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Crude oil is a complex system with unique physical and chemical properties. One of the most important physical properties of crude oil is viscosity. This paper demonstrates that the temperature dependence of crude oil viscosity can be described using the universal scaling model for viscosity over a wide temperature range. For the first time, a correlation has been established between the API gravity of crude oil and the fragility index, which is a measure of viscosity change with temperature in the glass transition region. It has been demonstrated that this correlation can be replicated by a linear function: the higher the API gravity the lower the oil density and the poorer the oil forms an amorphous state. The temperature range has been determined, at which molecular cooperation in crude oil can occur. The obtained results allow us to estimate/predict the viscosity of any crude oil at low temperatures, correlated with the glass transition temperature, based on high temperature experimental measurements near the melting point. [ABSTRACT FROM AUTHOR]

In this study, the thermoforming formability of continuous glass fiber-reinforced polypropylene (CGFRPP) laminates below the melting temperature were investigated. The forming limits of CGFRPP laminates were explored using flexural tests, Erichsen tests and deep drawing tests. The failure mechanism of CGFRPP in thermoforming was investigated by observing typical failure specimens using a microscope. The results show that the flexural performance and Erichsen performance are optimal at 130 °C and 2 mm/min. At 160 °C and 100 mm/min, the deep drawing performance is optimal. The restriction of fibers by the matrix is affected by the deformation temperature, and the creation of defects is affected by the deformation rate. During forming, the CGFRPP laminates undergo shear and extrusion deformations, resulting in wrinkles, delamination, and fiber aggregation. [ABSTRACT FROM AUTHOR]

During electroslag remelting (ESR), high MgO contents are typically added to CaF 2 –CaO–Al 2 O 3 slag to control magnesium content in iron- and nickel-based alloys. The melting temperature and viscosity of ESR slag are pivotal for energy consumption, production efficiency, smooth operation, and ingot quality. However, there is currently a notable scarcity of research on the melting temperature and viscosity of CaF 2 –CaO–Al 2 O 3 –MgO slag with high MgO levels. Thus, the melting temperatures and viscosity of CaF 2 –CaO–Al 2 O 3 –MgO slags with varying MgO contents and CaO/Al 2 O 3 (C/A) ratios were investigated. The results show that as the MgO content increases from 7.83 % to 13.18 %, the final precipitation content of the MgO phase significantly increases, resulting in an increase in the melting temperature from 1306 °C to 1319 °C. With the increase in the C/A ratio from 0.86 to 1.16, the precipitation completion temperatures of the Ca 12 Al 14 F 2 O 32 and MgO phases significantly decrease and the MgAl 2 O 4 phase transforms into the CaO phase. Hence, the melting temperature decreases from 1329 °C to 1314 °C. Further increasing the C/A ratio to 1.40, the final precipitation content of the CaO phase increases, resulting in a decrease in the melting temperature from 1314 °C to 1282 °C. Moreover, as the MgO content and C/A ratio increase, the slag viscosity exhibits different change trends within various temperature ranges. This depends on which of the depolymerization of the slag structure and the precipitation and clustering of the MgO phase has a greater effect on the slag viscosity. [ABSTRACT FROM AUTHOR]

The increasing global population has intensified the demand for energy and food, leading to significant greenhouse gas (GHG) emissions from both sectors. To mitigate these impacts and achieve Sustainable Development Goals (SDGs), passive thermal storage methods, particularly using phase change materials (PCMs), have become crucial for enhancing energy efficiency and reducing GHG emissions across various industries. This paper discusses the state of the art of bio-based phase change materials (bio-PCMs), derived from animal fats and plant oils as sustainable alternatives to traditional paraffin-based PCMs, while addressing the challenges of developing bio-PCMs with suitable phase change properties for practical applications. A comprehensive process is proposed to convert bacon fats to bio-PCMs, which offer advantages such as non-toxicity, availability, cost-effectiveness, and stability, aligning with multiple SDGs. The synthesis process involves hydrolysis to break down fat molecules obtained from the extracted lipid, followed by three additional independent processes to further tune the phase change properties of PCMs. The esterification significantly decreases the phase transition temperatures while slightly improving latent heat; the UV-crosslinking moderately raises both the phase transition temperature and latent heat; the crystallization remarkably increases the both. The future research and guidelines are discussed to develop the large scale manufacturing with cost effectiveness, to optimize synthesis process by multiscale modeling, and to improve thermal conductivity and latent heat capacities at the same time. [ABSTRACT FROM AUTHOR]

We perform an assessment of the Li2O${\rm Li}_2{\rm O}$‐La2O3${\rm La}_2 {\rm O}_3$═ZrO2${\rm ZrO}_2$ phase diagram using an array of computational methods to address significant gaps in available experimental data at high‐temperatures, due to lithium loss and high reactivity with most materials, which poses significant containment challenges. Free energies of the solids are calculated via the quasi‐harmonic approximation (QHA) and thermodynamic integration, based on the density functional theory (DFT) simulations. Free energies of the liquids are modeled as regular solutions, with enthalpies of mixing calculated from DFT molecular dynamics simulations. The melting temperatures of Li2O${\rm Li}_2{\rm O}$, LiLaO2${\rm LiLaO}_2$, La2Zr2O7${\rm La}_2 {\rm Zr}_2 {\rm O}_7$, and Li7La3Zr2O12${\rm Li}_7 {\rm La}_3 {\rm Zr}_2 {\rm O}_{12}$ (LLZO) are calculated using the small‐size coexistence method. Free energies from prior experimental assessments are combined with our computational results to generate a CALculation of PHAse Diagram (CALPHAD) model and phase diagrams. [ABSTRACT FROM AUTHOR]

