Model dependence of the multi-transonic behavior, stability properties and corresponding acoustic geometry for accretion onto a spinning black hole

Multi-transonic accretion for a spinning black hole has been compared among different disc geometries within post Newtonian pseudo potential framework. The variation of stationary shock characteristics with black hole spin has been studied in details for all the disc models and compared for adiabatic as well as for isothermal scenario. The variations of surface gravity with spin for all these cases have also been investigated.Comment: 18 pages. 19 figure

Studies on Phytochemical Analysis, Antioxidant, Antibacterial and Larvicidal Properties of the Acacia nilotica Fruit Extracts

In the present study fruit of Acacia nilotica was chosen to evaluate its antioxidant, larvicidal and antibacterial properties. Phytochemical screening of aqueous and alcohol extracts of the plant fruits affirmed the presence of carbohydrates, reducing sugar, phenol, flavonoid, terpenoid, saponin and steroid. The antioxidant properties of the aqueous and alcohol fruit extracts were noted as 10.11±0.035 and 9.75±0.023 mM of FeSO4 for Ferric Reducing Antioxidant Power (FRAP) assay respectively. The potency of antimicrobial activity of the aqueous and alcohol extract of A. nilotica fruit were tested against Pseudomonas aeruginosa, Staphylococcus aureus, Bacillussubtilis, and Escherichiacoli. The alcohol extract against E. coli, exhibited the highest antimicrobial activity. Aqueous extracts of A. nilotica fruit showed potential toxicity against Aedes albopictus larvae with LC50 value of 142.074 mg L-1. Present findings clearly indicated that A. nilotica fruit extracts could be most effectively used as a natural antioxidant, antibacterial and larvicidal agent

Bacterial Flora of Water and Rotifers in Outdoor Mass Culture Tanks Fed with Different Microalagal Diets

Investigations were carried out on the bacterial flora of water and the quality of rotifers in outdoor mass culture tanks. Brachionus plicatilis and B. rotundiformis were cultured in 10 numbers of 1 tonne tanks and the physico-chemical parameters and microbial loads of water, and total bacterial and Vibrio loads of microalgae and rotifers, during the period 2014-15, were studied. The study revealed a significant variation of the ammonia levels and total bacterial loads with different diets (P < 0.05). A positive correlation was observed between the total bacterial loads of algal concentrations and loads of rotifers, but no correlation was observed between Vibrio loads of water and rotifers. The prevalence of Vibrio loads of rotifers was low in tanks fed with Nannochloropsis oculata and maximum Vibrio loads were recorded in Chaetoceros calcitrans fed rotifers. The Vibrio loads significantly varied with days of culture and also with the algal diets. A positive correlation was observed between the total Vibrio loads of water and rotifers