Articles de revues sur le sujet « Transport Phenomena Engineering Thermodynamics »
Pour voir les autres types de publications sur ce sujet consultez le lien suivant : Transport Phenomena Engineering Thermodynamics.
Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres
Consultez les 50 meilleurs articles de revues pour votre recherche sur le sujet « Transport Phenomena Engineering Thermodynamics ».
À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.
Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.
Parcourez les articles de revues sur diverses disciplines et organisez correctement votre bibliographie.
1
Chang, Shyy Woei. « Recent Advances in Fluid Mechanics and Transport Phenomena ». Inventions 8, no 6 (27 octobre 2023) : 136. http://dx.doi.org/10.3390/inventions8060136.
Texte intégral
2
Soni, Surbhi, Gunjan Chauhan, Bhawna Pareek, Pankaj Sharma et Rajan Chopra. « Binary Liquid Mixtures Nonanol and Decanol with their Thermodynamic and Transport Behavior : A Review ». Research Journal of Chemistry and Environment 26, no 9 (25 août 2022) : 167–74. http://dx.doi.org/10.25303/2609rjce1670174.
Texte intégralRésumé :
The extensive knowledge about structural phenomena of mixtures is of indispensable importance in the development of theories in liquid state. The information about structural and molecular interactions of liquid mixtures is quite vital from both fundamental and engineering point of view and can be utilized for further studies. For a better understanding of the non-ideal behavior of complex systems, fundamental thermodynamic and thermo-physical properties are the varied sources in which information is required. The excess thermodynamic properties are very sensitive to variables such as size, shape, composition, temperature and pressure, therefore an important information about the differences in the intermolecular interactions was obtained using these binary liquid mixtures under a range of physiochemical conditions. By using thermodynamics quantities, we can calculate the deviation of thermodynamics properties from those of an ideal mixture. These properties are necessary for the development of thermodynamic models required in optimized processes of the chemical, petrochemical, pharmaceutical and other industries. Along with diverse industrial applications, binary liquid mixtures can have hazardous effects such as pollutants causing air, water and soil contamination and some of them may have cancerous features. Their organic compounds and derivatives prepared from them are employed in a range of industrial and consumer applications such as perfumes, cosmetics, paints, varnishes, drugs, fuels, explosives, fats, dyes, waxes, resins, plastics, rubber, detergents, DDT etc. making them commercially important.
3
Luca, Rodica. « Advances in Boundary Value Problems for Fractional Differential Equations ». Fractal and Fractional 7, no 5 (17 mai 2023) : 406. http://dx.doi.org/10.3390/fractalfract7050406.
Texte intégralRésumé :
Fractional-order differential and integral operators and fractional differential equations have extensive applications in the mathematical modelling of real-world phenomena which occur in scientific and engineering disciplines such as physics, chemistry, biophysics, biology, medical sciences, financial economics, ecology, bioengineering, control theory, signal and image processing, aerodynamics, transport dynamics, thermodynamics, viscoelasticity, hydrology, statistical mechanics, electromagnetics, astrophysics, cosmology, and rheology [...]
4
Del Río P., J. A., et M. López De Haro. « Extended irreversible thermodynamics as a framework for transport phenomena in porous media ». Transport in Porous Media 9, no 3 (novembre 1992) : 207–21. http://dx.doi.org/10.1007/bf00611967.
Texte intégral
5
Wachutka, Gerhard. « UNIFIED FRAMEWORK FOR THERMAL, ELECTRICAL, MAGNETIC, AND OPTICAL SEMICONDUCTOR DEVICE MODELING ». COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 10, no 4 (1 avril 1991) : 311–21. http://dx.doi.org/10.1108/eb051708.
Texte intégralRésumé :
The “thermodynamic model” constitutes a unified theoretical framework for the coupled simulation of carrier and energy flow in semiconductor devices under general ambient conditions such as, e.g., the presence of a quasi‐static magnetic field or the interaction with an electromagnetic radiation field (light). The current relations governing particle and heat transport are derived from the principles of irreversible phenomenological thermodynamics; the driving forces include drift, diffusion, thermal diffusion, and deflection by the Lorentz force. All transport coefficients may be interpreted in terms of well‐known thermodynamic effects and, hence, can be obtained from theoretical calculations as well as directly from experimental data. The thermodynamic model allows the consistent treatment of a wide variety of physical phenomena which are relevant for both the operation of electronic devices (e.g., lattice heating, hot carrier and low temperature effects) and the function of microsensors and actuators (e.g., thermoelectricity, galvanomagnetism and thermomagnetism).
6
Misra, N. N., Alex Martynenko, Farid Chemat, Larysa Paniwnyk, Francisco J. Barba et Anet Režek Jambrak. « Thermodynamics, transport phenomena, and electrochemistry of external field-assisted nonthermal food technologies ». Critical Reviews in Food Science and Nutrition 58, no 11 (2 juin 2017) : 1832–63. http://dx.doi.org/10.1080/10408398.2017.1287660.
Texte intégral
7
Shnaid,, Isaac. « Thermodynamical Proof of Transport Phenomena Kinetic Equations ». Journal of the Mechanical Behavior of Materials 11, no 5 (octobre 2000) : 353–64. http://dx.doi.org/10.1515/jmbm.2000.11.5.353.
Texte intégral
8
Oliveira, Idalmo M., Varadarajan Seshadri et Marcelo B. Mansur. « Analysis of Drying Kinetics of Iron Ores using Irreversible Thermodynamics and Transport Phenomena Principles ». Canadian Journal of Chemical Engineering 82, no 5 (19 mai 2008) : 956–67. http://dx.doi.org/10.1002/cjce.5450820511.
Texte intégral
9
Pañeda, Emilio Martínez. « Progress and opportunities in modelling environmentally assisted cracking ». RILEM Technical Letters 6 (19 juillet 2021) : 70–77. http://dx.doi.org/10.21809/rilemtechlett.2021.145.
Texte intégralRésumé :
Environmentally assisted cracking phenomena are widespread across the transport, defence, energy and construction sectors. However, predicting environmentally assisted fractures is a highly cross-disciplinary endeavour that requires resolving the multiple material-environment interactions taking place. In this manuscript, an overview is given of recent breakthroughs in the modelling of environmentally assisted cracking. The focus is on the opportunities created by two recent developments: phase field and multi-physics modelling. The possibilities enabled by the confluence of phase field methods and electro-chemo-mechanics modelling are discussed in the context of three environmental assisted cracking phenomena of particular engineering interest: hydrogen embrittlement, localised corrosion and corrosion fatigue. Mechanical processes such as deformation and fracture can be coupled with chemical phenomena like local reactions, ionic transport and hydrogen uptake and diffusion. Moreover, these can be combined with the prediction of an evolving interface, such as a growing pit or a crack, as dictated by a phase field variable that evolves based on thermodynamics and local kinetics. Suitable for both microstructural and continuum length scales, this new generation of simulation-based, multi-physics phase field models can open new modelling horizons and enable Virtual Testing in harmful environments.
10
Motolinía-Alcántara, Elizabeth Alejandra, Carlos Omar Castillo-Araiza, Mario Rodríguez-Monroy, Angélica Román-Guerrero et Francisco Cruz-Sosa. « Engineering Considerations to Produce Bioactive Compounds from Plant Cell Suspension Culture in Bioreactors ». Plants 10, no 12 (14 décembre 2021) : 2762. http://dx.doi.org/10.3390/plants10122762.
