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Gdańsk University of Technology

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Publications from the year 2020

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  • Początki i rozwój Katedry Automatyki na Wydziale Elektrycznym Politechniki Gdańskiej
    • Franciszek Milkiewicz
    • Kazimierz Kosmowski
    • Marcin Śliwiński
    2020 Full text Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    Niniejszy artykuł obejmuje historię powstawania i rozwoju Katedry Automatyki na Wydziale Elektrotechniki i Automatyki Politechniki Gdańskiej oraz związanego z tym powstawania i rozwoju na Wydziale kierunku studiów automatyka i robotyka. W kształceniu studentów tego kierunku studiów uczestniczyły także i inne katedry Wydziału. Zajęcia dydaktyczne z zastosowań automatyki prowadzili również pracownicy: Katedry Miernictwa Elektrycznego, Katedry Trakcji Elektrycznej, Katedry Maszyn Elektrycznych, Katedry Napędów Elektrycznych, Katedry Energoelektroniki i Maszyn Elektrycznych, Katedry Systemów Elektroenergetycznych. Oczywiście, w kształceniu studentów brały też udział katedry przekazujące studentom wiedzę ogólną oraz podstawową wiedzę techniczną.

  • Podstawowe procedury pomiarowe w ochronie katodowej
    • Kazimierz Darowicki
    • Krzysztof Żakowski
    2020

    Opracowanie zawiera opis podstawowych procedur pomiarowych stosowanych przez personel ochrony katodowej w sektorze lądowych konstrukcji metalowych. Znajomość opisanych metod jest wymagana od personelu na poziomie 1 oraz na poziomie 2 kompetencji zgodnie z wymogami normy PN-EN ISO 15257:2017-10: "Ochrona katodowa -- Poziomy kompetencji osób zajmujących się ochroną katodową -- Podstawa systemu certyfikacji". Opracowanie przeznaczone jest przede wszystkim dla personelu zajmującego się ochroną katodową podziemnych rurociągów stalowych. Opisane procedury pomiarowe mogą być jednak stosowane na dowolnej metalowej konstrukcji podziemnej.

  • Podstawy technologii selektywnego spiekania laserowego proszków polimerowych – SLS
    • Dawid Zieliński
    2020 Full text Tworzywa Sztuczne w Przemyśle

    W pracy zaprezentowano zbiór informacji oraz praktycznych wskazówek związanych z drukowaniem elementów metodą selektywnego spiekania laserowego proszków polimerowych – SLS. Zawarte treści dotyczą omówienia zasady działania, charakterystyki poszczególnych czynników procesu oraz powszechnie stosowanych materiałów. Przedstawiono ponadto najważniejsze korzyści i ograniczenia związane z wykorzystaniem metody SLS.

  • Poland's economic relations with Kazakhstan
    • Krystyna Gomółka
    2020 Full text Studia Wschodnioeuropejskie

    Before 2019, economic relations between Poland and Kazakhstan were regulated by 22 international agreements. Poland has been trading with Kazakhstan since the 1990s. Overall, Kazakhstan had a positive trade balance with Poland, with the exception of the 1996–1998 and 2006–2007 periods. Polish foreign investment in Kazakhstan was not very impressive; the first investments started only in 2005. In 2019, about 200 companies with Polish capital were registered in Kazakhstan, but only 100 of them started their own business. In 2005-2019, eight meetings of the Polish-Kazakh Intergovernmental Commission for Economic Cooperation were held. Their participants discussed investment projects, trade development strategies and proposals for regional cooperation.

  • Polarimetric studies of L-arginine-doped potassium dihydrogen phosphate single crystals
    • Mykola Shopa
    • Yaroslav Shopa
    • Michael Shribak
    • I. Pritula
    • E. Kostenyukova
    • O. Bezkrovnaya
    2020 Full text Journal of Applied Crystallography

    Conoscopic interference patterns, channelled spectra and polarimetric techniques have been used for the characterization of pure and doped (with L-arginine amino acid) potassium dihydrogen phosphate (KDP) single crystals. Experimental polarimetric data have been obtained for the frequently used wavelength of 633 nm and for two close wavelengths of 532 and 543 nm in a high-accuracy dual-wavelength polarimeter. The measurement of eigenwave ellipticity in the [100] and [010] directions and between 295 and 340 K shows small differences in the absolute values of the specific optical rotations of KDP crystals doped with L-arginine in the range of 0.7–3.8 wt%. It is found that the gyration tensor component g11, specific optical rotation and eigenwave ellipticity show different dispersion in the visible spectral region.

