A Waveform Reproduction Study of Time-Domain Reflectometry. II. Quick Determination of Dielectric Relaxation Time

1983 ◽  
Vol 22 (Part 1, No. 5) ◽  
pp. 874-877
Author(s):  
Shigeo Hayashi ◽  
Ariyuki Aihara
2007 ◽  
Vol 61 (4) ◽  
Author(s):  
K. Dharmalingam ◽  
K. Ramachandran ◽  
P. Sivagurunathan ◽  
B. Prabhakar Undre ◽  
P. Khirade ◽  
...  

AbstractDielectric relaxation measurements of butyl acrylate—alcohol mixtures at different concentrations and temperatures within the frequency range of 10 MHz to 10 GHz have been carried out using time domain reflectometry. Parameters such as the static permittivity, dielectric relaxation time, the Kirkwood correlation factor, the excess inverse relaxation time, and thermodynamic functions were determined and discussed to yield information on the molecular structure and dynamics of the mixture. The value of the dielectric properties decreases with increasing butyl acrylate concentration in alcohol and systematically varies with the length of alcohol alkyl chain. Negative values of the excess inverse relaxation time found for all concentrations and at all temperatures studied may indicate that the effective dipoles rotate slowly.


1974 ◽  
Vol 27 (1) ◽  
pp. 87 ◽  
Author(s):  
BS Sarma ◽  
V Venkateswara Rao

An empirical relation is proposed for the determination of the dielectric relaxation time .. of polar liquids with nearly spherical molecules from measurements of the dielectric constants at a single microwave frequency. The relation is obtained by introducing a concentration factor as a parameter in the expression for .. derived by Eyring et al. (1941). Its validity for suitable polar liquids is demonstrated by comparison of results with previously reported values. Thermodynamic parameters for a number of liquids at various concentrations have also been evaluated from experimental data using the relation.


2020 ◽  
Vol 17 (3) ◽  
pp. 230-235
Author(s):  
Sampandam Elangovan ◽  
Tilahun Diriba Garbi ◽  
Senbeto Kena Etana

The dielectric relaxation studies are vital in analyzing the strength of the inter molecular interaction between the binary liquid systems [1-4]. Jyostna et al. [5] reported thermodynamic parameters of isoamyl alcohols and mono clinic aromatic liquid mixtures. Shakila et al. [6] studied the dielectric properties of aromatic alcohols and aliphatic amines at different temperatures. In general, dielectric relaxation time varies with the inter molecular forces acting between the molecules in the selected liquid mixtures. Brompheniramine is one of the critical compounds of an amine group with spectacular applications, including pharmaceutical industries [7]. Higher carbon chain length alcohols are having self associated and proton donating ability in the liquid mixtures. The variations in the dielectric constant (є’), dielectric loss (є’’), static dielectric constant (є0) and the dielectric constant at an optical frequency (є∞) with a range of brompheniramine concentrations with 1-butanol,1-pentanol and 1-hexanol systems are useful in the applied research and chemical industries. Moreover, the variations in the dielectric constant and dielectric relaxation time should be useful in the analysis of intermolecular interaction between the functional group of the selected liquid mixtures. This research work attempts to analyse the intermolecular interaction between the brompheniramine and 1-butanol,1-pentanol and 1-hexanol at 303K using time domain reflectometry techniques.


2018 ◽  
Vol 08 (05) ◽  
pp. 1850032
Author(s):  
Shagufta Tabassum ◽  
V. P. Pawar

The study of complex properties in a binary mixture of 1,2-dichloroethane (DE) and [Formula: see text]-methylformamide (NMF) polar liquids has been carried out in the frequency range of 10[Formula: see text]MHz to 30[Formula: see text]GHz for 11 different concentrations using time domain reflectometry technique at 283, 288, 293 and 298[Formula: see text]K temperatures. Complex property of binary liquids indicates the type of distribution of the dielectric relaxation time. The Bruggeman parameter gives the information about molecular interactions within binary polar liquids. Thermodynamic parameter deals with the passing of a dipole across a potential barrier which separates the minima of energy.


2016 ◽  
Vol 06 (03) ◽  
pp. 1650022 ◽  
Author(s):  
C. M. Trivedi ◽  
V. A. Rana ◽  
P. G. Hudge ◽  
A. C. Kumbharkhane

Complex permittivity spectra of binary mixtures of varying concentrations of [Formula: see text]-picoline and Methanol (MeOH) have been obtained using time domain reflectometry (TDR) technique over frequency range 10 MHz to 25 GHz at 283.15, 288.15, 293.15 and 298.15 K temperatures. The dielectric relaxation parameters namely static permittivity ([Formula: see text]), high frequency limit permittivity ([Formula: see text]) and the relaxation time ([Formula: see text]) were determined by fitting complex permittivity data to the single Debye/Cole-Davidson model. Complex nonlinear least square (CNLS) fitting procedure was carried out using LEVMW software. The excess permittivity ([Formula: see text]) and the excess inverse relaxation time (1/[Formula: see text] which contain information regarding molecular structure and interaction between polar–polar liquids were also determined. From the experimental data, parameters such as effective Kirkwood correlation factor (geff), Bruggeman factor (fB) and some thermo dynamical parameters have been calculated. Excess parameters were fitted to the Redlich–Kister polynomial equation. The values of static permittivity and relaxation time increase nonlinearly with increase in the mol–fraction of MeOH at all temperatures. The values of excess static permittivity ([Formula: see text]E) and the excess inverse relaxation time (1/[Formula: see text] are negative for the studied [Formula: see text]-picoline — MeOH system at all temperatures.


Sign in / Sign up

Export Citation Format

Share Document