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Koleksiyondaki öğeler
- MakaleYalnız künye2024Scopus SJRQ1Optimization of Pectin Extraction from Lemon Peel Powder by Ohmic Heating Using Full Factorial Design
Çilingir, Seda; Duran, Gülseven; Gökyildiz, Beritan; Goksu, Ali; Sabanci, Serdal; Cevik, Mutlu
Ohmic heating-assisted extraction has emerged as an effective method preferred in recent years. This extraction method is affected by experimental factors such as temperature, process time, and voltage gradient. The present study aimed to optimize the pectin extraction process from lemon peel powder samples by the ohmic heating-assisted extraction method. In this study, the effects of 3 different voltage gradients (7, 9, and 11 V/cm), 3 different solid to liquid ratios (1:20 g/mL, 1:40 g/mL, and 1:60 g/mL), and 3 different holding times (0, 60, and 120 min) and their interactions were investigated to determine the optimum extraction condition at constant temperature (80 °C) and pH = 1 sulfuric acid solution. The factors examined in the optimization procedure were pectin yield, power consumption, and energy efficiency. The optimum conditions were found to be 11 V/cm voltage gradient, 1:60 g/mL solid to liquid ratio, and 120-min holding time with a desirability value of 0.778. The results of this study could give important information about the design of industrial scale ohmic heating units, especially from different food wastes in industrial pectin production.
AtıfScopus7WoS7OpenAlex5
İncele - MakaleYalnız künye2024Scopus SJRQ3Analyzing the Chemical Constituents and In Vitro Biological Effects of Extracts Artemisia absinthium L. Extracts Obtained Using Different Methodologies and Solvents
Yagi, Sakina; Zengin, Gokhan; Ibrahime Sinan, Kouadio; Yavuz Paksoy, Mehmet; Cziáky, Zoltán; Jekő, József; Dall'Acqua, Stefano
The present study aimed to investigate the chemical constituents of different extracts from aerial parts of A. absinthium and to evaluate their antioxidant and enzyme inhibition activity. Extracts were prepared by maceration, infusion or Soxhlet techniques. Results showed that the highest total phenolic and flavonoids contents was recorded respectively from the hexane extract prepared by maceration and ethyl acetate extract obtained by Soxhlet method. The characteristic compounds of Artemisia species artemetin, casticin, sesartemin and yangambin in addition to coumarins were identified in all extracts. Aqueous extract obtained by infusion exerted the highest radical scavenging and ions reducing properties while that prepared by maceration displayed the highest chelating power. Methanol extracts obtained by the two methods of extraction exerted the highest anti-Tyr activity while that obtained by maceration showed the best α-glucosidase inhibition activity. These findings indicated that A. absinthium is a rich source of bioactive molecules with possible therapeutic applications.
AtıfScopus2OpenAlex3
İncele - MakaleAçık Erişim2025Scopus SJRQ1Y2O3-Doped BioGlass Coatings for Ti-6Al-4V Alloy: Insights into Degradation, Bioactivity, Ion Release, Adhesion, and Corrosion Behavior
Say, Yakup; Aslan, Naim; Cihangir, Salih; Murat, Oğuzkağan; Çaydaş, Ulaş
The Ti-6Al-4V alloy is particularly favored for orthopedic applications. However, important issues such as corrosion resistance, biocompatibility, and ion release need to be addressed. Therefore, this study aims to enhance the corrosion resistance and biocompatibility and reduce the ion release of the Ti-6Al-4V alloy by applying Y2O3-doped bioglass bioceramic coatings. The coatings were synthesized using the sol-gel method, including pure BioGlass and BioGlass with 1, 5, and 10 wt pct Y2O3. These coatings were then evaluated for their corrosion resistance, adhesion strength, degradation behavior, bioactivity, and ion release. The results showed that all coatings exhibited homogeneous, crack-free, and porous morphologies, which are favorable for osteointegration. The addition of 10 wt pct Y2O3 to the BioGlass coating resulted in a 52 pct increment in adhesion strength, which increased from 13.72 ± 2.80 MPa for single BioGlass coatings to 20.81 ± 2.53 MPa. All samples showed degradation values lower than 1 wt pct. Single BioGlass coatings significantly enhanced the bioactivity of Ti-6Al-4V alloy. However, the addition of Y2O3 negatively impacted BioGlass bioactivity, leading to a noticeable decrease as the Y2O3 content increased. Conversely, the presence of Y2O3 negatively impacted bioactivity and corrosion resistance while increasing the release of Ti ions. Specifically, the release of Ti ions increased from 79.5 ± 0.8 ppb in uncoated samples to 253.7 ± 15.3 ppb in BG-coated samples. For 1, 5, and 10 pct Y2O3-added samples, Ti releases were measured as 192.2 ± 33.6 ppb, 168.5 ± 62.4 ppb, and 194.3 ± 54.4 ppb, respectively. This research highlights the potential of tailored BioGlass coatings to improve the performance of Ti-6Al-4V alloys in orthopedic implant applications, particularly for enhancing bone integration and reducing implant failure.
