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Koleksiyondaki öğeler
- MakaleAçık Erişim2025Scopus SJRQ2Design and Fabrication of Multi-Magnetron Microwave Oven for High-Temperature Applications
Özmen, Ahmet; Coşkun, Aykut; Ertuğrul, Mehmet
This article examines the design, manufacture, and performance of multi-magnetron ovens capable of reaching high temperatures. Firstly, an appropriate waveguide was simulated, and the production process was completed. Then, the proposed designs for multi-magnetron ovens were simulated, and appropriate dimensions were suggested. It was reported that the average power density (PD) value of the produced multi-magnetron oven was 0.37 mW/cm², which indicates its performance and efficiency. This value was found to be compliant with standards and safe for human use. The main objective of our study was to demonstrate that waveguides can reach high temperatures at the center of the oven without affecting each other. In this context, it was observed that the temperature created by magnetrons operating in single, double, triple, and quadruple modes gradually increased at the center of the oven. The simulation results supporting this showed that the S21 parameter was-177 dB. The design proposed and applied in our study was efficient, easy to produce, safe for human use, low cost, and usable in commercial and academic studies for reaching high temperatures. Overall, the multi-magnetron oven design proved to be a successful and practical solution for applications requiring high temperatures, showcasing its potential for both industrial and research purposes. The findings of this study contribute valuable insights into the development of advanced heating technologies, demonstrating significant improvements in efficiency and safety for high-temperature applications.
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İncele - MakaleAçık Erişim2026Scopus SJRQ3The relationship between cultural tourism and transportation: A global perspective
Durmuş, İbrahim
The importance of tourism and cultural values for countries, regions, or areas is increasing day by day. Cultural tourism includes many activities with a wide scope. Transportation, on the other hand, is a factor that directs tourists' choices in terms of tourism, providing access to the areas they have visited or will visit. The research aims to reveal the factors affecting the relationship between cultural tourism and transportation. For this purpose, the focus is on cultural tourism and transportation research in the WoS database. The bibliometric analysis method was used in the application. Important inferences were obtained by evaluating 433 studies in the literature. As a result of the analysis, authors who have conducted intensive research on the subject, publication production amounts, efficiencies, organizations, citations, highlighted keywords, changes over time, trends, co-occurrence networks, thematic maps, and thematic developments are included. In their research, the authors frequently emphasized the words tourism, sustainable tourism, development, transportation, China, cultural tourism, rural tourism, sustainable development, accessibility, and sustainable. The results reveal that sustainability and accessibility are effective factors in cultural tourism and transportation. The study shows that in the network of relationships, tourism, heritage, accessibility, transport, cultural tourism, management, and cultural heritage have strong connections. The findings indicate that in the relationship between cultural tourism and transportation, accessibility, management mechanisms, and cultural heritage values are highly influential. Regarding centrality and density, rural tourism, tourism development, sustainable and ecological tourism, Mexico, rural development, colonialism, competitiveness, Istanbul, and renewable energy demonstrate strong relationships. These results show that rural development, competitiveness, and colonialism play a significant role in the relationship between cultural tourism and transportation. Regarding Türkiye, Istanbul's central and dense network of relationships has been influenced by its accessible location and tourism potential. The results provide a unique and different perspective on the literature.
- MakaleAçık Erişim2026Scopus SJRQ1The effect of cognitive strategy instruction enriched with active learning techniques on word problem-solving skills of students with learning disabilities
Filiz, Tunahan
This study aimed to investigate the effectiveness of cognitive strategy instruction (CSI) enriched with active learning (AL) techniques in teaching word problem solving to primary school students with learning disabilities, as well as to examine the overall instructional process. Word problem solving is the process of using contextual information from real-life or fictional situations to develop mathematical solutions. The research was designed with an embedded mixed-method model. The quantitative phase included 30 third-grade students with learning disabilities, while the qualitative phase involved six randomly selected students from the experimental group. Quantitative analyses revealed that students in the experimental group showed significantly higher achievement in problem-solving tests, indicating the positive impact of CSI enriched with AL techniques. Qualitative findings highlighted increased class participation, enhanced collaboration, and more positive attitudes toward mathematics. Furthermore, teacher and peer interactions supported the problem-solving process, and the use of tools promoting mathematical thinking strengthened performance. The results demonstrated that CSI enriched with AL techniques encouraged strategic thinking and the generation of alternative solutions in word problem solving. The study, limited to three learning outcomes within the third-grade mathematics curriculum in Turkey, suggests that teachers should adapt and implement such instructional approaches across other mathematical domains, given the students’ positive experiences and outcomes.