Texte intégralRésumé :
The large-scale production of plant-derived secondary metabolites (PDSM) in bioreactors to meet the increasing demand for bioactive compounds for the treatment and prevention of degenerative diseases is nowadays considered an engineering challenge due to the large number of operational factors that need to be considered during their design and scale-up. The plant cell suspension culture (CSC) has presented numerous benefits over other technologies, such as the conventional whole-plant extraction, not only for avoiding the overexploitation of plant species, but also for achieving better yields and having excellent scaling-up attributes. The selection of the bioreactor configuration depends on intrinsic cell culture properties and engineering considerations related to the effect of operating conditions on thermodynamics, kinetics, and transport phenomena, which together are essential for accomplishing the large-scale production of PDSM. To this end, this review, firstly, provides a comprehensive appraisement of PDSM, essentially those with demonstrated importance and utilization in pharmaceutical industries. Then, special attention is given to PDSM obtained out of CSC. Finally, engineering aspects related to the bioreactor configuration for CSC stating the effect of the operating conditions on kinetics and transport phenomena and, hence, on the cell viability and production of PDSM are presented accordingly. The engineering analysis of the reviewed bioreactor configurations for CSC will pave the way for future research focused on their scaling up, to produce high value-added PDSM.
11
Chermyaninov, I. V., et V. G. Chernyak. « Non-equilibrium thermodynamics of light-induced transport phenomena in a binary gas mixture ». Physics of Fluids 33, no 12 (décembre 2021) : 127103. http://dx.doi.org/10.1063/5.0071582.
Texte intégral
12
Szücs, Mátyás, et Róbert Kovács. « Gradient-dependent transport coefficients in the Navier-Stokes-Fourier system ». Theoretical and Applied Mechanics, no 00 (2022) : 9. http://dx.doi.org/10.2298/tam221005009s.
Texte intégralRésumé :
In the engineering praxis, Newton?s law of viscosity and Fourier?s heat conduction law are applied to describe thermomechanical processes of fluids. Despite several successful applications, there are some obscure and unexplored details, which are partly answered in this paper using the methodology of irreversible thermodynamics. Liu?s procedure is applied to derive the entropy production rate density, in which positive definiteness is ensured via linear Onsagerian equations; these equations are exactly Newton?s law of viscosity and Fourier?s heat conduction law. The calculations point out that, theoretically, the transport coefficients (thermal conductivity and viscosity) can also depend on the gradient of the state variables in addition to the wellknown dependence of the state variables. This gradient dependency of the transport coefficients can have a significant impact on the modeling of such phenomena as welding, piston effect or shock waves.
13
Öttinger, Hans Christian, et David C. Venerus. « Thermodynamic approach to interfacial transport phenomena : Single-component systems ». AIChE Journal 60, no 4 (22 février 2014) : 1424–33. http://dx.doi.org/10.1002/aic.14399.
Texte intégral
14
Beris, Antony N., Soham Jariwala et Norman J. Wagner. « Flux-based modeling of heat and mass transfer in multicomponent systems ». Physics of Fluids 34, no 3 (mars 2022) : 033113. http://dx.doi.org/10.1063/5.0085444.
Texte intégralRésumé :
In the present work, the macroscopic governing equations governing the heat and mass transfer for a general multicomponent system are derived via a systematic nonequilibrium thermodynamics framework. In contrast to previous approaches, the relative (with respect to the mass average velocity) component mass fluxes (relative species momenta) and the heat flux are treated explicitly, in complete analogy with the momentum flux. The framework followed here, in addition to allowing for the description of relaxation phenomena in heat and mass transfer, establishes to the fullest the analogy between all transport processes, momentum, heat, and mass transfer, toward which R. B. Bird contributed so much with his work. The inclusion of heat flux-based momentum as an additional variable allows for the description of relaxation phenomena in heat transfer as well as of mixed (Soret and Dufour) effects, coupling heat and mass transfer. The resulting models are Galilean invariant, thereby resolving a conundrum in the field, and always respect the second law of thermodynamics, for appropriate selection of transport parameters. The general flux-based dynamic equations reduce to the traditional transport equations in the limit when mass species and heat relaxation effects are negligible and are fully consistent with the equations established from the application of kinetic theory in the limit of dilute gases. As an added benefit, for the particular example case of hyperbolic diffusion we illustrate the application of the proposed models as a method to allow the use of powerful numerical solvers normally not available for solving mass transfer models more generally.
15
Giona, Massimiliano. « Chemical Engineering, Fractal and Disordered System Theory ». Fractals 05, no 03 (septembre 1997) : 333–54. http://dx.doi.org/10.1142/s0218348x97000334.
Texte intégralRésumé :
This article critically discusses the applications of fractal and disordered system theory to chemical engineering problems in order to highlight some promising research directions and the difficulties that may be encountered. Starting from the analysis of transport and reaction kinetics, the question is addressed, with the aid of some examples, of whether and how engineering research could help in the study of complex phenomenologies on fractals and disordered systems. The effects of thermodynamical nonidealities in transport and adsorption, and the influence of nonlinearities in reaction kinetics are discussed in some detail. Examples of typical engineering problems in which fractal analysis may help towards a better understanding of the physical phenomenologies in the presence of complex porous substrata and fluid mixtures are discussed. The role played by the boundary conditions on transport phenomena involving fractal structures is also analyzed. A critical discussion on the perspectives in the characterization of disordered and fractal porous structures, and in the study of turbulent transport and mixing is also developed.
16
Delgado-Buscalioni, R., P. V. Coveney et G. De Fabritiis. « Towards multi-scale modelling of complex liquids using hybrid particle—continuum schemes ». Proceedings of the Institution of Mechanical Engineers, Part C : Journal of Mechanical Engineering Science 222, no 5 (1 mai 2008) : 769–76. http://dx.doi.org/10.1243/09544062jmes746.
Texte intégralRésumé :
Owing to the interplay between molecular and mesoscopic processes, the modelling and simulation of complex liquids at nano- and micron-scales require a multi-scale approach. A hybrid technique is proposed to handle multi-scale phenomena, which retains the full molecular nature of the system where it is of interest while coarse-graining it elsewhere. The method couples molecular dynamics (MD) and fluctuating hydrodynamics (FH) based on the Landau theory. Mean flows involving transport of transversal (shear) and longitudinal momentum (sound) are coupled across the interface of both MD and FH domains. Hydrodynamic fluctuations of mass and momentum are transferred, preserving consistency with hydrodynamics and thermodynamics. Here the hybrid method is illustrated by studying the reflection of water sound waves against a lipid (dimyristoylphosphatidylcholine) monolayer.
17
Mizushima, T., et K. Machida. « Multifaceted properties of Andreev bound states : interplay of symmetry and topology ». Philosophical Transactions of the Royal Society A : Mathematical, Physical and Engineering Sciences 376, no 2125 (20 juin 2018) : 20150355. http://dx.doi.org/10.1098/rsta.2015.0355.
Texte intégralRésumé :
Andreev bound states (ABSs) ubiquitously emerge as a consequence of non-trivial topological structures of the order parameter of superfluids and superconductors and significantly contribute to thermodynamics and low-energy quantum transport phenomena. We here share the current status of our knowledge on their multifaceted properties such as Majorana fermions and odd-frequency pairing. A unified concept behind ABSs originates from a soliton state in the one-dimensional Dirac equation with mass domain wall and interplay of ABSs with symmetry and topology enrich their physical characteristics. We make an overview of ABSs with a special focus on superfluid 3 He. The quantum liquid confined to restricted geometries serves as a rich repository of noteworthy quantum phenomena, such as the mass acquisition of Majorana fermions driven by spontaneous symmetry breaking, topological quantum criticality, Weyl superfluidity and the anomalous magnetic response. The marriage of the superfluid 3 He and nano-fabrication techniques will take one to a new horizon of topological quantum phenomena associated with ABSs. This article is part of the theme issue ‘Andreev bound states’.
