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Glass-ceramic coatings with different Al 2 O 3 content were prepared for oxidation protection of 06Ni9DR alloy steel. The microstructure and oxidation protection rate of coatings with different content of Al 2 O 3 at 1200 °C were investigated. The results showed that the average internal pore size decreased with Al 2 O 3 content and the protection of the coating increased after oxidation test for 3 h. The oxidation protection rate of coating with 20 wt% Al 2 O 3 was the worst due to many large-size pores in the coating and bad thermal stability, and the melting of FeO into the liquid phase accelerated the formation of cracks inside the steel and further deteriorate the oxidation protection. As the alumina content increased, the liquid phase in the coating significantly decreased, and correspondingly the thermal stability increased; At the same time, a large number of 0.5–3 μm pores were formed in the coating, which effectively prolonged the oxygen diffusion path, further enhanced the oxidation resistance of the coating. The glass-ceramic coating with 80 wt% Al 2 O 3 exhibited good oxidation protection, reaching 73.6 ± 1.6 % at 1200 °C for 3 h. [ABSTRACT FROM AUTHOR]

This paper proposes a novel strategy to fabricate porous calcium hex-aluminate (CA 6) ceramics using CaCl 2 -KCl as reactive medium. Effects of CaCl 2 -KCl content and sintering temperature on microstructure and properties of porous CA 6 ceramics are systematically studied. CaCl 2 -KCl serves as both a pore former and an additional source of CaO, eliminating the need for additional salt-washing treatment. By optimizing CaCl 2 -KCl content to 20 wt%, porous CA 6 ceramics with well cross-interlocking plate-like structures, possessing low thermal conductivity of 0.32 W·(m·K)−1 (1000°C), high apparent porosity of 68.28%, and desirable compressive strength of 6.76 MPa, are fabricated at 1300°C. This work not only validates the promising applicability of porous CA 6 materials for thermal insulation, but also introduces an auspicious fabrication methodology for thermal insulation materials. [ABSTRACT FROM AUTHOR]

Results of investigating the emissivity of metals of group II of the Periodic Table in the interval of temperatures "solid body–liquid" have been presented. Selection of the objects of investigation, i.e., metallic beryllium, magnesium, and calcium, has been argued by the absence, in practice, of data on the emissivity of these elements in a broad temperature range from periodic and reference literature. The measurement method was radiative, and the technique of heating of a metal specimen, resistive. A structure of a cylindrical model of an ideal black body with an emissivity factor no lower than 0.99 has been presented. The material of the equilibrium-radiation source was metallic tantalum. The estimate of experimental uncertainty amounted to 5–8%. Graphic illustrations of experimental results on each investigated element have been presented. The obtained complex experimental data on normal integral emissivity within the limits of each phase of state of the metals grew monotonically. In the region of phase transition of the first kind, the characteristic abrupt change in the emissivity of the metals was observed. Investigation results have been discussed and compared with the literature data of other authors. A theoretical calculation of the emissivity of these metals from the classical electromagnetic theory has been carried out with the Foot approximation. The conclusion has been drawn on the disagreement between the theoretical calculations on emissivity and the experimental data. [ABSTRACT FROM AUTHOR]

An algorithm for finding the parameters of equations of state is described. The proposed algorithm is based on the particle swarm optimization method, which is applied to three simple models based on the van der Waals equation (in the form of the dependence of pressure on specific volume and temperature) and two of its modifications. [ABSTRACT FROM AUTHOR]

Considerable scientific effort has been devoted to comprehending welding processes and establishing correlations between structure and properties in crystalline metals and alloys' welded joints. However, welding of bulk-metallic glasses (BMGs) presents unique challenges. The weldability of these glasses is complex due to their lack of long-range order and high propensity to crystallization. BMGs are joined through either supercooled-liquid-phase or liquid-phase welding techniques. To maintain the integrity of the glassy structure, it is imperative to meticulously control the welding temperature and duration during supercooled-liquid-phase welding to prevent crystallization or ensure a sufficiently rapid cooling rate in liquid-phase welding to suppress solidification. In most cases, the presence of crystalline phases adversely affects the mechanical and physical properties of the joints. This review article describes and critically analyzes the key aspects influencing BMG welding and the correlations between the welding conditions and BMG joint properties. The fundamental knowledge to understand the welding of BMGs is presented, and the many welding methods used are discussed. The review also offers recommendations for various opportunities and new directions for advancing the field of BMG welding. [ABSTRACT FROM AUTHOR]

