Role of pressure

The effects of pressure on the properties of perovskite fes and rls are manifestations of the influence of pressure on the soft fe mode frequency of the host lattice [14,24], This frequency is determined by a delicate balance between short-range and long-range forces, and these forces exhibit markedly different dependences on interatomic separation, or pressure. Specifically, pressure increases the soft-mode frequency at constant temperature, which reduces the polarizability of the host lattice, thereby reducing Ac. The result is a shift of the transition temperature, Tc (or Tm), to lower temperatures and a suppression of the e (T) response in the high temperature paraelectric phase [14,24], 

Recent neutron scattering measurements [25] have revealed a well-defined fe (TO) soft mode in pmn at high temperatures that becomes overdamped by the polar nanoregions below the Burns temperature, Td. Thus, while the soft mode below Td is not a well-defined excitation in the spectrum, the large value of e and its strong temperature and pressure dependences between Td and Tm clearly implicate low-lying optic mode excitations. 

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Huff, J. E., "The Role of Pressure Relief in Reactive Chemical Safety," in Proceedings of the International Symposium on Prevention of Major Chemical Accidents, p. 4. 43, Center for Chemical Process Safety/AIChE, New York, NY (1987). 

Finally, we focus on the role of pressure on the hydration of lipid bilayer membranes. Figure 8 displays the H, NOESY spectra of sonicated DMPC... 

The effect of pressure on the reaction rate constant can be interpreted by both the collision-, and the transition state or activated complex theories. However, it has generally been found that the role of pressure can be evaluated more clearly by the transition state approach [3]. 

G. D. Gilmore and R. S. Spencer, Role of Pressure, Temperature and Time in the Injection Molding Process, Mod. Plast., 27, 143 (April 1950) also, R. S. Spencer and G. D. Gilmore, Residual Strains in Injection Molded Polystyrene, Mod. Plast., 28, 97 (December 1950). 

Neugebauer J. (1973) The diagenetic problem of chalk The role of pressure solution and pore fluid. Jahrb. Geol. Palaeontol. Abhandlungen 143, 223-245. 

Henderson MA, White JM, Uetsukab H, Onishi H (2006) Selectivity changes during organic photooxidation on TiO role of pressure and organic coverage. J Catal 238 153... 

Colten-Bradley, V.A., 1987. Role of pressure in smectite dehydration - Effects on geopressure and smectite-to-illite transformation. The American Association of Petroleum Geologists Bulletin, Vol 71, no.ll, pp. 1414-1427... 

Reulen HJ, Grahm R, Spatz M, Klatzo 1 (1977) Role of pressure gradients and bulk flow in dynamics of vasogenic brain edema. J Neurosurg 46 24-34. 

Hemley R J., and Ashcroft, N. W. (1998) The revealing role of pressure in the condensed-matter sciences. Physics Today 51, 26... 

Therefore, the laser light also provides the activation energy for torsional isomerizations. The role of pressure is to act as a tool in tuning the equilibrium between the recombination into rings or chains (Table 25). 

In atomic structure there exists a kind of Mariotte s law the power 3/2 of the electric potential playing here the role of pressure. 

The recent AFM experimental data concerning plastic flow place severe restrictions on possible theoretical accounts of plastic deformation in crystalline solids due to shock or impact. The high spatial resolution of the AFM, = 2 x lO " m, reveals substantial plastic deformation in shocked or impacted crystal lattices and molecules. Understanding how this occurs and its effect on plastic flow requires a quantum mechanical description. The semi-permanent lattice deformation has necessitated the development of a deformed lattice potential which, when combined with a quantum mechanical theory of plastic deformation, makes it possible to describe many of the features found in the AFM records. Both theory and the AFM observations indicate that shock and impact are similar shear driven processes that occur at different shear stress levels and time durations. The role of pressure is to provide an applied shear stress sufficient to cause initiation. 

Yasuhara, H., Elsworth, D., and Polak, A. (2004a) The evolution of permeability in a natural fracture significant role of pressure solution. J. Geophys. Res., Vol. 109, B03204,... 

THE EVOLUTION OF PERMEABILITY IN NATURAL FRACTURES - THE COMPETING ROLES OF PRESSURE SOLUTION AND FREE>FACE DISSOLUTION... 

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