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Assessment of the solid particle erosion resistance, microstructure and failure mechanism of calcia, magnesia, and yttria-stabilized zirconia thermal barrier coatings
No full textIn thermal barrier coatings (TBCs), different stabilizing compositions are preferred to increase the strength and optimize the thermal expansion coefficient of zirconia-based ceramic top coatings. In this study, TBC systems containing ZrO2-CaO (CSZ), ZrO2-MgO (MSZ) and ZrO2-Y2O3 (YSZ) were produced by atmospheric plasma spraying (APS) method and solid particle erosion (SPE) tests were performed at 30 degrees, 60 degrees and 90 degrees impact angles in accordance with ASTM G76-95 standard. In tests using alumina powders, it was determined that erosion behavior is closely related to microstructural properties and mechanical strength. At low angles (30 degrees-60 degrees), the sliding of particles along the surface led to stress accumulation at lamellar boundaries, microcracks and especially in interconnected pores, which increased the wear. In addition, low hardness and high surface roughness reinforced this effect. In contrast, YSZ coatings exhibited the lowest wear rate at 90 degrees impact angle due to their higher hardness, low interconnected pore content and uniform surface morphology. The results revealed that microstructural integrity and mechanical properties play a decisive role in the erosion resistance of TBC systems.Sakarya niversitesi [2021-FEN-A-009]; Scientific Research Projects (BAP) Coordinatorship of Bartin UniversityWe greatly appreciate the support of The Scientific Research Projects (BAP) Coordinatorship of Bartin University with project number of 2021-FEN-A-009
Research on Genotoxicity Evaluation of the Fungal Alpha-Amylase Enzyme on Drosophila melanogaster
No full textAlpha-amylase is an extracellular enzyme abundantly produced from fungal sources. The catalytic activity of microbial enzymes is higher, more stable, and economical compared to plant and animal enzymes; they can be produced in large quantities in a short time and do not produce unwanted by-products. In this study, the genotoxic effect of different concentrations (25 mg/mL, 50 mg/mL, and 100 mg/mL) of a native fungal thermostable alpha-amylase enzyme, produced from the Aspergillus niger G2-1 isolate with an enzyme activity of 38.6 U/mg, was investigated on the Drosophila melanogaster model organism. The effect of the alpha-amylase enzyme added to the culture medium on the developmental performance of D. melanogaster was assessed through larval toxicity analysis, its effect on DNA damage through the comet assay, and its response to oxidative stress through various biochemical parameters. As a result, it was determined that low-dose alpha-amylase enzyme concentration (25 mg/mL) did not cause intracellular oxidative stress, did not cause genotoxicity, and did not adversely affect growth performance, although feeding with alpha-amylase at 50 mg/mL and 100 mg/mL concentrations caused a significant decrease in the survival rate of D. melanogaster larvae and an increase in DNA damage rate in imagos. However, oxidative stress parameters in adult D. melanogaster did not change after the same alpha-amylase application
The effect of plaster applied to the umbilical area (Shenque-CV8 point) on nausea and vomiting during pregnancy
No full textBackground: : Hormonal and physical changes, especially in the first trimester of pregnancy, can cause nausea and vomiting. Aim: : This study aims to investigate the effect of plaster applied to the umbilical area (Shenque-CV8 point) on nausea and vomiting during pregnancy. Methods: : It is a randomized-controlled study (Clinical trial number: NCT05788796). A total of 60 pregnant women, 30 in the CV8 group and 30 in the control group constituted the sampling of the study. Pregnant women in the CV8 group were regularly asked to fix a hazelnut-sized cotton ball to the umbilicus with plaster before going to bed at night for five days. Pregnant women in the control group were not asked to make any changes in their lives. The nausea-vomiting levels of pregnant women before and five days after the treatment were compared using the Rhodes Nausea Index and PUQE nausea scoring. The data was analyzed by the independent sample t-test, chi-square test, and paired sample t-test. The statistical significance value was accepted as P < 0.05. Results: : There was no statistically significant difference between the experiment and control groups in terms of sociodemographic and obstetric characteristics. The degree of nausea decreased in the experiment group compared to the pre-intervention period (p < 0.001), while no statistically significant change was found in the control group. In addition, while there was no difference between the two groups in terms of nausea scores before the application, there was a statistically significant difference between the two groups after the application, the nausea score of the experimental group was lower compared to the control group (p < 0.05). Conclusion: : The results show that the application of plaster to the Shenque-CV8 point reduces nausea and vomiting in pregnant women and has no side effects. This application is practical, non-invasive, and easy to apply
Light-transmitting wood-based composite comprising microencapsulated phase-change material for sustainable energy applications in buildings
