WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Polyaspartic Ester Polyurea-TiO2nanocomposite Coatings for UV Protection of Leading Edge of Wind Turbine Blades(Elsevier B.V., 2026) Olcer, Y.A.; Karabacak, B.D.; Demirkurt, M.; Yoldaş, İ.; Can y, Z.; Demir, M.Polyaspartic ester polyurea (PAEPU) supplies a promising matrix for high-durability coatings. However, its poor UV-A resistance make its usage limited. In this work, commercially available anatase TiO<inf>2</inf> particles (0.05–10 wt%) were dispersed in PAE matrix without any modification. PAEPU/TiO<inf>2</inf> composites were supplied by the reaction of PAE/TiO<inf>2</inf> matrix with an aliphatic isocyanate. UV–Visible spectra of spin coated PAEPU/TiO<inf>2</inf> composite thin films showed an exponential decrease in transmittance with increasing amount of TiO<inf>2.</inf> The optical response is dominated by UV blocking for TiO<inf>2</inf> amounts smaller than 0.3 wt%. For above 0.5 wt% TiO<inf>2</inf> amounts, transparency to translucency transition signifies the beginning of multiple scattering. The diameter of particles analyzed by AFM showed that particle diameter is 47 ± 11 nm taking into account of images of the PAEPU films containing 0.3 wt% of TiO<inf>2</inf> particles. Radial distribution function of the particle domains achieved from microscopy suggests that interparticle distance gets smaller than the wavelength of the incident light even at low the particle concentration. Accelerated weathering test were performed by applying 0.1, 0.5, 1.0, and 3.0 wt% TiO<inf>2</inf> containing PAEPU composite films on a white primer with Doctor Blade method. 0.1 wt% PAEPU/TiO<inf>2</inf> composites shows lower ΔE value compare to both neat and higher amounts of TiO<inf>2</inf> containing PAEPU composite films. The results suggest that without the complexity and cost of the surface modification, the low loading of commercial TiO<inf>2</inf> into PAE matrix may supply UV-stabilized PAEPU coatings relevant to the leading-edge protection of wind-turbine blades. © 2025 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.Article A Simplified Molecular Imprinting Strategy Through Electrospinning of Polyacrylonitrile for Thin Film Microextraction of Selected Pesticides(Elsevier B.V., 2026) Şahin, A.; Akpinar, Y.; Yildirim, E.; Eroǧlu, A.E.; Boyaci, E.Molecularly imprinted polymers (MIPs) have been extensively used as selective extractive phases for sample preparation because of their analyte-selective binding sites. However, MIP preparation requires optimized monomer-template interactions and long polymerization reactions. In this study, a novel and simple method of MIP preparation was proposed based on electrospinning. Instead of preparing analyte-monomer complexes before polymerization, model analytes (trifluralin and carbaryl) were directly dissolved in a polyacrylonitrile (PAN) solution, then electrospun into nanofibrous mats. This allowed for a means of preparation of highly crystalline, template-imprinted nanostructures with minimal synthetic complexity. Following the characterization studies for the new material, the extraction properties of the imprinted and nonimprinted electrospun mats were investigated in thin film microextraction (TFME) studies by extracting trifluralin and carbaryl from water samples, followed by gas chromatography-mass spectrometry (GC–MS) analysis. The optimization results showed that samplers containing 10.0 mg of MIP sorbents made by electrospinning of a solution containing 5.0 mg of template in 1.0 mL of PAN solution resulted in approximately 4 and 7 times enhanced extraction recoveries for carbaryl and trifluralin compared to samplers made of non-imprinted bulk PAN. Moreover, the cross-reactivity testing performed with non-template analytes (malathion and diazinon) suggested a more specific extraction towards trifluralin compared to carbaryl. The proposed new technique was also validated using computational methodology, which supported the experimental finding about higher selectivity towards trifluralin. This may signify a probability for structural orientation of partially charged trifluralin under an electrical field in electrospun PAN creating favorable extraction sites. © 2025 Elsevier B.V.Article Citation - WoS: 4Citation - Scopus: 4Novel Electrospun-Based Extractive Probes for Rapid Determination of Clinically Important Compounds in Human Plasma(Elsevier