bluuebunny/crossref_metadata_2025 huggingface dataset:
A phenomena-based model to investigate the possibility of scrap melting in an Open Slag Bath Furnace (OSBF) for green ironmaking
Authors:   Tata Steel, Emami A , van der Sluijs S ,   Eindhoven University of Technology, van Ende M ,   Eindhoven University of Technology, Tang Y ,   Eindhoven University of Technology
Published: September 2024

This paper presents a phenomena-based model for investigating the possibility of scrap melting in an Open Slag Bath Furnace (OSBF) for green ironmaking. The goal of this study is to enhance the circularity of the steelmaking process by utilising scrap as a green source of iron in OSBFs. The model takes into account the fundamental differences between OSBFs and traditional processes such as Electric Arc Furnaces (EAFs) and Basic Oxygen Furnaces (BOFs). The model considers three primary regions where scrap heating and melting occur: the solid feed pile, slag and hot metal. It accounts for factors such as the furnace geometry, scrap charging mechanism and specific heat and mass transfer properties of the reactor. The model was validated using literature data and was used to investigate the heating and melting behaviour of individual scrap particles under various process parameters. The study finds that the scrap melting process in OSBFs involves three stages: shell formation, shell remelting and subsequent melting of the parent scrap. The carbon content of the scrap and the liquid hot metal plays a critical role in determining the melting behaviour. Depending on the carbon concentration and temperature, the melting process can be heat transfer controlled or mass transfer controlled. The paper also examines the scrap feeding methods in OSBFs, including direct charging into the slag or charging through a feed pile. The model provides insights into the melting rate of scrap compared to Direct Reduced Iron (DRI) in OSBFs and highlights the role of carbon in this process. Overall, this phenomena-based model contributes to the understanding of scrap melting behaviour in OSBFs and provides valuable insights for optimising the circularity and efficiency of green ironmaking processes. The findings of this study can inform the design and operation of OSBFs, paving the way for increased utilisation of scrap as a sustainable feedstock in the steel industry.
An attempt towards ferrochromium production using molten oxide electrolysis
Authors:   IIT Bombay, Biswas J , Klemettinen L ,   Aalto University, Sukhomlinov D ,   Aalto University, Malan W ,   Aalto University, Lindberg D ,   Aalto University
Published: September 2024

In order to mitigate the effects of climate change, our society must be able to drastically reduce its CO2 emissions. As the metallurgical industry is a considerable contributor to these emissions, new greener technologies must be invented and developed. One option could be the direct production of metals from oxides using renewable electricity. The aim of this study was to investigate the possibility of using high-temperature molten oxide electrolysis (MOE) for iron and ferrochrome production. FactSage™, ver 8.2 (by Thermfact Ltd and GTT-Technologies) was utilised for estimating a feasible equilibrium electrolyte composition, and the experiments were conducted at 1550–1580°C in conical alumina crucibles with iridium wire as the cathode and platinum wire as the anode. The sources of iron and chromium were either pure FeO powder or industrial chromite pellets. Voltage was applied to the electrolysis cell for 6 hrs and the resulting current was measured, along with oxygen concentration in the off-gas line. The electrolyte comprised of SiO2, Al2O3, MgO and CaO. First, the effect of FeO concentration on iron reduction efficiency was investigated using only pure oxide powders as starting materials. The results indicated that 10 wt per cent FeO mixed with the electrolyte resulted in more efficient iron reduction compared to 20 wt per cent. In further experiments, industrial chromite pellets were ground and mixed with the CaO-free electrolyte. Iron and chromium reduction efficiencies were higher when approximately 19 wt per cent of the total sample mass consisted of pellets compared to increasing the pellet amount to 37 wt per cent. Generally, the chromium solubility in the liquid electrolyte was relatively low, and most of the chromium was confined to the spinel solid solution, from where its dissolution to the liquid electrolyte was very slow, resulting in slow reduction kinetics. For larger scale applications, economically more viable electrode materials should be investigated.
Effect of slag composition on titanium distribution ratio between ferrosilicon melt and CaO-SiO2-Al2O3 slag at 1773 K
Authors:   Hanyang University, Lee M J , Park J H ,   Hanyang University
Published: September 2024

Because the environmental problems are occurred by greenhouse gases such as CO2, the industries have tried to increase electric motor efficiency to reduce CO2 emissions. A core material of electric motor is high-silicon electrical steel. The ferrosilicon (FeSi) alloy, a raw material for the production of electrical steel, affects the electric properties of silicon steel. The main impurities such as Ca, Al and Ti make inclusions or precipitates that causes core loss. The slag treatment has been widely used to remove impurity elements. Thermodynamic principles for the refining of several impurities, specifically Ca and Al, have been investigated, whereas thermodynamic behaviour of Ti has not been fully understood yet. Therefore, in the present study, the titanium distribution ratio (𝐿􀀁􀀂) between ferrosilicon and CaO-SiO2-Al2O3 slag system at 1773 K was investigated. The results show that 𝐿􀀁􀀂 is influenced by both the basicity and stability of titanium ion in the slag. Specifically, 𝐿ri exhibits a minimum value at about C/S=0.7 indicating a shift in the titanate structure unit from [TiO5]-square pyramid to [TiO4]-tetrahedron because of lack of Ca2+ ions in a C/S<0.8 region, contributing to an increase in titanate capacity and 𝐿ri.
Sulfur distribution ratio in iron and steelmaking slags
Authors:   University of Alabama, Reddy R G , Yahya A ,   University of Alabama
Published: September 2024

