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Koleksiyondaki öğeler
- MakaleAçık Erişim2026Scopus SJRQ1A smartphone-based vibration dataset for induction motor fault diagnosis under different speed and load conditions
Ertarğın, Merve; Orhan, Ahmet; Yıldırım, Özal; Chauhan, Sumika; Vashishtha, Govind
Induction motors are foundational components across industrial applications, valued for their inherent robustness, operational simplicity, and cost-efficiency. Maintaining their reliable function is paramount for a wide range of mechanical and electrical systems. However, they are prone to various mechanical and electrical faults, such as bearing defects, rotor issues, and voltage imbalances, which can significantly impair their performance and reliability. This study presents a novel vibration dataset for induction motor fault diagnosis, uniquely acquired using a smartphone-based inertial sensor rather than conventional industrial accelerometers. Vibration signals were recorded along three orthogonal axes (gx, gy, gz), alongside gravity-compensated acceleration components (guserx, gusery, guserz), enabling detailed analysis of both raw and gravity-free vibration characteristics. Data were collected under diverse conditions, including healthy operation and several fault types, across varying rotational speeds and load states. The dataset features long-duration vibration recordings sampled at 100 Hz, suitable for both time-domain analysis and window-based feature extraction. Its inclusion of multiple operating speeds and load conditions is ideal for studying the impact of operational variability on fault signatures. By leveraging low-cost and readily accessible smartphone sensors, this dataset supports practical and accessible vibration data acquisition for supporting the development, benchmarking, and validation of data-driven fault diagnosis methods. This resource is expected to significantly advance research in condition monitoring of induction motor, particularly for machine learning and signal processing applications using vibration data.
- MakaleYalnız künye2025Scopus SJRQ2Nanoarchitectonics and radiation mitigation in Sm2O3-doped lithium borotellurite glass systems: From amorphous harmony to localized order
Kilic, G.; Durmus, Hasan; Birdogan, Selçuk; Ilik, E.; Perişanoğlu, Esra Kavaz; Saltık, Sevda; Guler, Ömer; ALMisned, Ghada; Tekin, H.O.
In this study, a novel series of nano-Sm2O3-doped lithium borotellurite glasses was synthesized and systematically investigated in terms of their structural, physical, and radiation shielding characteristics. X-ray diffraction confirmed the amorphous nature of all samples, while transmission electron microscopy revealed progressive nanoarchitectural refinement and particle growth with increasing Sm2O3 content, from uniformly dispersed nanodomains to dense agglomerates exhibiting short-range crystalline ordering. Energy-dispersive X-ray spectroscopy and elemental mapping validated the homogeneous incorporation of boron, oxygen, tellurium, and samarium throughout the glass matrix without phase separation. Gamma-ray shielding evaluations showed enhanced mass attenuation coefficients and reduced half-value layers, particularly in the Sm(n)8 sample, with significant performance gains at lower photon energies. Neutron shielding assessments further indicated elevated macroscopic removal cross-section values and dose attenuation, affirming the compositional benefit of Sm2O3 for fast neutron mitigation. It can be concluded that nano-Sm2O3 incorporation would play a multifunctional role on structural and radioprotective properties in addition to morphostructural features of lithium borotellurite glasses.
AtıfScopus5OpenAlex6
İncele - MakaleAçık Erişim2025Scopus SJRQ1Automated fault classification of asynchronous motor using mobile phone accelerometer and Parallel Residual CNN-GRU
Ertargin, Merve; Orhan, Ahmet; Yildirim, Ozal; Gurgenc, Turan
In this study, a fault detection system that classifies motor faults using deep learning without requiring any sensor connections inside or on the motor setup is proposed. The focus is on the electrical and mechanical faults of asynchronous motors, which are widely used in the industry. A mobile application developed using Flutter can collect vibration data using the three-axis accelerometer sensor in smartphones. By placing a smartphone with the application installed on the motor for which fault detection is desired, vibration data on three axes (x, y, z) is collected to train deep models. Subsequently, test data is used to identify the fault status and class of the electric motor. Different conditions and scenarios were created to test the adequacy of smartphone accelerometer sensors in detecting motor faults. Fault classification with vibration data obtained under different motor operating speeds in loaded and unloaded conditions achieved accuracy rates of over 99%.
