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Koleksiyondaki öğeler
- MakaleAçık Erişim2025Scopus SJRQ3Tailoring the optoelectronic properties of ZnO nanowires via TiO2 coating
Sarac, Mehmet Fahri; Mert, Merve; Solakyildirim, Tuba; Teber, Ahmet
The photosensing properties of TiO2/ZnO nanowires (NWs) were investigated by sequential deposition using thermal oxidation and sol–gel. It was found that TiO2/ZnO NWs with 5 mM concentration exhibit a higher aspect ratio compared to the 10 mM and 25 mM TiO2/ZnO NWs. The surface-to-volume ratio directly influences the photoluminescence (PL) intensity and electrical properties of the ZnO NWs. XPS confirmed the presence of TiO2 on the surface, while EDS detected titanium, with its concentration increasing as the TiO2 concentration rises. The photosensing performance of ZnO has been significantly improved by modifying it with TiO2. However, determining the optimum concentration is a critical factor in performance improvement. The findings show that high TiO2 concentrations improve surface properties, but excessive coating may limit carrier mobility. Photosensitivity has been increased at lower TiO2 concentration due to a higher surface-to-volume ratio (SVR) and, as a result, higher surface photoactivity. The 25 mM TiO2/ZnO NW array stands out in optimal detectability and photoresponsivity due to the reduced resistance caused by the increased Ti concentration on the surface. The 25 mM TiO2/ZnO NWs achieved the highest photoresponsivity (717 mA/W) and specific detectivity (1.48 × 101° Jones), while the 5 mM TiO2/ZnO NWs exhibited exceptional photosensitivity (320.11%), making them ideal for UV detection. The samples at varying concentrations show promise in photosensitivity, detectability, and photoresponsivity, making them suitable for environmental sensors, UV detectors, and other optoelectronic applications.
AtıfOpenAlex1
İncele - MakaleAçık Erişim2024FROM MONEY TRANSFERS TO MEAL TABLES: UNRAVELLING THE NEXUS OF REMITTANCES, FOOD SECURITY, AND ECONOMIC GROWTH IN TURKEY
Ari, Yılmaz Onur; Zeneli, Fjona
The link between remittances, food security, and economic growth is a complex and important element of the economic development of the society. The study aims to explore the causality relationships between Remittances, Food Security and Economic Growth in the Turkish economy. The period of study from 1974 to 2018 and annual data of Remittances, Calories intake (as a proxy for the food security) and Economic Growth are used in the framework of time series. Techniques such as Zivot-Andrews (ZA) unit root, Toda-Yamamoto (TY), Breitung-Candelon (BCG), and Hatemi-J tests are used to detect the causality assessing the direction of it. The main findings consist of: (i) the presence of cointegration of rank two among series, the lack of linear TY time domain causality; (ii) the presence of BCG spectral causality from Calories intake to Growth only in medium period at 10% significance and, (iii) the presence of asymmetric causality from Remittances to Growth in positive changes, from Growth to Calories intake in negative changes and from Calories intake to Remittances in positive changes respectively at 1,5, and 1% significance. These results provide policymakers with valuable insights into the complexity nature of the relationship among remittances, food security, and economic growth, guiding them in designing effective strategies for poverty alleviation, sustainable development, and inclusive growth.
AtıfOpenAlex1İncele - Kitap BölümüYayıncıda açık erişim2026Scientific Trends Towards the Use of Generative Artificial Intelligence Tools in Early Childhood STEM Education: A Bibliometric Analysis
Çakir, Zehra; Uğraş, Mustafa
This study aims to analyze scientific publications on the use of productive artificial intelligence tools in STEM education during early childhood between 2021 and 2025 using bibliometric methods. In this context, the international literature published during the relevant period was examined to identify scientific production trends, prominent authors, influential studies, institutional and international collaboration networks, and thematic focuses. A total of 1, 224 documents were included in the analysis. During the data analysis process, the Bibliometrix (Biblioshiny) software running on the R program was used; publication trends, keyword frequencies, citation analyses, author and institution collaborations, and scientific mapping techniques were utilized. The analysis findings show that academic interest in productive artificial intelligence tools has increased significantly between 2021 and 2025. The study also systematically identifies key trends, application areas, and research gaps related to the integration of these technologies into educational processes.
