İngilizce · Dil · Munzur Üniversitesi

Munzur ÜniversitesiAçık Erişim Arşivi · RDL Open

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MakaleYalnız künye2026Scopus SJRQ2/r/munzur/861
Correlative Investigation on physical, microstructure, magnetism, and gamma-neutron attenuation properties of mechanically alloyed multifunctional (Fe/Co/Ni)Nb10V10B10 soft magnetic alloy systems
Simsek, Tuncay; Simsek, Telem; Chattopadhyay, Arun K.; Avar, Barış; Yakin, Alican; Guler, Seval Hale; Almisned, Ghada; Sen Baykal, Duygu; Tekin, H.O.
In this study, mechanically alloyed Fe70Nb10V10B10, Co70Nb10V10B10, Ni70Nb10V10B10, and (FeCoNi) 70Nb10V10B10 high-entropy alloys were successfully synthesized, and their structural, magnetic, and radiation shielding properties were systematically investigated. Structural analysis revealed that Fe favored bcc phase formation, while Co and Ni stabilized fcc structures; the equiatomic alloy resulted in a single-phase fcc solid solution with the smallest crystallite size (2.1 nm). All samples exhibited soft ferromagnetic behavior, with the Fe-based alloy achieving the highest saturation magnetization (120 emu/g), and the (FeCoNi) 70Nb10V10B10 alloy displaying the lowest coercivity. Among all compositions, Co70Nb10V10B10 demonstrated the best gamma and neutron shielding performance, showing the highest linear attenuation coefficient and fast neutron removal cross-section. The equiatomic alloy also exhibited well-balanced and stable shielding behavior. These findings position Co70Nb10V10B10 as a promising candidate for multifunctional applications requiring both efficient radiation protection and favorable magnetic properties.
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MakaleYalnız künye2026Scopus SJRQ1/r/munzur/859
Oxidative Polycondensation of Pyrazolone-Based Schiff Bases: Synthesis, Structural Characterization, Thermal and Electrical Properties
Solmaz, Adnan; Çakmak, Reşit; Kaya, İsmet
Schiff base derivatives, namely 3-(((2-hydroxynaphthalen-1-yl)methylene)amino)-1-phenyl-1-pyrazole-5-one (3-APPHNA) and 4-(((2-hydroxynaphthalen-1-yl)methylene)amino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3-one (4-APPHNA), were synthesized via the condensation reaction of 3-amino-1-phenyl-2-pyrazolin-5-one (3-APP) and 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one, (4-APP) with 2-hydroxynaphthaldehyde (2-HNA) in ethanol. Synthesized monomers were then converted into their oligomeric derivatives via oxidative polycondensation carried out using NaOCl. The structural, thermal, optical, electrochemical, and morphological properties of the obtained monomers were comprehensively characterized using fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H-NMR), carbon-13 nuclear magnetic resonance (13C-NMR), ultraviolet-visible spectrophotometer (UV–vis), thermogravimetry-derivative thermogravimetry (TG-DTG), and cyclic voltammetric analyses. Spectroscopic studies confirmed the successful synthesis of Schiff bases and the presence of stable azomethine bonds. Molecular weight, glass transition temperature, and surface morphologies of oligomers were determined by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and field emission scanning electron microscope (FE-SEM) measurements, respectively. The Mn values of oligo(3-APPHNA) and oligo(4-APPHNA) were found to be 3400 and 2900 Da, respectively. The results revealed an oxidative oligomerization process yielding relatively narrow molecular weight distributions. Oligo(4-APPHNA) has shown more pronounced semiconductor properties compared to other oligomers, considering its 2.30 eV optical band gap and frequency-dependent electrical behavior. Additionally, dielectric measurements showed that oligo(4-APPHNA) exhibited higher dielectric constant, dielectric loss, and AC conductivity values throughout the investigated frequency range. These findings suggest that the synthesized oligomers are promising candidate materials for future optoelectronic and semiconductor applications, but further research at the device level is needed.
