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  • 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.
  • Revenko, Vitaliy Yu. (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The effects of precipitation of varying intensity on the operation of a ship’s radar are considered. It is shown that during the propagation of the electromagnetic wave emitted by the antenna of a ship’s radar, its energy is absorbed by precipitation. To determine the power loss of an electromagnetic wave due to its absorption by particles of precipitation, the effective absorption area, specific absorption coefficient, and specific effective total scattering area are used. The effective areas of absorption and total scattering depend on the shape of the precipitation particles, their size, state of aggregation, and the length of the electromagnetic wave emitted by the antenna of the ship’s radar. The dependence of the effective absorption area on the particle size of precipitation is obtained at two wavelengths of 3 cm and 10 cm, on which the ship’s radars operate. A decrease in the tracking range of an object tracked by a ship’s radar in the case of rain falling is established compared with the tracking range of an object in clear weather. It is shown that a decrease in the tracking range of an object occurs only with moderate, strong, and very heavy rain. The attenuation of electromagnetic energy in rain with an intensity of 12.5 mm/h at a wavelength of 3 cm is obtained by calculation, which amounted to 24 dB with a length of the falling rain zone of 50 km, as well as with rain with an intensity of 100 mm/h with the same length of the precipitation zone.
  • Mielniczuk, Sylwia (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This paper proposes a modified artificial potential fields (APF) method for collision avoidance at sea. The concept of artificial potentials used herein is derived from fields generated by electric charges. Attractive and repulsive forces are determined, accounting for the positions of an own vessel and a target vessel. The own vessel and its goal are considered as opposite charges. There is an attractive force between them, while the own vessel and target vessels or obstacles are considered as charges with a repulsive force between them. The values of these forces depend on the coefficients of attraction and repulsion. To solve a particular collision situation, the modified method of artificial potential fields is used. Due to the specific nature of the vessels’ movement, additional factors affecting the values of the attraction and repulsive forces are considered, as opposed to solutions used for robots. The main purpose of this article is to present the method for determining the coefficients of the APF method. This method will be used to avoid collisions at sea. From an analysis of factors influencing the execution of the vessel maneuver in a collision situation, a modified method for determining the attraction and repulsion coefficients is proposed. A case study of collision avoidance in a vessel encounter situation is also conducted.
  • Stopa, Michał (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    In recent years, a significant emphasis has been placed on the technological side of shipping. However, humans remain the operator of the vessel and the ones to make the final decision. With the increasing problem of fatigue, a properly designed bridge might offer great support for navigators. This includes the implementation of ergonomics in the workplace. This paper aims to better understand the needs of end-user operators and determine if there is still a need for improvement in bridge ergonomic design. To reach this goal, a custom-designed questionnaire survey of 200 professional navigators is performed. The Kano model is used to analyze the seamen’s wants and needs, but also expectations based on their satisfaction with proposed ergonomic solutions. The research results suggest that there is still room for improvement in this area, which is not only a matter of comfort or health but also safety.
  • Falkowski-Gilski, Przemysław; Uhl, Tadeus (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The COVID-19 pandemic has significantly limited user mobility, not least among students. Remote learning had a particular impact on resource allocation in relation to using terrestrial cellular networks, especially 4G systems in urban agglomerations. This paper presents the results of a quality evaluation of an outdoor environment, carried out between 2019 and 2021 on the campus of a technical university. Annual studies are conducted using our own custom-built mobile application, installed on 50 mobile devices (i.e., smartphones) running Android OS. This study aims to determine the impact of reduced user mobility on access parameters in mobile networks, that is, both download and upload throughput as well as delay (ping), with a particular focus on serving base transceiver stations (BTSs). This research scenario involves long-term evolution (LTE) compatible user equipment (UE) that operates under four Polish mobile network operators (MNO), which includes roaming connections and the newly launched 5G standard.