AtıfScopus4WoS3OpenAlex5İncele - MakaleAçık Erişim2025Scopus SJRQ1Evaluating the high-temperature resistance of self-compacting mortar incorporating waste andesite powder as a mineral admixture
Karataş, Mehmet; Bozcan, Emre; Dener, Murat
Significant amounts of waste material are generated at various stages of andesite stone processing, including mining, cutting, and polishing. Despite this, limited research has been conducted on the potential use of waste andesite powder (WAP) as a mineral admixture. The impact of WAP on the high-temperature resistance of cement-based composites remains largely unexplored. This study aims to evaluate the benefits of incorporating WAP as a partial substitute for Portland cement. Self-compacting mortars (SCMs) with varying WAP replacement rates (5%–30%) were produced and subjected to temperatures of 300°C, 600°C, and 900°C. Additionally, ternary mixtures of WAP and silica fume were produced for comparative analysis. The results showed that SCMs containing up to 10% WAP exhibited higher 90-day compressive strength compared to the control sample. Furthermore, WAP inclusion improved high-temperature resistance, and the use of WAP at higher replacement rates was feasible when combined with mineral admixtures possessing high pozzolanic activity, such as silica fume.
AtıfScopus6WoS3OpenAlex4İncele - MakaleYalnız künye2025Scopus SJRQ1Impact of controlled oxidation and incorporation of high entropy rare-earth alloys (HE-REAs) on the structural, physical, optical, and radiation shielding performance of zinc-borate glasses
Ilik, E.; Guler, Seval Hale; Güler, Ömer; Durmus, Hasan; Kavaz, E.; Birdogan, Selcuk; ALMisned, Ghada; Kilic, G.; Tekin, H.O.
This study investigates the influence of high entropy oxide (HEO) and high entropy alloy oxide (HEAO) dopants on the structural, optical, and radiation shielding properties of zinc-borate glasses. Two synthesis routes were employed through direct mechanical alloying of five rare-earth oxides such as Sm2O3, Ho2O3, Er2O3, Yb2O3, Gd2O3 to form (SmHoErYbGd)2O3 HEO, and mechanical alloying of the corresponding rare-earth metals followed by oxidation to produce HEAO of the same elemental composition. The central hypothesis proposed that the dopant structure and oxygen coordination, not just elemental presence, critically influence the on characteristic behaviors in terms of radiation attenuation. Structural analyses confirmed that HEAO-doped glasses exhibit more homogeneous, amorphous networks. Optical characterizations revealed red-shifted absorption edges and lower Urbach energies in HEAO samples, indicating reduced disorder. HEAO-doped glasses showed superior gamma-ray shielding, with higher linear attenuation coefficients and lower half-value layers than HEO or undoped samples. Most notably, HEAO glass achieved the highest fast neutron removal cross-section, surpassing water, graphite, and B4C. These findings demonstrate that rare-earth high entropy alloy oxides offer a structurally optimized pathway for designing next-generation multifunctional glasses for radiation-related applications.
AtıfScopus9OpenAlex8İncele - MakaleYalnız künye2025Scopus SJRQ2Elastic modulus, nuclear radiation transmission properties of Fe-based/contained novel alloys for critical radiation applications
ALMisned, Ghada; Susoy, Gulfem; Baykal, Duygu Sen; Alkarrani, Hessa; Güler, Ömer; Issa, Shams A.M.; Zakaly, Hesham M.H.; Tekin, H.O.