Hydrogels have the ability to retain large amounts of water within their three-dimensional polymer matrices. These attractive materials are used in medicine and the food industry; they can serve as the basis for structured food products, additives, and various ingredients. Gelatin is one of widely used biopolymers to create hydrogels that exhibit biocompatibility and tunable rheological properties. In this study, we offer a comparative analysis of rheological properties of gelatin-based hydrogels (C = 6.67%), including mammalian gelatins from bovine and porcine skins and fish gelatins from commercial samples and samples extracted from Atlantic cod skin. Mammalian gelatins provide high strength and elasticity to hydrogels. Their melting point lies in the range from 22 to 34 °C. Fish gelatin from cod skin also provides a high strength to hydrogels. Commercial fish gelatin forms weak gels exhibiting low viscoelastic properties and strength, as well as low thermal stability with a melting point of 7 °C. Gelatins were characterized basing on the analysis of amino acid composition, molecular weight distribution, and biopolymer secondary structure in gels. Our research provides a unique rheological comparison of mammalian and fish gelatin hydrogels as a tool for the re-evaluation of fish skin gelatin produced through circular processes. [ABSTRACT FROM AUTHOR]

This study aims to experimentally investigate the influence of several key factors, including basicity, Al2O3 content, TiO2 content, SiO2/Al2O3 ratio, and titanium reduction, on the melting properties of electric furnace slags containing titanium in the CaO–SiO2–MgO–Al2O3–50%TiO2 system. The findings revealed that the melting temperature decreased with an increase in the CaO/SiO2 ratio, Al2O3 content, and SiO2/Al2O3 ratio, while it increased with higher TiO2 content. To achieve a low melting temperature for the slags and an appropriate phase composition for titanium extraction, it is advisable to maintain a low CaO/SiO2 ratio within the range of 0.6–0.7, and an Al2O3 content of 13% is recommended. Higher TiO2 content is associated with elevated liquidus temperatures, while conversely, the SiO2/Al2O3 ratio exhibits an inverse relationship. Efforts were made to limit the titanium reduction during smelting to a maximum of 0.4. Anosovite (MgTi2O5), CaAl2Si2O8, Mg(Al, Ti)2O4, spinel (MgAl2O4), augite (Ca(Mg, Fe, Al) (Al, Si)2O6) and Ca12Al14O33 were the primary phases in titanium slag. The calculated viscosity results align with the trends observed in the melting property results. Furthermore, the liquidus temperatures were obtained through FactSage aligns with the pattern observed in the melting temperature. These findings will serve as a valuable technical foundation to support the development of the direct reduction smelting process for the comprehensive utilization of vanadium titanomagnetite. [ABSTRACT FROM AUTHOR]

In this approach, nanocomposites of PVDF/PMMA/CTAMag films have been successfully synthesized. Modified Maghnite was used as inorganic reinforcement. In this study, nanocomposite polymers were developed based on a mixed matrix of poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA) of composition (80/20 w/w) in dispersion containing 0, 1, 3, 5 and 7 wt % fillers of organomodified montmorillonite nanoclay (CTAMag) in the melt state. The results obtained by scanning electron microscopy (SEM), XRD traces and FTIR spectra highlighted the homogeneous flexible character of the PVDF/PMMA/CTAMag films and their intercalated and intercalated/exfoliated surface morphology, in addition to the presence of PVDF α, β and γ phase crystallites in these complex films. The increased presence of the modified clay in the host matrix of the PVDF/PMMA blend significantly influenced the melting temperature and the degree of crystallinity of the PVDF crystallites. The scattering of the dielectric spectra, which covers a wide range of frequencies from 20 Hz to 1 GHz, indicates the presence of the phenomenon of interfacial polarization associated with the dielectric capacitance complex at lower frequencies in these composites at 27 °C. The mechanical properties of these composites were evaluated as a function of the load and the mixed matrix of these composites. [ABSTRACT FROM AUTHOR]

Metal-mediated base pairs in DNA double helix molecules open up broad opportunities for biosensors based on DNA clusters with silver due to their low toxicity and applicability in drug design. Despite intensive experimental and computational research, molecular mechanisms of stabilization of a double helix by silver-mediated base pairs are mainly unknown. We conducted all-atom molecular dynamics simulations of a dodecameric DNA double helix (sequence 5′-TAGGTCAATACT-3′-3′ATCCACTTATGA-5′) with either cytosine–cytosine or cytosine–Ag+–cytosine mismatch in the center of the duplex. We extended the previously proposed set of interaction parameters for a silver ion in the silver-mediated pair in order to allow for its dissociation. With this new potential, we studied how the addition of a silver ion could stabilize a DNA double helix containing a single cytosine–cytosine mismatch. In particular, we found out that the helix with cytosine–Ag+–cytosine mismatch has a greater melting temperature than the helix with cytosine–cytosine one. This stabilization effect of the silver ion is in qualitative agreement with experimental data. The central region of the duplex with cytosine–Ag+–cytosine mismatch (unlike with cytosine–cytosine mismatch) is stable enough to prevent bubble formation at moderate temperatures during melting. The results of this simulation can be used to devise novel metal-mediated DNA structures. [ABSTRACT FROM AUTHOR]

