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Abstract In order to further reduce the impact of climate fluctuations on the typical meteorological year (TMY) database, this paper introduces an ensemble empirical model decomposition method to extract the periodic fluctuation and random fluctuation data from outdoor climate data separately, and to construct a comprehensive description parameter that eliminates the influence of random fluctuation data. An innovative TMY based on the comprehensive description parameter was developed in six selected cities of different climate zones in China. Compared with the existing Chinese TMY development method and outdoor design parameters, it is found that the typical meteorological months (TMMs) of each city and the outdoor design parameters from the improved TMY database have changed to a certain extent. Through the correlation analysis between improved TMY database and the cumulative long-average meteorological data, it reveals that the improved TMY can better describe the local average climatic characteristics. Finally, this paper discusses the impact of the improved TMY on the building heat loss index and outdoor thermal comfort in different building shapes. The results demonstrate that the energy demand and outdoor thermal comfort analysis based on the improved TMY are closer to long-term averaged outdoor climate, and the calculation deviations compared with conventional method are reduced by 1.18%–21.08% and 53.42%–76.82% respectively. This research will refine outdoor climate data for building design and analysis.

Abstract In this paper, a finned heat pipe assisted passive heat sink based on a newly emerging high performance phase change material (PCM), the low melting point metal (LMPM), was developed for thermal buffering of high power electronics which works intermittently with heat generation rate up to 1000 W (10 W/cm2). Firstly, thermal performances of the PCM heat sink under different thermal shocks (from 200 W to 1000 W) were experimentally evaluated, in comparison with that of an organic PCM which has similar melting point. It was found that, the former one can prolong the working duration 1.4–2.4 times that of the latter one. Then, the performance of the heat sink was improved through reducing the contact thermal resistance and by increasing the fin number. Furtherly, an air cooling radiator was configured to accelerate the solidification process of the PCM module, which makes it capable of maintaining its highest temperature below 85 °C under 1000 W periodic thermal shock (10 min on and 15 min off). Moreover, energy dispersive spectrometer (EDS) analysis was conducted to verify the compatibility of the LMPM PCM and the structural materials. Finally, a simplified numerical model was developed and validated for the currently constructed finned heat pipe assisted LMPM PCM heat sink, which can be much helpful for future practical thermal design and optimization of this kind of thermal buffering module.

In recent years, solar absorbers have received widespread attention, however, large‐scale preparation is difficult to achieve for many absorbers, and the raw materials are expensive. Halloysite (HNTs) and palygorskite (PAL) have the advantage of abundant reserves and low prices. Herein, solar absorbers with bilayer and porous features are prepared from mixed clays of HNTs and PAL; further studies focused on the solar–thermal conversion efficiency of the absorbers. The mixed clays are gelated by aqueous polymerization of acrylamide and N, N′‐methylene bisacrylamide, then the surface of the gel is carbonized to obtain the double‐layer solar absorbers (F‐HNTs/PAL). The F‐HNTs/PAL shows excellent thermal stability with a weight‐loss ratio of 13% at 1,000 °C, good mechanical properties with a compressed strength of up to 200 KPa at 80% strain, abundant porosity with an adsorption pore volume of 0.057 cm3 g−1, and low thermal conductivity (0.206 W m−1 K−1). Under 1 sun illumination, the F‐HNTs/PAL has a higher vapor rate of 1.215 kg m−2 h−1 that equals 84% solar‐to‐vapor efficiency, which is much more than 57% of F‐HNTs prepared by the same methods, but the F‐HNTs/PAL shows unique thermal stability and mechanical property.

To fix CO2 emissions efficiently from flue gas of coal-fired power plants, the culture medium, light intensity and bioreactors were comprehensively optimized in the process of CO2 fixation by Chlorella PY-ZU1. To make up for relative insufficiency of nutrients (except for the carbon source) resulting from continuous bubbling of 15% CO2, three chemicals were added into the culture to optimize the molar ratios of nitrogen to carbon, phosphorus to carbon, and magnesium to carbon in culture from 0.17 to 0.69, from 0.093 to 0.096, and from 0.018 to 0.030, respectively. Such adjustments led to a 1.25-fold increase in biomass (from 2.41 to 5.42 g L(-1)). By enhancing light intensity from 4500 to 6000 lux, the peak growth rate of Chlorella PY-ZU1 increased by 99% and reached to 0.95 g L(-1) day(-1). Use of a multi-stage sequential bioreactor notably improved the peak CO2 fixation efficiency to 85.6%.

