Search results for: Dental composites
439 Effect of Mercerization on Coconut Fiber Surface Condition
Authors: Sphiwe Simelane, Daniel Madyira
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The use of natural fibers requires that they should be treated in preparation for their use in Natural Fiber-reinforced polymer composites. This paper reports on the effects of sodium hydroxide (NaOH) treatment on the surface of coconut fibers. The fibers were subjected to 5%, 10%, 15% and 20% NaOH concentrations and soaked for 4 hours and thoroughly rinsed and allowed to dry in the open air for seven days, after which time they were dried in an oven for 30 minutes. Untreated and treated coconut fibers were observed under the Scanning Electron Microscope and it was noted that the surface structure of the fibers was modified differently by the different NaOH concentrations, and the resultant colour of the treated fibers got darker as the solution concentration increased, and the texture felt rougher to the touch as a result of the erosion of the fiber surface. Further, the increase in alkali concentration striped the surface of more constituents, thus exposing “pits” and other surface components rendering the surface rough.Keywords: coconut fiber, scanning electron microscope, sodium hydroxide, surface treatment
Procedia PDF Downloads 197438 Properties of Composite Materials Made from Surface Treated Particles from Annual Plants
Authors: Štěpán Hýsek, Petra Gajdačová, Milan Podlena
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Annual plants are becoming more and more popular source of lignin and cellulose. In those days a lot of research is carried out in order to evaluate the possibility of utilization of fibres and particles from these plants in composite materials production. These lingo-cellulosic materials seem to be a great alternative to wood, however, due to waxy and silica layers on the surface of these stalks, one additional technological step is needed–erosion of the layers for the purpose of achieving better adhesion between particle and adhesive. In this research, we used several kinds of particle pre-treatment, in order to modify surface properties of these particles. Further, an adhesive was applied to the particles using laboratory blender and board were produced using laboratory press. Both physical and mechanical properties of boards were observed. It was found out that the surface modification of particles had statistically significant effect on properties of produced boards.Keywords: annual plant, composites, mechanical properties, particleboard
Procedia PDF Downloads 192437 Combined Orthodontic and Restorative Management of Complex Cases: Concepts and Case Reports
Authors: Awais Ali, Hesham Ali
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The absence of teeth through either premature loss or developmental absence is a common condition with potentially severe impact on affected individuals. Management of these cases presents a clinical challenge which may be difficult to resolve given the effects of tooth loss or hypodontia over the course of a patient’s lifetime. Treatment of such cases is often best provided by a multi-disciplinary team, where the patient’s expectations and care delivery can be optimally managed. Orthodontic treatment is often used to prepare the dentition in advance of restorative replacement of missing teeth. Conversely, the placement of implants may precede the delivery of orthodontic treatment and indeed may function as an adjunctive orthodontic procedure. We discuss the use of both approaches here and illustrate their clinical implementation with two case reports. The first case demonstrates the use of fixed appliances to prepare the mouth for an opposing implant-retained complete denture. A second case demonstrates the use of implant-retained crowns to provide orthodontic anchorage in a partially dentate patient. We propose that complex cases such as these should always be planned and treated by a multi-disciplinary team in order to optimise the delivery of care, patient experience, and treatment outcome. The presented cases add to the body of evidence in this area.Keywords: orthodontics, dental implantology, hypodontia, multi-disciplinary
Procedia PDF Downloads 124436 Performance Evaluation of 3D Printed ZrO₂ Ceramic Components by Nanoparticle Jetting™
Authors: Shengping Zhong, Qimin Shi, Yaling Deng, Shoufeng Yang
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Additive manufacturing has exerted a tremendous fascination on the development of the manufacturing and materials industry in the past three decades. Zirconia-based advanced ceramic has been poured substantial attention in the interest of structural and functional ceramics. As a novel material jetting process for selectively depositing nanoparticles, NanoParticle Jetting™ is capable of fabricating dense zirconia components with a high-detail surface, precisely controllable shrinkage, and remarkable mechanical properties. The presence of NPJ™ gave rise to a higher elevation regarding the printing process and printing accuracy. Emphasis is placed on the performance evaluation of NPJ™ printed ceramic components by which the physical, chemical, and mechanical properties are evaluated. The experimental results suggest the Y₂O₃-stabilized ZrO₂ boxes exhibit a high relative density of 99.5%, glossy surface of minimum 0.33 µm, general linear shrinkage factor of 17.47%, outstanding hardness and fracture toughness of 12.43±0.09 GPa and 7.52±0.34 MPa·m¹/², comparable flexural strength of 699±104 MPa, and dense and homogeneous grain distribution of microstructure. This innovative NanoParticle Jetting system manifests an overwhelming potential in dental, medical, and electronic applications.Keywords: nanoparticle jetting, ZrO₂ ceramic, materials jetting, performance evaluation
