Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Bayraktar, Bülent(13)
- Yavuz, Mehmet(10)
- Kayalı, Bünyami(8)
- Erdoğan, Yaşar(7)
- Isik, Cem(7)
- Kul, Murat(7)
- Makas, Samet(7)
- Ongan, Serdar(7)
- Yayla, İbrahim Erdoğan(7)
- Akeren, Zahide(6)
- Akeren, İhsan(6)
- Boz, Emre(6)
- Bozkurt, Aras(6)
- Ecem Bayram, Nesrin(6)
- Engin, Mustafa Alptekin(6)
- Imamoglu, Ilyas Kays(6)
- Kalyoncuo, Servet(6)
- Kotan, Gökşad Cemil(6)
- Çolak, Murat(6)
- Ayata, Ümit(5)
- Aydemir, Uğur(5)
- Bayram, Sinan(5)
- Cakir, Mehmet(5)
- Ceylan, Halil Ibrahim(5)
- Ceylan, Nagihan Burcak(5)
- Colak, Murat(5)
- Dergaa, Ismail(5)
- Dertli, Enes(5)
- Dhahbi, Wissem(5)
- Dombak, Kübra(5)
- Esmer, Yusuf(5)
- Gul, Volkan(5)
- Kamiloğlu, Aybike(5)
- Kutlu, Naciye(5)
- Köktürk, Seda Nur(5)
- Muntean, Raul Ioan(5)
- Tutkun, Cansu(5)
- Yarımkaya, Erkan(5)
- Yıldız, Ümit(5)
- Çakır, Zekai(5)
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ1Assessment of malnutrition in hospitalized children: Comparison of stamp, PYMS and strong-kids screening tools
Mutlu, Elif; Köktürk, Seda Nur; Ersoy Söke, Nursena; Yardımcı, Hülya
Aim Early identification of malnutrition risk in hospitalized children is essential for timely nutritional intervention. This study aims diagnostic performance of three pediatric malnutrition screening tools validated in Turkish: STAMP, PYMS, and STRONG-Kids. Methods In this cross-sectional study, 148 hospitalized children were included. Nutritional risk was evaluated using STAMP, PYMS, and STRONG-Kids screening tools. Anthropometric measurements were performed, and height-for-age, Body Mass Index (BMI)-for-age, and Middle Upper Arm Circumference (MUAC)-for-age z-scores were calculated. The sensitivity and specificity of each tool were assessed in identifying chronic and acute malnutrition. Receiver operating characteristic (ROC) curve analysis was used to assess the discriminative ability of the screening tools. Results Chronic malnutrition was identified in 12.8% of patients and acute malnutrition in 15.5%. STAMP and STRONG-Kids showed the highest sensitivity for detecting chronic malnutrition (84.2% and 84.3%), while PYMS had the highest specificity. STRONG-Kids demonstrated the greatest sensitivity for acute malnutrition and low MUAC z-scores (100.0%). ROC analysis showed that PYMS had the highest Area Under the Curve (AUC) for acute malnutrition, whereas STRONG-Kids had the highest AUC for chronic malnutrition, although all tools demonstrated limited discriminative ability for chronic malnutrition. Conclusion STAMP and STRONG-Kids were more sensitive in detecting malnutrition risk, whereas PYMS showed higher specificity. Tool performance varied according to anthropometric indicators. Implications to practice In clinical practice, selecting the screening tool according to the targeted malnutrition type and available anthropometric indicators may improve early detection and allow more effective prioritization of nutritional interventions in hospitalized children.