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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/857
The Role of Graphene on Microstructural, Mechanical, and Tribological Properties of Cu–AlCrFeCuNi Metal Matrix Composites Fabricated via Spark Plasma Sintering
Yanar, Harun; Çelebİ, Müslİm; Sekban, Dursun Murat; Özkaya, Serdar; Karabacak, Abdullah Hasan; Çelİk, Ertuğrul
In this study, Cu-based AlCrFeCuNi high-entropy alloy (HEA) composites reinforced with graphene were fabricated using a mechanical-alloying-assisted spark plasma sintering (SPS) technique. The HEA reinforcement content was kept constant at 20 wt pct for all samples, while the graphene content was varied at 0, 0.5, 1.0, and 2.0 wt pct to investigate its influence on the microstructure, hardness, and tribological performance. The results indicate that both the HEA particles and graphene exhibit an almost homogeneous distribution within the matrix; however, increasing graphene content led to noticeable graphene accumulation along grain boundaries. With higher graphene fractions, the relative density decreased from 97.51 to 94.92 pct, whereas the hardness increased up to the 1.0 wt pct graphene addition, reaching 134.16 HB, followed by a slight decrease to 129.25 HB at 2.0 wt pct. Furthermore, graphene reinforcement significantly improved the tribological behavior of the composites, providing a substantial reduction in wear. The addition of graphene significantly decreased the coefficient of friction from about ~ 0.70 in the Cu–HEA alloy to 0.08 at 2.0 wt pct graphene. Graphene also suppressed the pronounced frictional fluctuations observed in the base alloy, leading to a much more stable sliding behavior. As a result, wear loss was reduced by nearly 99 pct, primarily due to the formation of a continuous lubricating tribofilm on the contact surface.
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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/852
Enhancing the mechanical and durability properties of fly ash/GGBS-based geopolymer mortars using dunite and polypropylene fibers
Cemalgil, Selim; Gülmez, Nihan; Yön, Merve Şahin; Karataş, Mehmet
Polypropylene (PP) fiber-reinforced geopolymer mortar reduces the high brittleness of conventional geopolymer made with natural aggregates. However, the effects of different precursor materials on the performance of PP fiber-reinforced self-compacting geopolymer mortar (SCGM) remain unclear. This study investigates the feasibility of using dunite (D), a magnesium-rich ultramafic rock with consistent mineralogy and low processing energy demand that enhances thermal stability and durability, as an alternative precursor for fly ash (FA)/ground granulated blast furnace slag (GGBS)-based geopolymers. The study examined the workability, flexural and compressive strengths, and sorptivity of mortars cured at 20 ± 2°C and 60 ± 5% relative humidity, as well as their durability under freeze–thaw cycles and high-temperature exposure. Interfacial interactions between aggregates and the geopolymer matrix, along with microstructural and morphological changes caused by fire, were analyzed using scanning electron microscopy (SEM). X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were also performed for detailed material characterization. The mix containing 30% dunite exhibited the highest flexural strength, reaching 5.70 MPa at 28 days, the highest among all mixes. Under fire exposure, the mix containing 10% dunite significantly reduced mechanical strength loss and retained about 33.3% higher residual flexural strength than the FA–slag control mix at 600°C.
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MakaleYalnız künye2026Scopus SJRQ2/r/munzur/850
A Parametric Study on a Thermoelectric-Integrated Battery Thermal Management System for Electric Vehicles: New Designs Utilizing Different Numbers of Thermoelectric Modules
Tuğan, Volkan
The safety, lifespan, and performance of battery systems in electric vehicles directly depend on the implementation of an effective thermal management strategy. In this study, a novel lithium-ion battery thermal management system integrated with a wavy cooling channel and different numbers of thermoelectric modules is proposed. Computational fluid dynamics-based numerical simulations were conducted at two ambient temperatures (298.15 K and 303.15 K) and three different thermoelectric temperatures (288.15 K, 293.15 K, and 298.15 K). Three configurations with four, six, and eight thermoelectric modules were analyzed and compared with the conventional case without thermoelectrics. The lowest maximum battery temperature was obtained with the design employing eight thermoelectric modules under the conditions of 298.15 K ambient temperature and 288.15 K thermoelectric temperature. It was found that integrating thermoelectrics into the battery thermal management system reduced the maximum battery temperature by up to 12.11 K and the maximum temperature difference by up to 5.83 K. Furthermore, maintaining the thermoelectric temperature approximately 5–10 K below the ambient temperature was identified as a critical design parameter to ensure both efficient cooling and thermal homogeneity. The use of different numbers of thermoelectric modules and the selection of appropriate operating temperatures were shown to play a decisive role in optimizing system performance.
