Dear Readers, With issue 57 (129), I have to say goodbye to you and my role as the Editor-In-Chief of the journal. On the 1st of February 2019, the Rector entrusted me with a new mission and asked me to oversee the entire publishing house of the University as its Head and Editor-In-Chief. I would like to express my gratitude for the trust placed in me by the University’s authorities. I would also like to thank the outgoing Editor-In-Chief of MUS Press, Prof. Bernard Wiśniewski, who has devoted several decades to MUS Press. During the last four years, I have managed to successfully complete many tasks, such as gaining sponsors and external funding from the Ministry of Science, establishing a recognised and international Scientific Board for the journal, designing and implementing detailed publication procedures in accordance with COPE regulations, designing and implementing an editorial system, designing and implementing an online journal repository with complete publications, modernising and uploading content to the journal’s website, gaining numerous renowned authors from around the world and introducing the quarterly to over a dozen indexes and bibliometric databases, such as Web of Science, DOAJ and InfoBase Index. All of those activities resulted in a continuous improvement in citability and other bibliometric indicators (Chybowski, 2018). I would like to use this opportunity to thank the members of the Scientific Board, the reviewers and the members of the editorial team for their cooperation and their efficient completion of the tasks related to the publication process. The time I spent as Editor-In-Chief taught me a lot about successful teamwork and shaping interpersonal relations. As of the 1st of February 2019, the role of Editor-In-Chief will be assumed by Dr Robert Jasionowski – Assistant Professor at the Institute of Basic Technical Sciences of the Maritime University of Szczecin. I am very happy that the mission relating to the further improvement of the journal’s ratings has been entrusted to this ambitious man. I sincerely hope that the new Editor-In-Chief will continue my quest of introducing the quarterly to the JCR database and gaining IF points. To achieve those goals, it is crucial to attract more international authors and continuously increase the citability of the published articles. I wish the new Editor-In-Chief all success in constantly improving the ranking of the Scientific Journals in peer-reviewed journal rankings and hope that the readers will continue to enjoy reading our quarterly publication.

The purpose of this research was to investigate the power and thrust coefficients of a horizontal axis tidal stream turbine (HATST) with different blade geometries, including twist angles, blade numbers, and section profiles. The RANS equations and Star-CCM+ commercial software were used to numerically analyze these variables. Furthermore, the turbulence model used in this study is a Realisable k-ε turbulent model. Nine different models were defined by changing the twist angle, thickness, camber, and blade numbers. The results are presented, and the power and thrust coefficients are compared against TSR for each of the nine different models. The pressure distribution and flow velocity contour are also presented and discussed.

Hot surfaces in ship engine rooms are the risk objects that most frequently contribute to fire ignition. Thermography, especially when using thermal cameras, offers many advantages over more common infrared thermometers, but dedicated systems are often prohibitively expensive. An affordable hybrid approach was thus tested in this study, where a low-cost thermal camera smartphone was paired with a common infrared thermometer. Measurements were taken in situ during a sea voyage in an engine room under normal operating conditions, and the surfaces of the main engine, the generating set auxiliary engine, and the exhaust gas boiler were tested. Several areas were discovered to be well above the generally-accepted temperature limit of 220°C, primarily due to absent or poor insulation. Clear recommendations for remediation are made, and the proposed testing method offers fast, easy, effective, and affordable inspection.

Satellite navigation systems are commonly used to precisely determine the trajectory of transportation equipment. The widespread deployment of GNSS is pushing the current receiver technology to its limits due to the stringent demands for seamless, ubiquitous and secure/reliable positioning information. This fact is further aggravated by the advent of new applications where the miniaturized size, low power consumption and limited computational capabilities of user terminals pose serious risks to the implementation of even the most basic GNSS signal processing tasks. This paper has presented the advantage of Cloud-based GNSS Navigation, which facilitates the possibility of developing innovative applications where their particularities (e.g. massive processing of data, cooperation among users, security-related applications, etc.) make them suitable for implementation using Cloud-based infrastructure.

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.

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

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.

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.

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).

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.

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.