The conformation and effective polarizability of mesogenic

1984 ◽  
Vol 24 (5) ◽  
pp. 740-745 ◽  
Author(s):  
E. M. Aver'yanov ◽  
V. Ya. Zyryanov ◽  
V. A. Zhuikov
Keyword(s):  
Effective Polarizability

scholarly journals Active, Reactive, and Apparent Power in Dielectrophoresis: Force Corrections from the Capacitive Charging Work on Suspensions Described by Maxwell-Wagner’s Mixing Equation

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 738
Author(s):  
Jan Gimsa
Keyword(s):  
Volume Fraction ◽  
Inhomogeneous Field ◽  
Effective Polarizability ◽  
Polarization Mechanism ◽  
Free Transition ◽  
Lossy Media ◽  
New Perspective ◽  
A Chain ◽  
A Charge ◽  
Induced Changes

A new expression for the dielectrophoresis (DEP) force is derived from the electrical work in a charge-cycle model that allows the field-free transition of a single object between the centers of two adjacent cubic volumes in an inhomogeneous field. The charging work for the capacities of the volumes is calculated in the absence and in the presence of the object using the external permittivity and Maxwell-Wagner’s mixing equation, respectively. The model provides additional terms for the Clausius-Mossotti factor, which vanish for the mathematical boundary transition toward zero volume fraction, but which can be interesting for narrow microfluidic systems. The comparison with the classical solution provides a new perspective on the notorious problem of electrostatic modeling of AC electrokinetic effects in lossy media and gives insight into the relationships between active, reactive, and apparent power in DEP force generation. DEP moves more highly polarizable media to locations with a higher field, making a DEP-related increase in the overall polarizability of suspensions intuitive. Calculations of the passage of single objects through a chain of cubic volumes show increased overall effective polarizability in the system for both positive and negative DEP. Therefore, it is proposed that DEP be considered a conditioned polarization mechanism, even if it is slow with respect to the field oscillation. The DEP-induced changes in permittivity and conductivity describe the increase in the overall energy dissipation in the DEP systems consistent with the law of maximum entropy production. Thermodynamics can help explain DEP accumulation of small objects below the limits of Brownian motion.

scholarly journals Molecular-Theory of High Frequency Dielectric Susceptibility of Nematic Nanocomposites

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 970
Author(s):  
Mikhail A. Osipov ◽  
Alexey S. Merekalov ◽  
Alexander A. Ezhov
Keyword(s):  
Plasmon Resonance ◽  
High Frequency ◽  
Volume Fraction ◽  
Simple Expression ◽  
Dielectric Anisotropy ◽  
Dielectric Susceptibility ◽  
Nanoparticle Volume Fraction ◽  
Effective Polarizability ◽  
Dielectric And Optical Properties ◽  
Analytical Expressions

A molecular-statistical theory of the high frequency dielectric susceptibility of the nematic nanocomposites has been developed and approximate analytical expressions for the susceptibility have been obtained in terms of the effective polarizability of a nanoparticle in the nematic host, volume fraction of the nanoparticles and the susceptibility of the pure nematic phase. A simple expression for the split of the plasmon resonance of the nanoparticles in the nematic host has been obtained and it has been shown that in the resonance frequency range the high frequency dielectric anisotropy of the nanocomposite may be significantly larger than that of the pure nematic host. As a result, all dielectric and optical properties of the nanocomposite related to the anisotropy are significantly enhanced which may be important for emerging applications. The components of the dielectric susceptibility have been calculated numerically for particular nematic nanocomposites with gold and silver nanoparicles as functions of the nanoparticle volume fraction and frequency. The splitting of the plasmon resonance has been observed together with the significant dependence on the nanoparticle volume fraction and the parameters of the nematic host phase.

