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1

Sustainable approach to river buoy production using recyclable composites based on thermoplastic polymer wastes

Czarnecka-Komorowska Dorota, Ćwirko Konrad, Baszak Karolina, Uriasz Janusz, Garbacz Tomasz, Kanciak Krzysztof

Advances in Science and Technology. Research Journal

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2026

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Vol. 20, no. 2

313--322

EN

This paper presents a novel approach to the production of river buoys, focusing on the use of new composite materials with high recyclability at the end of the buoy’s life cycle. The composites were produced from post-production thermoplastic waste - polyethylene and polyamide 6 - reinforced with glass fibre, and modified using block copolymer polyethylene maleic-grafted-anhydride (PE-g-MAH) to improve the heterogeneity of the waste structure. The composites were prepared by melt compounding with a corotating twin-screw extruder. The melting behaviour, rheology, degree of crystallinity, and moisture sorption characteristics of the rPE/rPA6-30GF/CoM compositions were investigated. Rheological behaviour was analysed using an oscillatory rheometer. Given the operating conditions of the new composites, key functional properties such as specific density and water absorption of the rPE/rPA6-30GF composites were also assessed. The structure of the composites was further examined using scanning electron microscopy (SEM). The results showed that modifying the rPE/rPA6-30GF composite with varying amounts of compatibilizer led to an increase in specific density and a decrease in water absorption, compared to unmodified polyethylene-polyamide 6 composites containing 30% glass fibre. These improvements were attributed to increased homogeneity of the composite structure as a result of the PE-g-MAH modification. The findings indicate that polyethylene–polyamide-based waste polymer composites can be effectively used as potential materials for constructing navigation buoys.

2

Modyfikacja zeolitów w celu poprawy ich zdolności do adsorpcji siarkowodoru z gazów

Abdirakhimov Mirzokhid

Przemysł Chemiczny

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2025

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T. 104, nr 12

1266--1270

PL

Siarkowodór jest obecny w różnych mieszaninach gazowych, w tym w gazie ziemnym, biogazie, powietrzu atmosferycznym i gazach z wentylacji górniczej. Ze względu na właściwości korozyjne i toksyczność konieczne jest jego usunięcie z tych mieszanin. Do tego celu stosuje się zeolity, które charakteryzują się doskonałą zdolnością adsorpcji tego gazu. Istnieją możliwości zwiększenia ich zdolności adsorpcyjnych poprzez odpowiednią modyfikację. Modyfikacje zeolitów mogą być prowadzone z użyciem metali lub tlenków metali. Przedstawiono ocenę zeolitów modyfikowanych wg różnych procedur i różnymi środkami w celu zwiększenia ich zdolności adsorpcji H₂S.

EN

A review, with 22 refs., of methods for modification of zeolites with metals and metal oxides to enhance their H₂S adsorption capability and recyclability as well as to improve processes for H₂S removal from various gaseous mixts.

3

Modyfikacja asfaltów drogowych odpadami z materiałów polimerowych

Makomaski Grzegorz, Mańska Lidia, Łyzińska Klaudia, Brzezińska Karolina, Zieliński Janusz, Lęcki Jakub, Niemyjski Kamil

Przemysł Chemiczny

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2025

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T. 104, nr 1

153--156

PL

Dokonano przeglądu literaturowego dotyczącego modyfikacji asfaltów drogowych odpadami z materiałów polimerowych. Omówiono wpływ odpadów z plastomerów na zmianę właściwości asfaltów drogowych w metodzie na mokro.

EN

A review, with 68 refs., of the modification of paving bitumens with waste polymeric materials. The effects of plastomers on changing the properties of paving bitumens were presented.

4

Czy modyfikacja stopu aluminium jest zawsze skuteczna?

Wróbel J.