AtıfScopus18OpenAlex15İncele - MakaleYalnız künye2026Scopus SJRQ2Adsorption of Reactive Red 120 dye from aqueous solutions using sepiolite clay with a channel-structured morphology: Mechanism, kinetics, isotherm, and thermodynamic studies
Fırat, Tülay
The effective treatment of dye-containing wastewater remains a major environmental challenge due to the high stability and solubility of reactive dyes. In this study, the adsorption behavior of Reactive Red 120 (RR120), an anionic reactive azo dye, from aqueous solutions was investigated using natural sepiolite clay possessing a channel-structured morphology. Batch adsorption experiments were performed to evaluate the effects of contact time (1–200 min), initial dye concentration (50–500 mg L−1), adsorbent dosage (0.1–1.5 g), solution pH (2–10), and temperature (25–50°C). The adsorption equilibrium was reached within approximately 75 min. The Langmuir isotherm provided the best fit to the equilibrium data, yielding a maximum monolayer adsorption capacity of 168.4 mg g−1 at 298 K. Thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic, with an activation energy of 32.41 kJ mol−1. Adsorption kinetics were analyzed using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, while equilibrium data were evaluated using Langmuir, Freundlich, and Temkin isotherm models. The kinetic data were best described by the pseudo-second-order model, while thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic. FTIR and XRD analyses further supported the important role of the channel-structured framework of sepiolite in RR120 adsorption. Unlike many clay-based adsorbents that require chemical modification, natural sepiolite exhibited high adsorption performance due to its intrinsic fibrous morphology, nano-channel structure, and high surface area. These findings demonstrate that natural sepiolite is a promising, low-cost, and sustainable adsorbent for the treatment of dye-contaminated wastewater.
- BildiriYalnız künye2026LLM Based Software Test Scenario Generation System From Bug Descriptions
Gundem, Merve Yilmazer; Karakose, Mehmet
Large, user-interactive software systems require extensive software testing for safe deployment. Manually generated test cases by software testers require extensive time and effort, and their scope remains limited. In this study, a system based on LLM is proposed for automatic test cases and test steps generation from bug descriptions. In the proposed system, bug descriptions were first collected from the Defects4J Dataset. Keywords relevant to the bug scope were extracted from the descriptions. Structured automatic prompts were generated from the extracted keywords. The generated prompts were fed into the LLM as input, and software test cases appropriate for the bugs were generated. The method was evaluated on actual bug descriptions by comparing it to a general (baseline) prompt. Experimental results show that the lengths of the generated scenarios are similar, but the proposed method increases the keyword match rate with error descriptions to an average of 89 %. The findings reveal that keyword-driven prompts are effective in generating more reliable and error-specific test scenarios without requiring additional data.
- MakaleYalnız künye2025Scopus SJRQ2Investigation of Mechanical Properties of Jute and Tea Waste-Reinforced Epoxy Composite Material Produced by Vacuum Assisted Resin Infusion Molding
Dogan, Akar; Mahmat, Aybars; Agar, Salih
Recently, the production of materials obtained from plant sources has been increasing due to their environmentally friendly and sustainable sources. Natural fibers and waste materials offer a remarkable alternative in composite production due to their biodegradability, low cost and renewability. In this study, composite materials were produced using hybrid Jute and industrial tea waste-reinforced epoxy materials by vacuum assisted resin infusion molding. In this context, the reason for using natural and industrial resources such as jute fiber and tea waste is to contribute to both the improvement of mechanical properties and the reduction of environmental impacts. It was observed that tensile and flexural strength decreased as the amount of tea waste increased. Conversely, the energy absorbed during the quasi-static punch shear and Charpy impact tests increased, unlike the tensile and flexural strength. Approximately 50% decrease was observed in the tensile strength of the 60% tea waste reinforced material compared to the pure jute composite material. In Charpy impact and quasi-static punch shear tests, a 5% increase in the energy absorbed in the 60% tea waste reinforced composite materials was obtained.
