2021 - Repozytorium publikacji - Politechnika Gdańska

Pokaż publikacje z roku

Publikacje z roku 2021

Pokaż wszystkie

The influence of the basic conditions of the forced feed of abrasive compound on the roughness of flat ceramic elements after lapping.
- Adam Barylski
- Maciej Gniot
2021 Technologia i Automatyzacja Montażu
W docieraniu standardowym zawiesina ścierna dostarczana jest do strefy obróbki w sposób ciągły - zalewowo lub kroplowo, co generuje duże straty ścierniwa. W artykule opisano innowacyjny system dozowania i nanoszenia zawiesiny ściernej na powierzchnię żeliwnego docieraka tarczowego, który eliminuje tą wadę. W przeprowadzonych eksperymentach badano wpływ procentowej zawartości ziaren ściernych w nośniku oraz wielkość dawki zawiesiny i lepkości nośnika płynnego na wartości poszczególnych parametrów chropowatości powierzchni docieranych elementów ceramicznych. Docieranie jest jedna z technologii stosowanej w montażu zespołów podczas zastosowania kompensacji technologicznej lb przy indywidualnym dopasowaniu składanych elementów.
The influence of the grid density of measurement points on damage detection in an isotropic plate by the use of elastic waves and laser scanning Doppler vibrometry
- Łukasz Doliński
- Marek Krawczuk
- Magdalena Palacz
- Wiktor Waszkowiak
- Arkadiusz Żak
2021 Pełny tekst SENSORS
Damage detection in structural components, especially in mechanical engineering, is an 2 important element of engineering practice. There are many methods of damage detection, in which 3 changes in various parameters caused by the presence of damage are analysed. Recently, methods 4 based on the analysis of changes in dynamic parameters of structures, i.e. frequencies or mode shapes 5 of natural vibrations, as well as changes in propagating elastic waves, have been developed at the 6 highest rate. Diagnostic methods based on the elastic wave propagation phenomenon are becoming 7 more and more popular, therefore it is worth to focus on the improvement of the efficiency of these 8 methods. Hence, a question arises whether it is possible to shorten the required measurement time 9 without affecting the sensitivity of the diagnostic method used. This paper discusses the results 10 of research carried out by the authors in this regard both numerically and experimentally. The 11 numerical analysis has been carried out by the use of the Time-domain Spectral Finite Element 12 Method (TD-SFEM), whereas the experimental part has been based on the measurement performed 13 by 1-D Laser Doppler Scanning Vibrometery (LDSV).
The influence of the type of halogen substituent and its position on the molecular conformation, intermolecular interactions and crystal packing for a series of 1-benzoyl-3-(halogenophenyl)thioureas
- Damian Rosiak
- Andrzej Okuniewski
- Jarosław Chojnacki
2021 Pełny tekst Acta Crystallographica Section C-Structural Chemistry
By the reaction of benzoyl chloride, potassium isothiocyanate and the appropriate halogenoaniline, i.e. 2/3/4-(bromo/iodo)aniline, we have obtained five new 1-benzoyl-3-(halogenophenyl)thioureas, namely, 1-benzoyl-3-(2-bromophenyl)- thiourea and 1-benzoyl-3-(3-bromophenyl)thiourea, C14H11BrN2OS, and 1-benzoyl-3-(2-iodophenyl)thiourea, 1-benzoyl-3-(3-iodophenyl)thiourea and 1-benzoyl-3-(4-iodophenyl)thiourea, C14H11IN2OS. Structural and conformational features of the compounds have been analyzed using X-ray diffraction and theoretical calculations. The novel compounds were characterized by solid-state IR and 1H/13C NMR spectroscopy. The conformations and intermolecular interactions, such as hydrogen bonds, pi–pi and S(6)... pi stacking, and X...O (X = Br or I) , I...S and I...pi, have been examined and rationalized, together with four analogous compounds described previously in the literature. The set of nine compounds was chosen to examine how a change of the halogen atom and its position on the phenyl ring affects the molecular and crystal structures.
