Wyniki wyszukiwania - BazTech

1

Tests of strengthened and unstrengthened masonry arches subjected to horizontal forces on supports

Biernacki Jan, Drobiec Łukasz

Materiały Budowlane

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2025

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nr 8

11--17

EN

The article discusses the influence of horizontal compressive and tensile forces on arched masonry structures, especially in the context of terrain deformations caused by mining activities. The results of laboratory tests on models of masonry rib reinforced with FRCM technology and prefabricated reinforced concrete reinforcement are presented. The analyses showed a significant increase in the load‑bearing capacity of the reinforced elements and a delay in the moment of damage occurrence. The results indicate the effectiveness of modern reinforcement methods in protecting historic structures.

PL

W artykule omówiono wpływ poziomych sił ściskających i rozciągających na murowane konstrukcje łukowe, przede wszystkim w kontekście deformacji terenu wywołanych działalnością górniczą. Przedstawiono wyniki badań laboratoryjnych przeprowadzonych na modelach fragmentów żeber wzmacnianych w technologii FRCM oraz prefabrykowanym wzmocnieniem żelbetowym. Analizy wykazały istotne zwiększenie nośności wzmocnionych elementów oraz opóźnienie momentu powstania uszkodzeń. Wyniki wskazują na skuteczność nowoczesnych metod wzmacniania w ochronie konstrukcji zabytkowych.

2

Patterns of acoustic emission changes with alterations in the damage area of a composite material according to the mises criterion

Filonenko Sergii, Stakhova Anzhelika

Journal of Automation Mobile Robotics and Intelligent Systems

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2025

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Vol. 19, No. 2

50--58

EN

This paper considers the use of a highly sensitive acoustic emission method for studying the deformation and failure processes of composite materials. This providesa substantial amount of information about phenomena occurring at the sub-micro, micro, and macro levels. However, the additional influence of various factors leads to the problem of interpreting and identifying the information yielded by this process. Addressing this problem involves determining the influence of different factors on acoustic emission-signal parameters and their sensitivity to the influencing factors. In this study, during the failure of composite material under transverse force according to the Mises criterion, an analysis is conducted on the impact of changes in the number of composite material elements (damage area) on the amplitude-time parameters of the acoustic emission signal based on a devel- oped signal model. The results of the simulation allow for the identification and description of patterns in the changes of amplitude-time parameters of acoustic emission signals (maximum amplitude, area under the signal curve, and signal duration), with variations in the number of composite material elements. These patterns enable the determination of the sensitivity of acoustic emission signal parameters to the influencing factor. The findings of this study may be of interest in the development of methods for monitoring, diagnosing, and predicting the failure of composite materials and products through the registration and analysis of acoustic emission signals.

3

Application of AI and machine learning to the theory of composite materials

Mityushev V. V., Nurtazina K. B., Nauryzbayev N. Zh.

Composites Theory and Practice

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2025

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R. 25, nr 1

11--20

EN

The homogenization for classifying composites and determining their effective properties is an important optimal design problem of material sciences studied by mathematical modeling. The application of artificial intelligence (AI) and machine learning (ML) in the theory of composite materials is discussed. One of the main problems is the choice of characteristic ML features to describe multi-scale dispersed random composites and to predict their macroscopic properties. The complexity drastically increases when confronted with tasks such as estimating the effective properties of random composites, exploring optimal design scenarios with variable properties of components, or determining the optimal location and shape of inclusions since the myriad use of numerical computations proves challenging due to constraints in time and memory. In such instances, analytical, exact, or approximate formulas with the optimized parameters in symbolic form are preferred because powerful calculus methods can be applied to select the optimal parameters. The present paper is devoted to adequately choosing the parameters called structural sums, and corresponding analytical formulas. Such a formula is often asymptotic, and its correctly determined asymptotic precision shows its application area. We consider the question of the RVE size equivalent to the number of inclusions N per periodicity cell. It can be investigated numerically by solving a periodicity problem with N increasing up to stable effective constants not depending on N . Though one can find works in literature following these lines, they concern special distributions of inclusions with the numerical results performed for small N and for a small number of statistically investigated samples. A comprehensive study of 2D two-phase composites with equal circular inclusions is developed. It is demonstrated that using the concentration of inclusions and a contrast parameter is insufficient to properly study dispersed composites. The method of structural sums in combination with ML to improve model accuracy is applied. Based on the study, a new approach is suggested for selecting optimal parameters to analyze and classify two-dimensional dispersed composite structures. The included content fits 2020 Mathematics Subject Classification: 74Q15, 74-10.

