Phosphorus pentoxide used on alumina (P2O5/Al2O3) as an inexpensive, eco-friendly and non-toxic acid catalyst for the one-pot synthesis of 1,8-dioxo-octahydroxanthenes via multi-component reactions under solvent-free conditions. The present approach offers several advantages such as short reaction times, high yields, easy purification, recovery and reusability of the catalyst.

Creating effective test cases is a difficult problem, especially for web applications. To comprehensively test a web application’s functionality, test cases must test complex application state dependencies and concurrent user interactions. Rather than creating test cases manually or from a static model, field data provides an inexpensive alternative to creating such sophisticated test cases. An...

this paper presents a finite element analysis and its related experimental test of corrugated steel web beams subjected to fatigue loading. a particular focus in this study was set on the fatigue failure arising from the web-to-flange welded joint of the corrugated steel web beam. a detailed three-dimensional finite element model which explicitly includes the geometry of the web-to-flange welds...

freshly prepared zno nanoparticles were used as an effective heterogeneous base catalyst for the synthesis of aryloximes. the conversion of arylaldehydes and arylketones into the corresponding oximes (up to quantitative yields) was achieved by simply mixing the liquid reactants and hydroxylamine hydrochloride with zno nanoparticles under solvent-free condition. the procedure was carried out und...

In this paper we investigate how much various classes of Web spam features, some requiring very high computational effort, add to the classification accuracy. We realize that advances in machine learning, an area that has received less attention in the adversarial IR community, yields more improvement than new features and result in low cost yet accurate spam filters. Our original contributions...

A facile and highly efficient protocol was applied successfully to synthesize 4H-pyrimido[2,1,b]benzimiazoles and 4H-pyrimido[2,1,b]benzothiazoles through one-pot three-component cyclocondensation reactions of 2-aminobenzimidazole or 2-aminobenzothiazole with dimedone and aromatic aldehydes in the presence of guanidinium chloride under solvent-free conditions. The reactions us...

sulfonated polystyrene/montmorillonite nanocomposite (ommt/ps-so3h) was prepared and used as a novel, efficient and inexpensive heterogeneous acid catalyst in the one-pot reaction three-component mannich reaction of ketones, aromatic aldehydes and amines under solvent-free conditions. the catalyst was characterized by xrd, sem, tg, bet and ft-ir techniques. this method has advantages of high yi...