18
Li, P. W., et M. K. Chyu. « Electrochemical and Transport Phenomena in Solid Oxide Fuel Cells ». Journal of Heat Transfer 127, no 12 (23 août 2005) : 1344–62. http://dx.doi.org/10.1115/1.2098828.
Texte intégralRésumé :
This paper begins with a brief review of the thermodynamic and electrochemical fundamentals of a solid oxide fuel cell (SOFC). Issues concerning energy budget and ideal energy conversion efficiency of the electrochemical processes in an SOFC are addressed. Chemical equilibrium is then discussed for the situations with internal reforming and shift reactions as an SOFC is fed with hydrocarbon fuel. Formulations accounting for electrical potential drops incurred by activation polarization, ohmic polarization, and concentration polarization are reviewed. This leads to a discussion on numerical modeling and simulation for predicting the terminal voltage and power output of SOFCs. Key features associated with numerical simulation include strong coupling of ion transfer rates, electricity conduction, flow fields of fuel and oxidizer, concentrations of gas species, and temperature distributions. Simulation results based primarily on authors’ research are presented as demonstration. The article concludes with a discussion of technical challenges in SOFCs and potential issues for future research.
19
Paik, Seungho, Hoa D. Nguyen et Jacob N. Chung. « A study of argon thermal plasma flow over a solid sphere ». Journal of Fluid Mechanics 252 (juillet 1993) : 543–64. http://dx.doi.org/10.1017/s0022112093003878.
Texte intégralRésumé :
The phenomena of momentum and heat transfer associated with an impulsively started spherical particle in a quiescent argon thermal plasma environment is considered. The changing plasma thermodynamics and transport property effects are studied using a Chebyshev-Legendre spectral method. Steady-state solutions for the case of constant sphere surface temperature are obtained and compared with previously published results. Transient solutions with particle internal heat conduction included are also presented. Results indicate that the magnitude of the drag force increases as the plasma free-stream temperature increases, while the Nusselt number decreases with increasing free-stream temperature. Effects due to different initial particle temperatures on the transient Nusselt number and drag coefficient are demonstrated.
20
Nagarajan, Ram, Prashun Gorai et Nidhi Chawla. « Modeling of Thermodynamic and Transport Phenomena in CVD Processes for Nano-Scale Applications ». ECS Transactions 13, no 9 (18 décembre 2019) : 7–18. http://dx.doi.org/10.1149/1.2993250.
Texte intégral
21
Mathias, Paul M. « The role of experimental data in chemical process technology ». Pure and Applied Chemistry 81, no 10 (26 septembre 2009) : 1727–43. http://dx.doi.org/10.1351/pac-con-08-10-06.
Texte intégralRésumé :
Experimental data have served two critical roles in chemical process technology: (1) by providing the definitive quantitative basis to evaluate competing processes, to optimize designs, and ultimately to guarantee plant performance; and (2) by guiding the form and structure of applied-thermodynamics correlations. This paper first presents two representative applications to highlight the role of thermodynamic and transport properties in chemical process technology: ammonia recovery from syngas using water as solvent, and design of a caustic-guard system to eliminate small residual concentrations of SO2 from a gas stream. These applications illustrate the first role of experimental data. The paper next studies the second role by examining the historical contribution of experimental data—over two centuries—in guiding the development of key concepts and correlations, such as Henry’s law (1802), group-contribution methods (Kopp, 1842), Raoult’s law (1878), second-virial-coefficient correlation (Berthelot, 1907), surface-tension correlation (Macleod, 1923), the use of one property to estimate another (Othmer, 1940), cubic equations of state (Redlich and Kwong, 1949), electrolyte systems (van Krevelen, 1949), acentric factor (Pitzer, 1955), and highly accurate equations of state (Span and Wagner, 2003). The analysis reveals that careful, accurate, and wide-ranging experimental data have identified the patterns of the underlying phenomena.
22
Cao, Jiaan, Lyuzhou Ye, Ruixue Xu, Xiao Zheng et Yijing Yan. « Recent advances in fermionic hierarchical equations of motion method for strongly correlated quantum impurity systems ». JUSTC 53, no 3 (2023) : 0302. http://dx.doi.org/10.52396/justc-2022-0164.
Texte intégralRésumé :
Investigations of strongly correlated quantum impurity systems (QIS), which exhibit diversified novel and intriguing quantum phenomena, have become a highly concerning subject in recent years. The hierarchical equations of motion (HEOM) method is one of the most popular numerical methods to characterize QIS linearly coupled to the environment. This review provides a comprehensive account of a formally rigorous and numerical convergent HEOM method, including a modeling description of the QIS and an overview of the fermionic HEOM formalism. Moreover, a variety of spectrum decomposition schemes and hierarchal terminators have been proposed and developed, which significantly improve the accuracy and efficiency of the HEOM method, especially in cryogenic temperature regimes. The practicality and usefulness of the HEOM method to tackle strongly correlated issues are exemplified by numerical simulations for the characterization of nonequilibrium quantum transport and strongly correlated Kondo states as well as the investigation of nonequilibrium quantum thermodynamics.
23
Chawla, Nidhi, Ramamurthy Nagarajan et Enakshi Bhattacharya. « Experimental and Theoretical Investigation of Thermodynamic and Transport Phenomena in Polysilicon and Silicon Nitride CVD ». ECS Transactions 19, no 23 (18 décembre 2019) : 53–68. http://dx.doi.org/10.1149/1.3248349.
Texte intégral
24
Animasaun, Isaac Lare, Qasem M. Al-Mdallal, Umair Khan et Ali Saleh Alshomrani. « Unsteady Water-Based Ternary Hybrid Nanofluids on Wedges by Bioconvection and Wall Stretching Velocity : Thermal Analysis and Scrutinization of Small and Larger Magnitudes of the Thermal Conductivity of Nanoparticles ». Mathematics 10, no 22 (17 novembre 2022) : 4309. http://dx.doi.org/10.3390/math10224309.
Texte intégralRésumé :
The uniqueness of nanofluids in the field of thermal analysis and engineering is associated with their thermal conductivity and thermodynamics. The dynamics of water made up of (i) single-walled carbon nanotubes with larger magnitudes of thermal conductivity of different shapes (i.e., platelet, cylindrical, and spherical) and (ii) moderately small magnitudes of thermal conductivity (i.e., platelet magnesium oxide, cylindrical aluminum oxide, spherical silicon dioxide) were explored in order to address some scientific questions. In continuation of the exploration and usefulness of ternary hybrid nanofluid in hydrodynamics and geothermal systems, nothing is known on the comparative analysis between the two dynamics outlined above due to the bioconvection of static wedges and wedges with stretching at the wall. Reliable and valid numerical solutions of the governing equation that models the transport phenomena mentioned above are presented in this report. The heat transfer through the wall increased with the wall stretching velocity at a smaller rate of 0.52 and a higher rate of 0.59 when the larger and smaller thermal conductivity of nanoparticles were used, respectively. Larger or smaller magnitudes of the thermal conductivity of nanoparticles were used; the wall stretching velocity had no significant effects on the mass transfer rate but the distribution of the gyrotactic microorganism was strongly affected. Increasing the stretching at the wedge’s wall in the same direction as the transport phenomenon is suitable for decreasing the distribution of temperature owing to the higher velocity of ternary hybrid nanofluids either parallel or perpendicular to the wedge.
25
Frohlich, K., G. Bimashofer, G. Fafilek, F. Pichler, M. Cifrain et A. Trifonova. « Electrochemical Investigation of Thermodynamic and Transport Phenomena in LP30 Electrolyte with Various Concentrations of Conducting Salt ». ECS Transactions 73, no 1 (15 septembre 2016) : 83–93. http://dx.doi.org/10.1149/07301.0083ecst.
