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Blida, Algeria

The University of Blida is a university located in Blida, Algeria. Wikipedia.

Moulay S.,Blida University
Journal of Polymer Engineering | Year: 2013

A unique feature of molecular iodine by far, is its ability to bind to polymeric materials. A plethora of natural and synthetic polymers develop complexes when treated with molecular iodine, or with a mixture of molecular iodine and potassium iodide. Many unexpected findings have been encountered upon complexation of iodine and the polymer skeleton, including the color formation, the polymer morphology changes, the complexation sites or regions, the biological activity, and the electrical conductivity enhancement of the complexes, with polyiodides (In ̄), mainly I 3 ̄ and I5 ̄, as the actual binding species. Natural polymers that afford such complexes with iodine species are starch (amylose and amylopectin), chitosan, glycogen, silk, wool, albumin, cellulose, xylan, and natural rubber; iodine-starch being the oldest iodine-natural polymer complex. By contrast, numerous synthetic polymers are prone to make complexes, including poly(vinyl alcohol) (PVA), poly(vinyl pyrrolidone) (PVP), nylons, poly(Schiff base)s, polyaniline, unsaturated polyhydrocarbons (carbon nanotubes, fullerenes C60/C70, polyacetylene; iodine-PVA being the oldest iodine-synthetic polymer complex.

Djendi M.,Blida University
Computers and Electrical Engineering | Year: 2012

This paper addresses the field of stereophonic acoustic echo cancellation (SAEC) by adaptive filtering algorithms. Recently, we have proposed a new version of the fast Newton transversal FNTF algorithm for SAEC applications. In this paper, we propose an efficient modification of this algorithm for the same applications. This new algorithm uses a new proposed and simplified numerical stabilization technique and takes into account the cross-correlation between the inputs of the channels. The basic idea is to introduce a small nonlinearity into each channel that has the effect of reducing the inter-channel coherence while not being noticeable for speech due to self masking. The complexity of the proposed algorithm does not alter the complexity of the original version and is kept less than half the complexity of the fastest two-channel FTF filter version. Simulation results and comparisons with the extended two-channel normalized least mean square NLMS and FTF algorithms are presented. © 2012 Elsevier Ltd. All rights reserved.

Moulay S.,Blida University
Designed Monomers and Polymers | Year: 2014

Not only does the molecular iodine play a leading role in organic synthesis but also in the polymer synthesis. Different kinds of polymerization initiated by molecular iodine are herein screened: cationic polymerization, radical polymerization, living/controlled radical polymerization (LCRP) such as reverse iodine transfer polymerization, polycondensation, and ring-opening polymerization (ROP). Also, the functionalization of polymers using molecular iodine, such as the acetylation of polysaccharides (cellulose, starch), and the use of iodine-polymer complex in organic synthesis are also discussed. Numerous natural and synthetic polymers are prone to make complexes with molecular iodine, and one feature of such complexes is their propensity as polymer-supported reagent and catalysts in many organic syntheses. © 2013 Taylor and Francis.

Moulay S.,Blida University
Polymer Reviews | Year: 2014

How does man dare to accept nature's challenges? A myriad of natural products with stunning structures and impressive properties fashion the research platforms of scientists, particularly the chemists and biologists. Indeed, research work undertaken by the latter scientists has unveiled concealed nature's mysteries. Of these mysteries, nature provides us with unusual adhesives in the form of L-DOPA-containing proteins, existing within the mussel feet and commonly called mussel foot proteins (fps). The uniqueness of these bioadhesives resides in their adhering performance to all kinds of surfaces and, more astonishing, under a wet environment. Up to six fps for Mytilus species (Mfps) were identified with varying extents of DOPA content. Improved adhesion performance was even observed for the recombinant Mfps expressed in Escherichia coli. Amine and catechol functionalities are crucial moieties and do play a synergetic effect for such adhesion. In addition, the in vivo crosslinking generated via an oxidative process of catechol units of DOPA to o-quinone groups at marine pH (8.5), takes part into this adhesion occurrence. In vitro crosslinking was achieved with oxidizing agents such as periodate ion and Fe(III), resulting in oxidative crosslinking (covalent crosslinking) and coordinative one (non-covalent crosslinking), respectively. To delve into the enigmatic phenomenon and unravel the chemistry behind, scientists strive to experiment their adhesive ability to substrata of different chemical natures, to make synthetic analogues, that is, bioinspired mussel adhesives, and apply the same work-up. Catechol and its derivatives such as DOPA and dopamine were either polymerized under simulated natural conditions or attached to skeletons of several synthetic polymers and biopolymers. The ongoing thus-biased research has now opened new avenues in biomedicals, hydrogels applications, antifouling processes, and nanotechnology. As friendly operation is greatly coveted, one promising fact is the surgical suture with such bioadhesive and the making of self-healing related materials. © 2014 Copyright Taylor & Francis Group, LLC.

Moulay S.,Blida University
Designed Monomers and Polymers | Year: 2011

This paper presents the trends in the halomethylation reaction of aromatic hydrocarbons and polymeric analogues. Much interest is devoted to the chloromethylation vis-à-vis other halomethylations, even though the incorporated chloromethyl group is the least chemically reactive among the common halomethyl groups (CH2Cl, CH2Br, CH2I). While bromomethylation stands second behind chloromethylation in terms of chemists' interest, a few cases of iodomethylation are cited, and only one case of fluoromethylation was reported. Various halomethylating systems have been devised, starting from the early one, paraformaldehyde/hydrogen halide, then those involving the in situ formation of halomethyl methyl ether (HalMME), and ending with those giving rise to other intermediate halomethylating species. Halomethylated aromatic polymers, including even the fluoromethylated ones, can be achieved by other means, such as polymerization of halomethyl-containing monomers, halogenation of pendent methyl groups and halogen exchange reaction (halex reaction) within halomethyl groups. Reaction conditions, i.e., solvents, catalysts and promoters, are surveyed. Exploitation of the concomitant Friedel-Crafts alkylation in the course of halomethylation is illustrated by some examples. In addition, the quaternization of halomethylated aromatic polymers (particularly the chloromethylation) is inevitably linked to halomethylation; thus, it is selectively evoked to valorize further the halomethylation reaction. © Koninklijke Brill NV, Leiden, 2011.

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