Shanshan Dai

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The presence of ZnO NPs in waste streams can negatively affect the efficiency of biological nutrient removal from wastewater. However, details of the toxic effects of ZnO NPs on microbial activities of wastewater biofilms have not yet been reported. In this study, the temporal and spatial inhibitory effects of ZnO NPs on the O2 respiration activities of(More)
The presence of ZnO nanoparticles (ZnO NPs) in natural waters has raised concerns about their environmental impacts, but the potential influences of ZnO NPs on fluvial biofilm have not been reported. In this study, the utility of antioxidant enzyme activities (AEA) as biomarkers of fluvial biofilm to ZnO NPs toxicity and a method that combines AEA into an(More)
Flume experiments were conducted to investigate the distribution and composition of extracellular polymeric substances (EPS) in biofilms and the detachment mechanism of biofilms grown under different flow velocity conditions. The results of biofilm growth kinetics showed that the growth trends were coincident with the logistic growth model. The growth(More)
An integrated current measurement system with ultra wide dynamic range is presented and fabricated in a 180-nm CMOS technology. Its dual-mode design provides concurrent voltage and frequency outputs, without requiring an external clock source. An integrator-differentiator core provides a voltage output with a noise floor of 11.6 fA/ [Formula: see text] and(More)
This paper presents a novel ultra-low-power dual-phase current-mode relaxation oscillator, which produces a 122 kHz digital clock and has total power consumption of 14.4 nW at 0.6 V. Its frequency dependence is 327 ppm/°C over a temperature range of -20° C to 100° C, and its supply voltage coefficient is ±3.0%/V from 0.6 V to 1.8(More)
The presence of nanoparticles (NPs) in natural aquatic environment is a potential risk to aquatic and human life. Periphyton, ubiquitous in aquatic environment, has been used to remove pollutants from aquatic systems. Understanding the interaction between NPs and periphyton will help to better predict the behavior and fate of NPs in aquatic media. This(More)
Zinc oxide nanoparticles (ZnO NPs) used in consumer products are largely released into the environment through the wastewater stream. The health hazard of ZnO NPs and the contribution of dissolved Zn(2+) in toxicity of ZnO NPs has attracted extensive worldwide attention. In this study, the toxic effects of ZnO nanoparticles (ZnO NPs) and the effects of(More)
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