The sulfur distribution ratio (Ls) is an expression of the amount of sulfur in slag to the amount of sulfur in molten metal. The sulfide capacities calculated from Reddy-Blander (RB) model were used to calculate the sulfur distribution ratio (Ls). A new Reddy model for sulfur distribution ratio (Ls) was developed for modelling Ls for ironmaking, steelmaking, and secondary steelmaking conditions. Besides calcium oxide, the major component in the ladle furnace (LF) slags is alumina. The Ls was calculated for typical LF slags as a function of temperature and composition. The model calculated Ls values are in good agreement with the experimental and industrial slags data. The extremely low oxygen potential in these furnaces after fully-killed steel is favourable for desulfurisation. For any given slag’s composition and temperature, its sulfide capacity can be calculated a priori. The equilibrium sulfur distribution ratio between this slag and liquid metal in a particular vessel can also be calculated a priori. The Ls for ladle furnace (LF) slags is about twice those for blast furnaces (BF) slags and ten times those of basic oxygen furnace (BOF) slags. The desulfurisation of pig iron in BF and desulfurisation of steel in LF during secondary steelmaking are recommended. Steel desulfurisation in steelmaking furnaces is not effective. Since the model used to calculate the sulfur distribution ratio (Ls) is a priori, it is a useful tool for the iron and steel makers in improving the product quality and optimisation of the industrial furnace operations.
Effect of mill-scale and calcined dolomite on high Al2O3 sinter and its reduction behaviour
Authors:   Pohang University of Science and Technology, Kim S J , Tomas da Rocha L ,   Pohang University of Science and Technology, Kim S W ,   POSCO, Jung S ,   Pohang University of Science and Technology
Published: September 2024

Al2O3 has been regarded as a harmful gangue component in iron ore, especially causing reduction degradation in industrial sintering of iron ore. The current study aimed to utilise low-grade iron ore containing high Al2O3 content in sintering process. In order to counteract the adverse effect of Al2O3 on reduction behaviour of iron ore sinter, mill-scale and calcined dolomite were chosen as FeO- and MgO-bearing materials. Firstly, mill-scale was added to high Al2O3 sinter and addition was optimised as 10 wt per cent, then calcined dolomite was added further. Magnetite and magnesio-ferrite were identified as the major phases in iron ore sinter when adding mill-scale and calcined dolomite. As the dosage of calcined dolomite increased beyond 4 wt per cent of in sinter mix, unreacted MgO particles were observed, which is ascribed to the limitation of MgO dissolution into magnetite matrix. Both mill-scale and calcined dolomite were effective in improving compressive load and Reduction Disintegration Index (RDI) of iron ore sinter although its reduction degree was highly decreased. The addition of both FeO and MgO-bearing materials to high Al2O3 sinter has a potential to improve the sinter quality, also contribute to the recycling of industrial by-product. However, the amount should be optimised in views of phase development and deterioration of reducibility.
Reoxidation of Al-killed ultra-low C steel by FetO in CaO-Al2O3-MgOsat.-FetO slag representing RH slag by experiment and kinetic modelling
Authors:   Pohang University of Science and Technology, Cho Y-M , Cha W-Y ,   POSCO, Kang Y-B ,   Pohang University of Science and Technology
Published: September 2024

Molten slag used in the secondary refining process (RH process) for the production of Ultra-Low C (ULC) steel is typically composed of CaO-Al2O3-MgOsat.-FetO with minor constituents. FetO in the RH slag is the main source of reoxidation of the molten ULC steel in the ladle by 2Al + 3(FetO) = (Al2O3) + 3Fe, thereby serving as the source of the alumina inclusions. On the other hand, FetO also enhances the fluidity of the slag, thereby increasing inclusion absorption capacity. Optimum slag chemistry design is therefore required to produce clear ULC steel. The reoxidation kinetics was investigated in the present study by employing high-temperature experiments and developing the reaction rate model. Initial compositions of slag ((% CaO)0/(% Al2O3)0 and (% FetO)0)) and reaction temperature were varied and change of [% Al] in the molten steel was measured. The rate-controlling step was analysed. It was found that the rate-controlling step in some cases changed during the reoxidation: from a mass transport of Al in the molten steel to a mixed transport including Al2O3 in the molten slag. The experimental data validated the reaction rate model based on the elucidated reaction mechanism and FactSage thermodynamic database. The model suggested that high (% CaO)0/(% Al2O3)0 suppresses the reoxidation only when (% FetO)0 is low (5 or lower in the present study).
Ferroalloy extraction from a Zimbabwean chrome ore using a closed DC furnace
Authors:   University of Zimbabwe, Dandi S , Masamvu M J ,   University of Zimbabwe, Masuka S M ,   University of Zimbabwe, Bright S ,   University of Zimbabwe, Chiwandika E K ,   Harare Institute of Technology,   University of Zimbabwe
Published: September 2024

