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Disordered materials in the glassy state show different gas sorption properties compared to same materials in the liquid or rubbery state. The sorption enthalpy becomes more exothermic, and the absorbed amount is greater compared to the liquid or rubbery state. The sorption data are often treated in the literature using the dual-mode theory—a three-parameter sorption model. This work presents another approach where a gas sorption isotherm model for glassy materials is derived from thermodynamic consideration of glass transition properties. The model is particularly applicable for describing sorption data that obey Henry's law in the limit of the liquid or rubbery state. The model parameters correspond to physically meaningful characteristics of the system's glass transition. We demonstrate that experimental gas sorption data, when plotted as ln(P/C) vs C, exhibit linear behavior in both the rubbery and glassy states, enabling accurate determination of the glass transition point from isothermal data. Additionally, gas sorption in glassy disordered materials can be effectively described using a two-parameter function based on the Lambert W function. [ABSTRACT FROM AUTHOR]

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]

Typical tropical cyclone (TC) attributes, including translation speed and intensity, have been demonstrated to affect TC intensification via modulating sea surface temperature (SST) cooling effect underneath TCs, while the effect of storm size is relatively less explored. Using satellite-observed SST during 2004–21, we examine the effect of storm size on TC-induced SST anomalies (SSTAs) and TC intensification in global TC-active oceans (including the western North Pacific, eastern North Pacific, North Atlantic, southern Indian Ocean, and southern Pacific) and compare their interbasin differences. In all basins, SSTAs have the strongest correlation with 34-kt (1 kt ≈ 0.51 m s−1) wind radius (R34), which is thus utilized as the representative storm size among various TC wind radii. Globally, large TCs induce stronger and more widespread SSTAs, which reduce ocean's enthalpy flux supply and thus suppress TC intensification, as compared to small TCs. This modulating effect emerges in each basin, suggesting a globally consistent effect of storm size on TC intensification through an oceanic pathway. Small TCs, occupying weaker SST cooling and larger enthalpy flux, are more likely to undergo rapid intensification, with the probability of 1.1–1.8 times larger than large TCs in global TC-active oceans. Storm size varies greatly across global basins, and thus its effect on TC intensification through this oceanic pathway exhibits considerable interbasin differences. The interbasin difference in storm size partly contributes to the interbasin difference in SSTA under same TC intensity. Our results suggest that accurately representing storm size in TC coupled models can potentially improve cooling estimation and TC intensity prediction. Significance Statement: Storm size is an important parameter which characterizes tropical cyclone (TC) wind structure. Existing studies report that storm size influences TC intensification from an atmospheric perspective via modulating vortex dynamics. By examining global TCs, here we propose an explanation from the oceanic perspective: large TCs tend to induce stronger SST cooling, reducing enthalpy supply and suppressing TC intensification compared to small TCs. Consequently, small TCs are more likely to undergo rapid intensification—an extremely TC-intensifying event. Despite interbasin differences, the modulating effect of storm size via this oceanic pathway is universal over global TC-active basins. Therefore, precisely characterizing storm size and this oceanic pathway are essential for evaluating ocean's energy to TCs and forecasting rapid intensification event and TC intensity. [ABSTRACT FROM AUTHOR]

This study investigates the effect of granules produced from dispersive fireclay using liquid glass as a binder on the hydration of calcium aluminate cement (CAC). The peculiarities of the hydration process were evaluated from the results of calorimetry, thermal analysis, X-ray diffractometry (XRD), scanning electron microscopy (SEM), and mechanical property tests, as well as the relative viscosity of the cement pastes. It was determined that the granules were capable of entrapping water and releasing it later, shortening the incubation period and increasing the maximal heat release rate during the CAC crystallisation stage and total cumulative heat as compared with the control samples with the same active cement part and containing dispersive fireclay particles, which are cement inert. The redistribution of water owing to the addition of granules also resulted in more C 2 AH 8 and AH 3 in CAC pastes containing granules than in those containing dispersive fireclay. Because of the reaction between the water solution containing dissolved cement minerals and sodium silicate film (dried liquid glass), the hydrogel-like phases form inside the granules during the hydration, which fill the gaps between the fireclay particles, and after firing at 1100 °C, form a glassy phase enveloping the fireclay particles and binding them to each other, providing the granules with integrity and contributing to their strength. The specific structure formed by the addition of fireclay granules did not change the density of the composite dramatically, resulting in 7.4%–18.5 % higher strength after drying with 7.5%–15 % granule addition and ∼11 % higher strength after sintering at 1100 °C with 5 % granule addition (compared with compositions containing dispersive fireclay). Granule addition of 30 % was excessive, causing significant strength loss. [ABSTRACT FROM AUTHOR]

