bluuebunny/crossref_metadata_2025 huggingface dataset:
Slope stability analysis of cement and silica fume stabilized expansive soil slope
Authors: Chiu Abraham C.F. , Mamoudou Ibrahim Moumouni , Al-Ajamee Mohammed , Mary Baguma Mbabazi
Published: May 2024

The objective of this study was to assess the impact of chemical stabilization on slope stability using water retention test data. The analysis focused on hypothetical expansive soil with a 10 m height and a 34° angle. Two critical unsaturated hydraulic properties were considered: (1) soil water retention curve and (2) hydraulic conductivity function. Chemical stabilizers were introduced at varying percentages relative to cement content, with silica fume (SF) partially replacing portions of the cement. The influence of stabilizers on slope stability was evaluated by examining changes in the factor of safety (FOS) with different stabilizer concentrations. Generally, the FOS increased with higher cement content, with further improvement observed when cement was partially replaced by silica fume. Additionally, the addition of silica fume enhanced water retention capacity, as evidenced by altered pore pressure distribution and water table levels post-rainfall infiltration.
Probabilistic three-dimensional finite element analysis of geosynthetic-reinforced pile-supported embankments
Authors: Agarwal E , Luo N
Published: May 2024

The current study focuses on a probabilistic three-dimensional finite element analysis of geosynthetic-reinforced pile-supported embankments. The probabilistic analysis utilizes a finite element technique and was executed using Python scripting in Abaqus. A deterministic model is established for both unreinforced and geosynthetic-reinforced pile-supported embankments, employing a basic linear elastic perfectly plastic Mohr-Coulomb constitutive model. This numerical model adopted a simplified methodology that eliminates the need to simulate actual piles and subsoil. The results are validated across different embankment heights and mesh sizes. Based on results from Monte-Carlo simulations, we aimed to show how results can vary even by considering only one random variable. Probability density functions for various parameters, including pile efficacy, maximum differential settlement, and maximum strain in the reinforcement, are shown. The findings illustrate the ability of probabilistic approaches to predict the most likely occurrences for different governing parameters of geosynthetic-reinforced pile-supported embankments. They also highlight the potential of probabilistic approaches to expand further into a full-scale comprehensive study which can offer deeper insights into the stability of these embankments considering various sources of uncertainties.
Design, construction, and monitored behavior of two large-diameter cylindrical diaphragm walls on an offshore reclamation island
Authors: Zhai J Q , Wang Q , Wang S S , Zhang Z B , Wan J C
Published: May 2024

Two semi-underground liquefied natural gas (LNG) storage tanks with an excavation depth of 25.6 m were constructed on an offshore reclamation island in Dapeng Bay, Shenzhen, China. Two cylindrical retaining diaphragm walls with a diameter of 100 m were adopted for the deep excavation. This paperpresents detailed information on the design and construction of these two cylindrical retaining diaphragm walls. As the elevation changes in the soil and rock layers were very severe, the non-axisymmetric distribution of the lateral pressure was significant. Diaphragm walls with different embedded depths were designed to cut off the seepage paths inside and outside the retaining structure. The strength of the rock was extremely high; therefore, a combination of predrilling using a rotary excavator and grooving using a milling machine was adopted in the trenching construction of the diaphragm wall. The monitored soil and rock pressures acting on the diaphragm wall are discussed. The lateral deformation of the diaphragm wall was described, and the hoop force and vertical bending moment of the retaining diaphragm wall were analyzed, which could be a reference for similar projects.
Research and engineering practice of 70-m long-distanceaxial-force servo steel support technology
Authors: Xie Xiaolin , Fang Yingang , Jia Jian , Zhai Jiequn , Yang Ke
Published: May 2024

For deep excavation projects in areas with soft soil and a sensitive surrounding environment, an axial force servo steel support is usually adopted to control the deformation of retaining structures; however, the traditional axial force servo steel support can only be applied to deep excavations with a width of approximately 20 m owing to its technological limitations. In this study, considering the deep excavation project of Shanghai Xuhui Riverside Area A as an example, relevant technical research on a 70-m long-distance axial force servo steel support was conducted and the effect of this steel support in engineering practice was analyzed. Through the successful application of the project, the engineering safety reliability and deformation control effectiveness of the 70-m long-distance axial force servo steel support were verified, which can provide a reference for the design of similar projects.
Mechanical performance and application of retaining structures doubling as permanent structures in deep excavations
Authors: Xie Jinli , Xu Qianwei , Yan Hui , Han Yufeng , Lu Linhai
Published: May 2024

This study examines the effectiveness of the prefabricated pile-wall composite retaining structure (PW-CRS), which is a cutting-edge construction technique that combines prefabricated retaining piles with internal structural walls and is being increasingly utilized in excavation engineering projects. To comprehensively assess its performance, the research adopts a simulated loading approach, using equivalent concentrated loads to mimic the actual conditions faced by the PW-CRS. The experimental analysis highlights inclined tension failure as the predominant form of structural failure, accompanied by extensive cracking in both the pile and wall components. Additionally, the study points to slip failure of the laminated surfaces as a significant factor influencing the load-bearing capacity of the structure. The strain assessments on both concrete and reinforcement elements further enrich the findings. This investigation enhances the understanding of the structural dynamics of the prefabricated PW-CRS and offers valuable insights for its effective application in excavation engineering projects.
Mechanism of the piping phenomenon in a granite residual soil foundation pit
Authors: Zhao Yu , Wang Chengfeng
Published: May 2024

