Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Bulut, Hasan(53)
- Baskonus, Haci Mehmet(52)
- Alataş, Mevlüt(39)
- Gul, Muhammet(39)
- Serdar, Osman(38)
- Güler, Ömer(37)
- Akkurt, Nevzat(31)
- Benzer, Fulya(30)
- Sulaiman, Tukur Abdulkadir(29)
- Yucesan, Melih(29)
- Zengin, Gokhan(29)
- Kocabaş, Mehmet(28)
- Topal, Murat(26)
- Batan, Nevzat(25)
- Kök, Mediha(25)
- Ezer, Tülay(24)
- Paksoy, Mehmet Yavuz(24)
- Yildirim, Ozal(23)
- Tekin, H.O.(22)
- Utku, Anıl(22)
- ALMisned, Ghada(21)
- Ince, Muharrem(21)
- Öbek, Erdal(21)
- Erten, Fusun(20)
- Aslan, Naim(19)
- Celik, Erkan(19)
- Yildirim, Numan(19)
- Cakilcioglu, Ugur(18)
- Dal, Murat(18)
- Dal, Nursel Alp(18)
- Sahin, Kazim(18)
- Özkaynak, Fatih(18)
- Aslan, Alper(17)
- Erata, Hüseyin(17)
- Orhan, Cemal(17)
- Ergen, Burhan(16)
- Tanyol, Mehtap(16)
- Demir, Yakup(15)
- Etli, Serkan(15)
- Işık, Erdem(15)
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ2Tribological Performance of SPS-Fabricated Cu-HEA/Gr Composites Under Current-Carrying Sliding Contact
Ozkaya, Serdar; Çelebi, Müslim; Yanar, Harun; Karabacak, Abdullah Hasan; Çelik, Ertuğrul; Güler, Onur; Coskun, Abdulkadir; Sekban, Dursun Murat
Cu-based hybrid composites reinforced with AlCrFeCuNi high-entropy alloy (HEA) particles and graphene were successfully fabricated by spark plasma sintering (SPS) to investigate the combined effects of microstructure, mechanical properties, and tribological performance under electrical current. Microstructural observations revealed a dense and homogeneous distribution of HEA particles within the Cu matrix, while the addition of 2.0 wt.% graphene promoted noticeable grain refinement due to its grain boundary pinning effect. Although graphene addition provided beneficial effects in terms of grain refinement and electrical conductivity, it also increased the porosity from 2.49% to 5.08%. Consequently, the beneficial contribution of graphene to mechanical strengthening was substantially offset by the adverse effect of increased porosity, resulting in only a marginal increase in hardness from 127 HB to 129 HB. The addition of 2.0 wt.% graphene led to a pronounced change in the tribological behavior of the composites. The Cu–HEA exhibited relatively stable friction behavior but experienced a higher wear rate under all test conditions. In comparison, the Cu–HEA–2.0 Gr composite demonstrated a lower coefficient of friction and wear rate at 0–10 A, which is consistent with the possible formation of a graphene-rich lubricating surface layer. A clear transition occurred at 30 A, where the coefficient of friction and wear rate began to increase, while at 50 A, further increases in both parameters were observed, suggesting progressive disruption of the proposed protective surface layer under the investigated current-carrying sliding conditions.
- MakaleAçık Erişim2026Scopus SJRQ1EBA-Net: A hybrid EfficientNetB3-BiLSTM-Attention model for species-level diatom classification
Balo Utku, Esen Damla; Kutlu, Banu; Utku, Anil
Species identification in diatoms is important for assessing water bodies, determining environmental quality, and analyzing biodiversity. Nonetheless, diatom classification has proven difficult due to intra-class variation, interclass similarity, and data imbalance in microscopic images. In this regard, we propose a new deep learning approach for species-level diatom classification. Various deep learning models, including traditional convolutional neural networks or CNNs (ResNet50, DenseNet121), state-of-the-art CNNs (EfficientNetB3, Xception, MobileNetV3), transformer-based architectures (ViT-B16, Swin-Tiny), and our proposed EBA-Net (EfficientNetB3-BiLSTM-Attention Network), were extensively compared under identical experimental settings. The EBA-Net integrates the advantages of convolutional feature extraction, sequence modeling, and an attention mechanism to improve classification accuracy. It first uses the EfficientNetB3 model as the backbone network to obtain higher-level features, followed by a BiLSTM layer to capture dependencies among the extracted features. Then, it applies the attention mechanism to the BiLSTM output to highlight the most informative features. Experimental results showed that the proposed EBA-Net model outperforms other models considered in the study, yielding 95.8% accuracy and 85.1% macro F1-score. In addition, Top-3 (98.9%) and Top-5 (99.6%) accuracies confirmed the efficiency of the proposed model for classifying objects from visually similar classes. An analysis of the model's interpretability was conducted using Gradient-weighted Class Activation Mapping, showing that the proposed model's attention is concentrated on relevant morphological features of diatoms. To the best of our knowledge, the suggested approach achieves state-of-the-art accuracy on the data set of diatoms used.
