Acoustics-turbulence interaction

An investigation of the instability frequency was undertaken. Measurements revealed that the hot wire probe induces and sustains stable upstream oscillation of the free shear layer. The characteristics of the free shear layer tone are found to be different from the slit jet wedge edgetone phenomenon. The shear tone induced by a plane wedge in a plane free shear layer was then examined in order to further document the phenomenon. The eigenvalues and eigenfunctions of the tone fundamental show agreement with the spatial stability theory. A comprehensive summary of the results is also included

Assessing the profitability of farming of disadvantaged smallholders inside and outside polder 29 in Khulna district of Bangladesh

The present study is designed to compare profitability of growing crops by the selected disadvantaged smallholders living inside and outside the Polder No. 29 in Khulna district of Bangladesh. Primary data were collected from 120 respondents, of which 65 from inside the Polder 29 and 55 from outside the Polder 29 were selected randomly. The disadvantaged people outside Polder 29 (Latabunia) followed only one cropping pattern a year such as: (i) T. Aman paddy and Bagda. On the other hand, the disadvantaged people inside polder area followed two distinct cropping patterns a year such as: (i) T. Aman paddy and Bagda; and (ii) Boro paddy and T. Aman paddy. No disadvantaged people outside Polder 29 were found to be involved in small trading and livestock keeping whereas it was common inside Polder 29. So, a wider variation in cropping patterns and profitability of the disadvantaged people was observed as the farm is located inside and outside the Polder 29 (Latabunia). Profitability of disadvantaged people for Bagda cultivation within and outside Polder 29 was not much differs but profitability of disadvantaged people for T. Aman production inside Polder 29 was higher than the profitability for T. Aman production of Latabunia farmers and the difference was Tk 19142.00 per hectare. The concerned scientists should give top most priority to develop salt tolerance new variety of T. Aman paddy and MV Boro paddy for this area. Necessary steps could be taken to protect the land of outside farmers from the salinity or other appropriate steps could be taken to decrease salinity problem of the area.Afsana Zaman, and Maksuda Manna