Faculty of technology_PPI

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Particle swarm optimization based optimal power flow for units with non-smooth fuel cost functions
(IEEE, 2009-11-15) Ben Attous, Djillani; Labbi, Yacine
This paper presents a Particle Swarm Optimization (PSO) based algorithm for optimal flow with generating units having non-smooth fuel costs curves while statisfying the constraints such as generator capacity limits, power balance, line flow limits, bus voltages and transformer tap setting, The conventional loed flow and incorporation of the proposed method using PSO has been examined and tested for standard IEEE 30 bus system. The PSO method is demonstrated and compared with conventional OPF method and the intelligence heuristic algorithm such as genetic algorithm, evolutionary programming. The superiority of th method over other methods has been demonstrated on two test cases. From simulation results, it has been found that PSO method is highly competitve for its better general convergence performance
Speed Control of a Doubly Fed Induction Motor using Fuzzy Logic Techniques
(School of Electrical Engineering and Informatics, Bandung Institute of Techonolgy, Indonesia, 2010-07-01) Ben Attous, D; Bekakra, Youcef
This paper presents a comparison between a fuzzy logic controller and a conventional IP controller used for speed control with a direct stator flux orientation control of a doubly fed induction motor. The effectiveness of the proposed control strategy is evaluated under different operating conditions such as of reference speed and for load torque step changes at nominal parameters and in the presence of parameter variation. Simulation results show that the fuzzy logic controller is more robust than a conventional IP controller against parameter variation and uncertainty, and is less sensitive to external load torque disturbance with a fast dynamic response.
In vitro Evaluation of Antioxidant Capacity of Algerian Propolis by Spectrophotometrical and Electrochemical Assays
(Asian Network for Scientific Information, 2011-01-01) Rebiai, A; Lanez, T; Belfar, ML
The aim of the present study was to evaluate the antioxidant capacity and the total phenolic content of propolis extract, obtained from colonies of honeybees located in El-Oued (south of Algeria). The total phenolic content was evaluated using the Folin-Ciocalteu method and the anticoxidant capacity was measured using the following methods: 2, 2-diphenyl-1-picryhydrazyl free radical scavenging capacity and reducing power capacity for spectrophotometrical techniques, ascorbic and gallic acids equivalent antioxidant capacity assays for electrochemical techniques. Both techniques allowed an evaluation of the antioxidant capacity of methanolic propolis extract. The electrochemical techniques were performed by cyclic voltammetry, the results suggest that propolis extract do not reveal similar electrochemical responses to that of ascorbic and gallic acids, suggesting a different electroactive chemical composition and oxidation potential more positive than that of the standard (ascorbic acid), however this does not suggest that propolis has a lower antioxidant capacity. The results suggest also that propolis extract possess antioxidant capacity in vitro conditions.
Sliding Mode Controls of Active and Reactive Power of a DFIG with MPPT for Variable Speed Wind Energy Conversion
(Australian Journal of Basic and Applied Sciences, 2011-12) Bekakra, Youcef; Ben Attous, D
This paper presents the study of a variable speed wind energy conversion system based on a Doubly Fed Induction Generator (DFIG) based on a sliding mode control applied to achieve control of active and reactive powers exchanged between the stator of the DFIG and the grid to ensure a Maximum Power Point Tracking (MPPT) of a wind energy conversion system. The proposed control algorithm is applied to a DFIG whose stator is directly connected to the grid and the rotor is connected to the PWM converter. To extract a maximum of power, the rotor side converter is controlled by using a stator flux-oriented strategy. The created decoupling control between active and reactive stator power allows keeping the power factor close to unity. Simulation results show that the wind turbine can operate at its optimum energy for a wide range of wind speed.
Elaboration and characterisation of ZnO thin films
(EDP Sciences, 2012) Benramache, S.; Benhaoua, B.; Khechai, N.; Chabane, F.
Abstract – Highly transparent ZnO thin films have been prepared on microscope glass substrate using dip-coating technique. The films were obtained at a concentration of solgel solution is 0.5 M. The structural and optical properties of the ZnO thin films were studied as a function of the annealing temperature varying between 450 to 600 ◦C. From the XRD analysis, the whole obtained films have a hexagonal wurtzite structure with a strong (002) preferred c-axis orientation. The grain size increased with annealing temperature indicating an improvement in the crystallinity of the films. The average transmittance of all the films is about 70–80% as measured by UV-vis analyzer. The band gap increased with the increase of temperature from 3.25 to 3.42 eV. The decrease of the strain of ZnO films is probably due to an improvement of the crystallinity of the films. The best result is achieved at 600 ◦C.
