Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(117)
- Kaya, Yunus(51)
- Şahin, Engin(48)
- İspirli, Hümeyra(47)
- Özen, Soner(46)
- Şenay, Volkan(45)
- Pat, Suat(44)
- Can, Zehra(39)
- Bayraktar, Bülent(37)
- Bayram, Sinan(37)
- Korkmaz, Şadan(36)
- Cuce, Erdem(35)
- Ecem Bayram, Nesrin(33)
- Kutlu, Naciye(33)
- Yilmaz, Mustafa Tahsin(32)
- Artar, Musa(31)
- Ertugrul, Mehmet(30)
- Öner, Erdal(30)
- Ayata, Ümit(29)
- Hasar, Ugur Cem(29)
- Esmer, Yusuf(28)
- Mercan, Emin(27)
- Cuce, Pinar Mert(26)
- Özdemir, Akın(25)
- Çolak, Murat(24)
- Bayram, Ozkan(23)
- Kamiloğlu, Aybike(23)
- Sert, Durmuş(22)
- Ayazoglu, Rabil(21)
- Abdioglu, Murat(20)
- Bayram, Nesrin Ecem(20)
- Kadakal, Mahir(20)
- Kara, Yakup(20)
- Kizil, Hamit Emre(20)
- Tozlu, Alperen(20)
- Birinci, Ahmet(19)
- Gerçek, Yusuf Can(19)
- Battal, Fetullah(18)
- Dirican, Ebubekir(18)
- Ergün, Mustafa(18)
Yayınlar
- 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.
AtıfScopus1WoS1OpenAlex1
İncele - 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.
AtıfScopus5WoS4OpenAlex7İncele - MakaleYalnız künye2026Scopus SJRQ4CORRELATION BETWEEN THE CHEMICAL COMPOSITION OF WOOD AND THE INCREASING OF ITS CALORIFIC VALUE THROUGH HEAT TREATMENT; [CORRELAÇÃO ENTRE A COMPOSIÇÃO QUÍMICA DA MADEIRA E O AUMENTO DO PODER CALORÍFICO ATRAVÉS DO TRATAMENTO TÉRMICO]; [CORRELACIÓN ENTRE LA COMPOSICIÓN QUÍMICA DE LA MADERA Y EL AUMENTO DE SU PODER CALORÍFICO MEDIANTE TRATAMIENTO TÉRMICO]
Domingos, Idalina; Ferreira, Miguel; Ferreira, José; Dulyanska, Yuliya; Ayata, Umit; Esteves, Bruno
Introduction: The greatest importance of biomass lies in its Higher Heating Value (HHV), when considered for energy production. The calorific value is significantly affected by the changes in the chemical composition of the wood that occur during heat treatment. Objective: To understand the effect of heat treatment on the calorific value of the chemical constituents of two hardwoods: Sapelli and chestnut, and two softwoods: Scots pine and Siberian pine. Methods: The calorific value was determined by a Parr calorimeter – model 6400. The content of extractives was determined by successive Soxhlet extraction using about 3 g of each sample and 150 ml of dichloromethane, ethanol, and water as solvents. The extractives content was determined in accordance with TAPPI 204, and insoluble lignin by the Klason method Tappi T 222 om-02. For the determination of holocellulose, the acid chlorite method was used. Results: The calorific value of untreated wood ranged from 18.98 MJ/kg for chestnut to 20.35 MJ/kg for Siberian pine. Heat treatment resulted in an increase in the calorific value for most of the wood samples studied. Conclusion: The rise in HHV observed during heat treatment in softwoods and hardwoods is mainly due to the increase in lignin content, although dichloromethane extractives also play an important role.
