Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Güler, Ömer(24)
- Tekin, H.O.(19)
- ALMisned, Ghada(18)
- Kocabaş, Mehmet(13)
- Baykal, Duygu Sen(11)
- Alkarrani, Hessa(10)
- Serdar, Osman(10)
- Yayla, Nihal(10)
- Kilic, G.(9)
- Özkul, İskender(9)
- Guler, Omer(7)
- Kocabaş, Filiz Kutluyer(7)
- Utku, Anıl(7)
- Çelikel, Baha Engin(7)
- Acar, Ramazan(6)
- Aglar, Erdal(6)
- Canbay, Canan Aksu(6)
- Garipcan, Ali Murat(6)
- Karaduman, Oktay(6)
- Koç, Ali(6)
- Özçiçek, Esin(6)
- Aydın, Ayşe Nur(5)
- Kutluyer Kocabaş, Filiz(5)
- Sarı, Sacit(5)
- Sezer, Süreyya Yonca(5)
- Sezgin, Eray Ekin(5)
- Yılmaz, Coşkun(5)
- Zengin, Gokhan(5)
- Akgül, Ceylan Sülü(4)
- Alataş, Mevlüt(4)
- Aslan, Naim(4)
- Batan, Nevzat(4)
- Cakilcioglu, Ugur(4)
- Ceylan, Tülay(4)
- Dal, Murat(4)
- Ertarğın, Merve(4)
- Ezer, Tülay(4)
- Gul, Muhammet(4)
- Kalay, Ece(4)
- Konurhan, Zekeriya(4)
Yayınlar
- MakaleAçık Erişim2025Scopus SJRQ1One-pot synthesis of quercetin-functionalized silver and copper nanoparticles for enhanced optical, antimicrobial, and computational properties
Aziz, Dara Muhammed; Amin, Alla Ahmed Muhammed; Hassan, Sangar Ali; Özmen, Habibe; INCILI, Gökhan Kursad; Say, Yakup
The emergence of multidrug-resistant bacterial strains has intensified the need for novel antimicrobial agents. Herein, we report a facile one-pot green synthesis of quercetin-stabilized silver (Qn@AgNPs) and copper (Qn@CuNPs) nanoparticles using quercetin as both reductant and capping ligand. The resulting nanocomposites were fully characterized by UV–Vis spectroscopy (surface plasmon resonance peaks at 420 nm for Ag and 580 nm for Cu), FTIR (confirming quercetin–metal coordination), SEM/EDX (spherical particles, and XRD (face-centered cubic Ag and Cu phases). Density functional theory (B3LYP/3-21G) calculations yielded frontier molecular orbital gaps of 0.164 eV for Qn@AgNPs and 0.245 eV for Qn@CuNPs, with corresponding high softness values (12.20 and 8.16 eV⁻¹), indicating enhanced electron-transfer propensity. Molecular electrostatic potential maps revealed increased charge polarization around the metal centers. Antibacterial assays against Escherichia coli and Staphylococcus aureus demonstrated minimum inhibitory concentrations of 2.11 ± 1.22 µg/mL and 4.69 ± 2.68 µg/mL for Qn@AgNPs, and 7.50 ± 0.00 µg/mL and 6.25 ± 0.17 µg/mL for Qn@CuNPs, significantly outperforming free quercetin (188 and 375 µg/mL). In silico docking against the S. epidermidis TcaR regulator (PDB: 1KZN) and E. coli DNA gyrase B (PDB: 1HSK) revealed strong binding affinities (–7.54 to − 10.15 kcal·mol⁻¹), consistent with the observed antimicrobial potency. This integrated experimental–computational study elucidates the mechanistic underpinnings of quercetin-mediated nanoparticle bioactivity and provides a rational framework for designing next-generation flavonoid-functionalized metal nanotherapeutics.
