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Gdańsk University of Technology

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Publications from the year 2023

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  • Mathematical modelling: Lessons from composite indicators
    • Marta Kuc-Czarnecka
    • Andrea Saltelli,
    2023

    We discuss here composite indicators as mathematical models, which can be looked at through the lenses of the five rules discussed in this volume. Composite indicators sit between analysis and advocacy, and their use has social and political implications. For this reason, the lenses of the manifesto can be used to build them better, to make them more transparent, as well as to inspect incumbent indicators for methodological or normative inadequacies.

  • Matrix Strengthening the Identification of Observations with Split Functional Models in the Squared Msplit(q) Estimation Process
    • Marek Zienkiewicz
    • Pawel S. Dąbrowski
    2023 MEASUREMENT

    This article addresses the issue of raising the level of identification of observations with either single or more split functional models in the squared Msplit(q) estimation process. The theoretical part of the study presents the theoretical grounds for the classical method for estimating parameters in a split functional model and proposes a modification of the computational algorithm to increase the quality of the determinations obtained. Theoretical considerations were verified through numerical tests concerning, e.g. issues of geodetic surveying practice and civil engineering.

  • Maximum transportation growth in energy and solute particles in Prandtl martial across a vertical 3D-heated surface: Simulations achieved using by finite element approach
    • Muhammad Bilal Hafeez
    • Marek Krawczuk
    • Wasim Jamshed
    2023 COMPUTERS & MATHEMATICS WITH APPLICATIONS

    The goal of this study is to determine the maximum energy and solute particles' transportation growth in a 3D-heated region of Prandtl martial through a dynamic magnetic field. The effects of this field on the properties of solvent molecules and heat conduction are studied. A correctly stated functional method and a finite element approach are comparable to a certain type of differential equations. In order demonstrate the effects of various factors such as mass diffusion, heat generation, and thermal diffusivity on the investigation of the diffusion coefficient and thermal mass in a three-dimensional Newtonian flow, the study of viscous and heat conduction rates is presented. The results show that the comparisons of hybrid nanofluid and with base fluid and w.r.t Local skin friction coefficient, Nusselt number and Sherwood number.

  • M-BDC (M = Co and/ or Fe) MOFs as effective catalysts for hydrogen generation via hydrolysis of sodium borohydride
    • Maria Alaide de Oliveira
    • Elibe Silva Souza
    • Jildimara de Jesus Santana
    • Natalia Łukasik
    • Bárbara Stefany Lima da Silva
    • Bráulio Silva Barros
    • Joanna Kulesza
    2023 APPLIED SURFACE SCIENCE

    Mono- (Co-BDC, Fe-BDC) and bimetallic FeCo-BDC Metal-Organic Frameworks are successfully synthesized by the solvothermal method in DMF at 150 °C within 15 h and tested as catalysts for sodium borohydride hydrolysis. The materials are characterized by FTIR, PXRD, TGA, ICP-OES, H2-TPR, BET model, and SEM-EDS. The catalytic activity of these materials is studied for dehydrogenation of sodium borohydride in water at various temperatures under basic conditions. Among tested catalysts, the most promising is Co-BDC, which provides hydrogen generation with a good rate of 1886.8 mL min−1 gcat−1 at 319 K and high efficiency (77.7 %) in the presence of a base. The activation energy determined as 25.4 kJ mol−1 is lower than most cobalt-bearing catalysts for NaBH4 hydrolysis described in the literature. The catalyst can be reused at least ten times, keeping a good overall hydrogen generation yield, and thus can be considered a promising candidate for portable hydrogen fuel systems.

  • Measuring the effectiveness of digital communication - social media performance: an example of the role played by AI-assisted tools at a university
    • Edyta Gołąb-Andrzejak
    2023 Full text

    The aim of the article is to show the role played by AI-powered tools in measuring the effectiveness of digital communication in social media using a university case study. Therefore, a research problem was formulated to identify the metrics (KPIs) used to measure the effectiveness – non-financial outcomes – of digital social media communication at the university using AI tools. The literature review on the role of AI in digital marketing in social media showed that it is used, inter alia, to measure the effectiveness of digital communication – social performance. The importance of KPIs in digital marketing – indicators for measuring non-financial performance – and the presentation of tools used to analyse the effectiveness of social media campaigns were based on a case study of a higher education institution in Poland. With the application of AI tools (such as ContentStudio, HelloWoofy or Sotrender etc.), it is possible to automate analytical processes for KPIs such as reach, engagement, content or customer service, among others, as well as systematic reporting. This, in turn, provides opportunities to systematically monitor and make improvements to the implemented social media marketing communication strategy – to create a kind of Decision Support System (DSS) to support the aforementioned process. The study is introductory and exploratory in nature. It indicates the importance of tools using AI in business practice – using the case study of a university as an example.

