Hidejiro Tanaka

The Torsional Quartz Crystal Method for Viscoelastic Measurements of Dilute Polymer Solutions

Masons torsional crystal method was improved for measuring the viscoelasticity of dilute polymer solutions. Resonant periods and conductances of the torsional crystals in liquids were measured by means of a universal electronic counter with a period multiplier unit up to 105 periods and a phase-sensitive detector, respectively. Three quartz crystals, one of which had a polished surface, were used to calibrate the constants of the crystals in Newtonian liquids at the frequencies of the fundamental and the third harmonic at a temperature of 30.0°C. Complex intrinsic rigidities of monodisperse poly-α-methyl styrenes in cyclohexane solutions were measured at 39.0°C.

Viscoelasticity of moderately concentrated polymer solutions

The complex modulus is phenomenologically calculated with the relaxation spectrum containing both the wedge region and the box region, in order to consider the concentration dependence and molecula...

Coherence and Fluctuations of the Electromagnetic Field

The first-order coherence condition is derived in terms of correlations between different field modes. Fluctuations of the electromagnetic field are shown to play an important role in the concept of coherence. The coherent states are shown to be the only ones which reduce these fluctuations to their minimum value. For the case of a field in which the different field modes are independent, the degree of first-order coherence and the visibility of interference fringes are shown to be specified completely by these fluctuations. Measurements of this visibility yield information on the statistical properties of radiation fields. For squeezed states, this visibility is expressed as a function of squeezed parameters. Moreover, the difference between generalized coherent states becomes manifest in measurements of this visibility.