  • Polish Academic Libraries in the Face of the Covid-19 Pandemic: Crisis Management and Communication within the Organisation
    • Anna Wałek
    2020 Full text Przegląd Biblioteczny

    The developing SARS-CoV-2 coronavirus pandemic, which was announced in March 2020, has had a significant impact on the activities of universities and their academic libraries. The article aims to present the activities of academic libraries at the time of introducing restrictions on their activities and closing for several months to users and reformulating the services they provide, on the example of the Library of the Gdańsk University of Technology. First of all, attention was paid to how the principles of crisis and problem management were introduced at universities. It was also essential to examine how the changes and management decisions were perceived by the library employees who worked according to the new rules in the indicated period. The article is based on the analysis of available scientific publications in Polish on crisis management, especially in the era of epidemiological threats. Legal acts and regulations dealing with both crisis management in general and issued in connection with the announcement of the SARS-CoV2 pandemic were also taken into account. The method of survey research based on a questionnaire was also used. Since the survey was addressed only to employees of one institution, it had a limited record. It aimed to collect the respondents’ opinions on the work of the GUT Library in the period from March 12 to May 24, 2020, when remote work in special conditions was in force. A sudden change in the work mode of the GUT Library itself and its employees, a change in tools and forms of services provided, the need to purchase appropriate equipment and personal protective equipment, the introduction of remote work and other factors became the subject of management decisions made during the emerging crisis. These decisions were in line with the applicable guidelines, both the laws and regulations issued at the national level, as well as the policies and recommendations regarding the functioning of libraries issued by various state institutions and the National Library (book quarantine). However, many of the decisions were individual due to the lack of guidelines and benchmarks on which to base. The reason was also the delayed emergence of procedures. A survey conducted among the employees of the Gdańsk University of Technology Library in May 2020, after the employees returned to stationary work, showed that the adopted solutions were well assessed.

  • Polish Polar Research: Green-and-White Paper under the aegis of the Polish Polar Consortium (PPC)
    • Robert Józef Bialik
    • Marek Ewertowski
    • Piotr Głowacki
    • Dariusz Gotlib
    • Agata Goździk
    • Mariusz Grabiec
    • Katarzyna Jankowska
    • Luks Bartłomiej
    • Michał Łuszczuk
    • Wojciech Majewski
    • Krzysztof Migała
    • Jerzy Nawrocki
    • Rajmund Przybylak
    • Krzysztof Pabis
    • Ireneusz Sobota
    • Mateusz Strzelecki
    • Waldemar Walczowski
    • Michał Węgrzyn
    • Marek Lewandowski
    • Żaneta Polkowska
    • Wiesław Ziaja
    2020

    Polar research is a colloquial term for cross-area, cross-domain and interdisciplinary research in the Arctic and Antarctic. Polar research is mainly the domain of natural sciences, but technical sciences and humanities also grow in importance. Being vulnerable to climate change, polar regions are commonly considered as a kind of litmus paper of changes in geosystems, hence the importance of research done there. It aims at a better understanding of the processes taking place in the polar environment and the search for links between the bio-, litho-, atmo- and hydrosphere on the one hand, and the anthroposphere on the other, which would provide a better knowledge on the genesis of the present glaciation and then a reliable forecast of future global changes. The document is composed of three main parts. The “Introduction” and presentation of the legal and organizational framework is followed by Part I, describing the potential of the polar scientific community in Poland along with the infrastructure and logistical means (on land and sea). Part II presents the research topics implemented in Polish scientific entities. In Part III we outline the future of polar research in Poland, trying to specify the most important directions, feasible with a view to the existing research potential. At the end of the document, the achievements of polar community are displayed collectively in the form of a bibliography of over 800 scientific publications through the years 2007–2018, covered by the Journal Citation Reports. Keeping in mind that it is an output of about 300 scientists managing just two active polar stations (in the Arctic and Antarctic) and operating two small (though brave) research vessels, this is a respectable achievement. Worth emphasizing is also an additional yet not minor aspect of our polar activities, namely, the daily effort put into organization, logistics and maintenance of the material research base in the extreme natural environment. To sum up, the general message of this document is a strong argument for promoting polar research in Poland, because the ratio of expenditures to cognitive and social effects seems to be very attractive from the point of view of the Polish Polar Policy and general scientific policy of the country

  • Polish waterfront in the process of transformation: The case of Elbląg port city
    • Justyna Breś
    2020 Full text PORTUSPlus

