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PERFORMANCE EVALUATION OF STONE COLUMNS IN FINE SOIL CONDITIONS: A FEM-BASED CASE STUDY

Baltic Journal of Road and Bridge engineering 2025年第1期20卷 114-144页

作者： Zarazvand, Bahman Frankovska, Jana Department of Geotechnics Faculty of Civil Engineering Slovak University of Technology Bratislava Slovakia

This paper presents a comprehensive case study on the numerical analysis of stone columns as a ground improvement technique for an expressway embankment. The primary objective is to assess the effectiveness of stone columns in enhancing the performance of predominantly fine-grained soils using Finite Element Method (FEM) analysis. To achieve the objective, detailed numerical models are developed in both three-dimensional (3D) and two-dimensional (2D) plane strain configurations to simulate embankment conditions accurately. Key geotechnical parameters, including the modulus of elasticity and hydraulic conductivity of the stone column material, are incorporated to account for the improved stiffness and drainage effects. The installation process considers critical factors such as vibration-induced changes and horizontal displacement to capture the evolution of soil stress conditions. A staged construction approach is implemented to realistically simulate the sequential embankment construction process and its impact over time. To ensure model reliability, validation is performed by comparing numerical results with field measurements obtained from horizontal inclinometers installed beneath the embankment. The analysis focuses on key performance indicators such as settlement behaviour, the generation and dissipation of excess pore water pressure, and overall stability assessments. The results demonstrate a strong correlation between numerical predictions and field observations, confirming the accuracy of the developed models. This study provides valuable insights into the performance of stone column-reinforced embankments, highlighting significant improvements in load-bearing capacity, reduction in settlement, and overall ground stability. By evaluating the role of stone columns in accelerating consolidation and enhancing the stiffness, strength, and stability of fine-grained soil layers, the research contributes to the optimisation of design and construction methodologie

关键词： Hydraulic conductivity

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The Role of the Working Fluid and Nonideal Thermodynamic Effects on Performance of Gas-Lubricated Bearings

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Journal of engineering for Gas Turbines and Power 2025年第6期147卷 061015页

作者： De Waart, Wessel Pini, Matteo Faculty of Aerospace Engineering Delft University of Technology Delft2629 HS Netherlands

Small-scale turbomachinery operating at high rotational speed is a key technology for increasing the power density of energy and propulsion systems. A notable example is the turbine of an organic Rankine cycle turbogenerator for thermal recuperation from prime engines and industrial processes. Such systems typically operate with organic compounds characterized by complex molecular structures to allow the design of efficient fluid machinery and flexibility in matching the heat source and sink temperature profiles. Gas-lubricated bearings are considered advantageous compared to traditional oil-lubricated rolling element bearings for supporting the turbine rotor, enabling greater machine compactness and reduced complexity, and avoiding contamination of the working fluid. In certain operating conditions, however, the lubricant of the gas bearing is in thermodynamic states near the saturated vapor line or in the vicinity of the fluid critical point, whereby nonideal effects are relevant and may affect bearing performance. This work investigates the physics of thin film flows in gas bearings operating with fluids made by complex molecules. The influence of nonideal thermodynamic effects on gas bearing performance is discussed by analysis of the fluid bulk modulus. Reduced values of the nondimensional bulk modulus near the critical point or saturated vapor line decrease bearing performance. The main parameter characterizing the influence of molecular complexity on bearing performance is shown to be the acentric factor. For complex fluids with large acentric factors, the impact of nonideal thermodynamic effects on nondimensional bearing load capacity and rotor-dynamic characteristics is less pronounced. Copyright © 2025 by ASME.

关键词： Gas lubricated bearings

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Impact of machine learning-based imputation techniques on medical datasets- a comparative analysis

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Multimedia Tools and Applications 2025年第9期84卷 5905-5925页

作者： Tiwaskar, Shweta Rashid, Mamoon Gokhale, Prasad Department of Computer Engineering Faculty of Science and Technology Vishwakarma University Pune India