AtıfScopus12WoS11OpenAlex14
İncele - MakaleYalnız künye2025Scopus SJRQ2Enhanced gastrointestinal disease classification using a convvit hybrid model on endoscopic images
Utku, Anıl
Endoscopy is a procedure that allows examination of the gastrointestinal system, including the stomach, esophagus, large intestine, and duodenum, with the help of an endoscope. Processing of endoscopic images is important for early detection and treatment of gastrointestinal diseases. In this study, hybrid ConvViT was developed using CNN and ViT to increase the classification accuracy of pathologies in gastrointestinal endoscopic images. CNNs are well-suited for capturing local spatial features through hierarchical convolutions, making them highly effective in detecting fine-grained textures and edge patterns. These capabilities complement the ViT’s global attention mechanism, which excels at modeling long-range dependencies in images. The motivation of this study is to increase the classification accuracy and reliability with the ConvViT model, which was developed by combining the practical features of CNN and ViT models, which are individually successful in different aspects of image processing. The ConvViT model was compared with VGG-16, ResNet-50, Inception-V3 and ViT. Comparable models were tested using a gastrointestinal endoscopic image dataset containing ulcers, polyps, inflammation, bleeding, and regular anatomical features. Experiments showed that ConvViT had better prediction performance than compared models, with 95.87% classification accuracy.
AtıfScopus5WoS2OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ1The contagion effect of the FTX cryptocurrency exchange's crash on the stock markets
Gençyürek, Ahmet Galip
The cryptocurrency market is very attractive for investors, but it has experienced several major crises in recent years due to its inadequacies with regard to transparency and auditing. The FTX cryptocurrency exchange's crash was one of the most crucial events for the cryptocurrency market. Therefore, I investigate the contagion impact of the FTX crash on stock markets (S&P 500, TSX, FTSE100, BIST100, SENSEX, SSE, NIKKEI 225, KOSPI 100 and ASX 200), using a time-varying parameter–vector autoregression (TVP-VAR) extended joint connectedness model and covolatility, cokurtosis, and coskewness tests. The empirical findings, based on a daily dataset for the period 2021–2023, indicate that the FTX collapse had a clear contagion impact solely on the BIST 100. One possible explanation for this is that Turkish investors who suffered losses on their FTX investment sought to compensate for their diminishing wealth, especially to meet margin calls, by liquidating their holdings in the BIST 100. Another possible explanation is the inherent fragility of the BIST 100, which prevents it from being perceived as a safe-haven asset during turbulent periods. The findings can help policy makers and investors develop policies and strategies to defend against the contagion impact of cryptocurrencies.
AtıfScopus2OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ1A novel deep learning-based statistical randomness evaluation test methodology for cryptographic applications
Kaner, Seyfullah; Garipcan, Ali Murat; Erdem, Ebubekir
The security of cryptographic systems is directly linked to the statistical randomness properties of the random numbers used. Traditional statistical randomness tests can be limited in evaluating the properties of these numbers and can require long processing times. While widely used test suites such as the National Institute of Standards and Technology (NIST) Special Publication (SP) 800–22 play a crucial role in assessing data randomness, they are slow on large data sets, can only evaluate certain statistical properties, and fail to detect complex data patterns and dependency structures. In this paper, we propose a new deep learning (DL) based method to overcome these limitations. In the study, bit sequences produced by an FPGA-based true random number generator (TRNG) and different pseudo-random number generators (PRNGs) were converted into image format, and classification experiments were carried out on the AlexNet, ResNet50, and EfficientNetB0 architectures. The results showed that AlexNet, with 87% accuracy and 99% recall, was by far the most successful method compared to the other models. Furthermore, the ablation analysis revealed that the components of data augmentation, early stopping, and cross-validation play a critical role in the model’s stability and generalizability. Providing a reliable randomness evaluation with high accuracy, this new method, as an alternative to traditional statistical test suites, demonstrates that AI-based solutions can enhance the effectiveness and accuracy of randomness assessment in cryptographic applications. The success of DL methods in complex data structures offers significant potential for improving the security of modern cryptographic systems.
