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A rational utilization of reinforcement material for flexural design of 3D-printed composite beams
(SAGE PUBLICATIONS LTD, 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND, 2019) Ciftci, Cihan; Sas, Hatice S.
Recent developments in composite industry address the adaptation of 3D printing technology to overcome the design and manufacturing challenges of the traditional composite processing techniques. This adaptation can be performed with the development of design methodologies corresponding to the type of structural load-carrying members in a structure. Considering the frequently use of beams in structures, the development of the design methodology of beams is essential for the adaptation of the additive manufacturing. Therefore, in this paper, the flexural loading concept is analytically formulated to derive moment capacity for the flexural behavior of 3D-printed composite beams. Then, the formulation is adapted to develop a design methodology of 3D-printed laminates under flexural loading. Additionally, the analytical solutions developed for the design methodology presented in this paper were verified with a good agreement with experimental studies.
Citation - WoS: 5
Near- and Far-Field Characterization of Planar mm-Wave Antenna Arrays With Waveguide-to Transition
(Springer, 2016) Salhi, Mohammed Adnan; Kazemipour, Alireza; Gentille, Gennaro; Spirito, Marco; Kleine-Ostmann, Thomas; Schrader, Thorsten
We present the design and characterization of planar mm-wave patch antenna arrays with waveguide-to-microstrip transition using both near- and far-field methods. The arrays were designed for metrological assessment of error sources in antenna measurement. One antenna was designed for the automotive radar frequency range at 77 GHz, while another was designed for the frequency of 94 GHz, which is used, e.g., for imaging radar applications. In addition to the antennas, a simple transition from rectangular waveguide WR-10 to planar microstrip line on Rogers 3003 (TM) substrate has been designed based on probe coupling. For determination of the far-field radiation pattern of the antennas, we compare results from two different measurement methods to simulations. Both a far-field antenna measurement system and a planar near-field scanner with near-to-far-field transformation were used to determine the antenna diagrams. The fabricated antennas achieve a good matching and a good agreement between measured and simulated antenna diagrams. The results also show that the far-field scanner achieves more accurate measurement results with regard to simulations than the near-field scanner. The far-field antenna scanning system is built for metrological assessment and antenna calibration. The antennas are the first which were designed to be tested with the measurement system.
Citation - WoS: 12
Citation - Scopus: 12
Glass Ceiling in Academia Revisited: Evidence From the Higher Education System of Turkey
(Routledge Journals, Taylor & Francis Ltd, 2021) Bulbul, Serap
Current study investigates the gender gap in academic promotions in Turkey taking a new perspective on the widely established existence of gender inequality in academia. The dataset includes the eight most-prominent research universities in Turkey and the nature of the 'glass ceiling' is explored by looking at the gendered distributions of: (1) academic seats -indicating academic performances, and (2) coauthorship patterns concerning genders. Findings suggest that there is gender disparity in academic performances as well as in academic promotions. In addition, gender is found to be a significant factor in explaining the current situation in academic ranks and subtle discrimination practices may exist instead of overt discrimination practices as it is also suggested in previous studies. In sum, results show two main points: (1) There is evidence of gender gap in academic promotions in Turkey, (2) A new variable -cross gender coauthorship- for glass ceiling research may provide further insight about the issue.
Positive Solutions of Multipoint Φ-Laplacian BVPS With First-Order Derivative Dependence
(World Scientific, 2023) Bachouche, Kamal; Tair, Hocine; Doǧan, Abdülkadir Muhittin
This paper concerns existence of positive solutions for a second-order boundary value problem of Sturm-Liouville type associated with a φ-Laplacian operator and posed on a bounded interval. Existence results are obtained by an adapted version of the Krasnosel'skii's fixed point theorem of cone expansion and compression. Some examples illustrate our results. © 2023 Elsevier B.V., All rights reserved.