Procedia PDF Downloads 174435 Study of Tribological Behaviour of Al6061/Silicon Carbide/Graphite Hybrid Metal Matrix Composite Using Taguchi's Techniques
Authors: Mohamed Zakaulla, A. R. Anwar Khan
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Al6061 alloy base matrix, reinforced with particles of silicon carbide (10 wt %) and Graphite powder (1wt%), known as hybrid composites have been fabricated by liquid metallurgy route (stir casting technique) and optimized at different parameters like applied load, sliding speed and sliding distance by taguchi method. A plan of experiment generated through taguchi technique was used to perform experiments based on L27 orthogonal array. The developed ANOVA and regression equations are used to find the optimum coefficient of friction and wear under the influence of applied load, sliding speed and sliding distance. On the basis of “smaller the best” the dry sliding wear resistance was analysed and finally confirmation tests were carried out to verify the experimental results.Keywords: analysis of variance, dry sliding wear, hybrid composite, orthogonal array, Taguchi technique
Procedia PDF Downloads 459434 Analysis of in Vitro Biocompatibility Studies of Silicate-Based Bioceramic Cements: A Scoping Review
Authors: Olphiara Rodolpheza Alexandre, Carla David, Rafael Guerra Lund, Nadia Ferreira
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Due to the increasing demand for biomaterials in the dental field, especially in endodontics, calcium silicate-based cements (CSCs) have gained prominence because of their biocompatibility and tissue regeneration capabilities. Originating from Mineral Trioxide Aggregate (MTA), the first bioceramic in endodontics derived from Portland cement, these materials are becoming increasingly prevalent in the market. For any drug released to the market, pharmacovigilance must ensure the absence of adverse health effects on consumers through rigorous toxicological testing. Although these materials have undergone in vitro and in vivo testing, such tests have typically been conducted over a limited period. Some effects may only become apparent after several years, and these studies are generally carried out on a non-specific population. However, the variety of calcium silicate-based products, including cement and sealers, raises questions about their toxicity, particularly considering potential long-term effects not addressed in existing studies. While the scientific literature includes comparative studies on the toxicity of these materials, the consistency of their conclusions is often controversial. Therefore, this project aims to map the scientific evidence from in vitro biocompatibility studies, including those investigating the toxicity of calcium silicate-based bioceramics.Keywords: toxicity, toxicity test, bioceramics, calcium silicate, genotoxicity
Procedia PDF Downloads 18433 Preparation, Characterization and Ionic Conductivity of (1‒x) (CdI2‒Ag2CrO4)‒(x) Al2O3 Composite Solid Electrolytes
Authors: Rafiuddin
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Composite solid electrolyte of the salt and oxide type is an effective approach to improve the ionic conductivity in low and intermediate temperature regions. The conductivity enhancement in the composites occurs via interfaces. Because of their high ionic conduction, composite electrolytes have wide applications in different electrochemical devices such as solid-state batteries, solid oxide fuel cells, and electrochemical cells. In this work, a series of novel (1‒x) (CdI2‒Ag2CrO4)‒xAl2O3 composite solid electrolytes has been synthesized. The prepared materials were characterized by X‒ray diffraction, differential thermal analysis, and AC impedance spectroscopy. The impedance spectra show single semicircle representing the simultaneous contribution of grain and grain boundary. The conductivity increased with the increase of Al2O3 content and shows the maximum conductivity (σ= 0.0012 S cm‒1) for 30% of Al2O3 content at 30 ℃.Keywords: composite solid electrolyte, X-ray diffraction, Impedance spectroscopy, ionic conductivity
Procedia PDF Downloads 398432 Preparation, Characterization and Photocatalytic Activity of a New Noble Metal Modified TiO2@SrTiO3 and SrTiO3 Photocatalysts
Authors: Ewelina Grabowska, Martyna Marchelek
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Among the various semiconductors, nanosized TiO2 has been widely studied due to its high photosensitivity, low cost, low toxicity, and good chemical and thermal stability. However, there are two main drawbacks to the practical application of pure TiO2 films. One is that TiO2 can be induced only by ultraviolet (UV) light due to its intrinsic wide bandgap (3.2 eV for anatase and 3.0 eV for rutile), which limits its practical efficiency for solar energy utilization since UV light makes up only 4-5% of the solar spectrum. The other is that a high electron-hole recombination rate will reduce the photoelectric conversion efficiency of TiO2. In order to overcome the above drawbacks and modify the electronic structure of TiO2, some semiconductors (eg. CdS, ZnO, PbS, Cu2O, Bi2S3, and CdSe) have been used to prepare coupled TiO2 composites, for improving their charge separation efficiency and extending the photoresponse into the visible region. It has been proved that the fabrication of p-n heterostructures by combining n-type TiO2 with p-type semiconductors is an effective way to improve the photoelectric conversion efficiency of TiO2. SrTiO3 is a good candidate for coupling TiO2 and improving the photocatalytic performance of the photocatalyst because its conduction band edge is more negative than TiO2. Due to the potential differences between the band edges of these two semiconductors, the photogenerated electrons transfer from the conduction band of SrTiO3 to that of TiO2. Conversely, the photogenerated electrons