Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Güler, Ömer(22)
- ALMisned, Ghada(15)
- Tekin, H.O.(15)
- Kök, Mediha(11)
- Güler, Seval Hale(10)
- Özkul, İskender(10)
- Aglar, Erdal(9)
- Aslan, Alper(7)
- Durmus, Hasan(7)
- Erten, Fusun(7)
- Orhan, Cemal(7)
- Yeşiltepe, Akgün(7)
- Baykal, Duygu Sen(6)
- Gul, Muhammet(6)
- Karataş, Mehmet(6)
- Sahin, Kazim(6)
- Sen Baykal, Duygu(6)
- Serdar, Osman(6)
- Taşgın, Yahya(6)
- Tuğan, Volkan(6)
- Acar, Ramazan(5)
- Macit, Arife(5)
- Ozturk, Burhan(5)
- Utku, Anil(5)
- Yılmaz, Demet(5)
- Çelik, Yusuf(5)
- Özyurt, Özcan(5)
- Şahin, Aykut(5)
- Almisned, Ghada(4)
- Aslan, Naim(4)
- Benzer, Fulya(4)
- Doğan, Fatih(4)
- Er, Besir(4)
- Gundogdu, Muttalip(4)
- Ilik, E.(4)
- Kanca, M. Sait(4)
- Karaduman, Oktay(4)
- Kavaz, E.(4)
- Kocabaş, Filiz Kutluyer(4)
- Kocabaş, Mehmet(4)
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ1Comparative effects of topical Maresin-1 and cyclosporine A in a capsaicin-induced rat model of neurotrophic keratopathy
Canan Sezis, Selen; Güngör Kobat, Sabiha; Kuloğlu, Tuncay; İlhan, Nevin; Erten, Füsun
Purpose: To evaluate and compare the effects of topical Maresin-1 (MaR1) and cyclosporine A (CsA) in a capsaicin-induced rat model of neurotrophic keratopathy (NK). Methods: A total of 40 Sprague-Dawley rats were allocated to five groups (n = 8 per group): Control, NK, NK + Vehicle, NK + CsA (0.05%), and NK + MaR1. Except for the Control group, all animals received a single subcutaneous injection of capsaicin (50 mg/kg) on postnatal day 2. Topical treatments were applied twice daily for 14 days. Corneal TrkA, TNF-α, and Caspase-3 expression were assessed by immunohistochemistry and Western blot. Results: Both treatment groups significantly restored TrkA expression and reduced TNF-α and Caspase-3 relative to NK + Vehicle (p < 0.05 for all). CsA produced greater suppression of TNF-α than MaR1 (p < 0.001), whereas MaR1 demonstrated greater reduction in Caspase-3 than CsA (p = 0.013), with no significant difference between groups for TrkA (p = 0.054). Conclusion: Both MaR1 and CsA significantly attenuated the neurotrophic, inflammatory, and apoptotic changes associated with experimental NK. The distinct efficacy profiles of the two agents suggest complementary mechanisms of action and warrant further investigation of MaR1 in neurotrophic keratopathy.
- MakaleAçık Erişim2026Scopus SJRQ1Knowledge Rent, Intangible Capital, and Core–Periphery Dynamics: Theory and Evidence
Ateş-Saygılı, Çiğdem
We study how ownership and pricing of intangible assets generate asymmetric macroeconomic dynamics between a core and a periphery. We develop a two-country dynamic stochastic general equilibrium (DSGE) model in which production uses tangible capital, domestically owned intangible capital, and rented foreign intangible services; the periphery pays a knowledge rent flow to the core, which acts as a wedge in its accumulation equation. Calibrated to observed income shares and depreciation patterns, the model yields sharp qualitative predictions. Following a positive technology shock in the core, core output jumps and consumption and labor rise persistently, while the periphery sees only modest output gains and slower capital build-up; a positive technology shock in the periphery can even reduce its output as rent payments drain resources, with only small, transitory effects in the core. A tighter repayment schedule modestly lifts core activity–mainly via consumption–while acting as a negative wealth shock in the periphery that lowers output, labor, and consumption. Sensitivity analyses–varying the periphery's intangible share and reliance on rented knowledge–preserve these qualitative rankings. Complementary evidence from OECD panels (2000–2019) using PVARs and state-dependent local projections shows that cross-border payments for the use of intellectual property co-move with financing conditions and macroeconomic dynamics, consistent with the model's mechanism. Policy implications include building domestic intangible capacity, easing diffusion at fair terms, and leveraging multilateral tools to reduce effective rent exposure in the periphery.
