6 research outputs found
Robots in machining
Robotic machining centers offer diverse advantages: large operation reach with large reorientation capability, and a low cost, to name a few. Many challenges have slowed down the adoption or sometimes inhibited the use of robots for machining tasks. This paper deals with the current usage and status of robots in machining, as well as the necessary modelling and identification for enabling optimization, process planning and process control. Recent research addressing deburring, milling, incremental forming, polishing or thin wall machining is presented. We discuss various processes in which robots need to deal with significant process forces while fulfilling their machining task
Assessment of toxicity and kinetic effects of erythromycin on activated sludge consortium by fast respirometry method
Background: The present study aimed to assess the acute impact of erythromycin (ERY) as an
inhibitor on peptone mixture utilization of activated sludge (AS) consortium.
Methods: For this purpose, the inhibition of oxygen consumption was used based on the ISO
8192:2007 procedure. In this method, the AS consortium (10-day age) was extracted from labscale
membrane bioreactor, then, percentage inhibition for total, heterotrophic, and nitrifying
microorganisms, in separate batch respirometric tests were calculated in the absence and
presence of N-allylthiourea (ATU) as a specific Nitrification inhibitor.
Results: The obtained data showed that the height of oxygen uptake rate (OUR) profiles and
amount of oxygen consumption reduced with increasing ERY dose. The half-maximal effective
concentration (EC50) of ERY for heterotrophic and nitrifier microorganisms were 269.4 and
1243.1 mg/L, respectively. In Run 1, the kinetic coefficients bH, fA,H, YH, and μH were calculated
as 2.61 d-1, 0.44, 0.4945 mg VSS/mg COD, and 0.047 d-1, respectively. Also, for maximum ERY
concentration (1000 mg/L), the kinetic coefficients bH., fA,H, YH, and μH were calculated as 2.27
d-1, 0.3, 0.4983 mg VSS/mg COD, and 0.0049 d-1, respectively.
Conclusion: The findings showed that the inhibitory impact of ERY was observed as a decrease
in the amount of oxygen consumption by OUR profiles in rapid respirometric method (ISO
8192), which offered a novel insight for the acute inhibitory impact of this antibiotic. Also,
chemical oxygen demand (COD) as an overall substrate parameter is most helpful in interpreting
the behavior and the metabolic functions of AS systems.
Keywords: Toxicity, Erythromycin, Activated sludge, Respirometry, Kinetic coefficient