transfer from the conduction band of SrTiO3 to that of TiO2. Then the photogenerated charge carriers can be efficiently separated by these processes, resulting in the enhancement of the photocatalytic property in the photocatalyst. Additionally, one of the methods for improving photocatalyst performance is addition of nanoparticles containing one or two noble metals (Pt, Au, Ag and Pd) deposited on semiconductor surface. The mechanisms were proposed as (1) the surface plasmon resonance of noble metal particles is excited by visible light, facilitating the excitation of the surface electron and interfacial electron transfer (2) some energy levels can be produced in the band gap of TiO2 by the dispersion of noble metal nanoparticles in the TiO2 matrix; (3) noble metal nanoparticles deposited on TiO2 act as electron traps, enhancing the electron–hole separation. In view of this, we recently obtained series of TiO2@SrTiO3 and SrTiO3 photocatalysts loaded with noble metal NPs. using photodeposition method. The M- TiO2@SrTiO3 and M-SrTiO3 photocatalysts (M= Rh, Rt, Pt) were studied for photodegradation of phenol in aqueous phase under UV-Vis and visible irradiation. Moreover, in the second part of our research hydroxyl radical formations were investigated. Fluorescence of irradiated coumarin solution was used as a method of ˙OH radical detection. Coumarin readily reacts with generated hydroxyl radicals forming hydroxycoumarins. Although the major hydroxylation product is 5-hydroxycoumarin, only 7-hydroxyproduct of coumarin hydroxylation emits fluorescent light. Thus, this method was used only for hydroxyl radical detection, but not for determining concentration of hydroxyl radicals.Keywords: composites TiO2, SrTiO3, photocatalysis, phenol degradation
Procedia PDF Downloads 217431 Magnetoelectric Effect in Polyvinylidene Fluoride Beta Phase Thin Films
Authors: Belouadah Rabah, Guyomar Daneil, Guiffard Benoit
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The magnetoelectric (ME) materials has dielectric polarization induced by the magnetic field or induced magnetization under an electric field. A strong ME effect requires the simultaneous presence of magnetic moments and electric dipoles. In the last decades, extensive research has been conducted on the ME effect in single phase and composite materials. This article reported the results obtained with two samples, the first is mono layer of PVDF bi-stretched and the second is the multi layer PVDF bi-stretched with the Polyurethane filled with micro particles magnetic Fe3O4 (PU+2% Fe3O4). Compare with non ME material like Alumine, a large ME polarization coefficient for the two samples was obtained. The piezoelectric properties of the PVDF and elastic proprieties of Pu+2% Fe3O4 give a big linear ME coefficient of the multi layer PVDF/(Pu+2% Fe3O4) than in the monolayer of PVDF.Keywords: magnetoelectric effect, polymers, magnetic particles, composites, films
Procedia PDF Downloads 390430 Mechanical Structural and Optical Properties of Lu₂SiO₅ Scintillator-Polymer Composite Films
Authors: M. S. E. Hamroun, K. Bachari, A. Berrayah, L. Mechernene, L. Guerbous
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Composite films containing homogeneously dispersed scintillation nano-particles of Lu₂SiO₅:Ce³⁺, in optically transparent polymer matrix, have been prepared and characterized through X-ray diffraction, differential scanning calorimetric (DSC), thermogravimetric analysis (ATG), dynamic mechanical analysis (DMA), electron scanning microscopy morphology (SEM) and photoluminescence (PL). Lu₂SiO₅:Ce³⁺ scintillator powder was successfully synthesized via Sol-Gel method. This study is realized with different mass ratios of nano-particles embedded in polystyrene and polylactic acid polymer matrix (5, 10, 15, 20%) to see the influence of nano-particles on the mechanical, structural and optical properties of films. The composites have been prepared with 400 µm thickness. It has found that the structural proprieties change with mass ratio on each sample. PL photoluminescence shows the characteristic Lu₂SiO₅:Ce³⁺ emission in the blue region and intensity varied for each film.Keywords: nano-particles, sol gel, photoluminescence, Ce³⁺, scintillator, polystyrene
Procedia PDF Downloads 115429 Coupled Field Formulation – A Unified Method for Formulating Structural Mechanics Problems
Authors: Ramprasad Srinivasan
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Engineers create inventions and put their ideas in concrete terms to design new products. Design drivers must be established, which requires, among other things, a complete understanding of the product design, load paths, etc. For Aerospace Vehicles, weight/strength ratio, strength, stiffness and stability are the important design drivers. A complex built-up structure is made up of an assemblage of primitive structural forms of arbitrary shape, which include 1D structures like beams and frames, 2D structures like membranes, plate and shell structures, and 3D solid structures. Justification through simulation involves a check for all the quantities of interest, namely stresses, deformation, frequencies, and buckling loads and is normally achieved through the finite element (FE) method. Over the past few decades, Fiber-reinforced composites are fast replacing the traditional metallic structures in the weight-sensitive aerospace and aircraft industries due to their high specific strength, high specific stiffness, anisotropic properties, design freedom for tailoring etc. Composite panel constructions are used in aircraft to design primary structure components like wings, empennage, ailerons, etc., while thin-walled composite beams (TWCB) are used to model slender structures like stiffened panels, helicopter, and wind turbine rotor blades, etc. The TWCB demonstrates many non-classical effects like torsional