bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of C/A ratio on the crystallisation behaviour and structure of calcium-aluminate based alternative mold fluxes for casting medium and high Mn/Al steels
Authors:   IIT Kanpur, Nigam A , Biswas K ,   IIT Kanpur, Sarkar R ,   IIT Kanpur
Published: September 2024

Because of the problems with 1st and 2nd generations of Advanced High-Strength Steels (AHSS), a 3rd generation of AHSS steels has become prominent and these steels have properties in between the 1st and 2nd generations of AHSS. However, although the 3rd generation of AHSS is a promising candidate as a replacement for its predecessors, there remain some challenges in processing these steels which are essentially medium Mn (Mn content ~ 5–7 wt per cent) and high Al (Al content ~ 1–3 wt per cent) steels. The use of conventional casting powders based on the CaO-SiO2 system is unsuitable for high and medium Mn/Al steels. This work investigates the development of CaO-Al2O3-based mold fluxes for casting third-generation AHSS steel. Mold fluxes, with otherwise similar compositions but different C/A ratios, are tested and their crystallisation behaviour is examined using differential scanning calorimetry (DSC). A calcium aluminate phase having a composition Ca12Al14O33 was found to be the main crystalline phase in the mold fluxes. A decrease in crystallisation temperature was observed as the CaO/Al2O3 ratio increased from 1.00 to 1.33. The effective crystallisation rate constant exhibited an increase with decreasing crystallisation temperature, indicating a potential influence of nucleation rate on the overall crystallisation rate and suggesting an anti-Arrhenius behaviour in the crystallisation process of these mold fluxes.
Characterisation and assessment of B2O3 added LF slag
Authors:   Rashtriya Ispat Nigam Limited, Varanasi S S , Kakara S ,   IIT Hyderabad, Mandalika B V R ,   Rashtriya Ispat Nigam Limited, Shaik M B ,   IIT Hyderabad, Kamaraj A ,   IIT Hyderabad
Published: September 2024

The properties of top slags play a very important role in secondary steelmaking. Fluxes should be chosen based on the ladle furnace (LF) slag requirements like viscosity, melting temperature, sulfide capacity, etc. CaF2 and CaO-Al2O3-based synthetic slags are the most used fluxes in secondary steelmaking to improve slag fluidity and interfacial chemical reactions. CaF2 is obsolete due to fluorine pollution and CaO-Al2O3 based slags have 40–50 wt per cent Al2O3 and 30–40 per cent CaO which is not beneficial for desulfurisation. Yet another drawback is that LF slag disintegrates into fine powder during cooling due to phase transformation C2S (2CaO.SiO2). Hence, there is a need for the development of low melting fluxes with high CaO content and the capability to prevent slag disintegration. The current work studied the effect of 0–9 wt per cent B2O3 on physico-chemical properties and characterisation of LF slags. X-ray diffraction (XRD) analyses were carried out to identify mineralogical phases present in slag and Fourier-transform infrared spectroscopy (FT-IR) analysis was done to understand the changes in bonds of B2O3 added LF slag. The characteristic temperature of slag was determined by a hemispherical method using high-temperature microscopy. Empirical models were used to calculate viscosity, break temperature, and sulfide capacity. FactSage™, ver 8.2 (by GTT-Technologies) simulations were carried out to find the equilibrium phase fractions and percentage of liquid slag at different temperatures. New phases such as Ca11B2Si4O22 and Ca2B3O5 were formed in LF slag with B2O3 addition. Based on the results, 0.5–1.0 wt per cent B2O3 was found to be sufficient to prevent C2S-driven disintegration of LF slag. Also, the melting temperature and viscosity of LF slag were reduced by adding 3–8 wt per cent B2O3 due to the formation of BO3 planar triangular structure and low melting eutectics in slag. Liquid slag started forming at a temperature as low as 800°C when B2O3 is >6 wt per cent. It was found that the sulfide capacity, viscosity, and break temperature of the slag decreased with increasing wt per cent B2O3. Based on the analysis carried out, B2O3 can be a promising fluxing material in secondary steelmaking, for improving the desulfurisation kinetics and valourisation potential of LF slag.
Continuous method of thermodynamic optimisation using first-derivative matrices for large multicomponent systems
Authors:   University of Queensland, Nekhoroshev E , Shishin D ,   University of Queensland, Shevchenko M ,   University of Queensland, Jak E ,   University of Queensland
Published: September 2024

