Istanbul Technical University
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Synthesis and characterisation of activated carbon supported catalysts: photocatalytic degradation of olive wastewater solutions using these catalysts
No full textAbstract The aim of this study is to synthesize and characterize four different types of activated carbon supported catalysts and evaluate their effectiveness in the photocatalytic degradation of olive mill wastewater (OMW) generated during the olive oil production process. The four photocatalysts synthesized by using the sol-gel method were: TiO2/AC, V2O5/TiO2/AC, WO3/TiO2/AC and V2O5/WO3/TiO2/AC. The photocatalysts were characterised by using TEM, SEM, XRD, FTIR analytical technniques and BET analyses. The degradation performance of these calatalysts was evaluated by investigating the the removal of pollutants such as color, phenol, lignin and COD from OMW. In addition, the effects on photocatalytic degradation were investigated in detail by considering the catalyst type, catalyst amount, suspension pH and contact time. From the experimental results, V2O5/TiO2/AC catalyst showed superior performance compared to the remaining catalysts. In order to increase the oxidation effect, ozone (O3) and hydrogen peroxide (H2O2) were used as supporting oxidising agents either together or separately in some experiments. When ozone and UV were used together, the highest removal rates for color, phenol, lignin and COD were 87%, 91%, 60% and 70%, respectively, and when the catalyst and H2O2 were used together, the highest removal rates were 24%, 55%, 35% and 42%, respectively, for color, phenol, lignin and COD. When the catalyst, UV/O3 and H2O2 were used together, the removal rates for color, phenol, lignin and COD were 95%, 90%, 60% and 58%, respectively, after 6 hours. Under optimum conditions, photocatalytic degradation of various pollutants in the presence of supporting oxidants such as O3 and H2O2 reached almost 80–95%. In conclusion, the findings of this research address a major environmental concern in the treatment of OMW by presenting an innovative catalytic method for the effective degradation of OMW wastewater. Graphical Abstracthttps://doi.org/10.1007/s10971-025-06833-2https://hdl.handle.net/20.500.12831/2696
Mycelium-Based Composites for Interior Architecture: Digital Fabrication of Acoustic Ceiling Components
No full textThis study examines the integration of digital fabrication technologies into the design and production of mycelium-based components, addressing the growing demand for sustainable and innovative interior design solutions. Using a parametric design approach, modular and customized suspended ceiling elements were developed for a specific interior setting to explore a material-specific design approach for mycelium-based components. Three-dimensional printing was employed to produce molds, which were subsequently tested with plaster, silicone, and mycelium across three different scales. Experimental observations focused on the overall form, surface details, growth behavior and dimensional accuracy, systematically capturing volumetric deviations arising from the living nature of the material. In parallel, acoustic performance was evaluated through simulations using the Sabine method. The untreated condition demonstrated the longest reverberation times, whereas conventional panels achieved reductions consistent with typical comfort standards. Prototypes produced with mycelium yielded measurable decreases in reverberation time compared to the untreated condition, particularly within the speech frequency range, and approached the performance of standard acoustic panels. These findings suggest that mycelium-based components, when further optimized in terms of density and geometry, hold the potential to contribute both aesthetic and acoustic value within sustainable interior environments.https://doi.org/10.3390/biomimetics10110729https://pmc.ncbi.nlm.nih.gov/articles/PMC12650300/https://pubmed.ncbi.nlm.nih.gov/41294402
Silver Embedded Electrospun Nanofibers as an Efficient Interlayers for High‐Performance Practical Li‐S Batteries