- MakaleAçık Erişim2026Scopus SJRQ1The Effect of Mindfulness Practices on Positive Thinking and Stress Coping Behaviors of Earthquake Survivor Nursing Students: A Nonrandomized Controlled Study
Bal, Betul; Kaba, Nagihan Koroğlu
Purpose: This study was conducted to reveal the effect of mindfulness practices on nursing students’ stress-coping behaviors and positive thinking skills. Method: This was a two-group parallel nonrandomized study. Mindfulness practices were applied to the students in the experimental group. Data were collected using research tools (Personal Information Form, Positive Thinking Skills Scale, and Stress Coping Behaviors Scale for Nursing Students) as pre- and posttests. Findings: After the intervention, there was no significant difference between the two groups in the posttest scores of positive thinking skills (t = 0.624; p = .541) and stress coping behaviors of staying optimistic (t = −0.957; p = .345), transfer (t = −2.028; p = .050), problem-solving (t = −0.663; p = .512), and avoidance (U = 132; p = .230). Conclusions: Mindfulness practices are ineffective in improving earthquake survivor nursing students’ coping behaviors and positive thinking skills.
- MakaleAçık Erişim2026Scopus SJRQ3Financial Management of Traditional and Complementary Medicine in Türkiye Public Hospitals: A Policy Analysis of Pricing, Accounting, and Performance Incentives
Kılınç, Mehmet
This article presents a policy analysis of the financial management of Traditional and Complementary Medicine (T&CM) practices in public hospitals in Türkiye, with a focus on the intersection of pricing, accounting, and performance-based supplementary payment systems. While integrating T&CM into the modern healthcare system expands treatment options, it introduces significant administrative challenges. In recent years, the presentation of T&CM applications in public hospitals in Türkiye has become widespread. However, this expansion has raised critical questions, such as how these services will be charged and how the revenue generated will be accounted for. In this context, the extent to which current pricing policies support the sustainability of T&CM services is discussed. Adopting a descriptive policy analysis approach supported by analytical simulations, this study assesses the adequacy of current pricing policies. The findings reveal a systemic “performance paradox”: although time-intensive, T&CM procedures yield significantly lower performance scores per hour than standard outpatient services, creating a structural disincentive for physicians. Furthermore, the lack of transparency in cost-center accounting complicates the financial sustainability of these units. The study concludes by offering tiered policy recommendations—ranging from low-effort coefficient adjustments to high-effort payment model reforms—to align financial incentives with the strategic goal of integrating T&CM into the public health system.
- Kitap BölümüYalnız künye2026Bullying in the Digital Age: The Anatomy of Cyberbullying in Organizations
Battal, Fetullah; Öz, Halil Hakdan
The increase in electronic and computer-based communication and information sharing has significantly altered individuals’ social communication, learning methods, and entertainment styles. Digitalization has made individuals a part of the virtual world in almost every field, such as education, communication, and trade. With the digital age, the tools used by individuals in business and daily life are changing. Internet technologies that facilitate working life for organizations have become indispensable today. Information and communication technologies have increased communication channels, which have improved formal and informal relations between employees, thus enabling them to solve their work in a fast, easy, and accessible way without waiting. However, in addition to the mentioned contributions, it is known that digitalization has negative effects on the individual’s psychology and business life. These negative effects cause the development of cyberbullying in organizations. Cyberbullying refers to intentional and hostile behavior that aims to harm the individual using digital and technological tools. Cyberbullying cases are also observed in organizations where digitalization is intense and strong. It is possible to see the presence of cyber bullies who do not feel effective and adequate when they interact directly in organizations, and therefore tend to create a negative and harmful effect by hiding themselves online, with the disturbing messages they send, humiliating comments on social networks, and threatening and intimidating posts they publish. For example, a manager criticizing an employee in a humiliating language in a public email or an employee spreading unfounded information about another employee on social media is considered in this context. Exposure to humiliating, threatening, and intimidating behaviors in digital environments negatively affects employees. Employees exposed to cyberbullying may have psychological symptoms such as work-related stress, anxiety, irritability, fear, and depression. Physically, insomnia, headache, and general health problems can be observed. This situation leads to behaviors that will negatively affect organizational activities, such as low job satisfaction, distrust towards the organization, decreased organizational commitment, and disengagement from work. Organizations need to develop effective policies to prevent cyberbullying. In order to increase the effectiveness of the policies to be developed, it is important to anatomically examine how cyberbullying behavior is shaped, with which tools it is done, and its effects. In this respect, this study aims to examine the antecedents, tools, and consequences of cyberbullying in detail and thus to develop recommendations to prevent cyberbullying.