ABSTRACT The FilmArray Pneumonia Panel (FilmArrayPN; bioMérieux) was tagged for potential false-positive seasonal coronavirus results, possibly caused by non-specific amplification or cross-reactivity with human genomic DNA. This study was conducted to determine the real-world false-positive rate of seasonal coronavirus infections using FilmArrayPN at a tertiary care hospital. We retrospectively reviewed FilmArrayPN results to detect lower respiratory tract pathogens from July 2023 to April 2024. Allplex Respiratory Panel (AllplexRP; Seegene) and/or FilmArray Respiratory Panel (FilmArrayRP) results for the same patient were considered as reference results. In the last month of the study period, all positive samples in FilmArrayPN were confirmed by AllplexRP and pan-coronavirus targeted PCR (pan-CoV PCR). A total of 2,120 specimens, including 1,847 expectorated sputum and 273 bronchial aspirate (BA) samples, were tested by FilmArrayPN. Of these, 161 (8.7%) sputum and 7 (2.6%) BA specimens from 152 patients were positive for coronavirus targets in FilmArrayPN. Of the 122 cases also tested by AllplexRP and/or FilmArrayRP, 106 specimens (86.9%) were coronavirus-negative, except for 9 OC43-positive, 6 229E-positive, and 1 NL63-positive. Notably, 83.1% of the 106 cases that tested negative in the other tests had melting temperatures above 83℃. A total of 61 specimens that tested positive for coronavirus in FilmArrayPN but negative in AllplexRP were confirmed to be negative in pan-CoV PCR. The coronavirus positivity of 7.8% in the FilmArrayPN resulted in 5% of samples being potentially misreported as false-positives. This report thus highlights the need for continuous monitoring of melting temperatures to avoid potential false-positives.IMPORTANCEThe FilmArray Pneumonia Panel (FilmArrayPN; bioMérieux) was tagged for potential false-positive seasonal coronavirus results, possibly caused by non-specific amplification or cross-reactivity with human genomic DNA. FilmArrayPN results were retrospectively reviewed from July 2023 to May 2024. Of 2,120 tested specimens, 168 specimens from 152 patients were positive for coronavirus targets in FilmArrayPN. Of the 122 cases also tested by Allplex Respiratory Panel and/or FilmArray Respiratory Panel, 106 specimens (86.9%) were coronavirus-negative. Notably, 83.1% of the 106 cases that tested negative in the other tests had melting temperatures above 83℃. A total of 61 specimens that tested positive for coronavirus in FilmArrayPN but negative in Allplex were confirmed to be negative in pan-coronavirus targeted PCR. The coronavirus positivity of 7.8% in the FilmArrayPN resulted in 5% of samples being potentially misreported as false-positives. This report highlights the need for continuous monitoring of melting temperatures to avoid potential false-positives.

The integration of ionic liquids and polymer composites has become a promising way to improve their thermal properties, representing a notable advancement in the development of advanced materials for specific applications. Their thermal properties heavily influence the suitability of polymer composites for particular applications. It is imperative to understand and manipulate the thermal behavior of these composites to optimize their performance across various fields. In this mini-review, diverse polymer matrices and fillers utilized in polymer composites containing ionic liquids are categorized. Additionally, various ionic liquids employed in studies related to the thermal properties of polymer composites are identified. The impact of ionic liquids on the thermal properties of these composites is also briefly reviewed. The knowledge illustrated in this review enriches the understanding of the types of polymer matrices and fillers used in conjunction with ionic liquids, as well as their thermal properties. In a nutshell, imidazolium-based ionic liquids with tetrafluoroborate, bis(trifluoromethylsulfonyl)imide, hexafluorophosphate, halides, and hydrogen sulfate anions have the impact of improving the glass transition temperature, melting temperature, degradation temperature, and thermal conductivity of thermoplastic, thermosetting, and elastomer composites.

Toward the construction of robotic and cybernetic systems with molecular reactions, development of a reaction that can rapidly generate single-stranded DNA (ssDNA) molecules in response to an input signal is an essential demand. This study explored the cascading of DNA generation reactions employing DNA polymerase and nicking endonuclease to achieve significant amplification of ssDNA molecules serving as signals to direct and fuel the operation of DNA-based systems. The modular architecture allows for interconnection with other reactions through primer-binding sequence or template design, making it adaptable to various molecular robotic components. The research aims to contribute to the development of efficient and reliable amplification circuits for molecular robotics and cybernetics. The cascading reactions, implemented up to three layers, exhibit enhanced amplification rates and sensitivities at physiological temperatures, enabling stable hybridization with complementary sequences. The investigation reveals the potential of the proposed approach to bridge the molecular quantity gap and restore signals in molecular systems including molecular robots and related applications. The experimental validation demonstrates the feasibility of achieving up to 100,000-fold amplification in response to low concentrations of primers within two hours, driving the structural transformation of DNA probes and nanomotors, while suppressing non-specific leak amplification, thereby showcasing practical applicability. The study's findings address fundamental challenges in ssDNA amplification and opens avenues for creating intelligent systems composed of molecular components with increased sensitivity and responsiveness. [ABSTRACT FROM AUTHOR]

The effects of liquid properties, such as pH and conductivity, on the thermal stability of electrostatically interacting colloidal silica crystals generated from heterogeneous nuclei were investigated mainly by measuring relative reflection spectra. The melting behavior of the colloidal crystals was also investigated. The melting points of both negatively and positively charged 3-aminopropyltriethoxysilane (APS)-treated substrates with different surface charges increased or decreased with increasing or decreasing pH. For both substrates, pH 5.5 was the modulation point of the crystal melting, and the melting point increased with increasing pH. For the negatively charged substrate, the melting point increased slowly as the pH decreased from pH 5.5. Meanwhile, the melting point of the APS-treated substrate increased more with decreasing pH from 5.5 than that of the negatively charged substrate. The cationisation of the substrate increased with decreasing pH, resulting in stronger electrostatic interactions with the negatively charged colloidal crystals and enhanced thermal stability. Next, we investigated the size of colloidal crystal grains in sample bottles for different liquid properties, and the results show that at the higher pH, the smaller crystal grains, indicating that pH affects both the substrates and crystals. Moreover, the binding effect of the APS-treated substrate on the crystals became stronger at lower pH, thereby enhancing the thermal stability of the crystals. [ABSTRACT FROM AUTHOR]

