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  • Ochin, Evgeny (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The need for accuracy, precision, and data registration in underwater positioning and navigation should be viewed as no less stringent than that which exists on the sea surface. In the same way in which GNSS (Global Navigation Satellite System) receivers rely on the signals from multiple satellites to calculate a precise position, undersea vehicles discern their location by ranging to the acoustic signals originating from several fixed underwater acoustic sources using the Time-of-Arrival algorithm (ToA) through the Ordinary Least Squares method (OLS). In this article, the scope has been limited to only considering underwater positioning systems in which the navigation receiver is acoustically passive. The receiver “listens” to the buoys, receives their messages and solves the problem of finding its own position based on the geographical coordinates of the buoys. Often, such systems are called GNSS-like Underwater Positioning Systems (GNSS-like UPS). It is important to note the distinction between general purpose GNSS-like UPS (mainly civil systems) and special purpose GNSS-like UPS (mainly military systems). In this article, only general purpose GNSS-like UPS systems have been considered. Depending on the scale of system’s service areas, GNSS-like UPS are divided into global, regional, zonal and local systems. Only local GNSS-like UPS systems have been considered in this article. The spoofing of acoustic GNSS-like UPS works as follows: the acoustic GNSS signal generator transmits a simulated signal of several satellites. If the level of the simulated signal exceeds the signal strength of the real satellites, the acoustic receiver of an underwater object will “capture” the fake signal and calculate a false position based on it. All receivers that fall into the spoofing zone will calculate the same coordinates, while the receivers located in different places will have a mismatch in the XYZ coordinates.
  • Gucma, Stanisław; Gucma, Maciej; Gralak, Rafał; Bilewski, Mateusz; Muczyński, Bartosz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The article presents a simulation method for determining the minimum safe pull of tugs assisting in port manoeuvres. The method can be used to determine the relationship between the minimum safe pull, understood as the tension on the line, of the assisting tugs and the overall length, cargo capacity or net capacity of ships manoeuvring in a given port under allowable hydrometeorological conditions. The method was verified through simulated tests of gas tankers’ entry, turning and berthing at the LNG terminal of Świnoujście
  • Gucma, Stanisław; Gucma, Maciej; Gralak, Rafał; Przywarty, Marcin; Muczyński, Bartosz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This article describes the methodology to design a universal berth for LNG discharge from tankers with a wide cargo capacity range of 500 m3 to 220,000 m3. Based on a waterway optimization simulation, the methodology has been used to determine parameters of the designed universal cargo handling berth located in the port of Świnoujście.
  • Herbin, Paweł; Woźniak, Marcin (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    In this paper, two automatic mini-crane control systems have been compared; utilizing feedback as well as both feedback and feedforward structures. The proposed control systems were implemented in a Master-Slave system to provide intuitive control for a mini-crane by human muscles. The control systems that have been designed were tested on constructions with similar structures i.e. an upper limb exoskeleton and a mini-crane with two joints, but using different actuation systems. The mini-crane had hydraulic actuators, whereas the exoskeleton was equipped with electrical actuators.
  • Panasiuk, Katarzyna; Kyzioł, Lesław; Hajdukiewicz, Grzegorz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Layered composites are materials that are widely used in industry due to their low manufacturing costs. They are used, among others, as a construction material for the construction of light aircraft, cars, wind turbine blades and the hulls of vessels. The universality of their use has contributed to the formation of a large amount of post-production and post-use waste from these composites. Layered composites, using recycled polyester and glass, or recycled composite waste, may be materials that could be used in the economy. The polyester-glass waste used in the composite was created by crushing and then grinding and sieving to obtain the appropriate granulation. Materials with a waste content of 0%, 10%, 20% and with granulation of this waste of ≤ 1.2 mm were made using the hand lamination method. Test specimens were prepared from the material plates that were obtained in accordance with the PN-EN ISO 179-1: 2010E standard (Plastics – Charpy Impact Assessment – Part 1: Non-instrumental impact test). Impact tests of samples were carried out according to the above-mentioned standards using a Zwick Roell RKP450 swinging hammer. Test bench instrumentation and software enabled the bending forces to be recorded, as well as the deflection of the samples for short time intervals and displacement, so a detailed force-deflection graph could be obtained. During the analysis, the results of the research were focused on describing the kinetics of the process where the samples were destroyed (fracture mechanics), this allowed for the initial determination of the material’s resistance to dynamic loads. The results obtained showed that the increase of the recycled content in the produced composite contributed to the lowering of the destructive force threshold in the impact tests, as well as the simultaneous increase of the plasticity of the material. The increase of the sample’s deflection with the occurrence of the maximum force resulted in the energy of the elastic state being increased (Ue).
