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1

Hydrożelowe okłady łagodzące objawy migreny

Piłat Edyta, Krysiak Natalia, Gawrycka Pola, Gnatowski Przemysław, Kucińska-Lipka Justyna

Wiadomości Chemiczne

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2025

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[Z] 79, 7-8

539--558

EN

Migraine is a chronic neurological disorder that directly affects up to one billion people worldwide. Current treatments for migraine involve acute treatment, including the use of analgesics, nonsteroidal anti-inflammatory drugs, triptans, and preventive treatment. One of the currently available solution relieving migraine symptoms is hydrogel patches. They typically provide a cooling effect due to the presence of an active substance, most commonly menthol. Unfortunately, despite menthol's undeniable advantages in cooling applications, its intense smell may be irritating for people with migraines, who suffer from olfactory hypersensitivity. Therefore, the following work proposes a novel solution that combines the benefits of hydrogels with a natural extract of feverfew, which is described in the literature as effective in relieving headaches, including migraines. In this study, hydrogel patches were developed based on a natural polymer and modified with feverfew extract. The physicochemical properties of the resulting materials were investigated, including swelling behavior, surface wettability, and substance release from the polymer matrix. The potential for use in the intended application was preliminarily assessed as possible, but requiring further studies.

2

Synthesis and characterization of methacrylamide- -based molecularly imprinted polymers for detection of di(2-ethylhexyl) phthalate

Fauziah St, Soekamto Nunuk Hariani, Paulina Taba, Hustim Muralia, Achman Annisyah Aprilia, Andekan Nital, Husain Husnia Paraditha, Sapar Ajuk

Polimery

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2025

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Vol. 70, nr 6

386--393

EN

Based on methacrylamide (MAM) and trimethylolpropane trimethacrylate (TRIM) as a cross-linking agent, molecularly imprinted polymers (MIPs) were obtained by precipitation polymerization and used for the detection of di(2-ethylhexyl)phthalate (DEHP) in drinking water in plastic packaging. The presence of functional groups –NH, –CH, –C=O, –C=C and –CO was confirmed by FT-IR. The formation of MIP_DEHP was also confirmed by EDS. Moreover, SAA analysis showed their mesoporous structure. The adsorption capacity was consistent with the isothermal Freundlich adsorption model, and the adsorption kinetics models with a pseudo-second-order reaction. Small, uniform, porous grains were observed in the MIP structure (SEM).

PL

Na bazie metakryloamidu (MAM) i trimetakrylanu trimetylopropanu (TRIM) jako środka sieciującego, metodą polimeryzacji strąceniowej, otrzymano polimery z nadrukiem molekularnym (MIP), które użyto do wykrywania di(2-etyloheksylo)ftalanu (DEHP) w wodzie pitnej w opakowaniach plastikowych. Obecność grup funkcyjnych –NH, –CH, –C=O, –C=C i –CO potwierdzono metodą FT-IR. Powstawanie MIP_DEHP potwierdzono również metodą EDS. Ponadto analiza SAA wykazała ich mezoporowatą strukturę. Pojemność adsorpcyjna była zgodna z izotermicznym modelem adsorpcji Freundlicha, a modele kinetyki adsorpcji z reakcją pseudodrugiego rzędu. W strukturze MIP zaobserwowano małe, jednolite, porowate ziarna (SEM).

3

Presence of microplastics in surface waters and sediments of urban tropical river: A case study in the Karang Mumus River along Samarinda City, Indonesia

Hamdhani Hamdhani, Abdunnur Abdunnur, Saputri Dea, Eppehimer Drew Elliot

Ecological Engineering & Environmental Technology

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2025

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Vol. 26, iss. 2

96--108

EN

The global prevalence of plastic use has raised concerns regarding microplastic pollution, which is widespread in water bodies around the world and poses significant risks to aquatic life. However, uncertainties still exist regarding the amount, types, and chemical composition of microplastics, particularly in tropical urban rivers. This study provides scientific novelty by offering the first comprehensive assessment of the abundance, distribution, types, and chemical makeup of microplastics in both the surface water and sediment of the urban tropical Karang Mumus River in Samarinda City, East Kalimantan, Indonesia – an area previously unexplored in this context. Microplastics were present in all surface water and sediment samples collected from six different sampling stations, with an average of 3.61 ± 1.26 particles/L in surface water and 1222.22 ± 308.80 particles/kg in sediment. The average microplastic concentrations observed in this study fall within the range reported in other urban river systems. No clear pattern was identified concerning the concentration of microplastics along the river from upstream to downstream. Microplastic fibers, fragments, and films were frequently detected, with films being the most common type found, followed by fibers and fragments in both surface water and sediment. In the surface waters, most particles were identified as polyethylene, followed by polystyrene, nylon, olefin fiber, and polypropylene. In the sediments, polyethylene was also the most common, followed by polypropylene, polystyrene, olefin fiber, and polyvinyl chloride. This research advances our understanding of microplastic pollution in under-studied tropical urban river systems and serves as a baseline for future studies and mitigation strategies.