Real-life applications require thermodynamic databases consisting of many elements. Currently, Pyrosearch supports a 20-component thermodynamic FactSage™, ver 8.2 (by Thermfact and GTT technologies) database for Cu-, Pb- and Fe-production provided to a group of industrial sponsors. The database development follows an agile cycle of experiment planning, modelling/update of database subsystems, quality tests and release. A unique challenge is development and maintenance of a database self-consistent across all binary/ternary and multicomponent systems. Practice shows that binary and ternary system data do not provide the necessary accuracy for predictions within multicomponent systems. Commercial databases are often developed using only available literature data and it is hard to estimate the prediction quality for industry-relevant multicomponent compositions. Therefore, to sustain a high reliability there is a need of targeted experiments including multicomponent data. To support the continuous development process, a new optimisation methodology has been developed. After long years of optimisation experience, it is an authors’ belief that for optimisation, it is essential to pinpoint a few trusted target points instead of using a whole cloud of available experimental data. In case if the optimisation procedure is automated, using all data, even with trust weights, still leads to inferior optimisation quality. This is caused by the fact that available optimisation algorithms usually assume a normal error distribution of experimental data which can be false in cases when experimental results are affected by sample contamination, evaporation, incomplete reactions, etc. Typically, iterative optimisation involves multiple re-calculations of targets values which can take significant time and the whole procedure is not interactive. It is hard to find an exact combination of target weights to achieve desired outcomes. This problem has been solved by the authors by replacing slow FactSage™/ChemApp™ calculations by parameter value/target value relations using first-order derivative matrices. Precalculated derivative matrices allow fast analysis of parameter influence across multiple systems, selection of interaction combinations with superior performance, and analytical matrix solution to the optimisation problems using weighted linear least squares. The current optimisation system supports in-sheet ChemApp™ (by GTT-technologies, version 614) calculations for Microsoft® Excel® using custom Python® binding code, graphical and statistical representation of experimental data and target points, and real-time first-derivative matrix analysis of parameter sensitivity.
Distribution of Pb, Zn, Fe, As, Sn, Sb, Bi and Ni between oxide liquid and metal in the ‘CuO0.5’-CaO-AlO1.5 system in equilibrium with Cu metal at 1400°C
Authors:   University of Queensland, Khartcyzov G , Shevchenko M ,   University of Queensland, Jak E ,   University of Queensland
Published: September 2024

The increasing complexity of ore resources and recycled materials in the feed of pyrometallurgical processes present a technical challenge to the metallurgical engineers working on maximising the recovery of the valuable elements and minimising the environmental impact of the processes. To address this challenge, the availability of computational tools that can predict the mass and energy balance in complex systems is required. Then the accurate description of phase equilibria in the complex multicomponent systems describing the chemistry of the pyrometallurgical processes becomes critical for the correct implementation of the indicated tools and facing the outlined industrial challenges. In the present study the distribution of selected elements (Pb, Zn, Fe, As, Sn, Sb, Bi and Ni) between oxide liquid and metal in the ‘CuO0.5’-CaO-AlO1.5 system in equilibrium with Cu metal at 1400°C (liquidus of CaAl2O4) was experimentally studied using the equilibration and quenching technique followed by the electron probe X-ray microanalysis of the resulted samples. The study covered a wide range of effective p(O2) over the system from 10-11 to 10-3.5 (corresponding to formation of immiscible CuO0.5-rich slag). To avoid loss of volatile elements (Pb, Zn, As, Sn, Sb and Bi), a correlation between ‘CuO0.5’ in oxide liquid and p(O2) in open system was obtained first, followed by studying the volatile elements distribution in closed conditions (Al2O3 crucible sealed in SiO2 ampoule), where ‘CuO0.5’ concentration was used as a marker to evaluate the effective p(O2) over the system. The experimental results were then used for the optimisation of the thermodynamic model parameters of the system as part of the integrated experimental and self-consisting thermodynamic modelling research program of phase equilibria in the Cu-Pb-Zn-Fe-Ca-Si-Al-Mg-O-S-(As, Sn, Sb, Bi, Ag, Au, Ni, Cr, Co and Na) gas/oxide liquid/matte/speiss/metal/solids system.
Conversion of hard-to-use wastes to new raw materials for low-energy glass/mineral-wool manufacturing
Authors:   University of Warwick, Yan Z , Htet T ,   BUSS Chem Tech., Zhang S ,   Chongqing University, Li C ,   University of Warwick
Published: September 2024

During the pyrometallurgical processes, a substantial quantity of high-temperature ironmaking and steelmaking slags, generated at temperatures ranging from 1400 to 1600°C, is wasted, as the heat contained in these slags is released into the environment during the tapping process without effective utilisation. On the other hand, a significant amount of energy is required to reheat the cold materials for the manufacturing of glass and mineral-wool, often necessitating the addition of high-silica materials to facilitate the production process. In this study, an innovative approach is presented to harness the heat present in molten metallurgical slags to directly produce new raw materials for glass and mineral-wool manufacturing while simultaneously reducing energy consumption and mitigating CO2 emissions. The theoretical amount of waste glass that can be effectively added in the process has been estimated via thermodynamic calculation. Experimental assessments were conducted to examine the impact of high-silica waste materials on the dissolution, melting and fluidity. Potential recipes for glass and mineral-wool manufacturing were suggested and an assessment of the energy savings, and reduction in CO2 emissions with manufacturing of glass and mineral-wool using this innovative approach were included. It was determined that the processes could lead to a reduction of over 26 kg of CO2 emissions per 100 kg of new material used, primarily due to the utilisation of heat from slag and the accelerated smelting process.
Effect of alumina on microstructures of iron ore sinters from the perspective of the phase equilibria of the CaO-SiO2-Fe2O3-Al2O3 system
Authors:   Tokyo Institute of Technology, Hayashi M , Takahashi A ,   Tokyo Institute of Technology, Uchisawa Y ,   Tokyo Institute of Technology, Watanabe T ,   Tokyo Institute of Technology, Susa M ,   Tokyo Institute of Technology
Published: September 2024

