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Gdańsk University of Technology

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Publications from the year 2020

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  • In vivo performance of intraperitoneal onlay mesh after ventral hernia repair
    • Izabela Lubowiecka
    • Agnieszka Tomaszewska
    • Katarzyna Szepietowska
    • Czesław Szymczak
    • Maciej Śmietański
    2020 Full text CLINICAL BIOMECHANICS

    Background: Ventral hernia repair needs to be improved since recurrence, postoperative pain and other complications are still reported in many patients. The behavior of implants in vivo is not sufficiently understood to design a surgical mesh mechanically compatible with the human abdominal wall. Methods: This analysis was based on radiological pictures of patients who underwent laparoscopic ventral hernia repair. The pictures show the trunk of the patient at rest in a standing position and under side bending. The change in the distance between different tacks due to trunk movement was analyzed, which allowed us to determine the in vivo elongation of the mesh incorporated into the abdominal wall. Findings: The relative elongations of the surgical mesh varied from a few percent to greater than 100% in two cases. The median of the median relative elongations obtained for all patients is 9.5%, and the median of the maximum relative elongations for all patients is 32.6%. The maximum elongation occurs between tacks that are next to each other. Trunk movement causes implant deformation, and this study provides quantitative information regarding changes in the distance between fasteners. Interpretation: The physiological movement of the human abdomen must be regarded as a very important factor in mesh deformation and should be considered in surgical practice to reduce the hernia recurrence rate and postoperative pain.

  • In vivoevaluation of the CB1allosteric modulator LDK1258 reveals CB1-receptor independent behavioral effects
    • Teresa Olszewska
    • Mustafa Mohammed
    • Giulia Donvito
    • Lauren Moncayo
    • Amelia Swafford
    • Justin Poklis
    • Ralph Grauer
    • Bogna Ignatowska-Jankowska
    • Debra A. Kendall
    • Dai Lu
    • Aron H. Lichtman
    2020 PHARMACOLOGY BIOCHEMISTRY AND BEHAVIOR

    In the present study, we examined whether LDK1258, which produces strong CB1receptor allosteric effects ininvitroassays, would elicitin vivoeffects consistent with allosteric activity. In initial studies, LDK1258 reducedfood consumption and elicited delayed antinociceptive effects in the chronic constrictive injury of the sciaticnerve (CCI) model of neuropathic pain, which unexpectedly emerged 4 h post-injection. UPLC-MS/MS analysisquantified significant levels of LDK1258 in both blood and brain tissue at 30 min post-administration thatremained stable up to 4 h. The observation that LDK1258 also produced respective antinociceptive and anorecticeffects in rimonabant-treated wild type mice and CB1(−/−) mice suggests an off-target mechanism of action.Likewise, LDK1258 produced a partial array of common cannabimimetic effects in the tetrad assay, which werenot CB1receptor mediated. Additionally, LDK1258 did not substitute for the CB1receptor orthosteric agonistsCP55,940 or anandamide in the drug discrimination paradigm. In otherinvivoassays sensitive to CB1receptorallosteric modulators, LDK1258 failed to shift the dose-response curves of either CP55,940 or anandamide inproducing thermal antinociception, catalepsy, or hypothermia, and did not alter the generalization curve ofeither drug in the drug discrimination assay. Thus, this battery of tests yielded results demonstrating thatLDK1258 produces antinociceptive effects in the CCI model of neuropathic pain, anorectic effects, and otherinvivopharmacological effects in a manner inconsistent with CB1receptor allosterism. More generally, this studyoffers a straightforward screening assay to determine whether newly synthesized CB1receptor allosteric mod-ulators translate to the whole animal.