  • Mechanical and structural behavior of high-strength low-alloy steel pad welded by underwater wet welding conditions
    • Rassim Younes
    • Jacek Tomków
    • Idir Abdelhak
    • Mohand Amokrane Bradai
    2023 Full text INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY

    The aim of the paper was to determine the metallurgical and mechanical behaviors of a high-strength low-alloy (HSLA) steel pad-welded specimen used in the structures of industrial and naval parts. Then to predict the metallurgical consequences (nature of the phases present) and the mechanical properties (hardness and impact strength) of the pad-welded steel obtained by underwater wet welding with different heat input values. The XRD patterns clearly reveal a ferritic alpha steel S460N for both parameters. The ferritic quantification is above 70 wt% for low-alloy steel. The welded specimens are characterized by the presence of different phases. In a specimen performed with higher heat input, the complex oxide Mn2TiO4 was found to be around 7 wt%. Moreover, the solid solution formed with iron and manganese was observed. The hardness results obtained by indentation showed that the higher heat input resulted in higher hardness values (54 HRC) than for specimen performed with lower parameters (45 HRC). The impact test showed that the toughness of both pad-welded layers is greater than the toughness of the base material (40 kV for S2 and 34 kV for S1 about 27 kV for low-alloy steel). Moreover, it was observed that higher heat input results in increasing the impact strength of pad welds.

  • Mechanical Properties and Wear Susceptibility Determined by Nanoindentation Technique of Ti13Nb13Zr Titanium Alloy after “Direct Laser Writing”
    • Magdalena Jażdżewska
    • Beata Majkowska-Marzec
    • Andrzej Zieliński
    • Roman Ostrowski
    • Aleksandra Frączek
    • Gabriela Karwowska
    • Jean-marc Olive
    2023 Full text Materials

    Laser treatment has often been applied to rebuild the surface layer of titanium and its alloys destined for long-term implants. Such treatment has always been associated with forming melted and re-solidified thin surface layers. The process parameters of such laser treatment can be different, including the patterning of a surface by so-called direct writing. In this research, pulse laser treatment was performed on the Ti13Nb13Zr alloy surface, with the distance between adjacent laser paths ranging between 20 and 50 µm. The obtained periodic structures were tested to examine the effects of the scan distance on the microstructure using SEM, the roughness and chemical and phase composition using EDS and XRD, and the mechanical properties using the nanoindentation technique. After direct laser writing, the thickness of the melted layers was between 547 and 123 µm, and the surface roughness varied between 1.74 and 0.69 µm. An increase in hardness was observed after laser treatment. The highest hardness, 5.44 GPa, was obtained for the sample modified with a laser beam spacing of 50 µm. The value of the distance has been shown to be important for several properties and related to a complex microstructure of the thin surface layer close to and far from the laser path.

  • Mechanical Properties of Twisted Carbon Nanotube Bundles with Carbon Linkers from Molecular Dynamics Simulations
    • Andrea Pedrielli
    • Maurizio Dapor
    • Konstantinos Gkagkas
    • Simone Taioli
    • Nicola Maria Pugno
    2023 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    The manufacturing of high-modulus, high-strength fibers is of paramount importance for real-world, high-end applications. In this respect, carbon nanotubes represent the ideal candidates for realizing such fibers. However, their remarkable mechanical performance is difficult to bring up to the macroscale, due to the low load transfer within the fiber. A strategy to increase such load transfer is the introduction of chemical linkers connecting the units, which can be obtained, for example, using carbon ion-beam irradiation. In this work, we investigate, via molecular dynamics simulations, the mechanical properties of twisted nanotube bundles in which the linkers are composed of interstitial single carbon atoms. We find a significant interplay between the twist and the percentage of linkers. Finally, we evaluate the suitability of two different force fields for the description of these systems: the dihedral-angle-corrected registry-dependent potential, which we couple for non-bonded interaction with either the AIREBO potential or the screened potential ReboScr2. We show that both of these potentials show some shortcomings in the investigation of the mechanical properties of bundles with carbon linkers.