4

Otrzymywanie polimeru sulfonamidowego oraz jego wpływ na efektywność mielenia cementu

Ke Kai, Yu Han, Li Xiang, Zhao Jun-hao, Lyv Yang, Li Xiang-guo

Cement Wapno Beton

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2025

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R. 30, nr 2

110--123

PL

Efektywne mielenie stanowi jedno z kluczowych narzędzi ograniczania zużycia energii w produkcji cementu, a projektowanie wysokoefektywnych środków wspomagających mielenie w oparciu o koncepcję projektowania struktury molekularnej stanowi obecnie istotny kierunek badań. W niniejszej pracy zastosowano kwas 2-akrylamido-2-metylo-propanosulfonowy [AMPS], akrylan hydroksypropylu [HPA] oraz monoeter winylowy glikolu dietylowego [DEGVE] jako monomery do syntezy nowego polimeru o małej masie cząsteczkowej. Następnie, poprzez wprowadzenie polioli polimerowych, opracowano polimerowy środek wspomagający mielenie klinkieru cementowego, a jego relację struktura-aktywność poddano systematycznej ocenie. Wyniki badań wykazały, że optymalne właściwości uzyskuje się przy zawartości inicjatora i regulatora długości łańcucha wynoszącej odpowiednio 1,39% oraz 5,84%, przy stosunku molowym nDEGVE: nAMPS: nHPA równym 1 : 1,85 : 0,5. Należy podkreślić, że ostateczna skuteczność procesu mielenia określana jest na podstawie wartości D50 oraz pozostałości na sicie o oczkach 45 μm, a nie poprzez powierzchnię właściwą cząstek czy intensywność hydratacji cementu, które nie stanowią głównych wskaźników oceny wydajności mielenia. W porównaniu z tradycyjnymi środkami wspomagającymi mielenie na bazie alkanoloamin, opracowany polimerowy dodatek pozwolił na istotną optymalizację rozkładu wielkości cząstek cementu. Udział objętościowy frakcji 0-32 μm oraz >64 μm uległ ograniczeniu odpowiednio o 1,5% i 51,7%, natomiast udział frakcji 32-64 μm zwiększył się o 59,5%. Ponadto, w odniesieniu do środków na bazie alkanoloamin, wytrzymałość na ściskanie cementu po 3 dniach zwiększyła się o 3,4%, a po 28 dniach o 8,3%.

EN

Efficient grinding is one of the important means to reduce energy consumption in cement production, and the development of efficient grinding aids based on molecular structure design is currently a research hotspot. In this work, 2-acrylamido-2-methylpropanesulfonic acid [AMPS], hydroxypropyl acrylate [HPA], and diethylene glycol monovinyl ether [DEGVE] as monomers was applied to synthesize a novel low molecular weight polymer. A polymer-based grinding aid for cement clinker was prepared by incorporating polymeric polylol, and its structure-activity relationship was systematically evaluated. The results showed that the optimal performance was achieved when the amounts of initiator and chain transfer agent were 1.39 % and 5.84 %, respectively, and the ratio of nDEGVE : nAMPS : nHPA was 1:1.85:0.5. It should be noted that the optimal grinding performance is determined by the D50 value and the 45 μm sieve residue, not by the particle specific surface area or the strength of cement hydration, which are not the primary indicators for evaluating grinding performance. Compared with alcohol amine grinding aids, the prepared grinding aid could significantly optimize particle size distribution of cement. The volume fraction of particles above 0-32 μm and 64 μm was decreased by 1.5 % and 51.7 %, respectively, while increased by 59.5 % for 32-64 μm; Compared with the alcohol amine grinding aid, the compressive strength of cement at 3 d and 28 d increased by 3.4 % and 8.3 %, respectively.

