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Article Citation - WoS: 22Citation - Scopus: 25Effect of Solution Heat Treatment on the Microstructure and Crystallographic Texture of In939 Fabricated by Powder Bed Fusion-Laser Beam(Elsevier, 2023) Dogu, Merve Nur; Ozer, Seren; Yalcin, Mustafa Alp; Davut, Kemal; Bilgin, Guney Mert; Obeidi, Muhannad Ahmed; Brabazon, DermotThe effect of various solution heat treatment temperatures (i.e., 1120, 1160, 1200 and 1240 & DEG;C) on the microstructure, grain morphology and crystallographic texture of IN939 fabricated by powder bed fusion-laser beam (PBF-LB) was investigated. Microstructural analyses showed that the high-temperature gradient and rapid solidification of the PBF-LB processing caused different resulting microstructures compared to conventionally pro-duced counterparts. The melt pool morphologies and laser scanning paths were examined in the as-fabricated samples in the XZ-and XY-planes, respectively. After the application of solution heat treatment at 1120 & DEG;C, the as-fabricated PBF-LB initial microstructure was still apparent. For solution heat treatments of 1200 & DEG;C and above, the melt pool and scanning path morphologies disappeared and converted into a mixture of columnar grains in the XZ-plane and equiaxed grains in the XY-plane. On the other hand, large equiaxed grains were observed when the samples were solutionized at 1240 & DEG;C. Additionally, g' phase precipitated within the matrix after all solution heat treatment conditions, which led to increase in the microhardness values. According to electron backscatter diffraction (EBSD) analyses, both as-fabricated and solution heat-treated samples had intense texture with {001} plane normal parallel to the building direction. The first recrystallized grains began to appear when the samples were subjected to the solution heat treatment at 1160 & DEG;C and the fraction of the recrystallized grains increased with increasing temperature, as supported by kernel average misorientation (KAM) and grain spread orientation (GOS) analyses.& COPY; 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Article Citation - WoS: 14Citation - Scopus: 14On Relations Between Transportation Cost Spaces and l1<(Academic Press inc Elsevier Science, 2020) Ostrovska, Sofiya; Ostrovskii, Mikhail I.The present paper deals with some structural properties of transportation cost spaces, also known as Arens-Eells spaces, Lipschitz-free spaces and Wasserstein spaces. The main results of this work are: (1) A necessary and sufficient condition on an infinite metric space M, under which the transportation cost space on M contains an isometric copy of l(1). The obtained condition is applied to answer the open questions asked by Cuth and Johanis (2017) concerning several specific metric spaces. (2) The description of the transportation cost space of a weighted finite graph G as the quotient l(1) (E(G))/Z(G), where E(G) is the edge set and Z(G) is the cycle space of G. (C) 2020 Elsevier Inc. All rights reserved.Article Citation - WoS: 25Citation - Scopus: 25A Model for the Prediction of Thermal Runaway in Lithium-Ion Batteries(Elsevier, 2024) Azuaje-Berbeci, Bernardo J.; Ertan, H. BulentThe increasing popularity of electric vehicles is driving research into lithium -ion batteries (LIBs). Thermal runaway (TR) in LIBs is a serious concern for the safe operation of these high-energy-density batteries that is yet to be overcome. A reliable model is needed to predict voltage variation, heat generation, temperature rise, and the process leading to TR of a LIB battery under its operating conditions (charging-discharging). Such a model can be used to design battery packs more resilient to thermal runaway or assess how a battery pack would perform under hazardous conditions. Furthermore, it can be used for generating a warning signal if there is a possibility of the battery going towards TR. This paper presents an approach to solving this problem, which is not currently well addressed in the literature. The approach adopted in this paper is based on a numerical analysis of a multilayered electrochemical-thermal model of LIB. Tuning the parameters of a LIB for accurate results from this numerical model is presented, as well as the details of the approach in the paper. Experiments are performed under several LIBs, and their voltage and surface temperature variations are measured under various operating conditions, including thermal runaway. The results of the experiments are compared with the predictions of the numerical simulations. An excellent agreement is observed with the experimental results, proving the accuracy of the proposed approach. This approach can be configured to give results in a few minutes. The paper also discusses how the developed approach can be used to create a TR warning during operating conditions or to change the mode of operation of a LIB before a hazard occurs.Article Citation - WoS: 1Citation - Scopus: 1Growth and Optical Properties of (na0.5bi0.5< (x=0.25) Single Crystal: a Potential Candidate for Optoelectronic Devices(Springer, 2024) Guler, I.; Isik, M.; Gasanly, N.Double tungstates (DT) and double molybdates (DM) have significant importance because of their optoelectronic applications. Regarding the importance of DT