The depletion of high-grade hard and lumpy chrome ores has forced Zimbabwean ferrochrome producers to resort to low-grade friable ores that have an average of 28 per cent fines against a set limit of 12 per cent. Submerged open arc furnaces currently in use are associated with eruptions within the furnace because of the high amounts of fines, high energy consumption, as well as high SO2 and CO2 emissions. Traditionally employed agglomeration methods such as pelletising and the use of coke in the furnace have been discarded because of the pressure to lower operational costs and to achieve higher profit margins. This research aims to develop a method to incorporate low-grade friable ore fines and unprocessed coal into production while lowering CO2 and SO2 emissions through a closed direct current (DC) arc furnace. The closed DC arc furnace could incorporate the friable ores and coal while maintaining above 90 per cent reduction rates. Preliminary findings also show that energy consumption could be reduced by up to 35 per cent by incorporating a pre-heating and pre-reduction system using the flue gases from the furnace. In the proposed circuit, the cost of production per ton of ferrochrome might be potentially lowered by an average of 30 per cent.
The effect of iron oxide on sulfide capacities of CaO-based molten slags
Authors:   Kyoto University, Hasegawa M , Saito K ,   Kyoto University
Published: September 2024

Removing sulfur and phosphorus from molten iron can be expressed by the following reactions, respectively. [S]Fe + (O2-)slag = (S2-)slag + [O]Fe [P]Fe + (3/2) (O2-)slag + (5/2) (FeO)slag = (PO43-)slag + (5/2) Fe(liquid) These equations indicate that desulfurisation and dephosphorisation have opposite oxygen potential conditions. If a small amount of desulfurisation slag not removed is carried over to dephosphorisation process, the reaction of sulfur mentioned above proceeds toward left hand resulting in increasing sulfur content in molten iron. For better understanding of such re-sulfurisation reaction in hot metal pre-treatments, the present study aimed at evaluating the effect of iron oxide on the sulfur distribution ratio between slag and hot metal. To measure sulfide capacities and FeO activities simultaneously at temperatures below the melting point of pure iron, CaO-SiO2-FeO and CaO-Al2O3-FeO ternary molten slags were brought into equilibria with copper-iron-sulfur liquid alloys, and the equilibrium oxygen partial pressures were determined with an electrochemical technique involving the stabilised zirconia solid electrolyte. The experimental results showed that the sulfide capacity increased with an increase in FeO content, and this trend was consistent with the fact that FeO was basic. Although the addition of FeO raised the FeO activity and oxygen potential, the calculated value for sulfur distribution ratio between slag and hot metal increased with increasing FeO content.
Pushing the boundaries of slag operability – processing of high-MgO nickel concentrates with the Ausmelt TSL process
Authors:   Metso Australia, Wood J , Coveney J ,   Metso Australia, Creedy S ,   Metso Australia, Grimsey D ,   BHP, Rich A ,   BHP
Published: September 2024

In 2021, BHP and Metso examined processing of high-MgO nickel sulfide concentrates using Metso’s Ausmelt Top-Submerged-Lance (TSL) technology. Test work was conducted in Metso’s pilot test work facility in Dandenong, Australia to explore operability of the SiO2-FeO-MgO-CaO-NiO slag system across a wide range of compositions, temperatures and bath oxygen potentials. Pilot-scale testing aimed to define slag ‘operability limits’, representing the lowest bath temperature at which stable process and equipment operation could be maintained. This work was supported by FactSage™, version 8.2 (by Thermfact/CRCT and GTT-Technologies) thermodynamic modelling, slag viscosity measurements, physical characterisation of quenched slag samples performed by the University of Queensland and benchmarking of commercial-scale TSL nickel smelting operations. A wide range of slag compositions were examined, with Fe/SiO2 ratios varying from 0.4–1.1, CaO content from 0.8–7.0 wt per cent and MgO content from 6–19 wt per cent. Slag SiO2/MgO ratio, wt per cent CaO and matte grade were found to have the greatest impacts on identified operability limits. Operability limits were found to be influenced by both the solids content in slag and viscosity of the remaining liquid slag phase, with the relative contribution of these parameters heavily influenced by the slag composition. In the majority of trials, limits were defined by a theoretical solids content of 40–50 per cent, however in trials with a low Fe/SiO2 ratio and/or low wt per cent CaO, limits were characterised by a much lower solids content due to the increased effect of the liquid slag viscosity in determining the behaviour of these slags. The test work highlighted inherent flexibility of the Ausmelt TSL process to operate across a wide slag range of slag compositions and recover from process disturbances without an interruption to feeding. The trials also demonstrated the possibility for Ausmelt TSL technology to process concentrates with an Fe/MgO ratio as low as 1.4, which has important implications to the commercial-scale processing of high MgO feeds. Arsenic rejection across the trials was very good, with only 30 per cent of arsenic in the feed inputs reporting to the matte phase. Such high levels of arsenic removal provide the Ausmelt TSL process with a notable advantage over alternative smelting technologies.
Molten slag flow in an ironmaking blast furnace – a mesoscopic level investigation
Authors:   University of Wollongong, Dong X F , Jayasekara A ,   University of Wollongong, Sert D ,   ArcelorMittal Maizieres Research SA, Ferreira R ,   ArcelorMittal Maizieres Research SA, Gardin P ,   ArcelorMittal Maizieres Research SA, Chew S J ,   BlueScope Ltd, Pinson D ,   BlueScope Ltd, Monaghan B J ,   University of Wollongong, Zulli P ,   University of Wollongong
Published: September 2024

