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The Mpemba effect describes the phenomenon that a system at hot initial temperature cools faster than at an initial warm temperature in the same environment. Such an anomalous cooling has recently been predicted and realized for trapped colloids. Here, we investigate the freezing behavior of a passive colloidal particle by employing numerical Brownian dynamics simulations and theoretical calculations with a model that can be directly tested in experiments. During the cooling process, the colloidal particle exhibits multiple non-monotonic regimes in cooling rates, with the cooling time decreasing twice as a function of the initial temperature—an unexpected phenomenon we refer to as the Double Mpemba effect. In addition, we demonstrate that both the Mpemba and Double Mpemba effects can be predicted by various machine-learning methods, which expedite the analysis of complex, computationally intensive systems. [ABSTRACT FROM AUTHOR]

We investigate the phase ordering (pattern formation) of systems of two-dimensional core–shell particles using Monte Carlo (MC) computer simulations and classical density functional theory (DFT). The particles interact via a pair potential having a hard core and a repulsive square shoulder. Our simulations show that on cooling, the liquid state structure becomes increasingly characterized by long wavelength density modulations and on further cooling forms a variety of other phases, including clustered, striped, and other patterned phases. In DFT, the hard core part of the potential is treated using either fundamental measure theory or a simple local density approximation, whereas the soft shoulder is treated using the random phase approximation. The different DFTs are benchmarked using large-scale grand-canonical-MC and Gibbs-ensemble-MC simulations, demonstrating their predictive capabilities and shortcomings. We find that having the liquid state static structure factor S(k) for wavenumber k is sufficient to identify the Fourier modes governing both the liquid and solid phases. This allows us to identify from easier-to-obtain liquid state data the wavenumbers relevant to the periodic phases and to predict roughly where in the phase diagram these patterned phases arise. [ABSTRACT FROM AUTHOR]

Purpose: Precooling (PreC) may only benefit performance when thermal strain experienced by an individual is sufficiently high. We explored the effect of mixed-method PreC on 20-km cycling time-trial (CTT) performance under 3 different apparent temperatures (AT). Methods: On separate days, 12 trained or highly trained male cyclists/triathletes completed six 20-km CTTs in 3 different ATs: hot-dry (35 °C AT), moderately hot-humid (40 °C AT), and hot-humid (46 °C AT). All trials were preceded by 30 minutes of mixed-method PreC or no PreC (control [CON]). Results: Faster 2.5-km-split completion times occurred in PreC compared with CON in 46 °C AT (P =.02), but not in 40 °C AT (P =.62) or 35 °C AT (P =.57). PreC did not affect rectal and body temperature during the 20-km CTT. Skin temperature was lower throughout the CTT in PreC compared with CON in 46 °C AT (P =.01), but not in 40 °C AT (P = 1.00) and 35 °C AT (P = 1.00). Heart rate had a greater rate of increase during the CTT for PreC compared with CON in 46 °C AT (P =.01), but not in 40 °C AT (P =.57) and 35 °C AT (P = 1.00). Ratings of perceived exertion (P <.001) and thermal comfort (P =.04) were lower for PreC compared with CON in 46 °C AT only, while thermal sensation was not different between PreC and CON. Conclusion: Mixed-method PreC should be applied prior to 20-km CTTs conducted in hot-humid conditions (≥46 °C AT). Alternatively, mixed-method PreC may be a priority in moderately hot-humid (∼40 °C AT) conditions but should not be in hot-dry (∼35 °C AT) conditions for 20-km CTT. [ABSTRACT FROM AUTHOR]

Hot carrier solar cells could offer a solution to achieve high efficiency solar cells. Due to the hot-phonon bottleneck in perovskites, the hot carrier lifetime could reach hundreds of ps. Such that exploring perovskites could be a good way to promote hot carrier technology. With the incorporation of large organic cations, the hot carrier lifetime can be improved. By using ultrafast transient spectroscopy, the hot carrier relaxation and extraction kinetics are measured. From the transient kinetics, 2-phenyl-acetamidine cation based perovskites exhibit the highest initial carrier temperature, longest carrier relaxation, and slowest hot carrier relaxation. Such superior behavior could be attributed to reduced electron–phonon coupling induced by lattice strain, which is a result of the large organic cation and also a possible surface electronic state change. Our discovery exhibits the potential to use large organic cations for the use of hot carrier perovskite solar cells. [ABSTRACT FROM AUTHOR]

Preparation of atomic Bose–Einstein condensate (BEC) with tunable interactions in a quasi-one-dimensional (quasi-1D) optical trap is essential for both the observation of bright matter-wave solitons and the quantum simulation based on the discrete atomic momentum states. However, the quasi-1D BEC has been obtained by a complex process, which includes the creation of a three-dimensional BEC and its adiabatic transform into a quasi-1D trap. Here, we report the direct creation of a quasi-1D BEC of 133 Cs atoms by the fast evaporative cooling of ultracold atoms prepared by the degenerated Raman sideband cooling. We produce the pure BEC of up to 5.5 × 10 4 atoms in a quasi-1D optical trap with an evaporative time of 6 s. We demonstrate the anisotropic expansion of the atomic cloud after the release from the quasi-1D trap and study the dependence of both the phase space density and the temperature on the number of atoms in the trap during the evaporative cooling. Our study facilitates the promising applications of quasi-1D interacting atomic gases. [ABSTRACT FROM AUTHOR]

Green methanol is considered an important future hydrogen carrier in the maritime sector, however, its wide scale use is expected to be limited by the scarcity of biogenic carbon. This paper proposes a concept where onboard carbon capture (OCC) is used to facilitate a cyclic use of biogenic carbon by storing the captured CO 2 which can be re-used to produce new green methanol. To enable this concept a novel methanol-fueled solid oxide fuel cell system with cryogenic CO 2 capture partly using absorption cooling is proposed. Three configurations of this system are developed. Based on steady-state thermodynamic models, it was found that the best system configuration was able to reach a steam-to-carbon ratio of 2, a system fuel utilization of 100%, zero emissions, and a lower heating value electrical system efficiency of 63.9%. This is on a par with the best power generation and OCC systems currently proposed in the literature. [Display omitted] • Three SOFC system configurations with onboard carbon capture are modeled. • The concept introduces circular use of CO 2 separated using absorption cooling. • Best performing configuration operates with 64%–65% LHV-based efficiency. • Very high efficiencies at part-load operation of the system. • 100% carbon capture rate and fuel utilization in two out of three configurations. [ABSTRACT FROM AUTHOR]

