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The adsorption of polymer-grafted nanoparticles at interfaces is a problem of fundamental interest in physics and soft materials. This adsorption behavior is governed by the interplay between interaction potentials and entropic effects. Here, we use molecular dynamics simulations and umbrella sampling methods to study the adsorption behavior of a Janus-like homopolymer-grafted nanoparticle at fluid–fluid interfaces. By calculating the potential of the mean force as the particle moves from fluid A to the interface, the adsorption energy Ea can be obtained. When two homopolymer chains with types A and B are grafted to the opposite poles of the particle, Ea shows a scaling behavior with respect to chain length N: Ea ∝ N0.598. This is determined by the interactions between polymers and fluids. The enthalpy dominates, and the entropy effects mainly come from the rotational entropy loss of the polymer-grafted nanoparticle at interfaces, which disfavors the stabilization of particles at interfaces. When the grafted polymer number m is large, the adsorption energy exhibits a linear dependence on m. While the enthalpy dominates the behavior, the entropy becomes significant at a larger chain length of N = 15, where the configurational entropy of the polymer chains dominates the entropy of the system. The globule–coil transition occurs when polymers move from poor solvents to good solvents, increasing the configurational entropy and favoring the stabilization of particles at interfaces. Our study provides novel insights into the stabilization mechanism of polymer-grafted nanoparticles at interfaces and reveals the stabilization mechanism favored by the configurational entropy of grafted polymer chains. [ABSTRACT FROM AUTHOR]

In this work, we studied the nature and dilemma of the inverse magnetocaloric effect using Ni50Mn36In14 magnetic shape memory alloy. In this context, the inverse magnetocaloric effects of Ni50Mn36In14 magnetic shape memory alloy polycrystalline samples were investigated as a function of annealing heat treatments by the thermo-magnetometry method. Two forms of Ni49TiMn36In14 magnetic shape memory alloy were studied: one that predominantly undergoes a magnetic phase transition and the other that exhibits both a magnetic and martensitic phase transition. The magnetic behaviors and magnetocaloric properties of these alloys were analyzed to investigate the competition between magnetic and lattice contributions to the total entropy change. Finally, the mutually contradictory role of magnetic and lattice contributions was demonstrated. [ABSTRACT FROM AUTHOR]

Dynamic heterogeneity is a fundamental characteristic of glasses and undercooled liquids. The heterogeneous nature causes some of the key features of systems' dynamics such as the temperature dependence of nonexponentiality and spatial enthalpy fluctuations. Commonly used phenomenological models such as Tool–Narayanaswamy–Moynihan (TNM) and Kovacs–Aklonis–Hutchinson–Ramos fail to fully capture this phenomenon. Here we propose a model that can predict the temperature-dependent nonexponential behavior observed in glass-forming liquids and glasses by fitting standard differential scanning calorimetry curves. This model extends the TNM framework of structural relaxation by introducing a distribution of equilibrium fictive temperature ( T f e ) that accounts for heterogeneity in the undercooled liquid. This distribution is then frozen at the glass transition to account for the heterogeneous nature of the glass dynamics. The nonexponentiality parameter βKWW is obtained as a function of temperature by fitting the Kohlrauch-Williams-Watts (KWW) equation to the calculated relaxation function for various organic and inorganic undercooled liquids and glasses. The calculated temperature dependent βKWW shows good agreement with the experimental ones. We successfully model the relaxation dynamics far from equilibrium for two silicate systems that the TNM model fails to describe, confirming that temperature dependent nonexponentiality is necessary to fully describe these dynamics. The model also simulates the fluctuation of fictive temperature δTf during isothermal annealing with good qualitative agreement with the evolution of enthalpy fluctuation reported in the literature. We find that the evolution of enthalpy fluctuation during isothermal annealing heavily depends on the cooling rate, a dependence that was not previously emphasized. [ABSTRACT FROM AUTHOR]

Owing to their ability for fast switching and the large property contrast between the crystalline and amorphous states that permits multi-level data storage, in-memory computing and neuromorphic computing, the investigation of phase change materials (PCMs) remains a highly active field of research. Yet, the continuous increase in electrical resistance (called drift) observed in the amorphous phase has so far hindered the commercial implementation of multi-level data storage. It was recently shown that the resistance drift is caused by aging-induced structural relaxation of the glassy phase, which is accompanied by a simultaneous decrease in enthalpy and fictive temperature. This implies that resistance is related to enthalpy relaxation. While the resistance is known to drift even at room temperature and below, evidence for enthalpy relaxation at room temperature in amorphous PCMs is still missing. Here, we monitor changes in enthalpy induced by long-term room-temperature aging in a series of PCMs. Our results demonstrate the simultaneity of resistance drift and enthalpy relaxation at room temperature, and thus provide further insights into the mechanism of resistance drift and its possible remediation. [ABSTRACT FROM AUTHOR]

The glass transition (Tg) behavior and enthalpy recovery of polystyrene nanorods within an anodic aluminum oxide (AAO) template (supported nanorods) and after removal from AAO (unsupported nanorods) is studied using Flash differential scanning calorimetry. Tg is found to be depressed relative to the bulk by 20 ± 2 K for 20 nm-diameter unsupported polystyrene (PS) nanorods at the slowest cooling rate and by 9 ± 1 K for 55 nm-diameter rods. On the other hand, bulk-like behavior is observed in the case of unsupported 350 nm-diameter nanorods and for all supported rods in AAO. The size-dependent Tg behavior of the PS unsupported nanorods compares well with results for ultrathin films when scaled using the volume/surface ratio. Enthalpy recovery was also studied for the 20 and 350 nm unsupported nanorods with evolution toward equilibrium found to be linear with logarithmic time. The rate of enthalpy recovery for the 350 nm rods was similar to that for the bulk, whereas the rate of recovery was enhanced for the 20 nm rods for down-jump sizes larger than 17 K. A relaxation map summarizes the behavior of the nanorods relative to the bulk and relative to that for the 20 nm-thick ultrathin film. Interestingly, the fragility of the 20 nm-diameter nanorod and the 20 nm ultrathin film are identical within the error of measurements, and when plotted vs departure from Tg (i.e., T − Tg), the relaxation maps of the two samples are identical in spite of the fact that the Tg is depressed 8 K more in the nanorod sample. [ABSTRACT FROM AUTHOR]

The glassy state of zeolitic imidazolate frameworks (ZIFs) has shown great potential for energy-related applications, including solid electrolytes. However, their thermal conductivity (κ), an essential parameter influencing thermal dissipation, remains largely unexplored. In this work, using a combination of experiments, atomistic simulations, and lattice dynamics calculations, we investigate κ and the underlying heat conduction mechanism in ZIF glasses with varying ratios of imidazolate (Im) to benzimidazolate (bIm) linkers. The substitution of bIm for Im tunes the node–linker couplings but exhibits only a minor impact on the average diffusivity of low-frequency lattice modes. On the other hand, the linker substitution induces significant volume expansion, which, in turn, suppresses the contributions from lattice vibrations to κ, leading to decreased total heat conduction. Furthermore, spatial localization of internal high-frequency linker vibrations is promoted upon substitution, reducing their mode diffusivities. This is ascribed to structural deformations of the bIm units in the glasses. Our work unveils the detailed influences of linker substitution on the dual heat conduction characteristics of ZIF glasses and guides the κ regulation of related hybrid materials in practical applications. [ABSTRACT FROM AUTHOR]

