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    ELECTROCHEMICAL AND THEORETICAL STUDIES INFLUENCING THE EFFECT OF HYDROXYL POSITION OF TETRAPHENOLIC SCHIFF BASES TOWARDS CORROSION INHIBITION OF MILD STEEL IN 1M HCl
    (Université de M'sila, 2018-02) KHENICHE, Abdelhakim; Ourari, A.; Dakhouche, achour; Ghanem, A; Meguellati, K.
    The effect of three tetrahydroxylated Schiff bases as N,N-bis(2,3-dihydroxybenzyl- idene)-4,4’-diphenylmethane, N,N-bis(2,4-dihydroxybenzyl- idene)-4,4’-diphenylmethane and N,N-bis(2,4-dihydroxybenzylidene)-4,4’-diphenylmethane were studied as inhibitors for mild steel in 1M HCl medium. The experiments were performed using potentiodynamic polarization. This inhibition proved an efficient increase according the position of second hydroxyl of salicylaldehyde suggesting that this inhibition is dependent on concentration and the compound nature. Among these position-isomers, the best inhibition efficiency was obtained with p-hydroxylated (94%) at 1mM. Tafel plots of these inhibitors are the mixed- type, their adsorption is spontaneous obeying to Langmuir’s isotherm. AFM/SEM-EDS characterized metal surface. DFT-calculations and molecular dynamics simulations are correlated to inhibition efficiency obtained.
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    Étude de l’effet du temps de traitement alcalin de fibres palmier sur le comportement mécanique des matériaux à base d’argile rouge de la région de M’sila
    (Université de M'sila, 2019-04) Zainate Koadri; Azzedine Benyahia; Nadir Deghfel; Kamel Belmokre; Brahim Nouibat; Ali Redjem
    Ce travail s’inscrit dans le développement de matériaux locaux, telle que la fibre végétale (fibre de palmier) et l’argile rouge du sud Algérien, largement utilisées dans la préparation des briques, comme matériaux de construction rurale. Les fibres végétales possèdent des propriétés très intéressantes, elles sont : renouvelables, biodégradables et le rapport coût/légèreté faible. Leurs propriétés mécaniques sont très importantes. Cependant, le problème prédominant dans ce type de matériaux composites est la faible adhésion de l’interface matrice-fibre, attribuée probablement, à la nature de la surface et au caractère hydrophobe des fibres naturelles, conduisant ainsi, à des propriétés mécaniques faibles pour le composite envisagé. Le but de cette étude consiste à traiter la fibre de palmier par une solution basique d’hydroxyde de sodium (NaOH 4% [m/v]) durant des périodes variables : 3, 7, 24 et 48 heures, afin d’améliorer l’adhésion interfaciale. Les résultats obtenus à partir des essais réalisés sur le composite renforcé par les fibres de palmier traitées durant 7 h ont montré une nette augmentation quant à la résistance, à la flexion et à la compression ; cette croissance est respectivement de l’ordre de 57 et 60 %, comparativement au composite renforcé par les fibres non traitées. On peut déduire que les fibres de palmier peuvent être considérées comme l’un des matériaux appropriés pour le renforcement de l’argile
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    Anti-inflammatory and hemostatic effects of Linaria reflexa Desf
    (Université de M'sila, 2019-09) Thamere, Cheriet
    The work presented here was aimed to investigate the in vivo anti-inflammatory and in vitro hemostatic activities of Linaria reflexa extract and to establish the relationship between its bioactivity and chemical composition. Twenty-three secondary metabolites were identified, most of them are good anti-inflammatory agents, in line with data by carrageenin-induced rat paw edema assays of the n-butanol extract showing high anti-inflammatory inhibition (63.90%) of edema swelling in the rat paw at the dose 200mg/kg after 4 h. Furthermore, both extent of inflammatory response and tissue injury were prevented keeping the levels of rate myeloperoxidase (60.16%) and of malondialdehyde, which is the final product of lipid peroxidation generated by free radicals (58.58%). The same extract showed also a remarkable hemostatic effect established by measuring the coagulation time of decalcified plasma (45 s), related to its flavonoid glycosides content
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    EFFECT OF CHEMICAL TREATMENT WITH OXIDANTS ON THE MECHANICAL PROPERTIES OF LUFFA SPONGE/UNSATURATED POLYESTER COMPOSITES
    (Université de M'sila, 2020) NOURI LAIB; AZZEDINE BENYAHIA; ALI REDJEM; NADIR DEGHFEL
