Browsing by Author "Djeziri, Mourad"

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Application of 35NCD 16 Steel Under Cyclic Loading by an Elastoplastic Model
(Jan-Evangelista-Purkyne-Universityc, 2024) Chebbab, Brahim; Djeziri, Mourad
The purpose of this paper is to study an application of the 35NCD 16 steel by a model generalizing the isotropic and kinematic strain hardening laws. The model in question is represented by a field of strain hardening moduli corresponding to the introduction of the configuration of the flow surfaces. Each flow surface is characterized by its constant elastoplastic modulus, its normal unit vector, its radius and its center coor- dinates. For cases of uniaxial or multiaxial (complex) loading, in particular for cases of cyclic loading or unloading, the instantaneous configuration can be determined by the position and dimensions of the flow surfaces, determining the strain increment for each strain increment.
Cross-cultural comparison of antidiabetic medicinal plants used in Algeria and Morocco
(Elsevier, 2025) Maamri, Sarra; Djeziri, Mourad; Mendil, Souhila; Terfi, Lydia
Diabetes is a chronic endocrine disease of global concern. The aim of this study is to provide a comparative analysis of ethnomedical practice used for diabetes management in Algeria and Morocco, offering a scientific basis for the development of alternative therapies and innovative drug discovery. Methods: Ethnomedical information was normalised from quantitative ethnobotanical studies. Principal component analysis (PCA) was used to compare regional data, complemented by hierarchical ascending classification (HAC) to identify similarity in plant use, plant parts, and preparation methods. Results: A total of 225 species (68 families) in Algeria and 222 species (64 families) in Morocco were identified, with 95 species common to both countries (around 30%). PCA revealed interregional variabilities of 42.60% (Algeria) and 43.43% (Morocco). HAC subdivided the heterogeneous dataset into homogeneous groups based on plant usage, plant parts, and preparation modes. These groupings reflect both a shared ethnomedicinal heritage and region-specific adaptations, highlighting the balance between redundancy and divergence within the phytotherapeutic practice, which underpins its stability and therapeutic diversity. Conclusion: This study demonstrates that ethnobotanical knowledge is a dynamic and valuable resource, transcending cultural boundaries and providing a robust foundation for the discovery of novel antidiabetic formulations. The nuanced balance between common frameworks and unique phytotherapeutic specificities supports the development of complementary or synergistic therapies
Effective biofertilizer trichoderma spp. isolates with enzymatic activity and metabolites enhancing plant growth
(Research square, 2022) Reghmit, Abdenacer; Benzina-tihar, Farida; Djeziri, Mourad; Hadjouti, Rima; Oukali, Zahia; Sahir-Halouane, Fatma
Trichoderma species have been widely recognized as biofertilizer fungi for their ability to produce phytohormones and enhancing plant growth. In our current study, fifteen strains of Trichoderma spp (T1- T15) were screened for their capacity to produce phytohormones and metabolites eliciting plant growth. The stains were previously isolated from olive rhizosphere soil in northern Algeria. Plant growth promoting (PGP) potential of Trichoderma spp. was evaluated in-vitro through the production of phosphatases, iron chelators (siderophores), cyanhydric acid (HCN) and ammonia (NH3). Besides, Plant growth phytohormones such as gibberellic acid and indole-3-acetic acid (IAA) were assessed quantitatively by a colorimetric assay. Results showed an effective potential of Trichoderma isolates in PGP biomolecules production. Importantly, qualitative estimation of phosphate solubilization indicates that T10 gave the highest P-solubilization on medium Pikovskaya’s with a solubilization index (SI) of 3, whereas, the high capacity nitrogen-fixing was related to T8. In other hand, quantitative analysis of IAA and gibberellic acid revealed a production varying between (1.30 µg mL − 1 − 21.15 µg mL − 1 ) and (0.53µg/ml − 7.87µg/ml), respectively, the highest amount of both phytohormones was obtained by T11 isolate. Indeed, analysis of ethyl acetate extracts of T11 isolate by high-performance liquid chromatography (HPLC) revealed a high amount (71.19 mgL − 1 ) of IAA. Overall, Results showed clearly that isolate T11 has promising plant growth promoting properties. Hence, this native Trichoderma isolate (T11) identified as Trichoderma harzianum strain (OL587563) could be used later as biofertilizer for sustainable olive crop agriculture
Formulation et caractérisation d'un aliment destiné à l'élevage de Tilapia (Oreochromis niloticus) d'eau douce