    The topic of waterfront transformation is a vast and challenging issue, which in small and medium-sized cities is still unexplored. With growing global interest in the matter of regeneration of city-water relationship and increasing public awareness of the value of waterfront public spaces, actions to transform abandoned waterfront areas have been undertaken in many Polish port cities. City of Elbląg, located in northern Poland, is an interesting example in which historic waterfront is undergoing process of transformation. The article presents the case of waterfront transformation in this medium-sized city, focusing on historic part of the waterfront, which has been significantly destroyed during World War. The article analyses the land use of the waterfront area, the usage of the wharf, the level of access to the water and municipal policy towards waterfront development in order to better understand the current state of waterfront area and water-land relation, to identify its weak points and to indicate possible future directions for its development. The research reveals a significant disproportion in development of eastern and western riverside, underdevelopment of large part of waterfront area and lack of coherent, comprehensive municipal strategy towards waterfront along the river. This lack of planning is not conducive to strengthening the water-land relationship. The article identifies key opportunities and threats for central waterfront and general directions for sustainable development of the city.

  • Politics and urban artifacts in cities: what are they and how are they interconected?
    • Saira Abbasi
    • Justyna Martyniuk-Pęczek
    2020 Full text Przestrzeń Ekonomia Społeczeństwo

    This research, analyses the effect of politics on a city and its image, via their control over the formation or changes on urban artifacts. It analyses the concepts introduced in Aldo Rossi’s architectural monograph, The Architecture of the City, in the chapter titled ‘Politics as Choice’, and his idea that a city’s image is a reflection of its political institutions and the choices people in authority make. Monuments and architecture of various cities world over are taken into consideration, and in the authors opinion it becomes evident that over the ages, irrespective of the location, architecture and urban planning are used as tools in achieving or furthering political goals and agendas. These choices made by people in authoritative positions can have long lasting effects on the shape, identity or image of the city. Qualitative analysis based on review of existing literature and urban plans has been done, along with semi-directed interview with experts in the urban history of Rome, Bilbao and Sydney. This approach was adopted as the study analyses concepts which are more analytical and a qualitative methodology is more appropriate for use. Lastly, this study is preliminary research in better understanding the urban artifacts of the 20th century and researches one of the factors that influence their formation, that is politics. Other aspects of socio-economic, historical and cultural factors will be researched in future studies.

  • Poloxamer: A versatile tri-block copolymer for biomedical applications
    • Payam Zarrintaj
    • Joshua D. Ramsey
    • Ali Samadi
    • Zhaleh Atoufi
    • Mohsen Khodadadi Yazdi
    • Mohammad Ganjali
    • Leila Mohammadi Amirabad
    • Ehsan Zangene
    • Mehdi Farokhi
    • Krzysztof Formela
    • Mohammad Saeb
    • Masoud Mozafari
    • Thomas Sabu
    2020 Full text Acta Biomaterialia

    Poloxamers, also called Pluronic, belong to a unique class of synthetic tri-block copolymers containing central hydrophobic chains of poly(propylene oxide) sandwiched between two hydrophilic chains of poly(ethylene oxide). Some chemical characteristics of poloxamers such as temperature-dependent self-assembly and thermo-reversible behavior along with biocompatibility and physiochemical properties make poloxamer-based biomaterials promising candidates for biomedical application such as tissue engineering and drug delivery. The microstructure, bioactivity, and mechanical properties of poloxamers can be tailored to mimic the behavior of various types of tissues. Moreover, their amphiphilic nature and the potential to self-assemble into the micelles make them promising drug carriers with the ability to improve the drug availability to make cancer cells more vulnerable to drugs. Poloxamers are also used for the modification of hydrophobic tissue-engineered constructs. This article collects the recent advances in design and application of poloxamer-based biomaterials in tissue engineering, drug/gene delivery, theranostic devices, and bioinks for 3D printing.

