Variational Theory for Liquid Crystals with Variable Degree of Orientation

Variational Theory for Liquid Crystals with Variable Degree of Orientation PDF Author: Zdzisław Naniewicz
Publisher:
ISBN:
Category :
Languages : en
Pages : 25

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A Variational Problem for Nematic Liquid Crystals with Variable Degree of Orientation

A Variational Problem for Nematic Liquid Crystals with Variable Degree of Orientation PDF Author: Victor J. Mizel
Publisher:
ISBN:
Category : Calculus of variations
Languages : en
Pages : 24

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Abstract: "A version of Ericksen's order parameter theory of liquid crystals is studied in the case of a cylindrical container with anchoring on the curved surface only. The solutions are determined rather explicitly and the equilibrium orientation field is shown to vary between that of the Frank solution (possessing an axial disclination) and that of the disclination-free Cladis-Kleman solution as a scalar parameter in the free energy varies from 0 to [infinity]."

Variational Problems for Liquid Crystals with Variable Degree of Orientation

Variational Problems for Liquid Crystals with Variable Degree of Orientation PDF Author: Victor J. Mizel
Publisher:
ISBN:
Category : Calculus of variations
Languages : en
Pages : 5

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Abstract: "The analysis of a nematic liquid crystal, filling a bounded cylindrical container, whose free energy is a (simplified) version of Ericksen's model with variable degree of orientation, leads to a variational problem of the form F[s, [phi]] = [integral]10[k (sʹ)2 + s2 (([phi]ʹ)2 + cos2[phi]/r2)]rdr subject to s(1) = s0, [phi](1) = 0, with k a positive constant. It will be shown that a surprisingly explicit solution is obtainable. Moreover an interesting bifurcation takes place at k = 1."

Variational Theories for Liquid Crystals

Variational Theories for Liquid Crystals PDF Author: E.G. Virga
Publisher: CRC Press
ISBN: 1351405659
Category : Mathematics
Languages : en
Pages : 398

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Book Description
Essentially there are two variational theories of liquid crystals explained in this book. The theory put forward by Zocher, Oseen and Frank is classical, while that proposed by Ericksen is newer in its mathematical formulation although it has been postulated in the physical literature for the past two decades. The newer theory provides a better explanation of defects in liquid crystals, especially of those concentrated on lines and surfaces, which escape the scope of the classical theory. The book opens the way to the wealth of applications that will follow.

An Elementary Course On The Continuum Theory For Nematic Liquid Crystals

An Elementary Course On The Continuum Theory For Nematic Liquid Crystals PDF Author: Giovanni Barbero
Publisher: World Scientific Publishing Company
ISBN: 9814365637
Category : Science
Languages : en
Pages : 385

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Book Description
This book was written to enable physicists and engineers to learn, within a single course, some topics in variational calculus, theory of elasticity, molecular models, and surface properties of nematic materials. It prepares graduate students for studies that require a simple knowledge in the physics of nematic liquid crystals.With this consideration in mind, the authors have formulated the problems concerning the continuum theory of liquid crystals into a precise form. In working out the solutions, they have analyzed, systematically and naturally, the techniques and methods of variational calculus. Special attention is dedicated to the analysis of well-posed and ill-posed variational problems. The presence of sub-surface discontinuity in the nematic orientation is analyzed using different techniques. A full chapter is devoted to this aspect of the theory of elasticity of nematic media.

Dissipative Ordered Fluids

Dissipative Ordered Fluids PDF Author: André M. Sonnet
Publisher: Springer Science & Business Media
ISBN: 0387878157
Category : Science
Languages : en
Pages : 333

