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All Journal Science and Technology Indonesia Piston: Journal of Technical Engineering METAL : Jurnal Sistem Mekanik dan Termal Jurnal Penelitian Hasil Hutan
Gunawarman
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Aerospace Engineering Agriculture, Biological Sciences & Forestry Automotive Engineering Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Control & Systems Engineering Decision Sciences, Operations Research & Management Engineering Environmental Science Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering Physics

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Synthesis of a 3D Porous Multicomponent Bioceramic Scaffold Sari, Yessie Widya; Munir, Ryaas Mishbachul; Saputra, Angga; Sari, Mona; Aminatun; Suciati, Tri; Mohamad, Che Wan Sharifah Robiah; Gunawarman; Yusuf, Yusril
Science and Technology Indonesia Vol. 9 No. 2 (2024): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2024.9.2.235-243

Abstract

In this study, 3D porous multicomponent bioceramic scaffolds were fabricated. Hydroxyapatite (HA) and carbonate-substituted hydroxyapatite (CHA) synthesized from Asian moon scallop shell (Amusium pleuronectes) served as the bioceramics, whereas alginate and chitosan served as the polymeric components. The study was focused on determining whether the presence of polyvinyl alcohol (PVA) in the scaffold exerted an impact. When PVA was not included, the morphological examination revealed that the samples exhibited porous structures characterized by effective pore interconnectivity and a substantial pore size. X-ray diffraction and scanning electron microscopic analyses indicated that the inclusion of PVA led to a decrease in the crystallinity, pore size, and porosity of the scaffolds. Those containing PVA exhibited porosity levels in the range of 56%–60%, and pore sizes ranged from 42 to 90 µm. These properties may provide advantages for the scaffold with respect to the ability for cell migration and cell attachment, thus enhancing new bone formation. Moreover, the compositions of HA and chemically modified HA (CHA) within the scaffold influenced the crystallinity and uniformity of the scaffold morphology. This finding suggests the potential for crafting a customized porous bioceramic scaffold based on specific compositions.
Synthesis and Characterization of Hydroxyapatite Derived from Pleco Fish (Hypostomus Plecostomus) Bone Waste via Calcination and Ball Milling for Biomedical Applications Sari, Nurfitri Rahmi; Thoriq, Andika; Gunawarman; Nanda, Is Prima; Indra, Ade; Yetri, Yuli; Verdian, Riza
METAL: Jurnal Sistem Mekanik dan Termal Vol. 9 No. 1 (2025): Jurnal Sistem Mekanik dan Termal (METAL)
Publisher : Department of Mechanical Engineering, Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/metal.9.1.14-20.2025

Abstract

Hydroxyapatite (HA), a calcium phosphate-based bioceramic, is widely recognized for its excellent biocompatibility and bioactivity, making it suitable for biomedical applications. This study aims to synthesize HA from waste bones of the pleco fish (Hypostomus plecostomus), a natural source of calcium and phosphate that is underutilized in West Sumatera. The synthesis was conducted through calcination at 900 °C followed by mechanical refinement using ball milling for 3, 6, and 9 hours. X-ray diffraction (XRD) analysis confirmed the formation of crystalline HA with dominant peaks at 25.9°; 31.8°; and 32.9°, which remained stable across all milling durations.
PENGARUH WAKTU TEKAN DAN UKURAN PARTIKEL KULIT TUSAM (Pinus merkusii Jungh. et. de Vr.) TERHADAP KUALITAS PAPAN PARTIKEL TANDAN KOSONG KELAPA SAWIT Asfarizal Saad; Anwar Kasim; Gunawarman; Santosa
Jurnal Penelitian Hasil Hutan Vol. 37 No. 3 (2019): Jurnal Penelitian Hasil Hutan
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/jphh.2019.37.3.171-183