For studying the corrosion behavior and mechanism of tubing in high temperature and pressure vapor-liquid phase of H2S/CO2 coexistence system, the dynamic corrosion simulation experiment of P110 steel for oil casing in CO2/H2S coexisting system was carried out using the high temperature autoclave. The uniform corrosion rates and pitting corrosion rates of samples were calculated by the weight loss method, and the corrosion behavior characteristics of P110 steel in liquid phase and gas phase of CO2/H2S coexistence system were analyzed and studied by XRD, SEM/EDS and 3D optical profile microscope. Results showed that the uniform corrosion rate and pitting corrosion rate of P110 steel in the liquid phase environment were 0.026 3 and 0.208 1 mm/a, respectively, which were higher than the uniform corrosion rate(0.014 8 mm/a) and pitting corrosion rate(0.156 9 mm/a) of P110 steel in the gas phase environment. Moreover, the corrosion products formed on the surface of P110 steel in the liquid phase environment were mainly red-brown powdery loose FeCO3, and the corrosion products formed on the surface of P110 steel in the gas phase were mainly FeCO3 and black-brown dense and uniform FeS. FeS inhibited the further corrosion of the base material from corrosive medium of CO2, H2S and Cl. Besides, the corrosion of P110 steel in liquid and gas phases was mainly uniform corrosion, with localized pitting and a tendency towards localized corrosion.

A production technique with the high yield and environmentally friendly process need be developed for ε-Caprolactam (CPL) in the chemical industry. This technology is highly desired to design and synthesize high−performance catalysts for liquid phase Beckmann rearrangement of cyclohexanone oxime (CHO) to CPL. In this work, 3-methyl-1-(propyl-4-sulfonyl) imidazolium methanesulfonate ([PHSO3MIM][MSA]) with highly efficient and excellent yield is synthesized successfully. When the optimum molar ratio of ZnCl2 over [PHSO3MIM][MSA] was 0.02, it exhibits the high selectivity (94%) of CPL at 90 °C for 1 h. Interestingly, Fourier-transform infrared (FT-IR) investigations show that the functional Brønsted−Lewis acidic types of ionic liquids (ILs) are formed by the uniformly distributed ZnCl2 and [PHSO3MIM][MSA]. In addition, the hydrogen bond (H-bond) is formed between CHO and ILs. After ten reaction cycles, no significant structure changes are observed in the recovered [PHSO3MIM][MSA]·ZnCl2. The solubilities of ILs are predicted by using COSMO-RS model, the results show that [PHSO3MIM][MSA] is a promising candidate for the liquid phase Beckmann rearrangement of CHO into CPL. Finally, a theoretical model of the H-bond interactions between ILs and CHO is further confirmed to support the advance of reaction mechanism. A feasible way is provided for the CPL production technique in the liquid phase Beckmann rearrangement reaction.

We have developed a new liquid‐phase noncatalytic selective oxidation of polyhydric alcohols such as glycerol. This method involves the use of a nonthermal atmospheric‐pressure plasma instead of precious‐metal catalysts. We found that noncatalytic selective oxidation of glycerol achieved a conversion comparable to that achieved by gold‐catalyzed oxidation, and the desired glyceric acid, which is a pharmaceutical raw material, was obtained. When the solution pH was changed from strongly alkaline to neutral, the main reaction switched from the one that occurs in the presence of gold catalysts to the one that occurs in the presence of platinum catalysts. These results suggest that the reactive oxygen species generated by nonthermal atmospheric‐pressure plasma irradiation vary depending on the solution pH. [ABSTRACT FROM AUTHOR]

We present a novel approach to characterize and quantify microheterogeneity and microphase separation in computer simulations of complex liquid mixtures. Our post-processing method is based on local density fluctuations of the different constituents in sampling spheres of varying size. It can be easily applied to both molecular dynamics (MD) and Monte Carlo (MC) simulations, including periodic boundary conditions. Multidimensional correlation of the density distributions yields a clear picture of the domain formation due to the subtle balance of different interactions. We apply our approach to the example of force field molecular dynamics simulations of imidazolium-based ionic liquids with different side chain lengths at different temperatures, namely 1-ethyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride, and 1-decyl-3-methylimidazolium chloride, which are known to form distinct liquid domains. We put the results into the context of existing microheterogeneity analyses and demonstrate the advantages and sensitivity of our novel method. Furthermore, we show how to estimate the configuration entropy from our analysis, and we investigate voids in the system. The analysis has been implemented into our program package TRAVIS and is thus available as free software. [ABSTRACT FROM AUTHOR]

An extensive thermodynamic study of N-methylformamide (CAS RN: 123-39-7) and N,N-dimethylformamide (CAS RN: 68-12-2), is presented in this work. The liquid heat capacities of N-methylformamide were measured by Tian–Calvet calorimetry in the temperature interval (250–300) K. The vapor pressures for N-methylformamide and N,N-dimethylformamide were measured using static method in the temperature range 238 K to 308 K. The ideal-gas thermodynamic properties were calculated using a combination of the density functional theory (DFT) and statistical thermodynamics. A consistent thermodynamic description was developed using the method of simultaneous correlation, where the experimental and selected literature data for vapor pressures, vaporization enthalpies, and liquid phase heat capacities and the calculated ideal-gas heat capacities were treated together to ensure overall thermodynamic consistency of the results. The resulting vapor pressure equation is valid from the triple point to the normal boiling point temperature. [ABSTRACT FROM AUTHOR]

