El-Oued University
  • Algiers, Wilaya d'El Oued , Algeria
Recent publications
This work is a component of the development of the aerial parts (leaves and stems) of Oudneya africana R., of the Bras-sicaceae family. For that purpose, the total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities (DPPH, ABTS, β-carotene, and phenanthroline assays), and antimicrobial activity of the ethanolic extracts of this plant were evaluated. Ethanolic leaf extract had a higher quantity of phenolics (69.75 ± 1.87 μg GAE/mg) and flavonoids (91.88 ± 1.94 μg QE/mg) than stem extract. Despite their significant antioxidant activities, leaf and stem ethanolic extracts had a weaker capacity to block the DPPH radical, as well as the ABTS radical, the β-carotene-linoleate bleaching assay, and the phenanthroline test, than industrial antioxidants, namely butylhydroxytoluene (BHT) and butylhydroxy-anisole (BHA). The remarkable antioxidant activity was observed in ethanolic stem extract on the ABTS assay with an IC50 value of 15.90 μg/mL and in the β-carotene with an IC50 value of 20.21 μg/mL. The ethanolic extract from leaves and stems showed excellent antibacterial activity against Candida albicans, with inhibition diameters of 13 mm and 12 mm, respectively. This work comprises a preliminary investigation, and as such, it suggests Oudneya africana R. as a potential candidate for having antibacterial and antioxidant properties and also draws attention to the potential value of using this plant as a traditional treatment.
This work aimed to develop innovative material by combining properties of magnetic-biochar (derived from peanut shells) and hydrogel bead (MBA-bead) and apply it for adsorbing Cu2+ in water. MBA-bead was synthesized by physical cross-linking methods. Results indicated that MBA-bead contained ∼90% water. The diameter of each spherical MBA-bead was approximately 3 mm (wet form) and 2 mm in (dried form). Its specific surface area (262.4 m2/g) and total pore volume (0.751 cm3/g) were obtained from nitrogen adsorption at 77K. X-ray diffraction data confirmed Fe3O4 presented in magnetic-biochar and MBA-bead. Its Langmuir maximum adsorption capacity for Cu2+ was 234.1 mg/g (30 °C and pHeq 5.0). The change in standard enthalpy (ΔH°) of the adsorption was 44.30 kJ/mol (dominant physical adsorption). Primary adsorption mechanisms were complexation, ion exchange, and Van der Waals force. Laden MBA-bead can be reused several cycles after desorbing with NaOH or HCl. The cost was estimated for producing PS-biochar (0.091 US$/kg), magnetic-biochar (0.303–0.892 US$/kg), and MBA-bead (1.369–3.865 US$/kg). MBA-bead can serve as an excellent adsorbent for removing Cu2+ from water.
Due to its promising features, cellulose, the most plentiful renewable material in nature, is used in a variety of industrial processes. In this work, we used peanut shells (Arachis hypogaea L.) for the purpose of producing microcrystalline cellulose (MCCs) and nanocrystalline cellulose (CNCs), respectively. The following process was used to separate cellulose from peanut shells: dewaxing, delignification/bleaching, and acid hydrolysis. The structural features of the isolated microcrystalline cellulose (MCCs) and cellulose nanocrystalline (CNCs) samples were tested by Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) was used to morphologically analyze of the samples (peanut shells, micro-crystalline cellulose, and nanocrystalline cellulose). The prepared CNCs' elemental composition was revealed by energy dispersive X-rays (EDX), and their crystallinity was shown by X-ray diffraction (XRD). The yield of peanut shells cellulose was (31.81%). FTIR analysis for the bleached peanut shells cellulose revealed the efficacious removal of the non-cellulosic materials and amorphous components from the polymer matrix. The obtained peanut shells' XRD results showed native cellulose's typical peaks (type I), along with a crystallinity index (CrI = 72.53%). Also, acid hydrolysis phase was used to adapt microcrystalline cellulose (MCCs) into cellulose nanocrystalline (CNCs) with higher crystallinity (CrI = 77.96%). According to each of these assays, the chemical treatment was successful in eliminating the non-cellulosic substances and obtaining a cellulose nanofiber.The antibacterial activity carried out against three bacterial strains (Staphylococcus aureus, Escherichia Coli, and Salmonella typhimurium) that cellulose nanofibers showed moderate antibacterial activity against a strain Staphylococcus aureus and Salmonella typhimurium.The current study demonstrates the viability of employing peanut shells as a cost-effective source for acquiring CNCs that are intended for use in the food and pharmaceutical industries.
