Search

In this study, a new control of the heat transport process utilizing phase-change materials (PCMs), as latent thermal energy storage, and nanofluid flow in a thermal system is explored numerically. The proposed model comprises PCM domain divided square enclosure, filled with two different nanofluids (TiO2 and CuO) heated and cooled, respectively, at the left and right sides of the enclosure. Horizontal walls are adiabatic. The coupled mathematical model comprises phase-change materials, nanofluids, and thermal gradients, which are solved numerically following the finite volume-based approach. The enthalpy-porosity technique is adopted to assess the melting behavior of the PCM domain. The thermo-hydraulic performance of the complex system of nanofluids and the melting process of PCM is assessed for the set of control variables such as Grashof numbers (Gr) and nanoparticle concentration (ϕ). Analysis revealed that the melting performance of the PCM domain is significantly influenced by the concentration of the nanoparticles on both sides. The results revealed that, for the early stage of the melting process, the thickness of the melted layer strongly depends on the interaction of the thermal gradient inside the cavity. Higher Gr value and ϕ lead to higher thermal convection in the heated section, which allows the faster melting process of the PCM domain and more amount of thermal energy storage inside the PCM. This transport process further enhances with the increase in the nanoparticles concentrations. A higher Gr value with higher nanoparticle concentrations is always beneficial for the higher amount of thermal energy storage and storage goes up to 35.80%. [ABSTRACT FROM AUTHOR]

Knowledge gaps about how the ocean melts Antarctica's ice shelves, borne from a lack of observations, lead to large uncertainties in sea level predictions. Using high-resolution maps of the underside of Dotson Ice Shelf, West Antarctica, we reveal the imprint that ice shelf basal melting leaves on the ice. Convection and intermittent warm water intrusions form widespread terraced features through slow melting in quiescent areas, while shear-driven turbulence rapidly melts smooth, eroded topographies in outflow areas, as well as enigmatic teardrop-shaped indentations that result from boundary-layer flow rotation. Full-thickness ice fractures, with bases modified by basal melting and convective processes, are observed throughout the area. This new wealth of processes, all active under a single ice shelf, must be considered to accurately predict future Antarctic ice shelf melt. [ABSTRACT FROM AUTHOR]

Melt track width can vary in a wire-arc-directed energy-deposited material (DED) using a constant set of process parameters, leading to a lower-quality build. In this work, a novel framework is proposed that uses the data from the process parameter development stage to create optimized process parameters for a target layer width at different interpass temperatures without hot cracking. Inconel 718 is used as the model material since it is known to suffer from hot cracking during DED processing. In the proposed framework, a process window containing a few sets of process parameters (torch travel speed and wire feed rate) is established for crack-free deposition of Inconel 718, and these parameters are used to create a small database. A linear regression model is then employed to generate interpass-temperature-specific optimized process parameters for a target melt track width. The results demonstrate that the proposed approach can reduce the melt track width variation in the deposited walls from 12% to 3% error on average under different printing conditions. It also demonstrates that interpass temperature (IPT) can be used as a controlled variable and the optimized process parameters as initial values when applying control techniques to the process. [ABSTRACT FROM AUTHOR]

A one-dimensional two-phase Stefan problem for the melting of a semi-infinite material with a power-type temperature-dependent thermal conductivity was considered. The assumption of taking thermal parameters as functions of temperature found its basis in physical and industries applications, allowing for a more precise and realistic description of phase change processes. By imposing a Dirichlet condition at the fixed face, a theoretical and approximate study was developed. Through a similarity transformation, an equivalent ordinary differential problem was obtained from which an integral problem was deduced. The existence of at least one analytical solution was guaranteed by using the Banach fixed point theorem. Due the unavailability of an analytical solution, a heat balance integral method was applied, assuming a quadratic temperature profile in space, to simulate temperature variations and the location of the interface during the melting process. For constant thermal conductivity, results can be compared with the exact solution available in the literature to check the accuracy of the approximate method. [ABSTRACT FROM AUTHOR]

Laser powder bed fusion (L-PBF) involves the coupling of multiple physical fields at different scales. Capturing the dynamic flow and thermal behavior of the melt pool during the L-PBF process through experimentation and predicting its quality is challenging, thus numerical simulation becomes a valuable method. The simulation results enable the prediction and assessment of the impact of material and process parameter changes on the quality of the final product. This paper reviews the methods for selecting appropriate models, performing simulation calculations, and analyzing the results. This paper makes several noteworthy contributions. It provides a comprehensive summary of the physical model, heat loss model, required heat source for simulations, and stresses generated within the melt pool. Furthermore, it explores the practical applications of L-PBF melt pool simulations, especially in defect analysis and the fabrication of complex structures. Finally, it concludes with an insightful analysis of the current trends in L-PBF simulations and outlines potential research directions to advance the development of melt pool simulations. [ABSTRACT FROM AUTHOR]

Refining ladle slags play an irreplaceable role in the production technology of appropriate quality steel of a given assumed grade. Without good slag, there is no high-quality steel. In this work, we have analyzed the behavior of the slag-forming powder used in industrial conditions, forming a typical refining slag system. The slag-forming powder, Al2O3-SiO2-CaO-MgO-Fe2O3, was examined using a microscope and a high-temperature rheometer. Rheometrical tests were carried out in variable shear conditions, at shear rates of 3–30 s−1 and temperatures in the range of 1451–1500°C. In addition, thermodynamic calculations were performed using FactSage 7.3 databases. Based on the tests performed and the results obtained, it can be concluded that it is impossible to perform rheometric tests of basic slag-forming powder in the analyzed conditions of chemical composition and temperature. In order to obtain rheological characteristics, a slag-forming powder, CaO, was added, modeling the refining slag system. Such a modification of the chemical composition gave the opportunity to perform experiments in the liquid and semi-liquid state. [ABSTRACT FROM AUTHOR]

The distribution of iron-bearing granular materials in the throat of a blast furnace (BF) plays a crucial role in influencing their performance at high temperatures. Therefore, it is essential to establish a quantitative relationship between the charging operation of the iron-bearing materials at ambient temperatures and their subsequent softening and melting behaviors at elevated temperatures. In this study, the discrete element method (DEM) is employed to quantify the instantaneous mass segregation of quaternary iron-bearing materials throughout the continuous charging process, starting from the feeding conveyor belt and continuing up to the throat. Subsequently, employing quaternary basicity (R4) as a pivotal bridge, softening and melting experiments (the temperature above 900 °C and in an atmosphere with a mole fraction of 30 pct CO to 70 pct N2) are conducted to assess the influence of physical segregation on chemical performances under simulated BF conditions. The results reveal that the sequence of loading quaternary iron-bearing materials onto the feeding belt causes fluctuations in R4, ranging from 1.08 to 1.75. Moreover, these fluctuations are propagated throughout the charging process, resulting in notable fluctuations in the mass fractions of iron-bearing materials and the R4 at the hopper outlet and the end of the chute. Therefore, the primary factor influencing the flowing characteristics of the granular materials is their distribution within the hopper. Then, the segregation in the throat is further characterized by the presence of two distinct R4 ranges (1.2 to 1.29, and 1.3 to 1.39) observed across a total of 48 equal-area blocks, and the significant difference between these two categories is determined by sinters. Besides, the influence of the R4 on softening and melting temperatures is quantitatively evaluated, resulting in a 'w'-shaped temperature distribution from the center to the edge of the BF. Our findings provide evidence of the inadequacy of evaluating the softening and melting behaviors of iron-bearing materials solely based on their initial proportions in the structure of iron-bearing materials. Instead, a quantitative examination of the granular segregation in the throat, arising from the BF charging operation, is deemed essential to provide substantial support for well-designed elevated-temperature experiments. This approach enables a more comprehensive understanding of the intricate journey of iron-bearing materials in the BF. [ABSTRACT FROM AUTHOR]