Typically, the X-ray diffraction spectrum of a highly oriented structure (HOS) MAX phase displays a prominent (002) characteristic peak. Surprisingly, this principle does not hold true for Ti 2 SC. Instead, the synthesized Ti 2 SC consistently exhibits a polyhedral structure (PS). Furthermore, even with hot-pressing sintering, the purity of Ti 2 SC remains relatively low. The primary factors contributing to anomalous crystal structures and low purity are insufficient crystal growth and limited reactant contact. In this study, we successfully achieved dual regulation of the crystal structure and purity of Ti 2 SC within the Ti/TiC/FeS 2 system, which was accomplished by enhancing reactant contact and controlling the growth rates of crystal planes. Notably, the intermediate products FeS and Fe, existing in a liquid phase at varying temperatures, played a crucial role in both the formation of Ti 2 SC and the growth of Ti 2 SC crystals. As a result, PS-Ti 2 SC and HOS–Ti 2 SC with purity greater than 99 wt% were successfully prepared. The formation of PS-Ti 2 SC can be attributed to the inadequate growth of each crystal plane at relatively lower temperatures (1500 °C). While the synthesis of HOS–Ti 2 SC necessitates the utilization of both a liquid phase and high temperature, as the epitaxial growth mechanism followed by vertical growth has been demonstrated to facilitate the generation of highly oriented crystals. The liquid phase facilitates the swift growth of Ti 2 SC crystals along the (001) crystal plane, while the (002) crystal plane necessitates a higher temperature (1760 °C) for relatively rapid growth. This work will open a new pathway for the development of the MAX phase from the perspective of crystal structure regulation and high purification preparation. [Display omitted] • The rationale behind the anomalous crystal structures in Ti 2 SC has been explicated. • The determinants governing the growth of individual crystal planes in Ti 2 SC have been identified. • Highly oriented structure Ti 2 SC was synthesized for the first time. • Two kinds of Ti 2 SC with purity greater than 99 wt% were successfully prepared. [ABSTRACT FROM AUTHOR]

Sintering with sintering aids is widely used to achieve a low sintering temperature of lead-based piezoelectric ceramics. In this study, two low-temperature sintering aids, namely Li 2 CO 3 and CuO, were doped into the x BiAlO 3 -(1- x) PZT + 0.2 wt% MnO 2 composition, and the microstructures and electrical properties were investigated for these ceramics prepared via solid-phase reaction method. Differential Scanning Calorimetry (DSC) indicated that the Li 2 CO 3 liquid phase formed at a lower temperature than that of CuO, while co-dopant of Li 2 CO 3 and CuO will result in a competition between Li+ and Cu2+ ions during the low-temperature sintering processes, which negatively impacts piezoelectric properties. The results demonstrated that the piezoelectric properties of ceramics with only Li 2 CO 3 or CuO additives are much better than ceramics with co-doped Li 2 CO 3 and CuO additives. Ceramics with 0.3 wt% Li 2 CO 3 or 0.1 wt% CuO sintering aid were sintered at 1000 °C, resulting in excellent piezoelectric coefficients (d 33) exceeding 300 pC/N and mechanical quality factors (Q m) of 500 were obtained, respectively. This work provides inspiration for low-temperature sintering strategies in other ceramic materials. [ABSTRACT FROM AUTHOR]

The distribution of iron oxides on firing ceramic brick produced from interstitial shale clay and iron-bearing slag from power plants, with no traditional materials, is studied by means of Mössbauer spectroscopy. A relation between the strength, frost resistance, and iron content is established. The calculated area of the spectral doublets indicates that the reduction of iron oxides by carbon oxides converts the iron compounds at the sample surface, where oxidant predominates, mainly to hematite, whereas those at the center, where reducing agents predominate, are converted to magnetite. The increased Fe2+ content in the samples hastens the appearance of liquid, which facilitates mullite formation and strengthens the ceramic structure. [ABSTRACT FROM AUTHOR]

Operando spectroscopy combines the in situ determination of material structure by spectroscopy/diffraction techniques with the measurement of material performance, which is conversion/selectivity in the field of heterogeneous catalysis. A central question in operando spectroscopy is whether the signatures visible by the characterization methods are responsible for catalyst performance. Individual analytical methods can provide useful information, but their combination (multi-technique approach) is essential to obtain a complete perspective on molecular reaction mechanisms. This approach must be coupled to experimental protocols and mathematical algorithms enabling the ability to disentangle the contribution of the active structure from the unresponsive one. Here, we report an account with examples from our own research activities in catalysis science.

SiC-diamond polycrystalline materials doping by diamond with different mass fraction were prepared by pressureless sintering with AlN−Y2O3−Sc2O3 as liquid phase. The microstructure and thermal properties were analyzed by scanning electron microscopy and laser flash method, respectively. The effects of mass fraction (1.0%, 2.5%, 5.0%) and particle size (0.25 μm, 1.00 μm) of diamond on the densification and mechanical properties of the SiC-diamond polycrystalline materials were studied. The results show that, the relative density of the sintered samples is over 94% when the diamond mass fraction is below to 5.0%, while the relative density of the sample with 5.0% diamond is lower than that of other samples. The relative density of SiC polycrystalline materials decreases with the increase of diamond content, and the excessive diamond in raw materials may reduce the densification of samples. Under the experimental conditions, the grain size does not grow abnormally. The hardness, fracture toughness, and bending strength of the samples are in ranges of 16~18 GPa, 3.8~4.4 MPa·m1/2, and 239~540 MPa, respectively. The thermal conductivity and thermal diffusion coefficient of samples decrease with the increase of temperature, and the porosity is the main factor affecting the thermal conductivity of the sintered samples.

