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We discuss the relaxation dynamics of glycerol-water mixtures, as studied by dielectric spectroscopy in the frequency range from 1 Hz to 250 MHz and at temperatures between 173 and 323 K. The experimental results obtained for the glycerol-rich mixtures suggest that the main dielectric relaxation process, as well as the so-called high-frequency "excess wing" (EW) and dc conductivity, follow the same temperature dependence. This result indicates that all of these processes are induced by the same molecular origin. A new phenomenological function is proposed to describe the whole dielectric spectrum in the covered frequency range, and some possible mechanisms of dielectric behaviors through the dc conductivity, the main relaxation process, and the EW are discussed.

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Between 20 and 120 MHz, the complex shear viscosity of n-tetradecane, n-pentadecane, n-hexadecane, and a n-eicosane/n-tetradecane mixture has been measured using a shear impedance spectrometer. The data are compared to ultrasonic absorption spectra of the liquids as measured between 1 MHz and 2 GHz. Relaxational behavior has been found. The extrapolated high-frequency shear viscosity ηs(∞) is distinctly smaller than the static shear viscosity ηs(0). The shear viscosity relaxation time is discussed in light of literature data of the orientational correlation time from depolarized Rayleigh scattering and also of the collision time as resulting from dielectric spectrometry. The assumption appears to be likely that the shear viscosity relaxation is due to rotational isomerizations of the chain molecules. A damped torsional oscillator model has been used to evaluate the spectra. The reasonable number of three carbon atoms per oscillator unit results. The activation energies and enthalpies are derived from measurements at different temperatures.

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In order to explain the apparent lack of renormalization of the vector j3 -decay coupling constant, Feynman and Ge 11 -Mann and Gerstein and Zeldovich have suggested the idea of a conserved vector current. 1 The proposed current is strictly conserved only in the approximation in which one neglects small deviations from isotopic spin conservation such as those originating from multiplet mass splittings and from the usual electromagnetic corrections. At present, the effect of these deviations is of considerable interest in view of the existence of an apparent small discrepancy between the beta and muon decay coupling constants. 2 It is the aim of this note to prove some theorems, valid to all orders in the strong coupling, concerning the effect of these mass splittings on the effective vector £-decay matrix element.These corrections can most easily be calculated by writing an "effective" Lagrangian which consists of the usual free and strongly interacting charge-independent boson-fermion Lagrangian, L 0 , the weak decay interaction L w , plus terms involving operators which represent the multiplet mass splittings (and which, when taken between physical states, give the experimentally observed mass differences). These mass operators may be interpreted as arising from interactions which violate charge independence, such as the electromagnetic coupling, and represent the clothing by such a field of the fermion and boson propagators. 3 The total Lagrangian may be written w ^"^./^^^H-.H-^S 8 **^"^,^^**^-,^^2 3 ' jL 2 =(6m \°, ff ±7rt(T 3 2 "^T 2)ir + ^( 6OT S° S + + 6W V s -) s ( T 3 2 "^r 2)S ' (1) where 6m ab z m t : -m b , (Sm 2 ) ab =m a 2 -m b 2 .It should be noted that in isotopic spin space, L 0 , L 19 and L 2 behave as spherical harmonics Y 0°, Y ±°, and F 2°, respectively. The weak-interaction Lagrangian will be expressed in the form L w =gj^j^9where j^ is the strangeness-conserving part of a conserved charged vector current. For the following theorems, we will assume that the part of j^ constructed from the strongly interacting fields satisfies the condition 4 SiW,where g =ee^7 lT 2. it is not necessary to specify further the form of j^ In momentum space, the most general vector matrix element for /3 decay arising from L is of the form (3) where T^ is the vertex operator F = (ay +bq + co q )r , and p f and p are the four-momenta of the neutron and proton, q=p f -p is the four-momentum transfer, and bm x and 6m 2 denote the various mass differences which appear in L x and L 2 , respectively. The quantities a, 6, and c are invariant functions of q 2 and of 6m x and 6m 2 . The first theorem states that a and c must be even functions and b an odd function of Sm^ In order to 186

A method for measuring the complex shear viscosity spectra of low viscosity liquids in the frequency range 6-120 MHz is described. Details of the resonator cell, based on a thickness shear (AT-cut) quartz resonator as central device, and of the RF bridge circuit for the compensation of the unloaded capacitance of the resonator are presented. A measuring and data-evaluation procedure that allows the careful consideration of spurious higher order vibration modes and also of intrinsic cell losses is discussed. Sources of experimental error are shown and the usability of the method is illustrated by reference measurements. The complex viscosity spectrum of n-dodecanol is displayed and its relaxation frequency is compared with the value resulting from broad-band acoustical attenuation spectrometry.