- MakaleYalnız künye2026Scopus SJRQ1Cognitive and Emotional Mediators of the Transformation of Adverse Childhood Experiences into Depression, Anxiety, and Stress: Testing a Model in Young Adults
Akeren, İhsan; Aktaş, Emirhan
Studies show that symptoms of depression, anxiety, and stress in college students increase with adverse childhood experiences (ACEs). If individuals in young adulthood cannot cope with the negative experiences they were exposed to in childhood, they are at risk of mental health problems later in life. This study aimed to determine whether the effects of the past continue into the present and to examine their scope by testing the effect of ACEs on depression, anxiety, and stress through positive and negative feelings and irrational beliefs. Using stratified convenience sampling, 708 volunteer undergraduate students, 458 female and 250 male, with a mean age of 20.84 years, were reached in their classrooms. In the cross-sectional correlational survey design, Hayes’ PROCESS macro (model 80) was used for conditional process analyses after the regression assumptions were tested. The mediator variables positive and negative feelings and irrational beliefs accounted for about two-thirds of the effect of ACEs on depression (total effect = 0.598, 95% CI [0.442, 0.755], direct effect = 0.209 [0.069, 0.348]), about half of the effect on anxiety (total effect = 0.650 [0.499, 0.802], direct effect = 0.360 [0.214, 0.506]), and more than half of the effect on stress (total effect = 0.676 [0.507, 0.844], direct effect = 0.302 [0.146, 0.458]). Finally, compared to males, females had higher mean scores for ACEs, negative feelings, and depression, anxiety, and stress, and lower mean scores for irrational beliefs. In conclusion, the study shows that the negative effects of the past continue to appear in the present and recommends taking steps to prevent their potential risks for the mental health of young adults.
- MakaleYalnız künye2026Scopus SJRQ2The Effect of Sugar Beet (Beta vulgaris L.) Varieties Grown Under Semi-Arid Conditions in Turkey’s Eastern Anatolia Region on Yield and Quality
Bagcı, Ikram; Gul, Volkan; Sefaoglu, Firat; Lan, Yuzhou; Coban, Furkan
Global climate change, which is increasingly evident today, leads to significant fluctuations in the yield and quality parameters of sugar beet varieties, particularly due to its direct impact on semi-arid regions. Therefore, the adaptation capacity of varieties especially in the semi-arid areas of eastern regions and their responses to drought and temperature stress are of critical importance. This study was conducted during the 2022–2023 growing seasons to evaluate the yield and quality performance of ten sugar beet varieties (Seranada, Lider, Mohican, Terronova, Aranka, Turbata, Bernache, Setenil, Tisserin, and Chevalier) within a continental agro-ecological zone characterized by high altitude and a semi-arid climate. The results revealed significant differences among the varieties in terms of all examined traits. The highest root yield was obtained from Chevalier (95.30 ton/ha) and Mohican (94.17 ton/ha), while Tisserin produced the lowest (71.34 ton/ha). In terms of sugar yield, Terronova ranked highest (16.18 ton/ha), whereas Tisserin (12.44 ton/ha) and Setenil (12.34 ton/ha) showed the lowest performances. The Lider variety recorded the highest sugar content (18.22%), indicating its potential as a quality-oriented genotype. Overall, Mohican and Terronova demonstrated the most favorable responses under semi-arid conditions. These findings underscore the importance of regional variety testing for identifying high-yielding and high-quality sugar beet genotypes, especially in environments affected by altitude, climate variability, and soil characteristics.
AtıfScopus1WoS1
İncele - MakaleAçık Erişim2026Scopus SJRQ1The 20-Year Evolution of Distance Education: A Bibliometric and LDA-Based Topic Model Analysis
Yavuz, Mehmet; Balat, Şener; Kayalı, Bünyami; Gülen, Emirhan
Although research on distance education has increased substantially in recent years, comprehensive analyses capturing the overall thematic development of the field remain limited. Modeling studies are necessary to address this gap and to uncover long-term research trends. This study aimed to reveal the trends of research conducted in the field of distance education in the last two decades by using machine learning methodology and bibliometric analysis. The unique aspect of the study was its use of the Latent Dirichlet Allocation (LDA) algorithm, a machine learning method for analysing large-scale data. Within the scope of the study, 54,444 articles in the Web of Science database were analysed. Bibliometric analysis revealed that distance education had gained significant momentum, especially in the post-pandemic period, with a wide range of applications in different disciplines such as education, management, and health. As a result of LDA analysis, 19 thematic topics were identified. Among these, digitalization, artificial intelligence, Web-based learning, and social interaction and collaboration stood out. Time series analysis showed an increasing trend for topics such as artificial intelligence and emergency distance education over the years, with less interest shown in topics such as Web-based learning and program design. The study emphasized that distance education is in a technology-driven transformation process and pointed to areas that will offer new opportunities for researchers. Furthermore, recommendations for decision-makers, such as investments in digital infrastructure, integration of artificial intelligence-based systems, and the establishment of quality standards, also emerged.