  • Jeleniewicz, Katarzyna; Rutkowska, Gabriela; Żółtowski, Mariusz; Kula, Dorota (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Caring for the environment, in accordance with the principles of sustainable development, as well as the increase in the standard of living of society, introduces the need to conduct proper waste management. Construction is an industry with great potential for the management of glass waste as part of material recycling. The construction sector is characterized by high material consumption, with a limited amount of natural resources, meaning that research is constantly being performed on the possibility of replacing them with other common ingredients. A feature of the building materials industry is also the pursuit of continuous improvement of the properties of manufactured materials. The paper presents the research results on the impact of the partial replacement of Portland cement and aggregate with glass waste on strength parameters and frost resistance. For the purpose of experimental work, a concrete mix based on the C20/25 standard concrete with CEM I 42.5R Portland cement, in which from 0 to 20% of the cement or aggregate weight is replaced with glass waste (i.e., glass flour and glass cullet), is designed. In the test range, the glass flour slightly affected the deterioration of the compressive strength, while the glass cullet had no effect on the compressive strength after 56 days of maturation. Moreover, the addition of glass flour increases the bending strength, while the addition of glass cullet maintains a comparable bending strength compared to the reference concrete. The obtained concretes are frost-resistant concrete F150.
  • Dębicka, Olga; Reszka, Leszek (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    A period of pandemics and distance learning has forced teachers to plunge headlong into the technological challenges of education. Today, it is possible to look back on this time as an educational milestone that, although forced, contributed to a much-needed leap into the digital age in higher education. Information and communication technologies (ICT) have contributed to a significant paradigm shift in learning and the roles of teachers and students in education today. ICT tools in the educational process have become indispensable, whether for on-site teaching, an exclusively online system, or a hybrid scheme. Therefore, this study aims to establish how modern technology has enabled a unity of resources in the education process and to identify how the pandemic conditions have affected the logistics process for didactics, particularly related to providing a unity of the right resources in the correct place. Moreover, the authors indicate the benefits of the described changes in the didactic process for teachers and students in the post-pandemic period.
  • Kaizer, Adam (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The main purpose of dredging is to maintain the required depth of harbors and marine and inland waterways. Any investment work in port infrastructure should be planned in such a way as to minimize interference with the port operations and vessel traffic. The research aims to analyze work scenarios involving a proposed dredging fleet using a Navi-Trainer Professional 5000 navigational and maneuvering simulator connected to the Transas Navi-Sailor 4000 navigation information system. An analysis performed using these electronic chart display and information system (ECDIS) simulators allows the operational parameters of the dredging project to be determined. These parameters include driving time, time taken to fill a TSHD dredger to full capacity, scale of maneuverability of the dredger within the port area, and determination of the safe distance between dredging vessels and other ships. The proposed solution may be supplemented with additional computer-based programs, providing a valuable tool in the research and monitoring of planned and current dredging projects.
  • Mocek, Piotr (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The article presents the results of measurements of environmental noise caused by devices operating in the surface facilities of hard coal mines and by the technological processes related to the loading and transport of spoil and materials necessary for production. The research results are part of the program “Consequences of excessive noise in the mining environment of hard coal mines”, the overarching goal of which is to reduce the emission of industrial noise. A sampling method was used to determine the actual values of noise levels emitted to the external environment from mines and mining plants as well as to identify the acoustic power levels of devices and processes constituting the main sources of noise in mines. The results showed that mines and mining plants are often not fully aware of the scale of the environmental impact of the undesirable noise they emit. Therefore, the current periodic measurements of environmental noise should be replaced with permanent monitoring, which will be beneficial not only for the environment and residents of housing estates located near mines but also for the mining plants themselves.
  • Kędziorski, Piotr; Kogut, Tomasz; Oberski, Tomasz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Radiometric correction is a process that is often neglected when developing unmanned aerial vehicle (UAV) images. The aim of the work was to test the radiometric correction of images taken from a Parrot Sequoia+ camera mounted on UAV. Therefore, a script was written in Matlab environment to enable radiometric correction of the obtained images. The images were subjected to the correction process using the Matlab script and the commercial software Pix4D. The results were compared, and the study found a significant improvement in the radiometry in both cases. The computational process eliminated the influence of variable in-flight insolation caused by cloud cover. The software developed for the article was found to be as good as the commercial one.
  • Dembińska, Izabela (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    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.
  • Maryniak, Anna; Pogorzelec-Glaser, Katarzyna (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    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.
  • Stempiński, Szczepan (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    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.
  • Korbiel, Tomasz; Czerwińska-Lubszczyk, Agnieszka; Brodny, Jarosław; Czerwiński, Stefan (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    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.
  • Mielimąka, Ryszard; Kleta, Henryk (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    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.

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