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Book Description
This is a book on the dissipative dynamics of ordered fluids, with a particular focus on liquid crystals. It covers a whole range of different theories, mainly concerned with nematic liquid crystals in both their chiral and nonchiral variants. The authors begin by giving a detailed account of the molecular origins of orientational order in fluids. They then go on to develop a general framework in which continuum theories for ordered fluids can be phrased. Within this unified setting, they cover both well-established classical theories and new ones with aspects that are not yet completely settled. The book treats a wide range of hydrodynamic theories for liquid crystals, from the original 1960s works by Ericksen and Leslie to new, fast-developing ideas of liquid crystal science. The final chapter is devoted to nematoacoustics and its applications. Old experiments on the propagation of ultrasound waves in nematic liquid crystals are interpreted and explained in the light of a new theory developed within the general theoretical infrastructure proposed in the body of the book. This book is intended both for graduate students and professional scholars in mathematics, physics, and engineering of advanced materials. It delivers a solid framework for liquid crystal hydrodynamics and shows the unifying concepts at the basis of the classical theories. It illustrates how these concepts can also be applied to a wide variety of modern topics. Andre M. Sonnet is in the Department of Mathematics and Statistics at the University of Strathclyde, Glasgow (Scotland) and Epifanio G. Virga is in the Department of Mathematics at the University of Pavia (Italy). They have a long history of working together in liquid crystal science and have contributed, in particular, to the theories of defects and biaxial nematics.

Liquid Crystals with Variable Degree of Orientation

Liquid Crystals with Variable Degree of Orientation PDF Author: University of Minnesota. Institute for Mathematics and Its Applications
Publisher:
ISBN:
Category :
Languages : en
Pages :

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The Static and Dynamic Continuum Theory of Liquid Crystals

The Static and Dynamic Continuum Theory of Liquid Crystals PDF Author: Iain W. Stewart
Publisher: CRC Press
ISBN: 1351989022
Category : Science
Languages : en
Pages : 377

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Book Description
Given the widespread interest in macroscopic phenomena in liquid crystals, stemming from their applications in displays and devices. The need has arisen for a rigorous yet accessible text suitable for graduate students, whatever their scientific background. This book satisfies that need. The approach taken in this text, is to introduce the basic continuum theory for nematic liquid crystals in equilibria, then it proceeds to simple application of this theory- in particular, there is a discussion of electrical and magnetic field effects which give rise to Freedericksz transitions, which are important in devices. This is followed by an account of dynamic theory and elementary viscometry of nemantics Discussions of backflow and flow-induced instabilities are also included. Smetic theory is also briefly introduced and summarised with some examples of equilibrium solutions as well as those with dynamic effects. A number of mathematical techniques, such as Cartesian tensors and some variational calculus, are presented in the appendices.

Variational Principle for Nonequilibrium Steady States Tested by Molecular Dynamics Simulation of Model Liquid Crystal Systems

Variational Principle for Nonequilibrium Steady States Tested by Molecular Dynamics Simulation of Model Liquid Crystal Systems PDF Author: Sten Sarman
Publisher:
ISBN:
Category : Electronic books
Languages : en
Pages : 0

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Book Description
The purpose of the work presented in this chapter is to test a recently proven variational principle according to which the irreversible energy dissipation rate is minimal in the linear regime of a nonequilibrium steady state. This test is carried out by performing molecular dynamics simulations of liquid crystals subject to velocity gradients and temperature gradients. Since the energy dissipation rate varies with the orientation of the director of the liquid crystal relative to these gradients and is minimal at certain orientations, this is a stringent test of the variational principle. More particularly, a nematic liquid crystal model based on the Gay-Berne potential, which can be regarded as a Lennard-Jones fluid generalized to elliptical molecular cores, is studied under planar Couette flow, planar elongational flow, and under a temperature gradient. It is found that the director of a nematic liquid crystal consisting of rod-like molecules lies in the vorticity plane at an angle of about 20° to the stream lines in the planar Couette flow. In the elongational flow, it is parallel to the elongation direction, and it is perpendicular to the temperature gradient in a heat flow. These orientations are the ones where the irreversible energy dissipation rate is minimal, so that the variational principle is fulfilled in these three cases.

Microwaves, Millimeter Wave and Terahertz Liquid Crystals

Microwaves, Millimeter Wave and Terahertz Liquid Crystals PDF Author: Anyong Qing
Publisher: Springer Nature
ISBN: 9819989132
Category :
Languages : en
Pages : 283

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