The Debye model has been developed to study the pressure dependence of the extended X-ray absorption fine structure Debye–Waller factor, the Debye frequency and temperature of hexagonal close-packed (hP2) metals. The effects of the non-ideal axial ratio c/a of hP2 structure on these thermodynamic quantities at high pressures have also been considered. Additionally, based on the combination of the Debye model and the Lindemann melting law, we derive the analytic expression of melting temperature of hP2 metals as a function of pressure. Numerical calculations have been implemented for Mg and Zn metals up to 20 and 50 GPa, respectively. We have shown that Debye frequency and temperature, as well as melting temperature of these two metals increase robustly with pressure and non-ideal axial ratio plays important role in these thermodynamic quantities. The remarkable consistency observed between our calculations and various experimental results validates the reliability of the currently presented melting curve. Meanwhile, at high pressure non-ideal axial ratio gives a small contribution to pressure-dependent Debye–Waller factor of Mg (up to 20 GPa) and Zn (beyond 20 GPa), and can be safely neglected in the suggested pressure range. [ABSTRACT FROM AUTHOR]

Freezing of water has a direct impact on the durability of cementitious materials, which include porous binding phases, like calcium-silicate-hydrate (CSH). Molecular dynamics (MD) simulations can capture behaviors of the water freezing in the pores and may give rise to insightful observations. In this work, the monoatomic water (mW) model and all-atom CSH model are combined to study low-temperature behavior of water molecules restricted within CSH layers. The developed model features good accuracy and accelerated computational rate, and is employed to study how ultra-confined water in CSH phases (≤6 nm) freezes. The threshold width of CSH gap that allows the stable existence of ice is 1.5 ± 0.1 nm. A non-icing layer with an average thickness of ∼0.65 nm exists ambient to CSH surface. The main factor affecting the melting point of confined water is the size of the confined space rather than the water filling fraction. The Gibbs-Thomson model is utilized to describe the relationship between the melting temperature and the width of the confined CSH layers. The utilization of this modeling technique presents a novel approach to replicate the freezing process of nanostructures in cementitious composites subjected to low-temperature erosion. [ABSTRACT FROM AUTHOR]

A numerical modeling methodology based on the finite element method is utilized in this investigation to predict the impact of the PCM characteristics on the system cooling performance and the solar module output power. The thermal analysis considers the transient nature and the nonlinearity of the problem. The boundary conditions include the cyclic variation with time of solar irradiance and ambient temperature in a hot climatic region, with peak temperatures close to 50 °C. Under these circumstances and owing to the various influencing parameters, choosing an appropriate PCM is a challenging task. By allowing the PCM characteristics to vary continuously over the applicable domains and not just by giving specified discrete values, a systematic approach is adopted in this work. This technique is applied to explore the relationships between system input parameters, as defined by the PCM properties, and output variables, as described by cell temperature and module efficiency. Due to the harsh boundary conditions, the obtained results demonstrated that PCM with high thermal conductivity is required to achieve efficient thermal regulation. The enhanced material characteristics can only be provided by composite PCMs with graphite or metal additives. The resulting optimized design variables of the suitable PCM, melting temperature, thermal conductivity, and thickness, can reduce the cell temperature to 57 °C (20% reduction). The corresponding efficiency and power output are raised by around 8%. The power output was found to increase from 125 W (reference case) to 135 W for the optimized case. The results suggest that using a passive cooling system based on PCM is a viable method for enhancing the power output of a solar PV module. The created coupled model predicts the thermal behavior of the PV module and significantly facilitates the PCM selection procedure to ensure its applicability. [ABSTRACT FROM AUTHOR]

The molecular dynamics simulation method with the embedded atom model/Finnis-Sinclair potential was used to investigate solid and hollow spherical platinum (Pt) nanoparticles under different heating rates during the additive manufacturing process. We concluded that the coalescence temperatures of solid and hollow spherical Pt nanoparticles range between 975 and 1450 K and between 561 and 1414 K, respectively. We concluded also that the melting temperatures of solid and hollow spherical Pt nanoparticles range between 1300 and 1535 K and between 1250 and 1500 K, respectively. In this study, we found that the lower the heating rate, the greater the diffusion of Pt atoms. The solid-state sintering of Pt nanoparticles can spontaneously occur at 300 K. We concluded that the melting temperatures of both solid and hollow spherical Pt nanoparticles are still lower than the macroscopic melting point of Pt (2041.4 K). [ABSTRACT FROM AUTHOR]

Methicillin-resistant Staphylococcus aureus (MRSA) infection has rapidly spread through various routes. A genomic analysis of clinical MRSA samples revealed an unknown protein, Sav2152, predicted to be a haloacid dehalogenase (HAD)-like hydrolase, making it a potential candidate for a novel drug target. In this study, we determined the crystal structure of Sav2152, which consists of a C2-type cap domain and a core domain. The core domain contains four motifs involved in phosphatase activity that depend on the presence of Mg2+ ions. Specifically, residues D10, D12, and D233, which closely correspond to key residues in structurally homolog proteins, are responsible for binding to the metal ion and are known to play critical roles in phosphatase activity. Our findings indicate that the Mg2+ ion known to stabilize local regions surrounding it, however, paradoxically, destabilizes the local region. Through mutant screening, we identified D10 and D12 as crucial residues for metal binding and maintaining structural stability via various uncharacterized intra-protein interactions, respectively. Substituting D10 with Ala effectively prevents the interaction with Mg2+ ions. The mutation of D12 disrupts important structural associations mediated by D12, leading to a decrease in the stability of Sav2152 and an enhancement in binding affinity to Mg2+ ions. Additionally, our study revealed that D237 can replace D12 and retain phosphatase activity. In summary, our work uncovers the novel role of metal ions in HAD-like phosphatase activity. [ABSTRACT FROM AUTHOR]