- MakaleAçık Erişim2026Scopus SJRQ4Sustainable land management under uncertainty: A hybrid Bayesian BWM and RPM framework for spatial prioritization
Konurhan, Zekeriya
Sustainable land management is a complex problem due to environmental constraints and decision-maker uncertainty. This study presents an integrated solution combining Geographic Information Systems (GIS), the Bayesian Best-Worst Method (Bayesian BWM), and the Ratio Product Model (RPM) to improve the accuracy of spatial prioritization in land-use decisions. The integration of the Bayesian BWM and RPM statistically minimizes the cognitive uncertainty in expert opinions whilst enabling the most suitable areas to be ranked with precision within their own categories, without any normalization constraints. The proposed model was developed for three main categories —residential, industrial, and agricultural— in the province of Balıkesir. The analysis results revealed that the ‘ease of access to services’ (0.5660) criterion was the most decisive factor for residential suitability, whilst ‘distance to power transmission lines’ (0.1322) and ‘average rainfall’ (0.1315) were the most decisive factors for industry and agriculture, respectively. The suitability maps show that the Bandırma-Susurluk corridor is strategically prioritized for industry, whilst the Manyas-Gönen basin is prioritized for agricultural production. RPM scores (0.2750 for settlement, 0.6036 for industry, and 0.3868 for agriculture) quantify implementation priorities, providing a reliable decision-support tool for managing uncertainty in spatial planning.
- MakaleYalnız künye2026Scopus SJRQ3Rényi holographic dark energy-inspired model and scalar field reconstruction in bianchi type III spacetime
Korunur, Murat; Korunur, Sibel
In this study, we consider a cosmological model based on Rényi holographic dark energy within the context of an anisotropic Bianchi type III spacetime geometry. The dark energy density is taken as a modified function of the Hubble parameter, which enables us to express the Einstein field equations in a closed dynamical system. By solving these equations, we obtain the evolution of the Hubble parameter and examine the main cosmological implications of the model. The physical behavior of the universe is discussed through the analysis of the equation-of-state parameter as well as the deceleration parameter. Our results indicate that the universe evolves from an initial decelerated expansion phase toward a late-time accelerated regime. In the asymptotic limit, the model tends to a de Sitter phase, suggesting the presence of a stable attractor configuration. In addition, we reconstruct the dark energy component in terms of different scalar field frameworks, namely quintessence, tachyon, and k-essence models. The associated scalar fields and their potentials are derived and numerically investigated. The obtained results show a coherent late-time behavior, which is in agreement with the observed accelerated expansion of the universe. The small value of the mean anisotropy parameter indicates that this evolution occurs within a quasi-isotropic Bianchi type III background.