- MakaleAçık Erişim2026Scopus SJRQ4INTEGRATED BIOLOGICAL TREATMENT AND ELECTROCOAGULATION FOR SLAUGHTERHOUSE WASTEWATER: A NOVEL APPROACH USING FRESHWATER SNAILS (Viviparus contactus, Planorbis rubrum, Melanoides tuberculata)
Öğedey, Ayşenur; Kocabaş, Filiz Kutluyer; Kizak, Volkan; Kocabaş, Mehmet; Benzer, Fulya; Erişir, Mine; Öğedey, Hayrullah
As a potential pollution source, slaughterhouse wastewater (SWW) with development of the meat production and processing sector is a threat in the world. Therefore, the determination of economical, favourable, cost-effective and proper treatment method is crucial for sustainable environmental protection. This study focused on the performance and efficiency of a two-stage process combining biological treatment (BT) with freshwater snails and electrocoagulation (EC) of SWW. Viviparus contectus, Planorbis rubrum, Melanoides tuberculata were used in primary treatment while secondary treatment was realized with EC process. The EC of SWW was performed for reducing both turbidity and chemical oxygen demand (COD) concentration to levels compliant with direct-discharge regulations. In addition, the stirring speed, current density, initial pH and reaction time were assessed for evaluation the optimum EC condition. Oxidative stress biomarkers and some antioxidants were assessed in freshwater snails exposed to SWW after 24 and 96 h. The best removal efficiencies of COD (91.43%) and turbidity (92.42%) were obtained at pH 5 and 20 min of operational time by P. rubrum. Notably, MDA (Malondialdehyde) was highest level in M. tuberculata compared to V. contectus and P. rubrum. Overall, removing organic and inorganic pollutants from SWW could be provided with the hybrid process BT/EC as a combining approach.
- MakaleAçık Erişim2026Scopus SJRQ2Corrosion behavior and constant load scratch adhesion properties of CeO2 doped ceramic composite layer via micro arc oxidation on Al 1050 alloy
Ayday, Aysun; Durmaz, Mustafa; Duru, Erhan; Kırsever, Derya; Doğan, Fatih
In this study, CeO2-doped ceramic coatings were produced on Al 1050 alloy by micro-arc oxidation (MAO) using a silicate-alkaline electrolyte containing 0, 0.5, 1, and 2% CeO2. The aim was to investigate the effect of CeO2 addition on the microstructure, phase composition, corrosion behavior, and constant-load scratch adhesion performance of the coatings. Surface characterization was carried out by SEM, EDS, XRD, and 3D profilometry, while corrosion performance was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy in 3.5 wt% NaCl solution. Scratch tests were also performed to assess the mechanical integrity of the coatings. The results showed that increasing CeO2 content improved coating uniformity, reduced surface roughness and porosity, and promoted the formation of a denser oxide structure. XRD analysis confirmed that γ-Al2O3 was the predominant alumina phase in all coatings, while Ce-containing species were incorporated into the oxide layer without forming additional detectable phases. Electrochemical results revealed that CeO2 addition significantly improved corrosion resistance by lowering the corrosion current density and increasing the polarization resistance. Scratch test results further showed improved adhesion-related behavior with reduced crack formation and surface damage. Overall, CeO2 addition effectively enhanced both the corrosion protection and mechanical performance of MAO coatings on Al 1050 alloy.
