Lower critical

AT LOW CONVERSION K30%), GEL FREE, 250°C, 40-100 hr BULK - CATALYZED TRIMER PURITY LESS CRITICAL LOWER TEMPERATURES (170°C - 220°CI... 

The probability of an RPT decreases when the hot liquid is initially at a much higher temperature than the critical lower limit temperature. 

The temperature of diazotization is critical. Lower yields are obtained if the temperature rises above 40°. 

The phase-behaviour of such a system thus may change completely with variations in pressure, temperature, molar mass, and chemical composition of the polymer(s). Thus, polymer systems may show upper critical, lower critical, or hourglass-type demixing behaviour. 

Slow crystallization promotes disentangling since the process of reeling-in of chains from the entangled melt onto the crystal surface is promoted and this in turn enhances the maximum drawability, despite the fact that this increases the crystallinity. However, there is a critical lower limit for the number of entanglements between crystals in order to achieve high drawability and in the extreme limit of very slow isothermal crystallization, linear standard polyethylenes (not the UHMW-PE grades) can lose their drawability completely and become brittle materials. 

The molecular weight distribution of the polymer can have a dramatic effect on rates of depolymerisation. This effect has been demonstrated for a number of polymers, where a critical lower limit must be present before the process will start. The molecular origin for this effect is still subject to speculation, and has been attributed to a range of causes such as changes in enzyme accessibility, chain flexibility, fits with active sites, crystallinity or other aspects of morphology. 

Temperature is less easy to control precisely. The temperature in the hold period in autoclaves is generally maintained by modulating valves which open to allow steam entry when the temperature (or pressure, because these valves are more often than not controlled through pressure transducers) begins to drop toward the critical lower limit of the specification. It is generally not possible to control an autoclave to run through a complete hold period at the lower limit of its temperature specification. However, even quite apparently trivial errors in temperature above or below the limit can make significant differences in the amount of lethality delivered. For instance, at a nominal temperature of 121°C, an error of 1 K can increase or decrease the amount of lethality by 25%. 

Norwegian Pentoxifylline Multicenter Trial Group. Efficacy and clinical tolerance of parenteral pentoxifylline in the treatment of critical lower limb ischemia. A placebo controlled multicenter study. Int Angiol 1996 15(l) 75-80. 

The reformation of chiral nematic phase from nematic phase sometimes goes through the transient state of band texture. The formation of band texture is also a relaxation phenomenon. For HPC/H2O solutions, the band texture is only observed when the molecules have been well orientated in the shear direction.A critical lower shear rate limit exists because of the stability of chiral nematic textures. 

Firms may decide not to pursue areas of research or product development where they fear excessive liability costs will critically lower the potential return for a particular drug (236). 

The effect of different soil moistures on the activity developed is shown in Table IV. There was a critical lower moisture level between 9 and 4.5% for this soil below which enhanced activity failed to develop. The enhanced activity developed at 36% (9x) was significantly lower than that developed at intermediate moistures. 

Baumgartner 1998 Critical lower extremity ischemia Critical ischemia, resistant to maximal medical therapy, not surgical candidates Naked plasmid VEGF 165 Intramuscular injection Phase I 2-11 months Improved Ankle-Brachial index, exercise time, new vessels on angiogram, limb salvage, improved tissue integrity... 

Ledermann/Traffic 2001 Critical lower extremity ischemia Recruiting FGF-2 protein Intra-arterial administration Phase 1/11 Recmiting ... 

Direct measurements have not been made, to my knowledge, regarding the lower limit of partial pressure of H2O in air necessary for formation of hydrogen peroxide. One can reason, however, that the limiting partial pressure ought to be the same as that necessary for a metal to corrode. Based on corrosion information, the critical lower limit for the partial pressure is more properly expressed in terms of relative humidity rather than absolute pressure. The critical relative humidity for corrosion is that which allows moisture to condense on the surface of a metal. This value, in turn, depends on the nature and concentration of hygroscopic impurities present both in the atmosphere and on the metal surface. For commercial steels in ordinary urban air, the critical relative humidity is about 50%, but for high purity metals in filtered air, the critical value is undoubtedly much lower. 

Criticality in Concentration. The sharp downturn of the disentanglement time vs. concentration curve for the flare effect (Figure 8) indicates that the flare sets in within a narrow concentration range as C is increased. This is the critical concentration already identified as C. The postulation of the existence of a critical lower concentration is consistent with the concept of a network, because for a network to arise there needs to be a pathway of contact across the whole macroscopic system, the establishment of which, as common with all such percolation problems, is a critical phenomenon. In our case the minimum contact criterion is clearly the existence of coil overlap. 

On the other hand. Fig. 20 shows the temperature dependence of the velocity at different frequencies of 1,3,5, and 7MHz, revealing a critical lowering phenomenon around the Curie temperature, which is characteristic of the ferroelectric phase transition phenomenon. The sound velocity at higher frequencies seems to show this lowering phenomenon at a lower temperature range compared with that at lower frequencies. 

In gas adsorption measurements, there is a critical lower value of relative pressure, e.g., / // o 0.4 for nitrogen, below which capillary condensate cannot exist as a separate phase, no matter whether the pore system extends to finer pores or not this is a consequence of the existence of so-called tensile strength limit [6]. As a result of this, a very narrow false maximum may appear on the differential pore size distribution at its fine-pore end, typically between 17 and 20 A in the case of nitrogen. 

Impact strength is critically lowered by the weakness of the interface. 

Withdrawing rods faster to approach critical. Lowering the pool temperature 20 deg. F. 

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