In an ironmaking blast furnace (BF), molten slag and hot metal form in the softening-melting (cohesive) zone and then trickle through the coke packed bed before being discharged from the taphole. During their downward flow, there are significant interactions occurring between liquids and other phases, such as gas and packing particles. Overall, the formation, dripping and discharging of these liquid phases, particularly molten slag, have a significant impact on BF operations in terms of furnace permeability, fuel consumption, process stability, product quality and ultimately, productivity. Hence, understanding the liquid flow behaviour in the BF lower zone is critical for designing optimal operations. In the current investigation, the flow behaviour of slag droplets was investigated at a mesoscopic level using a combined numerical and physical modelling approach. The interaction between slag and carbonaceous materials was studied using sessile drop wetting experiments, slag flow through a funnel and a high temperature packed bed and the Volume of Fluid (VOF) modelling technique. Molten slag flow and counter-current gas-slag flow in the packed bed was investigated in terms of superficial gas velocity, slag properties and packing structure. The gas-slag flow behaviour at a mesoscopic level was numerically visualised, with gas velocity gradually increased up to the flooding point. The strong interaction between gas and slag was uniquely identified, which can cause localised slag flooding as well as gas channelling. Detailed information concerning the effect on slag holdup distribution, residence time and flow patterns of wettability, slag properties and bed structure were obtained. The current investigation highlights the significant role of research at a mesoscopic level in understanding macroscopic slag flow behaviour. Gas channelling, which is a critical phenomenon in a packed bed with counter-current gas-slag flow, is predicted. It can be speculated that significant gas channelling in the BF can inevitably occur prior to operational limits being reached. In the BF process, the formation of permanent gas channelling and large slag rivulets should be avoided to maintain appropriate contact between phases and hence, furnace permeability.
The recovery of pig iron from the Zimbabwean limonite-coal composite pellet
Authors:   University of Zimbabwe, Maritsa S , Masuka S M ,   University of Zimbabwe, Chiwandika E K ,   University of Zimbabwe
Published: September 2024

The iron and steel industry is experiencing an increase in the use of iron and steel commodities within societies, decarbonisation pressures, depletion of high iron ore grades and high energy consumption. This necessitates scrap metal recycling, low-grade ore utilisation using the induction or electric arc furnace to achieve the global target of net zero CO2 emission. The available high-quality scrap metal cannot sustain the steel industry but the world has unused hematite-goethite ores. It is the aim of this research that this resource be utilised using the induction furnace to sustain the steel industry in an environmentally friendly manner. Indurated pellets prepared from the hematite-goethite ore, 5 wt per cent limestone and 5 wt per cent coal addition were smelted in the induction furnace at 1350 ± 50°C with 25 mins holding time. The effects of basicity and carbon content were also investigated to optimise the smelting parameters. The results showed that the careful control of the basicity, and iron-to-carbon ratio maximised total metal recovery. The optimal basicity ratio was determined to be 1.3 and a carbon to iron ratio of 1.4 achieved a total metal recovery of 73 per cent. The metal recovery was closely related to the estimated slag melting temperature. The basicity ratio of 1.3 achieved the lowest slag melting temperature estimated to be around 1380°C based on the CaO-SiO2-Al2O3 phase diagram. The recovered metal had a comparable chemical composition and microstructure to that products from an ITmk3 furnace.
Carbon distribution behaviour between molten iron and CaO-Al2O3-FeO-SiO2-MgO slag at 1873 K
Authors:   Hanyang University, Jun Y J , Park G H ,   Hyundai Steel, Park J H ,   Hanyang University
Published: September 2024

The carbon solubility of the CaO-Al2O3-FeO-SiO2-MgO slag, the main system formed in the Ruhrstahl-Heraeus (RH) vacuum degasser, was measured at 1873 K to understand the effect of slag compositions on the carbon contamination in the ultra-low carbon (ULC) steels. The stable form of carbon was demonstrated to be carbonate by plotting the log [(wt%C)/aC] ratio against the log p(O2) which ranged -11 < log p(O2,atm) < -9. The carbon solubility of the CaO-Al2O3-FeO-SiO2-MgO slag can be estimated using thermodynamic model. The distribution ratio of carbon increased with increasing concentration of FeO due to the FeO reduction reaction and increased basicity of slag. The carbonate capacity of the CaO-Al2O3-FeO-SiO2-MgO slag can be expressed as a linear function of the activity of lime and the optical basicity.
Recent advances in understanding phosphorus in oxygen steelmaking
Authors:   Swinburne University of Technology, Brooks G
Published: September 2024

