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1

Effect of fibers orientation on the health monitoring of multi-layers composite material

Abdulaziz Falah Hassan, Abd-Ali Nabel Kadum, Al-Mayali Maasi Faisal

Diagnostyka

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2025

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Vol. 26, No. 1

art. no. 2025103

EN

The major goal of this research is to create a reliable model for predicting the mechanical properties of composite material with fatigue failure and to determine how changing the fiber orientation and the layer arrangement with regard to the applied loading direction affects the mechanical characteristics of the result components in order to establish the service life with health monitoring of these structures. A multilayer composite consisting of five layers which represent shell structure, with the middle layer reinforced by carbon fiber and the top and bottom layers reinforced by glassfiber random mate and unidirectional glassfiber. According to the tensile test results, the orientation (2 L- GF- (0°/90°)s) had the maximum tension load (13 kN) due to the asymmetrical arrangement of layers and identical distribution of the load within layers, whereas the orientation (2 L- GF-0°) had the lowest tension load (5.6 kN) compared with other fiber orientations. The compression strength of the orientation 4 (2 L- GF- (0°/90°)2) with (1.72 kN) and orientation 7 (2 L- (90°/ RGF)s with (1.7 kN) is greater than that of the other orientations. The specimen fails in the test at about (519318 cycles) with time (352 minute) for orientation number 3.

2

Compressive strength and fractographic analysis of tooth crown models made of a short glass fibre-reinforced composite material

Tarczydło Janusz, Ostapiuk Monika, Jurek Karolina, Tarczydło Bożena

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 9

516--522

EN

The objective of this study was to evaluate the compressive strength of a glass fibre reinforced (GFR) composite material used in restorative conservative dentistry. The following dental composites were used in the work: EverX Posterior (GC Europe) GFR composite and Filtek Z250 (3M ESPE) conventional composite for fabricating phantoms which imitated molar crowns. Compression tests were performed and an analysis is provided here for the fractures formed during the application of compressive forces. It was found that the short fibres, rather than the polymer matrix itself, were responsible for the load transfer. The voids visible after removal of the fibres and the cracks in the polymer matrix are indicative of a force required to cause a GFR composite failure that is higher than the force required to cause a conventional composite filling failure. The phantoms made of the GFR composite showed greater strength than polymer-filled phantoms, devoid of short glass fibres.

3

Subjective quality evaluation of 8- and 10-bit MP4-coded video sequences from Netflix

Falkowski-Gilski Przemysław, Uhl Tadeus, Divakarachari Parameshachari Bidere

Zeszyty Naukowe Politechniki Morskiej w Szczecinie

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2024

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nr 79 (151)

30--38

EN

Recently, many researchers have been intensively conducting quality of service (QoS), quality of experience (QoE), and user experience (UX) studies in the field of video analysis. This paper is intended to make a new, complementary contribution to this field. Currently, streaming platforms are key products in relation to delivering video content online. Most often, they include the MP4 video format, which is most widely utilized among audio-visual codecs. This study involves a group of 38 individuals, aged between 21–35 years old, in a laboratory consisting of 20 iMacs with 4K retina display. The presented signal sequences included content sourced from the Netflix Chimera repository, with 8- and 10-bit depth, available in different resolutions of 270p, 432p, 720p, and 1080p. Tests included a subjective quality evaluation in a 5-step mean opinion score (MOS) scale, focused on the UX aspect. According to the obtained results, content with the lowest and highest resolutions is optimal in 8-bit depth, while movies with intermediate resolutions are better in 10-bit depth. For 8-bit content, the main problem is pixelation, whereas, in the case of 10-bit samples, the main issue is color noise, particularly in the case of the lowest resolution. Many viewers indicated that 10-bit encoding offered lower quality. Moreover, 8-bit movies caused a lower quality of the gradient, presumably due to the smaller range of the available color. However, 8-bit movies in the same situation generate visible stripes on static images in the background, causing a lower quality of the gradient, which is probably due to the smaller range of available colors. The results of the performed experiments may be of particular interest to content creators and distributors, particularly network and cable operators, as well as wireless and wired providers. coding, compression, QoE (Quality of Experience), UX (User Experience), video content, Netflix.