AtıfScopus1OpenAlex1
İncele - MakaleAçık Erişim2026Scopus SJRQ1Impact of Postharvest Oxalic Acid Treatments on Quality Properties and Biochemical Composition of Medlar (Mespilus germanica L.) Fruit
Çolak, Ayşen Melda; Gündoğdu, Özlem; Aglar, Erdal; Sezgin, Nevzat; Orman, Erdal; Gundogdu, Muttalip
This study was conducted to investigate the effects of oxalic acid (OA) applications at different concentrations on the quality traits and biochemical components of medlar (Mespilus germanica L.) fruit. Fruits harvested in Bolu province in 2024 were subjected to control (0) and 0.5, 1.0, and 1.5 mM OA applications and stored at 4°C and 90% ± 5% relative humidity for 45 days. Samples were taken from the fruits at certain intervals (0, 15, 30, and 45 days) and analyzed. Specifically, 1.0 and 1.5 mM OA applications significantly reduced fruit weight loss and decay rates. OA also inhibited increases in fruit respiration rate and pH and slowed the decline in total acidity, soluble solids content (SSC), vitamin C, phenolic compounds, and organic acids. Malic, citric, succinic, tartaric, and fumaric acids, vitamin C, and important phenolic compounds (chlorogenic acid, gallic acid, quercetin, catechin) were protected by OA applications, and this protection was most pronounced at 1.5 mM OA dose. The correlation analyses revealed significant relationships between quality parameters and biochemical contents. The weight loss and decay rate were negatively correlated with bioactive compounds such as gallic acid and ascorbic acid, indicating that quality deterioration progressed in parallel with the decrease in nutrient content. A strong positive correlation was found between titratable acidity and malic and citric acids. In principal component analysis (PCA), malic and citric acids were prominent in the early storage period, while weight loss, decay, and increased respiration became dominant in the late storage period. Phenolic compounds decreased significantly with storage time, and antioxidant capacity decreased. Heat map analysis visually supported the increase in spoilage parameters with the decrease in ascorbic acid and phenolic compounds. OA applications maintained the quality of medlar fruit and increased biochemical stability, extending postharvest life. 1.5 mM OA, in particular, stands out as an effective postharvest preservation method. These results demonstrate that OA offers significant potential for increasing the commercial value of perishable fruits like medlar and for developing preservation technologies.
AtıfScopus1OpenAlex1
İncele - MakaleAçık Erişim2026Scopus SJRQ1Numerical analysis of PCM integrated in solar dryers for thermal efficiency
Bakır Gür, Eda; Işık, Erdem; Uçar, Aynur
Solar dryers using phase change materials buffer heat, yet the combined influence of airflow regime and PCM placement on melting remains underexplored. A controlled like-for-like study fixed geometry and PCM properties while varying placement and operating conditions. A 3D transient CFD model simulated a forced-convection dryer with RT28HC over Re = 3000–9000 and inlet temperatures Ti = 50–60 °C. Raising either Re or Ti shortened melt time, and three-wall coverage melted faster and more uniformly than a rear-wall-only layout. For three walls, melt time dropped from 13 h (50 °C, Re = 3000) to 7 h (60 °C, Re = 9000) (−46 %) for the rear wall it fell from 19 h to 11 h (−42 %). A 10 °C increase in Ti reduced overall melt time by 4 h across Re. Practically, three wall PCM with Re ≥ 6000 at Ti = 60 °C achieved reliably 7–9 h melting, enabling late afternoon heat release without auxiliary heating.
AtıfScopus17WoS16OpenAlex12İncele - MakaleAçık Erişim2026Scopus SJRQ2Engineering Superior Soft Magnetic Properties Through FeCo/Cr and FeCo/Fe Nanocrystalline Architectures
Yüzüak, Gizem Durak
Soft magnetic materials are integral to various technologies, including high-frequency transformers, spintronic devices, and magnetic sensors, because of their low coercivity (HC) and high magnetization. This study investigates nanocrystalline Fe70Co30(100 nm)/Cr(2-10 nm) and Fe70Co30(100 nm)/Fe(2-10 nm) thin films, deposited via magnetron sputtering. X-ray diffraction analysis reveals that Fe70Co30 films without buffer layers crystallize in a body-centered cubic phase. The Cr and Fe buffer layers enhance it by minimizing lattice mismatch and promoting a uniform crystalline growth of the Fe70Co30 layer. The most significant particle size variations observed were approximately 24% for the Cr buffer and 31% for the Fe buffer. Microstructural characterization using atomic force microscopy and scanning electron microscopy identified nanograins with an average size of 30–80 nm. Magnetic characterization with a vibrating sample magnetometer showed a marked reduction in HC. Additionally, the remanence-to-saturation magnetization ratio remains nearly constant at 0.95 across all Fe-buffered films, whereas it increases from 0.80 to 0.92 in Cr-buffered films as the Cr thickness increases. The results highlight the importance of buffer layer engineering in enhancing the microstructural and magnetic properties of FeCo thin films, thereby increasing their suitability for advanced magnetic technologies.