We study heat exchange in temperature-biased metal–molecule–metal molecular junctions by employing the molecular dynamics simulator LAMMPS. Generating the nonequilibrium steady state with Langevin thermostats at the boundaries of the junction, we show that the average heat current across a gold–alkanedithiol–gold nanojunction behaves physically, with the thermal conductance value matching the literature. In contrast, the full probability distribution function for heat exchange, as generated by the simulator, violates the fundamental fluctuation symmetry for entropy production. We trace this failure back to the implementation of the thermostats and the expression used to calculate the heat exchange. To rectify this issue and produce the correct statistics, we introduce single-atom thermostats as an alternative to conventional many-atom thermostats. Once averaging heat exchange over the hot and cold thermostats, this approach successfully generates the correct probability distribution function, which we use to study the behavior of both the average heat current and its noise. We further examine the thermodynamic uncertainty relation in the molecular junction and show that it holds, albeit demonstrating nontrivial trends. Our study points to the need to carefully implement nonequilibrium molecular dynamics solvers in atomistic simulation software tools for future investigations of noise phenomena in thermal transport. [ABSTRACT FROM AUTHOR]

Both shock and shockless compression experiments were performed on laser powder bed fusion (LPBF) Ti–5Al–5V–5Mo–3Cr (Ti-5553) to peak compressive stresses near 15 GPa. Experiments were performed on the as-built material, containing a purely β (body centered cubic) microstructure, and two differing heat treatments resulting in a dual phase α (hexagonal close packed) and β microstructure. The Hugoniot, Hugoniot elastic limit (HEL), and spallation strength were measured and compared to wrought Ti-6Al-4V (Ti-64). The results indicate the LPBF Ti-5553 Hugoniot response is similar between heat treatments and to Ti-64. The HEL stress observed in the LPBF Ti-5553 was considerably higher than Ti-64, with the as-built, fully β alloy exhibiting the largest values. The spallation strength of the LPBF Ti-5553 was also similar to Ti-64. Clear evidence of initial porosity serving as initiation sites for spallation damage was observed when comparing computed tomography measurements before and after loading. Post-mortem scanning electron microscopy images of the recovered spallation samples showed no evidence of retained phase changes near the spall plane. The spall plane was found to have kinks aligned with the loading direction near areas with large concentrations of twin-like, crystallographic defects in the as-built condition. For the heat-treated samples, the concentrations of twin-like, crystallographic defects were absent, and no preference for failure at the interface between the α and β phases was observed. [ABSTRACT FROM AUTHOR]

We present the study of the structure–dynamics correlation for systems interacting via attractive Lennard-Jones (LJ) and its repulsive counterpart, the Weeks–Chandler–Andersen (WCA) potentials. The structural order parameter (SOP) is related to the microscopic mean-field caging potential. At a particle level, the SOP shows a distribution. Although the two systems have similar pair structures, their average SOP differs. However, this difference alone is insufficient to explain the well known slowing down of the dynamics in the LJ system at low temperatures. The slowing down can be explained in terms of a stronger coupling between the SOP and the dynamics. To understand the origin of this system specific coupling, we study the difference in the microscopic structure between the hard and soft particles. We find that for the LJ system, the structural differences of the hard and soft particles are more significant and have a much stronger temperature dependence compared to the WCA system. Thus, the study suggests that attractive interaction creates more structurally different communities. This broader difference in the structural communities is probably responsible for stronger coupling between the structure and dynamics. Thus, the system specific structure–dynamics correlation, which also leads to a faster slowing down in the dynamics, appears to have a structural origin. A comparison of the predictive power of our SOP with the local energy and two body excess entropy in determining the dynamics shows that in the LJ system, the enthalpy plays a dominant role and in the WCA system, the entropy plays a dominant role, and our SOP can capture both these contributions. [ABSTRACT FROM AUTHOR]

From the perspective of a bond-order-length-strength correlation, we put forward an analytical solution to describe the size, shape, and wall thickness dependency of melting temperature, entropy, and enthalpy for metallic nanostructures. Theoretical reproduction of measurements clarified that (i) when the crystal size reduces, the atomic coordination number lowers, the atomic cohesive energy decreases, and the surface-to-volume ratio increases; (ii) at the same equivalent radius, with the decrease in the number of sides for polyhedral nanoparticles and polygonal nanowires or nanotubes, the melting temperature, entropy, and enthalpy depress; and (iii) the melting temperature, entropy, and enthalpy of nanotubes are always lower than those of nanowires with the same cross-sectional radius. The present formulation is accurate and convenient, which not only shows deeper insight into the physical origins of a melting thermodynamic property response to perturbations but also provides guidance for the design and optimization of electronic nanodevices. [ABSTRACT FROM AUTHOR]

Two‐dimensional molybdenum disulfide (MoS2) nanosheets are seen as highly promising nanofillers for enhancing polymer properties, yet there is a need for methods that are low‐cost, simple, and environmentally friendly to facilitate the large‐scale production of MoS2 nanosheets. Furthermore, it is necessary to functionalize the MoS2 surface to ensure good interfacial compatibility with the polymer matrix. In this study, MoS2@Ag@PA hybrids were created by generating silver nanoparticles directly on the surface of MoS2 via radiation, followed by encapsulation on the surface of MoS2@Ag through the chelating properties of phytic acid. It is significant to note that, due to the excellent lubrication and physical cross‐linking effects of the MoS2@Ag@PA hybrids, adding one part of MoS2@Ag@PA hybrids can enhance the melt flow rate and elongation at break of the ethylene vinyl acetate copolymer (EVA)/MH composites by 140% and 17.3%, respectively. The simultaneous addition of one part of MoS2@Ag@PA hybrids decreased the peak heat release rate, total heat release, and total smoke release of the EVA composites by 48.7%, 42.7%, and 41.2%, respectively. Moreover, the toxic gasses (e.g., CO) generated by burning EVA composites were significantly reduced compared to pure EVA, indicating improved fire safety. This research not only provides significant opportunities for the green mass production of MoS2 nanosheets but also expands their potential applications in high‐performance nanocomposites. [ABSTRACT FROM AUTHOR]

In order to clarify the effect of feeding rate ratio (Rsr) for polylactic acid (PLA) to polyethylene glycol (PEG) on the performance of thermal regulation nanofibers, PLA and PEG solutions were used as the outer and inner spinning solutions, respectively, to develop PLA/PEG nanofibers (NFp‐p) through coaxial electrospinning. NFp‐p nanofibers with Rsr of 2:1, 3:1, and 4:1 were labeled PR1, PR2, and PR3, respectively. The morphology, chemical structure, mechanical properties, and thermal performance of NFp‐p were tested, and the thermal regulation function was investigated. The results showed that increasing Rsr could increase the diameter of NFp‐p, with PR1 having the smallest average diameter (520 nm). PR1 had the lowest water contact angle (122.4°), and higher Rsr enhanced the encapsulation effect of PLA on PEG. The mechanical properties of NFp‐p were significantly improved compared to pure PLA, with PR1 and PR3 exhibiting the highest breaking stress (2.5 MPa) and breaking strain (213%). The thermal performance of NFp‐p could be regulated by Rsr, with PR1 showing a more pronounced endothermic peak due to the melting of PEG, and the highest phase‐change enthalpy (13.2 J/g). Lower Rsr enhanced the thermal regulation function of NFp‐p, and PR1 showed superior thermal regulation performance. [ABSTRACT FROM AUTHOR]

The Pὃschl–Teller potential is a molecular potential energy function that has only been reported for bound state. This Pὃschl–Teller potential is a good representation of many molecules and has not been examined for any thermodynamic property irrespective of its fitness for molecular study. In this study, the molar entropy of four molecules (Pbr, BBr, CsCl, and CsO molecules) is calculated via the molar partition function. The predicted results are compared with the experimental data recorded in the National Institute of Standards and Technology (NIST) database. It is noted that the predicted values for the studied molecules perfectly agree with the experimental results with the following average absolute percentage deviation, PBr is 0.0158%, BBr is 0.0053%, CsCl is 0.0020%, and CsO is 0.0052%. The present model reproduces better results for CsCl and CsO molecules compared to the shifted Tietz–Wei potential and improved Tietz‐oscillator previously reported whose average absolute percentage deviation are 0.361% and 0.284% for CsCl and 0.272% and 0.228% for CsO, respectively. [ABSTRACT FROM AUTHOR]