AtıfScopus2WoS1OpenAlex1İncele - Derleme MakaleYalnız künye2025Scopus SJRQ2A critical review of the refractory high-entropy materials: RHEA alloys, composites, ceramics, additively manufactured RHEA alloys
Guler, Seval Hale; Yakin, Alican; Guler, Omer; Chattopadhyay, Arun K.; Simsek, Tuncay
In this study, the traits, production methods, and applications of refractory high-entropy materials—including refractory high-entropy alloys (RHEAs), refractory high-entropy composites (RHE-Cs), and refractory high-entropy ceramics (RHE-Ce)—which are part of the broader category of refractory high-entropy materials with a wide range of applications, have been thoroughly examined and discussed. RHEAs have emerged as materials that exhibit superior properties, such as high melting temperatures, excellent temperature resistance, and high wear and corrosion resilience, in addition to high mechanical and fatigue strength. These attributes have made them extensively studied materials in recent times. The properties of RHEAs suggest their safe operation in challenging environments such as nuclear reactors, gas turbines, aerospace, and energy production. Among refractory materials, RHE-Cs stand out for their high strength and low density, showing significant potential for use in the automotive, aerospace, and space industries. Another group with a wide range of applications, RHE-Ce materials, is distinguished by their high-temperature resilience, high hardness, and low thermal conductivity, making them suitable for high-temperature environments. Refractory materials are generally fabricated using traditional techniques such as arc melting, powder metallurgy, and magnetron sputtering. In this study, along with traditional production methods, additive manufacturing techniques which have revolutionized the manufacturing field are discussed concerning their applications in refractory material production. Additive manufacturing methods enable the achievement of high temperatures and the production of homogeneous, single-phase solid solutions, making them suitable for fabricating refractory materials with high melting points.
AtıfScopus37WoS35OpenAlex41İncele - MakaleAçık Erişim2026Scopus SJRQ1The mediating role of problem solving in the relationship between emotional intelligence and mental well-being
Erdoğan, Ramazan; Özcan, Büşra; Kızar, Oktay; Kızılkoca, Mustafa; Çalışır, İrem Kaptangil; Bozkurt, Eyüp; Uğurlu, Fatih Mehmet; Tan, Suriye; Koçal, Meryem
Background: This study aims to examine the relationship between emotional intelligence and mental well-being among university students and to reveal the mediating role of problem-solving skills in this relationship. Methods: Of these students, 707 participated, and the Emotional Intelligence Trait Scale, the Warwick-Edinburgh Psychological Well-being Scale, and the Problem-Solving Inventory were used as data collection tools. The SPSS software was used for data analysis. Results: Emotional intelligence appears to have a significant effect on mental well-being, and emotional intelligence directly significantly predicts problem-solving skills, but mental well-being does not have a significant effect on problem-solving skills. Emotional intelligence appears to have a direct effect on problem-solving, and mental well-being mediates this effect. The explanatory power of the model is moderate in terms of the role of emotional intelligence in predicting mental well-being and more limited in terms of its role in predicting problem-solving skills. Conclusion: In conclusion, emotional intelligence strengthens individuals’ mental well-being and directly positively impacts their problem-solving skills. However, mental well-being does not play a mediating role in the problem-solving process. This suggests that the direct effect of emotional intelligence is primary in improving problem-solving skills, and mental well-being does not serve as a decisive mediating factor in this process. Therefore, interventions aimed at strengthening emotional intelligence can be effective both in enhancing individuals’ mental well-being and in directly supporting problem-solving skills.
- MakaleYalnız künye2026Scopus SJRQ3A new lectin from Amanita vaginata mushroom with potent anti-inflammatory activity
Seliman, Thoiba Mogahid Hussein; Ozsoy, Nurten; Altiparmak-Ulbegi, Gulsum; Alp-Kavlo, Hevidar; Arcan, Gulsah Gamze; Akev, Nuriye; Can, Ayse; Aksoy-Sagirli, Pinar
This study used 80% ammonium sulphate fractional precipitation, followed by affinity chromatography to purify a new lectin (AVL) from the crude extract of the Amanita vaginata mushroom. The purification procedure achieved a 20% yield, a specific activity of 5120 HU/mg protein, and a 16-fold increase in purity. SDS-PAGE analysis showed a single band of 45 kDa. We assessed AVL's anti-inflammatory effect by measuring levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), induced by lipopolysaccharide (LPS), in RAW 264.7 macrophages. Western blot analysis showed that iNOS and COX-2 protein levels were barely detectable in the control groups, but markedly elevated in the LPS-treated groups. However, AVL treatment significantly inhibited the expression of both iNOS and COX-2 in LPS-stimulated cells. This effect was dose-dependent. These findings suggest that AVL's anti-inflammatory effects are mediated through the suppression of iNOS and COX-2 expression.
