Browsing by Author "Iratni, A."

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Adsorption of yellow bemacid CM-3R dye from aqueous solutions onto raw and sodium bentonite
(2012) Ouslimani, Nassira; Zibouche, Fatima; Iratni, A.; Abadlia, Mohamed Tahar
Discharges from the textile industries are heavily loaded with various dyes which requires their treatment. The most common method is to adsorb on solids high surface area, for example, clay material highly available and whose leaves are good natural adsorbents. In present study we used a local bentonite available in its natural form and sodium form for the adsorption of a dye CM-3R yellow bemacid provided by BEZEMA. The evaluation of the effect of various variables is driven by a series of experiments as the contact time, initial concentration of the dye, the initial pH. The different parameters show that the adsorption of the dye is favoured to 240 min, pH 2 and a temperature of 19 ºC. The sodium bentonite yielded good performance results due to the improvement of its adsorption properties. The best correlation of experimental results are obtained with the Langmuir model for sodium bentonite (R % = 0.998) and Freundlich for the raw bentonite (0997)
Antireflective sol–gel TiO2 thin films for single crystal silicon and textured polycrystal silicon
(Springer, 2012) Arabi, N. H.; Iratni, A.; El Hamzaoui, H.; Capoen, B.; Bouazaoui, M.; Vilcot, J. P.; Bastide, S.
In this paper, antireflective TiO2 thin films have been prepared on single crystal silicon, and textured polycrystal silicon by sol–gel route using the dip-coating technique. The thickness and the refractive index of the films have been optimised to obtain low reflexion in the visible region, by controlling both the concentration of the titanium isopropoxide (Ti(iOPr)4), and the annealing temperature. We showed that the use of a TiO2 single layer with a thickness of 64.5 nm, heat-treated at 450 or 300 °C, reduces the reflection on single crystal silicon at a level lower than 3% over the broadband spectral ranges 670–830 nm and 790–1010 nm, respectively. In order to broaden the spectral minimum reflectance as much as possible, we have proposed to texture polycrystal silicon wafers, and to coat these wafers by a TiO2 single layer with a thickness of 73.4 nm. In this case, the reflectance has been reduced from 27 to 13% in the spectral range 460–1000 nm
Effect of acid nature in the starting solution on surface and photocatalytic properties of TiO2 thin films
(Elsevier, 2014) Bensouici, F.; Souier, Tewfik; Iratni, A.; Dakhel, A.A.; Tala-Ighil, Razika; Bououdina, M.
Effect of back contact material on CZTS solar cells simulated with AMPS
(2015) Tala-Ighil, Razika; Toubane, Mahdia; Bensouici, F.; Slimani, Amel; Haouanoh, Djedjiga; Iratni, A.; Sali, S.
The effect of calcination temperature and SiO2 addition on the optical and structural properties of sol gel TiO2 thin films
(2015) Arabi, N. H.; Iratni, A.; Tala-Ighil, Razika; Capoen, B.; Bouazaoui, M.
The Effect of CO Reducing Atmosphere on the Structural and Optical properties of SnO2: F films Deposited on a Si( N+)/Si(P) solar cell
(2006) Zair Tala-Ighil, Razika; Boumaour, Messaoud; Maallemi, Abderrezak; Melhani, kheira; Iratni, A.
Effect of isothermal heat treatment time on structural transformation and crystallization of B2O3-PbO glass
(2008) Aboutaleb, Djamila; Iratni, A.; Safi, Brahim
Lead borate glass was prepared by the quench method, followed by treatment at its isothermal temperature at different time periods. When the sample was rapidly cooled from the melt, it showed two distinguished opalescent layers. The SEM analysis and XRD pattern provide characteristics of glass without XRD peaks and their morphology show the aggregated spherical particles in the phase separated glass. This data show that phase separation occurred even when the melts were rapidly cooled, however, the sample shows a Ostwald ripen with increasing time of heat treatment, which implies that the size of particles increases and their number decreases. When changing the sample's composition by adding lead oxide (PbO), the sample crystallizes directly upon heat treatment. The infrared absorption spectra show shift edge for sample glass with heat treatment, which indicates a change of structural configuration, i.e. conversion of tetrahedral boron on triangular boron coordination
Effect of the AL2O3 and BaO addition on the thermal and physical properties of ternary glass system (B2O3- BaO-AL2O3)
(DAVID PUBLISHING, 2013) Aboutaleb, Djamila; Safi, Brahim; Ayadi, A.; Iratni, A.
