Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Güler, Ömer(32)
- Akkurt, Nevzat(27)
- Tekin, H.O.(27)
- ALMisned, Ghada(24)
- Gul, Muhammet(20)
- Yucesan, Melih(14)
- Xu, Qian(12)
- Baykal, Duygu Sen(11)
- Güler, Seval Hale(11)
- Taşgın, Yahya(10)
- Kavaz, E.(9)
- Kilic, G.(8)
- Zengin, Gokhan(8)
- Durmus, Hasan(7)
- Guler, Omer(7)
- Xiong, Yaxuan(7)
- Yılmaz, Demet(7)
- Özkul, İskender(7)
- Yayla, Nihal(6)
- Zhang, Hui(6)
- Alkarrani, Hessa(5)
- Baloglu, Ulas Baran(5)
- Celik, Erkan(5)
- Du, Yanping(5)
- Ilik, E.(5)
- Kanca, M. Sait(5)
- Kök, Mediha(5)
- Mahomoodally, Mohamad Fawzi(5)
- Ortiz-Barrios, Miguel(5)
- Qiang, Yujie(5)
- Yang, Gang(5)
- Zakaly, Hesham M.H.(5)
- Aghakhani, S.(4)
- Basgoz, Oykum(4)
- Birdogan, Selcuk(4)
- Caprioli, Giovanni(4)
- Etli, Serkan(4)
- Guler, Seval Hale(4)
- Kahraman, Gökhan(4)
- Liu, Lin(4)
Yayınlar
- MakaleYalnız künye2025Scopus SJRQ1Modifying the magnetic characteristics of ferrimagnetic TbFeCo by adjusting the thickness of the L11-ordered CoPt
Yüzüak, Gizem Durak
This study investigates structural and magnetic properties of 200 nm TbFeCo ferrimagnetic thin films. These films were formed by depositing L11-ordered CoPt buffer layers on Si(100) substrates, followed by (111)-textured Pt layers. The TbFeCo films were produced at room temperature by magnetron sputtering, and their characteristics were analyzed using X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), vibrating sample magnetometry (VSM), atomic force microscopy (AFM), and magnetic force microscopy (MFM). The above-mentioned techniques were used to figure out the films’ crystallographic structure, magnetic properties, and the surface characteristics. XRD analysis showed that TbFeCo films without the CoPt layer were only crystalline in the Pt(111) and Pt(222) directions. Conversely, films that were buffered with a CoPt layer developed the L11-ordered CoPt phase, especially in the CoPt(222) and CoPt(444) directions. This issue was linked to an increase in the CoPt unit cell parameter, indicating bulk-like crystallinity, particularly in the 20 nm CoPt layer, while the TbFeCo layer remained amorphous. The FIB-SEM showed that the layers were all gathered the thickness of 20 nm for Pt, 10 or 20 nm for CoPt, and 200 nm for TbFeCo with homogeneous distributed the elements in the Tb46Fe41Co13 composition matrix. Magnetic characterization from VSM measurements ranged from 5 to 350 K and revealed significant differences based on CoPt thickness. At 300 K, the coercive field (HC) got stronger as the thickness of the CoPt layer risen up. For 0, 10, and 20 nm CoPt, the HC was 2.8, 3.3, and 4.1 kOe, and the MS values were about 205, 229, and 234 emu/cm³, respectively. The L11-ordered CoPt underlayer facilitated strong exchange coupling at the TbFeCo/CoPt interface, which is responsible for these improvements. AFM and MFM measurements indicated that surface roughness, and hence magnetic pinning sites, increased dramatically with CoPt thickness. These pinning sites inhibited magnetic domain wall motion, increasing HC values in the out-of-plane direction. This kind of magnetic stability leads to excellent qualities, like higher HC and better thermal stability up to 350 K, that make these films interesting for use in spintronics and data storage, where HC and thermal resilience are important.