- MakaleAçık Erişim2026Scopus SJRQ1Biogenic amine profiling of fruit wines by high-performance liquid chromatography with fluorescence detection after OPA derivatisation: effect of fruit type
Tok, Fırat; Çetin, Burcu; Karaca Sanyürek, Nesrin
This study aimed to characterise the biogenic amine (BA) profiles of fruit wines produced from different raw materials and to investigate their association with pH and fruit type. Ten commercially available fruit wines, including pomegranate, black mulberry, sour cherry, strawberry, melon, blackberry, and blueberry, were analysed using HPLC with fluorescence detection (HPLC-FLD) following pre-column derivatisation with o-phthalaldehyde. Putrescine, tyramine (TYR), and histamine were identified as the predominant amines, with total BA concentrations ranging from 11.62 to 53.96 mg/L depending on the fruit type. The pH values of the wines (3.28-3.60) were inversely related to acidity and showed a strong positive correlation with total BA content (r = 0.97, p < .001). Among the detected compounds, TYR exhibited the highest sensitivity to pH variation. Multivariate analysis using principal component analysis clearly differentiated the samples into two distinct groups: low pH-low BA wines (pomegranate and blueberry) and high pH-high BA wines (blackberry and strawberry). The HPLC-FLD method demonstrated excellent analytical performance, with high chromatographic stability (retention time RSD < 1%) and reliable compound identification. Overall, the results indicate that BA formation in fruit wines is closely associated with both pH and fruit type, reflecting the combined effects of raw material composition and fermentation conditions. These findings provide valuable insights into the biochemical characterisation, quality assessment, and safety evaluation of fruit wines in oenological applications.
- MakaleAçık Erişim2026Scopus SJRQ1Optimization of scours downstream of conduit aerators
Arici, Erdinc; Tuna, M. Cihat; Aytac, Ayca; Acar, Ramazan; Tunc, Mustafa
Dams, wastewater treatment plants, and aquaculture areas often require aeration, making it crucial for hydraulic engineers to predict the physical properties of scour holes occurring on the downstream side of conduits. Conduit systems that provide high aeration performance necessitate multiple optimization studies to simultaneously maximize the scour parameters and the system’s physical properties. In this study, the physical parameters of conduit systems and downstream scour parameters were optimized using Artificial Neural Networks (ANN). The optimum system parameters were identified based on the experimental results through ANN-based optimization. Additionally, the real and optimal effects of the parameters on aeration performance and scour were determined. The results of the study demonstrated that ANN can be effectively used in studies aimed at optimizing the aeration performance and scour values of conduits. This study is the first to apply ANN for the simultaneous optimization of both aeration efficiency (Qa/Qw) and scour characteristics (dmax and δ) in a conduit-based hydraulic system. Previous studies have typically focused on either scour or aeration individually; this study integrates both through a multi-objective ANN model. The findings provide novel insights for the design and retrofitting of energy-dissipating conduit structures in high-head dam applications. Unlike traditional empirical or regression-based approaches, the ANN model captures complex, nonlinear relationships among multiple interacting hydraulic variables. It identified optimal parameter combinations — such as 70% gate opening, 1.30–1.50 m conduit length, and 9 mm air hole diameter — that improve both aeration and scour behavior. These outcomes offer direct applicability for real-world hydraulic system optimization.
AtıfOpenAlex1İncele - BildiriAçık Erişim2026Scopus SJRQ4Investigation of Surface Leakage Currents of High Voltage Insulators Under Different Pollution Conditions at Power Frequency AC Voltage
Külekçioğlu, Abdülcelil; Çetin, Muhammed Sefa; Gülan, Harun; Özdemir, Mahmut Temel; Gençoğlu, Muhsin Tunay; Cebeci, Mehmet; Moldovan, L.; Gligor, A.
In this paper, the electrical behavior of high voltage insulators under different pollution conditions has been investigated experimentally at power frequency (50 Hz) alternating voltage. The main objective of the study is to reveal the effect of pollution layers on the surface leakage currents and flashover voltages of insulators. For this purpose, a climatic chamber with controllable temperature and humidity conditions, together with a 200 kV high voltage test system, was employed. Three types of insulators (standard porcelain, fog-type porcelain, and silicone composite) were tested, and artificial pollution layers of varying densities were applied to their surfaces in accordance with standard procedures. During the experiments, the surface leakage currents were recorded, and flashover voltages were determined by gradually increasing the applied voltage. The obtained data enable comparative analyses for different pollution levels and insulator types. The originality of this study lies in providing a comprehensive dataset through numerous experiments under controlled laboratory conditions, thereby addressing gaps in the existing literature. This dataset establishes a solid foundation for the modeling of insulators electrical behavior and for the development of new approaches in future research.
