Experience of Ultrasonic Use to Stabilize Archaeological Iron Artifacts with Active Corrosion

Of all the complex problems of museum storage of archaeological objects, iron objects represent one of the most difficult. In the process of corrosion, an iron object passes through several stages, from oxidation of the metal surface to full mineralization. The greatest problem consists of the items in the stages of oxidation, when the metal is almost completely corroded and converted into minerals. Mineral peels exfoliate under the influence of active corrosion, leading to a loss of historical significance of the object. In the world’s practice of archaeological iron conservation, there are several different ways of stabilization, but none of them can guarantee the integrity of the iron artifact during its museum storage. To date, the most effective conservation method of stabilizing archaeological iron is alkaline sulfite treatment. However, this method has a number of drawbacks, the main of which is the duration of the stabilizing treatment. The authors consider the possibility of increasing the efficiency of the method of processing archaeological iron objects in an alkaline sulfite solution by means of ultrasonic solution activation. In the course of the experimental study, it has been established that the use of ultrasonic in alkaline sulfite treatment hugely increases the efficiency of the method.

Novel Pd-catalyzed electroless Au deposition method using a sulfite solution

A novel method is reported for the electroless deposition of Au using nanoscale Pd catalysts in a sulfite solution. A uniform and high quality Au film was generated.

TRANSPOR IODIN MELALUI MEMBRAN KLOROFORM DENGAN TENIK MEMBRAN CAIR FASA RUAH

Vol 5 No 1ABSTRACT The transport of iodine through a bulk liquid membrane containing chloroform as the solvent and alkaline sodium sulfite solution as the receiving phase was studied .Iodine transport was performed by bulk liquid membrane technique consist of 10 mL I2/KI solution as feed phase, Na2SO3 (20 mL) and NaOH solution as receiving phase, and chloroform (30 mL) as membrane phase which was stirred 100 rpm. The presence of iodine both in feed and receiving phase then where determined by Spectrophotometer UV-Vis with λ max at 567 nm. The optimum conditions for iodine transport investigated from this work are 4x10-3 N, pH 4 in feed phase, pH 9 in receiving phase, I2 : KI ratio in feed phase (2 : 5), and a stirring duration is 180 minutes. As conclusion the bulk liquid membrane technique with Na2SO3 and NaOH as receiving and acception substances is potential for iodine transport resulting 78.6 % of iodin transport. Keywords: Iodine, transport, chloroform, bulk liquid membrane, Na2SO3, NaOH

A comparison of different methods to remove dissolved oxygen: Application to the electrochemical determination of imidacloprid

This study compares different methods for the removal of oxygen from the solution prior to the chronopotentiometric determination of the insecticide imidacloprid on glassy carbon electrode. The research included the application of the chemical method involving addition of sulfite ion, and the physical method of purging the sample with nitrogen stream, as well as their combination. By comparing analytical signals of imidacloprid, chemical method showed almost the same efficiency as conventional physical method, while the best reproducibility was achieved by applying chemical method with addition of the saturated sodium sulfite solution. The method is very simple and can be applied for deoxygenation of the solution prior to the chronopotentiometric analysis. The application of the chemical deoxygenation significantly shortened duration of the chronopotentiometric analysis of imidacloprid from approximately 15 min to 1 min.