- MakaleAçık Erişim2026Scopus SJRQ2Relationship Between Aluminum Liquid Metal Quality and Defects
Kutsal, Umit; Colak, Murat; Ertugrul, Onur
Aluminum alloys are commonly used in various industries today. In order to produce defect-free high-quality alloys with sustainable processes, defects must be reduced, and liquid metal quality must be improved. There are various methods that can be used for the measurement of liquid metal quality. Some of which are density index, bifilm index, K-Mold index, PoDFA, Prefil, fluidity test, and thermal analysis. The relationship and validation between these methods are still not clear. In this study, the relationship between aluminum liquid metal quality and defects is analyzed. Three different conditions were utilized. These conditions are (1) before a controlled degassing, (2) after the controlled degassing and (3) after the liquid metal is transferred to the holding furnace. According to the results, it was observed that the reduction of bifilms index did not reduce other inclusions and did not always favorably affect other measurement methods. It was also observed that the reduction of bifilm index did not improve the porosity level. Moreover, it was found that elongation values are related to the largest defect diameters. Bifilm index are not the only factor affecting the elongation and the density index directly affects the defect distribution. K-Mold index has an impact as it shows macro-inclusions. However, bifilm index, density index, fluidity index and K-Mold index are not as sufficient as numerical calculation of defect size by computed tomography (CT). The main factor directly affecting the elongation and tensile strength was found to be the inclusion size and diameter in the CT result. Examination of the fracture surfaces revealed that oxide contents are present, and the oxygen orientations and aluminum orientations are compatible. This harmony is thought to be related to the orientation of the bifilms in the structure.
AtıfScopus8WoS8İncele - MakaleYalnız künye2026Scopus SJRQ2Seismic performance of prestressed girder bridges considering soil-pile-structure interaction and isolation systems
Öner, Erdal; Aydoğan, Ayşe N.; Yurdakul, Muhammet; Ergün, Mustafa; Artar, Musa
This article presents a comprehensive numerical study to determine the seismic performance of the Kirazlıyalı Çenesuyu Bridge, currently in service in Kocaeli, Türkiye, under both seismically isolated and non-isolated conditions, considering different soil types. The study holds great importance due to Kocaeli’s status as one of Türkiye’s most developed industrial regions, its location in a high-seismic-risk area, and its complex geological structure. The Kirazlıyalı Çenesuyu Bridge is a structure consisting of simply supported prestressed girders, commonly used in highway transportation networks. Designed as a twin bridge, the structure is 134 meters in length and 20 meters in width. Currently, the bridge is not equipped with seismic isolators; instead, its superstructure rests on elastomeric bearings over abutments and piers. Within the scope of this study, the bridge was retrofitted with Single Curved Friction Pendulum (SCFP) seismic isolators. These SCFP isolators were specifically designed in accordance with the Turkey Building Earthquake Code (TBEC-2019) standards for two distinct soil classes: ZA (hard rock) and ZC (very dense sand and gravel). The soil-pile interaction was simulated using single-parameter Winkler spring models in both horizontal and vertical directions. The Finite Element Model (FEM) of the bridge was developed in SAP2000 software, and analyses were conducted on this platform. The seismic performance of the bridge was assessed through nonlinear dynamic time history analyses using real earthquake ground motion records from the Imperial Valley, Kocaeli, and Kahramanmaraş (Pazarcık) earthquakes under various scenarios. The seismic responses of the bridge were examined in terms of base shear forces, lateral displacements of the pile, shear forces at the pier, bending moments at the pier, deck accelerations, and the hysteresis curves of the isolator. The study results demonstrate significant improvements in the seismic behavior of the bridge when equipped with the seismic isolation system. Furthermore, these improvements are shown to be directly influenced by the interaction of the structure-pile-soil system, as well as the compatibility between the frequency characteristics of this system and the frequency content of the imposed earthquake. The numerical data supporting these results are presented in the relevant sections through tables and graphs.