Przegląd Odlewnictwa

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2025

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Vol. 75, nr 3-4

100--104

PL

Modyfikacja stopu aluminium ma bardzo istotny wpływ na uzyskanie zwiększonych właściwości mechanicznych wytwarzanego stopu. W celu jej przeprowadzenia stosuje się najczęściej preparaty zawierające tytan, bor lub oba te pierwiastki jednocześnie, a także związki zawierające metale ziem rzadkich. W omawianym artykule przedstawiono szczegółowo próby technologiczne, podczas których odlane aluminium z gatunku EN-AC-44300 podano zabiegowi modyfikacji. Miała ona służyć polepszeniu wytrzymałości na rozciąganie (Rm) i plastyczność odlewów (Rp02). W toku badań wytworzonego materiału i jego oceny okazało się jednak, iż zabieg modyfikacji nie przyniósł oczekiwanych rezultatów. Badania próbek modyfikowanego stopu wykazały ponad 40% spadek wytrzymałości (Rm), a także prawie 27% spadek plastyczności (Rp02) oraz 3% spadek twardości. Analiza wyników pozwala postawić wniosek, iż to sposób pobrania próbek do badań lub zastosowany rodzaj modyfikatora odpowiadają za niekorzystny wpływ na otrzymane wyniki.

EN

Modification of the aluminum alloy has a very significant impact on obtaining increased mechanical properties of the produced alloy. In order to carry it out, preparations containing titanium, boron or both of these elements at the same time, as well as compounds containing rare earth metals, are most often used. The discussed article presents in detail technological tests during which cast aluminum of the EN-AC-44300 grade wassubjected to a modification procedure. It was to serve to improve the tensile strength (Rm) and yield strength of castings (Rp0.2). However, in the course of tests of the produced material and its evaluation, it turned out that the modification procedure did not bring the expected results. Tests of the modified alloy samples showed over 40% decrease in strength (Rm), as well as almost 27% decrease in yield strength (Rp0.2) and 3% decrease in hardness. Analysis of the results allows us to conclude that the method of taking samples for testing or the type of modifier used are responsible for the adverse effect on the obtained results.

5

Polish research on saturation diving and its implementation. Part IV, Modernisation of the Af-2 diving system

Skrzyński Stanisław, Stoltmann Paweł, Siermontowski Piotr

Polish Hyperbaric Research

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2025

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nr 1(90)

7--30

EN

This part of the article presents the process of renovation and technical modernisation undertaken in the first decade of the 20th century in order to repair the system after it was leased to RANA, to secure PETOBALTIC’s investment and, most importantly, to adapt it to the requirements of classification societies and improve the safety and comfort of divers. The work was carried out in several stages and, as a result, the system is operating successfully to the present day. The investor was PETROBALTIC, while the main contractor and author of the modernisation was the Underwater Works Technology Department of the Polish Naval Academy.

6

Amino-functionalized dendritic mesoporous silica nanoparticles for removal of copper from aqueous solutions

Yu Junjie, Bondarieva Antonina, Pylypenko Ihor, Tobilko Viktoriia, Sabov Tomash, Gumenna Mariana, Tomila Tamara, Inshyna Olena

Journal of Ecological Engineering

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2025

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Vol. 26, nr 6

365--377

EN

The amino functionalisation of the surface of dendritic mesoporous silica nanoparticles (DMSN) was carried out via post-coupling using 3-Aminopropyltriethoxysilane (APTES) in an aqueous-alcohol medium. The physicochemical characteristics of the synthesised material were studied using Fourier-transform infrared spectroscopy (FTIR), low-temperature nitrogen adsorption/desorption, differential thermal analysis (DTA), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The quantity of specific functional groups presents on the DMSN surface before (-OH group) and after (-NH2 group) functionalisation was determined by means of titration. The adsorption capacity of the materials for copper ions was investigated in the concentration range of 10 to 100 mg/L. Additionally, the effects of the pH of the aqueous medium and the contact time between the potential adsorbent and the contaminated solution on Cu(II) removal efficiency were examined. The equilibrium copper concentration was determined using inductively coupled plasma atomic emission spectroscopy (ICP-OES). It was found that surface modification of DMSN led to a more than tenfold increase in the number of functional groups and corresponding adsorption centres. As a result, the efficiency of copper ion removal within the pH range of 3–6 increased to over 87%. The adsorption equilibrium time decreased from 60 to 15 minutes. The maximum adsorption capacity for the amine-functionalised sample reached 35 mg/g, compared to just 0.62 mg/g for the unmodified DMSN. Pseudo-first-order and pseudo-second-order kinetic models, along with Langmuir and Freundlich isotherm models, were applied to analyse the adsorption mechanism. XPS analysis of the spent adsorbent further supported assumptions regarding the copper ion adsorption process.