The energy-intensive nature of hydrogen liquefaction underscores the critical need for efficiency improvements. This study presents an approach to enhance the design and performance of hydrogen heat exchangers by optimizing the cold-to-hot fluid mass flowrate ratios across various temperature ranges, leading to substantial improvements in the Continuous Conversion Proximity Index (CCPI). A dynamic simulation model is developed to explore the complex interactions between temperature distribution, mass flowrate ratio, inlet conversion rate, and the heat transfer and catalytic efficiency in cryogenic hydrogen heat exchangers. Optimal cold-to-hot fluid mass flowrate ratios, ranging from 3.31 to 8.44 across the 80-33 K temperature range, are identified. In particular, a 23.0% improvement in CCPI is observed in the 40-33 K range, significantly optimizing the continuous catalytic conversion process. The results show that inlet conversion rates between 96% and 94% ensure effective heat transfer and high ortho-para hydrogen conversion efficiency, whereas rates below 94% lead to rapid conversion but insufficient cooling. These findings provide a theoretical foundation for the design of highly efficient hydrogen heat exchangers and demonstrate that optimizing the mass flowrate ratio can enhance the process within the exchanger, bringing it closer to an ideal continuous conversion form. [Display omitted] • The CCPI index is introduced to evaluate deviation from ideal continuous conversion. • The optimal fluid flowrate ratios across various temperature ranges are determined. • The dynamic model reveals the impact of inlet conversion rates on heat transfer efficiency. • A 23% increase in CCPI is achieved with optimal flowrate in the 40-33 K temperature range. • The validated model supports improved design of cryogenic hydrogen heat exchangers. [ABSTRACT FROM AUTHOR]

The development of new and more effective cooling technologies is required for several high thermal power dissipation applications such as in electronics cooling or high concentrated photovoltaic panels. The present paper addresses an experimental study on the development of a microchannel based heat sink to cool photovoltaic panels. Experiments focus on the test of a microchannel, with geometry and dimensions optimized from previous work. The analysis performed here emphasizes the experimental characterization of flow boiling in the microchannel under different working conditions. The results include pressure drop and heat flux maps, obtained combining pressure sensors with high-speed imaging and time resolved thermography. The analysis performed was able to identify where nucleation sites were formed. Slug flow interfacial heat transfer could be observed and accurately described in the heat flux maps. Overall, results show the high potential of combining high-speed imaging with time resolved infrared thermography to characterize complex flows. These results also show that there is a good potential for this microchannel based flow cooling in removing the required heat fluxes for the application considered here, when compared to other liquid and air-cooling technologies. [ABSTRACT FROM AUTHOR]

Subambient daytime radiative cooling enables temperatures to passively reach below ambient temperature, even under direct sunlight, by emitting thermal radiation toward outer space. This technology holds promise for numerous exciting applications. However, previous demonstrations of subambient daytime radiative cooling require surfaces that directly face the sky, and these cannot be applied to vertical surfaces that are ubiquitous in real-world scenarios such as buildings and vehicles. Here, we demonstrate subambient daytime radiative cooling of vertical surfaces under peak sunlight using a hierarchically designed, angularly asymmetric, spectrally selective thermal emitter. Under peak sunlight of about 920 watts per square meter, our emitter reaches a temperature that is about 2.5°C below ambient temperature, corresponding to a temperature reduction of about 4.3° and 8.9°C compared with a silica-polymer hybrid radiative cooler and commercial white paint, respectively. [ABSTRACT FROM AUTHOR]

Power dissipation of quad small form-factor pluggable-double density (QSFP-DD) interconnect system is increasing almost linearly with respect to the data speed. Fan cooling solution which was conventionally used for QSFP-DD is no longer adequate to meet the demanding thermal management requirements. In the current work, water-cooled cold plate thermal management solution was proposed for QSFP-DD. The study starts with experiments for 1 × 3 QSFP-DD system, in which temperature rise, pressure drop, flow rate, and power dissipation are measured and compared with simulation results. Subsequently, case studies were carried out in simulations to investigate the effects of cold plate number of channels, channel height, and pedestal area on the thermal-hydraulic performance of the cold plate. An empirical Nusselt number correlation was proposed to predict the thermal performance of water-cooled cold plate for QSFP-DD applications. The study reveals that number of channels plays the most significant role in heat transfer performance while channel height plays the most significant role in pressure drop of the cold plate. [ABSTRACT FROM AUTHOR]

During high-speed continuous casting, the effect of secondary cooling on the quality of the billet is more obvious, and the possibility of quality problems is higher. This study takes the continuous casting machine producing 165 mm × 165 mm billet as the research object. The six different secondary cooling schemes are designed with the 4.5 m/min casting speed. By comparing the shell deformation, surface stress, surface temperature recovery, and metallurgical lengths at different secondary cooling schemes, the secondary cooling scheme applied in the high-speed continuous casting process is selected. The results show that the surface temperature recovery and stress of the billet in Scheme 1 are higher than those of other cooling schemes. The metallurgical length and shell deformation of the billet in Scheme 4 are higher than those of other cooling schemes. In Schemes 2, 3, 5, and 6, the shell deformation of Schemes 3 and 5 is higher than that of Schemes 2 and 6. In Schemes 2 and 6, the maximum surface central stress of the continuous casting billet in the secondary cooling zone is 36.3 MPa and 31 MPa, respectively. Scheme 6 is used as the secondary cooling scheme of high-speed continuous casting in this study. The water quantity in secondary cooling zone 1 ~ 5 segments of Scheme 6 is 28 m3/h, 31 m3/h, 16 m3/h, 10 m3/h, and 6 m3/h, respectively. Finally, the industrial trial is carried out, which proves that Scheme 6 can be applied to high-speed continuous casting. [ABSTRACT FROM AUTHOR]

The enstatite chondrite class is known to have complex thermal histories, often interpreted to include impact melting and shock metamorphism. Highly equilibrated (type 6) EH group enstatite chondrites are rare and thought to have formed through collisional heating. We studied two EH6 chondrites, NWA 7976 and NWA 12945, for their textural, chemical, and mineralogical characteristics. The samples we studied contain subhedral to anhedral grains of enstatite and plagioclase, suggesting solid‐state recrystallization. They show low degrees of shock and no evidence of shock melting. Additionally, the ubiquitous occurrence of daubréelite exsolution lamellae in troilite and the Ni content of schreibersite suggest slow cooling at greater burial depths in the parent body, rather than rapid cooling as a result of an impact event. Based on the characteristics and scarcity of type 6 EH chondrites, and the ubiquitous shock effects and melt rocks in the enstatite chondrite class, we conclude that the unshocked NWA 7976 and NWA 12945 were formed by heat derived from impact melt sheets, analogous to contact metamorphism. [ABSTRACT FROM AUTHOR]

Self‐hygroscopic hydrogels, characterized by high evaporation enthalpy, cooling efficiency, and self‐regulating properties, have garnered significant attention. However, most current research focuses on enhancing the hygroscopic and desorption performance, often overlooking the importance of monitoring the self‐regulation process, which limits its further application. Advanced visualization technologies, such as in situ electrical impedance tomography, low‐field nuclear magnetic resonance, and hyperspectral imaging, offer potential insights into this behavior, yet they often require additional devices, incur high costs, and involve complex sample preparation processes. Therefore, drawing inspiration from nature, humidity‐color‐sensitive hydrogels (HCSHs) strategy is proposed for visualized cooling. Benefiting from the strong polar responsiveness of the aggregation‐induced emission (AIE) molecules, the hydrogel's fluorescence significantly changes with varying interior water content, thereby its self‐regulation process is monitored easily. Further, the obtained hydrogel could be applied in the electronic device cooling owing to the polymer skeletons’ high swelling ratio, strong adhesion, and excellent self‐hygroscopic properties. This strategy overcomes current limitations in the visual technology of self‐hygroscopic materials and provides new insights into intelligent thermal management for electronic devices. [ABSTRACT FROM AUTHOR]