Texte intégral
26
Cai, D., W. J. Mecouch, L. L. Zheng, H. Zhang et Z. Sitar. « Thermodynamic and kinetic study of transport and reaction phenomena in gallium nitride epitaxy growth ». International Journal of Heat and Mass Transfer 51, no 5-6 (mars 2008) : 1264–80. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2007.12.004.
Texte intégral
27
Taghikhani, Kasra, Alexis Dubois, John R. Berger, Sandrine Ricote, Huayang Zhu et Robert J. Kee. « Modeling Electro-Chemo-Mechanical Behaviors within the Dense BaZr0.8Y0.2O3−δ Protonic-Ceramic Membrane in a Long Tubular Electrochemical Cell ». Membranes 11, no 6 (22 mai 2021) : 378. http://dx.doi.org/10.3390/membranes11060378.
Texte intégralRésumé :
This paper reports an extended Nernst–Planck computational model that couples charged-defect transport and stress in tubular electrochemical cell with a ceramic proton-conducting membrane. The model is particularly concerned with coupled chemo-mechanical behaviors, including how electrochemical phenomena affect internal stresses and vice versa. The computational model predicts transient and steady-state defect concentrations, fluxes, stresses within a thin BaZr0.8Y0.2O3−δ (BZY20) membrane. Depending on the polarization (i.e., imposed current density), the model predicts performance as a fuel cell or an electrolyzer. A sensitivity analysis reveals the importance of thermodynamic and transport properties, which are often not readily available.
28
Sun, Feng, Yong Li, Bengt Sunden et Gongnan Xie. « The transport and thermodynamic characteristics of thermally oscillating phenomena in a buoyancy-driven supercritical fuel flow ». International Journal of Thermal Sciences 159 (janvier 2021) : 106550. http://dx.doi.org/10.1016/j.ijthermalsci.2020.106550.
Texte intégral
29
Alkire, Richard C. « Historical Perspectives on Electroplating during the Past 100 Years ». ECS Meeting Abstracts MA2022-02, no 24 (9 octobre 2022) : 1000. http://dx.doi.org/10.1149/ma2022-02241000mtgabs.
Texte intégralRésumé :
The development of electrodeposition practice and the underlying science and engineering methods that emerged during the past century will be traced. Beginning in the late 19th century, many large-scale electrolytic technologies became feasible owing to the invention of the electric generator. These included electrowinning, electrorefining, and electrodeposition, among others. Their early development and commercial use took place before the recognition of many fundamental scientific and engineering principles. As a result, these industries came to be characterized by slow evolutionary change based on past experience and intuitive insight. In 1913, a symposium on electrodeposition was arguably the first to apply systematic academic effort to the art of the plater, and thus promote cooperation between science and technology. The success of these activities led, in 1922, to formation of the Electrodeposition Division. For several subsequent decades, the growth of electrodeposition technology took place while electrochemists developed experimental tools (e.g. polarography), data (e.g., thermodynamic) and theories (e.g. non-ideal electrolytic solutions). By the 1950s there were an enormous number of electrodeposition applications, but the sense was emerging that progress based on empirical experimentation was rapidly coming to a close, and that further significant advances could be made only when the fundamentals of the plating processes are more completely understood. During the 1960s, the invention of new materials revolutionized the electrodeposition industries. In addition, the digital computer came into use for obtaining the current distribution in simple geometries. In addition, refined experimental research methods were developed, iincluding the potentiostatic power supply, rotating disk, “model” experimental systems, and various electroanalytical and surface-science techniques, In the 1970s, the field of electrodeposition technology saw significant new demands arising from changed availability of energy, feedstock, and capital as well as increased attention to waste treatment. These events shattered the empirical traditions of the past, and triggered new interest in ‘modern’ electrodeposition science and engineering built o a foundation of thermodynamics, kinetics, transport phenomena, and current distribution aspects. In the 1980s, the magnetic thin-film storage head, energized the entire microelectronics field of electrodeposition technology. Also, studies with single crystal electrodes and with surface scanning microscopies provided spectacular new capabilities for investigations at time scales, molecular specificity, and spatial resolution that were orders of magnitude superior to those of only a decade earlier. By the 1990s, important advances were made in understanding phenomena associated with defects, additives, solvent effects, nanoscale phenomena, surface films, mechanisms of lattice formation, among others. In addition, mathematical modeling of electrodeposition systems moved down-scale to include both continuum and non-continuum phenomena. During the 2000s, the shift from aluminum to electrodeposited copper for on-chip interconnections represented one of the most important change in materials since the beginning of the semiconductor industry. In the 2010s, the mathematical tools used to explore electrochemical systems expanded beyond the traditional continuum methods to include kinetic Monte Carlo, molecular dynamics, and quantum chemistry. In conclusion, throughout the history of electrodeposition science and technology, several high-level trends may be recognized: Advances often came from outside the electrodeposition field. It is important to read the literature widely, and with enough informed judgment to recognize analogies between seemingly different situations; Many electrodeposition systems have been improved over the course of many years. The literature contains a gold mine of applications worth further study. It is important to recognize when new science or engineering materials and methods can provide fresh insights to improving old, but very important, applications; Over the past century, there have been periods when significant gaps existed between scientific understanding of electrochemical phenomena, and our ability to incorporate it into engineering practice. It is important to identify problems worth solving and to release impedements to introduction of new ideas. Today, the ability to use numerical simulations to achieve precise quantitative understanding at new levels of magnitude, sophistication, and completeness offers a significant challenge. It is therefore important to develop re-usable electrochemical engineering methods, and to align tight integration of discovery science, application design, research prototyping and manufacturing collaboration.
30
Cappabianca, Roberta, Paolo De Angelis, Matteo Fasano, Eliodoro Chiavazzo et Pietro Asinari. « An Overview on Transport Phenomena within Solid Electrolyte Interphase and Their Impact on the Performance and Durability of Lithium-Ion Batteries ». Energies 16, no 13 (28 juin 2023) : 5003. http://dx.doi.org/10.3390/en16135003.
Texte intégralRésumé :
The nature of the electrode–electrolyte interface has an impact on the performance and durability of lithium-ion batteries (LIBs). The initial electrolyte’s thermodynamic instability at the anode–electrolyte interface in LIBs results in the formation of a passivation layer, called solid electrolyte interphase (SEI). The initial dense and intact layer allows Li+ transport and restricts electron tunneling, thus preventing electrolyte decomposition and ensuring the electrochemical stability of a battery. However, the growth of this layer can reduce the availability of active lithium and electrolyte, and ultimately lead to an irreversible battery capacity fade. Investigating the transport phenomena of lithium ions within SEI is crucial for understanding its formation and growth. Nonetheless, accurately describing all relevant mechanisms is challenging due to its complex and multiscale nature. An overview of current computational efforts to study Li+ transport within SEI is given in this article, ranging from electronic/atomistic scale simulations to macroscopic models. The drawbacks and advantages of the proposed numerical approaches are summarized along with the obstacles that need to be overcome to obtain accurate experimental data, identified on the basis of the most recent literature evidence. We highlight collaboration gaps between modeling and experimental approaches, as well as the urgent need for new multiscale models, to gain a better understanding of such a crucial transport phenomenon.
31
Dasgupta, Neil P. « (Invited) Interfacial Engineering of Battery Materials Using Atomic Layer Deposition ». ECS Meeting Abstracts MA2022-02, no 47 (9 octobre 2022) : 1732. http://dx.doi.org/10.1149/ma2022-02471732mtgabs.