  • Mechanika kontaktu w charakteryzowaniu materiałów inżynierskich
    • Alicja Stanisławska
    2023

    W pierwszej części pracy przedstawiono teoretyczne podstawy mechaniki kontaktu. Omówiono model kontaktu Hertza opisujący zależność pomiędzy obciążeniem przyłożonym do kulistego wgłębnika i jego przemieszczeniem. W dalszej części scharakteryzowano modele niehertzowskie, w których pod uwagę bierze się siły adhezji. Przedstawiono dwa modele uwzględniające adhezyjne przyciąganie sferycznego wgłębnika i podłoża, tj. model Johnsona, Kendalla i Robertsa (JKR), wykorzystujący równowagę pomiędzy zmagazynowaną energią sprężystą a utratą energii powierzchniowej pomiędzy kulistym wgłębnikiem i powierzchnią płaską, oraz model sprężystego kontaktu Derjaguina–Mullera–Toporowa (DMT). Model JKR uwzględnia wpływ nacisku kontaktowego i adhezji tylko wewnątrz obszaru kontaktu, natomiast model DMT uwzględnia dodatkowo siły przyciągania występujące pomiędzy ciałami, które oddziałują także poza strefą kontaktu. W dalszej części monografii zaprezentowano modele dla płaskich powierzchni biorące pod uwagę ich chropowatość. Opisano teorię Greenwooda i Williamsona (GW), która zakłada, że wysokości nierówności mają rozkład gaussowski, a odkształcenie nierówności jest opisane modelem Hertza, oraz teorie Greenwooda i Trippa. Następnie przedstawiono matematyczny opis odkształcania materiału przy jego kontakcie z wgłębnikiem w kształcie stożka, zaprezentowany przez Sneddona. W kolejnym rozdziale omówiono różne metody pomiaru twardości materiałów: Brinella, Meyera, Vickersa, Knoopa, Martensa i Rockwella. Następny rozdział opisuje metodę indentacji. Scharakteryzowano w nim naprężenia i odkształcenia w materiale podczas penetracji przez kulisty i ostry wgłębnik, sposoby określania twardości i sztywności materiału, opisano efekt skali występujący dla małych przemieszczeń wgłębnika, a także sposób wyznaczania gęstości dyslokacji występujących w materiale i ich mobilności. Rozdział ten zawiera też omówienie sposobu wyznaczania współczynnika umocnienia odkształceniowego, krytycznego współczynnika intensywności naprężeń oraz naprężeń własnych przy wykorzystaniu testu indentacji. Znajdują się tu również informacje na temat testu zarysowania. Ostatni rozdział przedstawia wyniki prac naukowych, których autorka jest współautorem, i wyniki badań własnych jeszcze nieopublikowanych, które zostały uzyskane za pomocą indentera.

  • Mechanism of antifreeze protein functioning and the “anchored clathrate water” concept
    • Jan Zielkiewicz
    2023 Full text JOURNAL OF CHEMICAL PHYSICS

    In liquid water, there is a natural tendency to form aggregates that consist of water molecules linked by hydrogen bonds. Such spontaneously formed aggregates are surrounded by a "sea" of disordered water molecules, with both forms remaining in equilibrium. The process of creating water aggregates also takes place in the solvation water of proteins, but in this case the interactions of water molecules with the protein surface shift the equilibrium of the process. In this paper, we analyze the structural properties of the solvation water in antifreeze proteins (AFPs). The results of molecular dynamics analysis with the use of various parameters related to the structure of solvation water on the protein surface are presented. We found that in the vicinity of the active region responsible for the binding of AFPs to ice, the equilibrium is clearly shifted towards the formation of "ice-like aggregates", and the solvation water has a more ordered ice-like structure. We have demonstrated that a reduction in the tendency to create "ice-like aggregates" results in a significant reduction in the antifreeze activity of the protein. We conclude that shifting the equilibrium in favor of the formation of "ice-like aggregates" in the solvation water in the active region is a prerequisite for the biological functionality of AFPs, at least for AFPs having a well-defined ice binding area. Also, our results fully confirm the validity of the "anchored clathrate water" concept, formulated by Garnham et al. (PNAS, (2011), 108, 7363).

