Entropy: Thermodynamics – Energy – Environment – Economy

Entropie - ISSN 2634-1476 - © ISTE Ltd

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Le Centre National de la Promotion Scientifique et de l’Innovation (CNPSI) représente un nouveau lien entre les chercheurs académiques et les professionnels, d’une part, et les institutions internationales, d’autre part, tout en couvrant un large éventail de disciplines liées à la recherche et à l’innovation. Le CNPSI est une organisation qui promeut la recherche scientifique et l’innovation dans le monde, sans aucune discrimination. Il agit comme un pont entre les jeunes et les professionnels expérimentés dans les domaines universitaire, industriel et des startups, à travers des événements et des activités scientifiques de pointe, ainsi que des activités socioculturelles.

This study investigates the optimization of the light naphta isomerization process at the Algiers Refinery, with a focus on the operational efficiency of the Deisohexanizer (DIH) column. Isomerization is a critical refinery process that upgrades low-octane linear alkanes into high-octane branched isomers, thereby enhancing the Research Octane Number (RON) of the gasoline pool. The research methodology employed Aspen HYSYS software to conduct rigorous steady state modeling and performance analysis of the unit. To quantify the added value of the fractionation section, a baseline simulation was first established for a once-through configuration that excluded the DIH. Subsequently, a comprehensive simulation integrated the Deisohexanizer into the process flow to evaluate its impact on the global system efficiency and product quality. The study focused on the sensitivity analysis of key operating parameters, including reflux ratios, feed tray locations, and reboiler duties. These adjustments aimed to maximize the separation of low-octane normal hexane (nC6) from high-octane dimethylbutanes, thereby optimizing recycling cycles and minimizing energy consumption. The final results identify several optimal operating points and provide a set of technical recommendations proposed to Sonatrach. These suggestions aim to enhance the RON of the final isomerate while maintaining cost-effective energy profiles within the Algiers refinery’s current infrastructure.

The increasing penetration of renewable energy sources (RES) significantly modifies power system dynamics by reducing inertia and amplifying nonlinear interactions. Conventional eigenvalue-based small-signal stability methods capture linearized behavior but fail to reveal hidden nonlinear oscillatory components emerging under renewable-rich conditions. This paper investigates the oscillatory stability of the Tunisian power grid projected for 2030 under a peak-load scenario with 35% RES penetration. Using a detailed nonlinear PSAT model, Classical Linear Modal Analysis (LMA) is combined with Koopman Modal Analysis (KMA), a data-driven operator-based approach extracting spatiotemporal dynamic structures from simulation data. Results show that LMA identifies the dominant inter-area mode near 0.8 Hz, while KMA reveals additional weakly damped nonlinear modes within the critical [0.7–1 Hz] band. Koopman mode shapes highlight a dominant North–[Centre + South] oscillation driven by the 400 kV transmission backbone, with time-domain reconstructions confirming long decay times. The study proposes targeted measures including PSS improvement, transmission reinforcement, PMU-based wide-area monitoring, and advanced control strategies. KMA is demonstrated as a powerful complement to classical modal analysis for future renewable-dominated grids.

Orange peel waste is inсrеasingly aсknоwlеdgеd аs аn effесtivе mаterial fоr anаerоbic digestiоn, which can generatе biоenergy suсh аs biоhydrоgеn and biоmethаnе. Hоwеver, its use as а renewablе enеrgy sоurcе is still limited оn a glоbаl lеvеl. Therefore, this study is to assess thе capaсity fоr biоgas prоductiоn frоm оrangе pееl wastе, collected during the ripening period of the Thomson variety (December–February 2024).The elemental composition and structure of the orange peels biomass were assessed through CHNS-O and SEM-EDX analyses. To evaluate the efficiency of hydrolysis and mass transfer, two particle size fractions were selected: D1 (63–250 μm) and D2 (250–500 μm). Various parameters were monitored during the anaerobic digestion experiments, including pH, total sugar concentration and biogas volume. It has been found that the orange peels contain 34.66 % carbon, 44.88 % oxygen, 0.40 % nitrogen, and 7.35 % hydrogen. The high oxygen content reveals a predominance of oxygenated organic compounds, particularly carbohydrates, which are available to anaerobic microorganisms and promote rapid biodegradation. The cumulative biogas produced is about 955.5 mL and 232 mL for D1 and D2, respectively. Thereby improving microbial accessibility, diffusion, and the stages of anaerobic digestion. Furthermore, the Geompertz modified model has been employed to follow the kinetics of biogas production.

Over the past three decades, humanity has achieved considerable progress in terms of technological innovations. This transformation has reshaped the urban landscape, offering territorial decision-makers variety of tools to design new public policies and innovative strategies and benefit from these new solutions. Emerging from the opportunities created by the use of Information and Communication Technologies, the concept of the "Smart City" appeared in the early 21st century, with the primary objective of ensuring the sustainable and efficient management of resources while improving the quality of urban life. To achieve these goals, the concept relies on six essential pillars: smart governance, smart citizens, smart mobility, smart economy, smart environment, and smart living. This paper indeed, focuses on smart living, particularly the Smart Home, and explores how new technologies are perceived by the residents of Casablanca, given that the city has been engaged since 2015 in its smartization project known as Casablanca Smart City. The main objective of this study is to examine the perception of home automation, adopting a mixed-method approach based on the exploratory sequential design and taking into account the personal, social, and environmental challenges that influence the way individuals perceive these complex systems.

This study proposes to establish an expression of the efficiency optimized in temperature in the case of an adiabatic irreversible driving Carnot cycle, for a converter of finite physical dimension and infinite reservoirs (constant temperature).

From the first steps in thermodynamics with Carnot in 1824 to today’s research advances in preparation for tomorrow. This book offers readers a broad overview of thermodynamics through 22 articles. It covers the historical aspects of thermodynamics as well as the future of our planet, the structures of the living world, promising extensions into the quantum world, and the potential of solar energy. It also looks at engines and materials, with an innovative project in powder metallurgy. There are many other gems to discover. It also discusses the teaching of thermodynamics and how to approach it in a fun way through comics. In short, this is a well-researched work on the scientific relevance of Carnot’s visionary message from 1824, opening the door to tomorrow!

Since 1857, the second law of thermodynamics has faced the challenge of Maxwell’s imagined demon. The widely accepted response to this challenge suggests that the demon requires a bit of information to work, and according to Landauer’s principle, the erasure of this bit must offset the entropy reduction achieved by the demon. Recent experiments involving two-state physical systems subject to thermal fluctuations at the nanoscale have aimed to either prove Landauer’s principle or to demonstrate Szilard engines or Maxwell’s demons in practice. We wrote the equations and developed a numerical model to simulate the evolution of these systems. The results highlight the distinction between thermodynamic entropy and information entropy. They demonstrate that Landauer’s principle has a limited range of applicability and that, using a two-state memory, it is possible to eliminate a small amount of entropy without expending energy—challenging the second law of thermodynamics at the nanoscale.