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Koleksiyondaki öğeler
- MakaleYalnız künye2025Scopus SJRQ1Momordica charantia L. Extract as a Potential Inhibitor of Heterocyclic Aromatic Amine Formation in Pan-fried Meatballs
Gumus, Damla; Macit, Arife; Guzel, Bengu; Tengilimoglu-Metin, M. Merve; Kizil, Mevlude
The primary objective of this study was to examine the effect of Momordica charantia L. extract (MCE) on the generation of heterocyclic aromatic amines (HAAs) in meatball samples. Meatballs were prepared with varying usage rates of MCE (0%, 0.5%, and 1%) and pan-fried at 150 °C, 200 °C, and 250 °C for a total cooking duration of 10 min. The samples were analyzed for proximate composition, pH, cooking loss, and HAA levels. Results indicated that increased cooking temperatures led to higher total HAAs, with specific types and quantities of HAAs varying according to both cooking temperature and MCE concentration. The total HAA content in the meatball samples ranged from 0.81 ng/g and 10.75 ng/g. Specifically, the total HAAs were 1.29 ± 0.38 ng/g, 3.40 ± 1.52 ng/g, and 7.60 ± 2.48 ng/g in meatballs cooked at 150 °C, 200 °C, and 250 °C, respectively (p < 0.05). The addition of MCE at different concentrations reduced the generation of total HAAs, with 0.5% MCE showing the highest inhibitory effect, reducing total HAAs by 30.8%. These findings underscore the significance of considering cooking conditions, including temperature and usage rate, when incorporating antioxidant compounds into meat products.
AtıfScopus2WoS2OpenAlex3
İncele - MakaleAçık Erişim2026Scopus SJRQ2Solvent 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.
AtıfScopus1WoS3OpenAlex1İncele - MakaleYalnız künye2026Scopus SJRQ2Oxide 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.
- MakaleAçık Erişim2026Scopus SJRQ1Path 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.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ1Effect 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.
- MakaleAçık Erişim2025Scopus SJRQ1Investigating forest fire causes through an integrated Bayesian network and geographic information system approach
Konurhan, Zekeriya; Yucesan, Melih; Gul, Muhammet
Forests are among the most critical natural resources worldwide and are essential for a sustainable ecosystem. In recent years, climate change and human activities have increased their impact on forests, and forest fires-especially in summer- have caused significant forest losses globally. This paper integrates Bayesian Network (BN) and Geographic Information Systems (GIS) to pinpoint the possible causes of forest fires and analyze their complex interactions. The study used data from 1465 fires between 2017 and 2022 in Muğla province in southwestern Türkiye. Within the scope of the study, 11 variables were chosen, such as elevation, slope, aspect, wind speed, population density, and road network, to build a BN model that combines physical and human geographical features. These variables overlapped using the pairwise intersect tool from ArcGIS Pro during the BN model setup, and probability values were calculated. The overall probability of fire in the BN model was determined to be 0.81, with probabilities ranging from 0.81 to 0.56 in low-altitude, moderately sloped, and south-facing areas. Scenario analyses examined fire risk under different conditions, highlighting the most influential variables for fire prevention efforts. The study identified fire-prone areas as spatial data, revealing that densely forested coastal and certain inland regions are at higher risk, whereas bare high-altitude areas with steep slopes pose lower risk. The BN model can be further enhanced by incorporating additional variables, making it a valuable tool for future fire risk assessment and mitigation strategies research.