Texte intégralRésumé :
In batteries, like all electrochemical systems, interfacial phenomena play a critical role in thermodynamic stability, charge transfer kinetics, and ionic transport phenomena. For example, in Li-ion batteries, the solid-electrolyte interphase (SEI) layer enables stabilization of liquid electrolytes against continual electrolyte decomposition. In solid-state batteries, the dynamic morphological evolution of the interface results in unique electro-chemo-mechanical properties, which dictate performance, degradation, and ultimate failure. As a result of these coupled phenomena, there is a continued need to improve both our fundamental understanding of interfacial dynamics, as well as new strategies to engineer rationally-controlled interfaces. Among the various interfacial engineering methodologies, atomic layer deposition (ALD) has risen in interest in recent years, owing to its unparalleled ability to impart atomically-precise control of surface composition and structure, while maintaining conformal coating of ultra-high aspect ratio structures. In this talk, I will describe recent progress in applying ALD for battery applications. In the field of Li-ion batteries, I will show how deposition of a single-ion conducting solid electrolyte on the surface of graphite anodes can eliminate electrolyte decomposition and SEI formation, resulting in a four-fold decrease in interfacial resistance [1]. This results in lower cell polarization during fast charging, eliminating deleterious Li plating on the anode. In the field of Li metal batteries, I will also show how ALD coatings can influence nucleation and growth, resulting in improved Coulombic efficiency [2]. Finally, I will describe efforts towards incorporation of ALD films into solid-state batteries, where mechanical properties play a critical role [3-4]. [1] E. Kazyak, K.-H. Chen, Y. Chen, T. H. Cho, N. P. Dasgupta, Adv. Energy Mater. 12, 2102618 (2022). [2] K.-H. Chen, A. J. Sanchez, E. Kazyak, A. L. Davis, N. P. Dasgupta, Adv. Energy Mater. 9, 1802534 (2019). [3] A. L. Davis, R. Garcia-Mendez, K. N. Wood, E. Kazyak, K.-H. Chen, G. Teeter, J. Sakamoto, N. P. Dasgupta, J. Mater. Chem. A 8, 6291 (2020) [4] E. Kazyak, M. Shin, W. S. LePage, T. H. Cho, N. P. Dasgupta, Chem. Commun. 56, 15537 (2020).
32
Xu, Feng, Kei Sakurai, Yuki Sato, Yuka Sakai, Shunsuke Sabu, Hiroaki Kanayama, Daisuke Satou et Yasuki Kansha. « Soft-Sensor Modeling of Temperature Variation in a Room under Cooling Conditions ». Energies 16, no 6 (20 mars 2023) : 2870. http://dx.doi.org/10.3390/en16062870.
Texte intégralRésumé :
Non-uniform temperature distributions in air-conditioned areas can reduce the energy efficiency of air conditioners and cause uncomfortable thermal sensations for occupants. Furthermore, it is impractical to use physical sensors to measure the local temperature at every position. This study developed a soft-sensing model that integrates the fundamentals of thermodynamics and transport phenomena to predict the temperature at the target position in space. Water experiments were conducted to simulate indoor conditions in an air-conditioning cooling mode. The transient temperatures of various positions were measured for model training and validation. The velocity vectors of water flow were acquired using the particle image velocimetry method. Correlation analysis of various positions was conducted to select the input variable. The soft-sensing model was developed using the multiple linear regression method. The model for the top layer was modified by the correction of dead time. The experimental results showed the temperature inhomogeneity between different layers. The temperature at each target position under two initial temperatures and two flow rates was accurately predicted with a mean absolute error within 0.69 K. Moreover, the temperature under different flow rates can be predicted with one model. Therefore, this soft-sensing model has the potential to be integrated into air-conditioning systems.
33
Lucia, Umberto, Debora Fino, Thomas S. Deisboeck et Giulia Grisolia. « A Thermodynamic Perspective of Cancer Cells’ Volume/Area Expansion Ratio ». Membranes 13, no 12 (30 novembre 2023) : 895. http://dx.doi.org/10.3390/membranes13120895.
Texte intégralRésumé :
The constructal law is used to improve the analysis of the resonant heat transfer in cancer cells. The result highlights the fundamental role of the volume/area ratio and its role in cancer growth and invasion. Cancer cells seek to increase their surface area to facilitate heat dissipation; as such, the tumour expansion ratio declines as malignant cells start to migrate and the cancer expands locally and systemically. Consequently, we deduce that effective anticancer therapy should be based on the control of some ion transport phenomena in an effort to increase the volume/area ratio. This emphasises restricting the local and systemic spatial expansion of the tumour system and thus gives further credence to the superior role of novel anti-migratory and anti-invasive treatment strategies over conventional anti-proliferative options only.
34
Makimura, Dai, Makoto Kunieda, Yunfeng Liang, Toshifumi Matsuoka, Satoru Takahashi et Hiroshi Okabe. « Application of Molecular Simulations to CO2-Enhanced Oil Recovery : Phase Equilibria and Interfacial Phenomena ». SPE Journal 18, no 02 (7 janvier 2013) : 319–30. http://dx.doi.org/10.2118/163099-pa.
Texte intégralRésumé :
Summary Molecular simulation is a powerful technique for obtaining thermodynamic properties of a system of given composition at a specific temperature and pressure, and it enables us to visualize microscopic phenomena. In this work, we used simulations to study interfacial phenomena and phase equilibria, which are important to CO2-enhanced oil recovery (EOR). We conducted molecular dynamics (MD) simulation of an oil/water interface in the presence of CO2. It was found that CO2 was enriched at the interfacial region under all thermal conditions. Whereas the oil/water interfacial tension (IFT) increases with pressure, CO2 reduces the IFT by approximately one-third at low pressure and one-half at higher pressure. Further analysis on the basis of our MD trajectories shows that the O=C=O bonds to the water with a “T-shaped” structure, which provides the mechanism for CO2 enrichment at the oil/water interface. The residual nonnegligible IFT at high pressures implies that the connate or injected water in a reservoir strongly influences the transport of CO2/oil solutes in that reservoir. We used Gibbs ensemble Monte Carlo (GEMC) simulation to compute phase equilibria and obtain ternary phase diagrams of such systems as CO2/n-butane/N2 and CO2/n-butane/n-decane. Simulating hydrocarbon fluids with a mixture of CO2 and N2 enables us to evaluate the effects of N2 impurity on CO2-EOR. It also enables us to study the phase behavior, which is routinely used to evaluate the minimum miscibility pressure (MMP). We chose these two systems because experimental data are available for them. Our calculated phase equilibria are in fair agreement with experiments. We also discuss possible ways to improve the predictive capability for CO2/hydrocarbon systems. GEMC and MD simulations of systems with heavier hydrocarbons are straightforward and enable us to combine molecular-level thinking with process considerations in CO2-EOR.
35
Terragni, Jacopo, et Antonio Miotello. « Laser Ablation of Aluminum Near the Critical Regime : A Computational Gas-Dynamical Model with Temperature-Dependent Physical Parameters ». Micromachines 12, no 3 (12 mars 2021) : 300. http://dx.doi.org/10.3390/mi12030300.
Texte intégralRésumé :
The complexity of the phenomena simultaneously occurring, from the very first instants of high-power laser pulse interaction with the target up to the phase explosion, along with the strong changes in chemical-physical properties of matter, makes modeling laser ablation a hard task, especially near the thermodynamic critical regime. In this work, we report a computational model of an aluminum target irradiated in vacuum by a gaussian-shaped pulse of 20 ns duration, with a peak intensity of the order of GW/cm2. This continuum model covers laser energy deposition and temperature evolution in the irradiated target, along with the mass removal mechanism involved, and the vaporized material expansion. Aluminum was considered to be a case study due to the vast literature on the temperature dependence of its thermodynamic, optical, and transport properties that were used to estimate time-dependent values of surface-vapor quantities (vapor pressure, vapor density, vapor and surface temperature) and vapor gas-dynamical quantities (density, velocity, pressure) as it expands into vacuum. Very favorable agreement is reported with experimental data regarding: mass removal and crater depth due to vaporization, generated recoil momentum, and vapor flow velocity expansion.