Solid-state cooling, represented by the electrocaloric effect (ECE) in (anti)ferroelectric materials, has emerged as an alternative green refrigeration technology by virtue of its high efficiency and miniaturization and is expected to substitute conventional vapor-compression. Significant progress has been made in developing high-performance EC materials since its revival. However, anomalous EC behaviors are frequently observed, including asymmetric and negative EC profiles, and the physical mechanism behind this is still under debate. Its rationalization is of great importance since full utilization of anomalous EC behaviors could enhance EC strength and/or cooling capacity. This mini-review gives a brief overview of research advances in EC anomalies in (anti)ferroelectrics with the hope of provoking thought on the design of reconstructed refrigeration cycles and superior EC materials for application in solid-state cooling devices. [ABSTRACT FROM AUTHOR]

In this work, a new heat dissipation method based on ultra-thin flattened heat pipe (UTHP) is developed for cooling watch-phones. The UTHP with a 0.4 mm thickness was designed to be a three-dimensional shape according to the watchcase shape. The UTHP cooling module (HPM) was soldered by three copper plates and a UTHP. The heat dissipation performance of the copper sheet cooling module (CSM) with the same dimensions was made for comparison with the HPM. The heat dissipation performance of the HPM was experimentally studied. The results indicate that the maximum heat dissipation powers of CSM and HPM were 0.8 and 0.9 W, respectively, at the surface temperature of the ceramic heater not exceeding 65 °C. At this time, ΔTc and Rhc of them were 9.18 °C and 9.86 °C/W, 3.98 °C and 2.63 °C/W, respectively. When the cooling module was cooled naturally from 65 to 37 °C, the heat dissipation time of HPM was 25 s shorter than that of CSM. The UTHP cooling module has a better heat dissipation performance, which can quickly reduce the chip temperature, eliminate the chip hotspot, and solve the heat dissipation issue of watch-phone. [ABSTRACT FROM AUTHOR]

The need for eco‐friendly cooling materials and material recycling are two urgent challenges to address. In this paper, the role of the ground tyre rubber treatment (cryo‐grinding and devulcanization) is investigated on the tensile and elastocaloric properties of Natural rubber (NR)/ ground tyre rubber (GTR). The GTR particles that are sieved (<63µm) and devulcanized by microwave irradiation (1 min at 800Watts) exhibit a low network chain density (0.53 × 10−4 mol.cm−3) resulting from crosslinks breakage and rubber chains scission, as supported by FTIR showing a decrease of S─S, C─S, and C─C bonds. The NR/GTR blends show a high elastocaloric effect as compared to the pristine NR, which can be ascribed to the high content of carbon black in the GTR (52 wt.%) and also the high level of devulcanization of the GTR. NR/GTR blends reach a heating of +8 °C and a cooling of >−6 °C, resulting in a material's coefficient of performance COPmat = 2.8–3 compared to 2.6 for the pristine NR. The concomitant effect of cryogrinding and microwave devulcanization is proposed as a way to improve the tensile and elastocaloric properties of natural rubber/waste rubber blends for their possible integration into elastocaloric devices for heating/cooling applications. [ABSTRACT FROM AUTHOR]

The plastic injection moulding industry is a constantly developing industrial field. This industrial process requires the manufacturing of metal moulds using complex heating and cooling systems. The purpose of this research is to optimize both the plastic injection moulding process and the mould manufacturing process itself by combining practices in this industry with current additive manufacturing technologies, specifically Wire Arc Additive Manufacturing (WAAM) technology. A mould punch was manufactured by using both WAAM technology, whose internal cooling system has been designed under the concept of Conformal Cooling, and conventional cooling channel designs and manufacturing techniques in order to carry out a comparative analysis. Theoretical results obtained by CAE methods showed an improvement in heat extraction in the WAAM mould. In addition, the WAAM mould was able to achieve better temperature homogeneity in the final part, minimizing deformations in the final part after extraction. Finally, the WAAM manufacturing process was proven to be more efficient in terms of material consumption than the conventional mould, reducing the buy-to-fly ratio of the part by 5.11. [ABSTRACT FROM AUTHOR]

Among many iron-based superconductors, isovalently substituted BaFe2(As1−xPx)2 displays, for x ≈ 0.3, apart from the quite usual Second Magnetization Peak (SMP) in the field dependence of the critical current density, an unusual peak effect in the temperature dependence of the critical current density in the constant field, which is related to the rhombic-to-square (RST) structural transition of the Bragg vortex glass (BVG). By using multi-harmonic AC susceptibility investigations in three different cooling regimes—field cooling, zero-field cooling, and field cooling with measurements during warming up—we have discovered the existence of a temperature region in which there is a pronounced magnetic memory effect, which we attributed to the direction of the structural transition. The observed huge differences in the third harmonic susceptibility at low and high AC frequencies indicates the difference in the time-scale of the structural transition in comparison with the timescale of the vortex excitations. Our findings show that the RST influence on the vortex dynamics goes beyond the previously observed influence on the onset of the SMP. [ABSTRACT FROM AUTHOR]

Personal cooling garment can effectively prevent human from heat injury and realize global energy saving. However, it is hard to optimize the system with simultaneously realize thermal comfort and high coefficient of performance. To overcome this challenge, a thermoelectric‐water hybrid cooling garment is designed. The key performance indicators of personal cooling garments and experimentally demonstrate the necessity of hybridizing thermoelectric cooler with the employed water cooling garment is first analyzed. Correspondingly, the influence of inlet temperature and volume flow rate are studied and optimized step by step. Finally, under the optimized inlet temperature of 24 °C and the volume flow rate of 5 L h−1, employing water as the cooling media, a coefficient of performance of 1.31 can be approached at the working time ranging from 10 to 60 min. This study demonstrates that the thermoelectric‐water hybrid cooling garment technology can realize an effective cooling with simultaneously high coefficient of performance and maintain thermal comfort. [ABSTRACT FROM AUTHOR]

Intraband carrier relaxation in quantum dots (QDs) has been a subject of extensive spectroscopic investigation for several decades, and have been used to optimize the efficiency of opto‐electronic processes. In the past few years, metal halide perovskites‐based QDs have been shown to exhibit slow hot‐carrier cooling characteristics that are desirable for photo‐energy harvesting technologies. While several mechanisms are proposed to rationalize the retardation of the cooling dynamics, including hot‐phonon bottleneck and polaronic effects, the role of inter‐particle connectivity in these dynamics is largely ignored. Here, an in‐depth study of photo‐excitation dynamics and carrier cooling on perovskite QD solids with varying degrees of inter‐dot coupling is presented. It is observed that inter‐particle connectivity has deterministic effects on the many‐body interactions that are relevant for carrier cooling. These include carrier–carrier interactions that result in Auger‐reheating of the carriers, and lattice characteristics that subsequently affect the phonon‐assisted cooling dynamics. This spectroscopic study of ultrafast carrier dynamics in perovskite QD solids establishes inter‐dot separation as a critical material design parameter for the optimization of photo‐generated carrier temperature, which fundamentally determines the luminescence characteristics and thus the opto‐electronic quality of the material. [ABSTRACT FROM AUTHOR]

