Suprapedi Suprapedi
Pusat Penelitian Fisika – Lembaga Ilmu Pengetahuan Indonesia

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Lipid Accumulation by Flavodon flavus ATH using Palm Oil Mill Effluent as Substrate Sudiana, I Made; Kanti, Atit; Helbert, Helbert; Octaviana, Senlie; Suprapedi, Suprapedi
BIOTROPIA - The Southeast Asian Journal of Tropical Biology Vol 21, No 2 (2014)
Publisher : SEAMEO BIOTROP

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Abstract

Large amount of palm mill effluent is generated annually. The waste would be potential for production of single cell oils (SCOs). The objective of study was to evaluate the lipid accumulation by fungi using palm mill effluent as substrate. To obtain most potential strains for lipid accumulation, seven filamentous fungi isolated from various biomes were evaluated for their ability to produce endoglucanase, and its lipid accumulation. Fungal hypae grown on palm oil mill effluent accumulated lipid of 34,3-87,5 of their dry cell mass. The profile of transesterified SCOs revealed a high content of saturated and monounsaturated fatty acids i.e., palmitic (C16:0), stearic (C18:0) and oleic (C18:1) acids similar to conventional vegetable oils used for biodiesel production. The strain was able to use organic substrates in POME implies that they are promising strain for biofuel feed stock as well as for meeting effluent quality for wastewater discharge.
EFFECT OF WET MILLING TIME OF Nd-Fe-B FLAKES MATERIALS ON PARTICLE SIZE, MICROSTRUCTURE, AND MAGNETIC PROPERTIES Sardjono, Prijo; Muljadi, Muljadi; Suprapedi, Suprapedi; Djauhari, Nenen Rusnaeni
Teknologi Indonesia Vol 39, No 2 (2016)
Publisher : LIPI Press

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Abstract

The refining of Nd-Fe-B alloy flakes has been done by a wet mechanical milling method using a ball mill. This process is used to produce a fine powder for making permanent magnet materials. The variation of milling time was 16, 24, 48 and 72 hours and a milling medium was used a toluene (pa- Emerck)) to protect the particle from oxidation during the milling process. After milling processes, the samples' distribution particle size were measured by using Particle Size Analyzer (PSA). Microstructure analysis has been conducted by using X-ray diffractometer (XRD) and Scanning Electron Microscope (SEM/EDX) for samples after and before milling. Vibrating Sample Magnetometer (VSM) was used to measure magnetic properties. The characterization results show that the refining process with the wet ball mill obtained finest powder with average size about 1.49 μm for milling time of 48 hours. According to SEM/EDX and XRD analysis, it shows that the crystal structure of the sample before milling was different compared to the sample after milling. It is found new magnetic phase with formula Nd2 Fe14 B. The magnetic properties of sample after milling 48 hrs is higher than that of sample before milling.