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Technology Assessment of Hydrogen Storage: Cases Enabling the Clean Energy Transition
No full textKayalica, M. Özgür/0000-0001-9828-7385; Guven, Denizhan/0000-0003-1605-7661; Kayakutlu, Gulgun/0000-0001-8548-6377In this article, we show the adequacy of power systems that can incorporate renewable energy sources and hydrogen for large-scale power consumption. Using the analytic hierarchy process with a focus on multiple criteria, six grid-scalable energy storage technologies are initially assessed to this end. The most suitable option for grid-scale application is green hydrogen storage technology. Then, an optimization model is developed to advance hydrogen solutions by minimizing the annual cost equivalent to capital and operational expenditures of the systems. The model is used to comprehensively examine the integration and operation of two distinct real-life applications: hybrid power systems that incorporate hydrogen alongside renewable energy sources without natural gas and with natural gas. In this direction, this study thoroughly examines the crucial role of green hydrogen in achieving a sustainable and clean energy landscape through a multidisciplinary investigation of hydrogen production and storage from a technology management perspective. Through case studies, the practicality of integrating green hydrogen into power systems to meet substantial power demands is shown. By decreasing the systems' current costs by similar to 60% and contributing to an increase in renewable energy penetration, the proposed systems provide cost-effectiveness, carbon reduction potential, and adaptability to existing infrastructure. In response to the imperative to overcome challenges in transitioning to cleaner energy, this research advocates for well-informed decision making by using the optimization model to attain a robust and eco-friendly energy future
Near-Infrared Triggered Degradation for Transient Electronics
No full textIstif, Emin/0000-0003-4700-7050; Bathaei, Yaren/0009-0000-9094-3819; ali, Mohsin/0000-0001-8626-6122Electronics that disintegrate after stable operation present exciting opportunities for niche medical implant and consumer electronics applications. The disintegration of these devices can be initiated due to their medium conditions or triggered by external stimuli, which enables on-demand transition. An external stimulation method that can penetrate deep inside the body could revolutionize the use of transient electronics as implantable medical devices (IMDs), eliminating the need for secondary surgery to remove the IMDs. We report near-infrared (NIR) light-triggered transition of metastable cyclic poly-(phthalaldehyde) (cPPA) polymers. The transition of the encapsulation layer is achieved through the conversion of NIR light to heat, facilitated by bioresorbable metals, such as molybdenum (Mo). We reported a rapid degradation of cPPA encapsulation layer about 1 min, and the rate of degradation can be controlled by laser power and exposure time. This study offers a new approach for light triggerable transient electronics for IMDs due to the deep penetration depth of NIR light through to organs and tissues.European Research Council [118C295]; European Research Council [101043119]; Scientific and Technological Research Council of Turkey (TUBITAK) [121Z184]; TUBITAK [121Z184, 3501]; Koc University Surface Science and Technology Center (KUYTAM); European Research Council (ERC) [101043119] Funding Source: European Research Council (ERC)L.B. acknowledges TUBITAK 2232 (grant no. 118C295) and the European Research Council (grant no. 101043119). E.I. acknowledges support through the Scientific and Technological Research Council of Turkey (TUBITAK) 3501 (grant no. 121Z184). E.Y.O. is supported by TUBITAK through the 3501 (grant no. 121Z184) program. We acknowledge Koc University Surface Science and Technology Center (KUYTAM) and Koc University Nanofabrication and Nanocharacterization Center (n2STAR) for access to the infrastructure.Science Citation Index Expande
Multimodal Online Dissident Culture in Instagram: a Critique of the Turkish Economy
No full textArda, Balca/0000-0002-3793-2472; Bas, Ozen/0000-0002-8895-9704Ever-present mass surveillance has blocked the flourishing of a traditional dissident culture in Turkey. Focusing on popular 'just for fun' Instagram accounts during the lira's freefall that began in the autumn of 2021, this study seeks to identify the creative strategies for digital social resistance embedded in multimodal content sharing of posts, which are composed of visuals, text, and sound. For this, we employed a multimodal-type analysis of Instagram posts regarding Turkey's economic crisis, followed by an interpretative content analysis aiming to (1) identify, categorize, and compile a typology of the main countersurveillance strategies inherent in multimodal posts, such as memes, edited videos, and animations, Photoshop-crafted still images, and (2) explore the contextual traits of the connected dissident culture. We discuss how these multimodal-type posts support connected dissident group formation while maintaining confidentiality while criticizing governmental conduct of economic policy making in Turkey