The thermal stability of DNA immobilized on a solid surface is one of the factors that affects the efficiency of solid-phase amplification (SP-PCR). Although variable temperature amplification ensures high specificity of the reaction by precisely controlling temperature changes, excessively high temperatures during denaturation can negatively affect DNA stability. Formamide (FA) enables DNA denaturation at lower temperatures, showing potential for SP-PCR. Research on FA's impacts on DNA microarrays is still limited, necessitating further optimization in exploring the characteristics of FA in SP-PCR according to particular application needs. We immobilized DNA on a chip using a crosslinker and generated DNA microarrays through bridge amplification based on FA denaturation on our automated reaction device. We optimized the denaturation and hybridization parameters of FA, achieving a maximum cluster density of 2.83 × 104 colonies/mm2. Compared to high-temperature denaturation, FA denaturation required a lower template concentration and milder reaction conditions and produced higher cluster density, demonstrating that FA effectively improves hybridization rates on surfaces. Regarding the immobilized DNA stability, the FA group exhibited a 45% loss of DNA, resulting in a 15% higher DNA retention rate compared to the high-temperature group, indicating that FA can better maintain DNA stability. Our study suggests that using FA improves the immobilized DNA stability and amplification efficiency in SP-PCR. [ABSTRACT FROM AUTHOR]

This article presents the results of studies of 15 low-melting borosilicate glasses of different compositions using the simplex-based method of mathematical planning. For each glass, the melting temperature and uniformity, as well as the rate and degree of leaching are determined in accordance with GOST (State Standard) R 52126–2003 [1] and NP-019-2015 [2]. Mathematical models are built based on the data obtained. As a result of the research, the most promising area for further research and development of the composition of borosilicate glass for a removable small-sized melter designed by Mayak Production Association is identified. [ABSTRACT FROM AUTHOR]

The results of laboratory measurements of the transparency of fresh ice blocks in the optical range in the temperature range from –15 to 0°C are presented. The studies were performed at two wavelengths in the visible range (at a wavelength of 535 nm) and the ultraviolet range (at a wavelength of 370 nm). We studied the ice of a natural fresh water body with a characteristic predominant spatial orientation of the main optical axis of the crystals. It has been established that when approaching a temperature of 0°, the sample becomes bleaching (decrease in attenuation). The effect occurs in the range –0.5–0°C. It is determined by the occurrence of plastic deformation due to thermal stresses caused by the initial stage of the ice-water phase transition. The bleaching in experiments with ice blocks ~10 cm thick was 3–25%. The results obtained are of interest for solving remote sensing problems, since melting ice is a widespread object due to its significant heat of phase transition. Previously, the effect of bleaching of fresh ice was also discovered in the microwave range when the temperature of the sample approached the phase transition point. [ABSTRACT FROM AUTHOR]

Composite film samples of polylactide-natural rubber with a rubber content of 5, 10, and 15 wt % were obtained by the solution method. The study of their morphology shows the presence of rubber inclusions in the form of drops in the polylactide matrix. The thermophysical characteristics are determined by differential scanning calorimetry (DSC). It is determined that when rubber is added and the peak of cold crystallization of polylactide (PLA) disappears on the melting thermograms, the melting temperature decreases by 1–4°C compared to 100% PLA. The structure of the obtained compositions is studied by nuclear magnetic resonance, electron paramagnetic resonance (EPR), and X-ray diffraction. The diffraction patterns of the samples contain reflections characteristic of the crystalline α-form of PLA. [ABSTRACT FROM AUTHOR]

Stable flow and discharge of the slag in an entrained flow gasifier are the key factors to ensure the long-term stable operation of gasifier. In this work, the melting and flow behavior of coal ash with different Fe2O3/SiO2 ratios was studied in a reduced atmosphere. The results show that the viscosity of slag decreases significantly with the increase of Fe2O3/SiO2. And the critical viscosity-temperature (TCV) decreases from 1309°C to 1226°C. It is found that more than 90% of iron ions exist in the form of Fe2+ in liquid slag by chemical titration. There are more simple ion clusters with low bridge oxygen number (BO) with the increase of Fe2+ and lead to depolymerization of slag. Furthermore, the ash with high SiO2 content can be transformed into slag with high viscosity at a low melting rate by the analysis of the slag area curve and X-ray diffraction pattern, which is considered to be controlled by the "softening-melting" mechanism. The ash with high Fe2O3/SiO2 can be transformed rapidly into a low viscosity liquid at a short melting interval, which follows the "melting-dissolution" mechanism. And it is helpful to promote the formation of low-temperature eutectics with the increase in Fe2O3/SiO2 by thermodynamic calculation. Research on the melting mechanism of slag will provide theoretical support for the regulation of slag flow characteristics. [ABSTRACT FROM AUTHOR]

The melting temperature serves as a pivotal physical property governing the thermal stability of metallic nanocrystals, notably exhibiting substantial variability with respect to size and dimensionality. While several quantitative models exist to elucidate how the melting temperature correlates with the size and dimensionality of metallic nanocrystals, these models often fall short of capturing the synergistic influence of both factors comprehensively. To address this gap, our study employs a novel thermodynamic framework grounded in cohesive energy theory, requiring no arbitrary adjustable parameters. We find that, under constant conditions, the melting temperature of metallic nanocrystals diminishes as their size decreases. In terms of dimensionality, we establish a hierarchy as follows: nanoparticles > nanowires > thin films. Moreover, we reveal a non-linear relationship between the melting temperature and the inverse of dimensionality. Through rigorous validation via both simulations and empirical experiments, we corroborate the high accuracy of this thermodynamic model in predicting the variations in the melting temperature of metallic nanocrystals due to changes in size and dimensionality. The model in this study is primarily applicable to metallic nanocrystals and the potential applicability to other types of nanocrystals under certain conditions is briefly mentioned..

