pure azo schiff bases were readily and conveniently accessible in high yields by mixing of the reagents either as aqueous slurry, or by grinding at room temperature. this method, unlike a classical method, needs neither harsh conditions nor organic solvents. the satisfactory results were obtained with excellent yields, short reaction time, and operational simplicity in the experimental procedur...

Molybdate sulfuric acid (MSA) has been prepared and used as catalyst for the Biginelli synthesis of some quinazolinones/thiones under solvent-free conditions. The catalyst loading is low and it shows recyclability. This method has advantages such as avoidance of the organic solvents, high yield of pure products, short reaction times and operational simplicity.

Partial nitrification was reported to be technically feasible and economically favorable, especially for wastewaterwith high ammonium concentration or low C/N ratio. In this study, the effect of dissolved oxygen (DO)and influent ratio of chemical oxygen demand to nitrogen (COD/N) ratio on biological nitrogen removal fromsynthetic wastewater was investigated. Experiments were c...

The application of Purolite A-510 anionic resin for an industrial effluent treatment generated by the technological process of streptomycin production is studied taking into account the recycling requirements of treated wastewater and recovery demands of all useful materials (e.g., solvents, antibiotics etc.). All the experiments were performed on a laboratory set-up scale by working into stati...

BACKGROUND Work-related musculoskeletal disorders (WMSDs) are a common health problem throughout the world and a major cause of disability in the workplace. OBJECTIVE To determine the prevalence rate of MSDs, assessment of ergonomics working conditions and identification of major risk factors associated with MSDs symptoms among employees of Iranian petrochemical industries between October 200...

a simple and green chemical procedure was reported for the synthesis of dihydropyrimidinones from various aldehydes, ethyl acetoacetate and urea or thiourea using  holmium chloride as catalyst. the reactions were performed under solvent free conditions with ultrasound irradiation as the energy source. the advantages of this protocol include the excellent yield, operational simplicity, short tim...

in this article we implement an operational matrix of fractional integration for legendre polynomials. we proposed an algorithm to obtain an approximation solution for fractional differential equations, described in riemann-liouville sense, based on shifted legendre polynomials. this method was applied to solve linear multi-order fractional differential equation with initial conditions, and the...

a simple, novel, efficient and three-component procedure for the synthesis of pyrimido[4,5-d]pyrimidine-2,4-dione derivatives by the reaction of 6-amino-1,3-dimethyluracil, aldehyde and 2-benzylisothiourea hydrochloride promoted by ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]br) under solvent-free conditions is reported. the presented method is benefited from operational simplicity,...

In the present research work, the kinetics of sunflower oil transesterification reaction in the presence of Ba-Sr/ZSM-5 nanocatalyst which prepared using incipient wetness impregnation method was investigated. The 10wt.%Ba-Sr/ZSM-5 (Sr/Ba=3/2) nanocatalyst was calcined at 600 °C for 6 h with a heating rate of 3 ºC/min. The experimental conditions were the methanol/oil 9/1molar ratio, reaction t...