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Refractory high-entropy alloys are under consideration for applications where materials are subjected to high temperatures and levels of radiation, such as in the fusion power sector. However, at present, their scope is limited because they are highly brittle at room temperature. One suggested route to mitigate this issue is by alloying with Ti. In this theoretical study, using a computationally efficient linear-response theory based on density functional theory calculations of the electronic structure of the disordered alloys, we study the nature of atomic short-range order in these multi-component materials, as well as assessing their overall phase stability. Our analysis enables direct inference of phase transitions in addition to the extraction of an atomistic, pairwise model of the internal energy of an alloy suitable for study via, e.g., Monte Carlo simulations. Once Ti is added into either the NbMoTaW or VNbMoTaW system, we find that there is competition between chemical phase ordering and segregation. These results shed light on observed chemical inhomogeneity in experimental samples, as well as providing fundamental insight into the physics of these complex systems. [ABSTRACT FROM AUTHOR]

Introduction: The main goal of this study was to describe the Czech population of patients with MG in terms of demographics, disease characteristics, management approaches, and treatment trends. Methods: We selected all patients, both incident and prevalent, who were enrolled in the Czech MyReg registry between August 24, 2015 and November 19, 2021. For the descriptive analysis, all patients enrolled in the registry, regardless of their date of diagnosis or date of enrolment, were included. We analyzed the following disease-related endpoints: myasthenia gravis composite (MGC) score, forced vital capacity (FVC), and Myasthenia Gravis Foundation of America (MGFA) clinical classification. Results: The incidence showed a consistent increasing trend from 0.62 to 3.13. The mean MGC score was 5.0 (median 4.0, 95% CI 4.7, 5.3) representing mild form of MG. The difference in FVC from the predicted value in patients during and without myasthenic crisis was 58.93% (95% CI 37.27, 80.59) and 75.93% (95% CI 74.87, 77.00), respectively. We identified 70 patients (5.0%) with refractory MG, of whom 58.6% were female. The MGFA classifications in those with refractory vs. non-refractory disease was as follows: IIa 21.8% vs 23.2%, IIb 45.3% vs 33.6%, and IIIb 14.1% vs 4.6%, respectively. Conclusion: Our analysis shows that the incidence of MG is increasing in the Czech Republic and that patients with refractory disease, of whom up to 58% are female, have a higher burden of disease than non-refractory patients. [ABSTRACT FROM AUTHOR]

Pebble accretion provides new insights into Earth's building blocks and early protoplanetary disk conditions. Here, we show that mixtures of chondritic components : metal grains, chondrules, calcium-aluminum-rich inclusions (CAIs), and amoeboid olivine aggregates (AOAs) match Earth's major element composition (Fe, Ni, Si, Mg, Ca, Al, O) within uncertainties, whereas no combination of chondrites and iron meteorites does. Our best fits also match the ε 54Cr and ε 50Ti values of Earth precisely, whereas the best fits for chondrites, or components with a high proportion of E chondrules, fails to match Earth. In contrast to some previous studies, our best-fitting component mixture is predominantly carbonaceous, rather than enstatite chondrules. It also includes 15 wt% of early-formed refractory inclusions (CAIs + AOAs), which is similar to that found in some C chondrites (CO, CV, CK), but notably higher than NC chondrites. High abundances of refractory materials is lacking in NC chondrites, because they formed after the majority of refractory grains were either drawn into the Sun or incorporated into terrestrial protoplanets via pebble accretion. We show that combinations of Stokes numbers of chondritic components build 0.35–0.7 Earth masses in 2 My in the Hill regime accretion, for a typical pebble column density of 1.2 kg/m2 at 1 au. However, a larger or smaller column density leads to super-Earth or moon-mass bodies, respectively. Our calculations also demonstrate that a few My of pebble accretion with these components yields a total protoplanet mass inside 1 au exceeding the combined masses of Earth, Moon, Venus, and Mercury. Accordingly, we conclude that pebble accretion is a viable mechanism to build Earth and its major element composition from primitive chondritic components within the solar nebula lifetime. [ABSTRACT FROM AUTHOR]

Background: Refractory esophageal stricture is the common complication of extensive endoscopic submucosal dissection (ESD), without satisfactory endoscopic treatment strategies. We evaluated the efficacy, safety, and long-term patency of the modified endoscopic radial incision and selective cutting combined with short-term stenting (RISC-STS) for the treatment of refractory esophageal stenosis. Methods: This was a retrospective study. Patients diagnosed with refractory esophageal stricture from June 2016 to June 2023 were enrolled. Efficacy, safety, and risk factors for dysphagia after RISC-STS operation were assessed. Results: Compared with clinical symptoms before RISC-STS, there was no significant improvement in the times of stricture recurred (p = 0.75). However, the narrowest diameter of esophageal stenosis was significantly larger after RISC-STS treatment (p = 0.04). Corresponding dysphagia scores after RISC-STS were obviously lowered according to the Mellow–Pinkas grading scale (p = 0.002). More cases ((14 (60.87%) vs 5 (21.74%)) received valid symptom-relief periods after RISC-STS (p = 0.0004). The complications of RISC-STS include perforation (4.35%), fever (4.35%), and pain (30.43%). Univariate Cox analysis suggested that resection length >7 cm of scar tissue was a risk factor for refractory dysphagia after RISC-STS. Conclusion: The present study revealed that RISC-STS is an effective and safe technique for refractory esophageal stricture with lower restenosis, higher valid symptom-relief rate, and fewer complications. [ABSTRACT FROM AUTHOR]

Background: Juvenile Idiopathic arthritis (JIA) is one of the most common chronic diseases in children. It still remains a challenge to treat refractory poly-articular course JIA patients, especially in Bangladesh, where patients from low socio-economic backgrounds are unable to manage biological agents. Tofacitinib is one of the alternative options to biological agents, which can be taken orally and is cost effective. The purpose of this prospective observational study was to evaluate the efficacy of tofacitinib in the treatment of refractory poly-articular course JIA cases. Materials and methods: This study was carried out in the Department of Pediatrics, Bangabandhu Sheikh Mujib Medical University (BSMMU). A total number of 50 refractory polyarticular course JIA patients received JAK-2 inhibitor, tofacitinib along with other drugs according to the recommended doses. The disease activity level was measured by Juvenile Arthritis Disease Activity Score-27 (JADAS-27). All the cases were assessed at baseline, 6th, 12th and52nd week of tofacitinib therapy. The relevant statistical tests were applied for data analysis. Results: After treating the refractory cases with tofacitinib, arthritis subsided, and laboratory parameters improved in all the cases. Overall JADAS-27 score improvement was 40.67%, 56.38% and 96% at 6th, 12th and 52nd week of follow-up respectively. It was also possible to taper the dose of steroid gradually and stopped it by 24 weeks. Tofacitinib was well tolerated with minimum side effects. Conclusions: Tofacitinib was effective to all the children with poly-articular course JIA. It was well tolerated and had very few tolerable adverse effects. [ABSTRACT FROM AUTHOR]