and constrained warping, transverse shear, coupling effects, heterogeneity, etc., which makes the analysis of composite structures far more complex. Conventional FE formulations to model 1D structures suffer from many limitations like shear locking, particularly in slender beams, lower convergence rates due to material coupling in composites, inability to satisfy, equilibrium in the domain and natural boundary conditions (NBC) etc. For 2D structures, the limitations of conventional displacement-based FE formulations include the inability to satisfy NBC explicitly and many pathological problems such as shear and membrane locking, spurious modes, stress oscillations, lower convergence due to mesh distortion etc. This mandates frequent re-meshing to even achieve an acceptable mesh (satisfy stringent quality metrics) for analysis leading to significant cycle time. Besides, currently, there is a need for separate formulations (u/p) to model incompressible materials, and a single unified formulation is missing in the literature. Hence coupled field formulation (CFF) is a unified formulation proposed by the author for the solution of complex 1D and 2D structures addressing the gaps in the literature mentioned above. The salient features of CFF and its many advantages over other conventional methods shall be presented in this paper.Keywords: coupled field formulation, kinematic and material coupling, natural boundary condition, locking free formulation
Procedia PDF Downloads 63428 Carbon Nanotubes Based Porous Framework for Filtration Applications Using Industrial Grinding Waste
Authors: V. J. Pillewan, D. N. Raut, K. N. Patil, D. K. Shinde
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Forging, milling, turning, grinding and shaping etc. are the various industrial manufacturing processes which generate the metal waste. Grinding is extensively used in the finishing operation. The waste generated contains significant impurities apart from the metal particles. Due to these significant impurities, it becomes difficult to process and gets usually dumped in the landfills which create environmental problems. Therefore, it becomes essential to reuse metal waste to create value added products. Powder injection molding process is used for producing the porous metal matrix framework. This paper discusses the presented design of the porous framework to be used for the liquid filter application. Different parameters are optimized to obtain the better strength framework with variable porosity. Carbon nanotubes are used as reinforcing materials to enhance the strength of the metal matrix framework.Keywords: grinding waste, powder injection molding (PIM), carbon nanotubes (CNTs), matrix composites (MMCs)
Procedia PDF Downloads 300427 Active Control of Multiferroic Composite Shells Using 1-3 Piezoelectric Composites
Authors: S. C. Kattimani
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This article deals with the analysis of active constrained layer damping (ACLD) of smart multiferroic or magneto-electro-elastic doubly curved shells. The kinematics of deformations of the multiferroic doubly curved shell is described by a layer-wise shear deformation theory. A three-dimensional finite element model of multiferroic shells has been developed taking into account the electro-elastic and magneto-elastic couplings. A simple velocity feedback control law is employed to incorporate the active damping. Influence of layer stacking sequence and boundary conditions on the response of the multiferroic doubly curved shell has been studied. In addition, for the different orientation of the fibers of the constraining layer, the performance of the ACLD treatment has been studied.Keywords: active constrained layer damping (ACLD), doubly curved shells, magneto-electro-elastic, multiferroic composite, smart structures
Procedia PDF Downloads 305426 Recent Nano technological Advancements in Antimicrobial Edible Films for Food Packaging: A Review
Authors: Raana Babadi Fathipour
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Researchers are now focusing on sustainable advancements in active packaging systems to meet the growing consumer demand for high-quality food with Eco-friendly packaging. One significant advancement in this area is the inclusion of antimicrobial agents in bio-polymer-based edible films, which effectively inhibit or kill pathogenic/spoilage microbes that can contaminate food. This technology also helps reduce undesirable flavors caused by active compounds directly incorporated into the food. To further enhance the efficiency of antimicrobial bio-based packaging systems, Nano technological concepts such as bio-nano composites and Nano encapsulation systems have been applied. This review examines the current state and applications of antimicrobial biodegradable films in the food packaging industry, while also highlighting ongoing research on the use of nanotechnology to develop innovative bio-based packaging systems.Keywords: active packaging, antimicrobial edible films, bioactive agents, biopolymers, bio-nanocomposites
Procedia PDF Downloads 65425 Difficulties in Pronouncing the English Bilabial Plosive Sounds among EFL Students
Authors: Ali Mohammed Saleh Al-Hamzi
