https://hdl.handle.net/20.500.12960/20 Mon, 25 May 2026 00:23:56 GMT 2026-05-25T00:23:56Z https://hdl.handle.net/20.500.12960/1825 From mill scale to Sr-ferrite permanent magnets; upcycling by additives Gunduz Akdogan, Nilay; Kalkavan, Duru; Ghorbanighoshchi, Shabnam; Akdogan, Ozan This study examines the sustainable production of strontium hexaferrite by recycling mill scale, a by-product of steel manufacturing, as a source of iron. Strontium, designated as a critical raw material by the European Union, is essential for high-demand magnetic applications. In this study, various additives, including Al2O3, Cr2O3, Co3O4, and La2O3, were incorporated during the synthesis process to enhance the magnetic properties of the resulting strontium hexaferrite. Additives were included in the structure using the mechanochemical method. The results show that the incorporation of these additives has a significant influence on the coercivity, remanence, and overall magnetic anisotropy of SrFe12O19. Thu, 01 Jan 2026 00:00:00 GMT https://hdl.handle.net/20.500.12960/1825 2026-01-01T00:00:00Z https://hdl.handle.net/20.500.12960/1798 The Impact of Fouling on Ship Energy Efficiency in Dual-Fuel Engine and Battery Hybrid Electric Ferry Operation Erol, Erdeniz; Cansoy, C. Elif; Aybar, Orhan Özgür; Beşikçi, Elif Bal This chapter presents a comprehensive analysis of fouling impact on operational ship energy efficiency in a dual-fuel engine and battery hybrid electric vessel. Utilizing raw data obtained from the vessel data sources coupled with physical parameters, the study employs a data-driven approach to detect anomalies and assess the impact of fouling on the operational energy efficiency of ships. Through elaborate data-driven analysis and modeling techniques, the chapter also reviews the correlation between fouling accumulation and energy consumption patterns. The data-driven approach allows for the identification of specific operational parameters affected by fouling, such as propulsion efficiency and power consumption. Studies have shown that even a thin slime layer, measuring only 0.5 mm and covering up to half of the hull’s surface, can potentially lead to a 25–30% increase in greenhouse gas emissions, depending on the ship’s characteristics, operating speed, and environmental conditions. Investigation into the automated inspection and cleaning process reveals that a measured reduction in biofouling on ship hulls leads to an approximate 10% decrease in energy consumption. The findings contribute to a deeper understanding of the interplay between fouling, energy efficiency, and hybrid propulsion systems, providing valuable insights for optimizing vessel performance and informing proactive fouling management strategies. Ultimately, this research supports the transition towards sustainable maritime transportation practices through enhanced operational efficiency and reduced environmental impact. Wed, 01 Jan 2025 00:00:00 GMT https://hdl.handle.net/20.500.12960/1798 2025-01-01T00:00:00Z https://hdl.handle.net/20.500.12960/1767 Thermodynamics of the most generalized form of holographic dark energy and some particular cases with corrected entropies Saha, Sanghati; Güdekli, Ertan; Chattopadhyay, Surajit; Açan Yıldız, Gizem Dilara A four-parameter generalized entropy has recently been developed based on the generalized cut-off of holographic dark energy (HDE) formalism. It reduces to various known entropies for appropriate parameter limits, as shown in recent studies by Odintsov and others. In the current work, we investigate the evolution of the universe in its early and late phases within the framework of entropic cosmology, where the entropic energy density functions are reconstructed within the framework of the equivalence of holographic dark energy and four-parameter generalized entropy (S-g). Also, we examined different entropic dark energy models in this regard, including the generalized holographic dark energy with Nojiri-Odintsov(NO) cut-off, the Barrow entropic HDE (BHDE), and the Tsallis entropic HDE (THDE) as IR cut-off, all of three particular cases of the most generalized four parameter entropic holographic dark energy. Inspired by the works of Nojiri and others, our current work reports a study on cosmological parameters and thermodynamics with entropy corrections to cosmological horizon entropy as well as black hole entropy with a highly generalized viscous coupled holographic dark fluid along with its particular cases. Wed, 01 Jan 2025 00:00:00 GMT https://hdl.handle.net/20.500.12960/1767 2025-01-01T00:00:00Z https://hdl.handle.net/20.500.12960/1733 Orbital motion, epicyclic oscillations, and collision of particles around conformally coupled charged black hole Mustafa G.; Açan Yıldız, Gizem Dilara; Javed, Faisal; Maurya, S. K.; Güdekli, Ertan; Atamurotov, Farruh The orbital and oscillatory motion of test particles around a non-rotating, conformally coupled charged black hole with scalar hair is studied in this work. The impact of the black hole parameters on particle motion is investigated. The stable circular orbits, specific angular momentum, and radial profiles with specific energy are computed using an analytical approach. We discuss the stability of circular orbits using the effective potential technique. We also compute the effective force and innermost stable circular orbits around a conformally connected charged black hole with scalar hair. In addition, we display the trajectories of particles around a conformally connected charged black hole with scalar hair and numerically integrate the equations of motion for the test particle. Additionally, we determine the formulae for the frequencies of latitudinal and radial harmonic oscillations about the mass of the black hole and the model's parameters. The main characteristics of quasi-periodic oscillations close to stable circular orbits in the black hole's equatorial plane are examined for test particles. Furthermore, the Periastron precession process is explored. We show particle motion around black holes strongly depends on the model parameters. It is important to note that the graphical behavior describing our findings is viable. Mon, 01 Jan 2024 00:00:00 GMT https://hdl.handle.net/20.500.12960/1733 2024-01-01T00:00:00Z