Melting Profile

Fig. 15 Representative thermal melting profiles of a poly(dT)-poly(dA)xpoly(dT) and b poly(U)-poly(A)xpoly(U) triplexes with increasing concentration of berberine. Reprinted in part from [221] with permission from Adenine Press...

K. Ritz, B. S. Griffiths, V. L. Torsvik, and N. B. Hendriksen, Analysis of soil and bacterioplankton community DNA by melting profiles and reassociation kinetics, FEMS Microbiol. Lett. 749 151 (1997). 

Figure 6.6 Melting profiles for a 63.5 mm diameter extruder running an ABS resin at 60 rpm for screws with a 8.89 mm deep feed channel, 6 diameters of feed section, and a metering channel depth of 3.18 mm (C = 2.8) (a) 8 diameters of transition section for R = 0.00342, and (b) 4 diameters of transition section for R = 0.00684 [13, 14]. The pushing flights are on the right side of the section photographs...

Altinkaynak, A., Gupta, M., Spalding, M.A., and Crabtree, S.L., Numerical Investigation of the Effect of Screw Temperature on the Melting Profile in a Single-Screw Extruder, SPEANTEC Tech. Papers, 53, 430 (2007)... 

CD and UV melting profiles in the presence of the ligands were carried ont to confirm the presence of a DNA-RNA hybrid duplex in the presence of the ligands. The addition of 2.2 tiM of neomycin and ethidium bromide results in a increase of 12°C, whereas the addition of 6 resnlts in a increase of 20°C. Increased concentration of 6 caused a gradual increase in the hybrid melting temperature. As the concentration of NM was increased from 0 p.M to 3 p.M, the melting temperature of the hybrid increases from 48.9°C to 70.1°C, a 21.2°C increase overall. 

Thermal denaturation profiles were done using one of the molecular beacon structures in solution, without the alkyl chain linker attached to the 3 -thymidine residue. The fully complementary and single base pair mismatched sequence targets were investigated. The differences of Tm from the melt profiles showed that single base pair mismatches could not be discriminated from the complementary target material. Melt curves were also... 

The derivation of In Kohs from UV melting profiles depends on the extrapolation of In Kohs to a temperature different than the Tm using a value of AII°... 

In addition, comparison of data obtained by isothermal titration and melting profile methods must assume... 

The next step in the analysis involves the use of DSC to observe the virgin melting profile. If a melt endotherm is not encountered, then the scan can be continued up to roughly 340°C to check for crosslinking exotherms. 

For additional confirmational information, the sample can be program-cooled from above the melt to below the recrystallization, then reheated at a slower rate. This melting profile is most likely to compare closely with other literature data on the material--both temperature and enthalpy data--since all processing history has been erased and thermodynamic effects are predominant. The faster scanning and shock cooling of the earlier experiments tend to exaggerate kinetic differences between the materials in addition to the thermodynamic differences. 

Slow heat Obtain conditioned melting profile... 

Similarly, differences in manufacturing substantially affect the DSC melting profile (7). In figure 8 we see thermal curves of nearly identical polyester yarns. Sample one and two are identical in composition--both contain a dyability additive--but were annealed at different temperatures as can readily be seen by the position of the annealing "scars" on the thermograms. The effect of the dyability additive apparently is that it lowers and broadens the melting peak destroying its characteristic first-run, double-peak behavior. 

Non-Polymeric Materials. Waxes, soaps, greases, asphalts, oils. Complex mixtures of hydrocarbons of different molecular weight when treated to a common thermal history (such as slow program-cooling from above the melt) give complex but highly repeatable characteristic DSC melting profiles (16,17). In the absence of any other forensic evidence, these thermal profiles should be sufficiently specific and repeat-able to be definitive evidence. 

Figure 8.17 (a) Melting profiles of the amylose-glycerol monostearate complex (polymorph /) as a... 

Depending on the subsequent process steps, achieving 100% melting at the end of the plastification zone may not be mandatory. Solid particles still present after the plastification zone can be melted in subsequent zones, e. g., in the dispersion or discharge zones. Figure 4.6 illustrates a typical melting profile along a plastification zone. 

Figure 4.6 Melting profile along a plastification zone [10]...

Figure 1.1. Melting profile of New Zealand milk fat, determined by differential scanning calorimetry (MacGibbon, 1988).

The fractions obtained by supercritical CO2 extraction are different from those by dry fractionation. There are differences in the fatty acid and triacylglycerol compositions and melting profiles (Table 8.1). As the characteristics of the fractions depend on the conditions of the processes and the number of fractions obtained, any comparison between fractions should take into account not only the type of processes employed but also the specific process conditions. 

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