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- MakaleYalnız künye2025Scopus SJRQ1Bridging experiment and simulation: Image processing-driven FEA of carbon fiber powder reinforced LDPE
ARIKAN, Volkan; DOGAN, Akar
Short fiber-reinforced polymers are widely used in engineering applications due to their improved mechanical performance and processability. However, accurately predicting the elastic behavior of such composites remains a challenge, especially when fibers are randomly distributed and lack defined orientation. To address this, this study investigates the mechanical properties of composite materials developed by incorporating carbon fiber powder (CFP) into a low-density polyethylene (LDPE) matrix at different reinforcement ratios (3 %, 6 %, and 9 %). The effects of CFP content on elastic modulus, tensile strength, and ductility were examined experimentally and through finite element analysis (FEA). Scanning electron microscopy (SEM) was used to analyze the microstructure, and image processing techniques were applied to quantify fiber orientation, which was then integrated into the FEA framework (Oriented FEA). Results indicate that CFP addition increases stiffness and tensile strength while reducing ductility, with 3 % CFP specimens showing the most favorable balance of mechanical properties. The proposed image-based orientation modeling approach provides improved simulation fidelity and offers a scalable methodology for evaluating the mechanical behavior of short fiber-reinforced composites.
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İncele - MakaleYalnız künye2024Scopus SJRQ2Dynamic Analysis and Metallographic Examination of Linings with Different Composite Contents used in the Brakes of a Hydraulic Turbine
Işık, Erdem; Kahraman, Gökhan
The main aim of this study was to find ways to increase the performance and life of generator brake linings, which can lead to cost reduction and adequate downtime periods for hydroelectric power plants. First, the dynamic analysis of the linings used in hydraulic turbines was realized and their reactions were examined under different operating conditions. Second, two types of brake linings with different composite components produced in the market were examined metallographically and tested to determine both the stopping performance and durability time of the turbine-generator unit for a sufficient period of time in the vertical 150-megawatt Francis turbine with approximately 500 tons of rotary weight. As a result of these experiments, the lining with the boron component led to much better results than the other brake linings. It has been determined that the boron-containing lining makes 100 stops more than the other lining and stops 20 s earlier in one stop. Therefore, the use of a composite lining with boron content in the braking systems of hydroelectric power plants significantly reduces maintenance incidents and operation costs as it prolongs brake replacement periods in these plants. Graphical Abstract: (Figure presented.)
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2024Scopus SJRQ1Preparation and characterization of the highly efficient tetraphenylimidazole substituted Phthalocyanine/ZnO composite and investigation of its effect on the photocatalytic degradation of Rhodamine B and 2,4,6-trichlorophenol
Karaoğlu, Kaan; Yüzüak, Gizem Durak; Yüzüak, Ercüment; Turan, Hanife; Akçay, Hakkı Türker
Growing concerns about industrial waste-induced environmental degradation have driven research towards sustainable solutions. Photocatalytic degradation, fueled by light and avoiding harmful chemicals, offers a promising avenue due to its minimal environmental impact. ZnO, TiO₂, and their derivatives are particularly effective and widely studied photocatalysts. This study aims to prepare new composite materials bearing phthalocyanine and investigate the photocatalytic properties on the degradation of Rhodamine B dye and 2,4,6-trichlorophenol (TCP) as the model compounds. In the initial step, ZnO materials were synthesized using the solvothermal method. Subsequently, a novel Zn(II) complex, including peripherally tetra phenyl imidazole substituted phthalocyanine, was successfully prepared. The composite catalysts were prepared from ZnO materials produced with the tetraphenyl imidazole phthalocyanine Zn(II) complex, called TFI-Zn. The were characterized using instrumental techniques. The photocatalytic characteristics of the composite materials developed were further examined under varying quantities of catalyst and Rhodamine B, variable pH conditions, and varying intensities of UV-A light. In addition, the reusability of the catalyst was investigated. With the new composite photocatalyst prepared within the scope of this study, 98% degradation efficiency and 8.0 × 10−4 min−1 degradation rate was obtained on Rhodamine B solution in 40 min. The newly developed photocatalyst displayed remarkable catalytic activity that remained virtually unchanged for five consecutive cycles, indicating excellent reusability and operational stability. The photocatalytic degradation performance of ZnO-TFI-Zn (1) was also examined on TCP and 90% degradation activity was obtained at the end of 80 min.
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