4

Tworzenie wielowidokowych sekwencji dla wizji wszechogarniającej

Mieloch Dawid, Klóska Dominika, Dziembowski Adrian, Szydełko Błażej, Grzelka Adam, Stankowski Jakub

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2024

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nr 4

183--186

PL

Wielowidokowe sekwencje wizyjne są niezbędne do rozwoju technologii wykorzystywanych dla celów wizji wszechogarniającej. Szczególnie ważną częścią tych badań są prace nad nowymi normami kompresji. W tym artykule przedstawiono przegląd metod, których użycie w procesie tworzenia sekwencji ma korzystny wpływ na ich końcową jakość, co potwierdzają wyniki przeprowadzonych badań eksperymentalnych. Proces tworzenia wielowidokowej sekwencji został przedstawiony na przykładzie sekwencji Choreo, obecnie wykorzystywanej w pracach ISO/IEC MPEG Implicit Neural Visual Representation.

EN

Multiview sequences are essential to develop technologies utilized for immersive video purposes. Especially important part of this research involves work on the new compression standards. This article provides an overview of methods that positively influence the final result of the test sequence creation process, as confirmed by results of conducted experiments. The process of multiview sequence acquisition was presented using the example of the Choreo sequence which is now used in the work of ISO/IEC MPEG Implicit Neural Visual Representation.

5

Lustrzany kodek video bazujący na głębokiej sieci neuronowej

Kaczyński Maciej, Piotrowski Zbigniew

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2024

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nr 4

397--400

PL

Zagadnienie stabilnego przekazywania informacji, a zwłaszcza stabilnej transmisji informacji w formie video w warunkach braku stabilnej prędkości przesyłania danych dla specyficznych zastosowań jest kwestią istotną. Celem niniejszego artykułu jest przedstawienie efektywnej metody modyfikacji kodeka video zapewniającej zwiększenie jakości video dla wysokich wartości kompresji wprowadzanej przez kodek video poprzez jego modyfikacje z wykorzystaniem jego lustrzanego odbicia bazując na głębokiej sieci neuronowej.

EN

The issue of stable information transmission, and especially stable information transmission in the form of video in the absence of a stable data transmission speed for specific applications, is an important issue. The aim of this article is to present an effective method of modifying the video codec ensuring an increase in video quality for high values of compression introduced by the video codec by modifying it using its mirror image based on a deep neural network.

6

Thickener design for a copper concentrate using rheology, sedimentation and compression parameters

Quiero-Gelmi Aldo, Olcay-Barreda Rubén, Mamani-Apala Paola

Mining Science

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2024

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Vol. 31

103--118

EN

This study was carried out to evaluate the operation of the thickener at mine site, in addition to increasing the geometallurgical information of the mining process. It analyzes the results of the sizing of a thickener that treats copper concentrate ore slurry from the flotation process. For this purpose, discontinuous sedimentation tests were carried out to determine: the effect of the flocculant dosage on the sedimentation velocity, on the sediment in compression, and on the thickener design by Adorjan’s method, which uses sedimentation parameters and compression parameters, and is complemented with rheological parameters obtained from the calculation of the effective solid stress and the measurement of the yield stress in slurries without the addition of flocculant. Batch sedimentation tests were performed for flocculant dosage between 0–20 g/TMS and volume fraction concentrations between 0.025–0.130. The results obtained show that the sedimentation velocity tends to constant and maximum values starting at a dose of 4 g/TMS; however, the analysis of the sediment granulometry indicates that the addition of flocculant is not necessary, since there is no significant size segregation for low dosage of flocculant; and finally, the design of the thickener by Adorjan’s method indicates that the optimum value would be 20 g/TMS. When evaluating the rheological parameters for the concentrate without the addition of flocculant, it is observed that the behavior of the effective solids stress and yield stress have a marked increase in their values for volumetric fractions of 0.45 (79.60% of solids by mass), which would indicate a change in the fluidity of the concentrate, so it is correct to design the thickener for a discharge volumetric concentration of 0.239, which corresponds to the range used in the industrial operation, and it is expected that the fluidity of the concentrate thickener discharge will have an adequate rheological behavior.