Abstract

Nowadays binderless particleboards have chance to be developed to replace particleboard with synthetic adhesive. Theobjectve of this research is to determine the quality of particleboards made from oil palm empty fruit bunches (OPEFB)and pine bark waste. The material composition of particleboard consist of 70% OPEFB and 30% pine bark powderwith a moisture content of 5−6%. The fiber length of OPEFB is 0.1−2.0 cm and the pine bark particle sizes usedto produce particleboard which passed through 30, 40, and 50 meshes. Four variations of pressing time are applied toproduce particleboard i.e 10, 15, 20 and 25 minutes. Quality assesments were undergone using the Indonesian standardfor particleboard product: SNI 03-2105-2006. Results showed that the best pressing time for making particleboardsusing OPEFB and pine bark is 20−25 minutes. The best MOR and IB are obtained from particleboard producedfrom oil palm fruit empty bunches with the particle size of 50 mesh. In this condition, except for MOE, the density,moisture content, MOR and IB meet the SNI requirements for particleboard.
Utilization of Coconut Shells as a Source of Graphene Nanosheets Fe/N-GNS for Environmentally Friendly Primary Battery Electrodes Giyanto; Affi, Jon; Gunawarman; Handayani, Murni; Yetri, Yuli
Piston: Journal of Technical Engineering Vol. 9 No. 2 (2026)
Publisher : Program Studi Teknik Mesin Universitas Pamulang

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Abstract

The research on the performance of carbon (C)/d-orbital metals (graphite/graphene, graphene/N-graphene, graphite/Fe-graphene, graphite/Fe-N-graphene, and graphene/Fe-N-graphene) in primary battery electrode systems was carried out using a simple technology by mixing coconut shell powder with N and Fe. The purpose of this study was to determine the preparation method of Fe/GNS and Fe/N-GNS electrodes and to evaluate the performance of the electrolyte on electron distribution in Fe/GNS and Fe/N-GNS electrodes as primary battery anodes based on electrical conductivity values. This research was conducted as a laboratory experimental study. GNS and N-GNS were synthesized using a modified Hummers method, while Fe/GNS and Fe/N-GNS electrodes were synthesized using the impregnation method. GNS, N-GNS, Fe/GNS, and Fe/N-GNS after electrolyte combination were characterized using SEM–EDX and a multimeter, respectively. The SEM–EDX results at 170 °C and 500–600 °C showed a folded and wrinkled graphene structure with dispersed Fe (5.3 wt% by EDX), dominated by C and O. The addition of Fe–NH₃ acted as a catalyst to form more regularly structured graphite. The DHL test showed the highest electrical conductivity (~51,400 at 40 V) for Fe-N-GNS samples synthesized at 170 °C and 600 °C, which were identified as the most optimal synthesis conditions.
Synthesis of Graphene-Like Carbon from Coconut Shell and Electrical Conductivity Properties Rohmat, Nur; Affi, Jon; Gunawarman; Handayani, Murni; Yetri, Yuli
Piston: Journal of Technical Engineering Vol. 9 No. 2 (2026)
Publisher : Program Studi Teknik Mesin Universitas Pamulang

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Abstract

Demand for batteries continues to increase in line with the growth of electric vehicles, while the availability of lithium in nature is limited. One alternative is the use of renewable natural materials, such as coconut shells, to produce functional carbon materials. This study aims to synthesize graphene-like carbon (GLC) from coconut shells using pyrolysis and sonication methods. The process was carried out through drying at 150–200 °C and pyrolysis at 700 °C. XRD characterization showed main peaks at 2θ ≈ 23.11° and 43.75° (150 °C/700 °C), and 23.15° and 43.38° (200 °C/700 °C), with an interlayer spacing of 0.35 nm and a shift in the C (002) peak from pure graphite, indicating the formation of nanosized graphene layers. FTIR analysis confirmed the presence of O–H, aromatic C=C, C=O, and C–O groups, indicating a hexagonal carbon framework with oxygen functionality on the surface. The Raman spectrum showed ID/IG ratios of 0.84 and 0.83, indicating structural disorder while still consistent with graphene-like characteristics. Conductivity tests showed relatively stable electrical conductivity with gradual electron energy loss at small current increases, allowing better control of electron mobility.
Co-Authors Ade Indra Aminatun Angga Saputra Anwar Kasim Anwar Kasim Asfarizal Asfarizal Saad Giyanto Is Prima Nanda Jon Affi, Jon Mohamad, Che Wan Sharifah Robiah Munir, Ryaas Mishbachul Murni Handayani Nofriady Handra Nur Rohmat Santosa Sari, Mona Sari, Nurfitri Rahmi Thoriq, Andika Tri Suciati Verdian, Riza Yessie Widya Sari Yuli Yetri Yusril Yusuf