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Two experimental groups were applied to measure oxygen consumption (OC) of young grey mullets Mugil cephalus (TL: 27.3±2.1 cm; TW: 187.9±45.8 g) at different temperatures (15, 20, and 25°C). Specimens of fish from seawater (30 psu) and freshwater (0 psu) were transferred in to brackish water (15 psu). Rate of fish OC after rearing in brackish water, showed significant difference (P2/kg/h at temperatures of 15, 20, and 25°C, respectively. In fish from freshwater transferred to brackish water, grey mullets consumed 80.5, 114.4, and 161.5 mg O2/kg/h at 15, 20, and 25°C, respectively (PP>0.05). It can be concluded, that the OC rate of grey mullets on brackish water has the tendency to increase by temperature rise.

A new device structure for a single-electron-tunnelling transistor with a dual-gate geometry has been fabricated based on the silicon-on-insulator structure prepared by SIMOX wafers. The split gate of the transistor is the lower-level gate and located above the inversion layer 2DEG active channel, which yields strong carrier confinement with a fully controllable tunnelling potential barrier. The transistor operates at low temperatures and exhibits single-electron tunnelling behaviour through a nano-size quantum dot. The Coulomb blockade oscillation is demonstrated at 15 mK and its periodicity is 16.4 mV in the upper gate voltage. For the nonlinear transport regime, Coulomb staircases are clearly observed up to four current steps in the range of 100 mV drain-source bias. The I-V characteristics near zero bias display a typical Coulomb gap due to the one-electron charging effect. From the width of the blockade regime the dot capacitance is estimated to be .

This work is devoted to the investigation of the discharge characteristics of an ac arc plasma torch with a well-type cathode working in air and CO2. The electrical characteristics, plasma jet image and optical emission profile are investigated by varying the discharge power and the gas flow rate. The dynamic behaviour of arc voltage and current is characterized by smooth-shaped waveforms, regularly iterated with a driving frequency. The moving of arc spot positions is inferred from the measured waveforms, and compared with that observed in dc torches. A simple lifetime test is performed to verify the speculation that the arc spots in ac operation move continuously over a wide region with a very high speed. The result shows that the electrode lifetime can be enhanced by combining the vortex motion of arc gas with the ac driving.