7

Video compression and optimization technologies: review

Uddin Syed, Leszczuk Mikolaj, Grega Michal

International Journal of Electronics and Telecommunications

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2024

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Vol. 70, No. 3

733-742

EN

The use of video streaming is constantly increasing. High-resolution video requires resources on both the sender and the receiver side. There are many compression techniques that can be utilized to compress the video and simultaneously maintain quality. The main goal of this paper is to provide an overview of video streaming and QoE. This paper describes the basic concepts and discusses existing methodologies to measure QoE. Subjective, objective, and video compression technologies are discussed. This review paper gathers the codec implementation developed by MPEG, Google, and Apple. This paper outlines the challenges and future research directions that should be considered in the measurement and assessment of quality of experience for video services.

8

Process parameters and the course of densification of bulk oil-bearing materials

Akangbe Olaosebikan Layi, Adamovský Radomír, Onwuegbunam Donatus Obiajulu

Infrastruktura i Ekologia Terenów Wiejskich

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2024

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Vol. 19, No. 1.1

23--35

EN

Bulk, porous oil-bearing materials acquire various degrees of densification under varying influences of equipment and process parameters with direct bearings on yield during compressive abstraction of oil from such materials. Effects of both aspect ratio and compression cycle on the course of densification were investigated. Mechanical response and oil expression indices were analysed for variances and treatment means were compared using Duncan’s multiple range test. All influence factors had significant effects on mechanical response and oil yield. Significant improvements in achievable deformation and specific energy demand were obtained through repeated induction of compressive stress; compression cycle correlated positively with both deformation and energy demand. Margin for the expenditure of energy became wider as pressure ratio at the oil point became lower. This study reveals that performance of compression schemes may be significantly enhanced through careful application of the pressure ratio.

9

Modeling of thermodynamic processes in internal combustion engine cylinder during cranking in compression measurement tests

Khrulev Alexander E., Saraiev Oleksii V., Saraieva Ігуnа Y., Vorobiov Oleksandr M.

Combustion Engines

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2024

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R. 63, nr 3

98--109

EN

The thermodynamics of in-cylinder processes of the internal combustion engine in cranking mode when measuring compression were examined. Analysis of various theoretical models and comparison of known data showed that the problems of constructing mathematical models of the engine operating cycle remain unresolved. The vast majority of practical data and recommendations for measuring cylinder compression are based on empirical knowledge, numerous experiments, and tests. In accordance with this, there is a need for computational models of the compression measurement process and their theoretical justification. To solve the identified problems, a mathematical model of the thermodynamic processes in the cylinder was developed. Unlike existing ones, the model describes the processes in the cylinder step by step, taking into account the real nature of the intake-exhaust processes, air leakage through the interfaces of parts, and heat exchange with the walls. Using modeling, the main patterns of changes in compression depending on the modes, the nature of damage to the associated parts of the valve mechanism and cylinder-piston group, the amount of leakage, and engine temperature were found. Based on the results of the study, the properties of the model which make its use effective in diagnosing and monitoring the technical condition of engines in operation were concluded.

10

The behaviour of Reinforced Concrete Beams by Using Expanded Polystyrene Beads and Palm Oil Fuel Ash as Replacement Materials

Osman Mohamad Hairi, Chin L. Y., Adnan Suraya Hani, Jeni Mohamad Luthfi Ahmad, Jusoh Wan Amizah Wan, Salim Salman, Rahim Nur Liza, Wysłocki Jerzy J.

Archives of Metallurgy and Materials

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2024

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Vol. 69, iss. 1

359--364

EN

The Reinforced Concrete (RC) beams containing Expanded Polystyrene Beads (EPS) and Palm Oil Fuel Ash (POFA) as sand and cement replacement with a percentage between 10% and 30% were studied in terms of load-deflection behaviour. RC beam’s size was 1000×150×150 mm and simply supported at spaced 750 mm apart. The 10% of POFA without EPS shows a slight increase which is 0.26% higher than normal concrete in compressive strength. The ultimate load and flexural performance of RC beams with EPS and POFA exhibited a decreasing trend. All beams’ ultimate load exceeds the design value. The cracks of the RC beam may be classified as vertical flexural cracks, and some of the cracks can be classified as shear cracks based on the crack angle. As the percentage of EPS and POFA increases above 20% for all specimens, cracking starts to change to shear cracking.

