Present status and future scope of fisheries in the Andaman group of islands

The coastal area of approximately 2000 km and the water-bodies in between the Andaman and Nicobar islands are rich in fishery potential which range from 0.012-0.47 million tonnes. The fishery is dominated by catches of sardines, perches, carangids, mackerels, Leiognathus elasmobranchs, seerfish, mullets and tunas. About 2050 fishermen, with 1150 country craft, 113 mechanised boats and 1367 different kinds of nets and lines are engaged in active fishing in the island. Numerous bays, lagoons and creeks are available among the group of islands for mariculture activities. The mangroves of these islands provide feeding and nursery grounds for juveniles of penaeid prawns, crabs and finfishes.

Comparison of model predictions and speed trial results for a group of 32' wooden trawlers

Speed trial results of six 32' wooden stern, trawlers built to the same design are analyzed to determine the EHP ship Froude number curves in each case and are compared with the model test results of the same design and for the corresponding, displacement, conditions.

Occurrence of Oriental bonito (Sarda orientalis Temmick and Schlegel) in the inshore waters of Ceylon

The oriental bonito (Sarda Orientalis T. and S.), locally known as thora-baleya, is the least abundant species of the bloodfish group commercially exploited from the inshore waters of Ceylon. The occurrence of this species in Ceylon waters has not been reported and hence it was considered valuable to present, the observations on this species, made in the course of the investigations into the more abundant relatives of this fish, in this preliminary report. In 1964 not more than few hundred pounds of this species was caught from the inshore waters of Ceylon. Since the popularisation of drift-nets for bloodfish fishery in the south, south-west and/west coasts of Ceylon, it is estimated that the annual production has risen to about one ton.

Process development on the monolithic fabrication of an ultra-compact 4×4 optical switch matrix on InP/InGaAsP material

We have fabricated an ultra-compact 4×4 optical matrix on InP/InGaAsP material. 1×4 MMI couplers and TIR mirrors are employed to produce a compact 1×2 mm2 device. A CH4/H2/O2 RIE dry etch process has been used to realize two-level dry etching: deep-etch for both the MMI couplers and the mirrors and shallow-etch for the rest of the routing waveguides. It was found that a metal/dielectric bilayer mask is essential for multi-dry-etch processes and high profile verticality. We have found a Ti intermediate mask for the deep-etch process which is removable by SF6 dry-etch before the following shallow process. Dry-etch removal of the intermediate mask is necessary to protect the deep-etched mirror sidewall.

Increase of storage shelf life of locally produced salted/dried fish by redrying and/or packeting

Experiments were undertaken to prolong the storage life of salted/dried fish by re-drying and/or packing. The storage life under normal conditions is 51 days; re-drying the fish at 50°C for 12 hours extends the storage life only by 7 days. However, re-drying and packing gizzard shad (Gonialosa manminna ) in polyethylene maintains the fish in excellent conditions for well over 87 days. The use of air tight bags for storing good quality salted dried fish is recommended.

A preliminary study on the keeping quality of locally produced marine and freshwater salted dried fish

Experiments were conducted on the storage life of salted dried fish from both freshwater and marine species. It was found that the storage life of salted dried products from the 2 freshwater species tested (Ompok bimaculatus and Labeo dussumieri) is much longer than that of the 2 marine species (Gonialosa manminna and Chorinemus lysan), i.e., 51 days.

Influence of voltage and frequency dimming on power losses in HF electronic ballasts for compact fluorescent lamps

Compact Fluorescent Lamps (CFL) incorporating electronic ballasts are widely used in lighting. In many cases the ability to dim the lamp is a requirement Dimming can be achieved by varying the voltage supplied to the inverter or by changing the switching frequency of the inverter. The effect of dimming by both approaches on the power losses in the inverter is studied in this work. The lamp and associated inverter has been modeled in PSPICE, using a behavioral model for the CFL. Predicted losses are in good agreement with experimental data obtained from calorimetry. The model was then used to determine the distribution of losses within the inverter, enabling a comparison of the effects of the two dimming methods to be made. © 2006 IEEE.