Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Gul, Muhammet(85)
- Serdar, Osman(72)
- Güler, Ömer(68)
- Akkurt, Nevzat(61)
- Baskonus, Haci Mehmet(54)
- Alataş, Mevlüt(53)
- Paksoy, Mehmet Yavuz(53)
- Yucesan, Melih(53)
- Bulut, Hasan(51)
- Tekin, H.O.(51)
- ALMisned, Ghada(48)
- Yildirim, Numan(48)
- Benzer, Fulya(47)
- Kocabaş, Mehmet(45)
- Yildirim, Nuran Cikcikoglu(44)
- Kutlu, Banu(41)
- Ince, Muharrem(39)
- Zengin, Gokhan(39)
- Batan, Nevzat(37)
- Utku, Anıl(35)
- Celik, Erkan(33)
- Topal, Murat(32)
- Ezer, Tülay(31)
- Tanyol, Mehtap(31)
- Can, Erkan(30)
- Sulaiman, Tukur Abdulkadir(29)
- Aslan, Naim(28)
- Özkul, İskender(28)
- Aslan, Alper(27)
- Cakilcioglu, Ugur(27)
- Erguven, Gokhan Onder(27)
- Kutluyer, Filiz(27)
- Kök, Mediha(27)
- Ates, Mehmet(26)
- Erten, Fusun(26)
- Kahraman, Gökhan(26)
- Onat, Onur(26)
- Dal, Nursel Alp(25)
- Danabas, Durali(25)
- Say, Yakup(25)
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ2Risk Assessment via Hazard Scenario in Cereal Production Under Rising CO
Susam, Selim Orhun; Peker, Ayse Esra; Hudaverdi, Burcu
Global food security has been seriously threatened by air pollution and climate change. The impact of CO on crop output is complicated because of its interactions with temperature, nutrient availability, and other pollutants, even though it is necessary for photosynthesis. This study develops a copula-based hazard modeling framework to assess how increasing CO concentrations affect cereal production risk across multiple crops. By integrating hazard scenario analysis with localized dependence measures, we estimate both failure probabilities and dynamic associations between CO emissions and cereal yields. A novel localized version of Kendall’s implemented via a Bernstein copula approximation, enables flexible modeling of heterogeneous and nonlinear dependence structures. As the relationship between CO emissions and crop-specific yields changes in both density and direction, it may indicate asymmetries or nonlinearities that are missed by measures of global dependence. Empirical results reveal distinct crop-specific responses. While CO levels enhance yields for rice, millet, and sugar beet, they reduce or destabilize production for rye and lentil, indicating asymmetric sensitivities. Failure probabilities increase with the time horizon, reflecting the accumulation of climate-related production risk. The findings emphasize the significance of integrating probabilistic hazard modeling into climate-resilient agricultural planning and food security policies, as crop-specific risk exposure has increased in recent time periods.
AtıfWoS1OpenAlex1
İncele - MakaleYalnız künye2026Scopus SJRQ2Institutions, gendered informality, and intrahousehold distribution: A dual-economy model
Ateş-Saygılı, Çiğdem
We study how enforcement institutions shape formalization and the intrahousehold distribution of resources in a developing economy. The model combines an enforcement wedge inside informal technology, gendered formal-attachment margins, and a collective household with a state-dependent female Pareto weight. In the benchmark wage-responsive specification, enforcement raises formalization by compressing informal wages and reallocating work toward formal jobs. Yet aggregate formalization and women's intrahousehold gains need not move together. When women are more exposed to informality and men convert the induced formal-to-informal wage ratio into formal attachment more strongly in level terms, enforcement can lower women's relative earnings, relative formal status, the female Pareto weight, and the consumption ratio during adjustment. An exact effective-access transition and local calculations for the effective-access and reduced-form labor-disutility margins show that this adverse incidence can be offset within the model while preserving formalization gains. Descriptive quarterly evidence for Türkiye documents gendered dynamics in non-agricultural social-security non-registration around salient macroeconomic and institutional episodes. The empirical evidence motivates the labor-market exposure and access channels but does not observe household bargaining or individual consumption.