AtıfScopus2WoS1OpenAlex2
İncele - MakaleAçık Erişim2025Scopus SJRQ1Pomological and Biochemical Properties of Blackberry (Rubus fruticocus) Genotypes
Dogan, Hande; Aglar, Erdal; Ozturk, Burhan; Tekin, Onur; Alan, Davut; Sumbul, Ahmet
The aim of this study was to examine the genotypes of wild blackberries growing naturally in Tunceli province in terms of fruit characteristics and to determine the ones with superior characteristics. Nine different genotypes were determined by population screening and 100 fruits were collected from each genotype. The physical properties such as fruit weight, length, width, as well as color, chemical content, and antioxidant properties were examined. Statistically significant differences were found among the genotypes; fruit weight, length, and width varied between 0.71 and 1.19 g, 10.08 and 12.63 mm, and 12.25 and 14.33 mm, respectively. The G9 genotype had the largest fruits, and the G6 genotype had the smallest fruits. In fruit color analyses, significant differences were observed among the genotypes, and the G2 genotype stood out with the highest L* value (20.05), but G9 had the lowest a* value (0.92). Total soluble solids (TSS) content varied between 11.95% in G2 and 21.10% in G7. Vitamin C content was highest in the G6 genotype (54.46 mg 100 g−1), while G9 had the lowest vitamin C content (22.66 mg 100 g−1). Significant differences were also observed among the genotypes in terms of phenolic content, flavonoids, anthocyanins, and antioxidant activity. As a result, in this study, significant differences in organic acid contents were determined among wild blackberry genotypes in Tunceli province. The G1 genotype was the richest in malic acid, while the G6 was the genotype with the highest ascorbic acid level. Various differences were also found among the genotypes in terms of oxalic acid, citric acid, and other organic acid contents. These findings may constitute an important resource in determining the commercial production and potential health benefits of wild blackberries. In the selection of blackberry genotypes, consideration of these organic acid contents is important, especially in terms of taste and nutritional value.
AtıfScopus3OpenAlex1İncele - MakaleAçık Erişim2025Municipal Solid Waste Landfill Site Selection: Integrating Multi-Criteria Decision-Making Methods and Mathematical Modelling-A Case Study
Derse, Onur; Polat, Elifcan Göçmen
Increasing solid waste amount arisen from the urbanization and population growth is an inevitable outcome in many countries. Solid waste has become one of the serious environmental problems and peculiar solid waste pathways are required to prevent contamination of environment. The optimal planning of the waste management should comprise the operations such as minimization, collection, landfilling and recycling of the waste. Also, location selection for landfill of municipal solid waste (MSW) is an effective step even essential, due to growing area shortage for waste disposal. In this respect, landfilling of MSW has been addressed in Tunceli, Turkey using an integrated approach. The Fuzzy Analytical Hierarchy Process (Fuzzy-AHP), a multi-criteria decision-making (MCDM) method, is utilized to decide the weights of the environmental, technical, economic, and social criteria regarding uncertainty. Then, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is conducted to rank the alternative landfill districts. Finally, the sub locations of selected district are mathematical modelled regarding transport cost, investment cost and demand with an integer linear programming model. The computational results indicate the proposed method effectiveness with a systematic approach by integrating MCDM and mathematical modelling.
AtıfScopus2OpenAlex3TR Dizin1
İncele - MakaleYalnız künye2026Scopus SJRQ2Influence of infill design on mechanical behavior of PLA-TPU hybrid sandwich beams
Arikan, Volkan; Dogan, Akar; Guler, Serkan
The purpose of this work is to analyze the mechanical behavior of hybrid sandwich beams that were printed using the Fused Deposition Modelling (FDM) technology. These beams were made of Polylactic Acid (PLA) and Thermoplastic Polyurethane (TPU) materials. Standard mechanical tests (ASTM C393 and C365) were utilized in order to assess the impact that several infill patterns (Cubic, Octet, and Trihexagonal) and infill densities (ranging from 15% to 40%) had on the flexural and compression performance of the material. According to the findings, trihexagonal patterns demonstrated improved energy absorption capabilities when subjected to compression, but octet designs offered superior flexural stiffness, particularly in hybrid constructions. According to the findings of tests conducted with hybrid constructions consisting of a TPU core and a PLA surface layer, the effect of infill patterns on component strength is directly influenced by the change in the material character, and it is possible that various materials would exhibit different manifestations of this effect. These findings offer useful information that may be used to optimize lattice geometry and hybridization procedures for the purpose of developing high-performance lightweight structures for engineering applications.