- MakaleAçık Erişim2026Scopus SJRQ3An Artificial Neural Network Modeling of Solar Drying of Mint: Energy, Exergy, and Drying Kinetics
Gülçimen, Fevzi; Karakaya, Hakan; Durmuş, Aydın
Abstract: Solar drying is an environmentally friendly method for preserving agricultural products; however, limited studies have jointly examined energy–exergy performance and data-driven prediction methods under varying airflow conditions, which restricts performance optimization. This study aims to investigate the effects of inlet airflow rate on energy utilization ratio, energy generation, exergy loss, exergy efficiency, and drying kinetics of mint leaves, and to evaluate the predictive capability of artificial neural network modeling. Thin-layer drying experiments were conducted in a forced convective solar dryer equipped with a newly designed solar air collector at different air mass flow rates. Energy and exergy analyses were conducted using experimental thermodynamic data, and energy utilization and exergy loss were modeled with a feed-forward back-propagation artificial neural network. The energy utilization ratio ranged from 7.45 to 87.1% and increased with decreasing airflow rate. The average exergy losses for air mass flow rates of 0.012, 0.026, and 0.033 kg s–1 were 16.2, 8.2, and 6.88 W, respectively. Both experimental and artificial neural network results showed that increasing airflow rate reduced energy utilization ratio and exergy loss. The artificial neural network predictions exhibited very close agreement with experimental data. The results show that artificial neural networks can accurately predict energy utilization ratio and exergy loss in a forced convective solar dryer. Airflow rate is a key parameter for thermodynamic performance, and the integrated experimental–ANN approach offers a robust tool for optimizing and designing solar drying systems.
AtıfOpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ1Influence of apple pomace and asparaginase on acrylamide levels in cookies and behavior during simulated gastric digestion: risk assessment perspectives
Sevim, Sumeyra; Macit, Arife; Farıa, Miguel A.; Viegas, Olga; Cunha, Sara C.; Kizil, Mevlude; Ferreira, Isabel M.P.L.V.O.
Cookies are widely consumed baked products; however, their contribution to dietary acrylamide (ACR) intake raises increasing health concerns. This study investigated the effects of apple pomace addition and asparaginase treatment on ACR levels in cookies, the fate of ACR during simulated gastric digestion using the INFOGEST semi-dynamic model, and the associated health risks of ACR exposure from cookie consumption. Risk assessment was conducted for adults (18–65 years) and children (3–10 years) using Monte Carlo simulation. Three formulations were evaluated: a control cookie, a cookie in which wheat flour was partially replaced with apple pomace, and a cookie containing asparaginase. Cookies formulated with apple pomace contained significantly lower ACR levels than the control (132 ± 8 μg/kg vs. 215 ± 11 μg/kg; p < 0.05), although the reduction was less pronounced than in cookies containing asparaginase (65 ± 14 μg/kg). During gastric digestion, ACR exhibited formulation-dependent release kinetics. Nevertheless, the total ACR released at the end of digestion was similar for control and pomace cookies, likely due to additional ACR formation in the stomach, despite differences in release patterns throughout digestion. Margin of Exposure (MOE) values for children remained well below 10,000, indicating a potential carcinogenic risk, although reductions of up to 59% were observed for control and pomace cookies after digestion. Target Hazard Quotient (THQ) values showed a slight increase after digestion in both age groups but remained below 1, suggesting no concern for chronic toxicity. Control cookies indicated a potential carcinogenic risk for children (ILCR = 1.56 × 10−4), whereas pomace and asparaginase formulations reduced this risk (ILCR = 9.59 × 10−5 and 4.72 × 10−5, respectively). However, simulated gastric digestion increased ILCR values for both control and pomace cookies (2.24 × 10−4 and 2.33 × 10−4, respectively). These findings indicate that dietary exposure to ACR cannot be assessed solely based on its concentration in food, and that digestive kinetics should be incorporated into health risk assessment.