This paper extensively investigates the performance of the representative SBE 3 deep-sea thermometer (Sea-Bird Scientific) under various stepwise pressure conditions. A high-precision pressure-temperature vessel was employed to simulate deep sea environments, conducting systematic pressure experiments with precise temperature control (0.5 mK) across a temperature range of -2 to 35°C and from atmospheric pressure to full ocean depth (0–12700 m). A Standard platinum resistance thermometer (SPRT), isolated from the pressure environment and placed adjacent to the SBE 3, served as a calibration reference throughout the experiments. The drift of the SBE 3, reaching up to 10 mK in this study, was meticulously quantified at varying pressures and temperatures. Subsequently, a linear calibration method was developed, ensuring that the thermometer maintained an accuracy of ±0.0005°C (± 0.5 mK) across all tested high-pressure conditions, including a maximum pressure of 1050 bar. Crucially, this study discusses the negative impact of pressure-induced temperature errors on the estimation of ocean heat content in the Pacific, emphasizing the importance of conducting high-pressure calibration tests before and after oceanographic deployments. These measures are vital for ensuring the accuracy of deep-sea temperature measurements, which are critical for understanding global climate dynamics and improving the calibration of deep-sea sensors. [ABSTRACT FROM AUTHOR]

The preparation of biomass flame retardants with efficient flame‐retardant properties is conducive to the realization of sustainable development and is of great practical significance. In this work, a green and sustainable biomass flame retardant PATAPEI was prepared by using phytic acid (PA), tannic acid (TA), and polyethyleneimine (PEI) as reactants via a one‐step method to develop biomass flame retardants that can synchronize enhanced flame retardation, smoke suppression, and mechanical performance of epoxy resin (EP). The EP with only a 3% PATAPEI (EP/3PTP) has a LOI value of 28.5% with a UL‐94 V‐0 classification. The peak heat release rate (PHRR), total heat release (THR), and total smoke release (TSR) of EP/3PTP were decreased by 29.72%, 25.80%, and 21.16%, respectively, in comparison with the ones of pure EP. Additionally, the tensile and impact strengths of EP/3PTP are higher than the ones of pure EP. PATAPEI on heating decomposes to produce phosphorus‐containing acids and biphenyltriol‐containing compounds, which promote to form a good char layer with the aromatic structures during the combustion of EP/3PTP. Therefore, PATAPEI has prospects of wide application in the development of sustainable biomass flame retardant EP. [ABSTRACT FROM AUTHOR]

A uniaxial material model for fatigue damage accumulation, established on the connection of unit elements, is presented in this paper. Although these units are regarded as micro-elements in the proposed model, they are based on a hysteretic operator that enables calculating hysteretic energy loss as an analytical expression. Further, this unit element represents a mechanical model with elastoplastic damage behavior in function of strain. The second level of modeling is defined by the connection of these units (micro-elements) with different values of total energy dissipated at failure. By changing the distribution of dissipated energy limit, various fatigue damage evolution laws are developed. Calculation of total and hysteretic energy loss in one loading cycle is also affected by fatigue damage as the varying number of unit elements are been eliminated when their maximum dissipation energy is reached. Material parameters for the model were defined based on the experimental monotonic and cyclic stress-strain tests, still, detailed comparison was not performed as the main advantage and aim of the paper was the development of the method for assessment of damage evolution in fatigue analysis. On the other hand, the number of cycles to failure (Nf) and total heat dissipation are compared in both qualitative and quantitative aspects with experimental results. Finally, based on the proposed model, mean strain and load sequence effect diagrams were constructed. It is shown that the proposed model can provide a reliable estimation of fatigue life in the low-cycle regime of loading. The maximum error for the calculated Nf was 3% for constant strain loading for experiments with strain amplitude less than 5%. In load sequence fatigue life estimation, the proposed model demonstrated good accuracy, with a maximum error of 34%. Further, obtained results were achieved with different types of damage evolution that could be defined for the same material and fatigue life. [ABSTRACT FROM AUTHOR]