7

Silicone pressure-sensitive adhesives modified by kaolinite

Antosik Adrian Krzysztof, Bartkowiak Marcin

Inżynieria Materiałowa

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2025

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Vol. 46, nr 4

16--20

PL

Zbadano właściwości kleju samoprzylepnego na bazie silikonu, modyfikowanego wypełniaczem. Opracowano nowe taśmy samoprzylepne z wykorzystaniem żywic silikonowych modyfikowanych kaolinitem. Te nowe materiały wykazały się lepszą odpornością termiczną przy jednoczesnym zachowaniu doskonałych właściwości klejących. Aby uzyskać dobre właściwości materiału, przeprowadzono testy sprawdzające najważniejsze właściwości kleju samoprzylepnego, takie jak przyczepność, kohezja, lepkość, skurcz oraz czas przydatności do użycia kompozycji klejowej.

EN

The characteristics of a silicone-based pressure-sensitive adhesive modified by a filler were explored. Novel self-adhesive tapes were developed using silicone resins modified with kaloinite. These new materials demonstrated improved thermal resistance while retaining excellent adhesive performance. To assess the material characteristics, tests were conducted to evaluate the most important properties of PSA, including adhesion, cohesion, tack, shrinkage, and pot-life of the adhesive composition.

8

A new approach in the production of cellulose membranes

Mylokost Sergii, Halysh Vita, Trus Inna, Krysenko Tamara, Hlushko Olena, Benatov Daniel, Sirenko Ludmila, Chuprinov Evhen

Ecological Engineering & Environmental Technology

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2025

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Vol. 26, iss. 4

334--341

EN

The research is related to the development of a method for modifying cellulose fiber to improve the operational characteristics of membranes. Epichlorohydrin and monoethanolamine were used as modifiers to plasticize the structure of the cellulose membrane. The consumption of modifiers, the temperature and duration of cellulose fiber modification, as well as the drying conditions of the resulting membranes on their properties were investigated. It has been shown that selected modifiers can act as plasticizers depending on the processing temperature. It was established that the resulting membranes are characterized by low productivity, but are capable of effectively reducing water color. It has been experimentally shown that the use of a modifier with a consumption of 15% allows to ensure the selectivity of color removal during filtration of a sodium humate solution at a level of more than 98%.

9

Changes in the structure of the AK7 alloy in terms of modification

Romankiewicz Remigiusz

System Safety : Human - Technical Facility - Environment

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2024

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Vol. 6, iss. 1

384--394

EN

On this work there was decided to verify the possibility of influence of micro additives of strontium and boron on structure of AlSi7Mg (EN-AC-42000) alloy with chemical composition according to PN-EN 1706. As the modifier there were used AlSr10 (0.3%) and AlTi5B1 (0.3%) master alloy, which were added separately and together. Changes in the structure of individual samples of the AK7 alloy were examined using a metallographic microscope. The chemical composition of complex intermetallic phases formed in the structure of the tested alloy was also examined. The most beneficial effect turned out to be the effect of strontium in the form of 0.3% AlSr10, ensuring a favourable conversion of lamellar silicon into the form of fine fibres. The presence of complex phases was observed in all test samples. Most often, these were phases with various needle shapes and variable Fe and Mn contents.

