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...

This paper investigates the implementation of stress in English noun-noun compounds. First, a perception experiment examines how listeners perceive prominence in compounds. After that, significant acoustic correlates of prominence are established. Finally, a cluster analysis is described that classifies compounds on the basis of their phonetic features and which is capable of separating differe...

Hydrogen can be inadvertently introduced at any of several steps in the fabrication of optoelectronic devices. The most common consequence of hydrogenation is the passivation of dopant impurities, which leads to a decrease in the electrical conductivity of the material. The most successfully applied experimental technique for directly determining the involvement of hydrogen has been infrared-ab...

Compound (or mixed) document images contain graphic or textual content along with pictures. They are a very common form of documents, found in magazines, brochures, web-sites etc. Because of the very distinct nature of those two image classes (text/graphics vs. pictures), their compression invariably involves multiple compression systems and a region segmentation (classification) method. We rev...

Non-negative matrix factorization models based on a hierarchical Gamma-Poisson structure capture user and item behavior effectively in extremely sparse data sets, making them the ideal choice for collaborative filtering applications. Hierarchical Poisson factorization (HPF) in particular has proved successful for scalable recommendation systems with extreme sparsity. HPF, however, suffers from ...

This thesis investigates computational approaches for analysing the semantic relations in compound nouns and other noun-noun constructions. Compound nouns in particular have received a great deal of attention in recent years due to the challenges they pose for natural language processing systems. One reason for this is that the semantic relation between the constituents of a compound is not exp...

acylisothiocyanate (1) was allowed to react with benzylidene malononitrile producing oxazine derivative (2). also, compound (1) was reacted with sodium azide followed by refluxing with sodium ethoxide affording thiazinotetrazole derivative (4). the reaction of acetylacetone with compound (1) gave pyridine derivative (5) by intramolecular cycloaddition while it was reacted with n-methyl aniline ...

synthesis, characterization, spectral and theoretical calculations of sodium tetrafluoroborate (iii) (stfb) has been studied in this research. sodium tetrafluoroborate (iii) was synthesized by a sonochemical method and characterized by ir, uv/vis, 11b-nmr and mass spectrometer techniques. the nano compound was characterized by scanning electron microscopy (sem), x-ray powder diffraction (xrd) a...

bacterial resistance is a major drawback in chemotherapy of infectious diseases. in this investigation a new series of 3,5-diarylamide dihydropyridines containing 2-benzylsulfonylimidazol at 4 position have been synthesized and studied for their enhancing effect on the antibacterial activities of different penicillins against a resistant clinical isolate of s. aureus using disc diffusion method...