Electric double layer capacitors (EDLCs) as promising electrical energy storage devices are faced with thermal management issues, which concern the performance and lifetime of the devices. Heat ...transfer at the solid-liquid interface has a crucial impact on the thermal management of EDLCs. In this work, the interfacial thermal resistance (Kapitza resistance) of the interface between ionic liquid (IL) and graphite electrode is determined, and the heat transfer resistance in the uncharged/charged system with different temperatures is investigated via molecular dynamics simulations. It is found that Kapitza resistance near the negative-charged interface decreases by 23% compared to that in the uncharged system, while the temperature effect on Kapitza resistance is little in our simulation. The unique ion layer structure of ILs formed at the interface may influence the thermal transport performance. Simulations are performed to investigate the effects of surface charge and working temperature on the heat transfer resistance of interfacial ILs from three aspects: ionic spacing, inter-ion interaction, and heat capacity. With the influence of surface charge, ionic spacing in the electric double layer is found to decrease while the inter-ion interaction and heat capacity increase, leading to the reduction in thermal resistance of interfacial ILs. However, rising temperature has small effects on the three thermal properties, with a slight tendency to increase the thermal resistance of ILs.
Thermal energy storage is highlighted as a crucial strategy for energy saving and utilization, in which domain, latent heat storage using phase change materials has gained great potential for ...efficient heat storage and thermal management applications. A strategy for developing high energy-storage-density and power-density latent heat storage units, through the compression-induced assembly of expanded graphite based stearic acid composites and the macro encapsulation method by using polyethylene shells, is demonstrated. The fabricated composite shows a satisfactory phase change enthalpy of 161.24 ± 0.5 J g−1, and enhances thermal conductivity to 13.4 ± 0.8 W m−1 K−1. The resulting heat storage unit also exhibits form-stable, leakage-proof, good homogeneity, and high-power-density behaviors. A 0.462 kWh proof-of-concept prototype of the packed-bed latent-heat-storage system by using 492 heat storage units has demonstrated its feasibility in fast heat charging/discharging operations. The outlet air temperature in the discharging process can maintain above 30 °C for over 1.74 h with a heat storage utilization efficiency of 90.3 ± 6.1% and an effective discharging efficiency of 93.5 ± 9.4%, under a volumetric flow rate of 30 m3 h−1 and heat storage temperature of 27–86 °C. The maximum and average power density, and effective energy density are obtained as 20.7 ± 1.6 kW m−3, 14.2 ± 0.9 kW m−3, 24.8 ± 2.5 kWh m−3, respectively, with a discharging threshold temperature of 30 °C. This high-power-density apparatus using form-stable heat storage units has realized hourly rapid heat charging-discharging processes, showing its prospective potential of low-temperature heat storage and thermal management.
•A compression-induced assembly and macro encapsulation method is developed to prepare phase-change heat storage units.•The fabricated EG-SA composite exhibits a satisfactory phase change enthalpy and enhanced thermal conductivity.•The resulting heat storage units show form-stable, leakage-proof, good homogeneity, and high-power-density behaviors.•A packed-bed latent-heat-storage prototype is demonstrated to realize hourly rapid heat charging and discharging processes.
Water-based adsorption thermal battery (ATB) could provide huge possibility in widespread applications; especially for space heating, leading to appreciable energy saving and low-grade heat energy ...utilization. A proof-of-concept prototype based on composite adsorbents has been constructed to investigate the thermal performances of a packed-bed ATB. A possible strategy of tunning airflow rate for performance regulation is proposed and studied to realize stable thermal output. Additional experimental results indicated that the output temperature and heating power can be synchronously stabilized through progressive tunability of loop airflow rate in the loop-cycle ATB system. The output RH spans 40–60% along the effective discharging process, enabling a controllable humidity management in the application of direct space heating considering human thermal comfort. A three-dimensional computational model for predicting the overall thermal output performances of a packed-bed adsorption thermal battery is further developed and established. The simulation results reveal that an effective heating time of 8.6 h with a discharging threshold temperature of 24 °C, and an average power density of 19.3 kW m−3 can be achieved with a maximum heat discharging efficiency of 63.4%. It is, therefore, apparent that the ATB is capable of achieving stable thermal outputs for space heating applications.
•An experimental and numerical parametric study analysis for the packed-bed adsorption thermal battery is conducted.•A strategy of tunning airflow rate for stable output performance is proposed and developed for adsorption thermal battery.•The proposed modelling and optimization method can be employed to analyze and predict overall thermal output performances.•Different combinations of open-cycle and loop-cycle modes in adsorption thermal battery can meet various heating demands.
Moisture-based adsorption thermal battery (ATB) holds great potential for addressing energy storage and utilization challenges. In this work, a proof-of-concept solar harvesting building envelope ...using the Trombe-wall (T-wall) based ATB design is proposed and investigated, featuring a developed composite sorbent as the porous wall for effective heat storage and utilization. To demonstrate the feasibility of employing the ATB-based building envelope for day-and-night space heating, a 3-dimensional simulation model of the ATB wall is meticulously designed and comprehensively studied. Parametric analyses of various working conditions, including examining the effects of solar radiation intensity, air temperature, air humidity, and airflow velocity on the heat charging and discharging performances of the ATB wall, are conducted using the numerical model. Simulation results indicate that, under a solar irradiance level of 700 W m−2 during the daytime, an average output air temperature of 42.4 °C and an average heating power density of 2.5 kW m−3 are achieved. Extending the heat charging time to 8 h and 12 h significantly improves the desorption efficiency, which is able to reach 47.2% and 75.0%, respectively. In terms of heat discharging performances, various working conditions investigated in the ATB wall model will lead to different thermal output performances.