Owing to the deterioration of iron ore, the Al2O3 concentration in iron ore increases, and thus it is important to investigate the effect of increment in Al2O3 concentration on the microstructures of iron ore sinters. During the sintering process, a melt is present in the sinter for only a few minutes, and therefore the microstructure of the sinter doesn’t reach thermodynamic equilibrium. Nevertheless, the formation process of the microstructures can be interpreted and predicted to some extent from the equilibrium phase diagram. This study investigated the liquidus isotherm in the CaO-SiO2-Fe2O3-5 mass% Al2O3 system at 1240°C in air and the phase equilibria of silico-ferrite of calcium and aluminium (denoted by SFCA) and SFCA-I by XRD (X-ray diffraction analysis) and electron probe micro analyzer (EPMA). The following results were obtained: 1. The ferrite melt region with a high Fe2O3 concentration shifts to the lower Fe2O3 side than the liquidus isotherm in the CaO-SiO2-Fe2O3 system. 2. The compositional region of SFCA extends in the CaOꞏ3Fe2O3-4CaOꞏ3SiO2 direction than the silico-ferrite of calcium (denoted by SFC) composition region with a 0 mass% Al2O3. 3. SFCA-I is observed in the present system, which suggests that the increment in the Al2O3 concentration contributes to the stability of SFCA-I. These results imply that an increment in Al2O3 concentration in iron ore leads to a decrement in the volume fraction of the bonding phase and that the fraction of the SFCA phase increases, and those of 2CaOꞏSiO2 and slag phases decrease in the bonging phase. The SFCA-I phase is also precipitated from the slag with an Al2O3 concentration around 5 mass%.
Modelling of gas-slag flow behaviour in the ironmaking blast furnace – a review
Authors:   University of Wollongong, Dong X F , Monaghan B J ,   University of Wollongong, Zulli P ,   University of Wollongong
Published: September 2024

In the lower zone of blast furnace (BF), slag trickles down through a packed bed of carbonaceous particles in the form of films, rivulets or droplets. During its downward flow, there are significant interactions occurring between slag and other phases, ie gas and packing particles. In particular, the interaction between gas and slag is closely associated with the key flow phenomena such as loading, flooding or channelling in the lower zone of the BF. With gas introduced laterally through tuyeres and slag flowing downward from the cohesive zone to the hearth, this interaction varies throughout the lower zone and in the cohesive zone: * strong cross-flow of gas relative to the slag occurs in front of the raceway * counter-current flow of gas and slag occurs in the upper parts of the lower zone * both strong cross- and counter-current flow of gas and slag around and within the cohesive zone. These interactions can be linked to furnace irregularities, affecting smooth operation and limiting production. Therefore, understanding the gas-slag interaction and its influencing factors remains critical for BF process control. In the current review, the physical behaviour and key influencing factors of gas and slag flow are initially examined. Numerical models describing gas and slag flows in a packed bed at micro-, meso- and macro-scopic levels, are reviewed. Each simulation approach has its advantages and limitations, as well as unique assumptions when used in BF process modelling. Applications of these approaches to gas-slag flow in key identified functional zones will highlight the differences between approaches and modelling outcomes. As no single approach can fully address all aspects of gas-slag interactions, an integration of different approaches is considered an effective and beneficial method in providing a more complete understanding of gas-slag flow in the BF process.
Electrodeposition and electrochemical behaviour of molybdenum ions in ZnCl2-NaCl-KCl molten salt
Authors:   Zhengzhou University, Zhang H , Li S ,   Zhengzhou University, Lv Z ,   Zhengzhou University, Song J ,   Zhengzhou University
Published: September 2024

In this paper, a method for extracting and refining metallic molybdenum using low-temperature ZnCl2-NaCl-KCl molten salt was proposed. The electrochemical behaviour of molybdenum ions in ZnCl2-NaCl-KCl molten salt was investigated in detail, and pure metallic molybdenum was collected on the cathode. The reduction and diffusion processes of Mo(V) ions in ZnCl2-NaCl-KCl molten salt were determined through a series of electrochemical methods. The diffusion coefficients and nucleation modes of Mo(V) ions were also studied, and electrolysis was conducted for a prolonged period at a constant current density. The results indicated that the electrode reduction of Mo(V) ions in ZnCl2-NaCl-KCl molten salt proceeds through a three-step reaction: Mo(V) → Mo(IV) → Mo(III) → Mo at 250°C. The Mo(V) → Mo(IV) reaction was reversible and diffusion-controlled, with a Mo(V) diffusion coefficient of 6.02 × 10-6 cm2 s-1. Additionally, the nucleation mode of Mo(V) ions was instantaneous nucleation. The products electro-deposited were confirmed of metallic molybdenum with a particle size of less than 1 μm.
Calcium based ternary nitrate salts for concentrating solar power applications
Authors:   Somaiya Vidyavihar University, Gandhre P , Shrotri V ,   C-DAC, Muhmood L ,   Somaiya Vidyavihar University
Published: September 2024

