WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Correction Chlorinated Phosphorene for Energy Application (vol 231, 112625, 2024)(Elsevier, 2024) Hassani, Nasim; Yagmurcukardes, Mehmet; Peeters, Francois M.; Neek-Amal, Mehdi[No Abstract Available]Article Citation - WoS: 1Citation - Scopus: 2First Measurement of the Forward Rapidity Gap Distribution in Ppb Collisions at √snn=8.16 Tev(Amer Physical Soc, 2023) Karapınar, Güler; CMS Collaboration; Ambrogi, F.; Bergauer, T.; Dragicevic, M.; Ero, J.; Zhokin, A.For the first time at LHC energies, the forward rapidity gap spectra from proton-lead collisions for both proton and lead dissociation processes are presented. The analysis is performed over 10.4 units of pseudorapidity at a center-of-mass energy per nucleon pair of ffisffi than in previous measurements of diffractive production in proton-nucleus collisions. For lead dissociation processes, which correspond to the pomeron-lead event topology, the EPOS-LHC generator predictions are a factor of 2 below the data, but the model gives a reasonable description of the rapidity gap spectrum shape. For the pomeron-proton topology, the EPOS-LHC, QGSJET II, and HIJING predictions are all at least a factor of 5 lower than the data. The latter effect might be explained by a significant contribution of ultraperipheral photoproduction events mimicking the signature of diffractive processes. These data may be of significant help in understanding the high energy limit of quantum chromodynamics and for modeling cosmic ray air showers.Article Citation - WoS: 3Citation - Scopus: 3Liquid Metal-Tunable Miniaturized Bimodal Cavity for Enhanced Measurement Accuracy in the Ism Bands(Ieee-inst Electrical Electronics Engineers inc, 2024) Karatay, Anil; Yaman, FatihEnhancing measurement accuracy or reducing the effect of the neighboring modes in resonant cavities may necessitate the separation of mode frequencies. However, in ISM-band measurement configurations utilizing a rectangular or cylindrical cavity, the placement of the first two modes at 2.45 and 5.8 GHz is unattainable, necessitating the presence of additional modes in between that would potentially degrade measurement accuracy. This article begins with an analytical approach, employing Lagrange multipliers for the first time to reveal the level of separation achievable in the frequency domain between the initial two modes within these types of conventional cavities. The analytical results were also verified with a numerical grid search. Subsequently, innovative strategies have been introduced to surpass this intrinsic constraint that reduces the measurement accuracy in various applications. A novel miniaturized cavity configuration has been proposed to operate bimodally at 2.45 and 5.8 GHz and manufactured with a 3-D printer. It has been ensured that there are no physical modes present in between, and measurements of the structure have been conducted. Another notable innovation of the article is the capability of tuning the proposed cavity structure by means of liquid metal displacement. Thus, a more flexible tuning method compared to mechanical tuning techniques can be achieved, enabling precise adjustment of the desired measurement frequency. Good agreement between the simulation and measurement results has been reported.Article Citation - WoS: 3Citation - Scopus: 3Light-Induced Synthesis of Single-Crystalline Gold Microplates in an Open System(Amer Chemical Soc, 2023) Akkuş, Betül; Mert Balcı, FadimeBottom-up synthesis of large single-crystalline gold microplates is of key importance to catalysis, nanophotonics, bioengineering, and plasmonics. However, easy, low-cost, room-temperature, and high-yield synthesis of large gold microplates with several micrometers in lateral size and a few tens of nanometers in thickness by using photochemical synthesis in an open system is still challenging. We herein report on an easy and cost-effective photochemical synthesis of single-crystalline gold microplates with lateral sizes up to around 40 mu m and tens of nanometers in thickness in a few hours of reaction time in an open system containing a lyotropic liquid crystal, which is formed by self-assembly of 10-lauryl ether in a strong acid, sulfuric acid, along with water. We have found that by changing the reaction parameters, such as the