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

Response of the Asian Summer Monsoons to a High-latitude Thermal Forcing: Mechanisms and Nonlinearities

This study investigates mechanisms and nonlinearities in the response of the Asian Summer Monsoons (ASM) to high-latitude thermal forcings of different amplitudes. Using a suite of runs carried out with an intermediate-complexity atmospheric general circulation model, we find that the imposed forcings produce a strong precipitation response over the eastern ASM but a rather weak response over the southern ASM. The forcing also causes a precipitation dipole with wet conditions over the eastern Tibetan Plateau (TP) and dry conditions over the Bay of Bengal (BoB) and southeast Asia. A moderate increase of precipitation along the southern margin of the TP is also produced. Simulations designed to isolate the causal mechanisms show that thermodynamic interactions involving the tropical surface oceans are far less important than the water-vapour feedback for the transmission of information from the high-latitudes to the ASM. Additionally, we assess the nonlinearity of the ASM precipitation response to the forcing amplitude using a novel application of the empirical orthogonal function method. The response can be decomposed in two overlapping patterns. The first pattern represents a precipitation dipole with wet conditions over the eastern TP and dry conditions over BoB, which linearly increases with forcing amplitude becoming quasi-stationary for large forcing amplitudes (i.e. amplitudes leading to Arctic temperature anomalies larger than 10 degrees C). The second pattern is associated with increased precipitation over the southeastern TP and is nonlinearly dependent on forcing, being most important for intermediate forcing amplitudes (i.e. amplitudes leading to Arctic temperature anomalies between 5 and 10 degrees C)

Islamic Market Mechanism According to Abu Yusuf and His Willingness to The Panorama Market Mechanism of Bengkulu City

The Islamic Market Mechanism According to Abu Yusuf and its Relevance to the Panorama Market in Bengkulu City, the research method used in this study is library research, the research approach, and data collection techniques used are qualitative data (qualitative research) and documentation. The analysis technique used is inductive deductive, and descriptive. Based on the specific fission and style that applies to the character, the inductive method is better understood than general conclusions are drawn. The deductive method is collecting, analyzing, and researching general data to draw specific conclusions. The descriptive method is the regular description of all conceptions of the characters regarding the topic or research discussion. From the results of this study, it was found that the market and price mechanism according to Abu Yusuf is a practice that provides general problems (al-mashlahah al'-ammah), both from the producer (seller) and the buyer, while the relevance of the Islamic Market mechanism at the Panorama Market in Bengkulu City irrelevant and can not be fully implemented as the Islamic market mechanism according to the thought of Abu Yusuf

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

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

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

A Revise On Ambler Stream Behavior Beside Pavement

We can find mixed traffic conditions, which mean that the flow routes include all kinds of vehicles like bicycles, bikes, cars, etc. During peak hours, the influx of NMVs is high. The presence of NMV in the transportation system affects traffic characteristics such as speed, volume and river flow. In order to plan a route, it is essential to understand how to travel. For mixed traffic conditions, the river behaviour is difficult to understand. In this article, an attempt is made to study the behavioural characteristics of NMVs in river mixtures. The entire project consists of two parts. The first is the sample section and the last is the sample section test. The first part of the study includes studying the basic foundations and finding potentials of the group and collateral settlement of the group to obtain the information obtained from the various parts of Guntur. The change in NMV ratio was viewed as a problem present in the model such as velocity, density, and flow. In a background study, it was observed that in one sector of transport traffic, the large number of NMVs occupying the left side and MVs occupying most of the area due to our Indian transport behaviour are left-handed and easy for the MV to pass slowly. In the case of two lanes intersecting, the traffic limit is available in the middle section but the lower part is in the left and right parts in light of the fact that vehicles are in fill in that

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