AtıfScopus3WoS3OpenAlex3
İncele - MakaleAçık Erişim2025Scopus SJRQ1Thermophysical properties and Optimization of modified palm Oil-Amine reinforced biocomposites for lightweight and insulating applications
Şahal, Hakan; Aydoğmuş, Ercan; Arslanoğlu, Hasan
The aim of this study is to investigate various thermophysical properties of modified palm oil-amine (MPOA) reinforced biocomposites to optimize these materials to meet the requirements of lightness and insulation. The effects of MPOA addition to biocomposites on bulk density, surface hardness, thermal conductivity coefficient, and activation energy have been evaluated. In addition, the structural and physical properties of these biocomposites are aimed to determine their potential use as lightweight and thermal insulation materials. The results show that MPOA incorporation significantly affects the bulk density, Shore A hardness, thermal conductivity, and thermal stability of biocomposites. The addition of MPOA provides significant benefits for lightweight biomaterials by reducing bulk density. However, high MPOA content decreases the surface hardness of the biocomposite, and with zirconium silicate (ZrSiO4), this drawback is eliminated and the curing time is reduced. Increasing MPOA ratios also improve the insulation properties of biocomposites by reducing the thermal conductivity coefficient. Thermal decomposition experiment results show that higher MPOA content reduces thermal stability. Scanning electron microscopy (SEM) reveals that high levels of MPOA lead to increased surface porosity and irregularities, negatively affecting surface morphology. An optimal MPOA reinforcement level of 5 wt% provides a balance between desirable properties such as reduced density and improved thermal insulation while minimizing adverse morphological effects. Fourier-transform infrared spectroscopy (FTIR) confirms the presence of epoxy resin and the successful chemical modification of palm oil to create bioepoxy feedstock. MPOA reinforcement offers benefits such as reduced bulk density and improved thermal insulation while addressing challenges in surface morphology, mechanical properties, and thermal stability. The study concludes that biocomposites with 5 wt% MPOA provide optimum stability, making them suitable for applications requiring lightweight and thermally insulating materials without significantly compromising structural integrity. This research, the long-term performance of biocomposites, and future investigations into their potential applications will further expand their practical applicability.
AtıfScopus2WoS2OpenAlex2İncele - MakaleYalnız künye2025Scopus SJRQ1Bridging experiment and simulation: Image processing-driven FEA of carbon fiber powder reinforced LDPE
ARIKAN, Volkan; DOGAN, Akar
Short fiber-reinforced polymers are widely used in engineering applications due to their improved mechanical performance and processability. However, accurately predicting the elastic behavior of such composites remains a challenge, especially when fibers are randomly distributed and lack defined orientation. To address this, this study investigates the mechanical properties of composite materials developed by incorporating carbon fiber powder (CFP) into a low-density polyethylene (LDPE) matrix at different reinforcement ratios (3 %, 6 %, and 9 %). The effects of CFP content on elastic modulus, tensile strength, and ductility were examined experimentally and through finite element analysis (FEA). Scanning electron microscopy (SEM) was used to analyze the microstructure, and image processing techniques were applied to quantify fiber orientation, which was then integrated into the FEA framework (Oriented FEA). Results indicate that CFP addition increases stiffness and tensile strength while reducing ductility, with 3 % CFP specimens showing the most favorable balance of mechanical properties. The proposed image-based orientation modeling approach provides improved simulation fidelity and offers a scalable methodology for evaluating the mechanical behavior of short fiber-reinforced composites.
AtıfScopus2WoS2OpenAlex2İncele - MakaleYalnız künye2025Scopus SJRQ2Eu2O3-driven tailoring strategies on Al6061-Alloy for nuclear applications: A comprehensive study on structural, physical, and radiation transmission properties
Basgoz, Oykum; Guler, Seval Hale; Guler, Omer; ALMisned, Ghada; Baykal, Duygu Sen; Kilic, G.; Tekin, H.O.
In this study, Al6061–Eu2O3 composites were fabricated via mechanical alloying and systematically characterized using X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy to evaluate structural and compositional features. The incorporation of Eu2O3 in varying weight percentages (1–20 wt%) was confirmed by XRD, revealing phase retention and crystallite refinement, while SEM–EDS analyses indicated uniform elemental distribution at low doping and localized clustering at higher reinforcement levels. Radiation shielding properties were comprehensively assessed through mass and linear attenuation coefficients, half value layer, effective atomic number, fast neutron removal cross section, buildup factors, and photon transmission factors. The results demonstrated a strong correlation between increasing Eu2O3 content and improved shielding performance. The E20 composite exhibited a mass attenuation coefficient of 22.33 cm2/g at 0.015 MeV, over threefold higher than the base alloy, and fast neutron removal cross section improved by 22.5 % compared to Al6061 alone. Additionally, EBF and EABF values decreased significantly, confirming reduced secondary photon build-up. These findings validate the effectiveness of Eu2O3 as a reinforcement phase for tailoring Al6061 for multifunctional applications, particularly in nuclear, aerospace, and radiological environments requiring lightweight materials with superior gamma and neutron attenuation.
