İstanbul Gelişim Üniversitesi Kurumsal Açık Erişim Arşivi
DSpace@Gelişim, İstanbul Gelişim Üniversitesi tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Influence of temperature and selenium substitution on electrical and dielectric characteristics of CoFe2O4 nanoparticles
(Elsevier B. V., 2025) Ünal, Bayram; Baykal, Abdülhadi; Almessiere, M. A.; Mihmanlı, Ahmet
This study investigates the influence of Se⁴⁺ ion substitution on the electrical and dielectric properties of CoFe2O4
nanoparticles (CoFe2-4xSe3xO₄ (x ≤ 0.1) (NPs)) synthesized via a hydrothermal method. The electrical and
dielectric characteristics were analyzed using a Novocontrol dielectric impedance analyzer. Results indicate that
activation energies (Ea) remain stable at approximately 600 meV at higher temperatures (T ≥ 45 ◦C) but decrease
significantly at lower temperatures, ranging from 300 meV (x = 0.02) to 20 meV (x = 0.08). A sharp reduction in
DC conductivity, from 1.2 nS/cm (x = 0.04) to 0.27 nS/cm (x = 0.08), suggests enhanced electron mobility at this
substitution level. AC conductivity exhibits strong frequency dependence, increasing from 0.15 nS/cm at 1 kHz to
0.13 μS/cm at 1 MHz for x = 0.08 at room temperature. Dielectric constant (ε′) and loss (ε′′) values exhibit
significant variation with frequency, with ε′ reaching a maximum of 3.95 at 100 Hz for x = 0.08, reflecting
enhanced polarization effects. Se⁴⁺ substitution also increases the real part of the electrical modulus (ReM) to
0.99 and the imaginary part (ImM) to 0.40 for x = 0.10, indicating improved energy storage and dissipation
capabilities. The ImZ/ReZ ratio analysis reveals shifts in conduction mechanisms and polarization effects, with a
notable transition at x = 0.04. Cole-Cole plots suggest multiple relaxation processes influenced by temperature
and substitution levels, with relaxation times decreasing from 13 ms (70 ◦C) to 0.76 ms (120 ◦C) for x = 0.02.
This study highlights the potential of Se⁴⁺-substituted Co-SFs for applications in electronic devices, particularly in
energy storage and dissipation systems, and underscores the need for combined experimental and theoretical
approaches to optimize these materials for advanced technological applications.
The Role of Artificial Intelligence Anxiety in the Relationship Between Organizational Learning and Performance in Organizations
(Ebru Bağcı, 2025) Şeker, Cemile; Kılıçaslan, Semiha; Karalinç, Turgay; Kaya, Aslı
The purpose of this study is to investigate the mediating role of artificial intelligence (AI) anxiety in the relationship between organizational learning and performance. The study sample consists of employees
from the healthcare sector, specifically those employed at a private hospital in Istanbul. Data were obtained from 177 healthcare employees through the
survey method. Statistical analyses were performed
using SPSS 27 software, ensuring a 95% confidence
interval. Initially, a normality test was conducted to
examine the data distribution. Subsequently, a reliability analysis was carried out to ensure the dataset’s consistency, and an exploratory factor analysis
(EFA) was applied to evaluate the factor structure. A
correlation analysis was performed to determine the
relationships between variables, followed by hierarchical regression analysis to assess the mediating
role. The findings of the study demonstrate that AI
anxiety does not have a significant mediating effect
on the relationship between organizational learning
and performance. These results suggest that the impact of AI anxiety on organizational dynamics requires further investigation. Given that AI anxiety can
adversely influence organizational learning and reduce overall performance, organizations must take
appropriate measures to mitigate concerns related
to AI.
The corrosion resistance effect of nanocomposites containing AuNPs coated onto titanium surfaces
(Yildiz Technical University, 2025) Yeni̇yol, Sinem; Mutlu, İlven; Di̇zman, H. Miraç; Arsu, Nergis
The purpose of this work was to evaluate the corrosion of commercially pure titanium (cpTi)
and polymeric AuNPs nanocomposite thin film coatings on cpTi in vitro in artificial saliva
by using different electrochemical tests and surface analysis techniques. Electrochemical impedance spectroscopy (EIS), open circuit potential (OCP) and inductively coupled plasma
mass spectrometry (ICP-MS) were associated with FESEM for surface characterization. OCP
tests revealed higher potential values for AuNPs-Coated surfaces. Increase of the corrosion
resistance for AuNPs-Coated surface was presented by EIS in artificial saliva. Average size
of 20 - 30 nm AuNPs in spherical morphology forming agglomerations were observed on
AuNPs-Coated surfaces. Compared to cpTi surfaces, a lower release tendency of Ti ions from
the AuNPs-Coated Ti surfaces after immersion into artificial saliva was confirmed by ICPMS. Results suggest that AuNPs-Coated Ti surfaces exhibit an enhanced corrosion resistance.
Effects of Fe Concentration on the Structural, Optical and Biological Properties of ZnMgO Nanoparticles
(John Wiley & Sons Inc., 2025) Şentürk, Kenan; Arda, Lütfi
ZnO nanoparticles co-doped with Fe and Mg, denoted as Zn0.99-xMg0.01FexO
with various compositions (x = 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, and 0.10), are
synthesized using the sol–gel method. The structural, morphological, optical,
and blood compatibility of these Zn0.99-xMg0.01FexO nanoparticles are
investigated. Structural properties are characterized using X-ray diffraction
(XRD) while scanning electron microscopy (SEM) is employed to examine the
surface morphology. It is determined that all nanoparticles exhibit a
single-phase ZnO hexagonal wurtzite structure. SEM images at different
magnifications reveal a dense, quasi-spherical, and agglomerated morphology
for the (Fe/Mg) co-doped ZnO nanoparticles. The optical properties of the
samples are analyzed via a UV spectrophotometer. The energy bandgaps for
the nanoparticles are computed and the impact of dopant elements are
explored on their optical behavior. The refractive index is determined through
five distinct models. Notably, the highest bandgap is observed Eg = 3.23 eV
for Znn.98Mgn.n1Fen.n1O and Znn.95Mgn.n1Fen.n4O nanoparticles. Hemolysis
tests are conducted to evaluate the blood compatibility of these nanoparticles.
Challenges in Teacher Education: Pedagogy, Management, and Materials
(2025) Bafralı, Görsev
Educators encounter many unique challenges when teaching students who are learning English as a second or foreign language. These students may find mastering a new language daunting, resulting in speaking anxiety. In addition to managing their lesson plans, schedules, and school social interactions, teachers may need to assist students with stress management. By including teaching strategies grounded in cognitive and metacognitive abilities as well as problem solving in teacher education, new teachers may improve their ability to navigate challenges faced in the classroom. Challenges in Teacher Education: Pedagogy, Management, and Materials explores the impact of different strategies to enhance teacher education, increasing problem solving skills and self-efficacy. It addresses challenges and strategies for teaching foreign language learners with cultural competence. Covering topics such as well-being interventions, educational technology, and global awareness, this book is an excellent resource for teachers, school administrators, principals, researchers, professionals, academicians, and more.