The solid carbon produced by the CO disproportionation reaction can cause severe damage to refractories, especially in the presence of H 2. To provide a theoretical basis for the design of refractories for low-carbon metallurgical equipment. Carbon deposition experiments of clay refractories, mullite refractories, and corundum-mullite refractories were researched at 550 °C under CO-H 2 atmosphere. The results show that carbon deposition occurs mainly in the vicinity of agglomerated iron. A small amount of agglomerated iron is sufficient to catalyze the production of large amounts of filamentous carbon and to damage refractories. In addition, the iron content and form have a significant influence on the refractory under CO-H 2 atmosphere. For mullite samples with less than 1 wt% iron, carbon deposition occurs mainly in the iron agglomerate regions and the damage rate of the samples is relatively low. For clay samples with 2.5 wt% iron, there are very large amounts of iron agglomerates in the aggregate and the matrix, and as a result most of the samples are damaged. Finally, the mechanism of refractory failure by carbon deposition under CO-H 2 atmosphere was revealed. The CO diffuses into the pores of the refractory, and the filamentous carbon produced by the CO disproportionation reaction grows near the agglomerated iron. As the pores fill with filamentous carbon, the carbon begins to densify and exerts an outward force on the refractory. When this force exceeds the bonding strength of the refractory, it will be damaged. [ABSTRACT FROM AUTHOR]

The copper industry continuously uses great amounts of Cr-containing refractories, which are installed in all heating devices, despite their known negative environmental impact. The development of alternative materials seems feasible via replacing chromite spinel with other Cr-free spinel, using magnesia or alumina as a dominant component in the composition of new refractories. In light of the longstanding issue, the article presents the properties of key refractory raw materials (magnesia and alumina) and potential Cr-free spinels which can be combined to emerge a new generation of refractories dedicated to the copper industry. Subsequently, the results of FactSage corrosion simulations were revealed for Cr-refractories and seven Cr-free magnesia-based refractories containing spinels of different chemistry against industrial copper converter slag with Fe/SiO 2 of 2.5. Through tracking the changes in solid and liquid phases appearing during interactions in a temperature range of 1100–1400 °C as well as liquid viscosity alterations, the most prospective solutions were identified with reference to the properties of commercial MgO-Cr₂O₃ refractories. [ABSTRACT FROM AUTHOR]

Refractory liner bricks in the hot zone of rotary lime kilns can sustain wear and corrosion during contact with fuel ashes and quicklime (QL), a product composed mainly of CaO. The effects on a MgO-based refractory after exposure at 1400 °C for 96 h to olive pomace ash (OPA) and coal ash (CA), with and without QL, were investigated. Exposure of the refractory to only OPA caused slag intrusion with no ash deposits remaining on top, while CaMgSiO 4 (monticellite) was also identified as a new phase. When exposed to only CA, the refractory exhibited dissolution into the molten slag and 0.5–2 mm cracks were found on the surface interfacing the ash. Mg 2 SiO 4 (forsterite) and CaMgSiO 4 were identified as new formed phases. Exposure of the refractory to OPA + QL and CA + QL caused less slag intrusion and substantial amounts of ash/QL deposit remained afterwards. No new phases were identified. The differences in interactions between the exposure materials and refractory were supported by thermochemical equilibrium analysis. Apparent Ca-Si–rich or Ca-rich melts were found in all the exposed samples, but potassium (K) was found to be depleted in all samples, including those involving OPA, which was rich in K. Furthermore, with the exception of exposure to only CA, the other exposures caused the cold crushing strength (CCS) of the refractory to increase compared to its original value. This was attributed to the sintering of the refractory microstructure. The CCS of the refractory decreased after exposure to only CA. The findings of this study enhance understanding of how CA and OPA impact MgO refractories in lime kilns, supporting initiatives aiming at reducing fossil fuel use. The results are encouraging and motivate further investigation. • MgO-based refractories were exposed to different fuel ashes with/without quicklime • Sintering of microstructure and cracks were observed in the exposed refractories • Mg 2 SiO 4 and CaMgSiO 4 formed in the refractories exposed to coal ash • Exposure of the refractory to a mixture of fuel ash and quicklime caused less slag intrusion than for exposure to only fuel ash • The refractory cold crushing strength was affected by all exposures and discussed in relation to changes in the microstructure [ABSTRACT FROM AUTHOR]

Corrosion resistance of refractory materials to the melt and slags is essential during scrap brass smelting. MgO-Cr 2 O 3 bricks exhibit remarkable high-temperature stability and corrosion resistance in the non-ferrous metallurgical industry. In this paper, the corrosion mechanism of MgO-Cr 2 O 3 bricks was explored by scrap brass slag. Through thermodynamic simulation, the possible chemical reactions were revealed between bricks and slag. Simultaneously, laboratory experiments were conducted to investigate the effects of temperature and time. The results showed that MgO-Cr 2 O 3 bricks were reacted with solid phase of ZnO, PbO, and Al 2 O 3 in slag, leading to the formation of CuAl 2 O 4 and MgAl 2 O 4. The bricks were deeply penetrated by liquid Cu and Zn through cracks and pores, resulting in the generation of PbO and ZnCr 2 O 4. Gas phases such as Zn vapor and HF vapor continued to infiltrate the interior and generate ZnCr 2 O 4. Especially, MgO serves as the main reactive substance in MgO-Cr 2 O 3 bricks. For every 100 °C improved in temperature, the corrosion mass increased by 0.003587 g/day. Besides, the time for an entire MgO-Cr 2 O 3 brick to be completely corroded at the average production temperature was 79.24 days. This paper introduces suggestions to refractory materials for scrap brass smelting. [ABSTRACT FROM AUTHOR]

Light, strong, and radiation-tolerant materials are essential for advanced nuclear systems and aerospace applications. However, the comprehensive properties of current radiation-tolerant materials are far from being satisfactory in harsh operating environments. In this study, a high-throughput-designed NbVTaSi refractory eutectic medium entropy alloy realizes the controllable formation of the β-Nb5Si3 phase with a high content and has outstanding comprehensive properties, i.e., lightweight, high yield strengths at room temperature and 850℃, and excellent He-ion irradiation resistance. According to density functional theory calculations and experimental findings, the prefabricated lattice distortion of the Nb50V42Ta8 phase leads to great phase stability under severe He-ion irradiation conditions, while the dual characteristics of the semi-coherent interface and hyperstatic lattice structure of the high-content β-Nb5Si3 phase dominate its outstanding He-ion irradiation resistance. This study sheds light on the design strategy for comprehensive properties and development of future radiation-tolerant materials for advanced nuclear systems and aerospace applications. [ABSTRACT FROM AUTHOR]

Background: Improving the understanding of how a refractory material responds to thermal shocks and allowing the validation of finite element models require a valuable tool for experimental data collection. Objective: This paper introduces an innovative, sophisticated, and highly reliable experimental device designed to apply a controlled cyclic thermal gradient in a disk-shaped ceramic refractory sample and to simultaneously monitor thermomechanical response and potential damage. Methods: This device, named Advanced measurements for in-situ Thermomechanical monitORing of large sample uNder thermal grAdient, is based on a CO2 laser beam to generate a calibrated thermal flux sequence at the top face while accurately measuring temperature field at the bottom face by an infrared camera. The displacement field of the bottom face is also continuously monitored by a stereo-vision system, enabling a precise measurement of 3D displacements and, thus, of the local strains. An accurate monitoring of the crack extension is performed thanks to the Two-Part Digital Image Correlation technique. Results: Throughout the thermal cycling sequence applied to an exemplar sample, the device has proved to be a robust and reliable system able to provide very accurate experiment data in terms of displacement, strain, temperature fields and crack length/opening. Conclusions: This device represents a significant advancement in in-situ monitoring of a refractory sample and contributes to the comprehensive characterization of materials under thermal gradients. More investigations and comparison with thermomechanical Finite Element modelling are shown in a second part of this paper. [ABSTRACT FROM AUTHOR]