- MakaleAçık Erişim2025Scopus SJRQ1ChatGPT in Early Childhood Science Education: Can It Offer Innovative Effective Solutions to Overcome Challenges?
Uğraş, Mustafa; Çakır, Zehra; Zacharis, Georgios; Kalogiannakis, Michail
This study explores the potential of ChatGPT to address challenges in Early Childhood Science Education (ECSE) from the perspective of educators. A qualitative case study was conducted with 33 Early Childhood Education (ECE) teachers in Türkiye, using semi-structured interviews. Data were analyzed through content analysis with MAXQDA 24 software. The results indicate that ECE teachers perceive ChatGPT as a partial solution to the scarcity of educational resources, appreciating its ability to propose alternative material uses and creative activity ideas. Participants also recognized its potential to support differentiated instruction by suggesting activities tailored to children’s developmental needs. Furthermore, ChatGPT was seen as a useful tool for generating lesson plans and activity options, although concerns were expressed that overreliance on the tool might undermine teachers’ pedagogical skills. Additional limitations highlighted include dependence on technology, restricted access to digital tools, diminished interpersonal interactions, risks of misinformation, and ethical concerns. Overall, while educators acknowledged ChatGPT’s usefulness in supporting ECSE, they emphasized that its integration into teaching practice should be cautious and balanced, considering both its educational benefits and its limitations.
AtıfScopus7WoS2OpenAlex8İncele - MakaleAçık Erişim2026Scopus SJRQ1Cognitive improvement and hippocampal BDNF/GFAP alterations by Schinus molle essential oil in a rat model of scopolamine-induced amnesia
Üçel, Umut İrfan; Kandemi̇r, Ümmühan; Yazici, Cevşen; Bi̇lgi̇n, Öznur; Turan Yücel, Nazlı; Özek, Temel; Demi̇r Özkay, Ümide; İşcan, Gökalp; Can, Özgür Devrim
Ethnopharmacological relevanceSchinus molle L. (Anacardiaceae) has been traditionally used for conditions related to the nervous system and emotional well-being, often through aromatic preparations. However, its cognition-specific effects have not yet been investigated.Aim of the studyTo assess the cognitive effects of the fruit-derived essential oil of Schinus molle L. (SMEO), administered via oral and inhalation routes, in a rat model of scopolamine-induced amnesia.Materials and methodsSMEO was obtained by hydrodistillation and characterised by GC–MS/GC–FID. Amnesic rats received SMEO for 14 days by inhalation (1% or 3%) or oral gavage (100 or 200 mg/kg). Cognition was assessed by Morris water maze (MWM), passive avoidance (PA), and novel object recognition (NOR) tests; locomotion was measured by activity-meter. Hippocampal BDNF and GFAP immunoreactivity were assessed by immunohistochemistry.ResultsSMEO was dominated by α-phellandrene (48.7%). Scopolamine impaired cognition, whereas SMEO attenuated deficits with efficacy comparable to piracetam. Key behavioural and immunohistochemical findings (main omnibus statistical effects) were as follows: In the MWM, treatment and time effects on escape latency were significant (both p < 0.001), and probe performance improved (p < 0.001). PA retention was restored (p < 0.001) and the NOR index improved (p < 0.001), without locomotor changes (all p > 0.05). Scopolamine reduced hippocampal BDNF immunoreactivity in CA1 and DG (p < 0.01) and CA3 (p < 0.001), which was restored by SMEO via both routes. GFAP immunoreactivity was reduced in CA1/CA3/DG (all p < 0.001) and was rescued selectively after inhalation.ConclusionsThese findings provide preclinical evidence consistent with an ethnopharmacological rationale for SMEO and support further translational work to clarify its relevance beyond this experimental paradigm.