This study explores the gamma-ray and neutron shielding properties and mechanical performance of eight Fe-based alloys with varying elemental compositions and densities. Different parameters such as mass attenuation coefficients, linear attenuation coefficients, half-value layer, tenth-value layer, mean free path, fast neutron removal cross-sections, transmission factors were analysed using PHITS and Phy-X/PSD codes. Moreover, elastic modulus values were calculated for each alloy sample. Our results reveal that the S9 alloy, with high density and tungsten contribution, exhibited superior shielding and mechanical properties, achieving the lowest TF, HVL, and TVL values. In contrast, the low-density S1 alloy performed weakest, reflecting its lighter elemental composition. Intermediate alloys like MAR-302 and Cupero-Nickel showed balanced performance, suitable for moderate shielding needs. Strong correlations between elemental compositions, particularly high-Z elements like tungsten and boron, and shielding efficiency were observed. It can be concluded that optimizing elemental composition and density is critical for designing alloys with enhanced multifunctional properties.
AtıfScopus3OpenAlex2İncele - MakaleAçık Erişim2026Scopus SJRQ1A multi-evidence computational and experimental strategy for Silene nerimaniae: combining phytochemical characterization, bioactivity assessment, and ADEFRank-HCT-116-based metabolite prioritization
Erharman, Ahmet; Yagi, Sakina; Uba, Abdullahi Ibrahim; Nikolić, Filip; Gašić, Uroš; Acar, Mikail; Dogan, Nurettin; Koyuncu, Ismail; Yapıcı, Ismail; Gulcin, Ilhami
This study presents the first comprehensive evaluation of the phytochemical composition, antioxidant properties, enzyme inhibitory effects, and cytotoxic potential of Silene nerimaniae G.E.Genç, Kandemir & İ.Genç (family Caryophyllaceae). Ethyl acetate, acetone, 70% acetone, and aqueous extracts were obtained from the aerial parts of the plant through maceration. Among the tested extracts, the acetone extract contained the highest total phenolic (24.37 mg GAE per g) and flavonoid (24.64 mg RE per g) contents. LC–MS analysis identified 52 bioactive constituents, including sugars, organic acids, phenolic acids, flavonoids, and fatty acids. The aqueous extract demonstrated the strongest radical scavenging activity against DPPH (23.02 mg TE per g) and ABTS (55.76 mg TE per g), as well as the highest Fe3+ reducing power (37.53 mg TE per g). In combination with the acetone extract, it also exhibited notable Cu2+ reducing activity (47.78 mg TE per g). Regarding enzyme inhibition, the ethyl acetate, acetone, and hydroacetone extracts displayed the strongest inhibitory activities against acetylcholinesterase (1.87 mg GALA per g), butyrylcholinesterase (2.92 mg GALA per g), and tyrosinase (60.44 mg KAE per g), respectively. All three extracts also inhibited α-amylase activity within the range of 0.73–0.77 mmol ACAE per g (p ≥ 0.05). In addition, the hydroacetone extract showed considerable inhibition of human carbonic anhydrase isoenzymes I (IC50 = 38.78 μg mL−1) and II (IC50 = 19.59 μg mL−1). The ethyl acetate extract exhibited the strongest cytotoxic effect against the colorectal cancer cell line HCT-116, with an IC50 value of 0.639 μg mL−1 and a selectivity index of 1.7. To contextualize this HCT-116-associated activity at the metabolite level, an ADEFRank-HCT116 (abundance–domain–evidence fusion ranking) workflow was applied by integrating EtOAc abundance, HCT-116-oriented QSAR evidence, applicability-domain confidence, and structure-assignment reliability. This analysis prioritized diosmetin, luteolin, eriodyctiol, acacetin, and isorhamnetin as core candidates for structure-based follow-up. Molecular docking screening predicted favorable docking profiles for the prioritized candidates, while 100 ns molecular dynamics simulations were used to assess the dynamic stability of the representative luteolin–PI3Kα, diosmetin–AKT1, and isorhamnetin–GSK-3β complexes. Taken together, these results indicate that S. nerimaniae may represent a valuable source of active compounds for various functional nutraceutical, cosmetic and pharmaceutical uses. This journal is