10

Korozja siarczanowa zapraw cementowych z dodatkiem szkła recyklingowego stanowiącego substytut kruszywa naturalnego

Jaworska-Wędzińska Monika, Jasińska Iga, Kaim Kacper

Przegląd Budowlany

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2024

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R. 95, nr 7

167--170

PL

W artykule przedstawiono wyniki badań przeprowadzonych na próbkach zapraw cementowych z zastosowaniem CEM I 42,5R, w których 10, 25, 50, 75 i 100% kruszywa drobnego zastąpiono stłuczką szklaną o frakcji 0-2 mm pochodzącą z recyklingu. Celem badań było określenie wpływu szkła recyklingowego na odporność siarczanową kompozytów cementowych. Zakres przeprowadzonych badań obejmował oznaczenie nasiąkliwości zapraw oraz odkształceń liniowych próbek poddanych działaniu 5% siarczanu sodu oraz próbek poddanych działaniu 5% siarczanu magnezu. Dokonano obserwacji mikrostruktury (SEM) i analizy składu fazowego (XRD) zapraw poddanych agresji siarczanowej. Otrzymane wyniki badań pozwoliły stwierdzić, że zaprawy, w których 10 i 25% kruszywa naturalnego zastąpiono szkłem recyklingowym, wykazują dobrą odporność siarczanową. Wpływ szkła recyklingowego na nasiąkliwość zapraw obserwowano w próbkach zawierających powyżej 50% stłuczki szklanej. Przeprowadzona analiza mikrostruktury potwierdziła, że zarówno w próbkach referencyjnych, jak i z udziałem stłuczki szklanej ettringit i gips są głównymi produktami korozji siarczanowej. W artykule podkreślono znaczenie recyklingu szkła dla ograniczenia ilości odpadów i zanieczyszczenia środowiska.

EN

The article presents the results of tests carried out on cement mortar samples using CEM I 42.5R which 10, 25, 50, 75 and 100% of the fine aggregate were replaced with recycled glass cullet with a fraction of 0-2 mm. The aim of the research was to determine the influence of recycled glass of the cement mortars on the sulphate resistance. The scope of the research included the determination of the water absorption of mortars and linear strain measure of samples immersed in 5% sodium sulphate and 5% magnesium sulphate, as well as observation of the microstructure (SEM) and analysis of the phase composition of the products (XRD). The obtained test results allowed the conclusion that mortars in which 10 and 25% of natural aggregate were replaced with recycled glass have good sulphate resistance. The influence of recycled glass on the absorbability of mortars was observed in samples containing more than 50% of glass cullet. The microstructure analysis confirmed that ettringite and gypsum are the main products of sulphate attack. The article highlights the importance of glass recycling in reducing waste and environmental pollution.

11

Sulfonation modification of guar gum and its performance as a fracturing fluids thickener

Yi Yonggen, Wu Lanbing, Zhang Jie, Wang Haiyang, Xie Xuan, Gang Chen

Polish Journal of Chemical Technology

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2024

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Vol. 26, nr 3

29--38

EN

To solve the contradiction between reducing water-insoluble content and maintaining high viscosity in the preparation of modified guar gum for oilfi eld fracturing fluid, in this work, sodium 3-chloro-2-hydroxypropylsulfonate was used as a modifier to prepare sulfonated guar gum. Orthogonal and single-factor extrapolation experiments were conducted to explore the effects of reaction conditions and the optimal process was determined as follows: reaction temperature of 26° C, reaction time of 2.0 h, sodium hydroxide as a mass fraction of guar gum of 1.0%, and sodium 3-chloro-2-hydroxypropyl sulfonate dosage as a mass fraction of guar gum of 0.5%. Furtherly, the temperature stability, filtration property, and inhibition of formation clay of the sulfonated products were investigated. The results showed that the apparent viscosity of 0.6% solution of guar gum was increased by 33%, the water-insoluble content was decreased by 0.42%, and the temperature stability, filtration resistance, and clay inhibition were all improved. Especially, the viscosity of cross-linked sulfonated guar gum is 100% higher than that of unmodified guar gum. The structure of sulfonated guar gum was characterized and confi rmed by infrared spectrum, DSC, thermogravimetric, and elemental analysis.

12

Methods for solving two-dimensional tasks of cutting raw materials

Aliyeva Sevda Y., Abishova Rabiya M.

