Application of the Fuoss–Onsager theory to conductance data for sodium and potassium iodide solutions in various solvents

1967 ◽  
Vol 45 (10) ◽  
pp. 1101-1108 ◽  
Author(s):  
George J. Janz ◽  
Malcolm J. Tait

The 1957 Fuoss–Onsager conductance equation has been used to analyze data for sodium iodide and potassium iodide solutions in 13 one-component solvents, ranging from water (dielectric constant 78) to pyridine (dielectric constant 12). Values of the unknowns Λ0, åJ, an ion size parameter, and, where appropriate, Ka, the ion association constant, are calculated. In solvents of high dielectric constant it is found that the salts are completely dissociated (Ka = 0) and the mean value of åJ is 4.5 Å for each salt. However, the ion size parameters from the conductance equation do not seem to have any physical significance in solvents of lower dielectric constant, where there is evidence of ionic association. An analysis of these data is considered in which the Fuoss–Onsager equation reduces to a one-parameter equation, with Ka as the unknown. The conductance data for sodium and potassium iodide can then be understood if the closest distance of approach of the ions is 4.5 Å in all 13 solvents.

Nano Energy ◽  
2017 ◽  
Vol 32 ◽  
pp. 73-79 ◽  
Author(s):  
Yash Thakur ◽  
Bing Zhang ◽  
Rui Dong ◽  
Wenchang Lu ◽  
C. Iacob ◽  
...  

Author(s):  
M.H.A. Wahab ◽  
N. A. M. Jamail ◽  
E. Sulaiman ◽  
Q.E. Kamarudin ◽  
N.A. Othman ◽  
...  

<p>Nowadays, XLPE cable has been widely used because it has better resistance than other cables. XLPE insulation has unique features including a high dielectric strength and high insulation resistance. A lot of researches based on hardware and software have been conducted to prove the effectiveness of XLPE cable such as AC and DC applications and Space Charge Distribution measurement under HVDC at High Temperature. This research focused on analysis of space charge and electric field on XLPE cable with effect of non-uniform contamination layer by using Quickfield Software. Non-uniform contaminations have been applied along XLPE cable using Arsenic Tribromide (AsBr3), Boron Bromide (BBr3), Ethylene Dichloride (CH2C1), Formic Acid (CH1O2), Formamide (CH3NO) and Alcohol element. Presence of these contamination elements represent of underground contamination. The size and layer of the contamination were non-uniform type. From the results, it is shown that lower dielectric constant of contamination will affect more on charge of XLPE insulation. As a conclusion, it can be seen lower dielectric constant value of contamination element greatly affecting the performance of XLPE insulation. Furthermore, size of contamination also influences the content of charge in contamination where the bigger the contamination size, the more charge contained in the contamination.</p>


1988 ◽  
Vol 66 (7) ◽  
pp. 1720-1727 ◽  
Author(s):  
Auaz Ahmad Ansari ◽  
M. R. Islam

Electrical conductivities of Me4NBr, Et4NBr, Pr4NBr, Bu4NBr, and Bu4PBr have been measured in isopropanol + water (2-PrOH + H2O) mixtures covering the approximate range of dielectric constant (71.40 ≥ D ≥ 19.40) at 25 °C. The conductance data have been analysed by using the Fuoss-1978 (F78) conductance equation and the results compared with those obtained from the Fuoss–Onsager–Skinner (FOS) equation. The values of the limiting equivalent conductance, Λ0, the association constant, KA, and the distance of ion-size parameter [Formula: see text] are computed from these data. A better fit of the conductance data was provided by the F78 equation. Ion–solvent interactions and effective sizes of tetraalkylammonium ions are also discussed in order to understand the magnitude of the ionic association. The overall association behaviour of these salts has been found to increase with decrease in dielectric constant of the medium.


1988 ◽  
Vol 66 (5) ◽  
pp. 1223-1228 ◽  
Author(s):  
Aijaz Ahmad Ansari ◽  
M. R. Islam

The molar conductivities of Pr4NBr, Bu4NBr, Pr4NI, and BU4NI have been measured in tert-butanol–water (t-BuOH–H2O) mixtures (61.30 ≥ D ≥ 16.50) over the maximum concentration range (2 × D3 × 10−7 mol dm−3) along with the densities and viscosities of the solvent mixtures at 25 °C. The conductance data have been analysed by using the Fuoss-1978 (F78) conductance equation and the results compared with the values obtained from the Justice (J), Pitt's (P), and Fuoss–Onsager–Skinner (FOS) equations. Molar conductivities at infinite dilution (Λ0), the thermodynamic ion association constants (KA) and the distance or ion-size parameters (R0 or a0) are evaluated from these data. The F78 equation fitted the data better and yielded KA and R values which are in accord with the ion-association theories. The interpretation of these parameters is discussed to provide some insight on the magnitude of the ionic association and the ion–solvent interaction.


1996 ◽  
Vol 19 (2) ◽  
pp. 119-123
Author(s):  
Prem Bhushan Mital

The effect of plasma on the radiation characteristics of curved rectangular microstrip antenna is studied by means of a new plasma simulation technique. Unlike previous techniques [1,2], a relative index of refraction less than unity is obtained by representing free space with a high dielectric constant sodium chloride powder and plasma by a medium of lower dielectric constant (air). A wide range of dielectric constants of simulated plasma could be possible with this technique using solid dielectrics instead of liquids. It is observed that the resonance frequency is not affected by the curvature of the antenna. However radiation patterns are significantly affected.


Author(s):  
E. L. Hall ◽  
A. Mogro-Campero ◽  
N. Lewis ◽  
L. G. Turner

There have been a large number of recent studies of the growth of Y-Ba-Cu-O thin films, and these studies have employed a variety of substrates and growth techniques. To date, the highest values of Tc and Jc have been found for films grown by sputtering or coevaporation on single-crystal SrTiO3 substrates, which produces a uniaxially-aligned film with the YBa2Cu3Ox c-axis normal to the film plane. Multilayer growth of films on the same substrate produces a triaxially-aligned film (regions of the film have their c-axis parallel to each of the three substrate <100> directions) with lower values of Jc. Growth of films on a variety of other polycrystalline or amorphous substrates produces randomly-oriented polycrystalline films with low Jc. Although single-crystal SrTiO3 thus produces the best results, this substrate material has a number of undesireable characteristics relative to electronic applications, including very high dielectric constant and a high loss tangent at microwave frequencies. Recently, Simon et al. have shown that LaAlO3 could be used as a substrate for YBaCuO film growth. This substrate is essentially a cubic perovskite with a lattice parameter of 0.3792nm (it has a slight rhombohedral distortion at room temperature) and this material exhibits much lower dielectric constant and microwave loss tangents than SrTiO3. It is also interesting from a film growth standpoint since it has a slightly smaller lattice parameter than YBa2Cu3Ox (a=0.382nm, b=c/3=0.389nm), while SrTiO3 is slightly larger (a=0.3905nm).


2020 ◽  
Vol 8 (32) ◽  
pp. 16661-16668
Author(s):  
Huayao Tu ◽  
Shouzhi Wang ◽  
Hehe Jiang ◽  
Zhenyan Liang ◽  
Dong Shi ◽  
...  

The carbon fiber/metal oxide/metal oxynitride layer sandwich structure is constructed in the electrode to form a mini-plate capacitor. High dielectric constant metal oxides act as dielectric to increase their capacitance.


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