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MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/843
Pollution estimation and health risks assessment related to the agricultural application of mussel shell-derived chitosan as organic amendment
Arslan Topal, E. Işil; Topal, Murat; Çelik, Erdal; Öbek, Erdal
In this study, estimation of pollution and assessment of health risks related to the agricultural application of mussel shell–derived chitosan as organic amendment were evaluated. Furthermore, considering WHO maximum permissible levels in soil, the application rates of chitosan to agricultural soils were calculated. Geo-accumulation index (Igeo), enrichment factor (EF), contamination factor (CF), pollution load index (PLI), and ecological risk index (ERI) were calculated. Mussel shell-derived chitosan generally did not contribute to soil metal loading when evaluated in terms of those indices. The highest hazard quotient for ingestion (HQing) across male (ML), female (FML), and children (CL) followed the order Cr > Ni > Mn >Pb >Zn >Cu, while maximum HQing among metals was observed in the order CL > FML > ML. For inhalation exposure, highest HQinh for all metals was also found in the order CL > FML > ML, with individual metal contributions following Mn > Ni > Cr >Zn >Pb >Cu. Maximum HQder exhibited the trend ML > FML > CL, and the metal-specific order for HQder was Cr > Pb > Ni >Zn >Mn >Cu. Hazard Index (HI) and Total HI for ingestion, inhalation and dermal exposure were all less than 1. Cancer risk was less than 1 × 10−6. Consequently, there were no pollution and health risks associated with the use of musselshell‑derived chitosan in agriculture as organic amendment.
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Derleme MakaleYalnız künye2026Scopus SJRQ1/r/munzur/834
Assessing the Impact of Climate Change on the Sustainability of Sorghum Production: A Bibliometric Analysis
Zheng, Mingke; Tutar, Halit; Shaghaleh, Hiba; Alhaj Hamoud, Yousef; Er, Hasan; Omac, Basri; Yildirim, Gokhan; Eren, Ömer; Khalifa, Muhammad; Mwamahonje, Andekelile
Sorghum is a crucial crop for sustainable agriculture due to its drought resistance, low carbon footprint, and diverse applications in food, feed, and bioenergy. However, understanding the impact of climate change on sorghum production is essential for ensuring its future sustainability. This study conducts a comprehensive bibliometric analysis of scientific publications related to sorghum and climate change using the Web of Science (WoS) database, covering the period from 1984 to 2024. A total of 1053 relevant papers were analyzed, revealing an average annual growth rate of 12.73% and an average citation count of 32.02 per document. Most of the publications (83.5%) were research articles, while 9.7% were review papers. Among the contributing researchers, Prasad PVV emerged as the most productive author based on an h-index of 13, whereas the United States was identified as the most influential country, contributing 235 documents and 13,750 citations. Keyword clustering analysis identified five major research themes, including sustainable energy and environmental impacts, climate resilience, socioeconomic effects of climate change, and key crops. The findings of this study offer valuable scientific insights to guide future research and policymaking on climate change and sorghum sustainability.
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MakaleYalnız künye2026Scopus SJRQ3/r/munzur/830
Optimization and Modeling of Brilliant Yellow Removal Via Neodymium-Infused Polymeric Hydrogel: A Central Composite Design Study
Pıhtılı Yıldız, Güzin; Tanyol, Mehtap; Demir, Ferhat
This study investigates the adsorption performance of a neodymium (III)-reinforced Poly(acrylamide-co-N-vinylimidazole) hydrogel composite [P(AAm-co-NVI)/Nd3+] for the removal of brilliant yellow (BY) dye from aqueous media. The hydrogel structure and metal–polymer interactions were characterized using FT-IR, TGA, SEM, and XRD analyses. The adsorption process was systematically optimized using a central composite design (CCD) approach combined with response surface methodology (RSM). The CCD-RSM second-order model exhibited a good fit to the experimental data (R2 = 0.9350), as supported by ANOVA. Numerical optimization revealed a maximum removal efficiency of 99.13% at a hydrogel dosage of 0.08 g/100 mL, an initial BY concentration of 81.68 mg/L, and a contact time of 61.73 min. Langmuir and the Freundlich isotherms were used in modeling the adsorption data. When the correlation coefficients of both models were compared, it was observed that the Langmuir isotherm provided a better fit for adsorption. The enhanced adsorption performance is attributed to the presence of Nd3+ ions, which promote additional electrostatic interactions and coordination sites between the hydrogel matrix and anionic dye molecules. The results demonstrate that Nd3+-reinforced hydrogels can serve as efficient and tunable adsorbent systems, particularly when process parameters are optimized statistically.