The surface temperature of a workpiece during abrasive belt grinding directly affects its surface quality and determines whether the workpiece surface burns. However, the surface temperature of the workpiece during the grinding process is determined by the total heat and the heat carried away by the chips. Under certain grinding parameters, accurately obtaining the heat removed by the chips is one of the key factors to accurately obtain the workpiece surface quality. Therefore, a new method for chip heat monitoring based on audio-visual information decision fusion is proposed in this study. By obtaining visual sparks and sound signals directly related to the chip, a real-time chip quality (i.e., material removal rate, MRR) monitoring model based on convolutional neural network (CNN) and multilayer perceptron (MLP) was established. The heat taken away by the chips in real time was calculated through theoretical formula. The results show that the RMSE of the proposed method for the material removal rate does not exceed 0.006, and the coefficient of determination R2 is not less than 99.4%. The maximum error between the predicted maximum temperature of the grinding surface and the experimental measurement value is 10 °C. The proposed method provides the theoretical basis for the prediction and control of workpiece grinding temperature. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel and simple scheme for loading aluminum hypophosphite on MOF derivatives. • The dual function of carboxymethyl cellulose: buffer and support layer. • The double-layer hollow nano hybrid is integrated with multiple flame retardant elements. • The flame retardancy of epoxy resin composites is significantly improved after the introduction of AHP/ACP@CMC due to its unique components and nanostructure. Aluminum hypophosphite (AHP) has been used as a flame retardant for a long time. Previous studies about AHP employed in flame retardant materials mostly focus on coating, modification, and complex system. It is valuable to explore simple experimental steps to prepare nano hybrids with AHP and metal–organic frameworks (MOFs). We found acidic substances could etch zeolitic imidazolate framework-67 (ZIF-67) to obtain MOF derivatives. Unfortunately, AHP and ZIF-67 could not directly form a hybrid. Therefore, carboxymethylcellulose (CMC) is introduced as a dual function layer (buffer and support). The CMC resists the complete conversion of ZIF-67 etched by phosphoric acid to amorphous cobalt phosphate hydrate (ACP). Meanwhile, CMC containing hydroxyl groups combines with AHP through electrostatic interaction and coordination bonds. A double-layer hollow MOF derivative is synthesized through this one-stone-two-birds strategy. Due to multiple flame retardant elements and unique nanostructure, this MOF derivative endows epoxy (EP) resin with excellent flame retardancy. With 2.0 wt% addition, the peak heat release rate (pHRR) and total heat release (THR) of EP/AHP/ACP@CMC are decreased by 47.8 and 21.0 %, respectively. This study proposes a novel scheme that converts AHP into MOF derivatives as high-performance FRs. [ABSTRACT FROM AUTHOR]

A robust MOF with diethylammonium cations in its pores, enhances pore partitioning and modifies the environment, enabling selective and dense SO2 packing through hydrogen bonds. It achieves a reversible SO2 uptake with a high adsorption enthalpy and record IAST selectivity of 1182 for SO2/CO2 at 298 K and 1 bar. [ABSTRACT FROM AUTHOR]

As for cellulose‐based aerogels, a feature of inadequate mechanics and easy‐flammability seriously restricts their practical applications. To address this issue, herein a lightweight, mechanical elastic and flame‐retardant phosphorylated lignin‐based cellulose nanofiber (PLCNF‐B) aerogel with the aid of boric acid was successfully obtained by freeze‐drying method. Due to the uniform and tough network structure benefitting by strong hydrogen bond between phosphorylated fibers and boric acid, the resultant aerogel showed excellent mechanical performance, that is, high compressive strength of 8.9 kPa (strain: 50%) and outstanding cyclic reliability (remain 90% after 10 cycles). Meanwhile, PLCNF‐B aerogel possesses highly improved flame‐retardant property, that is, a high LOI value (up to 46%), significantly reduced peak heat release rate (11.2 W/g) and total heat release rate (0.47 kJ/g). Based on structural observation and analysis, the flame‐retardant behavior should be attributed to the formation of PxOy/amorphous boron oxide protective layer, which is derived from the phosphorus containing group of PLCNF and boric acid. The splendid overall performance of aerogel material offers a potential material tactic for design and development of advanced bio‐based aerogels for practical applications. [ABSTRACT FROM AUTHOR]

Due to rising health concerns, consumers are increasingly inclined toward reduced‐fat products, which have driven the need for nutritious alternatives through modifications in recipes and production processes. Despite the growing popularity of coconut‐based products, there is limited research on baked coconut chips, particularly regarding the effects of baking temperatures and product thicknesses. This study addresses this gap by developing baked coconut chips samples (BCSs) as a healthier alternative to traditional fried chips. Baking experiments were conducted at temperatures of 140°C, 160°C, and 180°C, with 160°C identified as optimal for balancing processing time and product quality. The study also compared baked coconut chips with those that were dried and then baked (dried baked coconut chips samples [DBCS]). Among the trials, the 0.5‐mm‐thick coconut chips baked at 160°C exhibited favorable sensory attributes and notable biochemical properties, including 3.13% moisture content, 1.13% ash, 40.49% fat, and significant antioxidant activity. [ABSTRACT FROM AUTHOR]

Investigating the effect of nanoparticle dispersion morphology on the properties of the interfacial layer of polymer nanocomposites (PNCs) provides an important theoretical basis for designing and regulating the macroscopic properties of PNCs. Differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS) were used to investigate the characteristic parameters of the interfacial area, segmental dynamics and enthalpy relaxation of PNCs with nanoparticle agglomerates and uniformly dispersed morphology. The volume fraction of the interfacial area (φint) and the extent of influence of the interfacial area on the enthalpy hysteresis reduction (χint) in PNCs with agglomerated nanoparticles are lower than that of PNCs with uniformly dispersed nanoparticles for the same nanoparticle loading. Because of the irregular structure of the nanoparticle aggregate morphology, the linear relationships between φint and nanoparticle content is not valid in PNCs with agglomerated nanoparticles. Interestingly, φint obtained by BDS and χint have a clearly linear relationship in all PNCs, independent of nanoparticle dispersion morphology. Such universal quantitative relationship provides a new research methodology for investigating the characteristic parameters of the interfacial area in PNCs, and facilitates the construction of a correspondence between the microscopic parameters of interfacial area and the macroscopic properties of PNCs. Highlights: The linear relationships between φint and nanoparticle content are not valid in PNCs with agglomerated nanoparticles.The linear relationships between φint and the decreased degree of ΔHR can be noted in all PNCs, independent of nanoparticle dispersion morphology.The universal correspondence provides a new research methodology for investigating the characteristic parameters of the interface layer in PNCs. [ABSTRACT FROM AUTHOR]

Organic flame retardant 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) was used to decorate the pores of mesoporous silica (m‐SiO2) nanospheres to prepare a new composite flame retardant (DK‐SiO2). The content of DOPO in DK‐SiO2 is about 17 wt%. Due to the chemical bonding, DK‐SiO2 not only enhances the flame retardant performance, but also effectively avoids adverse effects of DOPO on the glass transition temperature and mechanical properties of epoxy resin (EP). At 9 wt% loading, the limiting oxygen index of the EP increased from 25.7 to 31.2, and successfully passed the UL‐94 V‐0 rating. Besides, DK‐SiO2 can significantly reduce the peak heat release rate, total heat release, and total smoke production of EP, with reductions of 26%, 32%, and 20.8%, respectively. Compared with the simple blended sample, DK‐SiO2 not only has better flame retardant performance but also shows significant advantages in thermodynamic properties. The glass transition temperature, impact, and tensile strength, as well as storage and flexural modulus have been improved. This excellent flame retardant performance is mainly attributed to the gas‐condensed synergistic flame retardant mechanism between DOPO and m‐SiO2. The good thermodynamic performance is due to the excellent dispersion of DK‐SiO2 nanospheres in the EP. [ABSTRACT FROM AUTHOR]

