Why is there no development tab in comsol 5.3

Mathematical modelling is a powerful tool to study the mechanisms of gas transport in plant material. For a better understanding of plant metabolism it is important to quantify the metabolic gas exchange and the effect of the external conditions on the intracellular metabolic gas concentration. In some fruits, such as pears, which are typically stored under controlled atmosphere (CA) condition, anoxia may occur, eventually leading to fermentation, which causes a chain of events ultimately leading to cell death, tissue damage, and commercial loss ( Franck et al., 2007). In leaves, gradients have been observed due to CO 2 assimilation ( Morison et al., 2005 Warren, 2008). In developing seeds, the combination of respiration and photosynthesis may cause large gradients in gas concentrations ( Rolletschek et al., 2003 Borisjuk and Rolletschek, 2009). In bulky organs, such as fruits and roots, these gradients exist due to O 2 consumption and CO 2 production during respiration and fermentation ( Kader, 1988 Geigenberger et al., 2000 Ho et al., 2008). Gas exchange is caused by differences in gas concentrations between the applied external atmosphere and the internal atmosphere of plant organs. The model presented is a valuable tool, as it can be used to study the effect of any modifications on the cell performance before fabricating and testing the new design in an extensive experimental study.Anoxia, controlled atmosphere storage, gas transport, multiscale modelling, pear IntroductionД®xchange of O 2 and CO 2 of plants with their environment is essential for metabolic processes such as photosynthesis and respiration. Using this model, the effect of porosity on the net power output of the fuel cell is investigated and an optimum value for porosity is calculated.

Using the numerical model, it is shown that the tapered geometry improves the fuel utilization by up to four times in addition to a substantial improvement in the power density.ДЄ similar numerical model is developed to study the performance of a microfluidic fuel cell with flow-through porous electrodes. In this thesis, a novel design of microfluidic fuel cell with a tapered channel is also proposed. The model is then used to assess the effect of different modifications, which have been applied on the microfluidic fuel cell since its advent, by calculating the polarization curves associated with each modification. The validity of the developed model is first checked by verifying it against the numerical and experimental results previously reported in the literature. Potential equations are used to model both the ionic conduction in the electrolyte and the electrical conduction in the solid electrodes. This model accounts for the mass and momentum transport phenomena inside the device as well as the electrochemical reaction kinetics which are described by the Butler-Volmer equations. In this work, a comprehensive numerical model of the microfluidic fuel cell is developed using COMSOL Multiphysics. This causes the anolyte and catholyte form a co-laminar flow inside the microchannel which is required to maintain the separation of the fuel and oxidant and limit the reactions to the appropriate electrodes.

The Reynolds number in the microchannel is low, and hence viscous forces are dominant over the inertial forces. Aqueous fuel and oxidant are introduced from the two inlets of the channel and flow together side-by-side toward the end of the channel.

The microfluidic fuel cell or laminar flow-based fuel cell is a membraneless fuel cell which typically consists of two electrodes mounted within a T- or Y-shaped microchannel.

Why is there no development tab in comsol 5.3