The current work deals with the measurement of some thermophysical properties of Ca(NO3)2 based ternary nitrate molten salts as HTF (heat transfer fluid) / TES (Thermal Energy Storage) material for CSP (Concentrating solar power) plants. The density and viscosity of different compositions of the ternary salt mixture containing Ca(NO3)2, NaNO3 and KNO3 close to the liquidus has been experimentally measured. An attempt has also been made to measure the melting point of the salt using the cooling curve technique as well as Differential Scanning Calorimetry (DSC). Thermogravimetric analysis has also been performed to estimate the peak operating temperature of the salt. Compatibility of suitable pipe material (SS304) with molten salt has also been discussed. The salt mixture proves to be a viable alternative to the already existing HTFs like Therminol VP-1 (organic oil) or Solar Salt® in regards to its lower melting point, wider operating range, low cost, non-toxicity, sufficiently high density and comparable viscosity.
Challenges facing non-ferrous metal production
Authors:   Aalto University, Taskinen P , Lindberg D ,   Aalto University
Published: September 2024

The increase in metals demand in the electrifying globe means significant growth in the smelting of copper, nickel, zinc, and lead, produced from primary sulfide sources or using sulfide mattes as the intermediates of the process chains. This means that leaner and complex mineral deposits will be evaluated as ores and are in the future traded in the commodity market for smelting and refining to pure metals. An important issue in the trend is the technology metals, like antimony, tellurium, and gallium, which exist as trace elements in sulfide ores and form no ores of their own. Their recovery becomes important in the coming decades as will be the case with growing slag amounts without use in other industries. The key is to produce environmentally acceptable slags in the smelting operations. It sets new boundary conditions to the treatment of flue dusts. This means that all material streams of smelting and refining must be re-evaluated for the deportments of the main and minority metals. In copper smelting, the recoveries of precious metals are today important for the feasibility of the custom smelters but due to low prices of many minority metals they are discarded in slag landfills. It is one of the emerging issues also in the secondary copper smelting today and once the demand grows, the same question will be faced also in the mining-beneficiation-smelting-refining chain of the primary production of nickel, zinc, and lead. The distributions of many technology metals in the copper and nickel smelting have been recently studied using methods where the chemically bound trace elements in the slag and its phases at the smelting conditions have been studied. Thus, the key data about options for process modifications and additional processing steps are piling up. Short processing routes in the metals smelting and refining are attractive due to their simplicity. At the same time, complexity of many raw materials challenges the fluxing at high oxygen partial pressures in low silica slags with high metal concentrations. The compromise between high primary recovery and safe operation is a demanding task in conditions where slag foaming outside the processing window is evident. The increase in the demand of pure nickel is challenging the raw material basis where low-grade sulfide ores are soon smelted along with nickel laterites to matte. It is a demanding task at high MgO concentrations. The low solubility of MgO in iron silicate slags requires new fluxing strategies and new smelting end points for the operation at reasonable temperatures; the direct nickel matte smelting in one-matte mode may be an option.
Reduction and melting behaviours of carbon – iron oxide composite using iron carbides and free carbon obtained by vapour deposition
Authors:   Tohoku University, Higashi R , Maruoka D ,   Tohoku University, Iwami Y ,   JFE Steel Corporation, Murakami T ,   Tohoku University
Published: September 2024

The ironmaking industry consumes a large amount of fossil fuel derived carbon as heat source, reducing agent of iron ores and carburising agent of reduced iron. Although the demand for drastic decrease of carbon dioxide emission, carbon is an essential element for smelting process of molten iron. The carbon recycling ironmaking process by circulating CO has been already proposed to achieve carbon neutrality. However, the production of molten hot metal is not considered in this process because sufficient amount of carbon does not dissolve in reduced iron by CO. Therefore, our group has suggested a new carbon recycling ironmaking process which can produce hot metal. In this process, free carbon and iron carbides produced by carbon deposition reaction using metallic iron as a catalyst are used. It is known that only Fe3C is obtained as iron carbide by using CO gas, however, Fe5C2 is also produced by adding H2 gas. The composite agglomerated with these carbonaceous materials and fine iron ore (Deposited Carbon-Iron oxide Composite: DCIC) is reduced and melted in a furnace. It is reported that Fe3C in DCIC accelerates the reduction reaction and melting of the composite. In this study, the effects of iron carbides and free carbon on the melting behaviour of DCIC are investigated. Fe3C, Fe5C2 and free carbon were produced by vapour deposition using porous iron whiskers and CO-CO2-H2 gas. These were agglomerated with hematite reagent at a certain ratio to prepare DCIC samples with and without Fe5C2. The samples were heated up to 1300°C in inert atmosphere. The DCIC containing Fe5C2 completely melted and iron nuggets were obtained after the experiment. This behaviour was not observed in the composite without Fe5C2. This indicates that using Fe5C2 is more preferable than Fe3C for molten iron production using DCIC.
Overview of the experimental phase equilibria studies of the Ni-Sn-S, Cu-Sb-S, Cu-Sn-S, Fe-Sb-As and Fe-Sn-As systems
Authors:   University of Queensland, Akhtar M , Shevchenko M ,   University of Queensland, Jak E ,   University of Queensland
Published: September 2024