- MakaleAçık Erişim2025Scopus SJRQ1Artificial neural network modelling of reactive red 45 Azo dye removal by peroxi-electrocoagulation
Bayar, S.; Erdoğan, M.; Taşdemir, A.; Kaleli, A.; Paloluoglu, C.
In the present study, the Peroxi-electrocoagulation process was employed to remove chemical oxygen demand and the decolorization of reactive red 45 dye wastewater. This process offers several advantages, including the oxidation of dye molecules by hydroxyl radicals and coagulation through iron hydroxide precipitation. The reactor was equipped with six iron electrodes, providing a total surface area of 546 cm2. The effects of applied current (0.3–0.18 A), hydrogen peroxide concentration (100–700 mg/L), initial pH (2.5–5.0), and dye concentration (100–500 mg/L) on chemical oxygen demand and color removal were investigated. Optimum operational conditions were determined to be applied current of 0.150 (corresponding to current density of 0.27 mA/cm2), pH of 3.0, H2O2 concentration of 600 mg/L, and dye concentration of 200 mg/L. Under these conditions, COD and color efficiencies reached 83% and > 99%, respectively. The specific energy consumption under optimal conditions was 33.4 kWh/kg COD with 82.8% COD removal. The findings indicate that increasing the applied current and H2O2 concentration enhances removal performance up to a certain threshold, beyond which no significant improvement is observed. This suggests that the availability of electrogenerated reagents governs the overall reaction efficiency. Additionally, an artificial neural network model was developed to predict COD and color removal efficiencies. The network employed a 4:10:2 architecture and was trained using a backpropagation algorithm. Input variables included applied current, pH, H2O2 concentration, and dye concentration. The model exhibited high predictive accuracy, with R2 of 0.9782 for COD removal and 0.9579 for Color removal, confirming the effectiveness of the ANN in modeling.
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İncele - MakaleAçık Erişim2026Scopus SJRQ1Ni- and Co-doped TiO2nanofibers for enhanced antibacterial and antibiofilm activities, and mechanistic insights
Özcan, Tuğçe; Çekceoğlu, İlknur Aksoy; Öner, Erkan; Ozel, Sultan Suleyman; Sarılmaz, Adem; Aslan, Emre; Özel, Faruk; Patır, İmren Hatay
Nowadays, with the growing need for alternative antibacterial materials for the treatment of bacterial infections, TiO2 with antibacterial properties has attracted attention as a potential antibacterial agent. Ni-TiO2 and Co-TiO2 nanofibers (NFs) were synthesized via an electrospinning process. The antibacterial activities of these NFs against S. aureus and E. coli were evaluated under UV-light illumination using optical density measurements. Co-TiO2 exhibited superior antibacterial activity against both S. aureus and E. coli under UV-light irradiation. The antibacterial mechanism was further investigated through a glutathione (GSH) oxidation assay and morphological analysis using scanning electron microscopy (SEM). Hydrophilicity was evaluated by contact angle measurement. The antibiofilm activities of TiO2, Ni-TiO2, and Co-TiO2 NFs were investigated with respect to E. coli and S. aureus biofilms. Ni-TiO2 and Co-TiO2 demonstrated more effective antibiofilm activities than bare TiO2. Under UV-light irradiation, the biofilm inhibition efficacy was increased for both Ni-TiO2 and Co-TiO2 NFs while Co-TiO2 NFs were found to have the greater antibiofilm performance. Additionally, in silico analysis was conducted to explore the molecular interactions of the NFs with S. aureus Immunoglobulin-Binding B Domain (PDB ID: 1BDD) and FimH lectin protein of E. coli (PDB ID: 4XO8). Co-TiO2 exhibited stronger binding to S. aureus, while TiO2 showed stronger binding to E. coli. This journal is
- MakaleAçık Erişim2026Scopus SJRQ1Permittivity extraction of sandy soils through uncalibrated and thickness-independent meniscus-free measurements using a hollow coaxial line
Hasar, Ugur C.; Korkmaz, Huseyin; Kaya, Yunus
