Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Exergy-Based Evaluation of High-CO2 Biogas/Diesel RCCI Combustion Heat Flow for Enhanced Mixture Distribution, Power Output, and Fuel-Energy Performance(Pergamon-Elsevier Science Ltd, 2026) Dalha, Ibrahim B.; El-Adawy, Mohammed; Wong, Nur Leena W. S.; Man, Hafsalina C.; Said, Mior A.; Koca, Kemal; Abdulsalam, MuhammedUtilising high-CO2 biogas in compression-ignition engines poses significant challenges due to poor mixture reactivity, inefficient combustion, and increased energy degradation. This work addresses these difficulties by conducting experimental research on a port-injection at the valve reactivity-controlled compression ignition (PIVE-RCCI) strategy. This study addresses these concerns by conducting experiments on a PIVE-RCCI technique to improve mixture distribution and combustion efficiency in biogas-diesel engines. The engine was modified to provide biogas through the inlet valve, allowing for controlled variations of biogas injection pressure (BIP: 1-4 bar) and port swirl ratio (PSR: 0-80%) at 1600 rpm and 4.9-5.7 bar IMEP. Energy and exergy analyses were used to determine the effect of intake flow dynamics on temperature uniformity, heat transfer, and power generation during combustion. The results reveal that normal airflow conditions minimise accounted heat loss, indicating higher thermal efficiency (ITE) and increased output power across all BIPs. In contrast, introducing a strong intake swirl dramatically improves combustion performance. The 80% PSR configuration resulted in the lowest exergy destruction and the maximum energy recovery potential, with an ITE of 26.54% at 4 bar BIP. Increasing BIP increased power output, whereas the optimal combustion work was found at 1 bar BIP and 40% PSR. The optimal working conditions were 1 bar BIP, 80% PSR, and 5.45 bar IMEP, which resulted in 26.00% exergy destruction, 39.38% destruction-to-released exergy ratio, 86.00% exergy-energy ratio of heat transfer, and 63.78% exhaust exergy-energy ratio. This work's novelty lies in integrating biogas injection, intake swirl control, and exergy-based evaluation to measure mixture distribution and energy recovery in high-COQ biogas RCCI combustion. The findings offer useful operational guidance for increasing energy efficiency and advancing the commercialization of renewable gaseous fuels in RCCI engines. As a result, operating the engine at half load, 80% PSR, and atmospheric air pressure (1 bar) conditions significantly enhanced the combustion efficiency and energy utilisation.Article Citation - WoS: 12Citation - Scopus: 12Edge Dislocation Depinning From Hydrogen Atmosphere in Α-Iron(Pergamon-Elsevier Science Ltd, 2024-07) Kapci, Mehmet Fazil; Yu, Ping; Marian, Jaime; Liu, Guisen; Shen, Yao; Li, Yang; Bal, BurakUnderstanding the dislocation motion in hydrogen atmosphere is essential for revealing the hydrogen-related degradation in metallic materials. Atomic simulations were adopted to investigate the interaction between dislocations and hydrogen atoms, where the realistic hydrogen distribution in the vicinity of the dislocation core was emulated from the Grand Canonical Monte Carlo computations. The depinning of edge dislocations in alpha-Fe at different temperatures and hydrogen concentrations was then studied using Molecular Dynamics simulations. The results revealed that an increase in bulk hydrogen concentration increases the flow stress due to the pinning effect of solute hydrogen. The depinning stress was found to decrease due to the thermal activation of the edge dislocation at higher temperatures. In addition, prediction of the obtained results was performed by an elastic model that can correlate the bulk hydrogen concentration to depinning stress.Article Development and Radiation Test of a Secondary Emission Ionization Calorimetry Module(Pergamon-Elsevier Science Ltd, 2025-06) Paran, Nejdet; Tiras, Emrah; Tekgun, Burak; Abubakar, SalehThe demand for precise, robust, and reliable radiation-resistant particle detectors and ionization calorimeters intensifies due to the escalating luminosity and unprecedented radiation conditions at particle colliders and accelerators. Secondary Emission (SE) Ionization Calorimetry is a novel technology designed to measure the energy of electromagnetic and hadronic particles, particularly in extreme radiation conditions. In this study, we have tested and investigated the development and radiation tests of the novel SE modules. The modules were developed by modifying the conventional