Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Seismic Risk Prioritization of Stone Masonry Building Stock in Urla Peninsula Based on Rapid Assessment Techniques(Turkish Chamber of Civil Engineers, 2026) Karavin, Y.S.; Akdag, N.; Demir, U.This study aims to investigate seismic risk of stone masonry buildings in the Urla Peninsula, a region of historical and architectural significance within İzmir, Türkiye. A total of 100 stone masonry buildings were surveyed and documented with a focus on their architectural characteristics, including construction techniques, material types, structural configurations, and age. Data on the properties of all surveyed buildings are provided in an open-access database. Based on the survey, multiple rapid seismic performance assessment methods were applied to evaluate the vulnerability of these structures. These included: i) FEMA P-154 Rapid Visual Screening, ii) Provisions for the Seismic Risk Evaluation of Existing Buildings under Urban Renewal Law (RBTE-2019), iii) Seismic Vulnerability Index for Vernacular Architecture (SVIVA), and iv) the Masonry Quality Index (MQI). The comparative use of different methods is intended to investigate the relative influence of parameters shaping the seismic performance of the masonry building stock rather than to align their scores. The outcomes of this research are expected to contribute to the current risk mitigation efforts for stone masonry buildings in İzmir, thereby supporting regional seismic resilience planning. © 2026, Turkish Chamber of Civil Engineers. All rights reserved.Article Citation - WoS: 2Citation - Scopus: 1Çelik Fiber Katkısının Farklı Boyuna Donatı Oranına Sahip Betonarme Döşemelerin Zımbalama Davranışı Üzerinde Etkileri(2019) Saatci, Selcuk; Yasayanlar, Suleyman; Yasayanlar, Yonca; Batarlar, BaturaySunulan çalışmada her iki yönde birbirine dik 0,004 (D1 serisi) ve 0,002 (D2 serisi) oranında boyuna donatıiçeren 2150x2150x150 mm boyutlarında iki grup betonarme döşeme, hacimce %0, %0,5, %1 ve %1,5oranında çelik fiber katkısı içeren beton karışımlarıyla dökülmüştür. Üretilen toplam sekiz döşeme ortanoktalarından statik yük altında test edilmişlerdir. Çelik fiber katkısı olmayan numunelerde yüksek boyunadonatı oranına sahip döşeme boyuna donatısında akma gerçekleşmeden gevrek bir şekilde zımbalamagöçmesi oluşurken düşük boyuna donatı oranına sahip döşeme zımbalama gerçekleşmeden önce çok dahasünek bir davranış göstermiştir. Çelik fiber katkısı her iki boyuna donatı oranında da iki kata varan oranlardazımbalama dayanımı artışlarına sebep olmuştur. Ancak D1 serisi döşemelerde çelik fiber katkısı maksimumyer değiştirmeleri önemli ölçüde arttırırken D2 serisinde maksimum yer değiştirmelerde önemli bir farkoluşmamış, bu döşemelerin yer değiştirmesi boyuna donatının akması tarafından kontrol edilmiştir. Çelikfiber katkısı oranının arttırılması D1 serisi döşemelerde dayanımın ve maksimum yer değiştirmelerinartmasına sebep olurken, D2 serisi döşemelerde %1'in üstü çelik fiber katkı oranları davranışta önemli birfark oluşturmamıştır. Yapılan deneyler Kritik Kesme Çatlağı Teorisi kullanılarak analitik olarakmodellenmiş ve bu tip modelleme ile ilgili bazı iyileştirmeler önerilmiştir.Article Experimental Study of Evolution of Breach Resulting From Piping at Upper Part of Earth-Fill Dam(Turkish Chamber Civil Engineers, 2025) Guney, Mehmet Sukru; Tayfur, Gokmen; Bor, Asli; Okan, Merve; Dumlu, Emre; Aklık, PelinPiping and overtopping are the most important causes of earth-fill dam failure. Such dams may erode under seepage, causing a reduction in the structural strength. The aim of this study was to investigate the temporal evolution of the breach and flow rate from the breach resulting from the piping in earth-fill dams. The experiments were carried out at Hydraulics Laboratory of Civil Engineering Department of İzmir University of Economics. The dam was constructed by using a mixture consisting of 85 % sand and 15 % fine (low plasticity clay). In the first scenario a circular tunnel with a diameter of 2 cm was created along the centreline at 6 cm below the dam crest whereas in the second one it was located at the upper edge. Six cameras at different locations recorded the evolution of the progress of the breach formation. The pump flow rate was measured by magnetic flow meter, and the continuity equation was used to calculate the flow rate values from the breach. The time-varied values of the total breach areas were determined using the Gauss Area formula. The image processing method was also applied in the determination of the breach areas. The time-dependent changes of water depth in the channel were also recorded. The obtained experimental findings are presented and commented, together with the universal dimensionless curves. The failure of the dams occurred mainly because of the head cut erosion developed from downstream to upstream. When breaching started, the orifice flow was converted to open channel flow where breach bottom behaved like a broad crested weir. In the second scenario, the rigid lateral side considerably influenced the flow rate and the development of the breach. The peak flow rate corresponding to the first scenario was found approximately 2.3 times greater than that of the second one. The maximum values of all the breach parameters were reached earlier in the case of the seepage along the centerline. The ratios between the values corresponding to the first and the second scenarios were found as 3.25 and 1.75 for maximum breach areas at downstream and at upstream sides, respectively. These ratios were 2.44 and 1.37 for the average breach widths at downstream and upstream sides, respectively. A very good agreement was found between the area values obtained from Gauss area method and image processing technique, in both scenarios. This fact demonstrated that either of these two approaches can be used to determine the time-dependent breach areas. These experimental findings provide the opportunities for the calibration and validation of the numerical models used in the relevant numerical investigations. This study also offers guidance for the strategies concerning emergency action plans related to the failure of homogeneous earth-fill dams when the piping starts at upper part of the homogeneous earth-fill dams.