Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 15Search for Supersymmetry in pp Collisions at √s=7 TeV in Events With a Single Lepton, Jets, and Missing Transverse Momentum(Springer, 2013) Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Swanson, J.Results are reported from a search for new physics processes in events containing a single isolated high-transverse-momentum lepton (electron or muon), energetic jets, and large missing transverse momentum. The analysis is based on a 4.98 fb(-1) sample of proton-proton collisions at a center-of-mass energy of 7 TeV, obtained with the CMS detector at the LHC. Three separate background estimation methods, each relying primarily on control samples in the data, are applied to a range of signal regions, providing complementary approaches for estimating the background yields. The observed yields are consistent with the predicted standard model backgrounds. The results are interpreted in terms of limits on the parameter space for the constrained minimal supersymmetric extension of the standard model, as well as on cross sections for simplified models, which provide a generic description of the production and decay of new particles in specific, topology based final states.Article Citation - WoS: 6Citation - Scopus: 7Physics-Based Machine Learning for Modeling of Laminated Composite Plates Based on Refined Zigzag Theory(Springer, 2025) Ermis, Merve; Dorduncu, Mehmet; Aydogan, GokayPhysics-based machine learning techniques have recently gained prominence for their ability to model complex material and structural behavior, particularly in laminated composite structures. This study introduces an innovative approach, being the first to employ physics-informed neural networks (PINNs) in conjunction with refined zigzag theory (RZT) for the stress analysis of laminated composite plates. A multi-objective loss function integrates governing partial differential equations (PDEs) and boundary conditions, embedding physical principles into the analysis. Using multiple fully connected artificial neural networks, called feedforward deep neural networks, tailored to handle PDEs, PINNs are trained using automatic differentiation. This training process minimizes a loss function that incorporates the PDEs governing the underlying physical laws. RZT, particularly suitable for the stress analysis of thick and moderately thick plates, simplifies the formulation by using only seven kinematic variables, eliminating the need for shear correction factors. The capability of the proposed method is validated through several benchmark cases in stress analysis, including 3D elasticity solutions, analytical solutions, and experimental results from a three-point bending test based on displacement measurements reported in the literature. These results show consistent agreement with the referenced solutions, confirming the accuracy and reliability of the proposed method. Comprehensive evaluations are conducted to examine the effects of softcore presence, elastic foundation, various lamination schemes, and differing loading and boundary conditions on the stress distribution in laminated plates.Article Ggnn: Group-Guided Nearest Neighbors for Efficient Image Matching(Springer, 2025) Cine, Ersin; Bastanlar, Yalin; Ozuysal, MustafaThe widely adopted image matching approach remains dependent on exhaustive matching of local features across images. Existing methods aiming to improve efficiency either approximate nearest neighbor (NN) search, compromising accuracy, or apply filtering only after establishing tentative matches, which restricts potential efficiency gains. We challenge the assumption that exhaustive NN search is necessary by proposing a more efficient hierarchical approach that maintains matching accuracy without relying on full-scale NN search. Our key insight is that efficiently identifying sufficiently similar, geometrically meaningful feature matches-rather than the most similar but geometrically random ones-can improve or maintain performance at a lower computational cost. We propose a novel method, Group-Guided Nearest Neighbors (GGNN), which matches groups of features first and then matches individual features only within these matched groups. This hierarchical pipeline reduces the computational complexity of feature matching from \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\theta (n<^>2)$$\end{document} to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\theta (n \sqrt{n})$$\end{document}, significantly improving efficiency. Experimental results on homography estimation demonstrate that GGNN outperforms standard NN search while achieving performance comparable to state-of-the-art methods. Additionally, we formulate GGNN as a general framework, where conventional NN search is a special case with a single global feature group. This formulation provides a continuum of feature matching methods with varying computational costs, enabling automatic selection based on a given time budget.Article Citation - WoS: 3Citation - Scopus: 2Cradle-To Life Cycle Assessment of Heavy Machinery Manufacturing: a Case Study in Türkiye(Springer, 2025) Üçtuğ, F.G.; Ediger, V.