5

Przydatność polimerów stosowanych w technologii druku 3D do budowy modeli doświadczalnych służących do badań dynamicznych na stole wstrząsowym

Dulińska Joanna, Boroń Paweł, Tatara Tadeusz, Budzik Grzegorz, Przeszłowski Łukasz

Materiały Budowlane

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2024

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nr 1

17--22

PL

Technologia druku 3D ma coraz większe zastosowanie w budownictwie. W artykule zaprezentowano ocenę przydatności wybranych polimerów do druku modeli laboratoryjnych służących do identyfikacji częstotliwości drgań własnych obiektów na stole wstrząsowym. Wyznaczono doświadczalnie parametry fizykomechaniczne polimerów, a także obliczono skale podobieństwa w przypadku modeli wydrukowanych z analizowanych polimerów. Wskazano na parametry materiałowe polimerów warunkujące możliwość i zasadność ich stosowania w badaniach dynamicznych na stole wstrząsowym.

EN

3D printing technology is gradually becoming more employed in civil engineering. The article assesses the suitability of selected polymers for printing laboratory models used to identify the natural frequencies of structures on a shaking table. Experimental physical and mechanical parameters of the polymers were determined, and similarity scales were calculated for models printed with the analysed polymers. The material parameters of the polymers determining the possibility and validity of their use in dynamic tests on a shaking table were also indicated.

6

Accessing the Composting Potential and Phytotoxicity of Acetate Waste-Market Implications and Legal Compliance

Bilkiewicz-Kubarek Aleksandra, Jarosz-Krzemińska Elżbieta, Adamiec Ewa

Journal of Ecological Engineering

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2024

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Vol. 25, nr 10

119--126

EN

he study investigates the properties and waste management potential of cellulose acetate waste, commonly used in cigarette filter production. The goal of the research is to address gaps in the state of the art by assessing compostability and phytotoxicity of acetate waste from cigarettes production, which significantly complement the current research focused on cigarette filters in the form of post-consumer buts. Under investigation was acetate in the form of homogenic, dye-free and non-contaminated tow from the beginning phase of the cigarette’s filters production process. The experimental framework adheres to the PN-EN 14045:2005 standard for controlled composting environments. Acute phytotoxicity assessment follows the PHYTOTESTKIT method based on PN-EN 11269-1:2013-06. Results indicate that under controlled conditions, acetate waste achieves a decomposition rate of 75.3% after 84 days. Phytotoxicity testing reveals varying germination rates for different plant species. Across substrates, only 81 out of 210 seeds germinated (39%). Specifically, green cucumber seeds showed no germination, oat seeds had a 29% germination rate (20% for compost with acetate), and cress seeds had a high 90% germination rate for each substrate. Overall, understanding these properties informs sustainable waste management practices, including potential applications in industries like geotextiles, crop mulching mats etc. The results led to the conclusion that additional testing should be perform according to the requirements specific for each industrial usage and to increase the compostability level under laboratory and natural conditions.

7

Evaluation of tensile strength and flexural strength of GFRP composites in different types of matrix polymers

Sulistyo A. B., Wirawan W. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2024

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Vol. 123, nr 2

49--57

EN

Purpose: Resin selection has a crucial role in determining the properties and performance of GFRP composites; this study aims to investigate the effects of different resin types, specifically epoxy, bisphenol, ripoxy, and polyester, on the mechanical strength of GFRP composites. Design/methodology/approach: The composites were fabricated using the conventional method of hand lay-up technique with a fiber to matrix ratio of 60:40 wt%. The glass fibre laminate arrangement consists of 4 layers, two layers of Woven Roving Mat (WRM) fibres (0°/90°) and 2 layers on the outer side of the Chopped Strand Mat (CSM). The composite specimens were molded using the ASTM D-838 tensile test standard and ASTM D-790 for the bending test. Findings: The research results found that the maximum tensile strength was obtained by GFRP composite with ripoxy matrix type of 181.6 MPa, strain of 0.028%, and flexural strength of 1387 MPa. Composites using polyester matrices can generally be classified as splitting in multiple areas where failure occurs in various areas, but the composite has very high strength. Research limitations/implications: Material experiments conducted on a scientific laboratory scale may not fully reflect the behaviour of composites in actual conditions. Furthermore, aspects such as environmental influences, sustained stresses, or fatigue effects may need to be considered in further research. This evaluation also does not consider the effects of long-term exposures or ageing on the mechanical properties of GFRP composites. Investigating the behaviour of materials over long periods can provide important insights into their durability and reliability in practical applications. Practical implications: In GFRP composites, the application of resin to the fibres is critical. The performance and mechanical characteristics of GFRP composites are largely determined by the polymer matrix. Composites with epoxy, polyester, or bisphenol matrices can be compared to composites with the most equivalent tensile strength values, but composites with ripoxy matrices can be suggested. However, the GFRP composite with bisphenol matrix has an excellent bending strength value. As a result, numerous applications exist for implementing matrix selection in producing GFRP composites. Originality/value: The reliability of the tensile properties of GFRP composites was obtained using the ripoxy matrix type. Furthermore, the reliability of the flexural properties of the composites was obtained using the bisphenol matrix type.