- MakaleAçık Erişim2026Scopus SJRQ1Integrating experimental and atomistic insights into the rejuvenation of aged binder using bio-based rejuvenators
Kurban, Mustafa; Yalcin, Beyza Furtana; Yilmaz, Mehmet; Akpinar, Sinan; Kök, Baha Vural; Hekim, Seda; Özdemir, Ahmet Münir; Yalcin, Erkut; Göktaş, Fahrettin
This study integrates experimental and computational methods to evaluate the rejuvenation performance of an aged asphalt binder using two novel bio-based additives, 1T and 2T. The aged binder, sourced from reclaimed asphalt pavement (RAP), was modified with 25 wt% of each rejuvenator (denoted as 1T25 and 2T25, respectively). SARA (Saturates, Aromatics, Resins, Asphaltenes) fractionation and colloidal indices were used to assess compositional recovery. Both additives increased aromatic and resin contents while reducing asphaltenes. The 2T-modified binder achieved the highest colloidal stability (Ic = 0.29) and the most pronounced improvement in stability indicators (CI and Ic) among the tested systems. Complementary molecular dynamics (MD) simulations using the COMPASSII force field modeled the structural and thermodynamic behavior of RAP and rejuvenated systems. The 2T25 system exhibited higher density and more compact molecular packing, suggesting stronger cohesive organization and reduced free volume, whereas 1T25 showed greater molecular spacing and flexibility. RDF analysis and converged thermodynamic/structural trajectories (energy, temperature, cell length, and density stabilization) further supported rejuvenator-dependent rearrangement of packing during equilibration. Overall, MD acts as a mechanistic bridge that interprets experimental SARA/CI/Ic trends and supports design-oriented development of sustainable rejuvenators.
AtıfScopus2OpenAlex1İncele - MakaleYalnız künye2025Scopus SJRQ3New Record of Two Melanopsid Species (Melanopsis costata and Melanopsis buccinoidea) in the Eastern Mediterranean Basin: Morphological Variation in the Söğütlü Stream (Hatay, Türkiye)
Kocabaş, Filiz Kutluyer; Kocabaş, Mehmet
Abstract: Melanopsis costata and Melanopsis buccinoidea are freshwater gastropods within the Melanopsidae family characterized by their wide geographical distribution. The geographical distribution of the two species was evaluated within the Eastern Mediterranean Basin as part of this study. Aquatic sites were surveyed across diverse habitats in Söğütlü Stream (Hatay, Türkiye). The shell characteristics [shell height (SH), shell width (SW), spire height (SpH), aperture length (AL), and aperture width (AW)] of the two species were also examined within the ecosystem. The maximum values recorded for M. costata were a shell length (SL) of 17.40 mm and a weight (W) of 0.62 g. The highest values for M. buccinoidea were 13.75 mm for SL and 0.30 g for W. The PCA analysis demonstrated a significant relationship between shell length and shell width, aperture length, aperture width, and weight. The initial evidence of the presence of M. costata and M. buccinoidea was identified in the water body, and the distribution of both species exhibited habitat-dependent variations in their morphological traits.
- MakaleAçık Erişim2025Scopus SJRQ2Parents’ Level of COVID-19 Fear, Anxiety and Their Attitudes and Behaviors Toward Vaccination of Their Children
Baş, Kazım; Gürarslan Baş, Nazan
The aims of this study were to investigate parents’ COVID-19 fear and anxiety levels and determine the relationship between parents’ COVID-19 fear and anxiety levels and their attitudes and behaviors toward having themselves and their children vaccinated. This descriptive and cross-sectional type of research was conducted with 950 parents with 12–18 years old children. Having a chronic disease, being vaccinated, intention to vaccinate their children, and the children’s age and school year were found to increase parents’ COVID-19 fear and anxiety (p < 0.005). A statistically significant correlation was found between the parents’ perceived levels of COVID-19 fear and anxiety and their intentions to vaccinate their children (p < 0.005). According to the study’s findings, the age of the child, the parents’ vaccination, and the parents’ intentions to vaccinate their children were predictors of COVID-19 fear and anxiety.
