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1

70 years of the Electrical Engineering Committee of the Polish Academy of Sciences (1952-2022)

Łukaniszyn Marian, Grochowicz Barbara

Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

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2024

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nr 77

31--34

PL

Artykuł przedstawia historię powstania oraz działalność Komitetu Elektrotechniki Polskiej Akademii Nauk od momentu jego utworzenia w 1952 roku do czasow obecnych. Omowiono strukturę, skład osobowy, wydawane czasopisma, organizowane konferencje, działalność naukową, ekspercką i społeczną oraz cele jakie stawia wspołczesność.

EN

The article presents the history of the creation and activities of the Electrotechnical Committee of the Polish Academy of Sciences from its establishment in 1952 to the present. The structure, staff, published journals, conferences, scientific, experts and social activities as well as the goals of modern times were discussed.

2

Tribological Tests of Acrylic Teeth for Removable Dentures

Ryniewicz Wojciech, Bojko Łukasz, Pałka Paweł, Osada Piotr, Ryniewicz Anna

Tribologia

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2024

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nr 1

105--116

EN

The functionality of removable dentures is ensured by proper diagnostics and clinical modeling. No less important are the structural conditions and the biotribological and biomechanical context, which determine the wear resistance in the contact of opposing teeth and the contact of the denture plate with the stomatognathic system. The aim of the study is to evaluate acrylic teeth used in prosthetic reconstructions based on microstructural, micromechanical and tribological tests. Samples for testing were taken from teeth for removable dentures made by various manufacturers. Microstructural analyses were performed using an optical microscope and a scanning microscope. Microhardness and elasticity coefficient measurements were performed on the NHT device. Tribological tests were performed on a Roxana Machine Works tester using a friction node: ball – 3 discs made of the tested material. The conducted research allowed for the evaluation of the structural quality of acrylic teeth and the determination of the tribological interaction resulting from the contact of synthetic and natural teeth in the presence of artificial saliva.

PL

Funkcjonalność protez ruchomych zapewnia prawidłowa diagnostyka i modelowanie kliniczne. Nie mniej ważne są uwarunkowania strukturalne oraz kontekst biotribologiczny i biomechaniczny, które decydują o odporności na zużycie w kontakcie zębów przeciwstawnych oraz o kontakcie płyty protezy z układem stomatognatycznym. Celem opracowania jest ocena zębów akrylowych stosowanych w rekonstrukcjach protetycznych na podstawie badań mikrostrukturalnych, mikromechanicznych i tribologicznych. Próbki do badań pobierano z zębów do protez ruchomych wykonanych przez różnych producentów. Analizy mikrostrukturalne wykonano na mikroskopie optycznym i mikroskopie skaningowym. Pomiary mikrotwardości i współczynnika elastyczności przeprowadzono na urządzeniu NHT. Badania tribologiczne wykonano na maszynie Roksana Machine Works z zastosowaniem węzła tarcia: kula – 3 krążki z materiału badanego. Przeprowadzone badania pozwoliły na ocenę jakości strukturalnej zębów akrylowych oraz na wyznaczenie interakcji tribologicznej wynikającej z kontaktu zębów syntetycznych i naturalnych w obecności sztucznej śliny.

3

DOCOL 1100M welding in the construction of electric means of transport

Szczucka-Lasota Bożena, Gołombek Klaudiusz, Węgrzyn Tomasz, Łazarz Bogusław, Lukaszkowicz Krzysztof, Pereira Silva Abilio, Antczak-Jarząbska Romana

Transport Problems

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2024

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T. 19, z. 2

219--228

EN

Advanced high-strength steels are important for the automotive sector. Metal active gas (MAG) is the most popular method for joining grades of steel. The goal of the paper is to analyze the mechanical properties of the MAG welding joint made of high-strength DOCOL 1100M intended for the construction of electric vehicles. The manuscript shows a basic understanding of the properties of DOCOL joints. This type of material is characterized by a martensitic microstructure, which makes it difficult to make a proper joint. The tensile strength, metallographic structure, and type of non-metallic inclusions were analyzed as a function of the oxygen amount in the protective gas mixture. Investigations of oxide non-metallic inclusions were carried out using scanning electron microscopy. This article attempts to obtain high joint strength of the electric vehicle structure by controlling the average size of non-metallic inclusions in the weld, which is influenced by shielding gas in the MAG welding process. The solution has application potential for the automotive industry, especially for electric vehicles.