In order to realize the comprehensive and efficient recovery of vanadium–titanium magnetite, a mass action concentration calculation model for direct melting reduction was established, and the mechanisms and limiting factors for the separation and enrichment between Fe, V, and Ti were also studied through molten vortex direct reduction experiments. The mass effect concentration modeling results show that increasing the temperature and carbon–iron ratio promotes Fe, Ti, and V reduction, while adding CaO and MgO inhibits Ti reduction. CaO and MgO in the slag preferentially combine with TiO2 rather than SiO2, and increasing MgO in the slag contributes to the decomposition of the Al2O3.TiO2. Vortex stirring efficiently prevents slag crusting, alleviates foam slag problems, and promotes full reaction in the melt. Appropriate increases in reaction temperature, carbon–iron ratio, and holding time are beneficial for reduction in the molten vortex direct reduction process, while excessive increases in these parameters will result in titanium reduction. Under optimal experimental conditions, the recovery of Fe and V in the metal is 99.61 to 99.74 pct and 92.63 to 94.3 pct, respectively, with TiO2 content in the slag being 50.9 to 51.2 pct, and TiO2 in the slag mainly concentrated in Mg0.6Ti2.4O5. [ABSTRACT FROM AUTHOR]

The formation and evolution of the South Pole‐Aitken (SPA) basin is critical to relating large impact basin formation and modification to lunar geophysical evolution. Most prior models of the SPA impact were conducted in 2D, making it difficult to compare model output to the 3D crustal structure and ejecta distribution. In order to better constrain the parameters of the SPA impactor and the expected post impact distribution of crust and ejecta, we conducted numerical simulations of the SPA impact in 3D. We tested a wide range of impact parameters and constrained model results with recent geophysical data. We found the crustal structure of the SPA basin is best fit by an oblique impact (30–45°) of a 350–400 km diameter projectile impacting at 12–16 km/s. The impact excavated material from as deep as 80–120 km, and ejecta was deposited in a butterfly pattern with a forbidden region uprange of the impact. Plain Language Summary: The South Pole‐Aitken (SPA) basin is the largest impact‐generated structure on the Moon. The large size of the basin (approximately 1,500–2,000 km in diameter) implies the impact that generated the basin globally influenced the early evolution of the Moon. In order to constrain the type of impact that formed the basin, we ran computer simulations of large projectiles (300–400 km in diameter) impacting the early lunar surface. We found the structure of the crust surrounding the basin best matches an impact of a 350–400 km diameter projectile (similar in scale to Saturn's moon Mimas) impacting the Moon with a velocity of 12–16 km per second. Our computer models show that the collision that generated the basin would have formed a non‐symmetrical distribution of impact ejecta, and excavated material from the lower crust and upper mantle. Our results constrain the type of impact that formed the SPA basin, and suggest that ejecta from the impact is prevalent at sites of current and future lunar exploration. Key Points: 3D simulations constrain the South Pole‐Aitken (SPA) impactor to 350–400 km diameter impacting at 12–16 km/s and 30–45°The SPA impact excavated lower crust and upper mantle lunar materials, and emplaced ejecta in a butterfly type ejecta patternThe thick crustal annulus present in model results requires further modeling of basin collapse and post‐impact relaxation [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Deer‐derived materials (antler, venison, fetus, penis, bone, tail, and others) are some of the most valuable traditional animal‐based medicinal and food materials in China. In production, processing, and trade, the quality of deer products varies. The market is confusing, and counterfeit and shoddy products are common. There is an urgent need to establish an accurate identification method.Two pairs of primers suitable for identifying deer‐derived medicinal materials were obtained by screening the cytochrome oxidase I (COI) sequences of 18 species from nine genera of the deer family. The two primers were used to identify the species and adulteration of 22 batches of commercially available deer‐derived products with a mini‐barcode combining high‐resolution melting (HRM) technology and methodical investigation. Deer‐derived materials (sika and red deer) were correctly identified by species using varying DNA amounts (1 to 500 ng). The two pairs of primers COI‐1FR and COI‐2FR yielded melting temperatures (Tm) of 80.55 to 81.00 °C and 82.00 to 82.50 °C for sika deer, and 81.00 to 82.00 °C and 81.40 to 82.00 °C for red deer. Twenty‐two batches of commercially available samples were analyzed by HRM analysis and conventional amplification sequencing, and it was found that the species samples had an error rate of species labeling of 31.8%. Four batches of samples were identified as mixed (adulterated) in the HRM analysis.The combination of DNA mini‐barcode with HRM analysis facilitated the accurate identification of species of deer‐derived materials, especially the identification of samples in an adulterated mixed state. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Winter continues to witness numerous automobile accidents attributed to graupel and hail precipitation in Japan. Detecting these weather phenomena using radar technology holds promise for reducing the impact of such accidents and improving road maintenance operations. Weather radars operating at different frequencies, such as C- and X-band, prove effective in graupel detection by analyzing variations in backscattered signals within the same radar volume. When particle diameters exceed 5 mm, the study of Mie scattering characteristics across different melting ratios reveals insights. The dual frequency ratio (DFR) shows potential for graupel detection. The DFR presents wider variations with ten-times difference in melting ratios with increased density, offering opportunities for precise detection. Additionally, the DFR amplitude rises with temperature changes. However, for hydrometeor diameters below approximately 3 mm, and within the Rayleigh region, the DFR exhibits minimal fluctuations. Hence, this technique is best suited for diameters exceeding 3 mm for optimal efficacy. Additionally, a "detection alert" for graupel/hail has been proposed. Based on this alert, and with realistic rain/graupel size distributions, graupel/hail can be detected with an approximate probability of 70%. [ABSTRACT FROM AUTHOR]

Electron beam selective melting is a metal powder bed fusion additive manufacturing technology. In order to study the temperature field and melt pool changes of high Nb-TiAl electron beam selective melting on a single scan line and multi-scan lines. In this paper, two three-dimensional thermal-fluid models are established to simulate the evolution of the melt pool and temperature field at different electron beam scanning speeds under a single scan line and the evolution of the temperature field under multi-scan lines. The simulation results of a single scan line show that the length of the bath increases with the increase in the electron beam scanning speed, while the width and depth of the bath decrease with the increase in the speed. The scanning speed has a significant impact on the length and depth of the micro-bath, but the impact on the width is relatively small. The simulation results of multi-scan lines show that the preheating temperature has a greater influence on the melting temperature field, while the size of the scanning current has a smaller influence on the temperature field. The conclusion drawn from the results obtained through simulation is that the temperature during the preheating process must be strictly controlled, and the melting process speed must be appropriately set in order to obtain high-quality samples. [ABSTRACT FROM AUTHOR]

