Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Book Part Energy Production from Gas Hydrates(Elsevier, 2025) Çifçi, G.; Parlaktuna, M.; Çelebi, S.S.; Günaydın, S.O.Gas hydrates are a type of natural formation that contains large amounts of mostly methane, which is also known as natural gas, and water, in the form of ice. Methane hydrates are cages of water molecules that surround and trap methane molecules. Gas hydrate is geophysical, geologically and economically important for several reasons: Gas hydrates are good cap rocks for oil and natural gas. The methane hydrate itself is an important energy source. A volume of gas hydrate can store up to 164 times per volume of gas as zipped gas, and the fact that gas hydrate occurs almost all around the world. Methane seepage may indicate the existence of a deeper hydrocarbon reservoir, and the methane production and migration in the slope sediments may cause massive slope failure. Last but not least Methane gas has a minimum 22 times more global warm absorption capacity compared to carbon dioxide if it is released into the atmosphere. In other words, greenhouse gas is due to its contribution to climate change. Gas hydrates have drawn significant interest as a potential near future energy resource. Research in the production field of gas hydrates has focused on several key areas, including the feasibility of commercial production, the environmental impacts, and the technological improvements associated with the safe recovery of gas. © 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.Book Part Sample Preparation Using Microfluidic Technologies for Non-Invasive Tests(Elsevier, 2025) Oksuz, C.; Tarim, E.A.; Ozcan, H.A.; Koc, S.; Tekin, H.C.The collection of a biological sample and the steps carried out to obtain the target in a sample covers the sample preparation procedures which are one of the important steps for diagnostic tests. Removing interferences in a complex sample, preventing undesirable reactions, separating, purifying, and enriching the sample are among the steps that can be applied to samples for analysis. Non-invasive tests include samples such as urine, saliva, sweat, tear, breath and are preferred because they are simple, painless, cost-effective and cause fewer complications. In traditional methods applied in clinics, most of the steps such as centrifugation, pipetting, staining, and washing are performed manually by a technician. For this reason, tests are costly, require long analysis time, and have a significant risk of contamination and manual errors. Microfluidic technologies allow automating sample collection and preparation steps by integrating many components on a single chip. Thereby, low-volume samples can be processed automatically with high efficiency and purity. In this chapter, the sample preparation methods used in microfluidic devices for non-invasive tests analyzing human samples including sweat, urine, saliva, tears, sexual samples, and other body fluids are reviewed. This information aims to facilitate the development of potential sample preparation methods and applications for non-invasive diagnostic tests. © 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.Book Part Waste to Energy Management(Elsevier, 2025) Yagmur Goren, A.Y.; Kalinci, Y.; Dincer, I.Today, the world faces growing challenges with waste problems since people have moved the problems from past to future. The key question is: is waste a problem or a resource? The correct response to this question can be found by investigating, in more detail, the types of waste and implemented waste management methods. The chapter consists of six main sections. The first section is focused on classification, which explains what waste is and categorizes it according to the producer (e.g., municipal, industrial, and hazardous) and chemical composition (for instance, organic, inorganic, and microbiological). The second section presents legislative trends. It is seen that the waste management legislations are changing from country to country. Also, it can change over time because every technological development emerges its waste. The third section covers waste management methods such as recycling, refuse-derived fuel, landfill, and thermal methods. The landfill method is the oldest and the cheapest one. It is seen that the method will continue in the near future, too, though a lot of legal regulations have been made to reduce its usage. Thermal methods are commonly used in the industrial sector. Hence, thermal methods such as incineration, pyrolysis, and gasification are examined in detail. Considering environmental issues, thermal technology moves toward gasification systems to reduce greenhouse gas emissions and the formation of by-products. The fourth section presents illustrative examples related to using waste management methods or their combinations. Further, a case study, which consists of a circulated fluidized bed gasification system, is investigated from the exergy and exergoeconomic points of view. The chapter presents exergy and exergoeconomic analyses in detail. The analyses show that it can produce 1.17 MWe power and 0.521kg/s hydrogen with 3.33 $/kg cost from 8.5kg/s biomass waste. Finally, future scenarios for waste management are investigated. Also, to achieve zero waste targets in the future, circular economy and industrial symbiosis concepts are examined, and some successful examples from around the world are presented. © 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.Article Robust Scheduling of Crude Oil Farming and Processing Under Uncertainty(Elsevier, 2026) Yalcin, Damla; Sildir, HasanThe sulphur content in crude