This article presents an overview of the experimental phase equilibria studies of S-containing systems (Ni-Sn-S, Cu-Sb-S, and Cu-Sn-S) and As-containing systems (Fe-Sb-As and Fe-Sn-As). These systems improve the prediction capabilities of FactSage in a 20-component ‘Cu2O’-PbO-ZnO-FeO-Fe2O3-CaO-SiO2-S-(Al2O3-MgO-CrO-Cr2O3-Na2O)-(As, Sn, Sb, Bi, Ag, Au, Ni, Co) system for complex pyrometallurgical operations during both refining and recycling. Experiments involved equilibration at predetermined temperatures (300–1200°C) with or without preheating, followed by rapid quenching in a brine. Quenched samples were then directly measured using an electron probe microanalyser. For the Ni-Sn-S system, liquid phases (NiS- and SnS-rich mattes and liquid metal) and solid phases (Ni1+xSn, SnS, Ni3Sn, FCC-Ni, Ni1-xS, NiS2, Ni3Sn4, SnS2, Sn2S3 and β-Ni3S2) were observed. A new Ni3Sn2S2 phase was found to melt incongruently. For the Cu-Sb-S system, liquid metal, matte, FCC-Cu, digenite, Sb, CuSbS2, Cu3SbS3 and Cu3SbS4 phases were observed. For the Cu-Sn-S system, liquid metal, matte, digenite, SnS and Cu3Sn phases were found at liquidus. Also, the immiscibility gaps spread from: 1. The Sn-S binary toward the Ni-rich side in the Ni-Sn-S system. 2. The Cu-S binary toward the Sb-S binary in the Cu-Sb-S system. 3. The Cu-S binary toward the Sn-S binary in the Cu-Sn-S system. The immiscibility gap in the Cu-Sn-S system is wider than in the Cu-Sb-S system. For the Fe-Sb-As system, liquid metal, FeAs2, Fe1-xSb, Fe2As, FeAs, FeSb2 and BCC-Fe phases were found. For the Fe-Sn-As system, an immiscibility gap near the Fe-Sn system was observed with liquid metal (Fe-rich and Sn-rich) and Fe5(Sn, As)3, Fe2As, FeAs and FeAs2 phases.
A fundamental investigation on welding flux tunability geared towards high heat input submerged arc welding for shipbuilding applications
Authors:   Northeastern University, Yuan H , Tian H ,   Northeastern University, Zhang Y ,   Northeastern University, Wang Z ,   Northeastern University, Wang C ,   Northeastern University
Published: September 2024

Submerged arc welding (SAW) is one of the significant metal-joining processes for manufacturing marine vessels, steel pipes, and offshore structures with high deposition rate and engineering reliability. Welding flux serves several essential functions, including atmospheric shielding, arc stabilisation, bead morphology control and weld metal (WM) refinement. Therefore, from a thermodynamic point of view, the focus for flux design and WM compositional/microstructural modification has been placed to elucidating the transfer pathways and mechanisms of major alloying elements, such as Si, Mn, Ti and O during welding. To this end, a thermodynamic model has been established to predict alloying element contents in the WM. Such functions are enabled by the physicochemical properties of the fluxes, which are inherently rooted in the nature of the fluxes. A unique yet systematical investigation, including physicochemical property changes and structural evolution behaviours, has been conducted over the wide range of fluxes applied to actual welding of EH36 shipbuilding steels. Combined with spectroscopic methods, structural behaviours of network formers such as SiO2, Al2O3 and TiO2 and network modifiers such as MgO, MnO and CaO have been illustrated. Viscosity and ionic conductivity have been found to be positively associated with the degree of polymerisation.
Analysis on composition and physico-chemical property change of PbO-bearing slag in Pb smelting
Authors:   Xian University of Architecture and Technology, Zhao J X , Cui Y R ,   Xian University of Architecture and Technology, Cao G ,   Xian University of Architecture and Technology, Wang G H ,   Xian University of Architecture and Technology, Li B ,   Xian University of Architecture and Technology, Ren M M ,   Xian University of Architecture and Technology, Wang Z M ,   Hanzhong Zinc Co. LTD, Gui H P ,   Hanzhong Zinc Co. LTD
Published: September 2024

Pyro-metallurgy is still the main process for lead production and a lot of lead direct smelting processes have been developed in recent years. All the processes will experience two steps in common. The first is the oxidisation of PbS to PbO and then reduction from PbO to Pb, furthermore, from ZnO to Zn. So, the composition of melts, especially the slag composition at reduction step change continuously. Up to now, there are few systematic results on the slag physical-chemical properties with its composition change. In this work, the typical lead direct smelting processes were analysed from theoretical and practical standpoints. The full-period slag composition and slag melting point change were compared. Especially, to the PbO and ZnO reduction steps, based on the full-period slag composition change, the slag properties were predicted. Based on dust composition and test results, the mechanism of Pb compound evaporation and its effect on practice and measurement of high PbO bearing slag physical-chemical property is discussed. It is suggested that to restrain the evaporation in practice and to obtain more accurate measurement results of physicochemical properties of smelting slag are the key problem not only to set high efficiency, energy saving process, but also to environmental pollution control.
Determining the properties of CaO-Al2O3-SiO2 slags from molecular dynamics simulation
Authors:   Norwegian University of Science and Technology, Zhu M , Safarian J ,   Norwegian University of Science and Technology
Published: September 2024