With the gradual increase in energy demand in global industrialization, the energy crisis has become an urgent problem. Due to high heat storage density, small volume change, and nearly constant transition temperature, phase change materials (PCMs) provide a promising method to store thermal energy. In this work, we designed and fabricated three kinds of porous metal structures with hexagonal, rectangular, and circular pores and explored the phase change process of PCMs within them. A two-dimensional numerical model was established to investigate the heat transfer process of PCMs within different shapes of porous metal structures and analyze the influence of heat source location on the thermal performance of the thermal storage units. Visualization experiments were also carried out to reveal the melting process of PCMs within different porous metal structures by a digital camera. The results show that paraffin in a porous metal structure with hexagonal pores has the fastest melting rate, while that in a porous metal structure with circular pores has the slowest melting rate. Under the bottom heating mode, the melting time of the paraffin in porous metal structures with hexagonal pores is shortened by 18.6% compared to that in porous metal structures with circular pores. Under the left heating mode, the corresponding melting time is shortened by 16.7%. These findings in this work will offer an effective method to design and optimize the structure of porous metal and improve the thermal properties of PCMs. [ABSTRACT FROM AUTHOR]

Various nondestructive diagnostic techniques have been proposed for in situ process monitoring of laser powder bed fusion (LPBF), including melt pool pyrometry, whole-layer optical imaging, acoustic emission, atomic emission spectroscopy, high speed melt pool imaging, and thermionic emission. Correlations between these in situ monitoring signals and defect formation have been demonstrated with acoustic signals having been shown to predict pore formation with especially high confidence in recent machine learning studies. In this work, time-resolved acoustic data are collected in both the conduction and keyhole welding regimes of LPBF-processed Ti-6Al-4V alloy. A non-dimensionalized Strouhal number analysis, used in whistle aeroacoustics, is applied to demonstrate that the acoustic signals recorded in the keyhole regimes can be directly associated with the vapor depression morphology. This mechanistic understanding developed from whistle aeroacoustics shows that acoustic monitoring during the LPBF process can provide a direct probe into the vapor depression dynamics and defect occurrence, especially in the keyhole regimes relevant to printing and defect formation. [ABSTRACT FROM AUTHOR]

Liquid–liquid phase transition (LLPT) is the transformation of a liquid from one distinctive structure to another with the same composition. However, the origin of the structural variation at LLPT is still controversial. Here, we used ab initio molecular dynamics simulation to verify and investigate a high-temperature LLPT in a Pd40Ni40P20 melt; this melt showed a reduction in the nuclei interference of the conventional low-temperature LLPT. An abnormal endothermic LLPT was confirmed with flash differential scanning calorimetry, indicating a change in the atomic short-range-order structure around the P–P bond and a decrease in the number of specific icosahedral-like clusters, such as ⟨0 2 8 0⟩ and ⟨0 2 8 1⟩. The structural change of the P-centered clusters changed the solidification path through potential energy adjustments. Our results showed the structural mechanism of the unusual endothermic phenomenon and provided a different insight into regulating the properties of metallic glasses. [ABSTRACT FROM AUTHOR]

The effect of Ru-substitution (5–15 %) on the charge ordering of Y 0.5 Ca 0.5 MnO 3 has been investigated in this paper. Ru, existing in different oxidation states such as Ru4+ and Ru5+, plays an immense role in causing ferromagnetic (FM) superexchange interactions with Mn3+ ions. This, combined with the FM double-exchange interactions between Mn3+ and Mn4+ ions, destroys charge ordering. The development of ferromagnetism in Ru-substituted compounds is understood experimentally through the remarkable enhancement of dc magnetization with a simultaneous shift of T C from 57 K to 95 K with increasing Ru content from x = 0.05 to x = 0.15. The appearance of hysteresis for higher doping concentrations further confirms the FM nature. Concomitant with the favorable impact on the magnetic nature, there is also a development of magnetocaloric properties upon Ru-substitution. The maximum magnetic entropy change for x = 0.05 to 0.15 that was found to peak at T C ranges from 1.08 J/kg/K to 2.8 J/kg/K respectively for a field change of 9 T. The corresponding relative cooling power (RCP) increases from 76 J/kg to 324 J/kg indicating a significant growth of RCP with Ru substitution. These salient features of Ru-doped Y 0.5 Ca 0.5 MnO 3 would make it a suitable candidate for magnetic refrigeration. [ABSTRACT FROM AUTHOR]

Polyurethane foams are widely used in daily life due to their superior performance. However, it is very challenging to recycle and reuse waste polyurethane foams since the three‐dimensional crosslinking network structure makes them non‐melting and insoluble. In this work, a low‐cost, green, room‐temperature solid‐state shear milling method is proposed to break the cross‐linking bonds of waste polyurethane foam (crosslinking density decreases from 0.768 to 0.489 mol dm−3). The recycled polyurethane (RPU) powders regain their thermoplastic processability. Recycled waste polyester (PET) fibers are modified through plasma treatment and used as reinforcing fillers for the reprocessed RPU elastomer. Compared to original PET fibers, modified polyester (m‐PET) fibers construct strong interfacial interactions and physical interlocks with RPU matrix, leading to significantly enhanced mechanical properties. Molecular dynamics studies demonstrate that RPU/m‐PET composites have higher cohesive energy density and lower free volume, and significantly improved compatibility, which greatly promotes stress dissipation upon stretching. This study provides a feasible strategy for the high‐value recycling of waste polymer materials. [ABSTRACT FROM AUTHOR]

Melting is an efficient method to turn municipal solid waste incineration (MSWI) fly ash (FA) into non-hazardous material. Coal fly ash (CFA) was selected as the silica-alumina source to carry out co-melting research with MSWI FA in this work. The effects of the temperature and the CFA content on mineral transformation and the migration characteristics of heavy metals were analyzed. The results showed that the mixtures of MSWI FA and CFA reacted at high temperatures to mainly generate Ca2Al2SiO7, Ca2SiO4, and CaAl2Si2O8 primarily and then melted and formed the amorphous-phase vitreous body when the CFA content was more than 40% and the temperature was higher than 1300 °C. During the melting process, Cd and Pb were almost volatilized, while Cr, Mn, and Ni were almost retained. Besides, the volatilization rates of Cu and Zn fluctuated with the temperature and the CFA content. Suitable treatment temperature and CFA content were conducive to the transformation of the heavy metals in the FA into stable forms, and the melting products were no longer hazardous wastes because the vitreous body could effectively encapsulate heavy metals. This study aims to help reuse the FA and CFA collaboratively and be more environmentally friendly. [ABSTRACT FROM AUTHOR]

The representational momentum for physical state changes refers to the fact that we remember objects as more changed in physical state than they actually were. It has been well documented that depressive disorder is associated with impairment of time perception. Thus, the present work was conducted with the aim to investigate the representational momentum for physical state changes in patients with depressive disorder, firstly. Forty patients with depressive disorder and forty-two healthy controls were administrated with the task of representational momentum for physical state changes and task of time perception. The stimulus comprises 10 videos showing object state changes (e.g., ice melting). During playing, the video would stop and immediately be obscured by mosaics at a specific point. Participants select from three detection images (the exact frame of the video just be masked, the frame after that, and the frame before that) to test representational momentum and estimate the duration of the video in seconds to test time perception. The depressive group showed diminished representational momentum (i.e., lower scores on the task of representational momentum) than normal controls (U = 215.00, Z = −5.83, p < 0.001). In addition, the scores on the task of representational momentum were significantly positively related with the scores on the task of time perception among depressive group (r = 0.446, p = 0.004). The findings indicate that patients with depressive disorder may exhibit diminished representational momentum for physical states, which may be correlated with their impairment of time perception. • The representational momentum in patients with depressive disorder has not been explored. • Impairment affects representational momentum and time perception. • Impaired representational momentum may be associated with impaired time perception. [ABSTRACT FROM AUTHOR]