36
Mantecca, Edoardo, Alessandro Colombo, Antonio Ghidoni, Gianmaria Noventa, David Pasquale et Stefano Rebay. « On the Development of an Implicit Discontinuous Galerkin Solver for Turbulent Real Gas Flows ». Fluids 8, no 4 (31 mars 2023) : 117. http://dx.doi.org/10.3390/fluids8040117.
Texte intégralRésumé :
The aim of this work is to describe an efficient implementation of cubic and multiparameter real gas models in an existing discontinuous Galerkin solver to extend its capabilities to the simulation of turbulent real gas flows. The adopted thermodynamic models are van der Waals, Peng–Robinson, and Span–Wagner, which differ from each other in terms of accuracy and computational cost. Convective numerical fluxes across elements interfaces are calculated with a thermodynamic consistent linearized Riemann solver, whereas for boundary conditions, a linearized expression of the generalized Riemann invariants is employed. Transport properties are treated as temperature- and density-dependent quantities through multiparameter correlations. An implicit time integration is adopted; Jacobian matrix and thermodynamic derivatives are obtained with the automatic differentiation tool Tapenade. The solver accuracy is assessed by computing both steady and unsteady real gas test cases available in the literature, and the effect of the mesh size and polynomial degree of approximation on the solution accuracy is investigated. A good agreement with experimental and numerical reference data is observed and specific non-classical phenomena are well reproduced by the solver.
37
Atgur, Vinay, G. Manavendra, Nagaraj R. Banapurmath, Boggarapu Nageswar Rao, Ali A. Rajhi, T. M. Yunus Khan, Chandramouli Vadlamudi, Sanjay Krishnappa, Ashok M. Sajjan et R. Venkatesh. « Essence of Thermal Analysis to Assess Biodiesel Combustion Performance ». Energies 15, no 18 (10 septembre 2022) : 6622. http://dx.doi.org/10.3390/en15186622.
Texte intégralRésumé :
The combustion phenomena are always complex in nature due to the involvement of complex series and parallel reactions. There are various methods that are involved in analyzing combustion phenomena. Viscosity is the first and foremost factor that acts as the DNA of fuel. By evaluating the viscosity, it is possible initially to understand the combustion phenomena. Thermophysical and transport properties are helpful during the intensification of the combustion process. Combustion experiments are economically infeasible and time-consuming processes. Combustion simulations demand excellent computational facilities with detailed knowledge of chemical kinetics. So far, the majority of researchers have focused on analyzing coal combustion phenomena, whereas less work has been carried out on liquid fuels, especially biodiesel combustion analysis. Traditional engine testing provides only performance parameters, and it fails to have oversight of the thermodynamic aspects. The application of thermal analysis methods in combustion research is useful in the design, modeling, and operation of the systems. Such investigations are carried out extensively in the combustor, engine, and process industries. The use of differential scanning calorimetry (DSC) and thermogravimetry (TG) to assess the properties of biofuels has been attracting researchers in recent years. The main objective of this paper is to discuss the application of TGA and DSC to analyze heat flow, enthalpy, thermal stability, and combustion indexes. Moreover, this paper reviews some of the other aspects of the kinetics of combustion, transport properties’ evaluation, and combustion simulations for biodiesels and their blends. TG curves indicate two phases of decomposition for diesel and three phases for biofuel. The B-20 blend’s (20% biodiesel and 80% diesel) performance was found to be similar to that of diesel with the combustion index and intensity of combustion nearly comparable with diesel. It is thermally more stable with a high offset temperature, confirming a longer combustion duration. A case study reported in this work showed diesel and B20 JOME degradation start from 40 °C, whereas jatropha oil methyl ester (JOME) degradation starts from 140 °C. JOME presents more decomposition steps with high decomposition temperatures, indicative of more stable compound formation due to the oxidation process. The peak temperature of combustion for diesel, JOME, and B20 JOME are 250.4 °C, 292.1 °C, and 266.5 °C, respectively. The ignition index for the B-20 blend is 73.73% more than that of diesel. The combustion index for the B20 blend is 37.81% higher than diesel. The B20 blend exhibits high enthalpy, better thermal stability, and a reduced peak temperature of combustion with an improved combustion index and intensity of combustion nearly comparable to diesel.
38
Kozieł, Katarzyna, Juliusz Topolnicki et Norbert Skoczylas. « The Intensity of Heat Exchange between Rock and Flowing Gas in Terms of Gas-Geodynamic Phenomena ». Entropy 23, no 5 (29 avril 2021) : 556. http://dx.doi.org/10.3390/e23050556.
Texte intégralRésumé :
Gas-induced geodynamic phenomena can occur during underground mining operations if the porous structure of the rock is filled with gas at high pressure. In such cases, the original compact rock structure disintegrates into grains of small dimensions, which are then transported along the mine working space. Such geodynamic events, particularly outbursts of gas and rock, pose a danger both to the life of miners and to the functioning of the mine infrastructure. These incidents are rare in copper ore mining, but they have recently begun to occur, and have not yet been fully investigated. To ensure the safety of mining operations, it is necessary to determine parameters of the rock–gas system for which the energy of the gas will be smaller than the work required to disintegrate and transport the rock. Such a comparison is referred to as an energy balance and serves as a starting point for all engineering analyses. During mining operations, the equilibrium of the rock–gas system is disturbed, and the rapid destruction of the rock is initiated together with sudden decompression of the gas contained in its porous structure. The disintegrated rock is then transported along the mine working space in a stream of released gas. Estimation of the energy of the gas requires investigation of the type of thermodynamic transformation involved in the process. In this case, adiabatic transformation would mean that the gas, cooled in the course of decompression, remains at a temperature significantly lower than that of the surrounding rocks throughout the process. However, if we assume that the transformation is isothermal, then the cooled gas will heat up to the original temperature of the rock in a very short time (<1 s). Because the quantity of energy in the case of isothermal transformation is almost three times as high as in the adiabatic case, obtaining the correct energy balance for gas-induced geodynamic phenomena requires detailed analysis of this question. For this purpose, a unique experimental study was carried out to determine the time required for heat exchange in conditions of very rapid flows of gas around rock grains of different sizes. Numerical simulations reproducing the experiments were also designed. The results of the experiment and the simulation were in good agreement, indicating a very fast rate of heat exchange. Taking account of the parameters of the experiment, the thermodynamic transformation may be considered to be close to isothermal.
39
Boury, Charles, Jonathan Paras et Antoine Allanore. « (Keynote) Experimental Insights for Extra-Terrestrial Application of Molten Oxide Electrolysis ». ECS Meeting Abstracts MA2023-01, no 56 (28 août 2023) : 2742. http://dx.doi.org/10.1149/ma2023-01562742mtgabs.
Texte intégralRésumé :
Molten oxide electrolysis (MOE) has been considered for several decades for oxygen generation from extra-terrestrial oxides. It consists in the electrolytic decomposition of the rocks or soils, which are mixture of the common earth oxides (silica, iron oxide(s), alumina, magnesia...). Therein the oxides mixture is acting as the electrolyte, in the molten state. The target anodic product is oxygen gas, and the cathodic product is a metal. In one version of MOE, the temperature is high enough to sustain the production of a liquid metal, offering the opportunity to conceive a fully continuous process thanks to periodic tapping of the cathodic product. A key attribute of such approach is the high current density (productivity) that can be anticipated thanks to the high concentration of oxygen and metal present in the electrolyte. This leads to electrochemical engineering questions that are not commonly discussed in other electrolysis methods. This presentation offers to review some of the prior findings related to the underlying thermodynamic of the process, as well as the oxygen evolution and transport phenomena that support the development of MOE. Recent findings combining a container-less method and advanced electrochemical techniques will be presented.