Based on the 3D heat transfer numerical simulation model, the evolution mechanism of blast furnace cooling plate slag‐hanging behavior with different cooling system structures is analyzed. Cooling plate reduced by 20 mm will not affect its slag‐hanging behavior. Copper cooling plate is best suited for high heat load areas. The vertical spacing of cooling plate is extended by 200 mm, the uniformity of the slag layer decreases by 5%, and the temperature of cooling plate and refractory material increases by 11 and 50 °C. Cooling plate vertical spacing of 510 mm or less can ensure stable slag hanging in the blast furnace. When using a single refractory material, the average uniformity of the slag layer is 95%, 86%, and 79% for graphite brick, semigraphite brick, and sialon‐SiC brick, respectively. Si3N4‐SiC brick cannot operate properly in high heat load areas. The factory can consider setting 125 mm sialon‐SiC brick in the furnace; graphite brick is used outside the furnace lining. The slag layer is well distributed, and the average value of uniformity is about 90%. Even if the slag layer is fully dislodged, the hot surface temperature of the furnace lining is 785 °C, and it can be quickly reslag hanging. [ABSTRACT FROM AUTHOR]

In the current study, effects of a carbon‐bonded magnesia (MgOC) refractory and a magnesia (MgO) refractory on the cleanliness of a high‐carbon Al‐killed steel and on the degree of refractory are investigated using laboratory experiments, thermodynamic calculation, and a kinetic modeling. The refractory/steel interface layer and inclusions in the steel are analyzed. After a 90 min contact between the refractory rod and the steel, the penetration of the molten steel into MgO refractory is small. An about 0.1 mm thick interface layer containing CaO–Al2O3–SiO2–MgO is generated at the boundary of magnesite particles while the composition of inclusions in the steel changes very little. The molten steel penetrated 1 mm into MgOC refractory through grain boundaries, forming channels due to the graphite consumption. A new 20 μm thick interface layer containing CaS and MgO is formed between the steel and MgOC refractory. The formation of CaS is favored at the steel/MgOC refractory and is rarely existed at the steel/MgO refractory during cooling process. The average content of MgO in inclusions increases from 6.22 to 30.05 wt% while the Al2O3 content in inclusions decreases from 84.57 to 69.95 wt% reacting for 90 min. [ABSTRACT FROM AUTHOR]

Semi‐rebonded periclase‐chromite refractories are commonly utilized in the working lining section of the molten pool in oxygen‐enriched top‐blowing furnaces for nickel production. Its resistance to nickel slag corrosion determines the safety and service life of the melting furnace. The composition of nickel slag influences the corrosion resistance of semi‐rebonded periclase‐chromite refractories. By comparing and analyzing specimens corroded by primary and modified nickel slag, the influence mechanism of w(CaO)/w(SiO2) variations on corrosion resistance of semi‐rebonded periclase‐chromite refractories was clarified. The results show that a spinel isolation layer is preferred to form at a lower w(CaO)/w(SiO2) ratio (< 0.576) and enhance the corrosion resistance of semi‐rebonded periclase‐chromite refractories. As the ratio increases, the slag viscosity falls and the corrosion products contain larger levels of Ca3Cr2Si3O12 and Ca3MgSi2O8, which prevent the creation of the isolation layer and establish a conduit for Ca2+ and Si4+ transport and reaction into the interior of the refractory. [ABSTRACT FROM AUTHOR]

Fiberboard (FB) is extensively utilized in heat‐insulating refractory materials owing to its lightweight nature and excellent resistance to high temperatures. Nevertheless, the inadequate mechanical properties and limited dimensional stability of FB hinder its further application. The vacuum filtration was utilized in this study to manufacture inorganically modified insulation FB, incorporating plus fiber/1260 fiber and silica sol as the primary constituents and sepiolite powder (HS) as the modifier. The experimental results show that the fabricated samples exhibited extremely high porosity (75.3%–90.2%) and low thermal conductivity (.063–.15 W m−1 K−1, 200–800°C). The fibers were arranged in a three‐dimensional structure, overlapping with each other, and the silica sol adhered to the fibers, forming a spatial mesh structure through cross‐linking. Importantly, the incorporation of HS was effective in controlling the agglomeration of the silica sol, leading to a more uniform distribution within the fibers. Additionally, the study found that the mechanical properties (high hardness (64–72 HA)) and high‐temperature durability of the FBs were enhanced due to the flocculant modification. This study highlights promising prospects for industrial applications and offers a cost‐effective admixture for modifying and preparing high‐performance FBs, which is expected to see broad adoption in thermal insulation and energy conservation applications. [ABSTRACT FROM AUTHOR]

The rapid development of the power industry has resulted in a significant amount of electric porcelain solid waste. To address the challenges of small‐scale utilization and low added value associated with the current utilization of porcelain solid waste, a new high‐temperature resistant material was successfully developed using waste electric porcelain with varying particle sizes as the primary raw material. The dependence of composition, structure, and mechanical properties on fine particle size and sintering temperature was explored. The research has determined that the most effective particle size for the synthesis of refractory materials using waste electric porcelain is 120 mesh, and the optimal temperature is 1600°C. When the temperature exceeds 1500°C, the expansion generated by the decomposition of sillimanite will counteract the shrinkage of the liquid phase reaction, thereby maintaining the morphology of the sample. This process forms a unique interwoven mullite morphology through the decomposition of sillimanite, thereby enhancing the strength of the material. As a result, the optimal bending strength of 74 MPa and the optimal compression strength of 207 MPa were obtained. The realization of high‐temperature resistant materials based on discarded electric porcelain has shown foreseeable potential in large‐scale high‐value utilization. [ABSTRACT FROM AUTHOR]

MgO–C refractories are of paramount importance in the converter side blowing system, requiring outstanding oxidation resistance under harsh conditions including high temperature, oxygen atmosphere, and high‐speed airflow. In this study, MgSiN2 phase reconstruction was used to improve the oxidation resistance of MgO–C refractories, as well as the mechanical properties and oxidation resistance of MgO–C refractories were evaluated. The results indicated that the cold modulus of rupture of the sample with 9 wt% MgSiN2 was increased by 93.3% compared with the MgO–C refractories without MgSiN2. After oxidation tests, the oxidation index and rate constant (k) of the sample with 9 wt% MgSiN2 were reduced by 38.9% and 35.3%. Furthermore, incorporating MgSiN2 facilitated the formation of layered dense structures consisting of plate‐like Mg‐Sialon and MgO–Mg2SiO4–MgAl2O4. This structural optimization effectively inhibited oxygen diffusion and reaction within the material, resulting in gradual oxygen potential mitigation. [ABSTRACT FROM AUTHOR]