AtıfScopus1OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ1MobileNet- and attention-based MLP-Mixer architecture for geographical-region recognition of a marine fish (Perciformes: Carangidae) using otolith images
Dürrani, Ömerhan; İşgüzar, Seda; İmak, Andaç; Ateşşahin, Tuncay; Cömert, Zafer; Dürrani, Syeda Zahra; Türkoğlu, Muammer
Fishery management is crucial to sustain marine ecosystems by preventing overfishing and ensuring a fair distribution of fishing quotas. Accurately identifying the geographical origins of fish stocks is a key challenge in region-specific management strategies. Otoliths, calcified structures found in the heads of all fish species (except sharks and rays), provide insights into the life history and geographical origins of these fish. Traditional otolith analysis is time-consuming and error-prone because of manual inspection. Our study presents a novel approach using deep learning and computer vision to automate the geographical recognition of fish using otolith images. We propose a model that integrates MobileNet, which is known for its efficiency, with an advanced Mlp-Mixer that incorporates an attention mechanism to extract enhanced features. When tested on a diverse dataset of otolith images from five regions, the proposed model achieved a remarkable 96% accuracy, significantly outperforming traditional methods. This high accuracy demonstrates the potential to revolutionise fishery management by providing a fast, reliable, and automated solution for geographical region identification. In conclusion, the proposed method demonstrates the transformative potential of combining MobileNet and an attention-based Mlp-Mixer for automated fish geographic recognition using otolith images. This innovative method addresses the limitations of traditional manual inspection and paves the way for more effective and sustainable fishery management practices.
AtıfScopus4OpenAlex4İncele - MakaleYalnız künye2025Scopus SJRQ1Evaluation of TiO2/ZnO/SnO2 multilayer thin films on Si(100) as triboelectric friction layer
Yüzüak, G. Durak; Yüzüak, E.
This study presents a novel multilayer-semiconductor triboelectric nanogenerator (MLSC-TENG) that enhances charge transfer and initial charge density to overcome the limitations of conventional TENGs by multilayer thin films composed of TiO2, ZnO, and SnO2. The device operates through contact electrification and electrostatic induction, featuring two distinct electrodes. The active negative layer is deposited on Si substrates with an Ag seed layer using magnetron sputtering, employing a PET/ITO counter-electrode. The system attains a maximum power density of 400 mW/m2 with a 100 MΩ load, a short-circuit current of 20 μA at 10 Hz, and an open-circuit voltage of ±55 V. Additionally, it powers 156 LEDs and exhibits an energy storage capacity of 16.9 μJ at 52 μF, highlighting its applicability for wearable electronics. This scalable and cost-effective approach highlights the significant role of semiconductor (SC) band structures in enhancing TENG performance and presents a viable pathway for sustainable energy harvesting. The demonstrated strategy has the potential to meaningfully influence the application of TENGs in energy harvesting systems, providing a cost-effective solution for powering wearable electronics. The study facilitates progress in sustainable energy solutions for future wearable technologies by tackling critical issues in energy conversion efficiency.
AtıfScopus2WoS3OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ1An efficient 2D hyper chaos and DNA encoding-based s-box generation method using chaotic evolutionary improvement algorithm for nonlinearity
Garipcan, Ali Murat; Aydin, Yılmaz; Özkaynak, Fatih
In this study, an innovative substitution box (s-box) method is proposed, which combines the complexity and unpredictability of chaotic systems with the natural randomness and security features of Deoxyribonucleic Acid (DNA) encoding, in response to the increasing security requirements in the field of modern cryptography. This method, based on the integration of a two-dimensional (2D) hyper-chaotic Vincent map (VM) and DNA encoding techniques, aims to produce secure and high-performance s-boxes. To evaluate the reliability of the s-boxes, fundamental cryptographic criteria such as nonlinearity (NL), strict avalanche criterion (SAC), differential probability (DP), linear approximation probability (LAP), and bit independence criterion (BIC) are considered. Additionally, a novel chaos-based evolutionary optimization algorithm is proposed to optimize the NL criterion of the s-boxes. This algorithm offers a cost-effective and highly efficient alternative compared to classical metaheuristic methods, providing a balanced structure between security and performance. Experimental findings and comparison results demonstrate that the proposed s-boxes offer effective and reliable solutions for modern cryptographic applications, such as secure data transmission and storage. From a broader perspective, the study makes a meaningful contribution to the literature in the field of data security by presenting a high-performance s-box design meeting the security requirements of cryptographic systems and is resilient against current threats.