- MakaleAçık Erişim2026Scopus SJRQ3The relationship between cultural tourism and transportation: A global perspective
Durmuş, İbrahim
The importance of tourism and cultural values for countries, regions, or areas is increasing day by day. Cultural tourism includes many activities with a wide scope. Transportation, on the other hand, is a factor that directs tourists' choices in terms of tourism, providing access to the areas they have visited or will visit. The research aims to reveal the factors affecting the relationship between cultural tourism and transportation. For this purpose, the focus is on cultural tourism and transportation research in the WoS database. The bibliometric analysis method was used in the application. Important inferences were obtained by evaluating 433 studies in the literature. As a result of the analysis, authors who have conducted intensive research on the subject, publication production amounts, efficiencies, organizations, citations, highlighted keywords, changes over time, trends, co-occurrence networks, thematic maps, and thematic developments are included. In their research, the authors frequently emphasized the words tourism, sustainable tourism, development, transportation, China, cultural tourism, rural tourism, sustainable development, accessibility, and sustainable. The results reveal that sustainability and accessibility are effective factors in cultural tourism and transportation. The study shows that in the network of relationships, tourism, heritage, accessibility, transport, cultural tourism, management, and cultural heritage have strong connections. The findings indicate that in the relationship between cultural tourism and transportation, accessibility, management mechanisms, and cultural heritage values are highly influential. Regarding centrality and density, rural tourism, tourism development, sustainable and ecological tourism, Mexico, rural development, colonialism, competitiveness, Istanbul, and renewable energy demonstrate strong relationships. These results show that rural development, competitiveness, and colonialism play a significant role in the relationship between cultural tourism and transportation. Regarding Türkiye, Istanbul's central and dense network of relationships has been influenced by its accessible location and tourism potential. The results provide a unique and different perspective on the literature.
- MakaleAçık Erişim2026Scopus SJRQ1The effect of cognitive strategy instruction enriched with active learning techniques on word problem-solving skills of students with learning disabilities
Filiz, Tunahan
This study aimed to investigate the effectiveness of cognitive strategy instruction (CSI) enriched with active learning (AL) techniques in teaching word problem solving to primary school students with learning disabilities, as well as to examine the overall instructional process. Word problem solving is the process of using contextual information from real-life or fictional situations to develop mathematical solutions. The research was designed with an embedded mixed-method model. The quantitative phase included 30 third-grade students with learning disabilities, while the qualitative phase involved six randomly selected students from the experimental group. Quantitative analyses revealed that students in the experimental group showed significantly higher achievement in problem-solving tests, indicating the positive impact of CSI enriched with AL techniques. Qualitative findings highlighted increased class participation, enhanced collaboration, and more positive attitudes toward mathematics. Furthermore, teacher and peer interactions supported the problem-solving process, and the use of tools promoting mathematical thinking strengthened performance. The results demonstrated that CSI enriched with AL techniques encouraged strategic thinking and the generation of alternative solutions in word problem solving. The study, limited to three learning outcomes within the third-grade mathematics curriculum in Turkey, suggests that teachers should adapt and implement such instructional approaches across other mathematical domains, given the students’ positive experiences and outcomes.