Abstract This paper discusses the minimization of the fuel consumption of a gasoline engine through dynamic optimization. The minimization uses a mean value model of the powertrain and vehicle. This model has two state variables: the pressure in the engine intake manifold and the engine speed. The control input is the throttle valve angle. The model is identified on a universal engine dynamometer. Optimal state and control trajectories are calculated using Bock’s direct multiple shooting method, implemented in the software MUSCOD-II. The developed approach is illustrated both in simulation and experimentally for a generic test case where a vehicle accelerates from 1100 rpm to 3700 rpm in 30 s . The optimized trajectories yield minimal fuel consumption. The experiments show that a linear engine speed trajectory yields an extra fuel consumption of 13 % when compared to the optimal trajectory. It is shown that, with a simple model, a significant amount of fuel can be saved without loss of the fun-to-drive.

Abstract Solid fuels such as firewood and coal are widely used for cooking and heating in the developing countries, which result in serious indoor air pollutions and health effects. Governments and international organizations have been devoted to addressing this issue for a long time. Based on the micro survey data from 1989–2011, this paper quantitatively investigate the situations and evolutions of cooking fuel using and its health effects in rural China. We have four findings: (i) most rural households still rely on solid fuels for cooking in modern China. (ii) the cooking fuels are slowly diversifying in the last two decades, (iii) there are considerably geographical differences in cooking fuel using across China, and (iv) those resident usually using solid fuel have lower levels of self-assessed health and higher prevalence of respiratory diseases. We then draw some policy implications to reduce cooking fuel use.

Sustainable food supply has gained considerable consumer concern due to the high percentage of spoilage microorganisms. Food industries need to expand advanced technologies that can maintain the nutritive content of foods, enhance the bio-availability of bioactive compounds, provide environmental and economic sustainability, and fulfill consumers’ requirements of sensory characteristics. Heat treatment negatively affects food samples’ nutritional and sensory properties as bioactives are sensitive to high-temperature processing. The need arises for non-thermal processes to reduce food losses, and sustainable developments in preservation, nutritional security, and food safety are crucial parameters for the upcoming era. Non-thermal processes have been successfully approved because they increase food quality, reduce water utilization, decrease emissions, improve energy efficiency, assure clean labeling, and utilize by-products from waste food. These processes include pulsed electric field (PEF), sonication, high-pressure processing (HPP), cold plasma, and pulsed light. This review describes the use of HPP in various processes for sustainable food processing. The influence of this technique on microbial, physicochemical, and nutritional properties of foods for sustainable food supply is discussed. This approach also emphasizes the limitations of this emerging technique. HPP has been successfully analyzed to meet the global requirements. A limited global food source must have a balanced approach to the raw content, water, energy, and nutrient content. HPP showed positive results in reducing microbial spoilage and, at the same time, retains the nutritional value. HPP technology meets the essential requirements for sustainable and clean labeled food production. It requires limited resources to produce nutritionally suitable foods for consumers’ health.

AbstractSolid‐state electrolytes (SSEs), being the key component of solid‐state lithium batteries, have a significant impact on battery performance. Rational materials structure and composition engineering on SSEs are promising to improve their Li+ conductivity, interfacial contact, and mechanical integrity. Among the fabrication approaches, the electrospinning technique has attracted tremendous attention due to its own merits in constructing a three‐dimensional framework of SSEs with precise porosity structure, tunable materials composition, easy operation, and superior physicochemical properties. To this end, in this review, we provide a comprehensive summary of the recent development of electrospinning techniques for high‐performance SSEs. Firstly, we introduce the historical development of SSEs and summarize the fundamentals, including the Li+ transport mechanism and materials selection principle. Then, the versatility of electrospinning technologies in the construction of the three main types of SSEs and stabilization of lithium metal anodes is comprehensively discussed. Finally, a perspective on future research directions based on previous work is highlighted for developing high‐performance solid‐state lithium batteries based on electrospinning techniques.

With the development of intelligent modern power systems, real-time sensing and monitoring of system operating conditions have become one of the enabling technologies. Due to their flexibility, robustness and broad serviceable scope, wireless sensor networks have become a promising candidate for achieving the condition monitoring in a power grid. In order to solve the problematic power supplies of the sensors, energy harvesting (EH) technology has attracted increasing research interest. The motivation of this paper is to investigate the profiles of harnessing the electric and magnetic fields and facilitate the further application of energy scavenging techniques in the context of power systems. In this paper, the fundamentals, current status, challenges, and future prospects of the two most applicable EH methods in the grid—magnetic field energy harvesting (MEH) and electric field energy harvesting (EEH) are reviewed. The characteristics of the magnetic field and electric field under typical scenarios in power systems is analyzed first. Then the MEH and EEH are classified and reviewed respectively according to the structural difference of energy harvesters, which have been further evaluated based on the comparison of advantages and disadvantages for the future development trend.