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Materials sciences And Engineering, (MSE’22)

Article de conférence

This work presents a study on the elaboration and characterization of Hydroxyapatite obtained from bovine bone calcined at 900°C for 3 hours with a particle size of around 125 μm and sintered at 1100°C. A prepared biological solution (Simulated Body Fluid, SBF), to study the biological response of our elaborated powder.We carried out a characterization by scanning electron microscopy (SEM) in order to observe the formation of the apatite layer during the immersion time. Voir les détails

Mots clés : hydroxyapatite, SBF, Biological response, Osteoconductivity

Study of the Bioactivity of Hydroxyapatite Elaborated

Article de conférence

This work presents a study on the elaboration and characterization of Hydroxyapatite obtained from bovine bone calcined at 900°C for 3 hours with a particle size of around 125 μm and sintered at 1100°C. A prepared biological solution (Simulated Body Fluid, SBF), to study the biological response of our elaborated powder.We carried out a characterization by scanning electron microscopy (SEM) in order to observe the formation of the apatite layer during the immersion time. Voir les détails

Mots clés : hydroxyapatite, SBF, Biological response, Osteoconductivity

Numerical study of polymer coating by UV photopolymerization.

Article de conférence

Polymer-based coatings are used to protect a structure or device against mechanical attacks such as scratches, abrasion and erosion or against chemical attacks such as humidity, temperature, UV rays. This work concerns the development by photopolymerization UV of new coating materials based on a polymer as (Polyurethane Acrylate, oligomers) deposited on heat-sensitive materials such as thermoplastics (PC; PMMA,). Now, the polymers, which are already used in thermal powder coating. They generally show very high melting temperatures (around 200 °C). They will not be suitable for depositing on supports sensitive to high temperatures without risk of damaging them. In this work, we proposed a numerical study of the effect of different synthesis parameters (energy and applied UV rays, exposure time, temperature, external medium, etc.) on the conversion rate to a 3D mesh (crosslinking rate) and model optimization of coating parameters on heat-sensitive substrates. Voir les détails

Mots clés : polymers, coatings polymer, photopolymerization UV

High overtone acoustic resonator HBAR based onIDT’s/c-tilted ZnO/Si for timing applications

F. Laidoudi, F. Medjili, C. CALIENDO, M. HAMIDULLAH, F. KANOUNI, F. Boubenider  (2022)
Article de conférence

In this paper, the frequency characteristics ofhigh overtone bulk acoustic modes, generated by interdigitaltransducers IDT’s on c-tilted ZnO/Si, are theoretically andexperimentally investigated. The origin and characteristics ofhigh overtone acoustic modes in ZnO piezoelectric layer onsilicon substrate are discussed and one port HBAR resonator,based on c-axis tilted ZnO/Si, is fabricated and tested bynetwork analyzer. The results achieved in this work are ofinterest in design and fabrication of radiofrequency sourcesand electronic timing devices based on thin film technology Voir les détails

Mots clés : High overtone bulk acoustic modes, HBAR resonator, piezoelectric thin film, c-tilted ZnO, Frequency characteristics

Optimizing MAG Welding Input Variables to Maximize Penetration Depth Using Particle Swarm Optimization Algorithm

Mohamed MEZAACHE, Omar Fethi BENAOUDA, Saad CHAOUCH, Badreddine BABES, Rachid AMRAOUI  (2021)
Article de conférence

Systems based on artificial intelligence, such as particle swarm optimization and geneticalgorithm have received increased attention in many research areas. One of the main objectives inthe gas metal arc welding (GMAW) process is to achieve maximum depth of penetration (DP) as acharacteristic of quality and stiffness. This article has examined the application of particle swarmoptimization algorithm to obtain a better DP in a GMAW and compare the results obtained with thetechnique of genetic algorithms. The effect of four main welding variables in GMAW process whichare the welding voltage, the welding speed, the wire feed speed and the nozzle-to-plate distanceon the DP have been studied. For the implementation of optimization, a source code has beendeveloped in MATLAB 8.3. The results showed that, in order to obtain the upper penetration depth,it is necessary that: the welding voltage, the welding speed and the nozzle-to-plate distance must beat their lowest levels; the wire feed speed at its highest level Voir les détails

Mots clés : Artificial intelligence, Particle Swarm Optimization, Genetic algorithm, GMAW, penetration depth, optimization, Matlab

A Comparative Study between the Two Applications ofthe Neural Network and Space Vector PWM for DirectTorque Control of a DSIM Fed by Multi-Level Inverters

O. F. Benaouda, M. MEZAACHE, R.ABDELKADER, A. Bendiabdellah  (2022)
Article de conférence

Nowadays, thanks to the development of control and power electronics, the dualstator induction machine DSIM has become among the most important multi-phase machinesincluded in the industrial application of welding process, this is due to its positive featuresamong them is its high reliability and reduce both losses and rotor torque ripple.This paper aims to apply both techniques of artificial intelligence represented by the neuralnetwork algorithm NNA and the Space Vector PWM SVM for direct torque control DTC of theDSIM to improve the machine performance to control speed wire of Gas Metal Arc Welding(GMAW), and control algorithms DTNC and DTC-SVM.Generalization capacity, the parallelism of operation, computational speed, and learning ca-pacity all these features made it possible to exploit the neural network algorithm to control themachine. Fixed switching frequency obtained, dispensed with the vector selection table and thehysteresis controller, the three pros allowed the inclusion of SVM technique in DTC strategy.The converters are included to feed the DSIM and the GMAW process. A several of the re-sults obtained prove the two applied techniques (NNA, SVPWM) in improving the quality ofboth electromagnetic torque and flux and the dynamic responses of the DSIM. Voir les détails

