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A novel conversion type cathode of α-Ag2S as a robust cathode for rechargeable Mg batteries with excellent performances.

The concentrations of methoxylated polychlorinated biphenyls (MeO-PCBs) and hydroxylated polychlorinated biphenyls (OH-PCBs) were measured in the sewage sludge samples collected from twelve wastewater treatment plants in China. Two MeO-PCB congeners, including 3′-MeO-CB-65 and 4′-MeO-CB-101, were detected in three sludge with mean concentrations of 0.58 and 0.52 ng/g dry weight, respectively. OH-PCBs were detected in eight sludge samples, with an average total concentration of 4.2 ng/g dry weight. Furthermore, laboratory exposure was conducted to determine the possible source of OH-PCBs and MeO-PCBs in the sewage sludge, and their metabolism by the microbes. Both 4′-OH-CB-101 and 4′-MeO-CB-101 were detected as metabolites of CB-101 at a limited conversion rate after 5 days. Importantly, microbial interconversion between OH-PCBs and MeO-PCBs was observed in sewage sludge. Demethylation of MeO-PCBs was favored over methylation of OH-PCBs. The abundant and diverse microbes in sludge play a key role in the transformation processes of the PCB analogues. To our knowledge, this is the first report on MeO-PCBs in environmental matrices and on OH-PCBs in sewage sludge. The findings are important to understand the environmental fate of PCBs.

Purpose – The purpose of this paper is to identify the key parameters that control the bonding formation of foils by the ultrasonic consolidation (UC) process and to build the correlations among process operating conditions and key control parameters through the concept of “process map”. Design/methodology/approach – The concept of “process map” is proposed based on the diffusion bonding mechanism for the UC process, and numerical simulations have been applied to the UC process to predict peak temperature and plastic strain at the contact interface by considering a wide range of process operating conditions. Findings – This map reveals that the formation of bonding among foils by the UC process requires a good match between temperature and plastic deformation at the contact interface. This limits the process operating window to a narrow region in the strain – temperature coordinate system. Originality/value – This work has identified the underlying mechanism for bonding formation and the key control parameters of the UC process. The concept of “process map” for the UC process was developed, which allows the process optimization through two critical process control parameters of temperature and plastic strain at the contact interface instead of five operating conditions.