AtıfScopus1WoS1OpenAlex3İncele - MakaleAçık Erişim2025Examination of Numerical Changes in Goat and Buffalo Population in TRB1 Region with Cluster Analysis; [Examination of Numerical Changes in Goat and Buffalo Population in TRB1 Region with Cluster Analysis]
Çimen, Murat; Güven, Alper
In this study, the effectiveness of using cluster analysis in determining the changes in the number of animals in the field of goat and buffalo breeding in the TRB1 region was tested. The numbers of goats and buffalos used in the research were obtained from the records kept by TÜİK between 2004 and 2023. According to the cluster analysis results, the numbers of buffalos in Elazığ and Bingöl provinces was found to be higher than Malatya and Tunceli provinces between 2004 and 2023. According to the specified years, while Bingöl province was found to be higher than other provinces in terms of the numbers of goats, it was determined that Malatya province had the lowest values. When analyzed by year, the numbers of buffalos in the provinces of the TRB1 region for the years 2004-2006 was found to be higher than the following years. In other words, it is understood that the numbers of buffalos has been decreasing in the TRB1 region since 2007. In the TRB1 region, goat numbers between 2012-2023 were found to be higher than those between 2004-2011. Accordingly, it can be said that there has been an increase in the number of goats in the TRB1 region since 2012. In the TRB1 region, appropriate regulations need to be made, taking into account the differences between provinces and years in terms of the numbers of buffalos and goats. In this study, it was seen that cluster analysis could be used successfully in determining the differences in animal numbers according to provinces and years.
AtıfOpenAlex3TR Dizin3
İncele - MakaleAçık Erişim2026Scopus SJRQ3Determination of Oxidative Stress Responses Induced by the Combination of 4 Different Rare Earth Elements in Dreissena polymorpha; [Determinacija odgovorov na oksidativni stres, ki ga povzroča kombinacija 4 različnih redkih zemljinskih elementov v Dreissena polymorpha]
Serdar, Osman; Aydin, Ayşe Nur
Rare Earth Elements (REE), whose usage areas are increasing day by day, are increasing in the amount of mixing with the environment, causing changes in antioxidant enzyme activities by causing oxidative stress in living organisms. In this study, it was aimed to examine the oxidative stress responses induced by the mixture of 4 different REEs (terbium, gadolinium, Lanthanum, Praseodymium) in Dreissena polymorpha. For this purpose, sublethal concentration values were determined by literature review. Experimental application was carried out within 24 and 96 hours. In the analyzes performed to determine biomarker responses, samples taken from living organisms were weighed and homogenization processes were performed for the analysis of samples taken from the experimental groups, including the control group. After homogenization, samples were centrifuged at 4.000 rpm for 15 minutes. Supernatants were kept at -86 °C until measurements were made. Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities, and glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) levels were determined using ELISA kits. Statistical analyses were performed using SPSS. One-way ANOVA (Duncan’s multiple range test; p < 0.05) was used for comparison of measured parameters among groups. As a result of the application, a decrease in CAT activity and GSH level and an increase in TBARS levels were observed after 96 hours compared to the control group, while no statistically significant difference was detected in SOD and GPx activities.
- MakaleAçık Erişim2025Scopus SJRQ1Was the Formation of the North Anatolian Fault Influenced by the Aegean Extension?
Uysal, I. Tonguç; Karabacak, Volkan; Aykut, Tunahan; Ring, Uwe; Liu, Entao; Sancar, Taylan; Leonard, Nicole; Tong, Kui; Todd, Andrew J.; Temel, Abidin
The North Anatolian Fault (NAF), one of the most prominent plate boundary continental fault systems on Earth, facilitates the westward movement of the Anatolian microplate into the Aegean region. The temporal and spatial evolution of the NAF is important for understanding the mechanism of escape tectonics during plate interaction in active orogenic regions. The driving force(s) behind the movement of the NAF and the time period over which this occurred remain controversial. Our U–Pb and K–Ar dating of syntectonic minerals shows that a predecessor faulting initiated as early as ~40 Ma due to shortening along the Neo-Tethyan suture zone. Fault reactivations occurred at ~20 and 10 Ma synchronously in eastern and western Anatolia, suggesting that the NAF already existed by ~20 Ma. Our data also show that the westward motion of Anatolia was not only controlled by the Arabia–Eurasia collision in eastern Anatolia, but also by Aegean extension.