  • Including the Dark Side of Entrepreneurship in the Entrepreneurship Education
    • Paweł Ziemiański
    • Jakub Golik
    2020 Full text Education Sciences

    Pursuing an entrepreneurial career is often rewarding in terms of both economic and psychological outcomes. However, becoming an entrepreneur also has its darker side that affects professional and personal life. Meanwhile, the positivity bias is prevalent in entrepreneurial education and research. It is recognized as emphasizing the advantages of becoming an entrepreneur and giving considerably less attention to potential downsides. Based on the theoretical model of met expectations, it is proposed that building an accurate and balanced image of the entrepreneurial career is crucial to help students prepare to pursue it successfully. Using data from SEAS (Survey on Entrepreneurial Attitudes of Students) Project, authors quantitatively test the perception of the severity of negative aspects of entrepreneurship among 513 business students from northern Poland. Further, the results of 16 semi-structured qualitative interviews conducted with mature and experienced entrepreneurs from the same region are presented. They are focused on the entrepreneurs’ perspective on the experienced dark sides and reveal employed coping strategies. A call is made to include these findings in designing university entrepreneurship programs by eliciting the awareness of the existence of the dark sides and indicating the means of their attenuation.

  • Incomplete Cross-Bonding in the MV Line. Experience from the Operation of MV Single Cable Lines
    • Krzysztof Dobrzyński
    • Zbigniew Lubośny
    • Jacek Klucznik
    • Janusz Grala
    • Dominik Falkowski
    2020 Full text ENERGIES

    Cable lines are one of the basic components of power systems. Medium and high voltage cables mainly comprise a metallic sheath, which is concentric to the main core conductor. There are several operating schemes of such cable lines, which differ in the place of earthing of sheaths and the possible use of the sheaths and/or conductors crossing. The sheaths cross-bonding is typically done in two places of one cable line section, and it allows to reduce power losses. Nevertheless, the use of incomplete sheaths crossing—only in one place on cable route may have economic justification. The paper presents an incomplete sheaths cross-bonding analysis of an existing medium voltage cable line. The results obtained by the mathematical model are validated by measurements taken on 30 October 2019 on an existing cable line. Measurements recorded on a real object for various systems of crossing sheaths are presented. The influence of incorrect sheaths crossing on the measured quantities was shown. In addition, the risk of excess voltage on the sheaths during short-circuits has been verified using a mathematical model.

  • Increasing the Geometrical and Interpretation Quality of Unmanned Aerial Vehicle Photogrammetry Products Using Super-Resolution Algorithms
    • Paweł Burdziakowski
    2020 Full text Remote Sensing

    Unmanned aerial vehicles (UAVs) have now become very popular in photogrammetric and remote-sensing applications. Every day, these vehicles are used in new applications, new terrains, and new tasks, facing new problems. One of these problems is connected with flight altitude and the determined ground sample distance in a specific area, especially within cities and industrial and construction areas. The problem is that a safe flight altitude and camera parameters do not meet the required or demanded ground sampling distance or the geometrical and texture quality. In the cases where the flight level cannot be reduced and there is no technical ability to change the UAV camera or lens, the author proposes the use of a super-resolution algorithm for enhancing images acquired by UAVs and, consequently, increase the geometrical and interpretation quality of the final photogrammetric product. The main study objective was to utilize super-resolution (SR) algorithms to improve the geometric and interpretative quality of the final photogrammetric product, assess its impact on the accuracy of the photogrammetric processing and on the traditional digital photogrammetry workflow. The research concept assumes a comparative analysis of photogrammetric products obtained on the basis of data collected from small, commercial UAVs and products obtained from the same data but additionally processed by the super-resolution algorithm. As the study concludes, the photogrammetric products that are created as a result of the algorithms' operation on high-altitude images show a comparable quality to the reference products from low altitudes and, in some cases, even improve their quality.

  • Increasing the lifetime of engineering structures through the use of composite laggings
    • Eligiusz Mieloszyk
    • Anita Milewska
    • Marcin Abramski
    2020

    The use of composite laggings prevents concrete (chemical and biological) corrosion. Columns coated with composite or reinforced composite are more resistant to negative environmental impact on concrete or steel. The mechanical properties of the reinforced casing also cause that these types of columns are more resistant to lateral forces. The applied casing limits carbonization of concrete and cyclical freezing and thawing with penetrating water, and thus increases the lifespan of columns exposed to water. Laboratory tests were carried out regarding the short-time load-carrying capacity of columns in a composite laggings.

