Abstract: The issue of turbulence base streams and the drag related to it have been of important attention for rockets, missiles, and aircraft. Different techniques are used for base drag reduction. This paper presents the numerical study of numerous drag reduction technique. The base drag or afterbody drag of bluff bodies can be reduced easily using locked vortex drag reduction technique. For bluff bodies having a cylindrical shape, the base drag is much larger compared to streamlined bodies. For such bodies using splitter plates, the vortex can be trapped between the base and the plate, which results in smooth flow. Splitter plate with round and curved corner shapes has influence in drag reduction. In this paper, the comparison is done between single splitter plate as different positions and with the bluff body. Base drag for the speed of 30m/s can be reduced about 20% to 30% by using single splitter plate as compared to the bluff body.
Abstract: The whole-cell protein-profiling technique was
evaluated for studying differences in banding pattern of three
different species of Cyanobacteria i.e. Anabaena fertilissima,
Aulosira fertilissima and Westiellopsis prolifica under the influence
of four different pesticides-2,4-D (Ethyl Ester of 2,4-Dichloro
Phenoxy Acetic Acid), Pencycuron (N-[(4-chlorophenyl)methyl]-Ncyclopentyl-
N'–phenylurea), Endosulfan (6,7,8,9,10,10hexachloro-
1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepine-3-
oxide) and Tebuconazole (1-(4-Chlorophenyl)-4,4-dimethyl-3-(1,2,4-
triazol-1-ylmethyl)pentan-3-ol). Whole-cell extracts were obtained by
sonication treatment (Sonifier cell disruptor -Branson Digital Sonifier
S-450D, USA) and were analyzed by sodium dodecyl sulfate
polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE
analyses of the total protein profile of Anabaena fertilissima,
Aulosira fertilissima and Westiellopsis prolifica showed a linear
decrease in the protein content with increasing pesticide stress when
administered to different concentrations of 2, 4-D, Pencycuron,
Endosulfan and Tebuconazole. The results indicate that different
stressors exert specific effects on cyanobacterial protein synthesis.
Abstract: Economically transformers constitute one of the largest investments in a Power system. For this reason, transformer condition assessment and management is a high priority task. If a transformer fails, it would have a significant negative impact on revenue and service reliability. Monitoring the state of health of power transformers has traditionally been carried out using laboratory Dissolved Gas Analysis (DGA) tests performed at periodic intervals on the oil sample, collected from the transformers. DGA of transformer oil is the single best indicator of a transformer-s overall condition and is a universal practice today, which started somewhere in the 1960s. Failure can occur in a transformer due to different reasons. Some failures can be limited or prevented by maintenance. Oil filtration is one of the methods to remove the dissolve gases and prevent the deterioration of the oil. In this paper we analysis the DGA data by regression method and predict the gas concentration in the oil in the future. We bring about a comparative study of different traditional methods of regression and the errors generated out of their predictions. With the help of these data we can deduce the health of the transformer by finding the type of fault if it has occurred or will occur in future. Additional in this paper effect of filtration on the transformer health is highlight by calculating the probability of failure of a transformer with and without oil filtrating.