Karamanoğlu Mehmetbey University
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Rational design of ZnO/SrTiO3 S-scheme heterojunction for photo-enhanced piezocatalytic hydrogen production
No full textPhotopiezocatalysis have been frequently investigated for hydrogen evolution reactions in recent years. Herein, ZnO, SrTiO3 and ZnO/SrTiO3 S-scheme heterojunction were investigated for photo/piezocatalytic hydrogen production. Piezocatalytic hydrogen production under ultrasonic vibration by using ZnO, SrTiO3 and ZnO/SrTiO3 was obtained as 270 mu mol g(-1)h(-1), 200 mu mol g(-1)h(-1) and 1265 mu mol g(-1)h(-1), respectively. In addition, ZnO/SrTiO3 S-scheme heterojunction showed 2200 mu mol g(-1)h(-1) photopiezocatalytic hydrogen production under simultaneous exposure to white LED light and ultrasonic sound. ZnO/SrTiO3 heterojunction displayed significantly higher hydrogen production rate due to the decreased charge recombination, increased charge transfer with strong piezoelectric polarization and internal electrical field. The piezoelectric effect of ZnO/SrTiO3 heterojunction is also confirmed by piezoresponse force microscope technique with butterfly and phase hysteresis loops. Also, piezoelectric coefficient of ZnO/SrTiO3 found about 2-folds higher than those of their pristine forms. Electron transfer and reaction mechanism of ZnO/SrTiO3 and activity differences are confirmed by advanced optical and electrochemical techniques such as diffuse reflectance spectroscopy, electronic impedance spectroscopy, Mott-Schottky calculation and chronoamperometry. The whole electrochemical measurements have been performed with or without mechanical stress and light irradiation, which signify their band bending properties, electron transfer mechanism and catalytic activities.Selcuk University Scientific Research Projects (BAP)The authors would like to thank Selcuk University Scientific Research Projects (BAP)
Investigation on tribo-properties of twaron pulp-reinforced brake friction composites
No full textDetermining the appropriate formulation in designing and developing brake friction materials is one of the most complex tasks. This study investigates the synergistic effect and optimization of twaron fiber on the fade and recovery performance of brake friction composites. For this purpose, a series of friction materials containing varying amounts of twaron between 1 and 9 wt% were developed, and their characterization and tribo evaluation were carried out. The tribo performance of the composites was evaluated in a Krauss-type friction test machine in line with the ECE R90 procedure in terms of their fade and recovery behaviors. It was noted that the fade-recovery friction response of composites was affected when fiber is added; that is, an increase in fiber content improved the fade performance, friction fluctuations decreased, and a higher recovery response was observed. The fade and average coefficient of friction were found to be the main determinants, while recovery was found to be the stabilizer. Analytical hierarchy process (AHP) was used to determine the priority of importance of criteria in the performance evaluation, and VIKOR (multi-criteria optimization compromise solution) was used for ranking evaluation. The formulation with a concentration of twaron 7 wt% was found to have exhibited an optimal braking performance. The worn surfaces scanning electron microscope (SEM) study confirms the general friction and wear mechanisms of friction layers with fiber content.Highlights Development of twaron pulp-reinforced eco-friendly brake friction composites. Use of MCDM approach in the development of BFCs for braking applications. VIKOR optimization positioned 7 wt% twaron-addition BFC as the optimal choice. It was observed that fiber amount is effective on the behaviors of composites
An efficient binary harris hawks optimization based on logical operators for wind turbine layout according to various wind scenarios
No full textNowadays, with the demand for renewable energy the interest in wind energy is increasing day by day and the use of wind turbines is becoming widespread. In order to efficiently generate electricity from wind turbines, it is important that the turbines are correctly positioned on wind farms. In this study, a standard wind farm area of 2 km × 2 km was used for wind turbine layout. In addition, different from the literature, a 4 km × 4 km wind farm area was also created. Both wind farming areas were divided into 10 × 10 and 20 × 20 grids as in the literature. In addition, 25 × 25, 40 × 40 and 50 × 50 grids were also created. Thus, the wind farming area is divided into more grids and more flexible positioning of the turbines is aimed. There are three different case scenarios for the layout of the wind turbines. Case A has a constant wind speed of 12 m/s and unidirectional wind, while Case B has a constant wind speed of 12 m/s with a 36-directional 10° angle. Case C has variable wind speeds of 8, 12 and 17 m/s with a 36-directional 10° angle. The HHO algorithm was used to perform all these processes. However, since the wind turbine layout problem is binary, the HHO algorithm is adapted to binary with logic operators. These binary methods are called HHOAND and HHOXOR. The proposed methods achieved competitive results compared to other algorithms in the literature and performed well for all grid structures. Thus, it can be said that the proposed methods are effective for the wind turbine layout problem. © 2025 The Author(s
Microbiome modulation as a novel therapeutic modality for anxiety disorders: a review of clinical trials
