WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394
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Article Citation - WoS: 1Citation - Scopus: 1Predictive Modeling and SHAP-Based Interpretability of Manganese and Iron Dissolution in Multi-Acid Leaching Systems Using Hybrid Machine Learning(Multidisciplinary Digital Publishing Institute (MDPI), 2026) Top, Soner; Altiner, Mahmut; Kursunoglu, Sait; Kuzu, EmrahHydrometallurgical leaching processes contain complex and nonlinear parameter interactions that are difficult to capture with conventional empirical models. In this study, a multiple hybrid machine learning approach was developed to predict manganese (Mn) and iron (Fe) dissolution efficiency in leaching systems and performed using sulfuric acid (H2SO4), hydrochloric acid (HCl), and nitric acid (HNO3). A large-format dataset consisting of 204 independent leaching experiments was generated in which acid type, acid concentration (0.5-5 M), temperature (25-90 degrees C), solid/liquid ratio (100-200 g/L), leaching time (1-4 h), and eight different reducing agent types were systematically varied. XGBoost, LightGBM, CatBoost, and Random Forest algorithms were individually trained and subsequently combined with a Soft Voting Ensemble architecture. Hyperparameters were optimized using the RandomizedSearchCV method with 3-fold cross-validation. The XGBoost model achieved the highest prediction accuracy for Mn dissolution (R-2 = 0.8993, RMSE = 8.06%), while CatBoost demonstrated the best performance in Fe dissolution (R-2 = 0.8415, RMSE = 4.43%). SHAP analysis suggested that the dosage and type of reducing agents are the most influential predictive features for Mn dissolution, while acid molarity and temperature were identified as the dominant predictors for Fe leaching. Friedman test confirmed that performance differences among both Mn and Fe models were statistically significant (Mn: chi(2) = 32.76, p < 0.001; Fe: chi(2) = 25.96, p < 0.001). The developed models contribute significantly to hydrometallurgical process optimization by predicting the nonlinear effects of leaching parameters on metal dissolution with high accuracy. This study presents a comprehensive and interpretable machine learning framework supported by an extensive experimental dataset, a substantial portion of which has not been previously utilized or comparatively analyzed within a unified multi-acid framework, enabling systematic modeling of selective Mn-Fe dissolution across multiple acid systems and reducing agents.Article A Machine-Learning-Based Multi-Hazard GIS-AHP Framework for Wind Turbine Siting under Earthquake–Landslide Coupling(IOP Publishing Ltd, 2026) Dinçer, Ali Ersin; Demir, Abdullah; Öztürk, Şevki; Kalpakcı, Volkan; Dilmen, ÖmerThis study presents a machine-learning-based multi-hazard geographical information system (GIS)-analytical hierarchy process (AHP) framework for wind turbine siting that explicitly accounts for the coupled effects of earthquake and landslide hazards. The primary innovation lies in the development of a conditional weighting algorithm that integrates machine-learning-derived hazard assessments with structural engineering logic. Landslide susceptibility is first modeled using a random forest classifier trained on a comprehensive inventory of historical landslide data and 12 geo-environmental conditioning factors, producing a high-resolution susceptibility map with excellent predictive performance (AUC = 0.86). Feature importance analysis indicates that slope, hydrological indices, and geological conditions are the dominant controls on landslide occurrence. This data-driven map is then integrated with earthquake hazard zones and additional environmental and technical constraints within a GIS-AHP framework to generate a comprehensive wind turbine suitability assessment. Results show that explicitly accounting for earthquake-landslide coupling leads to a nearly 20% reduction in high and very high suitability areas, accompanied by an expansion of low and moderate suitability zones, highlighting the limitations of single-hazard planning approaches. The main contribution of this study lies in advancing renewable energy planning through the explicit integration of interdependent natural hazards, demonstrating how earthquake-resistant foundation strategies can simultaneously mitigate landslide risks.Article Citation - WoS: 1Citation - Scopus: 1The Discouraged Worker Effect during the Covid-19 Pandemic in Türkiye(Cambridge Univ Press, 2026) Demirtaş, Burak Kağan; Güney, GülThe Covid-19 pandemic has negatively affected labour markets, among other aspects of life. This study examines the impact of the discouraged worker effect during the pandemic, focusing on the Turkish labour market from 2018 to 2021. Although few studies exist on this topic, they rely on labour force participation rates, whereas our dataset includes direct questions and data specifically related to the discouraged worker effect, allowing for a microeconomic analysis. Probit regression results show that the discouraged worker effect was stronger during the pandemic, with job seekers being 1.6% more likely to become discouraged than before. Higher education levels generally reduce this likelihood, both before and during the pandemic. While age negatively correlates with discouragement, this effect diminishes with increasing age. Single women were more adversely affected than single men and married