Abstract: The green approach-based nanoparticle synthesis is considered a more cost-effective and ecologically responsible method of producing nanoparticles than other standard techniques. A major accomplishment in resolving these issues is the use of nanoparticles for environmental pollution remediation. This article describes a simple method for producing MgO and ZnO nanoparticles (NPs) using aqueous extracts of Zingiber officinale and Glycyrrhiza roots as the stabilizing and reducing agents, respectively. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersed X-ray (EDX) spectroscopy methods were used to characterize the biologically synthesized metal oxide nanoparticles (MO NPs). The XRD results showed that the mean crystallite sizes of synthesized ZnO and MgO NPs, which have excellent purity, are 12.35 nm and 4.83 nm, respectively. The spherical or elliptical shape of the synthesized NPs was confirmed by the SEM analysis. The antibacterial activity of the synthesized NPs against both Gram-negative and Gram-positive bacteria was thoroughly investigated. With a medium zone of inhibition of 7 to 10 mm, the as-synthesized MgO NPs and ZnO NPs demonstrated moderate antibacterial activity towards various bacterial strains.
Green synthesis of metal oxide nanoparticles using plant extracts is a promising alternative to the traditional method of physical and chemical synthesis, as it is a wide research field and environmentally friendly methods. In the current study, iron oxide nanoparticles (α-Fe 2 O 3-NPs) were bio-synthesized by using Moltkia ciliata plant extract with different concentration of ferric chloride (FeCl 3). To improve the yield, we relied on changing the concentration of the saline solution (0.1, 0.05, and 0.025M(. These α-Fe 2 O 3 NPs were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and energy-dispersive X-ray (EDX). UV-Vis analysis shows absorption maximums at the range 200-400nm belonging to Fe-O, and FT-IR shows clear peaks in the range 450-500 cm −1 , which are attributed to the vibration of Fe-O, while the SEM and DRX results are constructed. There are similarities in the structure of the samples in terms of shape and size, despite their different concentrations. Antibacterial studies were used against Gram-positive and-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus). The sample synthesized at a concentration of 0.05M showed the highest antibacterial activity (inhibition zone) up to 11.7 mm at a concentration of 0.025 M for Klebsiella pneumoniae. This study concluded that the biosynthetic α-Fe 2 O 3 using Moltkia ciliata extract gave significant antibacterial activity.
The simulated device structures of ITO/ZnO/Perovskite absorber layers (PAL)/Spiro- OMeTAD/Au with distinct absorbers were modeled and investigated using solar cell capacitance simulator (SCAPS-1D) simulating software (version 3.8). The primary objective is to enhance the thermal stability of the solar device. As the absorber thickness and temperature impact PV performance parameters, thus main aim of this work is to determine the optimum thickness of PAL as well as the temperature affectability on the PV performance of the cells. It was also observed that the maximum PV parameters (among the cells under consideration), viz. 29% PCE, are achieved with the formamidinium tin iodide (FASnI3) at the thickness of 600 nm. Similarly, the temperature of 300 K shows a much-improved efficiency offering nearly 29%. Further, the external quantum efficiency (EQE) and J-V also confirm the determent of the more stable, lead-free, FASnI3-based device, which can provide an effective way to develop highly efficient, low-cost solar cell devices.
This research aims to explore the utilization of Ocimum basilicum leaf extract as a green and sustainable method for the synthesis of Fe3O4/NiO nanocomposites (Fe3O4/NiO NC) with potential applications in photocatalytic hydrogen evolution and organic dye degradation. The synthesized Fe3O4/NiO NC exhibited a unique bandgap energy of 2 eV, making it an effective visible-light photocatalyst. X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed the successful formation of the cubic crystal structure with an average crystallite size of 25.7 nm. Fourier transform infrared spectroscopy (FTIR) analysis revealed the presence of hydroxyl groups on the NC surface, which contributed to its photocatalytic properties. Under sunlight exposure, the Fe3O4/NiO NC demonstrated remarkable photocatalytic degradation efficiency of 99.3% for toluidine blue (TB), 99.0% for 4-bromophenol (4-BP), and 95.0% for methyl blue (MB) within 140 minutes. The photocatalyst also exhibited excellent reusability with only a slight decrease in efficiency after five cycles. Additionally, the Fe3O4/NiO NC displayed high photocatalytic activity in hydrogen evolution, generating 933.9 μmol/g of H2 over 8 hours at a concentration of 0.7 g/L. This green synthesis approach, utilizing Ocimum basilicum extract, provides a cost-effective and eco-friendly method to produce Fe3O4/NiO NC with enhanced photocatalytic properties, holding great promise for sustainable energy and water purification applications. The study contributes to the understanding of novel nanocomposites and their potential for addressing urgent environmental challenges, underscoring their scientific value in green chemistry and renewable energy research.