- MakaleAçık Erişim2026Scopus SJRQ1Comparative and systematically analysis of the effects of single and high-entropy rare earth oxide additives on the some physical properties and radiation shielding properties of copper composites
Kanca, Muhammed Sait; Yılmaz, Demet; Tasgın, Yahya; Kök, Mediha; Güler, Seval Hale
In this study, the effects of rare earth oxides (Gd₂O₃, La₂O₃, Eu₂O₃, Pr₂O₃, Dy₂O₃, and Y₂O₃) and high-entropy oxide (GdLaEuPrDyY)₂O₃ additives on the structural, mechanical, and radiation shielding properties of copper matrix composites were investigated. XRD and SEM-EDS analyses showed that the high-entropy oxide successfully formed in a single-phase bixbyite structure after mechanical alloying and was homogeneously distributed within the copper matrix. The rare earth oxide additive significantly reduced the crystal grain size of the Cu matrix and improved its mechanical properties. Specifically, the microhardness value reached 68.3 Hv in the composite with 20% high-entropy oxide additive, representing an increase of approximately 111% compared to pure copper (32.3 Hv). Gamma shielding results showed that the rare earth oxide additive significantly increased the photon attenuation capacity. Specifically, at 242 keV energy, the Dy₂O₃ additive increased the MAC value from 0.141 cm²/g to 0.246 cm²/g, providing a 74.5% improvement. The most important result is that the composite with 20% high-entropy oxide additive showed the highest shielding performance, achieving a MAC value of 0.278 cm²/g, which is significantly superior to pure copper. Furthermore, this composite exhibited the lowest HVL and MFP values, demonstrating the highest photon shielding efficiency. Neutron shielding analyses revealed that Gd₂O₃ and high-entropy oxide additives, in particular, increased thermal neutron attenuation performance to approximately 100%. These results demonstrate that high-entropy oxide additives provide a stronger impact compared to single oxide additives, offering superior performance in both gamma and neutron shielding. Consequently, copper composites doped with (GdLaEuPrDyY)₂O₃ stand out as promising alternative shielding materials for nuclear facilities, radiation protection systems, and advanced engineering applications due to their high shielding efficiency, improved mechanical properties, and non-toxic composition.
AtıfScopus1OpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ1A two-stage volunteer assignment model for post-disaster search and rescue operations
Ozdemir, Umit; Mete, Suleyman; Gul, Muhammet
Effective volunteer management requires ensuring operational continuity and maximizing benefits from all team members. Prioritizing volunteers with adequate knowledge and experience in task assignments is crucial for maintaining workflow continuity. This study employs a two-stage model for allocating areas and tasks to volunteers in search and rescue operations. The first stage identifies the optimal number of volunteer response centers using the P-median problem. Considering population density as demand, 7 out of 14 accessible and protected disaster collection areas meeting basic needs are selected as optimal response centers based on distance. In the second stage, a mixed-integer programming model is proposed for volunteer assignment, which prioritizes assigning the most knowledgeable and experienced volunteers to critical positions. The model’s flexibility and applicability are demonstrated by incorporating voluntary rest periods, which are allocated based on the urgent needs of response centers in various post-disaster scenarios. Solved using GAMS/CPLEX, the model’s results show that expert volunteers in low-demand scenarios are prioritized, working 5 out of 9 shifts, while other volunteers receive insufficient assignments. In high-demand scenarios, some response centers face volunteer shortages, with a deficit of 62 volunteers across 9 shifts in non-emergency areas. The study evaluates the benefits and drawbacks of the volunteer assignment model and offers recommendations for future research.
AtıfScopus2WoS2OpenAlex3
İncele - MakaleAçık Erişim2026Scopus SJRQ2Federated agricultural yield forecasting under an Edge–Fog–Cloud framework: a multi-country privacy-preserving approach
Utku, Anıl; Barut, Abdulkadir; Alofaysan, Hind; Henni, Mohamed Djafar; Amoozegar, Azadeh
Predicting agricultural yields is crucial for ensuring global food security and adaptation to climate change. However, the centralized collection of agricultural data across countries might pose governance, privacy, and data sovereignty issues. This research presents a privacy-preserving model for predicting agricultural yields using federated learning within an edge-fog-cloud integrated architecture. The experiments have been performed on a European cereal production dataset for the period 1990–2022, using a time-aware forecasting scheme. Centralized, edge-only, federated, and hybrid learning techniques have been systematically compared to examine the influence of distributed optimization on forecasting performance. It can be seen that central classical machine learning algorithms have yielded the best predictive performance. Federated deep learning models, meanwhile, showed relatively poor forecasting accuracy compared to their centralized counterparts under a non-IID distribution of multi-country agricultural data. Edge-only learning, meanwhile, has yielded comparatively low generalization capabilities due to the absence of collaborative learning.