4

Korelacje struktura-właściwości szkła borokrzemianowego w porównaniu ze szkłem sodowo-wapniowo-krzemianowym

Brandt-Slowik Juliane

Świat Szkła

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2024

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R. 29, nr 1

26--29

5

Badania zmian w strukturze płyt włóknisto-cementowych poddanych oddziaływaniom wybranych czynników eksploatacyjnych

Gorzelańczyk Tomasz

Przegląd Budowlany

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2024

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R. 95, nr 3

110--115

PL

W artykule przedstawiono wyniki badań wpływu zamrażania-rozmrażania oraz naświetlania promieniowaniem UV w komorze starzeniowej na strukturę płyt włóknisto-cementowych. W celu wykazania wpływu wyżej wymienionych czynników płyty w pierwszej kolejności przebadano z wykorzystaniem metody emisji akustycznej w próbie trójpunktowego zginania. Badania te wykazały wyraźny spadek liczby zarejestrowanych zdarzeń EA dla badanych płyt, szczególnie dla tych, które były poddane oddziaływaniu cykli zamrażania-rozmrażania w porównaniu z płytami referencyjnymi. Następnie w celu dokładniejszego zobrazowania zmian zachodzących w strukturze badanych płyt przeprowadzono badania z wykorzystaniem elektronowego mikroskopu skaningowego SEM.

EN

The article presents the results of research on the effect of cyclic freeze-thaw and UV irradiation on the structure of fibre-cement boards in an aging chamber. In order to demonstrate the impact of the above-mentioned factors, the panels were first tested using the acoustic emission method in the three-point bending test. These studies showed a clear decrease in the number of recorded EA events for the tested boards, especially for those that were subjected to freeze-thaw cycles compared to the reference boards. Then, in order to more accurately illustrate the changes occurring in the structure of the tested boards, tests were carried out using a scanning electron microscope (SEM).

6

Synergistic toughening and strengthening of an epoxy resin modified by simultaneous use of two different modifiers

Białkowska Anita, Suroń Patryk, Kucharczyk Wojciech, Hanulikova Barbora, Bakar Mohamed

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 3

art. no. e149176

EN

The present work investigates the effect of modifying an epoxy resin using two different modifiers. The mechanical and thermal properties were evaluated as a function of modifier type and content. The structure and morphology were also analyzed and related to the measured properties. Polyurethane (PUR) was used as a liquid modifier, while Cloisite Na+ and Nanomer I.28E are solid nanoparticles. Impact strength (IS) of hybrid nanocomposites based on 3.5 wt% PUR and 2 wt% Cloisite or 3.5 wt% PUR and 1 wt% Nanomer was maximally increased by 55% and 30%, respectively, as compared to the virgin epoxy matrix, exceeding that of the two epoxy/nanoparticle binaries but not that of the epoxy/PUR binary. Furthermore, a maximum increase in IS of approximately 20% as compared to the pristine matrix was obtained with the hybrid epoxy nanocomposite containing 0.5 wt% Cloisite and 1 wt% Nanomer, including a synergistic effect, due most likely to specific interactions between the nanoparticles and the epoxy matrix. The addition of polyurethane and nanoclays increased the thermal stability of epoxy composites significantly. However, DSC results showed that the addition of flexible polyurethane chains decreased the glass transition temperatures, while the softening point and the service temperature range of epoxy nanocomposites containing nanofillers were increased. FTIR analysis confirmed the occurrence of interaction between the epoxy matrix and added modifiers. All SEM micrographs showed significant roughness of the fracture surfaces with the formation of elongated platelets, explaining the increase in mechanical properties of the epoxy matrix.