International migration and the NGOs working in the field of migration in Turkey
No full textOzcetin, Burak/0000-0003-3091-237XThis study aims to analyse the activities and discourses of the non-governmental organizations (NGOs) working in the field of migration in Turkey. The research explores how the NGOs frame the issue of migration differently and how they define and comprehend migration, migrants, and refugees. The article discusses whether the NGOs view refugees as subjects needing help, support, and protection or as actors who have rights and must be empowered and argues that there is tension between the two approaches. These points are discussed through a field study, conducted in 2020 (between February and April), comprising in-depth interviews with representatives of 13 NGOs working in the field of migration. The study points to structural, historical, and conjectural causes and aspects of the weakness of rights-based attitudes and activities among the NGOs working in the field of migration in Turkey. The article finds out that the actions of the NGOs working in the field of migration are concentrated on the basic needs of refugees, and structural limitations, such as political pressure, political polarization, and capacity problems, push the NGOs to evaluate the issue of migration within relatively narrow frames. The article also stresses the importance of an enabling political and legal environment and a coherent and structured communication strategy to promote a rights-based migration agenda.Trkiye Bilimsel ve Teknolojik Arascedil;timath;rma KurumuNo Statement Availabl
Optical Identification and Follow-Up Observations of Srga J213151.5+491400 a New Magnetic Cataclysmic Variable Discovered With the Srg Observatory
No full textContext. The paper is comprised of optical identification and multiwavelength studies of a new X-ray source discovered by the Spectrum Roentgen-Gamma (SRG) observatory during the ART-XC survey and its follow-up optical and X-ray observations. Aims. We aim to identify SRGA J213151.5+491400 in the optical wavelengths. We determine spectra and light curves in the optical high and low states to find periodicities in the light curves and resolve emission lines in the system using optical ground-based data. We intend to study the spectral and temporal X-ray characteristics of the new source using the SRG surveys in the high and low states and NICER data in the low state. Methods. We present optical data from telescopes in T & uuml;rkiye (RTT-150 and T100 at the T & Uuml;B & Idot;TAK National Observatory) and in Russia (6-m and 1-m at SAO RAS), together with the X-ray data obtained with ART-XC and eROSITA telescopes aboard SRG and the NICER observatory. Using the optical data, we performed astrometry, photometry, spectroscopy, and power spectral analysis of the optical time series. We present optical Doppler tomography along with X-ray data analysis producing light curves and spectra. Results. We detected SRGA J213151.5+491400 in a high state in 2020 (17.9 mag) that decreased by about 3 mag into a low state (21 mag) in 2021. We find only one significant period using optical photometric time series analysis, which reveals the white dwarf spin (orbital) period to be 0.059710(1) days (85.982 min). The long slit spectroscopy in the high state yields a power-law continuum increasing towards the blue with a prominent He II line along with the Balmer line emissions with no cyclotron humps, which is consistent with a magnetic cataclysmic variable (MCV) nature. Doppler Tomography confirms the polar nature revealing ballistic stream accretion along with magnetic stream during the high state. These characteristics show that the new source is a polar-type MCV source. ART-XC detections yield an X-ray flux of (4.0-7.0) x 10-12 erg s-1 cm-2 in the high state. eROSITA detects a dominating hot plasma component (kTmax > 21 keV in the high state) declining to (4.0-6.0) x 10-13 erg s-1 cm-2 in 2021 (low state). The NICER data obtained in the low state reveal a two-pole accretor showing a soft X-ray component at (6-7)sigma significance with a blackbody temperature of 15-18 eV. A soft X-ray component has never been detected for a polar in the low state