Nonequilibrium cell model

Higler AP, Krishna R, Taylor R. Nonequilibrium-cell model for multicomponent (reactive) separation processes. AIChE J 1999 45 2357-2370. 

The rate-based models suggested up to now do not take liquid back-mixing into consideration. The only exception is the nonequilibrium-cell model for multicomponent reactive distillation in tray columns presented in Ref. 169. In this work a single distillation tray is treated by a series of cells along the vapor and liquid flow paths, whereas each cell is described by the two-film model (see Section 2.3). Using different numbers of cells in both flow paths allows one to describe various flow patterns. However, a consistent experimental determination of necessary model parameters (e.g., cell film thickness) appears difficult, whereas the complex iterative character of the calculation procedure in the dynamic case limits the applicability of the nonequilibrium cell model. 

A. Higler, R. Krishna, R. Taylor, Nonequilibrium Cell Model for Multicomponent (Reactive) Separation Processes, AIChE]., 1999, 45, 2357-2370. 

Baur R., Taylor R. and Krishna R. (20016). Dynamic behaviour of reactive distillation tray columns described with a nonequilibrium cell model. Chemical Engineering Science 56, 1721-1729. 2.9.3,... 

Higler A., Krishna R. and Taylor R. (1999a). Nonequilibrium cell model for packed distillation columns - the influence of maldistribution. Industrial and Engineering Chemistry Research 38, 3988—3999. 

Ca2+-ATPases exist in the plasma membranes of most cells and in the sarcoplasmic reticulum of myocytes, where they pump Ca2+out of the cytosol and into the lumen, respectively, while simultaneously counterporting H+ions. Ca2+-ATPase requires Mg2+on the side from which Ca2+is pumped. It is generally established that the Ca2+/ATP stoichiometries for the plasma membrane and sarcoplasmic reticulum are 1 and 2, respectively. Using a nonequilibrium thermodynamics model, the extent of slippage in the plasma membrane Ca2+-ATPase can be estimated from steady-state H+flow measurements. 

Franco has designed this model to coimect within a nonequilibrium thermodynamics framework atomistic phenomena (elementary kinetic processes) with macroscopic electrochemical observables (e.g., I-V curves, EIS, Uceii(t)) with reasonable computational efforts. The model is a transient, multiscale, and multiphysics single electrochemical cell model accounting for the coupling between physical mechanistic descriptions of the phenomena taking place in the different component and material scales. For the case of PEMFCs, the modeling approach can account for detailed descriptions of the electrochemical and transport mechanisms in the electrodes, the membrane, the gas diffusion layers and the channels H2, O2, N2, and vapor... 

The film formation in fhe spin-coating process for the polymer/fuller-ene blend system in the mixture solvent is a complex process because it is a nonequilibrium state that both thermodynamic and kinetic parameters can influence phase separation, and the system contains four components with dissimilar physical/chemical properties. We found the donor/acceptor components in the active layer can phase separate into an optimum morphology during the spin-coating process with the additive. Supported by AFM, TEM, and X-ray photoelectron spectroscopy (XPS) results, a model as well as a selection rule for the additive solvent, and identified relevant parameters for the additive are proposed. The model is further validated by discovering other two additives to show the ability to improve polymer solar cell performance as well. 

It is well-known that implicit solvent models use both discrete and continuum representations of molecular systems to reduce the number of degrees of freedom this philosophy and methodology of implicit solvent models can be extended to more general multiscale formulations. A variety of DG-based multiscale models have been introduced in an earlier paper of Wei [74]. Theory for the differential geometry of surfaces provides a natural means to separate the microscopic solute domain from the macroscopic solvent domain so that appropriate physical laws are applied to applicable domains. This portion of the chapter focuses specifically on the extension of the equilibrium electrostatics models described above to nonequilibrium transport problems that are relevant to a variety of chemical and biological S5 ems, such as molecular motors, ion channels, fuel cells, and nanofluidics, with chemically or biologically relevant behavior that occurs far from equilibrium [74-76]. 

The corresponding atomistic kinetics is then implemented into the nonequilibrium nanoscale MEMEPhys models collecting all the elementary events, catalytic and no-catalytic, to simulate the electrochemical observables. The nanoscale models introduce the electric field effect correction without empirical parameters and open interesting perspectives to scale up atomistic data into macroscopic models in a robust way. The impact of the catalyst chemistry and nanostructure on the electrodes and cell potentials can be then captured. 

The commercial application of polymer blend technology has grown significantly such that, today, compositions are available with properties that once were substantially unattainable with homopolymers. To date, polymer blends have been applied in optical fibers [13,14], microlenses [15], liquid crystal display components [16,17], solar cells [18-20], nonionizing radiation detection [21] and polymer light-emitting diodes [22-24]. In particular, the use of developed polymer blends in optoelectronics applications appears unlimited. Polymer blends may also provide model systems in statistical physics when studying the fundamental aspects of equilibrium and nonequilibrium properties [3], optical properties [25], and mechanical and electrical properties [26]. 

Nagayama et al. [57] carried out nonequilibrium molecular dynamic simulations to study the effect of interface wettability on the pressure driven flow of a Lennard-Jones fluid in a nanochannel. The velocity profile changed significantly depending on the wettability of the wall. The no-slip boundary condition breaks down for a hydrophobic wall. Siegel et al. [58] developed a two-dimensional computational model for fuel cells. 

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