Measurement techniques for accurate moisture level determination of various soil conditions are becoming popular in recent studies. Microwave-driven techniques, as positioned into indirect methods, could be tailored for precise and real-time detection of soil moisture. However, improper implementation of calibration techniques or usage of imperfect calibration standards required for precise measurements by these techniques presents a challenging limitation for their widespread usage. Besides, meniscus formation on top of soil samples with a sufficient moisture level could adversely influence the performance of these techniques. In this study, we present a microwave extraction method for eliminating the requirement of a formal calibration procedure and additionally removing the effect of meniscus on measurements through relative measurements of sandy soil samples while maintaining accurate permittivity extraction with no information of sample thickness. To achieve our goal, a mathematical framework unifying wave-cascading matrix and state-transition matrix presentations is proposed for permittivity determination from three measurement configurations (empty line, the (sandy) soil sample sandwiched between two identical plugs, and a shifted version of this plug-sample-plug configuration) and their inverses implemented by port switching operation. The proposed method is first validated by permittivity measurements of two liquid samples (distilled water and methanol). Then, permittivity measurements of two sandy soil samples (having more than 90% sand content) were conducted using Type-N-to-EIA 1-5/8” coaxial lines (with no universal calibration standard) over 0.05 GHz–3.0 GHz. From these measurements, it is noted that our meniscus-free method determines permittivity with a maximum absolute difference of 3.4% (evaluated from five independent measurements) while another similar method, suffering from meniscus presence, extracts permittivity with a maximum absolute difference of 4.0%. This indicates a clear advantage of our method for measurements of sandy soil samples having meniscus formation. We then utilized to construct a calibration curve, compared with other calibration curves using by other methods, allowing prediction of moisture volume content () of the tested sandy soil samples from measured permittivity data whose conformity analysis implemented by the three-pole Debye model and the Mironov-Fomin model. It is observed that this calibration curve could be utilized to predict within margin from measured permittivity data.
- MakaleYalnız künye2026Scopus SJRQ2Depth-dependent predictability of soil temperature under Mediterranean climatic conditions: a frequency-based perspective
Guleryuz, Didem; Yıldırım, Ümit; Güler, Cüneyt
Soil-temperature predictability is inherently depth-dependent because atmospheric forcing is progressively attenuated and transformed into smoother, lower-frequency thermal dynamics with increasing depth. Under Mediterranean climatic conditions, where pronounced seasonality and strong surface forcing coexist, this depth-dependent transformation provides an informative basis for evaluating model behaviour. This study examines soil-temperature prediction at depths of 5, 10, 20, 50, and 100 cm using a multivariate dataset comprising 5,285 retained daily observations from the Mersin meteorological station on Türkiye’s eastern Mediterranean coast. Precipitation, air temperature, relative humidity, wind speed, and evaporation were used as predictors. Support vector regression, random forest, and LightGBM were evaluated using R², RMSE, and MAE. All three models performed strongly in the near-surface layers, with test R² values ranging from 0.948 to 0.954 at depths of 5–20 cm. Predictive performance declined with increasing depth as short-period variability weakened and the thermal signal became smoother and more seasonally structured. RF and LightGBM showed a greater numerical decline at 50–100 cm, whereas SVR achieved test R² values of 0.923 at 50 cm and 0.847 at 100 cm; however, inter-model differences remained modest and were interpreted descriptively. Lomb–Scargle spectral analysis, applied using the actual observation dates, indicated that short-period variability became relatively less pronounced with depth while seasonal-scale and low-frequency components remained prominent. Overall, the findings suggest that soil-temperature prediction should be interpreted in relation to depth-dependent temporal signal characteristics rather than as a search for a universally superior algorithm.