40
Gurbanov, Abdulaga, Ijabika Sardarova et Javida Damirova. « Analysis of gas preparation processes for improvement of gas transportation technology ». EUREKA : Physics and Engineering, no 6 (18 novembre 2021) : 48–56. http://dx.doi.org/10.21303/2461-4262.2021.002081.
Texte intégralRésumé :
At production, collection and transport of low – pressure gas to deep water offshore platforms in sea conditions because of thermodynamic indices change in the system, complications are generated in connection with liquid phases – separation. These complications disturb normal operational well behavior, gas preparation unit and trunk (main) pipeline conditions. As a result of these phenomena high – volume losses of gas, gas condensate and chemical reagent take place.
In the process of testing, the following process parameters were determined: pressure, gas temperature, facility performance, regeneration temperature, amount of absorbent injected into the gas flow, concentration of regenerated and saturated absorbent, dry gas dew point and so on. In the process of investigating the effect of the amount of inhibitor on the degree of corrosion prevention, hydrate formation and salt deposit at the facilities, regression equations. That is why, to guarantee uninterrupted transportation of low-pressure gas in field conditions, new methods are required for these phenomena prevention.
On the basis of field study results some variants of calculation were given to increase efficiency of low-pressure gas transportation system in offshore oil and gas field’s conditions.
Results of high-pressure gas optimal working pressure calculation for precipitated liquid phase displacement at low-pressure petroleum gas transportation to deepwater offshore platforms are shown in the article.
As well, method for precipitated liquid phase displacement from low-pressure gas pipeline with usage of high-viscosity elastic gelling compositions on the basis of domestic petrochemical products
41
Bhatia, Harshit, et Chaouki Habchi. « Real Fluid Modeling and Simulation of the Structures and Dynamics of Condensation in CO2 Flows Shocked Inside a de Laval Nozzle, Considering the Effects of Impurities ». Applied Sciences 13, no 19 (29 septembre 2023) : 10863. http://dx.doi.org/10.3390/app131910863.
Texte intégralRésumé :
Because of the currently changing climate, Carbon Capture and Storage (CCS) is increasingly becoming an important contemporary topic. However, this technique still faces various challenges. For the compression of CO2 to its supercritical condition for efficient transport, one of the important challenges is mastering the two-phase flow in the pump. Indeed, phase changes that appear on the blade tips of an impeller or rotor in such pumps can lead to performance and stability issues. Moreover, these phase change phenomena (vaporization and condensation) can be significantly modified by the presence of impurities (N2, O2, H2S, etc.) whose nature depends on the source of the CO2 production. In this work, we focus on analyzing the high pressure flow behavior of CO2 mixed with varying levels of impurities in a de Laval nozzle, for which experimental results are available. Numerical simulations are performed using a real-fluid model (RFM) implemented in the CONVERGE CFD solver. In this model, a tabulation approach is used to provide the thermodynamic and transport properties of the mixture of CO2 with the impurities. The study is carried out with different inlet conditions, and the results are in good agreement with the available experimental data. In addition, the results provide insights on the interaction of the shock wave with the observed condensation phenomenon, as well as its impact on the amount of condensation and other thermodynamic variables. The research indicates that the presence of impurities mixed with CO2 significantly affects the observed condensation in gas streams, which is a crucial factor that cannot be overlooked when implementing CCS systems.
42
Swaney, Ross E., et R. Byron Bird. « Transport phenomena and thermodynamics : Multicomponent mixtures ». Physics of Fluids 31, no 2 (février 2019) : 021202. http://dx.doi.org/10.1063/1.5048320.
Texte intégral
43
BERKOVICH, Y., et G. GOLAN. « ELECTRIC MODELS OF LARGE-SCALE SYSTEMS AND THEIR ANALOGY TO THERMODYNAMIC SYSTEMS ». Journal of Circuits, Systems and Computers 15, no 04 (août 2006) : 505–19. http://dx.doi.org/10.1142/s0218126606003258.
Texte intégralRésumé :
The paper deals with electric models applied in the investigation of complex systems, such as transport, economic, and neuron systems. The increasing interest in such systems can be explained by the fact that they are characterized by parallel (collective) means of complex calculation processes, under the influence of inner information processes. Electric models can also be looked upon as original structures for neuron-like systems. The paper puts emphasis on comparison between the electric models suggested by the authors, on the one hand, and the mechanical and thermal models, on the other hand. It has been shown that entropy phenomena, typical for the latter, can be closely compared to those of electric models, which are distinguished by pure electric values. Also, it has been shown that irreversible processes of energy dissipation, e.g., entropy processes in mechanical models, are corresponded to processes of energy concentration, energy transfer, and/or energy exchange in electric models. This enables us to shed a new light on processes in electric circuit, especially those concerning with structural improvements of electric circuitry and their self-organization, meaning a neg-entropic information character of these processes. Models of two economic tasks have been considered, wherein the calculation process is characterized under the influence of these processes. Assumption on the importance of reactive elements such as carriers of neg-entropy in electric circuits was made as well.
44
Galenko, P. K., et D. V. Alexandrov. « From atomistic interfaces to dendritic patterns ». Philosophical Transactions of the Royal Society A : Mathematical, Physical and Engineering Sciences 376, no 2113 (8 janvier 2018) : 20170210. http://dx.doi.org/10.1098/rsta.2017.0210.
Texte intégralRésumé :
Transport processes around phase interfaces, together with thermodynamic properties and kinetic phenomena, control the formation of dendritic patterns. Using the thermodynamic and kinetic data of phase interfaces obtained on the atomic scale, one can analyse the formation of a single dendrite and the growth of a dendritic ensemble. This is the result of recent progress in theoretical methods and computational algorithms calculated using powerful computer clusters. Great benefits can be attained from the development of micro-, meso- and macro-levels of analysis when investigating the dynamics of interfaces, interpreting experimental data and designing the macrostructure of samples. The review and research articles in this theme issue cover the spectrum of scales (from nano- to macro-length scales) in order to exhibit recently developing trends in the theoretical analysis and computational modelling of dendrite pattern formation. Atomistic modelling, the flow effect on interface dynamics, the transition from diffusion-limited to thermally controlled growth existing at a considerable driving force, two-phase (mushy) layer formation, the growth of eutectic dendrites, the formation of a secondary dendritic network due to coalescence, computational methods, including boundary integral and phase-field methods, and experimental tests for theoretical models—all these themes are highlighted in the present issue. This article is part of the theme issue ‘From atomistic interfaces to dendritic patterns’.
45
Scully, John R. « Corrosion chemistry closing comments : opportunities in corrosion science facilitated by operando experimental characterization combined with multi-scale computational modelling ». Faraday Discussions 180 (2015) : 577–93. http://dx.doi.org/10.1039/c5fd00075k.