The Influence of Tool Shape and Process Parameters on the Mechanical Properties of AW-3004 Aluminium Alloy Friction Stir Welded Joints
- Anna Janeczek
- Jacek Tomków
- Dariusz Fydrych
2021 Pełny tekst Materials
The purpose of the following study was to compare the effect of the shape of a tool onthe joint and to obtain the values of Friction Stir Welding (FSW) parameters that provide the bestpossible joint quality. The material used was an aluminium alloy, EN AW-3004 (AlMn1Mg1). To theauthors’ best knowledge, no investigations of this alloy during FSW have been presented earlier. Fivebutt joints were made with a self-developed, cylindrical, and tapered threaded tool with a rotationalspeed of 475 rpm. In order to compare the welding parameters, two more joints with a rotationalspeed of 475 rpm and seven joints with a welding speed of 300 mm/min with the use of a cylindricalthreaded pin were performed. This involved a visual inspection as well as a tensile strength test ofthe welded joints. It was observed that the value of the material outflow for the joints made withthe cylindrical threaded pin was higher than it was for the joints made with the tapered threadedpin. However, welding defects in the form of voids appeared in the joints made with the taperedthreaded tool. The use of the cylindrical tool resulted in higher values for about 37% of mechanicalproperties compared with the highest result for the tapered threaded joint. As far as the parameterswere concerned, it was concluded that most of the specimens were properly joined for a rotationalspeed of 475 rpm. In the joints made with a welding speed of 300 mm/min, the material was notstirred properly. The best joint quality was given for a rotational speed of 475 rpm as well as a varietyof welding speed values between 150 and 475 mm/min.
The Influence of Water and Mineral Oil on Pressure Losses in Hydraulic Motor
- Paweł Śliwiński
- Piotr Patrosz
2021
In this paper, pressure losses in hydraulic motor supplied with water and mineral oil (two liquids that have significantly different viscosity and lubricating properties) are described and compared. The experimental tests were conducted using a hydraulic satellite motor that is dedicated to working with different liquids, including water. The methodology of measuring the pressure drop in internal channels of this motor is also described. The known mathematical formulas describing the pressure losses in the internal channels are presented also. Experimental studies have shown that a high flow rate in the motor causes the pressure losses in the motor supplied with water to be several percent greater than the pressure losses in the motor supplied with oil. However, low flow rates cause the pressure losses in the motor supplied with water to be about ten percent lower than the pressure losses in the motor supplied with oil. Furthermore, when the volume of the working chamber nears the minimum, additional pressure increase caused by compression of liquid occurs in this chamber.
The Interaction of Heptakis (2,6-di-O-Methyl)-β-Cyclodextrin with Mianserin Hydrochloride and Its Influence on the Drug Toxicity
- Sylwia Belica-Pacha
- Magdalena Małecka
- Mateusz Daśko
- Katarzyna Miłowska
- Maria Bryszewska
- Grażyna Budryn
- Joanna Oracz
- Bartłomiej Pałecz
2021 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
One tetracyclic antidepressant, mianserin hydrochloride (MIA), has quite significant side effects on a patients’ health. Cyclodextrins, which are most commonly used to reduce the undesirable features of contained drugs within their hydrophobic interior, also have the potential to alter the toxic behavior of the drug. The present paper contains investigations and the characteristics of interaction mechanisms for MIA and the heptakis (2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD) system, and evaluated the effects of the complexation on MIA cytotoxicity. In order to assess whether there was an interaction between MIA and DM-β-CD molecules, isothermal titration calorimetry (ITC) have been chosen. Electrospray ionization mass spectrometry (ESI-MS) helped to establish the complex stoichiometry, and circular dichroism spectroscopy was used to describe the process of complex formation. In order to make a wider interpretative perspective, the molecular docking results have been performed. The viability of Chinese hamster cells were investigated in the presence of DM-β-CD and its complexes with MIA in order to estimate the cytotoxicity of the drug and the conjugate with the chosen cyclodextrin. The viability of B14 cells treated with MIA+DM-β-CD is lower (the toxicity is higher) than with MIA alone, and no protective effects have been observed for complexes of MIA with DM-β-CD in any ratio.