AtıfScopus25WoS26OpenAlex23İncele - MakaleYalnız künye2025Scopus SJRQ1First exploration of Pr6O11 nanoparticle integration in borotellurite glasses: Synthesis, characterization, and performance for enhanced mechanical strength and radiation shielding
Kilic, G.; Ilik, E.; Kavaz, E.; Durmus, Hasan; Güler, Ömer; Birdogan, Selcuk; ALMisned, Ghada; Tekin, H.O.
This study investigates the incorporation of Pr6O11 nanoparticles into lithium borotellurite glass matrices to enhance their mechanical and radiation shielding properties. Glass compositions, synthesized with varying Pr6O11 concentrations from 0 to 8 mol%, exhibited increasing densities from 4.00783 g cm−3 to 4.94440 g cm−3 and reduced molar volumes, confirming nanoparticle-induced densification. X-ray diffraction analysis revealed amorphous structures with shifts in the hollow band indicating compact network rearrangements. Scanning electron microscopy and energy-dispersive X-ray analyses confirmed homogeneous Pr distribution up to 6 mol%, with clustering observed in 8 mol% samples. Vickers’ microhardness values progressively increased, highlighting enhanced mechanical strength due to reduced non-bridging oxygen ions and network cross-linking. Gamma-ray shielding experiments demonstrated superior performance of the 8 mol% sample (Pr8), with the highest mass attenuation coefficients, effective atomic number, and reduced half-value layer. Neutron attenuation assessments further confirmed improved shielding capabilities, with Pr8 achieving the highest effective removal cross-section. In conclusion, Pr6O11-doped lithium borotellurite glasses demonstrate significant potential for advanced radiation shielding applications.
AtıfScopus10OpenAlex11İncele - MakaleYalnız künye2025Scopus SJRQ2Exploring the gamma-ray shielding performance of boron-rich high entropy alloys
Alan, Hatice Yilmaz; Guler, Omer; Yilmaz, Ayberk; Susam, Lidya Amon; Kavaz, Esra; Kilic, Gokhan; Ilik, Erkan; Oktik, Sener; Akkus, Baki; ALMisned, Ghada
High entropy alloys (HEAs) are innovative materials combining multiple principal elements, known for their exceptional properties and wide-ranging applications. This study assesses the gamma-ray shielding capacity of twelve boron-based HEAs through advanced computational methods. Key parameters in terms of understanding the material's ability to reduce radiation intensity, specifically half-value layer (HVL) and tenth-value layer (TVL); its capacity to absorb or scatter photons, including mass attenuation coefficient (MAC) and linear attenuation coefficient (LAC); and other related factors such as equivalent atomic number (Zeq), effective atomic number (Zeff), effective electron density (Neff), mean free path (MFP), and fast neutron removal cross-section (FNRCS) were calculated for photon energies between 0.015 and 15 MeV using the computational method Phy-X/PSD (Photon Shielding and Dosimetry). Additionally, the interaction of alpha particles and protons with these alloys was assessed by calculating energy deposition KERMA (Kinetic Energy Released per Unit Mass) and mass stopping power (MSP) using PAGEX (interaction of protons, alpha, gamma rays, electrons, and X-rays with matter) software, while SRIM (Stopping and Range of Ions in Matter) was employed to estimate particle penetration depths. Electron interactions were evaluated using ESTAR (Stopping Power and Range Tables for Electrons) for stopping power and penetration depth. Among the alloys, Sample 10, S10, (Zr10.8%-Hf21.3%-Nb11.0%-Ta21.6%-W22.0%-B13.1%) exhibited efficient shielding properties due to its high density and interaction characteristics. It can be concluded that boron-based HEAs with optimized compositions and high densities demonstrate significant potential for advanced radiation protection applications.