Essential oils (EOs), being mixtures of various natural compounds, constitute an attractive source of novel antimicrobial agents. Along with multiple studies concerning their rich biological activity, there are different methods allowing to determine both antimicrobial activity in direct contact, as well as through the activity of vapours. Thyme constitutes one of the most common aromatic herbs used for pharmaceutical, cosmetic and culinary purposes. The aim of the study was to compare the antibacterial activity of liquid and vapour phases of Thymus vulgaris L. essential oil (TEO) against most common pathogenic Gram-positive (Staphylococcus aureus ATCC 25913, Enterococcus faecalis ATCC 29212, Bacillus cereus ATCC 10876) and Gram-negative (Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 14028, Pseudomonas aeruginosa ATCC 27853) microorganisms. To determine TEO antibacterial properties, two methods were used: disc-diffusion assay so as to test activity in direct contact; disc-volatilization assay so as to determine activity in gaseous contact.

Liquid-assisted processes that occur in iridium–silicon carbide diffusion couples have been studied in the temperature range 1500–1800°C at different heat treatment times. We have examined the microstructure and determined the elemental and phase compositions of the diffusion zone forming above eutectic temperatures and/or the melting points of individual reaction products: iridium silicides. The microstructure of the diffusion zone forming under liquid formation conditions has been shown to differ from that forming under the conditions of solid-state reaction between iridium and silicon carbide. At temperatures above 1700°C, the silicon content of the Ir–Si melt exceeds 50 mol %, which leads to crystallization of the Ir3Si4 and Ir3Si5 phases during cooling. The carbon resulting from reaction between iridium and SiC undergoes graphitization with increasing heat treatment temperature and time. [ABSTRACT FROM AUTHOR]

The temperature stability and temperature stability range of barium titanate-based pulse energy-storage ceramics were modified by Bi 2 O 3 tailoring in (Ba 0.98- x Li 0.02 Bi x) (Mg 0·04 Ti 0.96)O 3 (x = 0, 0.025, 0.05, 0.075, 0.1) and (Ba 1.03-1.5 x Li 0.02 Bi x) (Mg 0·04 Ti 0.96)O 3 (x = 0.125, 0.15, 0.2, 0.25) ceramics. Excellent pulse energy-storage performances of ceramic films are achieved via the new dual priority strategy of establishing cationic vacancies and forming a liquid phase. The dielectric constant plateau appears due to the cubic phase and space charges. Outstanding temperature stability, frequency stability and antifatigue performance are obtained in the ceramics, and their variations are all less than 15%. The comprehensive energy-storage properties with dual priority parameters of energy-storage density and efficiency of 3.13 J/cm3 and 91.71%, accompanied by an excellent pulse discharge energy density of 2.48 J/cm3, current density of 1313.23 A/cm2 and power density of 195.26 MW/cm3 are gained at x = 0.1. The perfect pulse energy-storage performances as well as ultrahigh stability are correlated with synergistic effects of multiphase coexistence, cubic phase, liquid-phase sintering, grain size, ceramic resistance, space charges and polar nanoregions. The comprehensive parameters indicate that the (Ba 0·88 Li 0·02 Bi 0.1) (Mg 0·04 Ti 0.96)O 3 ceramics have potential application in high precision fields. [ABSTRACT FROM AUTHOR]

High-aspect-ratio ZrB 2 rod crystals were synthesized via a molten-salt-mediated boro/carbothermal reduction using ZrOCl 2 · 8H 2 O/B 4 C/C as the raw material and NaCl as the flux material. This synthesis may improve the poor fracture toughness of monolithic ZrB 2 ceramics. X-ray diffraction and scanning electron microscopy confirmed that the heat-treatment temperature of 1550 °C and the addition of 50 wt% NaCl were the most effective in the preparation of ZrB 2 grains with a high aspect ratio. Thermogravimetric and differential scanning calorimetry was used to study the influence of NaCl addition, which increased the liquid-phase content. Finally, the growth of ZrB 2 grains along the c-axis into rod-like morphology at elevated temperatures was investigated by transmission electron microscopy. This work revealed that the addition of NaCl has a positive effect on the reducing of synthesis temperature and increasing of products particle size. The ZrB 2 rod crystals synthesized have diameters and aspect ratios of approximately 1 μm and 30, respectively. [ABSTRACT FROM AUTHOR]