[Display omitted] Enhancing the fire safety of epoxy resins (EPs) typically requires a significant amount of flame retardants, which often results in considerable degradation of their mechanical properties. To address this issue, a novel flame retardant known as PDCP@DPA@MXene was synthesized and integrated into EP to achieve notable improvements in flame retardancy, smoke suppression, and mechanical strength. By incorporating 1.5 wt% PDCP@DPA@MXene, the impact strength, tensile strength, and elongation at break of the resulting PDM-1.5 %/EP composite reached 12.1 kJ/m2, 57.4 MPa, and 13.0, respectively, reflecting enhancements of 63.5 %, 18.4 %, and 17.1 % compared to the pure EP. The enhancement in tensile strength may be attributed to the high rigidity of Ti 3 C 2 T x MXene, which reinforces the EP matrix. Additionally, the intertwined structure of PDCP@DPA@MXene chains effectively mitigates material fracturing and absorbs impact forces, thus toughening the EP. The presence of phosphorus, nitrogen, and titanate in PDCP@DPA@MXene contributes to the formation of a more compact char layer. The PDM-1.5 %/EP sample achieved a V-0 rating in the vertical UL-94 test and exhibited a high limiting oxygen index of 32.0. Furthermore, the sample containing 2 wt% PDCP@DPA@MXene showed a significant reduction in peak heat release rate (p -HRR) and total heat release (THR), recording values of 689 kW/m2 and 71.9 MJ/m2, which are decreases of 45.1 % and 26.9 %, respectively, compared to pure EP. Additionally, the incorporation of PDCP@DPA@MXene led to a reduction in CO production. These flame-retarded EPs demonstrate strong potential for various applications due to their elevated glass transition temperature and robust thermal stability. [ABSTRACT FROM AUTHOR]

Fundamentally, the heat source in the ball screw feed system accounts for the thermal behavior of ball screw. Due to the fact that cooling resources are not always sufficient, the main objective of this paper is to allocate cooling resources for multiple heat sources. The network model of ball screw thermal deformation and temperature at the heat source is constructed based on wavelet neural network (WNN). Combined with the mathematical analysis results, the explicit mathematical expression of thermal deformation and heat source under this working condition is deduced, and the explicit mathematical expression of heat source contribution is further obtained. After that, keeping the total heat source contribution constant under this working condition, the particle swarm optimization (PSO) algorithm is used to determine the heat source contribution distribution that can minimize the thermal deformation of the ball screw. Finally, through the design of the ball screw cooling system, the minimum thermal deformation of various heat sources at different cooling ratios under constant cooling flow is explored. The contribution of heat source is basically consistent with the optimal cooling ratio, which not only verifies each other, but also shows that the uniform cooling of heat source can best inhibit thermal deformation. [ABSTRACT FROM AUTHOR]

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Highlights: A transparent and ceramizable coating was developed by incorporating nano-layered double hydroxide nanosheets into hierarchical hydrogen bonding polymer networks. The resulting coating composites demonstrated excellent high-temperature stability and fire resistance, effectively withstanding the direct exposure to a butane flame (~ 1100 °C) in air atmosphere. The mechanisms behind the flame-retardant behavior and ceramicization behaviors were thoroughly investigated and explained. In recent decades, annual urban fire incidents, including those involving ancient wooden buildings burned, transportation, and solar panels, have increased, leading to significant loss of human life and property. Addressing this issue without altering the surface morphology or interfering with optical behavior of flammable materials poses a substantial challenge. Herein, we present a transparent, low thickness, ceramifiable nanosystem coating composed of a highly adhesive base (poly(SSS1-co-HEMA1)), nanoscale layered double hydroxide sheets as ceramic precursors, and supramolecular melamine di-borate as an accelerator. We demonstrate that this hybrid coating can transform into a porous, fire-resistant protective layer with a highly thermostable vitreous phase upon exposure to flame/heat source. A nanosystem coating of just ~ 100 μm thickness can significantly increase the limiting oxygen index of wood (Pine) to 37.3%, dramatically reduce total heat release by 78.6%, and maintain low smoke toxicity (CITG = 0.016). Detailed molecular force analysis, combined with a comprehensive examination of the underlying flame-retardant mechanisms, underscores the effectiveness of this coating. This work offers a strategy for creating efficient, environmentally friendly coatings with fire safety applications across various industries. [ABSTRACT FROM AUTHOR]

