Compressible models

These observations were the basis for the proposal that polymers, like ionic crystals, exhibit shock-induced polarization due to mechanically induced defects which are forced into polar configurations with the large acceleration forces within the loading portion of the shock pulse. Such a process was termed a mechanically induced, bond-scission model [79G01] and is somewhat supported by independent observations of the propensity of polymers to be damaged by more conventional mechanical deformation processes. As in the ionic crystals, the mechanically induced, bond-scission model is an example of a catastrophic shock compression model. 

Alternately, a benign shock compression model has been invoked to explain the polarizations. An elastic dipole-rotation model was first proposed... 

Use of the term mean-bulk temperature is to define the model from which temperatures are computed. In shock-compression modeling, especially in porous solids, temperatures computed are model dependent and are without definition unless specification of assumptions used in the calculations is given. The term mean-bulk temperature describes a model calculation in which the compressional energy is uniformly distributed throughout the sample without an attempt to specify local effects. In the energy localization case, it is well known that the computed temperatures can vary by an order of magnitude depending on the assumptions used in the calculation. 

The compressible models resolve a very early stage of droplet deformation when the compressible wave generated by impact has not yet traveled throughout the droplet. In this stage, the shock wave separates the compressed liquid from the undisturbed liquid that is above the compressed liquid and at the initial impact velocity. The intersection of the compressed and undisturbed liquids constitutes a contact ring. As long as the velocity of the contact ring is... 

Detailed modeling of a porous material under compression is a challenging task of applied structural mechanics. The reduced compression model employed in the current study is based on the unidirectional morphological displacement of solid voxels in the GDL structure under load and with the assumption of negligible transverse strain. The reduced compression model is detailed in our recent work.33 However, with the reduced compression model, it is difficult to find a relation between the compression ratio and the external load. The compression ratio is defined as the ratio of the thickness of compressed sample to that of the uncompressed sample. Nevertheless, this approach leads to reliable 3-D morphology of the non-woven GDL structures under compression. Figure 17a shows compressed, reconstructed non-woven GDL... 

For the system with very high adhesion strength between the clay and the stickers, the favorable enthalpy of the sticker-clay interaction dominates the unfavorable entropic contributions. Accordingly (Figure 11c), the composite now becomes exfoliated, as demonstrated by both compressible and incompressible models. Interestingly, within the compressible model, the old minimum at H 1.6-2 nm has not disappeared completely, indicating the presence of a metastable intercalated morphology. 

Sonnergaard, J. M. (2000), Impact of particle density and initial volume on mathematical compression models, Eur. J. Pharm. Sci., 11, 307-315. 

FIG. 17 Force-deformation relationship and description of Equation 16, shown in a four-parameter compression model (adapted from Yan and Barbosa-Canovas, 1997). 

Ma et al. [147,162,163] argued that pressure-induced covalency effects can be understood in terms of the radial expansion of the valence electron wavefunc-tions as the nearest neighbor bond length decreases with pressure. They considered an isotropic compression model based on the scaHng of the Slater integrals... 

Lee MY, Chen L, Toborek M (2009) Nicotine attenuates iNOS expression and contributes to neuroprotection in a compressive model of spinal cord injury. J Neurosci Res 87 937—947 Leker RR, Shohami E (2002) Cerebral ischemia and trauma-different etiology yet similar mechanisms neuroprotective opportunities. Brain Res Rev 39 55—73 Liu XZ, Xu XM, Hu R, Du C, Zhang SX, McDonald JW, Dong HX, Wu YJ, Fan GS, Jacquin MF, Hsu CY, Choi DW (1997) Neuronal and gjial apoptosis after traumatic spinal cord injury. J Neurosci 17 5395-5406... 

Compression modeling n. A technique principally for thermoset plastic molding in which the molding compound is placed in the heated open mold cavity, mold is closed under pressure, causes the material to flow and compress. 

An empirical representation of PVT data of polymer systans is given by the Tait equation. It can be viewed as an isothermal compressibility model. The general form of the Tait equation can be written as follows ... 

V. P. Schulz, P. P. Mukheijee, and A. Heiko, Compression modeling and transport characterization of the pern fuel cell diffusion medium . Proceedings of the ASME 2011 5 International Conference on Energy Sustainabihty 9 International Fuel Cell Science, Engineering and Technology Conference, Paper No. ESFuelCell2011-54298 (2011). ASME, Washington DC . 

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