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This study aims at finding out the most difficult position in pronouncing the bilabial plosive sounds at the fourth level of English foreign language students of the Faculty of Education, Mahweet, Sana’a University in Yemen. The subject of this study were 50 participants from English foreign language students aged 22-25. In describing sounds according to their place of articulation, sounds are classified as bilabial, labiodental, dental, alveolar, post-alveolar, palato-alveolar retroflex, palatal, velar, uvular, and glottal. In much the same way, sounds can be described in their manner of articulation as plosives, nasals, affricates, flaps, taps, rolls, fricatives, laterals, frictionless continuants, and semi-vowels. For English foreign language students in Yemen, there are some articulators that are difficult to pronounce. In this study, the researcher focuses on difficulties in pronouncing the English bilabial plosive sounds among English foreign language students. It can be in the initial, medial, and final positions. The problem discussed in this study was: which position is the most difficult in pronouncing the English bilabial plosive sounds? To solve the problem, a descriptive qualitative method was conducted in this study. The data were collected from each English bilabial plosive sounds produced by students. Finally, the researcher reached that the most difficult position in pronouncing the English bilabial plosive sounds is when English bilabial plosive /p/ and /b/ occur word-finally, where both are voiceless.Keywords: difficulty, EFL students’ pronunciation, bilabial sounds, plosive sounds
Procedia PDF Downloads 141424 Antioxidants Reveal Protection against the Biochemical Changes in Liver, Kidney, and Blood Profiles after Clindamycin/Ibuprofen Administration in Dental Patients
Authors: Gouda K. Helal, Marwa I. Shabayek, Heba A. El-Ramly, Heba A. Awida
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The adverse effects of Clindamycin (Clind.) / Ibuprofen (Ibu.) combination on liver, kidney, blood elements and the significances of antioxidants (N-acetylcysteine and Zinc) against these effects were evaluated. The study includes: Group I; control n=30, Group II; patients on Clind.300mg/Ibu.400mg twice daily for a week n=30, Group III; patients on Clind.300mg/Ibu.400mg+N-acetylcysteine 200mg twice daily for a week n=15 and Group IV; patients on Clind.300mg/Ibu.400mg+Zinc50mg twice daily for a week n=15. Serum malondialdehyde (MDA), alanine transferase (ALT), aspartate transferase (AST), γ glutamyl transferase (GGT), creatinine, blood urea nitrogen (BUN) were measured. Applying one way ANOVA followed by Tuckey Kramer post test, Group II showed significant increase in ALT, AST, GGT, BUN and decrease in Hb, RBCs, platelets than Group I. Group III showed significant decrease in ALT, AST, GGT, BUN than Group II. Moreover, Group IV showed significant decrease in ALT, AST, GGT and increase in Hb, RBCs, and platelets than Group II. Conclusively, Adding Zinc or N-acetylcysteine buffer the oxidative stress and improve the therapeutic outcome of Clindamycin/Ibuprofen combination.Keywords: clindamycin, ibuprofen, adverse effects, antioxidant, zinc, N-acetylcysteine
Procedia PDF Downloads 373423 Modeling Study of Short Fiber Orientation in Simple Injection Molding Processes
Authors: Ihsane Modhaffar, Kamal Gueraoui, Abouelkacem Qais, Abderrahmane Maaouni, Samir Men-La-Yakhaf, Hamid Eltourroug
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The main objective of this paper is to develop a Computational Fluid Dynamics (CFD) model to simulate and characterize the fiber suspension in flow in rectangular cavities. The model is intended to describe the velocity profile and to predict the fiber orientation. The flow was considered to be incompressible, and behave as Newtonian fluid containing suspensions of short-fibers. The numerical model for determination of velocity profile and fiber orientation during mold-filling stage of injection molding process was solved using finite volume method. The governing equations of this problem are: the continuity, the momentum and the energy. The obtained results were compared to available experimental findings. A good agreement between the numerical results and the experimental data was achieved.Keywords: injection, composites, short-fiber reinforced thermoplastics, fiber orientation, incompressible fluid, numerical simulation
Procedia PDF Downloads 462422 Dimensional Accuracy of CNTs/PMMA Parts and Holes Produced by Laser Cutting
Authors: A. Karimzad Ghavidel, M. Zadshakouyan
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Laser cutting is a very common production method for cutting 2D polymeric parts. Developing of polymer composites with nano-fibers makes important their other properties like laser workability. The aim of this research is investigation of the influence different laser cutting conditions on the dimensional accuracy of parts and holes from poly methyl methacrylate (PMMA)/carbon nanotubes (CNTs) material. Experiments were carried out by considering of CNTs (in four level 0,0.5, 1 and 1.5% wt.%), laser power (60, 80, and 100 watt) and cutting speed 20, 30, and 40 mm/s as input variable factors. The results reveal that CNTs adding improves the laser workability of PMMA and the increasing of power has a significant effect on the part and hole size. The findings also show cutting speed is effective parameter on the size accuracy. Eventually, the statistical analysis of results was done, and calculated mathematical equations by the regression are presented for determining relation between input and output factor.Keywords: dimensional accuracy, PMMA, CNTs, laser cutting
Procedia PDF Downloads 303421 Proecological Antioxidants for Stabilisation of Polymeric Composites
Authors: A. Masek, M. Zaborski
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Electrochemical oxidation of dodecyl gallate (lauryl gallate), the main monomer flavanol found in green tea, was investigated on platinum electrodes using cyclic voltammetry (CV) and differential pulse (DPV) methods. The rate constant, electron transfer coefficient and diffusion coefficients were determined for dodecyl gallate electrochemical oxidation. The oxidation mechanism proceeds in sequential steps related to the hydroxyl groups in the aromatic ring of dodecyl gallate. Confirmed antioxidant activity of lauryl gallate verified its use in polymers as an environment-friendly stabiliser to improve the resistance to aging of the elastomeric materials. Based on the energy change of the deformation, cross-linking density and time of the oxygen induction with the TG method, we confirmed the high antioxidant activity of lauryl gallate in polymers. Moreover, the research on biodegradation confirmed the environment-friendly influence of the antioxidant by increasing the susceptibility of the elastomeric materials to disintegration by mildew mushrooms.Keywords: polymers, flavonoids, stabilization, ageing