- MakaleAçık Erişim2026Scopus SJRQ4Effectiveness of organic tomato (Solanum lycopersicum L.) extracts added to yeast Cell Culture against H2O2 Toxicity; [Eficácia de extratos de tomate orgânicos adicionados à cultivos de células de levadura contra la toxicidad por H2O2]
Gonayli, Selahattin; Temizer, Ibrahim Akin; Aydin, Sevinq; Kirmizikaya, Gorkem; Okutan, Tuba; Yilmaz, Okke$
Growing tomatoes in season and organically are an important factor in terms of carrying higher levels of antioxidant molecules. This study aimed to demonstrate the protective effect of extracts obtained from naturally grown tomatoes, which are widely used as food, against oxidative damage caused by hydrogen peroxide on yeast cells (Saccharomyces cerevisiae L.). Lipophilic vitamins, phytosterol content, gluathione and oxidised gluathione content were analyzed by Shimadzu brand high performance liquid chromatography, while fatty acid analysis was performed by Shimadzu GC 2010 Plus Gas Chromatography. Protein content was analyzed spectrophotometrically. The study groups were designed as control, hydrogen peroxide, tomato and tomato + hydrogen peroxide. In all groups added with hydrogen peroxide and tomato extract compared to the hydrogen peroxide group; it was observed that vitamin D2, α-Tocopherol, β-Sitosterol and Stigmasterol contents increased significantly. Again, it was observed that ergosterol level increased significantly in the D + hydrogen peroxide group compared to the hydrogen peroxide group. When the fatty acid analysis results were examined, it was determined that in all groups added to the cultured yeast with hydrogen peroxide and tomato extracts (except the B + hydrogen peroxide group), there were increases in 16:0, 16:1, n-7, 17:0, 17:1 and 18:0 fatty acid levels compared to the hydrogen peroxide group. On the other hand, when its effect on protein and gluathione levels was examined, more significant increases were determined in all groups with tomato extract addition compared to the hydrogen peroxide group. At the end of the study, it was observed that tomato extracts had positive effects against hydrogen peroxide toxicity in yeast cells, although at different levels in terms of fatty acid, vitamin and phytosterol contents.
- MakaleAçık Erişim2026Scopus SJRQ2Cadmium-induced changes in haemato-immunological, oxidative stress and antioxidant parameters of Cyprinus carpio: Protective role of curcumin
Pala, Ayşegül; Eroğlu, Mücahit; Mişe Yonar, Serpil; İspir, Ünal; Yonar, Muhammet Enis
This study examined the adverse effects of sublethal concentrations of cadmium (Cd) and the potential of curcumin (CUR) to mitigate Cd-induced toxicity. We administered 1.5 and 3 mg/L of Cd and 100 mg/kg of CUR to fish (Cyprinus carpio) separately and in combination over 14 days. At the end of the experiments, various haematological and immunological parameters, oxidative stress levels and antioxidant parameters of fish were measured, and the differences between the groups were evaluated. Simultaneous CUR treatment with Cd reversed the changes in haematological parameters in fish, increased immune responses, reduced oxidative stress and normalized the impaired antioxidant enzyme activities. In summary, our study showed that dietary supplementation with CUR may be an effective strategy to reduce the toxic effects of Cd in carp.
- MakaleAçık Erişim2026Scopus SJRQ2Electrochemical analysis of tetracycline in drug formulations with glutardialdehyde-Fe2O3 modified glassy carbon electrode
Koçak, Berna; İpek, Yeliz
In this study, a glutardialdehyde-Fe2O3 modified glassy carbon electrode (GA2–Fe2O3/GCE) was used as a sensor for the electrochemical analysis of tetracycline (TC) in drug formulations. The electrochemical behavior of TC on GA2-Fe2O3/GCE was investigated using cyclic voltammetry (CV), while the quantitative determination was performed via differential pulse voltammetry (DPV). After optimizing the experimental conditions, the linear working range, limit of (LOD) detection, and limit of quantification (LOQ) of the GA2-Fe2O3/GCE electrode developed for the electrochemical analysis of TC were found to be 1.0 × 10−6–2.0 × 10−5 M and 2.0 × 10−5–9.9 × 10−6 M; 4.78 × 10−7 M; 1.59 × 10−6 M, respectively. In the sensor application study conducted on a Tetra® Gensenta tablet to demonstrate the applicability of the developed method, the linear working range, LOD, and LOQ values of the sensor were found to be 1.0 × 10−6–14.8 × 10−5 M; 5.72 × 10−7 M and 1.74 × 10−6 M, respectively. The applicability of the method was demonstrated through tablet recovery studies, and the tablet recovery ratio was determined to be 100.94%.