  • Industry 4.0 Implementation Challenges in Manufacturing Industries: an Interpretive Structural Modelling Approach
    • Ahmad Reshad Bakhtari
    • Vineet Kumar
    • Mohammad Waris
    • Cesar Sanin
    • Edward Szczerbicki
    2020 Full text Procedia Computer Science

    For the last few years, the fourth industrial revolution, known as Industry 4.0, has been a hot topic among academics. Industry 4.0 literature involves researches presenting studies related to its different aspects including challenges, opportunities, implementation and adoption. However, a detailed study of challenges and barriers towards the Industry 4.0 implementation in manufacturing industries is missing. Hence, this paper aims to study and analyze the Industry 4.0 implementation challenges in manufacturing industries based on the expert opinions and the Interpretive Structural Modelling (ISM). The ISM analysis investigates the challenges in a structural base, finds the relationships between these challenges and finally shows how challenges affect each other to uncover the root cause triggering the other challenges. The industrial practitioners and managers can then take advantage of this analysis to know which challenge acts as the main barrier towards Industry 4.0 implementation and to be focused first in order to reach a solution.

  • Indywidualne programy integracyjne dla uchodźców i cudzoziemców objętych ochroną uzupełniającą z państw poradzieckich w dobie przynależności Polski do Unii Europejskiej
    • Krystyna Gomółka
    2020

    Celem pracy jest analiza uwarunkowań i skali obejmowania indywidualnymi programami integracyjnymi obywateli państw poradzieckich, którym przyznawano status uchodźcy i ochronę uzupełniającą w Polsce w okresie od 2004 r. do 2018 r., tj. od przystąpienia przez Polskę do Unii Europejskiej. Omawiane są następujące zagadnienia: uwarunkowania formalno-prawne ochrony międzynarodowej w Polsce, zasady przyznawania indywidualnych programów integracyjnych, skala udziału obywateli państw poradzieckich objętych ochroną międzynarodową w programach integracyjnych na tle innych grup cudzoziemców. Zaprezentowano także ocenę skuteczności programów integracyjnych oferowanych uchodźcom w Polsce opartą na badaniach przeprowadzonych przez Beatę Samoraj i Mieczysława Bienieckiego. Z kolei ustalenia dokonane przez Sławomira Łodzińskiego i Jana Kruszyńskiego pozwoliły ujawnić oceny, jakie Polacy formułują pod adresem tych programów oraz pomocy przyznawanej cudzoziemcom.

  • Influence of addition of carbon nanotubes on rheological properties of selected liquid lubricants - a computer simulation study
    • Anjali Chopra
    • Szymon Winczewski
    2020 Full text TASK Quarterly

    This work is motivated by the improvement of anti-friction properties of lubricants by addition of CNTs proved experimentally in literature. In particular, a methodology is developed to compute the shear viscosity of liquid lubricants (Propylene Glycol) based on Molecular Dynamics simulation. Non-Equilibrium molecular dynamics (NEMD) approach is used with a reactive force field ReaxFF implemented in LAMMPS. The simulations are performed using the canonical (NVT) ensemble with the so-called SLLOD algorithm. Couette flow is imposed on the system by using Lees-Edwards periodic boundary conditions. Suitable parameters such as simulation time and imposed shear velocity are obtained. Using these parameters, the influence of addition of 27 wt% CNTs to Propylene Glycol on its viscosity is analyzed. Results show that 3.2 million time-steps with a 0.1 fs time-step size is not sufficient for the system to reach equilibrium state for such calculations. With the available computational resources, a shear velocity of 5 × 10−5Å/fs was observed to give viscosity value with approximately 43% error as compared to the experimental value. Moreover, the lubricant exhibited a shear thinning behaviour with increasing shear rates. CNTs enhanced the lubricant’s viscosity by 100-190% depending upon the averaging method used for calculation.

  • Influence of alkaline and oxidative pre-treatment of waste corn cobs on biohydrogen generation efficiency via dark fermentation
    • Karolina Kucharska
    • Piotr Rybarczyk
    • Iwona Hołowacz
    • Donata Konopacka-Łyskawa
    • Edyta Słupek
    • Patrycja Makoś-Chełstowska
    • Hubert Cieśliński
    • Marian Kamiński
    2020 BIOMASS & BIOENERGY

