WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394

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  • Article
    Optimizing Nanoclay-Enhanced Membranes for Oil Rejection Using Response Surface Methodology
    (Wiley, 2026) Gul, Ayse; Baris, Mesut; Boyraz, Pınar; Senol-Arslan, Dilek; Alibaz, Name Nur
    The efficient separation of waste oil from contaminated water is critical due to its challenges in environmental and industrial applications. This study investigated the production and optimization of polysulphone (PSF) membranes using two different types of clay (nanomer clay/CN and commercial nanoclay/NC). Response Surface Methodology (RSM) was applied to optimize the basic production parameters and nanoclay concentrations systematically to maximize oil rejection and permeability flow. The experimental results showed that NC and CN significantly increased the hydrophilicity, permeability, and fouling resistance of the membrane compared to pure PSF membranes. The contact angle significantly decreased from 64.34 degrees (pristine PSF) to 36.23 degrees (2% NC), indicating highly improved hydrophilicity. Consequently, the pure water flux increased from 177.2 L/m2 h to a maximum of 248.6 L/m2 h (1% NC). Furthermore, the modified membranes exhibited outstanding anti-fouling properties; the flux recovery ratio (FRR) improved from 88.09% to 96.20% (1% CN), while the decline ratio (DR) drastically dropped from 60.89% to 32.14%. The optimized condition for maximum removal efficiency using a modified quadratic model revealed that 2572 mg/L oil can be treated with a PSF membrane containing 2.0% CN to remove 98.271% of the oil. The model also suggests superiority of CN over NC with desirability factors of 0.978 and 0.900, respectively, while both demonstrated high efficiency. This theoretically modeled experimental comparative study highlights the importance of PSF membrane technology for efficient and sustainable oil-water separation and demonstrates the promising potential of nanoclay modifications.
  • Article
    Modal Characteristics of Fly Ash-Based Geopolymer Reinforced Concrete Columns under Dynamic Impact Loads
    (Techno-Press, 2026) Kucukgoncu, Hurmet
    Geopolymer concrete (GPC) stands out as an environmentally friendly, sustainable structural material with superior mechanical and thermal properties, as an alternative to ordinary Portland cement (OPC) concrete. Due to this, investigating the dynamic properties of GPC materials is particularly crucial for structures subjected to vibration loads such as earthquakes. Therefore, eight heat-cured class F fly ash-based GPC and two OPC column specimens were subjected to modal tests using the Experimental Modal Analysis (EMA) method. Thus, the modal characteristics of columns produced from GPC were investigated and compared regarding reinforcement ratio, alkali activator ratio, and curing method. Furthermore, the dynamic properties of GPC and OPC columns were also compared. Additionally, the relationship between these columns' resonance frequencies, damping ratios, mode shapes, and mechanical properties was evaluated. The results show that although the resonance frequencies of OPC columns are 8.19% higher than those of GPC columns, their damping ratios are 13.01% lower. For GPC columns, the alkali activator ratio and curing method had a greater impact on the modal characteristics of the column samples than the reinforcement ratio. Besides, the relationship between strength and resonance frequency was closely related. In contrast, the damping ratio was closely related to the static modulus of elasticity and rigidity values. In particular, it was concluded that GPC columns had higher energy dissipation capacities, which was an important design parameter, under dynamic loads due to the high damping ratio.
