In this study, the recovery of platinum and palladium from petroleum catalysts has been elaborated using a method consisting mainly of dissolving alumina substrate in sulfuric acid thereby concentrating the precious metals in the residue. The effect of dissolution temperature and time, concentration of sulfuric acid, and pulp density on the dissolution of alumina substrate was investigated syst...

The atmospheric effects of soot aerosols include interference with radiative transfer, visibility impairment, and alteration of cloud formation and are highly sensitive to the manner by which soot is internally mixed with other aerosol constituents. We present experimental studies to show that soot particles acquire a large mass fraction of sulfuric acid during atmospheric aging, considerably a...

The evaluation of the Kjeldahl digestion method was investigated by comparing measured values of total nitrogen, phosphorus and potassium using three salt and catalyst mixture in Standard Kjeldahl digestion method and Salicylic acid Modification method with certified values of plant material as well as comparison was made for determination of total nitrogen from steam distillation method verses...

Dental erosion, and specifically its symptoms, has long been studied in Japan as an occupational dental disease. However, in recent years, few studies have investigated the development of this disease or labor hygiene management aimed at its prevention. As a result, interest in dental erosion is comparatively low, even among dental professionals. Our investigation at a lead storage battery fact...

silica sulfuric acid is employed as solid acid catalyst for the clean and less hazardousprotection of carbonyl compounds as 2,4-dinitrophenylhydrazone under solvent-free conditions.

Cellulolytic enzymes consist of a catalytic domain, a linking peptide, and a binding domain. The paper describes research on carboxylic acids that have potential as catalytic domains for constructing organic macromolecules for use in cellulose hydrolysis that mimic the action of enzymes. The tested domains consist of the series of mono-, di-, and tricarboxylic acids with a range of pK(a)'s. Thi...

The temperature-dependent hydrolysis and solubility of chitosan in sulfuric acid solutions offer the possibility for chitosan extraction from zygomycetes mycelia and separation from other cellular ingredients with high purity and high recovery. In this study, Rhizomucor pusillus biomass was initially extracted with 0.5 M NaOH at 120 °C for 20 min, leaving an alkali insoluble material (AIM) rich...