oil has a significant impact on refinery operations, influencing the feasibility of crude blending, the distribution of product yields, and overall economic performance. Variations in sulphur content introduce uncertainty in the short-term scheduling of crude oil loading, blending, and distillation processes. This study introduces a scenario-based stochastic optimization framework in which sulphur uncertainty is treated as a central modeling element, represented through a regression-based relationship with specific gravity (SG). The approach systematically propagates uncertainty through blending decisions, crude distillation unit (CDU) feed composition, and product yields. The problem is modeled as a mixed-integer quadratically constrained programming (MIQCP) formulation within a continuous-time scheduling framework, enabling the simultaneous optimization of timing, blending, and processing strategies. The results indicate that increased sulphur uncertainty adversely affects the distribution of yields for nine end-products, resulting in profit losses. These findings underscore the importance of explicitly managing compositional uncertainty and provide insights into cost-performance trade-offs in refinery scheduling.Article Sustainable Recovery of Critical Raw Materials From Geothermal Igneous Systems: Geochemical, Mineralogical, and Techno-Economic Insights from the Dikili-Bergama Field (Western Anatolia, Turkiye)(Elsevier, 2026) Ayzit, Tolga; Baba, AlperThe sustainable co-extraction of critical raw materials (CRMs) with renewable geothermal energy offers a dual pathway to support the circular economy and low-carbon transition. In this study, an integrated geochemical and mineralogical approach is used to comprehensively assess the recoverable lithium (Li) boron (B), strontium (Sr) and other critical raw materials in the geothermal reservoirs of the Dikili-Bergama region Turkiye. A geochemical analysis was carried out by systematic sampling and multi-element testing of geothermal water and reservoir rock. Hydrogeochemical studies of the geothermal fluids indicated the presence of remarkable concentrations of B (4.6 ppm), Sr (2.8 ppm) and Li (1.2 ppm), suggesting the possibility of active leaching processes in the deposit. Mineralogical studies using X-ray diffraction (XRD) have revealed a number of secondary mineral phases, such as quartz and labradorite, indicating the interaction between water and rock. These interactions affect not only the permeability and porosity of the deposit, but also the mobilization and precipitation of CRMs. A techno-economic analysis will be used to identify potential synergies that could improve the economic feasibility of geothermal projects in the region. The Monte Carlo simulation has shown that the Dikili-Bergama geothermal reservoirs have a potential of similar to 712 tons of Li. In this study, the CRM potential that emerged during the geothermal energy exploitation process in the region was calculated. The temporality and the process of obtaining are completely related to the extraction technology. This offers the dual benefit of renewable energy and strategic mineral extraction, contributing to sustainable resource management in volcanic environments.Article Rice-Like, Hollow, and Rhombohedral Nano-Calcite Synthesis by Carbonization(Elsevier, 2026) Kilic, Sevgi; Toprak, Gorkem; Ozdemir, EkremControlling the morphology and size of calcium carbonate (CaCO3) remains an essential challenge in the production of high-performance fillers and advanced functional materials. Here, we report a continuous carbonization strategy that enables the synthesis of monodisperse nano-calcite particles with tunable rice-like, hollow, and rhombohedral morphologies through precise control of CO2 dissolution into a flowing Ca(OH)2 solution under diffusion-limited conditions. A two-stage reactor was designed to decouple nucleation and growth by separating the gas-liquid interaction zone from a stabilization tank. pH and conductivity analyses revealed that crystallization is primarily governed by the CO2 dissolution kinetics rather than mixing intensity in the stabilization tank. SEM and XRD analyses demonstrate a distinct crystallization sequence such that initial formation of rice-like calcite, subsequent development of hollow nanoparticles through selective tip dissolution, and final transformation into rhombohedral calcite via dissolution-reprecipitation mechanism. The method provides a reproducible, template-free route for fabricating hollow CaCO3 nanoparticles, overcoming limitations of bubbletemplating and additive-mediated techniques. This scalable process provides a robust foundation for producing high-surface-area CaCO3 nanomaterials which have potential applications in thin films, ceramics, protective coatings, lightweight composites, thermal/acoustic insulation, adsorption, and catalysis, where tailored particle morphology and size can significantly enhance performance.Article Fractionation of Guaiacyl and Syringyl-Lignin Units Using Organic Solvent Nanofiltration(Elsevier, 2026) Croes, Tim; Dutta, Abhishek; Van Aelst, Korneel; Sels, Bert; Van der Bruggen, Bart; Cornet, IrisA major obstacle to employing the full potential of lignin-based aromatics is the fractionation of the monomers present in lignin, specifically the separation of guaiacyl (G) and syringyl (S) units, which possess nearly identical molecular weights (196 Da versus 166 Da) and dimensions, and identical functional groups. Such similarities make their separation highly challenging using conventional techniques and are generally considered beyond the capabilities of size-based membrane processes. This