Balancing the enhancement of flame retardancy of epoxy resin while maintaining its mechanical capacities intact poses a significant challenge in the realm of flame‐retardant epoxy resins. To reach the above objectives, a COF‐based synergistic flame retardant with phosphorus, nitrogen, and silicon (PA‐COF@MT) was synthesized using phytic acid (PA), montmorillonite (MT), and covalent organic framework (COF). When PA‐COF@MT was added at 4 wt%, EP/PA‐COF@MT exhibited a reduction of 42.1% in peak heat release rate (PHRR), 45.84% in total heat release (THR), and 59.8% in total smoke production (TSP) compared with the pure EP. LOI increased by 30.5% and UL‐94 tested to V‐0 grade. flame‐retardant index (FRI) value of 3.03, achieving a "good" rating. Fire growth indices and mean effective combustion heat were increased while mechanical properties also improved. These findings suggest that the flame retarding mechanism of PA‐COF@MT is mainly through vapor phase and condensed phase actions. The combined effects of phosphorus, nitrogen, and silicon make the surface of carbon residue solid and dense, resulting in excellent heat insulation and smoke suppression effects. In simple terms, this study provides new insights into COF‐based flame retardants. Combining low‐cost and simple preparation methods, PA‐COF@MT has broad application prospects in flame‐retardant epoxy resin systems. [ABSTRACT FROM AUTHOR]

In order to improve the flame retardancy and smoke suppression of silicone rubber foam (SRF), the CoFe‐LDH was fabricated by coprecipitation method and used as flame‐retardant ingredient in SRF. The influence of CoFe‐LDH on the flame retardancy, combustion behavior, and thermal stability of SRF was investigated. The results demonstrate that SRF containing only 1.0 phr CoFe‐LDH can pass V‐0 rating in the vertical combustion test, with a limiting oxygen index of 28.6%. The total heat release and total smoke production are 22.2% and 61.1% lower than that of SRF, respectively. Moreover, CoFe‐LDH can improve the thermal stability of SRF in the high temperature range, and the char residue at 900°C of SRF/LDH composite is obviously higher than that of pure SRF. In addition, to further understand the flame‐retardant mechanism of CoFe‐LDH, the micromorphology of the char residue and the gaseous products during heating for SRF and SRF/LDH composite were analyzed. The results indicate that CoFe‐LDH exhibits excellent flame‐retardant effects in both condensed and gaseous phases for its functions of catalysis, carbonization, and nonflammable gas release. This study provides a more efficient and convenient strategy for the flame retardant and smoke suppression research of SRF. [ABSTRACT FROM AUTHOR]

Arctic warming has been substantially greater than that in the rest of the world and has had an important influence on the global climate. This study first explores the temporal and spatial evolutionary characteristics of marine heatwaves (MHWs) over the Arctic Ocean in multiyear ice (MYI), first‐year ice (FYI), and open‐water (OPW) regions from 1982 to 2020. MHWs in the Arctic Ocean show obvious spatial and seasonal variations, mainly occurring over the FYI region in the JAS (July–August–September, JAS), and their occurrences have a significant increasing trend in recent decades, accompanied by an abrupt increase since 2010. Furthermore, a multivariable network‐based method is adopted to delineate the relationship between different climatic factors and MHWs in the Arctic Ocean and the climatic impacts of MHWs. The results show that the correlations between different climatic factors and MHWs in JAS in 2010–2020 are generally stronger than those in 1982–2009, and the main influencing factors of MHWs in different ice covers are different. MHWs in the MYI region are mainly affected by freshwater dilution processes, such as sea‐ice concentrations (SIC), precipitation, and mixed‐layer salinity. For the FYI region, the 2‐m air temperature and total heat flux mainly affect MHWs by thermodynamic processes, and the 500‐hPa geopotential height affects MHWs mainly by large‐scale atmospheric circulation. The MHWs in the OPW region are mainly related to the SIC, 850‐hPa geopotential height, and 10‐m v‐wind, indicating that they are correlated with atmospheric processes and wind fields. MHWs in JAS are also revealed to reduce or delay the formation of sea ice in OND (October–November–December, OND) by storing more abnormal heat, indicating that unfrozen ocean surfaces may lead to enhanced Arctic amplification in the following seasons. [ABSTRACT FROM AUTHOR]

Cocrystals are assemblies of more than one type of molecule stabilized through noncovalent interactions. They are promising materials for improved drug formulation in which the stability, solubility, or biocompatibility of the active pharmaceutical ingredient (API) is improved by including a coformer. In this work, a range of density functional theory (DFT) and density functional tight binding (DFTB) models are systematically compared for their ability to predict the lattice enthalpy of a broad range of existing pharmaceutically relevant cocrystals. These range from cocrystals containing model compounds 4,4′‐bipyridine and oxalic acid to those with the well benchmarked APIs of aspirin and paracetamol, all tested with a large set of alternative coformers. For simple cocrystals, there is a general consensus in lattice enthalpy calculated by the different DFT models. For the cocrystals with API coformers the cocrystals, enthalpy predictions depend strongly on the DFT model. The significantly lighter DFTB models predict unrealistic values of lattice enthalpy even for simple cocrystals. [ABSTRACT FROM AUTHOR]

Thermodynamic modeling of metal oxide reduction is crucial for optimizing chemical processes and materials in systems dependent on off-stoichiometric reduction/re-oxidation cycling. Two prevalent methods for extracting reduction thermodynamics from thermogravimetric data are linearized van 't Hoff (VH) analysis and the compound energy formalism (CEF). This work evaluates the accuracy of these methods by constructing invertible ground truth thermodynamic models, generating hypothetical thermogravimetric data, and determining the reduction thermodynamic using both VH and CEF methods. Our findings reveal that the VH method produces absolute errors 3–5 times higher than the CEF in kJ/mol O or J/mol O K for enthalpy and entropy of reduction, respectively. In contrast, the CrossFit CEF (CF-CEF) method yields errors often less than 10 kJ/mol O or J/mol O K. Moreover, the CF-CEF method provides models based on mole fraction, temperature, and extent of reduction, while a typical VH analysis provides thermodynamics of only the specific compositions measured. Although simple to implement, the VH method suffers from significant, non-systematic errors due to entropy/enthalpy compensation and defect modeling. Consequently, we recommend the more complex but robust, CF-CEF method for extracting redox thermodynamics from thermogravimetric measurements. [ABSTRACT FROM AUTHOR]

Norbornadiene/Quadricyclane (NBD/QC) is a prototypical bridged bicyclic diene (BBD)‐based photoswitch that has been well‐studied for molecular solar thermal energy storage (MOST). Inspired by the recent synthetically accessed BBDs, herein several photoswitches are rationally designed with modulated ring strain energies (RSE) in photoisomers to incorporate high energy storage density (ESD) and storage time in a single couple. The storage energy (ΔGstr ${{{\rm \Delta }{\rm G}}^{str}}$) calculated at DLPNO‐CCSD(T)/Def2TZVP level is correlated with difference in RSE of two isomers (ΔRSE) whereas thermal back reaction (TBR) barrier calculated at (8,8)‐CASPT2/6‐311++G** shows correlation with RSE in metastable photoproduct. On the basis of these structure‐property‐RSE relationships, we recognized that two photoisomers need not to be highly strained. Instead, the RSE in the photoproduct and diene should be minimized while maintaining a large enthalpy difference between them to increase ESD and extend energy storage times in a single photoswitch. TBR barrier is governed by RSE in photoproduct and increasing strain in photoproduct may improve the ΔGstr ${{{\rm \Delta }{\rm G}}^{str}}$ but at the cost of the TBR barrier. Herein, the structural skeletons are explored that holds promise to remarkably improve thermochemical properties relative to the unsubstituted BBD‐based photoswitches reported so far. The BBD molecules with short saturated bridge length but elongated unsaturated bridges could bestow desirable thermochemical parameters and can be regarded as excellent candidates for MOST application. The work lays a theoretical foundation that guides to improve thermochemical properties via strain engineering of BBD‐based photoswitches and opens a new avenue for designing principles and future experimental investigations of MOST systems. [ABSTRACT FROM AUTHOR]