[Display omitted] • A hybrid Ce-MOF@MoS 2 with an advanced hierarchical structure is designed. • EP/Ce-MOF@MoS 2 -3 exhibits a notable increase in TS to 50.87 MPa and EB to 10.84 %. • The pHRR and THR of EP/Ce-MOF@MoS 2 -3 are reduced by 38 % and 12.64 %, respectively. • The hybrid's catalytic effects reduce CO and CO 2 production by 48.8 % and 38.7 %. This study demonstrates the preparation of needle-like Ce-MOF crystals on molybdenum disulfide (MoS 2) nanosheets using in-situ growth technology. This hybrid structure significantly enhances the thermal management and mechanical properties of thermosetting epoxy resin (EP). Specifically, EP/Ce-MOF@MoS 2 -3 exhibits a notable increase in tensile strength (TS) to 50.87 MPa and elongation at break (EB) to 10.84 %. Moreover, Ce-MOF@MoS 2 provides synergistic flame retardant benefits, reducing the peak heat release rate (pHRR) and total heat release (THR) of EP/Ce-MOF@MoS 2 -3 by 38 % and 12.64 %, respectively, compared to EP-0. Additionally, Ce-MOF@MoS 2 suppresses smoke and reduces toxic emissions; at a 3 % loading, it decreases CO and CO 2 production in EP nanocomposites by 48.8 % and 38.7 %, respectively. Thus, this Ce-MOF@MoS 2 hybrid, synthesized via in-situ growth, offers a novel approach for developing EP nanocomposites with superior thermal management and mechanical properties, along with effective flame retardancy and reduced hazardous emissions during thermal events. [ABSTRACT FROM AUTHOR]

The upper ocean provides thermal energy to tropical cyclones. However, the impacts of the subsurface ocean on tropical cyclogenesis have been largely overlooked. Here, we show that the subsurface variabilities associated with the variation in the 26 °C isothermal depth have pronounced impacts on tropical cyclogenesis over global oceans. The sea surface wind stress and its curl before tropical cyclogenesis are large enough to perturb the ocean interior down to more than one hundred meters due to entrainment and upwelling. The 26 °C isothermal depth can fluctuate by tens of meters to significantly modify the upper ocean heat content. Consequently, sea surface temperature anomalies under nascent tropical cyclones are induced, and tropical cyclogenesis is modulated. Our results substantiate an unexpected relation between ocean interior variations and tropical cyclogenesis. This study shows that subsurface ocean variability, and particularly changes in the 26 °C isothermal depth, has significant impacts on tropical cyclogenesis by altering upper ocean heat content and inducing sea surface temperature anomalies. [ABSTRACT FROM AUTHOR]

It is well recognised that endothermic processes such as dehydration and partial melting have the potential to exert measurable effects on the maximum temperatures reached in metamorphic rock systems. We show migmatitic metapelitic and mafic granulites record temperatures of ~ 820 °C, while spatially associated refractory Mg–Al-rich granulites record temperatures between 865 °C and > 920 °C. These thermally contrasting samples are separated by ~ 1500 m, with no apparent intervening faults or shear zones to explain the apparent difference in peak metamorphic conditions. Temperature versus enthalpy modelling of these samples along simple prograde P–T paths imply migmatisation slows the rate of temperature increase relative to rocks that do not melt. We speculate refractory rocks in the present study are created through early hydrothermal alteration and metamorphism, resulting in melt-resistant bulk compositions. There are many potential geological contexts where neighbouring rocks may have contrasting melt fertility; the deposition of a cover sequence, pre-metamorphic alteration, and the intrusion of igneous protoliths are all possibilities. With this in mind, variations in maximum modelled temperatures in granulite facies domains should be relatively common. [ABSTRACT FROM AUTHOR]

In the quest for glass materials with high nonlinearity and strong magnetism to meet the demands of advancing technology, magnetic nanocrystal (NC) doping emerges as a promising approach. The paper investigates the phase transition from KBiFe 2 O 5 to Bi 2 Fe 4 O 9 and Fe 3 O 4 NCs within a TeO 2 –Bi 2 O 3 –B 2 O 3 glass matrix. The novelty of this study lies in leveraging the coexistence of multiple phases to amplify both the polarization and magnetic moment of glass. Various techniques, including X-ray diffraction, transition transmission electron microscopy, X-ray photoelectron spectroscopy, Mössbauer spectroscopy, and vibrational sample magnetometer were employed to analyze the impact of NCs content and heat treatment temperature on crystallization, structure modification, and properties. KBiFe 2 O 5 NCs doping induces changes in crystal phases and modifies the glass network structure by forming multi-valence states and altering coordination numbers, such as FeO 4 →FeO 6 , TeO 4 →TeO 3 , and BO 4 →BO 3. Concurrently, appropriate temperature conditions result in reduced NC size, preserving glass transparency and thermal stability. Spinel Fe 3 O 4 NCs formation at higher temperatures enhances magnetic behavior. A glass sample containing 1 mol% KBiFe 2 O 5 NCs, heat-treated at 410 °C, exhibits a narrow bandgap (E g) of 1.82 eV, high nonlinear parameters (α 3 = 3.98 × 10−10 m/W, χ(3) = 8.65 × 10−11 esu), and a low limiting threshold (1.01 × 1012 W/m2). Additionally, owing to the incorporation of high spin states and active magnetic exchange interactions, the same glass demonstrates robust ferromagnetic behavior (M s = 2.3 emu/g and H c = 850 G). The approach developed in this study has been demonstrated to be highly effective in producing transparent glass with promising nonlinearity and magnetic performance suitable for photonics applications. [ABSTRACT FROM AUTHOR]