AtıfScopus1WoS1OpenAlex1
İncele - MakaleAçık Erişim2026Scopus SJRQ2The mediating role of social support in the relationship between social isolation and life satisfaction in families with and without children with special needs
Yayla, İbrahim Erdoğan; Turhan, Fatma Seher; Dombak, Kübra; Makas, Samet; İskender, Murat; Çelik, Eyüp
Objectives: The present study aims to examine the relationships between social isolation, social support, and life satisfaction in parents with and without children with special needs. Methods: The data for this study were obtained from 422 parents with children. Of the participants, 266 (63.0%) were mothers, and 156 (37.0%) were fathers, with an average age of 39.43 (SD = 7.62; range = 22–65). Convenience sampling was used in this study. When examining the marital status distribution, 386 participants (91.5%) were married, and 36 (8.5%) were single. Furthermore, 203 parents (48.1%) stated that they had a child with special needs, while 219 (51.9%) stated that they did not have a child with special needs. Results: The correlation analysis revealed that all variables are related to each other. Furthermore, structural equation modeling results showed that social support plays a mediating role in the relationship between social isolation and life satisfaction. Conclusions: This research evaluates parents with and without disabled children in terms of social isolation, social support, and life satisfaction, and indicates that social support is significantly more important for parents with disabled children compared to those without.
- MakaleAçık Erişim2025Scopus SJRQ1Characterization and immune-modulatory roles of branched glucan and acetylated gluco-oligosaccharides produced by glucansucrase 40 from Leuconostoc mesenteroides YTU 40
Dere, Sevda; İspirli, Hümeyra; Korkmaz, Kader; Tuncil, Yunus Emre; Sagdic, Osman; Narbad, Arjan; Ayyash, Mutamed; Dertli, Enes
Glucansucrases (GS) are functional enzymes for the production of distinct glucan and gluco-oligosaccharide structures with potential bioactive characteristics. In this study, an active glucansucrase (GS40) was identified within the genome of Leuconostoc mesenteroides YTU 40 that was further cloned, heterologously expressed and biochemically characterised. GS40 was capable of production of a branched dextran with ~ 20% (1→3)-α-D-Glc residues detected by1H and13C NMR analysis. Acceptor reactions of GS40 with maltose and cellobiose were performed and distinct maltose/cellobiose derivative acetylated gluco-oligosaccharides were produced detected by TLC, NMR and LC-MS analysis. The bioactive characteristics of branched dextran and gluco-oligosaccharides were tested by determination of their immune-modulatory roles in terms of triggering IL-12, IL-10, IL-4 and TNF-α cytokine levels. These findings can be important to unveil the role of glucansucrases for the production of gluco-oligosaccharides that can be used as functional ingredients for food and other industries.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2026Scopus SJRQ2Probiotic Yogurt With Chokeberry (Aronia melanocarpa (Michx.) Elliot) Sauce Flavored With Date (Phoenix dactylifera L.) Fruit: Comparison of Nero and Viking Cultivars
Arslaner, Ayla; Yücetepe, Aysun; Akköse, Ahmet
The present study investigated the effect of adding chokeberry sauce (CS) from different cultivars (Nero and Viking) on specific quality attributes, total phenolic contents, antioxidant activity, textural qualities, sugar profile, probiotic shelf life, and sensory properties of probiotic yogurts, which were assessed throughout 21 days of cold storage. The results revealed that CS decreased fat, hardness, adhesiveness, and gumminess while increasing ash, total sugar, dry matter, and total calories. From Day 1 to Day 14 of storage, the pH values of CS-added samples significantly decreased (p < 0.01), whereas those in the control remained unchanged (Ky: 0% CS). The springiness and cohesiveness values of the Ky and Vy (20% Viking-CS) samples were comparable. During storage, CS-added yogurt samples’ water-holding capacity (WHC) was significantly higher than that of the control (p < 0.01). Interestingly, yogurt samples showed a notable rise in viscosity up to 14 days of storage, after which they slightly reduced. Ny (20% Nero-CS) and Vy samples exhibited higher red-blue hues than Ky. Vy had greater Lactobacillus acidophilus La-5 survival rates (99.28%) than Ny (99.04%). CS-added samples exhibited significantly higher antioxidant activity, total phenolic content, and total monomeric anthocyanin content compared to Ky; Vy also had the highest values (p < 0.05). Vy showed relatively high scores regarding organoleptic properties, including appearance, taste, texture and consistency, fruit ratio, overall acceptability, and average score. These indicators could help develop a healthier, low-calorie probiotic CS-added yogurt that competes with natural fruit-added yogurt.
