Search results for: Wesam Bachir
64 Optimum Er: YAG Laser Parameters for Orthodontic Composite Debonding: An in vitro Study
Authors: Mohammad Zamzam, Wesam Bachir, Imad Asaad
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Several studies have produced estimates of Er:YAG laser parameters and specifications but there is still insufficient data for reliable selection of laser parameters. As a consequence, there is a heightened need for ideal specifications of Er:YAG laser to reduce the amount of enamel ablation. The objective of this paper is to investigate the influence of Er:YAG laser parameters, energy level and pulse duration, on orthodontic composite removal after bracket debonding. The sample consisted of 45 cuboids of orthodontic composite made by plastic moulds. The samples were divided into three groups, each was irradiated with Er:YAG laser set at different energy levels and three values for pulse durations (50 µs, 100 µs, and 300 µs). Geometrical parameters (depth and area) of cavities formed by laser irradiation were determined. ANCOVA test showed statistically significant difference (p < 0.0.5) between the groups indicating a potential effect of laser pulse duration on the geometrical parameters after controlling laser energy level. A post-hoc Bonferroni test ranked the 50µ Er:YAG laser pulse as the most influential factor for all geometrical parameters in removing remnant composite from enamel surface. Also, 300 mJ laser pulses caused the largest removal of the composite. The results of the present study demonstrated the efficacy of 50 µs and 300 mJ Er:YAG laser pulse for removal of remnant orthodontic composite.Keywords: enamel, Er:YAG, geometrical parameters, orthodontic composite, remnant composite
Procedia PDF Downloads 55363 A Single Loop Repetitive Controller for a Four Legs Matrix Converter Unit
Authors: Wesam Rohouma
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The aim of this paper is to investigate the use of repetitive controller to regulate the output voltage of three phase four leg matric converter for an Aircraft Ground Power Supply Unit. The proposed controller improve the steady state error and provide good regulation during different loading. Simulation results of 7.5 KW converter are presented to verify the operation of the proposed controller.Keywords: matrix converter, Power electronics, controller, regulation
Procedia PDF Downloads 150662 Thickness Effect on Concrete Fracture Toughness K1c
Authors: Benzerara Mohammed, Redjel Bachir, Kebaili Bachir
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The cracking of the concrete is a more crucial problem with the development of the complex structures related to technological progress. The projections in the knowledge of the breaking process make it possible today for better prevention of the risk of the fracture. The breaking strength brutal of a quasi-fragile material like the concrete called Toughness, is measured by a breaking value of the factor of intensity of the constraints K1C for which the crack is propagated, it is an intrinsic property of material. Many studies reported in the literature treating of the concrete were carried out on specimens which are in fact inadequate compared to the intrinsic characteristic to identify. We started from this established fact, in order to compare the evolution of the parameter of toughness K1C measured by calling upon ordinary concrete specimens of three prismatics geometries different (10*10*84) cm³ and (5*20*120) cm³ &(12*20*120) cm³ containing from the side notches various depths simulating of the cracks was set up. The notches are carried out using triangular pyramidal plates into manufactured out of sheet coated placed at the centre of the specimens at the time of the casting, then withdrawn to leave the trace of a crack. The tests are carried out in 3 points bending test in mode 1 of fracture, by using the techniques of mechanical fracture. The evolution of the parameter of toughness K1C measured with the three geometries specimens gives almost the same results. They are acceptable and return in the beach of the results determined by various researchers (toughness of the ordinary concrete turns to the turn of the 1 MPa √m). These results inform us about the presence of an economy on the level of the geometrie specimen (5*20*120) cm³, therefore to use plates specimens later if one wants to master the toughness of this material complexes, astonishing but always essential that is the concrete.Keywords: elementary representative volume, concrete, fissure, toughness
Procedia PDF Downloads 22461 Effect of Fabrication Errors on High Frequency Filter Circuits
Authors: Wesam Ali
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This paper provides useful guidelines to the circuit designers on the magnitude of fabrication errors in multilayer millimeter-wave components that are acceptable and presents data not previously reported in the literature. A particularly significant error that was quantified was that of skew between conductors on different layers, where it was found that a skew angle of only 0.1° resulted in very significant changes in bandwidth and insertion loss. The work was supported by a detailed investigation on a 35GHz, multilayer edge-coupled band-pass filter, which was fabricated on alumina substrates using photoimageable thick film process.Keywords: fabrication errors, multilayer, high frequency band, photoimagable technology