    Stages of waste corn cobs processing leading to the production of biohydrogen via dark fermentation are presented and discussed in this paper. Firstly, the effects of pretreatment conditions i.e. alkaline, alkaline-oxidizing and Fenton oxidizing pre-treatment of lignocellulosic biomass on the removal of lignin were examined. The solid residue obtained in the first stage was subjected to saccharification by means of enzymatic hydrolysis. The composition of enzymatic hydrolysates and fermentation broths were investigated in order to determine the content of sugars as well as phenolic compounds and fermentation broth composition containing organic acids. The dark fermentation process of the obtained hydrolysates was carried using mixed wastewater sludge from the municipal sewage treatment plant. The highest hydrogen production was obtained for alkaline pre-treated hydrolysates. The effects of investigated chemical pre-treatment methods were discussed in terms of the obtained saccharification efficiency and composition of the gas phase formed during the fermentation, and the composition of fermentation broth.

  • INFLUENCE OF CERAMIC COATING ON MECHANICAL PROPERTIES OF STAINLESS STEEL
    • Dionizy Czekaj
    • Agata Lisińska-Czekaj
    • Krzysztof Krzysztofowicz
    2020 Full text ARCHIVES OF METALLURGY AND MATERIALS

    Crystal structure and phase composition of stainless steel substrates (AISI 304 type) was studied and it was found that they adopted the cubic symmetry. The calculated elementary cell parameter for the mayor Fe-Ni phase (weight fraction 99%) was a = 3.593 Å, whereas the mean grain size was <D> = 2932 Å. Morphology of the stainless steel substrate surface was studied with profilometry. Mechanical properties of the stainless steel substrates and stainless steel substrates coated with ceramic layer of barium strontium titanate were studied with microhardness tester. For measurements performed according to the Vickers method the average microhardness was found HV = 189 or HV = 186 for the “in-line” and “mapping” measurement pattern, respectively. The sol-gel method was used to coat the surface of the stainless steel substrate with a thin ceramic layer of the chemical composition Ba0.6Sr0.4TiO3. It was found that the stainless steel substrate covered with sol-gel deposited ceramic coating exhibited the average hardness within the range HV = 217 up to HV = 235 for loading force F = 98 mN and F = 0.98 N, respectively. The Knopp method was also used and it was found that the stainless steel substrate with Ba0.6Sr0.4TiO3 coating exhibited hardness HK = 386.

  • Influence of chemical structure on physicochemical properties and thermal decomposition of the fully bio-based poly(propylene succinate-co-butylene succinate)s
    • Paulina Parcheta
    • Janusz Datta
    2020 Full text POLYMER TESTING

    In this work, two polyesters and four copolyesters were studied. All materials were synthesized to obtain the monomers dedicated for thermoplastic polyurethane elastomers. For this type of PUR, the monomers should characterize by appropriate selected physicochemical properties and macromolecular structure distribution, which depends on synthesis conditions. The study of chemical structure with extensive and knowledgeable analysis of formed macromolecules of synthesized bio-based copolyesters was conducted with the use of FTIR and 1H NMR spectroscopy and MALDI-ToF mass spectrometry. The results allowed to propose the majority of probable chemical structures of macromolecules formed during synthesis. Moreover, the impact of the structure on the thermal stability of the obtained copolyesters was also determined with the use of thermogravimetric analysis. The temperature of the beginning of thermal decomposition equaled even 330oC. Furthermore, the results of DSC-TG/QMS coupled method confirmed that all prepared polyesters degraded by α and β-hydrogen bond scission mechanisms.

  • Influence of Dielectric Overlay Dimensions on Performance of Miniaturized ESPAR Antenna
    • Mateusz Czeleń
    • Mateusz Rzymowski
    • Krzysztof Nyka
    • Łukasz Kulas
    2020 Full text

    In this paper, the influence of dielectric overlay size on miniaturized ESPAR antenna performance has been investigated. The dielectric overlay’s main function is antenna’s size reduction but it can also be used to modify its radiation pattern. This creates the possibility of easy adopting antenna parameters to different applications by swapping used overlay. In particular, the lowering of antenna’s main beam elevation direction has been considered. By using selected alternative overlay one can obtain a 20° lower beam. The design was confirmed by realization and measurements.

