The alternating current resistance and capacity of suspensions of unfertilized eggs of Asterias forbesi have been measured at frequencies from one thousand to sixteen million cycles per second. The plasma membrane of the egg has a static capacity of 1.10microf/cm.(2) which is practically independent of frequency. The suspensions show a capacity dependent on frequency at low frequencies which ma...

Alternating current measurements have been taken on single Nitella cells over a frequency range from 30 to 2,500,000 cycles per second with the current flow perpendicular to the axis of the cell. The measuring cells were so constructed that electrolytes of any desired concentration could be circulated during the course of the measurements. The cellulose wall which surrounds the cell is found to...

The U-slot micro-strip patch antennas were originally developed for bandwidth broadening applications. This study presents a transmission line feed to modify the U-slot stacked rectangular micro-strip patch antenna for Ultra-Wide Band (UWB) communications. The modified antenna has a U-cut loaded with parallel slits and corner slots and is printed on a dielectric substrate of FR4 with relative p...

To increase the usage of electric vehicles (EV), a safe and convenient method to charge the vehicles is essential. Recently, an efficient mid range wireless power transfer that uses magnetic resonant coupling, WiTricity, was proposed, and has received much attention due to its practical range and efficiency. Studies show that the resonance frequency of the antennas changes as the gap between th...

This paper is concerned with the study of low-cost, low-power thermoacoustic electricity generators. Based on target electrical output power values of 50 and 100 W, three standing wave prototypes (of both one-stage and two-stage prototypes) integrating a commercial loudspeaker with different coupling arrangements are conceived. Each stage consists of a square-pore stack sandwiched between hot a...

The emerging electro-mechanical impedance technology has high potential for in-situ health monitoring and NDE of structural systems and complex machinery. At first, the fundamental principles of the electro-mechanical impedance method are briefly reviewed and ways for practical implementation are highlighted. The equations of piezo-electric material response are given, and the coupled electro-m...