11

Optimization of Mechanical Properties of Raw Agave Fibre-Reinforced Lightweight Foamed Concrete

Mydin Md Azree Othuman, Abdullah Mohd Mustafa Al Bakri, Omar Roshartini, Dulaimi Anmar, Ibrahim Wan Mastura Wan, Jeż Bartłomiej, Nabiałek Marcin

Archives of Metallurgy and Materials

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2024

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Vol. 69, iss. 2

753--759

EN

The utilization of readily accessible natural fibres in lightweight foamed concrete (LWFC), which is already a widely used building material, can have a substantial positive impact on the environment. Therefore, the mechanical characteristics might be increased by using a correct mix proportion of fibre-reinforced LWFC. Innovative LWFC-agave fibre (AF) composites were created in this experiment. In order to get the best mechanical qualities, this investigation set out to establish the correct weight fraction of AF to be added to LWFC. Two LWFC densities of 750 and 1500 kg/m3 were produced with the addition of several weight fractions of AF, precisely 0.0%, 1.5%, 3.0%, 4.5%, 6.0%, and 7.5%, were used. To establish the mechanical characteristics of LWFCAF composites, flexural tests, tensile strength tests, axial compression tests, and ultrasonic pulse velocity tests were carried out. Test results revealed that the combination of LWFC together with a weight fraction of 4.5% of AF exhibited superior mechanical properties. Beyond 4.5% of AF’s weight fraction, the mechanical properties started to deteriorate. This study gives insight and crucial data on the mechanical characteristics of LWFC-AF composites therefore it will enable future researchers to explore other properties of LWFC reinforced with AF.

12

Engineering Properties of Foamed Concrete Reinforced with Sustainable Bamboo Fibre

Majeed Samadar Salim, Mydin Md Azree Othuman, Abdullah Mohd Mustafa Al Bakri, Omar Roshartini, Ahmad Romisuhani, Pietrusiewicz Paweł

Archives of Metallurgy and Materials

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2024

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Vol. 69, iss. 3

1183--1189

EN

The consumption of foamed concrete (FC) in conjunction with the incorporation of natural fibre is recognized as an outstanding effort in promoting sustainable practices. This effort is aimed at reducing greenhouse gas emissions and the impact it leaves behind on the environment. The goal of this experiment is to discover the viability of incorporating raw bamboo fibre (BF) into the fabrication of 1000 kg/m3 density FC. The shrinkage, flexural, compressive, and tensile strengths of the material were the four characteristics that were considered throughout the analysis. The weight fractions of BF that were utilized were 0.0%, 0.1%, 0.2%, 0.3%, and 0.4% respectively. According to the results, the FC-BF composites’ drying shrinkage, compressive, flexural, and tensile strengths were best achieved when 0.3% BF was present. This was caused by the BF’s adhesion to the cementitious matrix of the FC. Additionally, BF functioned as an anti-micro crack that prevented FC from developing internally induced microcracks and cracks.

13

Effect of Fibre Mercerization on Strength Properties of Agave Cantula Roxb. Strengthen Foamed Concrete

Majeed Samadar Salim, Mydin Md Azree Othuman, Omar Roshartini, Razak Rafiza Abd, Abdullah Mohd Mustafa Al Bakri, Ishak Shafiq