The interaction of the pulsed laser irradiation with titania nanotubes - Theoretical studies on the thermal effect
- Piotr Kupracz
- Katarzyna Grochowska
- Jakub Wawrzyniak
- Katarzyna Siuzdak
2021 INTERNATIONAL JOURNAL OF THERMAL SCIENCES
This paper reports temperature dispersion simulations of titania nanotubes irradiated by the 355 nm, pulsed, nanosecond laser. The modelling with the use of Finite Elements Method concerns titania nanotubes of the length and the wall thickness in the range of 0.5–2 μm and 5–20 nm, respectively. The uniqueness of the morphology was preserved by ensuring the wall thickness variation along the height of the tube, which was determined by an exponential equation. The easily adapted model of optical transition under the heat treatment in vacuum was successfully introduced. According to the obtained results, the change in titania nanotube shape and formation of the doping centres during laser annealing are crucial to accurately reproduce the temperature distribution along the nanotubes. The temperature profiles suggest that treatment with a fluence of 25 mJ cm−2 at 355 nm wavelength may lead to the re-solidification of the nanotubes surface only, if their wall is thinner than 15 nm. Such simulations are reported for the first time and are important for the understanding of thermal transport in nanomaterials with highly ordered, tubular architecture.
The Issue of Shading Photovoltaic Installation Caused by Dust Accumulation on the Glass Surface
- Małgorzata Rudnicka
- Ewa Klugmann-Radziemska
2021 Pełny tekst Ecological Chemistry and Engineering S - Chemia i Inżynieria Ekologiczna S
The issue of accumulation of dust and other pollutants on the surface of photovoltaic modules was thoroughly analysed over the years. One of the first surveys in this field of knowledge linked pollutant accumulation on the module surface with transmittance loss of its glass covering, which leads to lessened amount of solar radiation reaching solar cells. First stage of this accumulation process is linear transparency loss, and second stage - molecule agglomeration and settlement some grains on the already existing layer of dust. Additionally, the pace of working parameters reduction for photovoltaic installation is influenced by the type of dust itself. Molecules with smaller grains cover the surface much more densely, therefore limiting the amount of light passing though the top glass layer far more than molecules with bigger grains. The aim of the carried out study was to find the relationship between dust surface density and change in electrical parameters. Such approach makes it possible to compare electrical and physical parameters of different photovoltaic modules. Additionally, glass coverage itself was noted to have a significant impact on the overall decrease in working parameters of PV modules.
The law of the Iterated Logarithm for random interval homeomorphisms
- Klaudiusz Czudek
- Tomasz Szarek
- Hanna Wojewódka-Ściążko
2021 Pełny tekst ISRAEL JOURNAL OF MATHEMATICS
A proof of the law of the iterated logarithm for random homeomorphisms of the interval is given.
The Many Faces of Enterococcus spp.—Commensal, Probiotic and Opportunistic Pathogen
- Beata Krawczyk
- Paweł Wityk
- Mirosława Gałęcka
- Michał Michalik
2021 Pełny tekst Microorganisms
Enterococcus spp. are Gram-positive, facultative, anaerobic cocci, which are found in the intestinal flora and, less frequently, in the vagina or mouth. Enterococcus faecalis and Enterococcus faecium are the most common species found in humans. As commensals, enterococci colonize the digestive system and participate in the modulation of the immune system in humans and animals. For many years reference enterococcal strains have been used as probiotic food additives or have been recommended as supplements for the treatment of intestinal dysbiosis and other conditions. The use of Enterococcus strains as probiotics has recently become controversial due to the ease of acquiring different virulence factors and resistance to various classes of antibiotics. Enterococci are also seen as opportunistic pathogens. This problem is especially relevant in hospital environments, where enterococcal outbreaks often occur. Their ability to translocate from the gastro-intestinal tract to various tissues and organs as well as their virulence and antibiotic resistance are risk factors that hinder eradication. Due to numerous reports on the plasticity of the enterococcal genome and the acquisition of pathogenic microbial features, we ask ourselves, how far is this commensal genus from acquiring pathogenicity? This paper discusses both the beneficial properties of these micro-organisms and the risk factors related to their evolution towards pathogenicity.