7

Investigating the effect of electrospark alloying parameters on structure formation of modified nitrogen coatings

Haponova Oksana, Tarelnyk Viacheslav, Mościcki Tomasz, Tarelnyk Nataliia

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 5

art. no. e150802

EN

The quality parameters of surface layers synthesised using electrospark alloying (ESA) technology were analysed in this paper. The main focus was on the influence of equipment energy parameters on structure formation, specifically the effect of discharge energy and productivity. Microstructural analysis of the modified surface of C40 steel after nitriding by ESA using a paste containing nitrogen compounds injected into the interelectrode gap was conducted. The layer structure for all studied ESA parameters includes three areas: the upper “white layer”, the diffusion zone below it, and the substrate. The roughness of the surface is Ra ∼ 0.9 µm at low discharge energy Wp = 0.13 J and Ra ∼ 6 µm at Wp = 3.4 J. The microhardness, continuity, and surface roughness of the layers varied with Wp. The influence of ESA productivity on the structure was studied. The thickness of the hardened layer and the diffusion zone, as well as the microhardness and continuity, are affected by reduced productivity. For the same discharge energy, the thickness of the hardened layer increases by 10-18% with a decrease in productivity compared to the classical mode. Studies have shown that productivity loss has a positive effect on the quality characteristics of the coatings produced by the ESA process.

8

Analysis of mechanical properties and structure of samples filled with continuous glass fiber produced in composite filament fabrication technology

Marciniak Dawid, Sykutera Dariusz, Czyżewski Piotr

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 2

art. no. e148841

EN

The purpose of the study was to evaluate selected mechanical properties and structural characteristics of samples manufactured using composite filament fabrication (CFF) technology from Onyx material, whichwas filled with continuous glass fiber. Selected mechanical properties were correlated with the density of the resulting composite to determine the specific strength of the fabricated parts. The test specimens were manufactured on a Mark Two Enterprise machine (Markforged, USA) using composite filament fabrication (CFF) technology. The material used was polyamide 6.6 with a 20% short carbon fiber content with the trade name Onyx. Continuous glass fiber was used to reinforce the fabrication. The density of the manufactured samples was determined using a hydrostatic method. Methanol was used as the liquid. By determining the density of the samples, it was possible to estimate through appropriate calculations what specific strength and specific modulus the obtained composites would have. Determination of tensile and flexural strengths was carried out in accordance with ISO 527-1:2012 and ISO 178:2003. Determination of the impact tensile strength of the samples was carried out in accordance with ISO 8256, the beams were tested using the A method. Due to the high impact tensile strength, two 1 mm notches with an angle of 45°were made on the specimens. The image of the sample structure obtained by the CFF method was recorded using a CT scanner. A thermogravimetric test (TG) of the Onyx matrix material was carried out. The samples were tested approximately 72 hours after fabrication. Filling the samples with continuous glass fiber above 50% leads to a slight increase in impact resistance. The density of the composite increased by only 16% relative to the reference samples, resulting in a 389% increase in the maximum average flexural strength. Despite significant discontinuities in the structure of the produced composite, it was possible to record an increase in tensile strength and Young’s modulus by 606% and 370%, respectively.

9

Pickering emulsion polymerization of styrene towards alfa-functionalized polystyrene latex: parameters and process conditions

Tercki Dariusz, Orlińska Beata, Słotwińska Dominika, Sajdak Marcin

Polimery

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2023

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Vol. 68, nr 4

206--214

EN

Polymerization conditions in the Pickering emulsion of colloidal silica-stabilized polystyrene latex were optimized. The influence of process conditions on various parameters, including particle size and distribution was investigated. Monomodal particles distribution was obtained by conducting the process at a temperature of 80°C in a slightly acidic environment (pH = 5), while maintaining fast monomer conversion. It has been shown that the amount of stabilizer used in the polymerization process affects the rate of polymerization, therefore the temperature of the process should be adjusted to the amount of colloidal silica used in the process.

PL

Zoptymalizowano warunki polimeryzacji w emulsji Pickeringa lateksów polistyrenowych stabilizowanych krzemionką koloidalną. Zbadano wpływ warunków procesu na m.in wielkość i rozkład cząstek. Monomodalny rozkład cząstek uzyskano prowadząc proces w temperaturze 80°C w środowisku lekko kwaśnym (pH = 5), przy zachowaniu szybkiej konwersji monomeru. Wykazano, że ilość stabilizatora użytego w procesie polimeryzacji wpływa na szybkość polimeryzacji, dlatego też temperatura procesu powinna być dostosowana do ilości używanej w procesie krzemionki koloidalnej.

10

Stop 3. Bereśnik hill near Jaworki village (“mid”-Cretaceous pelagic shell beds, Late Cretaceous deposits and inversion structure)

Krobicki Michał

Geotourism / Geoturystyka

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2023

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nr 3-4 (74-75)

30--31

11

Influence of filler introduction method on structure and properties of polymer composites based on polyurethane and silver nanoparticles

Lysenkov Eduard A., Striutskyi Oleksandr V.