and DM, we investigated experimentally structural and optical properties of (Na0.5Bi0.5)(Mo1-xWx)O-4 (x = 0.25) crystal that belongs to the NaBi-DT and DM crystals group. Czochralski method was used to grow the single crystals. The structure of the crystal was identified using X-ray diffraction (XRD) measurements. Two sharp peaks associated with tetragonal crystal structure appeared in the pattern. Vibrational modes of the studied crystal were obtained from the Raman experiments. By the help of the Fourier transform infrared spectrophotometer (FTIR) measurements, infrared transmittance spectrum of the studied compound was recorded. Band gap energy wase found around 3.04 eV using two methods, Tauc and derivative analysis, based on transmission spectrum. Based on the analysis of absorption coefficient, Urbach energy was obtained as 0.22 eV. The revealed structural and optical properties of the crystal indicated that the material may be a candidate for optoelectronic devices in which NaBi(MoO4)(2) and NaBi(WO4)(2) materials are utilized.Review Citation - WoS: 41Citation - Scopus: 57Drawing the Big Picture of Games in Education: a Topic Modeling-Based Review of Past 55 Years(Pergamon-elsevier Science Ltd, 2023) Ekin, Cansu C.; Polat, Elif; Hopcan, SinanThe literature of games in education has a rich and multidisciplinary content. Due to the large number of studies in the field, it is not easy to analyze all relevant studies. There are few studies exploring the big picture of research trends in the field. For this reason, the purpose of this study is to examine longitudinal trends of game-based research in education using text mining tech-niques. 4980 publications were retrieved as an experimental dataset indexed by the SCOPUS database in the period 1968 to mid-2021. The results include descriptive statistics of game-based research, trends of the research topics, and trends in the frequency of each topic over time. They show that the number of studies focusing on the use of games in education has increased, particularly since the 2000s when Internet use accelerated and became widespread. Approxi-mately 70% of all the studies were conducted in the last 10 years. One third of the studies is related to the main topic of game-based learning. It is significant that in the last three decades the topic of serious games has been among the top three trends. Considering usage acceleration of the topics, the highest values belong to game-based learning, serious games and student science games, in that order. The findings of this study are expected to guide the field by providing a better understanding of the trends of games in education and offer a direction for future research.Article Citation - WoS: 3Citation - Scopus: 7Artificial Intelligence in Education: a Text Mining-Based Review of the Past 56 Years(Springer, 2025) Ekin, C.C.; Cantekin, Ö.F.; Polat, E.; Hopcan, S.Artificial Intelligence in Education (AIED) is a broad and multifarious area of study that spans across various academic fields. Due to the high numbers of studies in this field, it seems too challenging to analyze all of them in depth in a single study. Additionally, there is a lack of research that provides a comprehensive overview of the main trends and topics in AIED. This study, hence, aims to fill this gap by using text mining techniques to examine how artificial intelligence (AI)-related research in education has evolved over time. To this end, a total of 11,027 articles indexed by the Scopus database in the field of education between 1967 and 2023 were examined. Based on the findings, there has been a significant increase in AIED since 2014, covering 73% of the publications. Over the past three decades, AIED research has increasingly concentrated on engineering student populations and conference proceedings. Notably, AI solutions are extensively employed in education, with a strong focus on personalization, assessment, and evaluation. They also play a prominent role in research review processes, such as text mining and topic modeling for summarizing research findings. The findings contribute to the field, enhancing our understanding of the patterns of AI’s integration into education and offering guidance for prospective research endeavors. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.Article Citation - WoS: 26Citation - Scopus: 33Cyberloafing Behaviors Among University Students: Their Relationships With Positive and Negative Affect(Springer, 2023) Metin-Orta, Irem; Demirtepe-Saygili, DilekWith the technological advances, the use of digital devices, such as laptops, tablets, or smartphones in the educational setting has become prevalent among young people. Accordingly, there has been an increased concern among scholars on students' in-class Internet use for personal purposes; namely, 'cyberloafing'. Considerable research has demonstrated the adverse effects of in-class Internet use on students' learning environment and academic performance. The present study particularly investigates the relationship between cyberloafing behaviors and positive and negative affect among university students. It examines five different online activities including sharing, shopping, real-time updating, accessing online content, and gaming/gambling separately to gain greater