Procedia PDF Downloads 372420 An Intelligent Tutoring System Enriched with 3D Virtual Reality for Dentistry Students
Authors: Meltem Eryılmaz
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With the emergence of the COVID-19 infection outbreak, the socio-cultural, political, economic, educational systems dynamics of the world have gone through a major change, especially in the educational field, specifically dentistry preclinical education, where the students must have a certain amount of real-time experience in endodontics and other various procedures. The totality of the digital and physical elements that make our five sense organs feel as if we really exist in a virtual world is called virtual reality. Virtual reality, which is very popular today, has started to be used in education. With the inclusion of developing technology in education and training environments, virtual learning platforms have been designed to enrich students' learning experiences. The field of health is also affected by these current developments, and the number of virtual reality applications developed for students studying dentistry is increasing day by day. The most widely used tools of this technology are virtual reality glasses. With virtual reality glasses, you can look any way you want in a world designed in 3D and navigate as you wish. With this project, solutions that will respond to different types of dental practices of students who study dentistry with virtual reality applications are produced. With this application, students who cannot find the opportunity to work with patients in distance education or who want to improve themselves at home have unlimited trial opportunities. Unity 2021, Visual Studio 2019, Cardboard SDK are used in the study.Keywords: dentistry, intelligent tutoring system, virtual reality, online learning, COVID-19
Procedia PDF Downloads 199419 An Overview of Corroded Pipe Repair Techniques Using Composite Materials
Authors: Lim Kar Sing, Siti Nur Afifah Azraai, Norhazilan Md Noor, Nordin Yahaya
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Polymeric composites are being increasingly used as repair material for repairing critical infrastructures such as building, bridge, pressure vessel, piping and pipeline. Technique in repairing damaged pipes is one of the major concerns of pipeline owners. Considerable researches have been carried out on the repair of corroded pipes using composite materials. This article attempts a short review of the subject matter to provide insight into various techniques used in repairing corroded pipes, focusing on a wide range of composite repair systems. These systems including pre-cured layered, flexible wet lay-up, pre-impregnated, split composite sleeve and flexible tape systems. Both advantages and limitations of these repair systems were highlighted. Critical technical aspects have been discussed through the current standards and practices. Research gaps and future study scopes in achieving more effective design philosophy are also presented.Keywords: composite materials, pipeline, repair technique, polymers
Procedia PDF Downloads 507418 Fabrication and Assessment of Poly (butylene succinate)/ Poly (ԑ-caprolactone)/Eucomis Autumnalis Cellulose Bio-Composites for Tissue Engineering Applications
Authors: Kumalo F. I., Malimabe M. A., Gumede T. P., Mosoabisane M. F. T.
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This study investigates the fabrication and characterization of bio-nanocomposites consisting of poly (butylene succinate) (PBS) and poly (ԑ-caprolactone) (PCL), reinforced with cellulose extracted from Eucomis autumnalis, a medicinal plant. Bio-nanocomposite films were prepared using the solvent casting method, with cellulose content ranging from 1 to 3 wt%. Comprehensive analysis was conducted using FTIR, SEM, TEM, DSC, TGA, and XRD, to assess morphological, thermal, and structural properties. The results indicated significant improvements in the thermal stability and morphological properties with increasing cellulose content, showcasing the potential of these materials for tissue engineering applications. The use of cellulose extracted from a medicinal plant highlight the potential for sustainable and biocompatible materials in biomedical applications.Keywords: Bionanocomposites, poly(butylene succinate), poly(caprolactone), eucomis autumnalis, medicinal plant
Procedia PDF Downloads 44417 Development of a Compact Permanent Magnet Axial Flux Motor Using Soft Magnetic Composite
Authors: Nasiru Aliyu, Glyn Atkinson, Nick Stannard
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With increasing demand for electric motors used in nearly all sectors of our day to day activities, which range from the motor that rotates the washing machine and dishwasher to the tens of thousands of motors used in domestic appliance. The number of applications for soft magnetic composites (SMC) material is growing significantly. This paper presents the development of a compact single sided concentrated winding axial flux PM motor using soft magnetic composite as core for reducing core losses and cost. The effects of changing the flux carrying component to pressed SMC parts are investigated based on a comprehensive understanding of the properties of the material. A 3-D finite-element analysis is performed for accurate parameter calculation. To validate the simulation, a new static test measurement was fully conducted on a prototype motor and agree with the theoretical calculations and old measured static test.Keywords: SMC, compact development, axial field motor, 3DFA
