TR Dizin İndeksli Yayınlar / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7149
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Article Citation - WoS: 1Citation - Scopus: 2Lacoo3 Is a Promising Catalyst for the Dry Reforming of Benzene Used as a Surrogate of Biomass Tar(Tubitak Scientific & Technological Research Council Turkey, 2024) Çağlar, Başar; Üner, DenizTar build-up is one of the bottlenecks of biomass gasification processes. Dry reforming of tar is an alternative solution if the oxygen chemical potential on the catalyst surface is at a sufficient level. For this purpose, an oxygen-donor perovskite, $LaCoO_3$, was used as a catalyst for the dry reforming of tar. To circumvent the complexity of the tar and its constituents, the benzene molecule was chosen as a model compound. Dry reforming of benzene vapor on the $LaCoO_3$ catalyst was investigated at temperatures of 600, 700, and 800 °C; at $CO_2/C_6H_6$ ratios of 3, 6, and 12; and at space velocities of 14,000 and 28,000 h–1. The conventional Ni(15 wt.%)/$Al_2O_3$ catalyst was also used as a reference material to determine the relative activity of the $LaCoO_3$ catalyst. Different characterization techniques such as X-ray diffraction, $N_2$ adsorption-desorption, temperature-programmed reduction, and oxidation were used to determine the physicochemical characteristics of the catalysts. The findings demonstrated that the $LaCoO_3$ catalyst has higher $CO_2$ conversion, higher $H_2$ and CO yields, and better stability than the Ni(15 wt.%)/γ-$Al_2O_3$ catalyst. The improvement in activity was attributed to the strong capacity of $LaCoO_3$ for oxygen exchange. The transfer of lattice oxygen from the surface of the $LaCoO_3$ catalyst facilitates the oxidation of carbon and other surface species and leads to higher conversion and yields.Article Citation - WoS: 3Citation - Scopus: 3Β-Ketoenamine-linked covalent organic framework for efficient iodine capture(Tubitak Scientific & Technological Research Council Turkey, 2024) Büyükçakır, OnurExploring the materials that effectively capture radioactive iodine is crucial in managing nuclear waste produced from nuclear power plants. In this study, a β-ketoenamine-linked covalent organic framework (bCOF) is reported as an effective adsorbent to capture iodine from both vapor and solution. The bCOF’s high porosity and heteroatom-rich skeleton offer notable iodine vapor uptake capacity of up to 2.51g $g^{–1}$ at 75 °C under ambient pressure. Furthermore, after five consecutive adsorption-desorption cycles, the bCOF demonstrates high reusability performance with significant iodine vapor capacity retention. The adsorption mechanism was also investigated using various ex situ structural characterization techniques, and these mechanistic studies revealed the existence of a strong chemical interaction between the bCOF and iodine. The bCOF also showed good iodine uptake performance of up to 512 mg $g^{–1}$ in cyclohexane with high removal efficiencies. The bCOF’s performance in adsorbing iodine from both vapor and solution makes it a promising material to be used as an effective adsorbent in capturing radioactive iodine emissions from nuclear power plants.Article Citation - WoS: 1Citation - Scopus: 2Integration of Daylight Use and Analysis in Double Skin Facades: a Literature Review(Gazi Universitesi, 2024) Kazanasmaz, Tugce; Ünlütürk, Mustafa SerhanDouble skin facades (DSF) aim to save energy reducing the heat losses in buildings. They are visually appeal while allowing to use daylight efficiently. Such facade systems can reduce glare and distribute daylight evenly in the interior when compared to conventional facade systems. That is a result of cavities between two glass facades and locating sun shading elements in them, although this system provides a high level of transparency. As their primary purpose of application is to ensure thermal performance and ventilation, most studies in literature have focused on these. This study started with the hypothesis that studies examining daylight performance in DSFs are more limited than studies examining thermal performance and that daylight optimization methods are not used sufficiently in DSFs. In this context, the study aims to analyze studies focusing on daylight performance of DSFs. The review targets results of such current studies to guide future ones providing feedback knowledge. This may help to better technical developments in such facades and make them prevail in constructions or in retrofitting So, it contributes to literature in this sense. Recent studies are shown in tabulated form and interpreted in detail with graphics. considering their methodologies, daylight parameters and findings. Results show that the daylight parameter is one of the most important issues that architects or designers should consider from the moment they start the design, and they should make their designs based on the optimum penetration of daylight into the building. Consequently, this review presents that the use of daylight optimization has started to be used in recent studies dealing with DSFs. A DSF design can optimally get daylight into the interior can be made by using this method more frequently.Article Citation - Scopus: 3A Brief Overview on Geothermal Scaling(General Directorate of Mineral Research and Exploration (MTA), 2023) Isık, Tuğba; Baba, Alper; Chandrasekharam, Dornadula; Demir, Mustafa