Portail HAL IMT Mines Albi
Not a member yet
5440 research outputs found
Sort by
Phase Equilibrium Study of Hexafluoropropylene Oxide and Propane System at (283.05, 303.05, 323.05) K: Experimental Measurements and Thermodynamic Modeling
No full textInternational audienceThis study presents the vapour-liquid equilibrium data of two fluorinated systems: R116 + propane, as a test system to validate both the experimental setup and the procedure, and hexafluoropropylene oxide + propane, as a novel system. Measurements of vapour-liquid equilibrium data were achieved via a static-analytical setup equipped with the ROLSI device for phase sampling and gas chromatography for composition analysis. The expanded uncertainties for temperature, pressure, and composition measurements were estimated at 0.02 K, 0.008 MPa, and 0.006, respectively. Thermodynamic modelling of the experimental VLE data was via the direct method, using the Peng-Robinson equation of state with the Mathias-Copeman alpha function and the Wong-Sandler mixing rule, incorporating the nonrandom two-liquid activity coefficient model. The deviations AAD xy and Bias xy between the measured and the computed data were determined to be less than 2%, indicating a good agreement between the model and the measurements. The successful correlation of the experimental data demonstrates the reliability of the experimental approach used and provides valuable insights into the thermodynamic behaviour of the investigated fluorinated systems. The hexafluoropropylene oxide + propane system was found to exhibit azeotropic behaviour across the investigated isotherms, with azeotropic compositions not varying significantly with temperature
Open Review of "A Level Set Discrete Element Model for sintering with an optimization-based contact detection"
No full textThis is the open review of article https://doi.org/10.46298/jtcam.13721 published in JTCA
Immersive Crisis Training: Features, Observations and the Shift From Traditional Crisis Exercises
No full textInternational audienceThis article provides insights from the 'Lessons from the Field' perspective into crisis training using virtual reality (VR). Conventional crisis simulations often involve costly in‐person events, limiting accessibility and effectiveness. VR technology has emerged as a promising alternative to overcome these challenges. This article delves into the application of VR in crisis management training, examining real‐world exercise examples, and presenting innovative experimentation. A comprehensive experiment, grounded in real‐life exercise scenarios, was conducted to gather feedback from participants. The findings demonstrate the efficacy of VR in replicating crisis training environments, providing an innovative solution to simulate real‐world use cases. These results suggest that investing in VR research and development can significantly enhance training opportunities for public safety agencies
Recent developments on multi- versus single-metallic catalytic graphitisation of biocarbon: A review
No full textInternational audienceThe typical graphitisation process involves non-renewable carbon sources and high temperatures, which lead to increased carbon dioxide emissions and energy consumption in the resulting graphite. Biocarbon derived from biomass acts as a sustainable carbon source that can be graphitised at lower temperatures with the aid of catalysts. This review highlights the significance of both multi- and single-metallic catalytic graphitisation of biocarbon. Introducing a catalyst offers an effective means to modify the graphitisation conditions and the characteristics of graphitic layers formed at the atomic and molecular levels. Multi-metal catalysts demonstrate superior effectiveness in lowering the graphitisation temperature to 800 °C compared to single-metal catalysts (1000–1800 °C) and those without catalysts (>2000 °C), where the synergistic interaction of two distinct metals enhances the transformation of amorphous carbon into graphitic biocarbon, as opposed to single-metal catalysts. This paper establishes a hierarchy of the graphitisation conditions as follows: temperature > carbon precursors > heating rate. Furthermore, this work outlines the existing knowledge gap regarding metallic catalysts and clarifies the roles of transition, alkaline, and alkaline earth metal catalysts in the graphitisation of bioresources
What typology of risks and methods for risk management in innovation projects?: a systematic literature review
No full textInternational audiencePerforming an appropriate risk management methodology is essential to support early decision-making in innovation development projects. In parallel, research and practice in innovation have evolved over the last years, surpassing the sphere of new product development to address recent domains such as service development, business model innovation, and sustainability-oriented innovation. Henceforth, there is a need for comprehensive research to update the joint knowledge about innovation development and risk management. Through a systematic literature review, this research analyses and consolidates the knowledge of 98 articles published between 1998 and 2022. This analysis contributes to the literature by i) highlighting specific risks associated with the innovation development process; ii) classifying the methods and tools used to manage risks in innovation development projects; and iii) drawing out the future research directions crossing these two domains. The added value of our systematic review is based on an extended time frame and a broader definition of innovation, considering not only product or technology-oriented innovations but also service and business models ones. In practical terms, the study consolidates and presents the main risks project managers have to manage and, the best methods to manage them and, the importance of human-based approaches, especially in radical innovations