4

Material Inclusions and fiber orientation affect the aeroelastic stability of a composite wing

Abed Balsam H., Sowoud Khalid M., Hussein Emad Q.

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 12

361--369

EN

This study investigates the effects of fiber orientation and inclusion materials ( ), silica, and rubber) on the aeroelastic properties of a composite wing structure, including natural frequency, flutter speed, and damping ratio. A MATLAB-based model was created to analyze the dynamic responses, and the results were confirmed with ANSYS simulations. It was found that fiber orientation significantly influences structural dynamics, with zero fiber providing the highest natural frequency and flutter resistance; increasing the fiber angle reduces both. Adding raised flutter speed by 10.8%, while rubber doubled the damping ratio compared to the pure composite at a 90° fiber orientation. Silica improved both damping and stiffness characteristics in a balanced way. These results are important for optimizing composite wing designs to improve aeroelastic performance across different flight conditions.

5

A review of the state-of-the-art in improving piezoelectric properties

Al-Obiedy Ali N., Al-helli Ali H.

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 6

41--69

EN

This review will present a collection of previous research studies in the field of enhanced piezoelectric properties. At first, an introduction will be provided about the field of energy, methods of harvesting energy, the field of employing piezoelectricity, and also the concept of piezoelectricity to convert mechanical energy into electrical energy when used as a sensor. It can be employed as an actuator that can convert electrical energy into mechanical energy. This paper will provide an overview of techniques for enhancing the characteristics of piezoelectric materials. There are many of these methods, such as composite and hybrid materials, partial size, shape, and dimension, compressibility, lamination, 3D printed piezoelectric, coating, functional grid materials, hybrid systems, and more. For each method, different materials were used to prepare the piezoelectric. These materials can be broken down into several groups, such as smart materials that have piezoelectric effects, shape memory effects, and pyroelectric effects; reinforcement materials as Multi-Walled Carbon Nanotubes (MWCNT), CFRP (Carbon Fiber-Reinforced Polymer), or GFRP (Glass Fiber-Reinforced Polymer); matrix materials as UV-curable resin, and Polydimethylsiloxane (PDMS); materials that help with the distribution process as N,N-dimethylformamide (DMF); and electrode materials as copper, platinum, and graphene. Additionally, the size of the added materials was defined, as most are nanomaterials. We will display the hybrid system, which is multifunctional. It is considered an important aspect of future development. In this part, different effects are combined into one application. For example, the smart scaffold combines the piezoelectric and shape memory effects. The real benefit of the research is to make the material's properties work better in general, and piezoelectricity works better in particular. These improvements can be done by studying each method on its own and then trying to combine some improvement methods in future research to make piezoelectricity work better and make it useful in more situations.

6

Lifetime determination of ultralight helicopter blades

Dudnik Vitaly

Transport Problems

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2024

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T. 19, z. 3

81--92

EN

Determining the guaranteed operational time of helicopter blades is one of the important tasks necessary for successful vehicle use. Flight tests on different modes and special fatigue benches are used to solve such problems. The loads recorded during the flight are applied to ground tests on a bench. The ground fatigue tests of the ultralight helicopter blades have features associated with the influence of the scale factor comparison with the big helicopters. These features are presented in this article as the example of a ground test for a VA115 helicopter blade and a method of recalculating data. The purpose of these tests was to confirm the guaranteed service life of blades and define a reliable method for it.