Nafta-Gaz

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2024

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R. 80, nr 5

312--320

EN

The article discusses the methodology for solving two-dimensional material cutting problems, widely used in practice and applied to industrial equipment. Several modifications of the original problem are considered. An interactive optimization procedure is presented for a general two-dimensional material cutting problem. When cutting correctly, the two dimensions of the cut pieces (usually length and width) must be consistent with the length and width of the sheet. One of the problems most frequently encountered in literature and in practice is the problem of cutting a rectangular material into rectangular pieces. Therefore, this work focuses on this task. First, a two-dimensional problem of cutting material is formulated. Next, methods for solving the problem of cutting material and the related problem of constructing (creating) a template is outlined. The solution method includes a new interactive (dialogue) optimization procedure. A very interesting feature of 2D problems is that there are different options that arise from practical requirements due to the type of material and manufacturing process constraints. A description of the general technique would be incomplete without mentioning how it can be modified to apply specific practical problems. Therefore, the paper briefly discusses some practical applications and describes ways to modify the general methodology to solve these practical problems.

PL

W artykule omówiono metodologię rozwiązywania dwuwymiarowych problemów cięcia materiałów, szeroko stosowaną w praktyce i wykorzystywaną w urządzeniach przemysłowych. Rozważono różne modyfikacje pierwotnego problemu. Opracowano interaktywną procedurę optymalizacji dla ogólnego problemu dwuwymiarowego krojenia materiału. Podczas prawidłowego krojenia, dwa wymiary wyciętych elementów (zwykle długość i szerokość) muszą być zgodne z długością i szerokością arkusza. Jednym z najczęściej spotykanych w literaturze i praktyce problemów jest cięcie materiału prostokątnego na elementy prostokątne. Dlatego w niniejszej pracy skoncentrowano się na tym zadaniu. Przede wszystkim sformułowany został dwuwymiarowy problem materiału, a następnie omówiono metody rozwiązywania problemu krojenia materiału oraz pokrewnego problemu konstruowania szablonu. Metoda rozwiązania obejmuje nową interaktywną procedurę optymalizacji tego procesu. Bardzo interesującą cechą problemów 2D jest to, że istnieją różne opcje wynikające z wymagań praktycznych, podyktowanych rodzajem materiału i ograniczeniami procesu produkcyjnego. Opis ogólnej techniki byłby niepełny bez wzmianki o możliwości jej modyfikacji w celu zastosowania do konkretnych problemów praktycznych. Dlatego w artykule omówiono pokrótce niektóre zastosowania praktyczne i opisano sposoby modyfikacji ogólnej metodologii w celu rozwiązania tych problemów.

13

Recovery of the Properties of Spent Commercial Reverse Osmosis Membrane Elements and Ways of their Reuse

Tyvonenko Artem, Ivanova Tetiana, Halkina Kateryna, Mitchenko Tetiana, Vasilyuk Sergey, Kosogina Iryna

Journal of Ecological Engineering

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2024

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Vol. 25, nr 6

322--333

EN

In connection with the rapidly growing market of reverse osmosis membrane elements, particularly those intended for use in commercial water treatment installations, the problem of their regeneration and reuse has become acute. Today, the service life of such elements does not exceed 6–12 months, after which they turn into plastic waste and end up in landfills in the amount of no less than 60.000 tons per year, which leads to the emergence of serious environmental problems. This paper proposes methods and conditions for achieving almost complete restoration of the properties of used commercial reverse osmosis membrane elements by means of their regeneration and modif ication. The possibility of using restored elements in vending machines for filling safe physiologically complete drinking water has been demonstrated.

14

Study of applying chalcedonite for silicone pressure-sensitive adhesives

Antosik Adrian, Kucharska Edyta, Pełech Robert, Bartkowiak Marcin

Inżynieria Materiałowa

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2024

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Vol. 45, nr 4

5--12

EN

Silicones adhesives (including pressure-sensitive adhesives) are commonly used when high-performance materials are required due to harsh environmental conditions such as high temperatures, humidity, etc. To ensure high resistance to environmental conditions, including high temperatures, modifications to silicone adhesives are made using fillers. This work focuses on the properties of a silicone-based pressure-sensitive adhesive with filler modification. New self-adhesive tapes based on chalcedonite-modified silicone resins have been obtained. The new self-adhesive materials showed increased thermal resistance while maintaining excellent self-adhesive properties. In order to obtain a greater research spectrum and better compatibility with silicone resin, chalcedonite was modified using thiamine (vitamin B1, VitB1), and its effect on self-adhesive compositions was checked.