AtıfScopus9WoS9OpenAlex11İncele - MakaleYalnız künye2025Scopus SJRQ2Chromium removal with walnut shells and oak branches, adsorption studies, and kinetics
Fırat, Tülay
This study investigates the chromium sorption properties of walnut shells (WS) and oak branches (OB), both of which were modified using NaOH and lactic acid treatments. The characterization of these adsorbents was carried out using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), point of zero charge (pHpzc) analysis, and Brunauer–Emmett–Teller (BET) surface area measurements. According to BET results, WS exhibited higher surface area values compared to OB. The pH and pHpzc measurements revealed that acidic functional groups are more prevalent than basic ones on both adsorbents. Batch experiments were conducted to evaluate the chromium ion sorption capacities of WS and OB. To further understand the adsorption mechanism, the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models were analyzed, with the Langmuir and Freundlich models being widely recognized for describing adsorption in single-solute systems. The equilibrium data aligned best with the Langmuir isotherm, while the kinetic data were modeled using pseudo-first-order and pseudo-second-order kinetics. The maximum chromium sorption capacity for WS was determined to be 30.51 mg/g. The energy values calculated from the D-R equation for chromium adsorption onto WS and OB were 13.49 kJ/mol and 15.71 kJ/mol, respectively, indicating that the adsorption process is primarily driven by physical adsorption.
AtıfScopus3WoS3OpenAlex1İncele - MakaleYalnız künye2025Scopus SJRQ3Antioxidant Enzyme Responses to Lead Exposure in Daphnia magna
Sahilli, Yeliz Cakir
Abstract: Lead (Pb), a pervasive environmental contaminant, poses significant toxicological risks to freshwater ecosystems. Daphnia magna, a widely used model organism in aquatic toxicology, provides valuable insights into the sublethal effects of heavy metal exposure. This study investigated the effects of Pb exposure on antioxidant defense mechanisms in D. magna. Test organisms were exposed to aqueous Pb solutions at varying concentrations (0, 10, 20, 30 μg/L) for 96 h. The enzyme activities of glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) were measured using enzyme-linked immunosorbent assay (ELISA). SOD activity did not differ significantly between the exposed and control groups. However, CAT activity showed a significant decrease in all Pb-exposed groups compared to controls. GPx activity exhibited a non-significant decrease. In conclusion, Pb exposure may induce oxidative stress by generating reactive oxygen species (ROS) and inhibiting the function of sulfhydryl-containing antioxidant enzymes. Changes in antioxidant enzyme activity may serve as early biomarkers in ecotoxicological assessments of Pb pollution in aquatic environments. It is suggested that future studies incorporate molecular-level endpoints and chronic exposure scenarios to better elucidate the long-term impacts of Pb on aquatic invertebrates.
- MakaleYalnız künye2025Scopus SJRQ3Symmetry and Curvature in LP-Kenmotsu Manifolds with Generalized Tanaka-Webster Connection
Prakasha, D.G.; Deepika, M.V.; Ünal, İnan
In this study, we investigate Lorentzian para-Kenmotsu (LP-Kenmotsu (LPK)) manifolds in the context of the generalized Tanaka-Webster connection, denoted as D*. Initially, we derive the formulas for the curvature tensor, Ricci tensor, and scalar curvature of an LPK manifold with respect to the connection D*. We analyze the geometric properties of these manifolds, including their local symmetry, Ricci semi-symmetry, and local ψ-symmetry. Furthermore, utilizing the Q-curvature tensor, we analyze conditions under which LPK manifolds exhibit Q*-flatness, Q*-Ricci semi-symmetry, and ψ-Q*-flatness concerning the connection D*.
- MakaleAçık Erişim2025Scopus SJRQ3A study on copolymers of styrene with a methacrylamide containing benzofuran side group: Their monomer reactivity ratios, thermal stabilities, thermal degradation kinetics
Barim, Esra; Demir, Pınar; Değirmenci, Mustafa; Kirilmiş, Cumhur
The aim of this study was to determine the monomer reactivity ratios, thermal properties and thermal degradation behavior of new P(N-[2-(4-brombenzoyl)-benzofuran-3-yl]-2-methac-rylamide-co-styrene) polymers synthesized at different compositions. For this purpose, novel copolymers of N-[2-(4-brombenzoyl)-benzofuran-3-yl]-2-methacrylamide (NBBM) monomer with styrene (St) monomer were prepared using free radical polymerization method. The 1 H-NMR spectra was used to calculate the compositions of the copolymers. The reactivity ratios of monomers were calculated in line with the universal copolymerization equation using Kelen-Tüdös and Finemann-Ross linearization methods, and found to be r1:0,62 r2:1,09 and r1:0,61, r2:1,07 respectively (where r1 is reactivity ratio of NBBM). DSC, TGA and DTG were used to study the thermal behaviors of the copolymers. The Tg value of P(NBMM) was found to be 211oC and the Tg values of the studied copolymers were determined to increase from 144oC to 184oC with increasing concentration of NBMM units. Thermal data showed that the maximum degradation temperatures increased from 349oC to 391oC as the St units increased in the copolymer system. The activation energy (Ea) values of P(NBBM) and the studied copolymer were determined from the TGA curves obtained at different heating rates and the Flynn-Wall-Qzawa, Kissinger, Tang isoconversional methods were used. Solid state reaction mechanisms were also calculated by being used the Van Krevelen method, a non-isoconversion model. The Ea values obtained with isoconversion models for P(NBBM) and copolymer were found very close to the values obtained from non-isoconversion models. Moreover, the R3 mechanism was proposed for the homopolymer and copolymer.