Composites Theory and Practice

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2023

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R. 23, nr 3

145--152

EN

Polymer nanocomposites based on segmented polyurethane and silver nanoparticles (AgNPs) were synthesized using different methods of nanoparticle introduction. The dependence of their structure, thermophysical and antimicrobial properties on the method of introducing AgNPs was studied. It was established that the method of introduction affects both the spatial distribution of the filler particles and the final properties of the material. The introduction of AgNPs by the ultrasonic dispersion method leads to inhibition of the growth of the crystalline phase, which is associated with the formation of aggregates from AgNPs of small size, which have a large polymer-filler interaction surface. It is shown that the introducing AgNPs from a colloidal solution leads to an increase in the degree of crystallinity of the polymer matrix, which is a consequence of the nucleation effect of nanosized silver particles on the formation of the crystalline phase. It was established that the method of introducing nanoparticles does not affect their final antimicrobial properties. Owing to their unique characteristics, synthesized nanocomposite films can be promising for use as antimicrobial coatings.

12

Thermoplastic hardened Cu-Ni-Si-Ag alloy

Krupińska Beata, Chulist Robert, Kondracki Marcin, Labisz Krzysztof

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 2

art. no. e145683

EN

The paper aims to investigate the influence of silver addition on the microstructure of CuNi2Si1 alloys. The investigated copper alloy was cast and then supersaturated, plastically deformed on the Gleeble 3800 simulator and finally aged. Structural changes were examined using optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Orientation mapping was completed with FEI Quanta 3D field emission gun scanning electron microscope (SEM) equipped with TSL electron backscattered diffraction (EBSD) system. The effect of structural and microstructural changes on hardness and conductivity was also investigated. Based on the mechanical tests it was found that the mechanical properties and conductivity are improved due to heat and plastic treatment. It was also found that the precipitation hardening raises the hardness to the level of 40% whilst an increase in conductivity by 20% is observed.

13

Creating a Repeatable Nontechnical Skills Curriculum for the University of Southern Maine (USM) Cybersecurity Ambassador Program (CAP)

Sussman Lori L., Leavitt Zachary S.

Applied Cybersecurity & Internet Governance

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2023

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Vol. 2, No. 1

1--25

EN

The workforce demand for skilled cybersecurity talent has exceeded its supply for years. Historically, the pedagogical approach was to identify and create curricula for the most in-demand technical knowledge, skills, and abilities (KSAs). Unfortunately, the field has tended to neglect nontechnical counterparts. However, recent literature suggests a core set of nontechnical KSAs that employers seek after. This study explored the codification of a nontechnical curriculum for a cybersecurity internship program at the University of Southern Maine (USM). The USM faculty created the Cybersecurity Ambassador Program that can serve students and the community. The service to students is to make them more attractive to employers. The benefit to the community is to provide cybersecurity awareness training to vulnerable populations. This discussion about the USM CAP serves as a case study for other programs considering this type of enrichment using an internship model. CAP started as an informal program, but this research used objective data to create repeatable blueprints. The researchers designed these lesson plans to help students progress from novices to competent in crucial nontechnical skills delineated in the National Initiative for Cybersecurity Education (NICE) Workforce framework. The team used a mixed methods approach to baseline Tier 1/novice students’ skill levels, place them in a cybersecurity enrichment program, track their progress, and determine program efficacy in helping them achieve beginner status. The information shared can serve as a point of departure for a case study that might guide other programs interested in doing similar work.

14

Dobrze skrojony zielony dach

Lech Aleksander

Zieleń Miejska

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2022

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Nr 11

70--71

PL

Wiele jest czynników wymagających uwzględnienia w procesie projektowania układu warstw zapewniających właściwe warunki do uprawy roślin na utwardzonych powierzchniach architektonicznych. Jakie uwarunkowania dotyczą tego rodzaju struktur?

