https://hdl.handle.net/20.500.12960/20 2026-04-22T10:25:10Z 2026-04-22T10:25:10Z Erol, Erdeniz Cansoy, C. Elif Aybar, Orhan Özgür Beşikçi, Elif Bal https://hdl.handle.net/20.500.12960/1798 2025-11-21T05:50:19Z 2025-01-01T00:00:00Z

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.

2025-01-01T00:00:00Z Saha, Sanghati Güdekli, Ertan Chattopadhyay, Surajit Açan Yıldız, Gizem Dilara https://hdl.handle.net/20.500.12960/1767 2025-04-11T11:32:15Z 2025-01-01T00:00:00Z

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.

2025-01-01T00:00:00Z Mustafa G. Açan Yıldız, Gizem Dilara Javed, Faisal Maurya, S. K. Güdekli, Ertan Atamurotov, Farruh https://hdl.handle.net/20.500.12960/1733 2025-03-20T12:16:17Z 2024-01-01T00:00:00Z

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.

2024-01-01T00:00:00Z Özkal, Bünyamin Al-Jawfi, Nora Ali Abdo Saleh Ekinci, Gökhan Rameev, Bulat Z. Khaibullin, Rustam, I Kazan, Sinan https://hdl.handle.net/20.500.12960/1732 2025-03-19T07:26:27Z 2025-01-01T00:00:00Z

Artificial synapses based on HfOx/TiOy memristor devices for neuromorphic applications Özkal, Bünyamin; Al-Jawfi, Nora Ali Abdo Saleh; Ekinci, Gökhan; Rameev, Bulat Z.; Khaibullin, Rustam, I; Kazan, Sinan As a result of enormous progress in nanoscale electronics, interest in artificial intelligence (AI) supported systems has also increased greatly. These systems are typically designed to process computationally intensive data. Parallel processing neural network architectures are particularly noteworthy for their ability to process dense data at high speeds, making them suitable candidates for AI algorithms. Due to their ability to combine processing and memory functions in a single device, memristors offer a significant advantage over other electronic platforms in terms of area scaling efficiency and energy savings. In this study, single-layer and bilayer metal-oxide HfOx and TiOy memristor devices inspired by biological synapses were fabricated by pulsed laser and magnetron sputtering deposition techniques in high vacuum with different oxide thicknesses. The structural and electrical properties of the fabricated devices were analysed using x-ray reflectivity, x-ray photoelectron spectroscopy, and standard two-probe electrical characterization measurements. The stoichiometry and degree of oxidation of the elements in the oxide material for each thin film were determined. Moreover, the switching characteristics of the metal oxide upper layer in bilayer devices indicated its potential as a selective layer for synapse. The devices successfully maintained the previous conductivity values, and the conductivity increased after each pulse and reached its maximum value. Furthermore, the study successfully observed synaptic behaviours with long-term potentiation, long-term depression (LTD), paired-pulse facilitation, and spike-timing-dependent plasticity, showcasing potential of the devices for neuromorphic computing applications.

2025-01-01T00:00:00Z