    This study investigates a synergistic treatment comprising alkali, permanganate, dichromate, silane and bleaching pretreatment on Luffa sponge (LF) fibers intended to be used as reinforcement in an unsaturated polyester (UP) matrix to improve the mechanical properties of Luffa sponge fibers reinforced unsaturated polyester composites. Treatment effects by NaOH (5 wt%), K2Cr2O7 (0.2 wt%), KMnO4 (0.0125 wt%), NaClO (13°) and silane (0.5 wt%) on the performance of the prepared composites were evaluated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), SEM and mechanical tests (flexural strength and modulus). The results of the analyses indicated that composites reinforced with treated fibers have higher flexural strength than composites reinforced with untreated fibers
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    Electrochemical behavior of PbO2/PbSO4 electrode in the presence of surfactants in electrolyte
    (Université de M'sila, 2020-03) O. Saoudi; M. Matrakova; A. Aleksandrova; L. Zerroual
    The electrochemical behavior of PbO2/PbSO4 electrode is investigated in 4.5M H2SO4 in presence of three surfactants, Sodium Dodecyl Sulfate (SDS), Cetyltrimethylammonium bromide (CTAB) and Sodium tripolyphosphate (STPP), using cyclic voltametry, electrochemical spectroscopy impedance and galvanostatic discharge as techniques. The micro morphology of the surface of the modified PbO2 electrodes is examined by scanning electron microscopy. The results show that SDS and CTAB when added in the electrolyte could refine the coating particles and change the roughness of the surface of the electrode leading to a thin film of PbO2 with amorphous character. In addition, SDS and CTAB shift the hydrogen evolution potential towards more negative values, improve the discharge capacity of the anodic layer and accelerate the charge transfer. Under cathodic polarization, CTAB presents the lowest value of the charge transfer resistance Rct. In the contrary, STPP shifts the oxygen evolution potential towards more positive values, passivates the surface of the electrode and inhibits completely the reaction of PbO2 formation. 2020 Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under
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    Biochars issus de roseau commun pour l’adsorption du méthylorange en solution aqueuse Common reed biochars for the adsorption of methyl orange in
    (Université de M'sila, 2020-04) Melouki soriya; Abdelbaki Reffas; Abdellah Merrouche; Laurence Reinert; Laurent Duclaux
    L’industrie textile consomme de grandes quantités d’eau et utilise des colorants organiques pour teindre ses produits commerciaux. Ces colorants synthétiques sont à la fois toxiques et responsables de la coloration des eaux usées, ce qui nécessite de les traiter avant leur rejet. La plupart des colorants ne sont pas biodégradables et une fois rejetés provoquent une altération du milieu aquatique. Parmi les procédés de traitement des rejets liquides, l’adsorption sur charbon actif est une technique facile à mettre en oeuvre et peu onéreuse. L’objectif de cette étude consiste en la préparation de biochars à partir de roseau commun afin d’obtenir un adsorbant applicable pour la décoloration des effluents de l’industrie textile. Le roseau commun (Phragmites australis) de la rivière de Sed–Ksob de M’sila (Algérie) a été valorisé et utilisé comme précurseur pour la fabrication de biochars par activation à l’acide phosphorique. La chimie de surface des matériaux a été caractérisée par titrage sélectif (dosage de Boehm), analyse thermogravimétrique (ATG) et mesure du point de charge nulle (pHpzc). La texture poreuse a été étudiée par l’adsorption du bleu de méthylène (BM) et la mesure de l’indice d’iode. Les résultats de l’analyse ATG et du dosage de Boehm montrent la présence de nombreux groupes fonctionnels de surface sur les biochars. Les teneurs en groupes fonctionnels oxygénés dépendent du rapport d'imprégnation en acide phosphorique, à l'exception de celui obtenu à un rapport d'imprégnation de 150 %. L’adsorption du BM et le test d’indice d’iode indiquent une augmentation de la surface spécifique lorsqu’on augmente le rapport d'imprégnation. Ceci est dû au développement de la microporosité et de la mésoporosité. Les biochars ont été testés pour leur performance d'adsorption vis-à-vis d'un colorant anionique, le méthylorange (MeO). L’influence de différents paramètres expérimentaux a été étudiée : la concentration, le temps de contact et la température. L’étude des isothermes d'adsorption montre que le modèle de Langmuir décrit bien le processus de l’adsorption du MeO sur les biochars préparés. La cinétique d’adsorption peut être décrite par les modèles de pseudo-second ordre et de diffusion dans le film liquide. Le phénomène d’adsorption est de type physique et endothermique.