In the realm of medical datasets, particularly when considering diabetes, the occurrence of data incompleteness is a prevalent issue. Unveiling valuable patterns through medical data analysis is crucial for early and precise medical predictions. However, the quality of data and the proper handling of missing data hold significant significance. To address this challenge, imputation stands as a robust approach. The main goal of this paper aims to provide a comprehensive investigation into the effects brought about by Machine Learning (ML) based imputation techniques, specifically K Nearest Neighbor Imputation (KNNI), Multiple Imputation by Chained Equations (MICE), and MissForest. Results of all three techniques are compared with the complete dataset for five missing rates (10% to 50%), and evaluated using four categories of evaluation criteria i.e. (1) model performance, (2) imputation error rate (Mean Absolute Error (MAE), Root Mean Squared Error (RMSE), Coefficient of Determination (R^2) values), (3) Pearson correlation analysis and, (4) model selection basis (Bayesian information criterion (BIC), Akaike information criterion (AIC), values). Model performance includes accuracy, precision, recall, F1 score, and Matthews Correlation Coefficient (Mcoff) score of four ML classifiers viz. (a) Random Forest (RF), (b) Support vector machine (SVM), (c) AdaBoost, (d) XGBoost (XGB). For all missing rate cases, the MissForest technique is better than the KNNI and MICE in accuracy and Mcoff in 80% of cases, precision in 40% of cases, recall in 60% of cases, F1 score, MAE, RMSE, R^2 in 100% of cases, AIC in 80% of cases, and BIC values in 100% of cases. Also, the correlation analysis confirms that the MissForest imputation preserves association between the variables, like the complete dataset. Overall, our findings suggest that MissForest is a better machine learning-based imputation technique for handling missing data in diabetes research. © The Author(s), under exclusive lice

关键词： Adaptive boosting

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Preparation and Characterization of a Novel Energetic Cocrystal RDX:TNT (1:2)

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Central European Journal of Energetic Materials 2025年第1期22卷 94-106页

作者： Zohari, Narges Ghiasvand, Faezeh Akbari, Sara Faculty of Chemistry and Chemical Engineering Malek-ashtar University of Technology Tehran Iran

In this work, a new cocrystal named RDX:TNT is introduced and characterized. The DSC profile of the cocrystal exhibits a decomposition temperature of 217.71℃, a melting point of 78.30 ℃, and the thermal behaviour of melt-cast formulations. The results confirmed that the performance properties of the cocrystal are improved compared to TNT. The SEM images revealed that the cocrystal has a different morphology to its individual components. Furthermore, the existence of intermolecular hydrogen bonding is proven according to transitions in the FT-IR spectrum. The powder X-ray diffraction pattern verified the different crystal structure of the cocrystal by comparison to the individual components. Copyright © 2025 Lukasiewicz Research Network – Institute of Industrial Organic Chemistry, Poland

关键词： Hydrogen bonds

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Fabrication of PVA-PVC composite membrane for enhanced TDS removal from tannery effluent: sustainable water treatment approach

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Environmental Science and Pollution Research 2025年第2期32卷 976-992页

作者： Hasan, Md. Mahadi Noyon, Md Ashikur Rahaman Akash, Azmain Iktider Uddin, Md. Elias Islam, Rashedul Maafa, Ibrahim Yousef, Ayman Department of Leather Engineering Faculty of Mechanical Engineering Khulna University of Engineering & Technology Khulna9203 Bangladesh Department of Chemical Engineering Faculty of Engineering Jazan University Jazan11451 Saudi Arabia Department of Mathematics and Physics Engineering Faculty of Engineering at Mataria Helwan University Cairo11718 Egypt

The environmental burden of tannery wastewater, characterized by high levels of total dissolved solids (TDS) and other contaminants, presents a significant challenge for sustainable water management. This study addresses this issue by developing a novel polyvinyl alcohol (PVA) and polyvinyl chloride (PVC) composite membrane optimized for efficient TDS removal from tannery effluent. The membrane was fabricated using a solution casting technique, with glutaraldehyde employed as a crosslinking agent to enhance mechanical properties and stability. Characterization techniques, including Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), zeta potential analysis, and contact angle measurements, were used to evaluate the membrane’s surface chemistry, morphology, and hydrophilicity, which are crucial for pollutant separation. Performance testing demonstrated that the membrane achieved a TDS removal efficiency of 91.73% at an optimal pH of 8 and a transmembrane pressure of 3.5 bar, with a permeability of 194 Lm−2 h−1 bar−1. Additionally, substantial reductions in turbidity (94.51%), chemical oxygen demand (COD, 91.91%), biological oxygen demand (BOD, 89.70%), salinity (80.57%), and total suspended solids (TSS, 96.45%) were observed. The membrane exhibited impressive mechanical properties, with a tensile strength of 44 ± 0.43 MPa, 150 ± 0.67% elongation at break, Young’s modulus of 750 ± 0.47 MPa, and flexibility of 23 ± 0.53%, indicating its flexibility and durability. Its partial biodegradability and potential for scalable production contribute to its environmental sustainability. This work establishes the PVA-PVC composite membrane as a promising and cost-effective solution for industrial wastewater treatment, offering a sustainable approach to mitigating water pollution in the leather industry. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

