DFT-based, Monte Carlo and Grand Canonical Monte Carlo simulations of nitro-organic pollutants 4-nitrophenol, 2-nitrophenol, 9-nitroanthracene and nitrogen trifluoride interacting with water in zeolite imidazole framework (ZIF-8)

We report in this study the behaviour of adsorbed Nitrogen-volatile organic compounds (NVOCs) such as 2NP (2-Nitrophenol), 4NP (4-Nitrophenol), 9NAnt (9-Nitroanthracene), NF3 (Nitrogen trifluoride) with and without water in Zinc-Imidazolate Framework (ZIF-8) using the Density Functional Theory (DFT). The work considers both single and multiple molecular capture of different species of pollutants, along with theoretical research based on force fields to determine the maximum number of molecules that can be loaded inside the material. Negative adsorption energy is obtained when each pollutant is considered separately or in mixtures. The values range from −2.6 kJ/mol to −137.1 kJ/mol depending on the size of adsorbed species. Modelling of the adsorbed pollutants on ZIF-8 towards the use of the code CASTEP show the possible interaction with the imidazole rings of the bulk crystal. The interaction energy (Eint) indicates that the capture of 2NP and 4NP is more favourable with H2O than 9NAnt and NF3. More specifically, Eint corresponding to one water molecule with one pollutant (4NP, 2NP, 9NAnt, NF3) is −0.473, −5.580, +0.588, and +8.307 kJ/mol, respectively. The Connolly surface was calculated to gain a better understanding of the volume and surface accessibility of ZIF-8, which helps to predict and support CASTEP results. Finally, an isotherm study was conducted using a Monte Carlo simulation, which proved useful in interpreting the most probable mechanism of the competing mixed capture. The results obtained were similar to those provided by Density Functional Theory (DFT)

One-dimensional model of heat exchanging throughout a three-dimensional building room integrated by phase change material

This paper presents a numerical investigation aimed at analyzing heat exchange and thermal comfort conditions within a building room during the hot season. In this setup, one wall, the roof, and the floor are thermally insulated, while the remaining three walls are constructed with brick embedded with phase change material (PCM). These non-insulated walls are subjected to a constant external surface temperature. Additionally, a latent heat storage unit comprising a set of tubes is installed in the room's ceiling region. The mathematical model employed in this study is based on pure conduction in the brick and in the walls containing PCM, as well as natural convection in the room air. Natural convection within the liquid phase of the PCM storage unit is accounted for by considering the effective thermal conductivity's dependence on the liquid fraction. The enthalpy method is utilized to solve energy equations in both the solid and liquid phases of the PCM, whether in walls or tubes. Heat transfer within the room is assumed to be unidirectional through the walls and tubes, with zero-dimensional considerations in the air region. The developed model is thoroughly analyzed and compared with existing literature, showing good agreement. Subsequently, a parametric study investigating various geometrical and thermo-physical parameters of the building room is conducted. The results indicate that the PCM within the walls contributes to maintaining indoor temperatures within the comfort range. Furthermore, the heat storage unit helps sustain indoor temperatures at the comfort level as long as the PCM within the tubes is undergoing melting processes

Exceptional photocatalytic performance of hexagonal ZnO nanorods for anionic and cationic dyes degradation

This study presents an in-depth investigation of zinc oxide hexagonal nanorods (ZnO NRs) synthesized via a hydrothermal approach at three pH basic values conducted in high-pressure laboratory reactor provided by Parr Instrument Company. The research evaluates the catalytic properties of the ZnO NRs, highlighting their potential for environmental applications. The as-fabricated samples are characterized by various techniques including the X-ray diffraction (XRD), UV–visible spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) analysis, Field emission-scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDAX) and high-resolution transmission electron microscopy (HR-TEM). Rietveld refinement of X-ray diffraction data reveals the formation of high-purity hexagonal Wurtzite-type ZnO phase. Further, it is investigated that by decreasing the pH values, the grain size of ZnO NRs increases from 25.70 nm to 29.91 nm. SEM analyses further confirmed the hexagonal nanorod-shaped morphology of ZnO. The photocatalytic degradation performance of the as-fabricated ZnO NRs for Methylene Blue (MB) and Methyl Orange (MO) dyes increased with the increase in pH value, reaching almost 95 % and 64 %, respectively, after 30 min of UV irradiation. The optimum degradation is achieved at a pH value of 11

