Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 38Citation - Scopus: 43Quantitative Evaluation of the Damage To Rc Buildings Caused by the 2023 Southeast Turkey Earthquake Sequence(SAGE Publications, 2024) Pujol, Santiago; Bedirhanoğlu, İdris; Dönmez, Cemalettin; Dowgala, Jeffrey D.; Eryılmaz Yıldırım, Meltem; Klaboe, Kari; Köroğlu, Fahri Baran; Lequesne, Rémy D.; Öztürk, Baki; Pledger, Liam; Sönmez, EgemenData from 15 earthquakes that occurred in 12 different countries are presented showing that, without better drift control, structures built with building codes allowing large seismic drifts are likely to keep leaving a wide wake of damage ranging from cracked partitions to building overturning. Following the earthquake sequence affecting southeast Turkey in 2023, a team led by Committee 133 of the American Concrete Institute surveyed nearly 250 reinforced concrete buildings in the area extending from Antakya to Malatya. Buildings ranging from 2 to 16 stories were surveyed to assess their damage and evaluate the robustness of their structures in relation to overall stiffness, as measured by the relative cross-sectional areas of structural walls and columns. The majority of the buildings were estimated to have been built in the past 10 years. Yet, the structures surveyed were observed to have amounts of structural walls and columns comparable with amounts reported after the Erzincan (1992), Duzce (1999), and Bingol (2003) Earthquakes in Turkey. These amounts are, on average, much smaller than the wall and column amounts used in Chile and Japan. Because of that lack of robustness and given the intensities of the motions reported from Antakya to Malatya (with 10 stations with peak ground velocity (PGV) of 100 cm/s or more), it is concluded that structures in this region experienced large drifts. Excessive drift (1) exposed a myriad of construction and detailing problems leading to severe structural damage and collapse, (2) induced overturning caused by p-delta for some buildings, and (3) caused widespread damage to brittle masonry partitions. The main lesson is simple: ductility is necessary but not sufficient. It is urgent that seismic drift limits are tightened in high-seismicity regions worldwide. © The Author(s) 2024.Article Citation - WoS: 15Citation - Scopus: 17Effects of Nanosecond Laser Ablation Parameters on Surface Modification of Carbon Fiber Reinforced Polymer Composites(SAGE Publications, 2023) Martin, Seçkin; İplikçi, Hande; Barışık, Murat; Türkdoğan, Ceren; Yeke, Melisa; Nuhoğlu, Kaan; Esenoğlu, Gözde; Tanoğlu, Metin; Aktaş, Engin; Dehneliler, Serkan; İriş, Mehmet ErdemRemoval of contaminants and top polymer layer from the surface of carbon-fiber-reinforced polymer (CFRP) composites is critical for high-quality adhesive-joining with direct bonding to the reinforcing fiber constituents. Surface treatment with a laser beam provides selective removal of the polymer matrix without damaging the fibers and increasing the wettability. However, inhomogeneous thermal properties of CFRP make control of laser ablation difficult as the laser energy absorbed by the carbon fibers is converted into heat and transmitted through the fiber structures during the laser operation. In this study, the effect of scanning speed and laser power on nanosecond laser surface treatment was characterized by scanning electron microscope images and wetting angle measurements. Low scanning speeds allowed laser energy to be conducted as thermal energy through the fibers, which resulted in less epoxy matrix removal and substantial thermal damage. Low laser power partially degraded the epoxy the surface while the high power damaged the carbon fibers. For the studied CFRP specimens consisting of unidirectional [45/0/?45/90]2s stacking of carbon/epoxy prepregs (HexPly®-M91), 100 mJ/mm2 generated by 10 m/s scanning speed and 30 W power appeared as optimum processing parameters for the complete removal of epoxy matrix from the top surface with mostly undamaged carbon fibers and super hydrophilic surface condition. © The Author(s) 2023.Article Citation - WoS: 3Citation - Scopus: 3Selfless Subjectivities That (re)build the Nation: Remaking the Modern Turkish Woman in the Early Republican Period in Turkiye(SAGE Publications, 2023) Yakalı, Dikmen; Ataman, BoraThis study explores the newly constructed female identities of the Early Republican Era in Turkiye (1923-1945). Through a thematic analysis of three contemporary women's magazines (Aile Dostu, Ev-Is, and Asrin Kadini) it aims to examine how conceptualizations of marriage and family were refashioned in the magazines to fit in the images