AtıfWoS1OpenAlex2İncele - MakaleAçık Erişim2026Scopus SJRQ1Deep learning-based detection of bowel sound events in continuous recordings
Çelik, Yusuf
Accurate identification of bowel sound events is essential for the long-term and non-invasive monitoring of gastrointestinal activity. In this study, we present a band-aware multi-band deep learning approach that explicitly accounts for the distinct acoustic characteristics of bowel sounds across different frequency ranges by jointly analyzing low- and high-frequency components. The proposed method operates on time–frequency representations extracted from continuous recordings to produce frame-level bowel sound probabilities, which are subsequently integrated into recording-level decisions through a unified decision-making strategy. Despite the pronounced class imbalance in the dataset, the proposed system achieved accuracy levels exceeding 98% at the frame level and 99% at the recording level, yielding stable and consistent outcomes through probability aggregation and temporal smoothing steps. These results indicate that the proposed approach provides a reliable and well-structured framework for bowel sound event detection and establishes a solid methodological basis for the analysis of long-duration recordings.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ1One-pot synthesis of quercetin-functionalized silver and copper nanoparticles for enhanced optical, antimicrobial, and computational properties
Aziz, Dara Muhammed; Amin, Alla Ahmed Muhammed; Hassan, Sangar Ali; Özmen, Habibe; INCILI, Gökhan Kursad; Say, Yakup
The emergence of multidrug-resistant bacterial strains has intensified the need for novel antimicrobial agents. Herein, we report a facile one-pot green synthesis of quercetin-stabilized silver (Qn@AgNPs) and copper (Qn@CuNPs) nanoparticles using quercetin as both reductant and capping ligand. The resulting nanocomposites were fully characterized by UV–Vis spectroscopy (surface plasmon resonance peaks at 420 nm for Ag and 580 nm for Cu), FTIR (confirming quercetin–metal coordination), SEM/EDX (spherical particles, and XRD (face-centered cubic Ag and Cu phases). Density functional theory (B3LYP/3-21G) calculations yielded frontier molecular orbital gaps of 0.164 eV for Qn@AgNPs and 0.245 eV for Qn@CuNPs, with corresponding high softness values (12.20 and 8.16 eV⁻¹), indicating enhanced electron-transfer propensity. Molecular electrostatic potential maps revealed increased charge polarization around the metal centers. Antibacterial assays against Escherichia coli and Staphylococcus aureus demonstrated minimum inhibitory concentrations of 2.11 ± 1.22 µg/mL and 4.69 ± 2.68 µg/mL for Qn@AgNPs, and 7.50 ± 0.00 µg/mL and 6.25 ± 0.17 µg/mL for Qn@CuNPs, significantly outperforming free quercetin (188 and 375 µg/mL). In silico docking against the S. epidermidis TcaR regulator (PDB: 1KZN) and E. coli DNA gyrase B (PDB: 1HSK) revealed strong binding affinities (–7.54 to − 10.15 kcal·mol⁻¹), consistent with the observed antimicrobial potency. This integrated experimental–computational study elucidates the mechanistic underpinnings of quercetin-mediated nanoparticle bioactivity and provides a rational framework for designing next-generation flavonoid-functionalized metal nanotherapeutics.