AtıfScopus5WoS5OpenAlex7İncele - MakaleYalnız künye2025Scopus SJRQ1Aerodynamic characteristics of a symmetrical airfoil in the presence of segmentally distributed leading-edge tubercles
Seyhan, Mehmet; Demirci, Veysel; Çolak, Aleyna; Kan, Furkan Erman; Firat, Erhan; Sarioglu, Mustafa
In recent decades, experimental and numerical studies have demonstrated that wings with leading-edge (LE) tubercles exhibit advantageous aerodynamic performance at high attack angles compared to their unmodified counterparts. A substantial portion of these studies employed a single sinusoidal function to design the tubercles applied along the entire span. In this study, two functions were utilized to design tubercles. This experimental study was conducted to evaluate the effects of segmentally distributed (i.e., equally spaced) LE tubercles on the aerodynamic characteristics (ACs) of the National Advisory Committee for Aeronautics (NACA) 0018 airfoils and to associate them with the flow patterns observed on the suction surface. To this end, five different airfoil models have been produced and tested. The models consist of one plain airfoil, one fully tubercled airfoil, and three segmentally tubercled airfoils. The test results were obtained at Reynolds numbers (Re) of 0.6 × 10 5 to 1.2 × 10 5 . It has been determined that the distance between neighboring tubercled segments possesses a critical value with regard to performance enhancements in the post-stall regime. In the range below this critical distance, the tubercled segments lack the capacity to reattach the separated flow from the plain segments of the airfoil. Furthermore, the presence of a novel vortical structure (i.e., single rotating vortex cell, SRVC) under certain conditions was demonstrated qualitatively.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2026Scopus SJRQ1Multi-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.
- MakaleAçık Erişim2026Scopus SJRQ1Dietary 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.
- MakaleAçık Erişim2026Scopus SJRQ2Tribological Performance of SPS-Fabricated Cu-HEA/Gr Composites Under Current-Carrying Sliding Contact
Ozkaya, Serdar; Çelebi, Müslim; Yanar, Harun; Karabacak, Abdullah Hasan; Çelik, Ertuğrul; Güler, Onur; Coskun, Abdulkadir; Sekban, Dursun Murat
Cu-based hybrid composites reinforced with AlCrFeCuNi high-entropy alloy (HEA) particles and graphene were successfully fabricated by spark plasma sintering (SPS) to investigate the combined effects of microstructure, mechanical properties, and tribological performance under electrical current. Microstructural observations revealed a dense and homogeneous distribution of HEA particles within the Cu matrix, while the addition of 2.0 wt.% graphene promoted noticeable grain refinement due to its grain boundary pinning effect. Although graphene addition provided beneficial effects in terms of grain refinement and electrical conductivity, it also increased the porosity from 2.49% to 5.08%. Consequently, the beneficial contribution of graphene to mechanical strengthening was substantially offset by the adverse effect of increased porosity, resulting in only a marginal increase in hardness from 127 HB to 129 HB. The addition of 2.0 wt.% graphene led to a pronounced change in the tribological behavior of the composites. The Cu–HEA exhibited relatively stable friction behavior but experienced a higher wear rate under all test conditions. In comparison, the Cu–HEA–2.0 Gr composite demonstrated a lower coefficient of friction and wear rate at 0–10 A, which is consistent with the possible formation of a graphene-rich lubricating surface layer. A clear transition occurred at 30 A, where the coefficient of friction and wear rate began to increase, while at 50 A, further increases in both parameters were observed, suggesting progressive disruption of the proposed protective surface layer under the investigated current-carrying sliding conditions.
- MakaleAçık Erişim2026Scopus SJRQ1EBA-Net: A hybrid EfficientNetB3-BiLSTM-Attention model for species-level diatom classification
Balo Utku, Esen Damla; Kutlu, Banu; Utku, Anil
Species identification in diatoms is important for assessing water bodies, determining environmental quality, and analyzing biodiversity. Nonetheless, diatom classification has proven difficult due to intra-class variation, interclass similarity, and data imbalance in microscopic images. In this regard, we propose a new deep learning approach for species-level diatom classification. Various deep learning models, including traditional convolutional neural networks or CNNs (ResNet50, DenseNet121), state-of-the-art CNNs (EfficientNetB3, Xception, MobileNetV3), transformer-based architectures (ViT-B16, Swin-Tiny), and our proposed EBA-Net (EfficientNetB3-BiLSTM-Attention Network), were extensively compared under identical experimental settings. The EBA-Net integrates the advantages of convolutional feature extraction, sequence modeling, and an attention mechanism to improve classification accuracy. It first uses the EfficientNetB3 model as the backbone network to obtain higher-level features, followed by a BiLSTM layer to capture dependencies among the extracted features. Then, it applies the attention mechanism to the BiLSTM output to highlight the most informative features. Experimental results showed that the proposed EBA-Net model outperforms other models considered in the study, yielding 95.8% accuracy and 85.1% macro F1-score. In addition, Top-3 (98.9%) and Top-5 (99.6%) accuracies confirmed the efficiency of the proposed model for classifying objects from visually similar classes. An analysis of the model's interpretability was conducted using Gradient-weighted Class Activation Mapping, showing that the proposed model's attention is concentrated on relevant morphological features of diatoms. To the best of our knowledge, the suggested approach achieves state-of-the-art accuracy on the data set of diatoms used.