within the newly constructed domestic ideologies of the state. We argue that the selfless subjectivities offered by the magazines point to dialogically constructed narrative identities which are not stable but fluid. The women's magazines of the Era aimed to reconstruct new identities by representing the Republic's ideas and official ideology to its people. Thus, they became one of the tools of social engineering in the way of transforming the nation into a modern, Westernized one. Analysing these magazines help us identify the repertoire of subjectivities and narrative identities from which women drew while making sense of their selves during an era of transformation.Article Citation - WoS: 3Citation - Scopus: 5Deterioration of Pre-War and Rehabilitation of Post-War Urbanscapes Using Generative Adversarial Networks(SAGE Publications, 2023) Çiçek, Selen; Turhan, Gözde Damla; Taşer, AybükeThe urban built environment of contemporary cities confronts a constant risk of deterioration due to natural or artificial reasons. Especially political aggression and war conflicts have significant destructive effects on architectural and cultural heritage buildings. The post-war urbanscapes demonstrate the striking effects of the armed conflicts during the hot war encounters. However, the residues of the urbanscapes become the actual indicators of damage and loss. Since today we can make future predictions using a variety of machine learning algorithms, it is possible to represent hybrid projections of urban heterotopias. In this context, this research proposes to explore dystopian post-war projections for modern cities based on their architectural styles and demonstrate the utopian scenarios of rehabilitation possibilities for the damaged urban built environment of post-war cities by using generative adversarial network (GAN) algorithms. Two primary datasets containing the post-war and pre-war building facades have been given as the input data for the CycleGAN and pix2pix GAN models. Thus, two different image-to-image GAN models have been compared regarding their ability to produce legible building facade projections in architectural features. Besides, the machine learning process results have been discussed in terms of cities' utopian and dystopian future predictions, demonstrating the war conflicts' immense effects on the built environment. Moreover, the immediate consequence of the destructive aggression on tangible and intangible architectural heritage would become visible to inhabitants and policymakers when the AI-generated rehabilitation potentials have been exposed.Article Citation - WoS: 8Citation - Scopus: 8Improving Adhesive Behavior of Fiber Reinforced Composites by Incorporating Electrospun Polyamide-6,6 Nanofibers in Joining Region(SAGE Publications, 2022) Esenoğlu, Gözde; Barışık, Murat; Tanoğlu, Metin; Yeke, Melisa; Türkdoğan, Ceren; İplikçi, Hande; Martin, Seçkin; Nuhoğlu, Kaan; Aktaş, Engin; Dehneliler, Serkan; İriş, Mehmet ErdemAdhesive joining of fiber reinforced polymer (CFRP) composite components is demanded in various industrial applications. However, the joining locations frequently suffer from adhesive bond failure between adhesive and adherent. The aim of the present study is improving bonding behavior of adhesive joints by electrospun nanofiber coatings on the prepreg surfaces that have been used for composite manufacturing. Secondary bonding of woven and unidirectional CFRP parts was selected since this configuration is preferred commonly in aerospace practices. The optimum nanofiber coating with a low average fiber diameter and areal weight density is succeed by studying various solution concentrations and spinning durations of the polyamide-6.6 (PA 66) electrospinning. We obtained homogeneous and beadles nanofiber productions. As a result, an average diameter of 36.50 +/- 12 nm electrospun nanofibers were obtained and coated onto the prepreg surfaces. Prepreg systems with/without PA 66 nanofibers were hot pressed to fabricate the CFRP composite laminates. The single-lap shear test coupons were prepared from the fabricated laminates to examine the effects of PA 66 nanofibers on the mechanical properties of the joint region of the composites. The single-lap shear test results showed that the bonding strength is improved by about 40% with minimal adhesive use due to the presence of the electrospun nanofibers within the joint region. The optical and SEM images of fractured surfaces showed that nanofiber-coated joints exhibited a coherent failure while the bare surfaces underwent adhesive failure. The PA66 nanofibers created better coupling between the