women than married men. Higher unemployment rates increase discouragement, as expected, while an increase in the unemployment rate has a greater effect on individuals during the pandemic period. Findings suggest that the pandemic had a disproportionate impact on certain individuals, particularly with respect to education level and gender, while Türkiye's societal structure may help explain the observed gender-based differences.Article Citation - WoS: 3Citation - Scopus: 4Rare Earth Elements in the Global Economy: Usage, Recovery, and the Quest for Supply Security – A Review(Springer Heidelberg, 2026) Top, Soner; Ayten, Asim Mustafa; Altiner, Mahmut; Demir, Idris; Kursunoglu, SaitOften described as the vitamins of modern industry, rare earth elements (REEs) are indispensable for the deployment of low-carbon and clean energy technologies. However, ensuring a secure and sustainable REE supply remains a major challenge due to the strong interdependence between application-driven demand, extraction and processing technologies, and the geopolitical concentration of resources. This review adopts an integrated analytical framework in which these three dimensions are treated as interconnected components shaping the resilience of global REE supply chains. First, the major application sectors of REEs are examined to clarify how emerging energy and advanced manufacturing technologies drive demand for specific elements and amplify their strategic importance. Second, extraction and processing technologies are reviewed in relation to both primary and secondary resources, highlighting how technological maturity, process selection, and material characteristics constrain or enable supply expansion. Finally, geopolitical and strategic aspects of the REE supply chain are analyzed to demonstrate how resource concentration, policy instruments, and international dependencies directly influence technological deployment and industrial competitiveness. By explicitly linking application-driven demand, technological pathways for extraction and processing, and geopolitical supply structures within a unified framework, this review provides a coherent understanding of the systemic challenges facing the REE sector and identifies key leverage points for improving the robustness and sustainability of REE supply chains in the context of the global clean energy transition.Editorial Editors’ Introduction: Spring 2026(Cambridge Univ Press, 2026) Kolluoğlu, Biray; Dinçer, Evren M.; Yükseker, DenizArticle Sensitive Hybrid Plasmonic Refractive Index Sensor Based on Ag Cross-Grating Nanoantenna and Au Quantum Dot upon SiO2 Nanowire(IOP Publishing Ltd, 2026-04-03) Sanli, Atif Kerem; Kilic, Veli Tayfun; Tabaru, Timucin EmreThis study presents a distinctive hybrid plasmonic sensor architecture combining a silver (Ag) cross-shaped nanoantenna with a gold (Au) quantum dot (QD) for enhanced refractive index sensing applications. The structure consists of a silicon dioxide (SiO2) substrate and a cylindrically shaped SiO2 wire on it, topped with a silicon nitride (Si3N4) dielectric layer and an Ag cross grating, with an Au QD positioned at the center. Using free and open source 3D Finite-Difference Time-Domain (FDTD) simulations, exceptional electric field enhancement at the resonant wavelength of approximately 639-667 nm is demonstrated. The optimized structure achieves remarkable quality factors (Q-factors) exceeding 267 for biological media, representing among the highest reported values for plasmonic sensing structures. Unlike conventional red-shift sensors, our design exhibits a distinctive blue-shift sensing behavior arising from hybrid plasmonic mode coupling, achieving sensitivities ranging from 190 to 344 nm RIU-1 for various analytes, including water, blood, PDMS, body fat, ethanol, and glass. The ultrasharp resonances (FWHM similar to 2.3 nm) combined with intense field enhancement make this design highly suitable for biosensing applications.Article Feasibility Analysis of Granitic Rocks for Use in the Dimension Stone Industry(Univ Zagreb, FAC Mining, Geology & Petroleum Engineering, 2026) Koken, EkinThis study presents two objective evaluation tools for assessing the feasibility of granitic rocks in dimension stone applications. The developed methods integrate fundamental physical and mechanical properties, including dry density (rho d), effective porosity (ne), P-wave velocity (Vp), uniaxial compressive strength (UCS), and Böhme abrasion value (BAV). Feasibility analyses based on the conditional formatting (CF) and ranking method RM reveal that the adopted input parameters are essential for determining the suitability of granitic rocks as dimension stones. The strong relationship between the CF and RM results highlights their consistency and broad applicability. Both methods exhibit good agreement with the recommendations of the American standard for granitic rocks. Consequently, the suggested methods provide practical guidance for selecting suitable rock exposures in field studies, also offering a time- and energy-efficient decision-making framework for the dimension stone industry. To comprehensively evaluate the strengths and limitations of the proposed approaches, it is recommended that these tools be applied to a wider range of dimension stone types and geological settings.Article Follow-up of Health-Related Physical Fitness Elements in Mild Intellectual Disability for Three Years: A Sex