Hamamatsu single-anode R7761 Photomultiplier Tubes (PMTs). Three different voltage conditions for the same module were created and the new modules were tested using cosmic and gamma radiation sources, Co-60. The results show that all three modes have good sensitivity to electromagnetic showers, and they are suitable for harsh radiation environments. This study also indicates that the SE module is a promising technology shedding light on future radiation-resistant nuclear and high-energy detectors. Here, we discuss the technical design, test characteristics, and cosmic and particle interaction results of the newly developed SE modules.Article Citation - WoS: 17Citation - Scopus: 18Comparative Analysis of Hybrid Geothermal-Solar Systems and Solar PV With Battery Storage: Site Suitability, Emissions, and Economic Performance(Pergamon-Elsevier Science Ltd, 2025-01) Fedakar, Halil Ibrahim; Dincer, Ali Ersin; Demir, AbdullahRenewable energy integration has become a critical focus in the global effort to reduce carbon emissions and diversify energy sources. In regions with distinct geographic features, such as Turkiye, combining different renewable technologies can offer enhanced energy security. This study investigates the site suitability and economic and environmental performance of hybrid geothermal-solar systems and solar PV systems with battery storage across the provinces of Osmaniye, Hatay, and Kilis, of Turkiye. Using the fuzzy-AHP method, site suitability is evaluated, addressing a key gap in comparing these systems' adaptability to varying geographic conditions. This study is the first to directly compare these two renewable energy technologies in terms of site suitability. The findings reveal significant differences in site suitability, with solar PV systems with battery storage demonstrating broader applicability across the region. The suitable sites (20-100 % suitability) cover 1260.82 km(2) for solar PV systems with battery storage and only 122.18 km(2) for hybrid geothermal-solar systems. In terms of environmental impact, hybrid geothermal-solar systems exhibit significantly lower carbon emissions, averaging 44.6 kg CO2/MWh, compared to 123.8 kg CO2/MWh for solar PV systems with battery storage. Economically, hybrid geothermal-solar systems also outperform with a lower levelized cost of electricity of $0.091 kWh versus $0.254 kWh for solar PV systems. These results highlight the environmental and economic advantages of hybrid geothermal-solar systems, while also emphasizing their limited scalability to regions with geothermal activity. Conversely, solar PV systems, despite their higher emissions and costs, offer greater flexibility and potential for widespread deployment.Article Citation - WoS: 5Citation - Scopus: 9Assembling a Justified List of Academic Words in Veterinary Medicine: The Veterinary Medicine Academic Word List (VMAWL)(Pergamon-Elsevier Science Ltd, 2024-04) Ozer, Mustafa; Akbas, ErdemThe assembly of corpus-based discipline-specific word lists for pedagogical purposes has recently been on the rise (e.g., Arndt, 2022; Fraser, 2007; O'Flynn, 2019; Yang, 2015). In order to cater to the needs of learners in veterinary medicine (VM) and for field-specific academic literacy, this paper analyses a reiteration of the Veterinary Medicine Corpus (ozer and Akbas, , 2023; hereafter the VMC), assembling a specified list of academic words used in published research articles (RAs) in VM. So far, VM has remained largely unexplored with the exception of Durrant's (2009) limited coverage of VM texts. The analysis was conducted using LancsBox 6.0, prompted to yield a list of PoS-tagged lemmas (Plemmas) sorted by frequency (Coxhead, 2000; Yang, 2015) and dispersion (Arndt, 2022). The most frequent 1,000 lemmas for each content word category were collated into a candidate list. We then manually eliminated proper nouns and GSL (West, 1953) words. The final list, the Veterinary Medicine Academic Word List (VMAWL), contains 835 PoStagged lemmas (P-lemmas), a reiteration of which was produced by adding the types in Bauer and Nation's (1993) taxonomy at the second level to test coverage. The VMAWL was profiled and validated against the four parent categories independently on AntWordProfiler (Anthony, 2022a) with analysis showing the VMAWL comprises 13.75 % of the VMC and diverges greatly from generic word lists like the AWL, NGSL, new-GSL, and AVL. The list can be used to develop teaching materials for EAP or ESP academic writing courses. (c) 2023 Elsevier Ltd. All rights reserved.