The soil freezing-thawing characteristic curve (FTCC) can reflect the physical and mechanical properties of soil–water system during freezing-thawing (FT) process, which is of guiding significance to the study of soil moisture, heat and matter transport in cold regions. In this study, firstly, according to the evolution law of freezing-thawing hysteresis with freezing-thawing process, revealing the hysteresis mechanisms at different stages based on ice-water transformation theory. The freezing-thawing hysteresis can be divided into four stages as temperature decreasing. The hysteresis of the first three stages are due to nucleation and electrolyte effects, capillarity and pore clogging effects, structural damage effect, respectively; and the last stage is extremely weak and can be ignored. Secondly, evaluating freezing-thawing curves of soil–water system with three pore structures (cylindrical, spherical, and sphere-cylinder binary pore) based on the thermodynamic theory, quantitatively. The upper and lower boundaries of the freezing/thawing characteristic curve with natural pores are those with idealized cylindrical and spherical pores, respectively. Finally, the evaluation index (i.e., hysteresis degree) was introduced to quantitatively describe the variation of unfrozen water hysteresis degree with freezing-thawing process. The relationship between the unfrozen water hysteresis degree and temperature can be divided into four stages. The maximum hysteresis degree was found in the second stage, indicating that hysteresis was most significant in the second stage, followed by the first, third, and fourth stages. Our results provide theoretical support for studying hydrothermal characteristics and water, heat, and solute transport of geotechnical materials in seasonally frozen regions.

The melting point is a fundamental property that is time-consuming to measure or compute, thus hindering high-throughput analyses of melting relations and phase diagrams over large sets of candidate compounds. To address this, we build a machine learning model, trained on a database of ∼10,000 compounds, that can predict the melting temperature in a fraction of a second. The model, made publicly available online, features graph neural network and residual neural network architectures. We demonstrate the model's usefulness in diverse applications. For the purpose of materials design and discovery, we show that it can quickly discover novel multicomponent materials with high melting points. These predictions are confirmed by density functional theory calculations and experimentally validated. In an application to planetary science and geology, we employ the model to analyze the melting temperatures of ∼4,800 minerals to uncover correlations relevant to the study of mineral evolution.

The possibility of obtaining a new alternative source of clay raw materials for making ceramic materials based on muddy deposits, possessing functional properties, from reservoirs is considered. The physicochemical properties of sediments from the muddy bottom of the Tuyamuyun reservoir in Uzbekistan were studied. It was found that the ceramic bodies developed based on the dual muddy-kaolin composition can be used to produce ceramic materials intended for construction. [ABSTRACT FROM AUTHOR]

Mastering selective molecule trafficking across human cell membranes poses a formidable challenge in healthcare biotechnology while offering the prospect of breakthroughs in drug delivery, gene therapy, and diagnostic imaging. The cholera toxin B-subunit (CTB) has the potential to be a useful cargo transporter for these applications. CTB is a robust protein that is amenable to reengineering for diverse applications; however, protein redesign has mostly focused on modifications of the N- and C-termini of the protein. Exploiting the full power of rational redesign requires a detailed understanding of the contributions of the surface residues to protein stability and binding activity. Here, we employed Rosetta-based computational saturation scans on 58 surface residues of CTB, including the GM1 binding site, to analyze both ligand-bound and ligand-free structures to decipher mutational effects on protein stability and GM1 affinity. Complimentary experimental results from differential scanning fluorimetry and isothermal titration calorimetry provided melting temperatures and GM1 binding affinities for 40 alanine mutants among these positions. The results showed that CTB can accommodate diverse mutations while maintaining its stability and ligand binding affinity. These mutations could potentially allow modification of the oligosaccharide binding specificity to change its cellular targeting, alter the B-subunit intracellular routing, or impact its shelf-life and in vivo half-life through changes to protein stability. We anticipate that the mutational space maps presented here will serve as a cornerstone for future CTB redesigns, paving the way for the development of innovative biotechnological tools. [ABSTRACT FROM AUTHOR]

Thermal fluctuations, which occur in extreme climatic condition, increase the energy consumption of building. To solve the above issue, thermal insulation materials, which are used commonly in the current practice possess several practical limitations and issues such as reduction of net floor area, increase in dead weight of building, susceptibility to deterioration, and variation in thermal conductivity with changes in humidity and temperature. Hence, to address the above issues, this study mainly focuses to use low thermal conductive and high heat storage phase change material (PCM) in building. In order to get the maximum surface area of PCM, it is incorporated in cement mortar for non-structural applications in building. The micro-encapsulated phase change material (MPCM) used in the study has phase change temperature of 28°C, and latent energy of 183 kJ/kg. It is incorporated in mortar to replace some of the fine aggregate (5 and 10% by weight) to find its effects on mechanical and thermal properties. From the test results on mechanical behaviour, it is observed that incorporation of 10% MPCM by weight of fine aggregate reduced compressive strength by 70% and flexural strength by 61%. However, the achieved strength of MPCM incorporated mortar is sufficient for non-structural applications. Also, it was observed that 10% MPCM added to mortar decreased its thermal conductivity by 22%, increasing the material's thermal insulation. In addition, 10% MPCM incorporated mortar having 1 m2 surface area and 10 mm thick can store 246 kJ heat energy, which will further improve thermal comfort in building. Further, from thermal stability analysis of MPCM, it is observed that MPCM has no effect on thermal stability of mortar up to 250°C. Adding to above, the results of economic analysis are also found to be promising as the payback period of incorporated MPCM varies approximately from 4.54 to 7.56 years based on 100% to 60% utilization period in a year. [ABSTRACT FROM AUTHOR]

Some physical properties of AlNi alloy, which is known to be suitable for high-temperature applications, were analyzed theoretically by the DFT method under pressure. Structural parameters were calculated by fitting the Murnaghan equation, and the variation of lattice constant and volume values with pressure increase was determined. Mechanical properties were analyzed by the stress–strain method, and their changes with pressure were determined. Young's modulus, shear modulus, and Poisson's ratio anisotropy properties as mechanical properties were evaluated with the EIAM program in 2D and 3D. The electronic properties and the mechanical properties of the AlNi alloy were emphasized. The charge density and bond structure of the AlNi alloy were evaluated. By determining the vibration properties, it was concluded that the AlNi alloy is dynamically stable at 0 GPa and 50 GPa. [ABSTRACT FROM AUTHOR]