In this article, two‐phase experimental and numerical investigations are performed to study the effect of inert gas injection to ladle shroud on the hydrodynamic performance of tundish. It is widely known that the flow of molten steel through a shroud, with or without inert gas injection, can influence the flow behavior in the tundish and, consequently, the hydrodynamic performance. However, large throughput rates may promote refractory wear, slag entrainment, and large tundish eye, which are known to seriously impair steel cleanliness, implying a severe need for optimization of the inert gas injection rate into the ladle shroud. In this study, two distinct reduced scale slab‐casting tundishes (from different plants) with scale factors of 0.35 and 0.40 fitted with various flow modifiers are considered. Experiments are performed considering gas‐to‐liquid loading ratios of 10, 20, and 30%. An improved tundish hydrodynamic performance is observed during the experiments, which is validated with numerical modeling results using ANSYS Fluent 2021R1. Although gas injection to the shroud certainly enhances the hydrodynamic performance of tundishes, the effect fades away beyond 20% of the gas‐to‐liquid loading ratio, regardless of the tundish design, capacity, and different flow modifiers used. [ABSTRACT FROM AUTHOR]

Combining the advantages of both containing-B compounds and containing-Ti compounds, a new TiB 2 addition is proposed in MgO-C refractories. In this paper, the high-temperature oxidation behavior of low-carbon MgO-C refractories with TiB 2 addition was investigated, especially the effect of microstructure and phase evolution on the high-temperature oxidation behavior was discussed. The results show that in the materials, TiB 2 preferentially reacts with oxygen, forming TiC x N 1-x , Mg 3 (BO 3) 2 and Mg 2 TiO 4 ceramic phases, and catalyzing the decomposition of phenolic resin to form bamboo-like nanotubes and carbon nanospheres to bond aggregates and fill pores. Meanwhile, TiB 2 also promotes the formation of regenerated MgO compact zone, hindering the diffusion of oxygen into the materials to improve the oxidation resistance. Compared with the blank control specimen and the specimen with B 4 C addition, the oxidation resistance increased by 243.4 % and 79.2 %, respectively. [ABSTRACT FROM AUTHOR]

BackgroundAimMethodsResultsConclusionsRegistrationAlthough quality palliative care is available, some people at the end of life suffer from refractory symptoms for which conventional treatments have failed. Palliative sedation (PS) is an option recommended in these cases, including for the treatment of refractory existential suffering (ES) in people at the end of life.to analyze the evidence available in the literature on the use of PS to manage ES in people with serious illnesses.This is an integrative review based on the steps described by Whittemore and Knalf, and reported in line with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA-2020).A total of 38 studies published between 2000 and 2024 were included. Themes and sub-themes were identified based on patterns and recurring themes. The two main themes were: 1) PS in the management of ES: challenges for clinical practice, and 2) Definition and assessment of Existential Suffering.The acceptance of PS for the relief of refractory physical symptoms is widely consolidated, while its use for ES remains controversial. Ethical concerns, especially regarding the distinction between PS, euthanasia, and assisted dying, are common among healthcare professionals. The hesitation regarding the use of PS for ES by these professionals is legitimate, considering the lack of robust evidence showing the efficacy of PS for refractory ES, as well as clear guidelines to support these professionals regarding the definition of refractory ES, how to identify it, and how to use PS in these cases. In addition, the training and experience in PS of healthcare professionals influences decision-making, suggesting that their education and training are essential to ensure the adequate practice of PS.Open Science Framework (https://doi.org/10.17605/OSF.IO/XZ3UR). [ABSTRACT FROM AUTHOR]

CaO-MgO-SiO 2 insulating refractories were prepared using phosphorus tailings through in-situ pore-forming technology in this work, aiming to achieve the efficient utilization of solid waste phosphorus tailings. microsilica was used to react with free CaO generated by the decomposition of dolomite from phosphorus tailings during the calcination in order to prevent the hydration of CaO in the materials. The influence of microsilica addition and heating temperature on the properties of insulating refractories prepared from phosphorus tailings was investigated. The results showed that CaO-MgO-SiO 2 insulating refractories with 8.8 wt% microsilica addition exhibited excellent comprehensive performance after heating at 1300 °C for 3 h. The insulation refractories prepared from phosphorus tailings were anti-hydration, had lower thermal conductivity, and could be used as insulation refractories for high-temperature kilns. [ABSTRACT FROM AUTHOR]

The effect of refractory periods in partial resetting processes is studied. Under Poissonian partial resets, a state variable jumps to a value closer to the origin by a fixed fraction at constant rate, x → a x . Following each reset, a stationary refractory period of arbitrary duration takes place. We derive an exact closed-form expression for the propagator in Fourier–Laplace space, which shows rich dynamical features such as connections not only to other resetting schemes but also to intermittent motion. For diffusive processes, we use the propagator to derive exact expressions for time dependent moments of x at all orders. At late times the system reaches a non-equilibrium steady state which takes the form of a mixture distribution that splits the system into two subpopulations; trajectories that at any given time in the stationary regime find themselves in the freely evolving phase, and those that are in the refractory phase. In contrast to conventional resetting, partial resets give rise to non-trivial steady states even for the refractory subpopulation. Moments and cumulants associated with the steady state density are studied, and we show that a universal optimum for the kurtosis can be found as a function of mean refractory time, determined solely by the strength of the resetting and the mean inter-reset time. The presented results could be of relevance to growth-collapse processes with periods of inactivity following a collapse. [ABSTRACT FROM AUTHOR]

Many important archaeological sites in Iraq still need to be preserved. Some of these sites were subjected to destruction and negligence. So, exploring these sites represents a priority for its protection. A 2D Electrical Resistivity Imaging (ERI) as a non-invasive geophysical survey method was implemented at a part of the Borsippa archaeological site near Babylon to search for the subsurface archaeological artefacts/structures. Electrical resistivity measurements were carried out using a Dipole-Dipole array. Steps were taken to process and filter using Horizontal profiles, forward modelling, and 2D inverse models to analyze the resistivity measurements. The ERI inversion results show that the superficial conductive zone produced variations in ERI inverse models. The low resistivity caused by the relatively high conductivity was observed due to rainwater leaking into the topsoil zone. The ERI sections revealed a coherent depth of approximately 7 meters and the anomalies geometry and semi-layering soil. These changes can be attributed to the high resistivity contrast between the relatively high-resistivity anomalies and the surrounding intact soil. The soil types include dry silty and clayey soils and crushed refractory materials such as broken bricks and ruins mixed with rock pulp. These materials have resulted in the collapse of walls due to weathering and erosion. Based on the identified patterns, shallow-depth high-resistive anomalies are present and extend throughout some parts of the study area. These anomalies are represented in a SW-NE trend of the mound area. At the bottom of this zone is another zone with low resistance values and variable thickness, which varies from place to place within the study area. The results proved the efficiency of the ERI technique in detecting archaeological wall-like artefacts, which represents a data bank for any future archaeological prospection. [ABSTRACT FROM AUTHOR]