Mots clés : GMAW, DSIM, Neural Network Algorithm NNA, Space Vector PWM SVM, DTNC, DTCSVM, Three-level NPC inverter

Synthesis and characterization of hydroxyapatite powder derived of eggshell by precipitation method

Samira TLILI, Saida Bouyegh, kotbia LABIOD, Noura Traiaia Mohamed Hassani, Bilal Ariche  (2021)
Article de conférence

Hydroxyapatite is the inorganic material with formula Ca10(PO4)6(OH)2. It is one of bioceramic was used for one repairs, fixing defects of filing voids in biomedical fields. The use of chicken eggshell is one of the natural sources to obtain the calcium phosphate compounds. The main objective of this study is to synthesize the hydroxyapatite by precipitation method from eggshell. The raw eggshell was calcined at 850°C for 2 hours following by grinding for 16 hours. The HA powder was synthesized by wet chemical method, using eggshells and phosphoric acid (H3PO4). X-ray diffraction spectroscopy (XRD, Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR) were used to characterize the morphology, composition and distribution of the particles. The Thermos gravimetric analysis (TGA-DTA) was also carried out to evaluate the stability of the synthesized HA powder. The particle-size distribution (PSD) of the powder was determined by the laser scattering particle size distribution analyzer. The results showed that the sintered at 1000°C of HA powder resembles the feature of pure and single apatite phase having favorable Ca/P ratio. Voir les détails

Mots clés : hydroxyapatite, Bioceramics, synthesis, Eggshell, Precipitation

Preparation and characteristics of synthesized hydroxyapatite from bovine bones and by co-precipitation method

Saida Bouyegh, Samira TLILI, kotbia LABIOD, Mohamed Hassani, Grimet Mohamed, Bensalem Oussama  (2021)
Article de conférence

Hydroxyapatite (HA, (Ca10(PO4)6(OH)2) is a widely studied bioceramic due to its biocompatibility, bioactivity, and chemical similarity to the mineral component of bone. Generally, hydroxyapatite can be made from several natural and synthetic sources.The objective of this study is to prepare hydroxyapatite powders from different precursors (natural or chemical). Hydroxyapatite was synthetized by Co-precipitation method, the chemical precursors of which are [Ca(NO3)2.4H2O, (NH4)2HPO4] and the natural source was bovine bone. Bovine hydroxyapatite (BHA) was extracted from the bovine bone bio-waste via thermal method and milling process. Synthesized HA (SHA) was prepared by co-precipitation method with the pH 10.0 of mother liquor. The prepared powders were characterized using various analytical techniques such as XRD, FTIR spectroscopy, thermogravimetry (ATG), and scanning electron microscope (SEM). These techniques provide information about the structural, chemical, morphological and physicochemical of each of the prepared powders. The use of co-precipitation method produced a low crystallinity of HA while the thermal method increased crystallinity. On the other hand, the results showed that the Ca / P ratio of synthetic hydroxyapatite (SHA) as well as that of bovine bone source (BHA) was also stoichiometric. Voir les détails

Mots clés : hydroxyapatite, Bovine bone, synthesis, Co-precipitation.

Asymmetric Generalized Gaussian DistributionParameters Estimation based on MaximumLikelihood, Moments and Entropy

Nafaa Nacereddine, Aicha Baya Goumeidane  (2019)
Article de conférence

In this paper, we address the problem of estimatingthe parameters of Asymmetric Generalized Gaussian Distribution(AGGD) using three estimation mehods, namely, Maximum LikelihoodEstimation (MLE), Moment Matching Estimation (MME)and Entropy Matching Estimaion (EME). For this purpose, thesemethods are applied on an unimodal histogram fitting of animage corrupted with AGGD noise. Experiments show that theeffectiveness of each method comparatively to the other onedepends on the variation range of the shape factor. Voir les détails

Mots clés : Asymmetric generalized Gaussian distribution, Parameter estimation, maximum likelihood, Moments, Entropy.

Tool combination for the description of steel surface image and defect classification

Zoheir MENTOURI, Hakim DOGHMANE, Kaddour Gherfi, Rachid Zaghdoudi, Hocine Bourouba  (2021)
Article de conférence

In industry, the automatic recognition of surface defects of flat steel products still represents a real challenge. Indeed, in addition to constraints such as the image noise or blur, there is neither an agreed standard of these defects nor a standard method that can ensure the defect identification, whatever are their size, shape, orientation and location. Thus, the complexity of the algorithm that deals with this matter always depends on specific needs of the application. In this paper, we give details on an approach that combines Gabor wavelets (GW) and the local phase quantization technique (LPQ), to describe the steel surface images, and uses the histogram to extract their characteristics. The defect classification is carried out by means of two classifiers, namely the nearest neighbors and the support vector machine. The method assessment is based on testing different parameter values of the used tools. The approach shows a good performance in terms of recognition rates and feature vector length, which impacts the computing time. Also, the study reveals its suitability for an online steel surface defect recognition application. Voir les détails

Mots clés : Quality control, Computer vision, metal surface imaging, Filter bank application, pattern analysis and recognition