关键词： Tensile strength

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Point spread function modeling and engineering in black-box lens systems

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Optics Express 2025年第3期33卷 4211-4224页

作者： Xiao, Dafei Kedem, Reut Orange Shechtman, Yoav Russell Berrie Nanotechnology Institute Technion–Israel Institute of Technology Haifa Israel Faculty of Biomedical Engineering Technion–Israel Institute of Technology Haifa Israel Faculty of Electrical and Computer Engineering Technion–Israel Institute of Technology Haifa Israel

Point spread function (PSF) engineering in an imaging system involves the introduction of additional optical components to efficiently encode object information. It typically relies on a well-established mapping relation between object space, PSF engineering plane, and image plane. However, this reliance can limit its application in imaging systems with unknown ("black box") attributes, e. g. commercial photographic lenses, where a theoretical imaging model is not readily available. To address this limitation, we conduct wave-optics analysis of general lens systems, explicitly derive a general imaging model based on scaled Fourier transform, and develop an overall pipeline for automatic parameter determination of the model. When applied to a photographic lens, this pipeline demonstrates high PSF modeling accuracy, showcasing the capability of "seeing what you design". We then implemented PSF engineering in this lens to find its optimal PSF for 3D localization. This work improves computational imaging by enabling accurate wavefront shaping design in arbitrary imaging systems. © 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

关键词： Optical transfer function

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Development of Technologies for Prevention of Wild-Animal Related Losses to Agricultural Fields

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Journal of The Institution of Engineers (India): Series B 2025年第2期106卷 635-646页

作者： Doss, Srinath Kumar, Rajiv Paranthaman, Jothi Faculty of Engineering and Technology Botho University Gaborone Botswana School of Computer Science Engineering and Technology Bennett University Uttar Pradesh Greater Noida India Faculty of Engineering Gaborone University College of Law and Professional studies Gaborone Botswana

Over the past decades, integration of wireless sensor networks (WSNs) and computer vision (CV) technology has shown promising results in mitigating crop losses caused by wild animal attacks. Studies have demonstrated the effectiveness of these technologies in providing real-time monitoring and early detection of animal intrusions into agricultural fields. By deploying WSNs equipped with motion sensors and cameras, farmers can receive instant alerts when wild animals enter their fields, allowing for timely intervention to prevent crop damage. Furthermore, advancements in CV algorithms possess made possible to automatically detect and classify the animal species, facilitating targeted response strategies. For example, sophisticated image processing techniques can differentiate between harmless birds and destructive mammals, allowing farmers to focus their efforts on deterring the most damaging species. Field trials and pilot projects implementing WSN-CV systems have reported significant reductions in crop losses attributed to wild animal raids. By leveraging data collected through sensor networks and analyzed using computer vision algorithms, farmers can make informed decisions regarding pest and insect management strategies. This data-driven approach has led to more efficient utilization of resources, such as targeted application of insecticides and pesticides, resulting in both economic and environmental benefits. Moreover, the integration of WSN-CV technology has enabled the development of innovative deterrent systems that leverage artificial intelligence and automation. These systems can deploy non-lethal methods, such as sound or light-based repellents, to deter wild animals without causing harm to the environment or wildlife populations. Overall, the combination of wireless sensor networks and computer vision technology provides the promising resolution to the long-standing issue of wild animal-related losses in agriculture. By harnessing the power of data and a

关键词： Wireless sensor networks

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The Impact of Longitudinal and Stirrups Reinforcement Ratio to Shear Strength Capacity of Geopolymer Concrete Beam

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Archives of Metallurgy and Materials 2025年第1期70卷 341-350页

作者： Tajunnisa, Y. Apsari, A.K. Bayuaji, R. Mansur, Moh Safi'i Civil Infrastructure Engineering Department Faculty of Vocational Studies Institute Technology of Sepuluh Nopember Surabaya60111 Indonesia Civil Engineering Department Faculty of Civil Planning and Geo-Engineering Institute Technology of Sepuluh Nopember Surabaya60111 Indonesia