  • Polski PR-owiec w świecie ponowoczesnym – wyniki badań i ich analiza. Poza dobrem i złem
    • Ewa Hope
    2020

    W artykule analizuję wyniki badania Profesjonalizm public relations w Polsce, przeprowadzonego na potrzeby budowanego dokumentu Standardy profesjonalnego public relations – prezentowanego w tej pracy. Stawiam również pytanie o przyczynę częstych odpowiedzi respondentów „czasami” czy „nie mam zdania” i wykazuję niespójność systemów wartości respondentów zestawiając ich odpowiedzi na poszczególne pytania. Stawiam tezę, że niespójności te – i brak jednoznacznych odpowiedzi - są efektem sposobu funkcjonowania instytucji w społeczeństwie płynnej ponowoczesności, gdzie adiaforyzacja działań – sytuowanie ich poza kategorią oceny dobro-zło jest powszechnym zabiegiem. W czasach interregnum – pomiędzy epokami - bardzo trudno jest w związku z tym budować standardy etyczne zachowań zawodowych – szczególnie tych zawodów, mających bezpośredni wpływ na kondycję społeczeństw – jak zawód specjalisty public relations. Jednocześnie mamy świadomość konieczności i wagi takiego dokumentu dla środowiska osób zajmujących się budowaniem relacji organizacji ze społeczeństwem, komunikacją i mamy też świadomość nieuchronnych zmian, jakie zajdą po okresie pandemii, a których pierwsze oznaki można już dostrzec.

  • Polski rynek telekomunikacyjny – uwarunkowania społeczno-gospodarcze
    • Józef Woźniak
    2020

    Zaprezentowano rolę i znaczenie telekomunikacji we współczesnym świecie, prezentując wybrane aspekty konwergencji systemowej i usługowej, mając na względzie potrzeby i oczekiwania użytkownika indy­widualnego, instytucjonalnego oraz biznesowego. Zaprezentowano, na podstawie dostępnych danych, stan aktualny i perspektywy rynku telekomunikacyjnego w Polsce. Przedstawiono wybrane inicjatywy podejmowane na rzecz rozwoju rynku telekomunikacyjnego i usług informatycznych. Zasygnalizowano perspektywy wdrażania 5G w Polsce. Uwagę zwrócono też na stan zaawansowania przetwarzania w chmurze, a także wielu inicjatyw odnoszących się do rozwoju zasobów obliczeniowych i infrastruktury teleinformatycznej. Słowa kluczowe: telekomunikacja i teleinformatyka, konwergencja i synergia, stan i perspektywy rozwoju rynku telekomunikacyjnego, wybrane inicjatywy rządowe, rozwój infrastruktury badawczej, sieć PUIONIER, usługi w chmurze, stan wdrażania 5G.

  • Polybrominated diphenyl ether (PBDE) concentrations in dust from various indoor environments in Gdańsk, Poland: Prediction of concentrations in indoor air and assessment of exposure of adults
    • Monika Śmiełowska
    • Bożena Zabiegała
    2020 SCIENCE OF THE TOTAL ENVIRONMENT

    Monitoring of polybrominated diphenyl ethers (PBDEs) in indoor environments involves the determination of their concentrations in air, airborne particles, and settled dust. Each of these is a source of human exposure to PBDEs. In this study, we attempted to model PBDEs concentrations in various typical indoor environments on the basis of real PBDEs measurements in dust collected from them. The analytical procedure for determining the contents of eight analytes in dust was based on the matrix solid-phase dispersion (MSPD) technique. Based on the results obtained, the concentrations of other components of commercial PBDEs blends in dust were estimated. The obtained model of PBDEs distribution between dust and air was used to estimate the exposure of adults to PBDEs in the studied indoor environments. For each tested environment, the dominant route of exposure was dust ingestion. For congeners with log Koa > 12, this was practically the only exposure pathway. A comparison between total PBDEs exposure and oral reference dose (RfD) values enabled an assessment of the risks arising from PBDEs exposure. In all of the studied indoor environments, no risk associated with exposure to PBDEs was noted. However, there is still the need for the extension of environmental PBDEs monitoring in Poland.

  • Polyurethane Composite Scaffolds Modified with the Mixture of Gelatin and Hydroxyapatite Characterized by Improved Calcium Deposition
    • Iga Carayon
    • Paweł Szarlej
    • Marcin Łapiński
    • Justyna Kucińska-Lipka
    2020 Full text Polymers

