Transient electric conductance

Barker GC, Fowles P (1970) Pulse radiolytic induced transient electrical conductance in liquid solutions, part 3. Radiolysis of aqueous solutions of some inorganic systems. Trans Faraday Soc 66 1661-1669... 

The Peierls transition can be reversed in some DCNQI crystals through optical excitation. The conductivity of the crystal is in this case increased by up to eight orders of magnitude by a short light pulse. To detect this effect, the (transient) electric conductivity must be measured in the excited state. More on this subject will likewise be presented in Chap. 12. 

Identification is provided by liquid phase chromatography (HPLC). Following the laser pulse transient electric conductivity can be measured. In view of the intensity dependence a 2-photon process is suggested with the wellknown benzene ion as the intermediate. The observed... 

Fowles, P. (1971) Pulse radiolytic induced transient electrical conductance in liquid solutions. 

In a possible hypothesis, Smirnov et al. have proposed that a transient process such as [MX4]3- + [MXj] - —> [MX,] 2- + [MXJs- is the electrically conducting process. Their concept may he similar to the dynamic dissociation model. 

Pulse radiolysis, using as time-resolved detection methods optical absorption, luminescence, electrical conductivity or electron spin resonance can be expected to give information on the formation of transient or permanent radiation products and on their movement. 

W. Traube described the formation of what he called sulphimide, along with ammonia and imidosulphonic acid, when sulphamide is heated at 200°-210°. The solid product is treated with water, the soln. mixed with silver nitrate, and the precipitated silver sulphimide, purified by recrystallization, is decomposed with dil. hydrochloric acid. The aq. soln. decomposes when the attempt is made to isolate the solid, for when the soln. is evaporated below 40°, only ammonium hydrosulphate remains. A. Hantzsch and A. Holl found the soln. in ethyl acetate has properties in accord with the trimolecular formula sulphucyl trumide, or trisulphimide, (S02.NH)3—e.g. ebulliscopic determinations of the mol. wt. and the electrical conductivities of the aq. soln. of trisulphimide and its salts. They were able to isolate a crystalline solid by crystallization from ethyl alcohol which they considered to be trisulphimide itself. A. Hantzsch and B. C. Stuer, however, showed that the alleged compound is extremely unstable, and that the soln. obtained by W. Traube, and the solid obtained by A. Hantzsch and A. Holl, was really sulphuryl imidodiamide, only indications of the transient formation of trisulphimide in non-aqueous solvents were obtained. Trisulphimide acts as an acid, and a few salts have been reported. A. Hantzsch and B. C. Stuer consider that the compound has tautomeric forms—a true imide and an acid ... 

Recent measurements of fast transient photoconductivity (11) in trans-fCm have demonstrated that the photogenerated soiitons are mobile and contribute to the electrical conductivity. Figure 2 shows the transient photoconductivity following a 1 pJ pulse at 2.1 eV with a bias voltage of 300 V. The charge carriers are produced within picoseconds of optical excitation. The fast rise is foiiowed by (approximateiy exponentiai) decay with a time constant of - 300 ps. The magnitude and time decay of Oph(t) are temperature independent... 

These short pulses induce a non-equilibrium situation in a very short time scale, such that a sufficiently high concentration of transient free radical species is formed. These short-lived free radical species are detected in their lifetimes, by following the changes in their characteristic properties such as optical absorption, electrical conductivity, spin density, Raman spectroscopy, etc. Pulse radiolysis has been found to be extremely useful in studying several of these free radical reactions. Although modern pulse radiolysis techniques are capable of producing much shorter pulses seconds), most of the relevant... 

For completeness, let us note that if the volume fraction of the dispersed phase becomes sufficiently large, it is expected that the interactions between the globules will affect their shape. As these Interactions become greater, a percolation threshold occurs. The electrical conductivity of the system increases steeply at the threshold because of the transient interconnections between an infinite number of globules of water. 

The behavior of water in oil microemulsions has been studied using different techniques light scattering, electrical conductivity, viscosity, transient electrical birefringence, ultrasonic absorption. All these experiments lead us to propose a picture of the microemulsions structure which assignes an important role to the fluidity of the interfacial region. 

This paper describes some recently completed work on the electrical conductivity of paper. A reliable method of measuring bulk conductivity of paper, where the contact resistance is reduced to negligible values, has been developed. A study of the effect of some papermaking variables, such as the type of pulp, the degree of refining and the fiber orientation, on the bulk conductivity of paper is reported. Finally, an investigation has been made into the current transient phenomena exhibited by paper upon the application of an electric field. These transient currents were interpreted as the transport of ionic species within a water associated fibrous network making up the paper. 

Y. Nagasaka and A. Nagashima, Absolute measmement of the thermal conductivity of electrically conducting liquids by the transient hot wire method, J Phys E Sci Instrum., 14, 1435—1440 (1981). 

Distinguishing between interface-dominated currents and bulk-dominated (ohmic) currents often requires a self-consistent interpretation of a variety of electrical conductivity measurements. These may be steady-state and transient, equilibrium and nonequilibrium, and can use a variety of electrode materials and sample geometries. 

Demonstration of the creation of multilayer line structures in the seal will result in the collection of physical measurement data on the change in seal features during heat up, steady state operation, transients, or on cool down. A radar type image of the signal characteristics will show build up or relaxation of stresses, discontinuities in seal structure including porosity, delamination of the seal from either the cell or interconnect, and ultimately the catastrophic failure of the seal. Additionally with the ability to use a metal interconnect as one of the plane references coupled with a trace on the oxide coating on the interconnect, electrical conductivity and structural integrity of the thin oxide film on the metal interconnect can be determined within the vicinity of the trace. 

---