- MakaleYalnız künye2025Scopus SJRQ3Production and Partial Characterisation of Bifunctional Cellulase Genes of Anaerobic Gut Fungus Orpinomyces sp. GMLF19
Yazdic, F.C.; Akyol, I.; Ozkose, E.
Abstract: Fiber-degrading properties of anaerobic gut fungus, Orpinomyces sp. GMLF19, were investigated when it was grown on various carbon sources, namely carboxymethylcellulose, barley, oat, corncob and wheat straw. Fungi were developed under anaerobic conditions, and carboxymethylcellulase (CMCase), lichenase, and xylanase activities were determined by using DNS method. Meanwhile, the decreasing order of the enzyme activity of Orpinomyces sp. GMLF19 was observed to be lichenase > CMCase > xylanase. Relative activities of these enzymes in the isolate GMLF19 were found to be the highest when the culture was grown for 5 days. Cellulase gene domain was reproduced from chromosomal DNA and transferred into Escherichia coli with the aid of pCT plasmid vector and CMCase, lichenase and xylanase activities were determined using DNS method. The gene showed relatively higher CMCase activity and moderate lichenase activity while no xylanase activity was observed suggesting that the gene is bi-functional. The cell-associated activity of overexpressed Cel19 enzyme (E. coli cells containing this transferred gene were designated as C19) was relatively higher than extracellular activity. It was also recorded that this gene has 2 dockerin domains and 1 catalytic domain with the length of 1.585 bp, and it coded 50.59 kDa size of the protein which belongs to glycosyl hydrolase family 6.
AtıfOpenAlex1İncele - Kitap BölümüYalnız künye2025DLC coatings for optical and optoelectronic applications
Koç, Mümin Mehmet; Aslan, Naim
Diamond-like carbon (DLC) materials, special amorphous forms of carbon, are quite stable and durable, therefore finding applications in different industries. It baffles people from both industrial and scientific communities where tribological, mechanical, chemical, optical, and optoelectronic properties were used for various applications. DLC films were used in different optical applications regarding their optical performance. Having outstanding shear and mechanical performance and high chemical inertness makes DLC thin films a suitable candidate for optical applications and devices that work under tough conditions. Thus, they were preferred in photovoltaic devices, monitors, cameras, lenses, medical devices, fiber optic cable technologies, and illumination technologies. Their absorption, emission, and transmission characteristics were also addressed in various optical applications and studies.
AtıfScopus4OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ2Designing multifunctional ferromagnetic high-entropy shape memory alloys (FHESMAs): Cr and Mn influence on structural, physical, magnetic and nuclear radiation shielding in NiFeGaCo alloys
Özkul, İskender; Karaduman, Oktay; Şimşek, Tuncay; Şimşek, Telem; Canbay, Canan Aksu; Güler, Ömer; ALMisned, Ghada; Tekin, H.O.
