This study assessed the influence of gasoline fuels with varying levels of aromatics and ethanol on the primary emissions and secondary aerosol formation from a flexible fuel vehicle equipped with a port fuel injection engine
The vehicle was exercised over the LA92 and US06 driving cycles using a chassis dynamometer. Secondary aerosol formation potential was measured using a fast oxidation flow reactor. Results showed that the high aromatics fuels led to higher gaseous regulated emissions, as well as particulate matter (PM), black carbon, and total and solid particle number. The high ethanol content fuel (E78) resulted in reductions for the gaseous regulated pollutants and particulate emissions, with some exceptions where elevated emissions were seen for this fuel compared to both E10 fuels, depending on the driving cycle. Secondary aerosol formation potential was dominated by the cold-start phase and increased for the high aromatics fuel. Secondary aerosol formation was seen in lower levels for E78 due to the lower formation of precursor emissions using this fuel.
In addition, operating driving conditions and aftertreatment efficiency played a major role on secondary organic and inorganic aerosol formation, indicating that fuel properties, driving conditions, and exhaust aftertreatment should be considered when evaluating the emissions of secondary aerosol precursors from mobile sources.Selection and Molecular Response of AHL-lactonase (aiiA) Producing Bacillus sp. Under Penicillin G-induced Conditions.Quorum sensing (QS) is the process by which microorganisms employ chemicals called autoinducers (AIs) to communicate with their population. The QS mechanism generally controls the expression of the virulence related genes in bacteria. N-acyl homoserine lactones (AHLs) are the most widespread QS molecules. Seebio Photobase Generator to their diverse AHL-lactonase activities, Bacillus species make particularly suitable candidates for procedures such as demolition of pathogenic bacterial QS signals and bioremediation of β-lactam antibiotics from contaminated environments.
In this study, seven Bacillus strains with Quorum quenching (QQ) activity were isolated using an enrichment medium supplemented with Penicillin G (PenG). The AHL-lactonase encoding gene (aiiA) was amplified by PCR and sequenced. Amino acid sequences underwent multiple sequence alignment. Docking studies were carried out with both C6HSL and PenG ligand using AutoDock tools. The aiiA amino acid sequences of the isolates were found to be well conserved. Furthermore, amino acid sequence alignment revealed that 74% of amino acid sequences were conserved in the genus Bacillus. Docking of the C6HSL to wild type (3DHA) and H97D variant reduced the docking score by only 0 kcal/mol for the mutated protein.
When PenG docked with a higher (1 kcal/mol) score as a ligand to wild-type and mutant receptors, the docking score for the mutated protein likewise decreased by 0 kcal/mol. This research contributed to the diversification of organisms with QQ activity and beta-lactam antibiotic resistance. It also clarified the binding score of the PenG ligand to the Bacillus AHL lactonase molecule for the first time.Fast co-pyrolysis behaviors and synergistic effects of corn stover and polyethylene via rapid infrared heating.Rapid infrared heating with fast heating rates and the capacity to load materials on the gram scale help investigate the co-pyrolysis behaviors, minimizing the gap of materials' pyrolysis temperature and volatile release during the co-pyrolysis. This work explored the effects of temperature and heating rate on the co-pyrolysis product s behaviors and synergistic interactions of corn stove and polyethylene. Initial increases in oil yield were followed by decreases when the heating rate rose, and when the temperature increased from 500 °C to 600 °C, the oil yield rose from 171 wt% to 208 wt% before falling to 145 wt% at 800 °C.
High heating rate promoted the oil generation, and the maximum oil yield was at 25 °C/s with varying heating rates from 15 °C/s to 35 °C/s. The pyrolysis gas produced at 25 °C/s exhibited the highest LHV (Low heating value) and lowest CO2 yield, which were 173 MJ/nm3 and 399 vol%, respectively. The suitability of heating rate and temperature may improve the interaction between H-radicals of PE and oxygenated groups of CS to generate stable macromolecular compound and enhance oil production. GC-MS studies of the oil products demonstrated that oxygenated compounds such as furans, phenols and acids from lignocellulosic depolymerization had been converted to high molecular weight long chain alcohols (mostly C26, C20 and C14 alcohols) via stronger interactions during fast infrared-heated co-pyrolysis. The alcohols increased from 329 % to 656 % as temperatures rose from 500 °C to 800 °C. Few furan heterocycles, acids and phenols were detected, suggesting that the oil presented higher quality and stronger synergistic effects.