- MakaleAçık Erişim2026Scopus SJRQ2Sustainable epoxy based biocomposites reinforced with Melilotus officinalis: Structural, mechanical, thermal, and dielectric performance evaluation
Solmaz, Adnan; Açar, Mikail; Demirel, Maruf Hurşit; Deniz, Şermin; Aydoğmuş, Ercan
The aim of this study is to investigate the manufacturability of Melilotus officinalis (L.) reinforced epoxy biocomposites as a renewable biofiller and to characterize the mechanical, thermal, and dielectric properties of these materials. For this purpose, composites containing biomass at 0, 3, 6, and 9 wt.% were prepared; the samples were examined by tensile testing, FTIR, SEM, EDX, XRD, Shore D hardness, thermal conductivity, and dielectric analysis. The findings showed that with increasing M. officinalis content, tensile strength, hardness, and density decreased, while ductility and elongation at break improved. The significant decrease in thermal conductivity revealed an increase in heat insulation efficiency. Dielectric analyses showed that strong interfacial polarization occurred at low frequencies, and the dielectric constant and loss values decreased as the frequency increased. SEM examinations confirmed that the plant-derived filler was homogeneously distributed and formed acceptable interfacial adhesion with the matrix. In conclusion, although the use of synthetic epoxy matrix and the decrease in mechanical strength limit load-bearing structural applications, M. officinalis is a promising biofiller for lightweight and partially bio-based epoxy composites thanks to its increased ductility and improved thermal insulation properties. © The Author(s) 2026. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
- MakaleAçık Erişim2026Scopus SJRQ2A Genetic Algorithm-Optimized ConvNeXtV2-YOLOv8 Framework for Dental Caries Detection in Panoramic Radiographs
Sobahi, Nebras; Küçük, Deniz Bora; Kılıç, Kazım; İmak, Andaç; Çelebi, Adalet; Alghamedi, Yazyd; Yazicioglu, Cafer; Türkoğlu, Muammer; Şengür, Abdulkadir
Background/Objectives: Dental caries is one of the most common oral diseases worldwide, and early diagnosis is essential for effective treatment. However, detecting carious lesions in panoramic radiographs is challenging because of low image contrast, anatomical complexity, and overlapping structures. This study aimed to develop an improved object detection framework for dental caries localization in panoramic radiographs. Methods: A modified YOLOv8 architecture was developed by integrating ConvNeXtV2 blocks into the Cross-Stage Partial (C2f) modules to enhance feature extraction and gradient propagation. To improve detection performance and reduce overfitting, key training hyperparameters were optimized using a genetic algorithm. The proposed model was evaluated on a dataset of 474 panoramic dental radiographs annotated by experts using bounding boxes. Results: The optimized model achieved a box precision of 78.4%, a recall of 53.6%, and a mean average precision at 50% intersection-over-union threshold (AP50) of 62.6%. Compared with the baseline YOLOv8 model, the proposed approach improved precision and AP50. Visual and quantitative analyses demonstrated that the ConvNeXtV2-enhanced architecture enabled more accurate localization of carious regions. Conclusions: The results indicate that combining ConvNeXtV2-based architectural enhancement with genetic algorithm-based hyperparameter optimization is an effective strategy for dental caries localization in panoramic radiographs. Although recall remains a limitation, the proposed framework shows potential as a computer-aided diagnostic tool for supporting clinical caries assessment.
- MakaleAçık Erişim2026Scopus SJRQ2Effect of Dietary Supplementation with Omega-3 Fatty Acids on Seminal Plasma Arginase Activity and Semen Quality Parameters in Rainbow Trout (Oncorhynchus mykiss Walbaum, 1792)
Kaya, Seyma Ozer; Ozcan, Sinan; Kaya, Emre; Gur, Seyfettin; Koprucu, Kenan; Sonmez, Mustafa; Turk, Gaffari; Erisir, Mine
Background: This study was conducted to determine the effect of various fatty acid ratios added to diets of rainbow trout (Oncorhynchus mykiss, Walbaum) on some sperm parameters and parameters related to arginase activity. Methods: A total of 99 male rainbow trout were used in this study, with the fish averaging 3 years old. Semen was collected by abdominal massage. Four different experimental groups were created in the study: a control group without n-3 series fatty acids added to their diets, and groups with n-3 series fatty acids added at ratios of 1% (D1), 2% (D2), and 3% (D3), respectively. Results: While no significant difference in semen volume was observed between the D1 and D3 groups and the control group, semen volume was significantly higher in the D2 group. Compared with the control group, the time required for sperm motility to decline to both 50% and 0% was significantly prolonged in the D1 and D3 groups. Seminal plasma arginase activity did not differ significantly in the D2 and D3 groups compared with the control group but was significantly higher in the D1 group. Conclusions: Consequently, considering the doses used in the study, fatty acid supplementation was found to lead to changes in sperm quality parameters, specifically volume (only 2%) and arginase activity (only 1%). Given that the rate of decrease in sperm motility was later in groups D1 and D2, it was concluded that the added fatty acids may be beneficial.