Modeling Of Thermodynamic Properties Of H 2 And H 2 Mixtures Using A Three-Parameter Cubic Equation Of State
No full textInternational audienceThroughout the hydrogen value chain, industries increasingly rely on digital tools utilizing equations of state to develop safer, more efficient, and cost-effective processes. This paper compares the Peng-Robinson equation of state with volume translation (tc-PR EoS) and the Coquelet-El Abbadi-Houriez equation of state (CAH EoS), modified with the Feymann Hibbs correction to the covolume, to account for the quantum swelling phenomenon. The models were used to predict density, residual enthalpy, and Joule-Thomson coefficients over a temperature range of 20 to 353 K. It has been applied to binary mixtures relevant to the hydrogen industry, including H2/CO2, H2/CO, H2/CH4, and H2/N2. Model parameters were fitted to liquid-vapor equilibrium (VLE) data using the generalized Wong-Sandler (gWS) and van der Waals (vdW) classical mixing rules. The performance of the models in representing VLE data and densities over a wide range of thermodynamic conditions was assessed. These models can help design processes for hydrogen production, transport and use
A new ISO standard for the experimental characterization of in-plane permeability of fibrous reinforcements
No full textInternational audienceDuring Liquid Composite Molding, a fibrous reinforcement is impregnated with liquid resin. Process design requires knowledge of the reinforcement permeability for fluid flow, but until recently, there has been no standard available for its measurement. In 2023, following decades of benchmarking activities and a standardization project, an ISO standard for the experimental characterization of in-plane permeability of fibrous reinforcements for liquid composite molding was finally published. It focuses on the experimental characterization of unsaturated in-plane permeability and specifies the requirements for test equipment, methods and data analysis. Given the deficiency of standardized procedures within the composites industry, this paper intends to provide an example of the steps towards standardization and summarizes lessons learned. It illustrates the research milestones that led to the establishment of the standard, promotes the standard by detailing its general content and notable features and finally gives explanations and reasoning behind the developed guidelines
Thermophysical Properties: Viscosity, Density, and Excess properties of 2-propanol and n-Decane mixtures from 283.15 K to 343.15 K under atmospheric conditions
No full textInternational audienceTo study the effects of temperature as well as molecular interaction of a fluid system on the thermophysical properties of 2-propanol and n-Decane binary mixture, the density (ρ), dynamic viscosity (η), speed of sound (), and refractive index () of pure 2-propanol and n-Decane, along with their binary mixtures, were experimentally measured across the entire compositional range at temperatures from 283.15 to 343.15 K and atmospheric pressure. These experimental measurements helped in the evaluation of various thermophysical properties, such as excess molar volume , coefficient of thermal expansion (), and isentropic compressibility . The experimental dynamic viscosity (η) and density (ρ) data were used to evaluate kinematic viscosity (v) and Gibbs free energy (ΔG) of flow with an equation based on Eyring's absolute state theory, and their corresponding excess properties. The excess properties of the binary mixtures were correlated using a Redlich-Kister type polynomial equation via the least-squares regression method, with fitting parameters determined for the binary system. Moreover, the Prigogine–Flory–Patterson theory (PFP) was utilized to identify the primary molecular interactions contributing to the excess molar volume at 293.15, 308.15, and 323.15 K for the binary mixtures. Additionally, the capability of the Eyring-NRTL model was tested to predict the viscosity as well as vapor-liquid equilibrium (VLE) of the binary system, and the correlated model results agreed with literature data
Application de solvants eutectiques profonds dans l'extraction de composés aromatiques du fioul : modélisation, simulation et évaluation technico-économique du procédé
No full textThe chemical and petrochemical industries face growing pressure to implement sustainable and energy-efficient separation processes that reduce environmental impact while remaining economically viable. Aromatic-aliphatic separation, particularly the recovery of benzene, toluene, ethylbenzene, and xylenes (BTEX) from C4-C10 aliphatic hydrocarbons, is especially challenging due to close boiling points and azeotropic behavior, notably in low-aromatic streams (<20 wt%). Conventional technologies, such as sulfolane-based extractive distillation, are highly energy-intensive and economically unattractive for such feeds, highlighting the need for greener and more efficient alternatives. This thesis investigates choline chloride-based deep eutectic solvents (DESs), including binary (ChCl:Urea, 1:2) and ternary (ChCl:Urea:Ethylene Glycol, 1:2:1) systems, as sustainable solvents for the liquid-liquid extraction of aromatics from fuel oil. A multidisciplinary