This study systematically investigates the influence of Cr and Mn additions on the structural, magnetic, and radiation shielding properties of NiFeGaCo-based ferromagnetic high-entropy shape memory alloys (FHESMAs) synthesized via the arc melting method. The fabricated NiFeGaCo, NiFeGaCoCr, and NiFeGaCoMn alloys were comprehensively characterized in terms of their phase formation, microstructure, martensitic transformation behavior, and magnetic performance. The results demonstrated that Mn addition significantly improved the magnetic properties, yielding the highest saturation magnetization (56.64 emu/g) and lowest coercivity (5.55 Oe), making NiFeGaCoMn highly suitable for soft magnetic applications. In contrast, Cr addition provided moderate magnetic behavior but enhanced structural stability with the largest crystallite size and lowest lattice strain. Moreover, gamma-ray and fast neutron shielding investigations revealed that the Cr-containing alloy exhibited superior performance in terms of linear attenuation coefficient, half-value layer, effective electron density, and fast neutron removal cross-section values, while Mn addition slightly reduced these shielding capabilities. It can be concluded that Cr addition offers a balanced advantage in designing FHESMAs with combined magnetic sensitivity and radiation shielding efficiency, whereas Mn addition is more effective for maximizing magnetic performance with a compromise in shielding characteristics.
AtıfScopus2OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ1Physiological effects of MAP and calcium chloride treatments on biochemical metabolites and quality stability by reducing respiration rate in sweet cherry fruit during storage
Çolak, Ayşen Melda; Çelik, Kenan; Gündeşli, Muhammed Ali; Gündoğdu, Özlem; Küçüker, Emine; Berk, Selma Kuru; Aglar, Erdal; Gundogdu, Muttalip
Background: Sweet cherry (Prunus avium L.) is an important fruit species with its high nutritional value and fresh consumption rate. However, it is very sensitive to mechanical damage, decay, water loss and microbial spoilage in the post-harvest period. Therefore, new preservation methods are needed to extend shelf life and preserve quality. In this study, the effects of postharvest 4% calcium chloride (CaCl₂) and modified atmosphere packaging (MAP) treatments on quality traits (weight loss, decay rate, SSC, titratable acidity, pH, respiration rate) and biochemical compounds (organic acids, vitamin C and phenolic compounds) of sweet cherry fruit were investigated. Results: During the storage period, the weight loss reached 7.14%, the lowest loss was observed in the CaCl₂+MAP group. The highest decay rate was measured in the control group with 11.30%, and the CaCl₂+MAP combination was the method that limited decay the most. SSC increased over time, but the lowest levels remained in the CaCl₂+MAP group. The titratable acidity value decreased from 1.12% to 0.82%, CaCl₂+MAP application was the method that best preserved acidity. The pH value increased by 25.2%, the lowest pH was again determined in the CaCl₂+MAP group. The respiration rate decreased by 77%, the lowest respiration rate was determined in the CaCl₂+MAP application. Organic acid and vitamin C contents decreased over time, and the application that best limited these losses was CaCl₂+MAP. Significant decreases were also observed in phenolic compounds, and the combined application preserved phenolic stability at the highest level. Conclusion: CaCl₂ and MAP applications were effective in preserving the quality characteristics and bioactive compounds of sweet cherry fruit, especially the combined application (CaCl₂+MAP) gave the most successful results. Therefore, in order to prevent post-harvest quality losses and extend shelf life, it is recommended that CaCl₂ and MAP applications be evaluated together by the producer and the supply chain.
AtıfScopus4OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ2A New Ground-Motion Prediction Model for Shallow Crustal Earthquakes in Türkiye
Çeken, Ulubey; Sertçelik, Fadime; İçen, Abdullah
The recent expansion of the strong-motion observation network, along with the increase in data obtained during major earthquakes and efforts to create consistent metadata for source, path, and site effects for both old and new records, has significantly improved the quality of data and the level of modeling in Türkiye. The mainshock and aftershock records of the 6 February 2023 Kahramanmaraş earthquake doublet (MW 7.8 and 7.7), which are among the most destructive earthquakes in world history, constitute an up-to-date and important data source for this study. In this study, we present new ground-motion prediction models (GMPMs) for shallow crustal earthquakes using strong-motion data recorded in Türkiye. Our GMPMs are calibrated using 20,173 strong-motion records from 1565 shallow crustal earthquakes with depths of less than 35 km that occurred in Türkiye and its vicinity between 1976 and 2023. Our model is valid for magnitudes ranging from 4.0 to 7.8 (MW), and for the time-averaged 30 m shear wave velocity (VS30) values of 975 stations, which ranged from 131 to 1862 m/s. In the analyses performed, using the recently developed site amplification model, we calculated the model coefficients using the mixed-effects regression algorithms used by the GMPM developers. Additionally, a heteroscedastic model was created for aleatory variability as a function of MW. The closest distance to the surface projection of the fault plane (RJB) is between 0 and 350 km. Using the metadata prepared according to these criteria, we derived up-to-date ground-motion prediction models for horizontal-component peak ground velocity (PGV), peak ground acceleration (PGA), and 5% damped pseudo-spectral acceleration (PSA) response spectra, at 36 periods ranging from 0.01 to 10 s. The variability in the predictions was decomposed into within-event, between-event, and site-to-site deviations to determine the total standard deviations (σ). Compared to previous models, the proposed GMPMs were developed using a much richer database with recent major earthquakes, and the consistent estimates and lower residuals in the comparisons support the reliability of the models.
