Experimental Study and Modeling of Nonlinear Scattering in Polymer Dispersed Liquid Crystals

1999 ◽  
Vol 597 ◽  
Author(s):  
M. Pacilli ◽  
P. Sebbah ◽  
P. Sixou ◽  
C. Vanneste ◽  
H. Guillard
Keyword(s):  
Experimental Study ◽  
Liquid Crystal ◽  
Composite Materials ◽  
Time Domain ◽  
Nonlinear Scattering ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed ◽  
Linear And Nonlinear ◽  
The Time Domain ◽  
Nonlinear Light Scattering

AbstractWe investigate the optical limiting capabilities of composite materials consisting of nematic liquid crystal inclusions within a polymer matrix in the millisecond and CW regime. Preparation of the composite has been optimized to decrease the operation voltage. Clear evidence of light induced reorientation is observed. A numerical model is proposed to describe multiple linear and nonlinear light scattering in the time domain in this medium. Numerical simulations are compared to experiment and confirm promising limiting characteristics of such materials.

Experimental Study on the Performance of Constrained Damped Rail Vibration Reduction

2011 ◽  
Vol 42 (10) ◽  
pp. 9-14
Author(s):  
L.Y. Liu ◽  
J.Y. Li ◽  
X.J. Yin
Keyword(s):  
Experimental Study ◽  
Time Domain ◽  
Vibration Amplitude ◽  
Impact Load ◽  
Vibration Reduction ◽  
Time Domain Analysis ◽  
Experimental Basis ◽  
Vibration Acceleration ◽  
The Time Domain ◽  
Vibration Performance

To study the vibration reduction performance of damped rail, we take the standard rail and labyrinth constrained damped rail as the study target. By testing the vibration performance of both standard rail and labyrinth constrained damped rail in an anechoic room, we use the time-domain analysis to study the vibration changes with time passing. The results showed that: the labyrinth constrained damped rail vibration can effectively reduce the vibration amplitude and duration. Under the radial impact load, compared to the standard rail, vibration acceleration attenuation of the labyrinth constrained damped rail is 5% −19%, time of vibration and attenuation greater than 94%; under the axial impact load, compared to the standard rail, vibration acceleration attenuation of the labyrinth constrained damped rail is 9% −21%, time of vibration and attenuation greater than 92%. The results have provided an experimental basis for the design of new constrained damped rail.

Experimental study of UWB antenna in the time domain

2005 ◽  
Vol 47 (6) ◽  
pp. 554-558 ◽  
Author(s):  
Sung S. Lee ◽  
Sang S. Choi ◽  
Jong K. Park ◽  
Kyoung R. Cho
Keyword(s):  
Experimental Study ◽  
Time Domain ◽  
Uwb Antenna ◽  
The Time Domain

scholarly journals Electrical properties of a liquid crystal dispersed in an electrospun cellulose acetate network

2018 ◽  
Vol 9 ◽  
pp. 155-163 ◽  
Author(s):  
Doina Manaila Maximean ◽  
Octavian Danila ◽  
Pedro L Almeida ◽  
Constantin Paul Ganea
Keyword(s):  
Liquid Crystal ◽  
Cellulose Acetate ◽  
Indium Tin Oxide ◽  
Electric Energy ◽  
Equivalent Model ◽  
Electrical Characteristics ◽  
Impedance Measurements ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed ◽  
Crystal Composite

Electro-optical devices that work in a similar fashion as PDLCs (polymer-dispersed liquid crystals), produced from cellulose acetate (CA) electrospun fibers deposited onto indium tin oxide coated glass and a nematic liquid crystal (E7), were studied. CA and the CA/liquid crystal composite were characterized by multiple investigation techniques, such as polarized optical microscopy, dielectric spectroscopy and impedance measurements. Dielectric constant and electric energy loss were studied as a function of frequency and temperature. The activation energy was evaluated and the relaxation time was obtained by fitting the spectra of the dielectric loss with the Havriliak–Negami functions. To determine the electrical characteristics of the studied samples, impedance measurements results were treated using the Cole–Cole diagram and the three-element equivalent model.

