Browsing NTNU Open by Author "Kjelstrup, Signe"
Now showing items 1-20 of 85
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A Monte Carlo Algorithm for Immiscible Two-Phase Flow in Porous Media
Savani, Isha; Sinha, Santanu; Hansen, Alex; Bedeaux, Dick; Kjelstrup, Signe; Vassvik, Morten (Journal article; Peer reviewed, 2017)We present a Markov Chain Monte Carlo algorithm based on the Metropolis algorithm for simulation of the flow of two immiscible fluids in a porous medium under macroscopic steady-state conditions using a dynamical pore ... -
A procedure to find thermodynamic equilibrium constants for CO2 and CH4 adsorption on activated carbon
Trinh, Thuat; van Erp, Titus Sebastiaan; Bedeaux, Dick; Kjelstrup, Signe; Grande, Carlos Adolfo (Journal article; Peer reviewed, 2015)Thermodynamic equilibrium for adsorption means that the chemical potential of gas and adsorbed phase are equal. A precise knowledge of the chemical potential is, however, often lacking, because the activity coefficient of ... -
A thermodynamic study of the hydrogen dissociation by the Small System Method and the reactive force field ReaxFF
Eriksen, Nora Meling (Master thesis, 2016)The aim of this thesis was to study the reaction 2H=H2 using the reactive interaction potential ReaxFF. This was done by performing a thermodynamic study, using the ReaxFF and the Small System Method (SSM). The results ... -
Assessment of PEMFC Durability by Effluent Analysis
Aarhaug, Thor Anders (Doktoravhandlinger ved NTNU, 1503-8181; 2011:309, Doctoral thesis, 2011)A review of literature relevant for the understanding of chemical degradation in Polymer Electrolyte Membrane (PEM) systems was conducted. The proposed pathways to the formation of chemical species suspected of causing ... -
Bridging scales with thermodynamics: From nano to macro
Kjelstrup, Signe; Schnell, Sondre K.; Vlugt, Thijs J.H.; Simon, Jean-Marc; Bardow, André; Bedeaux, Dick; Trinh, Thuat (Journal article; Peer reviewed, 2014)We have recently developed a method to calculate thermodynamic properties of macroscopic systems by extrapolating properties of systems of molecular dimensions. Appropriate scaling laws for small systems were derived using ... -
Calculations of Resistivity Coefficients and Mass Flux in a Two-Phase Binary Lennard-Jones/spline System Using Non-Equilibrium Thermodynamics and Molecular Dynamics
Edvardsen, Laura (Master thesis, 2018)Fresh water has a vital role in our everyday life. However, it is also increasingly scarce and it is important to obtain better understanding of water purification processes to secure global access to clean water. There ... -
Calorimetry and exergy analysis in the context of renewable energy devices:: Supercapacitors and Solid State Thermoelectric Devices
Hauge, Hans Henrik R (Master thesis, 2014)The motivation for this master thesis is to establish methods for thermal characterization of technolog- ical devices necessary in a renewable energy society. More specifically in this thesis supercapacitors and thermoelectric ... -
Capillary forces and osmotic gradients in salt water - oil systems
Ellila, Georg (Master thesis, 2012)This project looks at the capillary systems with salt water and oil that can be found in porous stones in oil reservoir. The interactions between the different phases and how salt concentration differences can move the ... -
Characterization of ion selective membranes for application in reverse electrodialysis systems: Concentration dependency of the apparent transport number
Strand, Robin Viktor (Master thesis, 2014)Revers elektrodialyse (RED) er en fornybar, ikke-forurensende måte å generereelektrisitet på ved å blande vann med forskjellige saltkonsentrasjoner, e.g.elvevann og sjøvann. RED er avhengig av ioneselektive membraner. ... -
Coupled Transport of Heat, Mass and Charge in Ion Exchange Membranes - Aqueous Chloride Systems Relevant for Harvesting of Low-Grade Waste Heat
Kristiansen, Kim Roger (Master thesis, 2018)In this thesis, the theory of classical non-equilibrium thermodynamics is used as a tool for the analysis of transport processes in ion exchange membranes, and for designing experiments for the determination of coupling ... -