Establishment of high‐performance epoxy resin with satisfactory fire safety, mechanical properties, and excellent transparency is urgently desirable, but still remains significant challenges. Herein, a super‐tough yet high flame retardant epoxy resin (EP/BTD) was designed and prepared by incorporating bi‐DOPO structure and hydrogen‐bonding networks. Although the phosphorus content was only 0.69 wt% (10 wt% of bi‐DOPO flame retardant [BTD]), EP/BTD‐10 showed a high limiting oxygen index value (33.4%), satisfactory UL‐94 rating (V‐0), and good heat suppression ability (total heat release [THR] and peak heat release rate [PHRR] reduced to 29.0% and 42.2%, respectively). Furthermore, the flame retardant mechanism of EP/BTD was illustrated and attributed to dual‐phase fire‐retardant effect. Additionally, EP/BTD‐7.5 featured notably mechanical properties, of which the tensile strength, elongation at break and impact strength increased by 44.6%, 40.0%, and 232.6%, respectively, due to hydrogen‐bonding network and π–π interaction. More importantly, EP/BTD maintained high visible light transmittance and excellent UV‐blocking properties. In summary, this work provided a guidance for the development of high‐performance epoxy resin and was expected to expand the practical applications. [ABSTRACT FROM AUTHOR]

Epoxy resin (EP), as a widely used polymer material, is inherently flammable. Imparting it with high-efficiency flame-retardant properties has always been the focus of attention. In this work, using triallyl isocyanurate (TAIC) and 9,10-dihydro-9-oxa-10-phospha phenanthrene-10-sulfide (DOPS) as raw materials, a novel double-group flame retardant, tris(3-(9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide)-propyl)triazine-2,4,6-trione(DOPS-TAIC), has been synthesized via a one-step method. Before curing, the structure was characterized by FT-IR, 1H NMR, and 31P NMR. Subsequently, the flame retardant DOPS-TAIC was applied to EP, and a series of testing methods were employed to investigate the effects of DOPS-TAIC on the thermal stability, flame retardancy, and mechanical properties of EP. Furthermore, the flame retardant mechanism of DOPS-TAIC in the gas phase and condensed phase was further explored. The results showed that EP/DOPS-TAIC achieved a UL-94 V-0 rating with an LOI value of 31.6% when added at 12.5 wt%. In addition, the total heat release, peak heat release rate, and average heat release rate (av-HRR) of EP/DOPS-TAIC-12.5 wt% were significantly reduced by 35.05%, 61.83%, and 51.68%, respectively. SEM-EDS results showed that DOPS-TAIC can effectively promote the generation of expanded dense char layers and retain flame retardant elements (P and S) in the char layer. Meanwhile, TG-IR and Py-GC/MS demonstrate their radical quenching effect in the gas phase, indicating that DOPS-TAIC possesses both condensed-phase and gas-phase flame-retardant mechanisms. Therefore, this study provides a simple and effective method for developing flame-retardant epoxy resins. [ABSTRACT FROM AUTHOR]