  • Article
    Identification of Potential Dual HDAC6 and HSP90 Inhibitors for the Treatment of Cancer Using Molecular Docking, Molecular Dynamics and MM/PBSA Studies: A Comprehensive In Silico Study
    (Bentham Science Publ Ltd, 2026) Yucel, Muhsin Samet; Akcok, Ismail
    Background Histone deacetylase 6 (HDAC6) and heat shock protein 90 (Hsp90) are crucial therapeutic targets in cancer research with their interconnected roles in regulating protein homeostasis and cellular processes. The interaction of these proteins within the cytosolic complex plays a critical role in regulating cancer cell survival and progression. Notably, current studies highlight that the simultaneous inhibition of HDAC6 and Hsp90 can produce synergistic effects and offer a promising therapeutic potential for combating malignant cancers.Objective The objective of this study was to explore potential compounds that can inhibit both HDAC6 and Hsp90 proteins.Methods In this study, a number of in-silico computational techniques were employed. A total of 791 molecules, sharing at least 30% similarity with previously identified four HDAC inhibitors, were obtained from the ZINC15 database and subjected to docking on HDAC6 and Hsp90 proteins. The top eight ligands demonstrating the best binding scores against both targets, with panobinostat and ganetespib serving as reference compounds for HDAC6 and Hsp90, respectively, were selected for further analysis. Subsequently, ADME prediction and molecular dynamics simulations were conducted on the selected ligands.Results A detailed molecular docking, molecular dynamics simulations and ADME studies have revealed that ZINC27653366 exhibited the highest inhibitory potential against both Hsp90 and HDAC6 target proteins, making it the most promising inhibitor.Conclusion In conclusion, although additional in vitro and in vivo studies are required for the validation, in silico evaluation of ZINC27653366 may position it as a promising candidate for the treatment of different types of cancers.
  • Article
    Enhanced Mg–Zn–Ca Alloys Reinforced with Rare Earth Oxides for Biomedical Applications: Experimental Insights and ANFIS-Based Modeling
    (Springer, 2026) Mozafari, Farzin; Deka, Surja; Mallick, Ashis
    To enhance the corrosion resistance, biocompatibility, tribological, and mechanical properties of magnesium (Mg) alloys intended for biomedical implants, a new approach utilizing a microwave-sintered in situ hot extrusion-based powder metallurgy process was used to develop Mg-4Zn-0.5Ca/xCeO2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document} (x = 0.5, 1, and 1.5 vol%) nanocomposites. The introduction of ceria nanoparticles (CONPs) has improved the compression characteristics of the nanocomposites in comparison with the monolithic Mg, and the ternary base alloy. The corrosion test results revealed that the alloy and nanocomposites promoted the formation of the magnesium hydroxide (Mg(OH)2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document}) and hydroxyapatite (HA) layers on the sample surface. Among all samples, Mg-4Zn-0.5Ca /1.0CeO2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document} demonstrated the lowest corrosion rate. In vitro cytocompatibility assessments were conducted through an extract assay method for different time periods, employing MG-63 cells. The developed alloy and nanocomposites demonstrated no harmful effects on MG-63 cells. An investigation into the dry sliding tribological characteristics of the alloy and nanocomposites at varied loads revealed several wear mechanisms, including abrasion, adhesion, delamination, oxidation, and plastic deformation. The addition of CONPs significantly enhanced the wear resistance of the nanocomposites. Our results provide a new venue to enhance the biocompatibility and in vitro degradation behavior of well-established Mg-Zn-Ca alloys, with a particular focus on the mechanical integrity of the developed samples for their clinical usage. An Adaptive Neuro-Fuzzy Inference system (ANFIS)-based modeling approach was also developed to individually characterize nanocomposite corrosion, cell viability, and wear behavior. The predictions offer compelling evidence of the reliability and accuracy of the proposed modeling strategy.
