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- MakaleAçık Erişim2024Scopus SJRQ4Examining the Relationship between Foot Medial Arch Height and Short and Medium Distance Running Performances and Some Variables in Athletes
Temur, H. Bayram; Esen, Hüseyin; Inci, O. Bilge; Karadag, Hüseyin
In this study, the relationship between foot medial arch height, age, height, body weight, body mass index (BMI), calf and thigh thickness and 100-meter and 3000-meter running performances in athletes was investigated. 28 athletes competing in national competitions, with an average age of 18.29±5.68 years, were included in the study on a voluntary basis. The right foot medial arch heights, heights, body weights, calf and thigh thicknesses of the participants were determined. BMI's were calculated. Also, 100 m and 3000 m. running times were determined. Data analyzes were performed using descriptive statistics and correlation tests. As a result of the analysis, 100 m running performance had a negative relationship with the values of height (r= -.377), body weight (r= -.466), BMI (r= -.428) and thigh circumference (r= -.433). It was observed that there was a relationship with the calf circumference measurement value (-.496) at the p<0.01 level. On the other hand, it was determined that the relationship between foot medial arch height (r= -.178) was not significant (p>0.05). On the other hand, 3000 m running performance was negatively affected by height (r= -.493), body weight (r= -.641), BMI (r= -.625) and calf girth thickness (r= -.623). It was determined that it showed significance at the p<0.01 level. It was also determined that there was a significant relationship with medial arch height in a negative direction (r = -.404) and at p < 0.05. As a result, it can be said that foot medial arch height, height, body weight, BMI, thigh and calf circumference thickness values are effective on short and medium distance running performances.
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İncele - MakaleYalnız künye2025Scopus SJRQ2Bee bread from Anatolia: its chemical composition, phenolic and aromatic profiles, and antioxidant properties
Kolayli, Sevgi; Okumus Yukunc, Gulsah; Kara, Yakup; Demir Kanbur, Esra; Can, Zehra; Ozkok, Aslı; Tanugur Samanci, Aslı Elif
This study investigated the botanical origin, chemical composition, phenolic and volatile aromatic profiles, and antioxidant activities of 11 bee bread samples from different regions of Anatolia, Turkey. The bee bread samples contained high amounts of proteins (19.61 g/100 g) and lipids (6.43 g/100 g). The bee breads were determined to have a rich mineral content. The antioxidant potential of the bee breads was predicted using total phenolic content (TPC), total flavonoid content (TFC), total condensed tannin (TCT) content, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. The TPC of the bee breads ranged between 2.041 ± 0.170 and 3.224 ± 0.006 mg GAE/g, while the TFC ranged from 0.323 ± 0.004 to 1.903 ± 0.017 mg QE/g. The FRAP assay showed antioxidant activity ranging from 17.778 ± 0.207 to 49.752 ± 0.856 µmol FeSO4.7H2O/g, and the DPPH values were between 1.054 ± 0.009 and 4.366 ± 0.014 SC50 mg/mL. Using 25 standards, RP-HPLC-PDA quantified the composition of the phenolic compounds, attributed to their antioxidant activity. The highest concentrations were detected for t-cinnamic acid, rutin, and p-coumaric acid. One hundred nineteen volatile aromatic compounds were determined in the bee breads by solid-phase microextraction coupled with gas chromatography and mass spectrometry (SPME-GC-MS). The obtained values suggest that bee breads could serve as a potential source of nutrients and bioactive compounds for value-added food supplements and functional foods.
