They may also have to pay higher taxes because higher fuel consumption could alter their cars' carbon dioxide rating.
For the near future, electric-powered and fuel-cell vehicles will get a free pass: a zero-grams-per-mile carbon dioxide rating.
It is based on indirect calorimetry, which determines energy expenditure of a person by measuring both consumed oxygen and produced carbon dioxide rates.
The influence of the carbon dioxide flow rate, the flow rate of the extractant solution, the ratio of D2EHPA to hexane in the extractant solution, the temperature and the replacement of hexane by methanol are investigated in this study.
Cbiomass, dry weight of biomass concentration; Yx/s and Yx/c, growth yield on substrate and carbon; qCO2 and qO2, specific carbon dioxide evolution rate and oxygen consumption rate; RQ, respiratory quotient; qprotein-EC, specific extracellular protein production rate; C-recovery, carbon recovery.
Samples were taken when the fermentation reached the steady state, defined by constant values of carbon dioxide transfer rate (CTR), oxygen transfer rate (OTR) and biomass concentration.
The ratio of carbon dioxide evolution rate (CER) to oxygen uptake rate (OUR) has previously proven useful in inferring a lack of substrates in the growth medium and in the calculation of feeding rates [ 41].
Because carbon dioxide production rate can be less sensitive to drift than oxygen consumption rate, we repeated all analyses using carbon dioxide production rate.
After the carbon dioxide feed rate increased in week 88, the methane production rate also increased, confirming that methane production was carbon dioxide limited.
Lowering the carbon dioxide feed rate during the first 6 weeks gradually lowered the methane production rate.