Ş.; Küçüker, M.A.; Berk, İ.; İnan, A.; Moghadasi Fereidani, B.Purpose: Amidst accelerated industrialization and urbanization, the surge in heavy equipment production, crucial for construction, mining, industry, and transportation, necessitates a comprehensive examination of its environmental implications from a sustainability standpoint. This study aims to scrutinize the environmental impacts of manufacturing forklifts and semi-trailers in Türkiye, employing the life cycle assessment (LCA) methodology. Methods: The life cycle assessment (LCA) methodology is the foundational framework for evaluating the environmental impacts associated with forklift and semi-trailer manufacturing. A cradle-to-gate approach was employed. CCaLC2 software alongside the Ecoinvent 3.0 database and CML LCIA methodology was used. Results: The carbon footprint analysis reveals that the production of a single forklift and semi-trailer generates 10.8 tons CO2eq. and 24.9 tons CO2eq. of emissions, respectively. Considering the mass of the machinery, these figures translate to 2.8 ton CO2eq./ton machinery and 1.57 ton CO2eq/ton machinery for the forklift and semi-trailer, respectively. These results were found to be consistent with values reported for similar (but not identical) heavy machinery. Notably, the predominant share of environmental impact stems from raw material acquisition for both products, with subsequent contributions from various production stages. Steel utilization emerges as the primary contributor to all environmental impact categories, constituting an average contribution of 75%. Noteworthy exceptions include the acidification potential of forklift production, where the incorporation of the engine emerges as the primary hotspot with a significant 38% contribution. Conclusions: The findings present the environmental footprint associated with forklift and semi-trailer manufacturing, emphasizing the pivotal role of raw material acquisition, particularly steel utilization. Insights derived from this environmental impact assessment provide invaluable guidance for enhancing environmental sustainability. Decision-makers and industry stakeholders can leverage these conclusions to implement targeted measures, such as exploring alternative materials or refining production processes, to mitigate the environmental consequences of resource-intensive heavy equipment manufacturing, aligning with broader sustainability objectives. © The Author(s) 2025.Article Citation - WoS: 3Citation - Scopus: 3Hybrid Silica Aerogels From Bridged Silicon Alkoxides: Ultralow Thermal Conductivity for Low-Temperature Applications(Springer, 2025) Abebe, A. M.; Biesuz, M.; Vakifahmetoglu, C.; Cassetta, M.; Soraru, G. D.Hybrid silica aerogels are promising materials for thermal insulation applications. Highly porous aerogels were synthesized from bridged bis(triethoxysilyl)methane BTEM and triethoxysilane TREOS silicon alkoxides via the sol-gel process. The carbon content in the hybrid aerogels decreased with increasing amounts of TREOS. Crack-free monolith aerogels were synthesized through supercritical drying, which is crucial for thermal and optical investigations. The aerogels are characterized by high BET surface areas ranging from 700 to 1400 m(2)/g, pore volumes between 2.0 and 10.5 cm(3)/g, and a maximum porosity of 95%. The thermal conductivity of the aerogels at room temperature was measured via a hot disk apparatus. The materials exhibited ultralow thermal conductivity, reaching a minimum value of 15 mW/mK. This value ranks among the lowest reported values for silica-based aerogels in the literature. Optical transmittance measurements indicated high transparency, exceeding 80% in the visible region. Therefore, these exceptional properties of low density, high optical transparency, and low thermal conductivity make these materials promising candidates for transparent insulation applications.Article The Architecture of Relational Materialism: a Categorial