Electrocaloric (EC) cooling presents a promising approach to efficient and compact solid-state heat pumps. However, reported EC coolers have complex architectures and limited cooling temperature lift. In this work, we introduce a self-regenerative heat pump (SRHP) using a cascade of EC polymer film stacks, which have electrostrictive actuations in response to an electric field that are directed to realize efficient heat transfer, eliminating the need for additional transportive or regenerative mechanisms. The SRHP demonstrates a cooling of 8.8 kelvin below ambient temperature in 30 seconds and delivers a maximum specific cooling power of 1.52 watts per gram. The temperature lift of the SRHP is 14.2 kelvin. These results underscore the potential of the compact solid-state cooling mechanism to address the increasing need for localized thermal management. [ABSTRACT FROM AUTHOR]

This study investigates the impact of the salinity barrier layer (BL) on the upper ocean response to Super Typhoon Mangkhut (2018) in the western North Pacific. After the passage of Mangkhut, a noticeable increase (∼0.6 psu) in sea surface salinity and a weak decrease (< 1°C) in sea surface temperature (SST) were observed on the right side of the typhoon track. Mangkhut-induced SST change can be divided into the three stages, corresponding to the variations in BL thickness and SST before, during, and after the passage of Mangkhut. During the pre-typhoon stage, SST slightly warmed due to the entrainment of BL warm water, which suppressed the cooling induced by surface heat fluxes and horizontal advection. During the forced stage, SST cooling was controlled by entrainment, and the preexisting BL reduced the total cooling by 0.89°C d−1, thus significantly weakening the overall SST cooling induced by Mangkhut. During the relaxation stage, the SST cooling was primarily caused by the entrainment. Our results indicate that a preexisting BL can limit typhoon-induced SST cooling by suppressing the entrainment of cold thermocline water, which contributed to Mangkhut becoming the strongest typhoon in 2018. [ABSTRACT FROM AUTHOR]

• Comprehensive evaluation of Purge section and rotary dehumidifier configurations. • Purge section in desiccant wheel reduces energy use and exit air temperatures. • Multi-sector approach in single wheel enables two-stage dehumidification. • Review highlights the isothermal dehumidification potential of non-adiabatic wheels. This review provides a comprehensive summary of research pertaining to the purge section within desiccant wheels featuring multi-sector configurations. Additionally, it encompasses discussions on innovative wheel designs such as non-adiabatic desiccant wheels and the achievement of two-stage dehumidification from a single wheel employing multi-sector approaches. The review begins by providing a concise historical overview of the desiccant wheel, followed by a systematic classification of the research conducted in this area. Subsequently, various categorizations are presented in a logical sequence, offering a structured understanding of the subject matter. Central to the critical findings of this review is the identification of an optimal purge wheel sector angle, which not only decreases the energy consumption of the desiccant wheel but also significantly reduces the exit temperature of process air. Moreover, the review highlights the potential of achieving isothermal dehumidification through the utilization of non-adiabatic rotary desiccant wheels. Furthermore, the introduction of a multi-sector desiccant wheel is one of the key successes in obtaining two-stage dehumidification and getting multi-output like cooling, heating with dehumidification, and heating with humidification. These are all efficiently derived from a single wheel. [ABSTRACT FROM AUTHOR]

The repeated rapid heating and nonlinear cooling associated with electropulsing treatment (EPT) hinder the accurate modeling of temperature variations based on a constitutive approach using physical models. This objective is not attainable through conventional machine learning (ML) approaches as well, such as artificial neural network (ANN) and long short‐term memory (LSTM). The present study investigates the intricate nonlinear thermal history of Mg alloys induced by EPT to improve a predictive model under multipulse conditions. Furthermore, it enhances the predictivity and generalizability of a given problem using an ML model called i‐LSTM by specifically tailoring a dataset. The i‐LSTM model performance surpasses that of the constitutive approaches and conventional ML models when predicting the complicated thermal history of EPT specimens in a wide variety of processing parameters. The mechanisms underlying this improvement are discussed based on several experimental datasets. This study not only addresses challenges in existing models but also offers a promising avenue for understanding and predicting the thermal dynamics of Mg alloys subjected to the multipulse EPT process. [ABSTRACT FROM AUTHOR]

Featured Application: The results of the work may be used in the design of cooling systems for electronic components. Cooling of electronic components is of great importance currently. One of the most important methods of integrated circuit cooling is the use of microchannel heat sinks. The aim of this work is to analyze the cooling capacity of zigzag shaped microchannels. The heat exchange for four different microchannels was tested depending on the flow rate of the cooling liquid (water) and the temperature of the cooled element. The system of differential equations that describe fluid flow and heat transport is presented in the paper. The equations were solved using the finite volume method. The work showed that both the increase in the number of zigzag sections and the increase in the flow velocity cause an increase in the flow resistance. In contrast, an increase in the temperature of the cooled element causes a decrease in fluid viscosity, which results in a decrease in flow resistance. From the point of heat exchange, both the increase in the number of segments, the flow rate, and the temperature of the cooled element increase the cooling capacity of the microchannel. Research shows that zigzag shaped microchannels are excellent cooling elements, especially for geometrically small heat sources such as electronic components. [ABSTRACT FROM AUTHOR]

Leveraging the Copernicus high‐resolution multi‐year Mediterranean Sea Surface Temperature (SST) dataset, 15 selected tropical‐like cyclones (TLCs) are analyzed with the objective of elucidating the anomalies of SST at the time of cyclogenesis and the connection between the change in SST during the cyclone lifetime and its characteristics. The long‐term SST increase associated with climate change is identified by comparing detrended and original anomalies. Detrending removes the effect of the intensification of SST anomaly over time, revealing that no significant anomalies generally emerge in the early stages of the TLC lifetimes. Conversely, winter events exhibit early‐stage positive SST anomalies. Also, high SST values were observed during the intensification of the most intense cyclones. A cold SST anomaly is left after the passage of the cyclones, due to the intense sea surface fluxes extracting heat from the sea. Plain Language Summary: Mediterranean tropical‐like cyclones are severe weather events able to produce large socio‐economic and environmental impact, as well as considerable damage. On average, 1.5 such events affect the Mediterranean each year. In this study we assess the Sea Surface Temperature conditions related to the events reported in the literature of the past four decades. We use a high‐resolution multi‐year SST dataset over the Mediterranean Sea, to reveal the potential relationship between the change in SST before and during the cyclone's lifetime and their features. Our results show that SST plays an important role in the intensification phases of the events, while no significant SST anomaly emerges in the early stages for most of the cyclones. Key Points: No significant SST anomalies are found at the early stage of medicanes, except for the winter cases that exhibit a positive anomalySST value is particularly high for the most intense cyclones (September cases)The passage of the cyclones over the sea induces a cooling mainly during their mature phase [ABSTRACT FROM AUTHOR]