  • Mechanochemically synthesized Mn3O4@β-cyclodextrin mediates efficient electron transfer process for peroxymonosulfate activation
    • Huan Liu
    • Xiaohui Dai
    • Lingshuai Kong
    • Meng Xie
    • Chengji Sui
    • Qianyi Zhang
    • Grzegorz Boczkaj
    • Przemysław Kowal
    • Bin Cai
    • Jinhua Zhan
    2023 SEPARATION AND PURIFICATION TECHNOLOGY

    The rational surface engineering of heterogeneous catalysts is of great significance in advanced oxidation processes (AOPs) for eliminating refractory contaminants but remains challenging. In this study, β-cyclodextrin modified Mn3O4 (Mn3O4@β-CD) was prepared through a mechanochemical approach for peroxymonosulfate (PMS) activation, which achieved efficient bisphenol A (BPA) removal via electron transfer process (ETP). The reactive PMS* complex with elevated potential was identified to dominate the ETP by withdrawing electrons from BPA with Mn3O4@β-CD working as electron shuttle, as evidenced by spectroscopy and electrochemical techniques. Experimental results and density functional theory (DFT) calculations showed that the β-CD modification enhanced the interfacial accumulation of pollutants and shortened the migration distance between pollutants (electron donor) and catalysts (electron shuttle) to mediate electron transfer more effectively. Benefitting from the improved ETP, the Mn3O4@β-CD/PMS system showed efficient PMS utilization and practical adaptability in actual waterbodies. This study provides a rational approach for modulating the surface structure of heterogeneous catalysts in PMS-based AOPs for environmental remediation.

  • Membrane distillation assisting food production processes of thermally sensitive food liquid items: a review
    • Emilia Gontarek-Castro
    • Roberto Castro Muñoz
    2023 Full text CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION

    Physical separation technologies have become important tool for processing in the current food manufacturing industries, especially for the products containing bioactive compounds thanks to their health benefits in costumers. As for the processing of bioactive food ingredients implies the implementation of integrated systems oriented to their separation, fractionation, and recovery. In this field, membrane distillation (MD), which is a thermally driven membrane process, has been proposed as an alternative for the separation and concentration of liquid food items. In principle, MD can separate water and volatile compounds from aqueous feed solutions through a permeate that passes across microporous hydrophobic membranes. The separation via MD is thanks to the vapor pressure difference on both membrane sides. In this review, we analyzed the ongoing experimental efforts aimed to recover and purify food bioactive compounds from the concentration of fruit juices and extracts using MD. Also, the processing of dairy products, concentration of food by-products, and ethanol production and its removal from beverages using MD have been reviewed. Additionally, a feedback on the distinct membrane module configurations and membrane requirements for successful operation is addressed.

  • Merging Proline:Xylitol Eutectic Solvent in Crosslinked Chitosan Pervaporation Membranes for Enhanced Water Permeation in Dehydrating Ethanol
    • Roberto Castro Munoz
    • Maksymilian Plata-Gryl
    • Grzegorz Boczkaj
    2023 Full text Membranes

    The scope of this research aims at merging a new deep eutectic mixture (DES) into a biopolymer-based membrane for a pervaporation application in dehydrating ethanol. Herein, an L-proline:xylitol (at 5:1) eutectic mixture was successfully synthesized and blended with chitosan (CS). A complete characterization of the hybrid membranes, in terms of morphology, solvent uptake, and hydrophilicity, has been conducted. As part of their applicability, the blended membranes were assayed for their ability to separate water from ethanolic solutions by means of pervaporation. At the highest temperature (50 °C), a water permeation of ca. 0.46 kg m−2 h−1 was acquired, representing a higher permeation than the pristine CS membranes (ca. 0.37 kg m−2 h−1). Therefore, CS membranes demonstrated an enhanced water permeation thanks to their blending with the hydrophilic L-proline:xylitol agent, making these membranes a good candidate for other separations containing polar solvents.

  • Metaliczne nanostruktury i nanostopy na bazie Au i Ag
    • Robert Kozioł
    2023 Full text

    W niniejszej rozprawie doktorskiej opisano kontrolowane otrzymywanie metalicznych nanostruktur ze złota i srebra, o pożądanych właściwościach optycznych, w wyniku odwilżania termicznego ultracienkich warstw metalicznych. Pokazano w niej wpływ poszczególnych parametrów wytwarzania na końcowo uzyskiwane właściwości nanostruktur plazmonicznych. Dodatkowo, zaprezentowano skuteczność stosowanej preparatyki w otrzymywaniu jednorodnych nanostruktur stopowych, których właściwości optyczne, w konsekwencji kontroli nad zachodzącymi efektami synergistycznymi, były modulowane w zakresie 100 nm wewnątrz widma światła widzialnego. Co więcej, zaprezentowano również potencjalne zastosowanie otrzymywanych w ten sposób nanostruktur jako czujników w środowiskach ciekłych, demonstrując tym samym ich stabilność. Dodatkowo, zaimplementowano techniki z obszaru technologii informatycznej: symulacje metodą różnic skończonych w dziedzinie czasu do wyznaczenia rozkładu pól elektromagnetycznych w płaszczyźnie wytworzonych nanostruktur; oraz uczenia maszynowego celem predykcji wymaganych parametrów syntezy nanostruktur o żądanych właściwościach optycznych.