•A building envelope concept of solar ATB wall is proposed to realize continuous space heating and low energy consumption.•A 3-dimensional simulation model of the solar ATB wall is investigated for parametric analysis and performance prediction.•The effects of solar radiation, air temperature, humidity and flow rate on the heating performance of the model are examined.
Moisture-based adsorption thermal batteries (ATBs) have the potential to alleviate the temporal and geographic mismatch between heat producers and heat consumers, but realizing practical applications ...is still challenging, in spite of the huge developments in novel materials and system design. Here, a proof-of-concept solar Trombe-wall (T-wall)-based ATB prototype with honeycomb-design, scalable, and low-cost CaCl
2
-based fiber brick with ink (ICFB) sorbents is reported for the first time. The ICFB achieves an outstanding thermal storage capacity of 172.8 kW h m
−3
and good stability in heat charging-discharging cycles. Importantly, the idea of the solar chimney effect in passive building heating is introduced into the system structural design to pursue optimal thermal output and energy saving. Together with the rational operating strategy, the T-wall-based ATB prototype shows exceptional thermal performance, achieving a heat discharging power density of 1.97 kW m
−3
, a discharging efficiency of 64.8%, an energy utilization coefficient of 0.87 kW h
t
kW h
c
−1
, and an energy consumption coefficient of 1.32 kW h
e
kW h
ts
−1
reduced by 54.2% in comparison with 100%-electricity use, demonstrating its adaptability and possibility of realizing day and night heating in low-carbon scenarios.
A proof-of-concept realization of a solar ATB wall envelope integrated into a residential building, which comprises a high-performance thermal battery and solar wall design, aiming at achieving day and night space heating in low-carbon scenarios.
Urbanization is a significant indicator of city progress, and as urbanization advances, carbon emissions exhibit an increasing trend that must not be disregarded. Therefore, it is imperative to ...thoroughly examine the spatial and temporal variations as well as the factors influencing carbon emissions during the urbanization process. In this paper, based on the 2009–2019 PRD region, carbon emissions are measured from energy consumption, industrial production process, solid waste, and wastewater according to the IPCC coefficients, and spatial and spatial differences in carbon emissions are combined with spatial analysis and the drivers analyzed using the gray correlation scale. The results show that: (1) The total carbon emissions in the PRD region have been increasing over the study period, and the distribution of total carbon emissions shows a pattern of “strong in the east and weak in the west”, with energy consumption accounting for the highest proportion of carbon emissions. (2) The global Moran Index of carbon emissions in the PRD has been decreasing, with low and low clustering concentrated in Shaoguan and Zhaoqing, high and high clustering concentrated in Dongguan and Shenzhen, and low and high clustering concentrated in Shenzhen and Guangzhou, with cold spots mainly concentrated in Zhaoqing and hot spots mainly distributed in Guangzhou, Shenzhen, and Dongguan. (3) The degree of economic growth has a substantial influence on carbon emissions in the PRD cities, and the influence of technical advancement has intensified. Guangzhou City is propelled by low-carbon regulations that have a more equitable influence on all elements. Zhuhai City has a more significant influence on energy intensity, while Foshan City has a more noticeable decrease in the effect of foreign investment. To address the issue of carbon emissions, the government should establish appropriate rules to regulate carbon emissions in areas with high emissions, foster collaborative efforts across cities, and encourage the growth of environmentally friendly enterprises.
Background
Intermittent energy restriction (IER) is an effective weight loss strategy. However, the accompanying changes in spontaneous neural activity are unclear, and the relationship among ...anthropometric measurements, biochemical indicators, and adipokines remains ambiguous.
Methods
Thirty-five obese adults were recruited and received a 2-month IER intervention. Data were collected from anthropometric measurements, blood samples, and resting-state functional magnetic resonance imaging at four time points. The regional homogeneity (ReHo) method was used to explore the effects of the IER intervention. The relationships between the ReHo values of altered brain regions and changes in anthropometric measurements, biochemical indicators, and adipokines (leptin and adiponectin) were analyzed.
Results
Results showed that IER significantly improved anthropometric measurements, biochemical indicators, and adipokine levels in the successful weight loss group. The IER intervention for weight loss was associated with a significant increase in ReHo in the bilateral lingual gyrus, left calcarine, and left postcentral gyrus and a significant decrease in the right middle temporal gyrus and right cerebellum (VIII). Follow-up analyses showed that the increase in ReHo values in the right LG had a significant positive correlation with a reduction in Three-factor Eating Questionnaire (TFEQ)-disinhibition and a significant negative correlation with an increase in TFEQ-cognitive control. Furthermore, the increase in ReHo values in the left calcarine had a significant positive correlation with the reduction in TFEQ-disinhibition. However, no significant difference in ReHo was observed in the failed weight loss group.
Conclusion
Our study provides objective evidence that the IER intervention reshaped the ReHo of some brain regions in obese individuals, accompanied with improved anthropometric measurements, biochemical indicators, and adipokines. These results illustrated that the IER intervention for weight loss may act by decreasing the motivational drive to eat, reducing reward responses to food cues, and repairing damaged food-related self-control processes. These findings enhance our understanding of the neurobiological basis of IER for weight loss in obesity.
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