PL

Kleje silikonowe (w tym samoprzylepne) są powszechnie stosowane wszędzie tam, gdzie wymagane są materiały o wysokich parametrach użytkowych ze względu na trudne warunki eksploatacji (m.in. wysoka temperatura, wilgotność). Aby uzyskać wysoką odporność na warunki środowiskowe, w tym na wysoką temperaturę, dokonuje się modyfikacji klejów silikonowych za pomocą napełniaczy. W pracy zbadano właściwości silikonowych klejów samoprzylepnych modyfikowanych napełniaczem. Wytworzono nowe taśmy samoprzylepne na bazie żywic silikonowych modyfikowanych dodatkiem chalcedonitu. Wykazały one zwiększoną odporność termiczną przy zachowaniu dobrych właściwości samoprzylepnych. W celu zwiększenia zakresu badań i kompatybilności napełniacza z żywicą silikonową, chalcedonit modyfikowano tiaminą (witaminą B1) i sprawdzano wpływ jego ilości na właściwości otrzymanych kompozycji samoprzylepnych.

15

Application of fly ash/chitosan composites for heavy metal adsorption

Osmani Egzona, Dimitrievska Iva, Paunovik Perica, Atkovska Katerina, Rexhepi Fatos, Grozdanov Anita

Composites Theory and Practice

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2024

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R. 24, nr 2

87--94

EN

The aim of this paper is to investigate the potential of modified fly ash (FA) as an adsorbent for the removal of heavy metal ions from polluted waters. The effectiveness of unmodified FA was compared to FA modified with chitosan. The FA and FA/chitosan particles were characterized by means of SEM, XRF and FTIR methods. The FA and FA/chitosan composites were investigated as adsorbents for Cu(II) and Pb(II) ions from aqueous solutions. Experiments were carried out in a previously optimized pH (pH = 6), at room temperature for 3 hours. Langmuir and Freundlich isotherms were used to determine the maximum adsorption capacities of the fly ash samples for Cu(II) and Pb(II) ions. The experimental data indicate that the Langmuir isotherm fits better than the Freundlich isotherm for all the investigated systems. The obtained values of the qm, maximum adsorption capacity for the removal of Cu(II) and Pb(II) with the FA/chitosan composites were (1.068, 1.00, 1.042, 1.369 mg/g), and (2.532, 2.063, 1.036, 2.146, 2.482 mg/g), respectively. The efficiency trend was Pb(II) > Cu(II). The results indicate that the removal efficiency for Cu(II) and Pb(II) ions was 91.1 % and 99.7 %, respectively.

16

Effects of casting conditions on AlSi21CuNi hypereutectic alloy structure modified with P/Sr microadditions

Michalski M., Sękala A.

