Solid cell-level modeling

Mills and Zhu (1999) developed the closed-cell and opened-cell foams using the BBC lattice tetrakaidecahedral cell model were as shown in Table 5.1 where 0s is the volume fraction of solids in the cell edges (Zhu et al. 1997a, b Mills and Zhu 1999). Roberts and Garboczi (2001, 2002) investigated the modulus for both opened-cell and closed-ceU foam stracture of random models based on Voronoi tessellations and level-cut Gaussian random fields for a closed-cell tetrakaidecahedral model shown in Fig. 5.2. Lu et al. (1999) proposed macro-mechanic model to evaluate the modulus for low porosity. 

The theory on the level of the electrode and on the electrochemical cell is sufficiently advanced [4-7]. In this connection, it is necessary to mention the works of J.Newman and R.White s group [8-12], In the majority of publications, the macroscopical approach is used. The authors take into account the transport process and material balance within the system in a proper way. The analysis of the flows in the porous matrix or in the cell takes generally into consideration the diffusion, migration and convection processes. While computing transport processes in the concentrated electrolytes the Stefan-Maxwell equations are used. To calculate electron transfer in a solid phase the Ohm s law in its differential form is used. The electrochemical transformations within the electrodes are described by the Batler-Volmer equation. The internal surface of the electrode, where electrochemical process runs, is frequently presented as a certain function of the porosity or as a certain state of the reagents transformation. To describe this function, various modeling or empirical equations are offered, and they... 

In the IBM, the presence of the solid boundary (fixed or moving) in the fluid can be represented by a virtual body force field -rp( ) applied on the computational grid at the vicinity of solid-flow interface. Considering the stability and efficiency in a 3-D simulation, the direct forcing scheme is adopted in this model. Details of this scheme are introduced in Section II.B. In this study, a new velocity interpolation method is developed based on the particle level-set function (p), which is shown in Fig. 20. At each time step of the simulation, the fluid-particle boundary condition (no-slip or free-slip) is imposed on the computational cells located in a small band across the particle surface. The thickness of this band can be chosen to be equal to 3A, where A is the mesh size (assuming a uniform mesh is used). If a grid point (like p and q in Fig. 20), where the velocity components of the control volume are defined, falls into this band, that is... 

Ferrying of molecules into cells via entry through caveolae may represent a way to traffic specifically cytotoxic molecules to specific action sites. For example, elevating the intracellular level of the sphingolipid ceramide is known to exert antimitogenic and proapoptotic effects. While ceramide is cell-permeable and displays antiapoptotic properties in vitro, systemic in vivo use of ceramide is hampered by its hydrophobicity. Using a C6-ceramide formulation in pegylated liposomes was shown to elicit a sixfold reduction in solid phase tumors, when compared to unloaded liposomes in a mouse model of breast adenocarcinoma [68],... 

In chapter 7, all works discussed on model molecular systems for conjugated polymers refer to condensed molecular solid ultra-thin films, generally prepared by condensation of molecules from the effusion of a Knudsen-type cell, in UHV, on to clean metallic substrates held at low temperatures. Clean is defined as atomically clean as determined by core-electron level XPS, such that there is intimate contact between the molecules at the substrate-film interface, without the influence of, for example, a metallic oxide, hydrocarbon... 

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