English Polish
Akademia Morska w Szczecinie

DSpace Home

DSpace/Manakin Repository

74 Scientific Journals of the Maritime University of Szczecin, no. 74 / 2023


Recent Submissions

  • Bojanowska, Milena (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Rapeseed by-products of seeds de-oiling, particularly expellers and post-extracted meal, are currently considered an important biomass that can be used as an alternative energy source, either in raw form or after conversion to biochar. Rapeseed biomass represents a difficult-to-handle cargo, mainly due to its sensitivity to mechanical, climatic, and biological impacts, as well as its dusty nature. This study aims to determine the physical properties of rapeseed meals and their fractions. Morphological and chemical features of six particle sets are investigated in order to explain the variation in their physical properties having importance in handling and transportation processes. The true density of fractions increases when the particle size decreases due to the diminishing quantitative share of seed coats. No correlation is observed between true and bulk densities, as the particle shape, surface sculpture, and adhesion affect the mutual particle arrangements. Along with a decrease in the particle size from 0.4 mm, a rapid decrease in the flowability is observed. The tendency of the finest dust (d < 0.075 mm) to form agglomerated complexes causes its lower bulk density, higher porosity, and higher angles of repose in comparison to coarse dust (0.075–0.4 mm). It is concluded that a relatively low tendency to free flowing of natural RSM is mainly caused by its wide-ranging particle size distribution and their geometry differentiation, which facilitate mutual particle interlockings. The known cases of blockages of silos, bins, hoppers, and transfer chutes may be mainly caused by the powder fractions (< 0.2 mm), with a much lower flowability than other particles.
  • Dydkowski, Grzegorz; Urbanek, Anna (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The main purpose of this paper is to investigate the impact of fare integration on the demand for public transport and the role of IT technologies and cash-free payments in this process. The paper presents the results of a critical literature review of studies conducted in this area so far. This approach enables the integration of theoretical and empirical findings, and perspectives of fragmented and interdisciplinary studies. Fare integration in cities is one of the factors that increase the demand for urban public transport services. This results from an improved image of public transport, easier promotion of services, more eligible passenger information, and easier use of services due to the uniform regulations and fares. In addition, for travelers, fare integration means cheaper services because they do not need to buy separate tickets corresponding to various organizers or carriers. The implementation of solutions from the field of fare integration is also related to costs; one can primarily mention the transaction costs and those related to the introduction of new solutions into the sales systems. The increase in the demand for public transport services due to the implementation of fare integration, results in external benefits that affect the sustainability of city transport systems and, thereby, justifies the funding of it by the public sector, which is accountable for ensuring efficient public transport.
  • Gnaciński, Piotr; Muc, Adam; Pepliński, Marcin (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The presented study examines the effect of voltage subharmonics, which relates to components of the frequency less than the fundamental voltage harmonic, and the currents and vibration of the line start permanent magnet synchronous motor. The obtained experimental results corresponded to a production motor with a rated power of 3 kW and a rated speed of 1500 rpm. The main purpose of our study was to highlight that the subharmonic value had a non-linear effect on the vibration level of the considered motor. It was found that for subharmonic values up to approx. 0.5% of the vibration level could be considered acceptable for long-term operation, whereas vibration caused by voltage subharmonics of values greater than approx. 0.8% might promote machine damage.
  • Garczyńska, Ilona (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The conducted review presents the possibility of using artificial neural networks in sectors related to environmental protection, agriculture, forestry, land uses, groundwater and bathymetric. Today there is a lot of research in these areas with different research methodologies. The result is the improvement of decision-making processes, design, and prediction of certain events that, with appropriate intervention, can prevent severe consequences for society. The review shows the capabilities to optimize and automate the processes of modeling urban and land dynamics. It examines the forecasts of assessment of the damage caused by natural phenomena. Detection of environmental changes via the analysis of certain time intervals and classification of objects on the basis of different images is presented. The practical aspects of this work include the ability to choose the correct artificial neural network model depending on the complexity of the problem. This factor is a novel element since previously reviewed articles did not encounter a study of the correlation between the chosen model or algorithm, depending on the use case or area of the problem. This article seeks to outline the reason for the interest in artificial intelligence. Its purpose is to find answers to the following questions: How can artificial neural networks be used for spatial analysis? What does the implementation of detailed algorithms depend on? It is proved that an artificial intelligence approach can be an effective and powerful tool in various domains where spatial aspects are important.
  • Bukowska-Pietrzyńska, Agnieszka; Motowidlak, Urszula (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This article concerns the increasing complexity and variability of the business environment and the challenges faced by enterprises that operate within supply chains to properly identify and anticipate disruptions and adequately respond to them (i.e., the ability to resist and rebuild). This article aims to identify and evaluate the importance of the main factors that determine supply chains’ adaptability in the modern economy. A review of the literature on the subject, and the results of a survey conducted in the third quarter of 2022 among entities from the transport forwarding logistics (TFL) industry, diagnose the determinants of the adaptability of supply chains that operate when there are disruptions. They indicate the challenges faced by TFL companies that result from the COVID-19 pandemic and the war in Ukraine and the directions of changes that result from them, both from the short-term and strategic perspectives. The relationships between the development of adaptability of supply chains and the increase in the competitiveness of entities enable us to verify the research hypothesis that, in the face of increasing disruptions and uncertainty in the business environment, strengthens the adaptability of supply chains producing a great potential in terms of maintaining the competitiveness of enterprises in the TFL industry. To gain and maintain a long-term competitive advantage, companies should strive to create a resilient supply chain that can withstand challenges and disruptions.