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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/827
Post-disaster psychological effects: identifying earthquake-induced trauma in athletes
Uğurlu, Fatih Mehmet; Güler, Muhammed; Albayrak, Veysel; Aygören, Caner
Natural disasters not only cause physical destruction but also lead to various psychological problems affecting the mental health of individuals. This study was conducted to determine the levels of post-earthquake trauma in athletes who experienced earthquakes and whether certain variables made a difference in this situation. The sample of the study consisted of 359 athletes living in 11 provinces affected by the earthquakes centered in Kahramanmaraş, Turkey, on February 6, 2023. Participants were reached using the Snowball Sampling Method. The Sociodemographic Information Form and the Post-Earthquake Trauma Level Determination Scale were used to collect data. As a result of the descriptive statistics, it was seen that athletes experienced above-average earthquake trauma (M = 65.84). When examined in terms of sociodemographic variables, it was found that women showed more symptoms of earthquake trauma than men, those who experienced the loss of relatives showed more symptoms than those who did not, and those who experienced the loss of a home showed more symptoms than those who did not. In conclusion, while exercise and physical activity are methods used to cope with trauma, being an athlete alone is not sufficient to cope with earthquake trauma. Women, whether athletes or not, experience more earthquake trauma than men. Losing relatives exacerbates the trauma caused by the earthquake. Furthermore, the loss of a home, which prevents individuals from meeting some basic physiological needs, is a significant factor in earthquake trauma.
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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/825
RGO-CBPAC versus CBPAC for diluted leachate treatment: adsorption isotherms, kinetics and thermodynamics
Ogedey, A.; Oguz, E.
This study compares carbon-based activated carbon (CBPAC) and reduced graphene oxide-modified CBPAC (RGO-CBPAC) for removing COD, NH3–N, and turbidity from 1:4 diluted leachate from the Bingöl landfill site. Brunauer Emmett Teller (BET) analysis indicated severe micropore blockage in CBPAC after adsorption (887 → 0.76 m2/g), whereas RGO-CBPAC retained a higher surface area (908 → 23 m2/g) and mesoporous structure, demonstrating enhanced structural stability due to graphene incorporation. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDX) confirmed the presence of surface functional groups and effective pollutant uptake, with RGO-CBPAC showing stronger surface–pollutant interactions. Zeta potential analysis showed pH-dependent surface charge behaviour, with CBPAC exhibiting amphoteric characteristics and RGO-CBPAC maintaining a more negative surface. After adsorption, both became more negatively charged, indicating the accumulation of negatively charged species. Kinetic analysis showed that COD adsorption on CBPAC followed pseudo-first-order and intraparticle diffusion models, whereas NH3–N and turbidity followed pseudo-second-order kinetics. In contrast, RGO-CBPAC exhibited pseudo-second-order and intraparticle diffusion behaviour for all pollutants, suggesting chemisorption with diffusion-controlled contributions. Adsorption equilibrium was best described by the Langmuir isotherm, yielding maximum capacities of 500 and 588 mg O2/g for COD, 17.5 and 36.5 mg/g for NH3–N, and 18.1 and 58.5 mg/g ((NH2)2H2SO4)/g for turbidity on CBPAC and RGO-CBPAC, respectively. Thermodynamic analysis demonstrated that COD and turbidity removal using RGO-CBPAC were spontaneous (∆G° < 0) and endothermic (∆H° > 0), whereas NH3–N removal remained non-spontaneous for both adsorbents. RGO incorporation significantly enhanced adsorption performance.
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MakaleYalnız künye2026Scopus SJRQ1/r/munzur/818
Thermodynamic assessment of an equiatomic FeNiCoCrMn precursor for a spinel high-entropy oxide produced via mechano-oxidation with structure–radiation interaction correlation
Güler, Ömer; Güler, Seval Hale; Özkul, İskender; ALMisned, Ghada; Sen Baykal, Duygu; Tekin, H.O.
