Structural instability

Finally, the use of the constant pressure minimization algorithm allows searching for phenomena that can be considered as precursors of pressure-induced transitions. For example, the predicted behaviour of the anatase cell constants as a function of pressure shows that the a(P) and c(P) plots are only linear for P<4 GPa, the value that is close to both the theoretical and experimental transition pressures. At higher pressures the a constant starts to grow under compression, indicating inherent structural instability. In the case of ratile there is a different precursor effect, nami y at 11 GPa the distances between the titanium atom and the two different oxygens, axial and equatorial, become equal. Once again, the pressure corresponds closely to the phase transition point. 

Alewijnse, A. E., Smit, M. J., Hoffmann, M., Verzijl, D., Timmerman, H. and Leurs, R. Constitutive activity and structural instability of the wild-type human H2 receptor. /. Neurochem. 71 799-807,1998. 

The enormous surface area-to-volume ratio of nanopaiticles leads to excess surface free energy that is comparable to the lattice energy leading to structural instabilities. The nanoparticles have to... 

Emergency responses to incidents involving weapons of mass destruction are much different from responses to incidents involving conventional explosives. For example, while the debris from conventional explosives may be extensive and present hazards to the individuals responding, such as fires or structural instability, the materials are not inherently hazardous. In this situation, the site can be secured and forensic investigations can be conducted similarly to investigations at other crime scenes. 

Finding 17. The introduction of new structural risks during closure operations is a potential source of accidents. Dismantlement and removal of building structural components, such as the concrete floors of the explosion containment rooms, could pose added risks of structural instability during closure operations, as could temporary loadings from stacked materials or heavy equipment. 

J. P. Pouquet, Structural Instabilities E. M. Conwell, Transport Properties C. S. Jacobsen, Optical Properties... 

Classical BCS theory dictated that superconductors with the highest Tc s would not be thermodynamically stable phases. Softening the phonons would raise Tc but would ultimately lead to structural instabilities. Increasing the density of states at the Fermi level would raise Tc but would eventually lead to an electronic instability. 

The scientific community was attracted to the study of liposomes due to the relatively simple procedure of their preparation. Moreover, if prepared from natural phospholipids, they are biocompatible, and possess low cytotoxicity, low immunogenicity, and biodegradability [304], Liposomes, however, have two main disadvantages the structural instability both in vitro and in vivo, and low cell specificity [304], To increase the stability, the structure of the phospholipid layer has been modified to include artificial lipids and/or cholesterol. Polymerizable vesicles have also been prepared [305]. It is obvious that the biocompatibility of these modified systems has to be addressed. 

Diffuse crystal/crystal interfaces often appear in systems subject to incipient chemical or structural instabilities associated with phase separation, long-range ordering, or displacive phase transformations [2], Examples of interfaces associated with the first two types are shown in Fig. 18.7. 

Gether, U., Ballesteros, J. A., Seifert, R., Sanders-Bush, E., Weinstein, H., and Kobilka, B. K. (1997a). Structural instability of a constitutively active G protein-coupled receptor. Agonist-independent activation due to conformational flexibility. / Biol. Chem. 272, 2587-2590. 

Rasmussen, S. G., Jensen, A. D., Liapakis, G., Ghanouni, P., Javitch, J. A., and Gether, U. (1999). Mutation of a highly conserved aspartic acid in the beta2 adrenergic receptor Constitutive activation, structural instability, and conformational rearrangement of transmembrane segment 6. Mol. Pharmacol. 56, 175-184. 

In contrast to swollen homopolymer films, only a limited number of studies on thin films of block copolymers have been reported in which the degree of the film swelling has been directly accessed. In situ SE has been used to evaluate the polymer-solvent interaction parameters [144], to construct phase diagrams of surface structures [49, 51], and to control the mechanism of lamella reorientation in thick swollen films [118, 163, 164], Spectroscopic reflectometry combined with real-time GISAXS has been used to follow structural instabilities in swollen lamella films [165], Recently, it was demonstrated that swelling of diblock copolymer films in organic selective and non-selective solvents follows the same physical behavior as in thin films of homopolymers [119]. 

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