Texte intégralRésumé :
Recent advances in characterization tools, computational capabilities, and theories have created opportunities for advancement in understanding of solid–fluid interfaces at the nanoscale in corroding metallic systems. The Faraday Discussion on Corrosion Chemistry in 2015 highlighted some of the current needs, gaps and opportunities in corrosion science. Themes were organized into several hierarchical categories that provide an organizational framework for corrosion. Opportunities to develop fundamental physical and chemical data which will enable further progress in thermodynamic and kinetic modelling of corrosion were discussed. These will enable new and better understanding of unit processes that govern corrosion at the nanoscale. Additional topics discussed included scales, films and oxides, fluid–surface and molecular–surface interactions, selected topics in corrosion science and engineering as well as corrosion control. Corrosion science and engineering topics included complex alloy dissolution, local corrosion, and modelling of specific corrosion processes that are made up of collections of temporally and spatially varying unit processes such as oxidation, ion transport, and competitive adsorption. Corrosion control and mitigation topics covered some new insights on coatings and inhibitors. Further advances inoperandoorin situexperimental characterization strategies at the nanoscale combined with computational modelling will enhance progress in the field, especially if coupling across length and time scales can be achieved incorporating the various phenomena encountered in corrosion. Readers are encouraged to not only to use thisad hocorganizational scheme to guide their immersion into the current opportunities in corrosion chemistry, but also to find value in the information presented in their own ways.
46
Narkuniene, Asta, Gintautas Poskas et Gytis Bartkus. « Modelling of the Corrosion-Induced Gas Impact on Hydraulic and Radionuclide Transport Properties of Geological Repository Barriers ». Minerals 14, no 1 (19 décembre 2023) : 4. http://dx.doi.org/10.3390/min14010004.
Texte intégralRésumé :
The geological disposal of high-level radioactive waste is the final step in the nuclear fuel cycle. It is realized via isolating the high-level radioactive waste in the geological environment with an appropriate system of engineered barriers. Radionuclides-containing materials must be isolated from the biosphere until the radioactivity contained in them has diminished to a safe level. In the case of high-level radioactive waste, it could take hundreds of thousands of years. Within such a long timescale, a number of physical and chemical processes will take part in the geological repository. For the assessment of radionuclide migration from a geological repository, it is necessary to predict the repository’s behavior once placed in the host rock as well as the host-rock response to disturbances due to construction. In this study, the analysis of repository barriers (backfill, concrete, inner excavation disturbed zone (EDZ), outer EDZ, host rock) thermo–hydraulic–mechanical (THM) evolution was performed, and the scope of gas-induced desaturation was analyzed with COMSOL Multiphysics. The analysis was based on modelling of a two-phase flow of miscible fluid (water and H2) considering important phenomena such as gas dissolution and diffusion, advective–diffusive transport in the gaseous phase, and mechanical deformations due to thermal expansion of water and porous media. The importance of proper consideration of temperature-dependent thermodynamic properties of water and THM couplings in the analysis of near-field processes was also discussed. The modelling demonstrated that such activities as 50 years’ ventilation of the waste disposal tunnel in initially saturated porous media, and such processes as gas generation due to corrosion of waste package or heat load from the waste, also led to desaturation of barriers. H2 gas generation led to the desaturation in engineered barriers and in a part of the EDZ close to the gas generation place vanishing soon after finish of gas generation, while the host rock remained saturated during the gas generation phase (50–100,000 years). Radionuclide transport properties in porous media such as effective diffusivity are highly dependent on the water content in the barriers determined by their porosity and saturation.
47
Narȩbska, Anna, et Andrzej Warszawski. « Diffusion dialysis Transport phenomena by irreversible thermodynamics ». Journal of Membrane Science 88, no 2-3 (16 mars 1994) : 167–75. http://dx.doi.org/10.1016/0376-7388(94)87004-7.
Texte intégral
48
Jepps, Owen G., et Lamberto Rondoni. « Thermodynamics and complexity of simple transport phenomena ». Journal of Physics A : Mathematical and General 39, no 6 (24 janvier 2006) : 1311–38. http://dx.doi.org/10.1088/0305-4470/39/6/007.
Texte intégral
49
Di Profio, Pietro, Simone Arca, Raimondo Germani et Gianfranco Savelli. « Novel Nanostructured Media for Gas Storage and Transport : Clathrate Hydrates of Methane and Hydrogen ». Journal of Fuel Cell Science and Technology 4, no 1 (6 avril 2006) : 49–55. http://dx.doi.org/10.1115/1.2393304.
Texte intégralRésumé :
In the last years the development of fuel cell (FC) technology has highlighted the correlated problem of storage and transportation of gaseous fuels, particularly hydrogen and methane. In fact, forecasting a large scale application of the FC technology in the near future, the conventional technologies of storage and transportation of gaseous fuels will be inadequate to support an expectedly large request. Therefore, many studies are being devoted to the development of novel efficient technologies for gas storage and transport; one of those is methane and hydrogen storage in solid, water-based clathrate hydrates. Clathrate hydrates (CH) are nonstoichiometric, nanostructured complexes of small “guest” molecules enclosed into water cages, which typically form at relatively low temperature-high pressure. In nature, CH of natural gas represent an unconventional and unexploited energy source and methane hydrate technology is already applied industrially. More recently, striking literature reports showed a rapid approach to the possibility of obtaining hydrogen hydrates at room temperature/mild pressures. Methane hydrate formation has been shown to be heavily promoted by some chemicals, notably amphiphiles. Our research is aimed at understanding the basic phenomena underlying CH formation, with a goal to render hydrate formation conditions milder, and increase the concentration of gas within the CH. In the present paper, we show the results of a preliminary attempt to relate the structural features of several amphiphilic additives to the kinetic and thermodynamic parameters of methane hydrate formation—e.g., induction times, rate of formation, occupancy, etc. According to the present study, it is found that a reduction of induction time does not necessarily correlate to an increase of the formation rate and occupancy, and so on. This may be related to the nature of chemical moieties forming a particular amphiphile (e.g., the hydrophobic tail, head group, counterion, etc.). Moreover, a chemometric approach is presented which is aimed at obtaining information on the choice of coformers for H2 storage in hydrates at mild pressures and temperatures.
50
Esmailpour, Kazem, Behnam Bozorgmehr, Seyed Mostafa Hosseinalipour et Arun S. Mujumdar. « Entropy generation and second law analysis of pulsed impinging jet ». International Journal of Numerical Methods for Heat & ; Fluid Flow 25, no 5 (1 juin 2015) : 1089–106. http://dx.doi.org/10.1108/hff-05-2014-0148.
Texte intégralRésumé :
Purpose – The purpose of this paper is to examine entropy generation rate in the flow and temperature field due pulsed impinging jet on to a flat plate. Heat transfer of pulsed impinging jets has been investigated by many researchers. Entropy generation is one of the parameters related to the second law of thermodynamics which must be analyzed in processes with heat transfer and fluid flow in order to design efficient systems. Effect of velocity profile parameters and various nozzle to plate distances on viscous and thermal entropy generation are investigated. Design/methodology/approach – In this study, the flow and temperature field of a pulsed turbulent impinging jet are simulated numerically by the finite volume method with appropriate boundary conditions. Then, flow and temperature results are used to calculate the rate of entropy generation due to heat transfer and viscous dissipation. Findings – Results show that maximum viscous and thermal entropy generation occurs in the lowest nozzle to plate distance and entropy generation decreases as the nozzle to plate distance increases. Entropy generation in the two early phase of a period in the most frequencies is more than steady state whereas a completely opposite behavior happens in the two latter phase. Increase in the pulsation frequency and amplitude leads to enhancement in entropy generation because of larger temperature and velocity gradients. This phenomenon appears second and even third peaks in entropy generation plots in higher pulsation frequency and amplitude. Research limitations/implications – The predictions may be extended to include various pulsation signal shape, multiple jet configuration, the radiation effect and phase difference between jets. Practical implications – The results of this paper are a valuable source of information for active control of transport phenomena in impinging jet configurations which is used in different industrial applications such as cooling, heating and drying processes. Originality/value – In this paper the entropy generation of pulsed impinging jet was studied for the first time and a comprehensive discussion on numerical results is provided.