AtıfScopus4WoS3OpenAlex4İncele - MakaleYalnız künye2025Scopus SJRQ2Phase Stability, Structural Properties, Electronegativity, Mechanical Properties, and Neutron and Gamma-Ray Attenuation Properties of Cantor High Entropy Alloys for Advanced Nuclear Applications
Tekin, H.O.; Güler, Ömer; Özkul, İskender; AlMisned, Ghada; Baykal, Duygu Sen; Alkarrani, Hessa; Kilic, G.; Mesbahi, A.
High Entropy Alloys (HEAs) hold considerable potential for sophisticated nuclear applications, offering a vast spectrum of compositional tuning to enhance mechanical properties at high temperatures, as well as to increase resistance to radiation and corrosion. This study explores the suitability of Cantor HEAs, specifically the CoCrFeMnNi matrix enriched with elements such as Zr, Nb, Mo, Hf, Ta, and W, for nuclear applications. These elements were selected for their high atomic numbers and neutron capture cross-sections, vital for enhancing gamma-ray and neutron shielding properties. Utilizing advanced computational and theoretical methods, the elastic modulus of these alloys was theoretically estimated while their radiation attenuation capabilities were evaluated through different Monte Carlo simulation codes. CoCrFeMnNiW demonstrated the highest elastic modulus (340.9 GPa), indicating significant mechanical robustness. The addition of W resulted in superior gamma-ray attenuation, with the lowest gamma-ray transmission factors and highest neutron shielding effectiveness among the studied alloys. The calculated mass attenuation coefficients and effective removal cross-sections values demonstrate the potential of these HEAs to provide effective radiation shielding. Our results showed a clear correlation between the elastic modulus and radiation attenuation properties, suggesting that mechanical stiffness does not compromise shielding capabilities. The comprehensive analysis of thermodynamic and structural parameters, including entropy of mixing, mixing enthalpy, and Valence Electron Concentration (VEC), provided essential insights into phase stability and microstructural characteristics. It can be concluded that CoCrFeMnNiW and its related Cantor HEAs as promising materials for advancing nuclear technology, offering a new horizon for safer and more efficient nuclear systems.
AtıfScopus9OpenAlex13İncele - MakaleAçık Erişim2025Scopus SJRQ2Role of Rare-Earth Cerium in Martensitic Transformation and Magnetic Properties of Cu-Al-Mn Alloys
Özkul, İskender; Kalay, Ece; Karaduman, Oktay; Kizilgün, Yasİn; Güler, Ömer; Canbay, Canan Aksu
This study investigates the effects of different cerium additions on the properties of Cu-Al-Mn high-temperature shape memory alloy (HTSMA), such as the characteristic martensitic transformation temperatures, transformational kinetic parameters, and martensitic microstructures which are related to its shape memory mechanism and also to its magnetic behavior. Polycrystalline alloys with a base composition of Cu77.32Al21.02Mn1.67 (at.%) were synthesized, and varying concentrations of cerium (Ce-1 to Ce-4) were added for comparison. Differential scanning calorimetry tests revealed notable increments in transformation temperatures with cerium additions. Specifically, the austenite start temperature of the reference alloy increased from 143.75 °C to 194.88 °C by 0.05 at.% of Ce addition (Ce-3 alloy), corresponding to the formation of CeCu5 and Mn1.15Cu3.85Ce phases. However, excessive Ce addition in Ce-4 led to the over-stabilization of secondary phases, reducing the transformation temperatures. Microstructural analysis indicated that Ce addition of refined grains changed the crystallite size of the martensite structure and reduced lattice strain (from 0.72% to 0.34%). Magnetic characterization demonstrated that Ce addition shifted the alloy towards paramagnetic behavior, with M-H curves showing no significant coercive field or remanent magnetization across the studied alloy samples. These findings suggest that cerium can enhance the high-temperature performance of Cu-Al-Mn HTSMAs, with potential applications in environments requiring both shape memory and magnetic properties.
