Supercritical Conversion Of The 3rd Blue Phase To The Isotropic-Phase In A Highly Chiral Liquid-Crystal

The results of two independent experiments in the vicinity of the “transition” from the third blue phase ( BPIII) to isotropic phase ( I) are reported for a highly chiral liquid crystal. Heat capacity measurements using a high-resolution calorimeter and dynamic light-scattering measurements using circularly polarized light have been performed. The data show a continuous evolution of BPIII into I with no critical fluctuations. This is strong evidence that the BPIII-I transition in this compound is supercritical, indicating that the BPIII and I phases possess the same macroscopic symmetry

Autocorrelation Of Electrical Noise - An Undergraduate Experiment

An undergraduate experiment is described in which the output of a noise generator is sampled by a computer equipped with a data acquisition board, after which the autocorrelation function is calculated. If the output of the noise generator passes through a low‐pass filter before it is sampled by the computer, then the autocorrelation function is a decreasing exponential function with a decay constant equal to the time constant of the low‐pass filter. The theory necessary to understand this phenomenon involves basic concepts in electrical noise, the analysis of linear systems, and Fourier transforms. In this paper the theoretical background for the experiment is discussed, typical data are presented, and a full analysis of these data is described

Evidence For A Supercritical ‘Transition’ To The Isotropic Phase In A Highly Chiral Liquid Crystal

The results of two independent experiments in the vicinity of the “transition” from the third blue phase (BPIII) to isotropic phase (I) are reported for a highly chiral liquid crystal. Heat capacity measurements using a high-resolution calorimeter and dynamic light-scattering measurements using circularly polarized light have been performed. The data show a continuous evolution of BPIII into I with no critical fluctuations. This is strong evidence that the BPIII-I transition in this compound is supercritical, indicating that the BPIII and I phases possess the same macroscopic symmetry