- MakaleAçık Erişim2026Scopus SJRQ1Structural and radiation shielding properties of high-entropy rare-earth oxide-doped borosilicate glass
Güler, Ömer; Yılmaz, Demet; Kanca, Muhammed Sait; Kök, Mediha; Taşgın, Yahya
In this study, the incorporation of a high-entropy rare-earth oxide, (GdLaEuPrDyY)2O3 (RE-HEO), into a borosilicate glass matrix was investigated with the aim of improving radiation shielding performance while preserving the structural integrity of the glass. The RE-HEO was first synthesized by high-energy mechanical alloying and then introduced into the glass system at concentrations ranging from 0 to 8 wt% using a conventional melt-quenching process. The structural and microstructural properties of the prepared samples were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy combined with energy-dispersive spectroscopy (SEM–EDS). The analyses confirmed that the amorphous nature of the borosilicate glass was maintained and that the rare-earth elements were homogeneously distributed within the matrix. The radiation shielding performance was evaluated experimentally using Am-241, Ba-133, and Ra-226 gamma sources, and supported by theoretical calculations of key parameters including mass attenuation coefficient (MAC), half-value layer (HVL), mean free path (MFP), effective atomic number (Zeff), exposure buildup factor (EBF), and fast neutron removal cross-section (ΣR). The results showed that increasing RE-HEO content leads to a noticeable improvement in gamma-ray attenuation. In particular, the sample containing 8 wt% RE-HEO exhibited a MAC value of 0.131 cm2/g and an HVL of 2.03 cm at 356 keV, indicating shielding performance comparable to that of conventional lead-containing glasses. In addition, irradiation tests performed using a Co-60 gamma source revealed that the amorphous structure remains stable after exposure. Overall, the findings suggest that RE-HEO-doped borosilicate glass can be considered a promising lead-free alternative for radiation shielding applications.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ2Radiation shielding performance of CeO2-reinforced ternary nanocomposites based on biodegradable polymers and waste-derived polystyrene
Pekdemir, Mustafa Ersin; Yilmaz, Demet; Selçuk Pekdemir, Sibel; Gülhan, Aleyna; Yalçin Kuzu, Serpil; Altun, Sedanur; Taşgin, Yahya
The development of sustainable polymer-based materials for radiation shielding has attracted increasing interest, particularly for lightweight and flexible applications. In this study, ternary nanocomposites based on poly (hydroxyalkanoate) (PHA), poly (ε-caprolactone) (PCL), and polystyrene (PS) were prepared and reinforced with cerium oxide (CeO2) nanoparticles (5–15 wt%) to enhance radiation shielding performance. Structural characterization confirmed the preservation of polymer chemical structures and the successful incorporation of crystalline CeO2, while SEM observations revealed a relatively homogeneous nanoparticle dispersion within the ternary matrix, particularly at intermediate filler loadings. Thermal analysis demonstrated enhanced thermal stability with increasing CeO2 content, as evidenced by an increase in residual mass from 0.42% for the neat blend to 11.21% for the nanocomposite containing 15 wt% CeO2, along with a shift of degradation onset temperatures toward higher values. Photon shielding performance was experimentally evaluated in the energy range of 13.37–59.54 keV. The incorporation of 15 wt% CeO2 increased the mass attenuation coefficient (MAC) from 1.277 to 12.366 cm2 g−1 at 13.37 keV, corresponding to an approximately ninefold enhancement, while significantly reducing the half-value layer (HVL) and mean free path (MFP). Neutron shielding analysis showed a slight decrease in thermal neutron attenuation due to hydrogen dilution within the polymer matrix, whereas fast neutron attenuation and neutron removal cross sections exhibited only minor variations; the fast neutron removal cross section increased modestly from 0.1014 to 0.1047 cm−1 with 15 wt% CeO2 addition. Overall, the results highlight clear structure–property–performance relationships in CeO2-reinforced PHA/PCL/PS nanocomposites, demonstrating their potential as lightweight radiation shielding materials for low energy protection with improved thermal stability and shielding efficiency.