AtıfScopus3WoS3İncele - MakaleAçık Erişim2025Scopus SJRQ2High thermal stability and dielectric performance of phenylhydrazine-based Schiff base oligomers obtained via oxidative polycondensation
Solmaz, Adnan; Kaya, İsmet; Bayır, Erdal
In this study, the 2-PHMBD Schiff base, synthesized through the condensation of 2,4-dihydroxybenzaldehyde (2,4-DHBA) with phenylhydrazine (PH), was subjected to oxidative polymerization in a basic medium using hydrogen peroxide (H2O2), sodium hypochlorite (NaOCl), and molecular oxygen (O2) as oxidizing agents. Three oligomers, designated as o-(2-PHMBD)-P, o-(2-PHMBD)-H, and o-(2-PHMBD)-O, were successfully obtained and comprehensively characterized by FT-IR, 1H-13C-NMR, UV–Vis, CV, GPC, SEM, TGA, and DSC analyses. Spectroscopic results confirmed the successful polymerization, while morphological and thermal analyses revealed the distinct physical characteristics of the oligomers. According to GPC data, o-(2-PHMBD)-H exhibited the highest average molecular weight of 4700 Da, and TGA analysis demonstrated that o-(2-PHMBD)-O had the highest thermal stability with a residue of 46% at 1000 °C. The DSC results showed the highest glass transition temperature of 132 °C for o-(2-PHMBD)-H. UV–Vis and CV measurements indicated reduced optical and electrochemical band gaps compared with the monomer, with the lowest optical band gap determined as 2.74 eV. Dielectric measurements revealed that o-(2-PHMBD)-H displayed the highest dielectric constant of 2.57 and conductivity of 2.49 × 10⁻7 S cm⁻1. These results demonstrate that phenylhydrazine-based Schiff base oligomers possess high thermal stability and favorable dielectric properties, making them promising materials for optoelectronic and dielectric device applications.
AtıfScopus3WoS2OpenAlex4İncele - 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.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ3The Level of Intimate Partner Violence Against Women, Contributing Factors, and its Effects on Psychological Resilience: An Evaluation of Women in Turkey
Orhan, İ.; Ünal, E.; Ağralı, C.; Küçükkelepçe, D.Ş.
Background: Violence by intimate partners is a serious public health problem that negatively affects women’s physical, emotional, and social well-being. In Turkey, factors such as traditional gender roles, economic inequalities, and cultural norms contribute to the continuation of this form of violence. Understanding how such experiences influence women’s psychological strength is essential for effective support and prevention strategies. Aim: This study aims to determine the relationship between domestic violence against women, the factors affecting it, and levels of psychological resilience among women in Turkey. Patients and Methods: We conducted this research with 425 women residing in Tunceli, Turkey. In this cross-sectional, relational study, data were collected using a personal information form, the Violence Against Women Scale (SVAWS), and the Brief Resilience Scale (BRS). The relationship between scores obtained from the scales was determined through correlation and linear regression analyses. Cronbach’s alpha coefficient was calculated to assess the reliability of the scales. Results: The average age of the women who participated in the study was 41.22 ± 12.93 years. Approximately one in four women (24.5%) experienced violence, with the primary reasons for violence being financial problems (40.4%) and issues caused by family members of the couple (28.8%). A significant negative correlation was found between the SVAWS and BRS scores (r = −0.228, P < 0.01). Additionally, there was a significant negative relationship between all subdimensions of the violence scale and psychological resilience. Conclusion: The study found that as the level of violence experienced by women increased, their level of psychological resilience decreased.
- MakaleAçık Erişim2025Scopus SJRQ1Monitoring of organic micropollutant behavior and fate in a full-scale conventional biological urban wastewater treatment plant
Demirbilek, D.; İpek, U.; Yetis, U.