Procedia PDF Downloads 47360 Iterative Linear Quadratic Regulator (iLQR) vs LQR Controllers for Quadrotor Path Tracking
Authors: Wesam Jasim, Dongbing Gu
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This paper presents an iterative linear quadratic regulator optimal control technique to solve the problem of quadrotors path tracking. The dynamic motion equations are represented based on unit quaternion representation and include some modelled aerodynamical effects as a nonlinear part. Simulation results prove the ability and effectiveness of iLQR to stabilize the quadrotor and successfully track different paths. It also shows that iLQR controller outperforms LQR controller in terms of fast convergence and tracking errors.Keywords: iLQR controller, optimal control, path tracking, quadrotor UAVs
Procedia PDF Downloads 44759 Performance Improvement of Photovoltaic Module at Different Tilt Angle in Kuwait
Authors: Hussain Bunyan, Wesam Ali
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In this paper we will study the performance of a Silicon Photovoltaic (PV) system with different tilt angle arrangement in Kuwait (latitude 30˚ N). In this study the PV system is installed facing south, collecting maximum solar radiation at noon, and their angles are from 00 to 900 respectively, during full year at the Solstice and Equinox periods and aiming for a higher angle than 300 with competitive output power. The results show that the performance and the output power of the PV system with 50˚ tilt angle, is equivalent to the latitude tilt angle (30˚) during a full year.Keywords: photovoltaic model, tilt angle, solar collector, PV system performance, State of Kuwait
Procedia PDF Downloads 51458 Performance of Photovoltaic Module at Different Tilt Angles
Authors: Hussain Bunyan, Wesam Ali
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In this paper we will study the performance of a Silicon Photovoltaic (PV) system with different tilt angle arrangement in Kuwait (latitude 30˚ N). In the study the PV system is installed facing South, collecting maximum solar radiation at noon, and their angles are from 00 to 900 respectively, during full year at the Solstice and Equinox periods, aiming for a higher angle than 300 with competitive output power. The results show that the performance and the output power of the PV system with 50˚ tilt angle, is equivalent to the latitude tilt angle (30˚) during a full year.Keywords: photovoltaic model, tilt angle, solar collector, PV system performance, State of Kuwait
Procedia PDF Downloads 49257 Modeling Revolution Shell Structures by MATLAB Programming-Axisymmetric and Nonaxisymmetric Shells
Authors: Hamadi Djamal, Labiodh Bachir, Ounis Abdelhafid, Chaalane Mourad
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The objective of this work is setting numerically operational finite element CAXI_L for the axisymmetric and nonaxisymmetric shells. This element is based on the Reissner-Mindlin theory and mixed model formulation. The MATLAB language is used for the programming. In order to test the elaborated program, some applications are carried out.Keywords: axisymmetric shells, nonaxisymmetric behaviour, finite element, MATLAB programming
Procedia PDF Downloads 31856 Physico-Chemical Parameters and Economic Evaluation of Bio-Ethanol Produced from Waste of Starting Dates in South Algeria
Authors: Insaf Mehani, Bachir Bouchekima
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The fight against climate change and the replacement of fossil energies nearing exhaustion gradually emerge as major societal and economic challenges. It is possible to develop common dates of low commercial value, and put on the local and international market a new generation of products with high added values such as bio ethanol. Besides its use in chemical synthesis, bio ethanol can be blended with gasoline to produce a clean fuel while improving the octane.Keywords: bio-energy, waste dates, bio ethanol, Algeria
Procedia PDF Downloads 36555 Video Based Automatic License Plate Recognition System
Authors: Ali Ganoun, Wesam Algablawi, Wasim BenAnaif
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Video based traffic surveillance based on License Plate Recognition (LPR) system is an essential part for any intelligent traffic management system. The LPR system utilizes computer vision and pattern recognition technologies to obtain traffic and road information by detecting and recognizing vehicles based on their license plates. Generally, the video based LPR system is a challenging area of research due to the variety of environmental conditions. The LPR systems used in a wide range of commercial applications such as collision warning systems, finding stolen cars, controlling access to car parks and automatic congestion charge systems. This paper presents an automatic LPR system of Libyan license plate. The performance of the proposed system is evaluated with three video sequences.Keywords: license plate recognition, localization, segmentation, recognition