In the core accretion model of planet formation, envelope cooling regulates the accretion of material and ultimately sets the time-scale to form a giant planet. Given the diversity of planet-forming environments, opacity uncertainties, and the advective transport of energy by three-dimensional (3D) recycling flows, it is unclear whether one-dimensional models can adequately describe envelope structure and accretion in all regimes. Even in 3D models, it is unclear whether approximate radiative transfer methods sufficiently model envelope cooling, particularly at the planetary photosphere. To address these uncertainties, we present a suite of 3D radiation-hydrodynamics simulations employing methods that directly solve the transfer equation. We perform a parameter space study, formulated in terms of dimensionless parameters, for a variety of envelope optical depths and cooling times. We find that the thermodynamic structure of the envelope ranges from adiabatic to isothermal based on the cooling time and, by extension, the background disc temperature and density. By adopting a dimensionless framework, these models can be applied to a wide range of formation conditions and assumed opacities. In particular, we dimensionalize them to the case of a super-Earth and proto-Jupiter and place upper limits on the 3D mass accretion rates prior to runaway growth. Finally, we evaluate the fidelity of approximate radiative transfer methods and find that even in the most challenging cases more approximate methods are sufficiently accurate and worth their savings in computational cost. [ABSTRACT FROM AUTHOR]

Innovative solutions are required to make long-duration space missions feasible. Crew performance and health is paramount to the success of anticipated Moon and Mars missions. Metabolic reduction via a quasi-torpor state is a possible mitigation strategy that can reduce consumable payload, which is necessary given the lack of available resupply options, and to reduce psychological stress, which is a risk for such lengthy missions. Even in lunar or cis-lunar missions, a quasi-torpor state could be implemented as an emergency countermeasure for critical situations where life support becomes limited. However, to date no studies have tested a quasi-torpor state in humans, and the impacts of intentional prolonged metabolic reduction on physiological and psychological parameters are unknown. To this end, we planned a three-phase study to provide proof-in-principle of the tolerability, feasibility, and side effects of a nonintravenous alpha-2-adrenergic receptor agonist for moderate sedation. This was accomplished by 1) determining the dosing and metabolic effects for different non-intravenous routes of alpha-2-adrenergic receptor agonist drugs; 2) assessing the degree of metabolic reduction and side effects during a 24-h quasi-torpor protocol; and 3) evaluating participant performance and total metabolic reduction achieved over a 5-day quasi-torpor protocol. We also aim to determine how skeletal muscle health and performance are affected by this quasi-torpor state. Quasi-torpor induced changes in skeletal muscle health and performance, as well as impacts on cognition and psychological stress, also have implications for terrestrial situations that result in prolonged confinement (e.g., austere environments such as submarine or remote scientific or military deployment and protracted critical illness). The findings of this three-phase study will be immediately applicable as a rescue strategy for emergencies during current or upcoming space missions. They will also identify key physiological and practical questions that need to be addressed for future deployment in long-duration space missions. This paper reviews the relevant literature that informed our rationale and approaches for this three-phase study. [ABSTRACT FROM AUTHOR]

This perspective provides an overview of the state of research and innovation in the areas of magnetocaloric and pyromagnetic materials, and electrocaloric and pyroelectric materials, including the overlapping sub‐areas of multicaloric and multipyro materials that can operate simultaneously under the application of magnetic and electric fields. These materials are critically examined for their potential to revolutionize cooling, heating, and energy‐harvesting applications. This perspective first summarizes the state‐of‐the‐art advancements and highlights recent significant developments. Then, it is identified and discussed that the prevailing challenges hindering the widespread adoption of technologies based on these materials. In this context, after consulting with members of the caloric and pyro communities, a technology roadmap is outlined to guide research efforts in overcoming current barriers to applications, with the goal of achieving impactful results by 2040. This roadmap emphasizes the importance of focusing on under‐researched materials, novel devices, and application spaces, paving the way for interdisciplinary efforts that can lead to significant reductions in carbon dioxide emissions. [ABSTRACT FROM AUTHOR]

Southern Hemisphere (SH) storminess has increased in the satellite era and recent work suggests comprehensive climate models significantly underestimate the trend. Here, we revisit this reanalysis-model trend discrepancy to better understand the mechanisms underlie it. A comprehensive like-for-like analysis shows reanalysis trends exhibit large uncertainty, and coupled climate model simulations exhibit weaker trends than most but not all reanalyses. However, simulations with prescribed sea surface temperature (SST) exhibit significantly greater storminess trends, particularly in the South Pacific, implying SST trend discrepancies in coupled simulations impact storminess trends. Using pacemaker simulations that correct Southern Ocean and tropical east Pacific SST trend discrepancies, we show that storminess trends in coupled simulations are underestimated because they do not capture the enhanced storminess resulting from Southern Ocean cooling and La-Nina-like teleconnection trends. Our findings emphasize large reanalysis uncertainty in SH circulation trends and the impact of regional SST trend discrepancies on circulation trends. [ABSTRACT FROM AUTHOR]

Pine Island, Thwaites, Smith, and Kohler glaciers in the Amundsen Sea Embayment (ASE) sector of West Antarctica experience rapid mass loss and grounding line retreat due to enhanced ocean thermal forcing from Circumpolar Deep Water (CDW) reaching the grounding lines. We use simulated Lagrangian particles advected with a looping 1 year output from the Southern Ocean high‐resolution model to backtrack the transport and cooling of CDW to these glaciers. For the simulated year 2005–2006, we find that the median time needed to reach the grounding lines from the edge of the ASE is 3 years. In addition, the Antarctic Coastal Current contributes an equal number of particles as off‐shelf sources to the grounding lines of Pine Island and Thwaites. For CDW coming from off‐shelf, results from SOhi indicate that 25%–66% of the cooling occurs within ice shelf cavities. Plain Language Summary: The glaciers in the Amundsen Sea Embayment (ASE) sector of West Antarctica are contributing rapidly to sea level rise in response to enhanced melt by warm, salty Circumpolar Deep Water (CDW). We use an ocean numerical model to trace the sources, pathways, and cooling of warm waters to reach glacier grounding lines. We find that it takes multiple years for off‐shelf perturbations to reach the glaciers and that the colder Antarctic Coastal Current contributes the same amount of water to the grounding lines of Thwaites and Pine Island glaciers as off‐shelf CDW sources. The model also reveals that half of the cooling of CDW occurs under the ice shelves, which is an effect not accounted for in most models used for projecting sea level rise. Key Points: From a 2005–2006 simulation, it takes about 3 years for water to reach the grounding lines from the edge of the Amundsen Sea EmbaymentThe simulation shows the Antarctic Coastal Current contributing equal amounts of water to Pine Island and Thwaites as off‐shelf sourcesSOhi results indicate that 1/4 to 2/3 of the cooling between the shelf break and the grounding lines occurs within the cavities [ABSTRACT FROM AUTHOR]