  • Metallurgical characterization and high-temperature tensile failure of Inconel 617 alloy welded by GTAW and SMAW—a comparative study
    • Sachin Sirohi
    • Naveen Kumar
    • Amit Kumar
    • Shailesh M. Pandey
    • Balamurugan Adhithan
    • Dariusz Fydrych
    • Chandan Pandey
    2023 PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS

    Two types of the weld joint of Inconel 617 alloy were produced using gas tungsten arc welding (GTAW) and shielded metal arc welding (SMAW) processes with ERNiCrCoMo-1 filler metal and ENiCrCoMo-1 electrode, respectively. The weld metal showed the segregation of the principle alloying elements like Mo and Cr along the inter-dendritic spaces, triggering the formation of secondary phases. The microstructure characterization of the interface ensured the high dilution, which could be attributed to the closeness in melting point and chemistry of base and filler metal. Microhardness variation, tensile testing at room and high temperature, and Charpy impact test were conducted to investigate the effect of the Mo segregation in the weld zone and heterogeneity in the microstructure of weldments on the mechanical behavior of both the welded joints. The cross-weld tensile tests were conducted at room temperature and 550°C. The tensile test samples failed from the weld zone for each condition with a tensile strength value close to the base metal, which ensured the applicability of the joint for end service. The tensile strength of GTAW-RT, GTAW-HT, SMAW-RT, and SMAW-HT were measured as 766 ± 22 MPa, 570 ± 5 MPa, 760 ± 7 MPa, and 600 ± 8 MPa, respectively. A non-uniform hardness plot was witnessed with the hardness of the GTAW-weld and SMAW-weld zone of 257 ± 8 HV and 285 ± 5 HV, respectively, in the transverse direction. The impact toughness of the weld zone was 84 ± 2 J and 48 ± 4 J for GTAW and SMAW weld zone. The average impact toughness of the GTAW-weld zone was approximately 42% higher than the value of the SMAW-weld zone. In a nutshell, it can be concluded that the welded joint of Inconel 617 produced using the GTAW process with ERNiCrCoMo-1 filler had the best metallurgical and mechanical properties.

  • Metal-Organic Frameworks in Green Analytical Chemistry
    • Justyna Płotka-Wasylka
    • Małgorzata Rutkowska
    • Natalia Jatkowska
    • Zeraati Malihe
    • Sargaze Ghasem
    • Massoud Kaykhaii
    2023 Full text

    Taking into consideration the rapid expansion of MOFs applications in the analytical chemistry area, it is important to evaluate the existing and future analytical MOF-based methods according to GAC principles. From this point of view, eco-friendly MOFs-based methods should include features such as: green design and synthesis of MOF, evaluation of toxicity issues of MOFs, and incorporation of MOFs in GAC methods. This Chapter will put particular emphasis on the efforts made on greener synthesis of MOFs and the various routes and methods explored in this regard. In addition, their incorporation into less-harmful analytical chemistry methods is discussed.

  • Metamaterial-Based Series-Fed Antenna with High Gain and Wideband Performance for Millimeter Wave Spectrum Applications
    • Bashar Esmail
    • Sławomir Kozieł
    • Dustin Isleifson
    2023 Full text Electronics

    This paper presents a high-gain, wideband series-fed antenna designed for 5G millimeter-wave (MMW) applications. The structure employs a substrate-integrated waveguide (SIW)-based power splitter and metamaterials (MMs). The power divider functions effectively at 27.5 GHz, exhibiting an impedance bandwidth from 26.9–28.6 GHz. The series-fed dipole is assembled on the SIW-based power splitter, incorporating four dipoles with varying lengths and spacing. The di-poles are connected in series on both sides, running in parallel through a microstrip line. Effec-tively combining the resonances of the series-fed dipoles and the SIW results in a broad imped-ance bandwidth, ranging from 26.9 GHz to 34.75 GHz. The design offers a gain extending from 9 to 10.5 dBi within the operating bandwidth. To improve gain performance without a substantial increase in antenna size, 11 × 6 MM unit cells have been positioned in front of the antenna. As a result, the proposed antenna achieves a maximum gain of 14.1 dBi at 30.5 GHz while maintaining an operational bandwidth of 7.85 GHz. Additionally, due to the arrangement of the MM-based two series-fed dipoles, the antenna exhibits symmetrical dual-beam E-plane radiation at ±20° at 28 GHz in the end-fire direction. The developed system was experimentally validated and demon-strated excellent agreement between the simulated and measured data.