A reconstructed Cu-ZnO catalyst with improved stability was fabricated by organic acid treatment method for the liquid-phase hydrogenation of dimethyl succinate to 1,4-butanediol. According to the characterization results of the fresh Cu-ZnO and reconstructed Cu-ZnO, three different forms of ZnO were suggested to be presented on the catalysts: ZnO having strong interaction with Cu species, ZnO that weakly interacted with Cu species and isolated ZnO. The first form of ZnO was believed to be beneficial to the formation of efficient active site Cu+, while the latter two forms of ZnO took the main responsibility for the deactivation of Cu-ZnO catalysts in the liquid-phase hydrogenation of diesters. The reconstruction of the Cu-ZnO catalyst by the organic acid treatment method resulted in a new Cu-ZnO catalyst with more Cu+ and less ZnO species that leads to deactivation. Furthermore, the deactivation mechanism of Cu-ZnO catalysts in liquid-phase diester hydrogenation in continuous flow system was proposed: the deposition of the polyesters on the catalysts via transesterification catalyzed by weakly interacted ZnO and isolated ZnO leads to the deactivation. These results provided meaningful instructions for designing highly efficient Cu-Zn catalysts for similar ester hydrogenation systems. [ABSTRACT FROM AUTHOR]

We present a novel approach to characterize and quantify microheterogeneity and microphase separation in computer simulations of complex liquid mixtures. Our post-processing method is based on local density fluctuations of the different constituents in sampling spheres of varying size. It can be easily applied to both molecular dynamics (MD) and Monte Carlo (MC) simulations, including periodic boundary conditions. Multidimensional correlation of the density distributions yields a clear picture of the domain formation due to the subtle balance of different interactions. We apply our approach to the example of force field molecular dynamics simulations of imidazolium-based ionic liquids with different side chain lengths at different temperatures, namely 1-ethyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride, and 1-decyl-3-methylimidazolium chloride, which are known to form distinct liquid domains. We put the results into the context of existing microheterogeneity analyses and demonstrate the advantages and sensitivity of our novel method. Furthermore, we show how to estimate the configuration entropy from our analysis, and we investigate voids in the system. The analysis has been implemented into our program package TRAVIS and is thus available as free software.

An extensive thermodynamic study of N-methylformamide (CAS RN: 123-39-7) and N,N-dimethylformamide (CAS RN: 68-12-2), is presented in this work. The liquid heat capacities of N-methylformamide were measured by Tian–Calvet calorimetry in the temperature interval (250–300) K. The vapor pressures for N-methylformamide and N,N-dimethylformamide were measured using static method in the temperature range 238 K to 308 K. The ideal-gas thermodynamic properties were calculated using a combination of the density functional theory (DFT) and statistical thermodynamics. A consistent thermodynamic description was developed using the method of simultaneous correlation, where the experimental and selected literature data for vapor pressures, vaporization enthalpies, and liquid phase heat capacities and the calculated ideal-gas heat capacities were treated together to ensure overall thermodynamic consistency of the results. The resulting vapor pressure equation is valid from the triple point to the normal boiling point temperature.

Metal organic frameworks (MOFs) has been widely investigated as co‐catalysts for photocatalysis owing to their unique property for controlling the reaction kinetics. They are generally presented in a solid state. Recent studies have presented MOF in the liquid phase, meanwhile preserving the framework structure. Acting as a co‐catalyst, significantly improved efficiency has been realized for photocatalytic CO2 reduction. This concept article focuses on the chemical principle of liquid MOF (LMOF). Their applications in photocatalysis and CO2 adsorption have been discussed with showing key examples. In addition, the other relevant applications of LMOF have been presented. [ABSTRACT FROM AUTHOR]

The aim of study was the production of polyclonal antibody of erythropoietin hormone (Anti-EPO) to determine EPO in human serum by liquid-phase radioimmunoassay (RIA). Production of anti-EPO was performed by immunizing Balb/C mice with EPO antigen using primary immunization and four booster doses. EPO tracer (125I-EPO) was prepared using Chloramine-T method. Additionally, EPO standards were mad. Furthermore, the assay was optimized and validated in additional studies. In conclusion, the elaborated EPO-RIA system exhibits a simple, accurate, specific and sensitive method for determining EPO concentration in human serum and might be suitable for clinical diagnosis of myeloproliferative diseases. [ABSTRACT FROM AUTHOR]

It is necessary to strictly control the iron (Fe) impurity in Mg-Al alloys to guarantee good corrosion resistance and mechanical properties. In this work, the effects of alloying elements and temperatures on the solubilities of Fe in the Mg-Al-based alloy melts (Mg-rich liquid phases) at 963–1033 K were studied by combining the in situ sampling method for the high precision solution values and the multiple regression numerical analysis method for the feature analysis. The solubilities of Fe in Mg-xAl (x = 1 and 3 wt.%) alloy melts could be significantly reduced by adding the yttrium (Y) or manganese (Mn) elements. However, the solubilities of Fe in Mg alloy melts were not in a monotonous relationship with the contents of the alloying elements in the Mg alloys. For the addition of Mn or Y, the lowest solubilities of Fe presented in the Mg-rich liquid phases were for the Mg-xAl alloys with the addition of 2 wt.% Mn or 1 wt.% Y, respectively. Additionally, the Fe-containing precipitations in the related systems were analysed and the Fe was mainly combined with Mn or Y and precipitated, which contributed to the removal of Fe from the Mg melt. The present study provides fundamental thermodynamic information regarding Mg-Al-Fe based systems and the design principle for the removal of Fe in Mg alloys. [ABSTRACT FROM AUTHOR]

