A continuous butanol production system with high-density Clostridium saccharoperbutylacetonicum N1-4 generated by cell recycling was established to examine the characteristics of butanol fermentation from xylose. In continuous culture without cell recycling, cell washout was avoided by maintaining pH>5.6 at a dilution rate of 0.26 h(-1), indicating pH control was critical to this experiment. Su...

Comparison of flow rates measured from precordial dilution curves, simultaneous direct arterial dilution curves, and nearly simultaneous Fick determinations in 29 patients failed to indicate any difference in precision. Successive precordial determinations of flow rate were adequately reproducible. It is concluded that the precordial dilution method gives flow values comparable to those obtaine...

A comparative study of DC, RF and VHF excitation for the plasma enhanced chemical vapor deposition (PECVD) of intrinsic layers of a-Si:H is presented, with special emphasis on the effects of hydrogen dilution. Growth rates at comparable plasma power, for substrate temperatures between 100°C and 300°C and for various H2 dilution ratios are presented, along with optical bandgap, H content, and el...

The cerebrospinal fluid (CSF) formation rate (Vf) has been extensively studied by the ventriculocisternal perfusion, a method still regarded as the most precise one. This method as well as the equation for the calculation of the CSF formation rate (Vf) was established by Heisey et al on indicator dilution in perfusate. They assumed that the dilution of the indicator substance in perfusion is a ...

Modern chemical legislation requires measuring the bioconcentration factor (BCF) of large numbers of chemicals in fish. The BCF must be corrected for growth dilution, because fish growth rates vary between laboratories. Two hypotheses were tested: (1) that BCFs of multiple chemicals can be measured simultaneously in one experiment, and (2) that internal benchmarking using a conservative test su...

The yeast Pachysolen tannophilus was entrapped in calcium alginate beads to ferment D-xylose on a continous basis in the presence of high cell densities. Experimental operating variables included the feed D-xylose concentration, the dilution rate, and the fermentor biomass concentration. Under favorable operating conditions, cultures retained at least 50% of their initial productivity after 26 ...

One of the great challenges in pipeline transportation heavy crude oil is effect viscosity on flow rate. By using reduction techniques, ability can be enhanced. However, dual dilution and electric fields still not well addressed. The main goal this study to reduce improve rate through pipelines techniques electrical field dilution. optimization technique was used investigate interaction effects...