Article Per Year (5 Year)
p-Index From 2020 - 2025
0.444
P-Index
This Author published in this journals
All Journal Makara Journal of Technology Atom Indonesia
A. Dimyati, A.
Unknown Affiliation
Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Electrical & Electronics Engineering Energy Engineering Materials Science & Nanotechnology Mechanical Engineering Physics

Published : 2 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 2 Documents
Search

 1 
Effect of Arc Plasma Sintering on the Structural and Microstructural Properties of Fe-Cr-Ni Austenitic Stainless Steels Parikin, Parikin; Dani, M.; Dimyati, A.; Purnamasari, N. D.; Sugeng, B.; Panitra, M.; Insani, A.; Priyanto, T. H.; Mustofa, S.; Syahbuddin, Syahbuddin; Huang, A.
Makara Journal of Technology Vol. 25, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

X-ray diffraction techniques were performed to determine the actual crystal structure of A2 austenitic stainless steel (ASS) as-cast and A2 ASS after arc plasma sintering (APS) for 2 s. Computations were conducted on the basis of the Bragg arithmetic formula by comparing the S2 arithmetic with the interplanar spacing. The Bragg arithmetic formula is a simple series for the determination of the crystalline phase of materials based on the Miller indices of cubic shapes or other shapes. A2 ASS as-cast was identified to have a crystal structure of face-centered cubic with lattice parameter a = 3.58 Å. A similar crystal structure can still be detected in A2 ASS after APS for 2 s with lattice parameter a = 3.60 Å. This finding was confirmed by neutron diffraction measurements and optical–electron microscopy observations. Under the same conditions, both A2 ASS as-cast and A2 ASS after APS for 2 s have similar cast structures. The grain boundary formed in A2 ASS as-cast is thinner than that in A2 ASS after APS for 2 s, which is visible in its boundaries. Moreover, the grain structure of A2 ASS after APS for 2 s, which was originally elongated particles, became globular particles. Similarly, granular precipitates became concentrated and encompassed the steel matrix along the grain boundaries. Furthermore, scanning electron microscopy with energy-dispersive X-ray analysis showed that particles and islands in steel are distributed in the grains and at the grain boundaries, respectively. Precipitates are composed of C, Cr, Fe, and Ni. The elemental contents of Cr and C are dominant; thus, Cr23C6 precipitate is formed at the grain boundaries.
Atmospheric Plasma-Assisted Preparation of Graphene Oxide from Biomass: Characterization and Elemental Analysis Handayani, A. H.; Amalia, F.; Noviantana, E. V.; Mulyaningsih, T. R.; Waris, A.; Dimyati, A.
Atom Indonesia Vol 51, No 2 (2025): AUGUST 2025
Publisher : National Research and Innovation Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/aij.2025.1472

Abstract

Graphene oxide (GO) was successfully synthesized using the atmospheric plasma process with biomass precursors, including coconut fronds, palm fronds, and rambutan stems, within a five-minute processing time. Plasma technology converts near-waste materials into valuable resources with potential for various applications. Graphene oxide, in particular, exhibits high mechanical strength, excellent electrical conductivity, good biocompatibility, and a large surface area, making it a highly versatile material. Raman spectroscopy was used to analyze the formation of synthesized graphene. The presence of organic and inorganic elements in graphene oxide was characterized using a scanning electron microscope equipped with energy-dispersive X-ray spectroscopy (SEM-EDS) and neutron activation analysis (NAA). SEM-EDS analysis revealed that the C:O ratio in plasma-derived graphene oxide exceeded 80 % in each sample. NAA identified 22 inorganic elements, which are naturally present in biomass. Understanding the elemental composition of plasma-synthesized graphene oxide is essential for evaluating its potential applications and identifying necessary purification steps. The oxygen content in the synthesized material, which primarily originates from the inherent properties of biomass, can be regulated by optimizing plasma parameters. Using biomass precursors makes plasma-synthesized graphene oxide an economically viable option for large-scale production.
Co-Authors A. Insani A. Waris Amalia, F. Handayani, A. H. Huang, A. M. Dani Mulyaningsih, T. R. Mustofa, S. Noviantana, E. V. Panitra, M. Parikin Parikin Priyanto, T. H. Purnamasari, N. D. R. Iskandar, R. S. Purwanto Sugeng, B. Syahbuddin Syahbuddin