  • Behrendt, Zbigniew (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The article has presented a predictive output voltage regulator of a three-phase two-level voltage inverter with an LC filter with a prediction of the receiver current in the time domain and the frequency domain. Simulations of the operation of the regulator were conducted for a three-phase receiver. The circuit model and simulations of the operation of the predictive voltage regulator were performed in the PSIM program. The algorithm of the predictive regulator was written in the C programming language in the Microsoft Visual Studio compiler and attached to the model performed in the PSIM program by a block that supports the Dynamic-Link Library.
  • Chybowski, Leszek (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Retraction of: Kałkowska E. (2016) The role of stray currents in the evolution of damage in transport systems. Scientific Journals of the Maritime University of Szczecin, Zeszyty Naukowe Akademii Morskiej w Szczecinie, 48 (120), 134–137, 10.17402/186 (http://repository.scientific-journals.eu/bitstream/handle/123456789/2343/18-zn-am-48- 120-ka-kowska.pdf?sequence=1) The data published in this paper, as well as Figure 1, Figure 2, Table 2 and the associated text were taken from the Master’s thesis of Ms. Anna Pawłowska supervised by Prof. Jarosław Chmiel of the Faculty of Engineering and Economics of Transport, the Maritime University of Szczecin. Ms. Kałkowska submitted her paper to the Scientific Journals of the Maritime University of Szczecin on the 29th of April 2016, and failed to refer to the M.Sc. thesis where she took the figures and table from. The research results presented by Ms. Kałkowska were generated by means of the DASYLab software in March 2016 by Ms. Pawłowska in the Faculty’s Lab (Laboratory of Wear Processes), access to this is only granted for authorised personnel, and Ms. Kałkowska was not authorised. This fact was confirmed by the Dean of the Faculty of Engineering and Economics of Transport on the 9th of January 2019. Taking into account the principles of ethics regarding plagiarism and the uncertainty about the completeness of the list of references, the Editorial Board of the Maritime University of Szczecin has decided to retract Ms. Kałkowska’s paper.
  • Chybowski, Leszek (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    It is my great honour to introduce the latest 56 (128) issue of Scientific Journals of the Maritime University of Szczecin. The current issues contains the latest research in the field of marine technology, transport and logistics. The introductory paper entitled “Practical approach to calculating the hydrodynamic oscillating loads of a ship propeller under non-uniform wake field” has been written by the world-class expert in fluid mechanics, Prof. Hassan Ghassemi, professor of marine engineering at the Amirkabir University of Technology. The article presents selected issues related to hydrodynamic modelling of screw propellers. The publication was prepared in connection with our implementation of the project funded by the Ministry of Science and Higher Education of the Republic of Poland from the fund for science-popularising activities (grant No. 790/P-DUN/2016). The author’s remuneration and costs of publication were covered by the Rector of the Maritime University of Szczecin from funds for international cooperation. I hope that the relevance of the publication will contribute to its attractiveness to all readers interested in optimising the vessel power systems. The Marine Technology and Innovation section gathers articles devoted to the studies of austenitic-ferritic steel on cavitation erosion, modelling of brass/steel ingot structures, determining the properties of composites with glass-recycled polyester additives and assessing the quality of welding. In the section on Navigation and Maritime Transport, articles are devoted to communication using the R-Mode receiver for medium frequency signals and analysing the fairway capacity impacted by LNG carrier transit. The Transport Engineering section includes articles on marine emergency management digital platforms and analysing the risk of operating fishing vessels with regard to the possibility of damaging underwater cables. We are almost at the end of another publishing year which bears the fruit of higher bibliometric indices, denoting the increasing quality of the quarterly. The annual journal citation chart in the Web of Science Core Collection presented in Figure 1 indicates a growing recognition of research results published in the Scientific Journals of the Maritime University of Szczecin. According to Web of Science statistics for 1132 articles indexed in the Core Collection database, the average citation of each article is 0.45. This is a very good result, bearing in mind that out of the 507 citations, 388 (76%) citations have been generated from January 1, 2015 (as of 05.12.2018). In addition, it is worth emphasising that on September 25 we received a message from the Scientific Journals Evaluation Team of the Index Copernicus International saying that – based on the information submitted in our journal’s questionnaire – Index Copernicus experts have calculated the Index Copernicus Value (ICV) for 2017: ICV 1017 = 100.00. The ICV for 2017 is shown on the full list of indexed journals at the ICI Journals Master List 2017. The values of the indicator from the previous three years were respectively ICV 2014 = 79.38, ICV 2015 = 87.49 and ICV 2016 = 90.35 (Journals Master List, 2018). The above indicators show that the quarterly is constantly improving its