İstinye Üniversitesi Kurumsal Akademik Arşivi
DSpace@İstinye, İstinye 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
Advancing ZMF-spinel ferrites with Gd3+ doping: structural, magneto-optical enhancements, and superior gamma-ray shielding for high-tech applications
(Springer, 2024) Khalil, Huda F.; Issa, Shams A. M.; Elsharkawy, Sherif G.; Boudaghi Malidarreh, Roya; Gad, Sara; Badawi, Ali; Fakhry, Fatma; Zakaly, Hesham M. H.
In this investigation, the incorporation of Gd3+ ions into ZMF-spinel ferrites through the citrate sol-gel auto-combustion method significantly modified their structural, magneto-optical, and gamma-ray attenuation properties. Doping levels were varied across samples labeled ZMF0 to ZMF4 with Gd3+ concentrations ranging from 0.000 to 0.100. Advanced characterization techniques such as XRD, SEM, TEM, FT-IR, Raman spectroscopy, and XPS, alongside UV-vis spectroscopy and VSM measurements, highlighted the profound impact of Gd3+ doping. Notably, the incorporation of Gd3+ led to nano-sized cubic structures with an optimized crystallite size of 19.82 nm in the ZMF4 sample, and a notable reduction in the band gap from 3.21 eV to 2.99 eV was observed, indicative of enhanced electronic properties. Magnetic analysis revealed a transition towards superparamagnetic behavior, with a decrease in coercivity and squareness ratios, suggesting applications in areas such as data storage and optical waveguides. Furthermore, the study leveraged FLUKA Monte Carlo simulations to assess the gamma-ray shielding efficiency of these materials. It was found that increasing Gd3+ concentration or sample thickness markedly improved radiation attenuation, highlighting the material’s enhanced shielding capabilities against a range of photon energies. The most significant findings included the optimized sample (ZMF4) displaying superior magneto-optical characteristics and outstanding gamma-ray shielding performance, especially at higher Gd3+ levels. This investigation underlines the critical role of Gd3+ doping in advancing the functional properties of ZMF-spinel ferrites for technological and radiation protection applications, showcasing the potential of tailored nanomaterials in addressing complex challenges in material science. Graphical Abstract: (Figure presented.) © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.
Gd3+ ion doping in ZMF-spinel ferrites reduced crystallite sizes to an optimal 19.82 nm, significantly enhancing their magneto-optical properties. Spectral analysis showed a noticeable blue shift in band edge absorption, with optical band gaps narrowing from 3.21 eV to 2.99 eV, indicating improved electronic properties. Magnetic assessments revealed a transition to soft magnetic behavior and identified superparamagnetic regions, broadening potential technological applications. FLUKA Monte Carlo simulations demonstrated that increased Gd3+ concentration and sample thickness significantly boost the material’s gamma-ray shielding efficiency. The study’s comprehensive analysis establishes ZMF-spinel ferrites doped with Gd3+ ions as promising candidates for advanced applications, including radiation protection and energy systems. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024..
Ambient pressure dried graphene oxide-silica composite aerogels as pharmaceutical nanocarriers
(Springer, 2025) Salihi, Elif Çalışkan; Zarrabi, Ali; Zarepour, Atefeh; Gürboğa, Merve; Hasan Niari Niar, Shalaleh; Özakpınar, Özlem Bingöl; Wang, Jiabin; Daştan, Havva; Khosravi, Arezoo; Šiller, Lidija
Research on the production of graphene, its derivatives and composites has been enhanced in the past two decades. Graphene is well known for its exceptional physicochemical properties including extensive surface area, good biocompatibility, high loading capacity, and functionalization capability which make it an ideal candidate for drug delivery systems. When compared to the other nanomaterials, aerogels are relatively new materials characterized by their unparalleled porosities and extensive surface areas. The ability to carry drugs is crucial in drug delivery systems, and the large surface area of graphene coupled with the high porosity of aerogels presents a significant potential for use in this domain. In this study, graphene oxide-silica composite aerogel nanostructures were synthesized firstly, using the sol-gel method and ambient pressure drying technique which offer advantages in terms of both time and cost efficiency. Then, the formulation was also fabricated in the functionalized forms with sodium dodecyl sulfate, polyvinylpyrrolidone and ethylenediaminetetraacetic acid. Different physicochemical characteristics of these new materials were investigated using SEM/EDS, XRD, Raman spectroscopy, FTIR spectroscopy, TGA and DLS techniques. Drug loading tests were done using curcumin and methylene blue, while the biocompatibility of the nanocarriers was assessed through cell viability assay. Results of different tests confirmed the successful fabrication of the aerogels with different functionalizations, which had encapsulation capacity ranged between 20–90% and high biocompatibility after exposing with cells. Based on these promising results, this study confirms that aerogel-based platforms produced have potential to be used as nanocarriers for drug delivery systems. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.
