scholarly journals Direct estimation of the activation energy and relaxation times from the anomalies observed in the dielectric, AC and DC resistivity data using modified Lorentz equation

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
Rizwana ◽  
Mahboob Syed ◽  
G. Prasad ◽  
G. S. Kumar
Keyword(s):  
Activation Energy ◽  
Relaxation Times ◽  
Dc Resistivity ◽  
Direct Estimation ◽  
Resistivity Data ◽  
Lorentz Equation

Dielectric Relaxation Studies of Silver Nanoparticles dispersed Liquid Crystal

2015 ◽  
Vol 8 (3) ◽  
pp. 2176-2188 ◽  
Author(s):  
Keisham Nanao Singh
Keyword(s):  
Activation Energy ◽  
Silver Nanoparticles ◽  
Liquid Crystal ◽  
Dielectric Relaxation ◽  
Relaxation Process ◽  
Relaxation Times ◽  
Low Frequency ◽  
Bulk Liquid ◽  
Molecular Rearrangement ◽  
Relaxation Studies

This article reports on the Dielectric Relaxation Studies of two Liquid Crystalline compounds - 7O.4 and 7O.6 - doped with dodecanethiol capped Silver Nanoparticles. The liquid crystal molecules are aligned homeotropically using CTAB. The low frequency relaxation process occurring above 1 MHz is fitted to Cole-Cole formula using the software Dielectric Spectra fit. The effect of the Silver Nanoparticles on the molecular dipole dynamics are discussed in terms of the fitted relaxation times, Cole-Cole distribution parameter and activation energy. The study indicate a local molecular rearrangement of the liquid crystal molecules without affecting the order of the bulk liquid crystal molecules but these local molecules surrounding the Silver Nanoparticles do not contribute to the relaxation process in the studied frequency range. The observed effect on activation energy suggests a change in interaction between the nanoparticles/liquid crystal molecules.

Evaluation of the Influence of Vinasse Diposal on Soil by DC-resistivity Data Analysis

2008 ◽  
Author(s):  
J. I. Igarashi da Cruz ◽  
R. S. P. De Souza Portugal ◽  
A. T. U. Teixera Ustra ◽  
V. R. E. Roberto Elis ◽  
S. J. S. F. Junior da Silva Fachin ◽  
...  
Keyword(s):  
Data Analysis ◽  
Dc Resistivity ◽  
Resistivity Data

1D inversion of DC resistivity data using a quality-based truncated SVD

2001 ◽  
Vol 49 (4) ◽  
pp. 387-394 ◽  
Author(s):  
Elonio A. Muiuane ◽  
Laust B. Pedersen
Keyword(s):  
Dc Resistivity ◽  
Resistivity Data ◽  
Truncated Svd

On: “Two‐dimensional joint inversion of magnetotelluric and dipole‐dipole resistivity data” by Y. Sasaki (GEOPHYSICS, 54, 254–262, February 1989)

Geophysics ◽  
1989 ◽  
Vol 54 (9) ◽  
pp. 1212-1212
Author(s):  
D. J. Dodds
Keyword(s):  
Joint Inversion ◽  
Dc Resistivity ◽  
Two Dimensional ◽  
Resistivity Data

There appears to be an error in the formulation of the dc resistivity response in this paper. Equation (6) is valid only when the conductivity is constant, but the text and the notation imply that it is variable. Grant and West (1965) give the correct relation [their equation (14‐2)], which is restated here using Sasaki’s notation and accounting for source currents.

scholarly journals The Motion of the OH Group in p-Chlorophenol and its Influence on the 35Cl NQR Parameters

1986 ◽  
Vol 41 (1-2) ◽  
pp. 408-411 ◽  
Author(s):  
Mariano J. Zuriaga ◽  
Carlos A. Martin
Keyword(s):  
Activation Energy ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Frequency Difference ◽  
Spin Lattice Relaxation ◽  
Normal Behaviour ◽  
Spin Lattice ◽  
35Cl Nqr ◽  
Two Temperature ◽  
Nqr Parameters

The 35Cl NQR transition frequencies and the spin-lattice relaxation times, T1, for both lines in p-chlorophenol have been measured in the temperature range 90 - 310 K. The frequency difference and the temperature derivatives for both lines clearly show the existence of two temperature intervals with distinct lattice contributions to the EFG. Similarly, T1, data show a normal behaviour due to spin-phonon interactions up to 240 K. Above this temperature T1 begins to shorten in an exponential manner. The hindered motions of the OH group are proposed as responsibles of these effects, and an activation energy of 26 kJ mol-1 is determined.

scholarly journals Inversion of 2-D DC resistivity data using rapid optimization and minimal complexity neural network

2010 ◽  
Vol 17 (1) ◽  
pp. 65-76 ◽  
Author(s):  
U. K. Singh ◽  
R. K. Tiwari ◽  
S. B. Singh
Keyword(s):  
Neural Network ◽  
Poor Performance ◽  
Optimization Methods ◽  
Model Complexity ◽  
Earth Model ◽  
Dc Resistivity ◽  
Ann Model ◽  
Jammu And Kashmir ◽  
Resistivity Data ◽  
Artificial Neural Network Ann

Abstract. The backpropagation (BP) artificial neural network (ANN) technique of optimization based on steepest descent algorithm is known to be inept for its poor performance and does not ensure global convergence. Nonlinear and complex DC resistivity data require efficient ANN model and more intensive optimization procedures for better results and interpretations. Improvements in the computational ANN modeling process are described with the goals of enhancing the optimization process and reducing ANN model complexity. Well-established optimization methods, such as Radial basis algorithm (RBA) and Levenberg-Marquardt algorithms (LMA) have frequently been used to deal with complexity and nonlinearity in such complex geophysical records. We examined here the efficiency of trained LMA and RB networks by using 2-D synthetic resistivity data and then finally applied to the actual field vertical electrical resistivity sounding (VES) data collected from the Puga Valley, Jammu and Kashmir, India. The resulting ANN reconstruction resistivity results are compared with the result of existing inversion approaches, which are in good agreement. The depths and resistivity structures obtained by the ANN methods also correlate well with the known drilling results and geologic boundaries. The application of the above ANN algorithms proves to be robust and could be used for fast estimation of resistive structures for other complex earth model also.

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