Relationships between climate and atmospheric circulation in the Sonoran Desert region

The goal of this research is to identify key features of atmospheric circulation that influence winter climate variability in the Sonoran Desert region. This relationship between winter climate and atmospheric circulation is investigated through the use of indices, which describe the principal features of circulation patterns.

Fishery potential along the Indian coastal waters between Porbandar and Ratnagiri

As part of the ongoing marine pollution monitoring programme the coastal stretch between Porbandar and Ratnagiri was considered to assess the fishery potential. Regular experimental trawling was done off Porbandar, Veraval, Diu, Hazira, Daman, Bassein, Bombay, Murud and Ratnagiri at a depth range of 5-25 m during 1988 to 1992. The catch rate varied from 1.2 to 225 kg/h (av.20.3 kg/h). Zonewise maximum catch (av.56.8 kg/h) was observed off Ratnagiri followed by off Porbandar (av.30.1 kg/h), off Bombay (av.23.9 kg/h) and off Murud (av.19.8 kg/h). The area between Hazira and Daman was poor in fish catch. In general, the catch rate showed a fluctuating trend during the period of observation. Among the hundred species identified from the collections the most common species were Coilia dussumieri, Johnius glaucus, Scoliodon laticaudus, Lepturacanthus savala, Harpadon nehereus, Sardinella longiceps, Pampus sp. and Congresox sp. The community structure and species assemblage at different zones are discussed in detail.

Experimental and theoretical comparison between static and dynamic torsional soil tests

The dynamic properties of dry Leighton Buzzard sand have been investigated using a resonant column test apparatus. These data are compared with very low frequency cyclic tests on identical specimens of sand. The comparison indicates that the properties of dry sand are independent of frequency. A simple one-dimensional model of kinematic hardening plasticity is used to predict the dynamic behaviour of the sand. The input parameters for this model are based on the results of static tests. These may be conducted on standard laboratory equipment with only minor modifications. The predictions are in good agreement with the measured data.