- MakaleAçık Erişim2025Scopus SJRQ1Site Fidelity, Home Range Size and Movement Patterns of a Mega-Fish, Luciobarbus esocinus, in Keban Reservoir, Euphrates River
Alp, Ahmet; Akyüz, Adil; Gündüz, Fatih; Demirol, Ferhat; Çoban, Mehmet Zülfü; Yüksel, Fahrettin; Yerli, Sedat Vahdet
Luciobarbus esocinus (mangar), a critically endangered mega-fish species (≤ 140 kg) endemic to the Euphrates and Tigris river systems, faces severe threats due to habitat fragmentation. To assess its spatial ecology in the Keban Reservoir, 30 individuals were acoustically tagged and monitored for 218–437 days using 18 receivers deployed in the reservoir. The tagged fish exhibited low site fidelity, with station residency indices (RI) ranging from 0.00 to 0.46 and detection periods lasting 59–153 days. Depth and temperature data (115,318 and 112,789 records, respectively) revealed seasonal habitat shifts: individuals occupied deeper waters in winter (mean 10.1 m), shallower depths in spring (4.4 m) and summer (3.8 m), and tolerated temperatures of 7.4°C–28.4°C. Although depth use was weakly correlated with temperature, trends indicated shallower occupancy during warmer periods. Home range analyses showed a maximum linear home range (LHR) of 36.5 km and the areal home range estimated via minimum convex polygon (MCP) was 6422.8 ha. In addition, kernel density (KD) analysis revealed the 95% KD area was 2877.0 ha, the 75% KD area was 67.7 ha and the 50% KD area was 33.8 ha. Seasonal migrations spanned 25–30 km upstream/downstream from release sites, particularly toward tributaries in spring. Around the Keban Reservoir, 14 hydroelectric power plants (HPPs) present and most of these HPP are not designed suitable fish passages. Urgent conservation measures are needed, including Fish Conservation Zones in critical habitats and connectivity restoration via functional fishways, to safeguard this imperilled species in fragmented river-reservoir ecosystems.
- MakaleYalnız künye2026Scopus SJRQ2Damage diagnosis in CFRP/Al7075-T6 aeronautical structures using piezoelectric sensors: characterization and experimental monitoring
Gahlouz, Ibtissem; Guemmour, Mohamed Boutkhil; Chellil, Sadek; Chellil, Ahmed; Houari, Amin; Aribi, Chouaib; Polat, Alper; Adjout, Warda; Bey, Mohamed
Purpose – This study aims to design a damage detection and characterization system (targeting cracks and delamination) for aeronautical composite structures. Design/methodology/approach – This methodology relies on a multidisciplinary approach combining polymer-reinforced/metallic carbon fiber hybrid structures with an integrated network of PZT sensors. It leverages experimental data and employs advanced signal processing and imaging techniques to monitor structural integrity and assess the severity of damage. Findings – Verified experimental results confirm the method's reliability in real-life situations. Research limitations/implications – Research Limits: “The primary challenges involve signal processing complexity due to the hybrid nature of AL7075-T6 and CFRP materials, as well as the potential influence of environmental factors (temperature, pressure) on PZT sensor reliability”. Research Implications: “This work enables a shift toward condition-based maintenance, significantly reducing operational costs while enhancing structural safety and extending the service life of critical aerospace and maritime assets.” Practical implications – This study enables a shift from scheduled to real-time structural monitoring. There is a drastic reduction in inspection time and aircraft downtime. Monitoring the fatigue of hybrid AL/CFRP structures helps to safely extend their service life. The study helps in providing precise diagnostics to optimize repair strategies and minimize human error. Social implications – There is a drastic reduction of structural failure risks through early-stage damage detection. Cost savings in maintenance can lead to more affordable air travel for the general public. The study helps in promoting a circular economy by safely extending the lifespan of complex structures and reducing material waste and also in shifting maintenance roles toward high-tech data analysis and specialized software expertise. Originality/value – The study investigates the complex damage mechanics at the interface of AL7075-T6 and CFRP laminates and helps in combining PZT sensor networks with advanced imaging software for real-time damage characterization. Beyond mere detection, the system assesses “structural criticality, ” providing high-value diagnostic data for maintenance optimization and cost reduction.