AtıfScopus2WoS2İncele - MakaleYalnız künye2026Scopus SJRQ2Optimizing microwave drying parameters for rhododendron bee pollen: effects on antioxidant potential, polyphenols, and proteins
Kutlu, Naciye; Gercek, Yusuf Can; Ecem Bayram, Nesrin
Monofloral Rhododendron spp. bee pollen is a remarkable bee product due to its functional components as well as its potential pharmacological effects. In this study, Rhododendron spp. bee pollen was dried by the microwave method as an alternative to the conventional drying method. Different combinations of microwave powers (140, 210 and 280 W) and sample weights (10, 20 and 30 g) applied during microwave drying (MWD) were determined by Central Composite Design. Drying time, total protein, total carotenoid, total phenolic-flavonoid compounds, and proanthocyanidin yields of dried pollen were determined and antioxidant activity tests (CUPRAC and DPPH•) were performed. The analysis results were optimized by response surface methodology (RSM) and the optimum drying conditions were obtained when the microwave power was 280 W and the sample weight was 30 g. The optimal conditions have been established to reduce drying time and enhance the content of bioactive compounds. As a result of optimization, the composite desirability (d) was found to be 0.8. Experimental and predicted values were close to each other. In conclusion, MWD has demonstrated efficacy as a drying technique by significantly reducing drying time while maintaining and enhancing the yields of bioactive compounds in monofloral Rhododendron spp. bee pollen. In comparison to conventional techniques, the application of MWD in the drying process of monofloral Rhododendron spp. bee pollen is demonstrably more efficient and sustainable.
- MakaleAçık Erişim2026Scopus SJRQ2Experimental Electromagnetic Shielding Analysis of a Square-Resonator-Integrated Double-Concrete Structure Using Explainable Machine Learning
Cakir, Mehmet
Electromagnetic shielding has become a practical concern in buildings and structures exposed to persistent interference. This paper reports experimental measurements of the frequency-dependent shielding properties of a square-resonator-integrated double-concrete structure, using a free-space S-parameter setup built around WR229 waveguide adaptors and horn antennas. Three variables were tested: concrete thickness D, relative permittivity εr, and relative magnetic permeability μr. Both εr and μr were characterized experimentally from carbon-fibre- and copper-slag-modified concrete rather than taken from standard tables. The novelty of the study lies in combining experimentally characterized concrete electromagnetic properties, an embedded square-resonator geometry, and explainability-driven machine learning analysis within a single experimental framework for cement-based EMI shielding design. A total of 96 parameter combinations were evaluated using calibrated S11 and reference-corrected S21 responses across 3.3–4.9 GHz. Thickness and electromagnetic material properties interacted—neither governed shielding performance on its own. The strongest transmission attenuation occurred at D = 5, εr = 7, and μr = 1.2, where minimum S21 reached approximately −62.98 dB at 3.6392 GHz. S11 varied considerably less than S21 across the tested combinations, suggesting transmission suppression is the dominant mechanism rather than reflection enhancement. A machine learning analysis confirmed that nonlinear ensemble models outperformed the linear baseline and identified thickness as the most influential predictor of minimum S21.
- MakaleAçık Erişim2026Scopus SJRQ3Spiritual Monachopsis: Conceptualization, Scale Development, and Psychometric Analysis
Okur, Süheyb
In the modern era, individuals have increasingly experienced alienation from their religious environments and have been marked by a profound sense of “homelessness” within their worlds of faith. Based on the concept of “Monachopsis” —the subtle but persistent feeling of being out of place— this study was designed to develop the “Spiritual Monachopsis Scale” (SMS) to measure the spiritual manifestation of this phenomenon and to examine its psychometric properties in a sample of theology students. The scale development study was conducted with a total of 453 undergraduate theology students studying at Bayburt University in the 2025-2026 academic year, including 163 participants in the exploratory validation phase and 290 participants in the confirmatory validation phase. Exploratory Factor Analysis (EFA), Confirmatory Factor Analysis (CFA), Cronbach's Alpha coefficient, and Pearson correlation analysis were used for data analysis. The EFA indicated that the scale had a three-factor structure —Disconnection from the Divine, Alienation from the Belief System, Religious Social Alienation— which explained 57.66% of the total variance. The CFA results confirmed that the 18-item structure demonstrated a good fit to the data. The internal consistency of the scale was found to be high. In terms of criterion-related validity, a positive and significant correlation was found between the SMS and the Negative Religious Coping scale. The findings indicate that the Spiritual Monachopsis Scale is a valid and reliable instrument for assessing levels of spiritual homelessness and alienation, particularly among theology students. It is recommended that the SMS be used in future studies within higher religious education settings and campus-based spiritual counseling contexts to identify patterns of alienation in this population and to inform supportive psychoeducational programs.