The effectiveness of using borate (borax) and fluoride (sodium fluoride) fluxes in the sintering of crystalline (sand) and amorphous (diatomite) silicate raw materials was considered. The change in the density and appearance of samples with varying amounts of fluxes during their heat treatment at different temperatures was described. It was shown that the introduction of 4 wt.% of borax reduces the temperature necessary to reach a density of 1500 kg/m3 by 100°C, and 6 wt.% of borax by 200°C. It was shown that the introduction of fluxes increases the amount of x-ray amorphous glass phase due to depolymerization of the silicon-oxygen network and the formation of a low-temperature melt. [ABSTRACT FROM AUTHOR]

The non-equilibrium melting of Na crystals at high heating rates and the evolutions of the atomic clusters are studied by the MD method and PTM analysis. Results show that as the heating rate rises from 1 × 1011 K/s to 2 × 1013 K/s, the non-equilibrium melting temperature of Na increases non-linearly from 417 K to 480 K, the melting temperature difference experienced increases from 7 K to 27 K, while the melting time decreases from 70 ps to 1 ps. Through the PTM analysis, it is found that some BCC clusters transform into the disordered Other clusters through intermediate HCP and FCC clusters with increasing temperature, and the BCC cluster's reduction rate and the Other cluster's growth rate are getting slower with increasing heating rate. There is a good correspondence between the evolutions of the atomic clusters, the changes of macroscopic physical parameters, and the peaks and valleys of RDF with temperature. [ABSTRACT FROM AUTHOR]

The lithium cycling in the supra-subduction mantle wedge is crucial for understanding the generation of Li-rich magmas that may potentially source ore deposition in continental arcs. Here, we look from the mantle source perspective at the geological processes controlling the Li mobility in convergent margins, by characterizing a set of sub-arc mantle xenoliths from the southern Andes (Coyhaique, western Patagonia). The mineral trace element signatures and oxygen fugacity estimates (FMQ > + 3) in some of these peridotite xenoliths record the interaction with arc magmas enriched in fluid-mobile elements originally scavenged by slab dehydration. This subduction-related metasomatism was poorly effective on enhancing the Li inventory of the sub-arc lithospheric mantle, underpinning the inefficiency of slab-derived fluids on mobilizing Li through the mantle wedge. However, major and trace element compositions of mantle minerals in other xenoliths also record transient thermal and chemical anomalies associated with the percolation of slab window-related magmas, which exhibit an "adakite"-type geochemical fingerprint inherited by slab-derived melts produced during ridge subduction and slab window opening event. As these melts percolated through the shallow (7.2–16.8 kbar) and hot (952–1054 °C) lithospheric mantle wedge, they promoted the crystallization of metasomatic clinopyroxene having exceptionally high Li abundances (6–15 ppm). Numerical modeling shows that low degrees (< 10%) of partial melting of this Li-rich and fertile sub-arc lithospheric mantle generates primitive melts having two-fold Li enrichment (~13 ppm) compared with average subduction-zone basalts. Prolonged fractional crystallization of these melts produces extremely Li-enriched silicic rocks, which may stoke the Li inventory of mineralizing fluids in the shallow crust. [ABSTRACT FROM AUTHOR]

Vitrification of solid technological waste is currently under investigation. For this type of waste made up of metals, minerals, and organic matters, formulation studies were carried out in the NCAS (Na2O–CaO–Al2O3–SiO2) system in order to define a vitrifying additive to treat the entire waste deposit, while maximizing the waste loading. Main challenge related to this type of waste comes from the presence of alumina in very large quantities in the glass/glass–ceramics melt, enhancing the risk of melt solidification due to a fast and massive crystallization. Melt lock‐up can potentially occur at the operating temperature envisaged for the process (1400°C) and is prohibitive because it would lead to a premature stoppage of the process. The results obtained from casting tests, rheological experiments, and thermodynamic modeling enabled to provide an accurate estimation of the risk of melt lock‐up for NCAS compositions. It was highlighted that the composition had a major influence on the temperature at which massive crystallization might occur. From all the results obtained, the maximum Al2O3 content that could be incorporated in the final material was determined to be close to 50 wt%. The composition of a vitrifying additive was also statistically designed to treat the technological waste of interest. [ABSTRACT FROM AUTHOR]

We study the effect of particle size polydispersity (δ) on the melting transition (T *), local ordering, solid–liquid coexistence phase and dynamics of two-dimensional Lennard–Jones fluids up to moderate polydispersity by means of computer simulations. The particle sizes are drawn at random from the Gaussian (G) and uniform (U) distribution functions. For these systems, we further consider two different kinds of particles, viz., particles having the same mass irrespective of size, and in the other case the mass of the particle scales with its size. It is observed that with increasing polydispersity, the value of T * initially increases due to improved packing efficiency (ϕ) followed by a decrease and terminates at δ ≈ 8% (U-system) and 14% (G-system) with no significant difference for both mass types. The interesting observation is that the particular value at which ϕ drops suddenly coincides with the peak of the heat capacity (CP) curve, indicating a transition. The quantification of local particle ordering through the hexatic order parameter (Q 6), Voronoi construction and pair correlation function reveals that the ordering decreases with increasing δ and T. Furthermore, the solid–liquid coexistence region for the G-system is shown to be comparatively wider in the T – δ plane phase diagram than that for the U system. Finally, the study of dynamics reveals that polydisperse systems relax faster compared to monodisperse systems; however, no significant qualitative differences, depending on the distribution type and mass polydispersity, are observed. [ABSTRACT FROM AUTHOR]

In polar regions, sea ice is a crucial mediator of the interaction between Earth's atmosphere and oceans. Its formation and breakup is intimately connected with large-scale climatic processes, local weather patterns, and the use of sea ice in coastal Arctic regions by Indigenous people. In order to investigate the physical phenomena at the heart of this process, a set of targeted, intensive observations were made over spring sea ice melt and breakup in Kotzebue Sound, Alaska. These observations were planned and executed through a collaborative effort in which an Indigenous Elder advisory council from Kotzebue and scientists participated in co-production of hypotheses and observational research, including a stronger understanding of the physical properties of sea ice during spring melt. Here we present the results of observations performed using high-endurance, fixed-wing uncrewed aerial vehicles (UAVs) containing custom-built scientific payloads. Repeated flights over the measurement period captured the early stages of the transition from a white, snow-covered state to a broken-up, bare blue-green state. We found that the reflectance of sea ice features depends strongly on their size. Snow patches get darker as they get smaller, an effect owed to the geometric relationship between the bright interior and the darker, melting feature edges. Conversely, bare patches get darker as they get larger. For the largest ice features observed, bare blue-green ice patches were found to be ≈ 20 % less reflective than average across all observational cases, while large snowy white ice patches were found to be ≈ 20 % more reflective than that same average. [ABSTRACT FROM AUTHOR]