Effect of substrate temperature on the stability of transparent conducting cobalt doped ZnO thin films
(IOP Publishing, 2012-09-01) Benramache, Said; Benhaoua, Boubaker; Chabane, Foued
Transparent conducting Co doped ZnO thin films have been fabricated by Ultrasonic spray. The thin films were deposited at three different substrate temperatures of 300, 350 and 400 ℃. The obtained films had a hexagonal wurtzite structure with a strong (002) preferred orientation. The maximum crystallite size value of the film deposited at 350 ℃ is 55.46 nm. Spectrophotometer (UV-vis) of a Co doped ZnO film deposited at 350 ℃ shows an average transmittance of about 90%. The band gap energy increased from 3.351 to 3.362 eV when the substrate temperature increased from 300 to 350 ℃. The electrical conductivity of the films deposited at 300, 350 and 400 ℃ were 7.424, 7.547 and 6.743 (Ω·cm)-1 respectively. The maximum activation energy value of the films at 350 ℃ was 1.28 eV, indicating that the films exhibit a n-type semiconducting nature.
Comparison Study Between SVM and PWM Inverter in Sliding Mode Control of Active and Reactive Power Control of a DFIG for Variable Speed Wind Energy
(İlhami ÇOLAK, 2012-09-18) Bekakra, Youcef; Ben Attous, Djilani
t- In this paper, we present a comparative study between space vector modulation (SVM) and pulse width modulation (PWM) inverter in sliding mode control (SMC) of active and reactive power control of a doubly fed induction generator (DFIG) for variable speed wind energy. The feasibility and effectiveness of the two methods are demonstrated by simulation results. The obtained results showed that, the proposed SMC with SVM inverter have stator and rotor current with low harmonic distortion and low active and reactive powers ripples than PWM inverter.
Influence of annealing temperature on structural and optical properties of ZnO: In thin films prepared by ultrasonic spray technique
(Superlattices and Microstructures, 2012-12) Benramache, Said; Benhaoua, Boubaker
Transparent conducting indium doped zinc oxide was deposited on glass substrate by ultrasonic spray method. The In doped ZnO samples with indium concentration of 3 wt.% were deposited at 300, 350 and 400 °C with 2 min of deposition time. The effects of substrate temperature and annealing temperature on the structural, electrical and optical properties were examined. The DRX analyses indicated that In doped ZnO films have polycrystalline nature and hexagonal wurtzite structure with (0 0 2) preferential orientation and the maximum average crystallite size of ZnO: In before and annealed at 500 °C were 45.78 and 55.47 nm at a substrate temperature of 350 °C. The crystallinity of the thin films increased by increasing the substrate temperature up 350 °C, the crystallinity improved after annealing temperature at 500 °C. The film annealed at 500 °C and deposited at 350 °C show lower absorption within the visible wavelength region. The band gap energy increased from Eg = 3.25 to 3.36 eV for without annealing and annealed films at 500 °C, respectively, indicating that the increase in the transition tail width. This is due to the increase in the electrical conductivity of the films after annealing temperature.
Chemical composition and antioxidant activity of Apis mellifera bee pollen from northwest Algeria
(Journal of Fundamental and Applied Sciences, 2012-12-31) Rebiai, Abdelkrim; Lanez, Touhami
The aim of this study was to assess the nutritional composition and antioxidant activity of bee pollen produced in the North western region of Algeria. The content of total phenolic compounds, flavonoids, and antioxidant activity using the molybdate ion reduction method were determined. The mean contents of phenolic compounds and total flavonoids were 30.46 ± 8.22 mg of GAE.g–1 pollen and 8.92 ± 5.5 mg of RE.g–1 pollen, respectively. High antioxidant activities were found for the molybdate ion reduction method, with values that ranged from 71.95 to 101.5 μg of GAE.g –1 pollen. The bee pollen of Boufarik showed high antioxidant activity probably due to the high content of phenolic compounds present in pollen.
