Maulana, Achmad Yanuar
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Enhanced Anode Performance in Yeast Microbial Fuel Cells via Optimized Calcination of Eggshell Using Response Surface Method Christwardana, Marcelinus; Kuntolaksono, Satrio; Joelianingsih, J.; Maulana, Achmad Yanuar
Jurnal Kimia Sains dan Aplikasi Vol 28, No 4 (2025): Volume 28 Issue 4 Year 2025
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.28.4.183-194

Abstract

This study aims to explore the potential of calcined eggshells as an economical and effective anode material in microbial fuel cells (MFCs). This research examines the enhancement of calcined eggshells as an anode material in MFCs by operating condition optimization using the Response Surface Method (RSM). The experimental findings underscore the substantial influence of temperature and the eggshell/NaOH ratio on voltage and maximum power density (MPD). Raising the calcination temperature from 550°C to 700°C improves both voltage and MPD, with peak performance seen at 700°C. Nonetheless, performance stabilizes above 850°C. The eggshell/NaOH ratio is significant, with enhancements seen at an optimum ratio of 4. ANOVA analysis indicates that the model accounts for 79.89% of the variability in voltage and 82.74% in MPD, while the modified R-squared values imply possible overfitting. Optimal calcination parameters (704.55°C and a ratio of 2.52) improve the microstructural characteristics of calcined eggshells and crystallinity, which are essential for electron transport and bacterial adhesion. SEM study indicates a morphological transition to a rough, porous structure, whilst XRD and FTIR investigations validate the conversion from calcium carbonate to calcium hydroxide, enhancing electrochemical characteristics. This study highlights the promise of optimized calcined eggshells as economical and effective materials for microbial fuel cells, advancing sustainable energy and materials science.
Analytical Review of Numerical Analysis in Hydrodynamic Performance of the Ship: Effect to Hull-Form Modifications Bahatmaka, Aldias; Fitriyana, Deni Fajar; Anis, Samsudin; Maulana, Achmad Yanuar; Tamamadin, Mamad; Lee, Sang Won; Cho, Joung Hyoung
Mekanika: Majalah Ilmiah Mekanika Vol 23, No 1 (2024): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v23i1.83635

Abstract

This review paper provides an overview of simulation-based hydrodynamic design optimization for ship hull forms. It also includes a numerical analysis aimed at accomplish early-stage simulation-based design in terms of hydrodynamic performance. A hydrodynamic module, a hull surface modeling module, and an optimization module are the primary components of this numerical analysis. The hydrodynamic module includes both simple design approaches and high-fidelity numeric tools; these integrated tools are used to evaluate hydrodynamic performances at different design stages. The hull surface modeling module offers a variety of techniques for ship hull surface representation and modification. It is also used to automatically create hull forms or change existing hull forms based on hydrodynamic performance and design constraints. The optimization module includes several optimization algorithms and surrogate models used to determine optimal designs in terms of hydrodynamic performance. Numerical findings indicate that the current tool is well suited for hull form design optimization at the early design stage because it can produce effective optimal designs within a short time.