highly active cu (ii) complex with 1,4-dihydroxy anthraquinone as a cheap and accessable ligand could be used as a catalyst for the preparation of structurally different propargylamines from a one-pot, three-component reaction of terminal alkynes, aldehydes, and secondary amines with high yields under solvent-free conditions. the 1,4-dihydroxy anthraquinone is a very efficient cu(ii) scavenger ...

a general synthetic route to the synthesis of imidazoles has been developed using nano sbcl5/sio2 under solvent-free conditions. the multi-component reactions of aldehydes, benzil and ammonium acetate were carried out to afford some trisubstituted imidazole derivatives. this method provides several advantages like simple work-up, environmentally benign, and shorter reaction times along with hig...

Based on driving force for crystallization of one-component gas hydrate, in this report an expression for the supersaturation for crystallization of multicomponent gas hydrate is derived. Expressions for the supersaturation are obtained in isothermal and isobaric regimes. The results obtained are applied to the crystallization of hydrates of mixtures of methane plus ethane and can apply to ...

Active efflux of antibiotics mediated by multidrug transporters is a mechanistic basis of multidrug resistance in bacteria. The most versatile multidrug transporters are those found in Gram-negative bacteria. They have a high level of constitutive expression and provide an immediate response to structurally diverse antimicrobial agents including clinically important antibiotics. The versatility...

In this paper, a new class of hybrid expert system framework using relational database systems as integrating mechanism has proposed, designed and implemented to develop expert systems and neural networks, and, to couple them to/through the database systems using client/server model and blackboard model of problemsolving. A new coupling approach (database coupling) is used to integrate expert s...

A network with a logistic-like local dynamics is considered. We implement a mean-field multiplicative coupling among first-neighbor nodes. When the coupling parameter is small, the dynamics is dissipated and there is no activity: the network is turned off. For a critical value of the coupling, a non-null stable synchronized state, which represents a turned on network, emerges. This global bifur...

To be effective, a learning process must be adapted to the learner’s context. Such a context should be described at least from pedagogical, technological and learning perspectives. Current e-Learning approaches either fail to provide learning experiences within rich contexts, thus hampering the learning process, or provide extremely contextualized content that is highly coupled with context inf...

An efficient synthesis of polyhydroquinoline derivatives was reported via four-component coupling reactions of aldehydes, 1,3-dicarbonyl ketones (dimedone or 1,3-cyclohexanedione), ethyl acetoacetate or methyl acetoacetate and ammonium acetate in the presence of a catalytic amount of nanocrystalline TiO2 under solvent free conditions. The reported method is mild, rapid and has the advantages su...

Efficient ion-photon coupling is an important component for large-scale ion-trap quantum computing. We propose that arrays of phase Fresnel lenses (PFLs) are a favorable optical coupling technology to match with multi-zone ion traps. Both are scalable technologies based on conventional micro-fabrication techniques. The large numerical apertures (NAs) possible with PFLs can reduce the readout ti...