Bubble Formation Characteristic of Submerged Single-Hole Orifice in Inorganic Solution

Bubble column is regarded as a kind of wet filtration method. The solution used in filter containment vented system is composed of a large amount of inorganic salt including sodium hydroxide and sodium thiosulfate. Solution with high inorganic salt concentration is more viscous and has stronger surface tension than distilled water. This property has significant effect on bubble size and bubble deformation during formation process. Besides bubble coalescent is suppressed with inorganic concentration increase. This phenomenon is found to possess influence on bubble formation regime when bubble formation regimes belong double, paring and injection regime. The existence of aerosol in solution is another factor that has obvious effect on bubble formation regime and the transition velocity between regimes. This paper apply high speed camera to study the influence rule of inorganic salt and aerosol concentration on bubble size during formation and formation regimes transition.

Historical Note: Aqueous Chlorine Dioxide Bleaching at Christa Gaehde’s Studio in the 1990s

The preparation and use of aqueous 0.2% chlorine dioxide as it was practiced at the private conservation studio of paper conservator Christa M. Gaehde in the 1990s is described for the record. The bleach was used predominantly on prints printed in black printing inks on machinemade lignin-free paper. The treatment sequence involved washing in deionized water; immersion in the chlorine dioxide solution or a local brush application of the bleach in the print margins; rinsing in deionized water; neutralization of residual bleach by misting 1% sodium thiosulfate solution recto and verso; four rinsing baths in deionized water, the fourth one conditioned with calcium hydroxide to pH 9. Preparation of the bleach required special precautions in handling the sodium chlorite and formaldehyde.

Treatment performance of newly developed johkasous with membrane separation

In order to verify the treatment performance of newly developed johkasous with membrane separation, for household use, three johkasous of different types were used for experimental study. It was found that each of these johkasous has a high treatment performance for removing BOD, nitrogen, and can be operated steadily by monitoring the function and maintaining the devices at every three months and by withdrawing accumulated sludge at every six months. It was also found that periodical cleaning of the membrane by sodium hypochlorite solution and neutralizing cleaning wastewater by sodium thiosulfate solution at every six months is important to maintain a steady permeability of the membranes. No adverse effects on treatment performance was observed by leached sodium hypochlorite solution from the membrane at membrane cleaning.

Etches for the Microstructure of Dental Amalgams

An iodized sodium hydroxide solution. is suitable as an etch for conventional amalgams. In diluted form and followed by sodium thiosulfate solution, this may be used on dispersed phase, ternary and quaternary alloy amalgams for clearer results than with the cyanide method. Alternative etches are given for ternary-quaternary materials.