7

The advantage of composite materials used in downhole cutting tools

Mustafayev Amir G., Nasirov Chingiz R.

Nafta-Gaz

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2024

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R. 80, nr 1

19--29

EN

One of the important reserves for the growth of oil and gas production is the acceleration of emergency recovery work in production and exploration wells at minimal cost. A significant amount of work in downhole conditions is performed using downhole destructive and cutting tools. Each oil and gas producing country annually uses more than 100 standard sizes, thousands of cutting tool sets: downhole, annular, combined, pilot, internal and external pipe cutters, as well as reamers for cutting side “windows” in production strings. Therefore, the need for them is growing significantly every year. The conducted experiments show that during the operation of cutting tools, the working abrasive-cutting part of the tool wears out and collapses, but the body, other elements and the connecting thread remain suitable for further operation. Therefore, the restoration of working bodies, consisting of crushed particles of used borehole cutting tools, is an urgent scientific and technical task for the oil and gas industry. When repairing oil and gas wells, as well as eliminating the most complex accidents, more than a hundred standard sizes of downhole cutting and destructive tools are used. Currently, an acute shortage of this equipment in oilfield facilities makes it necessary to reconsider the technologies for restoring downhole cutting and destructive tools and introduce them into production. The conducted studies show that there is not enough information about the thickness and height of the layers of the material applied to the damaged area of the cutting and destructive tool, as well as the information necessary for the optimal mode of its operation and its effectiveness after restoration. Composite materials are widely used in the preparation of cutting-chopping and destructive elements of oil-field tools and equipment used in the drilling, operation and repair of wells. In order to increase the cutting capacity of the cutting part of the tool, it is necessary to investigate the advantages of tungsten-carbide (TC) type composite materials compared to other materials and ensure their resistance to high temperatures. As a result of theoretical studies, the stress-deformation state of the contact areas of the composite elements, where the working areas of the cutting and destructive tools are reinforced, and the dependence of the productivity of the composite materials on the speed of transition to metal and the sizes of the composite grains were determined by using the finite element method (two-dimensional simplex elements).

PL

Jedną z ważnych kwestii wpływających na wzrost wydobycia ropy naftowej i gazu ziemnego jest przyspieszenie awaryjnych prac naprawczych w odwiertach eksploatacyjnych przy minimalnych kosztach. Znacząca ilość pracy w warunkach wgłębnych w otworach wykonywana jest z zastosowaniem otworowych narzędzi niszczących i skrawających. Każdy kraj produkujący ropę i gaz rocznie stosuje ponad sto standardowych rozmiarów zestawów tysięcy narzędzi skrawających: otworowych, pierścieniowych, łączonych, pilotażowych, wewnętrznych i zewnętrznych przecinaków do rur, jak również rozwiertaki do wycinania „okien” bocznych w rurach eksploatacyjnych. Tym samym każdego roku zapotrzebowanie na te narzędzia znacząco wzrasta. Przeprowadzone doświadczenia pokazują, że podczas pracy narzędzi skrawających część robocza ścierająco-tnąca narzędzia zużywa sie i zapada, lecz korpus, inne elementy i gwint łączący pozostają odpowiednie do dalszej pracy. Tym samym, odbudowa korpusów roboczych, składających się ze zmiażdżonych cząstek zużytych otworowych narzędzi skrawających, jest pilnym zadaniem badawczym i technicznym dla przemysłu ropno-gazowego. Podczas naprawy odwiertów ropnych i gazowych oraz likwidacji najbardziej skomplikowanych awarii stosuje się ponad sto standardowych rozmiarów otworowych narzędzi skrawających i niszczących. Obecnie poważny niedobór tego sprzętu na złożach ropy naftowej wymusza konieczność ponownego rozważenia technologii dla naprawy otworowych narzędzi skrawających i niszczących oraz wprowadzania ich do produkcji. Przeprowadzone badania pokazują, że brak jest wystarczających informacji o grubości i wysokości warstw materiału nakładanych na uszkodzoną powierzchnię narzędzia skrawającego i niszczącego, oraz informacji koniecznych dla optymalnego trybu jego pracy i jej skuteczności po renowacji. Materiały kompozytowe są szeroko stosowane w przygotowywaniu elementów tnąco-skrawających i niszczących dla narzędzi naftowych i sprzętu stosowanego przy wierceniu, pracy i naprawie odwiertów. W celu zwiększenia wydajności cięcia części tnącej narzędzia konieczne jest zbadanie zalet materiałów kompozytowych typu węglik wolframu (TC) w porównaniu z innymi materiałami, oraz zapewnienie ich odporności na wysokie temperatury. W wyniku badań teoretycznych określono stan naprężeniowo-odkształceniowy obszarów styku elementów kompozytowych, w których wzmocnione są obszary robocze narzędzi skrawających i niszczących oraz zależność wydajności materiałów kompozytowych od prędkości przejścia w metal i rozmiarów ziaren kompozytowych metodą elementów skończonych (dwuwymiarowe elementy sympleksowe).