The aim of this paper is to give an existence theorem of a solution of the nonlinear evolution dam problem (P)$$ (P) $$, associated with compressible or incompressible flows, in an unbounded domain Q∞$$ {Q}_{\infty } $$ of ℝn+1$$ {\mathrm{\mathbb{R}}}^{n+1} $$. We approximate Q∞$$ {Q}_{\infty } $$ by a sequence of bounded domains (Qr)r$$ {\left({Q}_r\right)}_r $$, and we consider a regularized problem (Prϵ)$$ \left({P}_{r\epsilon}\right) $$ on the bounded domain Qr$$ {Q}_r $$ which has a unique solution. Now, we pass successively to the limit in (Prϵ)$$ \left({P}_{r\epsilon}\right) $$, as r→∞$$ r\to \infty $$ and then as ϵ→0$$ \epsilon \to 0 $$ to get a solution to (P)$$ (P) $$. Note that in a previos study of Gilardi and Kröner [7], an existence of a solution was given by using a different technique for the evolution dam problem related to an incompressible flow through a homogeneous porous medium.
In this work, we propose a new hybrid approach to optimize the reliability of Unmanned Aerial Vehicles (UAV) based on two complementary approaches. The first approach is based on the Failure Mode and Effects Analysis (FMEA), which is an informal method based on the establishment of a table describing the failure modes of the elements of the system and their effects, the aim of using this method is to optimize the search of critical scenarios that leads the system to the failure state. The second approach is based on Developed Stochastic Petri nets formalism coupled with the reliability laws (RLSPNs) according to the nature of the components (electronic, electrical, mechanical, software, …etc.) of the system, this simplifies the reliability evaluation of the system components as well as the reliability of the complete system. The goal of this approach is to determine the main causes of the failure of the system, optimize the search of critical scenarios, and study the reliability of system components; in order to have the most reliable and least reliable components. This detailed study will certainly make it possible to propose improvements that can in the future improve the reliability of the complete system.
Introduction Ehlers-Danlos syndromes (EDS) are a heterogeneous group of rare inherited collagen disorders. Clinical signs are dominated by generalized joint hyper laxity, skin hyper elasticity and tissue fragility. The diagnosis is clinical in the absence of genetic testing. There is no curative treatment but it is possible today to improve the quality of life of these patients. We report two cases of EDS from a non-consanguineous marriage, without similar cases in their families. Observations CASE 1: Mrs N.B, 31 years old, 2nd of 4 siblings, with a history of heterozygous beta thalassemia, she presented with mechanical gonalgias secondary to patellar dislocations associated with ankle sprains since the age of 5 years. On clinical examination: generalized hyper mobility (Beighton score 9/9), hyper elasticity of the skin, skin fragility, atrophic scarring, papery skin of the knees, hyper transparency of the skin, epistaxis at the slightest scratching, the rest of the somatic examination was unremarkable. The standard biological workup, X-ray and ultrasound of the knees and ankles were without abnormalities. Classic EDS (I and II) was retained according to the 2017 international classification. The patient responded to tier I analgesics. Case 2 Mrs B.L, 24 years old, the third of five siblings, with a history of bronchial asthma, presented with bilateral and symmetrical polyarthralgia affecting the large and small joints with mixed type spinal pain associated with spontaneous myalgia in a context of profound asthenia evolving for 14 years. On osteoarticular examination, generalized joint hypermobility was noted (Beighton score 9/9); on the cutaneous level, transparency and hyperextensibility of the skin with multiple ecchymoses due to tissue fragility associated with delayed healing with cutaneous hyperesthesia, all associated with exertional dyspnea, chronic abdominal pain and gastroesophageal reflux since the onset of his illness. Biologically, no inflammatory syndrome. The autoimmune workup (RF, ACPA, FAN) was negative and other investigations were without abnormalities. X-rays of the chest, hands, wrists and knees were unremarkable. The patient was classified as having hypermobile EDS (type III) according to the international classification of the disease. The patient responded only partially to analgesics (levels I, II and III) and to tricyclic antidepressants. Conclusion The diagnosis of EDS must be made early in order to ensure optimal symptomatic management. The management must be multidisciplinary, including an evaluation, a psychological follow-up, a treatment of the pain and physiotherapy.