In the construction of a subway foundation pit in a granite stratum, soil gushing in the foundation pit and a large settlement of the surrounding strata can occur. To explore the mechanism and treatment methods, in this study, seepage tests and numerical simulations of the granite residual soil were conducted. The results showed that the main reason for foundation settlement was that the residual soil pipes weakened under a large hydraulic slope. According to the research conclusion, a method of controlled pumping of foundation pits was proposed, and subsequent construction achieved good results.
Prediction of dredged soil settlement based on improved BP neural network
Authors: Li P P , Li J P , Liu G Y , Zhou P
Published: May 2024

Based on the measured settlement data from the Reclamation Project of Eastern Hengsha Shoal, two improved BP neural networks optimized by the particle swarm optimization (PSO) algorithm and genetic algorithm (GA) respectively are employed to predict the long-term consolidation settlement of the dredged soil in the reclamation area. By comparing the prediction results of the improved neural networks with those obtained from standard BP neural network and various curve fitting methods including hyperbola method, Hoshino method, and Asaoka method, as well as field-measured data, the improved neural network methods are validated to have a better predictive performance. The error analysis results indicate that compared with the standard BP neural network and curve-fitting prediction methods, the improved BP neural networks exhibit smaller prediction errors in terms of MAE, MSE, RMSE, MAPE, etc., and have a closer match between the predicted settlement values and the actual values. The selected GA-BP and PSO-BP neural network prediction methods in this study demonstrate higher prediction accuracy. Meanwhile, GA-BP demonstrates higher prediction accuracy and generalization ability than PSO-BP, but PSO-BP shows faster convergence in terms of prediction speed. The preferred methods presented in this paper exhibit good robustness and high reliability, which can achieve accurate prediction of dredged soil settlement. Additionally, unlike the traditional curve-fitting methods, the selected methods can effectively reduce the influence of subjective factors during the settlement prediction, and provide a new approach for settlement prediction, which can be effectively utilized as a substitute for long-term settlement monitoring and give reference for the design of settlement control of foundation of further construction projects.
Determining the number of soil layers using the surface wave method based on decision tree and random forest
Authors: Zhou Zan , Lok Thomas M H
Published: May 2024

The surface wave method is an efficient non-invasive technique to infer shear wave velocity profiles and has wide applications in civil engineering, earthquake engineering, and geophysics. Inversion analysis is a key step in this method. However, inferring the soil layer number is a challenging problem in inversion analysis and needs improvement. Machine-learning algorithms, including decision tree and random forest, are used in this study to infer the number of soil layers based on the dispersion curve of the surface wave. This process includes two steps for obtaining the model. In Step 1, a large set of synthetic dispersion curves is produced, and in Step 2, a model using machine-learning algorithms is trained based on the synthetic data. The analysis results showed that the obtained model could gain more than 75% accuracy in the test data. Comparing the results from the two machine learning models indicated that the random forest method produced a more favorable prediction. Furthermore, investigating the importance of features implied that the longest and shortest wavelengths were more important than other features.
Data-driven approach for intelligent tunnel dust concentration prediction
Authors: Yang Tongjun , Wu Chen , Chen Jiayao , Zhou Mingliang , Huang Hongwei
Published: May 2024

The precise evaluation of tunnel dust concentration (TDC) stands as a primary concern within engineering practices. However, comprehensive and accurate prediction of TDC becomes increasingly challenging due to the expanding multi-source datasets and cumulative errors. This study employs innovative data-driven ensemble learning methodologies, specifically random forest (RF) and gradient boosting regression tree (GBRT), to delineate the intricate relationships between TDC values and various rock tunnel characteristics. Five diverse variables sourced from multiple origins are examined and employed as inputs within the database, while the TDC values derived from the dust concentration meter serve as the target outputs. Subsequently, a Bayesian optimization approach, the Tree-structured Parzen Estimator (TPE), is introduced to automatically ascertain the optimal hyper-parameters for the ensemble models. A comprehensive comparison is conducted between the two ensemble learning models and a singular machine learning algorithm, the classification and regression tree (CART), concerning predictive accuracy and resilience via 10-fold cross-validation (CV). The findings reveal the superior performance of the hybrid ensemble learning models over the individual ML models. Notably, the TPE-GBRT algorithm adeptly captures the measurement evolution, showcasing the lowest prediction errors and the highest correlation coefficient. These predicted outcomes significantly contribute to enhancing the engineering comprehension of the interrelation between rock tunnel parameters and TDC values.
Soil classification based on unsupervised learning using cone penetration test data
Authors: Zhang Jinzhang , Mao Zhiyang , Huang Hongwei , Zhang Dongming
Published: May 2024