prestige (Chybowski 2016a; 2016b; 2017). I can also say with full confidence that during the four years of my duties as editor-in-chief the assumptions that I set and promised to fulfil to the former Rector of the Maritime University of Szczecin, Prof. Stanisław Gucma – to whom I am grateful for the trust granted to me then, have been achieved. I would like to express my thanks to the authors – we would not be publishing without their contribution and could not achieve such high and constantly rising bibliometric indicators. Moreover, I would like to highlight that the constant improvement of our journal’s publishing quality is a result of hard work of the editorial team, members of the Scientific Board, reviewers and university authorities through their policy supporting the development of our quarterly. I would like to thank all of those persons. I believe that our journal is on the right track to joining the group of publications included in the Journal Citation Reports and being finally noted in the Impact Factor® Index, which is a realistic goal for the next 2–5 years with the right strategy. I would like to use this opportunity to encourage authors from all over the world to publish the results of their research in the Scientific Journals of the Maritime University of Szczecin. All readers are welcome to visit our refreshed website. Going to http://scientific-journals.eu/ grants access to the electronic version of the current issue and archival volumes of the journal.
  • Ghassemi, Hassan (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Propellers usually operate in the ship’s stern, where the inflow of the non-uniform wake generates oscillating loads and changes the hydrodynamic performance. Therefore, determination of the forces on propellers and hydrodynamic performance due to a non-uniform wake field are the challenging problems for naval architects and hydrodynamists. The main objectives of the present study are to assess the hydrodynamic performance for a single blade and all the blades. The propeller is a B-series propeller under non-uniform wake field behind the Seiun-Maru (hereafter SM) ship hull. A practical approach is employed to calculate the hydrodynamic oscillating loads of the ship propeller under a non-uniform wake field. Results of the computations on the propeller behind the SM ship, due to a non-uniform wake field, are presented and analyzed using classical mathematical methods over a single cycle. The results show that a variation of thrust with the discussed parameters is the same as that shown for torque, also the blade-frequency of the total force, thrust and torque is an increasing function of radial sections, whereas these parameters decrease with increasing radial blade sections.
  • Jabłonka, Tomasz; Ornat, Marek; Żółkiewski, Sławomir (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Building Information Modelling (BIM) technology is briefly reviewed in this paper in order to demonstrate the potential application of this methodology in the shipbuilding industry. A properly-created BIM model is a valuable tool for the designers and future users of a given investment. BIM models improve the design and execution process and serve as a tool to maintain and manage any asset. The purpose of this article is to propose to use BIM technology in other construction industries, including the shipbuilding industry. A properly-constructed BIM model of a ship can be used both by the shipyard, as well as by the ship owner or target users. The information contained in the BIM model of the ship can be used to optimize the execution phase in the shipyard, as well as provide valuable assistance to the user of the unit during its operation.
  • Krawczyk, Janusz; Jasionowski, Robert; Ura, Daniel; Goły, Marcin; Frocisz, Łukasz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Cavitation is a one of many wear mechanisms which are related to the flow of liquid. It is one of the most destructive wear methods for stainless materials. The local changes in the pressure of the liquid stream related to the flow across the metal component cause straightening of the surface area, as well as its erosion and the formation of pits on the surface layer. The erosion value of cavitation is related to the material’s microstructure, the geometry of the element, the phase composition of the material and the surface roughness. In this paper the investigation of the cavitation process for duplex stainless steel has been performed. Samples examined in the first stages of the experiments were not significantly changed, but after a long time the hardness increase was very visible. The result of the cavitation was also cracking along the interphase boundaries, which resulted in the chipping of the material. One of the most important results was a description of the change in the wear mechanisms and its intensity during the cavitation exposure time. At first plastic micro deformation of the material’s surface occurred, then the plastic deformation increased significantly and after some time this resulted in erosion of the material and interfacial boundary decohesion; these two effects increased simultaneously. The last of the mechanisms was mechanical destabilization of the austenite, but the clear result of the mechanical destabilization of the austenite was only observed in the last sample. Martensitic transformation of the material changed the material’s mechanical properties, but for the stainless steels this resulted in electrochemical corrosion of the material, especially through the formation of an electrochemical potential between austenite and martensite.