- MakaleAçık Erişim2026Scopus SJRQ1FoMO and cyberstalking in adults: the mediating roles of early maladaptive schemas and phubbing
Koçak, Lokman
Introduction – It is noticeable that cyberstalking behavior, which has become widespread in recent years and has many negative effects, has been investigated to a limited extent. This study aimed to analyse the mediating role of early maladaptive schemas of abandonment and insufficient self-control and phubbing in the relationship between FoMO and cyberstalking among adult individuals. Methods – The study group comprised 540 adults aged 18–48 (71.1% female and 28.9% male). We adopted Pearson correlation analysis and PROCESS Macro Model 80 in regression analysis to explore the relationships among cyberstalking, FoMO, early maladaptive schemas and phubbing. Results – The results showed that there were significant relationships between the study variables. Also, results show that early maladaptive schemas of abandonment and insufficient self-control and phubbing mediate the relationship between FoMO and cyberstalking. Discussion – These findings suggest that the abandonment schema may be associated with FoMO-related cyberstalking through a theoretically informed pathway that may reflect attachment-related vulnerabilities, whereas the insufficient self-control schema may reflect a possible self-regulation-related dimension that may be associated with FoMO-related digital behaviors of this process. The inclusion of phubbing in the model further indicates that FoMO-related attentional and relational dysregulation may be linked to monitoring-oriented online behaviors. In this regard, these findings may provide a theoretical perspective for future studies examining attachment-related schema sensitivities, self-regulation processes, and mindful technology use in relation to FoMO-related digital behaviors.
- MakaleAçık Erişim2026Scopus SJRQ2Synthesis and pharmacokinetic profiling of a novel pyrimidine imidazole based thiosemicarbazone derivative for BRAF inhibition in lung cancer therapy
Ekincioğlu, Yavuz; Kızıl, Hamit Emre; Güllü, Eda; Özkan, Elvan Hasanoğlu; Nartop, Dilek
This study presents the design, synthesis, and comprehensive evaluation of a novel thiosemicarbazone derivative containing a pyrimidine-imidazole (C11H11N8SCl) as a potential BRAF inhibitor for the treatment of non-small cell lung cancer. The compound was synthesized by a condensation reaction and characterized by elemental analysis, molar conductivity, SEM-EDS, FT-IR, 1H, and 13C-NMR spectral techniques. DFT calculations at the B3LYP/6-311 + + G(d, p) level revealed a HOMO-LUMO gap of 2.8 eV, indicating appropriate molecular stability and reactivity. Molecular docking studies with BRAF (PDB ID: 1UWH) demonstrated favorable binding affinity (-6.85 kcal/mol) with key interactions at ILE512, HIS509, HIS584, GLN529, GLU585, LYS590, VAL510, and LEU587 residues. In vitro cytotoxicity assays revealed that the compound possesses anticancer potential against H-460 cells, with a significant inhibitory effect observed at a concentration of 200 µg/mL. Combined with its favorable binding affinity toward BRAF kinase, these results suggest that the pyrimidine-imidazole thiosemicarbazone may serve as a potential lead scaffold for further development in targeted lung cancer therapy.ADME profiling confirmed the compound’s compliance with Lipinski’s rule of five parameters, supporting its potential as an orally active drug candidate. These findings suggest that our pyrimidine-imidazole thiosemicarbazone represents a promising scaffold for the development of targeted BRAF inhibitors for lung cancer therapy.
- BildiriAçık Erişim2026Autism Awareness Levels of University Students and Their Relationship with Various Variables
Ari Arat, Ceren; Brunetto, D.; Domenech, J.; Alvarez-Hevia, D.M.; Mart�nez-Varea, A.