AtıfScopus2OpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ1Investigation of the structural, thermal and radiation shielding properties of (Er0.2Yb0.2Sm0.2La0.2Eu0.2)2Zr2O7 high entropy oxide reinforced tin matrix composite
Güler, Ömer; Yılmaz, Demet; Kanca, M. Sait; Kök, Mediha; Güler, Seval Hale; Taşgın, Yahya
This study investigates the structural, thermal, and radiation shielding properties of (Er0.2Yb0.2Sm0.2La0.2Eu0.2)2Zr2O7 high entropy oxide (HEO) reinforced tin (Sn) matrix composites. In the first stage of the study, HEO powders were synthesized by grinding at 350 rpm for 30 h using a solid-state method with mechanical alloying assistance, and then calcining at 1100 °C for 8 h. In the second stage, composites were produced by mixing HEO-reinforced Sn matrix materials containing 1%, 5%, and 10% reinforcement, pelleting them under 200 MPa pressure, and then sintering them at 300 °C for 3 h. In the first stage of the study, (Er0.2Yb0.2Sm0.2La0.2Eu0.2)2Zr2O7 HEO powders were synthesized using a mechanical alloying-assisted solid-state route. In the second stage, HEO-reinforced Sn matrix composites containing 1 wt%, 5 wt%, and 10 wt% reinforcement were produced. The phase formation and crystallographic structure of the synthesized powders and composites were characterized using X-ray diffraction. Thermal behavior and phase stability were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The thermal analysis results revealed dehydration and structural stabilization processes at intermediate temperatures, while crystallization of the HEO phase was observed at elevated temperatures. In addition, oxidation behavior of the Sn matrix composites was evaluated, showing that the presence of HEO particles significantly suppresses mass gain during high-temperature oxidation, indicating improved thermal stability. Finally, the radiation shielding performance of the samples was experimentally evaluated within the photon energy range of 59.54–609.2 keV using Am-241, Ba-133, and Ra-226 radioactive sources together with a Ultra-Low Energy Germanium (ULEGe) detector. The results demonstrate that the incorporation of HEO particles leads to minor, energy-dependent variations in the radiation attenuation capability of the tin matrix, influenced by the presence of high atomic number rare-earth elements and modified microstructural characteristics. The gamma radiation protection coefficient (RPC) values indicate strong attenuation in the low photon energy region, decreasing to approximately 16–19% at 609.3 keV. Moreover, the measured neutron equivalent dose rates increase from 0.054 µSv/h for pure Sn to 0.285 µSv/h for the Sn–10%HEO composite, indicating that HEO incorporation modifies the neutron interaction behavior of the Sn matrix composites.
- MakaleAçık Erişim2026Scopus SJRQ2Data-Driven Prediction of Climate Variables in Agricultural Cities of India With Hybrid GA-TCN-LSTM Model
Utku, Anil
Accurate prediction of climate variables is important in reducing the effects of natural disasters and taking preventive measures for agriculture and food security, energy sector, public health, and water resources management. For agricultural production, it is essential for producers to determine strategies for their agricultural activities and to increase agricultural productivity. Issues such as determining planting and harvest times, determining pesticides to be used against agricultural pests, selecting products to be planted, irrigation, and sustainable agriculture are directly related to climate variables. In this study, a GA-TCN-LSTM hybrid prediction model was created to determine climate variables such as relative humidity, temperature, wind speed, and dew point in Bhopal, Indore, Kanpur, Ludhiana, and Patna, which are among the prominent cities of India in terms of agricultural production. The hyper-parameters of the developed model using the temporal convolutional networks (TCN) and long short-term memory (LSTM) were optimized with the genetic algorithm (GA), and the GA-TCN-LSTM hybrid model was created. GA-TCN-LSTM was extensively compared with the base TCN-LSTM, convolutional neural network (CNN), LSTM, TCN, and CNN-LSTM. The compared models were tested using approximately 15 years of hourly, up-to-date, and real-time data of the cities. Experiments showed that GA-TCN-LSTM outperformed the compared models and had above 0.9 R-Squared (R2) for the majority of cities and climate variables.
AtıfScopus2WoS1OpenAlex2İncele - MakaleAçık Erişim2026Scopus SJRQ2Production and Thermal–Structural Characterization of Nano-Oxide-Doped Paraffin-Based Phase Change Composite Materials for Thermal Storage Applications
Yücel, Halit Lutfi; Özdemir, Osman; Kahraman, Gökhan
Paraffin-based composite phase change materials (PCMs) have been synthesized for thermal energy storage applications to enhance thermal conductivity and stability while maintaining latent heat storage capacity. In this study, RT42 paraffin was modified with inorganic nano-oxides (Al2O3, CuO, SiO2, and ZnO) in the presence of sodium dodecyl sulfate (SDS) as a surfactant. The incorporation of SDS improved nanoparticle dispersion and reduced agglomeration, resulting in enhanced phase-change behavior and improved structural homogeneity. Differential scanning calorimetry (DSC) analysis revealed slight variations in melting and crystallization temperatures, while the ZnO-doped composite retained up to 92% of the latent heat storage capacity of pure RT42. Among all the investigated composites, the Al2O3-doped sample exhibited the highest thermal conductivity and specific heat capacity. Thermogravimetric analysis (TGA) indicated an increase of approximately 15–20°C in the decomposition temperature, demonstrating enhanced thermal stability. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses confirmed the preservation of the crystalline structure and improved microstructural uniformity. The developed SDS-assisted nano-oxide/RT42 composites exhibit significant potential for passive thermal regulation in renewable energy and building applications.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ2Eigenfunction Expansion and Parseval Identity of β-Dirac Operators on the Whole Line
Koşar, Nida Palamut; Koşar, Cem; Akcay, Ozge
In the present work, we investigate a (Formula presented.) -Dirac problem on the whole-line. Our primary objectives are threefold: to demonstrate the existence of a spectral function, to deduce the associated Parseval identity, and to formulate an eigenfunction expansion theorem that characterizes the behavior of the problem under consideration.