AtıfScopus12OpenAlex13İncele - MakaleAçık Erişim2025Scopus SJRQ1Exploring the anticancer potential of Dianthus orientalis in pancreatic cancer: A molecular and cellular study
Yildirim, Mehmet Aykut; Sevinc, Burak; Paydas, Samet; Karaselek, Mehmet Ali; Duran, Tugce; Kuccukturk, Serkan; Vatansev, Hakan; Cetiz, Mehmet Veysi; Caprioli, Giovanni; Acquaticci, Laura
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies, characterized by limited therapeutic options and poor prognosis. This study investigated the anticancer effects of Dianthus orientalis extracts on pancreatic cancer cell lines (Panc-1 and BxPC-3) with a focus on apoptosis, invasion, and metastasis-related pathways. Chemical analysis using HPLC-MS/MS identified bioactive compounds (vanillic acid, syringic acid, p-coumaric acid, quercetin, hyperoxide) known for their anticancer properties. The Inhibitory Concentration 50 (IC50) value, which is half maximal inhibitory concentration of cancer cells, was determined to be 250 μg/mL at 48 h, and significantly induced apoptosis by decreasing anti-apoptotic gene expressions (Bcl-XL and Bcl-2) and increasing pro-apoptotic gene expressions (Casp3 and Bax) particularly in the Panc-1 cell line. Flow cytometric analysis revealed approximately 55% apoptosis in both cell lines. Molecular docking and dynamics analyses demonstrated strong binding affinities of quercetin and hyperoxide with important cancer-related proteins, including CHEK2 and PALB2. Gene expression analysis demonstrated the upregulation of pro-apoptotic markers like Bax and Casp3, and selective modulation of metastasis-related genes such as SNAI1, PALB2, and CHEK2. The findings highlight the potential of D. orientalis to modulate DNA repair mechanisms and epithelial-mesenchymal transition (EMT) pathways. Furthermore, network pharmacology and in silico tools corroborated its interactions with critical signaling pathways in cancer progression, including PI3K-Akt and MAPK. The study provides the first comprehensive evidence of D. orientalis's antiproliferative through apoptosis induction on pancreatic cancer cell lines, laying the groundwork for future therapeutic applications.
AtıfScopus19İncele - DüzeltmeYayıncıda açık erişim2025Scopus SJRQ1Corrigendum to “A short review of structural, mechanical and magnetic properties of high and medium entropy alloys added rare earth elements” [Mater. Today Commun. 47 (2025) 113264] (Materials Today Communications (2025) 47, (S2352492825017763), (10.1016/j.mtcomm.2025.113264))
Yayla, Nihal; Güler, Ömer
The authors regret that in the published version of the article, although the explanations for Figs. 13–16 (Also, Figure numbers and explanations given just below the figures) are correct in the text, the figure numbers in text are mixed up. The incorrect figure title and its correction are as follows: On page 9, throughout the text: - All sentences starting with Fig. 14 (Wrong) has been corrected to Fig. 13.- All sentences starting with Fig. 15 (Wrong) has been corrected to Fig. 14.- All sentences starting with Fig. 16 (Wrong) has been corrected to Fig. 15.On page 10, throughout the text: - All sentences starting with Fig. 13 (Wrong) has been corrected to Fig. 16.The authors would like to apologise for any inconvenience caused.
AtıfScopus1İncele - MakaleYalnız künye2025Scopus SJRQ1Mechanical, durability and microstructure properties of eco-friendly self-compacting mortars with addition of volcanic scoria, silica fume and boron waste as cement replacement
Şahin Yön, Merve
The objective of this experimental study is to investigate the mechanical and durability performances of self-compacting mortars containing industrial waste and natural stone to develop an environmentally friendly mortar. Binary series of boron waste (B), silica fume (S) and volcanic scoria (V) were formed by substituting up to 95 % by weight with Portland cement, and ternary series were formed by substituting up to 80 % by weight with Portland cement. A total of 14 mixtures and one reference mixture (R) were improved for the purpose of investigating the workability, mechanical strength and durability properties of self-compacting mortar with different binder compositions. Samples of 40x40x160 mm were produced to evaluate mechanical properties and freeze-thaw effect, 100x100x100 mm for abrasion testing and 50x50x50 mm to determine physical properties. Additionally, SEM/EDS and XRD analyses were performed to determine the microstructural characteristics of the mixtures formed. The test results demonstrated that the sole replacement of boron waste with Portland cement resulted in enhanced fluidity. Nonetheless, the 90-day compressive strengths of the S10V20 and B5S10V5 mixtures exhibited increases of 7.47 % and 5.57 %, respectively, relative to the reference, whilst the B15 series saw a 52.5 % reduction, marking the lowest 90-day compressive strength compared to the reference sample. When the freeze-thaw effect was assessed after 136 cycles, the compressive strength diminished by 8.57 %, 13.1 %, 4.13 %, 7.28 %, 6.22 %, 24.77 %, and 48.1 % in the R, B5, V5, V10, V15, B5S10V5, B5S10V10, and B5S10V15 samples, respectively. Among the samples subjected to abrasion tests, a loss of 6.5 per thousand occurred in the mass of the reference sample at the end of 6 minutes, while a loss of 11 per thousand occurred in the binary mixture containing 5 % B, which had the highest abrasion.