Insecticidal and Histological Effects of Extracts from Leaves of Juglans regia L. Against Sitophilus oryzae (Coleoptera: Curculionidae) Isolated from Soft Wheat in Post-harvest

In Algeria, the cultivation of soft wheat (Triticum aestivum Linn.) plays a crucial role in the food chain. However, the crop faces a threat from Sitophilus oryzae (Coleoptera: Curculionidae), which causes substantial economic losses. This study aims to discover novel bioactive compounds derived from Juglans regia Linn., a walnut tree grown in Algeria, to combat S. oryzae. This study focuses on extraction, phytochemical characterization, insecticidal effect against S. oryzae adults, and histological impact. GCMS analysis of the petroleum ether (EPJ) and chloroform (CHJ) fractions indicated the presence of a diverse range of bioactive molecules, including myrtenal (1.17%), eugenol (46.17%), methyl ester (25.84%), lycophyll (5.16%), and hexadecane (1.22%), which are derived from terpenoids, phenols, and fatty acids. LCMS/MS analysis of the ethyl acetate (AEJ) and butanolic (BTJ) fractions identified compounds mainly associated with hydrocinnamic acids, flavonols, flavones, and naphtoquinones, such as 3-caffeoylquinic acid, epi-catechin isomer, kaempferol-3-glucoside, and hydro-juglone derivative. Furthermore, the efficacy of the five extracts (hydromethanolic extract and the four fractions) against S. oryzae adults was evaluated at 625, 315, and 75 µg/mL concentrations over 7 days. EPJ and BTJ demonstrated the highest effectiveness among these extracts, as indicated by their relatively low LC50, LC90, LT50, and LT90 values. These results highlight the potential of EPJ and BTJ, derived from walnut leaves, as biocontrol agents against S. oryzae. Histological analysis of the treated insects revealed significant alterations in various tissues compared to untreated adults. This research gives the first evidence that J. regia grown in Algeria is a promising biocontrol agent against pest beetles in stored soft wheat

A novel fluid-based modeling approach using extended Hybrid Petri nets for power consumption monitoring in wireless autonomous IoT devices, with energy harvesting capability and triple sleeping strategy

This paper presents a novel approach to model and monitor the energy dynamics of smart devices within the context of the Internet of Things (IoT). The proposed approach employs eXtended Hybrid Petri nets (xHPN) to emulate the behavior of interconnected smart devices forming a wireless network. The novelty of this study lies in the utilization of a fluidic representation to model the battery behavior of smart devices, allowing for the simulation of continuous energy consumption and replenishment via renewable energy harvesting to reflect real-world scenarios. Furthermore, in order to conserve energy, we introduce a new sleeping mechanism named the Triple Sleeping Strategy (TSS). By considering the mean battery charge and the mean sleeping percentage as evaluation metrics, the experimental study showcases the predictive capabilities of the developed model in simulating the performance of IoT networks prior to their actual deployment. Comparative analysis against recent works that use simple and double sleeping strategies, demonstrates the benefits of our approach, in terms of energy efficiency and device lifespan. For instance, when the device is configured with a 90 % sleeping percentage, TSS maintains a decent mean battery level for ten days, almost 8% higher than the double sleeping strategy. Furthermore, the presented case study demonstrates the ability of the proposed model to select appropriate parameters and configurations such as solar panel area and position, battery capacity, packet length, and deployment zone, to cope with the desired performance criteria

Mise en place d'un algorithme pour améliorer le QOS dans un réseaux " cas ATM MOBILIS "

