http://dspace.univ-relizane.dz/home/handle/123456789/195 2026-05-20T13:24:28Z 2026-05-20T13:24:28Z Hadji Chikh Ali http://dspace.univ-relizane.dz/home/handle/123456789/942 2026-05-10T08:46:43Z 2025-01-01T00:00:00Z

Title: Ab initio study of the optoelectronic and thermal properties of double perovskites Authors: Hadji Chikh Ali Abstract: This thesis work aims to study double perovskites by numerical simulation calculation which allowed improved comprehension of the thermal and optical characteristics of these materials, perovskites are promising materials for optical and thermal applications, simulations showed that the band gap of perovskites is sensitive to the chemical composition and crystal structure and that the addition of ions can reduce the width of the band gap and increase the optical response, the simulations also revealed that the conductivity thermal properties of the atoms in the material and that this conductivity, Ab-inition studies thus provide valuable information for the creation of novel materials for thermal and optical uses, additionally, Wien2k software is used to simulate and optimize heterojunction PSCs with the suggested structure, this study's objective is to examine how well PSC with active layers of Cs₂ZnPbCl₆ and Cs₂ZnPbBr₆perovskite as permeable layer. The work uses the WIEN2k code and DFT to investigate the double perovskite compounds Cs₂ZnPbCl₆ and Cs₂ZnPbBr₆, The compounds exhibit strong electrical conductivity, high thermoelectric performance, and a stable cubic structure. The thermal conductivity patterns indicate an increase with temperature, and the Seebeck coefficients are excellent. Applications for the compounds in thermoelectric generators, in particular, hold promise for sustainable energy, additionally, the study validates the compounds' mechanical stability, which is essential for real-world device applications, these discoveries advance our knowledge and use of double perovskite materials, additionally, the double perovskite materials under investigation have a favorable At room temperature, their thermodynamic and thermoelectric qualities show promise for use in thermoelectric technology, as evidenced by their figure of merit.

2025-01-01T00:00:00Z AZZOUZ Belqassim http://dspace.univ-relizane.dz/home/handle/123456789/941 2026-05-07T11:05:26Z 2025-01-01T00:00:00Z

Title: Qualitative Study of a Class Fractional Differential Equations and Inclusions in a Banach Space Authors: AZZOUZ Belqassim Abstract: The main goal of this thesis is to present a set of results on the existence and uniqueness of certain classes of the initial value problems and boundary value problems for differential problems involving Caputo, Riemann-Liouville and Hilfer derivatives, under certain conditions. The results have been proven analytically, where the existence results are based on some classical fixed point theorems (Banach, Schaefer, Krasnoselskii) as well as M¨onch’s fixed point theorem combined with the technique of Kuratowski’s measure of noncompactness. To support our results, we provide different illustrative examples in each chapter.

2025-01-01T00:00:00Z SI-LARBI Ali http://dspace.univ-relizane.dz/home/handle/123456789/939 2026-05-07T10:34:32Z 2025-01-01T00:00:00Z

