Plating pulse

Figure Bl.23.5. Schematic illustration of tlie TOE-SARS spectrometer system. A = ion gun, B = Wien filter, C = Einzel lens, D = pulsing plates, E = pulsing aperture, E = deflector plates, G = sample, PI = electron multiplier detector with energy prefilter grid and I = electrostatic deflector.

The pulsed-plate column is typically fitted with hori2ontal perforated plates or sieve plates which occupy the entire cross section of the column. The total free area of the plate is about 20—25%. The columns ate generally operated at frequencies of 1.5 to 4 H2 with ampHtudes 0.63 to 2.5 cm. The energy dissipated by the pulsations increases both the turbulence and the interfacial areas and greatly improves the mass-transfer efficiency compared to that of an unpulsed column. Pulsed-plate columns in diameters of up to 1.0 m or mote ate widely used in the nuclear industry (139,140). 

Puippe, J. C. and Leamon, F., Theory and Practice of Pulse Plating, Amer. Electropl. Soc., Orlando (1986)... 

Using pulse plating techniques with a duty cycle of 50%, it is also possible to produce crack-free chromium deposits from a sulphate- or silicofluoride-catalysed solution with a hardness similar to deposits obtained by direct currenf . A high frequency (2 000-3 000 Hz) is required to give the hardest deposits at a current density of 40 A/dm and a temperature of 54°C. It is important to avoid conditions that will co-deposit hydrides. 

Pulse plating techniques with symmetric or asymmetric waves have been employed for improving the deposition of CdS in acidic aqueous baths of cadmium sulfate and thiosulfate precursors [46, 47], A better control of sulfur incorporation in the deposits was reported. 

Swaminathan V, Murali KR (2000) Influence of pulse reversal on the PEC performance of pulse-plated CdSe films. Sol Energy Mater Sol Cells 63 207-216... 

Bouroushian M, Kosanovic T, Spyrellis N (2006) A pulse plating method for the electrosynthesis of ZnSe. J Appl Electrochem 36 821-826... 

Lokhande CD (1987) Pulse plated electrodeposition of CulnSe2 films. J Electrochem Soc 134 1727-1729... 

This pulse plating technique has the advantage of simplicity, i.e., application of a simple waveform in current or potential in a single solution. Problems arise, however, because at the more positive potential a pure element or compound is deposited, while during the pulse the second element or compound formed is inevitably contaminated with the first. Switzer et al. [73] reported a variation on... 

Galvanostatic pulse plating techniques were used to probe the displacement or corrosion of A1 from Cu-Al by Cu+ in the AlCl3-EtMeImCl plating bath [103],... 

Logsdail, D. H. and Thornton, J. D. Trans. Inst. Chem. Eng. 35 (1957) 331. Liquid-liquid extraction. Part XIV. The effect of column diameter upon the performance and throughput of pulsed plate columns. 

Union Carbide Tetraethylene glycol 373 Pulsed plate column... 

Fig. 14.11 Acid recovery by pulsed plate column operation at Sdderfors Steel Works, Sweden. 

A diffusion layer is not formed immediately on turning on the voltage (potential). It takes on the order of several seconds, depending on agitation. One consequence of pulse plating is to avoid buildup of the layer. 

Pourbaix diagram 21 pseudomorphic growth 133 pulse plating 186,301... 

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