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Now showing 1 - 10 of 54
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Personal Response Systems Through the Prism of Students' Experiences
    (Wiley, 2020) Mishra, Deepti; Chew, Esyin; Ostrovska, Sofiya; Wong, Jojo
    Personal response systems (PRSs) today offer an opportunity to the field of education in terms of improving teaching and learning outcomes through active engagement in classrooms. The present paper investigates students' attitudes to different types of PRSs, namely, Socrative and Clickers. Both qualitative and quantitative data are gathered and classified. The performed thematic analysis reveals major categories within the framework of this study, namely educational efficacy, psychological aspects, technology-related issues, and administrative issues. It has been found that Socrative fares better in the "educational efficacy" and "administrative issues," whereas Clickers outperforms Socrative in the "technological-related issues." It is worth pointing out that both Socrative and Clickers are tantamount in "psychological aspects" yielding no negative experiences. The results of this study reveal that two main factors, cost and technological infrastructure, are determinative in the incorporation and appreciation of such systems in an educational setting.
  • Article
    Citation - WoS: 139
    Citation - Scopus: 140
    CaXH3 (X = Mn, Fe, Co) perovskite-type hydrides for hydrogen storage applications
    (Wiley, 2020) Surucu, Gokhan; Gencer, Aysenur; Candan, Abdullah; Gullu, Hasan H.; Isik, Mehmet
    Hydrogen storage is one of the attractive research interests in recent years due to the advantages of hydrogen to be used as energy source. The studies on hydrogen storage applications focus mainly on investigation of hydrogen storage capabilities of newly introduced compounds. The present paper aims at characterization of CaXH3 (X: Mn, Fe, or Co) perovskite-type hydrides for the first time to understand their potential contribution to the hydrogen storage applications. CaXH3 compounds have been investigated by density functional theory studies to reveal their various characteristics and hydrogen storage properties. CaXH3 compounds have been optimized in cubic crystal structure and the lattice constants of studied compounds have been obtained as 3.60, 3.50, and 3.48 angstrom for X: Mn, Fe, and Co compounds, respectively. The optimized structures have negative formation enthalpies pointing out that studied compounds are thermodynamically stable and could be synthesized experimentally. The gravimetric hydrogen storage densities of X: Mn, Fe, and Co compounds were found in as 3.09, 3.06, and 2.97 wt%, respectively. The revealed values for hydrogen storage densities indicate that CaXH3 compounds may be potential candidates for hydrogen storage applications. Moreover, various mechanical parameters of interest compounds like elastic constants, bulk modulus, and Poisson's ratio have been reported throughout the study. These compounds were found mechanically stable with satisfying Born stability criteria. Further analyses based on Cauchy pressure and Pugh criterion, showed that they have brittleness nature and relatively hard materials. In addition, the electronic characteristics, band structures, and associated partial density of states of CaXH3 hydrides have been revealed. The dynamic stability behavior of them was verified based on the phonon dispersion curves.
  • Article
    Enhanced Doxorubicin Cytotoxicity on Breast Cancer Spheroids by Aptamer Targeted Co-Delivery With Hyaluronidase
    (Wiley, 2025) Kavruk, Murat; Demirel, Dide Su; Bonyadi, Farzaneh; Guner, Buket Cakmak; Dursun, Ali Dogan; Vakifahmetoglu, Cekdar; Ozalp, Veli Cengiz
    Breast cancer is one of the most prevalent solid tumors in women and can be classified into subtypes based on molecular characteristics, such as hormone receptor status and HER2 expression. Aptamers, highly specific affinity molecules, are extensively studied for targeted drug delivery using nanocarriers to enhance anti-cancer efficacy. This study focused on HER2-responsive co-delivery of doxorubicin and hyaluronidase via aptamer-gated mesoporous silica nanoparticles to improve therapeutic outcomes in solid tumors. SK-BR-3 spheroids are employed as a model for resistant tumor environments in solid tumors. Previous research is shown that conjugating cytotoxic drugs with nanoparticles or cells enhances drug penetration into tumor spheroids. In this work, doxorubicin is loaded into mesoporous silica nanoparticles and capped with HER2-specific aptamers, while the particle surface is functionalized with hyaluronidase. This dual-functionalized nanocarrier system achieves an approximate to 8.5-fold increase in cytotoxicity compared to aptamer-targeted delivery lacking hyaluronidase. The enhanced effect is attributed to hyaluronidase-mediated loosening of the spheroid structure, facilitating nanoparticle penetration and localized release of doxorubicin at high concentrations on HER2-positive cells.
  • Article
    Citation - WoS: 19
    Citation - Scopus: 21
    Development of Effective Bimetallic Catalyst for High-Temperature Pem Fuel Cell To Improve Co Tolerance
    (Wiley, 2021) Al-Tememy, Mogdam Gassy Hussein; Devrim, Yilser
    In 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: 6
    Citation - Scopus: 4
    Is real per capita state personal income stationary? New nonlinear, asymmetric panel-data evidence
    (Wiley, 2020) Emirmahmutoglu, Furkan; Gupta, Rangan; Miller, Stephen M.; Omay, Tolga
    This 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: 1
    Optimizing 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, Murat
    The 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: 57
    Citation - Scopus: 66
    Country-Level and Individual-Level Predictors of Men's Support for Gender Equality in 42 Countries
    (Wiley, 2020) Kosakowska-Berezecka, Natasza; Besta, Tomasz; Bosson, Jennifer K.; Jurek, Pawel; Vandello, Joesph A.; Best, Deborah L.; Zukauskiene, Rita
    Men sometimes withdraw support for gender equality movements when their higher gender status is threatened. Here, we expand the focus of this phenomenon by examining it cross-culturally, to test if both individual- and country-level variables predict men's collective action intentions to support gender equality. We tested a model in which men's zero-sum beliefs about gender predict reduced collective action intentions via an increase in hostile sexism. Because country-level gender equality may threaten men's higher gender status, we also examined whether the path from zero-sum beliefs to collective action intentions was stronger in countries higher in gender equality. Multilevel modeling on 6,734 men from 42 countries supported the individual-level mediation model, but found no evidence of moderation by country-level gender equality. Both country-level gender equality and individual-level zero-sum thinking independently predicted reductions in men's willingness to act collectively for gender equality.
  • Article
    Citation - WoS: 21
    Citation - Scopus: 21
    Investigation 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, Yagmur
    In 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: 26
    Citation - Scopus: 28
    Mean residual life of coherent systems consisting of multiple types of dependent components
    (Wiley, 2018) Eryilmaz, Serkan; Coolen, Frank P. A.; Coolen-Maturi, Tahani
    Mean 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: 2
    Citation - Scopus: 2
    Ultrafast Green Synthesis of Superparamagnetic Hybrid Nanoparticle for Advanced Applications
    (Wiley, 2025) Kibar, Gunes
    The 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.