AtıfScopus6OpenAlex6İncele - MakaleAçık Erişim2025Scopus SJRQ2Chemical Characterization, Antioxidant and Enzyme-Inhibitory Activities of Different Extracts from Three Phlomis Species
Yagi, Sakina; Zengin, Gokhan; Cetiz, Mehmet Veysi; Cziáky, Zoltán; Jeko, József; Bahşi, Muammer; Çakılcıoğlu, Uğur; Turumtay, Halbay; Aktumsek, Abdurrahman
Phlomis species (family Lamiaceae) are highly valued as food and herbal medicine. The present study is designed to investigate the chemical composition and antioxidant and enzyme inhibitory activities of extracts from P. fruticosa, P. herba-venti, and P. kurdica aerial parts. Different classes of metabolites, including phenolic acids, phenylethanoids, flavonoids, iridoids, organic acids, terpenes, and fatty acids, are identified in the three species, with methanol as the best solvent to recover bioactive compounds from the three species in addition to ethyl acetate for P. kurdica. Around 70% methanol extract of P. herba-venti exerts the best radical scavenging and ions-reducing properties, while its methanol extract exhibits the highest acetylcholinesterase inhibitory activity. The ethyl acetate extract of P. fruticosa displays the best chelating power, and its other polar extracts have the highest total antioxidant activity. Furthermore, molecular docking and molecular dynamics simulations have underscored the therapeutic potential of bioactive compounds, including isoverbascoside, samioside, forsythoside B, and hattushoside. In conclusion, the study indicates that these three Phlomis species are a rich source of bioactive molecules with possible therapeutic applications, and the selection of appropriate extraction solvents is crucial for the targeted biological activity.
AtıfScopus23OpenAlex25İncele - MakaleAçık Erişim2025Scopus SJRQ2Impact of sub-eutectoid thermal aging on martensitic transformation, thermo-structural properties, and gamma-neutron shielding performance of CuAlMnFe high-temperature shape memory alloy
Karaduman, Oktay; Kalay, Ece; Ozkul, Iskender; Kurgun, Mehmet Ali; Canbay, Canan Aksu; Guler, Omer; ALMisned, Ghada; Baykal, Duygu Sen; Tekin, H.O.
A novel Cu-based high-temperature shape memory alloy (HTSMA) with the composition 70.84Cu–23.80Al–4.14Mn–1.22Fe (at. %) was successfully synthesized via arc melting in this study. The effects of thermal aging duration on the alloy’s martensitic transformation behavior, shape memory effect (SME), and microstructural evolution were systematically investigated. Six samples were prepared from the as-cast ingot: one was homogenized in the β-phase region and quenched into ice-brine to induce a martensitic structure, while five others were subsequently aged at 350 ℃ for varying durations and air-cooled. Thermal and structural characterizations were conducted. These included differential scanning calorimetry (DSC), X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and optical microscopy. Prolonged aging altered transformation temperatures and reduced both enthalpy and entropy values. It also promoted the formation of observed precipitates, vacancies, and coarsened 2H martensites. Prolonged aging altered the microstructure and thermal response, leading to partial SME degradation. Additionally, the alloy’s gamma-ray and fast neutron shielding parameters were theoretically estimated using simulation software to explore its potential functional scope. The calculated results indicate that the CuAlMnFe HTSMA is predicted to exhibit favorable attenuation performance across a wide energy spectrum, with appropriate values of mass attenuation coefficient (MAC) and half-value layer (HVL). In particular, the fast neutron removal cross-section was calculated as 0.139 cm−1, which is significantly higher than those of water (0.1023 cm−1), graphite (0.0773 cm−1), and B4C (0.0714 cm−1). In conclusion, the CuAlMnFe HTSMA developed in this study offers a unique profile combining tailorable shape memory behavior with a computationally predicted potential for nuclear radiation shielding. These properties offer novel insights into the alloy’s potential for applications in high-radiation environments that require both mechanical actuation and radiation protection, pending experimental validation of its shielding performance.