Fluoride is one of components of the traditional mold flux, but it causes environmental pollution. With the increasing requirement of environmental protection on the metallurgical industry, it is a trend to develop low fluorine or fluorine-free mold fluxes in the future. In recent years, many scholars have researched some low fluorine or fluorine-free mold fluxes. However, because the action mechanism of fluorine in mold flux is not completely clear, the performance of mold fluxes composed of fluorine-substituting components has not reached the effect of fluorine-containing mold fluxes. In view of this, this paper summarizes the effects of fluorine in protective slag from macro and micro aspects: in the study of the macro properties of mold flux, it is generally believed that a certain amount of fluorine plays an important role in adjusting the melting temperature, viscosity and surface tension of mold flux, but its adjusting mechanism is not clear; in terms of microstructure, the structural behavior of fluorine in mold flux is very complicated due to the influence of alkalinity, other components and fluorine content. The microstructure of slag determines the properties of slag. Therefore, the complexity of the structural behavior of fluorine leads to the complexity of the transformation mechanism of the physical properties of mold flux, which makes it impossible to control the properties of mold flux fundamentally and increases the difficulty in selecting the alternative component of fluorine in the process of developing low fluorine or fluorine-free mold flux. Therefore, it is necessary to further study the influence mechanism of fluorine on the structure of mold flux. [ABSTRACT FROM AUTHOR]

Copyright of Iron Steel Vanadium Titanium is the property of Iron Steel Vanadium Titanium Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of EMERG: Energy. Environment. Efficiency. Resources. Globalization is the property of Romanian National Committee of World Energy Council and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The models developed in this work are used to study various thermodynamic properties of nanomaterials. A better agreement between theory and experiment indicates the validity of the proposed model. Since the model is simple and easy to use, we extend the theory to understand, how the thermodynamic properties of different nanomaterials depend on size and shape. The results were compared with previous theoretical work and experimental data. We have concluded that the model predicts a better agreement with previous theoretical work and experimental studies. Current research produces thermodynamic models for the Debye frequency, melting entropy, melting enthalpy, and Einstein temperature. To the best of our knowledge, such models are not yet available in the literature that works well.

The Gd2O3 – GdSrFeO4 pseudo-binary phase diagram is presented for the first time. The liquidus and eutectic temperatures, metatectic points of the Gd2O3 transformations in the Gd2O3 – GdSrFeO4 section were defined using the Schröder–Le Chatelier equation, neglecting the effect of the isobaric heat capacity. The calculations were based on experimental data on the melting points of the end-members and the eutectic composition. From the results of phase relationships studies (subsolidus and high temperature region including literature data as well) and the above approach the Gd2O3–GdSrFeO4 pseudo-binary phase diagram in the temperature range 1400–2410 °C in air was constructed.It was shown that GdSrFeO4 of the K2NiF4- type is stable from 1100°С to a congruent melting temperature of 1560°С in air. The Gd2O3 – GdSrFeO4 system is eutectic with no intermediate compounds.

Metal-mediated base pairs in DNA double helix molecules open up broad opportunities for biosensors based on DNA clusters with silver due to their low toxicity and applicability in drug design. Despite intensive experimental and computational research, molecular mechanisms of stabilization of a double helix by silver-mediated base pairs are mainly unknown. We conducted all-atom molecular dynamics simulations of a dodecameric DNA double helix (sequence 5′-TAGGTCAATACT-3′-3′ATCCACTTATGA-5′) with either cytosine–cytosine or cytosine–Ag+–cytosine mismatch in the center of the duplex. We extended the previously proposed set of interaction parameters for a silver ion in the silver-mediated pair in order to allow for its dissociation. With this new potential, we studied how the addition of a silver ion could stabilize a DNA double helix containing a single cytosine–cytosine mismatch. In particular, we found out that the helix with cytosine–Ag+–cytosine mismatch has a greater melting temperature than the helix with cytosine–cytosine one. This stabilization effect of the silver ion is in qualitative agreement with experimental data. The central region of the duplex with cytosine–Ag+–cytosine mismatch (unlike with cytosine–cytosine mismatch) is stable enough to prevent bubble formation at moderate temperatures during melting. The results of this simulation can be used to devise novel metal-mediated DNA structures.

For long time, Sn-Pb solder alloys have been used extensively as the main interconnection materials in the soldering. It is no doubt that Sn-Pb offers many advantages including good electrical conductivity, mechanical properties as well as low melting temperature. However, Pb is very toxic and Pb usage poses risk to human health and environments. Owing to this, the usage of Pb in the electronic industry was banned and restricted by the legislation. These factors accelerate the efforts in finding suitable replacement for solder alloy and thus lead-free solder was introduced. The major problems associated with lead-free solder is the formation of large and brittle intermetallic compound which have given a rise to the reliability issues. Micro alloying with Sb seems to be advantageous in improving the properties of existing lead-free solder alloy. Thus, this paper reviews the influence of Sb addition to the lead-free solder alloy in terms of microstructure formations and thermal properties.