Understanding the slag composition-structure-property relationship remains challenging due to the amorphous nature of slag melts and the difficulty of high-temperature experimental investigations. Since the CaO-Al2O3-SiO2 slag system is maybe the most important slag system for various high-temperature metallurgical process, the present research employed high-throughput molecular dynamics (MD) simulations on the entire composition region of the CaO-Al2O3-SiO2 slag system to determine physical properties like molar volume, density and diffusivity, structural properties such as distribution of different oxygen types for each simulated slag melt. The obtained slag properties result from the simulations displayed good consistency with experimental data, underscoring the reliability of the MD simulation as a novel tool to predict reasonable slag properties and to study slag behaviour from atomistic insight. The simulated results demonstrate a near-linear relationship between molar volume changes and composition, highlighting the predominant role of oxygen atoms, which is attributed to the significantly larger size of oxygen compared to other cations in the slag melts. This disparity in size leads to oxygen ions occupying most of the space in slags, thereby playing a major role in determining the overall molar volume. The simulation results of slag density revealed a decreasing trend with increased SiO2 content and identified a local minimum at constant SiO2 when Al2O3 content increases, also consistent with established slag density models. Furthermore, the simulated oxygen self-diffusion coefficients reveal a strong composition-structure-property relationship, where an increase in CaO content enhances slag diffusivity, while a minimum in diffusivity is observed near a CaO/Al2O3 ratio of unity. The diffusivity minimum also corresponding to the local viscosity maxima, indicating effective simulation of charge compensation effects and dynamic characteristics of slag melts. The simulated distribution of oxygen types in slag — bridging oxygen (BOs), non-bridging oxygen (NBOs), free oxygen (FOs) and tricluster oxygen (TOs) — reveals a composition-dependent pattern: BOs peak near CaO/Al2O3 = 1, NBOs and FOs are abundant in CaO-rich areas with NBOs peaking near the Ca3SiO5 composition, FOs in the CaO corner, and TOs predominantly in the Al2O3 corner, highlighting the complex interplay of network formers and modifiers for the charge compensation effects on the slag’s structural properties. The successful application of MD simulations in this study paves the way for a powerful approach to explore the complex relationships in multicomponent slag systems and bridges the gap between mathematics modelling and experimental observations in high-temperature metallurgical processes.
Fundamental Drivers of Metal Fatigue Failure and Performance
Authors:   Mechanical Department, Faculty of Technology and Education, Beni-Suef University, Beni Suef, 62511, Egypt, Mohammed Moustafa M.
Published: September 2024

Understanding fatigue behavior is critical for ensuring the safety and reliability of various engineering components and structures. Fatigue-related failures have historically led to catastrophic events, including aviation accidents and infrastructure collapses, resulting in significant economic and reputational damage. This study delves into the fatigue processes, focusing on crack initiation, growth mechanisms, the impact of microstructure, stress concentrations, surface finish, mean stress, frequency, and environmental conditions on fatigue life. It also explores fatigue principles, stress cycles, S-N curves, fatigue limits, and the stages of crack formation and propagation. By comprehensively analyzing fatigue behavior, engineers can design safer components, optimize materials, and extend product lifespans, thus facilitating technological advancements, predictive maintenance, and risk reduction across industries such as aerospace, automotive, and biomedical sectors.
An outlook on modalities in Nordic forest governance
Authors: Nebasifu Ayonghe , Fridén Alexia , Ekström Hanna , Pietarinen Niina , Harrinkari Teemu , D’Amato Dalia , Droste Nils
Published: September 2024

The 1990s were significant for several events promoting environmental protection and the sustainable use of natural resources. For instance, both the United Nations Conference on Environment and Development in 1992, which stressed the need to stop the overconsumption of natural resources and the United Nations Framework Convention on Climate Change endorsed a framework to combat climate change. Since then, national governments have been increasingly called upon to deliver various commitments that can strengthen sustainable use of forest resources. While we must assess the capacity of these commitments to achieve various policy targets, it is not entirely clear what modes of forest governance will emerge in this process. Using the case of Nordic Forest governance, we investigate its modalities and influence on forest use between 1970 and 2023, focusing on a shift from state-based to interactive governance. While state-based governance included the use of conventional state arrangements tackling environmental problems in active forestry, interactive governance consisted of policy mixes aimed at climate-smart and multi-use forest management. We discuss our findings using relevant forest policies identified in four Nordic countries; Finland, Sweden, Norway, and Denmark, drawn from qualitative interviews conducted in 2023. The conclusions suggest the future potential for policy mixes in which they play a vital role in promoting best synergies and setting priorities for sustainable Nordic forest management.
Pengaruh Return On Asset, Debt To Asset Ratio dan Ukuran Perusahaan Terhadap Earning Per Share
Authors: Widyawati Feby , Ferdian Romi
Published: September 2024

Tujuan penelitian ini adalah untuk mengetahui pengaruh antara Return On Asset, Debt to Asset Ratio, dan Ukuran Perusahaan terhadap Earning Per Share pada Perusahaan sektor pertambangan. Sampel yang digunakan dalam penelitian ini adalah 46 perusahaan sektor pertambangan. Teknik pengambilan sampel dalam penelitian ini menggunakan purposive sampling. Adapun uji yang digunakan dalam penelitian ini adalah uji asumsi klasik, analisis regresi linear berganda, analisis koefisien korelasi (R), koefisien determinasi (R2), uji simultan (uji F) dan uji parsial (uji t). Hasil penelitian pada uji asumsi klasik menunjukkan data berdistribusi normal, tidak terdapat gejala multikolinearitas, tidak terjadi gejala heteroskedastisitas dan bebas dari autokolerasi. Analisis koefisien korelasi menunjukkan antara Return On Asset, Debt to Asset Ratio dan Ukuran Perusahaan terhadap Earning Per Share memiliki hubungan yang kuat, sedangkan koefisien determinasi dalam penelitian ini menunjukkan 60,9% Earning Per Share dipengaruhi oleh Return On Asset, Debt to Asset Ratio, dan Ukuran Perusahaan. Dalam uji F menunjukkan Return On Asset, Debt to Asset Ratio dan Ukuran Perusahaan secara bersama-sama memiliki pengaruh signifikan terhadap Earning Per Share. Uji t menunjukkan Debt to Asset Ratio tidak berpengaruh signifikan terhadap Earning Per Share, sedangkan Return On Asset dan Ukuran Perusahaan berpengaruh secara signifikan terhadap Earning Per Share.
Nursing care of a post-partum patient with severe preeclampsia in the obstetrics service of a national hospital
Authors: Ccorahua-Torres Carmen V. , Solis-Quispe Cinthia A. , Vivanco-Hilario Sofía D. , Cabanillas-Chávez María T , Morales-García Wilter C.
Published: September 2024