reaction time, the concentration of gold ions in the liquid crystal, etc., the thickness and size of the microplates can be easily controlled. Most importantly, the liquid crystalline phase is completely preserved after completion of the photochemical reaction. The microplates can be easily isolated and transferred to different media such as alcohol and water for further studies, or they can be immediately used on a substrate after completion of the reaction. The results obtained in this study will allow us to understand the growth mechanism of gold microplates in open systems, and they will find applications in a variety of critical areas, such as plasmonics, nanophotonics, and catalysis.Article Citation - WoS: 7Citation - Scopus: 9Politics of Waiting for Transformation in Protracted Urban Renewal Projects in Turkey(Sage Publications Ltd, 2023) Ay, Deniz; Penpecioglu, MehmetThis paper explores the politics of 'waiting' as a mode of governance in large-scale urban redevelopment projects. In designated renewal areas, residents/landowners are often subject to several episodes of waiting: waiting for the public authority for information on redevelopment visions; waiting for the plans and projects to become public; waiting for the court ruling if they appeal the plans; waiting for demolition upon plan approvals; and, finally, waiting for the constructions to be completed. Given the complexity of actors and institutions involved in the waiting, it becomes a conflictual political process. This prolonged waiting leads to an ongoing temporariness and precarious spaces of urban renewal. The course of waiting affects the reorganization of the city space now and in the future. We analyze two protracted urban renewal projects from Turkey, Fikirtepe in Istanbul and Karabaglar in Izmir, to explore how residents' decade-long waiting for urban change are shaped and how these diverse waiting experiences lead to different outcomes for the progression of the state-imposed urban renewal agendas. While Karabaglar residents have unified around active bottom-up resistance from the beginning to challenge the project-based plans the central government imposed, Fikirtepe residents pursued individual-level negotiations with developers to maximize private returns following the zoning incentives the public authority gave. Despite the socio-spatial similarities between these designated urban renewal project sites, variances in residents' collective waiting strategies have led to different urban politics around project-based urban change.Correction Chlorinated Phosphorene for Energy Application (vol 231, 112625, 2024)(Elsevier, 2024) Hassani, Nasim; Yagmurcukardes, Mehmet; Peeters, Francois M.; Neek-Amal, Mehdi[No Abstract Available]Article Citation - WoS: 6Citation - Scopus: 6Weak Dependence of Voltage Amplification in a Semiconductor Channel on Strain State and Thickness of a Multidomain Ferroelectric in a Bilayer Gate(American Chemical Society, 2023) Misirlioglu, I.B.; Yapici, M.K.; Sendur, K.; Okatan, M.B.Ferroelectric/dielectric layered stacks are of special interest as gate oxides in the pursuit of designing low-power transistors, where the electrostatics of such stacks are thought to provide a means to allow for voltage amplification in the semiconductor channel. Strain and thickness dependence of the response of such a gate stack in relation to voltage amplification in a semiconductor channel becomes important to identify, which is what we study in this work using a thermodynamic approach. For a ferroelectric multidomain state as the stable phase in the stack, our findings show that a limited magnitude of voltage amplification appears to be feasible. Voltage amplification at the semiconductor surface is computed to hardly exceed 1.2 in thick bilayers (40 nm) for strains stabilizing the multidomain state and attains even less than this value for the thinner stacks. © 2023 American Chemical Society.Article Citation - WoS: 11Citation - Scopus: 11A Comprehensive Characterization of the Effect of Spatter Powder on In939 Parts Fabricated by Laser Powder Bed Fusion(ELSEVIER SCI LTD, 2023) Dogu, Merve Nur; Mussatto, Andre; Yalçın, Mustafa Alp; Özer, Seren; Davut, Kemal; Obeidi, Muhannad Ahmed; Kumar, AjayThis study is focused on a comprehensive characterization of virgin and spatter IN939 powders