Influence of growth time on crystalline structure, conductivity and optical properties of ZnO thin films
(IOP Publishing, 2013-02-01) Benramache, Said; Chabane, Foued; Benhaoua, Boubaker; Lemmadi, Fatima Z
This paper examines the growth of ZnO thin films on glass substrate at 350 °C using an ultrasonic spray technique. We have investigated the influence of growth time ranging from 1 to 4 min on structural, optical and electrical properties of ZnO thin films. The as-grown films exhibit a hexagonal structure wurtzite and are (002) oriented. The maximum value of grain size G = 63.99 nm is attained for ZnO films grown at 2 min. The average transmittance is about 80%, thus the films are transparent in the visible region. The optical gap energy is found to increase from 3.26 to 3.37 eV with growth time increased from 1 to 2 min. The minimum value of electrical resistivity of the films is 0.13 Ω·cm obtained at 2 min. A systematic study on the influence of growth time on the properties of ZnO thin films deposited by ultrasonic spray at 350 °C has been reported.
Preparation of transparent conducting ZnO:Al films on glass substrates by ultrasonic spray technique
(IOP Publishing, 2013-07-01) Gahtar, Abdelouahab; Benramache, Said; Benhaoua, Boubaker; Chabane, Foued
Transparent conductive Al doped ZnO thin films were deposited by ultrasonic spray technique. Conditions of preparation have been optimized to get good quality. A set of aluminum (Al) doped ZnO (between 0 and 5 wt%) thin films were grown on glass substrate at 350 °C. Nanocrystalline films with a hexagonal wurtzite structure show a strong (002) preferred orientation. The maximum value of grain size G = 32.05 nm is attained of Al doped ZnO film with 3 wt%. All the films have low absorbance in the visible region, thus the films are transparent in the visible region; the band gap energy increased from 3.10 to 3.26 eV when Al concentration increased from 0 to 3 wt%. The electrical conductivity of the films increased from 7.5 to 15.2 (Ω·cm)−1. So the best results are achieved in Al doped ZnO film with 3 wt%.
Modélisation et Optimisation Multi -Objective de Robot Delta Linéaire
(University of Eloued جامعة الوادي, 2013-10-30) Mansouri, K.; Belaidi, I.
La conception d'architectures innovantes de machines agiles dédiées à l'UTVG nécessite la mise en oevre de modèles analytiques et numériques pour l'optimisation du comportement cinématique, statique et dynamique de la machine, avec prise en considération des déformation élastiques et leur compensation au niveau de la commande de la machine. Dans le contexte d'une optimisation multi-objectif, il s'agit dans une première partie d'identifier les paramètres et variables inhérents à chaque élément constitutif d'une machine de type robot DELTA, dont le but d'optimiser les éléments essentiels de sa structure. Ceci nécessite une formulation du problèùe multi-objectif en exprimant les fonctions objectives, les contraintes et les espaces de recherche correspondants, ainsi que la résolution du problème par l'utilisation de méthodes et outils mathématiques performants (Algorithmes génétique,...).
Preparation of transparent, conductive ZnO:Co and ZnO:In thin films by ultrasonic spray method
(Journal of Nanostructure in Chemistry. Springer Berlin Heidelberg, 2013-12) Benramache, Said; Benhaoua, Boubaker; Bentrah, Hamza
This paper examines the growth of undoped and doped thin films with (Co and In) on glass substrate at 350°C using ultrasonic spray technique. We have investigated the influence of doping concentrations ranging from 0 to 4 wt.% on structural, optical, and electrical properties of ZnO thin films. Zinc acetate dehydrate, CoCl3 4H2O or InCl3, ethanol, and monoethanolamine were used as a starting materials, dopant source, solvent, and stabilizer, respectively. The X-ray diffraction analysis indicated that the undoped and doped ZnO thin films have polycrystalline nature and hexagonal wurtzite structure with (002) preferential orientation. The maximum average crystallite sizes of ZnO:Co and ZnO:In were 55.46 and 45.78 nm at concentrations of 2 wt.% Co and 3 wt.% In, respectively, indicating that the crystallinity of doped films improved after doping. The optical absorption spectra showed that all undoped and doped ZnO films are transparent within the visible wavelength region. The band gap energy of ZnO:Co thin films increased after doping from 3.25 to 3.36 eV; however, the optical gap of ZnO:In decreases after doping from 3.25 to 3.18 eV, indicating the increase and decrease, respectively, in the transition tail width. The electrical conductivity of doped films is stabilized after doping. Transparent, conductive Co-doped ZnO thin films deposited by ultrasonic spray technique are of good quality.