To enhance the fire safety performance in polystyrene (PS), a novel organic–inorganic hybrid material (FGO–AHP) was successfully prepared by the combination of functionalized graphene oxide (FGO) and aluminum hypophosphite (AHP) via a chemical deposition method. The resulting FGO–AHP nanohybrids were incorporated into PS via a masterbatch-melt blending to produce PS/FGO–AHP nanocomposites. Scanning electron microscope images confirm the homogeneous dispersion and exfoliation state of FGO–AHP in the PS matrix. Incorporating FGO–AHP significantly improves the thermal behavior and fire safety performance of PS. By incorporating 5 wt% FGO–AHP, the maximum mass loss rate (MMLR) in air, total heat release (THR), and maximum smoke density value (Dsmax) of PS nanocomposite achieve a reduction of 53.1%, 23.4%, and 50.9%, respectively, as compared to the pure PS. In addition, thermogravimetry–Fourier transform infrared (TG–FTIR) results indicate that introducing FGO–AHP notably inhibits the evolution of volatile products from PS decomposition. Further, scanning electron microscopy (SEM), FTIR, and Raman spectroscopy were employed to investigate the char residue of PS nanocomposite samples, elaborating the flame-retardant mechanism in PS/FGO–AHP nanocomposites. [ABSTRACT FROM AUTHOR]

Epoxy resins (EPs) are highly flammable, and traditional flame retardant modifications often lead to a significant reduction in their mechanical performance, limiting their applications in aerospace and electrical and electronic fields. In this study, a novel flame retardant, bis(4-(((diphenylphosphoryl)oxy)methyl)phenyl)phenyl phosphate (DMP), was successfully prepared and introduced into the EP matrix. When the addition of DMP was 9 wt%, the EP/9 wt% DMP thermosets passed the UL-94 V-0 rating, and their LOI was increased from 24.5% of EP to 35.0%. With the introduction of DMP, the phosphoric acid compounds from the decomposition of DMP promoted the dehydration and charring of the EP matrix, and the compact, dense char layer effectively exerted the shielding effect in the condensed phase. Meanwhile, the produced phosphorus-containing radicals played a quenching effect in the gas phase. As a result, the peak heat release rate (PHRR) and total heat release (THR) of EP/9 wt% DMP were reduced by 68.9% and 18.1% compared to pure EP. In addition, the polyaromatic structure of DMP had good compatibility with the EP matrix, and the tensile strength, flexural strength and impact strength of EP/9 wt% DMP were enhanced by 116.38%, 17.84% and 59.11% in comparison with that of pure EP. This study is valuable for expanding the application of flame-retardant EP/DMP thermosets in emerging fields. [ABSTRACT FROM AUTHOR]

Using heat diffusion models in sonic infrared (IR) inspection technology that captures arbitrary frictional heat generation function along a crack lends itself to estimation of crack length using thermal images alone. This study introduces novel physics-based approach that relies on the governing heat diffusion model linearity and superposition of point heat sources along crack to reduce thermal noise effect in crack length estimation. It utilises thermal images and their timestamps in sonic IR inspection to deliver spatiotemporal average representation of the aforementioned point heat sources to reduce thermal noise effect in crack length estimation. The proposed methodology is tested against two-dimensional and three-dimensional finite element simulations with an arbitrary frictional heat generation function along crack. Virtual random thermal noise levels ranging between 50 and 200 mK, which are higher than IR cameras Noise Equivalent Temperature Difference values, are added to simulated results to reflect realistic and drastic thermal noise levels. Spatiotemporal averaging using combined sets of different thermal images captured at various times in single sonic IR inspection delivered about 16% total uncertainty in the estimation of a crack length at 95% confidence level based on 60 experiments. Similar uncertainty level is obtained using independently reported sonic IR experimental data. [ABSTRACT FROM AUTHOR]

The influences of CO2 incorporated in gas nanobubbles (NBs) on palm oil crystallisation and physical characteristics were investigated. Initially, CO2 NB-treated palm oil had a significantly (p ≤ 0.05) larger amount of dissolved CO2 (~ 1200–1700 ppm). The crystal morphology evaluation showed smaller size and higher number of palm oil crystals by the presence of CO2 NBs. Additionally, the attendance of NBs caused a slight increment in crystallising enthalpy magnitude and a significant reduction in final end-set melting temperatures (by 4.5–6 °C) of palm oil stored at 4 °C. There was also a significant (p ≤ 0.05) increase in melting enthalpies by 1.3–3.5 J/g and 6.5–9 J/g of the NB-treated samples under 48-h storage conditions at 23 °C and 4 °C, respectively. Furthermore, the CO2 NB-treated palm oil was characterised by both lighter colour and lower hardness. Research findings demonstrate that the introduction of food-grade gas NBs can be a sustainable and eco-friendly method to tailor thermal behaviour and physical properties of palm oil. [ABSTRACT FROM AUTHOR]

This paper investigates the hydrothermal behavior of leaky dielectric and perfect dielectric droplets impacting a superheated wall within a specific range of Weber numbers (We≤30) $(We\le 30)$ under an electric field. Through this investigation, we aim to provide a more comprehensive understanding of the dynamics involved in droplet‐superheated surface interactions under electric fields, which can be useful in various applications, such as the design of cooling systems and combustion chambers. The study utilizes the level‐set and ghost fluid techniques to capture the interface accurately. Under an electric field, different behaviors are observed during the impact process, depending on the electrical properties of the droplet. A perfect dielectric droplet experiences a reduction in spreading extent and an increase in contact time. However, no remarkable enhancement in total heat removal occurs in this case. For the leaky dielectric droplet exhibiting prolate deformation at the stationary state, increasing the electric field magnitude results in a slight decrease in the droplet spreading extent, while the droplet contact time and total heat removal from the surface increase. At an electric capillary number of 1.55E − 2 and a Weber number of 25, the enhancement in the contact time and total heat removal is about 43% and 15%, respectively. For the leaky dielectric droplet with oblate deformation at the stationary state, the spreading extent and total heat removal increase, with negligible changes in contact time. At the above‐mentioned electric capillary and Weber numbers, the enhancement in the spreading extent and total heat removal is about 7.5% and 15%, respectively. [ABSTRACT FROM AUTHOR]

Climate change is increasing both seasonal temperatures and the frequency and severity of heat extremes. As the endocrine system facilitates physiological adaptations to temperature changes, diseases with an endocrinological basis have the potential to affect thermoregulation and increase the risk of heat injury. The effect of climate change and associated high temperature exposure on endocrine axis development and function, and on the prevalence and severity of diseases associated with hormone deficiency or excess, is unclear. This Perspective summarizes current knowledge relating to the hormonal effects of heat exposure in species ranging from rodents to humans. We also describe the potential effect of high temperature exposures on patients with endocrine diseases. Finally, we highlight the need for more basic science, clinical and epidemiological research into the effects of heat on endocrine function and health; this research could enable the development of interventions for people most at risk, in the context of rising environmental temperatures. Climate change is causing human populations to be exposed to increasingly higher ambient temperatures and more frequent and extreme heatwaves than previously observed. This Perspective considers the available evidence on the endocrine effects of heat exposure, and maps out a path for future research into this field. [ABSTRACT FROM AUTHOR]