  • Influence of Dielectric Overlay Permittivity on Size and Performance of Miniaturized ESPAR Antenna
    • Mateusz Czeleń
    • Mateusz Rzymowski
    • Krzysztof Nyka
    • Łukasz Kulas
    2020 Full text

    In this paper, influence of dielectric overlay permittivity on miniaturized ESPAR antenna parameters is presented. ESPAR antenna is a low-cost and energy-efficient way to implement beam steering capability to a node and improve network performance. The antenna size reduction is obtained by embedding its active and passive elements in ABS based materials of relative permittivity equal to 4, 5.5 and 7.5 in order to achieve network node compact size. Simulation results of three optimized for particular dielectric constant designs are presented and tradeoff between dimensions reduction and performance is discussed. Selected materials and antenna design are dedicated to be fabricated in 3D print technology, so can be easily prototyped.

  • Influence of process of straightening ship hull structure made of 316L stainless steel on corrosion resistance and mechanical properties
    • Jakub Kowalski
    • Łukasz Licznerski
    • Milena Supernak-Marczewska
    • Krzysztof Emilianowicz
    2020 Full text Polish Maritime Research

    The AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries, for architectural elements, and many others. The chemical composition of corrosion-resistant austenitic steels provides them with an austenite structure that is stable in a wide temperature range, under appropriate conditions for heating, soaking, and cooling. 316L steel plate was subjected to a technological treatment of hot straightening with an oxyacetylene torch, which is not commonly used for this type of steel, mainly due to the lack of objective assessment of whether the austenitizing temperature has been achieved and the stability of the heat treatment process is ensured. The single-phase structure of austenite with high corrosion resistance, without precipitation of carbides, steel is obtained by supersaturation in water from 1100°C. The purpose of the presented research was to determine the usefulness of the flame straightening process for a ship structure made of 316L steel.

  • Influence of Selected Warm Mix Asphalt Additives on Cracking Susceptibility of Asphalt Mixtures
    • Marcin Stienss
    • Cezary Szydłowski
    2020 Full text Materials

    Warm mix asphalt (WMA) has been widely accepted as a future asphalt paving technology. Besides clear advantages, there are still some concerns regarding durability and long-term performance of pavements made with this type of asphalt mixtures. One of the most important issues is low temperature behaviour of WMA because certain additives used for temperature reduction can aect bitumen properties. This paper presents the evaluation of low-temperature properties of laboratory-produced asphalt concrete for wearing course with selected WMA additives. One type of bitumen with paving grade 50/70 and fiveWMAadditives of dierent nature (organic, surface tension reducer and combination of both) were used in this study. The production and compaction temperature of mixtures containing WMA additives was 25 C lower in comparison with the temperature of the reference mix. To assess the susceptibility of WMA to low-temperature cracking, Semi-Circular Bending (SCB) and Thermal Stress Restrained Specimen Test (TSRST) were used. Supplementary rating was made by analysing Bending Beam Rheometer (BBR) test results of asphalt binders.

  • Influence of several biodegradable components added to pure and nanosilver-doped PMMA bone cements on its biological and mechanical properties
    • Marcin Wekwejt
    • Marta Michalska-Sionkowska
    • Michał Bartmański
    • Małgorzata Nadolska
    • Krzysztof Łukowicz
    • Anna Pałubicka
    • Anna Maria Osyczka
    • Andrzej Zieliński
    2020 Full text Materials Science & Engineering C-Materials for Biological Applications

    Acrylic bone cements (BC) are wildly used in medicine. Despite favorable mechanical properties, processability and inject capability, BC lack bioactivity. To overcome this, we investigated the effects of selected biodegradable additives to create a partially-degradable BC and also we evaluated its combination with nanosilver (AgNp). We hypothesized that using above strategies it would be possible to obtain bioactive BC. The Cemex was used as the base material, modified at 2.5, 5 or 10 wt% with either cellulose, chitosan, magnesium, polydioxanone or tricalcium-phosphate. The resulted modified BC was examined for surface morphology, wettability, porosity, mechanical and nanomechanical properties and cytocompatibility. The composite BC doped with AgNp was also examined for its release and antibacterial properties. The results showed that it is possible to create modified cement and all studied modifiers increased its porosity. Applying the additives slightly decreased BC wettability and mechanical properties, but the positive effect of the additives was observed in nanomechanical research. The relatively poor cytocompatibility of modified BC was attributed to the unreacted monomer release, except for polydioxanone modification which increased cells viability. Furthermore, all additives facilitated AgNp release and increased BC antibacterial effectiveness.Our present studies suggest the optimal content of biodegradable component for BC is 5 wt%. At this content, an improvement in BC porosity is achieved without significant deterioration of BC physical and mechanical properties. Polydioxanone and cellulose seem to be the most promising additives that improve porosity and antibacterial properties of antibiotic or nanosilver-loaded BC. Partially-degradable BC may be a good strategy to improve their antibacterial effectiveness, but some caution is still required regarding their cytocompatibility.

