Thermal stability also

The term thermal stability (also thermostability) refers to the resistance of a protein to adverse intrinsic and extrinsic environmental influences, i.e., the thermal characteristic of the protein to remain steady against the dena-turation of its molecular integrity and inactivation of its biologic activity on facing high temperatures or other deleterious agents (6). One of the most important indices to measure protein stability is the decimal reduction time, or D-value, the time required to reduce 90% of the initial protein concentration exposed to the reference temperature. The D-value was used... 

The alkylidynetricobalt nonacarbonyl complexes all are highly colored, with colors ranging from red to purple to brown to black, depending on the apical substituent. Their thermal stability also depends on the apical substituent some survive heating to 100°-18o° and many may be sublimed in vacuum at 50°-80°C. Most, but not all, are air-stable (in contrast to their pyrophoric parent, dicobalt octacarbonyl) in the solid and in solution. 

Investigations of thermal stability also lead to lower stability of polymers compared with low molecular Pc. The decomposition of polymers prepared from tetracyanoben-... 

Liu et al. have described the solution structure of a mutant of the homodimer protein transcription factor 1, TFl. The dimeric core, consisting of the N-terminal helices and beta sheets, is more tightly packed than wire type, and this might be responsible for its increased thermal stability. Also, Gordon-Smith et al reported the dimeric structure of a C-terminal fragment of Bovine IFl, which inhibits the hydrol) ic action of the FIFO ATP synthase in mitochondria under anaerobic conditions. Most imusually, the molecule forms an anti-parallel coiled-coil in which three histidine residues occupy key positions at the dimer interface. ... 

MeV protons and also by Co gammas by Oblivantsev et al. [110] and Boldyrev [111], and their radiation stabilities were compared to their thermal stabilities. Also determined were the range and loss of energy of 4.7-MeV protons in alkali azides. 

The high thermal stability also has a significant influence on conversion rates in the esterification of phthalic anhydride with alcohols, e. g. 1-octanol or 2-ethylhexanol, to yield dioctyl phthalates. Product yields >99% for the diester are reported for residence times between 30 and 50 min and temperatures between 150 and 180 °C [15,17,18]. 

Properties of CPE are related to the content of chlorine. Traditionally, CPE containing 36% chlorine was used (and it is still used today) because of its better elasticity and less compatibility with PVC. More recently, CPE containing 25% chlorine is used because it promotes faster fusion and enhances the melt strength of the formulation. Faster fusion permits the partial or complete elimination of oxidized polyethylene, which is frequently used as fusion promoter. CPE has similar vulnerabilities to PVC, therefore regular PVC thermal stabilizers also stabilize CPE without a need to include special stabilizers. " ... 

Because polyvinyl chloride is thermally unstable and releases HCl so near its processing temperature, thermal stabilizers are required to react with the polyvinyl chloride chain upon HCl release. Thermal stabilizers also neutralize any released HCl to prevent total chain degradation. 

In situ-generated silica fillers improve creep resistance and compression set in cyclic deformation. Ihe filled samples show very little compression set (figure 9.7). Thermal stability also improves as reflected by higher decomposition temperatures, (figure 9.8) A possible mechanism... 

Thermal stability of zeolites Crystalline zeolites are more resistive to heat than amorphous materials the main reason being the geometrical structure of the crystalline framework. However, the effects of silica/alumina ratio and level of cation exchange on thermal stability also cannot be denied. Commercial zeolites having a high (Si02/Al203) ratio can resist... 

Many sulfur-containing PD antioxidants, especially the metal dithiolates, are very effective long-term thermal stabilizers (also melt and photo antioxidants see later). This versatility in antioxidant action is the direct consequence of their highly effective PD activity (54,105,107,136-140). Moreover, the effectiveness of dithiolate antioxidants, within any one series depends strongly on their solubility in the polymer. For example, in the case of nickel dialkyldithiophosphate (NiDRP, AO 23, Table 3) series, the lower molecular weight members of the series are less soluble, and less effective than the higher members (see Fig. 3) (141). The zinc dialkyl dithiocarbamate (ZnDRC, AO 21) series too show similar behavior (142). 

The thermal stability of the hydrogenated polymers was greatly improved as compared to that of the parent polymer. The thermal stability also increased with the increase in the degree of hydrogenation for the partially hydrogenated polymers. 

The thermal stability, also, depends on the types of side groups present. Amino side groups usually condense at high temperatures to yield crosslinked matrices. 

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