Borehole data obtained during geological surveys are the most essential source for understanding soil stratification. It is a prerequisite to know the soil classes up to some depths prior to any construction. However, the direct method to identify the soil classes by drilling boreholes and testing soil samples is costly. A cost-effective alternative is the Cone Penetration Testing (CPT), which is one of the most popular soil investigation methods. This paper explores the intelligent classification of soil layers based on CPT data using three unsupervised machine learning methods: K-means, Gaussian Mixture Process, and BIRCH. The research investigates the classification performance of different models in scenarios with 2 combinations, 3 combinations, 4 combinations, and 5 combinations. The results indicate that the Gaussian Mixture Process method exhibits the best classification performance, followed by the BIRCH method, while K-means performs relatively poorly. Using unsupervised learning for intelligent soil layer classification offers a fast and clear process, but the accuracy still requires further improvement. This study provides a valuable reference for future soil classification studies.
Microfluidic chips for microbially induced calcium carbonate precipitation: Advantages, challenges, and insights
Authors: Wang Yuze , Wu Qinghua , Chen Hongyu
Published: May 2024

Microbially induced calcium carbonate precipitation (MICP) has garnered significant attention as a biomineralization process with diverse applications spanning from construction to environmental remediation. To propel MICP research and deepen our comprehension of MICP mechanisms, microfluidic chips have emerged as potent tools offering precise control over environmental parameters and real-time observations. Herein, we explore the benefits and challenges associated with employing microfluidic chips as a platform for investigating MICP. The advantages of microfluidic chips lie in their capacity to create controlled microenvironments conducive to emulating specific conditions crucial for MICP. The high-throughput nature of these devices accelerates experimentation by facilitating simultaneous testing of various microbial strains and nutrient compositions. Throughout the MICP process, observations were made on the behaviors of both bacterial cells and CaCO3 cementation. The inherent reduction in reagent consumption offered by microfluidics is both cost-effective and environmentally friendly. However, scaling up from microscale findings to practical applications necessitates careful consideration. Fully replicating the three-dimensional complexity and heterogeneous structures of the soil matrix, which influence microbial behavior, mineral distribution, and overall precipitation dynamics, using microfluidic chips remains challenging. Additionally, certain environmental complexities, including macroscopic soil components such as organic matter and various particle types, which significantly affect microbial activities and mineral precipitation patterns, may be difficult to replicate in microfluidic setups. However, microfluidic chips stand as invaluable tools for advancing MICP research. By addressing the advantages and disadvantages outlined here, researchers can harness the capabilities of microfluidic systems to unravel the intricacies of MICP, ultimately bridging the gap between fundamental understanding and real-world applications.
Approaching road design from a sustainability perspective
Authors: Dagenais T L , Chatterjee A K , Pokharel S K , Breault M
Published: May 2024

The construction industry began emphasizing the three major pillars of sustainable development after the 1987 Brundtland Report. Sustainable design methodologies focus on life-cycle costs and the associated impacts of construction, operation, and maintenance. Maintaining road infrastructure accounts for a significant portion of the development budget owing to recurring costs, construction, and material extraction, while also resulting in other difficulties for the society. Poor road quality induce increased cost of living and degraded quality of life. Owing to front-end costs, road owners are typically motivated to pursue designs focused on the project’s initial cost. This is primarily attributable to a lack of understanding of sustainable development parameters. Life cycle cost attempts to quantify the environmental costs of sustainable construction. However, societal factors have been generally ignored. Currently, road section design is open to the designers’ choice of conventional unreinforced sections or a wide variety of planar and three-dimensional geosynthetic reinforcements. This study defined quantitative and scaled qualitative measures for designing road infrastructure using a sustainable approach. The methodology was explained using a full-scale real-life road project.
Influence on the surrounding vegetation’s spatiotemporal changes by Jinping II Hydropower Station
Authors: Jiao Y , Yan Y
Published: May 2024

The Jinping II Hydropower Station, located near Jinping Mountain, is a strategically significant hydropower project. The construction and operation of this project have impacted the surrounding ecological environment. The Normalized Difference Vegetation Index (NDVI) is widely used in remote sensing and serves as a crucial parameter for assessing vegetation health and ecological vitality. Through quantitative analysis using Sen’s slope and the Mann-Kendall non-parametric test on NDVI, we gained a deeper understanding of the impact of hydropower station construction on the surrounding vegetation. The primary objective of this study was to systematically investigate the spatiotemporal variations in NDVI before, during, and after the construction of the Jinping II Hydropower Station. The research findings contribute to the formulation of strategies aimed at mitigating potential adverse effects on the environment while promoting the region’s sustainable development goals.
Research on the Equivalent Criterion for Ratios of Safety Margin in Terms of the Factor of Safety and the Reliability Index Under Lognormal Distribution
Authors: Zhang J , Luo C , Li X S
Published: May 2024

