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Article Citation - WoS: 19Citation - Scopus: 21Development of Effective Bimetallic Catalyst for High-Temperature Pem Fuel Cell To Improve Co Tolerance(Wiley, 2021) Al-Tememy, Mogdam Gassy Hussein; Devrim, YilserIn this study, it is aimed to examine the effect of multi-walled carbon nanotube doped graphene nanoplatelet (MWCNT-GNP) supported PtPd bimetallic catalyst on the performance of the high-temperature proton-exchange membrane fuel cell (HT-PEMFC). In addition, PtPd/GNP and PtPd/MWCNT bimetallic catalysts were also investigated for performance comparison. The characterizations of these catalysts were examined by ICP-MS, XRD, HR-TEM, and TGA analysis. The electrochemical characterizations of the catalysts were performed for both cyclic voltammetry (CV) and CO stripping experiments, as well as HT-PEMFC tests. The specific surface area (SSA) for PtPd/GNP and PtPd/MWCNT catalysts was obtained as 148 and 137 m(2)/g, respectively, while the highest SSA was achieved as 164 m(2)/g for PtPd/MWCNT-GNP. The performance of the catalysts was confirmed with the HT-PEMFC tests, based on the H-2/air and reformate gas/air experiments. The electrocatalytic results display that PdPt bimetallic catalysts exhibited higher catalytic property than that of commercial Pt/C catalyst. The highest performance was achieved with PtPd/MWCNT-GNP catalyst as 0.390 and 0.310 W/cm(2)at 160 degrees C for H-2/air and reformat/air, respectively. The obtained results indicate that the PtPd/MWCNT-GNP catalyst is appropriate for HT-PEMFC operations.Article Citation - WoS: 6Citation - Scopus: 4Is real per capita state personal income stationary? New nonlinear, asymmetric panel-data evidence(Wiley, 2020) Emirmahmutoglu, Furkan; Gupta, Rangan; Miller, Stephen M.; Omay, TolgaThis paper re-examines the stochastic properties of U.S. state real per capita personal income, using new panel unit-root procedures. The new developments incorporate non-linearity, asymmetry, and cross-sectional correlation within panel-data estimation. Including nonlinearity and asymmetry finds that 43 states exhibit stationary real per capita personal income whereas including only nonlinearity produces 42 states that exhibit stationarity. Stated differently, we find that two states exhibit nonstationary real per capita personal income when considering nonlinearity, asymmetry, and cross-sectional dependence.Article Citation - Scopus: 1Optimizing the Stochastic Deployment of Small Base Stations in an Interleave Division Multiple Access-Based Heterogeneous Cellular Networks(Wiley, 2022) Noma-Osaghae, Etinosa; Misra, Sanjay; Koyuncu, MuratThe use of small base stations (SBSs) to improve the throughput of cellular networks gave rise to the advent of heterogeneous cellular networks (HCNs). Still, the interleave division multiple access (IDMA) performance in sleep mode active HCNs has not been studied in the existing literature. This research examines the 24-h throughput, spectral efficiency (SE), and energy efficiency (EE) of an IDMA-based HCN and compares the result with orthogonal frequency division multiple access (OFDMA). An energy-spectral-efficiency (ESE) model of a two-tier HCN was developed. A weighted sum modified particle swarm optimization (PSO) algorithm simultaneously maximized the SE and EE of the IDMA-based HCN. The result obtained showed that the IDMA performs at least 68% better than the OFDMA on the throughput metric. The result also showed that the particle swarm optimization algorithm produced the Pareto optimal front at moderate traffic levels for all varied network parameters of SINR threshold, SBS density, and sleep mode technique. The IDMA-based HCN can improve the throughput, SE, and EE via sleep mode techniques. Still, the combination of network parameters that simultaneously maximize the SE and EE is interference limited. In sleep mode, the performance of the HCN is better if the SBSs can adapt to spatial and temporal variations in network traffic.Article Citation - WoS: 21Citation - Scopus: 21Investigation of Hydrogen Production From Sodium Borohydride by Carbon Nano Tube-Graphene Supported Pdru Bimetallic Catalyst for Pem Fuel Cell Application(Wiley, 2022) Al-Msrhad, Tuqa Majeed Hameed; Devrim, Yilser; Uzundurukan, Arife; Budak, YagmurIn this study, hydrogen (H-2) generation from the hydrolysis of sodium borohydride (NaBH4) catalyzed by bimetallic Palladium-Ruthenium (PdRu) supported on multiwalled carbon nanotube-graphene (MWCNT-GNP) hybrid material is investigated. The effect of various parameters such as temperature, NaBH4 concentration, and