8

Effect of Zirconia and Graphene Nanoparticles Loading on Thermo-Mechanical Performance of Hybrid Polymer Nanocomposite

Singh Devendra Kumar, Verma Rajesh Kumar, Mishra Sanjay

Archives of Metallurgy and Materials

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2024

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Vol. 69, iss. 2

579--587

EN

This study demonstrates the development of a unique hybrid thermoplastic composite using reduced Graphene oxide (rGO) content and Zirconia (ZrO2) nanoparticles into the Ultra-High Molecular Weight Polyethylene (UHMWPE) biomaterials for continuous loading conditions. Specimens with different loadings of rGO (0 to 1.5 wt.%) and ZrO2 (5 to 10 wt.%) were fabricated using liquid phase ultrasonication followed by the hot press moulding method. The samples were analyzed using Thermogravimetric Analysis (TGA), Impact (Izod) testing, and Dynamic Mechanical Analysis (DMA). The developed material feasibility was assessed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analyses. The findings revealed that the 1 wt.% rGO/5 wt.% ZrO2/UHMWPE sample improved the storage modulus by 66.15%, and the Impact absorbed energy by 11.33% compared to the pristine UHMWPE. The proposed nanocomposite could be endorsed for artificial joints, prostheses, and other Artificial Bio-Bearing (ABB) applications.

9

Perspektywy rozwoju rozwiązań materiałowo-konstrukcyjnych belek zespolonych w świetle najnowszych badań

Nawrot Jacek

Przegląd Budowlany

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2023

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R. 94, nr 7-8

122--125

PL

Ciągły rozwój konstrukcji budowlanych powoduje doskonalenie istniejących oraz powstawanie nowych rozwiązań materiałowo-konstrukcyjnych, w tym również dotyczących belek zespolonych. W pracy dokonano przeglądu najnowszych badań w tym zakresie. Na ich podstawie wskazano, że największy potencjał rozwoju mają rozwiązania, których parametry wytrzymałościowe i użytkowe są porównywalne z tradycyjnymi konstrukcjami, bazujące na materiałach ekologicznych lub cechujących się niższą energochłonnością i emisyjnością niż stal czy beton, do produkcji których można wykorzystać odpady i surowce pochodzące z recyklingu.

EN

The continuous development of building structures results in the improvement of existing and the emergence of new material and structural solutions, including composite beams. The paper reviews the latest research in this field. On their basis, it was indicated that the greatest potential for development has solutions whose strength and performance parameters are comparable to traditional structures, based on ecological materials or characterized by lower energy consumption and emissivity than steel or concrete, for the production of which waste and recycled raw materials can be used.

10

Impact of orthodontic adhesive magnets on the mechanical properties and degree of conversion of a photopolymerized orthodontic adhesive

Al-Hayali Saud Khalil, Abed Mazin Ahmed, Al Qassar Sarmad Salih

Ochrona przed Korozją

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2023

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nr 10

329--334

EN

The purpose of this study was to calculate the effects of magnetic field (MF) on the degree of conversion (DC%) and mechanical properties of a photopolymerized orthodontic adhesive. In this investigation, Vega Ortho UV orthodontic adhesive was employed. The applied magnetic field had varying intensities (fixed at 0.01 T, 0.03 T, 0.05 T, 0.1 T, 0.15 T, and 0.2 T and a duration of 5 minutes) and a fixed frequency of 50 Hz. Vickers microhardness and DC% were investigated utilizing the specimens, which were created using circular molds and prepared for compression strength (CS) testing in accordance with ISO 4049. To evaluate DC% before and after MF exposure, Fourier-transform infrared spectroscopy (FTIR/ ATR) was performed. A microhardness tester was used to quantify the samples’ initial VHN while subjecting them to a 500 g load for 15 seconds. After that, properties were evaluated. With the aid of scanning electron microscopy (SEM), the surfaces were evaluated. The one-way analysis of difference and Tukey significant difference tests were used to evaluate the data. Analyses of statistical data showed that DC% tends to rise up to 0.05 T. When compared to the control, VHN and compression strength were considerably decreased after 0.03 T MF (p ≤ 0.05). However, there was a significant difference between the VHN and CS as their values increased with increasing magnetic field intensity. The surfaces of the Vega Ortho were deteriorated, as shown by SEM scans. It was found that the effect of the magnetic field caused changes in the physical and chemical properties.