15

Historia i rola głównego dworca kolejowego w rozwoju urbanistycznym Rzeszowa

Janda Magdalena

Wiadomości Konserwatorskie

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2022

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Nr 71

80--93

PL

Dworzec kolejowy w Rzeszowie przechodził liczne przekształcenia. Pierwotnie nawiązywał do florenckiej, wczesnorenesansowej architektury pałacowej, a później zyskał modernistyczny charakter. Lokalizacja obiektu przy granicy miasta z Ruską Wsią spowodowała gwałtowny rozrost osady i centrum Rzeszowa w kierunku północnym. Budowa, oprócz utworzenia nowego środka lokomocji, wpłynęła na układ komunikacyjny miasta oraz proces kształtującej się sieci dróg. Problematyka powstawania linii kolejowych z dworcami w kontekście wpływu na urbanizację Rzeszowa nie została przebadana w sposób całościowy. Poruszana jest najczęściej przy analizach rozwoju przestrzennego miasta w poszczególnych okresach historycznych. Celem artykułu jest przedstawienie roli, jaką odegrała kolej dla Rzeszowa: począwszy od utworzenia węzła kolejowego po przemiany stacji i otaczającej jej zabudowy pochodzącej z drugiej połowy XX wieku. W pracy zobrazowano etapy powstawania węzła na tle współcześnie zabudowanego obszaru miasta.

EN

The railway station in Rzeszów went through numerous changes. Originally, it referenced Florentine, Early Renaissance palace architecture, and was later given a Modernist character. The building’s siting near the Rzeszów–Ruska Wieś border led to the rapid northward development of the settlement and Rzeszów’s center. The project, apart from creating a new means of transport, affected the city’s circulation layout and the development of the emerging road network. The development of railway lines and stations, in the context of impacting Rzeszów’s urbanization, was not holistically investigated previously. It was typically discussed in analyses of the city’s spatial development across history. This paper is to present the role that the railway played in Rzeszów, ranging from the construction of the railway junction to the transformation of the station and its surrounding development from the late twentieth century. The paper depicts the stages of the junction’s construction against the background of the contemporary urban built-up area.

16

Investigations of the structure and hardness of dissimilar steel-to-aluminum joints made using laser welding technology

Misiura Karolina, Konieczny Jarosław, Labisz Krzysztof, Boris Renata

Transport Problems

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2022

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T. 17, z. 1

73--86

EN

Since welding technology is currently used to assemble the frame of driver’s seats, it is important to develop laser welding technology for steel and aluminium. For this reason, the purpose of the present work was to examine the structure and selected properties of aluminium-steel joints using the example of an EN AW-6060 aluminium alloy and DC04 low-alloy steel welded in laser technology. Overlapping joints were made, weld type -following the hole laser welding method -laser beam (LB) using a high power disk laser (TRUMPF TruDisk3302), in which the active medium is a yttrium-aluminium crystal (YAG). Metallographic microstructure investigations were carried out using a light microscope from Carl Zeiss - Observer Z1m, and the weld microstructures were investigated using an SEM Supra 35 microscope, also from Carl Zeiss. The chemical composition analysis in micro-areas was carried out using an X-ray energy dispersion spectrometer from EDAX, which was a part of the SEM Supra 35. The hardness of the substrate material and the welded area was measured following the Vickers method using an FM-ARS 9000 micro hardness tester from Tokyo, Japan. It was found that there is a potential for commercial use of laser welding to make a low-carbon steel-aluminium alloy joint. During the formation of the weld in its microstructure, intermetallic compounds of the FexAly type were created, which significantly reduced the mechanical and plastic properties of the joint. The hardness of the weld created wasabout seven times higher than that of DC04 carbon steel. The choice of laser welding parameters (primarily, laser power and beam speed) significantly impacted the weld structure and properties.

17

Energy generation, transition and sustainable growth in Turkey

Pashaev Ibragim

Polityka Energetyczna

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2022

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T. 25, z. 1

23--38

EN

The structural economic problems of Turkey have led to the significant challenges for the development of the country, especially in the postcoronavirus economy. One of such challenges is the achievement of the sustainable development imperatives in combination with the preservation of the competitive advantages of the Turkish economy. The loss of the major drivers of the economy of the country, including tourism and logistics, in complex with the economic deterioration of the monetary system of the country are the major components of the current crisis. This controversy is analyzed in the paper along with the search for the best options of the energy sphere development in Turkey. This search covers economic aspects of the current situation in the country. The authors put forward and prove a hypothesis that Turkey energy system can be more influential on its economic development. This proof is based on the energy mix analysis and on the thorough review of the potential of the country for the green energy development and its economic effectiveness for the country. The key findings of the article include the proof that the sustainable development and the green energy development in Turkey are quite different processes, which are on intention divided by political measures, the proof that Turkey has serious issues in development of the energy sector due to its low influence on the economic development in its current state, the developed recommendations for the better structuring of the energy sector development.