- MakaleAçık Erişim2025Scopus SJRQ2The role of NiO in isotype heterojunction photodiodes
Sevgili, Ömer; Orak, İkram; Özel, Sultan Süleyman; Özel, Faruk
This study presents a structural analysis of NiO and the fabrication of Al/NiO/p-Si isotype heterojunction photodiode (PD) as well as an investigation of the photo-response and photovoltaic (PV) properties of the PD in the various illumination intensities. The series resistance (RS) value of the Al/NiO/p-Si was calculated to be 0.11 kΩ using Ohm’s Law at 2 V. This result corroborates the assertion that RS is the pivotal parameter for attaining optimal performance in a PD. The NiO has made a notable improvement to the electrical parameters such as ideality factor, barrier height, and series resistance. The spectral responsivity R value of the PD was calculated as 1.59 A W−1 at −2 V. The Al/NiO/p-Si exhibited a short-circuit current density (JSC) of 60.38 mA·cm−2, an open-circuit voltage (VOC) of 149.0 mV, a fill factor (FF) of 27.67%, and a power conversion efficiency (PCE) of 2.49%. In view of the experimental results, it can be concluded that NiO represents a promising material for the optimization of heterojunction photodiode applications.
- MakaleAçık Erişim2024Scopus SJRQ2Electrical properties of Al/CZTSe nanocrystal Schottky diode
Kişnişci, Z.; Özel, F.; Karadeniz, S.; Tuğluoğlu, N.; Özel, S.S.; Yüksel, Ö.F.
In this study, electrical changes in diode parameters of Schottky diodes that made of a kesterite semiconductor were examined under different temperatures. For this aim, Cu2ZnSnSe4 (CZTSe) nanocrystals were fabricated using the hot injection technique, and it was covered by spin coating on an ITO glass substrate. We was introduced the physical and structural analyses using scanning electron microscopy and X-ray spectroscopy. Current–voltage measurements were fulfilled at different temperature (from 100 to 325 K) under dark environment. It was observed that its electrical parameters were strongly affected by temperature.
AtıfScopus11WoS10OpenAlex10İncele - MakaleYayıncıda açık erişim2024Scopus SJRQ1Do we need a guideline for all: a qualitative study on the experiences of male athletes following anterior cruciate ligament reconstruction
Gökmen, Mehmet Yiğit; Çepikkurt, Fatma; Belibağlı, Mehmet Cenk; Uluöz, Mesut; Özyol, Funda Çoşkun; Bavlı, Özhan; Karıncaoğlu, Ergin; Uluöz, Eren; Türkmen, Mutlu
Background: Considering the low rate of qualitative studies on athletes with anterior cruciate ligament reconstruction (ACLR), aiming to access in-depth data, we thought that the utilization of the qualitative method would allow us to collect the appropriate and sufficient data to yield novel findings and achieve sound conclusions. The study’s aim was to investigate anterior cruciate ligament (ACL) injury experience processes in athletes who had undergone isolated ACLR, reveal the clinically related milestones, and highlight the necessary gaps. Methods: Semi-structured interview techniques, in-depth follow-up questions, and thematic analysis were used to explore the experiences of participants with isolated ACL injuries 1–3 years after surgical treatment. The study was conducted in the Orthopaedics and Traumatology outpatient clinic of the Adana City Training and Research Hospital and included 14 male athletes who had undergone isolated primary ACLR. The study group’s demographic and qualitative data were collected in the first week of September 2023. The member checking process was completed in the third following week. A thematic analysis checklist was used to ensure the reliability of the thematic analysis. The Consolidated Criteria for Reporting of Qualitative Research (COREQ) guidelines were followed. Results: The experiences of 14 patients (22.78 ± 3.76 years, all males) were summarized into four themes that emerged from the data analysis process: ‘The Distinctions in the Participants’ Experiences Regarding the Moment of Injury,’ ‘Gathering Information about the ACL Injury,’ ‘Factors That Facilitate The Treatment Process and Reinforce Positive Experiences,’ and ‘Desperate Plight: Main Points of Patients’ Negative Experiences.’ Based on the main themes, there were 14 subthemes. Conclusions: Our study revealed that varying perceptions of ACL injury presented by the participants, which were caused by all stakeholders, including themselves, the professional environment, family members, social network, and the healthcare staff, showed that the physical and psychological impacts of the injury were observed in different severity levels at each stage of the process. We believe that an extensive guide for athletes with ACL injuries that includes all components of well-being and displays the required details for the sports club/coach, family/companion, and physician.