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İncele - MakaleAçık Erişim2025Scopus SJRQ1RETRACTED: Algorithmic management and reflexive ethnography: methodological innovations for practice-theoretical observation
Tutar, Hasan; Battal, Fetullah
Purpose – This study aims to reveal the alternative methodological possibilities offered by reflexive ethnography in this field, where classical observation techniques are inadequate, by conducting a sociological analysis of algorithmic management systems that have become widespread on digital platforms. Design/methodology/approach – In the research conducted with reflexive ethnography, which is a qualitative method, the researcher’s own experience, position and impact on the observation process are placed at the center of data production. This approach offers a more flexible and multi-layered analysis framework in digital environments shaped by variables and algorithms that replace fixed observation areas. Findings – Algorithmic management constantly controls the workforce with opaque decision processes. This situation creates behavioral orientations that are difficult to capture with classical ethnography. Reflexive ethnography provides a more holistic observation by including the researcher’s intuitive, technical and experiential data in understanding these systems’ internal logic. Research limitations/implications – Reflexive ethnography offers a strong methodological basis that is flexible enough to not only understand today’s governance systems but also to analyze the digital institutions of the future. Originality/value – Regarding future ethnographic research, reflexive ethnography has the potential to address not only algorithmic systems but also the effects of these systems on users, performance evaluation methods and the construction of affect and self. The interdisciplinary collaborations of this method with informatics, media studies, sociology and anthropology will provide methodological depth and analytical diversity. Furthermore, combining with other approaches such as cyber-ethnography, shadow ethnography and autoethnography, it can open up new research paths to understand the multi-layered structure of digital platforms. Thus, reflexive ethnography offers a strong methodological basis that is flexible enough to not only understand today’s governance systems but also to analyze the digital institutions of the future.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2023Scopus SJRQ1Optimum weight design of steel truss roof systems considering corrosion effect
Yaren Aydoğdu, Afranur; Artar, Musa; Ergün, Mustafa
In this paper, the ideal weight for steel truss roof systems is determined while corrosion is considered. Because one of the most crucial problems that steel truss roof systems may experience during their service life is the effect of corrosion. If a corroded structure is designed without considering this effect during the design phase, significant damages and even collapses may occur before it reaches its service life. For this reason, the aim of this study is to make weight optimizations by considering the corrosion effect of steel truss roof systems. Thus, it has been revealed how corrosion that may develop on the truss members' surfaces affects the structure's overall optimum weight. Swarm intelligence-based algorithm approaches, Ant Colony Optimization (ACO), and Butterfly Optimization Algorithm (BOA) are used for this purpose to determine the optimal weight design of five different steel truss roof systems that were previously researched. The main program, which includes structural analysis (FEA) and optimization algorithms, is coded in the MATLAB programming language. The compression and tension bars selected as the limiting functions of the optimization problems are obtained from the stress, displacement, and slenderness conditions specified in the American Institute of Steel Construction-Allowable Strength Design (AISC-ASD, 1989) standard. It is seen that the optimum weight results obtained from all optimization methods for each structure in the non-corrosive condition are relatively similar. This result proves the correctness of the algorithms proposed in this paper. Then, under the influence of corrosion, the optimal weight designs of the structures are carried out. When the findings for the two cases are examined, it can be seen that the optimum weight values for all structures have slightly increased. This is because larger profiles are required due to overcapacity brought on by section loss. The weight of the structure increases in lockstep with the severity of corrosion. All the results like this are presented in detail with the help of tables and graphs in the relevant sections.
AtıfScopus13WoS11OpenAlex18İncele - MakaleAçık Erişim2025Scopus SJRQ3A Systematic Review On Psychological Capital And Psychological Well-Being (1993-2023)
Battal, Fetullah
In the literature, many studies have been conducted on the terms of psychological capital and psychological well-being over the last thirty years. However, it has been observed that the interest in these concepts has increased today. Most of the studies have been obtained at the relational level or with quantitative methods. However, the number of studies in which the constructs of psychological capital and psychological wellbeing are examined systematically or qualitatively is quite limited. In this research, a systematic mapping was made for the relevant concepts using R and Rstudio programs together, with the help of data obtained from Wos. In this way, potential researchers will be capable of seeing the conditions of the relationship between psychological capital and psychological well-being in the last thirty years and will be able to have deeper and clearer information about the levels of related concepts. When we look at the most emphasised key concepts based on the analysis, it is sighted that keywords such as leadership, social capital, old age, hedonic wellbeing and good mood are at the forefront. When looking at niche areas of study, keywords such as climate change, adaptation, migration and innovation emerge. In other words, scientists doing research in the branches of administration and organisational or non-clinical psychology should look at graphs containing motor or basic concepts, if they want to do a deeper investigation and understand the subject in general. Based on these data, although the terms psychological capital and well-being are thought to be in the context of affirmative psychology, their relationship with the concepts that are popularly described as dark behaviours is also examined. By offering a systematic examination and guidance for the future, the data of the study adds something unique to the literature.