Procedia PDF Downloads 46454 The Relationship between Political Risks and Capital Adequacy Ratio: Evidence from GCC Countries Using a Dynamic Panel Data Model (System–GMM)
Authors: Wesam Hamed
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This paper contributes to the existing literature by investigating the impact of political risks on the capital adequacy ratio in the banking sector of Gulf Cooperation Council (GCC) countries, which is the first attempt for this nexus to the best of our knowledge. The dynamic panel data model (System‐GMM) showed that political risks significantly decrease the capital adequacy ratio in the banking sector. For this purpose, we used political risks, bank-specific, profitability, and macroeconomic variables that are utilized from the data stream database for the period 2005-2017. The results also actively support the “too big to fail” hypothesis. Finally, the robustness results confirm the conclusions derived from the baseline System‐GMM model.Keywords: capital adequacy ratio, system GMM, GCC, political risks
Procedia PDF Downloads 14753 A Techno-Economic Evaluation of Bio Fuel Production from Waste of Starting Dates in South Algeria
Authors: Insaf Mehani, Bachir Bouchekima
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The necessary reduction and progressive consumption of fossil fuels, whose scarcity is inevitable, involves mobilizing a set of alternatives.Renewable energy, including bio energy are an alternative to fossil fuel depletion and a way to fight against the harmful effects of climate change. It is possible to develop common dates of low commercial value, and put on the local and international market a new generation of products with high added values such as bio ethanol. Besides its use in chemical synthesis, bio ethanol can be blended with gasoline to produce a clean fuel while improving the octane.Keywords: bioenergy, dates, bioethanol, renewable energy, south Algeria
Procedia PDF Downloads 49052 Bee Colony Optimization Applied to the Bin Packing Problem
Authors: Kenza Aida Amara, Bachir Djebbar
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We treat the two-dimensional bin packing problem which involves packing a given set of rectangles into a minimum number of larger identical rectangles called bins. This combinatorial problem is NP-hard. We propose a pretreatment for the oriented version of the problem that allows the valorization of the lost areas in the bins and the reduction of the size problem. A heuristic method based on the strategy first-fit adapted to this problem is presented. We present an approach of resolution by bee colony optimization. Computational results express a comparison of the number of bins used with and without pretreatment.Keywords: bee colony optimization, bin packing, heuristic algorithm, pretreatment
Procedia PDF Downloads 63451 Metaphors in Egyptian News Headlines in Relation to the Egyptian Political Situation 2012-2013
Authors: Wesam Mohamed Abdel Khalek Ibrahim
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This paper examines the use of metaphors in Arabic political news discourse, focusing particularly on the headlines of the news articles relating to the Egyptian political situation in the period from June 2012 to October 2013. Metaphors are skilfully manipulated in the headlines to influence the public stance towards several events and entities including Egypt, Muslim Brotherhood (MB), Morsi, the June 30th uprising, Al-Sisi and the Armed Forces. The findings reveal that Arabic political news discourse shares basic features with its English counterpart, namely the use of metaphors as persuasive strategies and the presence of certain target domains. Insights gained from this study feed back into the conceptual metaphor theory by providing further evidence to the universality of metaphors.Keywords: conceptual metaphor theory, political discourse, news discourse, Egyptian political situation
Procedia PDF Downloads 50550 Sizing of Hybrid Source Battery/Supercapacitor for Automotive Applications
Authors: Laid Degaa, Bachir Bendjedia, Nassim Rizoug, Abdelkader Saidane
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Energy storage system is a key aspect for the development of clean cars. The work proposed here deals with the modeling of hybrid storage sources composed of a combination of lithium-ion battery and supercapacitors. Simulation results show the performance of the active model for a hybrid source and confirm the feasibility of our approach. In this context, sizing of the electrical energy supply is carried out. The aim of this sizing is to propose an 'optimal' solution that improves the performance of electric vehicles in term of weight, cost and aging.Keywords: battery, electric vehicles, energy, hybrid storage, supercapacitor
Procedia PDF Downloads 79349 Study of Hybrid Cells Based on Perovskite Materials Using Oghmasimultion
Authors: Nadia Bachir (Dahmani), Fatima Zohra Otmani