This cross-sectional quantitative study examined university students’ awareness of autism spectrum disorder (ASD). The sample consisted of 354 students from different academic departments at a public university in Türkiye. Data were collected using the Autism Awareness Scale and a Demographic Information Form and analyzed through descriptive statistics, Pearson correlation, and independent-samples t-tests. Findings indicated relatively high awareness in social interaction, communication, and restricted and repetitive behaviors, whereas knowledge was lower regarding physical characteristics and early warning signs. Core behavioral knowledge was positively associated with peer relationships and early diagnosis indicators. Gender differences were minimal, except for higher early warning scores among females. Prior interaction with individuals with autism and ASD-related coursework were associated with higher awareness across multiple domains, while students without formal education scored higher on physical characteristics. Overall, the findings highlight the importance of direct experience and structured education in improving autism awareness among university students in higher education settings.
- MakaleAçık Erişim2026Scopus SJRQ1When grief persists online: Development of the Digital Prolonged Grief Severity Scale
Çınar, Öznur; Cengiz, Ekrem
Bereaved individuals encounter the deceased through social media profiles, message histories, and algorithmic reminders, yet no validated instrument measures prolonged grief expressed through digital interactions. We developed and validated a multidimensional measure of digital-environment prolonged grief severity (DPGSS). Turkish bereaved adults (n = 577) bereaved at least 12 months earlier completed the DPGSS alongside grief, distress, and other less relevant measures, and 125 completed it again about three weeks later. Factor analyses supported a four-factor structure—digital separation distress and preoccupation, digital emotional responses, digital avoidance, and digital functional impairment—in 15 items. The correlated four-factor model fit the data well, outperforming a one-factor alternative. The DPGSS demonstrated strong internal consistency, test-retest reliability, and measurement invariance across nine demographic variables. Convergent associations with grief and distress, and negligible associations with rigidity and AI acceptance, supported its construct specificity. The DPGSS-15 is a reasonable tool for assessing digital prolonged grief.
- MakaleAçık Erişim2026Scopus SJRQ2An analytical study of contact mechanics in layered orthotropic–isotropic media with functional grading
Öner, Erdal; Artar, Pınar Tuğçe
Contact mechanics has played a central role in engineering progressing from early practices in ancient civilizations to the pioneering experimental studies of early scientists and more recently to advanced computational approaches. In modern research, functionally graded materials have gained increasing attention as their continuously varying properties enable the tailoring of stress fields, improvement of resistance to thermal and mechanical loads, and enhancement of the performance and reliability of layered systems.This study addresses the continuous contact problem of a two-layered medium composed of a functionally graded orthotropic layer (FGOL) placed over a functionally graded isotropic layer (FGIL). A rigid cylindrical punch applies a static concentrated load on the FGOL, while the lower surface of the FGIL is bonded to a rigid foundation. The layers are assumed to be unbonded at their interface, and frictionless contact conditions are imposed. To capture the effect of anisotropy, actual orthotropic materials are employed in the FGOL. An exponential through-thickness variation is adopted for the FGOL stiffness coefficients and density, and for the FGIL shear modulus and density. Under plane strain conditions, the contact formulation is reduced to a singular integral equation by applying the relevant boundary conditions. The equation is solved numerically using Gauss–Chebyshev integration techniques. The results provide detailed evaluations of contact lengths, stress distributions, critical load factors, and initial separation points as functions of selected nondimensionalized parameters and different orthotropic material choices, thereby contributing to a deeper understanding of the mechanics of graded layered systems.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2026Scopus SJRQ2Identifying the optimal flexural performance of metal-composite single-lap joints with copolyester-reinforced epoxy adhesive under various loading rates using the Grey Relation Analysis
Erbayrak, Engin; Erbayrak, Seda; Eker, Beril; Colak, Murat
This study examines the best flexural performance of metal composite single-lap joints fabricated with copolyester-reinforced epoxy adhesives at various loading rates using the Grey Relation Analysis (GRA). The study consists of three parts. The first part involves the formation of metal composite single-lap joints and their experimental approach under different loading rates. In the experimental approach, A356 aluminum was used as the metal material with the addition of titanium (Ti) and boron (B) additives. Plain-woven glass fiber-reinforced epoxy (GFRE) and plain-woven carbon fiber-reinforced epoxy (CFRE) were served as the composite materials. The lap joints were tested in three-point bending tests under loading rates of 1, 10, and 50 mm/min, respectively. In the second part, a numerical analysis was conducted using boundary conditions similar to the experimental conditions. In the numerical analysis, a 6-node pentahedral cohesive element was utilized, representing a novel approach for modeling adhesives in finite element analysis (FEA). When experimental and numerical results were compared, a difference of 4.36% was observed between the maximum load values and 6.80% between the failure displacements. Based on these results, it can be said that the experimental results converge with the numerical results. In the last part of the study, performance rankings of metal composite joints were determined using the Grey Relational Analysis (GRA) method, which enabled us to identify the optimum joint. This systematic approach facilitated the scientific design of joints that demonstrate optimal flexural performance under various loading conditions.
