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Hertz structure

Figure 15. Complex plane impedance plots for polypyrrole at (A) 0.1, (B) -0.1, (C) -0.2, (D) -0.3, and (E) -0.4 V vs. Ag/AgCl in NaCl04(aq). The circled points are for a bare Pt electrode. Frequencies of selected points are marked in hertz. (Reprinted from X. Ren and P. O. Pickup, Impedance measurements of ionic conductivity as a probe of structure in electrochemi-cally deposited polypyrrole films, / Electmanal Chem. 396, 359-364, 1995, with kind permission from Elsevier Sciences S.A.)... Figure 15. Complex plane impedance plots for polypyrrole at (A) 0.1, (B) -0.1, (C) -0.2, (D) -0.3, and (E) -0.4 V vs. Ag/AgCl in NaCl04(aq). The circled points are for a bare Pt electrode. Frequencies of selected points are marked in hertz. (Reprinted from X. Ren and P. O. Pickup, Impedance measurements of ionic conductivity as a probe of structure in electrochemi-cally deposited polypyrrole films, / Electmanal Chem. 396, 359-364, 1995, with kind permission from Elsevier Sciences S.A.)...
In homonuclear-shift-correlated experiments, the Ft domain corresponds to the nucleus under observation in heteronuclear-shift-correlated experiments. Ft relates to the unobserved or decoupled nucleus. It is therefore necessary to set the spectral width SW, after considering the ID spectrum of the nucleus corresponding to the Ft domain. In 2D /-resolved spectra, the value of SW depends on the magnitude of the coupling constants and the type of experiment. In both homonuclear and heteronuclear experiments, the size of the largest multiplet structure, in hertz, determines... [Pg.158]

Hertz, H.G., Chap VII.2 of Structure of Water and Aqueous Solutions (ed. W.A.P. Luck) Verlag Chemie Physik Verlag (1974). [Pg.158]

It was first obtained by Hertz [67] who proposed its use as an explosive, since (in the authors opinion) it develops greater explosive strength that PETN but is less sensitive. Tollens and Apel [68] have prepared the initial alcohol (m.p. 156°C) resulting from the reaction of acetone with formaldehyde in the presence of calcium hydroxide, to which they attributed the structure of an enneaheptitol anhydride without, however, determining which hydroxyl groups were dehydrated. [Pg.199]

Most spectroscopic techniques (e.g. infrared and Raman spectroscopy) provide a snapshot view of the structure of a liquid because the timescale of the techniques is of the order of lattice vibration. However, NMR can probe much lower frequency motions, motions which are important in the glass transition and the viscosity of a silicate liquid. In addition, the timescale of the NMR experiment may be varied (by changing the magnetic field, or the type of experiment, T or T fJ, or observing quadrupolar effects) from a few hertz to several hundred megahertz. [Pg.309]

An experimental basis has been suggested by Hepler (1969) for the classification of solutes for structure formers, (32F /9r2)>0 and for structure breakers <0. More recently, Ben-Naim (1975) has demonstrated how the difference between solubilities of a solute in D20 and H20 can also be used in a similar fashion. Ben-Naim (1972a, 1973a) has also shown from theoretical arguments how it is possible for a solute to stimulate H-bond formation, i.e. structure-formation, between water molecules. However, the effect of a structure-former on water is not straightforward, the induced structure being apparently different from that of pure water at a lower temperature (Hertz, 1970). [Pg.239]

Nevertheless, we must guard against too ready an acceptance of static structural models for aqueous solutions. Just as in the case of water itself, a complete picture of these solutions requires information concerning the dynamic parameters describing the motions of solute and solvent molecules (Goldammer and Hertz, 1970 Hertz, 1964 1970). Hertz in particular has emphasized the importance of dynamic models (Franks, 1973b). [Pg.246]

While the clathrate model is attractive, it is not correct to assume that the water is organized in some long-lived structure the observation that the self-diffusion coefficient for co-sphere water is larger than that for the solute rules this out. However, the rotational correlation time is shorter for ethanol and t-butyl alcohol in water (in the clathrate cage ) than in the pure liquid (Goldammer and Hertz, 1970 Goldammer and Zeidler, 1969). Nmr experiments show that in water the solvent dipole moments point away from the apolar groups (Hertz and Radle, 1973). [Pg.253]

The simple model (Fig. 20) can be criticized because it cannot readily be quantified. However, it does account for a wide range of properties, such as the tendency for the partial molar heat capacity and the viscosity -coefficient to become more negative with increase in ion size (Fortier et al., 1974a McDowell and Vincent, 1974 Kay, 1968 1973). Kay has collated conductance and viscosity data and shown how these lead to a classification of ionic properties (Fig. 21). The effects of added salts on the self-diffusion of ions is consistent with the Frank-Wen structural model (Hertz et al., 1974). It is noteworthy that in D20, which is argued to be more... [Pg.265]

Multiplets in NMR. The second effect yields a spin-spin coupling constant / (usually quoted in hertz), which it generates a multiplet structure that is due to nuclear spin-nuclear spin interactions between equivalent or inequivalent protons (in H1 NMR). The spin interaction is actually a tensor quantity due to... [Pg.720]


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See also in sourсe #XX -- [ Pg.1004 , Pg.1005 ]

See also in sourсe #XX -- [ Pg.1004 , Pg.1005 ]




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