This paper employs the inclusion-based boundary element method (iBEM) to delve into heat transfer phenomena in composites. Initially, we integrate the heat flow function and ellipsoidal integral into a bounded domain containing multiple ellipsoidal inhomogeneities. The eigen-temperature gradient is utilized to simulate the thermal mismatch between inhomogeneities and the matrix. Subsequently, the temperature field is computed considering boundary heat flux and temperature conditions, eigen-temperature gradient, and virtual heat source acting on inhomogeneities. The eigen-temperature gradient and virtual heat source are then solved using the equivalent heat flow conditions to obtain the steady-state heat conduction results within the bounded domain. Through comprehensive numerical examples, we analyze the temperature distribution within composite and scrutinize the impact of particle shapes, orientations, volume fractions, and thermal conductivity ratios on the effective thermal conductivity of composite. Furthermore, we explore the distinctive properties of functional gradient material. Additionally, a comparison between iBEM and the finite element method is conducted. The findings reveal a progressive enhancement in the thermal conductivity of composite as the particle shape transitions from spherical to fibrous. [ABSTRACT FROM AUTHOR]

In the study, the effects of hybrid reinforcement (nano-alumina and MWCNT) and heat treatment on the wear behavior of the Al–4Cu nanocomposites were investigated under dry sliding condition against W–6Co ball by means of a ball-on-disk type tribometer. The load and the sliding speed were kept constant and selected to be 10 N and 0.1 m s−1, respectively, in the course of the wear tests. Meanwhile, the wear tests were completed after a total sliding distance of 1500 m was reached for each case. During these tests, the wear loss of the nanocomposites was measured at every 250 m. The worn surfaces of the nanocomposites were examined with the help of stereo and scanning electron microscopes. The volumetric wear rates, wear coefficients and wear mechanisms were identified for the nanocomposites to clarify the influence of reinforcement content and heat treatment on their wear resistance. The volume loss at the wear distance of 1500 m was obtained as 24.9 and 8.2 mm3 for the annealed and aged Al–4Cu alloy, respectively. On the other hand, it decreased to 4.6 and 3.2 mm3 in the case of the nanocomposites with 15% hybrid reinforcement in the annealed and aged conditions, successively. Moreover, increasing the hybrid reinforcement amount decreased the wear loss of the aged nanocomposites substantially in such a way that it resulted in the mild wear. [ABSTRACT FROM AUTHOR]

Induction heating of asphalt concrete has the characteristics of high crack repair efficiency and environmental sustainability. However, the uneven temperature distribution and local overheating obstruct its widespread application. Therefore, this paper conducted a pixel-level quantitative analysis of the temperature distribution characteristics and local overheating phenomenon on both the upper and side surfaces of asphalt concrete with different steel fiber (SF) contents after continuous heating. The temperature distribution was visualized by three-dimensional (3D) heat maps and violin maps. The uniformity of temperature was analyzed by the slope absolute value of the linear fitting results and the ratio of the interquartile range to the range. Results indicated that high SF content accelerated the heating rate of asphalt concrete but decreased the temperature uniformity. Localized overheating caused thermal expansion damage in asphalt mixtures, and the sample with 10% SF had both 304.2°C (maximum) and 79.7°C (minimum) upper surface temperatures at 60 s of heating, with local structural disintegration of the mixture. Higher heating uniformity and faster heating rates were achieved for samples with 6% SF content. The heating rate decreased with increasing heating time. The upper surface of the sample with 8% SF can be heated up the fastest (2.28°C/s). It is recommended that the maximum temperature of the upper surface be controlled during induction heating to avoid thermal damage. This proposal provides a reference for the practical application of induction heating technology. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the effect of the retarders urea and sodium phosphate on the hydration process and leaching of Cr(VI) in calcium sulfoaluminate cement from solid waste (WCSA). We investigated the mechanical properties and hydration processes of WCSA with varying urea and sodium tripolyphosphate contents using thermogravimetry coupled with differential scanning calorimeter (TG-DSC), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) analysis, and scanning electron microscopy (SEM); the leaching behavior of the heavy metal Cr(VI) in the cement was analyzed using inductive coupled plasma emission spectrometry (ICP). The experimental results showed that lower urea or sodium tripolyphosphate (STPP) contents (0.2%) improved the compressive strength of cement specimens by 18.31% or 3.125% at 28 days, respectively. After incorporating STPP and urea, the hydration heat flow and total hydration heat of WCSA decreased. The porosity first decreased and then increased with increased STPP and urea content. The involvement of urea in hydration produced carbonate, which destroyed the structure of ettringite and formed a new calcium carbonate phase, leading to the release of Cr(VI). In the presence of STPP, a three-dimensional network structure of hydroxyapatite was generated. Chromium ions entered the three-dimensional network structure of hydroxyapatite, increasing the solidification of Cr(VI) in WCSA. [ABSTRACT FROM AUTHOR]

Weakly exothermic polymer grouting materials are used to repair the thaw settlement of roads in permafrost regions. In this study, the heat release characteristics of these materials were tested, and a visual polymer grouting model box consisting of steel plating and transparent acrylic glass was developed to conduct the model test of water and heat transfer in frozen soil. Based on the control equation of the water–heat coupling transfer in frozen soil, an analysis model of water–heat coupling in frozen soil was established, and the water–heat transfer process in frozen soil under exothermic conditions of the polymerization reaction of weakly exothermic polymer grouting materials was studied. The results demonstrate a power function relationship between the curing reaction temperature threshold and the density of weakly exothermic polymer grouting materials at different temperatures. The influence of the polymerization exothermic reaction on the moisture content and heat of frozen soil can be divided into two processes: thawing and freezing. The thawing process can be divided into three stages: slow, fast, and stable thawing. The maximum thawing depth of frozen soil has a positive correlation with the amount of grouting and the grout–soil contact area and a negative correlation with the water content of frozen soil. The initial temperature of frozen soil is selected as the common influence factor, and the prediction model of the influence of the amount of grouting, grout–soil contact area, and frozen-soil mass moisture content on the water content and heat of frozen soil is established. During the freezing process, with the continuous effect of low ambient temperature, liquid pore water at the thawing front will be refrozen. Therefore, in an actual project of the weakly exothermic polymer grouting repair of a subgrade in a permafrost region, the thermal disturbance of polymerization exothermic to the frozen subgrade can be further weakened by delaying the opening time to traffic. [ABSTRACT FROM AUTHOR]

Residual stress of a welding joint based on finite element simulation was predicted to gain popularity in the process equipment industry. As for the nuclear power industry, the weldment located in a primary coolant system should be evaluated to verify the boundary integrity. The weld residual stress is an important load for leaks before break or fatigue crack growth estimation. Heat input is a key factor to accurately simulate the weld's residual stress. Hence, heat transfer activities of weld beads, based on the theoretical volume heat generation rate of the weld element, were simulated using finite element analysis. The traditional method of controlling heat input in finite element method simulation of the welding process is achieved by setting the temperature monitoring point. When the melting temperature is reached, the calculation for weld bead melting is terminated. However, it does not comply with the real welding process because too many assumptions are involved. Therefore, a novel heat input function to modify the temperature differences of weld beads and weld layers was proposed to predict the temperature and residual stress field. Four simulations based on the modified heat input methods and traditional approaches were performed to predict the weld residual stress field of a butt-welded joint for thick-walled pipe and were compared with experimental data. Results show that more accurate thermal fields and weld residual stress fields were achieved using the proposed heat input approach. [ABSTRACT FROM AUTHOR]