Viscosity is an important property for CaO‐SiO2‐Al2O3‐based slag systems, which showcases different scenarios in basic and acid slag systems with temperature change. This article elucidates the mechanism of their difference in viscosity–temperature property from melt structure. Results reveal that basic slag shows a low degree of polymerization (DOP) and a low viscosity of the melt due to an excessive O2− ions depolymerizing the complex network structures, resulting in more low‐polymerized Q0(Si) units and less high‐polymerized Q3(Si) units. With the temperature decreases, the DOP and viscosity do not change significantly. However, the low DOP and viscosity favor crystal precipitation in the melt, leading to a solid–liquid mixed state of the slag, and thus a sharp increase in viscosity when the temperature decreases to 1275 °C. For acid slag, it undergoes a transformation into aluminosilicate structures with the introduction of numerous [AlO4]5− tetrahedra, accompanied by a significant increase in the relative mole fraction of high‐polymerized Q3(Si) units. Consequently, the DOP and viscosity are obviously higher than that of the basic slag. Furthermore, the DOP and viscosity of the acid slag increase continuously with the temperature decreasing, thus impeding crystal precipitation and enhancing the glass transition tendency of the molten slag. [ABSTRACT FROM AUTHOR]

High- to ultrahigh-pressure (HP–UHP) rocks recording high-temperature (HT) > 700 °C are well exposed in the Central Alps, making it an ideal region to study the timing of metamorphic stages and the mechanisms of deep-seated rocks exhumation. Here, we report an integrated dataset of petrological and U–(Th–)Pb dating of metapelites surrounding ultramafic lenses from the Cima Lunga unit. At the interface with ultramafics preserving (U)HP–HT assemblages (1.5–3.1 GPa, 650–850 °C), metapelites record higher P‒T values (1.3–2.7 GPa, 700–850 °C) and traces of partial melting, whereas the rest of the unit is dominated by amphibolite-facies conditions. U–Th–Pb dating on zircon and monazite from migmatites indicates that partial melting was episodic involving at least two stages at ~38 to 35 Ma and 33–30 Ma, respectively. While the 38–35 Ma stage matches the HP conditions (> 1.5 GPa) and it is recorded around only one lens with scarce volumes of melt, partial melting at 33–30 Ma is witnessed at lower pressure (~1 GPa) and more widely distributed around the lenses, as within the major shear zones. Far from the ultramafics, zircon from the amphibolite-facies metasedimentary rocks record inherited pre-Variscan ages, while monazite ages at ~22 Ma document mineral growth during the Barrovian cooling. Field and petro-chronological evidence highlight that multiple episodes of partial melting locally developed at the rheological interface promoted by the interplay of fluids extracted from the ultramafic lenses associated with shear heating. New evidence suggests that local variation of P‒T equilibria play a significant role during the exhumation history. [ABSTRACT FROM AUTHOR]

We have predicted melting temperatures of ionic and partially covalent compounds viz. NaCl, NaF, LiF, MgO, CaF2, SiC at high pressures. The volume dependence of Grüneisen parameter determined from the Jeanloz equation has been used in the Lindemann law to predict melting curves. The pressure–volume relationships used in computations are determined with the help of the Holzapfel equation of state based on the adapted polynomial expansion of second order. The results for melting curves of different solids obtained in the present study using γ ∞ = 1 / 2 at extreme compression are found to be in reasonably good agreement with the available experimental data. We have also calculated slopes of melting curves at different pressures for the six compounds under study. It is found that the melting slopes decrease continuously with the increase in pressure, and tend to zero in the limit of infinite pressure. The results obtained in the present study are found to compare well with the experimental data and molecular dynamics simulations. [ABSTRACT FROM AUTHOR]

Because Antarctic surface melt is mostly driven by local processes, its simulation necessitates high‐resolution regional climate models (RCMs). However, the current horizontal resolution of RCMs (≈25–30 km) is inadequate for capturing small‐scale melt processes. To address this limitation, we present SUPREME (SUPer‐REsolution‐based Melt Estimation over Antarctica), a deep learning method to downscale surface melt to 5.5 km resolution using a physically‐informed super‐resolution model. The physical information integrated into the model originates from observations tied to surface melt, specifically remote sensing‐derived albedo and elevation. These remote sensing data, in addition to a Regional Atmospheric Climate Model (RACMO) run at 27 km resolution, account for the diverse drivers of surface melt across Antarctica, facilitating effective generalization beyond the training region of the Antarctic Peninsula. A comparison of SUPREME with a dynamically downscaled RACMO run at 5.5 km over the Antarctic Peninsula shows high accuracy, with average yearly RMSE and bias of 5.5 mm w.e. yr−1 and 4.5 mm w.e. yr−1, respectively. Validation at five automatic weather stations reveals SUPREME's marked improvement with substantially lower average RMSE (81 mm w.e.) compared to RACMO 27 km (129 mm w.e.). Beyond the training region, SUPREME aligns more closely with remote sensing products associated with surface melt than super‐resolution models lacking physical constraints. While further validation of SUPREME is needed, our study highlights the potential of super‐resolution techniques with physical constraints for high‐resolution surface melt monitoring in Antarctica, providing insights into the impacts of localized melting on processes affecting ice shelf integrity such as hydrofracturing. Plain Language Summary: To improve surface melt monitoring in Antarctica, high‐resolution climate models are essential. Existing models, like the Regional Atmospheric Climate Model (RACMO), do not have a fine enough spatial resolution to capture small‐scale melt processes. To overcome this, we introduce SUPREME (SUPer‐REsolution‐based Melt Estimation over Antarctica), a method that refines surface melt data to a higher resolution of 5.5 km using an advanced super‐resolution model. We enhance this model with physical information derived from observations directly related to surface melt, specifically using albedo and elevation data from remote sensing. By incorporating these observations, along with RACMO data at 27 km resolution, we account for the various triggers of surface melt across Antarctica. SUPREME accurately predicts high‐resolution surface melt beyond the training region of the Antarctic Peninsula, showing promising results compared to existing melt observations. Further validation is needed, but this approach, combining super‐resolution techniques and remote sensing data, holds potential for accurate surface melt monitoring in Antarctica. This may advance our understanding of the impacts of localized features on processes affecting ice shelf integrity such as meltwater‐induced hydrofracturing. Key Points: Our method downscales Antarctic surface melt from a regional climate model, employing a physically‐informed super‐resolution architectureThe super‐resolution model relies on physical information derived from remote sensing data, specifically surface albedo and elevationIncorporating physical information boosts model generalization, enabling accurate high‐resolution surface melt beyond the training region [ABSTRACT FROM AUTHOR]

Estimation of the composition of planetary rocks and minerals is crucial for understanding their formation processes. In this study, we present the application of X‐ray nano‐computed tomography (nano‐XCT) for non‐destructive three‐dimensional (3‐D) phase analysis and estimation of phase abundances in rare Martian meteorite samples, specifically chassignite Northwest Africa (NWA) 2737. We determined the most suitable laser power for minimizing artifacts and maximizing phase contrast. By utilizing nano‐XCT, we successfully identified and segmented primary phases in the bulk meteorite sample. Additionally, we were able to locate and segment crystallized silicate melt inclusions within the meteorite. The phase abundances in bulk NWA 2737 and within melt inclusions calculated using nano‐XCT were in good agreement with previous studies that used thin section calculations, demonstrating the reliability of nano‐XCT as a non‐destructive alternative for estimating bulk phase abundances in rare samples. This study develops a benchmarking protocol and demonstrates the efficacy of nano‐XCT as a non‐destructive technique for generating an overview of phase distribution and assemblages of melt inclusions within rare samples. Future research can benefit from combining non‐destructive 3‐D phase assemblage estimations with non‐destructive 3‐D chemical analysis techniques to achieve a fully non‐destructive parental magma composition estimation of rare cumulate samples. [ABSTRACT FROM AUTHOR]