adhesive and the composite surface by increasing the surface area and roughness. As a result, electrospun nanofibers turned adhesive failure into cohesive and enhanced the adhesion performance composite joints substantially.Article Citation - WoS: 3Citation - Scopus: 3Determination of Activation Energy for Carbon/Epoxy Prepregs Containing Carbon Nanotubes by Differential Scanning Calorimetry(SAGE Publications, 2022) Uz, Yusuf Can; Tanoğlu, MetinThe aim of the present study is the thermal characterization of laboratory-scale carbon fiber/epoxy-based prepregs by incorporating single-wall carbon nanotubes (SWCNTs). Investigation of the cure behavior of a prepreg system is crucial for the characterization and optimization of the fiber reinforced polymeric (FRP) composite. To affect dispersion characteristics, SWCNTs were functionalized by oxidizing their surface with carboxyl (-COOH) group using an acid treatment. The modified resin system contained 0.05, 0.1, and 0.2 wt. % functionalized SWCNTs (F-SWCNTs). Carbon fiber (CF) reinforced prepregs containing various amount of F-SWCNTs were prepared using drum-type winding technique. FTIR was performed to identify new bonding groups formed after the functionalization of SWCNTs. Cure kinetics of prepregs prepared with/without F-SWCNTs were investigated using isoconversional methods.Article Citation - WoS: 25Citation - Scopus: 30Fabrication of 3d Printed Poly(lactic Acid) Strut and Wet-Electrospun Cellulose Nano Fiber Reinforced Chitosan-Collagen Hydrogel Composite Scaffolds for Meniscus Tissue Engineering(SAGE Publications, 2022) Güneş, Oylum Çolpankan; Kara, Aylin; Baysan, Gizem; Hüsemoğlu, Reşit Buğra; Akokay, Pınar; Ziylan Albayrak, Aylin; Ergür, Bekir Uğur; Havitçioğlu, HasanThe main goal of the study was to produce chitosan-collagen hydrogel composite scaffolds consisting of 3D printed poly(lactic acid) (PLA) strut and nanofibrous cellulose for meniscus cartilage tissue engineering. For this purpose, first PLA strut containing microchannels was incorporated into cellulose nanofibers and then they were embedded into chitosan-collagen matrix to obtain micro- and nano-sized topographical features for better cellular activities as well as mechanical properties. All the hydrogel composite scaffolds produced by using three different concentrations of genipin (0.1, 0.3, and 0.5%) had an interconnected microporous structure with a swelling ratio of about 400% and water content values between 77 and 83% which is similar to native cartilage extracellular matrix. The compressive strength of all the hydrogel composite scaffolds was found to be similar (∼32 kPa) and suitable for cartilage tissue engineering applications. Besides, the hydrogel composite scaffold comprising 0.3% (w/v) genipin had the highest tan δ value (0.044) at a frequency of 1 Hz which is around the walking frequency of a person. According to the in vitro analysis, this hydrogel composite scaffold did not show any cytotoxic effect on the rabbit mesenchymal stem cells and enabled cells to attach, proliferate and also migrate through the inner area of the scaffold. In conclusion, the produced hydrogel composite scaffold holds great promise for meniscus tissue engineering.Article Citation - WoS: 4Citation - Scopus: 5An Evaluation of the Relationship Between Everyday Life Rhythms and Urban Morphology: the Square of Bursa Kent Meydani Shopping Center, Turkey(SAGE Publications, 2022) Gümüş, İmran; Yılmaz, EbruThe aim of this study is to search for the relationship between the morphological character of urban space and the rhythms of everyday life. Initially, behavioral maps are created by observing daily life rhythms, video recordings are taken on weekend and weekday, the snapshot technique, video recordings, and the pedestrian count analysis are used. In the second step, morphological analyses of the study area are prepared by using space syntax approach. Connectivity, local, and global integration values are obtained through creating axial map, and, in addition, visibility graph analysis (VGA) is performed. Bursa Kent Meydani Shopping Center (BKMSC) consists of a square and the shopping units surrounding it. This area was the main transportation point as Central Bus Station Complex until 2006. The area was selected within the scope of the study because its changing public use due to the functional transformation of the area plays a significant role in the identity of the Bursa. The behavioral maps obtained from the observational data give information about user mobility, various actions, and the activities' locations on weekends and weekdays. By correlating and comparing