(2018) Djeziri, Mourad
L'objectif de cette étude consiste à étudier la possibilité de substituer un aliment à base de farine destinée aux poissons Tilapia (Oreochromis niloticus), par un autre aliment à base de sous-produits agro-industriels. Quatre sous-produits végétaux et animaux ont été sélectionnés pour la formulation de cet aliment, à savoir : la farine des plumes de Volailles (FPV), la farine de noyaux de dattes (FND), la farine des petits pois (FPP) et la farine de déchets de tomate (FT). Les quatre sous-produits suscités ont été combinés pour l'obtention de quatre aliments expérimentaux (AL1-AL4) isoprotéiques (25 à 30 % de protéines brutes) et isoénérgétiques (15-21 KJ d'énergie brute par g d'aliment), de manière à remplacer totalement et partiellement, la farine de poissons. Un cinquième aliment (AL5), à base de farine de poisson a servi comme témoin. Les résultats des analyses zootechniques et biochimiques, tels que : le taux de croissance spécifique (TCS), l'efficacité de conversion alimentaire (ECA), le coefficient d'efficacité protéique (CEP) et la rétention protéique apparente (RPA) montrent que les aliments expérimentaux AL3 et AL4 donnent de meilleurs résultats relativement à l'aliment témoin (AL5). Les résultats les moins intéressants ont été obtenus avec l'aliment expérimental AL1 pour la première phase d'élevage (prégrossissement). D'autre part, il a été constaté que les coefficients d'utilisation digestive apparente (CUDA) des protéines changent en fonction de la nature de l'aliment formulé, et que ce dernier est relativement important pour les deux aliments AL2 et AL3. Enfin, au regard de tous les résultats des analyses obtenus, il a été mis en évidence que l'aliment AL4, est relativement plus performant, sur le plan nutritionnel, qu'aux autres aliments formulés, ce qui donne un meilleur gain en poids. Les aliments formulés présentent un coût d'utilisation du kilogramme inférieur d'environ 500 DA à celui de l'aliment témoin, Les résultats ont indiqué que les propriétés, physicochimiques et rhéologiques des aliments de poissons étaient relativement uniformes. Sur la base des propriétés structurales, les aliments possèdent des propriétés souhaitables et, par conséquent, peuvent servir de matière première pour une variété de produits alimentaires et industriels
Hydrolyse des protéines végétales (gluten de blé) : caractérisation des propriétés fonctionnelles des hydrolysats
(2003) Djeziri, Mourad
Dans ce mémoire, nous avons caractérisé la matière première (matériel végétal). L'étude a porté sur la fraction protéique de deux variétés de blé tendre ANZA et HD1220. Nous avons déterminé quelques caractéristiques de la farine et du gluten, en commençant par un broyage des blés et une extraction du gluten, le suivi de l'opération était argumentée par des analyses technico-chimiques ainsi par des tests d'appréciation de la qualité du gluten…
Influence of ripening index on the yield and quality of virgin olive
(Université Saad Dahlab Blida, 2023) Mouas, Kamelia; Djeziri, Mourad; Benakmoum, Amar
Description of the subject: Algeria is considered one of the leading olive growing areas in the world. The maturity index is one of the most important factors contributing to oil quality. Objectives: This study was conducted to investigate the effect of olive maturity index on the physicochemical properties of oil using the chemlal cultivar in the region of Boumerdes. Methods: The study was conducted in a commercial chemlal olive planted in the village of chebat el Eumer. Seven samples were collected from 25 September 2018 to 03 February 2019. Each sample was tested for fruit characteristics including moisture maturity index, weight, length and width of fruits. Oil extracted by the mechanical method was tested for acidity, peroxide, UV light extinctions, oil fatty acid composition, pigments, polyphenols and functional analysis by FT-IR. Results: The oil content ratio increased significantly over the harvest dates, a clear correlation was observed between the colour index and each of the fruit weight ratios. Acidity and peroxide values increased during the harvest dates. K232, K272, ΔK were within the International Olive Oil Council specifications for extra virgin oil. Oleic acid and palmitic acid levels ranged from (64.04-70.63%) and (14.63-21.28%) respectively. Chlorophyll and carotenoids were all (31.07); (1.36) mg/kg respectively for the first ripening index. Total polyphenols show significant differences between harvest dates, the lowest value was observed at the last sampling date (259 mg/kg) and the highest at the date of 25/09/2018 (321 mg/kg). Conclusion: The results obtained could be useful in determining the optimal for picking olives, which is between the end of September and the end of October for the Chemelal variety.