Ablation material had been widely used in aerospace attributed to its reliability and strong adaptability but was usually accompanied by low strength at higher temperatures. Here, a high flexural strength of 66.91 MPa after ablation at 1500 °C of carbon fiber/boron phenolic resin (CF/BPR) composite modified by MoSi 2 and mica was reported. With the proportion of MoSi 2 and mica was 9:1, the formed appropriate content of the liquid phase improved the reactivity of MoSi 2 powders and provided a suitable interfacial state between CF and the matrix. The result of the oxygen-acetylene test showed that the mass ablation and the linear ablation reduced to 0.034 g/s and 0.006 mm/s, respectively. Owing to the formed liquid phase wrapping the carbon fiber and ceramic layer on the surface improved the ablation resistance. These high-strength CF/BPR composites have strong potential in new aerospace materials. [ABSTRACT FROM AUTHOR]

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Wet torrefaction of oil palm trunk with initial pressurisation of 1 and 6 MPa at 180 and 260 °C and residence times of 30, 60, and 180 min was carried out. The hydrochar's solid yield treated at 180 and 260 °C ranged from 45.97% to 49.94% and 13.84–20.16%, respectively. The higher heating values of the hydrochar treated at 180 and 260 °C were 17.76–18.60 MJ kg−1 and 24.72–27.62 MJ kg−1, respectively. Increasing the initial pressure at 260 °C resulted in decreased solid yield and higher heating values. The reduced solid yield and higher heating values was postulated to come from the suppression of dehydration and decarboxylation reactions along with partial lignin decomposition. Repolymerisation of lignin likely occurred; however, the contributions to solid yield and higher heating values from repolymerised lignin were insignificant compared to its depolymerisation that came from increased temperature. Glucose formation was promoted at high initial pressure (6 MPa) and low temperature (180 °C) and vice versa (i.e. 1 MPa and 260 °C gave higher glucose yield). Furthermore, the rehydration of 5-hydroxymethylfurfural to levulinic acid was enhanced with the increase in initial pressure due to the increased water density. Increasing the initial pressure inhibited lactic acid formation from glucose 1,2-enediol. [Display omitted] • High initial pressure enhances OPT decomposition at high temperature of 260 °C. • Effect of initial pressure was more pronounced at high temperature of 260 °C. • High initial pressure inhibits dehydration and decarboxylation reactions. • High initial pressure promoted levulinic acid formation. [ABSTRACT FROM AUTHOR]

In this study, one-step molten salt method followed by low-temperature sintering is employed for fabricating porous calcium hexaluminate (CA 6) ceramics with ideal plate-like structure and low thermal conductivity via the assistance of CaCl 2. The porous CA 6 ceramic containing 15 wt% CaCl 2 sintered at 1400 °C for 3 h exhibits desirable compressive strength (7.14 MPa), low bulk density (1.47 g/cm3), high porosity (61.12%), and low conductivity (0.439 W/(m·K)). The results imply that CaCl 2 , as a pore-forming agent and an additional source of CaO, provides a large number of liquid phases and resulting in quantities of closed pores. Moreover, the reactions between molten Al 2 O 3 and CaCl 2 alter the mass transfer modes of Al 2 O 3 and accelerate its phase transition to α-Al 2 O 3 in addition to contributing to the conversion of CaCl 2 to CaO and the subsequent formation of CA 6 , which results in the entire synthesis of low-temperature CA 6 at around 1400 °C. Therefore, there is no need for extra salt washing treatment owing to the consumption and evaporation of CaCl 2 , which makes this one-step molten salt method much more advantageous in terms of its economical and highly efficient. [ABSTRACT FROM AUTHOR]

Oxygenate fuels are a promising solution to urban air pollution, reducing soot emissions by big margins. Formaldehyde is a major building block for the synthesis of oxygen-rich fuels. Herein we report the synthesis, characterisation and testing of ruthenium on alumina catalysts for the methanol-mediated CO hydrogenation towards oxygenates with the formaldehyde oxidation state. We varied the synthesis parameters and could see interesting correlation between synthesis parameters, final metal loading, crystallite sizes and catalyst activity. The catalysts were tested in a high-pressure three-folded reactor plant in the CO hydrogenation in methanolic media. Interesting relationships between catalyst synthesis, structure and activity could be gained from these experiments. [ABSTRACT FROM AUTHOR]

Copyright of Transactions the Japan Society of Refrigerating & Air Conditioning Engineers is the property of Japan Society of Refrigerating & Air Conditioning Engineers 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.)