- MakaleYayıncıda açık erişim2026Scopus SJRQ1Thematic Structure of Pedagogical Agent Studies: LDA Analysis for the Period 2020–2025
Turgut, Yigit Emrah; Aktı Aslan, Seda; Kopuz, Tuba; Aslan, Alper; Allison, Jordan; Özyurt, Özcan
This study examines 2,360 pedagogical agent (PA) articles published between 2020 and 2025 to identify thematic structures, trends, and research gaps through bibliometric analysis and LDA-based topic modeling. The optimal model produced 10 themes (c_v = 0.4767). The dominant themes—Learner Interaction with Virtual Assistants in Education, Student-Centred Learning and Individual Guidance, and NLP Foundations for Pedagogical Agents—account for 51.3% of publications. Trend analyses revealed consistent growth in both Artificial Intelligence and Pedagogical Design in Education and NLP Foundations for Pedagogical Agents, while Learner Interaction with Virtual Assistants in Education reached saturation. Interaction network results showed these themes at the conceptual core of the field, whereas AI-Driven Medical Chatbots, Knowledge-Based Learning Models, and Student Experiences in Intelligent Learning Environments emerged as future research areas. Overall, findings highlight a strong thematic shift toward artificial intelligence, natural language processing, and student-centered learning.
- MakaleAçık Erişim2026Scopus SJRQ3Analysis of Visible Light Communication Performance in LOS Propagation Model with PSO-Cosh-Based Filter
Fethiye Merve, Kavak Imak; Fatmanur, Atar; Duygu, Kaya; Turgay, Kaya
Due to the increasing data transfer in wireless communication technologies, Visible Light Communication (VLC), one of the branches of wireless communication technology, is also developing within this framework. VLC holds an advantage over other communication branches in terms of energy efficiency, high bandwidth, and reliability. In this context, research on VLC-based Light Fidelity (Li-Fi) technology has gained momentum in recent years. In systems built with this Li-Fi technology, data is transmitted through an LED bulb, which is used for illumination. In this study, to analyze the performance of systems where data transmission is provided by VLC, the capacity to improve the shape of the transmitted signal is investigated using systems designed with different filtering techniques under LOS channel conditions. The main objective of this study is to demonstrate the improving effect of the proposed PSO-Cosh-based model on the shape of the transmitted signal compared with traditional filtering methods. In this way, in addition to IIR digital filtering techniques, the analysis of the filter coefficients obtained by optimizing the Cosh window function with Particle Swarm Optimization (PSO) demonstrates the originality of the study.
- MakaleAçık Erişim2026Scopus SJRQ1Thematic Evolution of Educational Technology Research: A Large-Scale Topic Modeling Perspective
Aslan, Alper; Aktı Aslan, Seda; Turgut, Yiğit Emrah; Allison, Jordan; Özyurt, Özcan
This study aims to reveal the thematic evolution of the educational technology field by analyzing 17,393 articles published between 2000 and 2024 in ten leading journals using the Latent Dirichlet Allocation (LDA) based topic modeling. Based on the analysis of title, abstract, and keywords, 20 themes were identified and grouped under seven broader meta-themes such as “Teacher Professional Competence and Technology Adoption”, “Digital and Disciplinary Literacy Development”, and “Immersive and Experiential Learning Technologies”. The model achieved its highest coherence at K = 20 (c_v = 0.4091), and the stability of the thematic structure was supported through additional runs with alternative hyperparameter configurations and expert validation. The findings show that there has been a significant increase in themes such as “Technology Integration”, “Teacher Roles in Online Learning Design”, and “Technology Acceptance and Self-Efficacy” in recent years. Temporal trend and growth analyses indicate that these themes will continue to shape the research landscape in the upcoming years. This holistic approach, which overcomes the contextual limitations of traditional bibliometric analysis, makes a significant contribution to the literature by mapping the last 25 years of scholarly accumulation in educational technology.