- MakaleAçık Erişim2026Scopus SJRQ2Effects of fenugreek and shatavari on vasomotor and hormonal balance in ovariectomized rats
Erten, Füsun; Er, Beşir; Orhan, Cemal; Morde, Abhijeet A.; Padigaru, Muralidhara; Şahin, Kazim
Trigonella foenum-graecum L. (fenugreek, TFG) and Asparagus racemosus Willd. (shatavari, AR) have been extensively used in Ayurvedic, Unani, and traditional folk medicine to support women’s health. TFG seeds are traditionally employed as galactagogues and hormonal modulators, while AR roots are valued as rejuvenating tonics with phytoestrogenic activity, prescribed for menopausal complaints and reproductive well-being. Both plants also exhibit antioxidant and hepatoprotective effects, suggesting their potential as safe, nonhormonal alternatives to conventional hormone replacement therapy. This study investigated the dose-dependent effects of TFG and AR, administered individually or in combination, on vasomotor symptoms, hormonal balance, oxidative stress, and neuroendocrine markers in an ovariectomized (OVX) rat model of menopause. Adult female rats underwent bilateral ovariectomy and were randomized into eight groups: Control, OVX, OVX+TFG (30 and 60 mg/kg), OVX+AR (30 and 60 mg/kg), and OVX+TFG/AR combinations. Treatments were administered orally for 8 days. Tail, core, and skin temperatures were recorded to assess thermoregulation, while blood and tissue samples were analyzed for hormone levels, oxidative stress, and molecular markers. OVX rats showed classical menopausal alterations, including increased follicle-stimulating hormone, luteinizing hormone, cortisol, and malondialdehyde, and decreased 17β-estradiol, progesterone, dopamine, and antioxidant enzymes, along with dysregulated neuroendocrine markers. All treatments partially reversed these changes, while the high-dose combination (TFG/AR 60 mg/kg each) demonstrated the most pronounced effects, normalizing hormone levels, reducing hot-flash-like temperature fluctuations, restoring antioxidant activity, downregulating neuroendocrine markers (c-FOS, GnRH, Kisspeptin, NKB, and TRPV1) expression, and elevating brain-derived neurotrophic factor levels (p < 0.05). High-dose combined supplementation of TFG and AR effectively alleviates vasomotor disturbances, restores hormonal and oxidative balance, and modulates neuroendocrine pathways in OVX rats. These findings validate their traditional use and highlight their potential as safe phytoestrogen-based, nonhormonal alternatives for the management of menopausal symptoms, warranting further clinical evaluation.
- MakaleAçık Erişim2026Scopus SJRQ2Water extracts of Fucus vesiculosus and Laminaria digitata enhance male reproductive parameters via antioxidant and NO/cGMP mechanisms in rats
Gencoglu, Hasan; Erten, Fusun; Er, Besir; Orhan, Cemal; Acisu, Tutku Can; Sahin, Kazim
Male sexual dysfunction is increasingly prevalent, driving interest in marine algal bioactives as potential natural modulators of reproductive physiology. Brown seaweeds such as Fucus vesiculosus and Laminaria digitata contain phlorotannins, fucoidans, and antioxidant compounds of applied relevance in phycology and biotechnology. This study assessed the effects of standardized water extracts of these two species on reproductive behavior, hormonal status, sperm quality, oxidative balance, and nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling in male Sprague–Dawley rats. Animals received the seaweed extracts orally by gavage (300 mg kg⁻1 day⁻1) for 52 days. Both extracts improved male reproductive behavior by reducing the time required to initiate mounting, intromission, and ejaculation (mount latency, intromission latency, and ejaculation latency), while increasing the number of these sexual behaviors during the test period (p < 0.05). Serum follicle-stimulating hormone and testosterone concentrations increased, alongside higher testicular superoxide dismutase, catalase, and glutathione peroxidase activities and lower malondialdehyde levels. Sperm count and motility improved, particularly with L. digitata extract. Western blot analyses revealed phosphorylated phosphodiesterase-5, endothelial NO synthase, and cGMP levels, with reduced endothelin-1 in testicular and epididymal tissues (p < 0.05–0.001). These findings indicate that extracts of F. vesiculosus and L. digitata, chosen for their well-documented antioxidant and phlorotannin-rich profiles, confer protective and prosexual effects associated with enhanced antioxidant defense and upregulation of NO/cGMP-related pathways, with the L. digitata extract exhibiting comparatively stronger activity.