The optimization of energy production in renewable energy systems is crucial to improve energy efficiency. In this context, the aim of this study focuses on maximizing the efficiency of a switched reluctance generator. This paper presents a novel approach to enhance the electrical power and efficiency of a switched reluctance generator by determining the optimal operating parameters based on the mechanical input power of the system. The proposed strategy consists of the following steps: First, an algorithm was developed that provides machine data for different power modes based on control parameters, including electrical and mechanical powers such as speed, torque, and turn-on and turn-off angles. In the next step, the obtained data were analyzed to identify the optimum points corresponding to the states with maximum power and efficiency for various scenarios. An algorithm for maximum power point tracking was also developed to determine the optimal parameters as a function of mechanical energy. Finally, the data and algorithms were integrated into the switched reluctance generator control system. Simulations were conducted to compare the proposed MPPT technique with other techniques. This comparison is essential to validate the effectiveness of the proposed strategy in achieving enhanced electrical power generation efficiency.
Plant extract-mediated synthesis is a simple, eco-friendly, and inexpensive method for the preparation of efficient antioxidant and photocatalytic nanoparticles. In this study, lemon peel aqueous extract was used to synthesize CuO nanoparticles (NPs) and then the obtained CuO NPs were modified using polyethylene glycol (PEG). The characteristics, optical properties, antioxidant, and photocatalytic activities of the synthesized nanoparticles were investigated. The CuO NPs and CuO/PEG NPs exhibited sphere-like morphology with an average size of 34 nm and 45 nm and optical bandgap energies of 1.2 eV and 1.5 eV, respectively. The antioxidant activity tests showed that the CuO/PEG NPs exhibited significant scavenging activity with IC50 values of 104.6 μg/mL for the β-carotene scavenging assay and 38.1 μg/mL for the ABTS scavenging assay, while CuO showed lower antioxidant activity of about 150.54 μg/mL for β-Carotene linoleic acid bleaching assay and 59.63 μg/mL for the ABTS scavenging assay. In terms of photocatalytic degradation, CuO/PEG NPs demonstrated higher activity compared to CuO NPs alone. They achieved degradation rates of 99.7% for 4-bromophenol (BP) dye and 99.5% for toluidine blue (TP) dye after 90 min, whereas CuO NPs achieved slightly lower rates. The CuO NPs and CuO/PEG NPs displayed significant photocatalytic degradation activity against amoxicillin (antibiotic), with degradation rates of 91% and 98%, respectively, after 120 min. The reaction kinetics of CuO/PEG NPs and CuO NPs followed a pseudo-first order model, with CuO/PEG NPs exhibiting a higher rate constant than CuO NPs. Overall, modifying the CuO NPs with PEG demonstrated excellent photocatalytic properties for environmental remediation and exhibited antioxidant activity, suggesting their potential use in wastewater treatment and therapeutic applications. Graphical Abstract
This study aimed to investigate the phytochemical composition and biological activity of Salsola tetragona Delile. (Amaranthaceae), a medicinal plant. The study evaluated the antioxidant potential of the crude extract and five fractions of S. tetragona using DPPH•, ABTS•+, CUPRAC, and metal chelating assays. The anti-inflammatory activity was determined using a protein denaturation assay, and the antibacterial activity was determined by the Minimum inhibitory concentrations (MICs) for the growth of Escherichia coli and Staphylococcus aureus strains. The MTT test and an in vitro scratch assay evaluated the effects on cell viability and cell migration. The potential anti-SARS-CoV-2 activity was assessed by analyzing the effects on the interaction between ACE2 and Spike protein. The bioactive compounds present in the plant were identified using LC-HR/MS analysis. The crude hydromethanolic extract (STM) and five fractions of S. tetragona, n-hexane (STH), dichloromethane (STD), ethyl acetate (STE), n-butanol (STB), and aqueous (STW) showed significant antioxidant activity in four different tests. In the anti-inflammatory assay, the ethyl acetate fraction exhibited significantly higher activity than Aspirin® (IC50 = 13 ± 5 µg/mL). The crude extract and its fractions showed positive antibacterial activity with similar MICs. In the cytotoxicity assay against the breast cancer cell line MCF7, the dichloromethane fractions (STD) were very effective and demonstrated superiority over the other fractions (IC50 = 98 µg/mL). Moreover, the potential of the extract and fractions as anti-SARS-CoV-2, the ethyl acetate, and dichloromethane fractions demonstrated important activity in this test. LC-HR/MS analysis identified 16 different phenolic compounds, Eleven of which had not been previously reported in the genus Salsola. The results suggest that the extracts of S. tetragona have the potential to become new sources for developing plant-based therapies for managing a range of diseases.