    The skeleton is a crucial element of the motion system in the human body, whose main function is to support and protect the soft tissues. Furthermore, the elements of the skeleton act as a storage place for minerals and participate in the production of red blood cells. The bone tissue includes the craniomaxillofacial bones, ribs, and spine. There are abundant reports in the literature indicating that the amount of treatments related to bone fractures increases year by year. Nowadays, the regeneration of the bone tissue is performed by using autografts or allografts, but this treatment method possesses a few disadvantages. Therefore, new and promising methods of bone tissue regeneration are constantly being sought. They often include the implantation of tissue scaffolds, which exhibit proper mechanical and osteoconductive properties. In this paper, the preparation of polyurethane (PUR) scaffolds modified by gelatin as the reinforcing factor and hydroxyapatite as the bioactive agent was described. The unmodified and modified scaffolds were tested for their mechanical properties; morphological assessments using optical microscopy were also conducted, as was the ability for calcification using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Moreover, each type of scaffold was subjected to a degradation process in 5M NaOH and 2M HCl aqueous solutions. It was noticed that the best properties promoting the calcium phosphate deposition were obtained for scaffolds modified with 2% gelatin solution containing 5% of hydroxyapatite

  • Polyurethane glycolysate from industrial waste recycling to develop low dielectric constant, thermally stable materials suitable for the electronics
    • Arunima Reghunadhan
    • Janusz Datta
    • Maciej Jaroszewski
    • Nandakumar Kalarikkal
    • Sabu Thomas
    2020 Full text Arabian Journal of Chemistry

    We are utilizing a new method to improve the dielectric properties of a conventional polymer using a recycled polymer product. The polyurethane foams are recycled by glycolysis process and the derived material was applied to improve the dielectric properties of the brittle DGEBA epoxy resin. Two main parameters that determine the applicability of the material as a dielectric (the dielectric constant and dielectric loss), were studied at room temperature for all the blends. The properties like dielectric constant and modulus were found to be very low by the inclusion of the different compositions of recycled polyurethane. 20 phr blend was selected for optimum properties and it shows a lower dissipation factor of 1.5 × 10−2. The blends are advised as good candidates for the use in microelectronics as insulations, encapsulation and or circuit boards. We presented here an easy to process material with all the good properties require for a dielectric material. The thermal and dielectric data showed improvement than the neat polymers. The dielectric data was supported by the low water uptake of 0.5% by 20 phr blend and slightly increased contact angle from 63° to 77°.

  • Polyurethane/Silane-Functionalized ZrO2 Nanocomposite Powder Coatings: Thermal Degradation Kinetics
    • Farimah Tikhani
    • Behzad Hadavand
    • Hamed Fakharizadeh Bafghi
    • Maryam Jouyandeh
    • Henri Vahabi
    • Krzysztof Formela
    • Hossein Hosseini
    • Seyed Paran
    • Amin Esmaeili
    • Ahmad Mohaddespour
    • Mohammad Saeb
    2020 Full text Coatings

    A polyurethane (PU)-based powder coating reinforced with vinyltrimethoxysilane (VTMS)-functionalized ZrO2 nanoparticles (V-ZrO2) for thermal stability was developed. Chemical structure, microstructure and thermal degradation kinetics of the prepared coatings were investigated. The peak of aliphatic C–H vibrating bond in the Fourier transform infrared (FTIR) spectrum of V-ZrO2 was a signature of VTMS attachment. Scanning electron microscopy (SEM) images reveled that, by increase of V-ZrO2 content from 0.1 to 0.3 wt.% and then 0.5 wt.%, some agglomerations of nanoparticles are formed in the PU matrix. Thermogravimetric analysis (TGA) of the PU/V-ZrO2 powder coatings was performed at different heating rates nonisothermally to capture alteration of activation energy (Ea) of degradation of PU/V-ZrO2 powder coatings as a function of partial mass loss by using Friedman, Kissinger–Akahira-Sunose (KAS), Ozawa–Wall–Flynn (FWO) and modified Coats–Redfern isoconversional approaches. It was observed that by addition of 1 wt.% V-ZrO2 to PU resin the early state degradation temperature at 5% weight loss increased about 65 °C, suggesting a physical barrier effect limiting the volatility of free radicals and decomposition products. Incorporation of 5 wt.% ZrO2 led to about 16% and 10% increase in Ea and LnA of blank PU, respectively, which was indicative of higher thermal resistance of nanocomposite powder coatings against thermal degradation. There was also obvious agreement between model outputs and experimental data. The results reveal that nanocomposite coating shows superior thermal properties compared to neat PU powder coatings, and the presence of nano ZrO2 in sufficient amount causes retardation of the thermal decomposition process.

