Structurally stable

Long term simulations require structurally stable integrators. Symplec-tic and symmetric methods nearly perfectly reproduce structural properties of the QCMD equations, as, for example, the conservation of the total energy. We introduced an explicit symplectic method for the QCMD model — the Pickaback scheme— and a symmetric method based on multiple time stepping. 

From Fig. 3.11, it can be seen that by increasing the chromium content while maintaining a limited amount of nickel-equivalent elements, first mixed martensite-ferrite structures are produced and then fully ferritic. This is 6-ferrite, that is a body-centred cubic structure stable at all temperatures. Relative to martensite it is soft, but it is also usually brittle. For this latter reason, usage has in the main been in small section form. This and some other disadvantages are offset for some purposes by attractive corrosion resistance or physical properties. 

The models also assume a steady-state condition which suggests that the carbon cycle is structured, stable, and balanced and will remain so indefinitely. This mechanistic view of biogeochemistry allows for little variation even though it is known that fluctuations and variation occur seasonally. The concentration of... 

Because such guest molecules usually interact with the frameworks through H-bonds, van der Waals s forces, or sometimes coordination bonds, it is crucial to remove the templates properly to form structurally stable, free-pore molecular sieves. 

Simple physical entanglements can be sufficient to produce a structurally stable gel if the polymer has a sufficiently great molecular weight and if the polymer is of only modest hydrophilicity. In this case, the polymer will swell in water without dissolving, even in the absence of covalent cross-links. Poly(2-hydroxyethyl methacrylate) (PHEMA) is a prominent example of this type of hydrogel when uncross-linked, it will dissolve in 1,2-propanediol but only swell in water. 

Rigid, brittle structure Structurally stable Only moulded articles (injection moulding possible with RIM)... 

Upon biosynthesis, a polypeptide folds into its native conformation, which is structurally stable and functionally active. The conformation adopted ultimately depends upon the polypeptide s amino acid sequence, explaining why different polypeptide types have different characteristic conformations. We have previously noted that stretches of secondary structure are stabilized by short-range interactions between adjacent amino acid residues. Tertiary structure, on the other hand, is stabilized by interactions between amino acid residues that may be far apart from each other in terms of amino acid sequence, but which are brought into close proximity by protein folding. The major stabilizing forces of a polypeptide s overall conformation are ... 

Figure 11.7 shows schematically the resulting calculated variation of H with p for the NaCl-type and the CsCl-type phases of CaO. The NaCl-type structure, which is stable at low pressures, is the rock salt structure in which the Ca and O atoms are 6-coordinate. In the CsCl structure, stable at high pressures, both cation and anion are 8-coordinate. In the static limit where the entropy is set to zero, the thermodynamically most stable phase at any pressure is that with the lowest value of H at the thermodynamic transition pressure, ptrs, the enthalpies of the two phases are equal. For CaO the particular set of potentials used in Figure 11.7 indicates a transition pressure of 75 GPa between the NaCl-type and CsCl-type structures, which compares with experimental values in the range 60-70 GPa. 

Due to their preparation methods, inorganic membranes are in general structurally stable. They do not suffer from any appreciable dimensional instability problems due to compaction and swelling which commonly occur among many organic polymeric membranes. 

The Tiukertoy aud Erector Sets were basically similar to woodeu blocks iu haviug a family of distiuct parts that could be assembled iu mauy differeut ways to create differeut outcomes. They were differeut iu oue importaut aspect the pieces couuected iu a way that made the growiug structures stable. These couuectious worked a good bit better thau gravity. They provided stability, just as chemical bouds provide stability for molecules. 

Tanabe and Kamasaki (52) observed the nucleation growth mechanism in the deposition of Au on Fe(OOl) and Fe(l 10) single crystals. The population of nuclei (TDCs) of Au electrodeposited in the initial stages of deposition was 3 X 10 cm . In further deposition, micro-TDCs were connected one to another forming a network structure. Stable coherent deposits of Au were formed when the surface coverage was about 80%. 

Silvery white metal soft and hght turns shghtly yeUow when exposed to air density 2.99 g/cm exhibits two aUotropic modifications a hexagonal close-packed structure stable up to 1,335° transforms to body-centered cubic form above 1,335°C, having a density 3.19 g/cm melts at 1,541°C vaporizes at 2,831°C electrical resistivity 56.2x10 ohm-cm thermal neutron absorption cross section 24 1 bams decomposes in water. 

A protein molecule has the same conformation whenever it exists under the same conditions, and protein molecules with the same sequence of amino acids have identical conformations under identical conditions (Flory 1969 Mangino 1984). Some structures in protein chains are seen frequently in a variety of proteins and have been given names such as a-helix and 0-sheet. Others, referred to as unordered structure (Swaisgood 1982), are regions of protein folding which may be found only once, but are structurally stable. Much space in globular proteins is filled with such unordered structure (Flory 1969). 

The reaction was carried out using Nafion-H and polystyrene sul-phonic acid resin catalyst at 180°C and 140°C, respectively, which are their maximum temperatures of use 2-nitrotoluene solvent and 10% w/w catalyst. Conversions of 20% and 1.5% were obtained at the end of six hours indicating that higher temperatures will be necessary to achieve appreciable rates on these catalysts. Since these catalysts are not structurally stable above the respective temperatures, they appear to be unsuitable for this application. The reaction was also carried out using triflic acid as catalyst at various temperatures. The results are shown in Fig.3. Surprisingly, the reaction did not proceed beyond 40% conversion in spite of the high acidity of the catalyst. 

The present study demonstrates suitability of sulphated zirconia for dehydration of carboxamides. It needs to be emphasised that the common inorganic acid catalysts are not sufficiently acidic to catalyst the reaction below 400°C while the strongly acidic resin catalysts are not structurally stable at temperature at which the reaction would occur at appreciable rate. Thus the sulphated zirconia appears to be a unique catalyst for this application. 

Holmes 1983) states that when the above transversal homoclinic intersection occurs, that there is a structurally stable invariant Cantor set like the one for the Horseshoe map. It has also been shown by Holmes (1982) that this invariant set contains a countable, dense set of saddles of all periods, an uncountable set of non-periodic trajectories and a dense orbit. If nothing else is clear from the above, it is at least certain that homoclinic bifurcations for maps are accompanied by some very unusual phase portraits. Even if homoclinic bifurcations are not necessarily accompanied by the formation of stable chaotic attractors, they lend themselves to extremely long chaotic like transients before settling down to a periodic motion. Because there are large numbers of saddles present, their stable manifolds divide up the phase plane into tiny stability regions and extreme sensitivity to perturbations is expected. 

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