The loss of boron (B) in the rack plate steel during the electroslag remelting process has a significant impact on its mechanical properties. Therefore, it is necessary to design appropriate slags to suppress the loss of B. CaF2–CaO–Al2O3 phase diagram was calculated to determine the basic slag. The influence of MgO and B2O3 on the performance of the basic slag was studied to determine the optimal amount of MgO addition. The equilibrium reactions between rack plate steel and the 50.48 mass% CaF2–24.81 mass% CaO–24.71 mass% Al2O3–2 mass% MgO-y mass% B2O3 (y was 1–10) slag were studied to examine the variation in B content in the steel. Results indicate the presence of a temperature-qualified eutectic point in the CaF2–CaO–Al2O3 phase diagram. With an increase in MgO content in the slag, the melting temperature of the basic slag initially decreases and then increases, while the electrical conductivity decreases. On the other hand, B2O3 reduces the melting point of the slag and increases the equilibrium B content in the steel. The 50.48 mass% CaF2–24.81 mass% CaO–24.71 mass% Al2O3–2 mass% MgO-y mass% B2O3 (y was 5–7) slag can achieve the target range of B content in the steel, and its viscosity meets the requirements of electric slag remelting.

The aim of this work was to develop a new, automated method for the detection of solid-liquid phase transitions in the presence of high-pressure carbon dioxide. This is allowed because of the dissolution of the medium in the sample during the solid-liquid-gas equilibrium measurement. The pressure of an empty reference cell and one containing a solid sample is compared by a differential pressure transmitter. A gradual heating program is conducted after their equal pressurization. The solid-liquid transition of the sample is marked by a sharp decrease in the pressure of the sample holder (compared to the reference cell). A processing algorithm for the recorded time – temperature – pressure-difference data was implemented, to determine the melting temperature range accurately and automatically. The apparatus was validated with racemic ibuprofen and benzoic acid, and provides a new, objective, and easy-to-automate alternative to determine the melting temperature in high-pressure carbon dioxide.

A lattice volume-based model is derived to calculate the nanosize-dependent melting temperature of solids T r in the simplest form of T r = T ∞ × Δ V r Δ V c , where T ∞ , Δ V r , Δ V c are bulk melting temperature, nanosize dependence in the lattice volume change and its maximum change in which at, the solids are melted at zero Kelvin. The equation is applicable to calculate the nanosize dependence of melting temperature for the nanoscale size down to the material's critical radius of 1.2 nm. Accordingly, the nanosize dependence melting temperature calculations for the entire range from that of the bulk state down to the critical size for Au nanoparticles are confirmed with those of the experimental data. This model confirms well to 10 nm size particles and less where other models are not, the size range in which the solids have its most sensitive dependence of thermodynamic, mechanic, and optoelectronic properties. The model also confirms the nanosize dependence reported in experimental data for Ag, Al, Bi, In, Pb, and Cu particles. Equations to calculate nanosize dependence of cohesive energy, Debye temperature, vibrational entropy, and enthalpy of melting for metallic particles are accordingly modified and applied on Au and Cu nanoscale sizes. [ABSTRACT FROM AUTHOR]

Red mud produced from the Bayer process was used for the high temperature metallurgical processing of ilmenite. The major components of the red mud were Fe2O3, Al2O3, Na2O, and TiO2, which play important roles in the flux material. The process temperature of ilmenite slag was lowered from 1794 K (1521°C) to 1687 K (1414°C), as a preliminary study by a high-temperature microscope. Thermochemical calculations using FactSageTM 7.0 confirmed the effect of red mud on the lowered melting temperature of ilmenite slag. The discrepancy between the observed results of the microscope and the calculated phase diagram was due to the slag viscosity, which was significantly affected by Al2O3 in red mud. The reduction of ilmenite at lower temperatures by the addition of red mud was investigated at 1723 K (1450°C). Ilmenite, pseudobrookite, and associated clay minerals were the major phases in the reduced ilmenites which was confirmed by X-ray diffraction (×RD) analysis. Microscopic images obtained by scanning electron microscopy (SEM) showed variations in the pseudobrookite phases according to the amount of fluxed red mud. The benefits of red mud utilization are discussed with regard to the lower energy consumption and recovery of resources. [ABSTRACT FROM AUTHOR]

Poly(vinyl alcohol) (PVA) is used in various fields as a degradable polymer with excellent physical properties. However, poor thermal processability impedes its development. Herein, cellulose nanofibers (CNFs) are added to the PVA matrix to form strong hydrogen bonding with molecular chains and achieve melt-processing of PVA under the synergy of plasticizers. Specifically, a facile but efficient mechanical exfoliation method with the aid of organic stone waste (OSW) is designed to realize scalable manufacturing of CNFs. As an industrial by-product, OSW has abundant oxygen-containing groups on the surface, which can interact with cellulose and enhance the shear and friction force of cellulose during the mechanical exfoliation process. The resulting CNFs with an average diameter of 33.85 nm can significantly expand the melt-processing window of PVA to 66.6 °C, and benefiting from the nucleation effect of CNFs, the grain size of the composite material is refined. The tensile strength of resulting composites is significantly improved by 72.5% with the incorporation of 10 wt% CNFs. This strategy not only opens up scalable manufacturing of CNFs but also provides a new path for PVA melt-processing. [ABSTRACT FROM AUTHOR]

We have developed an analytical method to quantitatively analyze differential scanning calorimetry (DSC) experimental data. This method provides accurate determination of thermal properties such as equilibrium melting temperature, latent heat, change of heat capacity which can be performed automatically without intervention of a DSC operator. DSC is one of the best techniques to determine the thermal properties of materials. However, the accuracy of the transition temperature and enthalpy change can be affected by artifacts caused by the instrumentation, sampling, and the DSC analysis methods which are based on graphical constructions. In the present study, an analytical function (DSCN(T)) has been developed based on an assumed Arrhenius crystal size distribution together with instrumental and sample-related peak broadening. The DSCN(T) function was successfully applied to fit the experimental data of a substantial number of calibration and new unknown samples, including samples with an obvious asymmetry of the melting peak, yielding the thermal characteristics such as melting and glass transition temperature, and enthalpy and heat capacity change. It also allows very accurate analysis of binary systems with two distinct but severely overlapping peaks and samples that include a cold crystallization before melting. [ABSTRACT FROM AUTHOR]