Abstract

Electrochemical impedance spectroscopy (EIS) allows detailed investigations of polarization processes and is widely used to study the kinetics of electrode reaction in lithium-ion batteries. The distribution of relaxation times (DRT) calculated from the EIS offers a model-free approach for a deeper understanding of various electrochemical processes. A joint estimation method is proposed to identify the differential capacity caused by diffusion processes and the DRT for all polarization processes simultaneously. The differential capacity from EIS and the incremental capacity from incremental capacity analysis (ICA) have an equivalence verified by mathematical derivation. Different types of lithium-ion batteries are tested by the EIS and the ICA methods to verify the equivalence. The differential capacity extends the application of the ICA method.

Abstract

Online ride-hailing is an emerging and popular transportation mode under the framework of sharing economy. Its emission issue has been focused by researchers for seeking a clean and efficient way to service passengers. In this paper, we based on stochastic optimization to proposed a smart matching method. The GPS dataset of Didi company in Chengdu city is employed to test the method. Compared with the shortest distance based matching method, the proposed method is able to reduce the invalid emission rate from 0.2834 to 0.2554 which proves the practicability of our method.

Abstract

This study aims to determine the losses of a permanent magnet synchronous machine used for propulsion of a railway electric vehicle in no-load and low-power operation conditions, found during vehicle coasting and low acceleration/deceleration speed profile. The simulation results are showing that it would be preferable to operate the electric machine at low power instead cutting the power from inverter.

Abstract

The condensation problem of thermal insulation walls is becoming increasingly serious. The problem not only affects the performance of the thermal insulation layer and durability of the envelope structure but also increases the risk of mildew. To explore the condensation characteristics of thermal insulation walls and the anti-condensation effect of the vapour barrier in hot and humid areas in China, a coupled heat and moisture transfer model of a one-dimensional wall with temperature and relative humidity as the driving potential was established and verified. Taking the internal and external thermal insulation walls of EPS-Clay brick as an example, the relative humidity distribution of eight types of envelope structures with vapour barriers at three different interfaces or without vapour barriers was simulated. The results show that the best anti-condensation effect is provided by creating a vapour barrier outside of the wall (Interface 1 of internal and external thermal insulation walls). Therefore, in the high-humidity area represented by Guangzhou, the vapour barrier layer is recommended to be set at Interface 1.

Abstract

In recent years, the Brazilian electricity sector has been experiencing high levels of non-technical losses, impacting both the electricity tariff paid by the consumer and the financial balance of the distributors. The high levels of NTP have multiple causes, ranging from the management difficulties of the distributors themselves in the fight against losses, even to the regional socioeconomic complexities. Aneel is the entity responsible for regulating the levels of these losses, using an own methodology applied in each rate review cycle. In this context, the present article sought to develop a metric capable of evaluating, measuring and classifying the effectiveness of the regulatory methodologies of NTP treatment, according to the results obtained at the end of each regulatory period. For this evaluation, it was identified the possibility of using Multicriteria Analysis techniques, such as the TODIM method. Because of their ability to handle different perceptions of interest.

Abstract

The Yellow River basin is an important coal production area in China, where are shortage of water resources also. Analysis water consumption in coal base is an important premise for China’s energy sustainable development. Based on the present situation of coal production in Yellow River basin, this paper uses the quota method to calculate the current water consumption of coal bases, and analyzes the trend of future water use. The research results show that coal bases’ water demand of Yellow River basin in 2015 and 2020 is 3.384 billion m3 and 4.315 billion m3, respectively. Thermal power is still the largest water user in coal bases, water consumption of coal mining and coal chemical industry has not increased significantly in the future. Overall, the increase of coal bases’ water demand in the Yellow River basin is not large in the future, watersupply of coal bases can be guaranteed. But the contradiction between supply and demand of water resources in Shendong base is prominent, and base development scale need reasonable control according to local water resources.

Abstract

Electric Distribution Loss is a problem in many countries, but some have managed to incentivize the distribution companies to combat these losses effectively. Thus, in order to broaden the debate on the topic, this article develops a mapping of different experiences in the regulatory treatment of distribution losses, focused on commercial losses. A comparison of experiences in 13 countries shows six major innovative approaches: individualized treatment, efficient company model, treatment based on companies’ similarity, specific treatment based on companies’ individual performance, and specific treatment for areas with high criminality.

Abstract

Application of electronic fuel injection lead to rate shaping of fuel at different injection pressures on
internal combustion engines. In the present study, an experimental investigation was performed to study the influence of multiple injections on a modified single cylinder air-cooled diesel engine operating in reactivity controlled compression ignition combustion mode-a clean combustion mode with higher thermal efficiency, in which extensive research is being performed now a days to meet emission norms. One of the key characteristics of this combustion mode is combustion phasing control, by varying fuel reactivity distributions prior to start of ignition that greatly influences combustion process. Diesel injection pressure and the split diesel fuel mass has a vast impact on fuel reactivity. Methanol has been injected at port (a low reactivity fuel) and diesel has been injected directly into the cylinder. The RCCI combustion strategy was realized at no load by varying high reactivity diesel injection pressure from 400 bar to 600 bar and start of injection mass variation from 40% to 80%. It was found from the investigation that increasing the injection pressure from 400 bar to 600 bar had a better effect on combustion parameters and emissions. At 60% fuel injection mass, the indicated thermal efficiency and emissions showed a better result than other combinations.