Melting treatment has emerged as a promising technology for managing municipal solid waste incineration (MSWI) fly ash owing to its advantageous features of effective detoxification and volume reduction. The melting treatment of MSWI fly ash involves the immobilization of heavy metals by crystals and liquid phase. Herein, the immobilization mechanism of heavy metals (Cu, Pb and Cd) by the crystals and the liquid phase was investigated using melting experiments, thermodynamic calculations and density functional theory (DFT) calculations. Results demonstrate that the immobilization of heavy metals is influenced by a combination of factors: the reaction of heavy metals, physical encapsulation ability of the liquid phase and chemical fixation ability of both the crystals and the liquid phase. An increase in the content of SiO 2 and Al 2 O 3 promotes the conversion of heavy metals oxides into heavy metals chlorides. Furthermore, an increase in the content and polymerization degree of the liquid phase facilitates the physical encapsulation of heavy metals chlorides. The chemical fixation ability of the crystals and the liquid phase differs for Cu and Pb, while Cd cannot be immobilized through chemical fixation. To enhance the immobilization of heavy metals during melting treatment, the chemical composition of MSWI fly ash should be adjusted within the anorthite region of the ternary phase diagram. This study provides valuable insights into the immobilization mechanism of heavy metals by the crystals and the liquid phase during the melting treatment of MSWI fly ash. [Display omitted] • SiO 2 and Al 2 O 3 promote the formation of heavy metals chlorides. • Increasing liquid phase content favors physical encapsulation of heavy metals. • High liquid polymerization degree favors physical encapsulation of heavy metals. • Cu and Pb can be chemically fixed by different crystals and liquid phase. • Cd cannot be chemically fixed by crystals and liquid phase. [ABSTRACT FROM AUTHOR]

In this study, we used a metal-organic framework (MOF) material named MIL-100(Fe) as a catalyst to activate the H 2 O 2 /NaOH system for the efficient removal of NOx. OH- attack the Fe-O bond to break it and Fe(III) is released into the solution·H 2 O 2 decomposes to HO 2 - in an alkaline environment and Fe(III) in the dissolved state reacts with it, producing Fe(II) and •O 2 -. The MOF material had a strong electron transfer capability, facilitating the efficient conversion of Fe(III) to Fe(II) by transferring the electrons released during the NO conversion process. This electron transfer process played a crucial role in slowing down the rate of pH increase in the solution and enhancing the utilisation of H 2 O 2. The main reactive oxygen species in this reaction are •O 2 - and •OH. By further analyzing the products of the quenching experiments, we propose an interaction mechanism between NO and •O 2 - as well as •OH. • In an alkaline environment, MIL-100(Fe) can catalyze the decomposition of H 2 O 2 , producing a large amount of •O 2 -. • The primary oxidation product of NOx with •O 2 - is NO 3 -, while the primary oxidation product of NOx with •OH is NO 2 -. [ABSTRACT FROM AUTHOR]

Catalytic oxidation of alcohols is an essential process for energy conversion, production of fine chemicals and pharmaceutical intermediates. Although it has been broadly utilized in industry, the basic understanding for catalytic alcohol oxidations at a molecular level, especially under both gas and liquid phases, is still lacking. In this paper, we systematically summarized our work on catalytic alcohol oxidation over size-controlled Pt nanoparticles. The studied alcohols included methanol, ethanol, 1-propanol, 2-propanol, and 2-butanol. The turnover rates of different alcohols on Pt nanoparticles and also the apparent activation energy in gas and liquid phase reactions were compared. The Pt nanoparticle size dependence of reaction rates and product selectivity was also carefully examined. Water showed very distinct effects for gas and liquid phase alcohol oxidations, either as an inhibitor or as a promoter depending on alcohol type and reaction phase. A deep understanding of different alcohol molecular orientations on Pt surface in gas and liquid phase reactions was established using sum-frequency generation spectroscopy analysis for in situ alcohol oxidations, as well as density functional theory calculation. This approach can not only explain the entirely different behaviors of alcohol oxidations in gas and liquid phases, but can also provide guidance for future catalyst/process design.

Calcium phosphate cements (CPCs) have been increasingly used as synthetic bone substitutes for repair and regeneration of bone defects given their biocompatibility, resemblance to bone and malleability. Moreover, their use as local antibiotic delivery systems is of main interest against bone infections, avoiding the adverse effects of high dosages of conventional therapy. The main goals of this work were to improve the properties of a commercial CPC (Neocement®), turning it injectable, and to provide it with a new functionality as a drug delivery system able to ensure a sustained release of an antibiotic commonly used in orthopaedics (gentamicin sulphate, GS). For this, the influence of the liquid phase amount (%LP) and type of polymer contained in the formulation (chitosan, Chi, or hydroxypropyl methylcellulose, HPMC) on the basic properties of the material was evaluated. It was found that the formulation containing 42%LP + HPMC+1.87% wt GS was the best one. It showed suitable setting and mechanical properties, and injectability around 87% (much superior to the original Neocement®, with 31%). It ensured a sustained release of GS for at least 14 days, at antibacterial levels. The antibiotic released is highly effective against S. epidermidis, but also presents some antibacterial activity against S. aureus. The CPC revealed to be non-cytotoxic. Moreover, it demonstrated good flowability and connectivity with human cadaveric trabecular bone. [ABSTRACT FROM AUTHOR]

