A Comprehensive Description on Ethnopharmacology and Therapeutics of Murdarsang: A Review

Murdarsang is a mineral that contains pbo, or lead oxide is an important medicine in the Unani system of medicine (USM) due to its multiple therapeutic properties. It can be prepared manually with different methods and used in different forms. Etymologically, it is known as 'Litharge' which is derived from Greek 'Litharguros' (lithos meaning stone and arguros for silver) which forms as a 'waste' during the last stage of silver smelting. Throughout human history, lead and lead minerals have been used for medicinal purposes. Galena was used as an eye salve in pre-dynastic Egypt, as well as by the ancient Indian civilisations of Mohendro-Daro and Harappa between 3200 and 2800 BC. Dioskourides in his De Materia Medica says about lithargyros that one is made from sand called molybditis which is roasted until it is totally burned, another from silver, a third from lead. According to Unani system of medicine Murdarsang possess different properties such as Astringent, Agglutinant, mildly Detergent, Desiccant, Anti-inflammatory Refrigerant, Corrosive and Rarefying properties. It is used as a base for making ointments. It composes the drugs and reduces the intensity of their dissolution, corrosion and astringency. It also have a corrosive, Resolvent and Insecticidal action. Many pharmacological activities mentioned in Unani medicine are validated, and many activities need further exploration due to the immense therapeutic scope in this drug. The current review designed to give an overview on the historical, chemical constituents, pharmacological and therapeutic effects of Murdarsang. Keywords: Murdarsang, Litharge, Lead oxide, Unani system of medicine.

Atomic Emission Spectroelectrochemistry: Real-Time Rate Measurements of Dissolution, Corrosion, and Passivation

Atomic emission spectroelectrochemistry (AESEC) is a relatively novel technique that gives real-time elemental dissolution rates for a material/electrolyte combination, either reacting spontaneously or with electrochemical polarization. This methodology gives direct insight into questions such as how specific elements of an alloy interact with one another, or how specific additives in a surface treatment solution will affect different alloying elements or different phases. This paper discusses AESEC instrumentation and presents the basic quantitative relationships between the electrochemical and spectroscopic measurements. A wide range of applications are used to illustrate these relationships including the surface pretreatment of aluminum alloys (etching and deoxidation) and the passivation of Fe-Cr and Ni-Cr alloys. The focus is on the use of in-line inductively coupled plasma atomic emission spectroscopy (ICP-AES), although a brief discussion of similar techniques using in-line inductively coupled mass spectroscopy (ICP-MS) is included.

Influence of High-Density electropulsing treatment on the interface corrosion characteristics of 316L steel in Lead-Bismuth eutectic at 823 K

In order to find an effective method to improve the corrosion resistance properties of the candidate structural materials for lead-alloy cooled fast reactors, the 316L steel was treated by high density single elec-tropulsing. And then the interface corrosion characteristics in stagnant lead-bismuth eutectic (LBE) at 823 K for 1000 h were examined. The results show that electropulsing treatment (EPT) has a significant influence on microcosmic appearance and corrosion depth of the corroded specimens. All the specimens were subjected to dissolution corrosion, but EPT with a current density of 1828 A mm-2 can improve obviously the corrosion resistance and reduce the extent of local corrosion of 316L in LBE. In addition, the corrosion depth of the 1828 A mm-2 EPT specimen decreases by 38%, compared with that of the non-EPT specimens.

Effect of Lead-Bismuth Eutectic Oxygen Concentration on the Onset of Dissolution Corrosion in 316 L Austenitic Stainless Steel at 450 °C

This work focuses on the effect of dissolved oxygen concentration in liquid lead-bismuth eutectic (LBE) on the onset of dissolution corrosion in a solution-annealed 316 L austenitic stainless steel. Specimens made of the same 316 L stainless steel heat were exposed for 1000 h at 450 °C to static liquid LBE with controlled concentrations of dissolved oxygen, i.e., 10−5, 10−6, and 10−7 mass%. The corroded 316 L steel specimens were analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). A complete absence of dissolution corrosion was observed in the steel specimens exposed to liquid LBE with 10−5 and 10−6 mass% oxygen. In the same specimens, isolated “islands” of FeCr-containing oxides were also detected, indicating the localized onset of oxidation corrosion under these exposure conditions. On the other hand, dissolution corrosion with a maximum depth of 59 μm was detected in the steel specimen exposed to liquid LBE with 10−7 mass% oxygen. This suggests that the threshold oxygen concentration associated with the onset of dissolution corrosion in this 316 L steel heat lies between 10−6 and 10−7 mass% oxygen for the specific exposure conditions (i.e., 1000 h, 450 °C, static liquid LBE).