AtıfScopus12WoS11OpenAlex14İncele - MakaleAçık Erişim2026Scopus SJRQ1Comparative effects of La2O3 and Sm2O3 on structural and radiation shielding properties of WO3 enriched borate glassy-ceramics
Taşgın, Yahya; Yılmaz, Demet; Kanca, M. Sait; Yayla, Nihal; Kök, Mediha; Güler, Ömer
This research comprehensively investigates the impact of incorporating rare earth oxides ‑samarium oxide (Sm2O3) and lanthanum oxide (La2O3)- into a borate glassy-ceramic system enriched with tungsten oxide (WO3), with a focus on both structural characteristics and radiation shielding performance. SEM-EDS, elemental mapping, and XRD analyses conducted on the synthesized glassy-ceramic samples revealed that the incorporated rare earth oxides, Sm2O3 and La2O3, were uniformly distributed throughout the glassy-ceramic matrix. The results also confirmed that the glassy-ceramic retained its inherently amorphous structure. Moreover, the nominal doping levels of the rare earth elements were found to be in agreement with both the qualitative and quantitative results obtained from EDS measurements. Also, the gamma ray shielding parameters of synthesized glassy-ceramic samples were measured in absorption geometry with Am-241, Ba-133 and Ra-226 radioactive sources. The neutron shielding parameters were theoretically calculated. The 241Am-Be fast neutron source was used to measure the equivalent dose of neutron absorption. At an incident photon energy of 74.8 keV, the mass attenuation coefficient of the tungsten oxide–enriched borate glassy-ceramic exhibited a remarkable improvement—rising by 17.98 % with the addition of 3 wt% Sm2O3 and by 11.58 % with the addition of 3 wt% La2O3. Notably, the N4 sample demonstrated a significant reduction in neutron-equivalent dose rate, reaching 19.80 % (μSv/h). The lead equivalent thicknesses (Pbeq) calculated at 356 keV were 0.02397 cmPb for N0, 0.0391 cmPb for N1, 0.0403 cmPb for N4, and 0.0389 cmPb for N7. When benchmarked against the undoped N0 sample, the N4 and N7 compositions exhibited reductions in Pbeq values by approximately 68 % and 62 %, respectively, indicating a marked improvement in gamma shielding efficiency. Among all tested formulations, the Sm2O3-doped variant demonstrated superior gamma-ray attenuation capability relative to the La2O3-doped glassy-ceramic. Furthermore, the N4 sample achieved an impressive thermal neutron attenuation rate of 96.46 %, underscoring its strong potential as an effective dual-purpose shielding material against both thermal neutrons and ionizing gamma radiation.
AtıfScopus1İncele - MakaleYalnız künye2025Scopus SJRQ2Enhanced gastrointestinal disease classification using a convvit hybrid model on endoscopic images
Utku, Anıl
Endoscopy is a procedure that allows examination of the gastrointestinal system, including the stomach, esophagus, large intestine, and duodenum, with the help of an endoscope. Processing of endoscopic images is important for early detection and treatment of gastrointestinal diseases. In this study, hybrid ConvViT was developed using CNN and ViT to increase the classification accuracy of pathologies in gastrointestinal endoscopic images. CNNs are well-suited for capturing local spatial features through hierarchical convolutions, making them highly effective in detecting fine-grained textures and edge patterns. These capabilities complement the ViT’s global attention mechanism, which excels at modeling long-range dependencies in images. The motivation of this study is to increase the classification accuracy and reliability with the ConvViT model, which was developed by combining the practical features of CNN and ViT models, which are individually successful in different aspects of image processing. The ConvViT model was compared with VGG-16, ResNet-50, Inception-V3 and ViT. Comparable models were tested using a gastrointestinal endoscopic image dataset containing ulcers, polyps, inflammation, bleeding, and regular anatomical features. Experiments showed that ConvViT had better prediction performance than compared models, with 95.87% classification accuracy.