PL

Strukturalne problemy gospodarcze Turcji doprowadziły do poważnych wyzwań dla rozwoju kraju, zwłaszcza w gospodarce po pandemii koronawirusa. Jednym z takich wyzwań jest osiągnięcie założeń zrównoważonego rozwoju w połączeniu z zachowaniem przewag konkurencyjnych tureckiej gospodarki. Utrata głównych sił napędowych gospodarki kraju, w tym turystyki i logistyki, w połączeniu z pogorszeniem się sytuacji gospodarczej systemu monetarnego kraju to główne elementy obecnego kryzysu. Kontrowersje te są analizowane w artykule wraz z poszukiwaniem najlepszych opcji rozwoju energetyki w Turcji. Poszukiwanie to obejmuje ekonomiczne aspekty aktualnej sytuacji w kraju. Autorzy stawiają i udowadniają hipotezę, że system energetyczny Turcji może mieć większy wpływ na jej rozwój gospodarczy. Dowód ten opiera się na analizie miksu energetycznego oraz na wnikliwym przeglądzie potencjału kraju dla rozwoju zielonej energii i jej efektywności ekonomicznej. Kluczowe wnioski z artykułu są takie, że zrównoważony rozwój i rozwój zielonej energii w Turcji to zupełnie różne procesy, które celowo dzieli się środkami politycznymi, powodując, że Turcja ma poważne problemy z rozwojem energetyki, ponieważ w obecnym stanie ma ona niewielki wpływ na rozwój gospodarczy. Zostały wypracowane rekomendacje, których realizacja pozwoli na lepsze ustrukturyzowanie rozwoju energetyki.

18

Assessment of the economic efficiency of industrial enterprise management during the Kazakhstan integration into the EAEU

Nurekenova Elvira S., Sholpanbayeva Kanshaim Zh., Apysheva Assel A., Rakhimberdinova Madina U., Shaikhanova Nurgul K.

Polish Journal of Management Studies

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2022

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Vol. 26, No. 1

233--249

EN

The purpose of this study is to examine the effectiveness of the measures taken and to identify areas for further integration cooperation. The originality of the study is determined by the fact that the formalisation of Kazakhstan integration into the Eurasian Economic Union (EAEU) structures allows expanding the possibilities of building cooperative ties. This requires greater involvement of enterprises in the integration and the development of a unified state system to assess the effectiveness of integration associations. The authors show that, in general, the integration of Kazakhstan and the EAEU can be assessed based on a common methodology for the economic efficiency of individual enterprises. The authors suggest the adapted methodology of the balanced scorecard system since it is appropriate in this case. The practical significance of the study is determined by the need to clarify the structural features of integration and calculate efficiency in general based on the results of the cooperation of Kazakh enterprises with external partners. The development of such an assessment system can also be implemented taking into account the need to counter the global economic crisis.

PL

Celem niniejszego opracowania jest zbadanie skuteczności podejmowanych działań oraz zidentyfikowanie obszarów dalszej współpracy integracyjnej. O oryginalności opracowania decyduje fakt, że sformalizowanie integracji Kazachstanu ze strukturami Eurazjatyckiej Unii Gospodarczej (EUG) pozwala na rozszerzenie możliwości budowania powiązań kooperacyjnych. Wymaga to większego zaangażowania przedsiębiorstw w integrację i budowy jednolitego systemu państwowego do oceny efektywności stowarzyszeń integracyjnych. Autorzy pokazują, że generalnie integrację Kazachstanu i EUG można oceniać w oparciu o wspólną metodologię efektywności ekonomicznej poszczególnych przedsiębiorstw. Autorzy proponują zaadaptowaną metodologię systemu zrównoważonej karty wyników, ponieważ jest ona w tym przypadku odpowiednia. Praktyczne znaczenie badania przesądza o potrzebie doprecyzowania cech strukturalnych integracji i obliczenia efektywności w ogóle na podstawie wyników współpracy kazachskich przedsiębiorstw z partnerami zewnętrznymi. Opracowanie takiego systemu oceny może być również realizowane z uwzględnieniem konieczności przeciwdziałania światowemu kryzysowi gospodarczemu.