- MakaleAçık Erişim2026Scopus SJRQ4INTEGRATED BIOLOGICAL TREATMENT AND ELECTROCOAGULATION FOR SLAUGHTERHOUSE WASTEWATER: A NOVEL APPROACH USING FRESHWATER SNAILS (Viviparus contactus, Planorbis rubrum, Melanoides tuberculata)
Öğedey, Ayşenur; Kocabaş, Filiz Kutluyer; Kizak, Volkan; Kocabaş, Mehmet; Benzer, Fulya; Erişir, Mine; Öğedey, Hayrullah
As a potential pollution source, slaughterhouse wastewater (SWW) with development of the meat production and processing sector is a threat in the world. Therefore, the determination of economical, favourable, cost-effective and proper treatment method is crucial for sustainable environmental protection. This study focused on the performance and efficiency of a two-stage process combining biological treatment (BT) with freshwater snails and electrocoagulation (EC) of SWW. Viviparus contectus, Planorbis rubrum, Melanoides tuberculata were used in primary treatment while secondary treatment was realized with EC process. The EC of SWW was performed for reducing both turbidity and chemical oxygen demand (COD) concentration to levels compliant with direct-discharge regulations. In addition, the stirring speed, current density, initial pH and reaction time were assessed for evaluation the optimum EC condition. Oxidative stress biomarkers and some antioxidants were assessed in freshwater snails exposed to SWW after 24 and 96 h. The best removal efficiencies of COD (91.43%) and turbidity (92.42%) were obtained at pH 5 and 20 min of operational time by P. rubrum. Notably, MDA (Malondialdehyde) was highest level in M. tuberculata compared to V. contectus and P. rubrum. Overall, removing organic and inorganic pollutants from SWW could be provided with the hybrid process BT/EC as a combining approach.
- MakaleYalnız künye2026Scopus SJRQ1Mechanical and durability properties of sustainable alkali-activated mortars with ceramic insulator waste and andesite powder as partial substitutes for GBFS
Cemalgil, Selim; Yön, Merve Şahin; Dener, Murat; Karataş, Mehmet
This study explores the use of andesite powder (AP) and ceramic waste powder (CWP), derived from discarded electrical insulators, as supplementary precursors to ground granulated blast furnace slag (GBFS) in alkali-activated self-compacting mortars. The originality of the work lies in the combined utilization of these regionally sourced aluminosilicate wastes in binary and ternary binder systems, aiming to reduce GBFS dependency while ensuring adequate mechanical and durability performance. AP and CWP were used to replace GBFS at up to 50%, and the mixtures were evaluated for flowability, mechanical strength, density, porosity, water absorption, and capillary sorptivity. Durability was assessed through freeze–thaw cycling and high temperature exposure, and microstructural characteristics were examined using scanning electron microscope analysis. Results showed that while partial substitution with AP or CWP reduced compressive strength compared to the GBFS control, the incorporation of CWP in ternary systems partially compensated for the strength losses associated with AP. High temperature resistance improved markedly with increased CWP content; at 900°C, the 50% CWP mixture retained 44% of its original compressive strength, in contrast to 8% for the control. Although all mixtures containing waste exhibited reduced freeze–thaw resistance, mortars containing CWP exhibited superior performance compared to those with only AP. These findings highlight the potential of CWP, particularly in ternary systems, for developing sustainable alkali-activated mortars.
AtıfScopus16WoS14OpenAlex12İncele - MakaleYalnız künye2025Scopus SJRQ2Removal of Impurities from Sepiolite by Gravity/Sizing Methods for Better Viscosity Development
Angur, G. Ersever; Çınar, M.; Çelik, M.S.
