Electric‐Field‐Induced Cholesteric–Nematic Phase Change in Liquid Crystals

1969 ◽  
Vol 51 (3) ◽  
pp. 1258-1260 ◽  
Author(s):  
George H. Heilmeier ◽  
Joel E. Goldmacher
Keyword(s):  
Liquid Crystals ◽  
Electric Field ◽  
Phase Change ◽  
Nematic Phase

Achiral H-shaped liquid crystals exhibiting an electric-field-induced chiral nematic phase

2019 ◽  
Vol 7 (23) ◽  
pp. 6905-6913 ◽  
Author(s):  
Shoumi Sayama ◽  
Atsushi Yoshizawa
Keyword(s):  
Liquid Crystals ◽  
Electric Field ◽  
Nematic Phase ◽  
Nematic Liquid Crystals ◽  
Chiral Nematic

Newly designed achiral H-shaped nematic liquid crystals exhibit an electric-field-induced chiral nematic phase showing domains with opposite helical senses.

Electric-Field-Induced Phase Change in Cholesteric Liquid Crystals

1968 ◽  
Vol 20 (19) ◽  
pp. 1024-1025 ◽  
Author(s):  
J. J. Wysocki ◽  
J. Adams ◽  
W. Haas
Keyword(s):  
Liquid Crystals ◽  
Electric Field ◽  
Phase Change ◽  
Cholesteric Liquid Crystals

Electric-Field Induced Phase Change in Cholesteric Liquid Crystals

1969 ◽  
Vol 8 (1) ◽  
pp. 471-487 ◽  
Author(s):  
J. Wysocki ◽  
J. Adams ◽  
W. Haas
Keyword(s):  
Liquid Crystals ◽  
Electric Field ◽  
Phase Change ◽  
Cholesteric Liquid Crystals

scholarly journals Liquid Crystals as Phase Change Materials for Thermal Stabilization

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Eva Klemenčič ◽  
Mitja Slavinec
Keyword(s):  
Liquid Crystals ◽  
Heat Source ◽  
Electric Field ◽  
Phase Change ◽  
Phase Change Materials ◽  
Thermal Stabilization ◽  
Phase Change Temperature ◽  
Thermotropic Liquid Crystals ◽  
Key Factor ◽  
Change Temperature

Thermal stabilization exploiting phase change materials (PCMs) is studied theoretically and numerically. Using the heat source approach in numerical simulations, we focus on phase change temperature as a key factor in improving thermal stabilization. Our focus is to analyze possible mechanisms to tune the phase change temperature. We use thermotropic liquid crystals (LCs) as PCMs in a demonstrative system. Using the Landau-de Gennes mesoscopic approach, we show that an external electric field or appropriate nanoparticles (NPs) dispersed in LCs can be exploited to manipulate the phase change temperature.

Torsional Shear Flow of Nematic and Cholesteric Liquid Crystals. Part I: Nematic Phase

1979 ◽  
Vol 34 (7) ◽  
pp. 818-831 ◽  
Author(s):  
J. Wahl
Keyword(s):  
Liquid Crystals ◽  
Shear Flow ◽  
Electric Field ◽  
Simple Shear ◽  
Nematic Phase ◽  
Simple Shear Flow ◽  
Cholesteric Liquid Crystals ◽  
Material Constants ◽  
Torsional Shear

The simple shear flow of a homeotropic nematic layer in an electric field normal to the layer is studied theoretically and experimentally. Several material constants of MBBA are determined as a function of temperature.

scholarly journals Identification of the mechanisms responsible for anomalies in the tropical lower thermosphere/ionosphere caused by the January 2009 sudden stratospheric warming

2019 ◽  
Vol 9 ◽  
pp. A39 ◽  
Author(s):  
Maxim V. Klimenko ◽  
Vladimir V. Klimenko ◽  
Fedor S. Bessarab ◽  
Timofei V. Sukhodolov ◽  
Pavel A. Vasilev ◽  
...  
Keyword(s):  
Electric Field ◽  
Phase Change ◽  
Lower Thermosphere ◽  
Upper Atmosphere ◽  
Electron Content ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Low Latitude ◽  
Plasma Drift ◽  
Solar Tide

We apply the Entire Atmosphere GLobal (EAGLE) model to investigate the upper atmosphere response to the January 2009 sudden stratospheric warming (SSW) event. The model successfully reproduces neutral temperature and total electron content (TEC) observations. Using both model and observational data, we identify a cooling in the tropical lower thermosphere caused by the SSW. This cooling affects the zonal electric field close to the equator, leading to an enhanced vertical plasma drift. We demonstrate that along with a SSW-related wind disturbance, which is the main source to form a dynamo electric field in the ionosphere, perturbations of the ionospheric conductivity also make a significant contribution to the formation of the electric field response to SSW. The post-sunset TEC enhancement and pre-sunrise electron content reduction are revealed as a response to the 2009 SSW. We show that at post-sunset hours the SSW affects low-latitude TEC via a disturbance of the meridional electric field. We also show that the phase change of the semidiurnal migrating solar tide (SW2) in the neutral wind caused by the 2009 SSW at the altitude of the dynamo electric field generation has a crucial importance for the SW2 phase change in the zonal electric field. Such changes lead to the appearance of anomalous diurnal variability of the equatorial electromagnetic plasma drift and subsequent low-latitudinal TEC disturbances in agreement with available observations. Plain Language Summary – Entire Atmosphere GLobal model (EAGLE) interactively calculates the troposphere, stratosphere, mesosphere, thermosphere, and plasmasphere–ionosphere system states and their response to various natural and anthropogenic forcing. In this paper, we study the upper atmosphere response to the major sudden stratospheric warming that occurred in January 2009. Our results agree well with the observed evolution of the neutral temperature in the upper atmosphere and with low-latitude ionospheric disturbances over America. For the first time, we identify an SSW-related cooling in the tropical lower thermosphere that, in turn, could provide additional information for understanding the mechanisms for the generation of electric field disturbances observed at low latitudes. We show that the SSW-related vertical electromagnetic drift due to electric field disturbances is a key mechanism for interpretation of an observed anomalous diurnal development of the equatorial ionization anomaly during the 2009 SSW event. We demonstrate that the link between thermospheric winds and the ionospheric dynamo electric field during the SSW is attained through the modulation of the semidiurnal migrating solar tide.

scholarly journals Electrically driven formation and dynamics of Pac-Man solitons in smectic A liquid crystals

2021 ◽  
Author(s):  
Yuan Shen ◽  
Ingo Dierking
Keyword(s):  
Liquid Crystals ◽  
Electric Field ◽  
Spatiotemporal Chaos ◽  
Practical Applications ◽  
Smectic A ◽  
Fundamental Science ◽  
Smectic A Liquid Crystals

Electric field driven instabilities of liquid crystals, such as electro-convections, spatiotemporal chaos, backflows, and solitons are of great importance for both fundamental science and practical applications. Here we demonstrate that...

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