This study was aimed to optimize the extraction process for Salvia miltiorrhiza Bunge polysaccharide using response surface methodology The results showed that four operating parameters including microwave power, microwave time and the particle size had notable effects on the polysaccharide extraction of Salvia miltiorrhiza Bunge. The effects could be ranked in decreasing order of importance as...

Sequential ultrasound-microwave associated extraction (SUMAE) is a combination of ultrasound waves and microwaves energies in which ultrasonic extraction is used as a pretreatment. It was performed to extract essential oil from Zataria multiflora. The extraction conditions were optimized by response surface methodology (RSM) and Central Composite Design (CCD). The antioxidant and antibacterial ...

In this paper measurement of real part of permittivity and loss tangent of (1-x) Zn.xMg.TiO3 (ZMT) material in powder form in S-band of microwave frequencies is presented and the associated accuracy estimated. This approach is based on the measurement of transmitted power from the cavity at and off resonance. Details of the design and fabrication of the rectangular cavity and the input and outp...

Analytical Modeling of Drain-Current Characteristics of AlGaN/GaN HFETs with Incorporation of the Impacts of Virtual-Gate and Transferred-Electron Effect Maziar Moradi GaN-based heterostructure field effect transistors (HFETs) have gained considerable attention in high-power microwave applications. So far, unsurpassed current levels and high output power at microwave frequencies have been achie...

High power, broad bandwidth, high linearity, and low noise are among the most important features in amplifier design. The broad-band spatial power-combining technique addresses all these issues by combining the output power of a large quantity of microwave monolithic integrated circuit (MMIC) amplifiers in a broad-band coaxial waveguide environment, while maintaining good linearity and improvin...

We report our studies on using microwave-optical double-resonance (DR) spectroscopy for a high-performance Rb vapour-cell atomic clock in view of future industrial applications. The clock physics package is very compact with a total volume of only 0.8 dm. It contains a recently in-house developed magnetron-type cavity and a Rb vapour cell. A homedmade frequency-stabilized laser system with an i...

We investigate the impact of pulse interleaving and optical amplification on the spectral purity of microwave signals generated by photodetecting the pulsed output of an Er:fiber-based optical frequency comb. It is shown that the microwave phase noise floor can be extremely sensitive to delay length errors in the interleaver, and the contribution of the quantum noise from optical amplification ...

Formerly, microwave emissions accompanying hypervelocity impacts were confirmed experimentally. In this paper, two kinds of analyses, output waveform analysis and spectral analysis, are discussed for the purpose of clarifying the mechanism of microwave emissions. In output waveform analysis, the microwave pulse is simulated on the basis of a microcrack model in consideration of discharge curren...

We show that the frequency bias caused by distributed cavity phase has a strong dependence on microwave power. We also show that frequency biases associated with microwave leakage have distinct signatures in their dependence on microwave power and the physical location of the leakage interaction with the atom.