Procedia PDF Downloads 320416 Photo-Fenton Degradation of Organic Compounds by Iron(II)-Embedded Composites
Authors: Marius Sebastian Secula, Andreea Vajda, Benoit Cagnon, Ioan Mamaliga
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One of the most important classes of pollutants is represented by dyes. The synthetic character and complex molecular structure make them more stable and difficult to be biodegraded in water. The treatment of wastewaters containing dyes in order to separate/degrade dyes is of major importance. Various techniques have been employed to remove and/or degrade dyes in water. Advanced oxidation processes (AOPs) are known as among the most efficient ones towards dye degradation. The aim of this work is to investigate the efficiency of a cheap Iron-impregnated activated carbon Fenton-like catalyst in order to degrade organic compounds in aqueous solutions. In the presented study an anionic dye, Indigo Carmine, is considered as a model pollutant. Various AOPs are evaluated for the degradation of Indigo Carmine to establish the effect of the prepared catalyst. It was found that the Iron(II)-embedded activated carbon composite enhances significantly the degradation process of Indigo Carmine. Using the wet impregnation procedure, 5 g of L27 AC material were contacted with Fe(II) solutions of FeSO4 precursor at a theoretical iron content in the resulted composite of 1 %. The L27 AC was impregnated for 3h at 45°C, then filtered, washed several times with water and ethanol and dried at 55 °C for 24 h. Thermogravimetric analysis, Fourier transform infrared, X-ray diffraction, and transmission electron microscopy were employed to investigate the structural, textural, and micromorphology of the catalyst. Total iron content in the obtained composites and iron leakage were determined by spectrophotometric method using phenantroline. Photo-catalytic tests were performed using an UV - Consulting Peschl Laboratory Reactor System. UV light irradiation tests were carried out to determine the performance of the prepared Iron-impregnated composite towards the degradation of Indigo Carmine in aqueous solution using different conditions (17 W UV lamps, with and without in-situ generation of O3; different concentrations of H2O2, different initial concentrations of Indigo Carmine, different values of pH, different doses of NH4-OH enhancer). The photocatalytic tests were performed after the adsorption equilibrium has been established. The obtained results emphasize an enhancement of Indigo Carmine degradation in case of the heterogeneous photo-Fenton process conducted with an O3 generating UV lamp in the presence of hydrogen peroxide. The investigated process obeys the pseudo-first order kinetics. The photo-Fenton degradation of IC was tested at different values of initial concentration. The obtained results emphasize an enhancement of Indigo Carmine degradation in case of the heterogeneous photo-Fenton process conducted with an O3 generating UV lamp in the presence of hydrogen peroxide. Acknowledgments: This work was supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS - UEFISCDI, project number PN-II-RU-TE-2014-4-0405.Keywords: photodegradation, heterogeneous Fenton, anionic dye, carbonaceous composite, screening factorial design
Procedia PDF Downloads 251415 Analysis of Drilling Parameters for Al-Mg2-Si Metal Matrix Composite
Authors: S. Jahangir, S. H. I. Jaffery, M. Khan, Z. Zareef, A. Yar, A. Mubashir, S. Butt, L. Ali
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In this work, drilling responses and behavior of MMC was investigated in Al-Mg2Si composites. For the purpose Al-15% wt. Mg2Si, was selected from the hypereutectic region of Al- Mg2Si phase diagram. Based on hardness and tensile strength, drill bit of appropriate material and morphology was selected. The performance of different drill bits of different morphology and material was studied and analysed using experimental data. For theoretical calculations of axial thrust force and required power calculation, material factor “K” was obtained from different data charts and at the same time cutting forces (drilling forces) were practically obtained using a Peizo electric force dynamometer. These results show the role of reinforcement particles on the machinability of MMCs and provide a useful guide for a better control and optimized drilling parameters for the drilling process. Furthermore, in this work, comparison of MMC with non -reinforced Aluminum Alloy regarding drilling operation was also studied.Keywords: drilling, metal matrix composite (MMC), cutting forces, thrust force
Procedia PDF Downloads 423414 Analysis of the Reaction to the Fire of a Composite Material the Base of Scrapes of Tires and Latex for Thermal Isolation in Vehicles
Authors: Elmo Thiao Lins Cöuras Ford, Valentina Alessandra Carvalho do Vale, R. M. Nascimento, J. U. L. Mendes
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Now the great majority of the applications of thermal isolation in the strip of drops and averages temperatures (up to 200ºC), it is made being used from aggressive materials to the nature such an as: glass wool, rock wool, polystyrene, EPS among others. Such materials, in spite of the effectiveness in the retention of the flow of heat, possess considerable cost and when discarded they are long years to be to decompose. In that context, trying to adapt the world politics the about of the preservation of the environment, a study began with intention of developing a material composite, with properties of thermal, originating from insulating industrial residues. In this research, the behavior of the composite was analyzed, as submitted the fire. For this, the reaction rehearsals were accomplished to the fire for the composites 2:1; 1:1; 1:2 and for the latex, based in the "con" experiment in agreement with the norm ASTM–E 1334-90. As consequence, in function of the answers of the system, was possible to observe to the acting of each mixture proportion.Keywords: composite, Latex, reacion to the fire, thermal isolation