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Due to its interesting optoelectronic properties, methylammonium perovskite CH3NH3PbI3 is used as the active layer in the development of several solar cells. In this work, the hybrid (organic-inorganic) cell with the architecture FTO/pedotpss/CH3NH3PbI3/pcdtbt/Al is simulated using the Organic and Hybrid Material Nano Simulation Tool (OghmaNano). We studied the influence of certain parameters, such as thickness, on the characteristics of the solar cell. The effect of the device temperature was also investigated. The photovoltaic characteristic curves, such as current-voltage (j-V), are presented in this work. The optimized final parameters are Voc = 0.947 V, FF = 0.8034%, and PCE = 23.16%.Keywords: OghmaNano software, hybrid perovskite cell, CH3NH3PbI3, conversion efficiency
Procedia PDF Downloads 1548 Optimization of the Aerodynamic Performances of an Unmanned Aerial Vehicle
Authors: Fares Senouci, Bachir Imine
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This document provides numerical and experimental optimization of the aerodynamic performance of a drone equipped with three types of horizontal stabilizer. To build this optimal configuration, an experimental and numerical study was conducted on three parameters: the geometry of the stabilizer (horizontal form or reverse V form), the position of the horizontal stabilizer (up or down), and the landing gear position (closed or open). The results show that up-stabilizer position with respect to the horizontal plane of the fuselage provides better aerodynamic performance, and that the landing gear increases the lift in the zone of stability, that is to say where the flow is not separated.Keywords: aerodynamics, drag, lift, turbulence model, wind tunnel
Procedia PDF Downloads 25247 Influence of Chemical Treatment on Elastic Properties of the Band Cotton Crepe 100%
Authors: Bachir Chemani, Rachid Halfaoui, Madani Maalem
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The manufacturing technology of band cotton is very delicate and depends to choice of certain parameters such as torsion of warp yarn. The fabric elasticity is achieved without the use of any elastic material, chemical expansion, artificial or synthetic and it’s capable of creating pressures useful for therapeutic treatments.Before use, the band is subjected to treatments of specific preparation for obtaining certain elasticity, however, during its treatment, there are some regression parameters. The dependence of manufacturing parameters on the quality of the chemical treatment was confirmed. The aim of this work is to improve the properties of the fabric through the development of manufacturing technology appropriately. Finally for the treatment of the strip pancake 100% cotton, a treatment method is recommended.Keywords: elastic, cotton, processing, torsion
Procedia PDF Downloads 38846 Stress Study in Implants Dental
Authors: M. Benlebna, B. Serier, B. Bachir Bouiadjra, S. Khalkhal
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This study focuses on the mechanical behavior of a dental prosthesis subjected to dynamic loads chewing. It covers a three-dimensional analysis by the finite element method, the level of distribution of equivalent stresses induced in the bone between the implants (depending on the number of implants). The studied structure, consisting of a braced, implant and mandibular bone is subjected to dynamic loading of variable amplitude in three directions corrono-apical, mesial-distal and bucco-lingual. These efforts simulate those of mastication. We show that compared to the implantation of a single implant, implantology using two implants promotes the weakening of the bones. This weakness is all the more likely that the implants are located in close proximity to one another.Keywords: stress, bone, dental implant, distribution, stress levels, dynamic, effort, interaction, prosthesis
Procedia PDF Downloads 40445 Features Dimensionality Reduction and Multi-Dimensional Voice-Processing Program to Parkinson Disease Discrimination
Authors: Djamila Meghraoui, Bachir Boudraa, Thouraya Meksen, M.Boudraa
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Parkinson's disease is a pathology that involves characteristic perturbations in patients’ voices. This paper describes a proposed method that aims to diagnose persons with Parkinson (PWP) by analyzing on line their voices signals. First, Thresholds signals alterations are determined by the Multi-Dimensional Voice Program (MDVP). Principal Analysis (PCA) is exploited to select the main voice principal componentsthat are significantly affected in a patient. The decision phase is realized by a Mul-tinomial Bayes (MNB) Classifier that categorizes an analyzed voice in one of the two resulting classes: healthy or PWP. The prediction accuracy achieved reaching 98.8% is very promising.Keywords: Parkinson’s disease recognition, PCA, MDVP, multinomial Naive Bayes
Procedia PDF Downloads 27844 A Comparative Analysis of Multicarrier SPWM Strategies for Five-Level Flying Capacitor Inverter
Authors: Bachir Belmadani, Rachid Taleb, Zinelaabidine Boudjema, Adil Yahdou
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Carrier-based methods have been used widely for switching of multilevel inverters due to their simplicity, flexibility and reduced computational requirements compared to space vector modulation (SVM). This paper focuses on Multicarrier Sinusoidal Pulse Width Modulation (MCSPWM) strategy for the three phase Five-Level Flying Capacitor Inverter (5LFCI). The inverter is simulated for Induction Motor (IM) load and Total Harmonic Distortion (THD) for output waveforms is observed for different controlling schemes.Keywords: flying capacitor inverter, multicarrier sinusoidal pulse width modulation, space vector modulation, total harmonic distortion, induction motor
