Partial discharge

The fact that a chemical bond may fomi between a metal and an anion, leading to, at least, a partial discharge of tire ion. 

There are several methods to determine and compare the resistance to partial discharges. Some tests are done on finished cables, such as the U-bend test, and others are done on laboratory samples molded from the insulation, that are subjected to partial discharges created by sharp objects, such as needles under high voltages. The tests compare either the energy required or the length of time required to erode or fail (short circuit) samples of similar thickness. 

Hogg. W.K., Miller, R., Rabech, G. and Ryder, D.M., The relationship of partial discharge amplitude distribution with electrie damage at different levels of voltage and frequency, IEEE Symposium on Electrical Insulation, USA, June (1984). 

Method for measuring partial discharges in instrument transformers 11.322/1990 BS 6184/1992 -... 

No memory problem when repeatedly partially discharged... 

Although the contribution is rather small, the partial discharging of the anesthetics in membranes can be important in the mechanism of the anesthetic action. The most plausible mechanism can be summarized as only a small portion of the cationic species are neutralized (deprotonated) at the bilayer surface and the neutral species are deeply penetrated and widely distributed in the hydrophobic bilayer interior, while the cationic species still remain at the hydrophilic bilayer surface where the hydration is significant. 

Thus, after partial discharge, the reaction (5) can be interchanged with... 

Both Ct and C2 are initially uncharged (OV). Then C1 is charged up to 10V. The switch is then flipped and C1 gets partially discharged into C2. What is the final voltage on C1 (and C2) ... 

Electrical stress can lead to partial discharge breakdown, thermal effects, electrochemical... 

Accelerated tests usually require the application of a higher electrical stress (voltage) coupled sometimes with an increase in temperature as a second accelerating factor. As in all accelerated testing, care must be taken to ensure that this does not introduce ageing mechanisms different to those that occur in service. The most common relation used to predict insulation life in the presence of partial discharges is the power law ... 

In IC-MS systems, the core of the equipment is the interface. In fact, inside the interface evaporation of the liquid, ionization of neutral species to charged species and removal of a huge amount of mobile phase to keep the vacuum conditions required from the mass analyzer take place. Two main interfaces are used coupled to IC, namely electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI). In the ESI mode, ions are produced by evaporation of charged droplets obtained through spraying and an electrical field, whilst in the APCI mode the spray created by a pneumatic nebulizer is directed towards a heated region (400°C-550°C) in which desolvation and vaporization take place. The eluent vapors are ionized by the corona effect (the partial discharge... 

As current is drawn from the cell, the positive electrode voltage is depressed due to concentration polarization as sulphuric acid within the pores is consumed. This effect is more marked for partially discharged cells. Formation of lead sulphate decreases the pore volume and produces a microporous film on the Pb02 matrix. 

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