No full textAbstract This study presents a practical approach for the synthesis of Ag nanoparticle‐containing polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) nanofibers from AgNO 3 ‐doped PVA and PVP precursor solutions at ambient temperature. The prepared nanofibers were coated on the glass fiber separator as efficient interlayers for long‐cycle life Li‐S batteries. The initial specific capacity of the cell with Ag@PVP composite is 1201 mAh g −1 . During the first 500 cycles, the specific capacity retains at 998 mAh g −1 . The specific capacity of Ag@PVA remains at 793 mAh g −1 , resulting in a lower capacity retention rate compared to Ag@PVP after 500 cycles. The best result was achieved by Ag@PVP, which exhibited a capacity retention rate of ≈83% and maintained a coulombic efficiency of 99%, indicating superior cycling stability even after 500 cycles. In addition, the Ag@PVA composite achieved a capacity retention rate of ≈80% and maintained a coulombic efficiency of 97.5% after 500 cycles. The incorporation of highly conductive Ag into the polymer structure can effectively reduce the shuttling effect by enhancing the chemical interactions between polysulfides and modified interlayers. Ag@PVP and Ag@PVA on glass fiber separators can improve cycling stability over long periods of time, making them promising candidates for use in scalable and practical Li‐S batteries.https://doi.org/10.1002/slct.20250073
Bee bread incorporated Chitosan films for food packaging: enhanced physical properties, antioxidant, and antibacterial activities
No full texthttps://doi.org/10.1007/s11694-025-03623-
Girdaplayıcı içeren kısmi karışımlı yanmanın araştırılması ıçın uygun maliyetli bir rans yaklaşımı
No full textThesis (M.Sc.) -- Istanbul Technical University, Graduate School, 2025With the increasing global energy demand driven by population growth and industrialization, the environmental impacts of energy production systems have become more critical. In particular, carbon emissions from fossil fuel-based systems have contributed to severe environmental issues such as climate change. Therefore, developing more efficient and lower-emission combustion systems is of great importance. However, designing such systems is challenging due to the coexistence of high temperatures, turbulence, and complex chemical reactions. Although experimental methods offer high accuracy, their high cost and infrastructure requirements limit their applicability. As a result, numerical methods, especially computational fluid dynamics (CFD), have gained increasing attention in combustion research. Nevertheless, high-fidelity approaches such as Large Eddy Simulation (LES) or Direct Numerical Simulation (DNS) require significant computational resources. This highlights the importance of low-order models that can offer faster and more practical solutions. In this thesis, turbulent flow and flame behavior in a partially premixed, swirl-stabilized combustion chamber are investigated using numerical simulations performed with OpenFOAM. The study focuses on axisymmetric modeling to reduce computational cost. A full model configuration was initially developed and then simplified into a wedge-type periodic model using axial symmetry assumptions. Reynolds-Averaged Navier-Stokes (RANS) turbulence modeling was employed together with the eddy dissipation concept (EDC) for combustion, and a reduced methane-air mechanism was used to model chemical reactions. Both non-reacting and reacting flow conditions were analyzed separately to evaluate the accuracy of the low-order axisymmetric model. Key outputs such as temperature distributions, chemical heat release rates, and species mass fractions were examined in detail. In the non-reacting case, both the full and periodic models produced results that were consistent with the experimental data. In particular, the full geometry showed good agreement in capturing the swirl jet and central recirculation zone structures. The velocity profiles obtained from the simulations indicated that both inner and outer shear layers were successfully predicted in both configurations. However, when three-dimensional flow structures were analyzed, it was observed that the periodic model tended to suppress these features further downstream from the swirl outlet. This suppression led to a relatively lower fuel mass fraction in the central recirculation zone for the periodic model compared to the full model. In the reacting flow simulations, the full and periodic models produced similar axial velocity profiles, both showing reasonable agreement with experimental data. However, both models failed to capture the secondary peaks observed in the tangential velocity profiles from the experiments. This limitation is attributed to the use of low-fidelity modeling. Furthermore, three-dimensional structures that developed in the full model could not be reproduced in the periodic configuration. As a result, combustion reactions and the formation of radicals were observed closer to the swirl outlet in the periodic model. This caused the temperature values to be higher near the outlet and lower in the downstream region compared to the full model and experimental data. Overall, the periodic model provided results close to the full model and experimental data in the non-reacting case, while also offering a significant reduction in computational cost. In the reacting case, however, it showed limitations in accurately predicting flame properties. Despite this, its low computational cost made it advantageous for testing ignition strategies. Therefore, the periodic configuration can be considered a useful tool for preliminary design and parametric studies, especially when rapid assessment is prioritized over full physical accuracy.M.Sc