  • Article
    Exergy-Based Evaluation of High-CO2 Biogas/Diesel RCCI Combustion Heat Flow for Enhanced Mixture Distribution, Power Output, and Fuel-Energy Performance
    (Pergamon-Elsevier Science Ltd, 2026) Dalha, Ibrahim B.; El-Adawy, Mohammed; Wong, Nur Leena W. S.; Man, Hafsalina C.; Said, Mior A.; Koca, Kemal; Abdulsalam, Muhammed
    Utilising high-CO2 biogas in compression-ignition engines poses significant challenges due to poor mixture reactivity, inefficient combustion, and increased energy degradation. This work addresses these difficulties by conducting experimental research on a port-injection at the valve reactivity-controlled compression ignition (PIVE-RCCI) strategy. This study addresses these concerns by conducting experiments on a PIVE-RCCI technique to improve mixture distribution and combustion efficiency in biogas-diesel engines. The engine was modified to provide biogas through the inlet valve, allowing for controlled variations of biogas injection pressure (BIP: 1-4 bar) and port swirl ratio (PSR: 0-80%) at 1600 rpm and 4.9-5.7 bar IMEP. Energy and exergy analyses were used to determine the effect of intake flow dynamics on temperature uniformity, heat transfer, and power generation during combustion. The results reveal that normal airflow conditions minimise accounted heat loss, indicating higher thermal efficiency (ITE) and increased output power across all BIPs. In contrast, introducing a strong intake swirl dramatically improves combustion performance. The 80% PSR configuration resulted in the lowest exergy destruction and the maximum energy recovery potential, with an ITE of 26.54% at 4 bar BIP. Increasing BIP increased power output, whereas the optimal combustion work was found at 1 bar BIP and 40% PSR. The optimal working conditions were 1 bar BIP, 80% PSR, and 5.45 bar IMEP, which resulted in 26.00% exergy destruction, 39.38% destruction-to-released exergy ratio, 86.00% exergy-energy ratio of heat transfer, and 63.78% exhaust exergy-energy ratio. This work's novelty lies in integrating biogas injection, intake swirl control, and exergy-based evaluation to measure mixture distribution and energy recovery in high-COQ biogas RCCI combustion. The findings offer useful operational guidance for increasing energy efficiency and advancing the commercialization of renewable gaseous fuels in RCCI engines. As a result, operating the engine at half load, 80% PSR, and atmospheric air pressure (1 bar) conditions significantly enhanced the combustion efficiency and energy utilisation.
  • Article
    Buffalo’s Captured Imaginary: Atmosphere, Absurdity and the Depoliticized Imagination of the Rust Belt
    (SAGE Publications Inc, 2026) Dincer, Evren M
    Using Buffalo, New York, as a key case study, this article examines the cultural grammar through which the American Rust Belt is represented as a site of terminal decline and absurdity. Analyzing films, novels, and memoirs, it argues that a captured imaginary has taken hold, one that converts the systemic crises of deindustrialization into mood, tone, and atmosphere. Narratives of the region frequently deploy irony and absurdity as aesthetic strategies that depoliticize decline, stylizing it as an ambient condition rather than a structural problem to be contested. This representational pattern, often centered on white protagonists, displaces political critique and renders local agency incoherent. By framing these cities as uniquely dysfunctional and incapable of self-renewal, these cultural texts create the ideological conditions for external, technocratic intervention. The article concludes that this aestheticization of collapse is a political act that forecloses democratic possibility and captures the urban imaginary for outside management.
  • Article
    AI-Driven Drug Repositioning: A Diffusion Model Approach on Knowledge Graphs
    (Elsevier, 2026) Erkantarci, Betul; Şen, Tarık Üveys; Bakal, Gokhan
    Drug repositioning - discovering new therapeutic applications for existing drugs - offers a promising pathway to accelerate cancer treatment development. This study proposes a diffusion model-driven framework that leverages biomedical knowledge graphs and graph-based learning to enhance drug repositioning predictions. The framework integrates data from the Semantic MEDLINE Database (SemMedDB), the Unified Medical Language System (UMLS), and the Repurposing Drugs Database (RepoDB) to construct a comprehensive therapeutic knowledge graph. Drug embeddings are generated using a one-layer Relational Graph Convolutional Network (R-GCN) incorporating semantic type-guided structural perturbations. These embeddings are refined through a flow-matching algorithm to denoise and reconstruct biologically meaningful representations. To evaluate the model's effectiveness, we apply a consensus strategy using Cosine Similarity, Euclidean Distance, and Manhattan Distance as proximity metrics. The model successfully identified, on average, 74 candidate drugs for repositioning in the context of leukemia. Qualitative analysis using t-distributed stochastic neighbor embedding (t-SNE) revealed enhanced clustering of pharmacologically relevant drugs in the denoised embedding space. Trastuzumab, in particular, emerged as a strong repositioning candidate for leukemia, supported by 156 co-mentions in PubMed. These findings demonstrate that the proposed framework improves embedding robustness and semantic fidelity, offering a powerful artificial intelligence (AI)-driven approach for precision oncology. Integrating structural noise modeling with diffusion-based denoising advances the discovery of novel drug-disease associations and holds potential for translational research and clinical hypothesis generation in drug repurposing.