Background and aim: The increasing frequency of heat waves worldwide is a major challenge for emergency care providers worldwide. The aim of this study was to analyze the clinical features, treatment options, and early outcomes of heat stroke patients presenting to a large academic emergency department (ED) in Hungary and to provide guidance in management for other emergency professionals. Methods: Patients presenting to the ED between June 1, 2024, and July 31, 2024, with a body temperature above 40 °C were analyzed in a retrospective cohort study. Data collection included demographic, clinical and laboratory parameters. Predictors of mortality were analyzed with Mann-Whitney U test. Results: Eight patients were included in our analysis. Three patients died in the ED (37.5%). Patients who died had significantly lower pH (7.07 vs. 7.4, p = 0.036), higher potassium (7.3 vs. 3.2 mmol/L, p = 0.036), higher calcium (1.19 vs. 0.97 mmol/L, p = 0.036), higher lactate (10.9 vs. 3.5 mmol/L, p = 0.036) and higher PaCO2 (57.2 vs. 28 mmHg, p = 0.036) at admission compared to those who did not die. Conclusions: The risk of heat stroke due to climate change-induced heat stress and the consequent thermoregulatory disruption may now be significant in temperate climate zones where it was not previously present. Standardization of differential diagnostic and therapeutic procedures could reduce mortality. pH, potassium, lactate and calcium levels may play an important role in predicting the outcome of heat stroke. [ABSTRACT FROM AUTHOR]

In this paper, we theoretically study the ground-state cooling of the mechanical oscillator by an electromagnetically-induced transparency (EIT)-like cooling mechanism in a two-cavity optomechanical system, with a quarter-wave plate placed inside, which plays a linear coupling role in the two cavities. Based on the perturbation theory and quantum Langevin equation, we derive the rate equation of the mechanical oscillator and the fluctuation spectrum of the effective optical force. We find that the maximum value of optical fluctuation spectrum corresponds to the cooling process of the mechanical oscillator, and the minimum value of optical fluctuation spectrum corresponds to the heating process of the mechanical oscillator. With the help of the quarter-wave plate, the heating process can be greatly suppressed due to the quantum interference effect. The ground-state cooling of the mechanical oscillator via such an EIT-like cooling mechanism can be implemented beyond the resolved sideband regime. [ABSTRACT FROM AUTHOR]

This research study presents a comparative analysis of the evaporator temperatures in a liquid desiccant refrigerator and a conventional refrigerator. The aim of the study is to investigate the performance and efficiency of the liquid desiccant refrigeration technology and its potential benefits compared to conventional refrigeration systems. Evaporator temperature data was collected over a period of time for both systems, and the results were analyzed to gain insights into their cooling capabilities. Results shows that where the conventional refrigerator's evaporator temperature decreases by 9.2℃, the liquid dessicant evaporator temperature only decreased by 0.6℃. Hence, the liquid desiccant refrigerator demonstrated a slower cooling rate, maintaining higher initial evaporator temperatures, and exhibiting a more gradual temperature reduction with a coefficient of performance of 0.13. In contrast, the conventional refrigerator exhibited a faster cooling rate, achieving lower evaporator temperatures within a shorter time frame. Furthermore, the study underscores the importance of energy-efficient and sustainable cooling solutions in today's context of environmental concerns and energy conservation. Conclusively, although the conventional refrigerator achieves a higher cooling rate at a much faster pace, the liquid dessicant refrigerator with advantages such as improved moisture control, potentially higher energy efficiency and slower temperature reduction indicates a more balanced and controlled cooling process which could boost refrigeration processes if widely adopted. [ABSTRACT FROM AUTHOR]

In this work, the features of the structure-conductivity relationship in polar (α) and ion-conducting (β and γ) phases of Na3Fe2(PO4)3 polycrystals obtained by the melt-quenching method have been investigated. Na3Fe2(PO4)3 polycrystals are synthesized by isothermal firing of glassy precursors (after grinding and pressing). The glassy precursors were prepared by melting a pre-calcined (350 C) mixture of initial reagents under the influence of thermal and infrared radiation energy and rapid cooling of the melt (or quenching). It was found that the deformations of the structure of polycrystals α-Na3Fe2(PO4)3 during synthesis by melt-quenching lead to an increase in the conductivity in polar (α) and ion-conducting (β and γ) phases because they contribute to the reduction of structural distortions of the samples. Polycrystals Na3Fe2(PO4)3 obtained by the melt-hardening method have high-quality crystallites, high density, and conductivity, and their synthesis is faster than samples obtained by other methods. The established advantages of synthesized polycrystals of α-Na3Fe2(PO4)3 are probably connected with deformations of structure and chemical activity of glassy precursors caused by nonequilibrium thermodynamic conditions of synthesis. For the first time, it was possible to detect domain structures in polycrystals of α-Na3Fe2(PO4)3 obtained by the melt-quenching method, which confirms the polarity of the α-phase, the appearance of which is associated with the ordered displacement of the cationic sublattice relative to the anionic sublattice under the influence of monoclinic distortion of the crystal framework. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive investigation into the static analysis of porous functionally graded material cooling plates with cutouts, employing a sophisticated multilayered modelling approach. The focus lies on understanding the nuanced effects of critical parameters, including volume fraction index, thickness ratio, porosity distribution, and porosity index, on the bending responses of shear-deformable porous FGM plates with cutouts. The research encompasses a diverse range of boundary conditions, both conventional and unconventional, shedding light on the collective influence of these variables on the bending response of the FGM plates featuring cutouts. In the instance of this porous FGM plate, the model integrates effective material properties obtained using a power-law distribution, which is then applied in a modified rule of mixture. The multilayered approach enhances the precision of the static analysis, providing a robust framework for exploring the mechanical behavior of porous FGM cooling plates in practical scenarios. [ABSTRACT FROM AUTHOR]

Heterogeneous multicore system could provide high flexibility for applications through integrating different types of cores. As the number of cores increases, more and more transistors are integrated which could lead to the rise of chip temperature, thus have a negative impact on the system performance. At present, the typical method to tackle this problem is dynamic voltage and frequency scaling (DVFS) which reduces the voltage and frequency to achieve cooling. However, DVFS will make the heterogeneous multicore system unable to take full advantage of its performance. This paper proposes a dynamic mapping method called TspDM which maximizes the system performance target under the premise of satisfying the temperature safety power. TspDM exploits the runtime performance counters of running threads to dynamically adjust thread mapping. Specifically, a lightweight Artificial Neural Network (ANN) model is proposed to obtain the thread-to-core type mapping when a remapping process is activated. Subsequently, TspDM determines the specific core locations of threads according to the number of threads mapped to a certain core type and the thermal safety power computation. The experimental results show that the proposed method is 21% better than that of PCMig while ensuring the thermal safety of heterogeneous platform. In addition, TspDM outperforms recent performance constrained and power constrained literature in terms of system throughput. [ABSTRACT FROM AUTHOR]

C14‐alkoxy/alkyl PBTTT‐OR‐R, a derivative of the prototype PBTTT polymer, is relevant for optoelectronic applications because it combines PBTTT‐like intercalation behavior with enhanced charge‐transfer absorption at longer wavelengths. Additionally, fundamental insights are achieved by comparing this alternating conjugated polymer in the presence and absence of homocoupling defects. While the homocoupling‐free oxidative variant, PBTTT‐OR‐R(O), as well as the Stille polymer with 19% homocoupling defects, PBTTT‐OR‐R(S), can both form co‐crystals when stoichiometrically mixed with PC61BM, the co‐crystal of the latter shows properties which are highly dependent on the thermal processing conditions because of the presence of these defects. The PBTTT‐OR‐R(S):PC61BM co‐crystal shows a low thermal stability and PC61BM can progressively be expelled upon heating. In cooling from the melt and depending on the cooling rate, mixtures of PBTTT‐OR‐R(S) and PC61BM show a competition between co‐crystallization (fast cooling) and separate crystallization (slow cooling). The PBTTT‐OR‐R(O):PC61BM co‐crystal is much more stable up to at least 260 °C and is not influenced by the applied cooling rate. These findings also translate to the device level. The performance of PBTTT‐OR‐R:PC61BM photodiodes is severely deteriorated after isothermal annealing in case of PBTTT‐OR‐R(S), whereas the thermally robust co‐crystals of PBTTT‐OR‐R(O) allow a more flexible design of optimized devices. [ABSTRACT FROM AUTHOR]