AtıfWoS1OpenAlex1İncele - MakaleYalnız künye2022Scopus SJRQ1Avanafil as a Novel Therapeutic Agent Against LPS-Induced Acute Lung Injury via Increasing CGMP to Downregulate the TLR4-NF-κB-NLRP3 Inflammasome Signaling Pathway
Aydin, Pelin; Magden, Zeynep Berna Aksakalli; Uzuncakmak, Sevgi Karabulut; Halici, Hamza; Akgun, Nurullah; Mendil, Ali Sefa; Mokhtare, Behzad; Cadirci, Elif
Aim: We demonstrate the effect of PDE5 inhibitors in cases of acute lung injury via the relationship between cGMP/NO and the TLR4-NF-κB-NLRP3 pathway. Materials and Methods: This study was performed with 30 male Wistar albino rats. Lipopolysaccharide (LPS) was administered intratracheally to the rats and acute lung injury (ALI) was induced. Twelve hours after LPS administration, avanafil, prepared at suitable doses according to the body weights of the animals, was administered by oral gavage. Lung tissue samples of all groups were examined histopathologically and by immunochemical staining (IL-1β, iNOS, TLR4, and NF-κB). The iNOS, NLRP3, and IL-1B mRNA expression levels in the lung tissues were measured by RT-PCR. The left upper lobes of the rat lungs were dried at 70 °C for 48 h and lung water content was calculated. Result: Statistically significant increases in iNOS, NLRP3, and IL-1β mRNA expressions were observed in the rats with ALI compared to the healthy controls (p < 0.0001). Those increased expressions were reduced at both doses of avanafil (p < 0.0001). This reduction was found to be greater at 20 mg/kg (p < 0.0001). IL-1β, iNOS, TLR4, and NF-κB immunopositivity was moderate/severe in the ALI group and mild in the group with ALI + avanafil at 20 mg/kg (p < 0.05). When the wet/dry lung ratios were calculated, a statistically significant increase was seen in the ALI group compared to the healthy rats (p < 0.05). That increase was decreased with both avanafil doses (p < 0.05). Conclusion: We suggest that avanafil may prevent the progression of ALI and be effective in its treatment. We hope that this study will be supported by future clinical studies to yield a new indication for avanafil.
AtıfScopus18WoS21OpenAlex17İncele - MakaleYalnız künye2023Scopus SJRQ1Assessing Acute Responses to Exercises Performed Within and at the Upper Boundary of Severe Exercise Domain
Norouzi, Mahdi; Cabuk, Refik; Balci, Gorkem Aybars; As, Hakan; Ozkaya, Ozgur
Purpose: The highest work-rate that provides maximal oxygen uptake ((Formula presented.)) may be one of the best exercise stimuli to yield both (Formula presented.) and lactate accumulation. The aim of this study was to analyze physiological and metabolic acute responses of an exercise modality performed at the upper boundary of the severe exercise domain, and compare those responses with exercise modalities applied within the severe exercise domain. Method: Ten trained male cyclists participated in this study. The (Formula presented.), corresponding power output (POVO2max), and the highest work-rate that provides the (Formula presented.) (IHIGH) were determined by constant work-rate exercises. Cyclists performed three high-intensity interval training (HIIT) strategies as follows; HIIT-1: 4–6 × 3-min at 95% of POVO2max with 1:1 (workout/rest ratio); HIIT-2: 16–18 × 1-min at 105% of POVO2max with 1:1; HIIT-3: 4–7 × 1-2-min at the IHIGH with 1:2. Capillary blood samples were analyzed before, immediately after HIIT sessions, and at the first, third, and fifth minutes of recovery periods. Lactate difference between the highest lactate response and resting status was considered as the peak lactate response for each HIIT modality. Results: Time spent at (Formula presented.) was greater at HIIT-1 and HIIT-3 (272 ± 127 and 208 ± 111 seconds, respectively; p = 0.155; effect size = 0.43) when compared to the HIIT-2 (~26 seconds; p < 0.001), while there was a greater lactate accumulation at HIIT-3 (~16 mmol·L−1) when compared to HIIT-1 and HIIT-2 (12 and 14 mmol·L−1, respectively; p < 0.001). Conclusions: In conclusion, HIIT-3 performed at IHIGH was successful to provide time spent at (Formula presented.) with a greater lactate accumulation in a single session.
