Venkata Rama Rao

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In a laboratory incubation study, the effect of select heavy metals on methane (CH4) oxidation in two rice soils was investigated under two moisture regimes. Heavy metals differed in their effect on CH4 oxidation in both soils under the two water regimes. Cr significantly inhibited CH4 oxidation in the alluvial soil at 60% moisture holding capacity, while(More)
The ecological risk assessment of East Fork Poplar Creek (EFPC) in Oak Ridge, Tennessee, investigated the nature and magnitude of the observed or expected adverse effects of the site's organic and inorganic contaminants on the ecosystem structure and function. Aquatic biota such as benthic macroinvertebrates, crayfish (Astacidae), redbreast sunfish (Lepomis(More)
The speech signal in general is corrupted by noise and the noise signal does not affect the speech signal uniformly over the entire spectrum. An improved Wiener filtering method is proposed in this paper for reducing background noise from speech signal in colored noise environments. In view of nonlinear variation of human ear sensibility in frequency(More)
A bulk acoustic mode micro-electro-mechanical dual resonator platform is utilised to study the evaporation of sub-microliter water droplets from the surface of the resonator. An analytical formulation for the observed frequency shift and the measure dependence of resonant frequency on the modes of evaporation which is consistent with the optically derived(More)
The influence of 2,4-dichlorophenoxy acetic acid (2,4-D) and ammonium on the nitrogenase activity of Azospirillum sp. under normal fixing and low-fixing conditions was evaluated. Nitrogenase activity was substantially stimulated following exposure to 2,4-D at various concentrations up to 5 ppm under normal fixing conditions. A pronounced enhancement in(More)
In a field study nitrogenase activity associated with rice rhizosphere was differently influenced by the applied herbicides. Pretilachlor at two application levels had no effect on nitrogenase activity while butachlor and benthiocarb exerted marginal stimulation. Cinmethylin consistently stimulated nitrogenase activity throughout the plant growth period.(More)
Nitrogen fixation by Spirillum sp. obtained from the roots of rice plants grown at different levels of combined nitrogen was studied. The roots of rice plants exposed to low levels of combined nitrogen (20--40 kg N/ha) harboured Spirillum sp. possessing higher nitrogen-fixing efficiency as compared to the cultures from plants receiving 60--100 kg N/ha.(More)