Comparison(PeerJ Inc., 2026-03-04) Bozdağ, Berkan; Sönmez, Hüseyin Gazi; Prieto-González, Pablo; Karahan, Mustafa; Canli, Umut; Ergin, Murat; Koçak, Çalık VeliChildren with mild intellectual disability (MID) have significant limitations in both intellectual functioning and cognitive, social, and motor skill behaviors. Understanding the development of physical fitness in boys and girls with MID, and identifying sex-related differences can help devise interventional programs to improve physical fitness in these groups. The aim of this study was to compare sex differences in the time-dependent changes in health-related physical fitness components in individuals with MID. A longitudinal design was employed over three years. A total of 111 individuals with MID (46 girls and 65 boys) aged between 10 and 14 years (mean age 11.97 +/- 1.39 years) participated in the study. The physical fitness levels of the participants were assessed using the Brockport Physical Fitness Test (BPFT) battery. The tests included body composition (body height, body mass, and body mass index), aerobic endurance (15 m Progressive Aerobic Cardiovascular Endurance Run (PACER) test), and musculoskeletal function (dominant handgrip strength, back-saver sit-and-reach, and trunk lift). The results revealed that, over time, the longitudinal developmental trajectories for body mass, body height, aerobic endurance, and dominant handgrip strength were more favorable for boys. However, the longitudinal development curves for body mass index (BMI), trunk lift, and flexibility were similar for both boys and girls. The findings of this study provide valuable evidence for developing targeted physical activity programs for individuals with MID, and demonstrate the need for programs aimed at increasing aerobic endurance and muscle strength in girls with MID.Article An Adaptation Mechanism of Model Reference Adaptive System Based on Variable Structure Control for Online Parameter Estimation of IPMSM(Wiley, 2026-01) Tekgun, Burak; Barut, Murat; Ates, ErtugrulThis study introduces stator currents-based model reference adaptive system (MRAS) estimators that employ variable structured control (VSC) in the adaptation mechanism to enable the online estimation of stator resistance and permanent magnet (PM) flux in interior permanent magnet synchronous motors (IPMSMs). These MRAS estimators estimate stator resistance and PM flux by analysing the error between the stator currents measured as the reference model and the stator currents generated by the adaptive model. The performance of the proposed estimators is assessed through simulation studies. Furthermore, the proposed approach is compared to a conventional MRAS employing a fixed-gain proportional-integral (PI) controller. Simulation results and error analyses indicate that the VSC-based MRAS algorithms outperform traditional PI-based MRAS in terms of accuracy and reliability. Additionally, the proposed method eliminates the reliance on a fixed-gain PI controller, a common component in conventional MRAS systems.Article Citation - WoS: 2Citation - Scopus: 2Depositional Model, Cyclicity, and Hydrocarbon Potential of the Eocene Sakesar Carbonate Ramp, Salt Range, Pakistan(Springer, 2026-02-02) Shah, Syed Bilawal Ali; Shah, Syed Haider AliThe Sakesar Formation in the Salt Range, Pakistan, represents a well-developed Eocene carbonate ramp deposited along the southern Tethyan margin. This study integrates petrographic analysis, palynofacies evaluation, organic geochemical measurements and sequence stratigraphic interpretation to characterise the depositional environments, diagenetic evolution, and petroleum system potential of the formation. Six microfacies (MF1-MF6) were identified through thin-section petrography ranging from high-energy shoal grainstones to low-energy lagoonal marls. Quantitative palynofacies analysis shows energy dependent trends in organic matter composition, with shoal facies dominated by opaque phytoclasts and lagoonal facies enriched in amorphous organic matter (AOM). Organic geochemical measurements including Total Organic Carbon (TOC), Hydrogen Index (HI), Oxygen Index (OI), and Rock-Eval pyrolysis parameters, combined with vitrinite reflectance (Ro) data, indicate that lagoonal marl-micrite facies (MF6) contain Type II kerogen with the highest TOC values (2.80%), elevated HI (293 mg hydrocarbons per gram TOC), and peak oil-window maturity (0.72% Ro). These attributes identify MF6 as the primary oil-prone source rock. Mid-ramp wackestones and packstones (MF3-MF4) possess moderate generative potential and serve as internal seals or baffles, whereas high-energy shoal facies (MF1-MF2) show favourable reservoir characteristics but limited source potential. Sequence-stratigraphic analysis demonstrates that maximum flooding surfaces (MFS) frequently coincide with organic-rich MF6 intervals, producing predictable vertical stacking of source, seal, and reservoir units at parasequence scale. The integrated petrographic, palynofacies, and geochemical framework confirms the dual role of the Sakesar Formation as both a reservoir and a source-seal interval, with metre-scale cyclicity enhancing hydrocarbon charge and trapping efficiency. These findings refine the depositional and petroleum system model of the Sakesar carbonate ramp and provide valuable predictive analogues for Eocene carbonate exploration within the Himalayan foreland basin and related Tethyan settings.