  • Method for determining of shallow water depths based on data recorded by UAV/USV vehicles and processed using the SVR algorithm
    • Mariusz Specht
    • Bartosz Szostak
    • Oktawia Lewicka
    • Andrzej Stateczny
    • Cezary Specht
    2023 MEASUREMENT

    Bathymetric measurements in waters shallower than 1 m are necessary to monitor seafloor relief changes in the coastal zone. This is especially important for ensuring the safety of navigation, navigation efficiency, as well as during the design and monitoring of hydrotechnical structures. Therefore, the aim of this article is to present a method for determining of shallow water depths based on data recorded by Unmanned Aerial Vehicle (UAV) and Unmanned Surface Vehicle (USV), as well as processed using the Support Vector Regression (SVR) algorithm. Validation studies of this method was carried out on two selected waterbodies (inland and sea) using the DJI Phantom 4 Real Time Kinematic (RTK) UAV and the AutoDron USV. Then, the geospatial data recorded by a drone was applied to determine depths of shallow waterbodies using the SfM algorithm. Subsequently, the determined depths were compared with the depths measured by a Global Navigation Satellite System (GNSS) RTK receiver or a Single Beam Echo Sounder (SBES), in order to assess the accuracy of the proposed method. The research showed that it is able to determine shallow waterbody depths with the accuracy requirements specified for the International Hydrographic Organization (IHO) S-44 special order (depth error ≤ 0.25 m (p = 0.95)), but only to depths not exceeding 1 m. In the inland waterbody, the depth accuracy was 0.22–0.24 m (p = 0.95), while in the sea waterbody the measurement accuracy was higher, amounting to 0.16 m (p = 0.95). However, for the depth range up to 2 m, the results are radically different, because the vertical position error with a 95% confidence level exceeds the value of 0.3 m in the analysed waterbodies.

  • Methodology for Performing Bathymetric Measurements of Shallow Waterbodies Using an UAV, and their Processing Based on the SVR Algorithm
    • Bartosz Szostak
    • Mariusz Specht
    • Paweł Burdziakowski
    • Andrzej Stateczny
    • Cezary Specht
    • Oktawia Lewicka
    2023 MEASUREMENT

    State-of-art methods of bathymetric measurements for shallow waterbodies use Global Navigation Satellite System (GNSS) receiver, bathymetric Light Detection and Ranging (LiDAR) sensor or satellite imagery. Currently, photogrammetric methods with the application of Unmanned Aerial Vehicles (UAV) are gathering great importance. This publication aims to present step-by-step methodology for carrying out the bathymetric measurements of shallow waterbodies with the use of UAV-Structure from Motion (SfM) and Support Vector Regression (SVR) algorithms. Proposed model is explained and verified on the basis of measurement campaign on Raduńskie Górne Lake located in Poland. The campaign included GNSS Real Time Kinematic (RTK) bathymetric measurements for robust training dataset and photogrammetric flight pass for SfM point cloud. The presented methodology will allow to perform bathymetric measurements with the accuracy provided for the International Hydrographic Organization (IHO) Special Order (horizontal position error ≤ 2 m (p=0.95), vertical position error ≤ 0.25 m (p=0.95)).

  • Methodology of experimental research on efficiency of hydro-mechanical automatic gearbox
    • Piotr Patrosz
    • Paweł Załuski
    • Marcin Bąk
    • Paweł Śliwiński
    • Mykola Karpenko
    2023 Full text

    The article shortly describes the design and principle of operation of the hydromechanical gearbox and presents the methodology and design of test stands used for testing hydromechanical proto-type gearbox developed at Technical University of Gdansk. The article presents an approach according to which, in order to obtain reliable measurement data, it is necessary to separate the tests of the hydraulic and mechanical parts of the gearbox. For this reason, the tests of the pump and the hydraulic motor are also presented. To validate this approach sample test results are in-cluded and discussed.