Preeclampsia is a multisystem disease with hypertensive symptoms above 140/90 mm Hg, which can occur during pregnancy after 20 weeks or in the postpartum period, affecting the mother as well as the fetus, accompanied by altered proteinuria. The objective was to manage the nursing care process in a pregnant woman with severe preeclampsia. Study with a qualitative approach, single case type and as a scientific method of the nursing care process (PAE). The subject of the study was a 31-year-old pregnant woman, to whom the 5 stages were applied: the assessment stage using the guide of Marjory Gordon's 11 functional patterns, three altered patterns were prioritized: health perception, self-perception - self-concept and perceptual - cognitive; With taxonomy II of NANDA-I, nursing diagnoses were developed and identified: CP gestational hypertension CR malignant hypertension, acute pain and anxiety, according to the SSPFR format (signs and symptoms, problem, related factor/risk factor/associated) . The activities were planned based on the interventions and results of the NOC and NIC classification. In the execution phase, the care plan was put into practice, continuing with the collection and assessment of data, aimed at resolving problems and needs; The evaluation of the activities was given by the difference between the baseline scores and the final score; As results, a change score (+1), (+1), (+1) was obtained. In conclusion, it was possible to manage the nursing care process by providing specialty and quality care to the patient.
Nursing care in post-surgical patient of adnexal cystectomy in the Obstetrics and Gynecology Service of a national hospital of Chincha, 2023
Authors: Chumpitaz-Saravia Vilma L. , Villaverde-Saravia Blanca , Vivanco-Hilario Sofía D. , Morales-García Wilter C.
Published: September 2024

The ovarian cyst is a sac with a collection of fluid that forms in the ovary or the wall of adjacent organs. The objective was to manage the nursing care process (PAE) for a post-surgical patient of adnexal cystectomy with right salpingo-oopherectomy with release of adhesions. The study has a qualitative approach, a single case type, the methodology was the PAE, which included a 22-year-old patient, in which the five stages were applied: in the assessment stage, the guide with the 11 functional patterns was applied by Maryori Gordon, 6 altered patterns were found, three being prioritized: cognitive perceptual, exercise activity and metabolic nutritional; In the diagnosis stage, it was developed based on taxonomy II of NANDA-I, 10 nursing diagnoses were identified, prioritizing three: Acute pain, Risk of surgical wound infection and Obesity, according to the SSPFR format (signs and symptoms, problem, related factor/risk factor/associated); In the planning stage, the care plan was developed based on the NOC, NIC Taxonomy; In the execution stage, specific care was provided according to the plan; and in the evaluation the differe nce between the final and baseline scores respectively was assessed, resulting in a score of +2, +1 and+1. In conclusion, the nursing care process for the patient was managed, which allowed quality and holistic care to be provided.
Exclusive breastfeeding. Factors that influence its abandonment
Authors: Diaz Cuervo Maria Elena
Published: September 2024

A descriptive study was carried out with the objective of identifying some factors associated with the abandonment of breastfeeding in a clinic in the health area of Puerto Padre, Cuba during the year 2022. The working universe was constituted by 170 infants under six months of age, the sample was constituted by 141 infants. For the elaboration of the project, the mothers or guardians of the infants were surveyed, and the clinical history was verified by childcare consultations using the variables time of exclusive breastfeeding, factors associated with the mother for the abandonment of breastfeeding, factors associated with the child for the abandonment of breastfeeding. Most of the children abandoned breastfeeding between three and four months of age. In relation to the factors associated with the mother for the abandonment of breastfeeding, it was found that the knowledge of the mothers related to breastfeeding is inadequate, most of them have an adequate level of schooling, the number of serious maternal diseases is not significant, predominantly mastitis and the age group of adolescents. In relation to the factors associated with the child, it was found that term birth predominated and most of the children were exclusively breastfed, and the number of children with oropharyngeal malformations was not significant
Clinical experience of a patient with hemopericardium
Authors: Suárez López Diego Ernesto , Echevarría Cruz Angel
Published: September 2024