Systematic overestimation of precipitation across China via climate models has existed for several decades, but the related reason has received little attention. Using simulations from 24 models participating in the sixth phase of the Coupled Model Intercomparison Project (CMIP6), we investigate the underlying physical processes responsible for annual wet biases across China. The overestimated precipitation is found to be mainly due to the unrealistic large-scale precipitation component in Southwest, Central, East, North and Northeast China. Compared to the observation, the simulated lower tropospheric temperature induces more net energy into the column atmosphere, resulting in anomalous ascending motions over Southwest, Central and East China. Meanwhile, the middle-to-upper tropospheric temperature underestimation over the Bering Strait causes an anomalous anticyclone east of Japan. The resultant enhanced southerly wind increases the moisture transport into Central and East China, further contributing to wet biases. In addition, the overestimated soil moisture is responsible for excessive precipitation in North and Northeast China. Our results indicate that tropospheric cooling is the dominant reason for the widespread precipitation overestimation over China. [ABSTRACT FROM AUTHOR]

Passive radiative cooling is a zero‐energy consumption approach, which can dissipate heat to outer space by emitting infrared radiation through the transparency window. Traditional cooling materials, such as photonic films, metafabrics, and polymer foams, still suffer from complex preparation processes and high costs. In this work, it is reported that natural cellulose can be converted into a "green" optical metamaterial by rational structure reconfiguration at the micro/nano level via scalable ball milling technology for efficient daytime radiative cooling. Specifically, fine‐tuning the shearing kinetics in the mechanochemistry process, cellulosic optical metamaterial (COM) with ≈98% solar reflectivity and ≈0.97 infrared emissivity has been successfully achieved, which can break through the theoretical value of photonic crystals as well as the conventional synthetic optical materials. The COMSOL simulation reveals that the excellent optical properties of the cellulose metamaterial are explained by the "confined scattering" effect caused by the rearranged heterostructure at the micro/nano level. Outdoor tests demonstrat that the COM‐based coating exhibits a daytime radiative cooling efficiency of 5.7 °C in hot Nanjing. Meanwhile, the COM can be produced into different scattering materials via spray coating, freeze casting, and solution casting technology. This study will facilitate the development of scalable and sustainable optical metamaterials for mitigating energy consumption. [ABSTRACT FROM AUTHOR]

The effect of entrained air bubbles on heat transfer enhancement inside 90° ribbed parallel channels has been experimentally studied to improve electrical efficiency inside future solar panels. In this work, the Reynolds number was measured from 200 to 600. The essential ratios of channel aspect, rib height, and rib pitch were all set to 0.4, 0.18, and 10, respectively. The volumetric flow fraction for all test conditions varied from 0.0 to 0.5. The overall heat transfer distributions on the surface were captured using an infrared thermography camera. The main finding showed that the average heat transfer rate and the thermal performance gained beyond 25–81% and 7–82% compared with the smooth wall. In addition, the volumetric flow fraction of 0.5 at the Reynolds number of 200 became the best. [ABSTRACT FROM AUTHOR]

This study aimed to determine a method to suppress thermal runaway in electric vehicles by passing water directly inside the battery case. A scaled-down model experiment was conducted using a lithium-ion battery pack consisting of six 18650 cells, which is equal to about one-thousandth of an electric vehicle's charging capacity. The heat generation rate, heat transfer coefficient, and time constant for cooling were measured using a simple model for the cooling methods, thermal runaway stages, and state of charge. When thermal runaway occurred during natural cooling, the battery temperature rose to 630 °C at a rate of 116 °C/s. Through water injection, the thermal runaway was quickly suppressed with a time constant of about 3 s and a heat transfer coefficient of 3400 W/m2·K. The water effectively prevented chain explosions and kept harmful gases emitted from the batteries. It was found that it is difficult to completely suppress thermal runaway using the latent heat of the stagnant water in the spaces between cylindrical batteries. If the experimental results of this study were to be applied to an actual vehicle, it is expected that thermal runaway could be suppressed with a time constant of about 170 s and 1 ton of water. [ABSTRACT FROM AUTHOR]

The pulsed magnet can generate a high magnetic field (up to 100T), promoting the development of high-frequency high-power gyrotrons. In this article, a fast cooling and long lifetime 40 T pulsed magnet is developed for a 1 THz gyrotron. To address the various challenges in thermal and mechanical aspects, copper conductors and internal fibers have been combined to enhance mechanical strength and minimize temperature rise, prolonging the lifetime and the admissible duration of the magnet operation. Internal cooling channels are introduced to increase the cooling speed without compromising mechanical strength. Experimental results have demonstrated the magnet's reliability and repeatability in achieving a 40 T pulsed field for tens of milliseconds with a cooldown time of 6 min. It is estimated that the lifetime is about 20,000 shots at 40 T. Importantly, the magnet is capable of realizing a 40 T flat-top pulsed field (flat-top time 10 ms) with a cooldown period of 16 min. This can facilitate the long-pulsed quasi-steady operation of gyrotron operation, which is attractive for numerous high-power THz applications. [ABSTRACT FROM AUTHOR]

Ocean temperature, redox state, circulation, and nutrient levels regulate the marine nitrogen (N) cycle, yet their specific impacts during greenhouse intervals remain poorly understood. Here, we examined the Smithian–Spathian hyperthermal event (∼250.5 Ma) during the Early Triassic greenhouse using stable N isotopes (δ15N) from sedimentary records in the Nanpanjiang Basin and Northern Yangtze Basin of South China. The δ15N profiles in both basins reveal consistent trends that correspond to fluctuations in temperature across the Smithian–Spathian transition. The Smithian hyperthermal interval exhibited low δ15N values (mostly <+2‰), indicating N deficiency and enhanced biological N 2 fixation. Bacterial blooms and the release of the potent greenhouse gas N 2 O, enhanced by high temperatures, may have triggered positive feedback mechanisms that sustained the warming and contributed to the late Smithian extinction. During subsequent cooling across the Smithian–Spathian transition, δ15N increased to a range of +3‰ to +7‰, likely reflecting signals of partial denitrification based on reconstruction of the NO 3 − inventory associated with oceanic cooling and oxygenation. The prevailing increases in sedimentary TOC/TN ratios signify heightened deamination (removal of amino groups) and N recycling across the Smithian–Spathian boundary. This transition is likely attributed to cooling-driven amelioration of seawater stratification and anoxia from the Smithian to the Spathian, which resulted in increased nitrate availability in the photic zone. Eukaryotic algae thrived while prokaryotes declined during the Spathian, evidenced by elevated δ15N and Δ13C carb-org (the difference between carbonate and organic carbon isotopes). The proliferation of eukaryotic algae had a positive impact on environmental conditions and facilitated biotic recovery due to more efficient burial of organic particles. A notable latitudinal gradient in the N cycle response was observed, with low-latitude regions showing a more pronounced response to cooling compared to mid-latitude areas. This significant gradient may suggest that the rapid recovery of nutrient cycles, despite relatively small decline in high temperature, was a key factor in the amelioration of climate and recovery of life in low latitudes. These findings highlight that the marine N cycle is highly sensitive to temperature changes, particularly in low-latitude regions, and that changes in N cycle under high-temperature conditions may be a critical life-limiting factor. [ABSTRACT FROM AUTHOR]