The ratio of safety margin is the bridge between deterministic design and reliability design. However, the equivalence criterion between the ratios of safety margin in terms of the factor of safety (FOS) and the reliability index is ambiguous. This paper considers the traditional and reliability-based design method at the same safety level. A general form of the FOS following lognormal distribution is adopted. It was found that the variability of FOS is affected by the normalized gradient and the coefficient of variation of random variable. The ratios of safety margin in terms of the FOS and the reliability index are equivalent in the specific project if the normalized gradient does not vary with the design parameters. The feasibility of applying the ratio of safety margin may be increased in engineering practice.
Experimental behavior of piggy-backed anchors in cohesionless soils
Authors: Lai Y , Yang M , Chen C , Zhu B , Chen Y
Published: May 2024

As the offshore wind platform ventured into deep water, improving anchor efficiency has become the main focus of foundation design. Plate anchors are attractive options due to factors such as high anchor efficiency and low cost. Appropriately attaching two plate anchors improves the total capacity of the piggy-backed anchors configuration, and generally, this capacity is greater than twice the capacity of an individual anchor. This paper presents the centrifuge drag embedment tests of an individual drag embedment anchor (DEA) and the piggy-backed DEAs in cohesionless soil. The piggy-backed configuration with the spacing between the two anchors at three fluke lengths and an attachment point at the back of the fluke can improve the anchor total capacity. The main reason is that a deeper penetration of the back anchor and the steeper pitch of the front anchor facilitate both anchors to dive deeper.
Digital twin-based quantification of carbon emission from foundation pit construction: A case study of a station in Shanghai Metro
Authors: Lai W , Hu R , Qin J , Pan Y , Chen J-J
Published: May 2024

This study focused on achieving the carbon peaking and carbon neutrality goal. A carbon emission calculation method based on the entire process of excavation construction and the emission factor method for the foundation pit construction of a metro station was proposed. This method facilitated quantitative calculation of total carbon emissions in metro foundation pit engineering, which was then incorporated into a self-designed digital twin platform to drive sustainability efforts. The proposed calculation approach was verified in the foundation pit of Huangpi South Road Station (Shanghai Metro Line No. 14). (1) The pit construction process of the targeted metro station emitted 127,439t of carbon dioxide equivalent. (2) From the material perspective, reinforcing steel and concrete accounted for a significant proportion of the overall carbon emissions. Whereas, from the construction perspective, the engineering process of supporting structures accounted for a considerable proportion of the carbon emissions. (3) A comparative analysis of different construction zones revealed that the carbon emissions during the construction stage of the metro pit project were closely related to the amount of earthwork and size of the deep excavation engineering. Practically, the discovered knowledge of carbon emission characteristics can be visualized in a digital twin.
Advanced geospatial modeling and statistical evaluation of heterogenous geotechnical facets at multiple depths using the improved formulation of modified Shepard IDW algorithm
Authors: Ijaz Zain , Zhao Cheng , Ijaz Nauman , Rehman Zia ur , Ijaz Aashan
Published: May 2024

A formidable challenge in geology and geotechnics is the significant spatial heterogeneity in the subsoil characteristics in fine-scale grids. To mitigate this problem, geotechnical data is integrated as geotechnical soil maps (GSMs), which uses sophisticated interpolation techniques and provides an advanced understanding and accurate depiction of subsurface variability. This study uses an improved formulation of inverse distance weighting (IDW) algorithm based on modified Shepard method, integrated with the Google Earth Engine platform. The prediction efficiencies of GSMs and traditional IDW algorithm are statistically evaluated and compared, considering heterogeneous geotechnical facets at multiple depths in an unexplored region. Pertinent geotechnical properties including soil type, plasticity index, and standard penetration test were considered to evaluate the algorithm performance based on critical performance metrics. The results demonstrate that the improved formulation of the IDW algorithm is more relevant to field values and tends to align with Tobler's first law of geography by inducing a smooth transition rather than a disruptive trend owing to high geotechnical variability. The prediction accuracy increased by 10 – 20% compared to the traditional IDW algorithm. This study demonstrates and promotes the use of an improved formulation of the modified IDW algorithm considering its better accuracy and relevance to field value
Voronoi-based 3D phase field model and numerical simulations of granite crack propagation
Authors: Wang Changhao , Zhao Cheng , Xing Jinquan , Chen Huiguan , Sun Zeyuan
Published: May 2024

The distribution of mineral grains within underground rocks and materials is crucial for understanding geological processes and the stability of engineering structures. However, numerical simulation methods that consider 3D mineral particles are still immature. This study presents a 3D phase-field fracture model of mineral grains based on Voronoi polygons, making some beneficial attempts in this regard. The phase-field method does not rely on mesh reconstruction or crack path tracking and can simulate complex crack propagation behavior. Meanwhile, the Voronoi polygon can better describe the microscopic structure of rock with grain boundaries. Rooted in Voronoi polygons, this model efficiently captures the complex geometric shapes of mineral grains and accurately characterizes their positions, shapes, and sizes. Therefore, this study combines Voronoi polygons to establish a 3D phase-field model. Through two numerical simulation cases, the model demonstrates its effectiveness in simulating the impact of three-dimensional mineral grains on crack propagation behavior, showing that cracks tend to propagate at the boundaries or inside softer mineral grains. The modeling approach proposed in this paper has good reference value for numerical simulation studies considering the microscopic structure of rocks.
Cyclic response of laterally loaded pile after storm loading
Authors: Wang Huan , He Ben , Wang Lizhong , Hong Yi
Published: May 2024