- MakaleAçık Erişim2025Scopus SJRQ1Validity and Reliability of a Novel AI-Based System in Athletic Performance Assessment: The Case of DeepSport †
Aydemir, Burakhan; Aydoğan, Muhammed Talha; Boz, Emre; Kul, Murat; Kırkbir, Fatih; Özkara, Abdullah Bora
This study aimed to examine the validity and reliability of the AI-based DeepSport application by comparing its outcomes with those from the reference device, OptoJump. The primary dependent variables measured were jump height and anaerobic power during vertical jump assessments. Twelve elite male basketball players voluntarily participated in the study (age = 21.53 ± 1.14 years; sports experience = 6.47 ± 1.01 years). DeepSport uses AI-based image processing from standard cameras, while OptoJump uses optical sensor technology. Both DeepSport and OptoJump systems were utilized to assess participants’ Countermovement Jump (CMJ) and Squat Jump (SJ) performances. A G*Power (version 3.1.9.7) analysis determined the required sample size, adopting a 95% confidence level, 90% test power, and an effect size of 0.25. Validity assessments were conducted using Bland-Altman plots and ordinary least products (OLP) regression analysis, while reliability was evaluated through intraclass correlation coefficient (ICC), coefficient of variation (CV), standard error of measurement (SEM), and smallest detectable change (SDC) analyses. DeepSport showed excellent reliability in CMJ and SJ tests with ICC values > 0.90, and CV ranged between 2.12% and 4.95%. Results were consistent with OptoJump, showing no significant differences according to t-test results (p > 0.05). Bland–Altman analyses indicated no systematic bias and random distribution. These findings confirm that both DeepSport and OptoJump devices demonstrate high reliability and consistency, suggesting their validity and reliability for use in athlete performance assessments by coaches and athletes.
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İncele - MakaleAçık Erişim2026Scopus SJRQ2Investigation of the levitation and drag force parameters of the electrodynamic maglev based on Halbach array of HTS bulks on aluminium rail
Ozturk, U.Kemal; Yıldız, Ali Suat; Abdioglu, Murat
This study aims to investigate the performance parameters of high-temperature superconducting (HTS) bulks and permanent magnets (PMs) as magnetic field sources in electrodynamic suspension (EDS) systems, with the goal of enhancing the currently low magnetic lift force and reducing the high drag force in such systems. A numerical analysis is conducted on an EDS system utilizing Halbach arrays of HTS and PM bulks. The H-formulation within the Partial Differential Equation (PDE) module is employed to simulate the flux-trapping performance of the HTS bulks, with results verified by experimental data from the literature. The lift and drag forces between the arrays and an aluminium rail are investigated using the Rotating Machinery-Magnetic module of COMSOL. It is observed that increasing the width of the central sample in the array results in a higher peak value of the vertical magnetic flux density and a broader peak profile, indicating a more extended effective magnetic field region across the rail surface. The HTS-based system exhibits significantly higher lift force and loading capacity compared to its PM-based counterpart. Specifically, a Halbach array composed of three HTS bulks (10 mm, 70 mm, 10 mm widths; HTS#10-70-10) achieves a better lift force representing a 211.5 % increase over the PM array. Furthermore, the lift-to-drag ratio (LDR) of the HTS array improves by 17.2 %. The results indicate that the HTS arrays offer superior performance in terms of both lift force and energy efficiency, highlighting their potential for enhancing the applicability of HTS-EDS systems in real-scale applications. This study features the advantages of HTS-based systems in achieving higher loading capacities and more efficient operation conditions compared to the PM arrays.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ1Cultural adaptation and psychometric validation of the Turkish MIND diet adherence scale for young adults
Esgin, Özge; Aslan Çin, Nazlı Nur; Kaplan, Özlem Nur; Baratzada, Leeda; Özçelik, Ayşe Özfer
Background: The MIND diet, which promotes brain health, has a potential role in preventing cognitive decline. To further establish its applicability, it is essential to validate the MIND Diet Adherence Scale in different populations with diverse dietary habits, including Turkish young adults. Objective: The aim of this study was to evaluate the construct validity, internal consistency and test-retest reliability of the Turkish version of the MIND diet assessment tool in the Turkish population. Methods: A total of 310 individuals aged between 19 and 39 (mean age 25.0 ± 5.1) voluntarily participated in this study. Data were collected through face-to-face interviews, incorporating socio-demographic characteristics, anthropometric measurements, the MIND Diet Adherence Scale, and the Mediterranean Diet Adherence Scale. Both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) of the MIND Dietary Adherence Scale were performed. In the CFA, the goodness of fit of the hypothesized model to the observed data was evaluated using a range of fit indices. Results: The study determined an adequate sample size (KMO = 0.67), with sufficient item correlations for factor analysis (χ2 = 449.74; p < 0.001). Confirmatory factor analysis and goodness-of-fit indicators supported the fit of the two-factor model to the Turkish data. The Cronbach’s alpha internal consistency coefficient for the MIND Diet Adherence Scale was 0.61. All items in the scale exhibited a positive correlation with the total score, exceeding 0.40. Furthermore, a substantial positive correlation was observed between the Mediterranean Diet Adherence Scale and the MIND Diet Adherence Scale. Conclusions: The Turkish adaptation of the MIND Diet Adherence Scale can be utilized in its entirety, without the need to remove any items. This study affirms that the MIND Diet Adherence Scale is a valid and reliable measurement tool for assessing dietary habits in Turkish society.
