Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - Scopus: 1Investigation of LiCoO2 Thin Films Grown Under Relatively Low Substrate Temperature for All Solid State Lithium Ion Battery Applications(Pergamon-elsevier Science Ltd, 2025) Ozcan, Polatkan; Esen, Nazlican; Cantas, Ayten; Ozyuzer, Lutfi; Ozdemir, Mehtap; Kosiel, Kamil; Aygun, GulnurThis study examines the effect of substrate temperature on the surface, structural and chemical properties of LiCoO2 (LCO) thin films deposited via magnetron sputtering. LCO thin films were grown for the purpose of being a cathode layer for all-solid-state lithium-ion batteries (ASSLIBs). Achieving crystalline LCO films at low substrate temperatures is advantageous for integration with flexible and temperature-sensitive substrates as well as minimizing energy consumption, which is highly important for industrial applications. In this work, LCO thin films were deposited on titanium-coated soda lime glass (SLG/Ti) at the substrate temperature ranging from room to 350 degrees C. Structural characterizations by XRD analyses confirmed that LCO thin films have (104) crystal orientation, which is critical for efficient lithium-ion transportation. SEM, Raman, and XPS analyses were used for further chemical and structural characterizations of grown LCO thin films. These analyses showed that LCO thin film grown at relatively low substrate temperature of 250 degrees C is a better growth condition when compared to others. Crystallization orientation (104) of LCO thin films is highly important for the potential usage of ASSLIBs technologies without any need of elevated temperatures. Moreover, results support the low-temperature adaption processes for applications like wearable electronics, offering safer and more sustainable solutions for future energy storage systems.Article Citation - WoS: 3Citation - Scopus: 7A Comprehensive Life Cycle Impact Evaluation of Hydrogen Production Processes for Cleaner Applications(Pergamon-elsevier Science Ltd, 2025) Goren, A. Yagmur; Dincer, Ibrahim; Khalvati, AliThe worldwide energy demands have greatly increased with urbanization and population growth. Air pollution, acid rain, greenhouse gas emissions, global warming originating from CO2 emissions, depletion of energy supplies, and environmental degradation resulting from climate change are all consequences of using non-renewable fossil fuel-based energy infrastructure. To minimize emissions, renewable energy-based alternative energy sources must be investigated. In this regard, hydrogen (H2) has emerged as a promising fuel to meet energy requirements, and green H2 production with net-zero emissions has gained significant interest in recent years. Therefore, this study uses the life cycle assessment approach to evaluate the atmospheric emissions and environmental impact parameters of the gasification, electrolysis, and dark fermentation-microbial electrolysis hybrid process and assess their sustainability levels, considering the sustainable development goals. Among the studied H2 production processes, the maximum CO2 emission originates from the coal gasification process, accounting for 18.6 kg-CO2/kg-H2, while the alkaline electrolysis process provides the lowest total CO2 emission of 6.39 kg-CO2/kg-H2. Furthermore, the biological-based dark fermentation-microbial electrolysis cell process is a promising option owing to its highest negative biogenic CO2 emission of -68.69 kg-CO2/kg-H2. The environmental impact parameters of the studied processes are calculated considering the emissions, and the highest global warming potential of 21.75 kgCO2-eq./kg-H2 is obtained for the coal gasification process, considering the life cycle assessment coefficients. Overall, the lowest atmospheric emissions and environmental impacts are obtained for the electrolysis process. Consequently, these results revealed that switching from the fossil fuel resources used in the conventional H2 production methods to fully sustainable sources, such as renewables, can make energy production methods entirely sustainable from an environmental point of view.Article Citation - WoS: 1Citation - Scopus: 1A New Safe Flexible Torsion Joint Design With Softening Stiffness Characteristics(Pergamon-elsevier Science Ltd, 2025) Gorgulu, Ibrahimcan; Dede, Mehmet Ismet Can; Kiper, GokhanThis paper introduces a novel flexible joint design that enhances mechanical versatility. The design shows how to obtain bidirectional deflections from a unidirectional spring. It enables the parallel and serial connections of springs. It features multiple stiffness regions determined by applied load levels, eliminating the need for a clutch mechanism. Mechanical limits can be added to customize stiffness, offering more hardening or softening regions. The design also allows for connecting multiple flexible joint units in series. In a case study, the series flexible joint design is developed with two flexible joint units, providing a softening stiffness characteristic. The joint has rigid, stiff, and soft regions. When used as a series elastic actuator in a robot manipulator, the rigid region aims to conduct the tasks at low torque levels, i.e., trajectory tracking. The stiff region is preserved for collaborative tasks in human-robot interaction, while the soft region enhances the robot's safety in case of control failure or collision. Static and dynamic test results comply with the ideal model. This flexible joint design improves mechanical performance, safety, and adaptability.Article Citation - WoS: 1Citation - Scopus: 1Assessing Seferihisar-Izmir (Turkiye) Geothermal Energy Prospects Through Marine Seismic and Field Geology Data Modelling(Pergamon-elsevier Science Ltd, 2025) Kilinc, Gizem; Cifci, Gunay; Gunaydin, Seda Okay; Hasozbek, Altug; Gurcay, Savas; Gungor, Talip; Cobanoglu, MelihSeferihisar (Izmir) is one of the most significant geothermal regions in the Aegean of Western Anatolia, Turkiye, due to its high geothermal gradient, extensive fault systems, and unique interaction between marine and meteoric waters that create distinct geothermal reservoirs. This study evaluates the geothermal potential and geological characteristics of the Seferihisar area by integrating marine seismic data