INTRODUCTION The literature has reported the association between lead and auditory effects, based on clinical and experimental studies. However, there is no consensus regarding the effects of lead in the auditory system, or its correlation with the concentration of the metal in the blood. OBJECTIVE To investigate the maturation state of the auditory system, specifically the auditory nerve and...

Ferrite grade zinc oxide was prepared through aqueous processing of zinc ash followed by calcination. Zinc was quantitatively dissolved in sulphuric acid medium. The ferrous iron present in the leach solution was oxidised with hydrogen peroxide followed by precipitation of total iron by pH adjustment to 4.5 with dilute sodium hydroxide solution. Copper was removed by cementation using zinc dust...

A great number of historic manuscripts, drawings, etc., many of which are stored and/or exhibited in museums, archives and various collections contain iron gall inks (IGIs) as base scripting material. Although the severe deterioration effect of IGIs on paper has been recognized and its chemistry has been explored, little focus has been given on IGIs on parchment. A study was designed to investi...

Agitated bacterial tank bioleaching reactors are currently sparged with air to satisfy both oxygen and CO(2) requirements of microbial cells. Under high-sulphide loading conditions, as is the case with high-grade metal sulphide concentrates, the microbial and chemical demand for oxygen is significantly increased during the bioleaching process. Sparging with enriched oxygen gas may offer an alte...

Abstract Magnetic Fe 3 O 4 nanoparticles (NPs) were successfully synthesized via co-precipitation method using ferric chloride and ferrous sulphate as the starting materials. The shape size of NPs controlled by different types additive including ammonium hydroxide sodium hydroxide. results revealed that adding hydroxide, particles attained a spherical with uniform size. On other hand, turned fr...