AtıfScopus3WoS3OpenAlex2İncele - MakaleYalnız künye2026Scopus SJRQ2Effects of Graphite Incorporation and Annealing on the Structural, Tribological, and Functional Properties of Electroless Ni-B Coatings
Bülbül, Ferhat; Kara, Adem; Bülbül, Leman Elif; Güneş, Kübra
This study explores the synergistic effects of graphite nanoparticles (0.1 wt.%) and thermal annealing (100–600°C) on electroless Ni-B coatings for AISI 4140 steel. Graphite-enabled multifunctional performance—crystallization control, friction reduction, and antibacterial activity—are unlike conventional Ni-B systems. XRD showed amorphous-to-crystalline (Ni3B/Ni2B) transformation, with graphite acting as a nucleation agent below 300°C before degrading at 600°C. The 300°C-annealed composite achieved optimal properties: 0.2 friction coefficient (75% lower than uncoated steel), 60% higher wear resistance, and hardness of 777 HV (+ 3.6% over as-deposited), attributed to graphite lubrication and nanocrystalline Ni3B formation. Antibacterial tests revealed a 3.4-mm inhibition zone against E. coli, though efficacy declined at higher temperatures due to graphite oxidation. All composites maintained superhydrophilicity (contact angle ≈ 0°) without mechanical compromise. By correlating annealing temperature with microstructure, this work provides a design framework for Ni-B/graphite coatings combining low friction (μ = 0.2), high hardness (785 HV), and antibacterial functionality—addressing critical needs for wear-resistant, hygienic surfaces in biomedical and industrial applications.
AtıfScopus1WoS1İncele - Derleme MakaleYalnız künye2026Scopus SJRQ4Touching relief: A complementary path to easing rheumatoid arthritis pain
Kalyoncuo, Servet
Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent synovial inflammation, leading to pain, joint stiffness, and functional impairment. Despite advances in pharmacological treatments, including disease-modifying antirheumatic drugs (DMARDs) and biologic agents, many patients continue to experience residual symptoms that negatively affect quality of life. This review aims to evaluate the potential role of massage therapy as a complementary approach in the management of RA, with a focus on its clinical effects and proposed mechanisms. A structured literature search was conducted in Medline/PubMed, Scopus, and the Directory of Open Access Journals (DOAJ) for studies published up to March 1, 2025. Studies were considered if they included individuals diagnosed with RA, evaluated any form of massage therapy (e.g., Swedish massage, aromatherapy massage, reflexology), and reported clinical or patient-reported outcomes. Both randomized controlled trials and quasi-experimental studies were included, while studies involving non-RA populations or insufficient methodological detail were excluded. However, this review was not designed as a fully systematic review and may be subject to selection bias. The available evidence suggests that massage therapy may be associated with improvements in pain, joint mobility, and patient-reported outcomes in individuals with RA. However, the overall strength of evidence is limited by methodological concerns, including small sample sizes, heterogeneity in intervention protocols, and the frequent lack of appropriate control groups. While some studies report reductions in inflammatory biomarkers such as interleukin-6 (IL-6) and C-reactive protein (CRP), these findings are based on limited evidence and should be interpreted cautiously, particularly in studies where massage therapy is combined with other interventions. Massage therapy may also contribute to psychological well-being by reducing stress and improving overall mental health. Evidence derived from non-RA populations was considered only as supportive background and was not central to the conclusions of this review. Additionally, the potential for publication bias should be acknowledged, as studies with positive findings are more likely to be published. The integration of massage therapy into RA management may benefit from nurse-led approaches; however, variability in practitioner training and the lack of standardized intervention protocols remain important challenges. Future research should prioritize well-designed, adequately powered randomized controlled trials focusing specifically on RA populations, with standardized massage interventions and clearly defined outcome measures.