Spinel high-entropy oxides (HEOs) can stabilize multiple transition-metal cations within a single lattice, yet their radiation-interaction behavior is scarcely explored. Here, a (FeNiCoCrMn)3O4 spinel HEO was produced via an alloy-to-oxide route: 40 h mechanical alloying of equiatomic FeNiCoCrMn powders followed by mechano-oxidation (1000 °C/3 h) and high-energy grinding. HEA-derived thermodynamic metrics were used to rationalize the stability of the equiatomic metallic precursor prior to mechano-oxidation, rather than to directly predict the formation of the final oxide phase. XRD evidenced progressive amorphization of the HEA and its conversion to a crystalline spinel oxide, while SEM–EDS confirmed homogeneous elemental distribution. XPS indicated a defect-rich, multivalent surface (Co2+/Co3+, Cr3+/Cr6+, Fe3+, mixed Mn states, Ni2+) with lattice oxygen and vacancy-related components. Moreover, the spinel oxide showed higher linear attenuation coefficients than 316L stainless steel, Inconel-718, and several lightweight Al-based entropy alloys, yielding lower HVL values, especially at low energies. Zeff exhibited the expected energy dependence and exceeded Al-dominant alloys across the spectrum. EBF/EABF at 1 and 40 mfp displayed Compton-region peaks and strong depth effects, consistent with attenuation behavior. It can be concluded that a (FeNiCoCrMn)3O4 spinel high-entropy oxide, produced via an alloy-to-oxide transformation route, exhibits structurally stable and compositionally homogeneous characteristics together with favorable gamma-ray attenuation behavior.
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MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/811
Hybrid Supervised Classification and Deep Embedding–Based Profiling Framework for Electricity Consumption Analysis
Gunay, Mihriban; Yildirim, Ozal; Demir, Yakup; Zhilevski, Marin; Mikhov, Mikho; Yordanov, Nikolay
This study proposes a hybrid deep learning framework that integrates supervised classification and unsupervised profiling for electricity consumption analysis. In the supervised phase, a one-dimensional Convolutional Neural Network combined with Long Short-Term Memory (1D CNN–LSTM) architecture is developed to classify daily load patterns. The performance of the proposed model is compared with traditional machine learning and deep learning approaches, including Support Vector Machine (SVM), k-Nearest Neighbors (KNN), a standalone Long Short-Term Memory (LSTM) model, a Transformer-based model, and a standalone 1D CNN model. Experimental results on the Precon house dataset and the CU-BEMS dataset demonstrate that the proposed hybrid architecture outperforms the benchmark models, achieving classification accuracies of 87.59% and 86.40%, respectively. In the unsupervised phase, the trained CNN–LSTM encoder is utilized as a deep feature extractor. The resulting 32-dimensional latent embeddings are clustered using K-Means, Gaussian Mixture Model (GMM), Agglomerative, Spectral, and Ensemble methods. Clustering robustness is evaluated through bootstrap-based stability analysis using the Adjusted Rand Index (ARI) and the Normalized Mutual Information (NMI). The results demonstrate stable and interpretable electricity consumption profiles, particularly in the residential dataset, where near-perfect clustering stability is observed for K-Means. The proposed framework provides both improved classification performance and robust consumption profiling based on deep embedding, offering a practical tool for energy management.
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MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/809
Ultrasound assisted extraction of phenolic compounds from Tunceli walnut varieties using deep eutectic solvents
Aydin, Çağlar Mert
This study aimed to improve a green way to enhance extraction of bioactive compounds from walnut, and to evaluate the effect of altitude on walnut bioactive content. Total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity were evaluated as bioactive compounds of walnut. In comparison with conventional solvents (water, ethanol and methanol), three DESs (Deep eutectic solvents) were formed from choline chloride, zinc chloride, and sorbitol as HBA and ethylene glycerol as HBD. The DESs (DES-1 and DES-2) generated from choline chloride and zinc chloride exhibited better extraction efficiencies for any bioactive compound than that of conventional solvents. Especially, the DES formed from the choline chloride: ethylene glycerol demonstrated the highest extraction efficiency. However, sugar-based DES showed the worst extraction efficiency. The altitude significantly affected extracted bioactive contents from walnuts (Hozat 1000m, Ovacik 1300m and Nazimiye 1550m). Walnut’s extracted bioactive content ordinarily decreased as the altitude increased, regardless of solvent type used in extraction. The result is a light to enhancing knowledge as to DES usage and its extraction efficiency of bioactive compounds for food applications. In addition, it gives better understanding of altitude effect on the content of bioactive compounds in walnuts.