AtıfScopus16WoS14OpenAlex16İncele - MakaleAçık Erişim2025Scopus SJRQ1Evaluation of Green Deal compliance performance with a hybrid comparative multi-attribute decision model
Karadag, Mehmet; Gul, Muhammet; Yucesan, Melih; Ortiz-Barrios, Miguel; Ishizaka, Alessio; Khan, Jehangir
The environmental and economic transformation initiated by the European Green Deal is influencing not only EU member states, but also other countries engaged in trade with the EU. This transformation mandates a shift towards sustainable practices in sectors such as agriculture, industry, transportation, energy, and finance. Compliance with the Green Deal is increasingly crucial for countries, particularly those with significant commercial ties to the EU. However, differing levels of development lead to varying degrees of implementation. While studies on the Green Deal compliance of EU member states exist, an evaluation of Türkiye—a candidate EU member with substantial trade relations—would address a significant gap in the literature. This study introduces a novel hybrid comparative multi-attribute decision model that combines subjective (Best Worst Method and its derivatives) and objective (Entropy) weighting to determine the relative importance of 14 sub-criteria under three main criteria: “Reducing” the impacts of climate change, “Protecting” the planet and health, and “Enabling” a green and just transition. Using the Ratio Product Model (RPM), Türkiye's Green Deal compliance from 2017 to 2021 was evaluated. Sensitivity analysis was conducted to validate the robustness of the findings, and comparisons were made using various multi-attribute decision models, including SAW, TOPSIS, and VIKOR, as well as benchmarking against EU countries. The criteria weights, derived from a combination of subjective and objective methods, highlighted the dominant importance of the “Reducing” criterion across all methods. The “Enabling” and “Protecting” criteria showed slight variations in importance depending on the method. The RPM results indicated that 2021 was Türkiye's best-performing year in terms of Green Deal compliance, while 2017 showed the weakest performance. Despite some fluctuations between 2018 and 2019, Türkiye demonstrated significant progress overall. The study not only advances the methodology for evaluating Green Deal compliance but also provides actionable insights for policymakers and industry stakeholders, enabling more informed decision-making. By highlighting Türkiye's trajectory, the findings offer strategic guidance for non-EU countries aiming to align with Green Deal objectives, fostering sustainable development and strengthening economic ties with the EU.
AtıfScopus11OpenAlex11İncele - MakaleYalnız künye2025Scopus SJRQ2Effects of Trace Rare Earth (TRE) additions on thermal, crystal structure, and radiation shielding properties of CuAlMn high-temperature S-M alloys: A closer look at Cerium effect
Kalay, Ece; Özkul, İskender; Karaduman, Oktay; Kızılgün, Yasin; Güler, Ömer; Canbay, Canan Aksu; Kilic, G.; Baykal, Duygu Sen; ALMisned, Ghada; Tekin, H.O.
This study systematically investigates the effect of Ce addition on the thermal, structural, and radiation shielding properties of CuAlMn-based high-temperature shape memory alloys (HTSMAs). Among the different compositions, Ce-III demonstrated the most balanced performance, exhibiting optimized phase transformation behavior, microstructural refinement, and enhanced gamma-ray attenuation. Differential Scanning Calorimetry (DSC) analysis revealed that Ce-III exhibited lower transformation temperatures, with austenite start (As) and finish (Af) temperatures of 378.13 °C and 429.75 °C, respectively, and martensite start (Ms) and finish (Mf) temperatures of 402.52 °C and 341.91 °C, suggesting improved thermal stability. Microstructural analysis indicated significant grain refinement, attributed to Ce's dislocation pinning effect, which contributed to enhanced strength and radiation attenuation. X-ray diffraction (XRD) patterns confirmed the formation of Ce-rich intermetallic phases, such as Mn1.15Cu3.85Ce and Cu8Ce4, which increased density and photon interaction probability. The Ce-III alloy exhibited superior linear attenuation coefficients and reduced half-value layer, reinforcing its effectiveness as a radiation shielding material. It can be concluded that Ce-III represents an optimal composition with a synergistic combination of structural stability, phase transformation control, and enhanced radiation shielding capabilities, making it a promising candidate for nuclear and high-radiation applications.
AtıfOpenAlex1İncele - MakaleYalnız künye2025Scopus SJRQ1Reduction of fluid forces on a circular cylinder in the laminar flow regime using a pair of airfoils
Fırat, Erhan; Oruç, Vedat; You, Rui; Biçer, Uğur; Devecioğlu, Atilla G.