- MakaleYayıncıda açık erişim2026Scopus SJRQ3Investigation of Fe and Mn Effects on the Fluidity Behavior of A356 Aluminum Alloys
Çolak, M.; Alkan, N.; Kutsal, Ü.
The fluidity behavior of Al–Si casting alloys is strongly influenced by impurity elements and intermetallic phase formation during solidification. In particular, iron (Fe) reduces melt fluidity by forming brittle Fe-rich intermetallics, whereas manganese (Mn) can mitigate this effect by modifying intermetallic morphology. In this study, secondary A356 aluminum alloys were produced with Fe contents of 0.10, 0.15, and 0.20 wt.% and nominal Mn additions of 0.05, 0.10, and 0.20 wt.% to investigate their combined effect on fluidity behavior. Melt quality was assessed using reduced pressure testing and density index measurements to ensure consistent casting conditions. Fluidity tests were conducted using spiral and eight-channel molds with section thicknesses ranging from 0.5 to 8 mm. To enable quantitative comparison across different section geometries, a Fluidity Index (FI) was defined based on section-normalized flow lengths. The results show that increasing Fe content generally reduces fluidity, while Mn additions significantly improve melt flow, with the most pronounced enhancement observed at 0.20 wt.% Mn. Thinner sections were found to be more sensitive to Fe-related flow restriction, whereas wider channels exhibited improved flow behavior. These findings demonstrate that appropriate Mn additions can effectively stabilize fluidity in secondary A356 alloys and provide practical guidelines for alloy control in recycled aluminum casting applications.
- MakaleAçık Erişim2026Scopus SJRQ1Screening-based low energy availability risk, disordered eating risk, and their co-occurrence among female volleyball players: a cross-sectional study
André, Hülya; Sarışık, Derya Çetin; Özçelik, Arda
Low energy availability (LEA) and disordered eating (DE) are important health concerns in female athletes, yet their occurrence and co-occurrence in team-sport contexts, particularly volleyball, remain underexplored. This cross-sectional online survey study examined the proportions of athletes classified as being at risk of LEA and DE overall and across competition levels, and assessed the co-occurrence between the two risk classifications in female volleyball players in Türkiye, using the Low Energy Availability in Females Questionnaire (LEAF-Q) and Eating Attitudes Test-26 (EAT-26). It also examined correlations between EAT-26 total score and LEAF-Q total and domain scores. A total of 213 athletes, recruited via non-probability convenience sampling, completed the LEAF-Q and EAT-26 to assess LEA risk and DE risk, respectively. In this sample, 33.3% of athletes were classified as being at risk of LEA, with no difference across competition levels (p = 0.825). A total of 17.4% were classified as being at risk of DE, with variation across competition levels and the highest proportion among Turkish Women’s Volleyball Second League athletes (p = 0.034). LEA risk and DE risk co-occurred in 10.3% of the sample, and DE risk was associated with higher odds of LEA risk (unadjusted OR = 3.80, 95% CI: 1.82–7.92). EAT-26 total score was positively correlated with LEAF-Q total and gastrointestinal function scores (p < 0.001) and injury history score (p = 0.004), but not menstrual function score (p = 0.133). These results suggest that LEA risk was commonly identified in this sample, DE risk was comparatively less common, and their co-occurrence was only partial, highlighting the value of screening for both risks rather than assuming one from the other.
- MakaleAçık Erişim2026Scopus SJRQ3Low-Data Modeling of Shallow Foundations on Cohesive Slopes: A Comparison between Hybrid FEM–RSM and ML Models*
Kâmiloğlu, Hakan Alper; Gücüyener, Alper
In geotechnical engineering, accurately predicting the seismic bearing capacity of shallow foundations on cohesive slopes requires proper consideration of nonlinear effects and parameter interactions. However, most studies in the literature address these complex effects inadequately, either with numerical methods that demand a large number of analyses or with machine learning (ML) models that require large and heterogeneous data sets. In this study, it is aimed to propose an approach that allows for a robust analysis of the system and at the same time provides accurate forecasting for situations where working with small and homogeneous data sets is mandatory. Within the scope of the study, seismic bearing capacity analyses were performed using Plaxis 2D for 273 cases where eight independent variables took different values according to the Face Centered Composite Design (FCCD), and a database was created. Multiple Linear (MLR), Multiple Nonlinear (MNLR) Regression Models were established, and ML models, such as Support Vector Regression (SVR), Random Forest (RF), and Extreme Gradient Boosting (XGBoost), were trained. The models were compared with both in-sample and out-of-sample estimation performance, and parametric sensitivity analyses were evaluated by methods such as ANOVA and SHAP. The results show that the MNLR model with natural logarithmic transformation is the most successful method in terms of both accuracy (R² ≈ 0.98) and reflecting parameter interactions, while the SVR algorithm demonstrates the best generalization ability among ML models under low-data conditions. The results also confirm that the ML models effectively capture the parameter effects.