AtıfScopus2OpenAlex2İncele - MakaleAçık Erişim2026Scopus SJRQ2Effect of Zinc Content on the Mechanical, Corrosion, Tribological and Electrical Properties of Spark Plasma-Sintered Copper/Graphene Composites
Özkaya, Serdar; Adabaş, Yaren; Çelebi, Müslim; Karabacak, Abdullah Hasan; Çelik, Ertuğrul
Copper-based hybrid metal matrix composites reinforced with graphene and zinc were developed to achieve a balanced combination of mechanical strength, corrosion resistance, wear performance, and electrical conductivity. In this study, Cu matrix composites containing a constant graphene content of 1 wt.% and varying Zn contents (0, 5, 10, and 15 wt.%) were fabricated through mechanical alloying followed by Spark Plasma Sintering (SPS). The effects of zinc content on microstructure, densification, hardness, corrosion behavior, tribological performance, and electrical conductivity were systematically investigated. Microstructural analyses revealed that the combined use of graphene and Zn significantly influenced grain refinement, interfacial stability, and densification behavior. The composite containing 10 wt.% Zn exhibited the highest relative density (~90.5%) and maximum hardness (62 HB), indicating an optimal reinforcement level. Corrosion tests conducted in 3.5 wt.% NaCl solution demonstrated that the 10 wt.% Zn composite showed the most noble corrosion potential and the lowest corrosion current density, which was attributed to reduced porosity and improved microstructural homogeneity. Tribological results confirmed that graphene contributed to a self-lubricating effect, while Zn enhanced load-bearing capacity, leading to improved wear resistance under increasing normal loads. Electrical conductivity measurements showed a gradual decrease with increasing Zn content, mainly due to solid-solution-induced electron scattering in the Cu matrix; however, the fixed graphene addition and effective SPS consolidation helped preserve conductive pathways, allowing all composites to retain acceptable conductivity levels. The results indicate that the hybrid Cu–graphene–Zn composites exhibit a balanced combination of mechanical, corrosion, tribological, and electrical properties, with 10 wt.% Zn emerging as the optimal composition.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ2Physical and gamma-ray shielding characteristics of Copper Matrix Refractory High Entropy Alloy Reinforced Composite: an extensive experimental and computational approach
Kuluöztürk, Zehra Nur; Kuluöztürk, Muhammed Fatih; Güler, Seval Hale; Doğru, Mahmut; Güler, Ömer
Refractory High Entropy Alloys (RHEAs) have become an attractive alternative for radiation shielding applications due to their high mechanical strength, thermal resistance, structural stability, and compositional diversity. In this study, Cu-based composites containing 0–20 wt% RHEAs were prepared, and the crystal structure, morphological properties, and radiation shielding performance of the synthesized Cu-RHEA were investigated experimentally and theoretically. Measurements were performed using a NaI(Tl) detector system with point sources of 133Ba, 137Cs, 22Na and 60Co emitting gamma energies in the range of 0.356–1.333 MeV. In addition, theoretical calculations were carried out using the FLUKA and Phy-X/PSD, showing good agreement with the experimental data. Linear attenuation coefficient (LAC) values were found to decrease with increasing photon energy and to increase with increasing RHEA content. In the 0.356–1.333 MeV energy range, the experimental LAC values ranged from 0.7599 to 0.3818 cm−1 for Cu-RHEA0 and from 0.9594 to 0.4221 cm−1 for Cu-RHEA20. At 0.662 MeV, the LAC value increased from 0.5426 cm−1 for Cu-RHEA0 to 0.6183 cm−1 for Cu-RHEA20. In terms of half-value layer (HVL), the Cu-RHEA20 sample exhibited a value of 0.729 cm at 0.356 MeV, approximately 20% lower than the 0.912 cm value of Cu-RHEA0. Compared with conventional shielding materials reported in the literature, the Cu-RHEA20 sample reached a maximum mass attenuation coefficient (MAC) of 76.279 cm2⋅g−1 at 0.015 MeV, demonstrating clear superiority over ordinary concrete with a value of 7.079 cm2⋅g−1. These findings demonstrate that increasing RHEA content improves gamma-ray attenuation performance, highlighting Cu-RHEA20 as a promising next-generation shielding material.