- MakaleAçık Erişim2026Scopus SJRQ1Ni- and Co-doped TiO2nanofibers for enhanced antibacterial and antibiofilm activities, and mechanistic insights
Özcan, Tuğçe; Çekceoğlu, İlknur Aksoy; Öner, Erkan; Ozel, Sultan Suleyman; Sarılmaz, Adem; Aslan, Emre; Özel, Faruk; Patır, İmren Hatay
Nowadays, with the growing need for alternative antibacterial materials for the treatment of bacterial infections, TiO2 with antibacterial properties has attracted attention as a potential antibacterial agent. Ni-TiO2 and Co-TiO2 nanofibers (NFs) were synthesized via an electrospinning process. The antibacterial activities of these NFs against S. aureus and E. coli were evaluated under UV-light illumination using optical density measurements. Co-TiO2 exhibited superior antibacterial activity against both S. aureus and E. coli under UV-light irradiation. The antibacterial mechanism was further investigated through a glutathione (GSH) oxidation assay and morphological analysis using scanning electron microscopy (SEM). Hydrophilicity was evaluated by contact angle measurement. The antibiofilm activities of TiO2, Ni-TiO2, and Co-TiO2 NFs were investigated with respect to E. coli and S. aureus biofilms. Ni-TiO2 and Co-TiO2 demonstrated more effective antibiofilm activities than bare TiO2. Under UV-light irradiation, the biofilm inhibition efficacy was increased for both Ni-TiO2 and Co-TiO2 NFs while Co-TiO2 NFs were found to have the greater antibiofilm performance. Additionally, in silico analysis was conducted to explore the molecular interactions of the NFs with S. aureus Immunoglobulin-Binding B Domain (PDB ID: 1BDD) and FimH lectin protein of E. coli (PDB ID: 4XO8). Co-TiO2 exhibited stronger binding to S. aureus, while TiO2 showed stronger binding to E. coli. This journal is
- MakaleAçık Erişim2026Scopus SJRQ1Permittivity extraction of sandy soils through uncalibrated and thickness-independent meniscus-free measurements using a hollow coaxial line
Hasar, Ugur C.; Korkmaz, Huseyin; Kaya, Yunus
Measurement techniques for accurate moisture level determination of various soil conditions are becoming popular in recent studies. Microwave-driven techniques, as positioned into indirect methods, could be tailored for precise and real-time detection of soil moisture. However, improper implementation of calibration techniques or usage of imperfect calibration standards required for precise measurements by these techniques presents a challenging limitation for their widespread usage. Besides, meniscus formation on top of soil samples with a sufficient moisture level could adversely influence the performance of these techniques. In this study, we present a microwave extraction method for eliminating the requirement of a formal calibration procedure and additionally removing the effect of meniscus on measurements through relative measurements of sandy soil samples while maintaining accurate permittivity extraction with no information of sample thickness. To achieve our goal, a mathematical framework unifying wave-cascading matrix and state-transition matrix presentations is proposed for permittivity determination from three measurement configurations (empty line, the (sandy) soil sample sandwiched between two identical plugs, and a shifted version of this plug-sample-plug configuration) and their inverses implemented by port switching operation. The proposed method is first validated by permittivity measurements of two liquid samples (distilled water and methanol). Then, permittivity measurements of two sandy soil samples (having more than 90% sand content) were conducted using Type-N-to-EIA 1-5/8” coaxial lines (with no universal calibration standard) over 0.05 GHz–3.0 GHz. From these measurements, it is noted that our meniscus-free method determines permittivity with a maximum absolute difference of 3.4% (evaluated from five independent measurements) while another similar method, suffering from meniscus presence, extracts permittivity with a maximum absolute difference of 4.0%. This indicates a clear advantage of our method for measurements of sandy soil samples having meniscus formation. We then utilized to construct a calibration curve, compared with other calibration curves using by other methods, allowing prediction of moisture volume content () of the tested sandy soil samples from measured permittivity data whose conformity analysis implemented by the three-pole Debye model and the Mironov-Fomin model. It is observed that this calibration curve could be utilized to predict within margin from measured permittivity data.