PL

Celem badania było określenie wpływu pola magnetycznego (MF) na stopień konwersji (DC%) i właściwości mechaniczne fotopolimeryzowanego kleju ortodontycznego. W badaniu zastosowano klej ortodontyczny Vega Ortho UV. Zastosowane pole magnetyczne miało różne natężenia (0,01 T, 0,03 T, 0,05 T, 0,1 T, 0,15 T i 0,2 T przez 5 minut) i stałą częstotliwość 50 Hz. Mikrotwardość Vickersa i DC% ustalono z wykorzystaniem próbek, które zostały wykonane przy użyciu okrągłych form i przygotowane do badania wytrzymałości na ściskanie (CS) zgodnie z normą ISO 4049. Do oceny DC% przed ekspozycją na działanie pola magnetycznego i po niej wykorzystano spektroskopię w podczerwieni z transformacją Fouriera (FTIR/ATR). Do ilościowego określenia początkowej wartości VHN próbek użyto mikrotwardościomierza, poddając je obciążeniu 500 g przez 15 sekund. Następnie dokonano oceny właściwości. Ocenę powierzchni przeprowadzono za pomocą skaningowej mikroskopii elektronowej (SEM). Dane poddano jednokierunkowej analizie różnic i testowi istotnej różnicy Tukeya. Analizy danych statystycznych wykazały, że DC% ma tendencję do wzrostu do poziomu 0,05 T. W porównaniu z próbką kontrolną wartości VHN i wytrzymałości na ściskanie uległy znacznemu zmniejszeniu po oddziaływaniu 0,03 T MF (p ≤ 0,05). Istniała jednak znacząca różnica między VHN i CS, ponieważ ich wartości rosły wraz ze wzrostem natężenia pola magnetycznego. Powierzchnie Vega Ortho uległy degradacji, jak wykazały skany SEM. Stwierdzono, że wpływ pola magnetycznego spowodował zmiany właściwości fizykochemicznych.

11

The experimental study of the effect of magnetically sensitive elastomers on oil recovery of reservoirs containing high-viscosity oils

Mustafayeva Rena E.

Nafta-Gaz

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2023

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R. 79, nr 2

110--113

EN

In world practice, low-viscosity oil accounts for the main share of production. As the development progresses, the share of high-viscosity oil in the total balance increases year on year. The growing unused reserves of high-viscosity oil oblige researchers to solve the issue of developing these reserves, which is an important task for the oil industry. Studies have been carried out to increase oil recovery during the development of oil reservoirs containing high-viscosity oil by pumping a solution of magnetically active polymer, namely silicone oligomer, the matrix of which contains 5–25% Fe+3 ions, treated with a constant transverse magnetic field with a strength of H = 51740 A/m. A mixture of 90% by weight of quartz sand and 10% by weight of bentonite clay, with a permeability of k = 1.4 D, was used as a reservoir model. The high-viscosity oil model consisted of St-45 aviation oil. A silicone oligomer of 159–360 brand was used as a matrix with an operating temperature range of 60°C to +300°C, into which particles of gamma-Fe2O3 Nano powder with a size of 0.5 nm are introduced, with a degree of filling of the matrix of 5–25% by volume of Fe. Magnetization saturation is 80 emu/g, residual magnetization is 460 emu/g, and coercive force is 670 Oh. Validation of the proposed method was carried out by physical modeling of the process of displacement of high-viscosity oil with a magnetic elastomer on a laboratory installation. The oil recovery coefficient was calculated according to a wellknown method. The use of magnetically sensitive polymer can be an effective method of developing heavy oil fields. For each heavy oil field, taking into account its specifics (reservoir properties of the rock, physicochemical properties of oil, etc.), an appropriate magnet active polymer is selected. As the experimental results show, the best indicator of the oil recovery coefficient is achieved at 65%, compared with 48% of recovery in the absence of magnetic field exposure.