Citation - WoS: 5
Citation - Scopus: 5
Personalization in Marketing: How Do People Perceive Personalization Practices in the Business World
(California State Univ, 2023) Aksoy, Nilsah Cavdar; Kabadayi, Ebru Tumer; Yilmaz, Cengiz; Alan, Alev Kocak
With emerging digital technologies, personalization has become a key activity for marketing strategy to gain competitive success in customer relationships. The aim of this study is to develop and empirically assess a general measurement model of perceived personalization. Multiple data gathering processes and rigorous empirical testing procedures are employed to assess and validate the proposed measurement model. The perceived personalization scale developed in the study rests on the focus of what is personalized and includes three main categories: (1) individuallevel, (2) social-level, and (3) situation-based personalization. A multidimensional measure of personalization is developed based on these categories and is validated via several tests, including a test of nomological validity exploring the effects of perceived personalization on critical customer responses such as positive emotions, negative emotions, perceived sincerity, satisfaction, and behavioral intentions. These findings shed light on and open new avenues of development for this growing practice for both researchers and practitioners in marketing.
Human identification using palm print images based on deep learning methods and gray wolf optimization algorithm
(SPRINGER, 2024) Alshakree, Firas; Akbas, Ayhan; Rahebi, Javad
Palm print identification is a biometric technique that relies on the distinctive characteristics of a person’s palm print to distinguish and authenticate their identity. The unique pattern of ridges, lines, and other features present on the palm allows for the identification of an individual. The ridges and lines on the palm are formed during embryonic development and remain relatively unchanged throughout a person’s lifetime, making palm prints an ideal candidate for biometric identification. Using deep learning networks, such as GoogLeNet, SqueezeNet, and AlexNet combined with gray wolf optimization, we achieved to extract and analyze the unique features of a person’s palm print to create a digital representation that can be used for identification purposes with a high degree of accuracy. To this end, two well-known datasets, the Hong Kong Polytechnic University dataset and the Tongji Contactless dataset, were used for testing and evaluation. The recognition rate of the proposed method was compared with other existing methods such as principal component analysis, including local binary pattern and Laplacian of Gaussian-Gabor transform. The results demonstrate that the proposed method outperforms other methods with a recognition rate of 96.72%. These findings show that the combination of deep learning and gray wolf optimization can effectively improve the accuracy of human identification using palm print images.
Citation - WoS: 8
Citation - Scopus: 8
Low Velocity Oblique Impact Behavior of Adhesively Bonded Single Lap Joints
(Taylor & Francis Ltd, 2019) Atahan, M. Gokhan; Apalak, M. Kemal; Atahan, M. Gokhan; Apalak, M. Kemal
This article addresses the low velocity oblique impact behavior of adhesively bonded single lap joints, and the effects of adherend strength and plastic ductility, impact energy, overlap length and oblique impact angle on the damage initiation and propagation in the adhesive layer. The experimental contact force-time, contact force-central displacement variations, axial separation lengths through the adhesive layer and permanent central deflections of overlap region, adhesive fracture surfaces were evaluated in detail. In the explicit finite element analyses, the adhesive layer was divided into three zones: upper and lower adhesive interfaces and the adhesive layer between these interfaces. The adhesive interfaces were modeled with cohesive zone approach to predict the failure initiation and propagation along both upper and lower adhesive-adherend interfaces, whereas the elastic-plastic material model was implemented for the middle adhesive region between the upper and lower adhesive interfaces. The proposed finite element model predicted reasonably the damage initiation and propagation through the adhesive layer, and the contact force-time/central displacement variations. Especially, the test and analysis results were compared with those of the adhesively bonded single lap joints under a normal transverse impact load. Increasing oblique impact angle resulted in lower peak contact forces, shorter contact durations and earlier damage initiation and propagation through the adhesive layer. The peak contact forces increased, the contact duration decreased with increasing impact energy. The strength and plastic deformation capability of adherend materials also affected the damage initiation and propagation through the adhesive layer as well as the after-impact joint geometry.
Citation - Scopus: 3
Subprime Mortgages and Lending Bubbles
(Bank Indonesia Institute, 2018) Polat, Ali Yavuz
We consider a model with two types of households: the poor with no initial endowment and the rich with positive endowment, and two types of assets: properties in a poor area and properties in a rich area. In the model, poor agents need credit to buy an asset, whereas the rich can draw from their endowment. We show that credit-fueled housing bubbles sometimes may improve welfare, making the poorer individuals better off. More precisely, there exist two types of equilibria in both property markets: one is a bubble equilibrium, and the other is an equilibrium where asset prices are stable over time. While the poor always obtain a positive surplus in the bubble equilibrium, this is not necessarily true for the rich. Our results suggest that there may be scope for market interventions aimed at sustaining the value of assets held by credit-constrained agents after the burst of a credit bubble. © 2025 Elsevier B.V., All rights reserved.