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İncele - MakaleAçık Erişim2026Scopus SJRQ3The Effect of Virtual Reality Training on Basic Hitting Performance in Tennis
ÇELİK, Hüsniye; TOZOĞLU, Erdoğan; AĞDUMAN, Fatih
The aim of this study was to investigate the effect of virtual reality (VR) training on basic stroke performance in tennis. In the fall semester of the 2023-2024 academic year at Atatürk University, 20 students without prior tennis experience participated. They were divided into two equal groups: the control group, which received only traditional training, and the experimental group, which received a combination of VR and traditional training. Each group included five male and five female students, all participating in an 8-week training program. A pre-test-post-test control group experimental design was used. Data were collected through a VR application and a performance test administered before and after training. Descriptive statistics and normality tests were conducted, with paired t-tests for intra-group comparisons and ANCOVA for inter-group comparisons, using SPSS 25. Results showed significant improvements in stroke performance in both groups. However, analysis revealed no statistically significant difference in forehand stroke performance between groups. In contrast, the experimental group demonstrated significant improvement in backhand performance compared to the control group. Findings suggest that both VR-based and traditional methods can effectively enhance basic stroke performance in tennis. Specifically, VR training proved particularly effective for improving backhand strokes, while no additional benefit was observed for forehand strokes compared to traditional training.
- Derleme MakaleAçık Erişim2026Environmental and economic analysis of industrial waste heat recovery with hybrid heat pump application
Kazici, Halil İbrahim; Tozlu, Alperen
Today, increasing energy demands and environmental concerns have made energy efficiency a necessity from both economic and ecological perspectives. High energy consumption in industrial facilities increases costs and raises CO2 emissions. Therefore, waste heat recovery and the use of renewable energy are among the fundamental goals of sustainable production. Energy efficiency is important not only for reducing consumption but also for lowering greenhouse gas emissions, protecting the environment, and strengthening the economics of the business. In this context, heat pump technologies, which extract energy from low-temperature sources and make it reusable, stand out as effective, environmentally friendly, and efficient systems in both heating and cooling applications. In this study, waste heat from a cooling tower generated during the production process in an industrial facility was recovered through a water-source heat pump and integrated into the facility's heating system. The heat pump increased the heat energy by using low-temperature water and reused it in the process. During periods when the waste heat was insufficient, the system was supported by natural gas boilers, thus creating a hybrid operating model between the heat pump and the boiler. As a result of the implementation, natural gas consumption and electricity usage were significantly reduced, leading to lower energy costs and a substantial decrease in CO2 emissions, thereby providing notable environmental benefits. The findings indicate that the proposed system achieves an annual natural gas saving of 6,788,251 kWh and a net financial gain of 5,703,864 TL. Additionally, the payback period of the investment is calculated as 2.41 years, demonstrating the economic feasibility of the system. Overall, this case study highlights that the widespread adoption of hybrid heat pump systems in the industrial sector can make significant contributions to Türkiye’s energy transition and carbon emission goals.
- MakaleAçık Erişim2025Scopus SJRQ2Investigation of the Effect of Vanadium Addition on Mechanical Properties in A356 Aluminum Casting Alloys
Çeker, Merve; Çolak, Murat
The superior properties of aluminum alloys are further improved by the addition of different elements and gain new qualities. In the aluminum casting industry, vanadium (V) addition plays an important role to improve the mechanical and physical properties of these alloys. In this study, different amounts of V (0.03%, 0.06% and 0.1%) were added to A356 alloy, and its effects on mechanical properties and microstructure were investigated experimentally. The liquid metal degassing process was applied in all experiments in order not to affect the results of gases and inclusions in the liquid metal before casting. In the study, degassing was assessed by the Reduced Pressure Test (RPT). Tensile and hardness test specimens were performed with specimens obtained from mechanical test molds. When the results were examined, the elongation amount, which was 2.7% in A356 casting without addition, increased with the addition of V and reached a maximum value of 7.6% with 0.1% V addition. Tensile stress values were 137 MPa in A356 castings without addition, 159 MPa with 0.03% V addition, 168 MPa with 0.06% V addition and increased up to 185 MPa with 0.1% V addition.