Isolation and identifcation of thermotolerant yeast strains producing bioethanol from agro‐food wastes
(Springer, 2023) Gherbi, Younes; Boudjema, Khaled; Djeziri, Mourad; Fazouane–Naimi, Fethia
Bioethanol production from agro-food industry waste is one of the suitable alternatives to fossil fuels. In this study, six agro-food wastes were evaluated to select those with a high concentration of starch or fermentable sugars for bioethanol processing. Yeast’s ability to produce biofuels by fermentation is afected by temperature. In this study, thermotolerant yeasts, obtained from natural sources in Algeria (soil and agro-food waste), were selected for their capacity to produce and tolerate bioethanol. Three wastes were selected, two of which had signifcant starch content. In order to get fermentable sugars, these wastes underwent chemical and enzymatic hydrolysis. The selected yeasts were identifed by morphological, physiological, biochemical, and molecular characterization. Enzymatic and acid hydrolysis of whole potato and durum wheat bran released (190 g/L and 130 g/L) and (138.40 g/L and 90.03 g/L) reducing sugars, respectively. Among the isolated strains, three were found to be able to produce bioethanol, namely Candida tropicalis, Candida glabrata, and Saccharomyces cerevisiae. These strains were identical to those stored in the data bank with 99%, 100%, and 100%, respectively. In addition, C. glabrata and C. tropicalis exhibited an ethanol tolerance of up to 14%, while S. cerevisiae tolerates up to 15%. Interestingly, enzymatic hydrolysis–treated potatoes produced a considerable amount of bioethanol after 48 h of fermentation by S. cerevisiae (7.525% (v/v)), C. glabrata (6.80% (v/v)), and C. tropicalis (4.50% (v/v)). Taken together, our fndings suggest that S. cerevisiae and whole potato waste could be considered good candidates for industrial bioethanol production at high temperatures.
Valorization of carob seeds as a functional food
(2023) Lagha-Benamrouche, Samira; Boudjema, Khaled; Rezgui, Walid; Djeziri, Mourad; Hezil, Djamila
Our study aims to promote carob seeds as a functional food. For this; the nutritional value, the compounds with beneficial physiological effects and functional properties (fibers and gums), as well as the antioxidant potential were determined. Analysis of the chemical composition of carob seeds reveals their high protein, ash and fat content. However, the total sugars content was estimated to be moderate. The quantification of the compounds with a beneficial physiological effect shows that the seeds are rich in crude dietary fibers (8.39%). Regarding the gums, the yields are evaluated at 39.44% for the crude gums and at 4.026% for the purified gums. The phytochemical assays reveal a richness of the seeds in total polyphenols, in total flavonoids with a moderate content of flavonols and hydrolyzable tannins. The antioxidant potential was studied using two methods: reduction of the free radical 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and the iron reduction method. According to the results, the carob seeds have a discreet antioxidant potential compared to the standards tested (gallic acid and quercetin).