- MakaleYalnız künye2026Scopus SJRQ3A multi-parametric unit distribution via Bernstein polynomials
Susam, Selim Orhun
This study develops the method of constructing a multi-parametric distribution on the unit interval using Bernstein polynomials and investigates its key statistical properties. The performance of the proposed distribution’s parameter estimators was evaluated by Monte Carlo simulation under both maximum-likelihood (MLE) and minimum-distance frameworks, with the MLE approach generally yielding lower estimation error. A real data example illustrates the advantages of the construction method. The results reveal that the Bernstein distribution provides superior goodness-of-fit to the dataset compared with competing models.
- MakaleAçık Erişim2026Scopus SJRQ4Comparison of the Performance of Machine Learning Methods with Intuitionistic Fuzzy Decision Making for Effective Fake News Detection
Tuğrul, Feride
In this paper, the success of machine learning models applied to two datasets consisting of fake news was examined. The performance of these methods was measured using Accuracy, Precision, Recall, and F1-Score. Evaluation metrics for all models were calculated using TF-IDF and N-gram TF-IDF for Dataset 1 and Dataset 2, respectively. In continuation of the study, a decision-making mechanism was created to measure the success of machine learning methods. The success of these models was compared by creating a decision-making mechanism using intuitionistic fuzzy sets. The PROMETHEE method was used here. In the first stage of the study, the dataset samples evaluated were expressed using classical sets, while in the second stage, the success of the models according to the metrics was expressed using intuitionistic fuzzy values. This was to minimize the uncertainty in the model success results. The results obtained in the first stage of the study were evaluated in the second stage using a decision-making mechanism. In this mechanism, machine learning models represent the alternatives, while classification metrics represent the criteria. When evaluating machine learning models, experts provide subjective opinions based on each classification metric to determine the successful model.
- MakaleAçık Erişim2026Scopus SJRQ2Examination of the thermal and metallographic characteristics at high temperatures of natural stones (andesite) extracted from different elevations
Işık, Erdem; Kahraman, Gökhan; Atalar, Aydın
This study examines the high‑temperature thermal response of andesite stones extracted from two different elevations of Mount Ağrı (Türkiye) in order to improve material selection strategies for engineering applications. Thermal conductivity and density values of the samples were first measured under laboratory conditions. The specimens were then heated to 850 °C and cooled by natural convection while surface temperatures were recorded at fixed time intervals using a thermal camera. Based on these measurements, convective heat transfer coefficients were determined, and the time‑dependent thermal diffusivity and Biot numbers were subsequently calculated using the first-term approximation of the Fourier series. Metallographic examinations were conducted to correlate the thermal behavior with microstructural characteristics. Results indicate a pronounced effect of elevation on thermal performance. The sample obtained from the higher elevation exhibited substantially greater thermal diffusivity, reaching 2.93 × 10⁻5 m2 s−1 at 360 s and decreasing to 8.96 × 10⁻6 m2 s−1 at 1300 s. In contrast, the lower‑elevation andesite showed lower diffusivity values (1.83 × 10⁻5 m2 s−1 at 360 s and 5.9 × 10⁻6 m2 s−1 at 1300 s). Conversely, Biot numbers were consistently higher for the lower‑elevation sample, decreasing from 0.60 to 0.29 during the cooling process, whereas the high‑elevation sample displayed values from 0.314 to 0.165. Metallographic analysis confirmed that variations in microstructure—linked to different geological formation conditions—directly influenced these thermophysical properties. Overall, the findings demonstrate that andesite sourced at higher elevations possesses superior thermal diffusivity and more favorable heat‑transfer characteristics at elevated temperatures. These results highlight the importance of geological origin in the design, assessment, and selection of natural stone materials for high‑temperature engineering applications.
