Changes in the fractions of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria in two laboratory-scale reactors were investigated using 16S rRNA probe hybridizations. The reactors were operated in intermittent aeration mode and different aeration cycles to treat anaerobically digested swine wastewater with ammonia concentrations up to 175 mg NH(3)-N/L. High ammonia removals (>98.8%) were...

BACKGROUND Prone position is used to recruit collapsed dependent lung regions during severe acute respiratory distress syndrome, improving lung elastance and lung gas content. We hypothesised that, in the absence of recruitment, prone position would not result in any improvement in lung mechanical properties or gas content compared to supine position. METHODS Ten healthy pigs under general an...

Because surface-applied manures can contribute to phosphorus (P) in runoff, we examined mechanical aeration of grasslands for reducing P transport by increasing infiltration of rainfall and binding of P with soil minerals. The effects of three aeration treatments and a control (aeration with cores, continuous-furrow "no-till" disk aeration perpendicular to the slope, slit aeration with tines, a...

Microbial fuel cell (MFC) technology provides a low cost alternative to conventional aerated wastewater treatment, however, there has been little comparison between MFC and aeration treatment using real wastewater as the substrate. This study attempts to directly compare the wastewater treatment efficiency and energy consumption and generation among three reactor systems-a traditional aeration ...

A small laboratory fermentor which employs mechanical agitation for the dispersion of air introduced under pressure has previously been described by Feustel and Humfeld (1946). This fermentor has an operating capacity of 500 to 2,000 ml and has been found very useful for small-scale, yeast-culturing investigations, as well as for studies on the production of subtilin activity by Bacillus subtil...

A bench-scale study on swine manure stabilization for odour control was conducted using batch aeration reactors. In trial 1, two aeration lengths, i.e., 0.5 and 4.0 day, were used under uncontrolled ambient temperature that increased gradually over the experimental period. While in trial 2, a 16.0-day aeration scheme was employed under constant 17 degrees C. An airflow rate of 1.2L/s/m(3) was u...

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 ...

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...