Publications Scientifiques
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Item Effect of concentration and temperature on the rheological behavior of hydroxylethyl cellulose solutions(2022) Remli, Samia; Benyounes, Khaled; Benmounah, AbdelbakiThe knowledge of the rheological properties of polymers makes their use interesting in various fields of applications, such as food industry, cosmetics, enhanced oil recovery or construction materials. Whatever the application, the effect of temperature and concentration on these properties is of great importance. This study covered a wide range of concentrations from 0.2 w/% to 1 w/%, and temperatures from 10 °C to 80 °C. The results obtained provide interesting information regarding the effects of the temperature and concentration of the aqueous solutions of the polymer since they reveal that the rheological properties remained practically unchanged in the temperature range considered. The impacts of shear rate, temperature and concentration on the flow behavior were analyzed. Small-amplitude oscillatory shear measurements were performed, and the results obtained show that the apparent viscosity is strongly influenced by the concentration of the aqueous solution of HEC, exhibiting a marked non-Newtonian shear-thinning behavior at different temperatures. The flow behavior is well described by several rheological models. The effect of temperature on the kinematic viscosity was fitted with the Arrhenius model; the behavior of this model in relation to experimental viscosity values was suitable and the linear fit showed good regression coefficients. The dynamic state was well described with the generalized Maxwell modelItem Viscosity-boosting effects of polymer additives in automotive lubricants(Springer Nature, 2024) Boussaid, Mohamed; Haddadine, Nabila; Benmounah, Abdelbaki; Dahal, Jiba; Bouslah, Naima; Benaboura, Ahmed; El-Shall, SamyThis study investigated polyethylene glycol (PEG), as a polymer improver of the paraffinic oil viscosity index (VI). The characterization of PEG/paraffinic oil blends at different concentrations (0%, 1%, 2%, 3%, 5%, and 10%), was performed using Raman spectroscopy and optical microscopy. The rheological parameters as the viscosity index and activation energy were determined using the kinematic viscosity measurements. Results showed that the VI improvement reached an optimal value for the blend containing 3% PEG, with greater value for blends containing 2% PEG than 5 and 10% PEG. The presence of polymer particles was observed by optical microscopy, which confirmed the lack of PEG distribution in the blend containing 5%, and more, whereas mixtures with 3 and 2% PEG exhibited good particle distribution, evidenced by smaller polymer particle sizes. This finding was corroborated by Raman spectroscopy, which revealed the absence of polymer–oil intermolecular interactions in the PEG/paraffinic oil blends. The rheological tests showed that increasing the blend temperature from 40 to 80 ℃, improved the PEG chains dispersion in the paraffin oil, for the blends containing up to 3% PEG. The difference of the activation energy of the pure paraffinic oil and the PEG/paraffinic oil blends, (ΔEa) was calculated, and the correlation between the ΔEa and the viscosity index values was established. Therefore, adding PEG to paraffinic oil appeared to be promising for the viscosity index improvement and promote industrial applications of paraffinic oil.Item Rheological behavior and microstructural properties of crude oil and emulsions (water/oil-oil/water)(Taylor & Francis, 2024) Yacine, Celia; Safri, Abdelhamid; Djemiat, Djamal Eddine; Benmounah, AbdelbakiAn experimental study on crude oil (from the Tin Fouye Tabankort oil field in southern Algeria) was carried out. This study allowed us to understand the rheological behavior of this crude oil with these different emulsions and how it reacts under the effects of temperature and the inversion of its phase from E/H to H/E. So we measured the rheological characteristics by tests flow and dynamic mode at different temperatures from 10 °C to 50 °C and at different water concentrations (20.40.50.60 and 70%) at a fixed temperature of 20 °C. The increase in temperature results in a 31.84% reduction in the initial viscosity of the crude oil. The addition of the volumic fractions of water results in an increase in viscosity at the point of inverse, which will decrease the apparent viscosity of these emulsions where the emulsions (W/O) come from (O/W). This crude oil and their emulsions exhibit a non-Newtonian behavior with shear thinning. The dynamic analysis depends on the temperature and the percentages of water added to the crude oil. At the end, a microscopic analysis was added to verify the relationship between the shape and diameter of the water droplets in each emulsion and the viscosity variation.Item A novel spherical hybrid material based on the combination of humic acid/alginate/Algerian Zeen Oak sawdust for removing chromium (VI) from