  • Poly(ε-Caprolactone)/Brewers’ Spent Grain Composites—The Impact of Filler Treatment on the Mechanical Performance
    • Aleksander Hejna
    2020 Full text Journal of Composites Science

    Waste lignocellulose materials, such as brewers’ spent grain, can be considered very promising sources of fillers for the manufacturing of natural fiber composites. Nevertheless, due to the chemical structure differences between polymer matrices and brewers’ spent grain, filler treatment should be included. The presented work aimed to investigate the impact of fillers’ reactive extrusion on the chemical structure and the poly(ε-caprolactone)/brewers’ spent grain composites’ mechanical performance. The chemical structure was analyzed by Fourier-transform infrared spectroscopy, while the mechanical performance of composites was assessed by static tensile tests and dynamic mechanical analysis. Depending on the filler pretreatment, composites with different mechanical properties were obtained. Nevertheless, the increase in pretreatment temperature resulted in the increased interface surface area of filler, which enhanced composites’ toughness. As a result, composites were able to withstand a higher amount of stress before failure. The mechanical tests also indicated a drop in the adhesion factor, pointing to enhanced interfacial interactions for higher pretreatment temperatures. The presented work showed that reactive extrusion could be considered an auspicious method for lignocellulose filler modification, which could be tailored to obtain composites with desired properties.

  • Poly(ε-Caprolactone)/Poly(Lactic Acid) Blends Compatibilized by Peroxide Initiators: Comparison of Two Strategies
    • Marta Przybysz-Romatowska
    • Józef Haponiuk
    • Krzysztof Formela
    2020 Full text Polymers

    Poly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA) blends were compatibilized by reactive blending and by copolymers formed during reaction in the solution. The reactive blending of PCL/PLA was performed using di-(2-tert-butyl-peroxyisopropyl)benzene (BIB) or dicumyl peroxide (DCP) as radical initiator. PCL-g-PLA copolymers were prepared using 1.0 wt. % of DCP or BIB via reaction in solution, which was investigated through a Fourier transform infrared spectrometry (FTIR) and nuclear magnetic resonance (NMR) in order to better understand the occurring mechanisms. The effect of different additions such as PCL-g-PLA copolymers, DCP, or BIB on the properties of PCL/PLA blends was studied. The unmodified PCL/PLA blends showed a sea-island morphology typical of incompatible blends, where PLA droplets were dispersed in the PCL matrix. Application of organic peroxides improved miscibility between PCL and PLA phases. A similar effect was observed for PCL/PLA blend compatibilized by PCL-g-PLA copolymer, where BIB was used as initiator. However, in case of application of the peroxides, the PCL/PLA blends were cross-linked, and it has been confirmed by the gel fraction and melt flow index measurements. The thermal and mechanical properties of the blends were also investigated by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and tensile strength.

  • POM/EVA Blends with Future Utility in Fused Deposition Modeling
    • Mateusz Galeja
    • Klaudiusz Wypiór
    • Jan Wachowicz
    • Przemysław Kędzierski
    • Aleksander Hejna
    • Mariusz Marć
    • Krzysztof Klewicz
    • Jadwiga Gabor
    • Hubert Okła
    • Andrzej Szymon Swinarew
    2020 Full text Materials

    Polyoxymethylene (POM) is one of the most popular thermoplastic polymers used in the industry. Therefore, the interest in its potential applications in rapid prototyping is understandable. Nevertheless, its low dimensional stability causes the warping of 3D prints, limiting its applications. This research aimed to evaluate the effects of POM modification with ethylene-vinyl acetate (EVA) (2.5, 5.0, and 7.5 wt.%) on its processing (by melt flow index), structure (by X-ray microcomputed tomography), and properties (by static tensile tests, surface resistance, contact angle measurements, differential scanning calorimetry, and thermogravimetric analysis), as well as very rarely analyzed emissions of volatile organic compounds (VOCs) (by headspace analysis). Performed modifications decreased stiffness and strength of the material, simultaneously enhancing its ductility, which simultaneously increased the toughness even by more than 50% for 7.5 wt.% EVA loading. Such an effect was related to an improved linear flow rate resulting in a lack of defects inside the samples. The decrease of the melting temperature and the slight increase of thermal stability after the addition of EVA broadened the processing window for 3D printing. The 3D printing trials on two different printers showed that the addition of EVA copolymer increased the possibility of a successful print without defects, giving space for further development.

  • Pomiary temperatury podczas gładzenia otworów
    • Adam Barylski
    2020

    Przedstawiono wyniki badań temperatury podczas gładzenia otworów w elementach stalowych. Analizowano obróbkę otworów o średnicach 75H7, 75H10 i 150H7 mm. W badaniach zastosowano metodę termowizyjną. Otrzymane wyniki pomiarów pozwolą właściwie zaplanować miejsce i czas kontroli.