In borate glasses, the main structural units are the [BO3] triangles and [BO4] tetradral which form different superstructural units like; boroxol rings, metaborate rings and chains, pentaborate, diborate, triborate and pyroborate. In this work, the Barium aluminoborate glasses were prepared. Some of properties were investigated by measure like density and chemical durability and the other by calculs. The dilatometric curves were determined and they revealed that the temperature of transition (Tg) and softening (Ts) and the dilatation coefficient increase by addition of Al2O3 and BaO content
Effect of Thickness on Photocatalytic Activity of TiO2 Thin Films
(Springer link, 2015) Bensouici, F.; Bououdina, Mohamed; Iratni, A.; Tala-Ighil, Razika
Electrical characterization of ethanol sensing device based on vanadium oxide/Porous Si/Si structure
(Elsevier, 2013) Chebout, K.; Iratni, A.; Bouremana, A.; Sam, S.; Keffous, A.; Gabouze, N.
Experimental study of macropore formation in p-type silicon in a fluoride solution and the transition between macropore formation and electropolishing
(2009) Slimani, A.; Iratni, A.; Chazalviel, J.- NJ.-N.; Gabouze, N.; Ozanam, F.
Anodic dissolution of p-Si is studied in diluted fluoride solution (HF 0.05M+NH4F 0.05 M, pH 3), with special focus on the physico-chemical parameters which govern the morphology of pore formation (crystallographic orientation, applied potential, and etching time). The effect of potential has been investigated in the transition region between macropore formation and electropolishing.Upon increasing the anodization potential, the pore cross-section changes from circular to square shape, and the bottom of the pores changes from a rounded to a V-shaped profile. Prolonged etching of the contour of (1 1 0) p-Si disks in the regime of porous silicon formation allows for a comparison of the etching characteristics of the (1¯1x) orientations. SEM observation indicates indeed different morphologies as a function of the crystal orientation, and the formation of fractal-like structures is obtained for some orientations. In the same geometry and at a potential just above the onset of the electropolishing regime, prolonged anodization allows for a direct measurement of the Si thickness removed as a function of the crystallographic orientation. We clearly observe the etching anisotropy, with etch depth (111) < (110) < (1 0 0). This sequence, similar to that observed for current density in more concentrated HF, differs from that observed for the chemical etching of Si in an alkaline solution
High temperature annealing of sprayed SnO2 : F layers in a silicon solar cell process with screen-printed contacts
(2006) Tala-Ighil, Razika; Boumaour, M.; Belkaid, M.S.; Mallemi, A.; Melhani, K.; Iratni, A.
In order to improve the solar cell conversion efficiency, a thin film of doped tin oxide (SnO2: F) has been deposited by the spray-pyrolysis technique on a monocrystalline diffused silicon wafer. Subsequently, the layer must undergo the firing step of screen-printed contacts with temperatures up to 830 °C. After annealing, one notices with the naked eye the appearance of speckles disturbing the uniformity of the as-deposited blue-coloured SnO2:F. Characterizations such as XPS, FTIR, RBS, XRD, SEM, Hall Effect, four point probe...etc, are all consistent to reveal a net increase of the SnO2:F layer resistivity which leads to efficiency degradation. Annealing the thin films under CO and 90% N2–10% H2 atmospheres was investigated to seek possibilities to preserve the expected improvements. Unlike forming gas, CO reducing ambient was found to be very effective for the high temperature contact firing with no thin film conductivity deterioration
Nonlinear sensitive control of centrifugal compressor
(2007) Laaouad, F.; Bouguerra, M.; Hafaifa, A.; Iratni, A.
In this work, we treat the problems related to chemical and petrochemical plants of a certain complex process taking the centrifugal compressor as an example, a system being very complex by its physical structure as well as its behaviour (surge phenomenon). We propose to study the application possibilities of the recent control approaches to the compressor behaviour, and consequently evaluate their contribution in the practical and theoretical fields. Facing the studied industrial process complexity, we choose to make recourse to fuzzy logic for analysis and treatment of its control problem owing to the fact that these techniques constitute the only framework in which the types of imperfect knowledge can jointly be treated (uncertainties, inaccuracies, etc..) offering suitable tools to characterise them. In the particular case of the centrifugal compressor, these imperfections are interpreted by modelling errors, the neglected dynamics, no modelisable dynamics and the parametric variations. The purpose of this paper is to produce a total robust nonlinear controller design method to stabilize the compression process at its optimum steady state by manipulating the gas rate flow. In order to cope with both the parameter uncertainty and the structured non linearity of the plant, the proposed method consists of a linear steady state regulation that ensures robust optimal control and of a nonlinear compensation that achieves the exact input/output linearization
Optical, structural and photocatalysis properties of Cu-doped TiO2 thin films
(Elsevier, 2017) Bensouici, F.; Bououdina, M.; Dakhel, A.A.; Tala-Ighil, Razika; Tounane, M.; Iratni, A.; Souier, T.; Liu, S.; Cai, W.