Investigations of trapped melt inclusions in minerals can yield insights into the compositions and conditions of parent magmas. These insights are particularly important for detrital grains like many of the lunar zircons found in samples returned by the Apollo missions. However, unlike their terrestrial counterparts, lunar zircons have potentially been exposed to billions of years of impact bombardment. Samples from terrestrial impact structures and impact shock experiments have revealed that deformation during an impact event produces melt and glass blebs that can mimic igneous melt inclusions in both morphology and composition. We have undertaken a geochemical and textural investigation of zircons from Apollo impact melt breccia 14311 to assess their formation mechanisms. The association of trapped melts with shock microtwins and monomineralic melt compositions suggests some inclusions formed as a result of the high pressures and temperatures of impact shock. All other inclusions in this study are associated with curviplanar features, planar features, crystal plastic deformation, or embayments (large regions in contact with adjacent melts or minerals) suggesting that they are not igneous melt inclusions. While these textures can be produced in tectonic environments, impacts are a likely formation mechanism since impacts are the main driver of tectonics on the Moon. The results of this study demonstrate that a combination of textural and compositional analyses can be employed distinguish between igneous melt inclusions and melt blebs in zircons from impact environments. [ABSTRACT FROM AUTHOR]

We present linear viscoelastic data with anionically synthesized and critically fractionated polybutadiene (rich in vinyl content) rings having about Z = 22 entanglements. These rings are experimentally as pure as currently possible. They exhibit a power-law stress relaxation G(t) that is well-described by the state-of-the-art fractal loopy globule (FLG) model (power-law exponent of − 3/7). Previously reported data with polystyrene rings, prepared by anionic synthesis in dilute solution and purified by liquid chromatography at the critical condition, having Z = 14 entanglements, showed a power-law G(t) as well. Recent developments with different synthetic methods yielding not so well-characterized rings with a very large number of entanglements (up to 300), suggest that a rubbery plateau emerges in the linear viscoelastic response for Z > 15. Our work confirms the power-law G(t) with the FLG exponent with another chemistry and contributes to the current discussion about different regimes of rheological behavior, indicating that a possible deviation from the power-law FLG type of behavior toward rubbery plateau may occur for Z > 22. To fully capture the experimental G(t) data, the FLG model is complemented by two additional relaxation modes which are attributed to ring-ring (RR) and ring-linear (RL) threading, in accordance with recent reports in the literature. The faster RR mode likely reflects a new mechanism of stress relaxation not described by FLG, and the slower RL mode is attributed to synthetic and material handling imperfections (for example, due to thermal treatment). However, it does not change the punchline of the work: no rubbery plateau for entangled rings with up to 22 entanglements. Stress relaxation modulus for entangled ring polybutadiene (exhibiting power-law decay) and its linear precursor (exhibiting rubbery plateau), along with fits to the data: tube model for linear chains, and fractal loopy globule (FLG) with slow modes (RR and Tsalikis et al.) for the ring. [ABSTRACT FROM AUTHOR]

Boninites (BONs), high-Mg andesites (HMAs), and related lavas and dikes of Palaeogene ophiolites of the SW Pacific in Papua, New Guinea, New Caledonia, and the North Island, New Zealand, interpreted as having formed subsequent to forearc basalt (FAB) during subduction initiation (SI) are investigated to determine whether these are similar to second-stage lavas and dikes of other SI ophiolites and the IBM forearc. SW Pacific second-stage lavas and dikes are mostly high-Si BONs, but range to HMAs with the latter appearing to have preceded the formation of the former. Partial melting was due to flux-melting of a depleted source with the addition of hydrous and LREE-, Sr-, and Zr-enriched sediment melts to the mantle wedge subsequent to extraction of first-formed FAB. New Caledonia second-stage BONs are mostly consistent with ~5–15% partial melting of a source, which had undergone two previous melt extraction events and in New Zealand, second-stage HMA dikes are consistent as the result of 10–20% partial melting of a depleted source having undergone initial FAB extraction followed by a maximum of ~25% partial melting of a source produced subsequent to the first extraction event. Thermobarometry calculations of primitive second-stage BON and HMA lavas and dikes record potential temperatures generally similar to but pressures lower than MORB. Although most PUB ophiolite and both New Zealand HMA samples plot within the field of MORB with TP of about 1280–1350°C and pressures of ~0.8–1.80 GPa, all remaining second-stage BONs and HMA exhibit TP and pressures lower than MORB. A clear demarcation exists between New Caledonia BONs and PUB HMA, the latter of which records much higher TP and lower pressures than the former and range from ~1330 to 1420°C and from 0.7 to 1.40 GPa. These anomalously high temperatures for the PUB may infer a plume-induced SI event. [ABSTRACT FROM AUTHOR]

Evaporation of silicate materials from Earth or its precursors may be important in shaping their primordial compositions represented by undifferentiated meteorites, e.g., enstatite chondrites; however, the conditions under which evaporation occurs and the extent of evaporation-induced elemental and isotope fractionation remain uncertain. Here, we experimentally determine the volatility and isotope fractionation of Si, Mg, Ca, Nb, and Ta during enstatite melt evaporation at 2423–2623 K using a high-temperature conical nozzle levitator. Homogenous glasses are recovered after experiments; then we use EPMA and LA-ICP-MS to measure the elemental compositions, MC-ICP-MS to measure the Si and Mg isotopes, and TIMS to measure the Ca isotopes. Our results show that the evaporation rates of Si are larger than Mg, and the mean vapor/melt isotope fractionation factors (α = Rvapor/Rmelt; R = isotope ratio) are 0.99585 ± 0.00002 for 29Si/28Si and 0.98942 ± 0.00130 for 25Mg/24Mg. However, neither evaporative loss of Ca, Nb, and Ta nor Ca isotope fractionation was observed within analytical uncertainty. In conjunction with previous studies, we find that in an evaporation experiment the saturation degree (partial vapor pressure/equilibrium vapor pressure) of Si (SSi) is larger than SMg when Si is more volatile than Mg, and vice versa. If the Mg/Ca and Si/Ca ratios and isotopes in the bulk silicate Earth are attributed to the evaporation of enstatite chondrite-like precursors, evaporation temperatures >5000 K and SSi < SMg are required. [ABSTRACT FROM AUTHOR]

In this study, the effect of carrot fiber and certain gums on the physicochemical, textural, microbiological, and sensory properties of block-type melting cheese, which holds a significant place in our daily food consumption, was investigated. The study also aimed to determine the impact of carrot fiber and other gums on cheese properties, as well as on yield and meltability. Carrot fiber was used at levels of 2.5% and 5.0% by weight, while carrageenan and xanthan gum were each used at levels of 0.25% and 0.50%. The cheeses were analyzed on days 1, 15, and 30. At the end of the study, it was determined that the highest total dry matter, fat, and protein values were found in the control sample due to the addition of water when preparing the cheeses with fiber and gum. The highest dry matter, fat, salt, and protein ratios were 59.65%, 29.40%, 1.48%, and 24.48%, respectively, in the control sample. The lowest fat, salt, and protein ratios were 25.00%, 1.31%, and 22.07%, respectively, in the 5.0% carrot fiber sample. The lowest dry matter value was found in the 0.5% xanthan sample, namely 53.62%. The highest L* value was measured in the control sample at 86.89, while the lowest was measured in the 5.0% carrot fiber sample at 81.86. The lowest a* and b* values were 2.82 and 29.42, respectively, in the control sample, while the highest values were 6.20 and 37.37, respectively, in the 5.0% carrot fiber sample. It was observed that the use of carrot fiber imparted an orangish color to the cheese. It was observed that the pH values of the samples were similar. According to the sensory evaluation results, the most liked sample was the control sample with 8.5 points, followed by the 0.25% xanthan sample with 8.0 points. The 5.0% carrot fiber sample received the lowest sensory appreciation with 6.1 points. It was understood that the use of carrot fiber gave the cheese an orangish color. Although the meltability varied according to the amount of gum and fiber used, it was measured at 6.92 cm in the 0.25% carrageenan sample on the first day and at 6.79 cm in the control sample on the last day of storage. It was observed that the use of fiber decreased the total bacterial count, while the use of gum increased it. [ABSTRACT FROM AUTHOR]