Traditional Japanese medicines, i.e., Kampo medicines, consist of crude drugs (mostly plants) that have empirical pharmacological functions ('Yakuno' in Japanese), such as clearing heat. Crude drugs with cold properties, such as Phellodendron bark, have the empirical function of clearing heat as they cool the body. Because we found that anti-inflammatory compounds were present in several crude drugs for clearing heat, it is speculated that the empirical function of clearing heat may be linked to anti-inflammatory activities. When 10 typical crude drugs were selected from 22 herbal crude drugs for clearing heat, we identified anti-inflammatory compounds in five crude drugs, including Phellodendron bark. In this study, the other crude drugs were extracted and partitioned with ethyl acetate (EtOAc) and n-butanol to obtain three crude fractions. All the EtOAc-soluble fractions, except that from Forsythia fruits, inhibited interleukin (IL)-1β-induced nitric oxide (NO) production in primary-cultured rat hepatocytes. Anti-inflammatory compounds were identified from these EtOAc-soluble fractions: baicalein from Scutellaria roots, (−)-nyasol from Anemarrhena rhizomes, and loniflavone from Lonicera leaves and stems. (+)-Phillygenin was purified from Forsythia fruits by removing cytotoxic oleanolic and betulinic acids. These compounds suppressed the production of NO and cytokines in hepatocytes. Anti-inflammatory compounds were not purified from the EtOAc-soluble fraction of Rehmannia roots because of their low abundance. Collectively, these findings indicate that anti-inflammatory compounds are present in all 10 crude drugs for clearing heat, confirming that these anti-inflammatory compounds in crude drugs provide the empirical functions for clearing heat. Other empirical functions of Kampo medicine can also be explained by modern pharmacological activities. [ABSTRACT FROM AUTHOR]

In this study, oil sludge from Jilin Petrochemical of China was selected to carry out the Fischer assay and proximate analysis. According to the properties of the Jilin oil sludge and its pyrolysates, the material and heat balance of the pyrolysis process was deduced theoretically based on 1000 kg of received base oil sludge. The results show that the solid heat carrier method can be used in the pyrolysis of oil sludge, and a new process flow is proposed. According to the heat required and heat provided in the rotary reactor and in the fluidized bed, 5940 kg of ash was needed as a solid heat carrier, and 25 kg of liquefied petroleum gas was needed as a supplementary fuel besides the semi-coke and retorting gas. The total input heat and output heat were 13.65 GJ and 10.04 GJ. The loss was 3.61 GJ and the thermal efficiency was 73.6%. [ABSTRACT FROM AUTHOR]

The time period around the Noachian–Hesperian boundary, 3.7 billionyears ago, was an epoch when great geodynamical and environmental changes occurred on Mars. Currently available remote sensing data are crucial for understanding the Martian heat loss pattern and its global thermal state in this transitional period. We here derive surface heat flows in specific locations based on the estimations of the depth of five large thrust faults in order to constrain both surface and mantle heat flows. Then, we use heat-producing element (HPE) abundances mapped from orbital measurements by the Gamma-Ray Spectrometer (GRS) onboard the Mars Odyssey 2001 spacecraft and geographical crustal thickness variations to produce a global model for the surface heat flow. The heat loss contribution of large mantle plumes beneath the Tharsis and Elysium magmatic provinces is also considered in our final model. We thus obtain a map of the heat flow variation across the Martian surface at the Noachian–Hesperian boundary. Our model also predicts an average heat flow between 32 and 50 mW m − 2 , which implies that the heat loss of Mars at that time was lower than the total radioactive heat production of the planet, which has profound implications for the thermal history of Mars. [ABSTRACT FROM AUTHOR]

Spontaneous combustion of coal is a major problem in coal industry. In order to improve the environmental performance and effectiveness of existing inhibitors used to inhibit coal spontaneous combustion, this study utilized physical inhibitors such as chitosan (CS), acrylic acid (AA), and acrylamide (AM) and copolymerized them with the chemical inhibitor procyanidin (OPC). The resulting composite inhibitor was then in situ polymerized with modified nano-TiO2 to create an environmentally friendly gel-based composite inhibitor, referred to as TiO2/OPC/CPAAM. Scanning electron microscopy analysis revealed a significant increase in the number of laminar folds and pores within the inhibited coal samples. Additionally, thermogravimetric analysis showed that all characteristic temperature points of the inhibited coal samples were raised, with an average increase of 21.34%. Differential scanning calorimetry also indicated a reduction in the total heat release and heat release intervals of the inhibited coal samples. Gas infrared spectroscopy provided evidence that the inhibitory treatment significantly slowed the growth of CO and CO2 during the heating process of the coal samples, leading to an improvement in environmental performance. Furthermore, diffuse reflection infrared spectroscopy testing demonstrated that the inhibitory treatment resulted in the passivation of active groups' free hydroxyls and an increase in the content of stable group ether bonds. Overall, the results of this study indicate that the composite inhibitor TiO2/OPC/CPAAM offers superior inhibition effects on coal spontaneous combustion. [ABSTRACT FROM AUTHOR]