Sepiolite, a natural strategic clay mineral within the phyllosilicate group, is utilized in numerous applications because of its physical, and rheological properties. In particular, outstanding rheological properties are utilized in areas including drilling mud, paint, cosmetics, adhesives, etc. Several studies have been performed for the purification of clays, such as air classification, calcination, hydrocyclone, and flotation, for different purposes. In this study, relatively easy physical upgrading methods involving hydroxyclone, Falcon, and shaking table have been tested with the aim of obtaining a high-viscosity sepiolite product for rheological applications. It is shown that dispersion time, particle size, and pH are the most critical parameters in the viscosity development of sepiolite. The results indicate that, depending on the dispersion time of the raw HS1 sepiolite sample used in this study, the highest quality rheological material remains in the size range of – 2 mm to + 1 mm. Below – 0.1 mm, the viscosity value of the sepiolite sample decreased to its lowest value of 6000 cP. The pH-dependent viscosity measurements of a raw HS1 sepiolite sample exhibited the highest viscosity value of 13,000 cP at its natural pH of 8.5. Polyacrylic acid sodium salt (PAA) is the most effective dispersing agent in the decantation process for the enrichment of HS1 sepiolite samples. Among the three gravity/sizing beneficiation techniques tested, the middlings product of the shaking table achieved the highest quality sepiolite product of 17,000 cP with 49.2 wt.% using the size range of – 2.83 mm to + 1 mm; this material is suitable for high-grade rheological applications.
- MakaleYalnız künye2026Scopus SJRQ2Investigation of the effect of ultrasonic assisted milling and minimum quantity lubrication methods on the machinability of Hardox 500 steel
Dalgıç, Aras; Mahmat, Aybars
Hardox steel is widely used in agriculture, mining and transportation due to its mechanical properties such as high wear resistance, high impact resistance, high hardness, high durability and long life. The machinability of Hardox 500 is difficult as its high hardness and wear resistance lead to tool wear and low machining speed. Recently, various processing and cooling methods have been developed to increase machinability. Ultrasonic assisted milling (UAM), one of these methods, is a method used as an alternative to conventional milling (CM) in the milling of traditionally difficult-to-machine materials. In addition, minimum quantity lubrication (MQL) is a cooling method used to provide lubrication and cooling in the cutting area. In this study, the impacts of machining method, feed rate and spindle speed on cutting force, surface roughness and tool wear in milling of Hardox 500 steel were investigated. In the MQL method, mixtures with nano-sized SiC particles were obtained and applied to the cutting area. In the study, MQL reduced cutting forces by up to 19 %, surface roughness by 18 %, and tool wear by 30 % compared to dry machining, while UAM further decreased cutting forces by 17 %, surface roughness by 15 %, and tool wear by 12 % compared to CM. These results demonstrate that MQL and UAM significantly enhance machining performance over conventional and dry methods.
- MakaleAçık Erişim2025Scopus SJRQ3The effect of addition of powder jujube (Ziziphus jujuba Mill.) fruit at different rates into mixed diets on antioxidant and some blood parameters of broiler chickens*
Arslan, S.; Parlak Ak, T.; Guler Ekmen, E.; Karakoc, Ş.; Ciftci, M.
This study was conducted to determine the effects of addition of jujube (Ziziphus jujuba Mill.) fruit at different rates into the mixed feed on intestinal morphology, antioxidant and some blood parameters of broiler chickens. A total of 160 male broiler (initial body weights were determined as 209.25±2.17, 209.18±2.13, 209.18±1.74 and 209.20±2.58, respectively) chickens (Ross-308), including 40 in each group, were used in the study. The groups were divided into 4 sub-groups, each of which include 10 broiler chickens. The study groups were the control group (the group without jujube fruit), the H-0.5% group (the group with 0.5% jujube fruit), the H-1 group (the group with 1% jujube fruit), and the H-2 group (the group with 2% jujube fruit). At the end of the experiment (42nd day), the control group had the highest levels of blood glucose, triglycerides, total cholesterol, very low density lipoprotein cholesterol, alanine aminotransferase, aspartate aminotransferase, and uric acid, and the lowest level of creatine (P<0.05). While the lowest malondialdehyde level was detected in the H-2 group (P<0.001), the highest glutathione peroxidase (P<0.01) and catalase (P<0.05) levels were observed in the H-1 and H-2 groups. The control group also had the lowest values for villus height and crypt depth and the highest values for villus height/crypt depth (P<0.001). As a result, it was concluded that jujube fruit, which is mainly used for its antioxidant properties, can be used in poultry compound feeds especially at the level of 1% due to its positive effects on antioxidant and blood parameters and intestinal morphology.