The Matter of Decision-Making Control Over Operation Processes of Marine Power Plant Systems with the Use of their Models in the form of Semi-Markov Decision-Making Processes
- Jerzy Girtler
- Jacek Rudnicki
2021 Pełny tekst Polish Maritime Research
The article presents the possibility to control the real operation process of an arbitrary device installed in the marine power plant based on the four-state semi-Markov process, being the model of the process, which describes the transition process of operational states of the device and the transition process of its technical states. All these states are precisely defined for the ship main engine (SG). A hypothesis is proposed which justifies the use of this model to examine real state transitions in marine power plant device operation processes. The article shows the possibility to make operating decisions ensuring a rational course of the device operation process when the proposed model of this process and the dynamic programming method based on the Bellman’s principle of optimality are applied. The optimisation criterion adopted when making operating decisions is the expected profit to be gained as a result of functioning of the device in the time interval , being the sum of the expected profit gained in interval and to be gained in interval.
The microbial community, its biochemical potential, and the antimicrobial resistance of Enterococcus spp. in Arctic lakes under natural and anthropogenic impact (West Spitsbergen)
- Agnieszka Kalinowska
- Katarzyna Jankowska
- Sylwia Fudala-Książek
- Mattia Pierpaoli
- Aneta Łuczkiewicz
2021 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT
The sustainable management of small human communities in the Arctic is challenging. In this study, both a water supply system (Lake 1) under the natural impact of a bird-nesting area, and a wastewater receiver (Lake 2) were analysed in the vicinity of the Polish Polar Station on West Spitsbergen. Microbial community composition, abundance and activity were assessed in samples of the treated wastewater, lake water and sediments using next-generation sequencing and direct microscope counts. Special attention was given to the faecal indicator, Enterococcus spp., whose occurrence and antimicrobial resistance were tested in water and wastewater samples. The results indicate that Lake 1, at a tundra stream discharge (L-TS) and at a water supply point (L-WS) were dominated by three phyla: Proteobacteria (57–58%) Bacteroidetes (27–29%) and Actinobacteria (9–10%) showing similar microbial composition up to the genus level. This suggests that nutrient-rich runoff from the bird colony was retained by surrounding tundra vegetation and reached Lake 1 at L-TS to a limited extent. Lake 2, being the wastewater recipient (WW-R), mirrors to some extent the core phyla of treated wastewater (WW-E), but in different shares. This suggests the possible washout of wastewater-related bacteria with activated sludge flocs, which was also supported by the microscopic observations. Compared to Lake 1, in WW-R an increase in all tested parameters was noted: total prokaryotic cell number, average cell volume, prokaryotic biomass and live cell percentage. The presence of Enterococcus spp. antibiotic resistance patterns highlights the importance of human associated microbiome and resistome dissemination via wastewater discharge. Additionally, it can be expected that temperature-related biochemical processes (e.g. nutrient cycling) may be accelerated by the ongoing climate change. Thus, proper wastewater treatment requires locally adapted solutions in increasingly visited and inhabited polar regions. Additionally, microbial community discharged to the environment with the treated wastewater, requires critical attention.
The Modernist Centre of Gdynia. Management Plan for the Nominated Property for the Years 2022-2027. Attachment to: Nomination Dossier on the inscription on the UNESCO World Heritage List of a part of Gdynia City Centre, Poland
- Robert Hirsch
- Celina Łozowska
- Anna Orchowska-Smolińska
- Katarzyna Piotrowska
- Maria Sołtysik
2021
The Management Plan is a document that helps in managing the Nominated Property and follows the Operational Guidelines for the Implementation of the Convention. The Plan is intended as a management tool to ensure the protection and maintenance of the Outstanding Universal Value (OUV) and the features that determine the integrity and authenticity of the place.