AtıfScopus8WoS8OpenAlex6İncele - MakaleAçık Erişim2024Scopus SJRQ1Investigating the Effectiveness of Augmented Reality Technology in Science Education in Terms of Environmental Literacy, Self-Regulation, and Motivation to Learn Science
Arici, Faruk
Augmented Reality (AR) is a technology that provides users with an engaging learning experience by placing interactive virtual 3D models in natural environments. It is known that the use of AR technology in science education has many educational benefits. This study investigated the impact of AR technology on the development of environmental literacy, self-regulation skills, and motivation for science learning, which are increasingly important skills. Acquiring these high-level skills is essential for supporting students’ development in preventing environmental problems, addressing the motivation decrease seen primarily due to distance learning, and acquiring the self-regulation skills that have gained importance due to distance learning. The study was conducted with a quasi-experimental design on fifth-grade students, with one experimental (34) and one control (36) group. The findings were analyzed through MANOVA and content analysis. The results showed that AR technology supports environmental sensitivity, positive behavior, and the development of environmental knowledge and skills. In addition, AR technology has significant contributions in terms of self-regulation. Finally, it is recommended to use AR technology in science education to develop these variables and positively affect participants’ motivation for science learning.
AtıfScopus22WoS17OpenAlex18İncele - MakaleAçık Erişim2023Evaluation of activity-based mathematics teaching to students with learning disabilities in out-of-school learning environments
Filiz, Tunahan; Güneş, Gönül
This study aimed to support primary school students with learning difficulties in out-of-school learning environments with artistic or sportive activities. The case study method, one of the qualitative research methods, was used in the study. The activities prepared for students with learning difficulties were shaped by considering four learning areas (numbers, geometry, measurement, and data processing). Each learning area was associated with music, visual arts, sports, and drama methods, respectively. The prepared activities were implemented for four days between 16-19 April 2023, when schools were on holiday. The activities were applied to students in 20 lessons in five lessons of 40 minutes each day. The project's target group consisted of 24 students officially diagnosed with learning disabilities and attending the third and fourth grades of primary school. This study collected data from interviews, observation, document review, and curriculum-based evaluation methods. The content analysis method was used for data analysis. The results of the study show that activity-based mathematics teaching has a positive effect on student learning. Artistic or sportive activities can be added to school programs for students with learning difficulties to learn in real-life environments.
AtıfScopus2OpenAlex1İncele - MakaleAçık Erişim2023Scopus SJRQ1Green Synthesis, Characterization, Antioxidant, Antibacterial and Enzyme Inhibition Effects of Chestnut (Castanea sativa) Honey-Mediated Silver Nanoparticles
Keskin, Merve; Kaya, Gülşen; Bayram, Sinan; Kurek-Górecka, Anna; Olczyk, Paweł
In this study, chestnut honey-based silver nanoparticles (CH-AgNPs) were synthesized at different temperatures (30, 60 and 90 °C) and these nanoparticles were characterized by different techniques such as UV–vis spectrophotometer, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The DPPH free radical scavenging assay was used to determine the antioxidant activity of the obtained nanoparticles. The inhibition effects of these nanoparticles for some clinically important enzymes such as myeloperoxidase and collagenase were investigated. In addition, the disk diffusion method (DDM), agar well diffusion (AWD), and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) techniques were used to determine the antibacterial activity of CH-AgNPs. In honey-based silver nanoparticle production processes using green synthesis, it was determined that the nanoparticle sizes decreased from 55 to 27 nm with an increase in temperature. In addition, it was determined that the rate of inhibition of myeloperoxidase (36.4% to 34.0%) and collagenase enzymes (74.2% to 68.7%) increased with a decrease in particle size. As a result of the antibacterial activity tests, it was observed that CH-AgNPs have antibacterial activity against all target pathogens including Gram-positive and Gram-negative bacteria. The obtained results show that CH-AgNPs produced using chestnut honey have the potential to be used in fields such as medicine, pharmacy and cosmetic technology.