The control of phosphorus in steelmaking is one of the famous challenges of pyrometallurgy. It is well established that highly basic slags, the presence of FeO in the slag and lower temperatures (less than 1650°C) are favourable for phosphorous removal. The thermodynamics of this reaction have been extensively studied under laboratory conditions and the general trends confirmed through industrial trials. However, in general, phosphorus slag/metal distributions measured in industry are far from equilibrium and quite specific to the oxygen steelmaking technology being used. This variability was quantified by Urban, Weinberg and Cappel (2015), who found that the phosphorus partition ratio measured in plants varied with blowing practice, stirring intensity and even converter life. Some recent kinetic studies by Gu, Dogan and Coley (2017) have shown how the kinetics of these reactions vary with FeO content and dissolved sulfur at the droplet scale. A global kinetic model by Rout et al (2018) provides meaningful predictions of where dephosphorisation occurs in an industrial basic oxygen furnace (BOF) and some recent heat transfer modelling by Madhavan et al (2021, 2022) implies that temperature difference between droplets and slag has a role to play in explaining why equilibrium is not achieved. This paper will review the current state of knowledge and provide suggestions on predicting phosphorous removal for industrial operations and how greater removal could be achieved.
Distribution behaviour of B and P in Si-slag system at 1500°C
Authors:   Swinburne University of Technology, Avarmaa K , Putera A ,   Swinburne University of Technology, Chen J ,   University of Queensland, Brooks G ,   Swinburne University of Technology, Rhamdhani M A ,   Swinburne University of Technology
Published: September 2024

Silicon-based photovoltaic cells are currently the most dominant types applied to convert solar energy to electricity. In solar-grade silicon (SG-Si), the control of boron (B) and phosphorus (P) is very critical. Generally, these elements are difficult to remove into acceptable sub-ppm levels from lower grade Si. This study investigates slag treatment as a process for Si refining, focusing on the behaviour of P and B. The experiments were conducted by equilibrating Si-B-P alloys with 43 wt per cent SiO2 – 47 wt per cent CaO – 10 wt per cent Al2O3 slag under inert atmosphere at 1500°C. Different crucible materials were used (Al2O3, SiO2 and MgO), which determined the primary saturation phase for the system and modified the final slag composition accordingly. The samples were equilibrated and analysed with microanalysis techniques (EPMA (electron probe microanalysis) and LA-ICP-MS (laser ablation inductively coupled plasma mass spectrometry)). New standards were prepared and applied in the LA-ICP-MS analyses. Experimental results show that silver is essentially fully dissolved in silicon, as well as most phosphorus with LP ( = wt per cent P in slag/wt per cent P in Si) between 0.1–0.3. The distribution coefficient of boron was measured to be between 1 and 2. The crucible material used had an influence on the phase compositions and slight influence on the distribution coefficients of boron and phosphorus. The experimental results provided new accurate data when considering applicability of slag treatment as a technique for Si refining and Si PV cell recycling.
Genetic design of personalised slag for manufacturing die steel via electroslag remelting method and an industrial application case
Authors:   Northeastern University, Jiang Z H , Li Y M ,   Northeastern University, Tian J L ,   Northeastern University, Dong J W ,   Northeastern University
Published: September 2024

Electroslag remelting is widely used to produce various special steels, mainly because of its ability to provide high cleanliness and excellent homogeneity of ingot. Undoubtedly an optimal slag plays a key role in removing inclusions and enhancing the mechanical properties of a specific special steel. In order to improve the metallurgical performance of the slag in electroslag refining of die steel, a variety of slags have already been developed using traditional trial-and-error methods. Nonetheless, these slags may not be inherently optimal for the specific requirements of actual die steel refining processes. In this work, we have designed a CaF2-CaO-Al2O3-SiO2-MgO quinary slag system using genetic algorithms method aiming to remove the existing large size inclusions (D and Ds type) in high quality die steel. The comprehensive effects of five components (CaF2, CaO, Al2O3, SiO2 and MgO) were studied based on existing fundamental theory. The slag composition was screened considering the parameters such as melting point, electrical conductivity, calcium ion concentration, and appropriate viscosity etc. Furthermore, the candidate optimal slag was applied in the industrial production of die steel by electroslag remelting method. The detection results indicate that majority large inclusions (D and Ds type) have been successfully removed, showing significant advantage to traditional slags. This result has demonstrated the genetic method to be efficient and reliable. In addition, depending on the personalised demand of other steel and alloys, this method allows for the adjustment of the screening frameworks and processes to develop the candidate optimal slags. This method has not been reported previously in the field of electroslag composition design, and compared with the traditional trial-and-error method, the new method will save a lot of time and experimental costs.
Effect of solid particle size on the viscosity of a secondary copper smelting slag
Authors:   Ghent University, Vergote O , Bellemans I ,   Ghent University, Verbeken K ,   Ghent University, Van den Bulck A ,   Umicore NV
Published: September 2024

Viscosity is one of the most important physicochemical properties during pyrometallurgical operations. In the sub-liquidus regime, an important factor is the presence of suspended solid particles, yet its influence is not well-described in earlier literature, despite the significance of this factor. This project aims to determine the influence of spinel particles (Zn(Al,Fe)2O4) on the rheology of a multiphase synthetic PbO-SiO2-ZnO-Fe2O3-CaO-Al2O3 slag system. Three data sets with a well-controlled methodology and three different spinel sizes (small (13 µm), medium (34 µm) and large particles (76 µm)) were published previously, using a custom-built high-temperature rheometer. This study presents an additional data set of slag viscosity measurements, performed using a different apparatus, the Anton Paar FRS 1800, to verify the consistency of the earlier determined viscosity behaviour. Within this data set, no consistent trend could be found between the predicted wt per cent spinel and the relative viscosity. Therefore, additional quenching experiments were conducted to identify the morphology and experimentally determined volume fraction of the spinel particles in the slag. These measurements revealed a difference in spinel size across the samples and corresponding viscosity behaviour, emphasizing the importance of spinel particle size on slag viscosity. Once the spinel size was taken into account, consistent viscosity results (relative apparent viscosity and flow index) were observed across the two devices. This study confirms that, once all parameters affecting slag viscosity are considered, the viscosity behaviour of a heterogeneous slag can be uniquely determined. The resulting optimised slag viscosity models can be used to predict viscosity before processing, addressing relevant phenomena such as slag tapping, slag foaming and copper droplet settlement.
Selection of Tuning Parameter and Comparison of Lasso and Adaptive Lasso on ZYZ Condition: A Monte Carlo Study
Authors: Shahzad Amir , Waqas Umar , Ali Nazakat , Bilal Ahmad Hafiz
Published: September 2024

