Publications Nationales
Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/14
Browse
5 results
Search Results
Item Enhancing heat transfer with new hybrid nanofluids type core@shell nanoparticles(Begell Digital Library, 2025) Lachachene, Farida; Achab, Louiza; Cheradi, HananeThis numerical study aims to enhance heat transfer in non-uniformly heated systems using a novel hybrid of core@shell nanoparticles with a ZnO@Ag structure. The primary objective is to evaluate the effectiveness of these nanoparticles in improving thermal performance. The analysis spans a range of Rayleigh numbers while maintaining a constant nanoparticle density of 0.1%. The finite volume method is employed to solve the governing equations, using the second-order upwind method for convection contributions and the SIMPLE approach for coupling velocity and pressure fields. Pressure discretization is performed using the PRESTO method, and convergence is ensured with an under-relaxation scheme, achieving an absolute residual below 10-6. The results demonstrate a significant improvement in Nusselt numbers, with ZnO@Ag nanoparticles achieving a 20.15% enhancement. This improvement is attributed to the even coating of Ag, which possesses superior thermal properties onto ZnO, leading to increased overall thermal conductivity. These findings underscore the promising potential of core@shell nanoparticles for enhancing heat transfer in engineering applications. This study motivates further research and optimization efforts to harness the full potential of these advanced materials in thermal management systems.Item IMC-PID-FOF Multi-loop controller design for Binary Distillation Column(Université M'hamed Bougara de Boumerdès, 2022) Chekari, Tassadit; Mansouri, Rachid; Bettayeb, MaamarThis paper deals with the fractional order multi-loop controller design for a distillation column. The idea is a generalization of the IMC-PID-FOF controller design method developed for monovariable systems to the distillation column model which is multivariable. The principle is based on the IMC paradigm and the choice of appropriate control configuration with minimum of interactions. The proposed method is illustrated with an example of a distillation column model taken from the literatureItem An Agrofood waste physicochemical characterization for its valorization(YYYY) Didouche, Yasmina-Fadila; Akssas, H.This study was focused on biorefinery byproducts mainly, based on distilled fatty acids from sunflower oil and coconut oil; for their valorization. They were characterized oleochemically, for sunflower oil, the Iodine Index: 120 g I2 / 100g fat noted the unsaturation of its fatty acids and the Refractive Index (RI) n 20: 1417 revealed its siccativity. As for the coconut oil, the saponification index: 250 mg KOH / g fat was on the rise, insured its ability to promote saponification and the IR n20: 1. 448 attested its un-siccativity; polyunsaturated fatty acids of these both oils were revealed via gas chromatography. These tests results were promoted for the development of a liquid soap, that was characterized physicochemically via the residual base: 0.02%, total fat content: 25.52%, residual glycerol content: 14.68%, pH: 07.90, lyophilic hydrophilic balance: 20. 02, surface tension: 34.10 dynes / cm, concentration micelle critic: 05. 103 mol /l and spectral methods such FTIR, XRD and SEM corroborated these analyses; which were confirmed the presence of carboxylic fatty acid salts. This work was conclusive, resulted in a liquid soap loaded with 14.68% of vegetable glycerin with moisturizing, emollient and softening properties, in conformity with hygiene standardsItem الآثار المحتملة للدفع الالكتروني على سير السياسة النقدية = The potential effects of electronic payment on the conduct of monetary policy(جامعة أمحمد بوقرة بومرداس, 2020) منصر, كريمةدفع التطوّر الهائل في مجال تكنولوجيات الإعلام والاتصال إلى استحداث أدوات دفع الكترونية انفردت بأدائها المتميّز في إتمام المبادلات التجارية وتسوية المعاملات المالية متجاوزة بذلك القيود التقليدية الزمنية والمكانية، ومزاحمة النقود القانونية في أداء المهام الأساسية، وسلبت البنك المركزي انفراده بوظيفة الإصدار النقدي. وعليه أثيرت إشكالية سير السياسة النقدية ضمن هذا المحيط، بما يعني إمكانية التحكم في الكتلة النقدية المتداولة في الاقتصاد والحفاظ على استقرار الأسعار وتحقيق أهداف التنمية الاقتصاديةItem دور التشريع في اقرار المسؤولية المدنية في المجال البيئي(جامعة امحمد بوقرة, 2020) عيسى, زهية