Archives of Materials Science and Engineering

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2024

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Vol. 129, nr 2

49--59

EN

Purpose: The study aims to evaluate the influence of selected modification parameters with phosphorus and strontium on the structure of the AlSi21CuNi alloy. Design/methodology/approach: Test smelting was conducted using a metal bath heating temperature of 850°C for 30 minutes. Once the temperature of the liquid metal was reduced to 750°C, the modification procedure was carried out. Casting was carried out using a metal mould at 10, 30 and 60 minutes after the modifiers were introduced into the metal bath. The first smelting involved the application of an AlCuP modifier at 350 ppm P by weight of the alloy. The next three smeltings were carried out by simultaneously introducing AlCuP (180 ppm P) and AlSr modifier (150, 250, 350 ppm Sr) into the metal bath. The last smelting was carried out to obtain samples of unmodified silumin. The smelting was carried out using the same procedure as for the modified alloy, omitting the introduction of modifiers into the metal bath. Findings: The conducted modification treatments were evaluated using qualitative and quantitative analysis methods of the microstructure of samples taken from test castings. The metallographic studies were carried out using a scanning electron microscope (SEM) and computer image analysis software. Research limitations/implications: It has been found that the simultaneous modification, i.e. with phosphorus and strontium additives of primary silicon crystals and refinement of the eutectic, represents a compromise between satisfactory fragmentation of the primary silicon crystals and the degree of refinement of the eutectic. The contact time of the modifiers with the metal bath is an important modification parameter in the given context. Further studies on the complex modification with phosphorus and strontium of other alloys from the group of hypereutectic silumins are justified in order to obtain material properties satisfactory to customers, i.e. manufacturers of various types of products. Practical implications: The simultaneous modification of primary and eutectic silicon into hypereutectic silumins is the key to improving their mechanical properties and wear resistance, which translates into the possibility of producing lightweight components for the automotive industry. Originality/value: The paper presents the results of metallographic studies of the AlSi21CuNi alloy before and after modification treatments in the form of qualitative and quantitative analyses of the microstructure of primary and eutectic silicon.

17

Kinetics of Solidification and Crystallization of Liquid Axial Zone of Fe-C Alloys in Cylindrical Molds

Khrychikov V., Semenov O., Aftandiliants Y., Gnyloskurenko S., Semenova T., Meniailo H.

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 4

163--170

EN

According to the results of digitization of the experimental studies carried out in the past concerning Fe-C alloys solidification in cylindrical molds of castings with a carbon content of 0.04%, 0.1%, 0.4%, 0.93%, 1.42%; 2.44%, 3.28%, 4.45%, 4.83% and their subsequent interpolation in the range of 0.04 ÷4.83%С there were obtained the curves of the advancement of the pour point, liquidus and solidus in the coordinates of the relative thickness of the solidified metal layer x/R and the parametric criterion τ/R2. Their usage is proposed for the development of modes of physical and chemical influence on the liquid metal in the axial zone of the casting after solidification of its calculated layer. Calculation of the mass of modifiers or deoxidizers for introduction into the axial zone was performed in relation to the total mass of metal in the liquid and liquid-solid zones of the casting. The technique for calculating the mass and time of introduction a graphitizing modifier into the axial zone of rolling rolls made of hypereutectoid steel with 1.7%C is proposed to reduce the negative impact of cementite, chromium and molybdenum carbides on the structure of the axial zone of the rolls. The obtained curves can also be used to assess the accuracy of computer modeling of the processes of Fe-C alloys solidification and further adaptation of mathematical models by the correction of thermophysical coefficients, the values of which are not always known in the liquidus-solidus temperature range.

18

Study of the Effects of Heat Exchanger Location on Turbofan Engine Performance

Jakubowski Robert, Bednarz Arkadiusz, Rogalski Łukasz

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no. 4

355--368

EN

The article presents a numerical investigation of the impact of heat exchanger (HE) location on the performance of the geared turbofan engine (GTF). It discusses the development trend for aero engines, with a primary focus on the modification of the turbofan engine cycle by the addition of the heat exchanger. This paper presents the current state of research on heat exchangers and their application in aero engines. The paper focuses on the thermodynamic model of the GTF engine, with particular emphasis on its modification to study the impact of heat exchangers on engine performance. The assumptions and limitations of the model are also discussed. The study examines the effects of various locations of the heat exchanger in the GTF engine, as well as its efficiency and pressure drop, on the engine overall performance, as measured by thrust and specific fuel consumption (SFC). The study demonstrates that the use of HE has a positive effect on engine thrust, but it also leads to an increase in SFC. According to the results, the HE should be positioned in the core engine of the GTF to achieve maximum thrust. This is achieved when the HE core flow inlet is located at approximately half the pressure ratio of the high-pressure compressor (HPC). It was found that the cold side pressure losses of the HE have a significant impact on engine performance for high bypass ratio turbofan engines. The additional conclusion can be drawn that, when designing a heat exchanger, it is of the utmost importance to take care to minimize its impact on pressure losses in the external channel of the engine.