19

Pre-treatment effect on the structure of bacterial cellulose from Nata de Coco (Acetobacter xylinum)

Rusdi Rusaini Athirah Ahmad, Halim Norhana Abdul, Nurazzi Mohd Norizan, Abidin Zul Hazrin Zainal, Abdullah Norli, Che Ros Fadhlina, Ahmad Nurazlin, Azmi Ahmad Farid Mohd

Polimery

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2022

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Vol. 67, nr 3

110--118

EN

This paper presents a structural analysis of various methods to produce bacterial cellulose (BC) from Nata de Coco (Acetobacter xylinum). BC sheet, BC chem and BC mech powders were successfully prepared using oven drying, chemical and mechanical treatment. The X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and field emission scanning electron microscopy (FESEM) were used to analyze the structure of prepared BC. The structure of bacterial cellulose was compared with the structure of commercial microcrystalline cellulose (MCC) and cotton fabric. The XRD results showed that the BC sheet sample had the highest degree of crystallinity (81.76%) compared to cotton cellulose (75.73%). The crystallite size of cotton was larger than the BC sheet, with the value of 6.83 ηm and 4.55 ηm, respectively. The peaks in the FTIR spectra of all BC were comparable to the commercial MCC and cotton fabrics. FESEM images showed that the prepared BC sheet, BC mech, and BC chem had an almost similar structure like commercial MCC and cotton fabric. It was concluded that simple preparation of BC could be implemented and used for further BC preparation as reinforcement in polymer composites, especially in food packaging.

PL

Niniejszy artykuł zawiera analizę struktury celulozy bakteryjnej (BC) wytworzonej z Nata de Coco (Acetobacter xylinum) różnymi metodami. Folia BC i proszki BC chem oraz BC mech zo -stały wytworzone poprzez suszenie w piecu, obróbkę chemiczną i mechaniczną. Do oceny struktury celulozy bakteryjnej stosowano dyfrakcję rentgenowską (XRD), spektroskopię Fouriera w podczerwieni (FTIR) i skaningową mikroskopię elektronową z emisją polową (FESEM). Strukturę celulozy bakteryjnej porównano ze strukturą handlowej celulozy mikrokrystalicznej (MCC) i tkaniny bawełnianej. Wyniki XRD wykazały, że najwyższy stopień krystaliczności miała próbka arkusza BC (81,76%) w porównaniu z celulozą bawełnianą (75,73%). Wielkość krystalitów bawełny była większa niż folii BC i wynosiła, odpowiednio, 6,83 ηm oraz 4,55 ηm. Piki widm FTIR wszystkich otrzymanych form celulozy bakteryjnej były porównywalne z komercyjnymi tkaninami bawełnianymi i z celulozy mikrokrystalicznej. Zdjęcia FESEM folii BC oraz proszków BC mech i BC chem również były podobne do komercyjnej MCC i tkaniny bawełnianej. Stwierdzono, że z wykorzystaniem prostych technik można otrzymać BC, która może być stosowana jako wzmocnienie w kompozytach polimerowych, w szczególności w opakowaniach do żywności.

20

Influence of chemical foaming on the structure and selected properties of glass fiber reinforced PA6

Konczal Natalia, Nowinka Bartosz, Bieliński Marek

Polimery

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2022

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Vol. 67, nr 10

475--482

EN

The effect of the chemical foaming on the structure (SEM) and selected properties of glass fi ber (30, 60 wt%) reinforced polyamide 6 (PA 6) was investigated. Density, tensile properties and Charpy impact strength were determined. Hydrocerol ITP 825 was used as a blowing agent in the amount of 2 wt%. The size of the pores and the foaming degree depended on the distance from the injection point. The smallest pore size (64 μm) was observed for 60 wt% glass fiber reinforced PA6.

PL

Zbadano wpływ procesu spieniania chemicznego na strukturę (SEM) oraz wybrane właściwości poliamidu 6 wzmocnionego włóknem szklanym (30, 60 % mas.). Oznaczono gęstość, właściwości mechaniczne przy rozciąganiu i udarność Charpy’ego. Jako porofor stosowano Hydrocerol ITP 825 w ilości 2% mas. Wielkość porów i stopień spieniania zależały od odległości od punku wtryskiwania. Najmniejszą wielkość porów (64 μm) stwierdzono w przypadku poliamidu zawierającego 60% mas. włókna szklanego.