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High-voltage heat release from batteries can cause safety issues for electric vehicles. Relevant scientific research work is carried out in the laboratory. The battery safety of laboratory experiments should not be underestimated. In order to evaluate the safety performance of batteries in the laboratory testing of driving conditions of electric vehicles, this paper simulated and compared the discharge characteristics of two common batteries (lithium iron phosphate (LFP) battery and nickel–cobalt–manganese (NCM) ternary lithium battery) in three different operating conditions. The operating conditions are the NEDC (New European Driving Cycle), WLTP (World Light Vehicle Test Procedure) and CLTC-P (China light vehicle test cycle) for normal driving of electric vehicles. LFP batteries have a higher maximum voltage and lower minimum voltage under the same initial voltage conditions, with a maximum voltage difference variation of 11 V. The maximum current of WLTP is significantly higher than NEDC and CLTC-P operating conditions (>20 A). Low current discharge conditions should be emulated in teaching simulation and experiments for safety reasons. The simulation data showed that the LFP battery had good performance in maintaining the voltage plateau and discharge voltage stability, while the NCM battery had excellent energy density and long-term endurance. [ABSTRACT FROM AUTHOR]

Experimental tests were conducted on a rectangular flume with different grid-type dam grid sizes, channel slopes and debris flow bulk density. We use the Bernoulli equation of energy conservation to deduce a formula to calculate debris-flow discharge. By combining the flume experiments with dimensional analysis methods, we mainly consider the bulk density of the debris flow, grid size of the grid-type dam, and flume slope to establish the discharge-coefficient correction formula and propose a method of calculating debris-flow discharge through a grid-type dam. The practical value of the formulas was illustrated using the Niwan gully, a tributary of Bailong River in Gansu province, China, as an example, which can be used as a reference in further practical engineering applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Characteristics of source-separated washing wastewater were investigated in China. • Onsite treatment of washing wastewater avoids use of sewage pipe and pump. • Removal of COD is improved by optimizing substrate, effluent is used for irrigation. China's toilet modernization has enabled thousands of villages to separate their feces and urines from the greywater or washing wastewater. Human feces and urine are usually used as raw materials for fertilizers, but the lack of understanding of discharge characteristics of washing wastewater in China rural areas affects the development of treatment technology and the reuse of treated water. In this study, a village in the lower reaches of the Yangtze River was selected to investigate the discharge characteristics of washing wastewater, and four kinds of subsurface constructed wetlands were used for treatment and reuse. The results showed that the production of washing wastewater in rural aeras was 59–232 L/(cap.d), with an average of 121 L/(cap.d). The bathing wastewater contributed the highest proportion of 46.19%. COD was identified as the key pollutants with average concentration of 337 mg/L. Compared with domestic wastewater, the concentrations of TN and TP were much lower with the average of 11.1 mg/L and 0.6 mg/L respectively. After treated by the constructed wetland with ceramsite, volcanic rock and anthracite as composite substrate, the effluent water met the requirements of paddy field crop irrigation, and the removal rates of COD, TN and TP achieved 61.5%, 68.8% and 70.5% respectively. Wetland plants and modular design had significant positive effects on the removal of nitrogen and phosphorous, but little effect on COD removal. The fecal coliforms in the effluent were all lower than 4.0 lg (MPN/L) in the four constructed wetlands, indicating they were not the limiting factors for irrigation reuse. [ABSTRACT FROM AUTHOR]