One of the fundamental objectives of statistics is to achieve accurate predictions. In high-dimensional settings (where the number of variables, p, exceeds the number of observations, n), the performance of ordinary least squares (OLS) is often suboptimal due to its high variance, which leads to lower prediction accuracy. Shrinking the variables is a promising approach, and methods such as ridge regression, elastic net, lasso, and adaptive lasso are well-known techniques for this purpose. While variable shrinkage introduces a small bias, it significantly reduces the variance compared to OLS. The effectiveness of shrinkage methods largely depends on the selection of the tuning parameter. Cross-validation and the Bayesian Information Criterion (BIC) are commonly used for this purpose, and an improved version of BIC has shown impressive results.???????? = (5.6,5.6,5.6,0), ???????? = (3,1.5,0,0,2,0,0,0), ???????? = (0.85,0.85,0.85,0) are the multiple regression models which are compared.
Cerebral meningitis due to tuberculoma and epstein barr: presentation of a clinical case
Authors: Gutiérrez Garcia Elizabeth , Ortega Martinez Rommer Alex , Calle Vilca Masziel Andrea
Published: September 2024

Neuroinfection is an inflammatory process that affects the meninges or brain parenchyma; it has various etiologies, including viral and non-viral, including autoimmune, bacterial and fungal; patients with this pathology represent a challenge for doctors; the severity varies, from benign, self-limiting to life-threatening. The Epstein-Barr virus (EBV) is a double-stranded DNA gamma herpesvirus that presents a latent infection and lytic replication; it can diffuse into the central nervous system and alter the integrity of the blood-brain barrier, being associated with neurocognitive impairment, neuronal damage and inflammation. In relation to tuberculosis, it became the second infectious disease that caused the most deaths in the world after COVID-19; tuberculous meningitis is considered the most severe form of extrapulmonary tuberculosis (TB) with a mortality of 70% in low-income countries. Below is the case of a 35-year-old man with a history of adrenal insufficiency and hyperthyroidism, who was receiving corticosteroids; he went to the emergency service with a 5-month history of clinical symptoms characterized by holocranial headache, focal retrograde amnesia, periods of altered state of consciousness, dizziness, nausea that led to vomiting on several occasions, with sudden loss of consciousness. , accompanied by involuntary tonic-clonic movements and hearing loss; after the diagnostic screening, EBV and TB are identified; receives specific treatment with good clinical evolution
Screening and diagnostic algorithm of hereditary metabolic nephropathies in newborns
Authors: Fuentes Milián Yangel , Tamayo Ribeaux Danyer Daniel , Cepero Rodríguez Anabel , Martínez Pérez Bárbara
Published: September 2024

Introduction: inborn errors of metabolism expressed as hereditary nephropathies, entail various biochemical abnormalities that facilitate their screening and diagnosis in the newborn.Objective: to offer a useful, ideal, simple and reliable screening alternative as a tool for the diagnosis of hereditary metabolic nephropathies in newborns.Methods: an observational and cross-sectional study was carried out during the period September 2021-February 2023, at the Abel Santamaría Cuadrado General Teaching Hospital, Pinar del Río province, Cuba. The universe consisted of 90 patients and a representative sample of 63 was taken. The variables were studied: glycemia, lactinemia, ammonemia, arterial hemogasometry, urinalysis, hyperazotemia, heel test and perinatal risk factors associated with hyperazotemia. Empirical, theoretical and statistical methods were used. Medical ethics were respected.Results: the correlation predominated hypoglycemia, hyperlactinemia and hyperammonemia with an incidence of 55.56% and patients with metabolic acidosis in 49.21%. A greater frequency was observed in the correlation of patients with alterations in the urinary supernatant and hyperazoemia, for 33.33% of the sample. The number of patients with negative neonatal screening was higher, at 87%. Low birth weight and prematurity were the perinatal risk factors most associated with hyperazoemia in the patients treated, 36.51% and 33.33% respectively.Conclusions: the results obtained show high sensitivity and low specificity, but they still give us a reliable parameter and a tool to help diagnose hereditary metabolic nephropathies
Improving Cleaning of Solar Systems through Machine Learning Algorithms
Authors: Asgarova Bahar , Jafarov Elvin , Babayev Nicat , Abdullayev Vugar , Singh Khushwant
Published: September 2024

