Wyniki wyszukiwania - BazTech

1

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.

2

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.

3

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.

4

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.

5

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.

6

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.

7

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.

8

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.

9

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.

10

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.

11

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.

12

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.

13

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.

14

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.

15

Analiza numeryczna belek ze zmodyfikowanymi połączeniami doczołowymi

Palacz Przemysław, Major Maciej

Materiały Budowlane

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2023

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nr 12

13--19

PL

Skręcane połączenia doczołowe są nieodzownym elementem każdej konstrukcji stalowej. Umożliwiają szybki i łatwy montaż elementów konstrukcji na budowie. W połączeniach doczołowych mogą wystąpić nierówności podczas spawania blachy czołowej do belki, co może uniemożliwić prawidłowe sprężenie śrub, a w efekcie doprowadzić do nierównomiernego rozkładu w nich sił. Artykuł obejmuje analizę zmodyfikowanych skręcanych połączeń doczołowych stalowych belek dwuteowych z dwuczęściowymi blachami czołowymi w porównaniu z powszechnie stosowanymi połączeniami doczołowymi z pełnymi blachami czołowymi. Przeprowadzono obliczenia analityczne oraz analizę numeryczną belek z połączeniami w przypadku dwóch schematów zamocowania belki: swobodnie podpartej oraz wspornikowej. Badanymi parametrami były: rozkład naprężeń w połączeniach, maksymalne ugięcie belek oraz sztywność obrotowa połączeń. Wyniki wykazały, że zaproponowane zmodyfikowane połączenia doczołowe charakteryzują się dużą efektywnością przenoszenia obciążeń oraz większą sztywnością obrotową w porównaniu ze standardowymi rozwiązaniami połączeń doczołowych.

EN

Bolted end-plate joints are an indispensable element of any steel structure. They enable quick and easy assembly of structural elements on the construction site. In end-plate joints irregularities may occur during the welding of the end plate to the beam, which may prevent proper prestressing of the bolts and, as a result, may lead to uneven distribution of forces in the bolts. The article includes an analysis of modified bolted end-plate joints with two-part end-plates in comparison to commonly used full end-plate end-plate joints. An analytical and numerical analysis of beams with connections was carried out for two beam attachment schemes: simply supported and cantilevered. The parameters tested were stress distribution in the connections, maximum beam deflections and rotational stiffness of the connections. The results have shown that the proposed modified end-plate joints are characterized by high load transfer efficiency and greater rotational stiffness compared to standard end-plate joint solutions.

16

Copy raising reconsidered

Melnik Nurit

Journal of Language Modelling

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2023

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Vol. 11, No. 2

297--341

EN

There is no consensus in the literature regarding the defining characteristics of copy raising (CR), or in other words what determines whether a CR-like expression is CR or not. As a result, existing analyses target different data sets. In this paper, I propose a different approach to these constructions, which takes a functional perspective. I propose to abandon the term copy raising, which is misleading in a number of ways. Instead, I distinguish between perceptual depiction reports and perceptual inference reports and show that the functions which they fulfill are not particular to CR-like constructions, but are in fact more general. Such an approach, I claim, resolves existing conundrums surrounding CR. The analysis is formalized in the framework of Head-driven Phrase Structure Grammar (HPSG) and is inspired by previous accounts of CR in related frameworks such as LFG and SBCG, as well as HPSG analyses. In the spirit of HPSG, the analysis employs type inheritance hierarchies to distinguish between what is shared by the two constructions and what is construction-specific in order to account for alternative realizations of a single lexeme and to ascribe constructional (or extra-lexical) meaning to linguistic elements.