Comparative Study of Honey Collected from Different Flora of Algeria
(Journal of Fundamental and Applied Sciences, 2014) Rebiai, A; Lanez, T
The aim of the present study was to evaluate the physical and chemical properties of five Algerian unifloral types of honey. Several physical parameters of honey, such as pH, moisture content, electrical conductivity, total dissolved solids, color intensity and total sugar content, were measured. The mean pH, moisture content, EC and water insoluble solids of Algerian honey were 4.41± 0.58, 15.3 ± 1.5%, 0.324± 0.116 mS/cm and 0.141± 0.065%, respectively. The mean color was 81 ± 72 mm Pfund. The majority of honey samples test results (moisture content, electric conductivity and acidity) levels were within the acceptable range of world honey standards.
total polyphenol contents, radical scavenging and cyclic voltammetry of Algerian propolis
(International Journal of Pharmacy and Pharmaceutical Sciences, 2014) Lanez, Touhami; Rebiai, Abdelkrim; Belfar, M Lakhdar
Objective: In this study, we will determine the antioxidant properties of methanolic extract of propolis from Ghardaia and Khanchla provinces of Algeria and will correlate the values with total levels of polyphenolic compounds. Methods: The total polyphenol contents of methanolic extract of propolis were measured by using Folin–Ciocalteu spectrophotometric method. Thereafter, the antioxidant properties of these polyphenols were determined by using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging. All polyphenols extracted were tested using cyclic voltammetry (CV) in aqueous media. The CV was realised to compare the results from spectroscopic method and to electrochemically characterise the propolis polyphenols. Results: The total polyphenolic content in methanolic extract of propolis from Ghardaia and Khanchla was 493.49 and 1423.32 mg gallic acid equivalent/100g of extract, respectively. The IC50 values for scavenging DPPH radical for Ghardaia and Khanchla propolis were 0.03917 mg/mL, 0.01211mg/mL respectively. Antioxidant activity measured by cyclic voltammetry method indicated that methanolic extract of Khanchla propolis had AEAC of 15,61 mg/g. Conclusion: Propolis samples had strong antioxidant activities, and the highest activities were found in Khanchla propolis. Also, among three assays employed in this study (DPPH, RP, CV), the cyclic voltammetry method was recommended as it represented a relatively clean chemical system
The effects of solvent nature on spray-deposited ZnO thin film prepared from Zn (CH3COO)2, 2H2O
(Urban & Fischer, 2014-01-01) Benramache, Said; Rahal, Achour; Benhaoua, Boubaker
Transparent conducting zinc oxide was deposited on glass substrate by ultrasonic spray method. The ZnO samples with concentration of 0.1 M were deposited at 300, 350 and 400 °C with 2 min of deposition time. The effects of substrate temperature, ethanol and methanol solution on the structural, electrical and optical properties were examined. The DRX analyses indicated that ZnO films have polycrystalline nature and hexagonal wurtzite structure with (1 0 0) and (0 0 2) preferential orientation corresponding to ZnO films resulting from methanol and ethanol, respectively. The crystallinity of the thin films improved with ethanol solution. All films exhibit an average optical transparency about 80%, in the visible range. The band gap energy of ZnO films obtained with methanol solution higher than of ethanol solution for all the films. The electrical resistivity decrease with ZnO obtained from ethanol indicated; due to the maximum crystallite size retched at this point.