B.V., 2024) Temel,E.R.; Eroğlu,A.E.; Salih,B.; Boyaci,E.Background: Coated blade spray (CBS) represents an innovative approach that utilizes solid-phase microextraction principles for sampling and sample preparation. When combined with ambient mass spectrometry (MS), it can also serve as an electrospray ionization source. Therefore, it became a promising tool in analytical applications as it can significantly reduce the analysis time. However, the current CBS coatings are based on the immobilization of extractive particles in bulk polymeric glue, which constrains the diffusion of the analytes to reach the extractive phase; therefore, the full reward of the system cannot be taken at pre-equilibrium. This has sparked the notion of developing new CBS probes that exhibit enhanced kinetics. Results: With this aim, to generate a new extractive phase with improved extraction kinetics, poly(divinylbenzene) (PDVB) nanoparticles were synthesized by mini-emulsion polymerization and then immobilized into sub-micrometer (in diameter) sized polyacrylonitrile fibers which were obtained by electrospinning method. Following the optimization and characterization studies, the electrospun-coated blades were used to determine cholesterol, testosterone, and progesterone in plasma spots using the CBS-MS approach. For testosterone and progesterone, 10 ng mL−1 limits of quantification could be obtained, which was 200 ng mL−1 for cholesterol in spot-sized samples without including any pre-treatment steps to samples prior to extraction. Significance: The comparison of the initial kinetics for dip-coated and electrospun-coated CBS probes proved that the electrospinning process could enhance the extraction kinetics; therefore, it can be used for more sensitive analyses. The total analysis time with this method, from sample preparation to instrumental analysis, takes only 7 min, which suggests that the new probes are promising for fast diagnostic applications. © 2024 Elsevier B.V.Article Citation - WoS: 10Citation - Scopus: 11Arabinoxylan-Based Psyllium Seed Hydrocolloid: Single-Step Aqueous Extraction and Use in Tissue Engineering(Elsevier B.V., 2024) Yildirim-Semerci,Ö.; Bilginer-Kartal,R.; Arslan-Yildiz,A.Biomacromolecules derived from natural sources offer superior biocompatibility, biodegradability, and water-holding capacity, which make them promising scaffolds for tissue engineering. Psyllium seed has gained attention in biomedical applications recently due to its gel-forming ability, which is provided by its polysaccharide-rich content consisting mostly of arabinoxylan. This study focuses on the extraction and gelation of Psyllium seed hydrocolloid (PSH) in a single-step water-based protocol, and scaffold fabrication using freeze-drying method. After characterization of the scaffold, including morphological, mechanical, swelling, and protein adsorption analyses, 3D cell culture studies were done using NIH-3 T3 fibroblast cells on PSH scaffold, and cell viability was assessed using Live/Dead and Alamar Blue assays. Starting from day 1, high cell viability was obtained, and it reached 90 % at the end of 15-day culture period. Cellular morphology on PSH scaffold was monitored via SEM analysis; cellular aggregates then spheroid formation were observed throughout the study. Collagen Type-I and F-actin expressions were followed by immunostaining revealing a 9- and 10-fold increase during long-term culture. Overall, a single-step and non-toxic protocol was developed for extraction and gelation of PSH. Obtained results unveiled that PSH scaffold provided a favorable 3D microenvironment for cells, holding promise for further tissue engineering applications. © 2024 Elsevier B.V.Article Citation - WoS: 4Citation - Scopus: 4Automating Modern Code Review Processes With Code Similarity Measurement(Elsevier B.V., 2024) Kartal,Y.; Akdeniz,E.K.; Özkan,K.Context: Modern code review is a critical component in software development processes, as it ensures security, detects errors early and improves code quality. However, manual reviews can be time-consuming and unreliable. Automated code review can address these issues. Although deep-learning methods have been used to recommend code review comments, they are expensive to train and employ. Instead, information retrieval (IR)-based methods for automatic code review are showing promising results in efficiency, effectiveness, and flexibility. Objective: Our main objective is to determine the optimal combination of the vectorization method and similarity to measure what gives the best results in an automatic code review, thereby improving the performance of IR-based methods. Method: Specifically, we investigate different vectorization methods (Word2Vec, Doc2Vec, Code2Vec, and Transformer) that differ from previous research (TF-IDF and Bag-of-Words), and similarity measures (Cosine, Euclidean, and Manhattan) to capture the semantic similarities between code texts. We evaluate the performance of these methods using standard metrics, such as Blue, Meteor, and Rouge-L, and include the run-time of the models in our results. Results: Our results demonstrate that the Transformer model outperforms the state-of-the-art method in all standard metrics and similarity measurements, achieving a 19.1% improvement in providing exact matches and a 6.2% improvement in recommending reviews closer to human reviews. Conclusion: Our findings suggest that the Transformer model is a highly effective and efficient approach for recommending code review comments that closely resemble those written by humans, providing valuable insight for developing more efficient and effective automated code review systems. © 2024 Elsevier B.V.Article Citation - WoS: 5Citation - Scopus: 5Van Der Waals Heterostructures of Alas and Inse: Stacking-Dependent Raman Spectra and Electric Field Dependence of Electronic Properties(Elsevier B.V., 2024) Yayak,Y.O.; Topkiran,U.C.; Yagmurcukardes,M.; Sahin,H.In the present work, the electronic and vibrational properties of a van der Waals type heterostructure, composed of single layers of AlAs and InSe, are investigated using density functional theory (DFT)-based first-principles calculations. Vibrational analyses reveal that dynamically stable single layers of AlAs and InSe form van der Waals type heterostructure which is shown to exhibit stacking-dependent Raman spectra by means of the frequency shifts. According to our findings, a type-II band alignment with a direct band gap of 1.84 eV is found in the ground state stacking of AlAs/InSe vertical heterostructure, in contrast to the indirect band gap behaviors of each individual layer. Moreover, the application of an external vertical electric field shows that the both band alignment type and the electronic behavior of the heterostructure can be tuned. The heterostructure is found to exhibit direct to indirect band gap transition under negative electric field as well as a transition from type-II to type-I heterojunction under negative fields up to 0.3 V/Å. The stronger fields along the same direction results in overlapping of valence states of each layer and lead to a non-linear change of the energy band gap. Overall, the predicted van der Waals type heterobilayer of InSe and AlAs with stacking-dependent vibrational features and well-controlled electronic properties under external field is shown to be potential candidate for optical and optoelectronic applications. © 2024 Elsevier B.V.Article Citation - WoS: 15Citation - Scopus: 15Granulation of Hydrometallurgically Synthesized Spinel Lithium Manganese Oxide Using Cross-Linked Chitosan for Lithium Adsorption From Water(Elsevier B.V., 2024) Recepoğlu,Y.K.; Arabacı,B.; Kahvecioğlu,A.; Yüksel,A.A drastic increase in demand for electric vehicles and energy storage systems increases lithium (Li) need as a critical metal for the 21st century. Lithium manganese oxides stand out among inorganic adsorbents because of their high capacity, chemical stability, selectivity, and affordability for lithium recovery from aqueous media. This study investigates using hydrometallurgically synthesized lithium manganese oxide (Li1.6Mn1.6O4) in granular form coated with cross-linked chitosan for lithium recovery from water. Characterization methods such as SEM, FTIR, XRD, and BET reveal the successful synthesis of the composite adsorbent. Granular cross-linked chitosan-coated and delithiated lithium manganese oxide (CTS/HMO) adsorbent demonstrated optimal removal efficiency of 86 % at pH 12 with 4 g/L of adsorbent dosage. The Langmuir isotherm at 25 °C, which showed monolayer adsorption with a maximum capacity of 4.94 mg/g, a better fit for the adsorption behavior of CTS/HMO. Adsorption was endothermic and thermodynamically spontaneous. Lithium adsorption followed the pseudo-first-order kinetic model. © 2024Article Citation - WoS: 5Citation - Scopus: 5Effects of Diborolane Containing Oxo/Amine Compounds on Clinically Important Bacteria and Candida Species(Elsevier B.V., 2024) Şahin,Y.; Çoban,E.P.; Özgener,H.; Bıyık,H.H.; Sevincek,R.; Aygün,M.; Gürbüz,B.A good yield of 1,2-diborolanderivatives 2-8 was obtained from the reaction of 1,2-dichloro-1,2-diborolane 1 and R2NLi/ArNHLi/PhOLi/H2O. The structures of these new derivatives were characterized by nuclear magnetic resonance spectroscopy. The molecular structures of 4 and 7a were also determined using single-crystal X-ray diffraction. The antimicrobial activities of synthesized compounds were tested against clinically important Gram-positive, Gram-negative bacteria, and Candida species. The most effective substances were found to be compounds 2, 3, 4, 6 and 8 among the tested compounds. Therefore, the activity of these substances were investigated against Staphylococcus aureus ATCC 43300 and Enterococcus faecalis ATCC 51575, which form biofilms and have antibiotic resistance. Compound 2, 6 and 8 appears to be a promising candidate for potential antibacterial agents against these bacterial strains, especially given its potent activity against biofilm-forming and antibiotic resistant strains. The results indicate that these new materials will be evaluated as potential drugs against infectious diseases in the future. © 2024 Elsevier B.V.Article Citation - WoS: 5Citation - Scopus: 7Search for Wγ Resonances in Proton-Proton Collisions at S=13 TeV Using Hadronic Decays of Lorentz-Boosted W Bosons(Elsevier B.V., 2022) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Alves, G.A.A search for Wγ resonances in the mass range between 0.7 and 6.0 TeV is presented. The W boson is reconstructed via its hadronic decays, with the final-state products forming a single large-radius jet, owing to a high Lorentz boost of the W boson. The search is based on proton-proton collision data at s=13 TeV, corresponding to an integrated luminosity of 137 fb−1, collected with the CMS detector at the LHC in 2016–2018. The Wγ mass spectrum is parameterized with a smoothly falling background function and examined for the presence of resonance-like signals. No significant excess above the predicted background is observed. Model-specific upper limits at 95% confidence level on the product of the cross section and branching fraction to the Wγ channel are set. Limits for narrow resonances and for resonances with an intrinsic width equal to 5% of their mass, for spin-0 and spin-1 hypotheses, range between 0.17 fb at 6.0 TeV and 55 fb at 0.7 TeV. These are the most restrictive limits to date on the existence of such resonances over a large range of probed masses. In specific heavy scalar (vector) triplet benchmark models, narrow resonances with masses between 0.75 (1.15) and 1.40 (1.36) TeV are excluded for a range of model parameters. Model-independent limits on the product of the cross section, signal acceptance, and branching fraction to the Wγ channel are set for minimum Wγ mass thresholds between 1.5 and 8.0 TeV. © 2022 The Author(s)Article Citation - WoS: 15Citation - Scopus: 19Study of J/Ψ Meson Production Inside Jets in pp Collisions at S=8 TeV(Elsevier B.V., 2020) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Bergauer, T.; Brandstetter, J.; Hensel, C.A study of the production of prompt J/ψ mesons contained in jets in proton-proton collisions at s=8TeV is presented. The analysis is based on data corresponding to an integrated luminosity of 19.1 fb−1 collected with the CMS detector at the LHC. For events with at least one observed jet, the angular separation between the J/ψ meson and the jet is used to test whether the J/ψ meson is part of the jet. The analysis shows that most prompt J/ψ mesons having energy above 15 GeV and rapidity |y|<1 are contained in jets with pseudorapidity |η<inf>jet</inf>|<1. The differential distributions of the probability to have a J/ψ meson contained in a jet as a function of jet energy for a fixed J/ψ energy fraction are compared to a theoretical model using the fragmenting jet function approach. The data agree best with fragmenting jet function calculations that use a long-distance matrix element parameter set in which prompt J/ψ mesons are predicted to be unpolarized. This technique demonstrates a new way to test predictions for prompt J/ψ production using nonrelativistic quantum chromodynamics. © 2020 Elsevier B.V.