Low frequency dielectric relaxation and light scattering under ac electric field of DNA solutions

1980 ◽  
Vol 11 (3-4) ◽  
pp. 309-316 ◽  
Author(s):  
Masanori Sakamoto ◽  
Takashi Fujikado ◽  
Reinosuke Hayakawa ◽  
Yasaku Wada
Author(s):  
Kshitiz Gupta ◽  
Dong Hoon Lee ◽  
Steven T. Wereley ◽  
Stuart J. Williams

Colloidal particles like polystyrene beads and metallic micro and nanoparticles are known to assemble in crystal-like structures near an electrode surface under both DC and AC electric fields. Various studies have shown that this self-assembly is governed by a balance between an attractive electrohydrodynamic (EHD) force and an induced dipole-dipole repulsion (Trau et al., 1997). The EHD force originates from electrolyte flow caused by interaction between the electric field and the polarized double layers of both the particles and the electrode surface. The particles are found to either aggregate or repel from each other on application of electric field depending on the mobility of the ions in the electrolyte (Woehl et al., 2014). The particle motion in the electrode plane is studied well under various conditions however, not as many references are available in the literature that discuss the effects of the AC electric field on their out-of-plane motion, especially at high frequencies (>10 kHz). Haughey and Earnshaw (1998), and Fagan et al. (2005) have studied the particle motion perpendicular to the electrode plane and their average height from the electrode mostly in presence of DC or low frequency AC (<1 kHz) electric field. However, these studies do not provide enough insight towards the effects of high frequency (>10 kHz) electric field on the particles’ motion perpendicular to the electrode plane.  


2011 ◽  
Vol 393-395 ◽  
pp. 24-27 ◽  
Author(s):  
Peng Fei Cheng ◽  
Sheng Tao Li ◽  
Jian Ying Li

There are two kinds of charges in dielectric materials, one is bound charge, and the other is free charge. Bound charge will introduce dielectric relaxation under applied AC electric field, which will be detected with dielectric spectroscopy. Free carrier will introduce DC conduction through the sample from one electrode to the other under DC electric field. But what can we do to obtain AC and DC properties of dielectric materials at the same time? In this paper, dielectric characteristics of ZnO varistor ceramics in a wide range of frequency and temperature are reported. DC conductivity is observed at low frequency and high temperature region and grainboundary Schottky barrier is obtained further. Dielectric loss peaks are observed at high frequency and low temperature region and single grainboundary electric breakdown voltage is calculated. At the end of the paper, the advancing trend of dielectric spectroscopy is discussed.


2001 ◽  
Vol 279 (3) ◽  
pp. 252-258
Author(s):  
S. Fujii ◽  
T. Isojima ◽  
N. Sasaki ◽  
K. Hamano

Sensors ◽  
2018 ◽  
Vol 18 (3) ◽  
pp. 784 ◽  
Author(s):  
Shunsuke Takahashi ◽  
Kazuki Kishi ◽  
Ryota Hiraga ◽  
Kazuki Hayashi ◽  
Youhei Mamada ◽  
...  

2013 ◽  
Vol 136 (3) ◽  
Author(s):  
Mahantesh S. Swamy ◽  
I. S. Shivakumara ◽  
N. B. Naduvinamani

This paper deals with linear and nonlinear stability analyses of thermal convection in a dielectric fluid saturated anisotropic Brinkman porous layer subject to the combined effect of AC electric field and time-periodic gravity modulation (GM). In the realm of linear theory, the critical stability parameters are computed by regular perturbation method. The local nonlinear theory based on truncated Fourier series method gives the information of convection amplitudes and heat transfer. Principle of exchange of stabilities is found to be valid and subcritical instability is ruled out. Based on the governing linear autonomous system several qualitative results on stability are discussed. The sensitive dependence of the solution of Lorenz system of electrothermal convection to the choice of initial conditions points to the possibility of chaos. Low frequency g-jitter is found to have significant stabilizing influence which is in turn diminished by an imposed AC electric field. The role of other governing parameters on the stability threshold and on transient heat transfer is determined.


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