- MakaleAçık Erişim2026Scopus SJRQ1Pomological and Biochemical Properties of Rosehip (Rosa canina L.) Genotypes
Ertugrul, Edanur; Aglar, Erdal; Ozturk, Burhan; Tekin, Onur; Alan, Davut; Ates, Umut
Rosehip (Rosa canina L.) is an important wild fruit species valued for its high nutritional and functional properties, particularly its richness in vitamin C, phenolic compounds, and antioxidant activity. Despite the widespread natural distribution of rosehip in Türkiye, many local genetic resources remain insufficiently characterized, limiting their effective utilization in breeding, conservation, and cultivation programs. The present study was conducted to evaluate the morphological, pomological, and biochemical characteristics of naturally growing rosehip genotypes in the Central District of Tunceli and to identify superior genotypes with potential for future breeding and cultivation efforts. Ten rosehip genotypes collected from natural populations at altitudes ranging from 1178 to 1256 m were evaluated for fruit and seed characteristics, fruit color, soluble solids content, titratable acidity, vitamin C, phenolic compounds, flavonoids, anthocyanins, antioxidant activity, and organic acid composition. Significant differences were observed among genotypes for all examined traits. Fruit weight ranged from 1.00 to 1.81 g, soluble solids content from 45.40% to 51.90%, titratable acidity from 1.03% to 2.77%, and vitamin C content from 235.67 to 1126.30 mg/100 g. Total phenolic content, total flavonoid content, total monomeric anthocyanin content, FRAP, and DPPH antioxidant activity values also varied significantly among genotypes. Organic acid analysis revealed considerable variation, particularly in citric and malic acid contents. Principal component analysis explained 92.4% of the total variation and grouped the genotypes into two major clusters. Based on the overall evaluation, genotypes TK2, TK5, TK9, and TK10 exhibited superior performance for several desirable traits. The results demonstrate the substantial genetic diversity present in the natural rosehip populations of Tunceli and highlight their potential value for germplasm conservation, selection breeding, and sustainable cultivation programs.
- MakaleYalnız künye2026Scopus SJRQ2Synthesis of Aminothiophene derivative complexes and electrochemical sensor application for carbofuran pesticide
Taş, Abdurrahim; İpek, Yeliz; Adiguzel, Ragip
In this study, a ligand named 2-amino-6-ethyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3‑carbonitrile (ATL), which is an aminothiophene ligand, was synthesized. ATL was used to synthesize ATL-Co(II), ATL-Cu(II), and ATL-Zn(II) complexes. The chemical structures of the complexes were elucidated by spectroscopic methods such as FT-IR, UV–visible, and LC-MS analysis, as well as TG-DTA analysis, magnetic susceptibility measurements, and elemental analysis. Finally, the electrochemical characterization of ATL and the electrochemical sensor application of its complexes was performed. In electrochemical sensor studies, a carbofuran pesticide sensor application was investigated. ATL exhibited an irreversible oxidation peak around 1.0 V. It was observed that ATL-Co(II), ATL-Cu(II), and ATL-Zn(II) complexes behaved similarly to ATL and exhibited an irreversible oxidation peak at the same potential. Carbofuran pesticide was added to the sensor medium using the standard addition method. The changes in peak current with different carbofuran concentrations constituted the data of the amperometric sensor application, and the changes in the peak potential constituted the data of the voltammetric sensor application. Linear working ranges, LOD, and LOQ values were calculated for ATL, ATL-Co(II), ATL-Cu(II), and ATL-Zn(II) complexes, separately. The widest operating range as a voltammetric sensor was achieved with the ATL: 20 μmol L−1 to 350 μmol L−1. The lowest LOD and LOQ values were achieved with the ATL-Co(II) complex for voltammetric detection as 8.8 μmol L−1 and 29.2 μmol L−1, respectively. The lowest LOD and LOQ values were achieved with the ATL-Co(II) complex as 1.6 μmol L−1 and 5.2 μmol L−1 with the amperometric technique, respectively.