Flow around the cylinder, with/without a pair of airfoils symmetrical to the cylinder's horizontal axis, was simulated for a diameter-based Reynolds number (Re) of 100. The objective of this numerical study is to simultaneously reduce the values of the time-averaged and fluctuating forces acting on a system consisting of a pair of airfoils and a cylinder below those of a single cylinder by using different combinations of the parameters chord (c), angle of rotation (β), angle of attack (α), and the shortest distance between the aerodynamic center of the airfoil and the surface of the cylinder (g). The values of these key parameters are determined primarily through two approaches. The first approach involves emulating the flow pattern surrounding the system to match the potential flow pattern. The second approach involves disrupting the interaction between the shear layers from the cylinder by stretching them in the mean flow direction. The second approach has been demonstrated to exhibit superior performance in terms of reducing both time-averaged and fluctuating forces concurrently. The second approach has been demonstrated to exhibit superior performance in terms of reducing both time-averaged and fluctuating forces concurrently. The optimal geometrical parameters that yield the desired end results are determined to be c = 0.5D, α = 0°, β = 60°, and g = 0.2D. Utilizing these parameters has been demonstrated to result in a substantial reduction in the time-averaged drag, fluctuating drag, and fluctuating lift coefficients of the system, with the respective percentage reductions reaching 14.4 %, 92.1 %, and 73 %, respectively, when compared to the values obtained for a single cylinder.
AtıfScopus4OpenAlex3İncele - MakaleYalnız künye2025Scopus SJRQ1Seasonally adjusted periodic time series for Mann-Kendall trend test
Güçlü, Yavuz Selim; Acar, Ramazan; Saplıoğlu, Kemal
In this study, temperature data trend analysis is conducted, which is thought to be influenced by global warming, climate change, and local factor impacts. The main objective of this paper is to obtain an acceptable autoregressive correlation value for the MK test. For this purpose, seasonality (periodicity) especially in monthly time series is adjusted. Autoregressive correlation and homogeneity test values decrease after seasonal adjusting, but reasonable results are not achieved. Then, prewhitening procedure is also applied to the seasonally adjusted data. This process resulted in the data becoming both homogeneous and free autoregressive correlation. The final version of the time series is suitable for the MK test. Furthermore, the time series are divided into different time intervals, and the efficacy of the method is investigated. The results demonstrated that the method is suitable for time series with less than 30 years of data. The study demonstrated that the proposed method enhances the reliability of the data. Also, multiplication by 12 (months) allows the MK test with Z score in place of the Student's t-test in short-term data sets. This suggested methodology can be used to identify MK trend conditions in monthly time series. The application is based on monthly and annual average temperature data between 1957 and 2022 from three stations within the Kızılırmak basin (Çankırı, Kırşehir, Sivas stations) and one station within Seyhan Basin (Adana station) in Türkiye. The test results exhibited a significant increasing trend.
AtıfScopus37WoS34OpenAlex41İncele - Derleme MakaleYalnız künye2025Scopus SJRQ1A short review of structural, mechanical and magnetic properties of high and medium entropy alloys added rare earth elements
Yayla, Nihal; Güler, Ömer
This study presents a comprehensive review of the structural, mechanical and magnetic properties of high and medium entropy alloys (HEA and MEA) with rare earth elements (REE) additions. The addition of REE has been shown to have significant effects on phase transformations, microstructural arrangements and thermodynamic stability. Studies in the literature show that REE addition improves properties such as hardness, strength, deformation resistance and magnetic performance. In particular, changes such as transitions from FCC to HCP, formation of intermetallic phases and grain refinement have been observed in phase types with the addition of elements such as Gd, Y and Nd. REE added HEAs offer great potential for modern engineering and advanced technology applications with their superior magnetic moments, magnetocaloric effects and thermal stability. However, there is limited information in the literature on REE added HEAs. This review aims to provide a comprehensive framework for the development of REE added HEAs and to serve as an important reference point for future research.
