Morphology Calculation

Figure 48. Pit morphology calculated by a two-dimensional Monte Carlo simulation,98 (a) polishing-state pit and (b) active-state pit. (Reprinted from R. Reigata, F. Sagues, and J. M. Costa, Monte Carlo simulation of localized corrosion, /. Chem. Phys. 101, 2329, 1994, Figs. 6 and 7. Copyright 1994, American Institute of Physics.)...

Whether a phase displays SD, PSD orMD behaviour, can be determined from the shape of its hysteresis loop. In MD particles the Bloch walls can be moved by lower energies than the directions of magnetization in SD particles. The hysteresis loops of MD particles, therefore, are much narrower than those of SD particles (Fig. 7.12). For ferrimagnetic phases, the ratios Jrs/Js and Har/Hc (Fig. 7.9) (Day et al., 1977) can be used to distinguish between SD, PSD, and MD particles (Fig. 7.12, right). It should be kept in mind, however, that the coercive forces also depend on particle morphology. Calculations by Butler and Banerjee (1975) show that deviations from the rounded isometric shape towards elongated needles stabilize the SD behaviour and even SP particles may become SD (Fig. 7.13). 

Figure 5.25 (a) as a fimction of shear strain qSxO for mono- (O), bi- (A), and trilayer (-I-) morphologies calculated in grand mixed isostress isostrain ensemble... 

Table 2 shows the results for cluster morphology calculations for 1200 EW polymer neutralized with various cations. As... 

Table I. Results of Cluster Morphology Calculations According to Equations 1-5 for Polymers with Difference Equivalent Weights in Na Ion Form. Samples Conditioned by Boiling 1 h in 0.2 % NaOH.

Molecular simulation approaches were used to investigate the effectiveness of template type on TS-1 crystal morphology. Calculations indicated that docking of hexane diamine on surfaces of TS-1 crystal strongly changes crystal size and morphology. It is also found that hexane diamine can pack together with TP A in TS-1 structure to play an important template effect. Simulation results consistent well with experimental results. 

Terephthalic acid (TA) is an important industrial chemical used in the production of polyester. Its purification involves multi-stage recrystallization under extreme conditions. The phase characterisation and morphologies of Forms I and II of TA were studied by HSM, thermal analysis, Raman spectroscopy, single crystal Laue X-ray diffraction, lattice energy and morphological calculations [ 157]. Contrary to earlier reports, this study revealed that Form 11 (not Form I) is the thermodynamically stable form of TA under ambient conditions. The apparent stability of Form I was shown to be due to twinning in microcrystals... 

Chen. B.D. Garside, J. Davey, R.J. Maginn. S.J. Matsuoka, M. Growth of nz-ehloronitrobenzene erystals in the presenee of tailor-made additives Assignment of the polar axis from morphological calculations. J. Phys. Chem. 1994. 98. 3215-3221. 

Ferritic Steels , Mater. Sci. Eng. A, A344, 92-102 (2003) (Morphology, Calculation, 27) [2004Aar] Aaronson, H.I., Reynolds, W.T., Purdy, G.R., Coupled-Solute Drag Effect on Ferrite Formation in Fe-C-X Systems , Metall. Mater. Trans. A, 35a(4), 1187-1210 (2004) (Morphology, Phase Relations, Experimental, Interface Phenomena, Kinetics, 148)... 

A crystal morphology simulation for ibuprofen was performed with Accelrys s Materials Studio software suite, utilizing the morphology module. The crystal structure was originally obtained from the CSD and then fully optimized using the COMPASS force field—a priori to morphological calculations. As shown in Figure 6.12, the unrelaxed vacuum slabs of crystal faces with thickness of 25 A were constructed from the optimized crystal stracture. 

Figure 3. Scratch morphology calculations performed on Image 9. a) Plot of critical points from automated analysis, b) Three dimensional image highlighting scan line used in c) for area integration.

The AFM used in these experiments is a precision large stage M-5 instrument from Park Scientific Instruments. The stage motion is calibrated with NIST traceable standards and the absolute reproducibility is within a few microns. The micro-scratch instrument and the AFM are in perfect registry so that images and morphological calculations are precisely related to the micro-mechanical measurement (i2). 

In the theory section we summarize the continuum Flory-Huggins theory for inhomogeneous solutions and the dynamical equations. In the application section we present a few examples of morphology calculations in polymer surfactant solutions and block copolymer thin films. 

Akd] Akdeniz, M.V., Mekhrabov, A.O., The Effect of Substitutional Impurities on the Evolution of Fe-Al Diffusion Layer , Acta Mater, 46(4), 1185-1192 (1998) (Morphology, Calculation, Experimental, Interface Phenomena, 55)... 

Wu] Wu, D., Baker, L, Munroe, P.R., The Effect of Substitutional Elements on the Strain-Induced Ferromagnetism in 52-Structured Fe-Al Single Crystals , Intermetallics, 12(7-9), 851-858 (2004) (Crys. Structure, Morphology, Calculation, Experimental, Magn. Prop., 19)... 

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