AtıfScopus5WoS5OpenAlex5İncele - MakaleAçık Erişim2025Scopus SJRQ2A Promising Antibacterial Inhibition of Propolis Extracts Against Carbapenem-Resistant Bacteria Isolated From Clinical Samples
Esertaş, Ülkü Zeynep; Inal, Neşe; Can, Zehra; Kolaylı, Sevgi
The increasing inadequacy of antibiotics against multidrug-resistant pathogens is a growing concern. In this study, the antibacterial activity of propolis extracts with different phenolic profiles against carbapenem-resistant clinical isolates was investigated. The antimicrobial activity of propolis extract was tested against Acinetobacter baumannii (K17, K16, and K21), Klebsiella pneumoniae (K22, and K19), and Stenotrophomonas maltophilia (E5, E7, and E4) bacterial strains isolated from tracheal aspirate and blood cultures. The total phenolic content and phenolic composition of the extracts were analyzed. Antimicrobial activity values examined according to the disk diffusion method were measured as minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The results showed that all propolis extracts showed different inhibition values against bacterial strains. As a result, the high inhibitory potential of the propolis extracts against resistant bacteria such as A. baumannii, K. pneumoniae, and S. maltophilia is promising for combating infections. However, the study needs to be supported by further randomized clinical studies.
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İncele - MakaleAçık Erişim2026Scopus SJRQ1Progressive Smartphone Restriction Combined with Psychoeducational Guidance and Pre-Sleep Autonomic Regulation Improves Sleep Efficiency and Time-of-Day Cognitive Performance in Physically Active Students with Nomophobia: A Randomized Controlled Trial
Alaya, Wiem Ben; Dhahbi, Wissem; Souissi, Mohamed Abdelkader; Jebabli, Nidhal; Ceylan, Halil İbrahim; Ceylan, Nagihan Burçak; Muntean, Raul Ioan; Souissi, Nizar
Aim: This study compared the effects of standard evening smartphone restriction with an adapted intervention combining progressive restriction, psychoeducational guidance, and pre-sleep relaxation on sleep, psychological state, cognitive performance, and physical performance in physically active physical education students with moderate-to-high nomophobia. Methods: Thirty participants (age 21.9 ± 1.2 years; intermediate chronotype) completed a randomized controlled trial consisting of a 7-day baseline period, a 14-day intervention phase, and post-intervention assessments. The standard group (n = 15) implemented a 2-h pre-bedtime smartphone restriction combined with general sleep hygiene guidance. The adapted group (n = 15) followed a progressive restriction protocol (30→60→120 min) supplemented with psychoeducational guidance targeting smartphone-related anxiety and a nightly slow-paced breathing routine. Objective sleep parameters were quantified using wrist-worn actigraphy. Subjective sleep quality, pre-sleep anxiety, and stress were assessed using visual analog scales. Cognitive performance (psychomotor vigilance task and choice reaction time) and physical performance (vertical jumps and agility) were evaluated at both morning and afternoon time points. Results: The adapted intervention produced significantly greater improvements in sleep efficiency (time × group: F(1,28) = 6.84, p = 0.014, ηp2 = 0.20; d = 0.78) and sleep onset latency (F(1,28) = 5.97, p = 0.021, ηp2 = 0.18; d = 0.72) compared with standard restriction. Significant reductions were also observed in pre-sleep anxiety (F(1,28) = 7.12, p = 0.012, ηp2 = 0.20; d = 0.81) and stress (F(1,28) = 6.45, p = 0.017, ηp2 = 0.19; d = 0.74). Cognitive performance showed significant time × group × time-of-day interactions, with improvements during afternoon assessments in psychomotor vigilance (F(1,28) = 7.48, p = 0.011; d = 0.83) and choice reaction time (F(1,28) = 6.89, p = 0.014; d = 0.79) exclusively in the adapted group. Physical performance outcomes remained stable across interventions. Conclusions: Progressive smartphone restriction combined with psychoeducational strategies and pre-sleep relaxation yields clinically meaningful improvements in sleep continuity, psychological arousal, and afternoon cognitive performance, exceeding the benefits achieved through behavioral restriction alone.