Offshore wind farms in China are in tropical cyclone zones, where typhoons or tropical revolving storms will pass through every year and can produce huge loads on the offshore wind turbines. Therefore, the stability of OWT foundations after storm loading is critical to ensure the safe operation and design life of turbines. While monopile is the most used foundation type for offshore wind, little studies exist on the cyclic response of monopile after storm loading. To fill the gap, this study presents a unique centrifuge and numerical study on the cyclic deflection response of monopile in medium dense sand after extreme storm loading. The centrifuge test was performed at 100g on a typical monopile with a prototype diameter (D) and embedded depth (L) of 4 m and 60 m, respectively. Finite element (FE) simulations using the advanced hypoplastic model for sand were performed to back-analyze the centrifuge test and provide further insights into the test results. From the centrifuge test, a unique “self-healing” beahviour of monopile was observed for the first time, where the foundation exhibited a deflection recovery response and tilted back to its initial position under the small amplitude cyclic load after the storm loading. This “self-healing” beahviour was also replicated by the FE model. By looking into the computed pile-soil interaction and soil element states around the pile, it was found that the “self-healing” response is attributed to the lock-in bending moment after the storm loading. This “lock-in” bending moment generated significant compressive horizontal stress on the soil elements behind the pile and produced more compressive strain under cyclic loading. As a result, the pile exhibited the “self-healing” response and tilted back against the loading direction.
Preface to the Proceedings of the 5th European Academic Symposium on EAF Steelmaking
Authors: Visuri V-V , Echterhof T
Published: May 2024

The European Academic Symposium on EAF Steelmaking (EASES) is a series of events targeted at researchers and doctoral candidates working with different aspects of electric arc furnace (EAF) steelmaking. Previously, four events were organised in 2015, 2016, 2018, and 2021 in Aachen, Germany. The 5th European Academic Symposium on EAF Steelmaking (EASES 2023) was organised jointly by the RWTH Aachen University (Department for Industrial Furnaces and Heat Engineering) and University of Oulu (Process Metallurgy Research Unit) and held at the University of Oulu in Oulu, Finland on 5-7 June 2023. A total of 29 presentations were held at the event, out of which 13 featured an accompanying full paper. After the symposium, the authors of the full papers were invited to submit their manuscripts to be included in the proceedings. The proceedings consist of a total of 12 peer-reviewed papers published in the IOP Conference Series: Materials Science and Engineering. Based on the presentations, the development of modelling and monitoring tools for process optimization, the use of biochar to replace fossil carbon for slag foaming, and the use of hydrogen as an alternative burner fuel were identified as current hot topics. In the future, the importance of the EAF process is expected to increase further due to the increasing availability of scrap and plans for ore-based production routes based on hydrogen direct reduction.
An In-Situ Analysis Method in EAF and BOF Steelmaking
Authors: Mitas B , Pauna H , Feldbacher J , Schenk J
Published: May 2024

An analysis was conducted to gage the feasibility of using a spectroscopic method to determine the chemical composition of the liquid metal phase in EAF and BOF steelmaking. The hypothesis that certain radiation intensities found in UV- and UV-near regions of an spectrum emitted from the hot-spot in the BOF or the impingement area of oxyfuel burners in EAF steelmaking can be used for analysing the chemical components present in the liquid metal is tested. Significant lab-scale experiment results and the conclusions regarding industrial scale implementation are presented.
Manipulation of the leaching behaviour of high-alloyed steel EAF slags through the particle size modulation
Authors: Mombelli D , Dall’Osto G , Cozzo S , Mapelli C
Published: May 2024

The safe disposal of EAF slag have become crucial due the environmental and health protection regulations. Its direct reuse is hampered by the possible release of toxic elements into the surrounding environment over time. Specifically, EAF slag from high-alloyed steel production could potentially release toxic metals (e.g., Ba, Cr, Mo and V). Currently, the assessment of leaching behaviour is carried out according to the EN 12457:2002 standard, which generically specify that the material should not be finely ground, limiting the particle size as much as possible. However, no guidance is given on reducing particle size and handling fine fractions, which could lead to manipulation of data and variability of results. In this work six different fractions (from <4 mm to <63 μm) of EAF slag from high-alloyed steel production were investigated. X-Ray Diffraction, Scanning Electron Microscopy and selective C2S dissolution were used to correlate the leaching behaviour with particle size and identify which mineral can alters the release of specific toxic elements. The pH of the water was measured immediately after filtration, and the solution was analysed by Inductively Coupled Plasma-Optical Emission Spectrometry. In addition, five mixtures were prepared using different mass fractions of the six granular fractions with the aim of unbalancing the mixtures toward coarser or finer fractions, respectively. All the mixtures were subjected to leaching under the same previous conditions and analysed to evaluate the behaviour of the different blended fractions. To investigate the predictability of the leaching behaviour of the mixtures, the experimental results were compared with the values predicted by a theoretical model calibrated using the results obtained from the leaching results of the six particle size fractions. The investigation showed that the leaching behaviour is negatively affected by the particle size reduction, mainly due to the increase of surface-to-volume ratio, which increases the dissolution rate. Similarly, the mass fraction of the main crystalline phases that regulate leaching (unstable spinels, brownmillerite and larnite) is also correlated with the change in particle size. Consequently, the leaching results for the mixtures highlighted a critical aspect contained in the European standard. Even small changes in particle size can lead to different concentrations of toxic metals in leachates, which can then be manipulated to achieve the desired result.
Application of hydrogen operated burners in the electric arc furnace
Authors: Schüttensack L , Reinicke A , Echterhof T
Published: May 2024

