Spark discharge chamber

Fig. 20 Schematic representation of an eiectric spark discharge chamber for the activation of gases at normal atmospheric pressure for the production of fluorescence in substances separated by thin-layer chromatography [2],...

Hot Spots. Combustion-Chamber Deposits) Surface ignition is the initiation of a flame front by any hot surface other than the spark discharge prior to the arrival of the normal flame front. The flame front or fronts so established propagate at normal velocities. This phenomenon can be further subdivided into preignition and postignition. 

Extensive measurements have been made on lead azide in the U.S.S.R. in recent years, but no description is provided of the lead azide. Sten gach [33] carried out a study on the sensitivity of lead azide to spark discharge in relation to density, size of crystals, interelectrode distance, temperature, and presence of inert impurities. The lead azide was pressed into a chamber containing a spark gap formed by two pointed electrodes. The mean density of the azide was varied from 1.1 to 2.7 g/ml and the interelectrode gap was varied from 0.020 to 0.50 mm (0.0008-0.020 in.). The 50% firing point was used as a measure of sensitivity. 

By opening this pressure chamber the dust sample is finely dispersed and blown past an inductive spark discharge. The dust concentrations approximately amount to 30, 100, 200 and 500 g/nt - The tube is closed by a spring-loaded lid. If a dust explo-... 

Poschl, U., Letzel, T., Schauer, C., Niessner, R. Interaction of ozone and water vapor with spark discharge soot aerosol particles coated with benzo[a]pyrene O3 and H2O adsorption, benzofm] pyrene degradation, and atmospheric implications. J. Phys. Chem. A 105, 4029-4041 (2001) Prince, A.P., Wade, J.L., Grassian, V.H., Kleiber, K.D., Young, M.A. Heterogeneous reactions of soot aerosols with nitrogen dioxide and nitric acid atmospheric chamber and Knudsen cell smdies. Atmos. Environ. 36, 5729-5740 (2002)... 

In spark sources, electrical discharges are used to desorb and ionize the analytes from solid samples [98]. As shown in Figure 1.42, this source consists of a vacuum chamber in which two electrodes are mounted. A pulsed 1 MHz radio-frequency (RF) voltage of several kilovolts is applied in short pulses across a small gap between these two electrodes and produces electrical discharges. If the sample is a metal it can serve as one of the two electrodes, otherwise it can be mixed with graphite and placed in a cup-shaped electrode. 

Ozone in the lower atmosphere is also produced as a result of modem technology. Equipment that produce sparks, arcs, or static discharge ultraviolet and other ionizing radiation commercial applications such as air purifiers and deodorizers in homes, hospitals, and offices and closed environmental systems such as aerospace cabins and submarine chambers due to electric discharge from equipment or ionizing radiation, are some examples. 

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