wastewater(Elsevier, 2023) Sadoun, Louiza; Benmounah, Abdelbaki; Ait-Ramdane-Terbouche, Chafia; Seffah, Karima; Terbouche, AchourA novel spherical hybrid material designed from the combination of humic acid (HA), sodium alginate (Al) and sawdust derived from Algerian Zeen Oak Waste (OS) has been prepared. After optimization of HA/Al/OS mass ratio, the structure of the synthesized hybrid spheres was established using various characterization techniques notably ATR, SEM-EDX, XRD, BET and the point of zero charge (pHpzc). Adsorption tests using this compound were applied to remove chromium(Cr (VI)) from aqueous solutions. The influence of the different parameters such as contact time, pH, temperature, initial metal concentration, and mass of the material were studied. The obtained results revealed that the mass of HA had a significant influence on the formation of the spheres. By varying the ratio of HA/Al/OS (1/16/16 (S1), 1/5/5 (S2), 1/3/3 (S3) and 1/2/2 (S4)), the humic acid allowed a good coating of the hybrid material. The ratio 1/5/5 (S2) was retained for the adsorption study. The efficiency of this material was subsequently tested for the removal of Cr (VI) from aqueous solutions. Optimizing the different experimental parameters allowed to obtain a removal efficiency of over 90 % for an initial Cr (VI) concentration of 60 mg L−1, at pH = 2 and temperature of 353.15 K, using 0.1 g of material. The kinetic study showed that the process of elimination of Cr (VI) followed the pseudo-second order model and well fitted with the Freundlich adsorption isotherm model with R2 value of 0.99 and a low value of χ2 (2.88). A maximum adsorption capacity of 50.328 mg.g−1 was determined by the Langmuir isotherm model. The hybrid spheres showed good regeneration efficiency even after four adsorption-desorption cycles. The thermodynamic study (ΔS = 0.091 kJ mol−1 K−1, ΔH = 24.427 kJ mol−1 and ΔG° = −2.883 kJ mol−1 at 298.15 K) revealed that the adsorption process was spontaneous, favorable and endothermic with a physisorption phenomenon. Finally, the adsorbent was successfully applied to real wastewater contaminated with chromium. This application has proved high removal efficiency of Cr (VI) and a yield of 94.31 % was obtained at 40 °C.Item Nutraceuticals compounds extraction optimization from open air and swell-dried banana peel powders(North University of Baia Mare, 2022) Nouioua, Abir; Benseddik, Abdelouahab; Besombes, Colette; Allaf, Karim; Benmounah, Abdelbaki; Djilali, Adiba BenahmedThe aim of this study was to optimize the operating conditions of two drying processes on banana peels: open air and Instant Controlled Pressure Drop technique (DIC) assisted Swell-Drying at 40°C in order to obtain high quality final powders. The optimization of three extraction conditions including extraction temperature (40-100°C), extraction time (10 – 60 min) and particle size (60 – 363 μm) from open air banana peel powder was investigated). Additionally, three DIC texturing conditions were improved. DIC involves maintaining banana peels at a high temperature for 20 to 220s, high steam pressure (p=0.3 to 0.6 MPa) and varying the Number of cycles from 1 to 7. Modelling of some nutraceutical compounds (Total Flavonoids Content and carotenoids) from open air and Swell-Dried banana peels powders by applying experiments design using Response Surface Methodology and Desirability Function. The antioxidant activity was also investigated by the determination of the % of DPPH inhibition. The optimal conditions derived from the multi-Responses-Desirability Function were as follows: 60.47°C; 10min; and particle size Φ= 348.648 μm yielding a TFC=5.13 (mg QE/g d.b), TCC=0.48 (mg /g d.b) and % of DPPH inhibition=73.05%, with an optimal desirability coefficient d=0.7 (open air process). The following optimized DIC operating parameters with maximum desirability coefficient d=1, t=24.46s P=0.59MPa and number of cycles N=6.38 yielding a TFC=4.07 (mg QE/g d.b), a TCC= 1.37 (mg /g d.b) and a % of DPPH inhibition=75.97 %. Banana peel could be a good source of bioactive substances, which could be further used as a natural antioxidantItem A Simple fiber optic temperature sensor for fire detection in hazardous environment based on differential time rise/decay phosphorescence response(IEEE, 2022) Fouzar, Samia; Bulgaria, Plovdiv; Kostova, Irena; Dimitrova, Todorka L.; Benmounah, Abdelbaki— In the present article, we report the development of a simple temperature sensor based on the difference in the temperature dependences of the rise and decay time and the intensity responses of Eu2+, Dy3+-doped strontium aluminates. A 374-nm pulsed LED was used as a UV source in combination with a lead-in and -out optical fiber to excite the sample and capture the phosphorescence. We show that because of the power law rise and decay time responses, the differential signals measured at earlier instants exhibit the highest sensitivities to temperature over the range from about 5 ◦C to 95 ◦C. Normalized differential signals