behavioral and space syntax maps analyses, the relationship between the rhythmic character and the morphological structure of the urban space is tested. The study presents original data by revealing the effects of the morphological elements of Bursa on the daily rhythms of the square of BKMSC. The case study is limited to the surveys conducted in 2 days and three different times of the day. The relationship between observational data and space syntax data shows that daily life rhythms are not independent of the morphological factors.Article Generating Plan Layouts: a Case Study on Visualization of Implicit Knowledge by “doctor Architects”(SAGE Publications, 2022) Kasalı, AltuğAim: This article presents an opportunistic case with particular focus on instances from an extended procurement operation in which medical professionals run a proactive process involving the generation of layouts through distinct modes of representational practices without any actual collaboration with designers. The questions of inquiry involve an analysis on how the visualizations came into being and a discussion into the content of drawings that was shaped by individuals without any formal design education. Background: Although the literature introduces examples of genuine participation, particularly in healthcare design practices, the instances in which nondesigners demonstrate accomplished skills in spatial reasoning and representation are limited. Method: The research was formulated as a qualitative case study including a series of observations of the activities of the participants followed by interviews recorded at different locations. The investigation also focuses on the features of these authentic graphics which illustrate the intentions of the medical professionals concerning the function of spaces. Results: In this research, the participants went through a labor intensive and elaborate effort to produce “architectural representations” with the intention to convey their implicit professional expertise in the domain. The layouts were introduced to be the vital elements to visualize the implicit knowledge regarding the functioning of space. Conclusions: The productive and creative engagement of clinicians within this research makes the case for a multidisciplinary approach that reframes the limits and potential contributions of participants alongside drawings, which are exclusively claimed by and strategically employed by architects as negotiation devices within participatory design processes.Article Citation - WoS: 1Citation - Scopus: 1Fatigue Life Prediction and Optimization of Gfrp Composites Based on Failure Tensor Polynomial in Fatigue Model With Exponential Fitting Approach(SAGE Publications, 2022) Güneş, Mehmet Deniz; İmamoğlu Karabaş, Neslişah; Deveci, Hamza Arda; Tanoğlu, Gamze; Tanoğlu, MetinIn this study, a new fatigue life prediction and optimization strategy utilizing the Failure Tensor Polynomial in Fatigue (FTPF) model with exponential fitting and numerical bisection method for fiber reinforced polymer composites has been proposed. Within the experimental stage, glass/epoxy composite laminates with (Formula presented.), (Formula presented.), and (Formula presented.) lay-up configurations were fabricated, quasi-static and fatigue mechanical behavior of GFRP composites was characterized to be used in the FTPF model. The prediction capability of the FTPF model was tested based on the experimental data obtained for multidirectional laminates of various composite materials. Fatigue life prediction results of the glass/epoxy laminates were found to be better as compared to those for the linear fitting predictions. The results also indicated that the approach with exponential fitting provides better fatigue life predictions as compared to those obtained by linear fitting, especially for glass/epoxy laminates. Moreover, an optimization study using the proposed methodology for fatigue life advancement of the glass/epoxy laminates was performed by a powerful hybrid algorithm, PSA/GPSA. So, two optimization scenarios including various loading configurations were considered. The optimization results exhibited that the optimized stacking sequences having maximized fatigue life can be obtained in various loading cases. It was also revealed that the tension-compression loading and the loadings involving shear loads are critical for fatigue, and further improvement in fatigue life may be achieved by designing only symmetric lay-ups instead of symmetric-balanced and diversification of fiber angles to be used in the optimization.
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