J- Revues scientifiqueshttp://univ-bejaia.dz/dspace/123456789/22052024-03-28T19:44:51Z2024-03-28T19:44:51ZAging by burial in soil of polylactic acid biocomposites reinforced
with Alfa fiber treated with dispersing agentKlaai, LisaHammiche, DalilaIbrahim, HananeImzi, SoniaBoukerrou, Amarhttp://univ-bejaia.dz/dspace/123456789/210992023-02-08T14:32:03Z2022-01-30T00:00:00ZAging by burial in soil of polylactic acid biocomposites reinforced
with Alfa fiber treated with dispersing agent
Klaai, Lisa; Hammiche, Dalila; Ibrahim, Hanane; Imzi, Sonia; Boukerrou, Amar
Soil burial test comprises of placing samples in soil/ compost for long durations and testing the mechanical properties/dimensional changes/ morphology before and after soil burial. In a bioreactor, samples are placed in a composting vessel containing a mixture of compost and the percentage of biodegradation is theoretically calculated by measuring the amount of CO2 evolved from the composting vessel for a period of 45 days. This present work is focused on the study of the durability of different PLA/Alfa biocomposite materials treated with BYK W-980 and untreated, prepared via burial in soil aging. The study of biodegradation by burial in soil showed that the biodegradability of biocomposites prepared with untreated and treated PLA/Alfa degrade in soil more than those prepared with BYK W-980 for the same burial conditions. Knowing that the PLA buried in the ground is biodegradable after 4 to 5 years, by consecrating in this time interval of burial, we only have the fibers which degrade.
2022-01-30T00:00:00ZDevelopment and validation of high-performance liquid chromatography assay method for simultaneous determination of Caffeic acid, Vanillin, and Cinnamic acid in Algerian propolis extractTOUTOU, ZahraCHIBANI, NaceraTAOUZINET, LamiaSALHI-AMRANI, YasminaFATMI, Sofianehttp://univ-bejaia.dz/dspace/123456789/210982023-02-08T14:07:13Z2022-01-30T00:00:00ZDevelopment and validation of high-performance liquid chromatography assay method for simultaneous determination of Caffeic acid, Vanillin, and Cinnamic acid in Algerian propolis extract
TOUTOU, Zahra; CHIBANI, Nacera; TAOUZINET, Lamia; SALHI-AMRANI, Yasmina; FATMI, Sofiane
Propolis is a natural bee substance and resinous material produced from various plants, which showed important biological activities. The current study aims to evaluate and validate simultaneous methods of identification and quantification of three phenolic compounds (caffeic acid, vanillin, and cinnamic acid) in propolis extract from different Bejaia regions using high performance liquid chromatography (HPLC). Chromatographic analyses were performed using gradient mode, in are versed-phase C-18 (150 x 4.6 mm, 5 μm) column. The mobile phase contained 0.5% v/v acetic acid in water (solvent A) and acetonitrile (solvent B), using a flow rate of 1 ml/min and by injecting 20 μl, at a wavelength of 290 nm. The method was validated according to ICH guidelines. Specificity, linearity, accuracy, precision, detection, and quantification limits studies were made. The results showed that the correlation coefficient (R2) was > 0.99 for Caffeic acid, Vanillin, and Cinnamic acid, the percentage of relative standard deviation (RSD) of all assays found below 2% and 5% for intra-day and inter-day, respectively, limits of detection were 0.024, 0.008, and 0.009 mg/ml and limits of quantitation was 0.074, 0.025, and 0,029 mg/ml, for Caffeic acid, Vanillin, and Cinnamic acid respectively. According to these various parameters: accuracy, precision, linearity, and specificity, the proposed method was successfully validated in the simultaneous assay of Caffeic acid, Vanillin, and Cinnamic acid.
2022-01-30T00:00:00ZAnalytical stress solution in hyperelastic thick-walled sphere under external pressure using different strain energy functionsBenslimane, AbdelhakimBenidir, Adelhttp://univ-bejaia.dz/dspace/123456789/210972023-02-08T13:50:53Z2022-01-30T00:00:00ZAnalytical stress solution in hyperelastic thick-walled sphere under external pressure using different strain energy functions
Benslimane, Abdelhakim; Benidir, Adel
Due to their large deformation, rubber-like materials are used in many industrial applications. However, few studies are available in the literature on the classification of rubber-like materials, their mechanical properties and the behavior of this material due to their hyperelastic and nonlinear behavior. In this work, an incompressible isotropic nonlinear elastic thick-walled spherical structure subjected to external pressure is studied using analytical formulation. The study aims to analyze the behavior and the stress field of such materials which are characterized by high deformability. Five different type strain energy functions are applied to a pressurized thick-walled hollow sphere to model the material behavior. A closed-form analytical solution is obtained and the results predicted from classic strain energy models (Neo-Hookean and Mooney Rivlin) and those obtained by Isihara, Biderman and Gent-Thomas models are compared in the prescribed case. The solution obtained, for different models, was used to determine the stress field (radial and hoop stresses) across thickness of the sphere. Finally, the influence of some parameters such as the radial pre-stretched sphere on stress components was examined. Comparisons are done to investigate the accuracy and evaluating the effectiveness of some existing constitutive models in the analysis of spherical vessel under external pressure.
2022-01-30T00:00:00ZPrickly pear seed: from vegetable fiber to advanced applications: A reviewBELLACHE, RebihaHAMMICHE, DalilaBOUKERROU, Amarhttp://univ-bejaia.dz/dspace/123456789/210962023-02-08T13:40:39Z2022-01-27T00:00:00ZPrickly pear seed: from vegetable fiber to advanced applications: A review
BELLACHE, Rebiha; HAMMICHE, Dalila; BOUKERROU, Amar
The prickly pear seed is a part rich in fatty substances; it can be exploited for the extraction of oils for food, cosmetic, pharmaceutical, and medical use. The focus of this review is to define one of the most expensive oils in the world "Prickly Pear Seed Oil" (PPSO). Its method of obtaining by cold pressing of its seeds makes it rich in active ingredients. For this, we will present a description of the cactus plant and its botanical classification, its chemical composition for either the pulp, the bark, or the seed. The morphology of the seed and its different applications, in addition to the seeds oil, presents extraordinary properties.
2022-01-27T00:00:00Z