The study focuses on the importance of maintaining photovoltaic (PV) systems for optimal performance in sustainable energy generation. It highlights the impact of dust accumulation on reducing system efficiency and proposes a method to predict system performance, aiding in scheduling cleaning activities effectively. Two prediction models are developed: one using time-series prediction techniques (LSTM, ARIMA, SARIMAX) to forecast Performance Ratio (PR), and another employing ensemble voting classifiers (RF, Log, GBM) to predict the need for cleaning. The SARIMAX model performs best, achieving high accuracy in PR prediction (R2 = 92.12%), while the classification model accurately predicts cleaning needs (91%). The research provides valuable insights for improving maintenance strategies and enhancing the efficiency and sustainability of PV systems.
Prediction of Flight Areas using Machine Learning Algorithm
Authors: Singh Khushwant , Yadav Mohit , Hacimahmud Abdullayev Vugar
Published: September 2024

Anyone who often uses the airways wants to predict when it will be best to purchase a ticket in order to get the best possible value. Aircraft firms continuously adjust ticket prices in an effort to maximize profits. When it's anticipated that demand for more income will grow, aircraft manufacturers may raise flying prices. Information analysis for a given air route, comprising the features like take-off time, entrance time, and airways during a specified period, has been gathered in order to decrease costs. To use the machine learning models, qualities are arranged based on the information that has been gathered. The machine learning approach to determine costs based on attributes is presented in the paper below.
Medical students’ satisfaction towards videos as flipped classroom materials
Authors: Omar Heba S. , Gamal Eldin Zaki Rania , Hayek Noha , Mohsen Lamiaa
Published: September 2024

A video with the complete workflow of colorimetric assay of serum glucose was shot and launched on the college Learning Management System (LMS) for first year medical students. The aim of this project was to assess students’ satisfaction with videos as flipped classroom (FC) materials. Year 1 medical students were instructed to watch the video through an available link before the practical session and answer a questionnaire measuring their satisfaction at the end of the session. 162 students responded to the questionnaire. 85.8% of students said that FC videos should be used for other practical/ clinical sessions. Students’ satisfaction indicates that videos may be useful as FC materials.
Image-based dietary assessment skills of undergraduate nutrition and dietetics students in a multicultural developing country
Authors: Yang Wai Yew , Lim Ker Shin , Fazal Rahman Sapnah , Ng Suet Chen , Tay Wei Ni , Tan Yi , Shankar Pathiyil Ravi , Ong Shu Hwa
Published: September 2024

Background: Image-based dietary assessment is a digital method relatively new in nutrition education. We aimed to evaluate the nutrient estimation skills of nutrition and dietetics students in Malaysia using image-based dietary assessment, and develop a tool to assess their image-based dietary assessment skills. Methods: The study was performed among undergraduate nutrition and dietetics students in two phases. Phase One (n=75) was conducted in four steps: 1) photography of food/beverage at two angles (45° and 90°) with and without a fiducial marker (ruler/dessert spoon); 2) study tool establishment; 3) pre-testing; and 4) conduct of the study. Incorporating changes from Phase One, 55 students participated in Phase Two. Participants were evaluated on their accuracy in recognizing and estimating portions and nutrients of a food/beverage. Data analysis included response frequency and percentages, and statistical differences (Wilcoxon Signed Rank test) in estimating nutrient content. Results: In both phases, the participants scored above 80% for the correct identification of most food items. Participants scored the lowest when estimating nutrient content in local snacks [median (IQR): Phase One, 12.5% (25.0); Phase Two, 16.7% (16.7)]. Participants in Phase One showed better nutrient estimation skills with both fiducial markers, however, no significant difference was observed in Phase Two [without: 21.1% (7.9%); with the dessert spoon: 19.0% (13.8%), p=0.197]. Participants’ knowledge, skills, and food images were the main barriers to accurate nutrient estimation. Conclusion: Our study found poor nutrient estimation skills among Malaysian undergraduate nutrition and dietetics students. These key findings warrant urgent attention to address this through innovative dietary assessment training on food and portion size from images.
Refugee child vision screening curriculum for multidisciplinary trainees
Authors: Guo Michelle , Botross Monica , Rigsby Devyn , Chen Yuchen , Lee Hannah , Montag Elena , Park Peter Sang Uk , Porco Maurizio , Briceño César A.
Published: September 2024

Background: Conflicts, natural disasters, and persecution have led to growing refugee populations worldwide. Vision impairment within these populations is a significant concern. Eye conditions in refugee children appear to peak during times of resettlement. Future medical and nursing professionals need to be trained to detect treatable conditions that could lead to permanent vision loss and significant morbidity if undiagnosed. While curricula regarding refugee health exist, no curriculum exists on identifying common eye conditions in refugee children and performing pediatric eye screening. Methods: We created and delivered a virtual, single-session curriculum on pediatric refugee eye conditions and screening to medical and nursing trainees. A needs assessment survey assessing trainees’ knowledge and confidence in detecting eye conditions in children and refugees informed curriculum design. Pre- and post-test assessments evaluated participants’ knowledge and confidence before and after the module. A two-sided signed-rank test was used to compare pre- and post-test scores. Results: Twenty-seven respondents completed the needs assessment survey, which revealed low levels of confidence in performing vision screening, especially in evaluating the eye surface. Fourteen participants completed the module and pre- and post-test surveys. Mean knowledge test score improved from 52% to 75% (P<0.001). Discussion: As the global refugee population grows, this study supports the value of incorporating a refugee child eye curriculum into trainee education to empower providers to detect and address refugee eye conditions.
Education of U.S. primary care physicians at the Latin American medical school in Cuba
Authors: Kirkland Deborah A , Lindley Lisa C , Meschke Laurie L
Published: September 2024