  • Article
    Minimization of Thermal Stresses in Instrumented Cutting Tools with Embedded Thin Film Thermocouples
    (Korean Society of Mechanical Engineers, 2026-04) Kesriklioglu, Sinan; Sivesoglu, Abdurrahman
    This study investigates the optimization of multilayer coatings on cutting tools to minimize thermal stress and temperature differences between the tool-chip interface and embedded thermocouples. The novelty of this study lies in directly linking coating architecture to temperature measurement accuracy, revealing that coatings not only affect heat dissipation and stress development but may also distort the apparent temperature recorded by embedded sensors. The types and thickness ranges of thin film layers in instrumented cutting tools were determined, and multi-physics finite element simulations were then used to evaluate coating configurations under thermal loading, assessing both stress distribution and temperature variance in the multilayer coating system. The Taguchi method, coupled with desirability analysis, identified optimal coating parameters that simultaneously minimize thermal stresses and temperature disparities, which are critical for accurate temperature measurements and extending the lifespan of cutting inserts. This framework enables a controllable trade-off between mechanical reliability and thermal measurement fidelity. The results reveal significant interactions among coating configurations (settings) and between thermal and mechanical properties of the materials used, demonstrating that careful selection of layer materials and thicknesses optimizes stress and temperature responses yielding thermal stress of 1628 MPa (second lowest and only 0.4 % higher than the minimum) and temperature difference of 12.1 degrees C (third lowest and 55 % lower than average). These findings underscore the potential of precise coating design to enhance tool performance and longevity in high temperature machining applications.
  • Article
    Unveiling the Therapeutic Role of 3D-Cultured Mesenchymal Stem Cells in Diabetic Foot Ulcers through Transcriptomic Integration and Fibroblast Modulation
    (Springer, 2026-03-31) Ozturk, Esengul; Bicer, Mesude
    Background Diabetic foot ulcers (DFUs) are among the most severe complications of diabetes mellitus and remain difficult to manage due to chronic inflammation, defective angiogenesis, delayed tissue repair, which increase the risk of recurrence and limb amputation. Standard treatments, such as debridement, infection management, pressure off-loading and revascularization, are commonly used, however; these interventions often inadequate to fully restore effective wound repair. Mesenchymal stem cells (MSCs) have attracted remarkable interest due to their potential regenerative ability and paracrine activity. Nevertheless, the molecular interaction between MSCs and fibroblasts under hyperglycemic conditions has not been fully elucidated. Objective This study aimed to examine differentially expressed genes (DEGs) associated with DFUs and MSC-related regenerative mechanisms using transcriptomic datasets (such as GSE143735, GSE199939, and GSE217709). Methods and results Differentially expressed genes and protein-protein interaction (PPI) network analysis were performed to determine central regulatory genes. Four key genes including CXCL1, MMP9, THBS1, and POSTN were recognized as hub genes related to inflammatory response, extracellular matrix reorganization, and angiogenesis. For experimental validation, L929 murine fibroblasts were exposed to high-glucose conditions to set-up an in vitro diabetic model and subsequently treated with MSCs with/without a 3D platform. Hyperglycemic conditions significantly reduced fibroblast proliferation and migration downregulated the expression of the identified hub genes and enhanced apoptotic activity. MSC treatment partially increased cellular function, while MSCs embedded into 3D culture enhanced a more pronounced recovery in both gene expression patterns and functional assays. Conclusions These findings suggest that high glucose impair fibroblast functions for wound repair, while 3D-cultured MSCs enhance regenerative responses and may represent a promising strategy for diabetic wound healing.