PL

W praktyce światowej główną część produkcji stanowią ropy o niskiej lepkości. W miarę postępu rozwoju udział rop o dużej lepkości w ogólnym bilansie rośnie z roku na rok. Rosnące niewykorzystane zasoby ropy naftowej o wysokiej lepkości obligują badaczy do rozwiązania kwestii zagospodarowania tych zasobów, co jest ważnym zadaniem dla przemysłu naftowego. W czasie zagospodarowania złóż ropy naftowej o dużej lepkości prowadzone były badania nad zwiększeniem wydobycia ropy poprzez tłoczenie roztworu magnetycznie aktywnego polimeru, jakim jest oligomer silikonowy, którego matryca zawiera 5–25% jonów Fe+3, poddanego działaniu stałego poprzecznego pola magnetycznego o natężeniu H = 51740 A/m. Jako model złoża zastosowano mieszaninę: 90% mas. piasku kwarcowego i 10% mas. glinki bentonitowej, o przepuszczalności k = 1,4 D. Modelem ropy o dużej lepkości był olej lotniczy St-45. Jako matrycę o zakresie temperatur pracy od 60°C do +300°C zastosowano oligomer silikonowy marki 159–360, do którego wprowadzone zostały cząsteczki nanoproszku gamma-Fe2O3 o rozmiarach 0,5 nm, a stopień wypełnienia matrycy jest w zakresie 5–25% obj. Fe. Nasycenie magnetyczne wynosi 80 emu/g, namagnesowanie szczątkowe wynosi 460 emu/g, a siła koercji wynosi 670 Oh. Walidację proponowanej metody przeprowadzono poprzez fizyczne modelowanie procesu wypierania oleju o dużej lepkości elastomerem magnetycznym w instalacji laboratoryjnej. Współczynnik odzysku oleju obliczono według znanej metody. Zastosowanie magnetycznie czułego polimeru może być skuteczną metodą zagospodarowania złóż ciężkich rop. Dla każdego złoża ciężkiej ropy naftowej, biorąc pod uwagę jego specyfikę (właściwości skały zbiornikowej, właściwości fizykochemiczne ropy itp.), dobierany jest odpowiedni polimer magnetycznie aktywny. Z eksperymentu wynika, że najlepszy współczynnik odzysku oleju osiągnięto na poziomie 65%, w porównaniu z 48% odzysku przy braku ekspozycji na pole magnetyczne.

12

Microplastics contamination in commercial fish landed at Lengkong Fish Auction Point, Central Java, Indonesia

Hidayati Nuning Vita, Rachman Fenina O.B., Muslih, Hidayat Rizqi R., Meinita Maria D.N., Hendrayana, Husni Iqbal A., Andriyono Sapto, Sanjayasari Dyahruri

Journal of Water and Land Development

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2023

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no. 58

70--78

EN

Plastic is one of the main pollutant sources that are difficult to decompose and then carried into the ocean and fragmented into smaller parts (microplastics) due to UV radiation and water currents. Their small size means that microplastics are often ingested by aquatic organisms, such as fish. This research aimed to determine the presence, abundance, and types of microplastics in the digestive tract of four dominant fishes landed at Lengkong Fish Auction Point, Cilacap, Central Java, i.e. threadfin (Eleutheronema tetradactylum), mackerel (Rastrelliger sp.), threadfin bream (Nemipterus japonicus), and hairtail (Trichiurus lepturus). We found microplastics in the digestive tract of four selected fishes with a frequency of occurrence of 100%. The concentration of microplastics in fish digestive tracts is relatively high, with a value range of 12 ±2.86 to 28.33 ±8.11 particles∙ind.-1. Microplastics were found in films, fibres, fragments, and granule shape types with various colours: brown, purple, blue, black, green, transparent, and yellow. The polymers found were polystyrene (PS), nylon, acrylonitrile butadiene styrene (ABS), polyurethane (PU), polypropylene (PP), high-density polyethylene (HDPE), and low-density polyethylene (LDPE). The present study provides baseline data for microplastics contamination in commercial fish species landed at Lengkong Fish Auction Point, Cilacap, Central Java, Indonesia. The fact that we discovered PU, the most harmful polymer, piques our attention.

13

Investigating Microplastics in the Mediterranean Coastal Areas – Case Study of Al-Hoceima Bay, Morocco

Achoukhi Iliass, El Hammoudani Yahya, Dimane Fouad, Haboubi Khadija, Bourjila Abdelhak, Haboubi Chaimae, Benaissa Chaimae, Elabdouni Aouatif, Faiz Hatim

Journal of Ecological Engineering

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2023

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Vol. 24, nr 5

176--190

EN

The issue of microplastics pollution is gaining increasing attention as a global environmental concern. These tiny particles, measuring no more than 5 mm in size and coming in various shapes, can affect all types of marine eco-systems as they are easily consumed by a wide range of marine species. Al-Hoceima Bay, with its semi-enclosed nature and heavily affected anthropized coastline, was chosen as the study area for this research. The main objective was to investigate the presence of various microplastic types in Al-Hoceima Bay by implementing a sampling strategy along the coastline. This comprehensive approach was applied on a local scale within the bay (located in the northwest Mediterranean). Three stations were established in the bay, each located at different levels: the supralittoral, medilittoral and interlittoral. Microplastics were collected from these locations and classified into four categories based on their abundance. Digital microscopy was used to count the plastic particles and they were identified by Fourier transform-attenuated total reflectance infrared spectroscopy (ATR-FTIR). Results showed a higher presence of microplastics in water at 114 particles/L compared to sediment at 70 particles/L. The classification of samples revealed fibers as the most prevalent form, followed by fragments and films being the least commonly found. The abundance of fibers was found to be higher in water 90%, while in sediment it was 31%, however, fragments and leaves were found in higher concentrations in sediment. Polypropylene and polyethylene were identified as the major polymers used in the microplastics analyzed.