Procedia PDF Downloads 432413 Modelling of Factors Affecting Bond Strength of Fibre Reinforced Polymer Externally Bonded to Timber and Concrete
Authors: Abbas Vahedian, Rijun Shrestha, Keith Crews
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In recent years, fibre reinforced polymers as applications of strengthening materials have received significant attention by civil engineers and environmentalists because of their excellent characteristics. Currently, these composites have become a mainstream technology for strengthening of infrastructures such as steel, concrete and more recently, timber and masonry structures. However, debonding is identified as the main problem which limit the full utilisation of the FRP material. In this paper, a preliminary analysis of factors affecting bond strength of FRP-to-concrete and timber bonded interface has been conducted. A novel theoretical method through regression analysis has been established to evaluate these factors. Results of proposed model are then assessed with results of pull-out tests and satisfactory comparisons are achieved between measured failure loads (R2 = 0.83, P < 0.0001) and the predicted loads (R2 = 0.78, P < 0.0001).Keywords: debonding, fibre reinforced polymers (FRP), pull-out test, stepwise regression analysis
Procedia PDF Downloads 239412 Micromechanical Analysis of Interface Properties Effects on Transverse Tensile Response of Fiber-Reinforced Composites
Authors: M. Naderi, N. Iyyer, K. Goel, N. Phan
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A micromechanical analysis of the influence of fiber-matrix interface fracture properties on the transverse tensile response of fiber-reinforced composite is investigated. Augmented finite element method (AFEM) is used to provide high-fidelity damage initiation and propagation along the micromechanical analysis. Effects of fiber volume fraction and fiber shapes are also studies in representative volume elements (RVE) to capture the stochastic behavior of the composite under loading. In addition, defects and voids influence on the composite response are investigated in micromechanical analysis. The results reveal that the response of RVE with constant interface properties overestimates the composite transverse strength. It is also seen that the damage initiation and propagation locations are controlled by the distributions of fracture properties, fibers’ shapes, and defects.Keywords: cohesive model, fracture, computational mechanics, micromechanics
Procedia PDF Downloads 287411 Silver Nanoparticles Impregnated Zeolitic Composites: Effect of the Silver Loading on Adsorption of Mercury (II)
Authors: Zhandos Tauanov, Dhawal Shah, Grigorios Itskos, Vasileios Inglezakis
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Removal of mercury (II) from aqueous phase is of utmost importance, as it is highly toxic and hazardous to the environment and human health. One way of removal of mercury (II) ions from aqueous solutions is by using adsorbents derived from coal fly ash (CFA), such as synthetic zeolites. In this work, we present the hydrothermal production of synthetic zeolites from CFA with conversion rate of 75%. In order to produce silver containing nanocomposites, synthetic zeolites are subsequently impregnated with various amounts of silver nanoparticles, from 0.2 to 2wt.%. All produced zeolites and parent materials are characterized by XRD, XRF, BET, SEM, and TEM to obtain morphological and microstructural data. Moreover, mercury (II) ions removal from aqueous solutions with initial concentration of 10 ppm is studied. According to results, zeolites and Ag-nanocomposites demonstrate much higher removal than parent CFA (up to 98%). In addition to this, we could observe a distinct adsorption behavior depending on the loading of Ag NPs in nanocomposites. A possible reaction mechanism for both zeolites and Ag-nanocomposites is discussed.Keywords: coal fly ash, mercury (II) removal, nanocomposites, silver nanoparticles, synthetic zeolite
Procedia PDF Downloads 270410 Development, Characterization and Properties of Novel Quaternary Rubber Nanocomposites
Authors: Kumar Sankaran, Santanu Chattopadhyay, Golok Behari Nando, Sujith Nair, Sreejesh Arayambath, Unnikrishnan Govindan
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Rubber nanocomposites based on Bromobutyl rubber (BIIR), Polyepichlorohydrin rubber (CO), Carbon black (CB) and organically modified montmorillonite clay (NC) were prepared via melt compounding technique. The developed quaternary nanocomposites were characterized analytically and their properties were compared against the standard BIIR compound. BIIR-CO nanocomposites showed improved physico-mechanical properties as compared to that of the standard BIIR compound. Hybrid microstructure (NC-CB) development, clay exfoliation and better filler dispersion in the quaternary nanocomposite significantly contributed to the overall enhancement of properties. Introduction of CO in the system increased the specific gravity and hardness of the compound as compared to that of the standard compound. XRD analysis, AFM imaging and HR-TEM measurements confirmed exfoliation and a good level of dispersion of the NC in the composites. Permeability of developed BIIR-CO nanocomposites decreases significantly as compared to that of the standard BIIR compound.Keywords: rubber nanocomposites, morphology, permeability, BIIR
Procedia PDF Downloads 430