No full textThe study explored an innovative building material that provides both lighting energy savings and thermal comfort by integrating microencapsulated phase change material (mu PCM) into light-transmissive wood-based composite material. The wood-based composite comprises epoxy resin (Er), wood chips (Wc), fibre (Gf), various mu PCM concentrations, and plastic optical grids to transmit light through the plate. The highest thermal conductivity, 0.21 W/mK, was observed for mu PCM0 samples. Differential scanning calorimetry (DSC) analysis presented that a composite containing 100 wt% mu PCM has a melting temperature of 25 degrees C and a latent heat storage of 35.0 J/g. mu PCM100 offered a lower surface temperature approximately 6 degrees C colder when the hot weather hours were taken into account. The wood composites with mu PCM contributed to maintaining lower peak room temperatures and extended temperature stability overnight. While 1.923 km/s UPV was obtained in mu PCM0 samples, the UPV value after 100% mu PCM addition compared to the weight of the old was 1.845 km/s. Compared to the mu PCM0 samples, the Er mu PCMWc samples had a light transmittance rate of almost 64% greater. The study's findings could improve artificial lighting efficiency, significantly lessening indoor temperature fluctuations, enhancing thermal comfort and promoting sustainable building solutions
Novel Schiff Bases: Synthesis, Characterization, Bioactivity, Cytotoxicity, and Computational Evaluations
No full textHypopharyngeal cancer is rare subtype of head and neck cancers with relatively poor prognosis. Current therapeutic modalities lack the potential to provide patients with better clinical outcome and quality of life. This study was conducted on the synthesis of 2-methoxy-4-((3-alkyl(aryl)-5-oxo-1H-1,2,4-triazol-4(5H)-ylimino)-methyl)-phenyl-4-(2-methoxy-4-((3-alkyl(aryl)-5-oxo-1H-1,2,4-triazol-4(5H)-ylimino)-methyl)-phenyl)-4-oxobutanoates (3) using biologically important 1,2,4-triazole. The condensation of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with 4-formyl-2-methoxyphenyl-4-(4-formyl-2-methoxyphenyl)-4-oxobutanoate yielded the biologically active 2-methoxy-4-((3-alkyl(aryl)-5-oxo-1H-1,2,4-triazol-4(5H)-ylimino)-methyl)-phenyl-4-(2-methoxy-4-((3-alkyl(aryl)-5-oxo-1H-1,2,4-triazol-4(5H)-ylimino)-methyl)-phenyl)-4-oxobutanoates (3). The compounds obtained were analyzed via FT-IR,1H-/13C-NMR spectrometers, elemental analysis, and HRMS spectroscopic techniques. Furthermore, we aimed at investigating the potential of compounds 3a-g against FaDu hypopharyngeal cancer cells. We demonstrated that compounds 3c, 3e, and 3 g had relatively lower IC50 values compared to the remaining tested compounds and more importantly their IC50 values were comparable to 5-FU, which suggests them as important therapeutic agent candidates. These newly synthesized compounds were assessed for their inhibitory activities toward two human carbonic anhydrase isoforms I and II (hCA I and II). Then, molecular docking calculations were made to compare the biological activities of studied molecules against cancer proteins. Compound 3c has a docking score of -7.15 against squamous cell carcinoma protein with ID: 2DO4 and -5.49 docking score against squamous cell carcinoma protein with ID:5PJZ. ADME/T analysis was performed to examine the drug properties of studied molecules. [GRAPHICAL ABSTRACT]Kafkas University [2018FM-46]; Kafkas University of Applied Sciences; Sivas Cumhuriyet University [RGD-020]This work was supported by Research Fund of the Kafkas University (Project Number: 2018FM-46), Research Fund of the Kafkas University of Applied Sciences, and Sivas Cumhuriyet University under the project number RGD-020. This research was made possible by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure)
Comparison of Different Bandwidth Determination Methods in Kernel Equating
No full textThe study aims to compare the presented methods for determining the bandwidth parameter in the kernel equating method on a real data set. A bandwidth parameter needs to be determined when kernel equating is used to equate two test forms. The bandwidth parameters determine the smoothness of the continuousized score distributions, so their effect on equating results is inevitable. Gaussian Kernel, Logistic Kernel and Uniform Kernel methods were used for bandwidth selection and the results were compared according to the Percentage Relative Error (PRE), the Standard Error and the Standard Error of Equating Difference (SEED). The findings of the study show that the three different approaches to minimizing the penalty function have similar results. Although the standard errors of the equated scores obtained with the uniform kernel method were slightly smaller, the results were almost the same as the other two approaches. When the three equating methods are compared according to the percent relative error, the distribution obtained from Gaussian kernel equating is more consistent with the population distribution
Advancing digital transformation in the mining industry: A novel rough interval-valued neutrosophic DEMATEL approach to challenge interdependencies
No full textThe mining industry (MI) underpins global economic and technological progress by supplying essential raw materials for energy, manufacturing, and infrastructure. Yet, its digital transformation, vital for enhancing sustainability and efficiency, is hindered by complex, interconnected challenges. Prior research often examines these challenges in isolation, lacking quantitative causal modeling. This study proposes the Rough Interval-Valued Neutrosophic Decision-Making Trial and Evaluation Laboratory (RIVN-DEMATEL) method to analyze interdependencies among challenges to digital technology adoption in the MI. Integrating rough set theory and neutrosophic logic, RIVN-DEMATEL robustly manages uncertainty in expert judgments, validated via Spearman and Pearson correlation analyses. Key findings identify scalability challenges, cultural inertia, and dynamic operational conditions as dominant causal drivers, which exacerbate effect factors such as resistance to change, cybersecurity risks, and ROI uncertainty. Scalability constraints, for instance, amplify integration issues and data complexity, while cultural