Background: Lysophosphatidic acid (LPA) receptor 3 (LPA3) is involved in many physiological and pathophysiological actions of this bioactive lipid, particularly in cancer. The actions of LPA and oleoyl-methoxy glycerophosphothionate (OMPT) were compared in LPA3-transfected HEK 293 cells. Methods: Receptor phosphorylation, ERK 1/2 activation, LPA3-β-arrestin 2 interaction, and changes in intracellular calcium were analyzed. Results: Our data indicate that LPA and OMPT increased LPA3 phosphorylation, OMPT being considerably more potent than LPA. OMPT was also more potent than LPA to activate ERK 1/2. In contrast, OMPT was less effective in increasing intracellular calcium than LPA. The LPA-induced LPA3-β-arrestin 2 interaction was fast and robust, whereas that induced by OMPT was only detected at 60 min of incubation. LPA- and OMPT-induced receptor internalization was fast, but that induced by OMPT was more marked. LPA-induced internalization was blocked by Pitstop 2, whereas OMPT-induced receptor internalization was partially inhibited by Pitstop 2 and Filipin and entirely by the combination of both. When LPA-stimulated cells were rechallenged with 1 µM LPA, hardly any response was detected, i.e., a "refractory" state was induced. However, a conspicuous and robust response was observed if OMPT was used as the second stimulus. Conclusions: The differences in these agents' actions suggest that OMPT is a biased agonist. These findings suggest that two binding sites for these agonists might exist in the LPA3 receptor, one showing a very high affinity for OMPT and another likely shared by LPA and OMPT (structural analogs) with lower affinity. [ABSTRACT FROM AUTHOR]

The temperature and pressure conditions experienced by rocks during an impact event can be constrained using petrologic and microstructural analysis and is crucial to providing ground truth to the impact cratering process. Suevite is a polymict, impact melt‐bearing breccia, specific to Ries crater in Germany. There are competing models for suevite formation and emplacement, such as clastic flows pushed out of the crater rim or ejecta plume fallback. Knowledge of the temperature and pressure pathways recorded by grains within the suevite can help distinguish between these and other models. The accessory phase zircon (ZrSiO4) and its high‐pressure polymorph reidite are particularly useful in such circumstances as they are highly refractory minerals that can record the high‐temperature and/or high‐pressure conditions of an impact event. Here, we present evidence for a wide array of temperature and pressure conditions recorded in zircon grains within a single thin section of suevite. Zircons in this study range from unshocked to highly shocked (>53 GPa), and record temperatures more than 1673°C. These findings confirm previous studies concluding that suevites contain material exposed to very diverse pressure and temperature conditions during initial shock compression and excavation but do not, as a whole, experience extreme temperatures (>1673°C) or pressures (>30 GPa). [ABSTRACT FROM AUTHOR]

Cost-effective decarbonization and structural strengthening of carbon-containing refractory materials are crucial for the development of low-carbon steel (LCS) and ultra-low-carbon steel (ULCS) technologies. In this study, a carbonaceous-ceramic reinforcement assembly structure composed of multilayer graphenes and silicon carbide whiskers/particles (MLGs-SiC w /SiC p) has been successfully designed and fabricated. By employing three-roll milling (TRM) for low-cost exfoliation of expanded graphite (EG) into MLGs in a phenolic resin (PF) medium, we optimized the exfoliation cycles to fine-tune the morphology of MLGs. Subsequently, the catalytical solid-state conversion of PF/MLGs reacting with Si into SiC w /SiC p at 1400 °C, under varying C/Si molar ratios and catalyst contents, not only retained the structural integrity of MLGs but also embedded them within a novel SiC w /SiC p composite matrix. Our research elucidates the catalytic conversion mechanism, underscoring the significant role of nickel catalysts in promoting efficient SiC conversion. This work offers a promising pathway for developing high-performance, economical, low-carbon refractories. [ABSTRACT FROM AUTHOR]

Alumina-silica based refractories have found vast applications in various industries due to their strong resistance to corrosion and price advantages. In this research work high temperature corrosion resistance of aluminosilicate refractories against silicate melt was investigated. Various refractory brick matrices based on bauxite, chamotte and andalusite were prepared. The microstructure and chemical characteristics before and after corrosion cup test, as well as physical and mechanical properties were evaluated. The results indicated that corrosion resistance is increased in the following order of chamotte < bauxite < andalusite. Chemical composition and porosity were considered as determinant factors influencing corrosion process and mechanical properties of the refractory bricks. Low porosity of the andalusite aggregates raised the corrosion resistance by making limitations for melt infiltration into refractory material. Low mullitization of andalusite reduced the density and mechanical strength in comparison with other aluminosilicates. [ABSTRACT FROM AUTHOR]

In the current research, a successful and fast synthesis of gold nanoparticles (AuNPs) by utilizing the leaf extract of Eryngium planum is reported. In order to analyze the influential synthesis parameters, the Plackett-Burman (PB) design was utilized, while the response surface methodology (RSM) was employed for optimization purposes. Furthermore, the achieved AuNPs were applied in the production of the Au-MoS2 nanocomposite. The efficiency of the visible-light photocatalyst was examined in the photocatalytic decolorization of the refractory azo dye, Acid Blue 113 (AB113). A high dye removal efficiency (94%) was observed under the optimal conditions of pH 7.6 using 15.5 mg of Au-MoS2, and 14 min. These results proved that the fabricated Au-MoS2 photocatalyst using biogenic AuNPs was more efficient than pure MoS2 and could be used as a promising catalyst for the degradation of dye-containing effluents. [ABSTRACT FROM AUTHOR]

Coatings based on refractory metals and compounds have been used in various industries since the last century due to their high thermal and heat resistance, as well as their excellent mechanical and tribological properties. Advances have made it possible to apply high-tech methods for their production, which has improved their availability and expanded their range of applications. A promising area of use of coatings based on refractory systems is the anticorrosion protection of structural materials. The high wear resistance and anticorrosion ability of these materials will allow for the protection of critical units of equipment of various industries from the complex destructive effects of factors of chemical and mechanical nature. For the effective choice of coating composition, it is necessary to know the basic characteristics of refractory material layers and the method of their production. The purpose of this article is to summarize modern scientific data on methods of obtaining refractory coatings, as well as on their composition, structure, and protective properties. The information presented in this review will bridge the gap between research and industrial development and expand the niche area of utilization. [ABSTRACT FROM AUTHOR]

Electric arc furnaces are commonly used in foamed slag technology for the production of steel from steel scrap through an electric process. The effects of using this technology include increased efficiency, reduced consumption of refractory materials, reduced energy consumption, reduced electrode wear, and improved arc stability. The world is constantly looking for solutions to optimize the feeding of the foaming agent to the electric furnace, including determining the moment of starting its feeding. The authors propose using two parameters to determine the optimal moment of introducing the foaming agent: the change in the sound level emitted by the arc furnace and the fluctuations in active power consumption. In order to determine the above parameters, tests were carried out on an industrial alternating UHP arc furnace with a capacity of 70 tons. The sound intensity level was determined at which the feeding of the foaming agent to the furnace's working space should begin. A moving coefficient of power consumption variation was developed and decision variables of the software for online foaming agent feeding were determined. As a result of implementing the developed solutions to the electric furnace control system and conducting comparative tests, savings were obtained in the form of reduced foaming agent consumption. [ABSTRACT FROM AUTHOR]

An important issue in obtaining a good casting surface without defects in contact with the liquid metal is the use of protective coatings on the surface of the moulding sand forming the mould cavity. Protective coatings are based on highly refractory materials that are finely ground and protect the moulding sand from thermal stresses from the molten metal. An important aspect of obtaining the appropriate properties of the protective coatings used is the method of application. This article presents the results of a quality study of the protective coatings obtained, which were applied by dip and painting with a brush. Four different coatings were applied to mould sand samples prepared on grain matrices with different average grain sizes. During the tests, the viscosity of the protective coatings, their gas-forming capacity, sieve analyses of the grain matrix used, the permeability of the moulding sand with the protective coating and the abrasiveness and adhesion of the protective coatings were determined. The quality of the coating obtained was found to depend on its type, the size of the grain matrix used in the moulding sand and the method of application. The experiments carried out indicate that a comparative study of the available protective coatings can indicate the best solution, taking into account the grain matrix used and the method of application adopted. [ABSTRACT FROM AUTHOR]

