic ports on air quality. A comparative analysis of air quality consisting of certain environmental parameters taken from selected measuring stations near the container terminals of the northern Adriatic ports of Rijeka, Trieste, Koper and Venice was carried out. The study showed that the increase in container throughput in the ports of the northern Adriatic did not affect the deterioration of air quality in the urban areas of the various port cities. Air quality values in the ports of the northern Adriatic are well below the limits set by the EU Directive in the area of air quality (2008/50), i.e., they do not negatively affect the health of the residents of the analyzed cities. The subject of the next article was the relationship between the seaport and the city in the aspect of sustainable development, particularly in environmental terms. The consideration was based on the thesis that the introduction of the concept of sustainable development in the port can stimulate the creation of green cities. A case study of the sustainable development of the Twin Port of Bremen was used in the deliberations. Port development has been shown to stimulate GDP growth, increase employment, develop urban infrastructure and contribute to the enrichment of port cities. And the development of ports on an environmental basis also becomes a stimulus for green city development. I hope that the presented studies will meet with wide interest, and at the same time inspire various interdisciplinary thoughts, discussions and research. dr hab. Izabela Dembińska, Associate Professor Editor-In-Chief Szczecin, 30.09.2022
  • Sokoła-Szewioła, Violetta; Poniewiera, Marian (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The largest problem that we encounter when creating a numerical model of a hard coal deposit is to insert discontinuity lines representing faults, seams junction lines, wedging, etc. The faults introduced on the map of the seam are mostly flat polylines, while we do not know the altitude ordinate. In order to determine the spatial position of the faults, authoring methods have been developed and implemented in the Geolisp software and in the CAD system. This article presents the method based on calculating the spatial position of the fault with respect to the existing contours, which arrive at it from both sides, the method based on the assumption that the inclination of the seam in front of and behind the fault is constant, the procedure involving the performing of independent surfaces of the upthrow and downthrow side with extrapolation by the Kriging method, and the procedure requiring the transfer of the fault from the above-lying seam or a Carboniferous roof. The solutions given in the article are successfully used in most mines in Poland. The correct introduction of the fault course is important for the accuracy of forecasting the impact of the mining operations on the rock mass and the surface area.
  • Ciecińska, Barbara; Oleksiak, Beata; Furtak, Julia (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Hazard identification and occupational risk assessment, defined as the probability of occurrence of unfavorable work-related events, is one of the areas of activity for employers in relation to current legislation and standards. Using occupational risk assessment it is possible to design and use workstations properly, respecting workers’ health. This article presents an issue related to the use of workstations with laser equipment, which describes the nature of work of lasers and the specific impact of the laser beam on the material. The subject of the analysis is the workstations with a CO2 laser for cutting polymers and a workstation with a fiber laser for marking and engraving. For the above-mentioned workstations, using a designed checklist, the features of lasers are verified, hazards are identified, and occupational risk is estimated using the risk graph method. The estimated risk at selected workplaces with lasers clearly indicated that special attention should be paid not only to the device, and the negative impact of their laser beam on the human body, but also on the treated materials. The article also draws attention to protective measures, which should be applied at laser workstations to ensure the safety of employees.
  • Jedliński, Mariusz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    A flat wooden pallet, being a simple logistics carrier in terms of its structure, can nonetheless be treated as a highly specialized logistical and marketing object applied in complex supply chains. Rigorous measures taken to standardize pallets are predominantly aimed at ensuring the highest possible safety level for the transported products and people handling the freight units during the complex logistical processes that involve pallets along supply chains. The goal of this article was to increase understanding of the operating strategies employed by entities using pallet pools, as well as the organizational, operational, and market challenges faced by them. It was hoped to achieve this goal via both theoretical and empirical studies. To this end, the research study applied theoretical synthesis and empirical evidence derived from primary research based on the industrial, transport, forwarding, and logistics markets. At the same time, the theoretical context was based on the literature on the subject, related to wooden pallet issues and their special role in logistical processes. Challenges connected with decisions made to enable effective and efficient management of pallet pools were addressed at legal and regulatory, as well as organizational and operational, levels. Diverse courses of action identified in several stakeholder groups were reflected in the adopted philosophy of managing the main feeding streams of pallet pools. Though limited to just the Polish market, the research study was sufficiently representative due to the strategic share of the European and global market of standard flat wooden pallets. The author proposes taking a perspective of value-added synergy as an alternative (to be understood as different and complementary rather than excluding possibilities) to other ways of approaching the value of supply chains. The undertaken considerations may contribute to increasing the awareness of the importance of taking a pallet, so common from the technical and technological point of view, as a value-added carrier in scientific considerations, due to its paradoxically low individual economic vulnerability.

Search repository

Advanced Search


My Account

RSS Feeds