Formation of Onto-Epistemological Premises(Springer, 2025) Derin, Ozan Ekin; Baytas, BekirThis study formulates the basic premises of materialism, which has largely lost its visibility despite being one of the fundamental philosophical approaches that have been effective in the development of modern scientific practice and the construction of philosophy of science, in an alternative way, and aims to develop a new materialist interpretation of it that is non-reductive, pluralistic and open to the use of more than one scientific discipline. This interpretation, expressed with the term relational materialism, first addresses matter with the concept of signifier and foregrounds the concept of beable as the general philosophical category of matter. Secondly, it formulates the category of beable within the irreducible integrity of the categories of relationality, nonstaticity, and finitude; and positions knownability in terms of its correspondence to these general onto-epistemological categories. Thirdly, it clarifies the conditions of existence and knownability of particular entities under general categories based on specially corresponding onto-epistemological categories (interactability, structurability, contextuality, transformability, scale-dependency, actuality, contingency). In this respect, this study offers a pluralistic philosophical framework within which different methodological positions and scientific disciplines can be formulated and criticized based on combinations of different particular categories under general categories. In the conclusion of this article, the meaning and potential of relational materialism for the development of scientific research programs are evaluated.Article Citation - Scopus: 1Investigating Early-Stage Mineralization Behavior and Bioactivity of Acid-Free Bioactive Glass 45s5 With Enhanced Dissolution Kinetics(Springer, 2025) Tuncer, Melisa; Yucesoy, Deniz T.; Karakus, Ceyda OkselNanostructured bioactive glass (BG) was synthesized through an acid-free sol-gel route (bioglass-AF) and the conventional acid-catalyst sol-gel process (bioglass-AC). The aim here is to eliminate the risk of residual acidic components in the BG while enhancing its functionality through nano-scale propduction. Scanning electron microscopy revealed the presence of highly porous structures and dense agglomerates composed of particles with a mean diameter of 45 nm in both samples. Bioglass-AC and bioglass-AF had specific surface areas of 1.48 m(2)/g and 2.73 m(2)/g, respectively, with an average pore size of similar to 5 nm. Faster mineralization kinetics were evident in bioglass-AF, compared to bioglass-AC, in Hepes-buffered salt solution. Following 14 days of immersion in artificial saliva, bioglass-AC and bioglass-AF lost 16% and 20% of their initial weight, respectively, confirming their bioactivity. None of the synthesized BGs stimulated cell growth up to 24 h but longer exposure to moderate concentrations (1.25 and 2.5 mg/mL) of bioglass-AF significantly enhanced cell viability, reaching 170% at 48 h. Overall, the comparative in vitro investigations proved that nano-structured 45S5 bioglass powders with improved mineralization and dissolution kinetics can be produced with an acid-free route, eliminating the risk of residual acidic components in the final product.Article Citation - WoS: 1Citation - Scopus: 1Imbalance in Redox Homeostasis Is Associated With Neurodegeneration in the Murine Model of Tay-Sachs Disease(Springer, 2025) Basirli, Hande; Ates, Nurselin; Seyrantepe, VolkanBackgroundTay-Sachs disease is a neurodegenerative disorder characterized by a build-up of GM2 ganglioside in the brain, which results in progressive central nervous system dysfunction. Our group recently generated Hexa-/-Neu3-/- mice, a murine model with neuropathological abnormalities similar to the infantile form of Tay-Sachs disease. Previously, we reported progressive neurodegeneration with neuronal loss in the brain sections of Hexa-/-Neu3-/- mice. However, the relationship between the severity of neurodegeneration and the imbalance in redox homeostasis was not yet clarified in Hexa-/-Neu3-/- mice. Here, we evaluated whether neurodegeneration is associated with oxidative stress in the tissues and cells of Hexa-/-Neu3-/- mice and neuroglia cells from Tay-Sachs patients.Methods and resultsCell death and oxidative stress-related markers were evaluated in four brain regions and fibroblasts of 5-month-old WT, Hexa-/-, Neu3-/-, and Hexa-/-Neu3-/- mice and human neuroglia cells using Western blot, RT-PCR, and