Stability self-stabilisation

It is also incorrect to assume that the increase of viscosity due to the decrease of temperature during the spinning process is essential for the stability. Nevertheless, both factors mentioned may have a very favourable effect on the process since they promote the stability the process becomes "self-stabilising" by them. 

Light water thermal reactors have a coolant that can be an appreciable moderator. Indeed, in the PWR and the conventional BWR, the two roles are intimately mixed. To promote inherent stability, the LWR is designed to be under-moderated, with a lattice pitch closer than optimum. In the event of a loss of moderator/coolant, by leakage or by turning from liquid to steam, the reactivity is lowered the reactor is self-stabilising if this voiding was caused by a rise in power. The water coolant in the RBMK has only a... 

Because process heating is expensive, lagging is invariably applied to heated process vessels to minimise heat loss, particularly during long-term hot storage. Such adiabatic or near-adiabatic systems are potentially hazardous if materials of limited thermal stability, or which possess self-heating capability, are used in them. Insufficiently stabilised bulk-stored monomers come into the latter category. 

Crowe proposed that benzylidene 6 would be stabilised, relative to alkylidene 8, by conjugation of the a-aryl substituent with the electron-rich metal-carbon bond. Formation of metallacyclobutane 10, rather than 9, should then be favoured by the smaller size and greater nucleophilicity of an incoming alkyl-substituted alkene. Electron-deficient alkyl-substituents would stabilise the competing alkylidene 8, leading to increased production of the self-metathesis product. The high trans selectivity observed was attributed to the greater stability of a fra s- ,p-disubstituted metallacyclobutane intermediate. 

The concept of interfacial mesophases promoting spontaneous emulsification (21.22) can be applied to the Tagat TO - Miglyol 812 system, where stable liquid crystalline dispersion phases are adequate to promote the process of self-emulsification. The stability of the resulting emulsion systems can also be accounted for by liquid crystalline interface stabilisation (23.24). Phase separation of material as observed above 55f surfactant, in conjuction with the increased viscosities of such systems, will inhibit the dynamics of the self-emulsification process and hence the quality of self-emulsified systems declines when the surfactant concentration is increased above 55. ... 

An RNA-HNA (hexitol) hybrid duplex structure has been studied by NMR. " The P-P distances across the minor groove are a determinant for cleavage by RNase H. In the structure, the duplex is in an A-form, and the P-P bond distance similar to that for an RNA-RNA duplex, which may explain the resistance of HNA duplexes to RNase H. A self-complementary HNA duplex h(GCGCTTTTGCGC) containing a central T-tract has been studied by NMR. " The duplex exists in the A-form in the stem regions, with minor distortions in the T-tract causing a 9 A displacement of the helical axes. The T-tract is stabilised by wobble pairs enhancing the overall stability of the duplex. 

Of course, it is often possible to resort to covalent cross-linking to stabilise a structure that has been self-assembled from an aqueous environment. Indeed, nature does this too in the case of fibrous materials such as hair (keratin) and tendons (collagen) that must exhibit extracellular stability for long periods of time. This approach will be acceptable if we want the product properties to reflect the presence of such cross-links, but otherwise it has to be avoided. 

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