  • Panasiuk, Katarzyna; Hajdukiewicz, Grzegorz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Polyester-glass composites are widely used in many industries, in various types of constructions, including dynamically loaded ones. This article examines the influence of the content of a glass-polyester recycled additive on the strength properties of layered composites. The recyclate was polyester-glass waste, which was pre-crushed and then milled into the appropriate fractions. Manual laminating technology was used to make the materials. The composite materials were made with a waste content of 0%, 10%, 20% and granulations of ≥ 1.2 mm and ≥ 3 mm. Samples for testing were prepared in accordance with the PN-EN ISO 179-1: 2010E standard (Plastics – Charpy Impact Assessment – Part 1: Non-instrumental impact test). Impact tests of the samples were performed using the Charpy method with the Zwick Roell RKP450 swinging hammer. The test results showed that the addition of polyester-glass recyclate, its content %, and its granulation size, have an impact on the composite resistance to loads in dynamic tests.
  • Szeleziński, Adam; Muc, Adam; Murawski, Lech (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The authors of this article have been looking for new parameters and dynamic characteristics which can be applied to the non-destructive testing of welded joints. All the characteristics have been based on the recorded data generated during the vibration tests of welded joints both with and without failures. This article has dealt with the methods of assessing welded joints using either 2D or 3D time-frequency dynamic characteristics. The calculation procedure that was used for analyzing the simultaneous changes of the response modules, registered by acceleration sensors, has been presented. The vibration amplitudes were transformed into a function of time and frequency (simultaneously) and presented over 2D or 3D time-frequency characteristics. The analyses of the characteristics were performed for a plate without a welded joint, for a plate with a non-defective welded joint and for a plate with a defective welded joint caused by edge bonding. Having analyzed and registered the 2D or 3D time-frequency dynamic characteristics it could be noticed that by presenting the responses, analyzed simultaneously against time and frequency, allowed for the evaluation of whether the examined system maintained non-linearity and, at the same time, allowed for the quality of the welded joint to be indirectly assessed. The proposed measurement parameters of the quality of a welded joint can be defined as a dispersion of the colors from the obtained characteristics. The faults (and the vibration nonlinearity) of the welded joints will be bigger if the dispersion is greater.
  • Wołczyński, Waldemar; Ivanowa, Anna A.; Kwapisiński, Piotr (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Metallographic studies performed on a cross-section of static steel ingot allow the observation of the following morphological zones: a) columnar grains (treated as austenite single crystals), b) zone of the columnar into equiaxed grains transformation (CET), and c) equiaxed grains at the ingot axis. These zones are reproduced theoretically by the numerical simulation. The simulation is based on the calculation of both the temperature field in a solidifying large steel ingot and the thermal gradient field obtained for the same boundary conditions. In particular, a new, innovative method based on the mathematical treatment applied to different functions resulting from both the aforementioned fields, are used in the structural predictions. The method developed, firstly for the massive steel ingot, has subsequently been applied to theoretically predict the structural zones in continuously cast brass ingots. In the case of continuously cast brass ingots three different morphologies were revealed experimentally: a) columnar structures, b) equiaxed structures preceded by the CET (sharp transition), and c) single crystals situated axially. The above model for the structural zones prediction is useful in plastic deformation design for: a) steel forging ingots assigned for the crankshafts applied to the ship engines, and b) continuously cast brass ingots assigned for special applications in the shipbuilding industry.
  • Grundhöfer, Lars; Gewies, Stefan (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Signals from Global Navigation Satellite Systems are the primary source for Position, Navigation and Time (PNT) information onboard any vessel today. As these signals are prone to interference, a maritime backup system is needed to provide reliable PNT data, R(anging)-Mode is such a system. It utilizes existing maritime radio beacons or base stations of the Automatic Identification System (AIS) by adding ranging components to the legacy signals. The first modified radio beacons transmit medium frequency (MF) R-Mode signals in northern Germany. This paper has described the current state of the authors’ research and development activities at the receiver level for MF R-Mode signals. The receiver platform has been introduced, which was based on off-theshelf components and the implemented algorithms for distance estimation have been explained. Furthermore, the results of the first ranging measurements have been presented, which have shown the general suitability of the R-Mode technology as a source for maritime positioning and timing data.

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