are characterized by a wide range of linear responses to temperature changes, sensitivity of up to ≈−1.89%/◦C, and a relative error of less than 0.5%. Application to fire prevention is discussed and argumentedItem Excitation and spectral dependence of the rise and decay time responses of Eu2+- and Dy3+-doped strontium aluminates(Springer, 2022) Fouzar, Samia; Kostova, Irena; Eftimov, Tinko; Benmounah, Abdelbaki; Ouchabane, Mohammed; Lakhssassi, AhmedIn this paper, we study the phosphorescence rise and decay time responses of Eu2+- and Dy3+-doped strontium aluminates prepared by different methods after scanning them with a narrow spectral width (15 nm FWHM) light from a monochromator. The experiments performed show that the time responses essentially depend on the excitation duration as well as on the excitation and the emission wavelengths. It has been found that at the excitation wavelength of maximum efficiency λ′max, a ‘fast track’ rise and decay of the phosphorescence exists. We suggest that by studying the normalized switch on and switch off time responses, we can determine the relative share of slow phosphorescence afterglow with respect to fast and slow phosphorescence decay as well as the rate of luminescence rise and decay processes. The relation to the synthesis technology and to the contents of the samples is discussedItem The effect of inhibiting molybdate used in anodizing-conversion treatment to improve corrosion protection of AA2030 aluminum alloy in different steps(Springer, 2022) Benmohamed, Manel; Benmounah, Abdelbaki; Haddad, Ahmed; Yahi, SarahIn this article, different treatment baths for corrosion protection of 2030 aluminum alloy in addition to replacing the hexavalent chromium due to the European recom- mendation were employed. This work is divided into three steps of treatment: first, anodization using molybdate inhibitor without and with phosphoric acid and, then, pre-oxidation with sodium hydroxide. In the last step, we studied the influence of conversion coating with the combination of sodium molybdate and fluoride on the anodic layer formed on aluminum alloy 2030. In order to characterize the formed lay- ers, we use microstructural characterization (SEM, AFM, and nano-indentation), which allows highlighting the surface condition as well as the morphological distribution, and electrochemical techniques such as potentiodynamic polarization and electro- chemical impedance spectroscopy which shows that the anodization treatment of the aluminum alloy with phosphoric acid and sodium molybdate offered better corrosion resistance. This resistance increased with the use of pre-oxidation and then reached a maximum value of 99.8% efficiency with the addition of the molybdate conversion coating which causes an increase in the double layer and gave an alternative possibility of chromium VIItem Rheological study of sodium carboxymethylcellulose: Effect of concentration and molecular weight(Elsevier, 2022) Chalah, Kaci; Benmounah, Abdelbaki; Mahdad, M'hamed; Kheribet, RabiaThis study deals with the rheological behavior of sodium carboxymethylcellulose (Na-CMC) using a rheological analysis. The rheological properties of Na-CMC in aqueous solution, at different mass concentrations (0.7, 0.9, 1.1, 1.3 and 1.5 wt%) and types including carboxymethylcellulose high viscosity (CMC HV), medium viscosity (CMC MV) and low viscosity (CMC LV), were investigated using a large deformation rheological measurements (0–700 s−1). The rheological behavior of CMC HV and CMC MV solutions was shear-thinning without yield stress. The flow curves were modeled by Ostwald de Waele and Cross laws (R2 > 0.99). The same models were used for fitting flow curves of various samples of CMC LV suspension but we noticed shear thickening behavior. On the contrary of the CMC HV and CMC MV, and according to the power law model, the flow index of CMC LV was increased with raising in concentration. The consistency of Na-CMC solution at 0.7w.% were 0.5 × 10−3, 0.039 and 0.252 Pa·s, and at 1.5%-CMC were 0.5 × 10−3, 0.065 and 3.162 Pa·s, for respectively CMC LV, CMC MV and CMC HVItem Effects of temperature on the time responses of strontium aluminates(Elsevier, 2021) Fouzar, Samia; Eftimov, Tinko; Kostova, Irena; Benmounah, Abdelbaki; Lakhssassi, AhmedIn this paper we study the effect of temperature on the rise and decay time responses of Eu and Eu, Dy doped strontium aluminates. Normalized switch on and switch off time responses are used to estimate the share of phosphorescence in the observed luminescence. The parameters of the power law time responses related to the relative share of phosphorescence in luminescence and to the rise/decay rates are found to be strongly temperature dependent. The results show that unlike luminescence intensity, the overall efficiency of phosphorescence increases strongly with temperature and reaches a maximum around 65 °C. Thе maximum correlates with the activation energy of the samples and depends on their doping and fabrication technology