Ceramide Is a Key Factor That Regulates the Crosstalk Between TGF-Β and Sonic Hedgehog Signaling at the Basal Cilia to Control Cell Migration and Tumor Metastasis
(Federation Amer Soc Exp Biol, 2016) Gencer, Salih; Oleinik, Natalia; Dany, Mohammed; Ogretmen, Besim
Citation - Scopus: 1
The Communication Strategies of Ideologically Polarized Civil Society Organizations on Twitter: The Case of Turkey
(Springer Nature, 2022) Akboga, Sema; Arik, Engin
We investigated how ideologically polarized civil society organizations (CSOs) in Turkey use Twitter. We analyzed tweets from 20 CSOs in Turkey for a period of 7 months by using the Information-Community-Action framework. For all types of CSOs, the number of information tweets was higher than the number of action tweets, which, in turn, was higher in number than the community tweets. Religious/conservative and anti-government CSOs posted significantly more tweets than secular and pro-government CSOs, respectively. Religious/conservative and pro-government CSOs posted more information and community tweets than secular and anti-government CSOs, respectively. The number of anti-government CSOs’ action tweets was higher than that of pro-government CSOs. We, therefore, propose that the ideological stance of a CSO is a factor affecting the content of its tweets in societies where CSOs are politically polarized. © 2024 Elsevier B.V., All rights reserved.
Enhancing the Freeze Thaw Resistance of Pozzolanic Lime Mortars by Optimising the Dewatering Process
(Springer, 2024) Su-Cadirci, Tugce Busra; Ince, Ceren; Calabria-Holley, Juliana; Ball, Richard James
Freeze-thaw weathering is commonly attributed to the premature degradation of lime mortars. This study is unique as it explores how the effect of incorporating pozzolanic brick dust, combined with the dewatering mechanism, can influence the resistance to freeze-thaw cycling. The combination of brick dust and hydrated lime constitutes a pozzolanic lime mortar with hydraulic character. Importantly, the addition of brick dust was shown to play a crucial role by modifying the pore structure of the mortar matrix, which affected the water transport kinetics, and durability. This rigorous investigation evaluates the freeze and thaw resistance of hardened young (7-day) and old (180-day) mortars in both dewatered and non-dewatered conditions. Quantitative analysis of the microstructure highlights the role of brick dust and dewatering in densifying the matrix, refining the pore structure, and enhancing the freeze and thaw resistance. The benefits of dewatered brick dust mortars were demonstrated as young-age dewatered mortars showed similar resistance to freeze and thaw compared to the older-age non-dewatered mortars. This was attributed to the reduction of the water/binder ratio due to dewatering. It has been successfully demonstrated that freshly mixed mortars can be enhanced on-site through the addition of brick dust and coupling with a substrate that promotes dewatering. Using this approach to produce mortars with greater freeze thaw resistance will improve longevity and reduce failure rates. Impact will be realised in mortars for both new build and conservation applications.
Citation - WoS: 5
Citation - Scopus: 5
Formation of a Very High-Density Amorphous Phase of Carbon and Its Crystallization into a Simple Cubic Structure at High Pressure
(Elsevier B.V., 2021) Durandurdu, M.
We report a direct computational evidence of a two-step transformation sequence for tetrahedral amorphous carbon (ta-C) with increasing pressure. First, ta-C gradually transforms into a very high-density amorphous phase (VHDA) phase. Second, the VDHA phase converts into a simple cubic (SC) crystal. The structural defects formed during the high-pressure treatment play important roles for the formation and stabilization of the SC structure, rather than favorable the SC4 crystal. These phase transformations are reversible. © 2021 Elsevier B.V., All rights reserved.
