an efficient, simple and convenient route is described for the synthesis of biscoumarin (3,3'-(arylmethylene) bis (4-hydroxy-2h-chromen-2-one)) by using of recyclable catalyst tio2@ksf. in this method, we synthesis biscoumarin derivatives via 3multi-component reactions (3mcrs) of two equivalent 4-hydroxycoumarin with one equivalent of aromatic aldehydes using 20 mg nano tio2@ksf as homogen...

permeability can be directly measured using cores taken from the reservoir in the laboratory. due to high cost associated with coring, cores are available in a limited number of wells in a field. many empirical models, statistical methods, and intelligent techniques were suggested to predict permeability in un-cored wells from easy-to-obtain and frequent data such as wireline logs. the main obj...

New control circuits and algorithms are frequently proposed to control the impedance (Z) source inverter in efficient way with added benefits. As a result, several modified control techniques have been proposed in recent years. Although these techniques are clearly superior to the simple boost control method which was initially proposed along with the Z-source inverter (ZSI), little or conf...

End-to-end available bandwidth estimation is very important for bandwidth dependent applications, quality-of-service verification and traffic engineering. Although several techniques and tools have been developed in the past, producing precise estimations in real-time still remains challenging, mainly due to the lack of control on the measured network path and environmental conditions, such as ...

The use of different optical-fiber sensors for weighing measurements is Abstract described. By using three different mechanical stressing mechanisms, the operation of the fiber-to-fiber transducer systems are tested and the results are presented. Parameters such as sensitivity, hysteresis, resolution, and dynamic range are measured. A comparison of the results has shown that the sensor system m...