before.IKI; KFU [1805, 1824]; SAO RAS; TUG [16ARTT150-949]; RSF [N 23-12-00292]; RFBR [19-32-60048, FZSM-2023-0015]; EROSITA X-ray telescopes aboard the SRG orbital observatory; Deutsches Zentrum fr Luft- und Raumfahrt (DLR); DLR; German eROSITA Consortium; Russian eROSITA Consortium; Russian Space Agency, Russian Academy of Sciences and State Corporation Rosatom; SRG project; Lavochkin Association (NPOL)We acknowledge TUBITAK National Observatory (TUG), IKI, KFU, and AST for a partial support in using RTT150 (Russian-Turkish 1.5-m telescope in Antalya) with SRG ART-XC project numbers 1805 and 1824. We thank the NICER Observatory for performing the X-ray and TUBITAK National Observatory (TUG) and SAO RAS (Special Astrophysical Observatory of the Russian Academy of Sciences) for the optical observations, particularly Dmitry Oparin for the successfull SCORPIO-1 spectroscopic observations. We thank the NICER calibration team, particularly Craig Markwardt for help with the SCORPEON background analysis and Ron Remillard, for checking the total background, low and high energy noise characteristics of our observation and confirming the soft excess in the data. We acknowledge ATLAS, ZTF, and Gaia for the availability of their data and light curves. H.H.E. thanks TUG for partial support with project number 16ARTT150-949. The analysis of eROSITA X-Ray data has been supported by RSF grant N 23-12-00292. This study was partially funded by RFBR, project number 19-32-60048. E.I. and N.S. were partially supported by the subsidy FZSM-2023-0015 allocated to the Kazan Federal University. This work is based on data from Mikhail Pavlinsky ART-XC and eROSITA X-ray telescopes aboard the SRG orbital observatory. The SRG observatory was built by Roskosmos in the interests of the Russian Academy of Sciences represented by its Space Research Institute (IKI) in the framework of the Russian Federal Space Program, with the participation of the Deutsches Zentrum fur Luft- und Raumfahrt (DLR). The eROSITA X-ray telescope was built by a consortium of German Institutes led by MPE, and supported by DLR. The SRG spacecraft was designed, built, launched and is operated by the Lavochkin Association and its subcontractors. The eROSITA data used in this work were processed using the eSASS software system developed by the German eROSITA Consortium and proprietary data reduction and analysis software developed by the Russian eROSITA Consortium. The ART-XC and eROSITA teams thank the Russian Space Agency, Russian Academy of Sciences and State Corporation Rosatom for the support of the SRG project and ART-XC telescope and the Lavochkin Association (NPOL) with its partners for the creation and operation of the SRG spacecraft
Simultaneous Impacts of Correlated Photovoltaic Systems and Fast Electric Vehicle Charging Stations on the Operation of Active Distribution Grids
No full textThis paper presents two novel probabilistic models developed to account for the uncertainties of aggregated fast electric vehicle charging stations (FEVCSs) demand and correlated photovoltaic (PV) injections in active distribution network (ADN) analysis. Both models are more precise than the available ones. A probabilistic model based on the Beta distribution is used for solar radiance, while the shared random variables technique is proposed considering correlated solar radiation random variables. Furthermore, a probabilistic negative exponential load model is extended for modeling the FEVCSs based on the Weibull probability density function. Moreover, the proposed probabilistic load flow (PLF) model is solved using the combined cumulants and saddle-point approximation method. Numerical tests are provided and discussed by applying the IEEE 69-bus distribution system for different PV correlation coefficients and FEVCS load models. The results demonstrate how the uncertainty of PLF outputs is increased by integrating FEVCSs and correlated PV resources into the distribution network. In addition, simulation results validate that the cumulants-based methodology provides satisfactory accuracy with a low computational cost.Scientific and Technological Research Council of Turkey [BI bull; DEB 2221]; [1059B212200475]This research is funded as a part of the BI center dot DEB 2221 Program orga-nized by The Scientific and Technological Research Council of Turkey (No. 1059B212200475) .Science Citation Index Expande
The Return of the State and Its Alla Turca Version
