Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article A Novel ORC-PEM Integrated System for Sustainable Hydrogen Production from Low-Grade Waste Heat in Oil Refineries(Elsevier, 2025) Nazerifard, Reza; Mohammadpourfard, Mousa; Zarghami, RezaThis study presents an integrated multi-generation system for sustainable hydrogen production by harnessing low-grade waste heat from the overhead stream of the NHT unit's stripper column in an oil refinery. The proposed system integrates an ORC with a PEM electrolyzer, forming a novel energy solution that efficiently converts waste heat into clean hydrogen through electricity generation. A detailed model of the proposed system is developed, enabling a comprehensive assessment of its performance from thermodynamic, economic, and environmental viewpoints. At the same time, key operational parameters are optimized using the RSM-BBD method to minimize the hydrogen production cost, thereby enhancing the system's economic viability and practical implementation. The results demonstrated that the system achieves a yearly hydrogen production of 304.53 tons under optimized conditions, for 2.36 $/kg. The integrated system's overall energy and exergy efficiencies are calculated at 8.62 % and 33.43 %, respectively, demonstrating its high thermodynamic performance. Additionally, the system mitigates 3047 tons of CO2 annually by displacing conventional hydrogen production methods.Article Citation - WoS: 1Citation - Scopus: 1Effect of Soil Water Content Changes on the Behavior of Buildings Equipped With Single and Double Tuned Mass Dampers Subjected To Earthquakes(Springer Science and Business Media Deutschland GmbH, 2025) Roozbahan, M.; Turan, G.Tuned mass dampers (TMDs) are one of the structural control systems that have been frequently used in the last century. A TMD is designed according to the properties of the main system. In building applications, the substructure’s soil affects the response of buildings, especially in soft-type soils. Therefore, the soil properties should be included in the analysis and design of tuned mass dampers. However, the soil properties are not always identical and vary due to different factor changes such as soil water content changes. Unlike previous research, which typically assumes constant soil properties, this study incorporates the impact of soil water content changes, a key factor that can significantly alter soil behavior. This study aims to evaluate the effectiveness of optimized single and double tuned mass dampers (DTMDs) in response reduction of buildings considering the changes in the water content of soil. In this study, a metaheuristic-based optimization method is programmed to optimize TMDs and DTMDs for low-, mid-, and high-rise buildings considering soil-structure interaction (SSI). The efficiency of the optimized tuned mass dampers on the response reduction of buildings due to changes in soil water content is evaluated. According to the investigated results of 14 near-field earthquake simulations, it is concluded that the efficiency of the TMDs is significantly affected by changes in soil water content. Moreover, according to the result, the DTMD efficiency is slightly better than the TMD-controlled structure. © Springer Nature Switzerland AG 2025.Article Citation - WoS: 5Citation - Scopus: 6Sequence Identification and in Silico Characterization of Novel Thermophilic Lipases From Geobacillus Species(WILEY, 2023) Sürmeli, Yusuf; Tekedar, Hasan Cihad; Sanli-Mohamed, GulsahMicrobial lipases are utilized in various biotechnological areas, including pharmaceuticals, food, biodiesel, and detergents. In this study, we cloned and sequenced Lip21 and Lip33 genes from Geobacillus sp. GS21 and Geobacillus sp. GS33, then we in silico and experimentally analyzed the encoded lipases. For this purpose, Lip21 and Lip33 were cloned, sequenced, and their amino acid sequences were investigated for determination of biophysicochemical characteristics, evolutionary relationships, and sequence similarities. 3D models were built and computationally affirmed by various bioinformatics tools, and enzyme-ligand interactions were investigated by docking analysis using six ligands. Biophysicochemical property of Lip21 and Lip33 was also determined experimentally and the results demonstrated that they had similar isoelectric point (pI) (6.21) and T-m (75.5(degrees)C) values as T-m was revealed by denatured protein analysis of the circular dichroism spectrum and pI was obtained by isoelectric focusing. Phylogeny analysis indicated that Lip21 and Lip33 were the closest to lipases from Geobacillus sp. SBS-4S and Geobacillus thermoleovorans, respectively. Alignment analysis demonstrated that S144-D348-H389 was catalytic triad residues in Lip21 and Lip33, and enzymes possessed a conserved Gly-X-Ser-X-Gly motif containing catalytic serine. 3D structure analysis indicated that Lip21 and Lip33 highly resembled each other and they were alpha/beta hydrolase-fold enzymes with large lid domains. BAN Delta IT analysis results showed that Lip21 and Lip33 had higher thermal stability, compared to other thermostable Geobacillus lipases. Docking results revealed that Lip21- and Lip33-docked complexes possessed common residues (H112, K115, Q162, E163, and S141) that interacted with the substrates, except paranitrophenyl (pNP)-C10 and pNP-C12, indicating that these residues might have a significant action on medium and short-chain fatty acid esters. Thus, Lip21 and Lip33 can be potential candidates for different industrial applications.Article Citation - WoS: 9Citation - Scopus: 10On the Estimation and Optimization Capabilities of the Fatigue Life Prediction Models in Composite Laminates(SAGE Publications, 2018) Deveci, Hamza Arda; Artem, Hatice SeçilIn this study, the estimation and optimization capabilities of the multiaxial fatigue life prediction models, namely, Failure Tensor Polynomial in Fatigue, Fawaz-Ellyin, Sims-Brogdon and Shokrieh-Taheri are investigated comparatively. Fatigue life predictions are obtained for multidirectional graphite/epoxy, glass/epoxy, carbon/epoxy and carbon/PEEK composite laminate data taken from the literature. The prediction study shows that the models can predict the fatigue behavior of the multidirectional laminates at different degrees of proximity. In the optimization, a hybrid algorithm combining particle swarm algorithm and generalized pattern search algorithm is used to search the optimum stacking sequence designs of the laminated composites for maximum fatigue life. The hybrid algorithm shows superior performance in terms of computational time and finding improved global optima compared to the best results presented in the literature. After the capability of the models and the reliability of the algorithm are revealed, several lay-up design problems involving different cyclic loading scenarios are solved. The results indicate that the reliability of the optimization may considerably change according to the used model even if the model may yield reasonable prediction results.Article Citation - WoS: 32Citation - Scopus: 38Buckling Optimization of Composite Laminates Using a Hybrid Algorithm Under Puck Failure Criterion Constraint(SAGE Publications Inc., 2016) Deveci, Hamza Arda; Aydın, Levent; Artem, Hatice SeçilIn this study, an optimization procedure is proposed to find the optimum stacking sequence designs of laminated composite plates in different fiber angle domains for maximum buckling resistance. A hybrid algorithm combining genetic algorithm and trust region reflective algorithm is used in the optimization to obtain higher performance and improve the quality of solutions. As a novelty, Puck fiber and inter-fiber failure criteria are directly implemented to the optimization problems as nonlinear function constraints, which have allowed more consistent and feasible results. The performance of the hybrid algorithm is demonstrated by comparing with the individual performances of genetic and trust region reflective algorithms via test problems from the literature. Also, a study is performed to exhibit the effectiveness of the selected failure criterion as constraint among the other common criteria. The proposed procedure is used to solve many problems including various design considerations. The results indicate that reliable stacking sequence designs can be achieved in specific configurations even for the composite plates subjected to superior buckling loads when Puck physically based (3D) failure theory is considered as a first ply failure constraint in the buckling optimization.