No full textAnxiety disorders are one of the major conditions in psychiatry characterized by symptoms such as worry, social and performance fears, unexpected and/or triggered panic attacks, anticipatory anxiety, and avoidance behaviors. Recent developments have drawn attention to the putative involvement of peripheral systems in the control of anxiety, and the gut microbiota has come to light as an emerging peripheral target for anxiety. The relationship between the gut-brain axis, a bidirectional communication network between the central nervous system (CNS) and enteric nervous system (ENS), and anxiety has been the subject of some recent studies. Therefore, this systematic review analyzed clinical trials evaluating the potential of microbiome modulation methods in mitigating and ameliorating anxiety disorders. Clinical studies on probiotic, prebiotic, synbiotic supplements, dietary interventions, and fecal microbiota transplantation in anxiety disorders were screened. All of the studies examined the effects of probiotic intervention. One of these studies compared a prebiotic-rich diet with probiotic supplementation. Longitudinal analyses showed that the probiotic intervention alleviated anxiety. However, most of the controlled studies reported that the probiotic intervention did not make a difference compared to placebo. Thus, the current findings suggest that it is too early to consider the promising role of microbiome modulation in the treatment of anxiety disorders. However, it is obvious that more clinical research is needed to clarify issues such as probiotic strains, prebiotic types, and their doses that may be effective on anxiety disorders. © 2025 Elsevier B.V
Prediction of drying kinetics and energy consumption values of purple carrots dried in a temperature-controlled microwave dryer by decision tree, random forest and ada boost approaches
No full textIn the literature have focused on modeling data obtained under drying conditions with different methods and comparing them with each other. However, any studies have been found on estimating the behavior of the same material under different drying conditions. Therefore, a study was conducted to predict the behavior of the same material under different drying conditions. In the study, primarily purple carrot slices were reduced from 6.13 ± 0.05 to 0.14 ± 0.018 g moisture/g dry matter value. Among the models, the drying rates were best estimated by the Midilli-Küçük (R2: 0.9993) model. The lowest energy consumption was determined as 0.285 kWh in the drying process at 70 °C. Estimation of intermediate values is very useful because experimental studies can be length and expensive. Sometimes, even if cost is not a concern, long-term experimental studies and the high number of experiment repetitions increase the importance of estimation methods for researchers. The decision tree, random forest and ada boost methods, which are fast operating methods, were used as estimation methods in this study. MAPE and R2 success values are expressed for all three methods. The Decision Tree method was found to be the most successful technique with the highest R2 value (0.96) and the lowest MAPE value (0.03). © 2025 Elsevier B.V
Metal catalyst-free ?-amination of branched rac-C 8 N-type such as C7N carbasugars via intramolecular aza-michael addition: Biological evolution, DFT studies and ADME properties
No full textIn this study, a new stereospecific strategy for the preparation of C8N aminocyclohexenols such as C7N, validamine analogs were developed from starting compound 4 via intramolecular aza-michael /3-amination reaction between alpha, /3-unsaturated ketones and ammonia in methanol. The strategy was to produce C8N derivatives such as validamine C7N via Kornblum-DeLaMare rearrangement, which involves stereocontrolled amination of a double bond, esterification, carbonyl group reduction, benzofuran ring opening, ammonolysis of acetate groups. The mechanism of target molecules is discussed. Pseudosugars with different configurations containing an amino group at the anomeric position were tested against alpha-glucosidase, /3-glucosidase, and alpha-amylase. Among these compounds, compound 12 against alpha-glucosidase, compound 14 against /3-glucosidase, and compound 21 against alpha-amylase exhibited the best activity compared to acarbose. Moreover, enzyme kinetic studies to understand the enzyme inhibition mechanism and DFT studies to investigate binding interactions with enzyme active sites were performed on these compounds (12, 14 , and 21 ). Additionally, the pharmacokinetic parameters (ADME) were examined using the QikProp module to determine their potential as drug candidates.Scientific and Technological Research Council of Turkey (TUBITAK) [217Z043, 115Z446]; Departments of Chemistry at Sakarya UniversityFinancial support for this work was provided by the Scientific and Technological Research Council of Turkey (TUBITAK, Grant Nos. 217Z043 and 115Z446) , the Departments of Chemistry at Sakarya University. We also thank Dr. Onur Sahin for X-ray crystallographic analysis assistance at Scientific and Technological Research Application and Research Center Sinop University. The authors are also grateful for using TUBITAK-ULAKBIM, High Performance and Grid Computing Center resources. Finally, the authors dedicate this paper to Professor Metin Balci on the occasion of his 75th birthday
Recurrent hepatocellular carcinoma is associated with the enrichment of MYC targets gene sets, elevated high confidence deleterious mutations and alternative splicing of DDB2 and BRCA1 transcripts