Organic micropollutants, found at trace levels in nature, are causing significant concern due to their toxic, carcinogenic, and mutagenic effects. In this study, the fate and removal of organic micropollutants were monitored covering all seasons in an urban wastewater treatment plant in Turkey. The plant influent, effluent, and aeration basin were sampled seven times in the years of 2019–2020; and three surfactants (linear alkylbenzene sulfonate, nonylphenol mono-di-ethoxylate, nonylphenol), polychlorinated biphenyls and polyaromatic hydrocarbons were monitored in this context. The plant was being operated in the endogenous respiration phase during the monitoring period without sludge removal. Results obtained showed that the highest NH3-N removal (41%) of the study period was realized in March when the lowest mixed liquid volatile suspended solids value (380 mg/L) and the lowest sludge age were observed. In this month, the highest organic micropollutants removal efficiency was obtained in relation to the increased metabolic activity. On the other hand, in August, when the highest mixed liquid volatile suspended solids value (1,750 mg/L) was observed, the lowest organic micropollutants removal was recorded, with the lowest NH3-N removal (6%). The removal of linear alkylbenzene sulfonate and nonylphenol mono-di-ethoxylate was high during the period, and microorganisms could metabolize these pollutants efficiently. Polychlorinated biphenyls, polyaromatic hydrocarbons, and nonylphenol were resistant to metabolic degradation, so they were present in high amounts at various stages of the treatment process. Due to the poor plant treatment performance, a high quantity of organic micropollutants was discharged into the receiving environment.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ1Hybrid GA-ConvLSTM for data-driven prediction of climate variables: a case study of the most biodiverse cities in India
Utku, Anıl; Akyol, Sinem
Climate variables affect ecosystems’ structure, sustainability, and biodiversity. Monitoring and analysis of climate variables are essential for the management of ecosystems and the conservation of biodiversity. Temperature affects the distributions, habitats, and phonological events of living things in ecosystems. Humidity is essential for meeting plants’ water needs and the habitat’s quality and health. Dew point is essential for water quality, balance, plant health, and microclimate. Wind speed is essential for pollinating plants, microhabitats, and the health of living things. For such reasons, accurate prediction of climate variables using artificial intelligence methods can effectively predict the future of ecosystems and biodiversity and develop future strategic plans. This study aimed to predict the climate variables of temperature, humidity, dew point, and wind speed of Bhubaneshwar, Dehradun, Guwahati, Mysore, and Nagpur, among the cities with the highest biodiversity in India. It aimed to determine the long-term impacts of climate change on managing ecosystems and biodiversity protection. The hyperparameters of the ConvLSTM model, developed using CNN and LSTM, were optimized with a genetic algorithm, and the GA-ConvLSTM hybrid model was created. GA-ConvLSTM was tested with XGBoost, SVM, ANFIS, CNN, LSTM, and base ConvLSTM using approximately 15 years of hourly, up-to-date, and real-time climate variable data of cities. This work is one of the pioneering studies using GA to optimize deep learning hybrid models for multi-city climate prediction through extensive long-term high-resolution datasets. The experimental results reveal that GA-ConvLSTM outperforms conventional models, producing an R2 score exceeding 0.9 for each city across all climate variables. GA-ConvLSTM produced temperature predictions with 0.833 RMSE and 0.995 R2 for Bhubaneswar, humidity predictions with 3.461 RMSE and 0.990 R2, dew point predictions with 0.632 RMSE and 0.995 R2, and wind speed predictions with 2.278 RMSE and 0.993 R2. The experimental findings confirm the improved performance over conventional models due to SVM and XGBoost failing to achieve these R2 values and high RMSE scores. The research meets three principal obstacles because of the combination of stochastic climate datasets and complex nonlinear patterns, which also encounter limitations in conventional methods for managing scale-dependency relationships and manual parameter adjustments. This approach delivers three main strengths because it combines CNN and LSTM networks through genetic programming while tracking temporal and spatial relationships and processing noisy data automatically, leading to improved results compared to other methods. Unlike other published models in the field, the hybrid model GA-ConvLSTM combines optimized CNN and LSTM elements with genetic algorithm elements. The proposed model received its first application in this research for multi-city climate prediction through training with 15 years of hourly data. Standard methods encounter challenges when detecting long-term dependencies, but GA-ConvLSTM successfully addresses this issue.
AtıfScopus1OpenAlex1İncele