and the effects of a certain amount of spatter powder on the part quality of IN939 fabricated by the L-PBF process. A brown tint coloration formed Al2O3 oxide, pores, a 124.4% increase in the average particle size, a 10.2% decrease in the powder circularity, and a 7.5% decrease in the powder aspect ratio were observed in the spatter powder. Additionally, higher average grain size and lower nanohardness were obtained for the spatter powder. In order to understand the effect of a certain amount of spatter powder on the part quality, 10 wt% spatter powder was mixed with the virgin powder. This addition was found to decrease the flowability of the powder. Moreover, this addition decreased relative density by around 0.3% and increased surface roughness by around 80.8% in the fabricated samples (termed as V and SV). On the other hand, there was no considerable microstructural, texture, microhardness, and nanohardness difference between V and SV samples, although the spatter powder addition caused a 30.2% increase in the average grain size of SV. The overall texture for both V and SV samples exhibit (00 1)//BD.Article Citation - WoS: 4Citation - Scopus: 5Investigation of Resonant Properties of Metamaterial Thz Filters Fabricated From Vanadium Dioxide Thin Films(WORLD SCIENTIFIC PUBL CO PTE LTD, 2023) Zeybek, Şehriban; Demirhan, Yasemin; Noori, Aileen; Tugay, Halime; Altan, Hakan; Sabah, Cumali; Aygun, GülnurVanadium dioxide (VO2) is a promising candidate for electronic and optical switching applications in the terahertz frequency range due to the metal to insulator transition (MIT). In this study, the use of VO2 patterned as a metamaterial surface or coupled as a homogeneous layer with a metallic metamaterial surface on top is investigated in terms of performance. High-quality VO2 thin films were deposited on c-cut sapphire substrates by using the dc magnetron sputtering technique. A change in resistivity by a factor of 104 MIT in VO2 was observed allowing to investigate its use as a controllable metamaterial. The layer was patterned using a unique geometry (four-cross shaped) that operates in the THz frequency range. To understand its performance as a tunable THz filter, the four-cross structure fabricated from VO2 is compared to one fabricated from Au on VO2 bare film using UV lithography and ion beam etching techniques. The spectral performances of metamaterials were assessed using THz-Time Domain Spectroscopy (THz-TDS) and results were compared with simulations based on CST Microwave Studio. Absence of the resonant effects in the purely developed VO2 device, while clear observation of the MIT behavior shows the strong dependency of the inductive and/or capacitive effects of the four-cross structure on conductivity of the surface metamaterial, which is clearly observable for the Au-based device. In the latter case, the resonant transmittance of the filter can be effectively modulated by change in temperature.Article Citation - WoS: 2Citation - Scopus: 1A Review of the Geothermal System Evolution and Distribution in the Central Anatolian Crystalline Complex (türkiye)(TUBITAK, 2023) Şener, M.F.; Öztürk, M.Z.; Baba, A.Türkiye is located in the Mediterranean sector of the Alpine–Himalayan tectonic belt and is among the foremost seven countries in the world having an abundance of geothermal resources. The Central Anatolian Crystalline Complex (CACC) is one of the most important geothermal regions in Türkiye. This study aims to evaluate the geothermal system of CACC using the geological, structural, and hydrogeochemical properties that were obtained from previous studies. The present study investigated and evaluated the hydrogeochemical and isotopic properties of 762 water samples belonging to 45 different localities from 41 scientific studies. The result shows that CACC has different heat sources and different hydrogeochemical processes. Major element chemistry of the water reveals that the geothermal fluids are mostly of the Ca-Mg-HCO3, Na-Cl-HCO3, and Ca-Cl water types. Silica geothermometers suggest that the reservoir temperature ranges from 48 to 180 °C. Based on the δ18O-δD relationship, water samples have a high-altitude meteoric origin. Stable isotopic data indicate that the geothermal fluids are formed by local recharge and deep circulation of meteoric waters. © TÜBİTAK.