I-MCM: IoT Malware Counter Measures for Cross-Architecture IoT Malware Detection
No full textThe recent attacks initiated by malware-infected IoT devices illustrate that these attacks have tremendous impacts not only on the targeted systems but also on the entire internet infrastructure. Due to the vast number of infected IoT devices, the Quality of Service of the target system can be severely hampered by DDoS attacks. Despite the severity of the threat, the security measures against IoT malware are highly limited, and mostly, users are unaware that their devices are infected by malware. Due to the constrained nature of IoT devices, high-resource-demanding anti-malware tools cannot be run on edge devices, and lightweight malware detection systems are highly needed to secure those devices against IoT malware. In this regard, we propose the I-MCM framework for IoT malware detection on IoT devices by utilizing Tiny ML techniques based on static malware analysis data. Our proposed I-MCM framework is capable of detecting IoT malware in a Raspberry Pi Node deployed with Random Forest Classifier in 7.87 s. (including file analysis and data preprocessing) with 99.8% accuracy and in an Arduino Nano 33 BLE Sense microcontroller deployed with a Tiny ANN model in 8.16 s. (including file analysis and data preprocessing) with 97.1% accuracy. Besides, the I-MCM framework can detect IoT malware regardless of CPU architecture with only one ML model by utilizing our Opcode Purification Technique. Last but not least, this research presents a cross-architecture IoT Malware dataset that includes both malware and benignware samples.https://doi.org/10.1109/access.2025.3573942https://doi.org/10.1109/ACCESS.2025.3573942https://doaj.org/article/f49f2d46de394542a74a91cc0be81fa8https://hdl.handle.net/20.500.12831/2648
Primary systemic carnitine deficiency: Phenotypic variability, diagnostic challenges, and long‐term outcomes
No full textAbstract Background Primary systemic carnitine deficiency (CDSP) is a rare inherited metabolic disorder characterized by impaired carnitine transport due to mutations in the SLC22A5 gene, leading to impaired mitochondrial fatty acid oxidation. The aim of this retrospective, descriptive study was to investigate the clinical, biochemical, and molecular features of CDSP in Turkey, where the lack of a national expanded metabolic screening program contributes to delayed diagnosis and severe complications. Methods The clinical, biochemical, and molecular profiles of 12 patients from eight families diagnosed between 2003 and 2025 were retrospectively analyzed. Data on family history, consanguinity, clinical manifestations—including cardiomyopathy, muscle weakness, neurological symptoms, and liver dysfunction—plasma free carnitine levels, and echocardiographic measurements were collected and analyzed. Results The majority of patients (92%) were from consanguineous families. Cardiomyopathy was the most common clinical feature (75%), followed by muscle weakness (50%), neurological symptoms (42%), and liver dysfunction (33%). A novel SLC22A5 variant (c.125T>C; p.Leu42Pro) was identified that expands the known genetic spectrum of CDSP. Oral carnitine supplementation significantly increased plasma free carnitine levels ( p = 0.01) and improved long‐term interventricular septal thickness Z‐scores ( p = 0.045). In addition, cholestasis was observed in two patients, suggesting an expanded disease phenotype. Conclusion These results emphasize the crucial role of early detection and family screening in the prevention of life‐threatening complications associated with CDSP. Long‐term carnitine therapy improves metabolic and cardiac outcomes, underscoring the need for early intervention and inclusion of CDSP in national newborn screening programs.https://doi.org/10.1111/ped.7021
Improved Z-number and Bayesian network analysis to predict accommodation electrical fire risk on a tanker ship
No full texthttps://doi.org/10.1080/17445302.2025.251668
A Holistic Approach Weighing Up the Pros and Cons of Winter Road Maintenance Operations: A State-of-Art Review
No full texthttps://doi.org/10.1007/s13369-025-10419-
From Theory to Practice: A Testbed for DL-Based Semantic Communication Architecture
No full texthttps://doi.org/10.1109/ccnc54725.2025.10975952https://doi.org/10.1109/CCNC54725.2025.1097595