- MakaleAçık Erişim2026Scopus SJRQ1Shape-Directed Hydrothermal Design of Zinc Oxide Nanoparticles for Antimicrobial and Anticancer Applications
Özkan, Elvan Hasanoğlu; Yetim, Nurdan Kurnaz; Kızıl, Hamit E.; Öğütçü, Hatice
The emergence of antibiotic-resistant bacteria represents one of the most pressing challenges in global healthcare. In this study, metal oxide–based nanomaterials are gaining prominence due to their antimicrobial and anticancer potential. In the present study, six new zinc oxide nanoparticles (ZnO-NPs) synthesized via the hydrothermal method using different surfactants were characterized, and their biological activities were evaluated. ZnO-NPs, whose structural properties were determined by a range of analytical methods including BET, FT-IR, SEM-EDX, XRD, and XPS, exhibited significant antibacterial and antifungal effects on a range of bacterial and fungal strains. The study revealed that variations in the morphology and surface area had a direct impact on antimicrobial efficacy. In antimicrobial assays, the inhibition zones ranged from 10.5 mm to 25.5 mm, with ZnO-6 exhibiting the highest efficacy against S. epidermidis (25.5 mm). In cytotoxicity assays, ZnO-6 demonstrated the strongest anticancer potential against H460 cells with the lowest IC50 value of 31.9 µg/mL. Furthermore, a strong correlation was revealed between the physicochemical properties of ZnO-NPs and their anticancer activity, as evidenced by the results of tests conducted on H460 lung cancer cells. Specifically, ZnO-6, which possesses a flower-like morphology and the highest surface area, exhibited the strongest anticancer effect with an IC50 value of 31.9 µg/mL. The parallel enhancement in both antimicrobial and anticancer activities observed in ZnO-6 suggests a common underlying mechanism, likely driven by the high surface area and specific flower-like morphology that facilitates increased interaction with cell membranes and ROS generation. The findings demonstrate that the controlled design of ZnO-NPs in terms of morphology and surface area offers significant potential in both antimicrobial and anticancer applications.
AtıfScopus3WoS3OpenAlex2İncele - MakaleYalnız künye2025Scopus SJRQ1An attraction–repulsion chemotaxis with logistic source involving the exponents depending on the spatial variables
Ayazoglu, Rabil
We study the quasilinear attraction–repulsion chemotaxis system of parabolic–elliptic type with logistic source involving the exponents depending on the spatial variables: ut=Δu-χ∇·uu+1r-1∇υ+ξ∇·uu+1r-1∇ω+au-bum(x), 0=Δυ-βυ+αu, 0=Δω-δω+γu, where α, β, δ, γ, χ, ξ, b>0, a≥0, r∈R and m:Ω→1,∞ is a measurable function, subject to the homogeneous Neumann boundary conditions in a bounded domain RNN≥1 with smooth boundary. We prove that this system possesses a unique global bounded classical solution, which is an extension of known results, if the repulsion cancels the attraction in the sense that (balance) χα=ξγ with essinfx∈Ωmx>r+N-2+N,1, and if the attraction prevails over the repulsion in the sense that χα>ξγ with essinfx∈Ωmx>maxr+1,1, and if the repulsion prevails over the attraction in the sense that χα<ξγ.