- MakaleYalnız künye2026Scopus SJRQ2Depth-dependent predictability of soil temperature under Mediterranean climatic conditions: a frequency-based perspective
Guleryuz, Didem; Yıldırım, Ümit; Güler, Cüneyt
Soil-temperature predictability is inherently depth-dependent because atmospheric forcing is progressively attenuated and transformed into smoother, lower-frequency thermal dynamics with increasing depth. Under Mediterranean climatic conditions, where pronounced seasonality and strong surface forcing coexist, this depth-dependent transformation provides an informative basis for evaluating model behaviour. This study examines soil-temperature prediction at depths of 5, 10, 20, 50, and 100 cm using a multivariate dataset comprising 5,285 retained daily observations from the Mersin meteorological station on Türkiye’s eastern Mediterranean coast. Precipitation, air temperature, relative humidity, wind speed, and evaporation were used as predictors. Support vector regression, random forest, and LightGBM were evaluated using R², RMSE, and MAE. All three models performed strongly in the near-surface layers, with test R² values ranging from 0.948 to 0.954 at depths of 5–20 cm. Predictive performance declined with increasing depth as short-period variability weakened and the thermal signal became smoother and more seasonally structured. RF and LightGBM showed a greater numerical decline at 50–100 cm, whereas SVR achieved test R² values of 0.923 at 50 cm and 0.847 at 100 cm; however, inter-model differences remained modest and were interpreted descriptively. Lomb–Scargle spectral analysis, applied using the actual observation dates, indicated that short-period variability became relatively less pronounced with depth while seasonal-scale and low-frequency components remained prominent. Overall, the findings suggest that soil-temperature prediction should be interpreted in relation to depth-dependent temporal signal characteristics rather than as a search for a universally superior algorithm.
- MakaleAçık Erişim2026Scopus SJRQ2Investigation of the levitation and drag force parameters of the electrodynamic maglev based on Halbach array of HTS bulks on aluminium rail
Ozturk, U.Kemal; Yıldız, Ali Suat; Abdioglu, Murat
This study aims to investigate the performance parameters of high-temperature superconducting (HTS) bulks and permanent magnets (PMs) as magnetic field sources in electrodynamic suspension (EDS) systems, with the goal of enhancing the currently low magnetic lift force and reducing the high drag force in such systems. A numerical analysis is conducted on an EDS system utilizing Halbach arrays of HTS and PM bulks. The H-formulation within the Partial Differential Equation (PDE) module is employed to simulate the flux-trapping performance of the HTS bulks, with results verified by experimental data from the literature. The lift and drag forces between the arrays and an aluminium rail are investigated using the Rotating Machinery-Magnetic module of COMSOL. It is observed that increasing the width of the central sample in the array results in a higher peak value of the vertical magnetic flux density and a broader peak profile, indicating a more extended effective magnetic field region across the rail surface. The HTS-based system exhibits significantly higher lift force and loading capacity compared to its PM-based counterpart. Specifically, a Halbach array composed of three HTS bulks (10 mm, 70 mm, 10 mm widths; HTS#10-70-10) achieves a better lift force representing a 211.5 % increase over the PM array. Furthermore, the lift-to-drag ratio (LDR) of the HTS array improves by 17.2 %. The results indicate that the HTS arrays offer superior performance in terms of both lift force and energy efficiency, highlighting their potential for enhancing the applicability of HTS-EDS systems in real-scale applications. This study features the advantages of HTS-based systems in achieving higher loading capacities and more efficient operation conditions compared to the PM arrays.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2026Scopus SJRQ2Effects of Graphite Incorporation and Annealing on the Structural, Tribological, and Functional Properties of Electroless Ni-B Coatings
Bülbül, Ferhat; Kara, Adem; Bülbül, Leman Elif; Güneş, Kübra
This study explores the synergistic effects of graphite nanoparticles (0.1 wt.%) and thermal annealing (100–600°C) on electroless Ni-B coatings for AISI 4140 steel. Graphite-enabled multifunctional performance—crystallization control, friction reduction, and antibacterial activity—are unlike conventional Ni-B systems. XRD showed amorphous-to-crystalline (Ni3B/Ni2B) transformation, with graphite acting as a nucleation agent below 300°C before degrading at 600°C. The 300°C-annealed composite achieved optimal properties: 0.2 friction coefficient (75% lower than uncoated steel), 60% higher wear resistance, and hardness of 777 HV (+ 3.6% over as-deposited), attributed to graphite lubrication and nanocrystalline Ni3B formation. Antibacterial tests revealed a 3.4-mm inhibition zone against E. coli, though efficacy declined at higher temperatures due to graphite oxidation. All composites maintained superhydrophilicity (contact angle ≈ 0°) without mechanical compromise. By correlating annealing temperature with microstructure, this work provides a design framework for Ni-B/graphite coatings combining low friction (μ = 0.2), high hardness (785 HV), and antibacterial functionality—addressing critical needs for wear-resistant, hygienic surfaces in biomedical and industrial applications.