After a long device enhancement phase, scientific operation resumed in 2022. The main new device components are the water cooling of all plasma facing components and the new water-cooled high heat flux divertor units. Water cooling allowed for the first long-pulse operation campaign. A maximum discharge length of 8 min was achieved with a total heating energy of 1.3 GJ. Safe divertor operation was demonstrated in attached and detached mode. Stable detachment is readily achieved in some magnetic configurations but requires impurity seeding in configurations with small magnetic pitch angle within the edge islands. Progress was made in the characterization of transport mechanisms across edge magnetic islands: Measurement of the potential distribution and flow pattern reveals that the islands are associated with a strong poloidal drift, which leads to rapid convection of energy and particles from the last closed flux surface into the scrape-off layer. Using the upgraded plasma heating systems, advanced heating scenarios were developed, which provide improved energy confinement comparable to the scenario, in which the record triple product for stellarators was achieved in the previous operation campaign. However, a magnetic configuration-dependent critical heating power limit of the electron cyclotron resonance heating was observed. Exceeding the respective power limit leads to a degradation of the confinement. [ABSTRACT FROM AUTHOR]

Low-temperatures during winter are a serious problem in the cultivation of tropical fruit trees in temperate regions. The study investigated whether root zone heating treatments could improve cold injury tolerance in papaya. Leaf water potential was −2.22MPa and leaves wilted in the Control, where the root zone was not heated. However, where the root zone was heated to 20°C or only during the daytime, leaf water potentials were −1.31MPa and −1.41MPa, respectively, and no signs of leaf wilting were observed, suggesting that cold wind damage was suppressed unless temperatures fell below freezing. In contrast, where the root zone was heated, leaves wilted rapidly as temperature fell below the freezing point, and all trees had died by 12 January 2018 (72 days of experiment), suggesting that freezing injury could not be controlled by heating the root zone. It is therefore suggested that in addition to root zone heating, heating the greenhouse only on days when the temperature is below the freezing point would also prevent freezing injury. This has the potential to reduce the total greenhouse heating time by 97%. It also has the potential to reduce fuel costs for overwintering papaya, a tropical fruit tree cultivated in a temperate region. [ABSTRACT FROM AUTHOR]

In this study, in-situ modification by TEMPO oxidation was performed after nanocomposite synthesis to improve its properties toward dye molecule removal. The unoxidized and oxidized polymeric-based nanocomposite was denoted as PNC6 and PNC6O respectively. The nanocomposites were characterized using FESEM, FTIR, contact angle, XRD and BET analysis. Measurements of swelling ratio and chemical stability were also performed to provide insight into the durability of the nanocomposites. The effects of changing variables included contact duration, pH of aqueous solution, initial pollutant concentration, and temperature were observed. The kinetic study showed that the experimental data is best fitted with pseudo-second-order kinetics (R2 = 0.988 and 0.997 respectively), whereas on observing isotherm data, in both unoxidized and oxidized nanocomposite it fits well with Langmuir isotherm (R2 = 0.951 and 0.993 respectively). In addition, the effects on Gibb's free energy, Enthalpy, and Entropy were measured in terms of thermodynamic characteristics, it was established that dye molecules adsorption mechanism is endothermic and spontaneous in behaviour. To check regeneration tendency of the nanocomposite seven consecutive adsorption desorption cycles were run and about 90% and 80%, regeneration ability could be seen in an unoxidized state (PNC6) and an oxidized state (PNC6O) respectively upto 5th cycle after that the tendency get reduced. This study suggests that this novel polymeric nanocomposite can be employed as an efficient and relatively inexpensive adsorbent for dye removal from aqueous solutions. [ABSTRACT FROM AUTHOR]

Variable-temperature convective drying (VTCD) is a promising technology for obtaining high-quality dried mushrooms, particularly when considering rehydration capacity. However, accurate numerical models for variable-temperature convective drying and rehydration of shiitake mushrooms are lacking. This study addresses this gap by employing a model with thermo–hydro and mechanical bidirectional coupling to investigate five dehydration characteristics (moisture ratio, drying rate, temperature, evaporation rate, and volume shrinkage ratio) and a drying load characteristic (enthalpy difference) during VTCD. Additionally, a mathematical model combining drying and rehydration is proposed to analyze the effect of VTCD processes on the rehydration performance of shiitake mushrooms. The results demonstrate that, compared to constant-temperature drying, VTCD-dried mushrooms exhibit moderate shrinkage rates and drying time (16.89 h), along with reduced temperature variation and evaporation rate gradient (Max. 1.50 mol/(m3·s)). VTCD also improves enthalpy stability, reducing the maximum drying load by 58.84% compared to 338.15 K constant-temperature drying. Furthermore, drying time at medium temperatures (318.15–328.15 K) greatly influences rehydration performance. This study quantitatively highlights the superiority of variable-temperature convective drying, offering valuable insights for optimizing the shiitake mushroom drying processes. [ABSTRACT FROM AUTHOR]

The Argo array of profiling floats has considerably increased the observing capability of the three-dimensional global ocean and the knowledge of the ocean response to climate change. In particular, the Argo sampling has allowed observing relevant ocean indicators over the whole Mediterranean Sea especially during the last decade. In this study, the Mediterranean Argo network is comprehensively described from its spatio-temporal coverage to its capability to observe ocean monitoring indicators at sub-regional scale. For this purpose, the Argo array, as a non-interpolated product of profiles, is used to estimate the ocean heat and salt contents integrated within the upper, intermediate and deep layers over the period 2013-2022 in the different sub-regions of the basin. The same computational method is also applied to a model reanalysis product to estimate the impact of sampling of the sole Argo array. The sampling error is defined at sub-regional scale by comparing estimations from the whole model grid (full-sampled model) and from the Argo-like sampled model grid (sub-sampled model). Warming and salinification trends are well captured by the Argo array over the period of study, warming trends being the highest in the sub-regions of the western Mediterranean Sea from surface to depth and salinification trends being higher in the eastern sub-basin for the upper layer and in the western sub-basin for the deeper layers. This study also demonstrates the capability of the Argo array to capture local ocean structures and dynamics (e.g. anticyclonic and cyclonic gyres, intermediate and deep convection events and Atlantic Water inflows) and to account for their impact in the sub-regional variability of ocean heat and salt contents in the upper, intermediate and deep layers from seasonal to interannual scales. Considering these structures is fundamental for the understanding of the thermohaline circulation and changes observed in the Mediterranean Sea, and thus for future climate studies. [ABSTRACT FROM AUTHOR]

A thorough understanding of the reactor core thermal hydraulic behavior is essential for the design and safety analysis of Sodium-cooled Fast Reactors (SFR). Due to the application of hexagonal subassembly, the core thermal hydraulic behavior is significantly affected by the flow field within the subassemblies, the inter-wrapper region and the hot pool. Analysis of the core thermal hydraulic behavior requires a model coupling the three regions mentioned above, which has been identified as one of the thermal hydraulic challenges in SFR. In the present study, a 3D model that covers the three regions was developed for the core of the China Experimental Fast Reactor (CEFR) with the Computational Fluid Dynamic (CFD) code, Fluent. The inter-wrapper region and the hot pool were modeled in detail, while the subassemblies were modeled with a special porous medium model. The core thermal hydraulics behavior under steady state was studied, more specifically, information for the flow field distribution at the core outlet, the inter-wrapper flow and the duct wall temperature distribution was obtained. Under steady state, liquid sodium in the inter-wrapper region is supplied by the inner region of the hot pool. And it enters the inter-wrapper region from the core outer region and returns back to the hot pool inner region from the core central region. The inter-wrapper flow is cooled by non-fuel subassemblies and heated up by fuel subassemblies. For non-fuel subassembly, the ratio of the total heat transfer rate between the inter-wrapper flow and the subassemblies to the heat generated within subassemblies could reaches 96%; for fuel subassemblies, the maximum ratio of the total heat transfer rate between the inter-wrapper flow and the subassemblies to the heat generated within subassemblies is 2.45%. Significant temperature gradients have been observed on the duct wall, with maximum values of 156.69 K/m in the vertical direction and 2,196.00 K/m in the circumferential direction. The largest temperature gradient appears on the duct of subassemblies adjacent to the transition region of fuel subassemblies and non-fuel subassemblies. [ABSTRACT FROM AUTHOR]

