Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Valorization of Recycled Waste in Green/White Purification and LC-QTOF/MS Analysis of Beverages Adulterated with Incapacitating Drugs(Elsevier B.V., 2026) Anilanmert, Beril; Yonar, Fatma Cavus; Er, Elif Ozturk; Pekcaliskan, Elif Yılmaz; Cengiz, SalihIncapacitating drugs constitute a growing threat for the community, since victims may drink adulterated beverages without noticing. A validated eco-friendly/economical purification/analysis kit prototype, along with an LC-QToF/MS method has been developed in coke and mixed fruit-juice, for simultaneous determination of 10 drugs used for incapacitating victims (zaleplone, zolpidem, zopiclone, mephedrone, fentanyl, phenytoin, thiopental, sertraline, ketamine and GHB). A combination of two different waste nut-shells which yielded the highest recovery for these drugs were directly used as adsorbent after grinding and modification and a reusable separation apparatus recycled from waste were utilized for the first time in a toxicological analysis. In the method, after adding the adsorbent on to the sample, pH was adjusted. Following 25-min (min) automatic vortexing for adsorption, matrix was removed easily, using the separation apparatus. After 25-min desorption via cold ultrasonication using 500 μL methanol, a 9.5-min LC-QToF/MS analysis was performed. The validated method in fruit-juice and coke, extraordinarily gave successful results also in urine and saliva. Assessment tools for greenness/whiteness and pictograms confirmed the environmental friendliness of the method kit. © 2025 Elsevier B.V.Article Reduced Phase Space Quantization and Quantum Corrected Entropy of Schwarzschild-De Sitter Horizons(Elsevier B.V., 2026) Jalalzadeh, S.; Moradpour, H.This paper investigates the quantization of the Schwarzschild–de Sitter (SdS) black hole (BH) using the Misner–Sharp–Hernandez (MSH) mass as the internal energy in a reduced phase space framework. After introducing the canonical variables of the reduced phase space, we derive a discrete spectrum for the surface areas of the BH event horizon (EH) as well as MSH masses. We utilized the MSH mass spectrum to obtain the entropy of the BH. The entropy of the BH and cosmic EHs reveals a logarithmic correction to the Bekenstein–Hawking term. Our results support the robustness of the logarithmic form of quantum corrections in SdS thermodynamics. © 2026 The Authors.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 Simultaneous Topology Design and Optimization of Pde Constrained Processes Based on Mixed Integer Formulations(Elsevier B.V., 2024) Erturk,E.; Deliismail,O.; Sildir,H.Simultaneous topological design and optimization of complex processes that are described by partial differential equations is a challenging but promising research area. Widely adopted nested and sequential approaches are mostly applicable based on heuristic solutions, hindering the theoretical improvement potential due to decentralized decision-making in subsequent stages with a significant number of trial-and-error procedures. This study introduces a mixed integer formulation addressing the governing equations and case-dependent topological constraints at each discretization point, enabling solutions through rigorous solvers under process-related constraints and objectives. Nonlinear expressions in the formulations are further tailored using piecewise linear approximations, still representing the major nonlinear trends through a mixed-integer linear nature to favor global optimality and benefit from computational advancements, when needed. Heat and Stokes flow problems are used as case studies to demonstrate the applicability of the methodology. © 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. © 2024