barriers fuel workforce resistance. These results underscore the need to address root causes to mitigate downstream impacts. Practical implications include launching modular pilot projects to demonstrate scalability, fostering cultural change through transformational leadership, and implementing reskilling programs to build digital literacy. Moreover, policymakers should establish adaptive regulatory frameworks and offer financial incentives, such as grants for small and medium-sized enterprises (SMEs), to reduce adoption challenges. By synthesizing fragmented insights into a structured decision-support model, this study fills critical literature gaps, providing mining companies, policymakers, and technology providers a roadmap to advance operational efficiency, environmental sustainability, and social responsibility through digital innovation. © 2025 Elsevier B.V., All rights reserved
Pair or Group-Design Activities: The Effect of Design Activities on Problem-Solving, Design Thinking Disposition, and Design Thinking Traits
No full textDesign thinking has become an important process in many fields to encourage innovation toward problem solving skills in various fields. In the field of education, design thinking has been incorporated into curriculums as it contributes both to higher order thinking skills and to the learning process with its flexible and dynamic nature. However, there is a growing need and interest in exploring how design thinking affects students' learning experiences and its potential in group work (collaborative or pair). The purpose of this study is to determine the effect of design thinking activities carried out as a pair or group in a design-based learning process on problem-solving, design thinking disposition, and design thinking traits. Sixty-seven students (64.2% male and 35.8% female) who took the graphic design course participated in this study. The average age of the students participating in the study was 21.85 years. The study was designed with the mixed method. Studies enriched with design thinking activities were conducted with participants in pairs or groups. A demographic information form, three scales and a semi-structured interview form were used. The data were analyzed with Mann-Whitney U tests and qualitative data analysis methods. According to the results of the study, students who participated in pair-design activities emphasized the contributions of the process in defining the problem and visualizing solutions, while students who participated in group-design activities reported that the design thinking approach facilitated their problem solving processes. These findings suggest that design thinking can be an important tool in developing students' problem solving skills. According to the results regarding its contribution to design thinking disposition, it was found that there was a significant difference between the post-test scores of the experimental groups in the relationship dimension. It was also concluded that the experimental study had a significant effect on the collaboration dimension of design thinking characteristics. This study can provide students with tips on how to manage group work and how to share tasks correctly to improve their problem solving and design thinking processes
Impacts of Car-Following Models on Simulation-Based Safety Evaluation of Freeways
No full textThis study investigates the sensitivity between car-following model selection, cooperative adaptive cruise-controlled vehicle penetration (CACC), and freeway traffic control on surrogate safety outcomes. We examine six calibrated car-following models, GM, GHR, Gipps, Krauss, Wiedemann-99, and IDM under three freeway traffic control strategies (No Control, ALINEA ramp metering, and an H infinity\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}\end{document} integrated RM + VSL) and CACC market penetration rates from 0-100 %. Using time-to-collision and post-encroachment-time thresholds extracted from 108 microsimulation runs of an 11 km Istanbul corridor, we quantify how surrogate conflicts respond to each experimental factor. Results demonstrate that safety evaluations are inherently affected by the selected car-following model, and model sensitivity should be taken into account when claiming safety benefits of emerging vehicle technologies and control measures.Scientific and Technological Research Council of Turkey (TUBITAK) [120M576]This work is supported in part by the Scientific and Technological Research Council of Turkey (TUBITAK) under the project 120M576
Exploring social media burnout, anxiety, and self-control in Turkish University students: Gender and engagement as moderators
No full textSocial media still plays a dominant role in individuals' lives today. These environments, where negative emotions such as burnout and anxiety are fostered, are examined in terms of various variables. The current study investigated the multifaceted relationship between the social media burnout levels of Turkish students who are social media users and their self-control, anxiety, age, and duration of social media use. The moderating effects of gender and active or passive social media use on these relationships were examined. The study included 347 university students, 140 women and 207 men. A personal information form, social media burnout scale, social media anxiety scale, and self-control desire scale were used to gather the data. Partial least squares structural equation modelling the proposed structural model indicated that individuals with low self-control in social media use have high social media anxiety. Social media burnout was found to be high in individuals with high social media anxiety. In addition, the results demonstrate a positive relationship between social media anxiety and burnout, and this relationship is moderated by active-passive social media use