Thermal variations

The pressure dependence of the thermal variation of has proved to be a useful diagnostic probe to show that the formation of [HS-LS] spin pairs is not fortuitous but that they are the preferentially formed species in the dinuclear-type complexes [9]. It is shown next that application of external hydrostatic pressure can help to unravel features of this whole class of compounds, which usually can be revealed by variation of chemical composition. 

Fig. 26. Example of the data reduction process. Each data block of a multi-block sequence (in this case simple FIDs) is reduced to a single value by means of averaging over a predefined data window and plotted against the block s x-value. The resulting relaxation curve is then fitted to estimate its decay rate(s). The algorithm gives a lot of freedom in setting the data window and including/excluding any number of initial or final blocks. Notice that in the PP case shown here, the T-value decreases from left to right. This helps to minimize thermal variations of the magnet.

Figure 6.43. Thermal variation of p in the hybrid material [BEDT-TTF]3 [MnCr(C204)3]. The inset shows the low-temperature magnetoresistance with B applied perpendicular to the layers (open circles). The p values have been multiplied by a factor lO. Reprinted with permission from Coronado et al, 2000. Copyright (2000) by the Nature Publishing Group.

Mixed valency or metallic behavior has not been observed by thermal variation except Ag(DMDCNQI)2... 

Thermal variations. A solid propellant grain may be exposed to temperature extremes ranging from conditions of low temperature in the upper atmosphere, to tropical heat. The grain must not be too brittle at low temperature nor too soft at high temperature. The problem can be aggravated by case-bonding since different coefficients of expansion of the metal-case and the propellant can produce a very harmful effect. 

The thermal variation of the equilibria (Scheme 11) shown by about 100 spirophosphoranes has clarified the role played by a number of factors148,149, and the interactions among them have been abundantly discussed85,150. These factors are ... 

Phosphoranes devoid of polycyclic or spiran structures but with a PH bond can still be prone to P(III) P(V) equilibria, as shown by the study of the changes in the 31P NMR spectra brought about by the thermal variations to which were submitted the monocyclic phosphoranes159 82 (Scheme 15), which are intermediates in the synthesis of the spirophosphoranes 83 and whose structure and properties provide a good explanation for the redistribution of ligands observed in this series160,161. 

Fig. 58. Thermal variation of the magnetoelastic coupling parameter BY for the superlattices Hob/Yb) too ( ) and H03 [ /Lu 19) 30 (A), and for bulk Ho (dashed —). The dash-dotted and continuous lines are calculated (see...

Frequently, a major limitation of DS-based collection systems is that they operate at substantially subquantitative collection efficiencies at the typical sampling rates used. This situation increases the probability of error because of large thermal variations that affect diffusive transport. For these reasons, should wet denuders (vide infra) prove to be viable continuous collection devices, they may well replace DS-based systems. Their ability to more quantitatively remove gases may also spur the development of combined gas-particle analyzer systems in which, for example, the acid gases are removed by the denuder and analyzed the particles are then collected by the impactor equivalent of a wet denuder, and the acidity associated with... 

Figure 6. Thermal variation of the magnetoelastic stress parameter Br 2 of the La0 7Sr0 3C0O3 film. taken at 120 kOe.

Figure 11.3 Steady-state fluorescence polarization vs. lemperalure/viscosity ratio for Mble Zn. Data were obtained by thermal variation of temperature. Xex = 517 nm and X,-m = 600 nm.

Figure 11.4 Steady-state fluorescence anisotropy vs. temperature/viscosity ratio for tryptophan residues of cytochrome b2 core. Data are obtained by thermal variations in the range 10-36°C.

The plot of a master curve of the thermal variations of rio for various molecular weights and temperatmes (Fig. 23) shows that the expansion coefficient Uf can be considered as a constant in a wide range of temperatures. The vertical and horizontal shift factors respectively describe the mass dependence of the radius of gyration and temperature T . 

Structure and dynamics of the lowermost mantle. This region includes the D layer, which is characterized by major chemical and thermal variations. It is likely of fundamental importance to the chemical evolution of the mantle and may function as a (temporary) resting place for subducted slabs. It is also expected to influence the stability of mantle plumes (Davaille et al., 2002 Jellinek and Manga, 2002), the entrainment and residence times of chemical heterogeneity (Olson and Kincaid, 1991 Schott et al., 2002, and the thermal, chemical, and seismological characteristics compositional variations (Kellogg et al., 1999 Tackley, 2002). 

Deser C., Alexander M. A., and Timlin M. S. (1996) Upper-ocean thermal variations in the North Pacific during 1970-1991. J. aim. 9, 1840-1855. 

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