Archives of Metallurgy and Materials

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2024

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Vol. 69, iss. 3

1175--1182

EN

Researchers are increasingly becoming fascinated by the possibilities of utilizing natural fibre, which is a byproduct of production processes, as an addition in concrete. This fibre exhibits a low density and is amenable to chemical changes. The primary aim of this research study is to examine the influence of agave cantula roxb. fibre (ACRF) in low-density foamed concrete (FC) after being subjected to different doses of alkali treatment using sodium hydroxide (NaOH). Various weight fractions of treated ACRF were employed in the FC mix, namely 0% (as the control), 1%, 2%, 3%, 4%, and 5%. FC with a density of 1060 kg/m3 was produced and subsequently tested. The three types of strength properties that have been evaluated and analysed included flexural, tensile, and compressive strengths. The findings from this study have revealed that the inclusion of 3% of treated ACRF in FC yields highly favourable results in relation to strength properties. The use of treated ACRF improves the FC’s strength characteristics, particularly its bending and tensile strength, by bridging microscopic cracks and filling up gaps. It is noteworthy to emphasize that accumulation and unequal dispersion of ACRF are possible if the weight fraction of ACRF applied above the optimal value of 3% which led to decrease in FC’s strength properties. This exploratory work will lead to a better understanding of the potential applications of treated ACRF in FC. It is critical to encourage the long-term development and implementation of FC products and technology.

14

Effect of pore architecture of 3D printed open porosity cellular structures on their resistance to mechanical loading. Part II, Numerical analysis

Aladag Mehmet, Bernacka Monika, Dubicki Adrian, Zgłobicka Izabela

Acta Mechanica et Automatica

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2024

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Vol. 18, no. 3

427--433

EN

The objective of this study was to investigate pore shape effect on resistance to compression of open porosity lattice structures obtained with 3D printing. To this end, three distinct pore architectures were investigated: ellipsoidal, helical and X-shape. Open porosity of these structures was 54%, 50% and 60%, respectively. Their mechanical properties were evaluated through compression tests, and their behaviours were analysed using finite element modelling (FEM). The results indicated that the pore size has a significant effect on the stiffness of cellular structures. It was observed that the helical structure exhibited superior properties among the structures tested due to homogenous stress distribution. It was also found that ellipsoidal and x-shape structures are much more sensitive to localisation of the deformation.

15

Badania doświadczalne ściskanych kształtowników giętych na zimno

Górski Marcin, Budziński Rafał, Sieńkowska-Szpetnar Katarzyna

Inżynieria i Budownictwo

|

2023

|

R. 79, nr 1-2

25--29

PL

W artykule przedstawiono przebieg oraz wyniki badań doświadczalnych przeprowadzonych na elementach składających się z dwóch kształtowników giętych na zimno: ceowych lub zetowych długości 1 m. Porównano nośności na ściskanie otrzymane z badań doświadczalnych dla przekrojów bazowych oraz przekrojów z dodatkowymi usztywnieniami na środniku i obliczone wartości nośności przekroju brutto.

EN

The article presents the course and results of experimental tests carried out on elements consisting of two cold-formed sections: channel or zeta sections, 1 m length. The compressive resistance obtained from experimental tests for basic sections and sections with additional stiffeners on the web are compared, as well as the calculated values of the gross section resistance.

16

Steganography in Audio Files: COTS Software Analysis

Marszałek Piotr, Bilski Piotr

International Journal of Electronics and Telecommunications

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2023

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Vol. 69, No. 1

121--126

EN

The paper presents the analysis of the Commercial Off-The-Shelf (COTS) software regarding the ability to be used in audio steganography techniques. Such methods are a relatively new tool for hiding and transmitting crucial information, also being used by hackers. In the following work, the publicly available software dedicated to audio steganography is examined. The aim was to provide the general operating model of the information processing in the steganographic effort. The embedding method was analyzed for each application, providing interesting insights and allowing classifying the methods. The results prove that it is possible to detect the hidden message within the specific audio file and identify the technique that was used to create it. This may be exploited further during the hacking attack detection and prevention.