No full textEconomic nationalism and state intervention recently gained attraction in many countries including Turkey. This paper questions whether Turkey has changed its economic policy framework towards a statecentric model and, if so, whether these changes are well thought-out and sustainable. The examination of key areas of state capitalism, that is the monetary, industrial, trade, financial, and state economic enterprise (SEE) policies put forward in the officially adopted five-year plans and annual programs, suggests that the changes in the economic policy framework began after the 2008 global crisis and accelerated after the transition to a presidential system. Upon examination, the policy framework does not reflect a definitive, coherent, and wholistic approach but rather a pragmatic attitude that swings back and forth, which exposes the country to swings in the global system.Social Science Citation Inde
Data-Driven Local Control Design for Dead Band Control of Load Tap Changers
No full textThis study presents an off-line optimization-guided machine learning approach for coordinating the local control rules of on-load tap changers (OLTCs) and step-voltage regulators (SVRs). Based on a bang-bang control rule, these legacy devices autonomously regulate the feeder voltage around the nominal level by varying the tap position in the lower or raise direction. The characterizing parameter of the local control rule is the dead band, which affects the number of tap switching in operation and is directly related to the economical use life of the equipment. The bandwidth is typically set within a standard voltage range and is generally kept constant in daily operation. However, adjusting the bandwidth dynamically can prevent excessive tap switching while maintaining satisfactory voltage regulation for varying loading and distributed generation conditions. Our approach aims to set the bandwidth parameter systematically and efficiently through a machine learning-based scheme, which is trained with a dataset formed by solving the distribution network optimal power flow (DOPF) problem. The performance of learning the bandwidth parameter is demonstrated on the modified 33-node feeder, which is promising for integrated voltage control schemes.Conference Proceedings Citation Index - Scienc
Permissioned Blockchain-Based Monitoring Framework for Der-Integrated Distribution Networks
No full textSCADA systems are used for real-time monitoring of key systems and the status of critical assets in both transmission and distribution networks. The trend towards different types of”new” loads and sources such as photovoltaic (PV), electric vehicle (EV) charging stations and battery storage systems is changing the operational approach of distribution grids. Well-known fit-and-forget philosophy is being replaced and requires more operational activities and more thorough monitoring of end devices in new active distribution networks (ADNs). In this paper, a permissioned blockchain-based monitoring framework for distribution networks hosting different types of distributed energy resources (DERs) is presented. The proposed tool operates independently of the SCADA system while it can utilise SCADA measurements for anomaly and fraud detection. In addition, seamless integration and visibility is facilitated by the flow of information between DERs and the distribution system operator through adapters between the blockchain network and the main protocols used for smart metering, inverter management and EV charging stations. The coordinated use of SCADA and the proposed framework will provide a redundant set of observations that will contribute to unbiased state estimation and successful anomaly detection. © The Institution of Engineering & Technology 2024
Insights From the ‘Acoustics Workshop in Educational Buildings’ by Turkish Acoustical Society
No full textThis paper focuses on "Acoustics Workshop in Educational Buildings" organized by the Turkish Acoustical Society as part of International Noise Awareness Day 2023 Activities. The workshop brought together 34 participants, including designers, acoustic experts, teachers, and health and occupational safety professionals. Through interdisciplinary discussions, participants identified and prioritized acoustic problems, expectations and requirements for educational buildings, focusing on improving the quality of education. The workshop unfolded in two stages: firstly, participants were grouped by profession to identify primary acoustic challenges. Subsequently, multi-disciplinary teams collaboratively developed mitigation strategies to address these challenges. The results revealed profession-specific insights into main acoustic issues and proposed actionable solutions. This paper specifically provides insights into the use of qualitative content analysis to have a deeper understanding of different professions, people's experiences, behavior and priorities in relation to acoustics in school. © 2025 Elsevier B.V., All rights reserved