In this work, alternative fuel and other types of products were obtained from car tire waste and their components were determined as a result of physical and chemical analysis. To determine the optimal temperature during pyrolysis, one of the modern methods for studying physical chemistry, derivatographic analysis, was carried out. As a result, it was determined that the temperature for the optimal process is 450-550 °C and the amount of liquid, solid and gaseous substances released as a result of this temperature. [ABSTRACT FROM AUTHOR]

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Recent advances in liquid phase scanning transmission electron microscopy (LP-STEM) have enabled the study of dynamic biological processes at nanometer resolutions, paving the way for live-cell imaging using electron microscopy. However, this technique is often hampered by the inherent thickness of whole cell samples and damage from electron beam irradiation. These restrictions degrade image quality and resolution, impeding biological interpretation. Using graphene encapsulation, scanning transmission electron microscopy (STEM), and energy-dispersive X-ray (EDX) spectroscopy to mitigate these issues provides unprecedented levels of intracellular detail in aqueous specimens. This study demonstrates the potential of LP-STEM to examine and identify internal cellular structures in thick biological samples. Specifically, it highlights the use of LP-STEM to investigate the radiation resistant, gram-positive bacterium, Deinococcus radiodurans using various imaging techniques., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

Nitrites (NO 2 - /HONO), as the primary source of hydroxyl radicals ( • OH) in the atmosphere, play a key role in atmospheric chemistry. However, the current understanding of the source of NO 2 - /HONO is insufficient and therefore hinders the accurate quantification of atmospheric oxidation capacity. Herein, we highlighted an overlooked HONO source by the reaction between nitrophenols (NPs) and • OH in the aqueous phase and provided kinetic data to better evaluate the contribution of this process to atmospheric HONO. Three typical NPs, including 4-nitrophenol (4NP), 2-nitrophenol (2NP), and 4-nitrocatechol (4NC), underwent a denitration process to form aqueous NO 2 - and gaseous HONO through the • OH oxidation, with the yield of NO 2 - /HONO varied from 15.0 to 33.5%. According to chemical composition and structure analysis, the reaction pathway, where the ipso addition of • OH to the NO 2 group on 4NP generated hydroquinone, can contribute to more than 61.9% of the NO 2 - /HONO formation. The aqueous photooxidation of NPs may account for HONO in the atmosphere, depending on the specific conditions. The results clearly suggest that the photooxidation of NPs should be considered in the field observation and calculation to better evaluate the HONO budget in the atmosphere.

This paper proposed a novel low-pressure sintering process contraposing to characteristics of pre-alloyed aluminum powders and analyzed its feasibility. The low pressure was set to 0.1 MPa in this study. Meanwhile, 0 MPa and 10 MPa were set as control group. With gas-atomized 2024 aluminum powders as raw material, the microstructure and tensile properties of specimens sintered under three orders of magnitude of pressure (0 MPa, 0.1 MPa and 10 MPa) at two representative temperatures (525 °C and 575 °C) were compared. The results showed that it was difficult for pressureless sintering (0 MPa) to densify pre-alloyed aluminum powders, but low-pressure sintering could. As the liquid phase formed at supersolidus temperature was squeezed out, the loss of alloying elements such as Cu and Mg, which would play an important role in subsequent heat treatment, during low-pressure sintering was apparently less than that of 10 MPa. The density of aluminum sintered under 0.1 MPa at 575 °C was 2.732 g/cm3 and the ultimate tensile strength was 228.16 MPa with ductility of 12 %, which achieved a good balance of plasticity and strength. These findings will bring new insights to the industrialization of aluminum powder metallurgy (APM).

It is necessary to strictly control the iron (Fe) impurity in Mg-Al alloys to guarantee good corrosion resistance and mechanical properties. In this work, the effects of alloying elements and temperatures on the solubilities of Fe in the Mg-Al-based alloy melts (Mg-rich liquid phases) at 963–1033 K were studied by combining the in situ sampling method for the high precision solution values and the multiple regression numerical analysis method for the feature analysis. The solubilities of Fe in Mg-xAl (x = 1 and 3 wt.%) alloy melts could be significantly reduced by adding the yttrium (Y) or manganese (Mn) elements. However, the solubilities of Fe in Mg alloy melts were not in a monotonous relationship with the contents of the alloying elements in the Mg alloys. For the addition of Mn or Y, the lowest solubilities of Fe presented in the Mg-rich liquid phases were for the Mg-xAl alloys with the addition of 2 wt.% Mn or 1 wt.% Y, respectively. Additionally, the Fe-containing precipitations in the related systems were analysed and the Fe was mainly combined with Mn or Y and precipitated, which contributed to the removal of Fe from the Mg melt. The present study provides fundamental thermodynamic information regarding Mg-Al-Fe based systems and the design principle for the removal of Fe in Mg alloys.