AC-Calorimetry and Dielectric Spectroscopy on Anisotropic Liquid Crystal and Aerosil Dispersions

This thesis presents an experimental study of the influence of an external field and alignment upon a colloid of a liquid crystal (octycyanobiphenyl denoted 8CB) and a silica gel of aerosil nano-particles. The first techniques used was an AC-calorimetry (alternating current heating) and the systems under investigation were firstly put under the influence of a magnetic field at John Hopkins University in Baltimore by professor Leheny\u27s group. The experiments revealed changes in transition temperatures, nematic range and critical coefficient that could account for what we called a \u27memory\u27 of the above mentioned structures. The second technique, dielectric spectroscopy, was applied to the same very densities of mixture s mentioned in the first paragraph. The samples were applied in one procedure an increasingly higher alternating electric field. An overall increase of the capacitance of the sample was measured. The second experiment was to reproduce the application of the magnetic field from the AC-calorimetry experiment now with an electric field. In dielectric spectroscopy case, an increase in transition temperature after the application of the procedure was revealed

Spinors in the hyperbolic algebra

The three-dimensional universal complex Clifford algebra is used to represent relativistic vectors in terms of paravectors. In analogy to the Hestenes spacetime approach spinors are introduced in an algebraic form. This removes the dependance on an explicit matrix representation of the algebra.Comment: 9 pages Latex2

Lithium: a key to the genetics of bipolar disorder

Since the 1950s, lithium salts have been the main line of treatment for bipolar disorder (BD), both as a prophylactic and as an episodic treatment agent. Like many psychiatric conditions, BD is genetically and phenotypically heterogeneous, but evidence suggests that individuals who respond well to lithium treatment have more homogeneous clinical and molecular profiles. Response to lithium seems to cluster in families and can be used as a predictor for recurrence of BD symptoms. While molecular studies have provided important information about possible genes involved in BD predisposition or in lithium response, neither the mechanism of action of this drug nor the genetic profile of bipolar disorder is, as yet, completely understood

Analysis of the Effects of Curvature on the Solutions of Shallow Water Equations

The most used form of the Shallow Water Equations doesn't take into account the variation of the curvature of the base flow surface. In this paper, we compare the theoretical and numerical solutions of the standard model and with the solutions of an extended model and for a large class of base flow surfaces. We find that the solution of the standard model is still a good approximation for the extended model for many real life applications