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    ADSORPTION PERFORMANCE OF ANIONIC TEXTILE DYE (NYLOSAN RED N-2RBL) ONTO RAW, SODIC AND FRACTIONATED SODIC INORGANIC CLAY MATERIAL
    (Université de M'sila, 2021) Smail TERCHI; Naziha LADJAL; Belkacem ZIDELKHEIR; Khaldoun BACHARI
    The inorganic montmorillonitic clay material in raw and modified forms (sodic and fractionated sodic materials) was evaluated as adsorbent for anionic textile dye (Nylosan Red N- 2RBL). A various characterization using XRD, XRF, AFM, FTIR, TG, adsorption of methylene blue and pHPCN of the considered samples was realized. The experimental results show that, the adsorption was pH dependent with a high adsorption capacity of NR dye in acidic range. The pseudo-second-order kinetic model provided the best fit to the experimental data for the adsorption of dye by clay materials. The equilibrium adsorption data were analyzed by Langmuir, Freundlich and Dubinin–Radushkevich isotherm models. The best fit of experimental data was obtained by the Dubinin–Radushkevich isotherm model. The maximum adsorption capacity of the raw clay calculated by the latest isotherm model is 62.05 mg/g. It is increased in modified forms (170.11 and 201 mg/g for sodic clay and fractionated sodified clay materials, respectively). Increasing solution ionic strength (NaCl, KCl, NaNO3, and Na2SO4) increased significantly the adsorption of dye
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    Extraction, separation and biological activities of some secondary metabolites from the plant Cytisus purgans
    (Université de M'sila, 2021) BENAICHE Ghania
    In this study, Seseli praecox of Algerian flora was investigated regarding their polyphenolic and flavonoids contents using the Folin–Ciocalteu and aluminum chloride colorimetric methods, respectively. TPC of crude aqueous ethanolic extract was 44mg± 0.09GAE/gDw, while, TFC have values of 1.53mg±0.01 QuercetinE/gDw and 6.93mg±0.01 RutinE/gDw for ethanolic extract, which mean that this plant is relatively poor source of polyphenols and flavonoids . In the other side, the polyphenolic extract of this plant was evaluated for its reducing power. The capacity of the extract to reduce the ferricferricyanide complex to the ferrous-ferricyanide complex mention that Seseli praecox showed a very high iron reducing power activity with Ec50=0.25mg/ml.