The steel making industry has one of the highest carbon dioxide emissions worldwide. The recycling route with the electric arc furnace (EAF) as the central aggregate emits less carbon dioxide in comparison to the blast furnace. Still, the EAF offers high potential for a reduction of the carbon dioxide emissions. One possibility is the substitution of natural gas by hydrogen in the auxiliary burners of the EAF. This substitution is investigated and analysed using a dynamic EAF process model. The model is able to simulate the combustion of natural gas as well as hydrogen. The differences in the operating conditions and properties by the hydrogen operated burners can be analysed in the results of the EAF process model.
Effects of synthesis conditions on particle size and pore size of spherical mesoporous silica
Authors: Xu Shu , Meng Xiaohui , Zhang Bokai , Li Shanshan
Published: May 2024

The particle size and pore size of spherical mesoporous silica materials play significant roles in their application. However, relatively limited systematic research has been conducted on how preparation conditions influence these properties. In particular, the effects of some important factors have not been adequately studied, including reaction time, reaction temperature, and organic solvent type. In this work, octane and water were used as solvents, and tetraethyl orthosilicate was used as the silicon source to systematically study the effects of reaction time, reaction temperature, different organic solvents, octane/water mass ratio, styrene template concentration, and surfactant (cetyltrimethylammonium bromide, CTAB)/H2O mass ratio on the particle morphology, particle size, and pore size of silica. The results suggest that the above-mentioned neglected factors exert a substantial influence on both particle size and pore size. In the experimental temperature range, the pore diameter decreases and the particle size increases with increasing temperature. The maximum particle size and pore size are achieved after a reaction time of 3 h, and a further increase in reaction time leads to a smaller particle size and pore size. As the number of carbon atoms in the organic solvent decreases, the pore size also gradually increases. Styrene and organic solvents that dissolve in CTAB micelles are crucial factors in pore formation, while the aggregation of the swollen CTAB micelles influences the particle size. The changes in the pore structure stability and hydroxyl density of the synthesized samples in water were also studied. After undergoing water treatment at temperatures ranging from 20 to 60 °C for 72 h, both the pore structure and morphology remain relatively unchanged. When the temperature increases, the surface hydroxyl density exhibits a more pronounced increase in the presence of water. After water treatment for 5 h, the surface hydroxyl density reaches saturation.
Development of red mud based sintered artificial aggregates with various industrial wastes
Authors: Narendra Somepalli , Vasugi V
Published: May 2024

Red mud (RM) has drawn a lot of attention in the search for potential uses in the production of sintered artificial aggregate from industrial waste products. The main objective of the study is to produce an RM-based sintered artificial aggregate (SAA), with several blends (binary, ternary, and quaternary) using various industrial wastes. This study includes assessing the mechanical and physical properties of SAA as well as the sintering parameters in order to determine the appropriate material mix ratio. To achieve these objectives, a comprehensive experimental approach was adopted. A total of 35 different mixtures were formulated by incorporating various industrial wastes as binders and sintering additives. The green pellets were preheated at 105 °C for 24 h, and consecutively sintered at different temperatures, namely 700 °C, 900 °C, 1100 °C, and 1150 °C with a duration of 30 min. A compressive strength test was performed in order to find the mechanical property of SAA similarly water absorption and bulk density tests were conducted to find the physical properties of SAA. To characterize the SAA, scanning electron microscope analysis (SEM), X-ray diffraction (XRD) and energy dispersive x-ray analysis were conducted, and also data analysis was performed using Artificial Neural Network (ANN) tools, yielding accurate predictions. Successfully best compressive strength low water absorption SAA was produced. The best material weight mix ratio for the production of SAA was identified as (A18) RM: Fly Ash: Waste Glass Powder; 78:10:12. Out of all blends the ternary blend (A18) SAA exhibited impressive properties after 30 min of sintering at 1150 °C: high compressive strength of 22.92 MPa, water absorption of 4.26%, and bulk density of 1296.12 kg m−13. This was made possible by the high amount of Al2O3, SiO2, in the combination of fly ash, and waste glass powder with RM. SEM and XRD analysis also confirmed that the (A18) SAA achieved the best compressive strength, and low water absorption due to turning the surface and core area into a solid, reduced internal pores and formed quartz, and hematite phases. The findings of this study serve as a foundation for future work and pave the way for the development of sustainable construction materials.
Sputter deposition of ZnO–AlN pseudo-binary amorphous alloys with tunable band gaps in the deep ultraviolet region
Authors: Urakawa Seiichi , Magdy Wafaa , Wada Yoshiharu , Narishige Ryota , Kaneshima Kentaro , Yamashita Naoto , Okumura Takamasa , Kamataki Kunihiro , Koga Kazunori , Shiratani Masaharu , Itagaki Naho
Published: May 2024