Efficiency in the process industry: Three thermodynamic tools for better resource use
Kjelstrup, Signe; Magnanelli, Elisa (Peer reviewed; Journal article, 2020)In a world where resources are limited and their use will necessary have an impact, efficient handling of resources becomes essential. This review concerns three thermodynamic tools that can be systematically used to ... -
Electrolyte Melt Compositions for Low Temperature Molten Carbonate Thermocell
Kandhasamy, Sathiyaraj; Solheim, Asbjørn; Kjelstrup, Signe; Haarberg, Geir Martin (Journal article; Peer reviewed, 2018)Industrial processes for the production of metals and alloys by metallurgical and electrochemical methods generate a great deal of waste heat due to irreversible losses. This waste heat may be used as a power source to ... -
Energy efficiency of respiration in mature and newborn reindeer
Solberg, Simon Birger Byremo; Kjelstrup, Signe; Magnanelli, Elisa; Kizilova, Nataliya; Barroso, Iratxe Lorea Casado; Acquarone, Mario; Folkow, Lars (Peer reviewed; Journal article, 2020)Reindeer (Rangifer tarandus) have evolved elaborate nasal turbinate structures that are perfused via a complex vascular network. These are subject to thermoregulatory control, shifting between heat conservation and ... -
Energy efficient design of membrane processes by use of entropy production minimization
Magnanelli, Elisa; Wilhelmsen, Øivind; Johannessen, Eivind; Kjelstrup, Signe (Journal article; Peer reviewed, 2018)To minimize entropy production means to reduce the lost work in a process, and to optimize the use of energy resources. Due to the need for re-compression, membrane units for separation of CO2 from natural gas require large ... -
Energy-Efficient Designs of Systems: From Nature to Chemical Engineering
Solberg, Simon Birger Byremo (Master thesis, 2019)Dette masterprosjektet omfatter en undersøkelse av to forskjellige emner. Vi bruker teorien om irreversibel termodynamikk som et rammeverk for å betrakte effekten av geometri på energi-effektivitet av systemer i naturen. ... -
Ensemble distribution for immiscible two-phase flow in porous media
Savani, Isha; Bedeaux, Dick; Kjelstrup, Signe; Vassvik, Morten; Sinha, Santanu; Hansen, Alex (Journal article, 2017)We construct an ensemble distribution to describe steady immiscible two-phase flow of two incompressible fluids in a porous medium. The system is found to be ergodic. The distribution is used to compute macroscopic flow ... -
Entropy facilitated active transport
Rubi, Miguel; Lervik, Anders; Bedeaux, Dick; Kjelstrup, Signe (Journal article; Peer reviewed, 2017)We show how active transport of ions can be interpreted as an entropy facilitated process. In this interpretation, a particular change in the pore geometry through which substrates are transported gives rise to a driving ... -
Entropy facilitated active transport
Rubi, J.M.; Lervik, Anders; Bedeaux, Dick; Kjelstrup, Signe (Journal article; Peer reviewed, 2017)We show how active transport of ions can be interpreted as an entropy facilitated process. In this interpretation, a particular change in the pore geometry through which substrates are transported gives rise to a driving ... -
Entropy production beyond the thermodynamic limit from single-molecule stretching simulations
Bering, Eivind; Kjelstrup, Signe; Bedeaux, Dick; Rubi, Miguel; de Wijn, Astrid S. (Peer reviewed; Journal article, 2020)Single-molecular systems are a test bed to analyze to what extent thermodynamics applies when the size of the system is drastically reduced. Isometric and isotensional single-molecule stretching experiments and their ... -
Entropy Production Minimization as Design Principle for Membrane Systems: Comparing Equipartition Results to Numerical Optima
Magnanelli, Elisa; Johannessen, Eivind; Kjelstrup, Signe (Journal article; Peer reviewed, 2017)Entropy production minimization procedures presented in literature show that under different assumptions the optimal solution might be characterized by different thermodynamic quantities being constant. These constant ...