AtıfScopus5WoS2OpenAlex2İncele - MakaleAçık Erişim2026Scopus SJRQ1Effect of Y2O3 rare earth oxide on the microstructure and growth kinetics of TiO2-based ceramic coatings fabricated by micro arc oxidation
Ayday, Aysun; Duru, Erhan; Kırsever, Derya; Doğan, Fatih
This study investigates the influence of Y2O3 addition on the microstructure, growth kinetics, and mechanical properties of TiO2-based ceramic coatings formed on Ti–6Al–4V alloy through the Micro Arc Oxidation (MAO) process. The experiments were carried out using Ti–6Al–4V plates coated in silicate-based electrolytes, with and without 1 g/L Y2O3, under a constant current density of 5 A/dm2 and a voltage of 360 ± 20 V for different treatment times (1, 3, 7, and 10 min). The coatings were evaluated by weight gain measurements, SEM/EDS analyses, X-ray diffraction (XRD), and constant load scratch testing supported by profilometry. Results revealed that Y2O3 significantly accelerated coating growth during the initial stages, leading to higher weight gains and denser, less porous morphologies compared to Y2O3-free coatings. XRD analysis indicated amorphous TiO2 and anatase phases at short durations, while rutile formation became dominant with longer treatments. Kinetic modeling demonstrated that both coatings initially followed a linear reaction-controlled mechanism (n ≈ 1), with calculated growth constants of 3.44 × 10⁻4 mg/mm2·s for Ti-MAO and 7.45 × 10⁻4 mg/mm2 s for Ti–Y2O3–MAO. However, after approximately 420 s, the Y2O3 coatings exhibited a marked reduction in growth rate due to electrical insulation effects of the thickened ceramic layer, resulting in multi-stage kinetics. Constant load scratch testing showed that Y2O3 incorporation reduced groove depth and width by nearly 45%, improving adhesion strength and mechanical durability. These findings confirm that rare-earth oxide addition is an effective strategy for enhancing the performance of MAO coatings on titanium alloys.
AtıfScopus2WoS1OpenAlex2İncele - MakaleAçık Erişim2026Scopus SJRQ3Changes in common carp (Cyprinus carpio) sperm quality and membrane lipid composition related to cryopreservation by Tribulus terrestris; [Alterações na qualidade do esperma e na composição lipídica da membrana da carpa comum (Cyprinus carpio) relacionadas à criopreservação por Tribulus terrestris]
Ölçülü, Abdullatif; Özçiçek, Esin; Kocabaş, Filiz Kutluyer; Kocabaş, Mehmet; Kızak, Volkan; Yilmaz, Ökkeş
Docosahexaenoic acid (DHA) was the major polyunsaturated fatty acid (PUFA) in the sperm plasma membrane, and the levels of PUFAs decreased in treated groups during the cryopreservation process. The supplementation of TT (Tribulus terrestris) to Cyprinus carpio sperm at 200 µg∙L-1 positively affected the maintenance of motility parameters and FAs levels after the freeze-thaw cycle, and TT can be used as an herbal medicine instead of synthetic pharmaceuticals to improve the productive performance in aquaculture.
- MakaleAçık Erişim2025Scopus SJRQ1The contagion effect of the FTX cryptocurrency exchange's crash on the stock markets
Gençyürek, Ahmet Galip
The cryptocurrency market is very attractive for investors, but it has experienced several major crises in recent years due to its inadequacies with regard to transparency and auditing. The FTX cryptocurrency exchange's crash was one of the most crucial events for the cryptocurrency market. Therefore, I investigate the contagion impact of the FTX crash on stock markets (S&P 500, TSX, FTSE100, BIST100, SENSEX, SSE, NIKKEI 225, KOSPI 100 and ASX 200), using a time-varying parameter–vector autoregression (TVP-VAR) extended joint connectedness model and covolatility, cokurtosis, and coskewness tests. The empirical findings, based on a daily dataset for the period 2021–2023, indicate that the FTX collapse had a clear contagion impact solely on the BIST 100. One possible explanation for this is that Turkish investors who suffered losses on their FTX investment sought to compensate for their diminishing wealth, especially to meet margin calls, by liquidating their holdings in the BIST 100. Another possible explanation is the inherent fragility of the BIST 100, which prevents it from being perceived as a safe-haven asset during turbulent periods. The findings can help policy makers and investors develop policies and strategies to defend against the contagion impact of cryptocurrencies.
AtıfScopus2OpenAlex1İncele - MakaleYalnız künye2026Scopus SJRQ3H-SEMI-SYMMETRY IN KÄHLER MANIFOLDS AND APPLICATIONS TO COMPLEX CONTACT MANIFOLDS
Ünal, İnan
Complex manifolds include different subclasses, and one of the most significant ones is the class of Kähler manifolds. These types of manifolds have valuable curvature properties that are related to almost complex structures. For this study, we focused on Kähler manifolds having semi-symmetry conditions associated with H-curvature tensors. Another important subclass is of IK-normal complex contact metric man-ifolds, which are complex manifolds with a contact structure. Since the complex structure of this type of manifold is Kähler, it has important ap-plications. In the last section, we used the results obtained for a Kähler manifold to an IK-normal complex contact metric manifold.