- MakaleAçık Erişim2026Scopus SJRQ1Seismic Performance Assessment of a Historical Masonry Mosque Minaret Under Pulse-like and Non-Pulse-like Near-Fault Ground Motions
Gürbüz, Ali; Demirtaş, Betül; Tonyali, Zeliha
Historical masonry minarets are highly vulnerable to seismic actions due to their slender geometry, limited tensile capacity, and material heterogeneity. However, their response to near-fault ground motions characterized by velocity pulses remains insufficiently explored. This study investigates the seismic response of the historical Tavanlı Mosque Minaret (1894, Trabzon, Türkiye) subjected to pulse-like (PL) and non-pulse-like (NPL) near-fault ground motions. A three-dimensional finite element model (FEM) was developed in ANSYS Workbench and systematically calibrated using empirical formulations to represent the current dynamic condition of the structure. Seismic performance was evaluated through linear dynamic analyses in terms of displacement demands, principal stress distribution, and drift-ratio-based performance levels. The results indicate that model calibration significantly modifies the dynamic characteristics, increasing the fundamental frequency from 0.734 Hz to 1.126 Hz and reducing displacement demands by approximately 35–76% across the considered records. Despite this improvement, PL ground motions consistently generate more critical deformation demands than NPL motions, frequently exceeding Collapse Prevention (CP) limits even when Peak Ground Acceleration (PGA) values are relatively low. A key finding is that seismic demand cannot be reliably predicted by peak intensity measures or pulse-period ratios ((Formula presented.)) alone; rather, velocity-related parameters and pulse coherence govern the structural response. These results demonstrate that integrating empirical model calibration with pulse-sensitive seismic analysis is essential for reliable seismic assessment and conservation planning of slender historical masonry structures located in near-fault regions. The study offers a systematic framework that integrates model calibration and pulse-sensitive seismic analysis for evaluating the drift-controlled response of slender historical masonry minarets in near-fault regions.
AtıfScopus5WoS4OpenAlex4İncele - MakaleYalnız künye2026Scopus SJRQ1The effect of digital and traditional methods on learning and retention in preschool education: a comparison of virtual reality, augmented reality, web-based, and manipulative materials
Tutkun, Cansu
The pedagogical use of digital technologies in early childhood education is increasingly prevalent today. Augmented reality, virtual reality, and web-based content have the potential to make children’s learning processes more interactive and lasting. In this context, the study compared the effects of different teaching methods presented with augmented reality, virtual reality, web-based, and manipulative (traditional) materials on children’s learning and retention levels. In the quasi-experimental study, a total of 400 children attending preschool education institutions in Bayburt, Turkey, were divided into four different groups and evaluated using a “pre-test–post-test–retention test” model. The results revealed that the virtual reality group achieved the highest scores in both learning and retention levels, followed by the augmented reality and web-based groups, while the manipulative group demonstrated the lowest performance. In addition, the virtual reality environment was evaluated by children as the most enjoyable and satisfying method, and children in this group were the most willing to use the training again. These results show that digital technologies such as virtual and augmented reality in preschool education should be evaluated as effective tools in terms of achieving pedagogical goals and increasing children’s interest in learning.