AtıfScopus48WoS41OpenAlex42İncele - MakaleAçık Erişim2026Scopus SJRQ4Comparative analysis of stress distributions and safety factor in tensile test specimens with different notch and hole geometries by finite element method
Korkmaz, Sümeyye Erdem; Gavgali, Esma
This study analyzes the effects of different notch and hole geometries (V-Notched, U-Notched, circular hole) on stress concentration in Ti-6Al-4V (Grade 5) Titanium alloy tensile specimens to provide optimized design recommendations for aerospace and biomedical applications. Finite element method (ANSYS Workbench) was employed to analyze three geometries under 15000 N static tensile loading. Von Mises stress distributions and stress concentration factors (Kt) were calculated and validated against Peterson and Neuber theoretical formulas with average error ±1.5%. Results revealed that V-Notched exhibited highest stress concentration (Kt = 5.78, σmax = 1156 MPa), while circular hole showed lowest (Kt = 2.25, σmax = 454.12 MPa). U-Notched demonstrated intermediate performance (Kt = 2.84, σmax = 995.45 MPa). Increasing notch root radius from 0.5 mm to 2.0 mm achieved 51% reduction in stress concentration factor. Maximum shear stress values were 232.74 MPa, 506.38 MPa, and 640 MPa for circular, U-Notched, and V-Notched respectively, while maximum normal stress values reached 467.06 MPa, 1015.1 MPa, and 1809 MPa. Safety factor analysis showed that circular hole configuration meets aerospace standards (FS = 2.05 > 1.5), while U-Notched (FS = 0.93) and V-Notched (FS = 0.80) fall below minimum safety criteria. U-Notched exhibited highest total displacement (1.210 mm), indicating compliance effects. For aerospace and biomedical applications, circular holes should be preferred over sharp notches (154% stress reduction), and minimum corner radius ≥2.0 mm is recommended. The critical finding that geometric optimization provides 2.6× safety improvement without material changes demonstrates the powerful role of design in structural reliability for weight-critical applications.
- MakaleAçık Erişim2025Scopus SJRQ1The relationship between emotional intelligence levels, stress management skills and hormonal and cerebral responses in university students
Bayraktar, Bülent; Battal, Fetullah
Background: Emotional intelligence is a person’s ability, capacity and ability to understand, use, understand, manage, anticipate, manage and direct the emotions of oneself or others. Students with high levels of emotional intelligence express themselves better, are more resistant to stress in their lives, and are individuals who can direct their emotions. Leaders with strong emotional intelligence will create synergy for all employees. Therefore, emotional intelligence and stress management skills are important issues in the field of leadership and organizational behavior. At the same time, emotional intelligence and stress management skills interact with hormones. This study aims to examine the emotional intelligence levels and hormone (apelin, cortisol) and cerebral (Brain-derived neurotrophic factor (BDNF)) response of 4th-year students of the faculty of health sciences at the university, who are potential managers of the future in terms of some variables. Methods: The research was conducted using the cross-sectional data method with 167 university students aged 18–24 who were reported to be clinically healthy in Türkiye. Apelin, cortisol hormone and BDNF levels in the participants’ saliva samples were analyzed using the ELISA technique. The relationship between emotional intelligence level and total scores from the stress coping scale and salivary apelin, cortisol and BDNF levels were evaluated. Results: In the study, it was determined that the average level of apelin hormone in saliva was “2.36 ± 0.076)’’ ng/mL in girls and “2.57 ± 0.071’’ ng/mL in boys. In girls, the BDNF level was “3.19 ± 0.97’’ and the cortisol level was “2.04 ± 0.72’’. BDNF level in boys is “3.41 ± 0.94’’and cortisol level is “1.92 ± 0.59’’. There is a significant difference between the participants’ allowances (income levels) and the average levels of salivary apelin hormone, BDNF and emotional intelligence scale (p < 0.01). A positive, strong and statistically significant relationship was found between the participants’ emotional intelligence level and stress management skills and apelin and BDNF levels, and a negative, strong and statistically significant relationship was found between salivary cortisol levels (p˂0.01). Conclusions: High emotional intelligence and stress management skills are an important element of strategic importance for a successful management and professional success process in individuals who will work in fields that need people such as health, marketing, law, consultancy, medicine, teaching and the service sector. Our study determined that as university students’ emotional intelligence levels strengthened, the participants’ stress management skills, salivary apelin, and BDNF levels increased, and cortisol hormone levels decreased. As a result, monitoring and examining apelin, BDNF, cortisol hormones can be useful parameters in evaluating the interaction between individuals’ emotional intelligence level and stress management skills and hormone response.