Poly(OEGMA)-B Block Copolymer Nanocarriers for Anticancer Agent Release
(Wiley, 2018) Aksit, N. N.; Topuzogullari, M.; Isoglu, I. A.; El Khatib, M.; Isoglu, S. Dincer
Citation - WoS: 1
Educating Masses: The Committee of Union and Progress Clubs and Schools in the Late Ottoman Empire
(Routledge Journals, Taylor & Francis Ltd, 2022) Tozoglu, Ahmet Erdem
This article examines the social and architectural context of an extensive building campaign in Turkey in the early twentieth century. The Committee of Union and Progress (CUP), one of the Second Constitutional Period's prominent political and cultural actors (1908-18), commissioned club and school buildings for social outreach operations. Influenced by their European counterparts, the Committee's protagonists believed that a social revolution could be accomplished by employing the education of the masses. Moreover, education was also essential to create a national identity for an Empire in a struggle. In this context, many clubs (for adults) and schools (for the youngsters) mushroomed in many cities simultaneously. Accordingly, the architecture of new club and school buildings reflected societal concerns and provided remarkable examples of their kinds. The education of the masses and the use of social propaganda by state agents in Republican Turkey have been scrutinized so far. Still the origins of the social engineering projects should be examined to contextualize Republican period developments. Thus, this article examines the building and impact of the clubs and schools of the CUP in the provinces and constitutes a contextual frame for their formative role in Turkish modernization.
Citation - WoS: 43
Citation - Scopus: 45
Highly Efficient Cd-Free Alloyed Core/Shell Quantum Dots With Optimized Precursor Concentrations
(Amer Chemical Soc, 2016) Altintas, Yemliha; Talpur, Mohammad Younis; Unlu, Miray; Mutlugun, Evren
The chemical composition, the emission spectral bandwidth, and photoluminescence quantum yield of a semiconductor quantum dot (QD) play an important role in the assessment of the performance of the applications related to the quantum dots. Quantum dots based on environmentally friendly compositions with high optical performance have been in demand for high-end technological applications. In this work, we propose and demonstrate a detailed synthesis approach for environmentally friendly and highly efficient InPZnS alloy/ZnS shell quantum dots. Following a systematic study of the ratio and type of the precursors involved, we achieved alloyed core shell InPZnS/ZnS QDs with tunable emission across the visible spectrum, having a record quantum efficiency up to 78% along with a full width at half-maximum as narrow as 45 nm. The effect of the systematic shell growth has been further investigated using time-resolved photoluminescence characterizations along with the observation of the suppression of the nonradiative decay channels, with the photoluminescence lifetime prolonged from 20.3 to 50.4 ns. The development of highly efficient and environmentally friendly QDs will pave the way for robust, sustainable optoelectronic applications.
Citation - WoS: 27
Citation - Scopus: 34
Full-Length Effects of the Circular Economy, Environmental Policy, Energy Transition, and Geopolitical Risk on Sustainable Electricity Generation
(Elsevier Sci Ltd, 2023) Chishti, Muhammad Zubair; Dogan, Eyup; Zaman, Umer
The recent global paradigm shift toward sustainable green development necessitates revealing the likely green determinants of sustainable electricity generation in order to derive key policy recommendations for dealing with the global energy crisis. As a result, the current study focuses on the drivers of global electricity generation (EG) and identifies environmental policy (EP), energy transition (ET), geopolitical risk (GPR), and circular economy (CE) as novel determinants. The study employs a battery of advanced econometric techniques, including quantile VAR, quantile slope estimate, and wavelet-based correlation methods, for empirical analysis. The quantile VAR -based connectedness confirms the modeled series' significant interconnectedness. Furthermore, the findings suggest that CE plays an important role in promoting the global EG process, as evidenced by positive effects across quantiles. When the effects of ET and EP are considered, a positive relationship between ET, EP, and EG is discovered, implying that ET and EP are important drivers of electricity generation. Furthermore, GPR has significant and negative effects on EG across most quantiles, indicating that the EG process suffers a significant loss as a result of GPR. Furthermore, the wavelet-based correlation method confirms the significant association between selected series, supporting the preceding findings. In order to achieve sustainable electricity generation, several results-based policies are proposed for local and global authorities.

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