  • INFLUENCE OF TACK WELDS DISTRIBUTION AND WELDING SEQUENCE ON THE ANGULAR DISTORTION OF TIG WELDED JOINT
    • Jacek Tomków
    • Konrad Sobota
    • Sławomir Krajewsk
    2020 Full text Facta Universitatis-Series Mechanical Engineering

    In this paper the influence of tack welds distribution and welding sequence on angular distortion of the Tungsten Inert Gas (TIG) welded joint was tested. Additionally, the effect of welding current on angular distortion was assessed. For research X2CrTiNb18 (AISI 441) stainless steel (2.5 mm thick) was chosen. During research specimens were prepared with different distributionsof tack welds. Then they were welded by different welding sequenceswith the use of different welding current values. After welding the angular distortion of each specimen was measured by using thecoordinate measuring machine. In the next step specimens were cut. Cross-sections were polished and the metallographic macroscopic testing was conducted to check the geometry of performed welds. Performed experiments allowed determining the optimal tack weld sequence and welding parameters for welding thin stainless steel sheets.

  • Influence of Two-Stage Anodization on Properties of the Oxide Coatings on the Ti–13Nb–13Zr Alloy
    • Agnieszka Ossowska
    • Andrzej Zieliński
    • Jean-marc Olive
    • Andrzej Wojtowicz
    • Piotr Szweda
    2020 Full text Coatings

    The increasing demand for titanium and its alloys used for implants results in need of such innovative surface treatment that may jointly increase corrosion resistance and biocompatibility, and demonstrate antibacterial protection at no cytotoxicity. The purpose of this research was to characterize the effect of two-stage anodization, performed for 30 min in phosphoric acid, at the presence of hydrofluoric acid in the second stage. The scanning electron microscopy, atomic force microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Raman spectroscopy, glow discharge optical emission spectroscopy, nanoindentation and nano-scratch tests, potentiodynamic corrosion studies, and water contact angle measurements were performed to characterize microstructure, mechanical, chemical and physical properties. The biological examinations were carried out to determine the cytotoxicity and antibacterial effects of oxide coatings. The research results demonstrate that two-stage oxidation affects several features and, in particular, improves mechanical and chemical behavior. The processes influencing the formation and properties of the oxide coating are discussed.

  • Initial Field Validation of Poroelastic Pavement Made with Crumb Rubber, Mineral Aggregate and Highly Polymer-Modified Bitumen
    • Piotr Jaskuła
    • Jerzy Ejsmont
    • Marcin Stienss
    • Grzegorz Ronowski
    • Cezary Szydłowski
    • Beata Świeczko-Żurek
    • Dawid Ryś
    2020 Full text Materials

    Tire/road noise in most driving conditions dominates other sources of traffic noise. One of the most efficient ways of reducing tire/road noise is to use the so-called “low noise pavement”. According to numerous studies, at present, poroelastic road pavement that is composed of rubber and mineral aggregate and polyurethane or bituminous binder gives the best noise reduction up to 12 dB. Unfortunately, there are many problems with making durable poroelastic pavements. This article presents the first results of a project that is executed in Poland and aims at the development of a durable, low noise poroelastic pavement based on polymer-modified asphalt binder called Safe, Eco-friendly POroelastic Road Surface (SEPOR). Two test sectionswere built in 2019 to test the production technology and performance of the SEPOR pavement. It is observed that some of the problems with previous poroelastic materials were mainly eliminated (especially delamination from the base layer and raveling) but noise reduction is a little less than expected (up to 9 dB). Rolling resistance for car tires is acceptable and fire properties (damping of spill fuel fires, toxic gas emission) are very good.