  • Kacprzak, Paweł (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Experienced ship roll during loading is the easiest parameter to observe and measure on board of a loaded ship. Therefore, the ship’s significant roll amplitudes should be the key limiting factor in view of the safety and efficiency of cargo handling operations at sea. For the example of three standard bulk carriers, the authors prepared a method of assessment of bulk carrier suitability to perform safe and efficient cargo handling operations in the Clarion-Clipperton Zone in view of significant amplitudes of roll. Via a calculation of the efficiency index for a set of limiting amplitudes of roll during loading simulation, we are able to analyze ship effectiveness. The application of the above-mentioned method can be employed as a useful tool to predict the lowest allowable significant amplitudes of roll when the required efficiency level is specified. Additionally, a calculation is made for the operable days where cargo operations are possible. Investigations show that, according to applied criteria, the effectiveness drops, and not every bulk carrier can perform safe cargo handling operations at sea.
  • Magryta-Mut, Beata (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This study aims to improve an earlier safety analysis of port and maritime transportation systems in two cases. The first case does not consider outside impacts and the second case operates under the assumption that they are impacted by their operation processes. New and original suggestions on separate and joint system safety and operation cost optimization are also described and future research is also outlined. Probabilistic modeling methods are used as the research methods. The proposed research procedures enable the determination of the safety function and risk function for the port oil terminal critical infrastructure and the maritime ferry technical system in both examined cases, based on the strictly exact statistical data about their operation processes and on the improved approximate evaluations of their components safety parameters through expert opinion methods that originate directly from the users of these systems. Other proposed practically significant safety and resilience indicators are the mean lifetime up to the exceeding of a critical safety state, the moment when the risk function value exceeds the acceptable safety level, the intensity of ageing/degradation in both cases, the coefficient of operation process impact on system safety, and the coefficient of system resilience to operation process impact in the second case. As a result of this research, it is originally found that the proposed cost optimization procedures and the finding of the corresponding system safety indicators deliver an important possibility for the system total operation cost minimizing and keep fixed the corresponding conditional safety indicators during the operation. It was also established that the proposed system safety optimization procedures, and corresponding system operation total costs, deliver an important possibility for the system safety indicators maximization and keep fixed the corresponding system operation total costs during the operation.
  • Wiktorowska-Jasik, Anna (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Modern cities are focused on the implementation of the assumptions of sustainable transport development. They invest in modern solutions and intelligent technologies that improve the mobility of residents and reduce energy consumption and pollution emitted by means of transport. This article deals with issues of smart urban mobility and carsharing, in particular, as one of the examples of the implementation of sustainable transport policy. The objective of this article is a comparative analysis of the pace of development of the carsharing markets in Poland and Germany. The analysis is carried out using statistical and comparative analysis methods. In addition, for a complete presentation of the problem raised, a literature analysis is performed. The research area covers two countries, Poland and Germany, from which ten cities for each are selected for analysis. In addition, to achieve the assumed objective, we also present the basic assumptions of smart mobility and solutions used in cities, and then determine the increase in the number of cars driving in the carsharing system. In addition, the factors influencing the change in transport patterns of urban residents are analyzed, and the importance of modern communication technologies in the development of carsharing systems is emphasized. The results of the analysis can be used as a tool to support the decisions of city authorities in the field of transportation management and, in particular, the implementation of carsharing systems. They also present the dependencies of the spread of this solution in a given urban space. They indicate the largest problems that may affect the introduction of this solution as an element of the city’s transportation system.
  • Herdzik, Jerzy (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Currently, about 90% of world transport is via water, which means that maritime transport is a decisive factor in the development of civilization. In order for it to effectively continue and compete with other means of transport, it is necessary to use the cheapest marine fuels on ships. The demand for machines generating mechanical energy to propel ships resulted in their dynamic development and, simultaneously, forced the search for primary energy sources (fuels) that enable the production of the working medium. The era of coal and petroleum fuels began in the 19th and 20th centuries, respectively. Today, in the 21st century, we stand at a crossroads – what next? The transition fuel will likely be LNG and biofuels. Ammonia will also occupy a significant share of the fuel market, but the target fuel will be hydrogen. Based on historical and contemporary sources, this article discusses the changes in the use of marine fuels that have occurred since the 19th century

Search repository

Advanced Search


My Account

RSS Feeds