- MakaleYalnız künye2026Scopus SJRQ3Analytical Solution of Discontinuous Contact Problem in Functionally Graded Layer and Homogeneous Layer
Kaya, Yusuf; Polat, Alper; Şükrü Özşahin, Talat; Bora, Pınar
In the study, the problem of discontinuous contact in two layers, one of which is functionally graded is solved using the theory of elasticity. In this problem functionally graded (FG) layer resting on homogeneous layer and loaded with two different rigid flat blocks. In addition, homogeneous layer is resting on a rigid plane. Frictions on all surfaces are neglected. The heights of the FG layer and the homogeneous layer are h1 and h2, respectively. When solving the problem, displacement and stress equations are substituted in the boundary conditions. Then the problem is demained to singular integral equations. Wherein unknown functions are the contact stresses under the two rigid flat blocks and the slope of the separation. These singular integral equations are solved numerically using the Gauss- Chebyshev integration formulas. The analyzes were performed for different inhomogeneity parameter (βh1), shear modulus ratio (μ2/μ-h1). distance between the rigid blocks ((a3-a2)/h1) and density parameter (γh1). Consequently, the stress distributions and starting and ending points of the separation area between the FG layer and homogeneous layer are determined for several dimensionless quantities.
- MakaleYalnız künye2026Scopus SJRQ1Assessment of microstructure and tribological performance of ZrO2-reinforced MAO coatings on 7075 aluminum alloy using grey relational analysis
Yıldıztaş, Mesut; Ayday, Aysun; Candan, Gökçe; Duru, Erhan; Doğan, Fatih
In this study, micro-arc oxidation (MAO) coatings containing different concentrations of ZrO2 were fabricated on 7075 Al alloy in a silicate-based electrolyte to evaluate their microstructural evolution, surface characteristics, and tribological performance. The coatings were produced at 390 V for 30 min in an electrolyte containing 10 g/L Na2SiO3 with ZrO2 additions of 0, 3, 6, and 9 g/L. Surface and cross-sectional morphologies were examined by SEM/EDS, while surface topography and wear track profiles were characterized by profilometry. Tribological behavior was evaluated under dry sliding conditions using a reciprocating tribometer. The results revealed that ZrO2 incorporation markedly influenced the coating growth behavior and surface morphology. The Zr0-MAO coating exhibited a rough and porous structure with large discharge channels, whereas the addition of ZrO2 led to a more compact and homogeneous morphology with reduced porosity. Among the coated samples, Zr6-MAO exhibited the most refined microstructure and the lowest surface roughness (Ra = 4.24 µm). This sample also showed the best tribological performance, with the lowest coefficient of friction (0.27), wear volume (0.0065 mm3), and wear rate (1.63 × 10−4 mm3/N·m). To provide a comprehensive multi-criteria assessment, grey relational analysis (GRA) was employed by simultaneously considering coating thickness, surface roughness, friction coefficient, wear volume, and wear rate. The GRA results were consistent with the experimental findings and identified Zr6-MAO as the optimum coating condition. These findings demonstrate that a moderate ZrO2 addition is highly effective in improving the compactness and wear resistance of MAO-coated 7075 Al alloy.
- MakaleYalnız künye2026Scopus SJRQ2Correlative Investigation on physical, microstructure, magnetism, and gamma-neutron attenuation properties of mechanically alloyed multifunctional (Fe/Co/Ni)Nb10V10B10 soft magnetic alloy systems
Simsek, Tuncay; Simsek, Telem; Chattopadhyay, Arun K.; Avar, Barış; Yakin, Alican; Guler, Seval Hale; Almisned, Ghada; Sen Baykal, Duygu; Tekin, H.O.
In this study, mechanically alloyed Fe70Nb10V10B10, Co70Nb10V10B10, Ni70Nb10V10B10, and (FeCoNi) 70Nb10V10B10 high-entropy alloys were successfully synthesized, and their structural, magnetic, and radiation shielding properties were systematically investigated. Structural analysis revealed that Fe favored bcc phase formation, while Co and Ni stabilized fcc structures; the equiatomic alloy resulted in a single-phase fcc solid solution with the smallest crystallite size (2.1 nm). All samples exhibited soft ferromagnetic behavior, with the Fe-based alloy achieving the highest saturation magnetization (120 emu/g), and the (FeCoNi) 70Nb10V10B10 alloy displaying the lowest coercivity. Among all compositions, Co70Nb10V10B10 demonstrated the best gamma and neutron shielding performance, showing the highest linear attenuation coefficient and fast neutron removal cross-section. The equiatomic alloy also exhibited well-balanced and stable shielding behavior. These findings position Co70Nb10V10B10 as a promising candidate for multifunctional applications requiring both efficient radiation protection and favorable magnetic properties.