Periodic electric current pulses, i.e. electropulses, were applied on selective laser melting prepared 15-5 precipitation hardening stainless steel for direct aging. Traditional aging treatment typically takes hours to achieve peak hardening and could induce reverted austenite. Herein, electropulsing treatment on as-built sample can dramatically reduce the processing time to 6 min. Moreover, the nucleation of reverted austenite triggered by the segregation of Ni atoms on the interfaces between Cu-rich precipitates and martensite was not observed. These two unique phenomena were rationalized to the unsynchronized enhancement of diffusivity of Cu and Ni atoms under electropulses due to their different electron configurations. Electropulsing treatment selectively boosted the diffusivity of Cu atoms in additive manufactured maraging stainless steel and dramatically reduced the direct aging time from hours to minutes without inducing reverted austenite. [ABSTRACT FROM AUTHOR]

In the selective-laser-melting process, it is difficult to monitor the evolution of the melt pool in real time via experimental methods due to the complexity and fine scale of laser–powder interaction; numerical simulation has become an important technical way to study the selective-laser-melting process. A coupled thermal–fluid model of the SLM single-layer melt-channel-forming process is constructed based on hydrodynamic theory for AlSi10Mg metallic materials, and the SLM single-layer melt-channel-forming process is investigated by combining parametric experiments and numerical simulation methods. A binarised spatial-random-function pore material model is proposed, and a multiscale finite-element numerical model of the melt-channel-forming process is constructed to compare and verify the first-layer melt-channel-forming process and to analyse the evolution of the melt pool and the change in the temperature field in multi-layer melt channel formation. The results of this study show that the multiscale numerical model of the SLM multilayer melt-channel-forming process has a reliable computational accuracy, with an average error of 6.77% for the melt pool length and 1.69% for the melt pool width; Marangoni convection effects increase the melt pool size, and the presence of pores significantly affects the evolution of the powder bed temperature field. With laser scanning and powder bed stacking, the overall temperature of the powder bed and the peak temperature of the molten pool gradually increased, and the length, width, and height dimensions of the molten pool increased by 44.9%, 21.7%, and 33.8%, respectively. [ABSTRACT FROM AUTHOR]

Sodium (Na) metal batteries (SMBs) have emerged as promising alternatives to lithium metal batteries for large-scale energy storage applications, owing to their cost-effectiveness, abundance, and favorable redox potential. However, the practical implementation of SMBs faces several challenges associated with the Na metal anode, including the formation of dendrites, low Coulombic efficiency, and capacity fading. Here, we propose a novel approach to enhance the electrochemical performance of Na metal anodes through a porous Al-Cu alloy host (PAC) fabricated by a local eutectic melting engineering. The local eutectic melting facilitates the development of a conductive network, offering mechanical support, and the porous structure provides abundant channels for the diffusion of Na ions and accommodates volume fluctuations in the Na metal during charge–discharge cycling. Moreover, the PAC exhibits a high average Coulombic efficiency of 99.8% at 1 mA·cm−2 for 1 mAh·cm−2 and a low voltage polarization of 19 mV during 500 cycles. This study provides valuable insight into the design and fabrication of high-performance Na metal anodes, which hold significant promise for the advancements of next-generation energy storage systems. [ABSTRACT FROM AUTHOR]

Ice shelves in the Amundsen Sea have experienced the most rapid melting in the Antarctic and are expected to accelerate throughout this century under climate warming. In this study, a high‐resolution ocean‐sea ice‐ice shelf model is employed to conduct sensitivity experiments to explore the effects of increasing melt rates of the Amundsen Sea ice shelves on hydrography, sea ice and ice shelf in the Ross Sea. The results indicate that the substantial inflow of meltwater significantly freshens the Ross Sea, inhibiting the formation and export of the Dense Shelf Water, the volume of which is reduced by 19%–33% on the shelf. Temperatures in the eastern and western Ross Sea exhibit different responses to the enhanced meltwater input. The freshening of the western Ross Sea weakens the mesoscale eddy activities which are efficient in carrying warm Circumpolar Deep Water onto the shelf, leading to an average temperature decrease of 0.02–0.08°C. Conversely, in the eastern Ross Sea, there is a marked warming outside the shelf under increased meltwater, which results from zonal pressure gradients associated with the meltwater distributions. This consequently causes stronger on‐shelf heat transport and shows warming of 0.12–0.22°C on the eastern Ross Sea shelf. The narrow shelf in the eastern Ross Sea allows the warmer water to reach the Ross Ice Shelf (RIS) front, resulting in an about 6%–9% increase in the RIS melting. These results suggest a possible mechanism for acceleration in the RIS melting in the future that is associated with enhanced meltwater inflow. Plain Language Summary: Many studies suggest that the Amundsen Sea ice shelf will experience accelerated melting throughout this century, leading to the release of a substantial amount of freshwater, which will be transported westward and impact the Ross Sea downstream. In this study, a numerical model including ocean, ice shelves and sea ice is used to simulate the effects of increased melting rates of the Amundsen Sea ice shelves on the Ross Sea ocean and ice environments. The results indicate pronounced differences in temperature changes in the eastern and western Ross Sea under enhanced meltwater input. The freshening of the western Ross Sea weakens the warm water intrude onto the shelf, resulting in cooling of the western Ross Sea. In the eastern Ross Sea, there is warming associated with changes in large‐scale flows caused by the distributions of meltwater. More heat transport into the eastern Ross Sea shelf can reach the front of the Ross Ice Shelf (RIS) — the largest Antarctic ice shelf and promotes its melting. Our study proposes a mechanism for acceleration in the RIS melting in the future, highlighting the role of meltwater from the Amundsen Sea ice shelves. Key Points: Enhanced Amundsen Sea ice shelf melting causes marked freshening of the Ross Sea and inhibits the formation of Antarctic Bottom WaterThe increased meltwater inflow from the Amundsen Sea causes cooling of the western Ross Sea and warming of the eastern Ross SeaMore heat transport into the eastern Ross Sea shelf can reach the front of the Ross Ice Shelf and increase its melting rate [ABSTRACT FROM AUTHOR]

In this study, lavender essential oil (LEO) was added to ice creams as ingredient at 0, 0.02, 0.05 and 0.1% ratios. Some physicochemical, viscosity, rheological, colorimetric, sensory properties, and pathogen inhibition, including L. monocytogenes ATCC 7644 and S. aureus ATCC 29213, of the ice cream samples with the LEO were investigated. It was determined that the melting rate of the ice creams with the LEO was lower (P<0.05) and the overrun values were higher (P<0.05) than the control sample. The highest L* and a* values were determined in the control samples and the sample with 0.1% LEO, respectively. While C* value of the sample with 0.02% LEO was higher than the other samples (P<0.05), the highest white index (WI) value was determined in the control and the sample with 0.01% LEO. The sample containing 0.01% LEO had the highest viscosity values at 20 and 50 rpm. It was determined that there was no statistically significant difference in the consistency coefficients of the samples (P>0.05) and all samples had pseudolplastic flow. The control sample had the highest sensory score, followed by the sample with 0.02% LEO. It was determined that the LEO addition only had a decreasing effect on the count of S. aureus ATCC 29213. [ABSTRACT FROM AUTHOR]