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    Preparation and Characterization of a new plasticized polymer electrolyte for "all solid state" Zn/MnO2 cell
    (Université de M'sila, 2021) Z. Gharnout; L. Telli; A. Merrouche; L. Zerroual; S.Walter
    A solid polymer electrolyte with a polyvinyl alcohol (PVA) matrix and a mixture of ethylene glycol (EG) and phosphoric acid as proton conductor has been developed. These complexes have been studied by X-ray diffraction (XRD), infrared Fourier transform spectrometry (FTIR) and electrochemical impedance spectrometry (EIS).The optimum ionic conductivity value of the ternary PVA-EG(45 wt.%)-H3PO4(5 wt.%) complex film has been achieved to be 5.2 10-3 S cm-1 at RH = 100% with adequate mechanical properties (especially flexibility) and with a low activation energy of 9 kJ mol-1. Due to their good electrical as well as mechanical properties, such material has been successfully used as solid state protonic electrolyte in Zn/MnO2 cell with a capacity of 220Ahkg-1andan energy density up to 286 Wh kg-
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    The effect of chemical treatment on the mechanical and thermal 3 properties of composite materials based on clay reinforced with 4 sawdust
    (Université de M'sila, 2022) Fadhila Mouissa; Azzedine Benyahia; Mokhtar Djehiche; Kamel Belmokre; Nadir Deghfel; Ali Redjem; Zine El Abidine Rahmouni
    This study investigates the effect of the chemical treatment of sawdust on the mechanical and 16 thermal properties of a clay composite reinforced with sawdust in variable mass proportions: 0.5, 1, 1.5, 2 and 17 2.5%, intended for use as brick in rural houses in desert areas. The sawdust was chemically treated with 5 wt% 18 NaOH and 0.01 wt% KMnO4 solutions. The mechanical test results of the reinforced composite with alkali- 19 treated sawdust show an increase in flexural and compression strength, reaching a maximum value of 0.89 and 20 4.85 MPa, respectively. However, the thermal test results show a significant decrease in the thermal conductivity 21 of the sawdust-reinforced composite. The best result recorded is that of untreated sawdust, which has a value of 22 0.37 (W.m 1.K 1) compared to the one reinforced with treated sawdust
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    DFT study of the condensation products of 2‑chloro‑3‑formylquinolines with o‑aminophenol, o‑aminothiophenol and o‑phenylenediamine
    (2023) Nabila Benabila; Hafda Merouani; Nadjia Latelli; Abd Alghani May; Christophe Morell; Lynda Merzoud; Henry Chermette
    The reaction mechanism for the synthesis of quinoline-fused benzo/dia/oxa/thia/zepins is investigated using the DFT/ B3LYP/6-31G(d) method. DFT conceptual reactivity indices analysis allows classifcation of o-aminophenol (2, X =O), o-aminothiophenol (2, X=S) and o-phenylenediamine (2, X=N) and R-substituted 2-chloroquinoline-3-carbaldehydes (1 ac) as strong electrophiles, suggesting a polar process. Besides, Parr functions and Fukui indices predict the most reactive sites for observed experimentally product formation, in agreement with the dual descriptor analysis. In the energy aspect, there is no efect of the R (R= CH3, OCH3) substituent on the thermodynamic quantities, whereas the substitution of the X has a remarkable efect. The products (4a–c, X=N) are the most stable, and their cyclizations are the easiest. An extended analysis was performed using the activation strain model/energy decomposition analysis ASM/EDA model. The obtained results indicate that the orbital interaction and electrostatic stabilizations are the principal factors favoring the reaction with X=N. Topological analysis of the electron localization function (ELF) of the bending point structures along the reaction path indicates that the reaction occurs via a non-concerted two-step mechanism
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    Degradation by hydrolysis of three triphenylmethane dyes: DFT and TD‑DFT study
    (2023) Djamel Taharchaouche; Nadjia Latelli; Hafda Merouani; Boussebbat Wahiba; Naima Mechehoud; Nadia Ouddai; Christophe Morell; Lynda Merzoud; Henry Chermette
    DFT reactivity descriptors, the ultraviolet–visible spectra and hydrolysis mechanism of three cationic dyes [Malachite Green (MG), Brilliant Green (BG) and Ethyl Green (EG)] are performed with several exchange–correlation functional (global GGA, hybrids and range-separated). Using time-dependent density functional theory, the theoretical ultraviolet–visible absorption spectra of the three cationic dyes are obtained and obey the trend for the λmax: GGA>hybrid>range-separated functional. Thanks to the transition state theory, the barriers of hydrolysis mechanism of the cation structures dyes were obtained in gas and solution phase. It is shown that, for these systems the barriers are in order: BG+ < MG+ < EG2+ in gas and solution phase. In the two phases, the CAM-B3LYP functional gives the highest barriers and the M06 gives the lowest ones