AtıfScopus1WoS1OpenAlex2İncele - MakaleAçık Erişim2026Scopus SJRQ3From black box to pedagogical partner: Students’ sense-making of LLM-based automated assessment
Kara, Abdulkadir; Yıldırım, Serkan
While current educational research on automated assessment heavily emphasizes technical validity, a significant gap remains in understanding students’ sustained, real-world experiences with these systems in authentic learning environments. This study examines students’ experiences with a large language model-based automated assessment system embedded in the regular flow of a university course. The study employed a mixed-methods design with 47 university students over a seven-week period. Quantitative data were obtained from system interaction logs and student feedback ratings, while qualitative data were collected from focus group interviews with 24 students and 175 written feedback responses. The results reveal that students perceive the LLM-based assessment system as a learning assistant, an impartial evaluator, and a self-assessment tool. The transparency of explanations was identified as a decisive factor in building trust in the algorithmic system by helping students understand the rationale behind scores and feedback. Sustained interaction with the system triggered a shift from high-frequency trial and error to more efficient and strategic participation, indicating that the assessment criteria were gradually internalized. The system appeared to create an environment free from perceived social judgment, providing favorable conditions for productive failure, repeated attempts, and self-directed revision. Overall, the study demonstrates that artificial intelligence can be positioned as a tool that scales pedagogical intent without replacing the teacher and can be effectively integrated within the framework of human–AI complementarity in higher education.
- MakaleAçık Erişim2026Scopus SJRQ4The Validity and Reliability Study of the Turkish Version of the E-Learning Satisfaction Scale
Karaman Özlü, Zeynep; Günaydinli, Azime; Kaya, Merve; Uçan, İzzet; Taşgin, Adnan; Özlü, İbrahim; Küçükoğlu, Adnan; Saraçoğlu, Ayhan
Objective: With the widespread adoption of e-learning during the COVID-19 pandemic and advances in internet technology, the need for a validated tool to assess student satisfaction has become increasingly important. This study aimed to examine the validity and reliability of the Turkish version of the e-Learning Satisfaction Scale (e-LSS). Methods: This cross-sectional, methodological study was conducted with 537 students enrolled in health sciences programs at Erzurum Atatürk University between November 2022 and February 2023. In this study, a non-probability sampling method was used by selecting units that met specific criteria. Content validity was evaluated by expert review of the scale items. Construct validity was assessed through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Reliability and stability of the scale were tested using the equivalent (parallel) forms method. Results: EFA results showed a Kaiser-Meyer-Olkin value of 0.94 and a significant Bartlett’s test result (χ² = 126.773, p<.001), indicating sample adequacy. Factor loadings ranged from .825 to .354 for the “Content” subscale, .859 to .571 for “Interface,” and .802 to .654 for “Communication.” CFA demonstrated acceptable model fit indices: χ²/df = 4.332, TLI = .915, RMSEA = .079, SRMR = .0481, AGFI = .857, GFI = .896, IFI = .931, and CFI = .930. The final scale consisted of 17 items across 3 subscales. Cronbach’s alpha values were 0.86, 0.86, and 0.83 for the subscales, and 0.93 for the overall scale. Conclusion: The scale was found to be a valid and reliable tool for measuring e-learning.
- MakaleAçık Erişim2025Scopus SJRQ1Moderated Mediation in Problematic Digital Gaming Among Adolescents: Self-Esteem, Social Anxiety, Self-Concealment, and Sensation Seeking
Yayla, İbrahim Erdoğan; Makas, Samet; Koçak, Lokman; Yıldırım, Murat; Dombak, Kübra
Background: Problematic digital gaming among adolescents is a common behavioral issue that has negative consequences on school functioning and mental health. Theoretically, it is predicted that low self-esteem paves the way for problematic gaming by increasing social anxiety and self-concealment; this indirect pathway may be stronger in sensation seeking adolescents. Aims: The aim of this study is to examine the relationship between self-esteem and problematic digital gaming among adolescents, first through the PROCESS Model 6 in terms of social anxiety and self-concealment as mediators, and subsequently through Model 89 in terms of moderated mediation by sensation seeking. Method: The sample consisted of 448 Turkish adolescents (243 (54.2%) males, 205 (45.8%) females) aged between 13 and 18 years (M = 15.9). Participants completed the Game Addiction Scale for Adolescents—Short Form, Rosenberg Self-Esteem Scale, Self-Concealment Scale, Brief Sensation Seeking Scale and the Social Anxiety Scale-8. Results: A significant negative relationship was found between self-esteem and problematic digital gaming. Social anxiety and self-concealment fully mediated this relationship (indirect effects were significant). Sensation seeking conditioned the mediation by strengthening pathways to problematic digital gaming (moderated mediation was significant). The indirect effect was greater in those with high sensation seeking. Conclusions: The findings indicate that the negative effect, ranging from self-esteem to problematic digital gaming, progresses through social anxiety and self-concealment, and that this mediation is strengthened in adolescents with high sensation seeking. These results emphasize the need to integrate social anxiety reduction and self-expression skills into interventions in a target-sensitive manner, taking into account differences in sensation seeking.
