Türk-Alman Üniversitesi Kurumsal Akademik Arşivi
DSpace@TAÜ, Türk-Alman 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
Solar–Hydrogen Coupling Hybrid Systems for Green Energy
(Wiley, 2023) Bilge Coşkuner, Filiz; Balkanlı Ünlü, Esra; Civerek Yörüklü, Hülya; Karaismailoğlu Elibol, Meltem; Akar, Yağmur; San, Ali Turgay; Figen, Halit Eren; Figen, Aysel Kantürk
Green hydrogen production coupled with solar energy became a universal concept to provide more efficient energy caring for the environment within the 2030 sustainable development goals target. The green energy concept provides energy systems without negative impact on the environment, economy, and society. At this point, hydrogen became a suitable energy and energy carrier for the green to green (G2G) concept, which evaluates green resources and green systems together. Producing hydrogen energy using solar radiation lowers greenhouse emissions. It allows people to participate in environmental improvements actively, makes the energy supplied cycles more sustainable, and protects the right to life of future generations. Solar energy is a primer source that can be directly adapted to provide steady power for the G2G system. Nowadays, recent trends on fuel cell, electrolyzer, and photovoltaic and photoelectrochemical technology within solar energy systems as a hybrid combination have a critical approach to realize G2G systems based on hydrogen and solar energy. This chapter focuses on G2G system, the combination of solar energy – hydrogen, fundamentals on electrolysis, photovoltaic panel, fuel cell, and electrolyzer or their hybrid combinations used for green hydrogen production from solar energy; also, thermochemical, photobiological, and photoelectrochemical production methods have been briefly introduced compared and outlined the future remarks.
Characteristic Influence of Cerium Ratio on PrMn Perovskite-Based Cathodes for Solid Oxide Fuel Cells
(2025) Karaismailoğlu Elibol, Meltem; Balkanlı Ünlü, Esra; Figen, Halit Eren
In this study, cerium with different ratios (x = 0 (zero), 0.1, 0.15, 0.5) was added to the PrMn structure as an A-site material to evaluate characteristic behavior as a potential cathode material for solid oxide fuel cells. The PrxCe1−xMnO3−δ electrocatalysts were synthesized using the sol–gel combustion method and were assessed for their electrochemical, phase, and structural properties, as well as desorption and reducibility capabilities. Phase changes, from orthorhombic to cubic structures observed upon cerium additions, were evaluated via the X-Ray diffraction method. X-Ray photoelectron spectroscopy (XPS) showed the valence states of the surface between the Ce4+/Ce3+ and Pr4+/Pr3+ redox pairs, while oxygen temperature programmed desorption (O2-TPD) analysis was used to evaluate the oxygen adsorption and desorption behavior of the electrocatalysts. Redox characterization, evaluated via hydrogen atmosphere temperature-programmed reduction (H2-TPR), revealed that a higher cerium ratio in the structure lowered the reduction temperature, suggesting a better dynamic oxygen exchange capability at a lower temperature for the Pr0.5Ce0.5MnO3−δ catalyst compared to the electrochemical behavior analysis by the electrochemical impedance spectroscopy method. Moreover, the symmetrical cell tests with Pr0.5Ce0.5MnO3−δ electrodes showed that, when combined with scandia-stabilized zirconia (ScSZ) electrolyte, the overall polarization resistance was reduced by approximately 28% at 800 °C compared to cells with yttria-stabilized zirconia (YSZ) electrolyte
Amorphous Metal−Organic Framework-Coated Halloysite Nanotubes as Efficient Sulfur Immobilizers for Lithium−Sulfur Batteries
(2025) Sijia, Cao; Karaismailoğlu Elibol, Meltem; Rodriguez, Ayllon Yael; Qingping, Wu; Johannes, Schmidt; Yan, Lu
Lithium−sulfur (Li−S) batteries, known for their high theoretical energy density, have been considered as one of the most promising candidates for next-generation batteries. However, further
optimization of their electrochemical performance is often hindered by a sluggish polysulfide conversion process. Recently, amorphous metal−organic frameworks (aMOFs) with numerous unsaturated
metal sites have emerged as efficient catalysts, particularly in boosting polysulfide conversion. However, the collapse of the long-range periodic porous structure makes it difficult to access the internal part
of micrometer-sized aMOFs, thereby limiting the further improvement of their catalytic activity. Herein, we propose a promising core−
shell structure, constructed by using a sustainable halloysite nanotube as a substrate to support aMOF. The triethylamine vapor diffusion method is applied to regulate the kinetics of aMOF growth by modulating the deprotonation of organic ligands, leading to the
successful deposition of nanosized aMOF shells onto halloysite nanotubes. This aMOF/halloysite composite structure exhibits
better catalytic activity toward polysulfide adsorption and conversion in the Li−S battery when compared with the pure halloysite. In
addition, the composite also shows a better cycling performance, retaining a specific capacity of 510 mAh g−1 after 350 cycles at 1.0
C. This work presents an efficient amorphous MOF shell-coating structure as a catalyst in facilitating the process of polysulfide conversion, paving the way for the development of highly active aMOF-based catalysts in the future.
Life cycle and characteristic analysis of bismuth doped barium zirconate perovskites: Towards enhanced oxygen mobility with reduced ecotoxicity
(Elsevier, 2025) Salt, Selin; Koşma, Elvan Burcu; Figen, Halit Eren; Karaismailoğlu Elibol, Meltem
BaZrO3-based perovskite oxides are promising for electrocatalytic applications due to their high chemical stability and electrical conductivity. In this study, BaZrO3 perovskite was modified by various amounts of bismuth
doping, and BaZr(1-x)BixO3 (x = 0.1, 0.2, 0.3, 0.4) perovskites obtained were characterized physicochemically. The results reveal that by generating oxygen vacancies and increasing oxygen mobility, proven by enhanced
oxygen adsorption ability, Bi doping significantly improves the redox ability. Among synthesized perovskites, BaZr(1-x)BixO3 (x = 0.2) demonstrates the highest potential in promising electrocatalytic reactions. Additionally, the Life Cycle Assessment (LCA) of all perovskites reveals that energy consumption during the synthesis is the primary contributor to environmental impacts. However, the results show that the ecological implications for perovskites with doping levels up to x = 0.2 are lower than for samples with higher doping levels.
Paylı Mülkiyette Pay Üzerinde Tasarruf ve Payın Korunması
(Filiz Kitabevi, 2025) Şahin, Samet
Mülkiyet, tek kişi mülkiyeti ve birlikte mülkiyet şeklinde yapılan ayrıma göre iki çeşittir. Birlikte mülkiyet de kendi içerisinde paylı mülkiyet ve elbirliği mülkiyeti olmak üzere ikiye ayrılmaktadır. Elbirliği mülkiyetinin sadece kanunda öngörülen hallerde mümkün olduğu (TMK m.701/1) düşünüldüğünde asıl olan birlikte mülkiyet türünün paylı mülkiyet olduğu anlaşılmaktadır. Bu nedenle paylı mülkiyet ilişkisinin uygulamada sıkça karşımıza çıkması gündeme gelmektedir. Paylı mülkiyet ilişkisinin temelini oluşturan "pay" kavramı ise bu ilişkinin temelini oluşturmakta ve üzerine inceleme yapılmayı gerektirmektedir. Bu kapsamda paydaşların kendi payları üzerinde gerçekleştirebilecekleri tasarruf işlemleri ve paylarına karşı gerçekleşecek ihlallere karşı paylarını hangi yollarla koruyabilecekleri çalışmamızın ana konusunu oluşturmaktadır.
