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...

Nowadays, centrifugal compressors are commonly used in the oil and gas industry, particularly in the energy transmission facilities just like a gas pipeline stations. Therefore, these machines with different operational circumstances and thermodynamic characteristics are to be exploited according to the operational necessities. Generally, the most important operational parameters of a gas pipel...

The energy efficiency and consumption of mobile networks have received increasing attention from academics industry in recent years. This has been provoked by rapid increases data traffic projected further over the next decade. As a result, dramatic improvements are required to ensure that future levels both environmentally economically sustainable. In this context, good deal research focused o...

In this note we review recent progress about fluctuation relations and their applicability to free energy recovery in single molecule experiments. We underline the importance of the operational definition for the mechanical work and the non-invariance of fluctuation relations under Galilean transformations, both aspects currently amenable to experimental test. Finally we describe a generalizati...

The introduction of inductive storage/opening switCh pulse forming networks as an operational reality in the llUllti-megajoule, sub-microsecond range, makes possible the design and operation of very large high power systems at modest cost.l• 2 The operational simplicity and economy of the pulse shortening system shifts the emphasis from opening switches to that of finding suitably simple, highl...