17

Quality Evaluation of Speech Transmission via Two-way BPL-PLC Voice Communication System in an Underground Mine

Falkowski-Gilski Przemysław, Debita Grzegorz

Archives of Acoustics

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2023

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Vol. 48, No. 4

585--592

EN

In order to design a stable and reliable voice communication system, it is essential to know how many resources are necessary for conveying quality content. These parameters may include objective quality of service (QoS) metrics, such as: available bandwidth, bit error rate (BER), delay, latency as well as subjective quality of experience (QoE) related to user expectations. QoE is expressed as clarity of speech and the ability to interpret voice commands with adequate mean opinion score (MOS) grades. This paper describes a quality evaluation study of a two-way speech transmission system via bandwidth over power line – power line communication (BPL-PLC) technology in an operating underground mine. We investigate how different features of the available wired medium can affect end-user quality. The results of the described study include: two types of coupling (capacitive and inductive), two transmission modes (mode 1 and 11), and four language sets of speech samples (American English, British English, German, and Polish) encoded at three different bit rates (8, 16, and 24 kbps). Our findings can aid both researchers working on low-bit rate coding and compression, signal processing and speech perception, as well as professionals active in the mining and oil industry.

18

Theoretical probabilistic nonlinear analysis of post-tensioned bridge cross-sections with the application of random fields

Owerko Piotr

Architecture Civil Engineering Environment

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2023

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Vol. 16, no. 2

127--136

EN

The paper presents a proprietary procedure for the analysis of normal stress distributions in post-tensioned cross-sections. It has a significant advantage over conventional commonly used approaches based solely on the envelope analysis as it provides stress levels in all components of the cross-section. The procedure was used in a series of probabilistic analyses with the adoption of random fields. These fields represented uncertainties in strain-stress relationship in concrete. The analysis covered several types of cross-sections and several types of random fields. Key observations from the conducted simulations are as follows: (I) the widest ranges of the probable maximum stresses (i.e. the lowest indexes of reliability) were obtained for sections with relatively low heights of the compressive zone. (II) The highest probabilistic sensitivity to the type of random field used was found in tall sections with a relatively large compressive zone. (III) The greatest sensitivity to batch uncertainties was evident in all cross-sections when using squared exponential random fields. (IV) The greatest relative sensitivity to the batch uncertainties in the form of the random field compliant with the guidelines of the Joint Comity of Structural Safety (JCSS) was evident in the analyses of the tallest cross-section corresponding to the incrementally launched bridges.

19

The Impact of FDM Process Parameters on the Compression Strength of 3D Printed PLA Filaments for Dental Applications

Hamed Mostafa Adel, Abbas Tahseen Fadhil

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no. 4

121--129

EN

This study evaluated Fused Deposition Modeling (FDM) for printing objects with maximum compression strength by focusing on critical process parameters. Infill density, outer shell width, infill pattern, and layer thickness were examined. Taguchi studies tested all parameter values with the fewest possible tests. Infill density (55.488 Mpa) affected compressive resistance the most, followed by outer shell width (1.8 mm), infill pattern (75%), infill pattern type (concentric), nozzle diameter (0.6 mm), and layer thickness (0.3 mm) and the liner regression model which use to prediction experimental value shown minimum percentage error(4%). The study also demonstrated the fabrication of 3D-printed crowns using PLA and FDM printing as temporary crowns, which remained intact without any discomfort until the permanent prosthesis was ready. The average printing time for temporary crowns was approximately 7 minutes. This study indicates that 3D printing of temporary crowns with PLA using FDM printing is a convenient process for dentists the result for crowns for teeth 13 and 16 of the human case study showed good accuracy and good resistance to compression.

20

A simulation strategy to determine the mechanical behaviour of cork-rubber composite pads for vibration isolation

Lopes Helena, Silva Susana P., Machado José

Eksploatacja i Niezawodność

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2022

|

Vol. 24, no. 1

80--88

EN

The present work aimed to determine the performance of new cork-rubber composites, applying a modelling-based approach. The static and dynamic behaviour under compression of new composite isolation pads was determined using mathematical techniques. Linear regression was used to estimate apparent compression modulus and dynamic stiffness coefficient of compounds samples based on the effect of fillers, cork and other ingredients. Using the results obtained by regression models, finite element analysis (FEA) was applied to determine the behaviour of the same cork-rubber material but considering samples with different dimensions. The majority of the regression models presented R2 values above 90%. Also, a good agreement was found between the results obtained by the presented approach and previous experimental tests. Based on the developed methodology, the compression behaviour of new cork-rubber compounds can be accessed, improving product development stages.