scholarly journals Computation of Nonlinear Hydrodynamic Loads on Floating Wind Turbines Using Fluid-Impulse Theory

2015 ◽  
Author(s):  
Godine Kok Yan Chan ◽  
Paul D. Sclavounos ◽  
Jason Jonkman ◽  
Gregory Hayman
Keyword(s):  
Free Surface ◽  
Green Function ◽  
Wind Turbines ◽  
Time Domain ◽  
The Body ◽  
Nonlinear Loads ◽  
Frequency Wave ◽  
Linear And Nonlinear ◽  
The Time Domain ◽  
Nonlinear Free Surface

A hydrodynamics computer module was developed to evaluate the linear and nonlinear loads on floating wind turbines using a new fluid-impulse formulation for coupling with the FAST program. The new formulation allows linear and nonlinear loads on floating bodies to be computed in the time domain. It also avoids the computationally intensive evaluation of temporal and spatial gradients of the velocity potential in the Bernoulli equation and the discretization of the nonlinear free surface. The new hydrodynamics module computes linear and nonlinear loads — including hydrostatic, Froude-Krylov, radiation and diffraction, as well as nonlinear effects known to cause ringing, springing, and slow-drift loads — directly in the time domain. The time-domain Green function is used to solve the linear and nonlinear free-surface problems and efficient methods are derived for its computation. The body instantaneous wetted surface is approximated by a panel mesh and the discretization of the free surface is circumvented by using the Green function. The evaluation of the nonlinear loads is based on explicit expressions derived by the fluid-impulse theory, which can be computed efficiently. Computations are presented of the linear and nonlinear loads on the MIT/NREL tension-leg platform. Comparisons were carried out with frequency-domain linear and second-order methods. Emphasis was placed on modeling accuracy of the magnitude of nonlinear low- and high-frequency wave loads in a sea state. Although fluid-impulse theory is applied to floating wind turbines in this paper, the theory is applicable to other offshore platforms as well.

Holographic Polymer Dispersed Liquid Crystals: Effect of Partial Matrix Fluorination on Electro-Optical and Morphological Properties

2001 ◽  
Vol 709 ◽  
Author(s):  
Michael D. Schulte ◽  
Stephen J. Clarson ◽  
Lalgudi V. Natarajan ◽  
C. Allan Guymon ◽  
Timothy J. Bunning
Keyword(s):  
Liquid Crystal ◽  
Low Voltage ◽  
Morphological Properties ◽  
Acrylate Monomer ◽  
Polymer Dispersed Liquid Crystal ◽  
Morphological Studies ◽  
Polymer Dispersed Liquid Crystals ◽  
The Matrix ◽  
Polymer Dispersed ◽  
Morphological Differences

ABSTRACTHolographic polymer dispersed liquid crystal (H-PDLC) films with partially fluorinated matrices were investigated. Electro-optical and morphological studies revealed that fluorinated composites were substantially different from non-fluorinated analogues. The addition of a fluorinated monofunctional acrylate monomer to a pentaacrylate-derived polymer matrix resulted in improved diffraction efficiency. These findings suggest that the partial fluorination of the host polymer decreases the compatibility between the matrix and liquid crystal phase. Morphological differences between fluorinated films and non-fluorinated control specimens were verified using low-voltage, high-resolution scanning electron microscopy (LVHRSEM).

Side-chain liquid-crystal epoxy polymer binders for polymer-dispersed liquid crystals

1992 ◽  
Vol 25 (1) ◽  
pp. 133-137 ◽  
Author(s):  
Liang Chy Chien ◽  
C. Lin ◽  
David S. Fredley ◽  
James W. McCargar
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Epoxy Polymer ◽  
Side Chain ◽  
Polymer Binders ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed
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