In this paper, we study the quantum-corrected Schwarzschild AdS black hole surrounded by quintessence matter in two folds: its thermal quantities and shadows. For this purpose, first, we present a detailed analysis of the influences of the quintessence matter field on Hawking temperature, mass, Gibbs free energy, and specific heat functions. Then, we examine the shadows by following Carter’s approach. We find that the shadow radius value takes smaller values for greater quintessence state parameter values. On the other hand, we see that the shadow radius takes greater values for greater values of the normalization parameter. Finally, in a brief section, we discuss the energy emission rate and show that the Gaussian-type plots’ peak values are also affected by the quintessence matter field parameters. [ABSTRACT FROM AUTHOR]

The Time Domain Reflectometry (TDR) technique was used to analyse the complex permittivity spectra of the Pyridine-n-propyl alcohol mixture across the concentration and temperature range of 10–25°C. The Cole-Davidson model was used to match the Pyridine- n-propyl alcohol complex permittivity spectra. The nonlinear least squares fit approach has been used to obtain the Static dielectric constant (ε0), Relaxation time (τ), Effective Kirkwood correlation factor (geff) Excess permittivity$\left({\varepsilon _0^E} \right)$ε0E, Thermodynamic parameters (activation enthalpy and activation entropy), and Bruggeman factor (fB). Furthermore, the analysis of excess characteristics and the Bruggeman factor points towards the presence of hydrogen bonding between the pyridine and n-propyl alcohol molecules. [ABSTRACT FROM AUTHOR]

ABSTRACT Located at the confluence of the Arctic and North Pacific and with Alaska at its heart, the Pacific Arctic Region (PAR) is a unique and interconnected regional climate system. Significant climatic changes in the PAR are described by a novel, mobile monthly Alaska Arctic Front (AAF) index, which is defined by sea level pressure differences between the migratory cores of the Beaufort High and Aleutian Low. Regional climate variability associated with the AAF shows prominent decadal signatures that are driven by the opposing effects of the North Pacific and the Arctic atmospheric pressure fields. Low AAF (negative phase) is dominated by North Pacific forcing, whereas high AAF (positive phase) is dominated by Arctic atmospheric processes. The recent (2011–2021) negative AAF phase, which is associated with the westward displacement of Aleutian Low explaining stronger northward winds and enhanced water transport northward through Bering Strait, is conducive to increased oceanic heat and freshwater content, reduced regional sea ice cover in the PAR, and to the expansion of Pacific species into the Arctic. These factors are all indicators of the Pacification of the Arctic Ocean, a key feature of climate change related to progression of anomalous Pacific water masses and biota into the polar basins. It is not yet clear if or when the recent phase of decadal variability will change and alter the rate of Pacification of the Arctic climate system. [ABSTRACT FROM AUTHOR]

Replacing antimony trioxide (Sb2O3) with an environmentally friendly alternative is of great scientific and commercial value for studying the flame retardant properties of flexible PVC (fPVC) films in automotive interior materials. This study develops flame retardant fPVC films with reduced Sb2O3 content by introducing stannic oxide (SnO2) and zinc borate (ZB). The results indicate that the fPVC film with ZB partially replacing Sb2O3 exhibits superior flame retardancy and smoke suppression compared to the product containing SnO2. The peak heat release rate (PHRR), total heat release (THR), and total smoke release (TSR) of 2ZB/2Sb2O3 fPVC film are reduced by 32.1%, 27.5%, and 22.1%, respectively, compared to that of 4Sb2O3 contained fPVC film. The increase in flame retardancy is attributed to the presence of ZB, which compensates for the deficiency of char formation ability of Sb2O3 in the condensed phase. The PHRR and THR of 2SnO2/2Sb2O3 fPVC film decrease by 27% and 12.5%, respectively, compared to that of 4Sb2O3 fPVC film, while the TSR increases by 16.5%. This study develops a straightforward approach to creating a flame retardant fPVC film that is suitable for the latest industrial application in automotive interior materials. [ABSTRACT FROM AUTHOR]

To investigate the effects of hydrogen addition on the ignition characteristics and engine performance of ammonia-hydrogen fuel, a reaction kinetics mechanism suitable for high-pressure engine conditions was proposed. The study explores the influence of hydrogen blending ratios on the ignition delay time (IDT) of ammonia-hydrogen fuel, revealing the sensitive reactions and evolution characteristics of reaction pathways during the ignition process of ammonia-hydrogen fuel promoted by hydrogen. The study also investigates the impact of hydrogen blending ratios on the engine performance of ammonia-hydrogen fuel. The results show that the IDT of ammonia significantly decreases with increasing hydrogen blending ratios and temperature. The addition of hydrogen to ammonia significantly lowers the autoignition temperature boundary of the mixture. Under low-temperature and low-pressure conditions, ammonia, which would not ignite originally, ignites due to the addition of hydrogen. The addition of hydrogen shifts the sensitive reactions of the mixture from NH 3 and NH 2 -related reactions to H 2 /O 2 -related reactions, without altering the reaction pathway of ammonia, only changing the pathway flux of components such as NH 2 , H 2 NN, H 2 NO, and HONO. In a spark-ignition (SI) engine, maintaining the total fuel heat value and ignition timing constant, an increase in hydrogen blending ratio significantly raises the peak cylinder pressure. However, due to the forward movement of the heat release process, the power performance of engine experiences varying degrees of reduction. Therefore, it is necessary to delay the ignition timing of engine with the increase in hydrogen blending ratio, moving the combustion center beyond the top dead center (TDC). Furthermore, increasing the hydrogen concentration in the blend significantly raises the temperature and pressure during the engine combustion process, leading to an increase in the concentration of thermal NO X in the emissions. • A reaction kinetic mechanism for ammonia-hydrogen fuel was constructed, which included 38 species and 343 reactions. • The variation trend of the autoignition boundary of ammonia-hydrogen fuel is revealed quantitatively. • The effects of hydrogen on ignition sensitivity and fuel reaction pathway of ammonia-hydrogen fuel were explored. • The effect of hydrogen blending ratio on the performance of SI engine is analyzed at fixed fuel energy and ignition time. [ABSTRACT FROM AUTHOR]

The optimization of flame retardancy and thermal conductivity in epoxy resin (EP), utilized in critical applications such as mechanical components and electronics packaging, is a significant challenge. This study introduces a novel, ultrasound‐assisted self‐assembly technique to create a dual‐functional filler consisting of carbon nanotubes and ammonium polyphosphate (CNTs@APP). This method, leveraging dynamic ligand interactions and strategic solvent selection, allows for precise control over the assembly and distribution of CNTs on APP surfaces, distinguishing it from conventional blending approaches. The integration of 7.5 wt.% CNTs@APP10 into EP nanocomposites results in substantial improvements in flame retardancy, as evidenced by a limiting oxygen index (LOI) value of 31.8% and achievement of the UL‐94 V‐0 rating. Additionally, critical fire hazard indicators, including total heat release (THR), total smoke release (TSR), and the peak intensity of CO yield (PCOY), are significantly reduced by 45.9% to 77.5%. This method also leads to a remarkable 3.6‐fold increase in char yield, demonstrating its game‐changing potential over traditional blending techniques. Moreover, despite minimal CNTs addition, thermal conductivity is notably enhanced, showing a 53% increase. This study introduces a novel approach in the development of multifunctional EP nanocomposites, offering potential for wide range of applications. [ABSTRACT FROM AUTHOR]