On the rising demand for eco‐friendly refractories, reducing the use of likely toxic magnesia‐chromium aggregates remains a challenge. Previous studies by some of the authors have proposed Cr‐free alternative compositions, although the morphology of the spinel precipitates has varied across the different suggested systems. The mechanisms involved in the formation of these distinct morphologies were unclear and, therefore, are the focus of this work. In all compositions, SEM/electron backscatter diffraction revealed cube–cube orientation relationships between matrix and precipitates, indicating that their formation is influenced by the lattice parameter misfit (δ), which was measured using synchrotron X‐ray diffraction. It could be concluded that coarser and spherical precipitates form to minimize their surface‐to‐volume ratio in compositions with high absolute δ‐values. Conversely, low‐misfit systems enable the spinel to form a 3D‐network. The potential use of this knowledge to tailor the microstructure of novel compositions was demonstrated by a small Nb2O5 addition into one of the proposed compositions. [ABSTRACT FROM AUTHOR]

Reducing dependence on toxic electrofused magnesia‐chromium aggregates is essential to meet demands for eco‐friendly refractories. Some authors have proposed alternative compositions using lab‐scale electrofusion to produce small specimens (< 0.5 g). However, this size limits the evaluation of key refractory properties, such as thermal expansion. As an alternative, this study explored conventional sintering at 1600°C for 5 h and both methods resulted in equivalent chemical and mineralogical compositions. Despite presenting higher porosity (24 % – 30 %) than the electrofused ones (4 % – 6 %), consistent microstructural parameters supported using the sintering route to produce larger specimens (5 × 5 × 25 mm3), which were assessed for dilatometric profiles up to 1400°C. Combined with thermodynamic calculations, Rietveld's refining of X‐ray diffraction patterns and differential scanning calorimetry, the dilatometric analysis indicated that spinel dissolution in the periclase causes a high expansion during heating, whereas its re‐precipitation results in shrinkage. As this behavior could result in challenges for the refractory lining design, computational thermodynamics was used to find additives capable of increasing this transition temperature. TiO₂ was identified as a promising candidate and its effectiveness was attested. [ABSTRACT FROM AUTHOR]

Boron phosphide (BP) is a (super)hard semiconductor constituted of light elements, which is promising for high demand applications at extreme conditions. The behavior of BP at high temperatures and pressures is of special interest but is also poorly understood because both experimental and conventional ab initio methods are restricted to studying refractory covalent materials. The use of machine learning interatomic potentials is a revolutionary trend that gives a unique opportunity for high-temperature study of materials with ab initio accuracy. We develop a deep machine learning potential (DP) for accurate atomistic simulations of the solid and liquid phases of BP as well as their transformations near the melting line. Our DP provides quantitative agreement with experimental and ab initio molecular dynamics data for structural and dynamic properties. DP-based simulations reveal that at ambient pressure, a tetrahedrally bonded cubic BP crystal melts into an open structure consisting of two interpenetrating sub-networks of boron and phosphorous with different structures. Structure transformations of BP melt under compressing are reflected by the evolution of low-pressure tetrahedral coordination to high-pressure octahedral coordination. The main contributions to structural changes at low pressures are made by the evolution of medium-range order in the B-subnetwork and, at high pressures, by the change of short-range order in the P-subnetwork. Such transformations exhibit an anomalous behavior of structural characteristics in the range of 12–15 GPa. DP-based simulations reveal that the Tm(P) curve develops a maximum at P ≈ 13 GPa, whereas experimental studies provide two separate branches of the melting curve, which demonstrate the opposite behavior. Analysis of the results obtained raises open issues in developing machine learning potentials for covalent materials and stimulates further experimental and theoretical studies of melting behavior in BP. [ABSTRACT FROM AUTHOR]

Valence electron concentration (VEC), atomic size difference (δ), and Pugh's ratio (B/G) are a few of the empirical parameters widely used to design ductile refractory alloys. Here, we used the intrinsic ductility parameter (D), which is the ratio of surface energy (γ s) and unstable stacking fault energy (γ u s f e ), to design ductile refractory alloy. We found that the D correctly captures the experimentally observed ductility in concentrated refractory alloys. Here, we studied the enthalpy of formation (Δ E f), lattice distortion, and D of 9 refractory metals and 36 equiatomic refractory alloys using density functional theory simulations. We found that the Δ E f strongly influences the D of concentrated refractory alloys. The positive Δ E f and δ lead to large lattice distortion in concentrated refractory alloys. However, we did not find a strong correlation between lattice distortion and D in the presently studied alloys. We found that the success of VEC and Pugh's ratio in designing ductile refractory alloys has a strong dependence on the underlying Δ E f of the alloy. We have developed a bottom-up method, which drastically reduces the number of alloys to be studied, to design ductile concentrated refractory alloys that can be thermodynamically stable. [ABSTRACT FROM AUTHOR]

Conventional preheating methods for large steelmaking ladles typically use natural gas or liquified petroleum gas burners, which often have low thermal efficiencies depending on the fuel and oxidizer used. Common issues with these burners include lower overall bottom ladle temperatures and initiating decarburization in newly lined ladles with carbon‐rich refractory materials caused by the entrainment of air and combusting by‐products. In response to these issues, this study investigates the feasibility of using DC plasma torches for ladle preheating with nitrogen as carrier gas. Numerical models are developed to simulate ladles preheated by plasma torches, considering two variations: a 0.7 and a 1.5 MW torch. Additionally, a comparative model for a natural gas‐heated ladle is developed. The numerical results show that ladles heated by plasma torches achieve higher overall bottom temperatures due to strong convective heat flux, with average bottom temperatures of 983 and 1402 °C for 0.7 and 1.5 MW torch respectively, compared to 874 °C for natural gas heated ladle. The developed models are validated with industrial measurements on full‐sized ladles, confirming the feasibility of using plasma torches for preheating steelmaking ladles to temperatures similar to or higher than those achieved by conventional gas burners. [ABSTRACT FROM AUTHOR]

The manufacture of products from refractory ceramics requires high temperatures due to the high activation energies of the sintering process of refractory oxides. Processing temperatures for ceramics made of ZrO 2 , Al 2 O 3 , MgO can be reduced if a flux or glass-forming component is selected. Furthermore, in multicomponent ceramics it is possible to create more favorable thermoresistive properties. This study examines the synthesis, structural, phase and mechanical properties of multicomponent porous ZrO 2 -WO 3 -Al 2 O 3 -MgO ceramics with varying weight concentrations of components. Experimental samples were obtained by standard solid state reaction method. The analysis of fabricated samples was carried out using X-ray phase analysis, scanning electron microscopy and the Vickers microhardness test. In this work, a new approach to increasing the microhardness of porous refractory ceramics is presented, in which WO 3 -based flux forms a matrix composed of glass-like formations that "attach" particles of ZrO 2 and MgAl 2 O 4 phases. The obtained ceramics demonstrates high microhardness values HV0.05 for porous materials ranging from 500 to 600. Studies have shown that the selected composition of multicomponent ceramics (x = 0.10–0.25) can be used as a refractory material up to temperatures of ∼1300 °C. The fabricated refractory ceramics potentially possess chemical stability and optimal microhardness properties, which makes these materials promising as a heat insulating lining in the metals, ceramics and glass manufacturing, as well as for components in the chemical industry. [ABSTRACT FROM AUTHOR]