AtıfScopus2WoS2OpenAlex3İncele - MakaleYalnız künye2025Scopus SJRQ4EFFECT OF ELECTROMAGNETIC FIELD DERIVED FROM ELECTRIC FENCE SYSTEM ON SPERM ACTIVITIES OF HONEYBEES (Apis mellifera L.); [Elektrikli Çit Sistemi Tarafından Oluşturulan Elektromanyetik Alanın Bal Arılarının (Apis mellifera L.) Sperm Aktivitesine Etkisi]
Erdoğan, Yaşar
This study investigated the effects of electromagnetic fields (EMFs) from electric fence systems on physiological and reproductive parameters of male honeybees (Apis mellifera caucasica). The study was conducted between May and August 2024 at the Bayburt University Beekeeping Application and Research Center, with five experimental groups. Hives were positioned at varying distances (1–2.5 m) from the fence. The findings showed that the average body weight (245.4 mg), sexual maturity rate (58.56%), and sperm concentration (0.87 ± 0.04 × 10 ⁶/μL) of drones closest to the electric fence were significantly reduced (p < 0.05). The electric field effect was limited in groups at greater distances, with statistically insignificant differences in some parameters. No significant differences were found between groups in sperm volume. Results demonstrate that electric fields from fence systems suppress developmental processes and reproductive physiology of drones in a distance-dependent manner. Lower body weight, decreased sperm concentration, and proportion of mature males in colonies near the fence show electromagnetic stress is a significant risk for bee health. Future studies should examine the effects of electromagnetic fields at different frequencies and strengths on larval development, sperm morphology, oxidative stress markers, and gene expression profiles.
- MakaleAçık Erişim2024Scopus SJRQ1Turkish validity and reliability of the Haptotherapeutic Well-Being Scale
Küçükkaya, Burcu; Işık, Hafsa Kübra; Rathfısch, Gülay
Objectives: Haptotherapy fosters a sense of unity between the body, mind, and emotions. In addition, it contributes to expanding the woman’s perception of her pregnancy and developing a more positive attitude towards pregnancy and childbirth. The study aims to examine the Turkish validity and reliability of the Haptotherapeutic Well-Being Scale, which will be used to evaluate the well-being levels of haptonomy and haptotherapy practices in women. Design: The study was methodological type. Methods: The study conducted between October 20 and December 20, 2023, with 242 women who volunteered to participate by sharing forum pages on social media (Facebook, Instagram) via the web. Data were collected using a personal information form, including sociodemographic and obstetric characteristics and the Haptotherapeutic Well-Being Scale. Results: The Haptotherapeutic Well-Being Scale consists of 14 items and five sub-dimensions. In confirmatory factor analysis, all path coefficients were statistically significant (p < 0.001). The overall Cronbach’s Alpha and sub-dimension values of the scale are above 0.90. There is a positive and very strong correlation between all sub-dimensions of the scale (p < 0.001). Conclusion: The Haptotherapeutic Well-Being Scale was found to be valid and reliable for the Turkish sample. Trials registration: https://clinicaltrials.gov identifier NCT06467188; registered June 14, 2024.
AtıfScopus1WoS1OpenAlex3İncele - MakaleYalnız künye2022Scopus SJRQ2Determination of the gas/particle phase concentrations of PCBs in urban and rural atmosphere in Erzurum, Turkey
Paloluoğlu, Cihan; Bayraktar, Hanefi
Active sampling was conducted for the first time in Erzurum, Turkey, between August 2012 and January 2013, in order to investigate the presence of 82 polychlorinated biphenyls (PCBs) congeners. Urban and rural ambient air samples, including gas and particle phase atmospheric concentrations (GAPPACs) of PCBs, were collected simultaneously using high volume air sampler (HVAS) at two different sampling points of Erzurum. GAPPACs of PCB samples taken using HVAS in Palandöken Mountain Region (2565 m) and Ataturk University Campus (1870 m) were analyzed in GC–MS following appropriate extraction steps. Throughout the sampling period, total ambient air concentrations (gas phase + particulate phase) were 10 ± 6 and 27 ± 13 pg/m3 (mean) for Palandöken Mountain Region (PMR) and Atatürk University Campus (AUC), respectively. Low molecular weighted PCBs were found to be dominant in both rural an urban sampling sites. Meteorological parameters especially temperature (from Clausius–Clapeyron equation), wind direction, wind velocity, and precipitation were found to be effective on PCB concentration and distribution. The gas-particle distributions of PCBs in the summer and winter period were found to be 82% (gas phase) and 18% (particle phase) in the PMR and 90% (gas phase) and 10% (particle phase) in AUC, through Junge-Pankow adsorption model. In the light of these findings, total PCB concentrations detected in urban atmosphere (due to possible PCB sources) were observed to be higher than those determined in rural area.