AtıfScopus1OpenAlex1İncele - MakaleYalnız künye2026Scopus SJRQ2An Investigation of the Variability of Short-Term Drought with SPEI-Based Severity, Duration and Magnitude Parameters in a Transboundary Basin
Akbas, Ergun; Acar, Ramazan; Eşit, Musa; Koycegiz, Cihangir
Climate change-induced variability in the water budget leads to significant drought events. In this study, severity, duration, and magnitude parameters obtained from 1-month and 3-month series of the Standardized Precipitation Evapotranspiration Index (SPEI) were used to investigate short-term drought from different perspectives. The lower part of the Euphrates-Tigris Basin, which is a transboundary basin, was preferred as the study area within the borders of Türkiye. In this study, monthly total precipitation and monthly mean temperature data for the period 1963–2021 were used. Both graphical (Şen Innovative Trend Analysis) and statistical (Mann–Kendall, Spearman’s Rho, Sen’s Slope Estimator) trend analysis methods were applied to detect, categorize, and analyze the variability of drought. The Combination of Wilcoxon Test and Scatter Diagram (CWTSD) method, which offers both graphical and statistical trend analysis capabilities, was preferred to enhance consistency and facilitate comparison of results. According to the findings, more severe droughts are observed in the eastern part of the basin compared to the western part. Across the basin, severity and magnitude are decreasing, while duration is increasing. The increase in duration indicates that droughts are shifting from short-term to long-term periods. This situation is of great importance in terms of planning agricultural strategies.
AtıfOpenAlex3İncele - MakaleYalnız künye2026Scopus SJRQ1Compositionally segmented thermoelectric BiSbTe thin films on Cr/Si(100)
Yüzüak, G. Durak; Yüzüak, E.
Compositionally segmented thermoelectric (CS-TE) structures improve thermal energy conversion efficiency across large thermal gradients. However, their increased design complexity complicates performance modeling and optimization. In this study, we fabricate CS-TE BiSbTe thin films on Cr-buffered Si(100) substrates. By adopting a multidisciplinary approach, we aim to broaden the technological applicability and strategic relevance of advanced TE systems. We systematically analyze the influence of deposition pressures (5, 7, and 10 mTorr) on TE performance. Variations in working pressure alter the Bi/Sb atomic ratio in the films, while the Te content remains stable. This enables the controlled formation of CS structures. At 323 K, the power factor (PF) of TE thin films reaches 0.7, 2.4, and 7.3 mW/mK2 under 5, 7, and 10 mTorr deposition conditions, respectively. The Cr-buffered layer significantly improves the electrical conductivity of CS-TE BiSbTe films. We further engineer a p-type single-leg device integrating nanostructured Bi0.35Sb1.65Te3, Bi0.37Sb1.63Te3, and Bi0.4Sb1.60Te3 layers. These materials are optimized to achieve peak TE PF values across a wide temperature range (320 to 500 K) while ensuring robust interfacial adhesion. The CS-TE device generates 3 mW/cm2, showing a 15% improvement over single-composition samples at a 100 K temperature difference.
AtıfScopus3WoS3OpenAlex2İncele - MakaleYayıncıda açık erişim2026Scopus SJRQ1Geoeconomic dependency in selected rare-earth metals and compounds: A product-level trade network analysis
Ateş, Erdem
This study examines trade concentration, network structure, and China-centered import dependency in three selected rare-earth metal and compound categories (HS 280530, HS 284610, and HS 284690) over 2012–2024. Using bilateral trade data from the CEPII BACI database, the analysis combines concentration ratios and the Herfindahl–Hirschman Index with bilateral trade-flow networks, centrality measures, cosine-similarity networks, and country-level China Import Dependency Ratios (CID). The results reveal substantial product-level heterogeneity. Trade concentration and network structure evolve differently across the three categories, while changes in similarity-network density, community structure, and modularity are particularly pronounced for HS 284690. Trade shares and network centrality do not always move in parallel, indicating that market concentration and structural network position capture distinct dimensions of trade organization. Country-level dependency analysis further shows increasing reliance on China across all three product categories: both mean CID and the share of importing countries sourcing at least 50% of their imports from China increase between 2012 and 2024. Overall, the findings demonstrate the value of integrating concentration, network, and dependency measures to identify product-specific patterns of geoeconomic exposure in selected rare-earth metals and compounds.