M.; Isık, Tuğba; Baba, Alper; Demir, Mustafa MuammerHot spring waters are rich in terms of minerals. Since there are dramatic changes in thermodynamic parameters in geothermal power plants, such as a decrease in temperature and pressure, severe precipitation occurs throughout the system components in an uncontrolled manner. There are three main chemistries in deposits: carbonates (mainly calcium carbonates), silicates (metal silicates), and sulphides (antimony sulphide-stibnite). Energy harvesting is remarkably reduced out of the insulating nature of the deposit. Various actions need to be taken to mitigate this undesirable issue of scaling in geothermal systems. Geothermal systems are in fact quite complex, and the composition of brine and, accordingly, the chemistry of the deposit are not identical. Therefore, each system should be studied individually, and a tailor-made remedy should be developed. In this overview, the types of deposits in terms of chemistry and the actions (pH modification or antiscalant dosing) that should be taken to reduce scaling are mentioned, and potential chemistries of antiscalants are given.Article Citation - WoS: 1Citation - Scopus: 2Geothermal Power Corridor-Connecting the Middle East Countries(Maden Tetkik ve Arama Genel Mudurlugu-mta, 2023) Chandrasekharam, DornadulaThe Middle East economy and life depend on imports, be it food, water, or energy, despite each country in the region having enormous energy resources to exploit and reduce dependency on countries outside the region and develop a socioeconomic model of regional cooperation and synergy. An estimated 371 TWh of electricity available from geothermal energy resources can be utilized by these countries to support basic needs and be free from food-energy-water imports by sharing their energy resources. The total amount of CO2 emissions from these countries is currently 945 x 106 kg, so these countries can further earn about 92 million euros from carbon savings, by using geothermal energy along this corridor. This amount can be utilized for augmenting the energy supply from geothermal sources. In this work, the available geothermal resources are evaluated, and suggestions are made how this energy can be best utilized for peaceful existence and cooperation in the region.Article Citation - WoS: 6Citation - Scopus: 8The Potential, Utilization and Development of Geothermal Energy in Türkiye(Maden Tetkik ve Arama Genel Mudurlugu-mta, 2023) Sener, Mehmet Furkan; Uzelli, Taygun; Akkus, Ibrahim; Mertoglu, Orhan; Baba, AlperGeothermal energy is a natural resource that can be utilized directly or by converting to other types of energy. Considering the diversity of the geological structure of Turkiye, the geothermal systems have developed depending on young tectonic and volcanic active rock. Western and Central Anatolia are especially rich in geothermal resources. The geothermal well with the hottest well-bottom temperature was drilled in Central Anatolia, and the well-bottom temperature was measured as 341 degrees C at a depth of 3845 meters. In 2022, Turkiye's electricity generation capacity and the total installed direct heat use reached 1663 MWe and 5113 MWt, respectively. Considering Anatolia's Curie depth and heat flux, the probable thickness of the batholith can be regarded as 10 km. For example, the total granitoid area of Western Anatolia is 4221 km2 and at least 2% of this granitoid can provide approximately 8x107 MWh of electricity by Enhanced Deep Geothermal Systems (EDGS). When all granites in Turkiye are considered, it is expected that the future capacity of Turkiye will be much higher with drilling research and development studies and the discovery of new fields. This capacity will exceed 100.000 MWt levels in the medium term, especially with the addition of EDGSs.Article Yüksek Derecede Kurum Üreten 2b Gazyağı/hava Difüzyon Alevleri Üzerinde Diferansiyel Yayılımın ve Basıncın Etkileri(Gazi Üniversitesi, 2024) Korucu, Ayşe; Miller, RichardBu çalısmada, dört farklı ortam basıncında kurum, oluşum ve yıkım süreçlerini incelemek amacıyla, yoğun kurum üreten Gazyağı/Hava alevleri, gerçek gaz (GG) ve ideal gaz (İG) hal denklemleri ve Lewis (Le) sayısının bir olarak kabul edildiği modeller ele alınmıştır. Yarı-genel kurum oluşum ve yıkım modelini içeren indirgenmiş Gazyağı/Hava mekanizması (29-adım, 10 çeşit gaz) 2 boyutlu (2B) Direk Sayısal Simülasyon (DNS) verilerini oluşturmak için MPI FORTRAN ile kodu yazılmış bir program kullanılmıştır. Le sayısının bire eşit kabul edildiği alev tahminlerinin, Le sayısının bire eşit olmadığı (genelleştirilmiş difüzyon) durumların sayısal sonuçlarından elde edilen alev yapısı ve kurum özelliklerinin istatiksel olarak benzerlik sağlayıp sağlamadığı araştırılmıştır. Bu bağlamda yapılan çalışmanın sonucunda, ortam basınçları 1, 5, 10 ve 35 atm olan Le sayısının bir olarak kabul edildiği GGLE ve İGLE modelleri ile üretilmiş 2B DNS alev tahminlerinin kurum özelliklerinin ve alev yapılarının yanlış hesaplanmasına yol açtığı belirlenmiştir.Article Citation - WoS: 5Citation - Scopus: 5Evaluation of Liposomal and Microbubbles Mediated Delivery of Doxorubicin in Two-Dimensional (2d) and Three-Dimensional (3d) Models for Breast Cancer(Galenos Publishing House, 2021) Aydın,M.; Özdemir,E.; Altun,Z.; Kılıç,S.; Aktaş,S.Objective: Liposomal cancer treatment