Background: Growing global health disparities have led to an international call for reform in physician education to meet the need for more responsive providers, emphasizing social accountability, with its four main criteria being relevance, quality, cost-effectiveness, and equity. In contrast to traditional models, Cuba’s Latin American Medical School (la Escuela Latinoamericana de Medicina, ELAM) promotes primary healthcare for disadvantaged populations by providing free medical education to foreign students from low-income communities, including United States (U.S.) citizens. This study examines the processes and standards by which the Latin American Medical School provides socially accountable education, with an emphasis on current and former students from the U.S. The objective of this study is to assess the efforts of ELAM to educate medical students in socially accountable and ethical ways. Methods: Guided by the four abovementioned criteria of social accountability, we thematically analyzed survey comments from 56 past U.S. graduates of the ELAM and interviews with four current U.S. students and eight instructors. Results: Relevance of the ELAM´s training was reflected in the integration of public health practices (e.g., community assessments) and medical care relevant to local and international health concerns. Quality is manifested in the school’s promotion of evidence-based care through tailored academic content for the U.S. students, expanded educational facilities throughout Cuba, and extensive clinical experiences. ELAM exhibits cost-effectiveness via free education and other financial assistance. Promoting equity in healthcare is evident in students’ desire to care for underserved populations with whom they identify. Graduates, current students, and instructors demonstrate that educating physicians from marginalized communities helps to answer the call for social accountability; this was supported by the educational processes and achieved outcomes. Discussion: These findings indicate that the Latin American Medical School’s mission and core activities meet the WHO’s criteria for social accountability and advance current understanding of such programs.
Financial Performance's Impact on Firm Value: How Managerial Ownership Mediates the Relationship
Authors: Kristanti Farida Titik , Nurhayati Imas , Fariska Putri
Published: September 2024

Banks play a significant role in facilitating the generation of economic growth opportunities, which can impact the achievement of government-set economic growth objectives. Hence, it is imperative to foster a climate that promotes banks' competitive growth and resilience, enabling them to effectively confront many problems in the face of escalating global complexities. To maintain a competitive edge, the bank must exhibit strong performance that positively influences corporate value. For that, the objective of this study is to ascertain the key determinants that exert a substantial impact on the valuation of firms, specifically examining the potential influence of capital structure, profitability, profits per share, and dividend payout ratio on the value of financial institutions. Another aim of the study is to ascertain the potential moderating effect of managerial ownership on the independent variable of company value. The sample selection included purposive random sampling, with the criterion of including only those with complete data from the research period spanning 2011 to 2022, using Moderation Regression and data panel Analysis. This study shows that earnings per share and dividend payout ratio significantly impact banks' valuation. In the interim, the Moderation Regression Analysis has yielded findings indicating that management ownership is a moderating factor in the relationship between earnings per share and banking value.
Meningkatkan hasil belajar mata pelajaran Pendidikan Agama Islam dan budi pekerti dengan strategi pembelajaran active learning information search siswa kelas IX SMP Negeri 2 Sentolo
Authors: Baharudin R Bagus
Published: September 2024

Tujuan penelitian ini adalah: (1) untuk mengetahui bagaimana penerapan pelaksanaan pembelajaran Pendidikan Agama Islam dan Budi Pekerti dengan menggunakan strategi pembelajaran active learning information search, (2) untuk mengetahui apakah terdapat peningkatan hasil belajar dengan diterapkannya strategi pembelajaran active learning information search, (3) untuk menggambarkan hasil pembelajaran Pendidikan Agama Islam dan Budi Pekerti dengan strategi pembelajaran active learning information search. Strategi yang digunakan dalam Penelitian Tindakan Kelas ini adalah dengan strategi pembelajaran active learning information search. Penelitian Tindakan Kelas dilaksanakan dengan harapan mengatasi permasalahan yang muncul didalam kelas. Strategi ini dilakukan dengan empat tahap, yaitu perencanaan, tindakan, pengamatan, dan refleksi. Keempat tahap tersebut terdapat dalam satu siklus yang dilakukan berulang dengan langkah-langkah yang sama dan tetap difokuskan pada pencarian informasi dengan menggunakan strategi pembelajaran active learning information search. Hasil penelitian ini menunjukan bahwa hasil belajar siswa dengan menggunakan dengan strategi pembelajaran active learning information search mengalami peningkatan. Peningkatan tersebut dapat dilihat dari hasil tiap siklus yang dilakukan. Perincian nilai rata-rata pretest siklus I pada pertemuan pertama sebesar 68,69, pretest siklus II pada pertemuan pertama sebesar 70,00. Postest siklus I pada pertemuan kedua rata-rata sebesar 80,83, postest siklus II pada pertemuan kedua rata-rata sebesar 86,41. Peningkatan hasil belajar dapat dilihat dari nilai normaligain tiap siklusnya,yakni N-gain siklus I: 0,34 dan N-gain siklus II: 0,51. Hasil belajar siswa pada mata pelajaran Pendidikan Agama Islam dan Budi Pekerti dengan menggunakan strategi pembelajaran active learning information search dirasa sudah maksimal karena pencapaian nilai diatas KKM sudah melebihi target yang cukup tinggi yaitu 97%.