Title: Study of the Nutritional Properties and Antioxidant Activities of an Edible Mushroom and a Variety of Vegetables : underlying mechanisms and implications for the prevention of chronic diseases. Authors: SI-LARBI Ali Abstract: This study evaluated the nutritional and biological activities of the edible mushroom Pleurotus eryngii and Foeniculum vulgare leaves from western Algeriaby analyzing their composition, secondary metabolites (phenolic compounds and flavonoids), and antioxidant, anti-inflammatory, antimicrobial, and α-amylase inhibitory activity. Nutritional analysis of P. eryngii (on a dry weight basis( revealed high protein (14.81 ± 0.54 g/100 g), sugars (49.61 ± 3.16 g/100 g), carbohydrates (77.26 ± 0.52 g/100 g), minerals (5.27 ± 0.21 g/100 g), low fat (2.67 ± 0.23 g/100 g), energy (391.62 ± 1.55 kcal/100 g), and moisturecontent (81.4 ± 1.68 %). F. vulgare leaves showed lower protein (4.62 ± 0.37 g/100 g) and fat (1,54 ± 0.06 g/100 g), but higher carbohydrates (90.14 ± 0.23 g/100 g). Phytochemical analysis indicated that the aqueous extract of P. eryngii had higher polyphenols and flavonoids (20.65 ± 0.27 mg gallic acid equivalent/g extract, 5.69 ± 0.07 mg quercetin equivalent/g extract, respectively), while F. vulgare leaves were richest in the ethanolic extract(23.80 ± 0.19 mg gallic acid equivalent/g extract, 17.62 ± 0.99 mg quercetin equivalent/g extract, respectively). LC-MS/MS identified three main bioactive compounds in P. eryngii (predominantly trans-cinnamic acid) and ten in F. vulgare leaves (mainly chlorogenic acid). Antioxidant activity was higher in the aqueous extract of P. eryngii (DPPH, FRAP, TAC, β-carotene, H₂O₂ assays), whereas F. vulgare leaves showed superior activity in the ethanolic extract. Regarding anti-inflammatory activity, the aqueous extractof P. eryngii showed a strong ability to inhibit albumin denaturation, whereas for F. vulgare leaves, the effect was more pronounced in the ethanolic extract. Molecular docking confirmed the activity of compounds such as rutin and quercetin against key proteins of the inflammatory response. Enzymatic activity showed greater α-amylase inhibition in P. eryngii aqueous extract, and in F. vulgare ethanolic extract. Antimicrobial activity was assessed by the agar well diffusion method against four bacterial and fungal strains, with higher activity observed in ethanolic extracts for both species. Overall, these results confirm the nutritional and pharmacological potential of P. eryngii and F. vulgare leaves as natural sources of bioactive compounds with antioxidant, anti-inflammatory, and antimicrobial properties.:Pleurotus eryngii;

2025-01-01T00:00:00Z CHIKR DJAOUTSI ZINEB http://dspace.univ-relizane.dz/home/handle/123456789/938 2026-05-06T12:15:44Z 2025-01-01T00:00:00Z

Title: THERMAL MODEL NUMERIC DEVELOPMENT BY USED NANOFLUIDE IN COMPLEX CAVITY Authors: CHIKR DJAOUTSI ZINEB Abstract: Heat and mass transport by natural convection in magnetohydrodynamics in traditional fluids has drawn substantial research interest due to its broad Science and engineering applications, especially in solar energy technologies. Incorporating factors such as heat sources/sinks, chemical reactions, radiation absorption into fluid flow and porous medium analyses introduces greater complexity but also increases the practical relevance of these studies for advanced engineering systems. These aspects have become key focus areas in contemporary research, given their critical importance across multiple industrial and scientific fields. This work computationally simulates the convective motion of nanoparticles in permeable space in the presence of a magnetic field using a non-Darcy model and porous terms in momentum equations. A nano fluid serves as the working fluid. The radiation effect for various nanoparticle forms will be reported. The impact of physics parameters on nanofluid performance will also be illustrated, and the impacts of Rayleigh number, magnetic force, nanoparticle shape, and shape factor radiation parameter on nanofluid will be investigated. The creation of entropy in nanofluid mixed convection flow has been the subject of further research. A mathematical model has been constructed to describe this phenomenon. The Galerkin weighted residual finite element method was used to discretize the resulting nondimensional equations. This thesis uses computational fluid dynamics (CFD) software to investigate the steady-state incompressible free convection flow of nanofluid in various enclosures. The study examines the impact of Rayleigh numbers (Ra) from 102𝑡𝑜106, Hartman numbers (Ha) from 0𝑡𝑜100, Darcy numbers (Da) from 10−5𝑡𝑜10−2, geometrical parameters (undulation number and inner cylinder position), and solid volume fractions (0, 2%, 3%, 4%, 5%, and 8%) on isotherm, streamline, average Nusselt number (Nuavg), and the total entropy generation. According to the study, injecting nanofluid under particular circumstances increased heat transmission. The biggest increase in heat transmission occurs in the conduction-dominated flow regime, where the improved thermal characteristics of nanofluids are crucial. When convection is the main route of heat transmission, nanofluids do not considerably increase efficiency. The buoyant force grew as the temperature differential between hot and cold sources widened.

2025-01-01T00:00:00Z