ZnO–AlN pseudo-binary amorphous alloys (a-ZAON hereinafter) with tunable band gaps in the deep ultraviolet (DUV) region have been synthesized using magnetron sputtering. The miscibility gap between ZnO and AlN has been overcome using room-temperature sputtering deposition, leveraging the rapid quenching abilities of sputtered particles to fabricate metastable but single-phase alloys. X-ray diffraction patterns and optical transmittance spectra revealed that the synthesized films with chemical composition ratios of [Zn]/([Zn] + [Al]) = 0.24–0.79 likely manifested as single-phase of a-ZAON films. Despite their amorphous structures, these films presented direct band gaps of 3.4–5.8 eV and thus high optical absorption coefficients (105 cm−1). Notably, the observed values adhered to Vegard’s law for crystalline ZnO–AlN systems, implying that the a-ZAON films were solid solution alloys with atomic-level mixing. Furthermore, atomic force microscopy analyses revealed smooth film surfaces with root-mean-square roughness of 0.8–0.9 nm. Overall, the wide-ranging band gap tunability, high absorption coefficients, amorphous structures, surface smoothness, and low synthesis temperatures of a-ZAON films position them as promising materials for use in DUV optoelectronic devices and power devices fabricated using large-scale glass and flexible substrates.
Mechanical properties and damping characteristics of Egyptian granite-epoxy composite material
Authors: Abdelrhman Yasser , Omar Mohamed , Hassab-Allah Ibrahim M , Shewakh W M , Khierldeen Wael M , Hedaya Mohammed , Omar Refaie , Younes Mohamed F
Published: May 2024

Vibrations generated during the operations of machine tools, especially at high-speed operation impact several issues in machined parts such as imprecision dimensions and a poor surface finish. This prompts research and studies into alternative materials for machine tool structures to provide considerable damping performance and acceptable stiffness compared to traditional materials. This paper deals with the experimental study of a developed granite-epoxy composite, made from waste granite and local epoxy as an alternative material for machine tool structures. A waste of Egyptian Red Aswan granite was used as filler after being crushed and sifted into three sizes: fine (less than 1 mm), medium (1 to 5 mm), and coarse (5 to 8 mm). A local commercial epoxy resin kemapoxy 150 was added to a granite aggregate mixture having grain proportions 50:25:25 for fine, medium, and large, respectively. The influence of the variation of the epoxy weight ratio on the static and damping characteristics of a proposed granite–epoxy composite material was experimentally investigated. To ensure a coherent granite-epoxy composite, the required minimum resin content of 13.88 wt% was determined, and the granite/epoxy ratios were selected as 85:15 wt%, 80:20 wt%, and 75:25 wt%. The findings exhibit that the largest compressive strength of 76.8 MPa and the greatest flexural strength of 35.4 MPa is achieved at the highest epoxy weight ratio of 25%. The largest damping ratio of 0.0202 is observed at the epoxy ratio of 20% and it decreases to 0.015 when the epoxy ratio is increased to 25%. An Egyptian granite-epoxy composite, made from waste granite and local epoxy, is a promising alternative material for machine tool structures. It offers both economic and environmental benefits, along with high mechanical and damping properties compared to traditional machine tool materials.
The impact of COVID-19 on heat-related ambulance calls and the challenges for emergency medical transport in the Kansai region, Japan: a mixed methods approach
Authors: Ke Deng , Ialnazov Dimiter S , Takara Kaoru
Published: May 2024

The COVID-19 pandemic, coupled with more frequent and stronger heatwaves, has introduced a novel confluence of challenges. In Japan, emergency medical transport staffs are facing increasing difficulty in distinguishing between COVID-19 and heat stroke at the scene because they share some similar symptoms. This study explored the impacts of the COVID-19 pandemic on heat-related ambulance calls and identifies the challenges faced by local fire departments in the Kansai region of Japan over 2020–2022. Both historical data analysis and an online questionnaire survey were used in this study. We utilized a heat-related ambulance calls prediction model developed in our previous research based on the historical data (2008–2019) to project the expected number of heat-related ambulance calls from 2020 to 2022. Subsequently, we compared expected number and the actual number of daily heat-related ambulance calls to examine the variations of heat-related ambulance calls across six prefectures in the Kansai region. Our findings reveal a significant decrease in the number of heat-related ambulance calls during the COVID-19 pandemic across all Kansai prefectures, ranging from 3.2% to 22.9%. The decline in heat-related ambulance calls can be attributed to shifts in daily routines, such as the increase of remote work and decrease of outdoor exercise. However, it may also be influenced by the strain on the emergency medical resource. Furthermore, this study has also highlighted substantial pressures on local fire departments and emergency medical transport systems during the pandemic. A primary challenge for local fire departments was securing available medical facilities for patients. Improving the efficiency of the emergency medical transport system and enhancing the coordination between emergency medical services and healthcare facilities may offer a more resilient response in future crises.
The Qua Problem in the Value Interaction Debate
Authors: Song Moonyoung
Published: May 2024

