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Thermal comfort is of critical importance to people during hot weather or harsh working conditions to reduce heat stress. Therefore, personal cooling garments (PCGs) is a promising technology that provides a sustainable solution to provide direct thermal regulation on the human body, while at the same time, effectively reduces energy consumption on whole-building cooling. This paper summarizes the current status of PCGs, and depending on the requirement of electric power supply, we divide the PCGs into two categories with systematic instruction on the cooling materials, working principles, and state-of-the-art research progress. Additionally, the application fields of different cooling strategies are presented. Current problems hindering the improvement of PCGs, and further development recommendations are highlighted, in the hope of fostering and widening the prospect of PCGs.

Stone fruit trees of genus Prunus, like other temperate woody species, need to accumulate a cultivar-specific amount of chilling during endodormancy, and of heat during ecodormancy to flower properly in spring. Knowing the requirements of a cultivar can be critical in determining if it can be adapted to a particular area. Growers can use this information to anticipate the future performance of their orchards and the adaptation of new cultivars to their region. In this work, the available information on chilling- and heat-requirements of almond, apricot, plum, peach, and sweet cherry cultivars is reviewed. We pay special attention to the method used for the determination of breaking dormancy, the method used to quantify chilling and heat temperatures, and the place where experiments were conducted. The results reveal different gaps in the information available, both in the lack of information of cultivars with unknown requirements and in the methodologies used. The main emerging challenges are the standardization of the conditions of each methodology and the search for biological markers for dormancy. These will help to deal with the growing number of new cultivars and the reduction of winter cold in many areas due to global warming.

Heat barrier, the unrestricted increase in airplane or rocket speeds caused by aerodynamic heating, which—without adequate provisions for cooling the exposed surfaces—can lead to the loss of a hypersonic vehicle’s reusability, maneuverability, and cost-effectiveness. To date, indirect thermal protection methods, such as regenerative cooling, film cooling, and transpiration cooling, have proven to be complex and inefficient. Here, we propose a direct liquid cooling system to mitigate the heat barrier, utilizing a blunt-sharp structured thermal armor (STA)—a recently proposed material [36] to elevate the Leidenfrost point. The fiber-metal nano-/micro-STA withstands rigorous simulated hypersonic aerodynamic heating using butane and acetylene flames, ensuring effective temperature management in scenarios where flame temperatures reach up to 3000 °C—far exceeding the melting point of the STA substrate. Systematic cycling and durability tests further confirm the STA’s exceptional tolerance and robustness under extreme conditions. This work offers an efficient thermal protection method for hypersonic vehicles. Heat barriers pose significant challenges to hypersonic flight. Here, authors demonstrate a direct liquid cooling system using a structured thermal armor that elevates the Leidenfrost point, effectively managing temperatures up to 3000 °C.

The use of accelerated beams of electrons, protons or ions has furthered the development of nearly every scientific discipline. However, high-energy muon beams of equivalent quality have not yet been delivered. Muon beams can be created through the decay of pions produced by the interaction of a proton beam with a target. Such ‘tertiary’ beams have much lower brightness than those created by accelerating electrons, protons or ions. High-brightness muon beams comparable to those produced by state-of-the-art electron, proton and ion accelerators could facilitate the study of lepton–antilepton collisions at extremely high energies and provide well characterized neutrino beams 1 – 6 . Such muon beams could be realized using ionization cooling, which has been proposed to increase muon-beam brightness 7 , 8 . Here we report the realization of ionization cooling, which was confirmed by the observation of an increased number of low-amplitude muons after passage of the muon beam through an absorber, as well as an increase in the corresponding phase-space density. The simulated performance of the ionization cooling system is consistent with the measured data, validating designs of the ionization cooling channel in which the cooling process is repeated to produce a substantial cooling effect 9 – 11 . The results presented here are an important step towards achieving the muon-beam quality required to search for phenomena at energy scales beyond the reach of the Large Hadron Collider at a facility of equivalent or reduced footprint 6 . Ionization cooling, a technique that delivers high-brightness muon beams for the study of phenomena at energy scales beyond those of the Large Hadron Collider, is demonstrated by the Muon Ionization Cooling Experiment.

Introduction HRV is considered a marker of ANS function. It has become a marker of interest in evaluating nervous system function following traumatic brain injury. This study validates prior research using larger sample sizes proposes a model for establishing baseline HRV reactivity in healthy participants. Methods 62 healthy college athletes were recruited for this study. Following an informed consent process they were evaluated supine using the Elite HRV Cor-sense monitor and platform to record LF/HF ratio and RMSSD over 5 minutes. A bag of ice was placed on their face, then RMSSD and LF/HF ratio were collected over 3 successive 1-minute intervals. Results RMSSD was elevated at 1 and 2 minutes (+47.4 ms, P <.0001; +16.5 ms P = .014) following face cooling and fell to baseline at 3 minutes (+4.6 ms, P = 0.52). LF/HF ratio decreased following face cooling at 2 and 3 minutes (change from rest %: 2 minutes: -33%, P=.007; 3 minutes -50%, P=<.0001). Conclusion The Elite HRV platform can detect an elevation in RMSSD in the first minute following face cooling with a successive return to baseline in the second and third minutes. It can also detect a consistent decrease in LF/HF following face cooling.

