Order Parameter Measurements Of Dichroic Dyes Dissolved In Smectic Liquid Crystals That Tilt Without Layer Contraction

Measurements of the orientational order parameter of dissolved dichroic dyes are reported for two smectic-A liquid crystals that tilt in the presence of an in-plane electric field without any decrease in the layer spacing. The dye order parameter is determined by measuring the anisotropic absorption of linearly polarized light. Different dyes are used and measurements are also performed on a smectic liquid crystal that tilts with the expected layer contraction to check how closely the measurements reflect the order parameter of the liquid crystal. The variation of the dye order parameter with electric field is in accordance with the recently proposed model of azimuthal disorder of the tilt angle direction, but the surprising finding is that the local dye orientational order parameter is significantly lower than for the smectic liquid crystal that tilts with the expected layer contraction. This suggests that another mechanism might be contributing significantly to the smectic order, one possibility of which is the tendency for different parts of these siloxane-containing molecules to segregate within each layer. Another possible explanation is that the azimuthal disorder is due to a modulated phase with a high enough density of defects to decrease the value of the local order parameter

Monte Carlo Simulation of Smectic Liquid Crystals and the Electroclinic Effect: the Role of the Molecular Shape

Using Monte Carlo simulation methods, we explore the role of molecular shape in the phase behavior of liquid crystals and the electroclinic effect. We study a "bent-rod" mesogen shaped like the letter Z, composed of seven soft spheres bonded rigidly together with no intra-molecular degrees of freedom. For strongly angled molecules, we find that steric repulsion alone provides the driving force for a smectic-C phase, even without intermolecular dipole-dipole interactions. For weakly angled (nearly rod-like) molecules, we find a stable smectic-A (SmA) phase and a strong electroclinic effect with a saturation tilt angle of about 19 degrees. In the SmA phase we find evidence of vortex-like point defects. We also observe a field-induced nematic-smectic phase transition.Comment: 10 pages, including 10 postscript figures, uses REVTeX 3.0 and epsf.st

Some comments on the determination of enthalpies of liquid crystalline transitions by differential scanning calorimetry

We demonstrate a simple practical method of improving the accuracy of determination of enthalpies of liquid crystalline transitions by differential scanning calorimetry. The method involves measurements at different heating rates and interpolation to zero heating rate

Pressure dependence of the pitch of cholesteryl oleyl carbonate

Pollmann and Stegemeyer have shown that the pitch of a cholesteric mixture of cholesteryl oleyl carbonate (COC) and cholesteryl chloride (CC) increases very rapidly with pressure, approaching infinity at a critical pressure pc whose value depends on the composition of the mixture. At first sight, this result is surprising as one would anticipate only slight "red shift" when the sample is compressed. The aim of this note is to show that the observed critical divergence is in fact to be expected from theoretical considerations

Near neighbour correlations and the dielectric properties of liquid crystals

It is demonstrated experimentally that there can be a reversal of the sign of the dielectric anisotropy (Δε) with decreasing temperature in a nematic. The results are explainable in terms of the Maier-Meier mean field theory and indicate that the occurrence of the smectic phase and the consequent dipole correlations within the smectic layers is not a necessary condition for the sign reversal of Δε

Pengaruh Kebijakan Deviden Dan Corporate Social Responsibility (CSR) Terhadap Return Saham Pada Perusahaan Lq 45 Periode 2015

Return stock are influenced by various variable of them are its dividend policy and corporate social responsibility (CSR). This study aims to to look at the and test variable influence its dividend policy and CSR, to return stock to companies that a listing on LQ 45 2015. This research used a quantitative approach that is associative causality to technique purposive sampling and analysis of multiple regression. The result of research proven that variable its dividend policy and CSR have had a positive impact significantly to return stock. Suggestions for next researchers is to distinguish sample based on type of industryReturn saham dipengaruhi oleh berbagai variabel diantaranya adalah kebijakan deviden dan corporate social responsibility (CSR). Penelitian ini bertujuan untuk melihat kondisi dan menguji pengaruh variabel kebijakan deviden dan CSR, terhadap return saham pada Perusahaan yang listing di LQ 45 tahun 2015. Penelitian ini menggunakan pendekatan kuantitatif yang bersifat asosiatif kausalitas dengan teknik purposive sampling dan analisis regresi berganda. Hasil dari penelitian terbukti bahwa variabel kebijakan deviden dan CSR berpengaruh positif signifikan terhadap return saham. Saran untuk peneliti selanjutnya adalah agar membedakan sampel berdasarkan jenis industri

Policy Implementation Planning Of Health Promotion In Universitas Airlangga Hospital

Hospital is a health institution that provide comprehensive health service which is including aspects of promote, preventive, curative, and also rehabilitative. To achieve the goal, the government has been releasedRegulation of the Minister of Health Number 4 Year 2012 about Technical Instructions of Health Promotion in Hospital. In means by all hospitals must implement health promotion in their institution. Based on the earliersurvey, the implementation of the regulation of Health Promotion Hospital (PKRS) in the Universitas Airlangga Hospital was considered less than optimal. The purpose of this research was to analyze the planning factor ofHPH policy implementation. The number of respondents are seven which chosen by purposive sampling. This research was conducted by deep interview and observation method. The results showed that the planning ofPKRS unit has not been prepared as it should be as set out in the regulations. There is neither strategic planning nor operational planning. Unit PKRS not yet have a systematic and structured organization. Qualification ofhuman resources in general are already qualified, but need additional quantity. PKRS unit does not have special health worker health promotion