AtıfScopus2WoS2İncele - MakaleYalnız künye2026Scopus SJRQ2Social support mediates relationship between death anxiety and stress in chronic illness
Akeren, Zahide; Kalyoncuo, Servet
Background: Fear of death may become salient among individuals with chronic illness. This study examined the mediating role of perceived social support in the relationship between death anxiety and perceived stress in individuals with chronic illness. Methods: The study was conducted with 265 individuals diagnosed with chronic illness. The sample included participants with hypertension (20.7%), diabetes (19.6%), and cardiovascular diseases (16.2%), among conditions. Data were collected using the Templer Death Anxiety Scale, the Perceived Stress Scale, and the Multidimensional Scale of Perceived Social Support. Results: A weak negative correlation was found between death anxiety and perceived social support (r = -0.156, p = 0.011), while a positive correlation was observed between death anxiety and perceived stress (r = 0.362, p < 0.001). The proportion of the total effect mediated by perceived social support was 32.7%. Death anxiety was associated with perceived stress (β = 0.347, p < 0.001). The of perceived social support as a mediator, the coefficient decreased (β = 0.234, p < 0.001), indicating partial mediation. Conclusion: Perceived social support partially mediated the relationship between death anxiety and perceived stress. Higher levels of death anxiety were associated with higher perceived stress, and this association was attenuated in the presence of perceived social support.
- MakaleYayıncıda açık erişim2026Scopus SJRQ3Effects of Artificial Weathering Resistance on the Hardness Value of Ash Wood Surfaces Coated with Polyurethane Modified Water-Based Varnish after Heat Treatment
Akter, Mete; Ulay, Göksel; Peker, Hüseyin; Çakıcıer, Nevzat; Atilgan, Abdi; Ayata, Ümit
Pendulum hardness test is important for determining the mechanical durability and long-term performance of the film layer formed on the surface of wood thermally treated at high temperatures and coated with water-based varnish (WBV). In this study, the effect of artificial weathering conditions on the pendulum hardness (König method) of ash (Fraxinus angustifolia Vahl.) wood samples varnished with polyurethane modified WBV was investigated. The samples were thermally treated under two conditions (190°C for 1.5 h and 212°C for 2 h) and compared with untreated control samples. The samples were exposed to artificial weathering conditions (for periods of 0, 168, 336 and 504 h). Pendulum hardness values were measured at the end of each weathering period. According to the results, increases in hardness values were observed in both heat-treated and untreated ash wood samples treated with varnish after weathering. In the varnished samples treated at 212°C for 2 h, the post-weathering hardness increases were lower compared to the samples treated at 190°C for 1.5 h and the control group. Additionally, analysis of variance for the pendulum hardness test, heat treatment, weathering time and their interaction were determined to be statistically significant. The significant increases in hardness values observed in the unweathered samples highlight the importance of the wood, varnish, and weathering process.
- MakaleAçık Erişim2025Scopus SJRQ1Investigation of notch effect in the optimum weight design of steel truss towers via Particle Swarm Optimization and Firefly Algorithm
Yilmaz, Elif; Artar, Musa; Ergün, Mustafa
In this study, the optimal weight designs of steel truss towers are determined, considering the notch effect. Thus, the impact of discontinuities in the cross-sections of steel elements on the total weight of the structure is revealed. For this purpose, the optimal weight designs of different truss towers analyzed by other researchers in previous years are reexamined using Particle Swarm Optimization and Firefly Algorithm. The main program where finite element analyses and optimization algorithms are encoded has been developed in MATLAB. Displacement, stress, geometric, and section height constraints are used in optimization methods. The effectiveness of these methods has been demonstrated by comparing both the results in the literature and with each other under un-notched conditions. Subsequently, considering the notch effect on the tension bar with the highest stress capacity in each structure, the impact of stress concentration on the minimum weight sizing of the structure is investigated using these proven methods. When the analysis results of both cases are examined, it is observed that the optimum weights of all structures under the notch effect have slightly increased. The stress concentration around the notch severely raises the nominal stress in the cross-section. In this case, the cross-section becomes insufficient due to the overcapacity, requiring larger profiles. The structure’s weight shows an increasing trend depending on the number of notched elements and the severity of stress concentration. Additionally, SAP2000 software is utilized for numerical simulations of the structures under identical conditions, enhancing the research content and providing further support for the comprehensive design optimization analyses. Consequently, minimizing the adverse effects of notches through careful material selection, proper manufacturing and assembly techniques, and regular maintenance is essential. The effects of notches should be considered in structural analysis and design, with measures taken to mitigate these effects when necessary.
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