methodology combining literature data, thermodynamic modeling, process simulation, and techno-economic evaluation was adopted. In the absence of extensive experimental data, phase equilibrium and solubility behavior were predicted using the Hansen solubility parameter (HSP) and COSMO-SAC models, supported by group contribution methods and quantum chemistry calculations. The Non-Random Two-Liquid (NRTL) model enabled data regression and process design, allowing the implementation of user-defined DES components in Simulis® Thermodynamics and Aspen Plus®. Model validation against available literature data demonstrated high aromatic distribution coefficients and selectivities. Notably, the m-xylene/n-octane system exhibited selectivities of 33.45 for ChCl:Urea and 22.49 for ChCl:Urea:EG at 298.15 K, outperforming conventional industrial solvents. The DES-based process achieved aromatic and aliphatic recoveries and purities exceeding 98%. Compared to sulfolane and ionic liquids, DESs offer enhanced extraction efficiency, reduced solvent losses, and lower environmental impact due to their low toxicity, biodegradability, and negligible volatility. Ternary DESs further improve process operability owing to lower viscosity and melting point. Techno-economic analysis confirms significant reductions in energy demand and operating costs, positioning DES-based extraction as a promising and sustainable alternative for industrial aromatic separation.Les industries chimiques et pétrochimiques sont soumises à une pression croissante pour mettre en œuvre des procédés de séparation durables et économes en énergie qui réduisent l'impact environnemental tout en restant économiquement viables. La séparation aromatique-aliphatique, en particulier la récupération du benzène, du toluène, de l'éthylbenzène et des xylènes (BTEX) à partir d'hydrocarbures aliphatiques C4-C10, est particulièrement difficile en raison des points d'ébullition proches et du comportement azéotropique, notamment dans les flux à faible teneur en aromatiques (<20 % en poids). Les technologies conventionnelles, telles que la distillation extractive à base de sulfolane, sont très gourmandes en énergie et peu intéressantes sur le plan économique pour ces flux, ce qui souligne la nécessité de trouver des alternatives plus écologiques et plus efficaces. Cette thèse étudie les solvants eutectiques profonds (DES) à base de chlorure de choline, notamment les systèmes binaires (ChCl:urée, 1:2) et ternaires (ChCl:urée:éthylène glycol, 1:2:1), en tant que solvants durables pour l'extraction liquide-liquide des composés aromatiques du fioul. Une méthodologie multidisciplinaire combinant des données issues de la littérature, la modélisation thermodynamique, la simulation de processus et l'évaluation technico-économique a été adoptée. En l'absence de données expérimentales exhaustives, l'équilibre de phase et le comportement de solubilité ont été prédits à l'aide des modèles Hansen solubility parameter (HSP) et COSMO-SAC, appuyés par des méthodes de contribution de groupe et des calculs de chimie quantique. Le modèle NRTL (Non-Random Two-Liquid) a permis la régression des données et la conception du processus, permettant la mise en œuvre de composants DES définis par l'utilisateur dans Simulis® Thermodynamics et Aspen Plus®. La validation du modèle par rapport aux données disponibles dans la littérature a démontré des coefficients de distribution et des sélectivités élevés pour les composés aromatiques. Il convient de noter que le système m-xylène/n-octane a présenté des sélectivités de 33,45 pour le ChCl:urée et de 22,49 pour le ChCl:urée:EG à 298,15 K, surpassant les solvants industriels conventionnels. Le processus basé sur les DES a permis d'obtenir des taux de récupération et des puretés aromatiques et aliphatiques supérieurs à 98 %. Par rapport au sulfolane et aux liquides ioniques, les DES offrent une efficacité d'extraction améliorée, des pertes de solvant réduites et un impact environnemental moindre en raison de leur faible toxicité, de leur biodégradabilité et de leur volatilité négligeable. Les DES ternaires améliorent encore la facilité d'utilisation du procédé grâce à leur viscosité et leur point de fusion plus bas. L'analyse technico-économique confirme des réductions significatives de la demande énergétique et des coûts d'exploitation, positionnant l'extraction à base de DES comme une alternative prometteuse et durable pour la séparation industrielle des composés aromatiques
Modeling and Simulation of Surgical Procedures with an Application to Laparoscopic Cholecystectomy
No full textInternational audienceSurgeons' actions are key to surgical success. Our objective is to develop a decision-support tool to help prioritize patient safety and reduce risks during surgery. We propose a structured mathematical framework that defines key components of a surgical procedure, making it adaptable to various types of surgeries. Using the CholecT50 dataset, we generate and pre-process event logs to construct a process map that models the surgical workflow through Process Mining techniques. This process map provides insights into procedural patterns and can be visualized at different levels of granularity to align with surgeons' needs. To validate its effectiveness, we simulate synthetic surgeries and assess the process map's performance in replicating real surgical workflows. By demonstrating the generalizability of our approach, this work paves the way for the development of an advanced decision-support tool that can assist surgeons in real-time decision-making and post-operative analysis