We present thermodynamic properties for liquid uranium obtained from classical molecular dynamics (MD) simulations and the first-principles theory. The coexisting phases method incorporated within MD modeling defines the melting temperature of uranium in good agreement with the experiment. The calculated melting enthalpy is in agreement with the experimental range. Classical MD simulations show that ionic contribution to the total specific heat of uranium does not depend on temperature. The density of states at the Fermi level, which is a crucial parameter in the determination of the electronic contribution to the total specific heat of liquid uranium, is calculated by ab initio all electron density functional theory (DFT) formalism applied to the atomic configurations generated by classical MD. The calculated specific heat of liquid uranium is compared with the previously calculated specific heat of solid γ-uranium at high temperatures. The liquid uranium cannot be supercooled below Tsc ≈ 800 K or approximately about 645 K below the calculated melting point, although, the self-diffusion coefficient approaches zero at TD ≈ 700 K. Uranium metal can be supercooled about 1.5 times more than it can be overheated. The features of the temperature hysteresis are discussed. [ABSTRACT FROM AUTHOR]

As fire safety issues receive increasing attention, the development of efficient flame-retardant materials has become particularly important. This study explores the preparation methods of nano-violet phosphorus (NVP) and nanocellulose (NCC) composite films and their superior performance in flame retardancy applications. NVP was successfully prepared using a liquid-phase exfoliation method and was then non-covalently self-assembled with NCC to form a novel composite film with good uniformity. The microstructure, mechanical properties, and flame-retardant performance of the composite film were comprehensively characterized. The results indicated that the NVP/NCC composite film with only 1 wt% NVP exhibited significantly enhanced self-extinguishing capability (<2 s) and a peak heat release rate (23.31 kW m−2) and total heat release (1.78 MJ m−2), indicating its effectiveness in delaying the combustion process under flame exposure. The introduction of NVP made the decomposition rate of the composite film slower and the decomposition behavior more stable in an aerobic environment. In addition, the presence of NVP delayed the dehydration process of NCC, and promoted the carbonization reaction, thereby reducing the release of H2O, thus forming a protective carbon layer and removing active free radicals, significantly improving the thermal stability and safety of the composite. This work provides important theoretical foundations and practical guidance for the development of new flame-retardant materials. [ABSTRACT FROM AUTHOR]

Microbial activity in the deep continental subsurface is difficult to measure due to low cell densities, low energy fluxes, cryptic elemental cycles and enigmatic metabolisms. Nonetheless, direct access to rare sample sites and sensitive laboratory measurements can be used to better understand the variables that govern microbial life underground. In this study, we sampled fluids from six boreholes at depths ranging from 244 m to 1,478 m below ground at the Sanford Underground Research Facility (SURF), a former goldmine in South Dakota, United States. The heat produced by microorganisms in these samples was measured in a nanocalorimeter as a proxy for activity. Heat flow measurements on unamended groundwater samples from five of the six boreholes comprising the Deep Underground Microbial Observatory (DeMMO) fell below the limit of detection, suggesting very low metabolic rates. Fluid samples from the borehole that registered a heat signal (DeMMO 6) from 1,478 m deep, were amended with a series of electron donors, electron acceptors, and amino acids before being introduced into the calorimeter. The addition of formate resulted in more than a ~500 nW increase in heat flow relative to the signal for unamended fluids during the first 100 h of incubation while the next highest heat flow arose from nitrate and acetate co-addition, at ~125 nW. Notably, both amendment conditions led to a ~1.5 orders of magnitude increase in cell density without causing major changes to community composition, suggesting that these electron donors and acceptors may be exploited by these communities in-situ. The addition of ~0.4 mM casamino acids resulted in a total heat flow of 2.25 μW within 35 h and a more than three orders of magnitude increase in cell density. In these experiments, Hydrogenophaga grew to dominate the amino acid amended borehole fluids. The strong microbial response to amino acid addition indicates a deep continental surface community that is limited by the availability of amino acids. A high potential for amino acid metabolism was proposed in genomic studies from this and similar sites but has not been shown in actively growing communities. [ABSTRACT FROM AUTHOR]

