M/echanical Engineering

The experiment was conducted to evaluate the comparative efficacy of ivermectin, neem and trichlorfon against humpsore in cattle. A total of 2765 cattle from different villages of Barisal and Patuakhali district were selected for the diagnosis of humpsore. The prevalence of humpsore was found to be 7.52% in the southern part of Bangladesh. Out of humpsore infected cattle, twenty five (25) cattle between 2 – 7 years of age and irrespective of sexes having typical lesion on hump and neck were selected for the experiment divided into five equals groups (A, B, C, D and E) and each group consists of 05 cattle. Group A kept as control group. Group B was treated with ivermectin (Vermic® @200 ug/kg body weight subcutaneously on 1th and 14th day), group C with neem ointment (20%) topically twice daily for 25 days and group D with trichlorfon 10% (Negotox®) topically twice daily for 25 days and group E was treated with combined ointment (Neem + Trichlorfon 10%) topically twice daily for 2...

Some of the results of a numerical investigation of the flow field characteristics of a transonic compressible flow over a flat plate with backward facing step of different heights are presented. The study has been performed by solving Two-Dimensional Navier-Stokes equations. The system of governing equations has been solved, using an explicit Harten-Yee Non-MUSCL Modified flux type TVD scheme and a zero-equation algebraic turbulence model to calculate the eddy viscosity coefficient. The results presented in this paper are computed for fixed Mach number, M=0.8 and for different step heights, h=2.5, 5 and 7.5mm. The details on pressure, temperature and velocity field, together with recirculation length, expansion shock, reattached shock, interaction of shock wave are reported. The variations of flow characteristics due to change of step heights are also presented.

The boundary layer separation of turbulent flow and its subsequent reattachment to a solid surface occurs in many engineering systems, and it has attracted many researchers due to its practical applications. Flows over air foils, in a channel with a sudden area increase, in gas turbines and many heat transfer devices are some of these applications. The combustor of a typical gas turbine represents some similarities with the turbulent flow over a backward facing step as the flame is stabilized by the recirculating area. Besides, due to the blockage, the sudden † To whom corresponding should be addressed.