High-performance 4H-SiC based metal-semiconductor-metal ultraviolet photodetectors with Al2O3 SiO2 films

4H-silicon carbide (SiC) metal-semiconductor-metal (MSM) ultraviolet (UV) photodetectors with Al2O3/SiO2 (A/S) films employed as antireflection/passivation layers have been demonstrated. The devices showed a peak responsivity of 0.12 A/W at 290 nm and maximum external quantum efficiency of 50% at 280 nm under 20 V electrical bias, which were much larger than conventional MSM detectors. The redshift of peak responsivity and response restriction effect were found and analyzed. The A/S/4H-SiC MSM photodetectors were also shown to possess outstanding features including high UV to visible rejection ratio, large photocurrent, etc. These results demonstrate A/S/4H-SiC photodetectors as a promising candidate for OEIC applications. (C) 2008 American Institute of Physics.

Economic assessment of shrimp (Penaeus monodon) hatchery industry in Panay Island, Philippines

Results of the economic assessment of shrimp hatchery industry in Panay Island, Philippines are presented. In order to ensure continuous viability of hatcheries, the critical areas of concern are: financing of operating capital and improvement of facilities; collective marketing efforts through cooperatives; updating of technology especially in disease prevention and control; and diversification strategies.

Seaweed industry in India

The seaweed industry in India is mainly a cottage industry and is based only on the natural stock of agar yielding red seaweeds, such as Gelidiella acerosa and Gracilaria eduli and algin yielding brown seaweed species such as Sargassum and Turbinaria. India produces 110-132 t of dry agar annually utilizing about 880-1100 t of dry agarophytes, and 360-540 t of algin from 3600-5400 t of dry alginophytes.