The non-invasive evaluation of heart function in patients with an acute myocardial infarction: The role of impedance cardiography
- Łukasz Lewicki
- Maria Fijałkowska
- Maciej Karwowski
- Konrad Siebert
- Grzegorz Redlarski
- Aleksander Pałkowski
- Radosław Targoński
- Janusz Siebert
2021 Pełny tekst Cardiology Journal
Background: The purpose of this study was to analyze hemodynamic changes in patients treated with percutaneous coronary intervention (PCI) at an early stage of acute myocardial infarction (AMI) and at one-month follow-up. Methods: Patients with AMI (n = 27) who underwent PCI were analyzed using impedance cardiography (ICG). ICG data were collected continuously (beat by beat) during the whole PCI procedure and thereafter at every 60 s for the next 24 h. Blood pressure was taken every 10 min and stored for analysis. Additionally the following parameters were measured: cardiac index (CI), stroke volume index (SVi), left cardiac work index (LCWi), contractility index (CTi), ventricular ejection time (VET), systemic vascular resistance index (SVRi), thoracic fluid content index (TFCi) and heart rate (HR). Results: In the first 24 h after PCI all the contractility parameters including CI, SVi, LCWi, CTi and VET significantly decreased, whereas HR, SVRi and TFCi increased compared to baseline. All of the parameters examined got normalized at one month. The CI, SVi, LCWi, CTi, SVRi did not significantly differ from baseline, however the HR and VET were significantly lower compared to first day after PCI. Conclusions: 1. Cardiac performance deteriorates early after PCI and normalizes after one month in patients with an AMI. 2. ICG is useful for hemodynamic monitoring of AMI patients during and after invasive therapy.
The Opening of Central and Eastern European Countries to Free Trade: A Critical Assessment
- Marta Kuc-Czarnecka
- Andrea Saltelli,
- Magdalena Olczyk
- Erik, S. Reinert
2021 Pełny tekst Structural Change and Economic Dynamics
Three decades after the fall of the Berlin wall and one and a half decades after the Big Bang enlargement of the European Union (2004-2007), we revisit contrasting narratives about the benefit of both free trade and the EU enlargement for Central and Eastern European (CEE) countries. We distinguish old, pre-2004 EU countries from CEE countries that joined the EU in 2004-2007, as well as from the CEE countries that have not become part of the EU, in particular Belarus, Moldova, and Ukraine. Our analysis looks at two temporal windows: one from 1991 – the demise of the Eastern European free trade zone (COMECON) – to today, and the second zooming on the period following the enlargement process of 2004-2007. Our analysis points to an unfavourable turn of events for CEE countries, which appear to have experienced significant losses in their process of rapid integration in the world and EU economies. We are comparing these events in Central and Eastern Europe with the patterns of de-industrialisation and migration that took place in Latin America after a similar free trade shock starting in the 1970s.
The Optical Coherence Tomography and Raman Spectroscopy for Sensing of the Bone Demineralization Process
- Maciej Jerzy Głowacki
- Aleksandra Kamińska
- Marcin Gnyba
- Jerzy Pluciński
- Marcin Strąkowski
2021 Pełny tekst SENSORS
The presented research was intended to seek new optical methods to investigate the demineralization process of bones. Optical examination of the bone condition could facilitate clinical trials and improve the safety of patients. The authors used a set of complementary methods: polarization-sensitive optical coherence tomography (PS-OCT) and Raman spectroscopy. Chicken bone samples were used in this research. To stimulate in laboratory conditions the process of demineralization and gradual removal of the hydroxyapatite, the test samples of bones were placed into 10% acetic acid. Measurements were carried out in two series. The first one took two weeks with data acquired every day. In the second series, the measurements were made during one day at an hourly interval (after 1, 2, 3, 5, 7, 10, and 24 h). The relation between the content of hydroxyapatite and images recorded using OCT was analyzed and discussed. Moreover, the polarization properties of the bones, including retardation angles of the bones, were evaluated. Raman measurement confirmed the disappearance of the hydroxyapatite and the speed of this process. This work presents the results of the preliminary study on the possibility of measuring changes in bone mineralization by means of the proposed methods and confirms their potential for practical use in the future.