The (Al 1-x Cr x) 2 O 3 solid solution (ACS) is expected to be an low pollution chromium source for high-performance alumina-chromium oxide refractory materials. In this work, the effects of Cr 2 O 3 content and reaction conditions on the solid solution behavior in the Al 2 O 3 -Cr 2 O 3 system were explored and the mechanism was revealed. The relationship between the lattice parameters of the formed ACS phase and the content of Cr 2 O 3 was closer to a linear one as the temperature rose, serving as an indicator for a higher degree of reaction. The solid solution reaction between Al 2 O 3 and Cr 2 O 3 was governed by the diffusion processes of Al3+ and Cr3+ at 1300–1500 °C and 1200 °C, respectively, and thus the increase of Cr 2 O 3 content slowed the solid solution reaction at a low temperature whereas promoted it at elevated temperatures. The diffusion process of solid solution reaction within the Al 2 O 3 -Cr 2 O 3 system was consistent with the Cater model; The diffusion activation energy (E a) decreased as the content of Cr 2 O 3 increased at 1300–1500 °C. When the content of Cr 2 O 3 increased from 25 to 60 mol%, the diffusion activation energy decreased from 92.48 to 86.49 kJ/mol−1, which was attributed to the augmentation in the diffusion rate of Cr3+ caused by the increase of Cr 2 O 3 content and its vapor-phase transport mechanism at high temperatures. [ABSTRACT FROM AUTHOR]

MgO-SiC-C refractories demonstrate distinguished thermal shock resistance and slag resistance, making them a promising alternative to magnesia-chrome refractories in matte smelting furnaces. Herein, we propose a novel approach to enhance both oxidation resistance and slag penetration resistance of such refractories by incorporating Si 3 N 4 -Fe powder. The results demonstrated that adding Si 3 N 4 -Fe powder effectively enhanced their overall performance. The oxidation resistance of the specimen with 6 wt% Si 3 N 4 -Fe was greatly improved because Si 3 N 4 in Si 3 N 4 -Fe could promote in-situ reactions to form more forsterite, and the FeO formed by iron oxidation could react with SiC to form Fe-Si alloys; the formed forsterite and Fe-Si alloys worked together to prevent oxygen intrusion. Meanwhile, Si 3 N 4 in Si 3 N 4 -Fe promoted the formation of forsterite layer in the corrosion area of refractories, and the reaction of Si 3 N 4 and Fe in Si 3 N 4 -Fe formed Fe-Si alloys to prevent slag penetration, which greatly improved the resistance to matte slag penetration of the refractories. [ABSTRACT FROM AUTHOR]

This study investigated the degradation mechanisms of SiC-MgAl 2 O 4 refractory materials in a bench-scale entrained flow gasifier. Layered degradation and protective SiO 2 formation on SiC aggregates were observed by macroscopic, microscopic, phase analysis, and thermodynamic calculations. A comparative investigation of erosion rates revealed that SiC-MgAl 2 O 4 materials located away from the burner had an unusually low erosion rate of 0.0017 mm/h, which was significantly lower than that reported in their counterparts situated near the burner (0.0167 mm/h). This performance surpassed even that of high-chrome refractory materials positioned at a similar distance from the burner. The findings underscore the remarkable durability of SiC-MgAl 2 O 4 , demonstrating its significant potential as a sustainable and chrome-free alternative for application in harsh gasification conditions. The environment-specific degradation patterns, characterized by the formation of mullite and cordierite, revealed the complex interaction between refractory materials and gasification environments. This understanding offers valuable insights that can inform the development and implementation of chrome-free refractory materials under industrial gasification conditions. [ABSTRACT FROM AUTHOR]

Tantalum carbide (TaC) is an extremely hard, brittle, refractory ceramic material with excellent physical properties, which makes it a desirable material in e. g. aerospace industries. In order to explore the range of feasible modifications of TaC, we have executed a crystal structure prediction study of the TaC chemical system using a multi‐methodological approach, via enthalpy landscape explorations of pristine TaC at different pressures, supplemented by data mining searches in the ICSD database. Local structure relaxations have been accomplished by using Density Functional Theory (DFT). The global minimum is found to correspond to the equilibrium rock salt (NaCl) type modification. Additionally, eight new phases of tantalum carbide are predicted to be feasible: the WC‐type, the NiAs‐type, the 5‐5‐type, the ZnS‐type, the Ring_TaC‐type, the CsCl‐type, the Ortho_TaC‐type, and the Tetra_TaC‐type. Furthermore, the elastic and mechanical properties of the predicted TaC modifications were explored on the DFT level of computation. The promising values of some of the mechanical properties of the proposed tantalum carbide modifications suggest that various scientific, industrial, and technological applications of TaC should be possible. [ABSTRACT FROM AUTHOR]

Pyrometallurgical recycling of lithium-ion batteries (LIB) has emerged as the go-to approach in industrial recycling solutions, yet it encounters significant challenges, such as lithium (Li) slagging. This study explores a reactor for pyrometallurgical recycling, that offers the potential to overcome this bottleneck by simultaneously recovering lithium and phosphorous (P) via the gas stream, more noble elements including cobalt (Co), nickel (Ni) and copper (Cu) as an alloy and less noble elements like aluminum (Al), calcium (Ca) and silicium (Si) as a slag. However, to enhance the efficiency and performance of this reactor, a critical focus is placed on evaluating refractory materials with reduced corrosion and diffusion characteristics. Already explored refractory materials, including aluminum oxide (Al 2 O 3) or magnesium oxide (MgO), have exhibited severe issues, such as accelerated corrosion and diffusion rates, leading to diminished performance and compromised efficiency. To evaluate a more suitable refractory material for pyrometallurgical recycling of LIB, tests using silicon carbide (SiC), chromium(III)-oxide (Cr 2 O 3) and zirconium dioxide (ZrO 2) were performed up to 1600 °C. The test results indicate that the investigated refractory materials offer distinct advantages and disadvantages. While SiC shows minimal to no wear by corrosion, Cr 2 O 3 exhibits higher resistance to Li diffusion. Contrary, ZrO 2 experienced severe corrosion and crack formation, showing unsuitability for LIB recycling. Based on these findings, a continuously operated reactor could use different refractory materials in specific zones. While the degasification zone could benefit from Cr 2 O 3 's minimal diffusion properties, areas with intense contact between the crucible and melt could utilize SiC's corrosion resistance. However, partial oxidation at the outer surface of the SiC crucible led to the formation of SiO 2 , another critical point to consider for scale-up plans, as it might influence the mechanical integrity long-term. [ABSTRACT FROM AUTHOR]