with onshore geological observations. Specifically, this study combines: (i) geological and geochemical data from geothermal wells along the Tuzla Fault, (ii) high-resolution multichannel seismic reflection data from the Sigacik and Kusadasi Bays, and (iii) correlated onshore and offshore geological and geophysical datasets to develop a 2D conceptual cross-section and a 3D fault model. Geochemical analyses, including water geochemistry, XRF, and isotope studies, reveal that geothermal fluids in the region originate from a mix of meteoric and marine sources. Chloride concentrations in geothermal wells reach approximately ranging from 11,692 to 12,000 ppm, confirming significant seawater intrusion, while geothermometers estimate reservoir temperatures in the range of 220-280 degrees C. Isotopic data, such as He-3/He-4 ratios (similar to 0.9 Ra), suggest minor mantle involvement, and Ar-40/Ar-36 ratios ranging 301 that indicate crustal contributions to the geothermal fluids. These isotopic signatures provide critical insights into the sources and circulation dynamics of geothermal systems. Through integrated 2D conceptual cross-sections and 3D fault modeling, the study identifies the marine extension of the Tuzla Fault and its role in fluid dynamics, including up-flow and out-flow processes. The fault's continuities are linked to geothermal gradients and active fluid pathways, making the Tuzla Fault a critical target for geothermal exploration. The harmonized models suggest three potential drilling sites with high thermal gradients and fault-controlled fluid flow, optimizing the exploration strategy. Scaling and corrosion challenges in production wells are addressed through the application of inhibitors, which are integral to ensuring sustainable operation and long-term system performance. These multidisciplinary findings provide likely actionable insights into optimizing resource extraction, reducing environmental impact, and improving the long-term performance of geothermal systems. The study supports sustainable geothermal energy development in the Seferihisar region by addressing production challenges and guiding effective resource management.Article Citation - WoS: 1Citation - Scopus: 1Dynamic and Stochastic Optimization of Algae Cultivation Process(Pergamon-elsevier Science Ltd, 2025) Kivanc, Sercan; Beykal, Burcu; Deliismail, Ozgun; Sildir, HasanThis study offers a realistic representation of system dynamics which accounts for light intensity, biomass, substrate, and nitrogen concentration, by employing stochastic programming techniques to account for spatial and temporal variations for algae growth. The optimization task focuses on lipid productivity and selectivity, which are crucial factors in the context of algal biofuel production. Different scenarios from likely and unlikely cases of model parameters were evaluated. Optimal initial conditions for key variables such as nitrogen, substrate, light, biomass, lipid, and surface light intensity are calculated, considering the uncertainty of the parameters as well as other governing equations. The results show that a remarkable 11.18% increase in lipid productivity compared to a reference scenario. Furthermore, in the stochastic case, our results highlight that uncertainty has a disproportionately large effect on biomass in comparison to lipid concentration, providing valuable insights into the behavior of the system under varying conditions. This provides a comprehensive exploration of the parameter uncertainty on lipid productivity and algal growth.Article Citation - WoS: 3Citation - Scopus: 3A Selective Bodipy-Based Fluorescent Sensor for the Detection of Cu2+ Ions in Biological and Environmental Samples(Pergamon-elsevier Science Ltd, 2025) Eldem, Asli; Kibris, Erman; Ucuncu, MuhammedIn this study, we present the design, synthesis, and characterization of a 'turn-on' fluorescent probe, BOD-HDZ, for the selective detection of Cu2+ ions in semi-aqueous solutions, environmental samples (water and soil), and MCF-7 cancer cells. BOD-HDZ was synthesized by functionalizing meso-formyl-BODIPY (BOD-ALD) with a 2-hydrazinopyridine, resulting in fluorescence quenching via a photoinduced electron transfer (PET) mechanism. The 1:1 coordination between Cu2+ and the probe was confirmed through Job's plot analysis and 1H NMR spectroscopy, leading to a 210-fold fluorescence enhancement at 515 nm. BOD-HDZ demonstrated exceptional sensing properties, including a rapid response time (<1 min), a broad operational pH range (2-12), and high sensitivity with a detection limit of 141 nM.Article Citation - WoS: 7Citation - Scopus: 7Hydrogen Production From Energetic Poplar and Waste Sludge by Electrohydrogenesis Using Membraneless Microbial Electrolysis Cells(Pergamon-elsevier Science Ltd, 2024) Goren, A. Yagmur; Kilicaslan, A. Faruk; Dincer, Ibrahim; Khalvati, AliMembraneless microbial electrolysis cells (MECs) are potentially considered to produce biohydrogen (bioH2) in a green manner and simultaneously minimize agricultural and wastewater facility wastes. However, effective, sustainable, and cost-effective system configuration and improvement of operating variables, working at ambient conditions, are needed to make the MEC a sustainable process. Therefore, this study investigates the bioH2 production from poplar leaves and anaerobic sludge mixture by incorporating nanomaterials comprising Al2O3, MgO, and Fe2O3 metal oxides at various dosages. Moreover, the effects of applied cell voltage (0.5-1.5 V) and inoculum amount (20-40 mL) on bioH2 production and organic matter removal performance are evaluated. The maximum bioH2 production value is 417 mL at an applied voltage of 1.5 V with a chemical oxygen demand (COD) removal efficiency of 37.6 % under operating times of 5 min using 40 ml of inoculum. The bioH2 production of the MEC system is reduced with the decrease in inoculum amount. The highest bioH2 production of 828 mL is obtained at improved conditions in the presence of 1 g of Fe2O3 metal oxide. Overall, this study provides the potentiality of simultaneous waste minimization and bioH2 production under ambient conditions that highlight the waste-to-energy pathway for membraneless and green bioelectrochemical process.