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MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/802
Solvent extraction of rare earth elements and α-alumina production from pregnant leaching solution obtained from Turkish bauxite-related ore
Erust, Ceren; Uysal, Turan
The use of bauxite-related shales as a secondary source for the extraction of rare earth elements (REEs) is very important to meet the raw material supply, which is the keystone of advanced technology applications. This study presents the investigation into the recovery of REEs from Kızıldağ shale ore and the potential utilization of its leach residue as a silica source. Mineralogical analysis revealed that the ore predominantly consists of paragonite, muscovite, quartz, pyrophyllite, and calcite. Calcined ore was subjected to acid leaching, and the resulting pregnant solution was purified using solvent extraction to separate from aluminum the ∑REEs with a content of 1887.35 ppm. Optimal solvent extraction conditions 1.5 M D2EHPA, 50% O/A ratio, pH 1.5, and 15-minute mixing time achieved 95% total REE extraction, with efficiency in the order Pr > La > Nd > Ce > Dy > Y > Sc. To purify Al from the Fe- and K-rich solution post-SX, electrolysis was performed, resulting in 97.16% precipitation efficiency of Al as Al(OH)3 at pH 5. The precipitate was subsequently roasted at 1100°C to produce α-alumina with 75.2% Al2O3 content. These findings confirm the technical feasibility of recovering REEs and producing coarse-purity alumina from Kızıldağ shale ore.
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MakaleYalnız künye2026Scopus SJRQ2/r/munzur/800
Oxide Dispersion, Microstructure, and Functional Evolution in La2O3 Modified Cu-Al-Mn-Fe Shape Memory Alloys
Karaduman, Oktay; Doğan, Fatih; Dehghanpour, Heydar; Yüzüak, Gizem Durak; Yüzüak, Ercüment; Canbay, Canan Aksu
Cu-Al-Mn-Fe high-temperature shape memory alloys containing 0-1.0 wt.% La2O3 were fabricated by vacuum arc remelting to investigate oxide-dispersion effects on microstructure, martensitic transformation, wear, and corrosion behavior. XRD and SEM analyses revealed that low La2O3 additions (0.2-0.4 wt.%) promoted β1′ martensite refinement and enhanced crystallinity, while higher contents induced structural heterogeneity. The alloy with 0.4 wt.% La2O3 exhibited the highest transformation enthalpy (7.49 J g−1), reduced friction coefficient (~0.55), and the narrowest wear scar (~501 µm). Electrochemical tests in 3.5 wt.% NaCl showed a fivefold decrease in corrosion current density and increased charge-transfer resistance (2512 Ω cm2) for the same composition. Excessive La2O3 led to performance degradation due to particle agglomeration and interfacial defects. The results demonstrated that controlled La2O3 addition enabled microstructural refinement and multifunctional performance enhancement in Cu-based shape memory alloys.
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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/797
Path Dependence and Spatial Spillovers in Regional Digitalization: Evidence from Dynamic Spatial Panel Analysis in Europe
Kazar, Görkemli; Kazar, Altuğ
Digitalization is the driver of regional competitiveness and sustainable development, but its geographical impacts differ significantly across Europe. This study was conducted to determine if digital transformation results in regional sustainability or if it increases spatial inequalities, concentrating on European NUTS-1 regions for the period 2021–2025. A composite Regional Digitalization Index was developed by means of Principal Component Analysis (PCA) based on indicators measuring internet access, internet usage, and the availability of digital public services. Dynamic spatial panel econometric models were used for empirical investigation, including a Spatial Autoregressive (SAR) model and a Spatial Durbin model (SDM), which facilitated the exploration of both temporal dependence and spatial spillover. Three main conclusions can be derived from the results, as follows: The level of digitalization in a region is highly stable over time, whereby the development depends most on previous paths. Subsequently, human capital is highly significant for digital development, and its effects are not only local but also spill over to neighboring regions. Lastly, spatial interactions consist of two opposite forces—the positive diffusion from digitally advanced neighboring regions and the competitive effects related to the economic strength of neighboring regions—that further intensify the core–periphery divide.
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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/795
Effect of dilute rare-earth addition on structural evolution, mechanical, magnetic, and radiation shielding properties of CoFeNiMnTi high-entropy alloy
Özkul, İskender; Kalay, Ece; Güler, Ömer; Karaduman, Oktay; Canbay, Canan Aksu; Hameed, Louis Ibrahim; Almisned, Ghada; Baykal, Duygu Sen; Tekin, H.O.