- MakaleAçık Erişim2026Scopus SJRQ1Waveguide-Based Microwave S-Parameter Measurements for Machine Learning-Assisted Classification of Paprika Powder Adulterants
Alptekin Engin, Mustafa
Detecting food adulteration in powdered spices through visual inspection is difficult, and paprika powder is particularly susceptible to adulteration due to its fine particulate structure and intense color. This study proposes a waveguide-based microwave S-parameter measurement approach combined with machine learning for the classification of organic and mineral adulterants in paprika powder. The experimental dataset was created by intentionally adulterating a commercial paprika brand with five organic and five mineral materials in varying proportions. The S11 and S21 scattering parameters, measured in the 3.3-4.9 GHz frequency range, of these samples, comprising a total of 11 different classes including pure paprika, were used as input in the machine learning-based classification process. The proposed framework directly uses frequency and S11 and S21 responses to distinguish pure paprika from ten adulterant types without complex feature extraction. S-parameter measurements were performed iteratively for each condition using a vector network analyzer, and the average values were used in the analyses. The frequency-point-level performance of the model was examined with different training/test data splitting ratios during the classification process. Furthermore, 10-fold cross-validation was performed during the training phase, and the performance of different classifiers was evaluated comparatively using overall and balanced validation and test accuracies. Under random point-wise partitioning, Subspace KNN achieved the highest numerical performance, with a mean frequency-point-level test accuracy of 99.86±0.06% across 10 independent runs. The findings demonstrate the frequency-point-level separability of microwave S-parameter responses under the investigated experimental conditions.
- MakaleAçık Erişim2026Scopus SJRQ1Effect of fiber architecture and CNT reinforcement on the mechanical behavior and formability of thermoplastic PE composites
Gavgali, Esma; Dilmec, Murat
Lightweight thermoplastics with improved mechanical performance and formability are critical for aerospace, defense, and automotive applications. Despite this, the coupled effects of nanoscale carbon nanotube (CNT) reinforcement and fiber architecture on formability-dominated deformation remain insufficiently explored. This study investigates polyethylene (PE) matrix fiber-reinforced composites manufactured with and without CNT modification to clarify these effects. Mechanical behavior was evaluated through tensile, flexural, hardness tests, while biaxial formability was assessed using the Erichsen test. Fracture mechanisms were analyzed by scanning electron microscopy (SEM). The results indicate that CNT addition significantly improved glass fiber laminates, with peak forming loads increasing by up to 152% for plain weaves and 211% for twill weaves. In contrast, carbon fiber laminates showed only marginal improvements (≤5%), attributed to their inherently high interfacial efficiency. The CNT-reinforced twill carbon fiber composite achieved the highest tensile strength (240.32 MPa) and hardness (66.8 Shore D), while the CNT-reinforced plain glass composite exhibited the highest flexural strength (43.19 MPa). SEM observations revealed composites predominantly failed through fiber–matrix debonding, matrix plastic deformation, and fiber pull-out. Overall, the results show that optimizing fiber type, textile architecture, and CNT reinforcement enables PE-based composites with balanced strength, stiffness, and formability for multiaxial loading applications.
- MakaleAçık Erişim2026Scopus SJRQ1Investigating the relationship between social presence and transactional distance in online distance learning environments through structural equation modeling analysis
Yavuz, Mehmet; Kayalı, Bünyami; Üstün, Ayşin Gaye; Uçar, Hasan; Erdoğdu, Erdem; Bozkurt, Aras
While digitalization has increased flexibility in online distance learning, it has also brought challenges such as emotional strain, interactional issues, and social isolation. In this context, students’ sense of social “presence” is vital for sustaining their well-being and ensuring high-quality interaction. Grounded in Transactional Distance Theory (TDT) and the Community of Inquiry (CoI) framework, this study modeled the relationships between social presence (SP) and interaction types within the using Structural Equation Modeling (SEM). The Social Presence and Transactional Distance Scales were used as data collection instruments. The sample comprised 574 online distance learners, with data collected via an online questionnaire. The results of the SEM analysis showed that SP was a significant positive predictor of all interaction types. Findings show that SP most strongly influences student–student and student–learning environment interactions, while also significantly enhancing student–instructor, student–content, and student–interface interactions. These results indicate that online learning environments should support not only content delivery but also meaningful social interaction. The study highlights the value of SP-oriented design in open, online and distance education systems and offers strategic recommendations for instructors, content developers, and digital learning administrators. Future research should compare synchronous and asynchronous learning structures.
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