- MakaleAçık Erişim2026Scopus SJRQ2Experimental and numerical analysis of ceramic fiber geopolymer concrete under blast effect
Dalğıç, Aras; Yılmazer Polat, Berivan; Savaş, Sedat
This study employs both experimental and numerical methods to investigate the blast resistance of ceramic fiber-reinforced geopolymer concrete (CFGC), a cement-free material often referred to as green concrete due to its environmentally friendly nature compared to Portland cement concrete (PCC). Geopolymer concrete specimens, formulated with ground granulated blast furnace slag, silica fume, and varying proportions of ceramic fibers, were subjected to blast tests using 50, 100, 150, 200, and 250 grams of trinitroglycerin (TNG). A standard PCC specimen was utilized as a control. The results demonstrate that the incorporation of 10% ceramic fibers significantly enhances the blast resistance of the geopolymer concrete, reducing crater diameters by up to 20% compared to conventional PCC. Furthermore, the finite element model developed in ANSYS Workbench exhibits a strong correlation with the experimental data, validating the predictive capability of the numerical simulations. Overall, this research highlights the immense potential of CFGC as a sustainable, highly durable alternative for structures exposed to blast loads.
- MakaleAçık Erişim2026Scopus SJRQ1Natural propolis-based coatings as an effective strategy to control microbial growth and quality losses of kiwifruit during cold storage
Ozturk, Burhan; Gun, Sefa; Erturk, Omer; Aglar, Erdal; Yıldız, Kenan; Ozturk, Ahmet
Background: this study investigated the effects of ethanol-extracted propolis applications on the quality characteristics, microbial growth, and microstructural changes of kiwifruit (Actinidia deliciosa) during cold storage. Four different application groups were created: control, 70% ethanol application (ETH), 3% propolis coating (PRO1), and 6% propolis coating (PRO2). After dip coating, the fruits were stored for 150 days at 0 ± 0.5 °C and 90 ± 5% relative humidity, and analyses were performed on days 0, 30, 60, 90, 120 and 150. During storage, weight loss, respiration rate, fruit firmness, color, soluble solids content (SSC), titratable acidity (TA), vitamin C, total phenolics, total flavonoids, antioxidant activity (DPPH and FRAP assays), individual phenolic compounds, and microbial growth were determined in fruit samples. In addition, microstructural changes on the fruit surface were examined using scanning electron microscopy (SEM), and the elemental surface composition was determined using energy dispersive X-ray spectroscopy (EDX). Results: propolis coating applications maintained the quality characteristics of kiwifruit during storage. In particular, PRO1 and PRO2 reduced weight loss and respiration rate, better preserved fruit firmness, and maintained more stable color parameters. Propolis coatings also contributed to the preservation of ascorbic acid, total phenolic compounds, and total flavonoids, ensuring that antioxidant activity remained at higher levels throughout the storage period. Microbiological analyses showed that propolis coatings markedly reduced total bacterial counts on the kiwifruit surface, indicating their potential to limit microbial contamination during cold storage. SEM images showed that propolis coatings formed a homogeneous film layer on the fruit surface and limited microbial colonization by sealing surface pores. EDX analyses showed treatment-dependent changes in the surface elemental composition of kiwifruit peel, whereas SEM observations confirmed the formation of a continuous propolis-derived surface layer. Conclusions: overall, ethanol-extracted propolis coatings reduced total bacterial counts and quality losses in kiwifruit during cold storage and may serve as an effective natural preservative for extending cold-storage life. This journal is
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