8

Wood-based composite materials in the aspect of structural new generation materials. Recognition research

Czajkowska Anna, Rydzkowski Tomasz, Laskowska Dorota

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 1

art. no. e146618

EN

Composite materials are a constantly evolving group of engineering materials, which has significantly changed their current, and potential role as structural materials over the past decades. Composites offer greater strength, stiffness, and less deformation to structural designers than previously available engineering materials. Resin matrix composites are widely used in the transportation, marine, aerospace, energy, and even sports industries. The manufacturing stage has a profound influence on the quality of the final product. This paper presents the production of composite materials by gravity casting in silicone moulds, using an epoxy/polyester resin matrix reinforced with wood chips and shredded glass fiber reinforced composite from recycled wind turbine blades. Some of the fabricated samples were degassed in a reduced-pressure chamber. The mechanical properties of the produced material were then examined. It was noted that the silicone moulds did not affect the resin self-degassing due to the large surface area to weight ratio, and the remaining small air bubbles had a limited effect on the mechanical properties of the samples. The filler used also played a significant role. Composites filled with crushed GFRC showed better strength properties than composites filled with wood chips. The conducted research is aimed at selecting materials for further testing with a view to their use in the manufacture of next-generation wood-based composite structural materials.

9

Fibreglass Reinforcement Influence on the Mechanical Behaviour of an ABS - PMMA - Fibreglass Composite Material

Platon Mihai Andrei, Nemes Ovidiu

Archives of Metallurgy and Materials

|

2024

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Vol. 69, iss. 4

1637--1642

EN

This study’s aim is to provide detailed information on how to control the mechanical behaviour of a short fibre unoriented composite material and adapt it for various applications. This study focusses on the challenging problem of recycling fibreglass waste mixed with thermoplastic polymers. The used method was thermoforming; preliminary studies have indicated this method as the most suitable for closing the loop in a manufacturing process - under the principles of a circular economy. Although this method is sustainable for this type of mixed waste, the research process is at an early stage and further studies and characterisations are required. From the data collected so far, this recycling method is the most efficient, both energetically and considering the added value of the final product. The results are encouraging and indicate a predictable behaviour of the studied reinforced composite material.

10

Fabrication of Silver-Impregnated Silica Aerogel Composite for Energy Applications

Kapadnis Pratik S., Kim Kyungsun, Park Hyung-Ho, Hwang Haejin

Archives of Metallurgy and Materials

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2024

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Vol. 69, iss. 1

77--80

EN

In this study, Ag-impregnated silica aerogel composites were fabricated via wet impregnation. In this approach, silver salt was reduced with ethylene glycol in the presence of polyvinylpyrrolidone (PVP) at reaction temperature 80°C. PVP was used as a capping agent to protect the Ag nanoparticles (NPs) from agglomeration. Wet impregnation was used to synthesize the Ag/SiO2 composite by combining the reduction of AgNO3 with a silica aerogel slurry. Experimental results showed that the AgNO3 concentration and PVP: AgNO3 ratio had an active influence on the growth of Ag NPs on silica surfaces. The X-ray diffraction (XRD) patterns of the composite material showed no imprints of impurities or parasitic materials except for Ag and SiO2. Scanning electron microscopy (SEM) images revealed that the Ag NPs were well impregnated into the porous silica aerogel structure. It was found that SiO2 aerogel surfaces were homogeneously surrounded by the Ag NPs.