- MakaleAçık Erişim2026Scopus SJRQ1Effects of sulfuring, drying and storage on the formation of α-dicarbonyl compounds and 5-hydroxymethylfurfural in dried apricots
Aktağ, Işıl Gürsul; Cömert, Ezgi Doğan; Gökmen, Vural
This study investigated the impact of sulfuring, various drying methods, and storage with different packaging on the formation of α-dicarbonyl compounds and 5-hydroxymethylfurfural in dried apricots. Changes in the concentrations of α-dicarbonyl compounds, 5-hydroxymethylfurfural, sugars, and color were monitored in the samples (sulfured/non-sulfured, oven-/sun-dried, polyethylene/vacuum/modified atmosphere packaging) during storage at room temperature for 12 months. Among α-dicarbonyl compounds, 3-deoxyglucosone was the most prevalent, reaching 1356.8 ± 70.6 mg/kg dry matter in sulfured oven-dried apricots after drying. Methylglyoxal reached its peak at 723.2 ± 9.9 mg/kg dry matter in sulfured sun-dried apricots after storage. 5-Hydroxymethylfurfural remained at significantly lower levels than the dominant α-dicarbonyl compounds. Both α-dicarbonyl compounds and 5-hydroxymethylfurfural increased significantly during storage, irrespective of packaging, while sulfuring influenced the type of α-dicarbonyl compounds formed. These findings underscore the significance of processing and storage in influencing α-dicarbonyl compounds accumulation, providing valuable insights into maintaining the safety and quality of dried apricots.
AtıfScopus2WoS2OpenAlex2
İncele - MakaleYalnız künye2026Scopus SJRQ2Structural evolution and radiation shielding performance of nano-HfO2 doped lithium borotellurite glasses
Durmus, Hasan; Kilic, G.; Ilik, E.; Kavaz, E.; Güler, Ömer; Birdogan, Selcuk; ALMisned, Ghada; Tekin, H.O.
This study investigates the structural evolution and radiation shielding performance of lithium borotellurite glasses reinforced with nano-sized HfO2. We report on the competitive dynamics between the depolymerizing nature of the Li + network modifier and the high field strength Hf4+ nano-dopant, a relationship not previously explored in this matrix. Structural analysis via XRD and TEM reveals that the glass remains fully amorphous with homogeneously dispersed Hf rich nanodomains up to 4 mol%. A critical solubility threshold is identified at 6 mol%, where the precipitation of HfO2 and HfTe3O8 crystalline phases marks a distinct transition from an amorphous state to a glass-ceramic microstructure. Physical property measurements indicate that Hf4+ ions primarily occupy interstitial free volumes, leading to enhanced material density without significant network dilation. The incorporation of nano-HfO2 significantly augments gamma-ray attenuation efficiency, particularly in the low-energy region, by substantially increasing the effective atomic number and reducing the half value layer. Furthermore, the glasses exhibit robust fast-neutron shielding capabilities, outperforming conventional materials such as graphite and B4C. These findings establish nano-HfO2 as a potent structural and radiative modifier, providing a novel roadmap for designing high-density, multifunctional glass-ceramic shields for advanced nuclear applications.
AtıfScopus1OpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ1Large-eddy simulation of flow over a square prism with moving belts
You, Rui; Fırat, Erhan
This three-dimensional (3D) numerical study investigates the feasibility of controlling the intermittently reattaching flow (IRF) by using the moving-surface boundary-layer control (MSBC) method. To this end, a fixed square prism was preferred due to its geometric simplicity and was equipped with moving belts that placed side surfaces close to the trailing edges. The effects of three dimensionless key parameters including velocity ratio (i.e., VR, the ratio of the velocity of the moving belt to the freestream velocity), length ratio (i.e., LR, the ratio of the belt length to the edge length of the square prism), and gap ratio (i.e., GR, the ratio of the spanwise distance between the neighboring belts to the edge length of the square prism) mainly on the aerodynamic characteristics were investigated using large-eddy simulation (LES). The findings suggest that the rise in VR and LR parameters leads to a proportional decrease in the time-averaged drag, 〈CD〉, attributable to their contribution to the linear momentum transfer mechanism by the moving surfaces. This mechanism, firstly, provides an additional thrust to the prism in the opposite direction of the main flow. Secondly, this mechanism increases the base pressure by stretching the shear layers from the leading edges of the prism in the streamwise direction. For LR = 0.4 and VR = 4, a 17 % reduction in 〈CD〉 was observed. Additionally, the root-mean-square (RMS) values of fluctuating drag and lift coefficients, CD-RMS and CL-RMS, have decreased by 71 % and 55 %, respectively. Conversely, the increase in the GR parameter led to an increase in the spanwise distance between each individual moving belt and a reduction in the positive effect of the linear momentum transfer mechanism on the 〈CD〉 reduction. The segmentation of moving belts along the spanwise direction also triggered the vorticity redistribution mechanism concurrently. The study also elucidated the underlying mechanisms that led to the failure of the vorticity redistribution mechanism to adequately reduce the 〈CD〉.