AtıfScopus1WoS1İncele - Derleme MakaleYalnız künye2026Scopus SJRQ4Touching relief: A complementary path to easing rheumatoid arthritis pain
Kalyoncuo, Servet
Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent synovial inflammation, leading to pain, joint stiffness, and functional impairment. Despite advances in pharmacological treatments, including disease-modifying antirheumatic drugs (DMARDs) and biologic agents, many patients continue to experience residual symptoms that negatively affect quality of life. This review aims to evaluate the potential role of massage therapy as a complementary approach in the management of RA, with a focus on its clinical effects and proposed mechanisms. A structured literature search was conducted in Medline/PubMed, Scopus, and the Directory of Open Access Journals (DOAJ) for studies published up to March 1, 2025. Studies were considered if they included individuals diagnosed with RA, evaluated any form of massage therapy (e.g., Swedish massage, aromatherapy massage, reflexology), and reported clinical or patient-reported outcomes. Both randomized controlled trials and quasi-experimental studies were included, while studies involving non-RA populations or insufficient methodological detail were excluded. However, this review was not designed as a fully systematic review and may be subject to selection bias. The available evidence suggests that massage therapy may be associated with improvements in pain, joint mobility, and patient-reported outcomes in individuals with RA. However, the overall strength of evidence is limited by methodological concerns, including small sample sizes, heterogeneity in intervention protocols, and the frequent lack of appropriate control groups. While some studies report reductions in inflammatory biomarkers such as interleukin-6 (IL-6) and C-reactive protein (CRP), these findings are based on limited evidence and should be interpreted cautiously, particularly in studies where massage therapy is combined with other interventions. Massage therapy may also contribute to psychological well-being by reducing stress and improving overall mental health. Evidence derived from non-RA populations was considered only as supportive background and was not central to the conclusions of this review. Additionally, the potential for publication bias should be acknowledged, as studies with positive findings are more likely to be published. The integration of massage therapy into RA management may benefit from nurse-led approaches; however, variability in practitioner training and the lack of standardized intervention protocols remain important challenges. Future research should prioritize well-designed, adequately powered randomized controlled trials focusing specifically on RA populations, with standardized massage interventions and clearly defined outcome measures.
- MakaleYayıncıda açık erişim2026Scopus SJRQ3Investigation of Fe and Mn Effects on the Fluidity Behavior of A356 Aluminum Alloys
Çolak, M.; Alkan, N.; Kutsal, Ü.
The fluidity behavior of Al–Si casting alloys is strongly influenced by impurity elements and intermetallic phase formation during solidification. In particular, iron (Fe) reduces melt fluidity by forming brittle Fe-rich intermetallics, whereas manganese (Mn) can mitigate this effect by modifying intermetallic morphology. In this study, secondary A356 aluminum alloys were produced with Fe contents of 0.10, 0.15, and 0.20 wt.% and nominal Mn additions of 0.05, 0.10, and 0.20 wt.% to investigate their combined effect on fluidity behavior. Melt quality was assessed using reduced pressure testing and density index measurements to ensure consistent casting conditions. Fluidity tests were conducted using spiral and eight-channel molds with section thicknesses ranging from 0.5 to 8 mm. To enable quantitative comparison across different section geometries, a Fluidity Index (FI) was defined based on section-normalized flow lengths. The results show that increasing Fe content generally reduces fluidity, while Mn additions significantly improve melt flow, with the most pronounced enhancement observed at 0.20 wt.% Mn. Thinner sections were found to be more sensitive to Fe-related flow restriction, whereas wider channels exhibited improved flow behavior. These findings demonstrate that appropriate Mn additions can effectively stabilize fluidity in secondary A356 alloys and provide practical guidelines for alloy control in recycled aluminum casting applications.