The structural, optical and electrical properties of nanocrystalline ZnO: Al thin films
(Academic Press, 2014-04) Benhaoua, Boubaker; Rahal, Achour; Benramache, Said
The Al doped ZnO thin films were deposited by ultrasonic spray technique. The influence of Al doping on structural, optical and electrical properties of the ZnO thin films was studied. A set of Al doped ZnO (0–3.5 wt.%) were deposited at 350 °C. Nanocrystalline films with a hexagonal wurtzite structure with a strong (0 0 2) preferred orientation were observed after Al doping. The maximum value of grain size (33.28 nm) is attained with Al doped ZnO at 3 wt.%. Texture coefficient TC(h k l) of the four major peaks where evaluated. Optically, in visible region the transmissions spectra T(λ) show that the whole doped films exhibit lower values than the non doped one which has as transmittance more than 80%; whereas in the same region the optical transmissions of the doped films are affected by the doping ration. The band gap (Eg) increased after doping from 3.267 to 3.325 eV with increasing concentration of doping from 0 to 2.75 wt.%, respectively, according to the Burstein–Moss effect (blue shift of Eg) then beyond 3 wt.% in doping the band gap exhibit a slight decreasing due to the coexistence of Roth and Burstein–Moss effect. The electrical resistivity of the films decreased from 20 to 5.26 (Ω cm). The best results are achieved with 2.75 wt.% Al doped ZnO film.
Effects of speech codecs on a remote speaker recognition system using noval SAD
(University of Eloued جامعة الوادي, 2014-04-02) Ajgou, Ridh; Sbaa, Salim; Ghendir, Said; Chamsa, Ali; Taleb- Ahmed, A.
This paper deals with the effects of speech codecs on remote texit-independent speaker recognition performance in VoIPapplications, considering three types of speech codec: PCM, DPCM and ADPCM conforming to International Telecommunications Union-Telecoms (ITU-T) recommendation used in telephony and VoIP (Voice over Internet Protocol). In order to improve the speaker recognition performance in noisy environment we propose a new robust speech activity detection algorithm (SAD) using "Adaptive Threshold", which can be simulated with speech wave files of TIMIT database submerged in an additive noise. Moreover, the speaker recognition system is based on Vector Quantization and Mel-Frequency Cepstral features extraction algorithm. Where, the feature extraction proceed after (for testing phase) and before (for training phase ) the speech is sending over communication channel. Therefore, the digital channels can introduce several types of degradation. To overcome the degradation of channel, a convolutional code is used as error-control coding with the AWGN channel, Finely, the best overall performance of speech codecs was observed for the PCM code in terùs of recognition rate accuracy and execution time.
Water pollution in Souf- Algerian Sahara
(University of Eloued جامعة الوادي, 2014-05-14) Meziani, Assia; Meguellati, Soumia
In Souf, the bad management of waters provoked two important problems:the ascent and the pollution of water. These two problems caused an ecological unblance and the negative environùental impacts. In order to solve these environment problems, some best technical solutions have been adopted: purfication of waters by a aired lagoon for one time in 5 days to 10 days in order to preserve the public health and the integrity of the receiving environment, deletion of the nuisances and the present risks of contamination to level of the urbanized zones, drainage and evacuation of treated waters without negative impact on the environment, preservation of water resources while reusing and valorizing the treated waters.
Effect of fluorine doping on the structural, optical and electrical properties of SnO2 thin films prepared by spray ultrasonic
(Superlattices and Microstructures, 2014-06) Benhaoua, Atmane; Rahal, Achour; Benhaoua, Boubaker; Jlassi, Mohamed
Abstract The undoped and fluorine doped tin oxide (SnO2) thin films are synthesized by using cost-effective spray ultrasonic technique; the films are sprayed on heated glass substrates at 480 °C. The dependence of structural, optical and electrical properties of SnO2 films on the concentration of fluorine is investigated. X-ray diffraction, Optical absorption, four-point probe and Hall Effect studies have been performed on undoped and fluorine doped SnO2 (FTO) films. X-ray diffraction pattern reveals the presence of cassiterite structure with (2 0 0) as preferential orientation for FTO films. The crystallite size varies from 10.3 to 27.12 nm and was affected by F concentration which was lying between 0 and 12 wt.%. All films exhibit optical transmission T(λ) more than 83.9% in visible region; the optically estimated film thickness varies from 700 to 975 nm for the same given time (3 min deposition) and band gap (Eg) varies from 3.651 to 3.902 eV. The electrical study reveals that the films have n-type electrical conductivity and depend upon fluorine concentration too. The sprayed FTO film doped at 6 wt.% has the minimum resistivity of 1.47 × 10−3 Ω cm and minimum resistance sheet (Rsh) of 21 Ω/cm2 whereas the carrier concentration and mobility were about 2.04 × 1019 cm−3 and 208.4 cm2 V−1 s−1 respectively.

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