Procedia PDF Downloads 41043 FE Analysis of the Notch Effect on the Behavior of Repaired Crack with Bonded Composite Patch in Aircraft Structures
Authors: Faycal Benyahia, Abdelmohsen Albedah, Bel Abbes Bachir Bouiadjra
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In this paper, the finite element analysis is applied to study the performance of the bonded composite reinforcement or repair for reducing stress concentration at a semi-circular lateral notch and repairing cracks emanating from this kind of notch. The effects of the adhesive properties on the variation of the stress intensity factor at the crack tip were highlighted. The obtained results show that the stress concentration factor at the notch tip is reduced about 30% and the maximal reduction of the stress intensity factor is about 80%. The adhesive properties must be optimized in order to increase the performance of the patch repair or reinforcement.Keywords: bonded repair, notch, crack, adhesive, composite
Procedia PDF Downloads 39242 Effect of Water Absorption on the Fatigue Behavior of Glass/Polyester Composite
Authors: Djamel Djeghader, Bachir Redjel
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The composite materials of glass fibers can be used as a repair material for damage elements under repeated stresses, and in various environments. A cyclic bending characterization of a glass/polyester composite material was carried out with consideration of the period of immersion in water. These tests describe the behavior of materials and identify the mechanical fatigue characteristics using the Wohler Curve for different immersion time: 0, 90, 180 and 270 days in water. These curves are characterized by a dispersion in the lifetimes were modeled by straight whose intercepts are very similar and comparable to the static strength. This material deteriorates fatigue at a constant rate, which increases with increasing immersion time in water at a constant speed. The endurance limit seems to be independent of the immersion time in the water.Keywords: fatigue, composite, glass, polyester, immersion, wohler
Procedia PDF Downloads 31441 Sliding Mode Control of an Internet Teleoperated PUMA 600 Robot
Authors: Abdallah Ghoul, Bachir Ouamri, Ismail Khalil Bousserhane
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In this paper, we have developed a sliding mode controller for PUMA 600 manipulator robot, to control the remote robot a teleoperation system was developed. This system includes two sites, local and remote. The sliding mode controller is installed at the remote site. The client asks for a position through an interface and receives the real positions after running of the task by the remote robot. Both sites are interconnected via the Internet. In order to verify the effectiveness of the sliding mode controller, that is compared with a classic PID controller. The developed approach is tested on a virtual robot. The results confirmed the high performance of this approach.Keywords: internet, manipulator robot, PID controller, remote control, sliding mode, teleoperation
Procedia PDF Downloads 33140 Valorization of Clay Material in the Road Sector By Adding Granulated Recycled Plastic
Authors: Ouaaz Oum Essaad, Melbouci Bachir
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The experimental study conducted has a dual purpose: to valorize the clay material in the road domain and improve the lift of the shape layers by strengthening with plastic waste (in the form of aggregates). To do this, six mixtures of Clay and sand of different percentages were studied: 100% Clay, 95% Clay + 05% Sand, 90% Clay + 10% Sand, 85% Clay + 15% Sand, 80% Clay + 20% Sand, 75% Clay + 25% Sand. Proctor compaction and simple compression tests have been carried out on mixtures (sand + clay + plastic waste). The results obtained show a clear evolution of the characteristics of the Proctor test and the compressive strength of the mixtures according to the different types and percentages of the recycled plastic Plasticity and consistency index are important parameters that play a role in the toughness of plastic soil.Keywords: valorization, recycling, soil mixture, mechanical tests
Procedia PDF Downloads 10339 Theoretical Density Study of Winding Yarns on Spool
Authors: Bachir Chemani, Rachid Halfaoui
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The aim of work is to define the distribution density of winding yarn on cylindrical and conical bobbins. It is known that parallel winding gives greater density and more regular distribution, but the unwinding of yarn is much more difficult for following process. The conical spool has an enormous advantage during unwinding and may contain a large amount of yarns, but the density distribution is not regular because of difference in diameters. The variation of specific density over the reel height is explained generally by the sudden change of winding speed due to direction movement variation of yarn. We determined the conditions of uniform winding and developed a calculate model to the change of the specific density of winding wire over entire spool height.Keywords: textile, cylindrical bobbins, conical bobbins, parallel winding, cross winding