The widespread use of nonbiodegradable synthetic dyes in various industries has led to significant toxic contamination and water pollution. The release of these dyes into aquatic environments poses serious risks to human health and ecosystems. To address this issue, rapid and efficient techniques for dye removal or transformation are required. In this article, we present a pioneering approach for the synthesis of a highly efficient photocatalyst material, PPAH/Ag@ZnO nanocomposites, for the degradation of organic dyes in wastewater. By integrating silver (Ag) and zinc oxide (ZnO) nanoparticles within the potassium polyacrylate hydrogel (PPAH) matrix, a two-step method was employed to create stable and effective photocatalytic nanocomposites. The successful formation of PPAH/Ag@ZnO nanocomposites was confirmed through comprehensive characterization using UV–visible spectroscopy, FTIR, XRD, and SEM techniques. The photocatalytic performance of the PPAH/Ag@ZnO nanocomposite was evaluated for the degradation of o-toluidine blue (o-TB) and 4-bromophenol (4-Bph) under sunlight. The experimental results demonstrate that the PPAH/Ag@ZnO nanocomposite effectively degrades 98.77% of o-TB and 98.05% of 4-Bph. Moreover, the kinetics of the photocatalytic degradation reactions were investigated, revealing apparent reaction rate constants of 0.0229 and 0.018 min−1 for the degradation of o-TB and 4-Bph, respectively. Additionally, the reusability of the prepared PPAH/Ag@ZnO photocatalyst was evaluated over 5 consecutive cycles, demonstrating its exceptional effectiveness and stability. This innovative approach with hydrogel-based nanoparticles offers a potential breakthrough in the field of photocatalysis for addressing water contamination caused by organic dyes.
This paper discusses the impact of the feature input vector on the performance of DGA-based intelligent power transformer fault diagnosis methods. For this purpose, 22 feature vectors from traditional diagnostic methods were used as feature input vectors for four tree-based ensemble algorithms, namely random forest (RF), tree ensemble (TE), gradient boosted tree (GBT), and extreme gradient tree (XGB). To build the proposed diagnostics models, 407 samples were used for training and testing. For validation and comparison with the existing methods of literature 89 samples were used. Based on the results obtained on the training and testing datasets, the best performance was achieved with feature vector 16, which consists of the gas ratios of Rogers’ four ratios method and the three ratios technique. The test accuracies based on these vectors are 98.37, 96.75, 95.93, and 97.56% for the RF, TE, GBT, and XGB algorithms, respectively. Furthermore, the performance of the methods based on best input feature were evaluated and compared with other methods of literature such as Duval Triangle, modified Rogers’ four ratios method, combined technique, three ratios technique, Gouda triangle, IEC 60599, NBR 7274, clustering, and key gases with gas ratio methods. On validating dataset, diagnostic accuracies of 92.13, 91.01, 89.89, and 91.01% were achieved by the RF, TE, GBT, and XGBoost models, respectively. These diagnostic accuracies are higher than 83.15 % of the clustering method and 82.02 % of combined technique which are the best existing methods. Even if the performance of DGA-based intelligent methods depends strongly on the shape of the feature vector used, this study provides scholars with a tool for choosing the feature vector to use when implementing these methods.
Biochar has shown large potential in water treatment because of its low cost, good textural properties, and high reusability. In this study, two porous biochars were developed from the Melia azedarach seeds via direct pyrolysis process (B-700) and through hydrothermal carbonization followed with pyrolysis (HB-700). They were characterized by morphology, structural characteristics, and surface features and used to adsorb the crystal violet (CV) dye in water environment. Results of the isotherm approaches demonstrated that the removal capacity of these biochars reached 119.4 mg/g for B-700, and 209 mg/g for HB-700 (at 45°C). Also, the Avrami model best fitted the kinetic data. The electrostatic attraction was regarded as one of the adsorptions mechanisms of CV dye. The regeneration tests reveal that both B-700 and HB-700 are good reusable adsorbents. Finally, findings of the study showed that the hydrothermal carbonization method that precede the pyrolysis process can improve significantly the adsorption capacity of the produced biochar.
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1,630 members
Abdelkrim Rebiai
  • Department of Chemistry
Djilani ben attous
  • Electrical Engineering
Zoheir Tir
  • Electrical Engineering
Abdelkader Laouid
  • Computer Science
Lejdel Brahim
  • Computer science departement
BP 789 Poste centrale d'El Oued, 39000, Algiers, Wilaya d'El Oued , Algeria
Head of institution
Prof. Omar FERHAT
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