No full textPurpose: Recurrence is the main cause of hepatocellular carcinoma (HCC) related deaths. Underlying recurrence biology can be better understood by comparative analysis of the complete set of transcripts between recurrent and non-recurrent HCC. In this study, transcriptomic data (GSE56545) from 21 male patients diagnosed with either recurrent or non-recurrent HCC were reanalyzed to identify deregulated pathways, somatic mutations, fusion transcripts, alternative splicing events, and the immune context in recurrent HCC. Materials and methods: DESeq2 was used for differential expression analysis, Mutect2 for somatic mutation analysis, Arriba and STAR-Fusion for fusion transcript analysis, and rMATs for alternative splicing analysis. Results: The results revealed that MYC targets gene sets (Hallmark_MYC_targets_V1 and Hallmark_MYC_targets_V2) were significantly enriched in recurrent HCC. Among the MYC targets, CBX3, NOP56, CDK4, NPM1, MCM5, MCM4 and PA2G4 upregulation was significantly associated with poor survival. Somatic mutation analysis demonstrated that the numbers of high confidence deleterious mutations were significantly increased in recurrent HCC. Alternative splicing-mediated production of non-functional DDB2 and oncogenic BRCA1 D11q were discovered in recurrent HCC. Finally, CD8+ T-cells were significantly decreased in recurrent HCC. Conclusions: These results indicated that the enrichment of MYC targets gene sets is one of the most critical factors that leads to the development of recurrent HCC. In addition, elevated deleterious mutation numbers and alternative spliced DDB2 and BRCA1 isoforms have been identified as prominent contributors to increasing genomic instability in male patients with recurrent HCC
Quality changes in chicken meat marinated with antioxidant-rich fruit and vegetable juices
No full textThis study investigated the effects of marination with antioxidant-rich fruit juices-pomegranate, black carrot, and red beet-on the textural, physicochemical, technological, and sensory properties of chicken breast meat. Key parameters, including color, pH, water-holding capacity (WHC), marinade absorption, cooking loss (CL), textural properties, TBARS (thiobarbituric acid reactive substances), and sensory attributes, were evaluated. Among the tested juices, pomegranate had the highest acidity. Black carrot contained the highest total phenolic content (TPC) but showed the lowest ABTS and DPPH radical scavenging activity (p 0.05). CL values were significantly reduced in marinated samples (p 0.05). Sensory evaluation revealed no significant differences in flavor and texture, although color was notably influenced by the marination process (p < 0.05). Control and RB gave the highest values in terms of general acceptability. These findings suggest that marination with pomegranate, black carrot, and red beet juices may contribute to improving antioxidative properties and improve the textural quality of chicken breast meat
Constraints on the higgs boson self-coupling from the combination of single and double higgs boson production in proton-proton collisions at √s=13 tev
No full textThe Higgs boson (H) trilinear self-coupling, lambda(3), is constrained via its measured properties and limits on the HH pair production using the proton-proton collision data collected by the CMS experiment at root s = 13 TeV. The combination of event categories enriched in single-H and HH events is used to measure k(lambda), defined as the value of lambda(3) normalized to its standard model prediction, while simultaneously constraining the Higgs boson couplings to fermions and vector bosons. Values of k(lambda) outside the interval -1.2 < k(lambda) < 7.5 are excluded at 2 sigma confidence level, which is compatible with the expected range of -2.0< k(lambda) < 7.7 under the assumption that all other Higgs boson couplings are equal to their standard model predicted values. Relaxing the assumption on the Higgs couplings to fermions and vector bosons the observed (expected) k(lambda) interval is constrained to be within -1.4 < k(lambda) < 7.8 (-2.3 < k(lambda) < 7.8) at 2 sigma confidence level
Elastic and acoustic properties determination of epoxy/polystyrene/nanoclay/red mud waste hybrid composites by ultrasonic method
No full textUltrasonic methods are more sensitive to defects such as voids, pores, and discontinuities that can diminish the true elastic and acoustic properties of materials compared to destructive testing. Therefore, the elastic properties and some acoustic properties of the epoxy phenol novolac modified with polystyrene (EPN-PS) matrix-based nano- and hybrid composites were determined for the first time using ultrasonic method. Montmorillonite-type nanoclay (NC) and industrial red mud waste (RMW) at a rate of 1–4 and 15–35 wt% respectively, were used as fillers in the composite preparation. According to the results, the highest elastic coefficient values (L = 8.14 GPa, G = 1.76 GPa, K = 5.79 GPa and E = 4.80 GPa) were obtained in the EPN-PS/NC1 (with 1 wt% NC) nanocomposite sample compared to the elastic properties of pure EPN and EPN-PS, while the highest elastic coefficient values (L = 8.97 GPa, G = 2.19 GPa, K = 6.06 GPa, and E = 5.86 GPa) among hybrid composites (HC) were obtained for the HC35 containing 2 wt. % NC and 35 wt% RMW. Due to both its high elastic and good acoustic properties, wall panels and floors produced using HC35 hybrid composite can be used for sound insulation in noisy environments. Highlights: First evaluation of the acoustic characteristics of epoxy phenol novolac modified with polystyrene-nanoclay/red mud waste (EPN-PS-NC/RMW) composites. NC4 with 4 wt% nanoclay showed the lowest elastic and acoustic properties. Nanoclay ratio above 1 wt% reduces elastic and acoustic properties. The increasing RMW ratio in hybrid composites increases elastic properties. High elastic and acoustic properties make HC35 ideal for sound insulation. © 2024 The Author(s). Polymer Composites published by Wiley Periodicals LLC on behalf of Society of Plastics Engineers.Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, TÜBİTA