- MakaleAçık Erişim2026Scopus SJRQ3Optimized bioleaching of spent FCC catalysts for the recovery of critical metals
Erust, Ceren; Altındaş, Mediha Demet Okudan
Spent fluid catalytic cracking (FCC) catalysts, generated in large volumes by petroleum refining, represent a promising secondary source of critical metals such as lanthanum, cerium, titanium, and vanadium. In this study, a biohydrometallurgical approach was applied to recover these metals using Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans. The spent FCC catalyst, supplied by petroleum refinery, was characterized through WD-XRF, XRD, SEM-EDS, and ICP-OES analyses, confirming significant concentrations of La2O3 (1.44%), TiO2 (1.43%), and CeO2 (0.23%). Bioleaching experiments were conducted under varying initial ferrous ion concentrations (1–9 g/L) and pulp densities (5–20% w/v) at 35°C over 14 days. Results revealed that the optimal conditions for maximum recovery occurred at 5 g/L Fe2+ and 10% pulp density, achieving leaching efficiencies of 95.5% for La, 90.5% for Ce, 92.5% for Ti, and 60.8% for V within seven days. Beyond this period, efficiency decreased due to jarosite formation and microbial activity constraints. The findings confirm that bioleaching is a cost-effective and sustainable route that aligns with circular economy principles by reducing reliance on virgin rare earth mining while mitigating the environmental impact of catalyst disposal.
- MakaleYayıncıda açık erişim2026Scopus SJRQ2Sperm cryopreservation of sex-reversed rainbow trout (Oncorhynchus mykiss): incorporation of amino acids and anti-oxidants to the extender media to improve the anti-oxidant system
Kocabaş, Filiz Kutluyer; Kocabaş, Mehmet; Benzer, Fulya; Erişir, Mine
Anti-oxidants are vital for protecting sperm and can mitigate the negative effects associated with cryopreservation. This study was conducted to evaluate the protective effects of adding anti-oxidants (vitamins and amino acids) to extender in sex-reversed rainbow trout (Oncorhynchus mykiss) sperm. The collected sperm was diluted at the ratio of 1: 5 by the extenders supplemented with different anti-oxidants including 1.00 mM of ascorbic acid and L-tryptophan, 2.00 mM of cysteine and α-tocopherol, and their combination. After dilution, the semen was aspirated into 0.50 mL straws, and the straws were placed on the tray, frozen for 10 min, and plunged into liquid nitrogen. Straws were thawed in a 30.00 ˚C water bath for 15 sec. The Sperm Class Analyzer System was used to evaluate sperm kinematics. The activity of anti-oxidant enzymes and lipid peroxidation were determined as oxidative stress indices. Our data indicated that the incorporation of anti-oxidants and amino acids increased sperm motility duration. The elevated activity of glutathione peroxidase, superoxide dismutase, and catalase in post-thaw samples indicates that the anti-oxidant system in sex-reversed rainbow trout sperm likely plays a crucial role in protecting membrane compounds from oxidation. In conclusion, the combination of 1.00 mM L-tryptophan and ascorbic acid to the extender media caused a prolonging effect in sperm motility after thawing and they have the potential to serve as effective agents for improving sperm cryosurvival.
