No abstract

No abstract

No abstract

Eight pharmaceuticals, the anti-epileptic carbamazepine, two antibiotics sulfamethoxazole and erythromycin, and five non-steroidal anti-inflammatory drugs ibuprofen, naproxen, diclofenac, ketorolac, and ketoprofen were analyzed in influents and effluents of wastewater treatment plants in Jordan. After solid phase extraction at pH 4, the analytes were determined by LC-MS/MS using multiple reaction monitoring mode. For quantitation purposes, external calibration was applied first. Regression coefficients of !0.995 indicated the linearity in the concentration range of 0.5-100 ng/mL. Finally, single-point standard addition was applied to compensate matrix effects. The instrumental detection limits were between 0.05 and 20 pg amount injected. The method quantitation limits for spiked influent and effluent samples were 0.5 and 0.2 mg/L, respectively. Recovery rates were !78%. Precision given as relative standard deviations for within-day precision and time-different intermediate precision ranged from 2 to 21 and 1 to 19%, respectively. In this study, the maximum average concentrations found for ibuprofen were 5.7 mg/L in the influent and 2.2 mg/L in the effluent samples. The other pharmaceuticals ranged from 0.7 to 5.2 and 0.2 to 1.3 mg/L, respectively. Ketorolac and ketoprofen were not detected.

Summary The removal of condensate water droplets from gas channels is necessary for proper operation of proton exchange membrane fuel cells. In the current work, it is shown that corrugated wall gas channels can help in the removal of condensate water droplets formed on the channel walls. Removal of sessile droplets from channels having semicircle, rectangular dent, and saw‐tooth corrugation and at different gas velocities is modeled numerically. It is shown that the time of condensate removal is much shorter in a corrugated channel as compared with that in an uncorrugated channel. Three different droplet removal regimes are identified: droplet, film, and misty flow regimes. The transition from one to another regime is mapped based on the inlet flow velocity and the type of the channel corrugate.