- MakaleYalnız künye2026Scopus SJRQ1Mineralogical and geochemical controls on Co-V-Pt-Ni enrichment in manganese mineralization: evidence from the Dilli deposit, Eastern Türkiye
Gücer, Mehmet Ali; Çimen, Okay; Aktağ, Alican; Keskin, Serdar
The growing demand for critical minerals driven by the global energy transition and advanced technologies highlights the importance of unconventional metal reservoirs. This study investigates the Ni-, Co-, V-, and Pt-enriched Dilli manganese deposit (Kemaliye-Erzincan, Eastern Türkiye) to constrain the mineralogical, geochemical, and genetic controls on critical metal enrichment in Mn oxide mineralization. An integrated approach combining field observations, petrography, X-ray diffraction (XRD), whole-rock geochemistry, mineral chemistry, and stable C-O isotope analysis was applied to better understand the potential origin of critical mineral enrichments. The mineralization is dominated by Mn4+-bearing oxides, principally pyrolusite and hollandite, accompanied by minor rhodochrosite. High MnO (39-64 wt%) and very low Al2O3 and Fe2O3 contents indicate chemical precipitation with negligible detrital input. Discrimination diagrams and trace-element systematics consistently support a structurally controlled hydrothermal origin. Chondrite-normalized REE patterns display low total REE and very low Nd contents comparable to typical hydrothermal deposits, whereas neutral to slightly positive Ce anomalies and non-chondritic Y/Ho ratios suggest limited oxidative interaction with surface-derived fluids rather than primary marine hydrogenetic growth. Stable C–O isotope compositions of co-genetic calcite are inconsistent with a purely marine depositional environment and indicate precipitation from low-to moderate-temperature hydrothermal fluids. Mineral chemistry reveals strong phase-specific partitioning: hollandite preferentially incorporates V and Ba, whereas pyrolusite is enriched in Ni. Cobalt occurs in both phases, whereas Pt may also be present in both Mn oxide phases, suggesting that trace-element distribution is influenced by both crystallochemical and physicochemical controls. The enrichment of Ni, Co, and Pt is most plausibly linked to hydrothermal fluid circulation through ultramafic units, which likely acted as the primary metal source prior to precipitation. The Dilli deposit thus represents a structurally controlled hydrothermal Mn system enriched in critical metals, emphasizing the exploration relevance of Mn oxide mineral chemistry in identifying alternative sources of critical metals in Türkiye.
- MakaleAçık Erişim2026Scopus SJRQ2Corrosion behavior and constant load scratch adhesion properties of CeO2 doped ceramic composite layer via micro arc oxidation on Al 1050 alloy
Ayday, Aysun; Durmaz, Mustafa; Duru, Erhan; Kırsever, Derya; Doğan, Fatih
In this study, CeO2-doped ceramic coatings were produced on Al 1050 alloy by micro-arc oxidation (MAO) using a silicate-alkaline electrolyte containing 0, 0.5, 1, and 2% CeO2. The aim was to investigate the effect of CeO2 addition on the microstructure, phase composition, corrosion behavior, and constant-load scratch adhesion performance of the coatings. Surface characterization was carried out by SEM, EDS, XRD, and 3D profilometry, while corrosion performance was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy in 3.5 wt% NaCl solution. Scratch tests were also performed to assess the mechanical integrity of the coatings. The results showed that increasing CeO2 content improved coating uniformity, reduced surface roughness and porosity, and promoted the formation of a denser oxide structure. XRD analysis confirmed that γ-Al2O3 was the predominant alumina phase in all coatings, while Ce-containing species were incorporated into the oxide layer without forming additional detectable phases. Electrochemical results revealed that CeO2 addition significantly improved corrosion resistance by lowering the corrosion current density and increasing the polarization resistance. Scratch test results further showed improved adhesion-related behavior with reduced crack formation and surface damage. Overall, CeO2 addition effectively enhanced both the corrosion protection and mechanical performance of MAO coatings on Al 1050 alloy.
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