Although there appears to be some evidence to suggest that the concentration of CO2 in the soil may have A model that couples the diffusion of O2 to plant roots at the an effect on plant growth, the major effect of poor microscale to diffusion of O2 through the soil at the macroscale is derived. The solution is complex, but if the length scales (Zr and Zm; aeration on plant growth is the lack o...

Within the limits of this study, it was found that 5 ppm of cobalt was adequate to give good levels of vitamin B(12). The vitamin B(12) precursor 5,6-dimethylbenzimidazole was found to be adequate at 10 ppm in the absence of aeration. In the presence of aeration, a zero level of precursor was found to be most desirable. The analysis of variance showed aeration to be highly significant, and the ...

The parameters affecting the production of pectate lyase from P. polymyxa N10 were studied using the response surface methodology agitation rate (X1, 100-300 rpm), temperature (X2, 25-45 o C) and pH (X3, 5.5-9.5). The most significant factors influencing enzyme production were temperature and pH. The second order polynomial regression model obtained was fitted and found adequate, with an R 2 of...

A laboratory scale aeration treatment system was built to study the fate of nitrogen during aeration of pig slurry. For each run evaluated, the nitrogen mass balance was determined including measurement of the nitrous oxide gas emissions. Intermittent aeration led to a nitrogen removal of about 53% of the total nitrogen content of the raw slurry. About 18% of the total nitrogen content of the r...

Surface transfer and bubble transfer both contribute significantly to oxygen transfer in a diffused aeration system. In the present study, liquid-film-forming apparatus is successfully developed on a laboratory scale to improve considerably the surface transfer via the unique liquid film transfer technique. The experimental results show that the volumetric mass transfer coefficient for liquid-f...

Quantitative analysis of computed tomography (CT) is essential to the study of acute lung injury. However, quantitative CT is made difficult by poor lung aeration, which complicates the critical step of image segmentation. To overcome this obstacle, this study sought to develop and validate a semiautomated, multilandmark, registration-based scheme for lung segmentation that is effective in cond...

conclusions the streptomyces sp. suk 25 culturing was optimized using thronton media, at ph 7 and aeration of 140 rpm. further isolation and identification of bioactive compounds will develop anti-mrsa therapeutics. materials and methods disc diffusion and minimum inhibitory concentration (mic) assay were used to determine the antibacterial activity of streptomyces sp. isolates. optimization of...

with its well-known biological toxicity, the excessive concentrations of sulfide in tannery wastewaters may upset the biological treatment processes, thus leading to a substantial decrease in the efficiency of treatment plants. the presence of sulfide in wastewaters may dramatically interfere with microbial activities and consequently disturb the function of the system as a whole. in this study...

This study evaluated the effects of aeration (constant aeration, intermittent aeration and a lack of aeration) and hydraulic retention time (HRT) (2, 3 and 4 days) on a continuous process with cell recycling, using chitosan as a natural coagulant for the sedimentation of a C1 mixed culture. This culture was used for the biodegradation of hydrocarbons present in the effluent contaminated with di...