The performance of lithium-ion batteries is closely related to temperature, and much attention has been paid to their thermal safety. With the increasing application of the lithium-ion battery, higher requirements are put forward for battery thermal management systems. Compared with other cooling methods, liquid cooling is an efficient cooling method, which can control the maximum temperature and maximum temperature difference of the battery within an acceptable range. This article reviews the latest research in liquid cooling battery thermal management systems from the perspective of indirect and direct liquid cooling. Firstly, different coolants are compared. The indirect liquid cooling part analyzes the advantages and disadvantages of different liquid channels and system structures. Direct cooling summarizes the different systems’ differences in cooling effectiveness and energy consumption. Then, the combination of liquid cooling, air cooling, phase change materials, and heat pipes is examined. Later, the connection between the cooling and heating functions in the liquid thermal management system is considered. In addition, from a safety perspective, it is found that liquid cooling can effectively manage thermal runaway. Finally, some problems are put forward, and a summary and outlook are given.

We present results of a radiant cooling system that made the hot and humid tropical climate of Singapore feel cool and comfortable. Thermal radiation exchange between occupants and surfaces in the built environment can augment thermal comfort. The lack of widespread commercial adoption of radiant-cooling technologies is due to two widely held views: 1) The low temperature required for radiant cooling in humid environments will form condensation; and 2) cold surfaces will still cool adjacent air via convection, limiting overall radiant-cooling effectiveness. This work directly challenges these views and provides proof-ofconcept solutions examined for a transient thermal-comfort scenario. We constructed a demonstrative outdoor radiant-cooling pavilion in Singapore that used an infrared-transparent, lowdensity polyethylene membrane to provide radiant cooling at temperatures below the dew point. Test subjects who experienced the pavilion (n = 37) reported a “satisfactory” thermal sensation 79% of the time, despite experiencing 29.6 ± 0.9 °C air at 66.5 ± 5% relative humidity and with low air movement of 0.26 ± 0.18 m−1. Comfort was achieved with a coincident mean radiant temperature of 23.9 ± 0.8 °C, requiring a chilled water-supply temperature of 17.0 ± 1.8 °C. The pavilion operated successfully without any observed condensation on exposed surfaces, despite an observed dew-point temperature of 23.7 ± 0.7 °C. The coldest conditions observed without condensation used a chilled water-supply temperature 12.7 °C below the dew point, which resulted in a mean radiant temperature 3.6 °C below the dew point.

Buildings account for 36% of global final energy demand and are key to mitigating climate change. Assessing the evolution of the global building stock and its energy demand is critical to support mitigation strategies. However, most global studies lack granularity and overlook heterogeneity in the building sector, limiting the evaluation of demand transformation scenarios. We develop global residential building scenarios along the shared socio-economic pathways (SSPs) 1–3 and assess the evolution of building stock, energy demand, and CO 2 emissions for space heating and cooling with MESSAGEix-Buildings, a modelling framework soft-linked to an integrated assessment framework. MESSAGEix-Buildings combines bottom-up modelling of energy demand, stock turnover, and discrete choice modelling for energy efficiency decisions, and accounts for heterogeneity in geographical contexts, socio-economics, and buildings characteristics. Global CO 2 emissions for space heating are projected to decrease between 34.4 (SSP3) and 52.5% (SSP1) by 2050 under energy efficiency improvements and electrification. Space cooling demand starkly rises in developing countries, with CO 2 emissions increasing globally by 58.2 (SSP1) to 85.2% (SSP3) by 2050. Scenarios substantially differ in the uptake of energy efficient new construction and renovations, generally higher for single-family homes, and in space cooling patterns across income levels and locations, with most of the demand in the global south driven by medium- and high-income urban households. This study contributes an advancement in the granularity of building sector knowledge to be assessed in integration with other sources of emissions in the context of global climate change mitigation and sustainable development.

Abstract Reducing cooling loads in hot countries requires thermal insulation, and cooling methods be improved. Evaporative cooling, although problematic, is one solution that can be explored since it is significantly more efficient than regular compressor air conditioners, and the net result of using one is cooling. Furthermore, while compressor air conditioner efficiency decreases with rising temperatures in summer, evaporative ones, up to a point, are the exact opposite. A novel hybrid cooling system capable of combining both showed an 80% decrease in cooling load. The system’s efficacy was assessed in this paper by thermally simulating designs that are suitable for the hot Middle East region. Two locations with different environments and building guidelines that are representative of the variations in the area were selected. The first was the hot, dry Baghdad environment; the other was Dubai’s coastal, more humid city. Two different houses were designed to suit the municipal rules of each and accommodate the hybrid cooling system. As expected, the simulation results showed that savings in the dry Baghdad climate were high at 78% compared to a non-insulated alternative. In Dubai, unsurprisingly, they were less at 52% on the more humid coast. Further simulations revealed that this latter figure in the humid coast could also be achieved using good thermal insulation.