11

Thermal stresses in a multi-layered spherical tank with a slowly graded structure

Kulchytsky-Zhyhailo Roman

Acta Mechanica et Automatica

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2024

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Vol. 18, no. 2

274--281

EN

The central-symmetrical problem of thermoelasticity for a multi-layered spherical tank is considered. The thermal stresses were caused by a temperature difference between the inner and outer surfaces of the tank. Two approaches to solving this problem have been proposed. In the first approach, the boundary problem defined in the components of a considered inhomogeneous spherical tank was solved. In the second approach, the homogenization method with microlocal parameters was used. Good agreement between the solutions was obtained.

12

Tribological properties of materials designed for contact wire / current collector slider contacts

Posmyk Andrzej, Myalski Jerzy

Tribologia

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2023

|

nr 4

53--58

EN

The article describes basics of production as well as a structure and tribological properties of a composite with a B101 bronze matrix and glassy carbon acting as a solid lubricant. The composite is intended for use as a sliding cover of a current collector in a rail transport. It is intended to replace the previously used carbon-copper composites, which have insufficient mechanical properties for high-speed rail. The results of comparative tribological tests of the matrix and composite material in contact with a traction copper (Cu-ETP) confirmed lower wear of the composite than that of the matrix under friction in air, without current load. The addition of 10% of a large-cell glassy carbon foam (90% porosity) reduced the wear of the contact (by 28% and 10%) but did not significantly reduce (by 8.4–5.8%) the friction forces. In the tested contacts abrasive and adhesive wear, caused by the presence of copper, dominated. Self-mated materials tend to develop adhesive bonds. Therefore, the next stage of the research optimising a composite production process, e.g. by using a glassy carbon foam with smaller elementary structure or glassy carbon microparticles will be used.

PL

W artykule opisano podstawy wytwarzania, budowę i właściwości tribologiczne kompozytu z osnową z brązu B101 i węglem szklistym pełniący rolę smaru stałego. Kompozyt jest przewidziany do zastosowania jako nakładka ślizgowa odbieraka prądowego w transporcie szynowym. Ma on zastąpić stosowane dotychczas kompozyty węglowo miedziane, które mają niewystarczające właściwości mechaniczne dla kolei wysokich prędkości. Wyniki porównawczych badań tribologicznych materiału osnowy i kompozytu we współpracy z miedzią trakcyjną (Cu-ETP) potwierdziły mniejsze zużycie kompozytu niż osnowy w warunkach tarcia technicznie suchego, bez obciążenia prądowego. Dodanie 10% wielkokomórkowej pianki (porowatość 90%) z węgla szklistego zmniejszyło zużycie skojarzenia (o 28% i 10%), ale nie zmniejszyło znacząco (o 8.4–5.8%) sił tarcia. W badanych skojarzeniach dominowały zużywanie ścierne i adhezyjne spowodowane obecnością miedzi. Materiały jednoimienne mają skłonność do sczepień adhezyjnych. Dlatego w następnym etapie badań zostanie wykorzystana optymalizacja procesu wytwarzania kompozytu, np. przez zastosowanie pianki z węgla szklistego o mniejszych wymiarach elementarnej komórki struktury oraz mikrocząstek węgla szklistego.