Contraction of solid elements and compounds by cooling from room temperature to 0 K or by mechanical pressing to the same volume at 298 K is experimentally determined. We found that the energy cost of cold compression exceeds the energy of mechanical compression on average by two orders of magnitude. This fact is caused by the different mechanisms of contraction: pressing directly reduces interatomic distances, cooling mainly reduces the amplitudes of harmonic vibrations of atoms, whereas the anharmonic part of the vibration energy, responsible for the thermal contraction, is very small, ca. 1%. [ABSTRACT FROM AUTHOR]

In industrial processes involving both heat and mass transfer, the enthalpy or total energy difference, not the temperature difference, is a more comprehensive driving-force potential for the design of heat exchanger systems, such as cooling towers. However, current enthalpy methods based on the Merkel integral require numerical integration with implied linear distributions of water temperature. If the cooling range of the cooling tower is relatively small, the outcome of the integration may carry little error. However, for a large cooling range and a substantially increased temperature, the error involved may be significant. Like log-mean temperature difference, a log-mean enthalpy difference method may require only the inlet and outlet conditions without prior knowledge of the enthalpy distributions of the fluids within the heat exchanger. The known Berman's enthalpy difference method requires correction factors and was derived based on the linearization of the interfacial enthalpy and the enthalpy difference between the interfacial moist air and the bulk moist air without underlying interpretation to demonstrate that the method could be broadly used. In this paper, an equivalent enthalpy model is proposed, and the log-mean enthalpy difference is derived without retaining model assumptions. The derived method is compared with some results of Merkel's method from literature with excellent agreement. Thus, the work in this paper would open up the possibility for broad uses of the log-mean enthalpy difference method for many industrial processes involving both heat and mass transfer. [ABSTRACT FROM AUTHOR]

Battery energy storage systems (BESSs) play an important role in increasing the use of renewable energy sources. Owing to the temperature sensitivity of lithium-ion batteries (LIBs), battery thermal management systems (BTMSs) are crucial to ensuring the safe and efficient operation of BESSs. Previous works mainly focused on evaluating the performance of BTMS; however, little attention has been paid to the minimum cooling requirements of BESSs, which are important for optimizing the design and operation of BTMSs. To bridge the knowledge gap, this work investigated the performance of air cooling for a battery cabin under different charge/discharge (C) rates by using a computational fluid dynamics (CFD) model, which is coupled with a battery model. Simulation results show that the inlet airflow rate has the strongest influence. For the studied cases, when the battery operates at C-rates lower than 3, the inlet temperature should be controlled below 35 °C, and the gap between the batteries should be greater than 3 mm to meet the minimum heat dissipation requirement. At a C-rate of 0.5C, natural convection is sufficient to meet the cooling need, whereas at 1C or higher C-rates, forced convection has to be used. Increasing the number of batteries, for example, from 6 to 8, has negligible impact on the inlet flow required to assure the heat dissipation. [ABSTRACT FROM AUTHOR]

[Display omitted] Energy consumption from air cooling systems in summer, water scarcity in hot regions, and the functional reusability of waste paper are emerging environmental problems. Finding solutions to these problems simultaneously remains a significant challenge. Herein, a superhydrophobic passive cooling Cellulose-CaCO 3 film with hierarchical nano-sheets was fabricated to realize daytime radiative cooling with a temperature drop of 15–20 °C in summer and water harvesting with harvesting efficiency of 387 mg cm−2h−1 bd utilization of recycled waste paper. The superhydrophobic Cellulose-CaCO 3 film demonstrates its self-cleaning properties against inorganic and organic pollutants. Furthermore, the superhydrophobicity of the film was maintained after base/acid corrosions, dynamic water flushing, and thermal treatment at 100 °C for 7 h, exhibiting good durability of the superhydrophobicity. Moreover, the superhydrophobic Cellulose-CaCO 3 film is nonflammable after exposure to fire combustion for 1 min. In addition to waste paper, waste maize straws, and pasteboards were also collected to produce superhydrophobic passive cooling films. Results indicate that the above three cellulose-based raw materials can be well used to prepare durable superhydrophobic passive cooling materials. Environmental toxicology assessments confirm the safety of the material. This study not only provides a protocol for preparing superhydrophobic materials; but also demonstrates their potential for passive cooling and water harvesting. [ABSTRACT FROM AUTHOR]

Both composition and temperature play a crucial role in determining the NO radiative cooling in lower thermosphere as observed by TIMED/SABER. In this work, we present a detailed investigation of seasonal variation in thermospheric NO radiative cooling. We have carried forward the investigation of Li et al. (2018) regarding the variations in local nighttime peak NO radiative cooling and its altitude during solar maximum and solar minimum conditions. By analyzing latitudinal changes over quiet times for each month in year 2018, it is evident that both the investigated parameters exhibit summer-winter variability. The qualitative contribution of different species (i.e., NO, and O), and temperatures in determining the vertical profile of NO radiative cooling for different latitudes is investigated by utilizing the NRLMSISE-00 estimated parameters, and SNOE observed NO density. The temperature, NO density, and compositional variations due to asymmetrical solar heating and associated summer-to-winter circulation in both the hemispheres during solar minimum conditions seem to be the dominating factor in controlling the NO radiative cooling during different seasons. The altitudes at which maximum cooling by NO occurs exhibits an inverse correlation with the amount of radiative cooling. The region of enhanced NO densities (polar and summer hemispheric low-mid latitude regions) have larger NO radiative cooling with lower peak altitudes in comparison to other regions (equatorial to winter hemispheric low-mid latitude regions), where NO radiative cooling is low with higher peak altitude values. [ABSTRACT FROM AUTHOR]

In hot and arid regions like the Saharan area, effective methods for cooling and humidifying intake air are essential. This study explores the utilization of a water trickle cooler as a promising solution to meet this objective. In particular, the HASSI MESSAOUD area is considered as a testbed. The water trickle cooler is chosen for its adaptability to arid conditions. Modeling results demonstrate its effectiveness in conditioning air before it enters the compressor. The cooling system achieves a significant temperature reduction of 6 to 8 degrees Celsius, enhancing mass flow rate dynamics by 3 percent compared to standard cases without cooling. Moreover, the cooling system contributes to a remarkable 10 percent reduction in power consumption of gas turbines and a notable 10 percent increase in turbine efficiency. These findings highlight the potential of water trickle coolers in improving the performance and efficiency of gas turbine systems in hot and dry climates. [ABSTRACT FROM AUTHOR]