AtıfScopus7WoS7OpenAlex6İncele - MakaleAçık Erişim2025Scopus SJRQ2Tungsten carbide-based shape memory biopolymer nanocomposites as a promising new gamma radiation shielding material
Pekdemir, Mustafa Ersin; Yılmaz, Demet; Selçuk Pekdemir, Sibel; Taşgın, Yahya; Ekmen, Busenur
In this study, structural, thermal and radiation shielding properties of Polylactic acid (PLA)/polyhydroxyalkanoates (PHAs)/Tungsten Carbide (WC) nanocomposite films were investigated. PHA/PLA/WC composite films were prepared by using different amounts of WC (5%, 10%, 18%, 28%). Characterization of the composite films was carried out by Attenuated Total Reflection Infrared Spectroscopy (ATR-IR), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The linear and mass attenuation coefficients (LAC and MAC), mean free path (MFP), Half-Value Layer (HVL), Tenth Value Layer (TVL), effective atomic numbers (Zeff), and effective electron densities (Nel) of the synthesized composite films were experimentally measured from 53.16 to 383.85 keV. Also, the neutron equivalent dose rates for the prepared film samples were determined. Exposure buildup factor (EBF) and fast neutron removal cross section (ΣR) were theoretically calculated. The particle shielding characteristics of the composite films were evaluated. The MFP values at 356.01 keV are 8.211 cm, 7.772 cm, 7.360 cm, 6.710 cm and 5.942 cm for PLA/PHA, PLA/PHA/5%WC, PLA/PHA/10%WC, PLA/PHA/18%WC and PLA/PHA/28%WC, respectively. It was observed that an increase in WC content enhances the gamma shielding abilities in PHA/PLA films. The results revealed that PHA/PLA/WC composite materials can be used as protective coating materials.
AtıfScopus5WoS5OpenAlex6İncele - MakaleAçık Erişim2025Scopus SJRQ1A novel post-processing approach for improving minimum nonlinearity in S-boxes: A case study based on 2D hyper chaotic Schaffer transformation map
Aydın, Yılmaz; Garipcan, Ali Murat; Özkaynak, Fatih
Substitution boxes (s-boxes), providing nonlinearity in block cipher algorithms, constitute a fundamental security layer against linear and differential cryptanalysis attacks. In this study, an innovative s-box generation method is proposed by integrating a 2D hyper-chaotic Schaffer map (SM) with biomolecular DNA-based encoding techniques. Furthermore, to enhance the security of s-box structures, a novel post-processing algorithm is developed, aiming to simultaneously optimize both the average (NLavg) and minimum (NLmin) nonlinearity levels by targeting linear components. Unlike traditional meta-heuristic methods, the proposed algorithm avoids random exploration across large search spaces, instead identifying dominant linear components through Walsh spectrum analysis and applying targeted permutation operations to suppress their effects. This strategy not only increases the NLavg value but also balances the contribution of each Boolean function to security, thereby establishing a homogeneous and consistent security structure across all input–output combinations. Comparative experimental analyses with existing methods demonstrate that the proposed approach outperforms prior techniques in terms of both cryptographic security metrics and computational efficiency. In this respect, the study presents an advanced s-box design framework, characterized by high nonlinearity and a balanced spectral distribution, suitable for integration into modern block cipher systems.
AtıfScopus12WoS13OpenAlex13İncele - MakaleAçık Erişim2025Scopus SJRQ1Examining the trade-off between structural, mechanical properties and shielding performance of Pr2O3-enhanced 316L stainless steel
Yayla, Nihal; Albayrak, M.Gökhan; Güler, Ömer; Baykal, Duygu Sen; Alkarrani, Hessa; ALMisned, Ghada; Zakaly, Hesham M.H.; Tekin, H.O.
This study explores the structural, mechanical, and radiation shielding properties of 316L stainless steel composites reinforced with varying weight percentages of Pr2O3. The aim is to enhance radiation attenuation capabilities while maintaining structural integrity for nuclear applications. The composites were fabricated using the mechanical alloying method, followed by detailed characterization through X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Key radiation shielding parameters, including mass attenuation coefficient, linear attenuation coefficient, half-value layer, and effective atomic number, and transmission factor values were analysed using theoretical and computational models. Additionally, elastic modulus calculations were performed to assess mechanical properties. The results indicate that incorporating Pr2O3 significantly enhances shielding performance. The 316L-SS%20Pr2O3 composite exhibited the highest mass and linear attenuation coefficients values, with a notable reduction in half value layer values compared to the unreinforced 316L stainless steel. At lower photon energies, effective atomic number improved by 39.3 % for the 316L-SS%20Pr2O3 sample, while neutron shielding efficiency also increased. However, the elastic modulus decreased with higher Pr2O3 content, reflecting a trade-off between mechanical stiffness and radiation shielding efficiency. The findings demonstrate that 316L-SS%20Pr2O3 is a promising material for applications requiring superior radiation shielding, particularly in environments where mechanical load is secondary.
AtıfScopus8OpenAlex8İncele