14

A comprehensive review of polymer materials and selective laser sintering technology for 3D printing

Jabri F. E., Ouballouch A., Lasri L., Alaiji R. El

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 118, nr 1

5--17

EN

Purpose: This review analyses different approaches used to study selective laser sintering (SLS) technology of polymer materials. These main approaches concern: thermal behaviour, fatigue and surface roughness. Design/methodology/approach: Regarding the first behaviour, researchers extensively studied the impact of process parameters, including scan speed, laser, power and laser energy density, on the thermal behaviour of 3D printed parts. Numerical and experimental analyses are used to conduct process parameter evaluations. Findings: Laser power and scan speed are the most significant parameters of the laser energy density. For the second, according to test protocols and quantitative analysis performed, the authors concluded that the combination of small and large laser energy density particles generates higher sintering and better fatigue resistance. Moreover, tensile analysis in different environments showed that testing in the water decreased the fatigue life of polymer samples. The influence of process parameters on the mechanical properties and surface roughness of 3D parts is also analysed. In addition, the investigators found that the additives increase the surface roughness of 3D printed parts. Practical implications: This review shows that researchers can focus on creating a combination of these approaches to expand the use of this process for industrial part production. Originality/value: All these investigations have made it possible to determine the optimal process conditions to ensure higher quality, optimal surface quality and better fatigue strength.

15

Using Own Algorithms to Increase the Quality and Fatigue Resistance of FDM Printing for Use in Drones and Small Aircraft

Szafran Krzysztof Stanisław, Jeziorek Łukasz Andrzej

Fatigue of Aircraft Structures

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2023

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Iss.15

28--43

EN

The present article discusses the three-dimensional (3D) printing process in the fused deposition modeling (FDM) or the fused filament fabrication (FFF) technique using the author’s own philosophy of shaping the printing head path. The main requirements are the possibility of eliminating supports and reducing or even eliminating the need for the mechanical processing of 3D prints before their final assembly. The presented methodology was implemented in a computer program written by the author and was used to print typical parts used in aviation. Individual methods of shaping parts typical for the construction of small flying models, such as wings and fuselages, and methods of strengthening and connecting them have been discussed. The proposed solutions are illustrated with photos of readymade prints. This article also discusses the issues that printing high-quality parts may encounter and how to avoid them. Some attention has also been paid to the materials used for printing and their suitability in the construction of aircraft and their fatigue strength.

16

Microbial Fluidized Bed Reactor Removing Pharmaceutical Contaminants from Wastewater – Review

Abbas Mays, Al Kindi Ghayda Yaseen, Hussein Amal Ali

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 7

266--279

EN

Pharmaceutical contaminants are difficult to remove with standard treatment techniques and are one of the current problems in wastewater treatment. These bioactive substances are considered emerging pollutants due to their persistence and potential impact on aquatic ecosystems. They will continue to function even in small amounts. Efficient wastewater treatment methods are needed to address this issue. As a result, the efforts to develop more efficient wastewater treatment methods have recently intensified. Fluidized bed reactors offer a special opportunity for efficient treatment of wastewater containing recalcitrant pollutants. This article discussed FBBR and covered its advantages, disadvantages, modifications, and applications. Additionally, the FBBR design was briefly discussed.

17

Material Production and the Effect of the System on Biocompatibility in the Modified Metal Injection Method

Çiçek Bünyamin, Sun Yavuz

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

195--204

EN

In this study, the bio state of the alloy produced in the modified metal injection system was monitored after sintering. A new system operating with high gas pressure, far from the traditional injection model, has been established for material production. In this system, 316L stainless steel powders were molded using a PEG/PMMA/SA polymer recipe. During molding, approximately 60% 316L and 40% binder by volume were used. The samples obtained were sintered at different temperatures (1100-1300°C) after de-binding. Density measurement (Archimedes) and hardness tests (HV1) of the samples were measured as 6.74 g/cm3 and ~285 HV1, respectively. A potentiodynamic corrosion test was applied to monitor the effect of the amount of oxide in the structure of the 316L stainless steel produced. Corrosion tests were carried out in artificial body solutions. The corrosion rate was measured at the level of 17.08×10-3 mm/y. In terms of biocompatibility, a cytotoxicity test was applied to the samples and the life course of the bacteria was monitored. For the 316L alloys produced, the % vitality reached approximately 103%.