AtıfScopus1WoS1İncele - MakaleAçık Erişim2024Scopus SJRQ2Reflective Polarization Conversion with Multi-Functional, Ultrathin Metasurface for Ku-and K-Band Applications
Teber, Ahmet
Reflective polarization conversions with a simplistic design of an ultrathin, single-layered, and multi-functional anisotropic metasurface as a polarization converter is utilized for Ku-and K-band applications. The designs with two substrate thicknesses (0.095λ0 and 0.069λ0, respectively) are capable of a cross-polarization converter (CPC) and a linear-to-circular (LTC) polarization conversion. The design with 0.095λ0 thickness achieves a CPC between 17.96 and 26.90GHz with the efficiency of more than 90% and a relative bandwidth of 40% under normal incidence. It maintains angular stability by altering the oblique incidence angles up to 300 with greater than 80% of the PCR in the K-band. Meanwhile, an LTC in two frequency bands, 10.30-10.53GHz and 28.65-29.70GHz, is also numerically demonstrated. The second design with 0.069 λ0 thickness provides a CPC above the PCR value of 87% in the frequency range from 10.46-23.05GHz (covering the entire Ku-and part of the K-band) with angular stability of 40 above the PCR value of 80%. In the meantime, an LTC with relative bandwidth of 75% in the frequency range from 9.53-9.79&24.74-25.27GHz is numerically revealed. These polarization converters exhibit relatively good performances of facile structure and multi-functional properties, which can be useful in Ku-and K-band applications.
AtıfScopus5WoS3OpenAlex5TR Dizin1İncele - MakaleYalnız künye2026Scopus SJRQ2Hydrodynamic characterization and design evaluation of a conical spout–fluidized bed under geometric and gas-distribution effects
Çutay, Arif; Tozlu, Alperen; Özahi, Emrah
Spout–fluidized beds are widely used in gas–solid processing and thermal conversion applications because of their enhanced particle circulation, mixing, and heat-transfer characteristics. However, the combined effects of reactor geometry, distributor configuration, and gas-flow distribution on the hydrodynamic organization of conical spout–fluidized beds are still not sufficiently quantified from a design perspective. In this study, a three-dimensional transient numerical analysis was performed to assess the effects of cone angle, auxiliary-hole number, and auxiliary-to-total flow-rate ratio on gas–solid flow behavior in a conical spout–fluidized bed reactor. The simulations were carried out using an Eulerian–Eulerian two-fluid model coupled with the kinetic theory of granular flow and the Syamlal–O'Brien drag model. Three cone angles (50°, 60°, and 70°), three distributor configurations with 70, 140, and 210 auxiliary holes, and two auxiliary-to-total flow-rate ratios (Qf/QT≈0.15 and Qf/QT=0.43) were investigated. The hydrodynamic response was evaluated using particle velocity, voidage distribution, and two compact flow indices: the radial spout heterogeneity index (RSHI) and the axial spout regularity index (ASRI). The results show that the flow field is governed by a characteristic core–annulus structure consisting of a dilute, high-velocity spout core and a denser recirculating annulus. Increasing Qf/QT enhances auxiliary gas penetration, particle suspension, and radial expansion of the gas-penetrated region; however, it also increases RSHI and ASRI, particularly at lower cone angles, indicating stronger radial heterogeneity and axial irregularity. Increasing the cone angle from 50° to 70° reduces radial hydrodynamic heterogeneity and improves axial spout regularity, whereas the number of auxiliary holes has a secondary and configuration-dependent influence compared with the gas-flow distribution and cone angle. Overall, the findings indicate that the auxiliary-to-total flow-rate ratio primarily controls gas distribution and gas–solid momentum exchange, while the cone angle governs radial uniformity and axial spout regularity. The proposed RSHI–ASRI framework provides a design-oriented basis for comparing conical spout–fluidized bed configurations and selecting operating conditions according to the desired balance between gas–solid interaction intensity, radial uniformity, and axial spout regularity.