immunohistochemistry analyses. We further analyzed oxidative stress levels in the samples using flow cytometry analyses. We discovered neuronal death, alterations in intracellular ROS levels, and damaging effects of oxidative stress, especially in the cerebellum and fibroblasts of Hexa-/-Neu3-/- mice.ConclusionsOur results showed that alteration in redox homeostasis might be related to neurodegeneration in the murine model of Tay-Sachs Disease. These findings suggest that targeting the altered redox balance and increased oxidative stress might be a rational therapeutic approach for alleviating neurodegeneration and treating Tay-Sachs disease.Article Citation - WoS: 1Citation - Scopus: 1Euler–Euler Numerical Model for Transport Phenomena Modeling in a Natural Circulation Loop Operated by Nanofluids(Springer, 2025) Kamenik, B.; Vovk, N.; Elcioglu, E.B.; Sezgin, F.; Ozyurt, E.; Karadeniz, Z.H.; Ravnik, J.This paper explores a computational approach to model multiphase heat transfer and fluid flow in a natural circulation loop utilizing nanofluids. We propose and implement an Euler–Euler framework in a CFD environment, incorporating an innovative boundary condition to preserve mass conservation during thermophoretic particle flux. The model’s accuracy is verified through a one-dimensional example, by comparing results against both an Euler–Lagrange model and an in-house finite volume solution. Experimental validation is conducted with aluminum oxide nanofluids at varying nanoparticle concentrations. We prepared the nanofluids and measured their thermophysical properties up to 60∘C. We assess the thermal performance of the nanofluid in natural circulation loop at different heating powers via experiment and numerical simulations. The findings reveal that the heat transfer enhancement offered by the nanofluid is modest, with minimal differences observed between the proposed Euler–Euler approach and a simpler single-phase model. The results underscore that while the Euler–Euler model offers detailed particle–fluid interactions, its practical thermal advantage is limited in this context. © The Author(s) 2025.Article Citation - WoS: 1Citation - Scopus: 1Analysis and Comparison of the Projectile Impact Response of an Electron Beam Melt-Ti64 Body Centered Cubic Lattice-Cored Sandwich Plate(Springer, 2025) Erten, H.İ.; Çimen, G.; Yıldıztekin, F.M.; Güden, M.Background: One potential application of additively fabricated lattice structures is in the blade containment rings of gas turbine engines. The blade containment rings are expected to be able to absorb the kinetic energy of a released blade (broken blade) in order to protect the engine parts from damaging. Metallic lattice-cored sandwich plates provide a gap (free space) between two face sheets, which helps to arrest the released blade and increases the energy absorption capability of containment rings. Objective: The objective was to investigate numerically the projectile impact response of Body-Centered-Cubic (BCC) Electron-Beam-Melt (EBM) lattice-cored/Ti64 face sheet sandwich plates as compared with that of an equal-mass monolithic EBM-Ti64 plate. Methods: The projectile impact simulations were implemented in LS-DYNA using the previously determined flow stress and damage models and a spherical steel impactor at the velocities ranging from 150 to 500 m s−1. The experimental projectile impact tests on the monolithic plate were performed at two different impact velocities and the results were used to confirm the validity of the used flow stress and damage models for the monolithic plate models. Results: Lower impact stresses were found numerically in the sandwich plate as compared with the monolithic plate at the same impact velocity. The bending and multi-cracking of the struts over a wide area in the sandwich plate increased the energy absorption and resulted in the arrest of the projectile at relatively high velocities. While monolithic plate exhibited a local bent area, resulting in the development of high tensile stresses and the projectile perforations at lower velocities. Conclusions: The numerical impact stresses in the sandwich plate were distributed over a wider area around the projectile, leading to the fracture and bending of many individual struts which significantly increased the resistance to the perforation. Hence, the investigated lattice cell topology and cell, strut, and face sheet sizes and the lattice-cored sandwich plate was shown potentially more successful in stopping the projectiles than the equal-mass monolithic plates. © The Author(s) 2025.