18

Mechanical analysis of multilayer composite materials with duroplastic matrix after exposure to low temperatures

Krzak Anna, Nowak A. J.

Archives of Materials Science and Engineering

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2023

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Vol. 122, nr 2

49--57

EN

Purpose: Cryogenic engineering is gaining more and more interest in various industry sectors, which leads to an intensive search for effective solutions. The article presents the findings of mechanical testing conducted on glass-epoxy laminates at room temperature and after long- term contact with liquid nitrogen. Design/methodology/approach: To compare the impact properties and flexural strength, the samples were tested under cryogenic and room conditions, and then the fracture locations were identified using the Leica DVM6 microscope. The study brings value to the emerging field of cryogenic engineering by providing valuable information on the mechanical properties of glass-epoxy composites under cryogenic conditions. Findings: It has been found out that immersing the glass-epoxy composites into the Dewar had minimal influence on impact and flexural strength properties. The most noticeable changes were observed in the case of the EP_4_2 composite. The material consists of a solution of brominated epoxy resin in an organic solvent. It is used to produce laminates in electrical engineering and printed circuits in electronics, where it should exhibit excellent impact properties. Research limitations/implications: One of the prospective research directions is a thorough analysis of the mechanical properties of the developed composite materials during cryogenic cycles. Originality/value: The study aims to determine the effect of different compositions of glass fabric-reinforced resin with a weight of 205 g/m2 on the mechanical properties of the developed composite materials at both room temperature and after long-term exposure to liquid nitrogen. Those investigations serve as surveillance for developing of new material solutions directed towards cryogenic applications and are essential for subsequent stages of research.

19

Investigation of the effect of polymer concentration in fracturing fluid on crack size and permeability during hydraulic fracturing

Moroz L. B., Uhrynovskyi A. V., Kogut G. M.

Archives of Materials Science and Engineering

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2023

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Vol. 122, nr 2

70--77

EN

Purpose: This article aims to investigate the impact of polymer type and concentration in the fracturing fluid on the size and permeability of fractures during hydraulic fracturing. The aim is to predict the conductivity and productivity of the formed fractures in order to evaluate the cumulative gas production. Design/methodology/approach: The influence of polymer concentration in the fracturing fluid on the size and permeability of fractures was studied using the GOHFER software from Haliburton. Findings: The results of the study show that by combining the effect of increasing fracture size and decreasing the permeability of the proppant, a gas flow rate increase of 3.5 times was achieved. Research limitations/implications: High polymer concentrations lead to reduced permeability due to the accumulation of polymer residues and polymer skin. Practical implications: The conducted study on the impact of polymer concentration in the fracturing fluid on the size and permeability of fractures will allow for a more qualitative hydraulic fracturing process. Originality/value: This article presents how the concentration and type of polymer affect the width, thickness, length, and conductivity of fractures during hydraulic fracturing.

20

Leading-edge polymer/carbonaceous nano-reinforcement nanocomposites — opportunities for space sector

Kausar Ayesha, Ahmad Ishaq

Advances in Materials Science

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2023

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Vol. 23, nr 4(78)

99--122

EN

Carbonaceous or nanocarbon nano-reinforcement nanocomposites have been found as emergent candidates for aerospace industry. Consequently, the multifunctional nanocomposites have been fabricated using marvelous nanocarbon nanostructures like graphene, carbon nanotube, fullerene, carbon black, etc. Manufacturing techniques have also been engrossed for the formation of high performance engineering nanocomposites having fine strength, heat stability, flame resistance, and other space desired features. These practices include solution, in situ, and melt procedures, on top of specific space structural design techniques, for the formation of aerospace structures. The aerospace related material property enhancements using various carbonaceous nano-reinforcements depends upon the type of nanocarbon, dimensionality, as well as inherent features of these nanostructures (in addition to the choice of manufacturing methods). Furthermore, carbon nano-reinforcements have been filled, besides carbon fibers, in the epoxy matrices. Nanocarbon coated carbon fibers have been filled in epoxy resins to form the high performance nanomaterials for space structures. The engineering features of these materials have been experiential appropriate for the aerospace structures. Further research on these nanomaterials may be a key towards future opportunities in the aero systems. Additionally, the explorations on structure-property relationships of the carbonaceous nanocomposites have been found indispensable for the development of advanced aerospace structures.