17

Mechanochemically Activated Shungite as an Additive to Improve Bitumen Characteristics

Zhambolova Ainur, Ongarbayev Yerdos, Kenzhegaliyeva Aliya, Abdikhan Dinmukhamed

Journal of Ecological Engineering

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2023

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Vol. 24, nr 11

218--226

EN

One of the urgent problems of improving the quality of road surfaces is to improve the properties of bitumen used as binders. For this purpose, various modifiers are used, which are mainly obtained synthetically. Modification of bitumen with natural raw materials is favorable from an economic and environmental points of view. The modification of road oil bitumen with samples of shungite from the Koksu deposit (Kazakhstan) was carried out in the work. The shungite samples were previously crushed by mechanochemical activation to improve their surface and adhesive properties. As a result of modification with shungite, an increase in the softening temperature and a decrease in the extensibility and penetration of bitumen were observed. The optimal amount of added shungite turned out to be 1 mass %. The shungite of carbonate origin on a mineral basis is more favorable as a modifier compared to samples of shale origin.

18

Statistical methods in the analysis of strength parameters of epoxy-glass composites modified with rubber recyclate

Drewing S., Abramczyk N., Żuk D., Dyl T.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 117, nr 2

71--78

EN

Purpose: The article presents a statistical analysis of strength parameters of newly developed epoxy-glass composite materials modified with the addition of rubber recyclate. Design/methodology/approach: Three variants of materials with a percentage of recyclate content in the composite matrix of 3%, 5%, 7% and a reference variant without the addition of recyclate were used for the study. The samples were subjected to an impact test on a ZWICK RKP 450IR-GE impact hammer. Resilience measurement values were subjected to statistical analyses at the significance level α = 95%, such as: testing the normality of distributions with the Shapiro-Wilk test, testing differences between pairs with the Student's t-test for dependent groups, and testing ANOVA differences for independent groups. Findings: The Shapiro-Wilk test confirmed that the resilience variables for all tested samples were in normal distributions; therefore the highest power parametric tests were used to test the differences. Using the Student's t-test, it was confirmed that between pairs of variables in configurations: standard sample with the modified sample, there were significant statistical differences in the distribution of resilience values for all samples. ANOVA confirmed significant changes in impact strength in 10 comparison variants. Research limitations/implications: The obtained test results showed that in 9 compared cases, there were significant statistical differences, and in one case, there were no significant differences. Practical implications: The performed statistical analyses confirmed their significant usefulness in the process of qualification of strength parameters for materials with high anisotropy, such as composites. Originality/value: The manufactured products are innovative in terms of the method of using the addition of rubber recyclate as a filler for epoxy-glass composites. The use of static methods for their study also has practical value. It optimizes the analysis methods of the results of measurements of strength parameters of new composite materials.

19

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.

20

The Melting Process and its Impact on the Properties of High-Chromium Cast Iron and the Economic Calculation

Mędoń Jan, Szczęsny Andrzej, Ziółkowski Eugeniusz, Guzik Edward, Czarny M., Kopyciński Dariusz

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 4

54--64

EN

The subject of this study is to show that the parameters of the melting process of high chromium cast iron affect the cost of casting and the properties of the cast iron. The analysis of the quality of the casting and its price was conducted in terms of the metal charge of high chromium cast iron. As is well known, in order to obtain the correct structure of the casting, and thus good strength properties, it is necessary to use clean batch components free of undesirable impurities. Unfortunately, the quality of the metal charge is proportional to its price. Thus, the use of expensive batch components offers the possibility of obtaining healthy and meeting the strength properties of castings. However, there is a flaw in this approach. And it is from the point of view of economics that production plants are forced to look for savings. Expensive feedstock materials are replaced by cheaper counterparts giving the possibility of obtaining castings with similar properties often, however, at the cost of increased inferior quality. It seems that a way out of this situation is to introduce a modification procedure into the alloyed iron manufacturing technology. The selected modifiers should affect the fragmentation of the structure of the primary austenite. At this point, it can be hypothesized that this will result in the elimination of hot cracking in high chromium cast iron. The industrial research carried out at the "Swidnica" Foundry Ltd. made it possible to show by means of the Althoff-Radtke method that by using the modification of the liquid metal of the so-called "inferior and cheaper" composition of the metal charge, a reduction in the occurrence of hot cracks and shrinkage cavities can be achieved. In addition, iron-niobium modification not only reduced the formation of casting defects in castings, but also slightly improved the impact strength of high-chromium cast iron. The work was written as part of an implementation PhD.