127 p. : ill. ; 30 cmDans un contexte de connectivité croissante, la qualité de service (QoS) des réseaux de télécommunication est cruciale, particulièrement pour ATM MOBILIS à Relizane, Algérie. Ce mémoire se concentre sur l'optimisation de la QoS en développant des algorithmes intelligents pour la vérification de santé et le dépannage des réseaux. Utilisant des outils de simulation comme ENSP et de gestion comme master NCE de Huawei, des configurations complexes telles que IS-IS, MP-BGP, VRF, et MPLS sont déployées sur une topologie simulée. Les algorithmes en Python automatisent la surveillance et la correction des anomalies, réduisant les interventions manuelles et améliorant la stabilité du réseau. Les résultats démontrent une amélioration significative de la QoS, avec une détection rapide des problèmes et une gestion proactive du réseau. L'automatisation contribue à la résilience et à l'efficacité opérationnelle, promettant des développements futurs en intégrant l'intelligence artificielle pour une gestion encore plus robuste et continue du résea

Data Caching in Edge Computing: A Survey

As the Internet of Things (IoT) generates ever-increasing data streams, traditional cloud-centric architectures face crippling challenges in network latency, bandwidth consumption, and resource constraints. This paper explores how data caching in edge computing environments emerges as a potent solution, significantly impacting latency reduction, network efficiency, and overall system performance. We comprehensively review the landscape of edge IoT and data caching, analyze caching benefits and complexities, and delve into architectural integration, caching strategies, and algorithms tailored to address specific IoT challenges. Through case studies in chosen application domains, we quantify the performance improvements enabled by effective caching and pave the way for future research exploring novel caching methodologies and optimization techniques in the dynamic world of edge IoT.NNEF Public InformationNursultan Nazarbaev Qor

Maintenance des puits producteurs en utilisant différentes technologies de «Water Shut-Off» dans le champ d'Ourhoud

155 p. : ill. ; 30 cmL'Étude a examiné et analysé l'effet de la production d'eau dans la Central Processing Facility (CPF) située dans le champ d'Ourhoud. Le processus d'évaluation repose sur : le choix des trois puits candidats (puit 1, puit 2, puit 3), la collecte et les interprétations de tous les logs nécessaires, des données géologiques et de toutes les caractéristiques pétrophysiques essentielles pour détecter les sources (zone) d'entrées d'eau indésirables et réaliser notre opération de l'isolation (water shut off). L'objectif de notre travail est d'analyser les principaux paramètres en sélectionnant les puits candidats (avec WC élevée) pour le système de Water shut off et d'évaluer les résultats obtenus avant et après l'exécution des opérations. Cette stratégie appliquée dans le champ d'Ourhoud a eu des résultats positifs dans les trois puits enréduisant le water cut et en augmentant le débit d'huile : Puit 1 : WC=87.1%, Qh=183 Sm3/d, Puit2 : WC=42%, Qh=576Sm3/d, Puit 3 : WC=44.4%, Qh=258 Sm3/d)

Contribution to the study of nanofluid thermophysical properties with the objective of enhancing the heat transfer

123 p. : ill. ; 30 cmIn this thesis we provided an overview of fundamental heat transfer principles, including conduction and convection, emphasizing the utilization of nanofluids to improve heat transfer across diverse engineering applications. Essential applications, principles, and physical characteristics of nanoparticles were explored, alongside strategies and methodologies for preparing nanofluids and assessing nanoparticle stability. The experimental setup, featuring a square-shaped spiral heat exchanger, and associated measurement equipment was detailed. Mathematical equations relevant to heat transfer with nanofluids were examined, and modeling equations were formulated incorporating mass, momentum, and energy conservation principles. The numerical methodology used to solve these equations under specific boundary conditions was explained, along with a comprehensive overview of the steps for conducting CFD simulations with ANSYS Fluent, including mesh generation, boundary conditions, solution selection, and convergence criteria. The results of experimental work on the square-shaped spiral heat exchanger and numerical simulations were presented, demonstrating significant improvements in heat transfer flux and Nusselt numbers with nanofluids compared to pure water. Notably, a 13.46% increase in heat transfer flux was observed with a 5% nanofluid concentration and a 4.3 L/m flow rate. Additionally, there were significant increases in Nusselt numbers and heat transfer coefficients for nanofluids, indicating enhanced heat exchange performance with higher nanofluid concentration or flow Reynolds number