19

Influence of the binder on the properties of cold mixtures

Krasowski Maciej, Buczyński Przemysław, Mušuta Juraj

Structure and Environment

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2023

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Vol. 15, no. 4

185--195

EN

The paper aims to present the basic properties of cold mixes in terms of the type of binding agent. In the theoretical part of the article, a description of the technology for producing cold recycled mixtures and the types of road binders used in cold mixtures was presented. The research part presents the experimental design, and gives an overview of the research methodology used to assess the impact of the type of binding agent. Mixes differing in type and binder content were designed. During the laboratory work, mixtures were prepared with cement binder (CBGM), cement-modified polymer binder (CBGM+P), mineral-cement-emulsion modified with polymer binder (BE-RCM+P), and mineral-cement mixtures with foamed bitumen modified with polymer binder (FB-RCM+P). The project aimed to produce cold mixtures with variations in the type and amount of binder used. The mixtures were prepared using cold mix technology. The effect of the binder on the cold mix properties was studied. During the research, the following properties were examined: void content (Vm), indirect tensile strength (ITS), resistance to water damage (TSR), stiffness modulus using the IT-CY method and an axial compressive strength. On the basis of the research carried out, an analysis was made. Among other things, the polymer modification was found to have a positive effect on the void content of the mix. The research carried out in this way made it possible to show the influence of the binder on the properties of cold mixes.

PL

Praca miała na celu przedstawienie podstawowych właściwości mieszanek na zimno w aspekcie rodzaju środka wiążącego. W części teoretycznej artykułu przedstawiono opis technologii wykonywania mieszanek metodą recyklingu głębokiego na zimno oraz rodzaje spoiw drogowych wykorzystywanych w mieszankach na zimno. W części badawczej przedstawiono plan eksperymentu oraz przybliżono metodykę badawczą wykorzystaną w ocenie wpływu rodzaju środka wiążącego. Zaprojektowano mieszanki związane cementem (CBGM), mieszanki związane cementem modyfikowane polimerem (CBGM+P), mieszanki mineralno-cementowo-emulsyjne modyfikowane polimerem (MCE+P) oraz mieszanki mineralno-cementowe z asfaltem spienionym modyfikowane polimerem (MCAS+P). Projekt zakładał wykonanie mieszanek w technologii na zimno, zróżnicowanych pod względem rodzaju oraz ilości zastosowanego spoiw. W ramach badań sprawdzono zawartość wolnych przestrzeni Vm, wytrzymałość na rozciąganie pośrednie ITS, odporność na szkodliwe działanie wody TSR, moduł sztywności według metody IT-CY oraz przeprowadzono badanie wytrzymałości na ściskanie osiowe po 28 dniach pielęgnacji. Na podstawie wykonanych badań dokonano analizy. Tak przeprowadzone badania pozwoliły na ukazanie wpływu spoiwa na właściwości mieszanek na zimno.

20

Rice starch as a polymer sorbent of iron cations

Schmidt Beata, Zubala Adriana

Polimery

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2023

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Vol. 68, nr 9

473--479

EN

Native, gelatinized and cross-linked rice starch was used to prepare “green sorbents”. FTIR, XRD, SEM, DSC and TGA methods were used to evaluate the properties of the obtained materials. The influence of the type of starch, sorbent dose and contact time on the sorption efficiency was examined. The swelling properties, the degree of solution purification and the efficiency of Fe(III) ion removal were determined. The sorption properties of the materials strongly depended on the type of starch and the conditions of their use.

PL

Skrobię ryżową natywną, zżelowaną i usieciowaną użyto do otrzymywania „zielonych sorbentów”. Do oceny właściwości otrzymanych materiałów zastosowano metody FTIR, XRD, SEM, DSC i TGA. Zbadano wpływ rodzaju skrobi, dawki sorbentów i czasu kontaktu na efektywność sorpcji. Oznaczono właściwości pęczniejące, stopień oczyszczania roztworu i skuteczność usuwania jonów Fe(III). Właściwości sorpcyjne materiałów silnie zależały od rodzaju skrobi i warunków ich stosowania.