Considerations of a classical model for spontaneous emission in a nonhomogeneous medium

1992 ◽  
Vol 70 (8) ◽  
pp. 631-636
Author(s):  
André Reid ◽  
Michel Piché
Keyword(s):  
General Solution ◽  
Frequency Shift ◽  
Spontaneous Emission ◽  
Transition Rate ◽  
Classical Model ◽  
Nonhomogeneous Medium ◽  
Effective Polarizability ◽  
Analytical Expressions

The classical model for spontaneous emission from a source embedded in a nonhomogeneous medium is examined in a new light. It is shown that the general solution may be expressed in terms of an effective polarizability associated with the transition being modeled. The case of a transition occurring in the vicinity of a perfect mirror is then studied as an illustration. Analytical expressions for the frequency shift and changes in the transition rate as a function of distance are found.

scholarly journals Effective Polarizability Models

2017 ◽  
Vol 121 (51) ◽  
pp. 9742-9751 ◽  
Author(s):  
Johannes Fiedler ◽  
Priyadarshini Thiyam ◽  
Anurag Kurumbail ◽  
Friedrich A. Burger ◽  
Michael Walter ◽  
...  
Keyword(s):  
Effective Polarizability

Refractive index of biodiesel-diesel blends from effective polarizability and density

Fuel ◽  
2018 ◽  
Vol 211 ◽  
pp. 130-139 ◽  
Author(s):  
M. Colman ◽  
P.A. Sorichetti ◽  
S.D. Romano
Keyword(s):  
Refractive Index ◽  
Effective Polarizability

Molar Kerr constants and solute polarizability anisotropies of ammonia, trimethylamine, trimethylamine oxide and 1,4-Diazabicyclo[2,2,2]octane

1977 ◽  
Vol 30 (7) ◽  
pp. 1411 ◽  
Author(s):  
RS Armstrong ◽  
MJ Aroney ◽  
KE Calderbank ◽  
RK Pierens
Keyword(s):  
Dipole Moment ◽  
Electric Dipole ◽  
Dipole Moments ◽  
Polar Solvents ◽  
Effective Polarizability ◽  
Electric Dipole Moments ◽  
Trimethylamine Oxide ◽  
Solute Interactions ◽  
Kerr Constants

Electric dipole moments and molar Kerr constants are reported for ammonia, trimethylamine, trimethylamine oxide, 1,4- diazabicyclo[2,2,2]octane and its monohydrate in non-polar solvents. The dipole moment now found for 1,4-diazabicyclo[2,2,2]octane differs substantially from previously recorded values. Effective polarizability anisotropies are derived for each of the anhydrous molecules and for the N-H and N-C bonds. The effect of solute interactions with benzene is explored.

Electrical strengthening of clays by dielectrophoresis

1994 ◽  
Vol 31 (2) ◽  
pp. 192-203 ◽  
Author(s):  
K.Y. Lo ◽  
J.Q. Shang ◽  
I.I. Inculet
Keyword(s):  
Shear Strength ◽  
Electric Field ◽  
Soil Improvement ◽  
Nonuniform Electric Field ◽  
Experimental Program ◽  
Effective Polarizability ◽  
Clay Particles ◽  
Shearing Resistance ◽  
Preconsolidation Pressure ◽  
Sensitive Clay

The theory of dielectrophoresis in clay–water–electrolyte systems is developed in this paper. Dielectrophoresis is the motion of particles generated by a nonuniform electric field. The dielectrophoretic forces on clay particles are determined by the effective polarizability and configuration of the nonuniform electric field. In most clay–water–electrolyte systems, including natural clays, the dielectrophoretic forces are directed towards the lower field intensity, determined by the negative polarizability. In the experimental program, an ac voltage of 60 Hz and 15 kV was applied through insulated electrodes on block samples of Leda clay for 28 days. The relationship between the soil undrained shear strength after treatment and the distribution of electric field provides direct experimental support for the theory developed. Under three electrical-field configurations, the overall shear strengths increased up to 44.0%, concurrent with significant reduction of sensitivity. The improvement of soil properties was also reflected as increases of preconsolidation pressure and shearing resistance in terms of effective stresses. The electrochemical reactions associated with electric current were minimized by insulation to the electrodes. Key words : dielectrophoresis, electrokinetics, soil improvement, sensitive clay, shear strength.

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