The glow-to-arc transition is a critical phenomenon in plasma discharges, commonly leading to detrimental effects. The physical mechanisms triggering this transition remain poorly understood. The advent of a discharge called Hyper-Power Impulse Magnetron has opened possibilities. Hyper-Power Impulse Magnetron allows the glow mode to be maintained over long periods (1 ms) and at high-current densities (>5 A . cm − 2 ), which has unveiled certain features in the glow-to-arc transition. This work focuses on a graphite target that transits easily in the arc regime. The high-speed video-camera analysis revealed specific properties of graphite in ExB discharges, and the statistical study of the arc transition revealed differences from other refractory target materials. The early stage of cathodic spot formation, observed as bright dots, will be presented and analyzed within the known "ecton" and "vaporization" models for spot formation. This experimental study highlights the role of luminous spot formation prior to arc transition, with possible optimization on the stability of magnetron discharges. [ABSTRACT FROM AUTHOR]

High-purity magnesia refractories were fabricated by brine magnesium hydroxide from the salt-lake brine (Qinghai Salt Lake) and Y 2 O 3 as an additive at 1780 °C. It avoided the substantial CO 2 emissions and ultra high temperature sintering process (＞1900 °C) when compared with the conventional magnesite-calcination technical approach. The results confirmed that Y 2 O 3 was dispersed on the MgO grains boundaries in the fabricated MgO aggregates, resulting in a decrease in apparent porosity and enhancing the grains' boundaries. With 3 wt% addition of Y 2 O 3 , the apparent porosity and bulk density of the sample reached to 15.9 % and 3.10 g/cm3 from 37.9 % to 2.30 g/cm3 of blank control group, respectively. Compared to the blank control without Y 2 O 3 -adding, the sample with 5 wt% Y 2 O 3 exhibited a 54.17 % increase in the resistance to molten slag. SEM results indicated that the incorporation of Y 2 O 3 in samples increased the porosity of small pores and enhanced grains boundaries, thereby suppressing slag's penetration. Furthermore, the Y 2 O 3 -adding was employed to disperse the MgO grains boundaries and existed as separate phases for grains boundaries enhancement. The slag attack of the fabricated MgO–Y 2 O 3 refractory raw materials were controlled by an inter-crystalline corrosion process. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) are crucial additives in the iron and steel industry. The accurate determination of thermodynamic data is fundamental for applying REEs in steel production; however, this has proven challenging due to their strong reactivity with refractory materials. This study assessed the thermodynamic data for the yttrium–oxygen equilibrium in liquid iron, using high‐temperature experiments with high‐purity Y2O3 crucibles as the smelting container. More reliable equilibrium constants and first‐order interaction coefficients are obtained by minimizing the reactions between yttrium and the crucible while ensuring favorable kinetic conditions. The results confirm that the deoxidation product of yttrium in liquid iron is Y2O3, and the equilibrium constant for the reaction Y2O3(s) = 2[Y] + 3[O] can be expressed as follows: logKY(KYO=aY2aO3/aY2O3)=−63585/T+20.18, 1600−1700 °C$$ \mathrm{log}{K}_{\text{Y}}({K}_{\text{Y}}^{\text{O}}={a}_{\text{Y}}^{2}{a}_{\text{O}}^{3}/{a}_{{\text{Y}}_{2}{\text{O}}_{3}})=-63585/T&amp;amp;amp;amp;amp;amp;amp;amp;plus;20.18,&amp;amp;amp;amp;amp;amp;amp;amp;nbsp;1600-1700&amp;amp;amp;amp;amp;amp;amp;amp;nbsp;&amp;amp;amp;amp;amp;amp;amp;amp;deg;\mathrm{C}$$. K′Y=([%Y]2[%O]3)$K &amp;amp;amp;amp;amp;amp;amp;amp;aposx;_{\text{Y}} &amp;amp;amp;amp;amp;amp;amp;amp;equals; \left(\right. \left(\left[\right. \% \text{Y} \left]\right.\right)^{2} \left(\left[\right. \% \text{O} \left]\right.\right)^{3} \left.\right)$ can be expressed as: logK′Y=logKY−(−31028/T+8.06)(3[%Y]+11.1[%O]), 0.003 wt%<[Y]<0.23 wt%$$ \mathrm{log}K{\prime }_{\text{Y}}=\mathrm{log}{K}_{\text{Y}}-(-31028/T&amp;amp;amp;amp;amp;amp;amp;amp;plus;8.06)(3[\%\text{Y}]&amp;amp;amp;amp;amp;amp;amp;amp;plus;11.1[\%\text{O}]),&amp;amp;amp;amp;amp;amp;amp;amp;nbsp;0.003&amp;amp;amp;amp;amp;amp;amp;amp;nbsp;\text{wt\%}&amp;amp;amp;amp;amp;amp;amp;lt;[\text{Y}]&amp;amp;amp;amp;amp;amp;amp;lt;0.23&amp;amp;amp;amp;amp;amp;amp;amp;nbsp;\text{wt\%}$$. The first‐order interaction coefficient can be presented as: eOY=−31028/T+8.06$e_{\text{O}}^{\text{Y}} &amp;amp;amp;amp;amp;amp;amp;amp;equals; - 31028 / T &amp;amp;amp;amp;amp;amp;amp;amp;plus; 8.06$. [ABSTRACT FROM AUTHOR]

Preventing the oxidation of oxide‐C refractories used as working linings in steelmaking vessels is crucial for maintaining their performance and extending their lifetime. This study introduces a novel methodology for evaluating and quantifying the protective effect that adhered slag can have on the oxidation of the refractory lining of steelmaking ladles. The article details the ad‐hoc methodology itself, including the technique for adhering the slag to the refractory sample and the specifically developed equipment used. The proposed experimental approach includes the evaluation of how the environmental degradation of the slag layer affects the protection it provides to the refractory against attack by environmental oxygen. Finally, the methodology's ability to provide reliable and reproducible results is shown by its application on MgO–C refractories, the most widely used type of oxide‐C products in the steelmaking industry. [ABSTRACT FROM AUTHOR]

The valorization of slag from the production of high-carbon ferrochrome is a challenge for ferrochrome producers. The recycling of high-carbon ferrochrome slag was explored through the smelting route to recover Fe–Si–Al–Cr alloys and reengineer the residual slag for alumina-enriched refractory material. In this research, the focus was to reduce the SiO2% and enrichment of Al2O3% in the final slag and recover the metallic value in the form of a complex alloy containing Fe, Si, Cr and Al. The manuscript consists of a thermochemical simulation of the smelting of FeCr slag followed by smelting experiments to optimize the process parameters such as temperature and the addition of coke, cast iron and alumina. An experimental investigation revealed that the maximum recovery of Si (57.4% recovery), Al in the alloy (20.56% recovery) and Al2O3 (85.78% recovery) in the slag was achieved at a charge mix consisting of 1000 g of FeCr slag, 300 g of alumina, 200 g of cast iron and 300 g of coke. The present study also demonstrated the usefulness of prior thermochemical calculations for smelting metallurgical wastes such as slag from high-carbon ferrochrome production for value creation and reutilization purposes. [ABSTRACT FROM AUTHOR]

Uruguayan philosopher Carlos Vaz Ferreira published in 1910 Lógica viva, his main philosophical work. In it he presents a logical exploration program, its foundations and some of its applications. As part of these, he studies various paralogisms which can be enhanced by appealing to a methodology that I called "model M". But this model does not manage to cover all the paralogisms proposed by Vaz. Other types of stereotyped errors are refractory to such treatment, which I call non-argument paralogisms; for example, false precision. In this paper I will suggest an alternative model M* and apply it to false precision. [ABSTRACT FROM AUTHOR]