Plastic recyclates can be contaminated with a variety of impurities due to their previous life, which cannot always be perfectly separated in recycling pretreatment steps. Hence melt filtration is an important step in reprocessing plastic recyclates to achieve material of sufficient purity, but it also leads to more stress on the material due to higher pressures and longer processing times. In our study, we investigated the influence of typical particulate impurities as may occur in recyclate on the mechanical and rheological properties of ABS. Even low amounts of contaminations lowered the key properties. Melt filtration of post‐consumer ABS recyclate with different mesh size melt screens showed little improvement of mechanical properties, but longer idle times and loss of material. Damage to the material caused by finer filtration could be shown by thermal measurements. Highlights: Determination of properties of ABS contaminated with 0.5–2.0 wt.% of selected impurities (wood and rubber particles).Melt filtration of post‐consumer ABS recyclate with different melt screens.Investigation of process and properties of filtered ABS recyclate. [ABSTRACT FROM AUTHOR]

Mineralogy and chemical composition are the main indicators for selecting operational parameters for copper leaching from mineral resources and smelting furnace dust. The main goal of this research is to evaluate the dust composition of chalcopyrite concentrate smelting furnaces to improve copper leaching efficiency. In this regard, for four months, samples were taken daily from the dust of the smelting furnaces of Sarcheshme copper complex. Using X-ray diffraction analysis, X-ray fluorescence spectroscopy, scanning electron microscopy with energy dispersive spectroscopy, and reflective light microscopy, the composition of the samples was determined and leaching tests were designed and implemented to determine the main operational parameters. The results of this study showed that the grain size distribution of the samples did not change significantly during the sampling period, but the amount of some elements such as arsenic was varried and fluctuated between 0.17 and 3.90%. The changes of copper and iron were also about 2%. The results of leaching tests of flash furnace dust showed that the solid percentage, acid concentration and temperature are the most important operating parameters. Under the optimal operating conditions, about 65% of copper is dissolved without the use of an oxidizer within a maximum of 60 minutes. By using a two-stage electrochemical process, the conditions for extracting more than 95% of copper from flash furnace dust was provided. [ABSTRACT FROM AUTHOR]

Control of multicomponent alloys during welding is challenging because it lacks a real‐time understanding of composition. The optical emissions of plasma formed during laser‐induced metal welding correlate with the composition of particles ejected from the melt pool. Plasma emissions observed in this study contain large iron, manganese, chrome, and copper signatures, which match the composition of emitted particles. Particles recovered closest to the melt pool exhibit a core–shell morphology that is composed of iron‐manganese‐chrome intermetallic cores within copper shells. Particles collected farther from the melt pool, do not share this core–shell morphology, though similar elemental compositions are observed. The correlation between plasma optical emissions and particle composition can be used to predict the composition of the melt pool, allowing for real‐time welding and sintering control. [ABSTRACT FROM AUTHOR]

Heat transfer analysis of Casson nanofluid flow with single and multi-walled carbon nanotubes and Al2O3 or GO nanoparticles, which are suspended in kerosene oil, is elucidated. The impact of second slip conditions on the flow system’s velocity, temperature, and solutal is considered, along with the effect of melting heat transfer and nanoparticle shape factor. The appraisal’s novelty is the incorporation of second slip conditions on kerosene oil flow containing with new three distinct nanoparticles. Similar variables are used to convert the governing equations into ordinary equations which are then solved using homotopy perturbation method (HPM). The profiles of velocity, temperature, concentration, and Bejan number are estimated for various values of relevant parameters. Results demonstrate that the Bejan number declines due to enhance the first thermal parameter and second velocity parameter, while the contrary tendency is examined by raising the Casson fluid parameter and first velocity parameter. Al2O3-SWCNT-MWCNT TNF responds more strongly than GO-SWCNT-MWCNT TNF when the temperature is coupled with (nanoparticles volume fraction, first thermal parameter), axial velocity with (nanoparticles volume fraction, first velocity parameter, first thermal parameter), and Bejan number with melting parameter. This study is to help rocket engine designers identify the optimal nanofluids for cooling and fuel.

Global warming in tandem with surface albedo reduction caused by black carbon (BC) deposition on glaciers accelerated glacier melting; however, their respective contributions remain unclear. Glaciers in the Qilian Mountains are crucial for the development of oases in the Hexi Corridor; however, their area has decreased by more than 20% over the past half-century. Thus, this study developed a dynamic deposition model for light-absorbing particles (LAPs), coupled with a surface energy and mass balance model. We comprehensively assessed the effects of BC and warming on the melting of a typical glacier in the Qilian Mountains based on the coupled model. BC on the glacier surface caused 13.1% of annual glacier-wide melting, of which directly deposited atmospheric BC reduced the surface albedo by 0.02 and accounted for 9.1% of glacier melting. The air temperature during 2000–2010 has increased by 1.5 °C relative to that during the 1950s, accounting for 51.9% of current glacier melting. Meanwhile, BC emission have increased by 4.6 times compared to those of the early Industrial Revolution recorded in an ice core, accounting conservatively for 6.3% of current glacier melting. Mitigating BC emissions has a limited influence on current glacier melting; however, in the long-term, mitigation should exert a noteworthy impact on glacier melting through the self-purification of glaciers.

Abstract The effect of nanofluids on the melting process of PCMs (RT58 paraffin wax) in a rectangle container is a topic of interest for many researchers. The use of nanofluids in PCMs can lead to faster and more efficient melting, resulting in improved energy storage and cooling performance. This paper has studied four cases with varying percentages of nanofluids. The percentage of nanofluid in PCM can affect the material's thermal conductivity and heat transfer performance. By varying the percentage of nanofluids, researchers aim to optimize the use of these in PCMs to achieve the best melting performance. Findings have shown that increasing the percentage of nanofluids in PCM can lead to improved thermal conductivity and heat transfer performance. However, at high concentrations (30% percent), the viscosity of the nanofluid can increase, leading to a decrease in heat transfer performance. Results show that at 30 min, PCM with 30% nanofluid melts 13.79% more than PCM without. Using 20% nanofluid in the PCM results in a melting percentage of 7.41%, decreasing to 3.85% at 10%.The specific application and the type of nanofluid used determine the optimal concentration of nanofluid in PCMs. This study is important for the use of phase-change materials in the cooling of large electronic devices.

Development of new plasma facing components (PFC) draw attention of numerous scientific groups in fusion energy field. Tungsten as a main PFC material main have poor machinability, thus various designs were proposed to overcome this problem. However, such technologies as functional graded layers, sintering and additive technologies are limited in production size and have low cost-efficiency. This research considers the alternative approach of steel melt injection or melt infiltration of tungsten mesh. The results obtained establish the mechanism of phase evolution during interaction of solid W with liquid steel and iron. Energy dispersive spectroscopy, X-ray diffraction and Thermocalc calculations used to analyze the phase composition of tungsten wetted with various steels and pure iron. Results show that interaction rate significantly depends on melt temperature and overheating above its liquidus. Then the overheating exceeds 150 °C erosion of tungsten occur.