The shear capacity of reinforced beam concrete was designed to resist the stirrup reinforcement, Vs, and by the concrete itself, Vc. Previous studies of geopolymer concrete show the mechanical properties of this proposed green concrete, yet the structural investigation is infrequently investigated. These studies mostly observed the impact of using alternative binder resources that affect the workability, setting time, compressive strength, split tensile strength, and drying shrinkage. Therefore, this study aims to observe the structural behavior of geopolymer concrete, precisely its shear capacity. Four geopolymer concrete beam types were designed to have shear failure mode when tested using a Universal Testing Machine by four-point load bending method. The results showed that geopolymer concrete has ductile behavior. Comparison between the Vu value of the test results with Vn calculation of nominal cross-sectional capacity according to standard concrete rules in an average of 2.11 higher than the nominal capacity conventionally calculated according to SNI. Two models of linear regression equations for concrete Vc values were created to explore this further. It was found that the presence of a constant increases the value of the coefficient of determination by up to 29% for the Vc equation in geopolymer concrete. In addition, cracking patterns observed with the DIC method using GOM Correlate software also showed that all the beam specimens had failure both in flexure and shear, even though they all are designed in a shear failure state. © 2025. The Author(s).

关键词： Geopolymer concrete

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Defining application areas of corn husk fibre by studying its characteristics

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Environmental Science and Pollution Research 2025年第12期32卷 7368-7373页

作者： Chokshi, Savan P. Bambhaniya, Sanjay B. Mandot, Aadhar A. Department of Textile Engineering Faculty of Technology and Engineering The Maharaja Sayajirao University of Baroda Gujarat Vadodara390001 India

Natural fibres have attracted more attention compared with synthetic fibre because they exhibit several benefits over synthetic fibre, such as being cost-effective, readily available, and lightweight apart from offering better mechanical properties. Corn husk fibres being a natural crop fibre have attracted more attention due to their renewability and biodegradability. Corn husk is an outer protective layer of maize which is generally discarded as waste. However, this agro-waste can be utilized exclusively for various applications with a sustainable approach by extracting fibres out of them. This paper aims to revolutionize the usage of corn husk fibres in conventional as well as technical textile industries by enlisting various application areas. A comprehensive understanding of corn husk fibre extraction techniques and their effect on various fibre properties are also discussed. These properties are compared with properties of other natural fibres, to enable the possibility of converting corn husk fibres into different textile forms such as yarn, woven and nonwoven fabric, and composites. This will fulfill the increasing demand for natural fibre along with biodegradability and reduced petroleum dependency while contributing to the purpose-driven use of agro waste. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

关键词： Cost effectiveness

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Simultaneous removal of salt and dissolved petroleum compounds by a two-stage process: spiral wound capacitive deionization three-dimensional electro-Fenton

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Environmental Science and Pollution Research 2025年第15期32卷 9570-9592页

作者： Tekyeh, Saeed Amini Rad, Hasan Kebria, Daryoush Yousefi Department of Environmental Engineering Faculty of Civil Engineering Babol Noshirvani University of Technology Babol47148-7313 Iran

Produced water (PW) is the main by-product of oil and gas extraction operations that can be reused. The concentration of ions in produced water is high, so to remove both dissolved minerals and petroleum compounds in the produced water, this study aimed to design and evaluate a two-stage electrochemical process: spiral wound capacitive deionization (SW-CDI), three-dimensional electro-Fenton (3D-EF). The experiments were designed using the Design Expert software version 13, and the effects of five independent parameters on two dependent parameters (desalination and oil removal efficiencies) were investigated. The experimental results were modeled and optimized using the response surface method-central composite design (RSM-CCD). The results showed that the desalination process can be described by a linear two-factor interaction model, while the oil removal process can be described by a quadratic model. At the optimal conditions (an initial salinity of 30 mgL−1, an initial petroleum concentration of 40 mgL−1, a CDI voltage of 1.8 V, an EF voltage of 5 V, and a flow rate of 10.2 mLmin−1), the maximum salt sorption capacity and oil removal efficiencies were 217 mgg−1and 99.9%, respectively. Also, the salt electro-sorption capacity of the CDI reactor is 37 mgg−1, which is more than twice the maximum salt electro-sorption capacity of conventional flow-by CDI reactors (15 mgg−1). Finally, the designed two-stage process removed salt and dissolved petroleum compounds with high efficiency. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.

关键词： Desalination

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