catalyst loading and effect of base concentration are examined to observed optimum operating conditions. Experimental results show that the PdRu/MWCNT-GNP bimetallic catalyst has high catalytic activity on NaBH4 hydrolysis reaction. It has been found that PdRu/MWCNT-GNP catalyst shows low activation energy of 22.33 kJ/mol for hydrolysis reaction of NaBH4. The PdRu/MWCNT-GNP catalyst also exhibits H-2 generation rate of 79.2 mmol/min center dot g(cat) at 45 degrees C. It shows good cycle stability in the catalyst reusability test and retained 89% of its initial catalytic activity after fifth use. The high catalytic activity of the PdRu/MWCNT-GNP catalyst makes it promising in H-2 generation from NaBH4 hydrolysis for commercial proton exchange membrane fuel cell (PEMFC) applications.Article Citation - WoS: 26Citation - Scopus: 28Mean residual life of coherent systems consisting of multiple types of dependent components(Wiley, 2018) Eryilmaz, Serkan; Coolen, Frank P. A.; Coolen-Maturi, TahaniMean residual life is a useful dynamic characteristic to study reliability of a system. It has been widely considered in the literature not only for single unit systems but also for coherent systems. This article is concerned with the study of mean residual life for a coherent system that consists of multiple types of dependent components. In particular, the survival signature based generalized mixture representation is obtained for the survival function of a coherent system and it is used to evaluate the mean residual life function. Furthermore, two mean residual life functions under different conditional events on components' lifetimes are also defined and studied.Article Citation - WoS: 2Citation - Scopus: 2Ultrafast Green Synthesis of Superparamagnetic Hybrid Nanoparticle for Advanced Applications(Wiley, 2025) Kibar, GunesThe integration of superparamagnetic iron oxide nanoparticles (SPIONs) into functional hybrid nanostructures remains a challenge, particularly in preserving their magnetic properties within composite frameworks. Herein, we present a rapid and environmentally friendly synthesis strategy for SPION-decorated polyhedral oligomeric silsesquioxane (POSS) nanoparticles. The process involves UV-induced polymerization to form POSS nanoparticles, followed by in situ SPION precipitation, with comprehensive characterization performed via SEM, FTIR, XRD, and VSM analyses. This approach enables the fabrication of hybrid nanoparticles (similar to 160 nm) within 5 min and subsequent SPION decoration in under an hour, ensuring (10 emu/g) superparamagnetic behavior. The developed method is highly scalable, efficient, and compatible with green chemistry principles, making it a promising platform for engineering advanced hybrid nanostructures. These nanoparticles hold significant potential for applications in biomedicine, catalysis, and next-generation material science.Article Citation - WoS: 4Citation - Scopus: 4An Integrated Economy-Demography Model Reframed in a System Dynamics Setting(Wiley, 2019) Dural-Selcuk, Gozdem; Tunc, Huseyin; Tarim, S. ArmaganIn recent history, there has been an increasing concern about population aging and the associated increased economic burden in terms of high health-care expenses and pension payments. The need for decision support tools that can explore population dynamics has become a prominent issue. This study presents a comprehensive framework where one can scrutinize the key demographic drives of fertility (Total Fertility Rate/Age-Specific Fertility Rate) over macroeconomic indicators (technology, education, human capital) under exogenous mortality. The integrated model in this article is developed based on a reformulation of the unified growth theory. In the reformulated model, namely the "economy-demography model," the population age/sex structure is preserved, age-specific mortality is included, and fertility is measured in conventional demographic terms. The model is then presented in system dynamics framework, and its practical use is showcased with data obtained from the Turkish Statistical Institute. Copyright (c) 2020 System Dynamics SocietyArticle Validating the Turkish Adaptation of the Fear of Being Single Scale(Wiley, 2024) Kirimer-Aydinli, Fulya; Kucukkomurler, SanemPeople may experience anxiety regarding their future romantic relationship status. Fear of being single (FOBS) is a potential cause of this anxiety, characterized by distress about the idea of being single and assessed through the FOBS Scale. In the current study, the FOBS Scale was adapted into Turkish. The study included 349 individuals