13

Wybrane właściwości gruntowych materiałów kompozytowych jako materiału konstrukcyjnego do budowy niskich nasypów obwałowań przeciwpowodziowych

Brzeziński Bartłomiej, Olchawa Andrzej, Wierzbicka Marianna

Materiały Budowlane

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2023

|

nr 6

32--36

PL

W artykule przedstawiono wyniki badań laboratoryjnych właściwości fizycznych i mechanicznych (zagęszczalności, ściśliwości, przewodności hydraulicznej oraz wytrzymałości na ścinanie) gruntowych materiałów kompozytowych stanowiących mieszaninę torfu, popiołu lotnego i wapna hydratyzowanego. W świetle uzyskanych wyników, parametry geotechniczne wszystkich kompozytów są porównywalne, co stanowi, że o przydatności materiału może decydować kryterium roboczego przedziału wilgotności.

EN

The paper presents the results of laboratory tests of physical and mechanical properties (compaction, compressibility, hydraulic conductivity, and shear strength) of ground composite materials made of peat, fly ash and hydrated lime. The results showed that the geotechnical parameters of the all composites are comparable. Given to these properties it may be accepted that range of working moisture is most usefulness parameter to assessment of composite as an embankment construction material.

14

Adaptacja historycznych konstrukcji do nowych wymagań eksploatacyjnych na przykładzie klatki schodowej z początku XX wieku

Bajno Dariusz

Materiały Budowlane

|

2023

|

nr 9

29--32

PL

W artykule opisano przypadek badawczy i aplikacyjny, pozwalający na akceptowalny zakres ingerencji oraz zastosowaną technologię wzmocnienia z użyciem nowoczesnych materiałów w celu zachowania wartości historycznej obiektu. Pojedyncze wdrożenie nowych rozwiązań pozwoli na ocenę skuteczności i przydatności takich metod w ratowaniu unikatowych konstrukcji obiektów historycznych i zabytkowych. Inspiracją do takiego podejścia było docelowe wprowadzenie bezinwazyjnej techniki wzmacniającej, która nie zmieniła cennego i autentycznego wyglądu historycznych konstrukcji, zapewniając jednocześnie im odpowiednią nośność, ponieważ stosowane pierwotnie materiały budowlane nie znajdują swoich odpowiedników w aktualnych przepisach i normach. Przedmiotem artykułu jest żelbetowa klatka schodowa, wykonana w 1910 r., stanowiąca komunikację pionową szpitala, która powinna zostać dostosowana do współczesnych wymagań użytkowych i bezpieczeństwa.

EN

The article describes both, research and application case, allowing for an acceptable range of interference and the strengthening technique in order to preserve the historical value of the object, using the modern materials. Such a single implementation of new solutions will make it possible to assess the effectiveness and usefulness of such methods, saving unique structures of historical and historic buildings. The inspiration for this approach was the targeted introduction of a non-invasive reinforcing technique that will not change the valuable and authentic appearance of historical structures, while providing them with adequate load-bearing capacity, because the originally used building materials do not find their equivalent in current regulations and standards. The subject of the article is a reinforced concrete staircase, made in 1910 that has been used for the vertical communication of the hospital, which should have been adapted to modern safety requirements.

15

Preparation and characterization of BiOCl/TiO2/MMT composite materials

Tuo Biyang, Shi Xiulong, Tian Jinwang, Wang Jianli

Materials Science Poland

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2023

|

Vol. 41, No. 2

354--367

EN

To broaden the light response range of TiO2 and improve its photocatalytic activity, BiOCl/ TiO2 /MMT composite materials (BTMC) with outstanding photocatalytic performance were prepared by the sol-gel method with montmorillonite (MMT) as the supporting material, tetrabutyl titanate as titanium source and, bismuth nitrate pentahydrate as the bismuth source. The properties of the prepared materials were characterized by X-ray diffractometer (XRD), surface and porosity analysis (BET), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), X-ray photoelectron spectrometry (XPS), and ultraviolet-visible diffuse reflection spectroscopy (UV-Vis DRS). When the Bi/Ti molar ratio was 20%, the composite material exhibited a slit mesoporous structure, and its specific surface area was 109.02 m2/g, with optimum photocatalytic activity. TiO2 and BiOCl formed the type-II heterojunction on the surface of MMT, which facilitates the transfer of photogenerated electrons and holes, thus enhancing the photocatalytic activity of BTMC-20. The results of this study indicated that BTMC-20 is a promising photocatalytic composite material and has better photocatalytic properties under visible light.