AtıfScopus3WoS3OpenAlex5İncele - MakaleYalnız künye2026Scopus SJRQ2Effect of Erbium Addition to A380 Aluminum Alloy on Mechanical and Microstructural Properties
Gültekin, Çağrı; Çolak, Murat; Tabak, Yasemin; Şensoy, Abdullah Tahir
There are many studies on improving the properties of aluminum alloys, but the addition of rare earth elements occupies a particularly important place among them. In this study, the effect of erbium (Er) addition on the microstructure and mechanical properties of A380 aluminum casting alloy was systematically investigated. A series of alloys with varying Er contents (0.03%, 0.05% and 0.1 wt.%) was fabricated using the conventional casting method. The addition of Er led to significant grain refinement, primarily due to the formation of Al3Er intermetallic particles, which acted as potent nucleation sites during solidification. Optical microscopy and SEM analyses confirmed the morphological transformation of the eutectic silicon phase into a finer and more fibrous structure. Mechanical testing revealed that the alloy containing 0.1 wt.% Er exhibited the highest ultimate tensile strength (236 MPa), elongation (4.56%), and hardness (87.6 HB), indicating an optimal balance between strength and ductility. The improvement is attributed to both microstructural refinement and dispersion strengthening mechanisms. These results suggest that controlled Er addition can be an effective strategy for enhancing the performance of cast Al–Si alloys, making them promising candidates for demanding structural applications in the automotive and aerospace industries.
AtıfScopus3WoS1İncele - MakaleYalnız künye2026Scopus SJRQ2Multi-Pathway Renoprotection by Betanin Against Docetaxel Nephrotoxicity: Modulation of Inflammation, ER Stress, Apoptosis, and Ferroptosis
Süzen Celbek, Büşra; Akaras, Nurhan; Şimşek, Hasan; Mutlu, Hüseyin; Kızıl, Hamit Emre; Kandemir, Özge; Aygörmez, Serpil; Kandemir, Fatih Mehmet
Docetaxel (DTX), a cornerstone chemotherapeutic agent, has its clinical utility significantly limited by dose-dependent nephrotoxicity. This study investigated the multi-pathway renoprotective mechanisms of betanin (BTN), a natural antioxidant derived from beetroot, against DTX-induced kidney injury. Male Wistar rats received DTX (30 mg/kg, i.p., single dose) with or without BTN (100 mg/kg/day, p.o.) for 7 days. DTX induced severe renal dysfunction with elevated serum urea and creatinine, and significant oxidative stress characterized by increased MDA and decreased GSH, GPx, SOD, and CAT. Molecular analysis demonstrated widespread upregulation of pro-inflammatory (NF-κB, TNF-α, IL-1β), endoplasmic reticulum stress (PERK, ATF6), pro-apoptotic (Caspase-3, Bax, Apaf-1), and pro-ferroptotic (PTGS2, TfR1) mediators, with concurrent downregulation of protective Bcl-2 and GPx4. Histopathological examination revealed extensive tubular injury, while immunohistochemical analysis showed markedly increased kidney injury marker KIM-1 and decreased aquaporin-1 expression. Remarkably, BTN co-administration significantly attenuated all biochemical, molecular, and structural derangements, restored tissue architecture, and normalized KIM-1 and AQP-1 expression. In conclusion, betanin provides robust, multi-pathway renoprotection against docetaxel-induced nephrotoxicity by concurrently targeting oxidative stress, inflammation, ER stress, apoptosis, and ferroptosis.