This study investigates the effect of 1 at.% rare-earth (RE = Sm, Gd, Dy) addition on the structural, mechanical, magnetic, and radiation shielding properties of CoFeNiMnTi high-entropy alloys produced by arc melting. X-ray diffraction results reveal an FCC-dominant structure accompanied by secondary Laves-type phases, with increased phase complexity observed in Gd- and Dy-containing alloys. Mechanical evaluation shows a significant hardness enhancement, reaching 581 HV for Gd and 548 HV for Dy, compared to 447 HV for the reference alloy. Magnetic measurements indicate soft-ferromagnetic behaviour for all compositions, with magnetization increasing in the order S0<S1<S2<S3, highlighting the strong influence of Dy on magnetic response. Elemental mapping confirms a homogeneous distribution with minor local compositional variations contributing to phase evolution. Thermodynamic analysis suggests that rare-earth addition increases lattice distortion and chemical complexity without strongly differentiating among RE types. In terms of radiation shielding, linear attenuation coefficients and effective atomic number values demonstrate improved gamma-ray attenuation, particularly at low energies, with Dy exhibiting the highest performance. In contrast, fast neutron removal cross section values remain nearly unchanged, indicating limited sensitivity to dilute RE addition. It can be concluded that the incorporation of Dy results in the most balanced multifunctional performance, whereas Gd primarily enhances mechanical strength, emphasizing the importance of rare-earth selection in the design of high-entropy alloys for radiation-related applications.
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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/789
Multi-Response Kinetic Modeling of the Maillard Reaction in Milk During Heating at Ultra-High-Temperature Range
Hamzalıoǧlu, Aytül; Aktaǧ, Işıl; Gökmen, Vural
This study developed first a comprehensive multiresponse kinetic model to elucidate the mechanism of the Maillard reaction in milk during ultrahigh-temperature treatment. The model incorporates the alterations in precursors (sugars, amino acids), intermediates (α-dicarbonyl and Amadori compounds) and products (N-ε-carboxymethyllysine, N-ε-carboxyethyllysine) that occur in milk during heating between 110 and 140 °C. Kinetically important reactions steps were identified by multiresponse kinetic modeling. Results indicated that N-ε-carboxymethyllysine and N-ε-carboxyethyllysine were formed predominantly by the oxidation of lactulosyllysine. Among the intermediates, the formation of 1-deoxyglucosone and glucosone, and methylglyoxal from 1-deoxyglucosone and glyoxal from glucosone, were determined to be the kinetically important steps. The rate-limiting step was identified as lactulosyllysine formation, while methylglyoxal generation occurred most rapidly across all heating temperatures. In this study, the multiresponse kinetic modeling approach was applied to milk, offering a comprehensive understanding of the critical pathways leading to the formation of α-dicarbonyl compounds and advanced glycation end-products.
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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/787
Dietary exposure and health risk assessment of fumonisins through the consumption of maize and maize-based gluten-free products in individuals with celiac disease
Tuyben, Eylem Ezgi; Sevim, Sumeyra; Macit, Arife; Kizil, Mevlude
Introduction: Individuals with celiac disease (CD) must adhere to a gluten-free diet (GFD) and are therefore at high risk of fumonisin exposure due to their high consumption of maize and maize-based products. This study aimed to determine the concentrations of fumonisins (FB1, FB2, and FB3) in packaged gluten-free (GF) maize and maizebased products sold in Turkey and to assess dietary exposure and health risks in adults with CD using a probabilistic approach. Methods: Fumonisin concentrations of 51 GF products were analyzed by Enzyme-Linked Immonosorbent Assay (ELISA) and daily food consumption data were collected from 67 individuals with CD through a food frequency questionnaire. Exposure was estimated using Estimated Daily Intake (EDI) values and probabilistic risk assessment with Monte Carlo simulation. Results: The highest fumonisins concentrations were detected in the pasta/rice/bulgur group, while the flour/starch group was the food group contributed most to total fumonisins exposure due to higher consumption. Although the average EDI values were below the Tolerable Daily Intake (TDI; 1 μg/kg bw/day) set by European Food Safety Authority’s (EFSA) and Provisional maximum tolerable daily intakes (PMTDI; 2 μg/kg bw/day) established by Joint Expert Committee on Food Additives’s (JECFA) values, individuals at the 95th percentile approached 132.88–167.89% of the PMTDI value in the flour/starch group and 79.00–82.38% in the pasta/rice/bulgur group. Discussion: These findings highlight the need for continuous monitoring and stricter regulatory oversight and dietary guidance to protect vulnerable populations.
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MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/785
Tribological 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.
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