This essay aims to elucidate the so-called 'qua problem' often invoked in the debate on the interaction between moral and artistic values. The qua problem is currently understood as the failure to establish a direct value interaction. I argue that this way of understanding the qua problem is flawed because it does not make the qua problem a real problem, that is, a problem that makes an interactionist argument unsuccessful in virtue of having the problem. Instead, I propose that the qua problem should be understood as the failure to show that the fact that an artwork is (im)moral (as opposed to other related facts, such as those that ground this fact) explains, whether directly or indirectly, the work’s artistic value (as opposed to being connected to the artistic value in some other way).
Human Epidemiology and Response to SARS-CoV-2 (HEROS): objectives, design, and enrollment results of a 12-city remote observational surveillance study of households with children, using direct-to-participant methods
Authors: Fulkerson Patricia C , Lussier Stephanie J , Bendixsen Casper G , Castina Sharon M , Gebretsadik Tebeb , Marlin Jessica S , Russell Patty B , Seibold Max A , Everman Jamie L , Moore Camille M , Snyder Brittney M , Thompson Kathy , Tregoning George S , Wellford Stephanie , Arbes Samuel J , Bacharier Leonard B , Calatroni Agustin , Camargo Jr Carlos A , Dupont William D , Furuta Glenn T , Gruchalla Rebecca S , Gupta Ruchi S , Hershey Gurjit Khurana , Jackson Daniel J , Johnson Christine C , Kattan Meyer , Liu Andrew H , Murrison Liza , O’Connor George T , Phipatanakul Wanda , Rivera-Spoljaric Katherine , Rothenberg Marc E , Seroogy Christine M , Teach Stephen J , Zoratti Edward M , Togias Alkis , Hartert Tina V , HEROS Study Team on behalf of the
Published: May 2024

The Human Epidemiology and Response to SARS-CoV-2 (HEROS) Study is a prospective, multicity, 6-month incidence study conducted from May 2020 to February 2021. The objectives were to identify risk factors for SARS-CoV-2 infection and household transmission among children and people with asthma and allergic diseases, and to use the host nasal transcriptome sampled longitudinally to understand infection risk and sequelae at the molecular level. To overcome challenges of clinical study implementation due to the coronavirus pandemic, this surveillance study used direct-to-participant methods to remotely enroll and prospectively follow eligible children who are participants in other National Institutes of Health–funded pediatric research studies and their household members. Households participated in weekly surveys and biweekly nasal sampling regardless of symptoms. The aim of this report is to widely share the methods and study instruments and to describe the rationale, design, execution, logistics, and characteristics of a large, observational, household-based, remote cohort study of SARS-CoV-2 infection and transmission in households with children. The study enrolled a total of 5598 individuals, including 1913 principal participants (children), 1913 primary caregivers, 729 secondary caregivers, and 1043 other household children. This study was successfully implemented without necessitating any in-person research visits and provides an approach for rapid execution of clinical research.

 

Trial registration: ClinicalTrials.gov. Identifier: NCT04375761
On adjustment for temperature in heat-wave epidemiology: a new method for estimating the health effects of heat waves
Authors: Kim Honghyok , Bell Michelle L
Published: May 2024

Defining the effect of an exposure of interest and selecting an appropriate estimation method are prerequisites for causal inference. Current understanding of the ways in which an association between heat waves (ie, consecutive days of extremely high temperature) and an outcome depends on whether adjustment was made for temperature and how such adjustment was conducted is limited. In this paper we aim to investigate this dependency, demonstrate that temperature is a confounder in heat-wave–outcome associations, and introduce a new modeling approach with which to estimate a new heat-wave–outcome relationship: E[R(Y)|HW = 1, Z]/E[R(Y)|T = OT, Z], where HW is a daily binary variable used to indicate the presence of a heat wave; R(Y) is the risk of an outcome, Y; T is a temperature variable; OT is optimal temperature; and Z is a set of confounders including typical confounders but also some types of T as a confounder. We recommend characterization of heat-wave–outcome relationships and careful selection of modeling approaches to understand the impacts of heat waves under climate change. We demonstrate our approach using real-world data for Seoul, South Korea. Our demonstration suggests that the total effect of heat waves may be larger than what may be inferred from the extant literature. An R package, HEAT, has been developed and made publicly available.

This article is part of a Special Collection on Environmental Epidemiology.