Pure and Cu+2 doped TiO2 thin films have been successfully deposited onto glass substrate by sol–gel dip-coating. The films were annealed at 450 °C for 1 h and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM-EDX), atomic force microscopy (AFM), UV–vis spectrophotometer and photocatalytic degradation of methylene blue. XRD confirmed the presence of two phases at higher Cu concentration; TiO2 anatase and CuO. AFM analysis showed that the surface roughness increases within increasing Cu content as well as the presence of large aggregates at higher Cu content. SEM observations confirmed the granular structure of the films, and EDX analysis revealed a low solubility limit (effective doping) of Cu into TiO2 lattice. It was found that the optical band gap energy decreases with increasing Cu content. At constant irradiation time, the photo-degradation of methylene blue rate decreased with increasing concentration of Cu+2
Ostwald ripening phenomena in B 2O 3-PbO glass system
(2010) Aboutaleb, Djamila; Iratni, A.; Safi, Brahim
Phase separation and chemical durability in the SiO2-B2O3-Na2O (SBN) glass system
(2012) Aboutaleb, Djamila; Safi, Brahim; Jbara, O.; Iratni, A.; Douglad, J.
Sodium borosilicates glasses were treated isothermically several times. In present work, the effect of phase separation on chemical durability and the electric resistivity was investigated. In addition, the effect of chemical composition and addition of calcium on the kinetics and rate of leaching of these glass materials in hydrochloric acid (3M HCl) was also investigated. The system studied exhibited phase separation starting from 550 ºC. Present results showed that the chemical durability was weakened upon phase separation. On the other hand, chemical durability increased with increasing SiO2 content and reducing the alkaline oxides (Na2O) content. Results also showed a drastic decrease in the ionic electric conductivity (increase in resistivity) with decreasing C = (Na2O + B2O3)/SiO2 (reduction of Na2O). The effect of chemical composition on the rate of leaching showed that boron and sodium are dissolved much more quickly than silicon. The greater the content of Na2O and B2O3 in glass, the more soluble the glass becomes. However, addition of silica results a decrease in glass solubility. These results indicate that substitution of sodium by calcium induces an acceleration of the kinetics of deterioration
Séparation Des Phases Dans Le Système sio2- B2O3- Na2O (ISBN)
(2009) Aboutaleb, Djamila; Iratni, A.; Safi, Brahim; Douglad, J.
Sol concentration effect on ZnO nanofibers photocatalytic activity synthesized by sol–gel dip coating method
(IOP Publishing, 2017) Toubane, Mahdia; Tala-Ighil, Razika; Bensouici, F.; Bououdina, M.; Souier, M.; Liu, S.; Cai, W.; Iratni, A.
Synthesis and thermal evolution of Gd2O3-B 2O3-SiO2 glass prepared by sol gel process
(2013) Iratni, A.; Ladjouzi, S.
Synthesis, characterization and photocatalytic behavior of Ag doped TiO2 thin film
(Elsevier, 2015) Bensouici, F.; Souier, T.; Dakhel, A.A.; Iratni, A.; Tala-Ighil, Razika; Bououdina, M.
In this study, structure, microstructure, optical properties and photocatalytic degradation of Rhodamine B (RhB) have been investigated in an aqueous heterogeneous media containing pure and Ag doped TiO2 nanostructures thin films which were prepared by a simple sol–gel route. Thermal analysis demonstrated that Ag content decreased the temperature of anatase-to-rutile phase transformation. X-ray diffraction analysis confirmed that the prepared nanostructures crystallize within anatase-type structure and that the dopant Ag ions were not fully incorporated within TiO2 host lattice, meanwhile both the refractive index and optical band gap were affected by Ag concentration. The photodegradation of Rhodamine B under UV-C radiation by using pure and Ag-doped TiO2 nanostructures showed that Ag played an important role in a significant improvement of the photodegradation efficiency and that the optimum content of Ag ions was found to be 0.5% molar ratio