- MakaleYalnız künye2026Scopus SJRQ1Enhancing waiting time performance of clinical laboratories for pregnant patients with seasonal respiratory diseases: a simulation-based Lean Six Sigma approach
Ortíz-Barrios, Miguel; Celani de Souza, Helder Jose; Petrillo, Antonella; Gul, Muhammet; Yücesan, Melih; Navarro-Jiménez, Eduardo; Alfaro-Saíz, Juan-José; Ariza-Ortíz, Andrés
Purpose – Clinical laboratory performance is critical in managing seasonal respiratory diseases (SRDs); however, prolonged waiting times can lead to patient dissatisfaction and nonquality costs. This challenge is particularly acute for pregnant patients, who face increased health risks from diagnostic delays. This study aims to improve waiting times before sample collection in clinical laboratories serving pregnant patients with SRDs by integrating Lean Six Sigma (LSS) and Discrete-Event Simulation (DES). Design/methodology/approach – The proposed framework was validated in a public clinical laboratory using the DMAIC (Define–Measure–Analyze–Improve–Control) methodology. DES was embedded within the Analyze and Improve phases to model patient flow and assess improvement scenarios before implementation. Findings – The integrated LSS–DES approach resulted in a significant reduction in waiting times. During SRD peak periods, waiting time before sample collection for pregnant patients decreased from 1.01 to 0.10 h per patient. These results demonstrate the framework's effectiveness and practical usefulness for decision-makers seeking performance improvements in resource-constrained healthcare environments. Originality/value – This study enhances existing literature by integrating LSS and DES to address laboratory performance challenges associated with SRDs. The combined LSS-DES used for pregnant patients during outbreak periods is novel. The study offers contextual innovation for a vulnerable population, methodological advancement through embedding DES within the DMAIC cycle, and practical laboratory validation. The framework is particularly valuable for low- and middle-income countries (LMICs), where scalable solutions are essential.
- MakaleAçık Erişim2026Scopus SJRQ1Change in phase stability and transformation kinetics of NiTiCuW alloy after heat treatment at 650–850 °C
Tatar, Cengiz; Kök, Mediha; Kanca, M. Sait
In this study, the effects of different heat treatment temperatures (650 °C, 750 °C, and 850 °C) on the phase transformation behavior, microstructure, thermodynamic parameters, and microhardness of the NiTiCuW alloy, produced by adding tungsten (W) to the NiTiCu shape memory alloy, were investigated. The crystal structure change was determined by X-ray diffraction (XRD), the transformation temperatures were determined by differential scanning calorimetry (DSC), the microstructure was examined by scanning electron microscopy (SEM), and the mechanical properties were evaluated by Vickers microhardness measurements. XRD results showed that the reference and 850 °C samples were predominantly in the B2 (austenite) phase at room temperature, while martensitic phases (B19/B19′) became prominent at 650 °C and 750 °C. DSC analyses revealed that the transformation peaks became sharper at 650 °C and the R-phase transformation could be observed; at 750 °C, the peaks broadened, indicating a decrease in transformation stability. The austenite finish temperature (Af) increased from 2.1 °C (reference) to 52.9 °C at 650 °C and 60.3 °C at 750 °C, while it remained low (4.5 °C) at 850 °C. Thermodynamic evaluations showed that ΔS increased at 650 °C (0.053 J/g K) and decreased at 750–850 °C (≈0.032 J/g K). Microhardness reached its maximum value at 650 °C (398 Hv), decreased at 750 °C (271 Hv), and showed an upward trend again at 850 °C (351 Hv), compared to the reference value (243 Hv). These results indicate that the heat treatment temperature critically determines the functional and mechanical performance of the NiTiCuW alloy.
- MakaleAçık Erişim2026Scopus SJRQ2Occurrence of Antimicrobial Resistance in Kocuria rhizophila Bacteria Isolated From Salmo munzuricus (Teleostei: Salmonidae) Samples in Natural Resources
Kar, Bülent
Global warming and environmental pollution trigger the emergence of antimicrobial-resistant (AMR) opportunistic pathogens in the aquatic microflora. This study aimed to determine the characterization and AMR profile of the opportunistic pathogen Kocuria rhizophila isolated from the tissues of Salmo munzuricus (Munzur trout), an endemic species. Samples collected from the Munzur River were identified using morphological and molecular (16S rDNA) methods; bacterial isolates were characterized by MALDI-TOF and sequencing. The resistance status against 11 different antibiotics was analyzed with the Kirby-Bauer method. The findings revealed that the isolates (with 99.51% accuracy as K. rhizophila) showed full resistance to Penicillin G (p < 0.01) and were moderately sensitive to gentamicin and tetracycline. High sensitivity to amoxicillin and ampicillin was detected. These findings demonstrate that even in natural environments, the fish microbiome in wild endemic populations can be susceptible to the development of AMR in response to environmental changes. Therefore, determining the resistance of opportunistic pathogens in wild fish species such as Salmo munzuricus to different classes of antibiotics and studying their spread is extremely important for natural ecosystems.