strategies are useful in removing the side effects that were the main concern in recent years. In this study, we prepared microbubble (MBs) conjugated with DOX-loaded liposomes (DOX-loaded MBs) and investigated their effectiveness in in vitro breast cancer cells in two dimensions (2D) and three dimensions (3D). Materials and Methods: With this aim, breast cancer cells with different features (4T1, MDA-MB231, MCF-7) were growth in 2D and 3D dimensions. The cytotoxic and cell death effects under different conditions, durations and doses were evaluated with WST-1, trypan-blue, colony counts. Apoptotic effects were investigated with flow cytometric Annexin-V-PI and immunohistochemical (Ki-67, caspase 3, 8, 9) methods. Results: After free DOX and LipoDOX were applied, the proliferation index of three cell lines reduced. Intrinsic and extrinsic apoptotic pathways were activated in both 2D and 3D models. However, this effect was observed at lower levels in the 3D model due to the difficulty of diffusion of DOX into the spheroids. Additionally, the suitability of the 3D model for breast cancer cells was supported by formation of ductus-like structures and spheroids. Cell deaths were not observed significantly with the DOX-loaded microbubbles due to rising of MBs to the surface and not reaching spheroids held in matrigel of 3D model. Conclusion: DOX and LipoDOX showed anti-proliferative and apoptosis-inducing effects in breast cancer cells. However, these effects indicated variability depending on the cell lines and 2D or 3D model types. ©Copyright 2021 by the the Turkish Federation of Breast Diseases Societies.Article Citation - WoS: 4Citation - Scopus: 4Recent Nation Gardens and Historical Development of Public Green Spaces in Turkey;(Istanbul University Press, 2020) Uzun,I.K.; Şenol,F.; Uzun, İpek Kaştaş; Şenol, FatmaFocusing on contemporary Turkey's "nation gardens" and the state and governmental policies to build them, this study investigated the development processes and design features of these public green spaces with respect to those from past eras of Turkey (extending to Ottoman and pre-Ottoman history) and the development of public green spaces as the state's symbolic and spatial tools. The study relied on secondary sources about public green spaces from past eras of Turkey and also on the review of online news about "nation gardens" initiated after President Erdoǧan's announcement in May 2018. Our findings suggested that public green spaces in Turkey have played an important role in displaying the state's power nationally and internationally as well as to transfer the state's ideologies to people and thus, to build new identities of 'citizens.' Interestingly, in sharing these intentions of past policies for public green spaces, the recent introduction of nation gardens differs from those in the 19th and 20th century. Without any emphasis on modernization goals in the western-style, recent official talks described nation gardens as a way to raise Turkey and the government's reputation both nationally and internationally, while also referring to past eras but with other characteristics as the source of "traditions" extending to today. © 2020 The authors.Article Citation - WoS: 1Citation - Scopus: 1Proposals for Monitoring Current Conservation Condition of Historical Masonry Buildings: Matrone Church and Çardak Han Cases;(Istanbul University Press, 2020) Durmuşlar,F.; Ipekci,E.; Turan,M.H.; Aktaş,E.The aim of this study is to transfer the international developments related to the process of diagnosis and monitoring of historical masonry structures to the national area. The method chosen is to test the recommendations made at the international level on national cases and to discuss the results obtained by comparing them. A review of preliminary studies, on-site observations, measured surveys, material characterizations, mapping and visual analysis have been carried out. An examination of structural characteristics and observed failures have also been detailed. Related risks have been evaluated with criteria developed by taking into consideration condition classes defined in the UNI EN 16096, titled Conservation of Cultural Property - Condition Survey and Report of Built Cultural Heritage. According to the defined risks and classes, priorities of interventions were determined. Two historical masonry buildings which possess characteristics of different periods and present different damage types were selected: Matrone Church in Ildiri, Çeşme, Izmir and Çardak Han in Çardak, Denizli. The condition reports of the selected buildings have been prepared. The critical points in the condition reporting of historical masonry buildings were determined: accurate comprehension of the authentic structural characteristics and related failures have priority in maintaining historical masonry structures. Identification of condition class and risk assessment of each historic masonry building should be made in accordance with a standard specific to the cases of our country, but in line with the European standards and current developments in the field of architectural restoration. Thus, it will be possible to evaluate the conservation state of our masonry assets in comparison with each other. The content and priority of interventions can be well planned with the participation of the necessary disciplines. © 2020 The authors.