- MakaleYalnız künye2026Scopus SJRQ1Innovative solutions for aquaculture: detecting fish diseases with hybrid deep learning model and explainable artificial intelligence
Utku, Anıl; Barut, Abdulkadir; Alofaysan, Hind
Early identification of fish diseases is critical to maintain aquaculture and minimize its financial burden. In the diagnosis of diseases, time is critical and scientists’ experience is imperative, which makes the artificial intelligence-based models necessary. It is intended by this study to integrate deep learning with explainable artificial intelligence methods to establish an artificial intelligence-powered framework for early detection of disease in fish. In this study, we developed a hybrid artificial intelligence system designed to detect diseases in freshwater fish by analyzing skin images. The primary objectives of the system are to minimize economic losses, prevent further disease spread, and ultimately increase aquaculture productivity. For this purpose, we used a dataset consisting of images from seven different disease categories, with 250 images in each class. A new hybrid model, Residual Network-50–Vision Transformer, was developed by integrating the strengths of Residual Network-50 and Vision Transformer architectures to improve classification accuracy. The proposed model was subjected to rigorous comparison with established architectures, including Visual Geometry Group 16, Mobile Convolutional Neural Network Version 2, Efficient Neural Network–Baseline Model B0, standalone Vision Transformer, and the original Residual Network-50. The results demonstrated that Residual Network-50–Vision Transformer outperformed the model, achieving an impressive 99.14% accuracy rate. Furthermore, the study employed local interpretable model-independent explanations to explain which image features most significantly influence the model’s classification decisions, thereby enhancing the interpretability and confidence in the model’s output. The application of such advanced image processing models in combination with explainable AI techniques demonstrates significant potential to support sustainable aquaculture by reducing disease outbreaks and associated financial losses.
AtıfScopus3OpenAlex2İncele - Derleme MakaleAçık Erişim2025Scopus SJRQ1Automated Detection of Neurological and Mental Health Disorders Using EEG Signals and Artificial Intelligence: A Systematic Review
Uyanik, Hakan; Sengur, Abdulkadir; Salvi, Massimo; Tan, Ru-San; Tan, Jen Hong; Acharya, U. Rajendra
Mental and neurological disorders significantly impact global health. This systematic review examines the use of artificial intelligence (AI) techniques to automatically detect these conditions using electroencephalography (EEG) signals. Guided by Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), we reviewed 74 carefully selected studies published between 2013 and August 2024 that used machine learning (ML), deep learning (DL), or both of these two methods to detect neurological and mental health disorders automatically using EEG signals. The most common and most prevalent neurological and mental health disorder types were sourced from major databases, including Scopus, Web of Science, Science Direct, PubMed, and IEEE Xplore. Epilepsy, depression, and Alzheimer's disease are the most studied conditions that meet our evaluation criteria, 32, 12, and 10 studies were identified on these topics, respectively. Conversely, the number of studies meeting our criteria regarding stress, schizophrenia, Parkinson's disease, and autism spectrum disorders was relatively more average: 6, 4, 3, and 3, respectively. The diseases that least met our evaluation conditions were one study each of seizure, stroke, anxiety diseases, and one study examining Alzheimer's disease and epilepsy together. Support Vector Machines (SVM) were most widely used in ML methods, while Convolutional Neural Networks (CNNs) dominated DL approaches. DL methods generally outperformed traditional ML, as they yielded higher performance using huge EEG data. We observed that the complex decision process during feature extraction from EEG signals in ML-based models significantly impacted results, while DL-based models handled this more efficiently. AI-based EEG analysis shows promise for automated detection of neurological and mental health conditions. Future research should focus on multi-disease studies, standardizing datasets, improving model interpretability, and developing clinical decision support systems to assist in the diagnosis and treatment of these disorders.
AtıfScopus58OpenAlex46İncele