- MakaleAçık Erişim2026Scopus SJRQ1Assessment of radiological hazards arising from natural radioactivity in Bayburt stones used in buildings and possible effects on public health
Dizman, Serdar; Umar, Muttaka; Hatipoglu, Yavuz Selim
Background – Since ancient times, natural stones have served as essential materials in construction, landscaping, and artistic applications. Bayburt stone is one of the most important stones used in and around Bayburt, in the Eastern Black Sea region of Türkiye. It has been frequently used in buildings (castle, house, etc.), street flooring, fountains, and places of worship from ancient times to the present day. Due to their underground origin, natural stones contain natural radioisotopes in various concentrations, making the assessment of their radioactivity levels important for public health. Objective – This study aims to determine the natural radioactivity levels of Bayburt stones used in buildings and to assess the potential radiological hazards and possible effects on public health. Methods – Natural radioactivity levels (226Ra, 232Th and 40K) were determined in a total of 36 Bayburt stone samples, 30 from five different quarries and 6 from a natural stone factory in Bayburt province. High-purity germanium (HPGe) spectrometry was employed to measure radioactivity concentrations. Additionally, several radiological hazard indices (Raeq, Hin, Iγ, D, AEDE, AGDE, and ELCR) were calculated and compared with reference limits proposed by international organizations. Results – The radioactivity concentrations in the Bayburt stone samples ranged from 1.56 to 23.54 Bq/kg for 226Ra, from 0.53 to 23.69 Bq/kg for 232Th, and from 10.31 to 505.35 Bq/kg for 40K. The average activity concentrations were found to be 5.56 ± 0.90 Bq/kg for 226Ra, 4.62 ± 0.65 Bq/kg for 232Th, and 179.12 ± 9.88 Bq/kg for 40K. The average values of Raeq, Hin, Iγ, D, AEDE, AGDE, and ELCR were found to be 18.68 Bq/kg, 0.07, 0.14, 8.91 nGy/h, 43, 72 μSv/y, 63.06 μSv/y, and 17.07 × 10−5, respectively. All calculated radiological hazard indices were below the recommended safety limits. Conclusion – The findings indicate that the Bayburt stone samples investigated are suitable for construction purposes and do not pose significant radiological hazards to human health when used in building environments.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2026Scopus SJRQ1Influence of Salt Type on the Physicochemical, Microbiological, Sensory Properties, Mineral, Free Fatty Acid, and Volatile Composition of PDO Erzincan Tulum Cheese
Arslaner, Ayla; Yılmaz, Özlem
This study evaluated the quality attributes of Protected Designation of Origin (PDO) Erzincan Tulum cheese by comparing control cheeses made with Kemah spring salt (KS) to those made with Sivas spring salt (SS), Çankırı rock salt (CS), and a low-sodium salt (rock salt–KCl blend, 50:50, LNaS). Cheeses were ripened at −2 to 0 °C for 120 days. Analyses included chemical composition, mineral profile, proteolysis, lipolysis, fatty acid composition, volatile compounds, and sensory properties. During ripening, dry matter and pH increased significantly (p < 0.05). Mineral content varied by salt type: LNaS had higher potassium and lower sodium, KS-C had the highest sodium and phosphorus, and SS-C the highest magnesium (p < 0.05). Proteolysis increased in all samples, with the highest levels in LNaS (p < 0.05). Lipolysis increased in all samples (p < 0.05), with CS-C showing the highest free fatty acid (FFA) content. Fifty volatile compounds were identified; carbonyl compounds were highest in LNaS-C and esters were highest in SS-C. Sensory evaluation showed that CS-C had the highest overall acceptability score and SS-C the lowest (p < 0.05). CS-C outperformed the control in sensory quality, and LNaS-C achieved similar sensory acceptance without compromising quality. Salt content and type were identified as critical factors in determining the authenticity of PDO Erzincan Tulum cheese.
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