Procedia PDF Downloads 37738 Degradation of the Mechanical Properties of the Polypropylene Talc Nanocomposite in Chemical Environment
Authors: Ahmed Ouadah Bouakkaz, Mohamed Elmeguenni, Bel Abbes Bachir Bouiadjra, Mohamed Belhouari, Abdulmohsen Albedah
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In this study, the effect of the chemical environment on the mechanical properties of the polypropylene-talc composite was analyzed. The talc proportion was varied in order to highlight the combined effects of time of immersion in the chemical environment 'benzene' and talc concentration on the mechanical properties of the composite. Tensile test was carried out to evaluate the mechanical properties of PP-talc composite and to analyze the effect of the immersion time on the variation of these properties. The obtained results show that increasing the time of immersion has a very negative effect on the mechanical strength of the PP-talc composite, but this effect can be significantly reduced by the augmentation of the talc proportion.Keywords: polypropylene (PP), talc, nanocomposite, degradation
Procedia PDF Downloads 38537 Perception and Knowledge of the Jordanian Society of Occupational Therapy
Authors: Wesam Darawsheh
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Background: there are scarcity of studies done to investigate the level of knowledge and the level of awareness and perception of Jordanians about occupational therapy (OT). Aim: to investigate the level of awareness of lay people, clients receiving services and healthcare professionals of OT, identify the common misconceptions about OT, and to explore ways whereby the knowledge and awareness about OT can be increased. Methodology: a cross sectional design was employed in this study where a survey was distributed in the Northern, Southern, Western, Eastern provinces and the Middle (capital city: Amman) province of Jordan. The survey consisted of eight section and 61 questions that aims to investigate the demographics of participants, self evaluation concerning knowledge and awareness about OT, sources of knowledge about OT, the perception of the aims, fields of practice, OT settings, misconceptions about OT, and suggestion to improve knowledge and awareness about OT. Results: A total of 829 participants were enrolled in this study: 459 lay people, 155 clients who are currently receiving OT services, 215 healthcare professionals. About 57% of the participants did not hear about OT, and 48% of those who reported to hear about OT did not have sufficient knowledge about it. There are several misconceptions associated with OT. The statistical analysis was executed using IBM SPSS software, Version 22.0 (SPSS, Chicago, USA). Conclusion: it is the responsibility of OTRs to increase the knowledge and awareness about OT in Jordan. This is required for the profession to proliferate and to be given its status.Keywords: knowledge, occupational therapy misconceptions, healthcare professionals, lay people, Jordan
Procedia PDF Downloads 36236 Hybrid Control Strategy for Nine-Level Asymmetrical Cascaded H-Bridge Inverter
Authors: Bachir Belmadani, Rachid Taleb, M’hamed Helaimi
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Multilevel inverters are well used in high power electronic applications because of their ability to generate a very good quality of waveforms, reducing switching frequency, and their low voltage stress across the power devices. This paper presents the hybrid pulse-width modulation (HPWM) strategy of a uniform step asymmetrical cascaded H-bridge nine-level Inverter (USACHB9LI). The HPWM approach is compared to the well-known sinusoidal pulse-width modulation (SPWM) strategy. Simulation results demonstrate the better performances and technical advantages of the HPWM controller in feeding a high power induction motor.Keywords: uniform step asymmetrical cascaded h-bridge high-level inverter, hybrid pwm, sinusoidal pwm, high power induction motor
Procedia PDF Downloads 57135 Computation of Thermal Stress Intensity Factor for Bonded Composite Repairs in Aircraft Structures
Authors: Fayçal Benyahia, Abdelmohsen Albedah, Bel Abbes Bachir Bouiadjra
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In this study the Finite element method is used to analyse the effect of the thermal residual stresses resulting from adhesive curing on the performances of the bonded composite repair in aircraft structures. The stress intensity factor at the crack tip is chosen as fracture criterion in order to estimate the repair performances. The obtained results show that the presence of the thermal residual stresses reduces considerably the repair performances and consequently decreases the fatigue life of cracked structures. The effects of the curing temperature, the adhesive properties and the adhesive thickness on the Stress Intensity Factor (SIF) variation with thermal stresses are also analysed.Keywords: bonded composite repair, residual stress, adhesion, stress transfer, finite element analysis
Procedia PDF Downloads 417