AtıfScopus1İncele - MakaleYalnız künye2026Scopus SJRQ1Oxidative Polycondensation of Pyrazolone-Based Schiff Bases: Synthesis, Structural Characterization, Thermal and Electrical Properties
Solmaz, Adnan; Çakmak, Reşit; Kaya, İsmet
Schiff base derivatives, namely 3-(((2-hydroxynaphthalen-1-yl)methylene)amino)-1-phenyl-1-pyrazole-5-one (3-APPHNA) and 4-(((2-hydroxynaphthalen-1-yl)methylene)amino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3-one (4-APPHNA), were synthesized via the condensation reaction of 3-amino-1-phenyl-2-pyrazolin-5-one (3-APP) and 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one, (4-APP) with 2-hydroxynaphthaldehyde (2-HNA) in ethanol. Synthesized monomers were then converted into their oligomeric derivatives via oxidative polycondensation carried out using NaOCl. The structural, thermal, optical, electrochemical, and morphological properties of the obtained monomers were comprehensively characterized using fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H-NMR), carbon-13 nuclear magnetic resonance (13C-NMR), ultraviolet-visible spectrophotometer (UV–vis), thermogravimetry-derivative thermogravimetry (TG-DTG), and cyclic voltammetric analyses. Spectroscopic studies confirmed the successful synthesis of Schiff bases and the presence of stable azomethine bonds. Molecular weight, glass transition temperature, and surface morphologies of oligomers were determined by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and field emission scanning electron microscope (FE-SEM) measurements, respectively. The Mn values of oligo(3-APPHNA) and oligo(4-APPHNA) were found to be 3400 and 2900 Da, respectively. The results revealed an oxidative oligomerization process yielding relatively narrow molecular weight distributions. Oligo(4-APPHNA) has shown more pronounced semiconductor properties compared to other oligomers, considering its 2.30 eV optical band gap and frequency-dependent electrical behavior. Additionally, dielectric measurements showed that oligo(4-APPHNA) exhibited higher dielectric constant, dielectric loss, and AC conductivity values throughout the investigated frequency range. These findings suggest that the synthesized oligomers are promising candidate materials for future optoelectronic and semiconductor applications, but further research at the device level is needed.
- MakaleAçık Erişim2026Scopus SJRQ1The Role of Graphene on Microstructural, Mechanical, and Tribological Properties of Cu–AlCrFeCuNi Metal Matrix Composites Fabricated via Spark Plasma Sintering
Yanar, Harun; Çelebİ, Müslİm; Sekban, Dursun Murat; Özkaya, Serdar; Karabacak, Abdullah Hasan; Çelİk, Ertuğrul
In this study, Cu-based AlCrFeCuNi high-entropy alloy (HEA) composites reinforced with graphene were fabricated using a mechanical-alloying-assisted spark plasma sintering (SPS) technique. The HEA reinforcement content was kept constant at 20 wt pct for all samples, while the graphene content was varied at 0, 0.5, 1.0, and 2.0 wt pct to investigate its influence on the microstructure, hardness, and tribological performance. The results indicate that both the HEA particles and graphene exhibit an almost homogeneous distribution within the matrix; however, increasing graphene content led to noticeable graphene accumulation along grain boundaries. With higher graphene fractions, the relative density decreased from 97.51 to 94.92 pct, whereas the hardness increased up to the 1.0 wt pct graphene addition, reaching 134.16 HB, followed by a slight decrease to 129.25 HB at 2.0 wt pct. Furthermore, graphene reinforcement significantly improved the tribological behavior of the composites, providing a substantial reduction in wear. The addition of graphene significantly decreased the coefficient of friction from about ~ 0.70 in the Cu–HEA alloy to 0.08 at 2.0 wt pct graphene. Graphene also suppressed the pronounced frictional fluctuations observed in the base alloy, leading to a much more stable sliding behavior. As a result, wear loss was reduced by nearly 99 pct, primarily due to the formation of a continuous lubricating tribofilm on the contact surface.
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