16

Influence of surface-modified nanoclay on the flexural strength of unsaturated polyester resin

Stępka Dominik

Inżynieria Materiałowa

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2023

|

Vol. 44, nr 5

5--10

EN

This study delves into the influence of surface-modified nanoclay on the flexural strength of Unsaturated Polyester Resins (UPRs). UPRs, known for their robust mechanical properties, find extensive applications across various industries. With the aim of further enhancing these properties, nanofillers, specifically surface-modified nanoclay, were incorporated into the resin matrix. Our research revealed a significant improvement in flexural strength with an optimal nanoclay addition of 0.1% by weight. However, the morphological analysis identified the presence of nanoclay agglomerates, indicating potential areas for optimization in the dispersion process. The findings present a promising direction for developing advanced UPR-based materials, emphasizing the pivotal role of nanofillers in achieving superior mechanical performance.

PL

Analizowano wpływ nanoglinki o modyfikowanej powierzchni na wytrzymałość na zginanie nienasyconych żywic poliestrowych (UPR). UPR, znane ze swoich solidnych właściwości mechanicznych, znajdują szerokie zastosowanie w różnych gałęziach przemysłu. W celu dalszej poprawy tych właściwości do matrycy żywicznej wprowadzono nanonapełniacz, a dokładnie nanoglinkę z modyfikowaną powierzchnią. Badania wykazały znaczną poprawę wytrzymałości na zginanie przy optymalnym dodatku nanoglinki w ilości 0,1% mas. Analiza morfologiczna wykazała obecność aglomeratów nanoglinki, wskazując potencjalne obszary optymalizacji w procesie dyspersji. Odkrycia wyznaczają obiecujący kierunek rozwoju zaawansowanych materiałów na bazie UPR, podkreślając kluczową rolę nanonapełniaczy w osiąganiu doskonałych parametrów mechanicznych.

17

Adsorption of Phenol Using Hydrochar Modified Layered Double Hydroxide – Kinetic, Isotherm, and Regeneration Studies

Palapa Neza Rahayu, Ahmad Nur, Utami Hasja Paluta, Zahara Zaqiya Artha, Mohadi Risfidian, Lesbani Aldes

Ecological Engineering & Environmental Technology

|

2023

|

Vol. 24, iss. 5

275--281

EN

In this work, hydrochar using to modified nickel aluminum layered double hydroxide (hydrochar@NiAl LDH). The collected data by XRD indicate that 2θ of material at 11.38°, 22.90°, 35.20°, and 61.60°. The FTIR spectrum of hydrochar@NiAl LDH at wavenumber 3448, 1650, 1500–1600, 1348, 1056, and 500–800 cm-1. NiAl LDH and hydrochar have surface areas of 3.288 m2/g and 7.366 m2/g, respectively. The precursors enhance the composite’s surface area by 11.879 m2/g. NiAl LDH, hydrochar, and hydrochar@NiAl LDH have optimal pH values of 3, 6, and 6 respectively. The adsorption process is determined by the kinetic model of pseudo-second order and the model of Freundlich isotherm. NiAl LDH, hydrochar, and hydrochar@NiAl LDH had respective maximum adsorption capacities of 25.445, 21.008, and 25.773 mg/g. The increase in regeneration cycles decreases the percentage of adsorbed.