In this study, to improve the flame‐retardant properties of ramie fabrics (RFs), a polyelectrolyte complex (PEC) was prepared in a one‐step process using biobased guar gum (GG), polyethyleneimine (PEI), and ammonium polyphosphate (APP) and deposited on the surface of the RF to construct an intumescent flame‐retardant coating. Fabrics treated with PEC coatings exhibited excellent flame‐retardant properties. Specifically, the cone calorimeter test results revealed that an increase in sample weight of only 13.23 wt% resulted in significant reductions in the peak heat release rate (pHRR), total heat release (THR), and fire growth rate (FGR) of 91.37%, 65.12%, and 95.28%, respectively. Additionally, the limiting oxygen index (LOI) increased from 19.4% to 33.5%, and the fabrics self‐extinguished immediately after the ignition source was removed during the UL‐94 test. Scanning electron microscopy (SEM) of the char residue revealed expansion bubbles on the surface, suggesting that the PEC coating provides flame retardancy through a synergistic effect involving both the gas phase and the condensed phase. This study provides a simple and convenient solution for realizing green and efficient flame‐retardant coatings on RF. [ABSTRACT FROM AUTHOR]

This paper explores the secondary surge during compressor surge recovery. Utilizing the test rig at Northwestern Polytechnical University, the surge is induced by tail cone adjustment. A secondary surge follows tail cone retraction post-initial surge. Signal changes are analyzed, and causes are expounded from energy and fluid dynamics. Experimental outcomes confirm the secondary surge is repeatable and observable under set conditions. Its frequency stabilizes at 4.83 Hz across consecutive events and rotor axes, being system-inherent. From energy, with enthalpy as a proxy, potential energy amasses as the compressor interacts with cavity potential shifts from tail cone changes. Exceeding kinetic supply instigates violent airflow oscillations. Peak pressure trends and simulations suggest surge likelihood at ∼3.33 × 105 J enthalpy. In fluid dynamics, post-initial surge, a stall state ensues. Tip clearance vortices from spillage and backflow expand, merge, and fill the passage. Their pre-secondary surge breakdown elevates pipeline pressure, causing gas reflux and surge recurrence. Conclusively, this research enhances compressor secondary surge comprehension, offering support for design optimization and anti-surge strategies. [ABSTRACT FROM AUTHOR]

Encapsulation is an effective method for enhancing the reaction to fire of timber structures. Mortar coatings are widely used to encapsulate traditional timber structures due to their excellent mechanical properties. However, there is a significant lack of data on the reaction to fire and fire mechanisms of timber structures with mortar encapsulation, and little is known about the influence of mortar composition on the burning characteristics of timber substrates. This study investigated the fire properties of organic–inorganic composite multilayer mortar coatings with fibre-reinforced layers commonly employed in encapsulating traditional Chinese wooden structures. The burning phases of timber encapsulated by multilayer mortar coatings were examined using thermogravimetric analysis and constant radiation ignition experiments. The fire propagation apparatus was used to measure the critical fire parameters of the encapsulated timber structures, including ignition time, heat release rate, total heat release, and time to peak heat release rate under a constant radiation heat flux of 30 kW/m2. Comparative experiments between finished and semi-finished coating encapsulated samples were conducted to investigate the influence of coating composition. The cracking behaviour of the coating was synchronously observed, with crack length analysis using image recognition techniques. It was found that the topcoat property of the coating mainly influenced the ignition time, and adding the fibre layer can effectively inhibit the bending of the timber substrate. Additionally, reducing the aggregate size may effectively prolong the time to reach the peak of the heat release rate. The relationship between the rise in heat release rate in encapsulation coatings, the appearance of surface cracks, and the maximum crack length with the heat release rate peak has been well established. [ABSTRACT FROM AUTHOR]

High altitude region has different characteristics from the normal pressure region due to its low air pressure and low oxygen content. The aim of this study is to investigate how solar panel's ignition time, critical heat flux, combustion time, flame height, and mass loss vary as a function of external heat flux from 25 kW/m2 to 45 kW/m2 and air pressure from 60 to 100 kPa. It was found that external heat flux and air pressure negatively correlated with ignition and combustion time. Calculated from Delichatsios's formula, the critical heat flux under different air pressures differs significantly from experimental data. Therefore, the parameters in Delichatsios's formula are corrected based on experimental data. By relating critical heat flux, thermal response parameters, and air pressure, an overall formula for ignition time, radiation intensity, and air pressure can be derived. Mass loss rate and flame height are positively correlated with external heat flux and air pressure. Mass loss rate is expressed as a function of air pressure. Also, based on the relationship between mass loss rate and external heat flux and air pressure, a mathematical model between flame height, heat flux and air pressure is established. [ABSTRACT FROM AUTHOR]