study examines the feasibility of organic solvent nano-filtration for fractionation of guaiacyl and syringyl units, and how membrane and process parameters affect separation of these two molecules. Sixteen commercially available membranes were tested with methanol and ethyl acetate as solvents. The results demonstrate that, despite the extreme similarity of the solutes, selective separation is achievable and is primarily governed by membrane material and solvent selection rather than the pore size-based molecular weight cut-off. Polyimide-based solvent-resistant membranes exhibited the highest selectivity, with a maximum observed separation factor of 3.33 obtained using a DuraMemTM 500 membrane in methanol. These findings demonstrate the potential of nanofiltration to address previously unresolved separation challenges in lignin valorization and provide a basis for further process development.Article Comparison of the Photoresponse Characteristics for 4H-SiC Schottky Barrier UV Photodetector with Graphene and Ni/Cr Electrode(Elsevier, 2026) Dulcel, Atilla Mert; Gozek, Melike; Unverdi, Ozhan; Celebi, CemGr/4H-SiC and Ni/Cr/4H-SiC Schottky junction UV photodetectors were fabricated and investigated to reveal the effect of electrode materials on the device performance such as spectral response and response speed. I-V characterization, spectral response, and response speed (on-off) measurements were conducted for the UV wavelength range between 200 and 400 nm. The maximum photo-responsivity was obtained as 0.081 A/W for Gr/4H-SiC and 0.041 A/W for Ni/Cr/4H-SiC at a wavelength of 260 nm. This result was attributed to the higher optical transmittance of the graphene electrode compared to the semitransparent Ni/Cr electrode. Zero bias response speed measurements were done under 280 nm wavelength UV light pulsed at different frequencies such as 100 Hz, 500 Hz, and 1000 Hz. The Gr/4H-SiC and Ni/Cr/4H-SiC photodetectors show distinctly different decay times of 5.04 ms and 305.1 mu s, respectively, while their rise times were found to be similar. This observation has been explained by the inclination of graphene to act as a trap site for photogenerated holes.Article Continuous Direct Lithium Extraction from Seawater Via an Unconventional Selective Solid Electrolyte(Elsevier, 2026) Li, Jinghui; Gao, Jiaxuan; Yu, Zihao; Yan, Linxue; Guo, Yafei; Demir, Mustafa; Deng, TianlongWith the significant depletion of terrestrial lithium resources, attention has shifted toward seawater, which holds the largest lithium reserves on Earth. However, extracting lithium from seawater presents a complex challenge due to its intricate composition and extremely low concentration of lithium ions. Herein, we demonstrated inexpensive Li4Ti5O12 as a selective solid electrolyte for direct lithium extraction from seawater. It extracted lithium ions from seawater at an initial concentration of 0.17 mg/L and enriched them to 22.25 mg/L in the receiving solution. The sodium and magnesium ion concentrations were only 33.5 mg/L and 0.66 mg/L. The Li/ Na selectivity (SLi/Na) and Li/Mg selectivity (SLi/Mg) were remarkably high, reaching 42,000 and 240,000, respectively. Furthermore, DFT showed that the energy required for both processes-desolvation of sodium ions and migration of ions within the crystal-is significantly higher than that for lithium ions, which explains the high selectivity of this method. XAS and XRD refinement revealed that the lithium-ion conductor remained stable without any decomposition. In addition, we designed a comprehensive process using the phase equilibrium method, enabling the direct separation of lithium hydroxide without waste when Li4Ti5O12 serves as the selective solid-state electrolyte, thereby highlighting its strong potential for industrial applications.Article Chloroaluminum Phthalocyanine Loaded Bovine Serum Albumin Nanoparticles as a Dual-Functional Nanoplatform for Sono-Photodynamic Cancer Therapy(Elsevier, 2026) Akyol-Karpuzcu, Cansu; Nartas, Eylem Doga; Calibasi-Kocal, Gizem; Akdogan, YasarChloroaluminum phthalocyanine (ClAlPc) loaded bovine serum albumin (BSA) nanoparticles (NPs) were synthesized as a dual-functional platform for photodynamic and sonodynamic therapies (PDT and SDT). ClAlPc loading did not disturb the morphology of the BSA NPs. Their spherical structure, with a size around 200 nm, was preserved upon ClAlPc loading (1 %w/w). Singlet oxygen productions in the presence of ClAlPc loaded BSA NPs or free ClAlPc were determined by ultraviolet absorption (UV-vis) spectroscopy and electron paramagnetic resonance (EPR) spectroscopy. While a slower rate of singlet oxygen formation rate after both PDT and SDT was detected by UV-vis measurements in the presence of ClAlPc loaded BSA NPs, EPR results showed a similar rate of singlet oxygen formation for both ClAlPc loaded BSA NPs and free ClAlPc. Confocal microscopy confirmed the efficient cellular uptake and perinuclear localization of the ClAlPc loaded BSA NPs in HCT-116 cancer cells. In vitro cytotoxicity studies demonstrated a dose and time dependent photo-and sonotoxic effects in the presence of ClAlPc loaded BSA. In particular, simultaneous application of light and ultrasound as sono-photodynamic therapy (SPDT) resulted in 15 % cell viability in the presence of ClAlPc loaded BSA NPs, which is much lower than individual PDT and SDT results, confirming the effect of the combination therapy on cell viability. In comparison, free ClAlPc reduced cell viability to 27 %. These findings suggest that ClAlPc loaded BSA NPs is a promising "one-for-two" nanoplatform for combined cancer therapy to reduce the limitations of both methods.