18

Selected energy aspects of GFRP drilling

Polasik Robert

Developments in Mechanical Engineering

|

2023

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nr 19(11)

15--22

EN

Original research results of GFRP drilling, using HSS steel drill bit, process energy indicators were presented in the article. The research stand was a 5-axis DMU50 machining center, equipped with a Kistler force gauge with a signal amplifier and a DAQ data acquisition system. The obtained measurement data were processed using the force gauge manufacturer's software, a spreadsheet and the Statistica statistical data analysis package. As a result of the analysis, on the basis of technological parameters and measured and determined values of cutting force and torque, changes in the values of selected process status indicators were determined; total and specific energy (per unit of material volume removed) generated when making individual holes as a function of the number of holes made. Moreover, the empirical value of the specific cutting resistance kc was determined. As a result of the experimental work carried out and the analysis of available literature in the scope of the article, conclusions were formulated regarding the energy indicators of the process - total and specific energy generated during processing, as well as possible causes of thermal damage to the processed material were indicated.

19

A review of the seismic performance behaviour of hybrid precast beam-to-column connections

Ghayeb Haider Hamad, Sulong N. H. Ramli, Razak Hashim Abdul, Mo Kim Hung, Ismail Zubaidah, Hashim Huzaifa, Gordan Meisam

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e35, 2023

EN

In order to withstand challenges such as earthquakes, it is important to appropriately design the beam-to-column connection of precast structures. Numerous precast connections were designed to be used worldwide to attain satisfactory seismic performance. The failures observed for many beam-column connections were primarily due to the brittle behaviour of poor connection details between the precast concrete members. This review article examines past experimental studies which used hybrid precast connections comprised of three types: (1) dry and wet connections with steel sections (Type I), (2) composite concrete (Type II), and (3) composite concrete and steel sections (Type III). The seismic performance behaviour of these connection types was evaluated and compared with that of the monolithic connections. The analysis showed that both the dry semi-rigid and rigid connections Type I can be implemented in the seismic zones. In addition, most of the wet connections Type I, Type II, and Type III can simulate the behaviour of monolithic rigid connections. Therefore, the wet connections Type I, Type II, and Type III can withstand high seismic excitations. Overall, the performance of hybrid dry connection Type I can be improved by using strengthening technique methods in the connection to maintain the continuity of the PC beam. Moreover, the use of composite materials with and without the steel sections as connector elements in the connection (Type II and Type III) can be a feasible method to simulate the seismic performance of monolithic connections.

20

Effect of Volume Percentage of Reinforcement on the Microstructure and Mechanical Properties of an Al6061-T6/SiC Surface Composite Fabricated Through Friction Stir Processing

Ansari Abdul Jabbar, Anas Mohd

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no. 2

247--257

EN

In this research, aluminium metal matrix composites (AMMCs) have been manufactured through friction stir processing (FSP) by reinforcing nano-sized SiC particles in an Al6061-T6 alloy. The consequences of the volume percentage of reinforced SiC particles on mechanical properties and microstructural features were analyzed for the developed AMMCs. Microstructural evaluation of a cross-section of a friction stir processed (FSPed) sample has been conducted through Electron backscatter diffraction (EBSD) Energy dispersive spectroscopy (EDS) and a scanning electron microscope (SEM) technique. Microhardness tests were conducted athwart the cross section of FSPed specimen to obtain microhardness feature. A tensile test of FSPed samples has been conducted on a universal testing machine (UTM). Homogeneous distributions of SiC particles were found in the stir zone without any consolidation of particles. The size of the reinforcement particles was decreased slightly by increasing the volume fraction. It has been found that increasing the volume fraction of SiC particles, enhance the tensile strength and microhardness, but decreases the ductility of the aluminium. The maximum ultimate tensile strength (UTS) and microhardness were obtained as 390 MPa and 150.71 HV, respectively, at 12% volume percentage of reinforcement particles. UTS and microhardness of the FSPed Al/SiC have been improved by 38.29% and 59.48% respectively as compared to Al6061-T6. The brittle nature of the FSPed Al/SiC has increased due to a rise in the volume fraction of nanosized SiC particles, which causes a decrease in ductility.