A Different Result of Minor Head Trauma; Aggressive Periosteal Reaction
(Galenos Publishing House, 2025) Altunrende, Muhittin Emre; Ekin, Elif Evrim; Kımıloğlu, Elife
While the literature reports cases of calvarial lytic lesion, the association with aggressive periosteal reaction is rare. There are various opinions about the mechanics and treatment of these lesions. This article discusses a case of periosteal reaction, which caused a calvarial lytic lesion after minor head trauma, within the framework of existing literature. © 2025 The Author.
Cost-Effective Optimization of Sizing and Charging Profiles for PHEV Parking Lots in Smart Microgrids Using Harmony Search Algorithm
(Institute of Electrical and Electronics Engineers Inc., 2025) Kamarposhti, Mehrdad Ahmadi; Shokouhandeh, Hassan; Ahmed, Emad M.; Zaki, Zaki A.; Çolak, İlhami; Barhoumi, El Manaa; Eguchi, Kei
This paper presents an optimization approach for managing the charging and discharging of electric vehicles (EVs) in parking lots using the Harmony Search (HS) and Differential Evolution (DE) algorithms. The study is conducted on a standard IEEE 33-bus grid considering three EV penetration levels: 11.3%, 35%, and 45%. The objective is to minimize operational costs while improving grid performance. Simulation results indicate that increasing EV penetration slightly raises overall expenses due to the higher cost of vehicle charging compared to the revenue from discharging. However, EV participation significantly reduces ohmic losses and improves the grid load profile. The proposed HS algorithm outperforms the DE algorithm by achieving lower microgrid costs and better convergence efficiency. Specifically, HS reduces energy losses by up to 40%, demonstrating its effectiveness in optimizing energy management for microgrids with high EV integration. © 2013 IEEE.
TrueCome: Effective data truth discovery based on fuzzy clustering with prior constraints
(Elsevier Inc., 2025) Gao, Lijun; Wu, Fei; Wang, Jie; Yan, Zheng; Pedrycz, Witold
Data truth discovery is a process to determine accurate information from multiple conflicting data sources. Existing truth discovery schemes suffer from low efficiency and insufficient accuracy caused by noisy data and source unreliability, particularly facing three key limitations: (1) inability to leverage inter-attribute constraints for distance metric learning, (2) lack of effective mechanisms for distinguishing truth clusters from noisy streaming data. Few of them can discover the truth for streaming data with noise, and (3) static source reliability estimation that fails to adapt to streaming data dynamics. Few of them can discover the truth for streaming data with noise. To overcome these problems, we propose TrueCome, a possibilistic C-Means truth discovery scheme that leverages constraints between different attributes of an object and applies dynamically updated data source reliability to discover truth for both static and streaming data. TrueCome contains two functional modules: distance learning and truth discovery. The distance learning module constructs a distance function by mining prior constraints of object attributes. Then, the truth discovery module obtains the true values of an object through three steps: data clustering based on data sample distance and data source reliability and attribute weights, truth cluster identification by calculating cluster trust degrees, and truth acquisition derived from True Value Clusters (TVCs). In particular, TrueCome employs Maximum A Posteriori (MAP) estimation to adaptively update source reliability (i.e., source weight), allowing it to handle both static and streaming data effectively. Extensive experiments on two real-world datasets and one synthetic dataset exhibit the superiority of TrueCome over several baselines in terms of accuracy and efficiency, particularly for streaming data with noise. We also validate the design rationality of TrueCome through ablation studies. © 2025 Elsevier Inc.