The Physicochemical and Antibacterial Properties of Chitosan-Based Materials Modified with Phenolic Acids Irradiated by UVC Light
- Beata Kaczmarek-Szczepańska
- Marcin Wekwejt
- Olha Mazur
- Lidia Zasada
- Anna Pałubicka
- Ewa Olewnik‐Kruszkowska
2021 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
This paper concerns the physicochemical properties of chitosan/phenolic acid thin films irradiated by ultraviolet radiation with wavelengths between 200 and 290 nm (UVC) light. We investigated the preparation and characterization of thin films based on chitosan (CTS) with tannic (TA), caffeic (CA) and ferulic acid (FA) addition as potential food‐packaging materials. Such materials were then exposed to the UVC light (254 nm) for 1 and 2 h to perform the sterilization process. Different properties of thin films before and after irradiation were determined by various methods such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimeter (DSC), mechanical properties and by the surface free energy determination. Moreover, the antimicrobial activity of the films and their potential to reduce the risk of contamination was assessed. The results showed that the phenolic acid improving properties of chitosan‐based films, short UVC radiation may be used as sterilization method for those films, and also that the addition of ferulic acid obtains effective antimicrobial activity, which have great benefit for food packing applications.
The Polish adaptation of the Burnout Assessment Tool (BAT-PL) by W. Schaufeli et al.
- Beata Basińska
- Ewa Gruszczyńska
- Wilmar B. Schaufeli
2021 Pełny tekst Psychiatria Polska
Aim. The study aimed to present the Polish version of the Burnout Assessment Tool (BAT-PL) by Schaufeli et al. and to assess its validity and reliability. The tool measures the core symptoms of burnout (BAT-C): exhaustion, mental distance, cognitive and emotional impairment, and its secondary symptoms (BAT-S): psychosomatic complaints and psychological distress. Method. The participants were 255 nursing staff members. The construct validity was assessed with a one-point job satisfaction scale, the Utrecht Work Engagement Scale (UWES-3) by Schaufeli et al. and the Job-related Affective Well-being Scale (JAWS) by van Katwyk et al. Results. The results of the confirmatory factor analysis supported an assumed bi-factor structure. This applies to both BAT-C as the four core symptoms and a general factor (metatrait) representing burnout and BAT-S as a set of two secondary symptoms and a general factor. Both scales were strongly correlated with one another and differed from other measures of jobrelated well-being (job satisfaction, work engagement and negative emotions). The values of Cronbach’s alpha and composite reliability indicated BAT-PL as a reliable measurement tool. Conclusions. BAT-PL by Schaufeli et al. has good psychometric characteristics to be used in research on burnout and further validated in clinical practice.
The potential of web awareness as a determinant of dually defined customer value
- Wiesława Caputa
- Izabela Krawczyk-Sokolowska
- Agata Pierścieniak
2021 TECHNOLOGICAL FORECASTING AND SOCIAL CHANGE
In the conditions of increasing demand barrier, the enterprise’s basic capital is customers. From an enterprise point of view, this means the need to create a dual perceived and defined customer value which remains related to market value (income and development potential) and customer resource value (reference, information and cooperative potential). The progressing digitisation process transfers business processes, and thus relationships, into virtual space. We identify customers consumers’ behaviour in virtual space and the goals they connect with participation in relational networks. We believe that the use of the potential of the virtual space in which the customer moves is determined by the awareness of the potential of the web, which is related to its readiness and ability to use it. This factor determining customer value (customer equity) exerts and will exert a significant impact on the process of creating value for the customer in the future, strengthening its position as a partner in the process of creating value.
The Prospects of Retail Payment Developments in the Metaverse
- Oleksandr Melnychenko
2021 Pełny tekst Virtual Economics
In the age of technological development, rapid technological progress, and the metaverse development in which humans interact with each other and with the environment using virtual real-world metaphors, payment systems may also need to be re-considered. The study aims to find an answer to the question of what should be retail payments in the metaverse and to begin interdisciplinary discussions about their implementation in this environment. The author reviews the literature which shows that i) socio-economic relations are being implemented in the metaverse, but they still require the money to participate in the exchange relationships, as well as to support such a system; ii) it is impossible to abandon all forms of physical exchange, which is the basis of modern society; iii) the metaverse is an environment usually of anonymous users, who do not have the right to make significant purchases without their identification; iv) accounting of transactions remains the basis of payments in the metaverse as well