insight into students' cyberloafing behaviors. The sample consisted of 267 undergraduate students who filled out questionnaires measuring cyberloafing behaviors, positive and negative affect, and demographical information including the use of the Internet and mobile technologies. The initial analyses showed that male students had higher scores in shopping, accessing online content, and gaming/gambling than females. The latent variable analysis revealed that among different activities of cyberloafing, accessing online content and gaming/gambling were positively correlated with positive affect, while sharing was positively associated with negative affect among students. The findings emphasize the importance of evaluating cyberloafing as a part of students' psychological well-being rather than a variable merely related to academic achievement. The findings of the study also enlighten researchers and educators in developing appropriate policies and interventions to manage misuse of the Internet in class.Article Neopatrimonial Rule Through Formal Institutions: The Case of Turkey(Cambridge University Press, 2025) Bektas, EdaThis study examines how formal institutions in hybrid regimes, particularly presidentialism, party organization and electoral rules, actively foster and sustain clientelistic networks, leading to particularistic outcomes. While existing literature highlights the weakening of formal institutions and pervasive clientelism as drivers of democratic breakdown, this study uses the concept of neopatrimonialism to analyse how formal institutions themselves consolidate patron-client relationships to maintain power and stability. Focusing on Turkey, the analysis demonstrates that the institutional incentive structure consolidates the president's role as the central ‘patron’, controlling resources and offices, and encourages clientelistic networks to coalesce around the presidency. The discretionary allocation of resources through patron-client relationships sustains neopatrimonial authority as long as clients' loyalty is rewarded. However, this governance increases clients' dependence on the patron, binding them at the expense of representation and responsiveness. The analysis offers insights into how such institutional configurations contribute to authoritarianism and particularistic governance in hybrid regimes. © 2025 Elsevier B.V., All rights reserved.Article Citation - WoS: 30Citation - Scopus: 39A Transformative Solution for Construction Safety: Blockchain-Based System for Accident Information Management(Elsevier, 2023) Ahmadisheykhsarmast, Salar; Aminbakhsh, Saman; Sonmez, Rifat; Uysal, FurkanEffective management of accident information is a crucial component of safety management within the construction industry, as it reflects the safety performance of the company and allows them to identify the root causes of accidents and prevent similar accidents in the future. However, existing safety information systems provide self-owned, isolated, and centralized environments and fail to present a secure, transparent, and trustworthy platform for monitoring and management of accident information. To address these issues, this paper presents a novel decentralized blockchain-based system for accident/incident information management of construction projects. The proposed system leverages the benefits and advantages of blockchain, smart contracts, and decentralized IPFS storage to address the security transparency, tampering, and trustworthiness issues of the conventional approaches. The proposed system is simulated by using real-world construction accident data to demonstrate how blockchain technology can provide a novel solution to assure security, transparency, authenticity, availability, and immutability of the accident/incident data for improving safety management.Article Citation - WoS: 8Citation - Scopus: 9Expanding the Role of Exosomes in Drug, Biomolecule, and Nanoparticle Delivery(Pergamon-elsevier Science Ltd, 2025) Saka, Ongun Mehmet; Dora, Devrim Demir; Kibar, Gunes; Tevlek, AtakanExosomes are nanoscale extracellular vesicles released by diverse cell types, serving essential functions in intercellular communication and physiological processes. These vesicles have garnered considerable interest in recent years for their potential as drug delivery systems, attributed to their natural origin, minimal immunogenicity, high biocompatibility, and capacity to traverse biological barriers, including the blood-brain barrier. Exosomes can be obtained from diverse biological fluids, rendering them accessible and versatile vehicles for therapeutic medicines. This study emphasizes the burgeoning significance of exosomes in drug administration, concentrating on their benefits, including improved stability, target selectivity, and the capacity to encapsulate various biomolecules, such as proteins, nucleic acids, and small molecules. Notwithstanding their potential applications, other problems remain, including as effective drug loading, industrial scalability, and the standardization of isolation methodologies. Overcoming these hurdles via new research is essential for fully harnessing the promise of exosomes in therapeutic applications, especially in the treatment of intricate diseases like cancer and neurological disorders.