aged 28-55 years (M = 23.63 years, SD = 6.45 years). The reliability and validity of the measure and the associations with particular variables were investigated for the first time in the cultural context of Turkey. The confirmatory factor analysis revealed an acceptable model fit for the single-factor structure. Measurement invariance of the scale across relationship status was supported at configural and metric levels, but not at the scalar level. The convergent and divergent validity analyses indicated that FOBS is distinct from generalized anxiety, attachment anxiety, and the personality trait of neuroticism. FOBS was found to be related to the need to belong but not to the inclusion of close others into the self. It has been determined that FOBS is a distinctive phenomenon, and the Turkish version of the FOBS Scale is a valid and reliable tool for assessing FOBS in Turkey.Article The Role of Background Acoustic Stimuli in Dual Tasks: A Study on Postural Control Performance(Wiley, 2025) Saricamlik, Selin; Avci, Nizamettin Burak; Yigit, OznurIntroduction: Performing everyday tasks requires the use of multiple cognitive, sensory, and emotional systems. The interference of different variables in these multitasking systems affects our motor-balance system. This study was conducted to investigate how acoustic stimuli presented during a cognitive-motor dual task affect postural control in healthy young adults. Methods: Fifty-four healthy participants (39 females, 15 males; total age 21.87 +/- 1.18, range 19-24) were randomly assigned to control (silent), noise (multi-talker babble), or music (Mozart-Jupiter) groups based on testing environment. During the Stroop test, conducted with acoustic stimuli, postural sway velocity was measured on firm and foam surfaces with eyes open. The dual-task effect was assessed using the Wilcoxon test, and group comparisons employed one-way ANOVA or Kruskal-Wallis tests. Independent t tests and Mann-Whitney U tests were used for two-group comparisons. Statistical significance was set at p<0.05 (Bonferroni-adjusted p<0.017). Results: The silent cognitive-motor dual task increased postural sway on firm (median increased from 0.18 to 0.26 deg/s) and foam (median increased from 0.21 to 0.32 deg/s) surfaces. Music did not significantly affect cognitive performance or postural sway compared to the control group. However, noise reduced postural sway on firm and foam surfaces compared to the control group but did not affect cognitive performance. There was no significant difference in average Stroop response times between the groups or between the firm and foam surface comparisons. Conclusions: During inhibitory control tasks, cognitive effort prioritized in young people in easy-to-balance situations. Background noise affects motor-cognitive interaction, highlighting its potential for enhancing vestibular rehabilitation strategies in multitasking and guiding future research.Article Predicting Stroke Risk Using Machine Learning: A Data-Driven Approach to Early Detection and Prevention(Wiley, 2025) Sutcu, Muhammed; Jouda, Dana; Yildiz, Baris; Katrib, Juliano; Almustafa, Khaled MohamadStroke is a major global health concern and a leading cause of disability and mortality, emphasizing the need for early risk prediction and intervention. This study leverages statistical analysis, machine learning (ML) classification, clustering, and survival modeling to identify key stroke predictors using a dataset of 5110 records. Descriptive statistics reveal that age, glucose levels, BMI, hypertension, and heart disease are the most influential risk factors. Stroke prevalence is notably higher among hypertensive (13.25%) and heart disease patients (17.03%), as well as among former (7.91%) and current smokers (5.32%). Clustering analysis using PCA and t-SNE highlights high-risk groups with elevated glucose levels and advanced age. Among ML models, XGBoost offers the best trade-off between precision and recall, while na & iuml;ve Bayes achieves the highest recall (0.404), detecting more stroke cases despite higher false positives. Feature importance analysis ranks glucose, BMI, and age as dominant predictors, with XGBoost emphasizing cardiovascular conditions. Survival analysis confirms increasing stroke risk beyond age 60, with the Kaplan-Meier and Cox models showing a 31.9% risk increase linked to hypertension. These findings underscore the importance of early screening, lifestyle intervention, and targeted care. Future research should explore data-balancing methods like SMOTE and develop real-time tools to support clinical decision-making.