Introduction: pericardial effusion is a frequent entity in daily practice, which can occur due to a wide range of pathologies, it is the result of an increase in the blood content of the pericardial sac.Case presentation: female patient, white skin, 93 years old, presented with a fall on her own feet, was taken to the Orthopedics and Traumatology Department where a diagnosis of intertrochanteric right hip fracture was made and admission to the observation room was indicated for subsequent surgical treatment.  The patient began to become tachycardic 110/min, hypotensive 80/50 mmHg, she began to resuscitate with volume responding to fluid minirection (4ml/Kg).  Hematocrit was repeated and found to be 0.25, her state of shock was attributed as hypovolemic hemorrhagic. Signs of tissue hypoperfusion persisted, despite the prescribed measures and increased vasopressor requirements. It was decided to perform an echocardiogram where there were evident signs of pericardial effusion. Pericardial window and hemostasis of the bleeding site were performed, achieving the survival of this case. Conclusions: hemopericardium is an entity with a reserved prognosis, which may occur due to a wide range of traumatic and non-traumatic pathologies; imaging methods are a key diagnostic tool, transthoracic echocardiography is the first line method for its evaluation. Therapeutic percutaneous approach, surgical exploration, as well as pericardiocentesis are therapeutic methods
Patient experiences of a student-led physiotherapy neurological rehabilitation clinic: a mixed methods study
Authors: Wynne Donna , Hancock Elizabeth , Stage Emma , Cooper Kay
Published: September 2024

Background: Student-led clinics (SLCs) are becoming increasingly prevalent across allied health professions curricula; however, little is known about patient experiences of these clinics. This study explored the experiences of patients attending a physiotherapy neurological rehabilitation SLC. Methods: This study utilized a sequential explanatory mixed methods approach focusing on people with neurological conditions who voluntarily attended a SLC of 12 weeks duration. The data collection process was initiated following the conclusion of the final SLC session. The methodology employed a survey followed by semi-structured interviews to explore emerging areas in more depth. Interview data were descriptively analyzed, and reflexive thematic analysis guided the analysis of the interview data. Results: Twelve participants completed the survey, and seven also participated in a semi-structured interview. Overall, patients were very satisfied with the service received at the SLC. Three themes were identified from the interview data: patients’ perceptions of the benefits and impact of the SLC; the importance of individualized care, and patients' preferences for SLC delivery. Discussion: The findings of this study indicate that participants perceived this SLC positively in relation to care quality, student skills, and individualized rehabilitation. This suggests that SLCs of this type may potentially be acceptable and applicable across different settings, student groups, and possibly for those living with other health conditions. Future research should investigate patient experiences of SLCs with larger sample sizes, different student cohorts, stages, and patient groups and establish the effectiveness of patient clinical outcomes.
Staircase model for community involvement in community-oriented/based medical education: Steps to achieve CO/CBME
Authors: Talaat Wagdy , Asaad Amin Mariam
Published: September 2024

Problem: For institutions to successfully implement a community-oriented/based education strategy, it is necessary to have full support from the community. Without such support, there may not be sufficient foundation to train students within the community, or to orient curricula to address community health needs and priority problems. Building mutual trust between communities and academia takes time and effort. Some educators think it is easy to "enter" the community and send students for training. Approach: It is essential to approach this education strategy with compassion and empathy. Careful planning and adequate time allocation are crucial to engage communities at different levels. Communities are often apprehensive, but they can be highly responsive when treated with respect and their requests given consideration. To ensure a successful engagement with local communities, it is imperative to consider their perspective and tailor the engagement process to suit their unique needs and expectations. Failure to do so may result in negative consequences, which could jeopardize the success of the initiative. Outcomes: This article outlines a staircase model for medical schools to effectively engage their local community and progress towards achieving community partnership followed by weaning. The model is innovative and aligns with the social accountability principles set forth by the World Health Organization. Building a strong community–university partnership requires careful planning and implementation of various components. Next Steps: By considering all factors, we can build a sustainable, collaborative partnership that benefits both the community and the university with tremendous relief from the burden on the local government.
Gamification approach to addiction education for internal medicine residents
Authors: Falleni Alyssa , Brienza Rebecca
Published: September 2024

Background: People with a substance use disorder (SUD) outnumber the trained provider workforce. The Accreditation Council for Graduate Medical Education (ACGME) recognized this gap in 2022 and now requires addiction education for internal medicine (IM) residents. However, traditional lecture formats struggle to deliver education on this stigmatized condition with meaningful retention and changes in attitudes. Gamification is an evidence-based educational strategy with positive outcomes in graduate medical education, but to our knowledge, has not been used for an entire addiction curriculum. Intervention: This six session IM-focused, stigma-free, interactive curriculum used published physician competencies for content selection. Games were matched to topics based on complexity and need for skill practice. Each hourly session included 10 minutes on introduction, 45 minutes on gameplay, and 5 minutes on feedback. This addiction curriculum was incorporated into existing didactics for IM residents where participants’ comfort, psychological safety, and learning expectations were pre-established. Methods: Sixteen IM residents participated in the curriculum. Curriculum evaluation was conducted using Kirkpatrick’s four levels of evaluation. Resident feedback was obtained via online survey software at the conclusion of each session and behavior impact through an anonymous single question prompt. We used descriptive statistics and summative content analysis to evaluate findings, respectively. Results: All residents were highly satisfied with the curriculum design and use of gamification. Residents reported high levels of engagement and learning, despite use of various games. Findings support an increase in medication prescribing and utilization of harm reduction strategies following curriculum implementation. Conclusion: Gamification may be a preferred educational strategy for addiction curriculum for IM residents. We plan to distribute our curriculum widely for further evaluation in health professions’ programs.