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: 2Application of Endurance Time Method in Seismic Assessment of Rc Frames Designed by Direct Displacement-Based Procedure(Turkish Chamber of Civil Engineers, 2024) Karımzada, Nisar Ahmad; Shırkhanı, Amir; Aktaş, EnginThis paper addresses the Direct Displacement-Based Design (DDBD) approach of multi-story RC frame structures consistent with changes to design criteria between Turkish earthquake codes of TSC-2007 and TBEC-2018. The corresponding response modification factor (R) of structures designed based on the DDBD approach is also estimated in this research. The design base shear forces of both codes are compared considering different R factors and also with that of the DDBD approach. The results showed that the DDBD approach, as per TBEC-2018, provides RC frame structures with higher R values compared to the similar approach in accordance with TSC-2007. The Endurance Time (ET) method is a time history-based procedure for seismic assessment of structures under intensifying dynamic excitations aided to judge their performance at various intensity levels. Since, up to now, the ET method has not been considered to evaluate the performance of the structures designed by the DDBD approach, this paper addresses this issue. The ET performance curves of RC frames show that structures designed by the DDBD approach in accordance with TBEC-2018 exhibit higher Interstory Drift Ratios (IDRs) values than TSC-2007 at various hazard levels.Article Blank Frame and Intensity Variation Distortion Detection and Restoration Pipeline for Phase-Contrast Microscopy Time-Lapse Images(Aves, 2024) Ucar, Mahmut; Iheme, Leonardo O.; Onal, Sevgi; Pesen-Okvur, Devrim; Yalcin-Ozuysal, Ozden; Toreyin, Behcet U.; Unay, DevrimIn this study, we propose a preprocessing pipeline for the detection and correction of distorted frames in time-lapse images obtained from phase-contrast microscopy. The proposed pipeline employs the average intensities of frames as a foundational element for the analysis. In order to evaluate the degree of correction required for intensity variance, a normalization technique is applied to the difference between the average intensity of a specific frame and the median average intensity of all frames within the study. Our restoration method increases the histogram similarity between the distorted and non-distorted frames, preserves trans-passing pixels in regions of interest, and mitigates the development of additional distortions. The efficacy of the proposed method was evaluated using 15 395 time-lapse image frames from 27 experiments using our own dataset and 830 time-lapse images from four different experiments obtained from the cell tracking challenge. The results of the validation demonstrate a high degree of numerical and visual accuracy of the proposed pipeline.Article Citation - WoS: 7Citation - Scopus: 8Ascorbic Acid Enhances the Metabolic Activity, Growth and Collagen Production of Human Dermal Fibroblasts Growing in Three-Dimensional (3D) Culture(Gazi Üniversitesi, 2023) Dikici, SerkanTissue engineering (TE) enables the development of functional synthetic substitutes to be replaced with damaged tissues and organs instead of the use of auto or allografts. A wide range of biomaterials is currently in use as TE scaffolds. Among these materials, naturally sourced ones are favorable due to being highly biocompatible and supporting cell growth and function, whereas synthetic ones are advantageous because of the high tunability on mechanical and physical properties as well as being easy to process. Alongside the advantages of synthetic polymers, they mostly show hydrophobic behavior that limits biomaterial-cell interaction and, consequently, the functioning of the developed TE constructs. In this study, we assessed the impact of L-Ascorbic acid 2-phosphate (AA2P) on improving the culture conditions of human dermal fibroblasts (HDFs) growing on a three-dimensional (3D) scaffold made of polycaprolactone (PCL) using emulsion templating. Our results demonstrated that AA2P enhances the metabolic activity and growth of HDFs as well as collagen deposition by them when supplemented in their growth medium at 50 µg/mL concentration. It showed a great potential to be used as a growth medium supplement to circumvent the disadvantages of culturing human cells on a synthetic biomaterial that is not favored in default. AA2P's potential to improve cell growth and collagen deposition may prove an effective way to culture human cells on 3D PCL PolyHIPE scaffolds for various TE applications.Article Vascularized Mini Cooling Channels To Achieve Temperature Uniformity: Battery Thermal Management and Electronic Cooling(MIM RESEARCH GROUP, 2023) Coşkun, Turgay; Çetkin, ErdalHere we propose to use of distinct vascularized plates to be used in the applications of battery thermal management and electronic cooling. The temperatures of battery cells increase during charge and discharge; and elevated temperature values in them accelerated degradation and even may trigger battery fire because of the thermal runaway. Therefore, thermal management system is a necessity for battery packs to increase the battery performance and diminish the risk factors in the electric vehicles. Generally, high amount of heat is released in the high capacity (>15 Ah) cells in short time interval under fast charge/discharge conditions; thus, thermal management of the battery system can be achieved with liquid cooling in that situation. A silicon heater system which represents the thermal behavior of a battery cell is manufactured based on the literature and it is used in experiments. Such a method has not proposed up to now in the literature, so the study may be creating a new experimental procedure for future studies without the risk of battery fire/degradation to uncover even extreme conditions experimentally. Electronic cooling is also in prime importance due to enhanced computing requirement of current systems, and vascularized plates can solve the hot spot problems occurring with decreased energy consumption. According to the results, the cooling capacity of the vascularized plates are calculated as 20W, and a battery cell can be kept within its optimal operating temperature range when the heat loads up to 30W. Also, the temperature uniformity along the surface of mimic of the battery is satisfied by vascularized plates.