Pudji Untoro
Pusat Teknologi Bahan Industri Nuklir (PTBIN)-BATAN Kawasan Puspiptek, Serpong 15314, Tangerang Selatan

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HIDROKSIAPATIT BERPORI DARI KULIT KERANG ., Saryati; S., Sulistioso Giat; Handayani, Ari; Supardi, Supardi; Untoro, Pudji; Sugeng, Bambang
Jurnal Sains Materi Indonesia 2012: Desember 2012
Publisher : BATAN

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Abstract

Hidroksiapatit (HAp) Ca10(PO4)6(OH)2 merupakan material keramik bioaktif dengan bioafinitas yang tinggi dan bersifat biokompatibel terhadap tubuh manusia. Hidroksiapatit berpori saat ini sudah menjadi kebutuhan yang mendasar bagi rekonstruksi tulang yang patah atau retak. Sementara banyak limbah kulit kerang yang dapat digunakan sebagai bahan dasar pembuatan HAp untuk diproses lebih lanjut menjadi HAp berpori. HAp berpori dibuat melalui pembuatan komposit HAp-porogen. Telah dilakukan pembuatan hidroksiapatit dari kulit kerang dengan jalan reaksi pengendapan. Kulit kerang diubah menjadi CaO kemudian direaksikan dengan diamoniumfosfat dan endapannya dikalsinasi sehingga terbentuk HAp dimana kitosan digunakan sebagai porogen. Hasil yang diperoleh dikarakterisasi dengan X-Ray Diffractometer (XRD) dan Scanning ElectronMicroscope (SEM). Dari Data XRD terlihat bahwa kemurnian fasa HAp dipengaruhi oleh suhu kalsinasi. Diperoleh untuk HAp murni, suhu kalsinasi tidak lebih dari 700 oC. Morfologi permukaan serbuk HAp dan HAp berporogen, tidak terlihat perbedaan yang berarti, tersusun oleh bentuk granular (aglomerasi) dari partikel dengan ukuran berkisar 0,1 μm hingga 1 μm dan membentuk pori-pori dengan ukuran berkisar pada 0,1 μm hingga 1,0 μm. Sementara dalam bentuk pelet, permukaan HAp berporogen terlihat mempunyai pori-pori yang lebih besar dan lebih banyak dari HAp yang tidak berporogen.
POROUS HYDROXYAPATITE FROM CLAMSHELLS ., Saryati; S., Sulistioso Giat; Handayani, Ari; ., Supardi; Untoro, Pudji; Sugeng, Bambang
Jurnal Sains Materi Indonesia 2012: Desember 2012 - Edisi Khusus
Publisher : BATAN

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Abstract

Hydroxyapatite (HAp) Ca10(PO4)6(OH)2 is a bioactive ceramic material with high bioaffinity and biocompatible to the human body. Porous HAp is now a fundamental requirement for the reconstruction of a broken or fractured bones. There are waste a lot of clamshell waste in Indonesia that can be used as a base formanufacture of Hap and continued into porous HAp. Generally the porous HAp was made through HAp-porogen composite. Have been studied the manufacture of clamshells HAp by precipitation reactions. Clamshells converted into CaO and then reacted with diammonium phosphate and calcinated to form sediment Hap. It was used chitosan as a porogen. The results obtained were characterized by X-Ray Diffractometer (XRD) and Scanning Electron Microscope(SEM). From the XRD data shows that the phase purity of HAp is affected by calcination temperature. The conclusions are that to obtain pure HAp calcination temperature not exceeding 700 °C. Surface morphology of HAp and porous HAp powder, look no significant difference, composed of granular forms (agglomeration) of particles with a size range from 0.1 - 1 μm and form pores-pore size is about 0.1 - 1.0 μm. Meanwhile, in the form of pellets, porous HAp surface pores seem to have a bigger and more of HAp are not porous.Keywords: Hydroxyapatite, Chitosan, Clamshell.
UJI OKSIDASI BAJA AISI 316L UNTUK BAHAN KOMPONEN PLTN MAJU. Bandriyana, B; Untoro, Pudji; Sugiono, Bambang
Jurnal Sains dan Teknologi Nuklir Indonesia Vol 4, No 1 (2003): Agustus Edisi Khusus 1 2003
Publisher : BATAN

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Abstract

UJI OKSIDASI BAJA AISI 316L UNTUK BAHAN KOMPONEN PLTN MAJU. Pengujian oksidasi dilakukan untuk evaluasi ketahanan korosi baja AISI 316L sebagai bahan komponen PLTN maju. Pengukuran laju oksidasi dilakukan dengan uji termogravimetri pada temperatur oksidasi 700°C selarna 5000 menit. Pengujian struktur mikro dan sifat oksida dan pengukuran kekerasan bahan dilakukan dengan uji metalografi, pengujian X-ray Difractometer (XRD) dan uji kekerasan Vickers. Dari pengujian termogravimetri diperoleh penambahan berat sebesar 0,35 mg/cm2, dengan laju oksidasi awal mengikuti kaidah parabola. Foto struktur mikro menunjukkan perubahan bentuk dan ukuran butir dan tebal lapisan oksida 2,3 µm. Kekerasan bahan sesudah oksidasi mengalami penurunan dari 186 menjadi 174 skala Vickers. Hasil pengujian XRD menunjukkan terbentuknya oksida Cr2O3 sebagai lapisan pelindung oksidasi yang mantap dan fasa Cr23C6 yang menjadi penyebab sensitisasi tidak terbentuk. Berdasarkan hasil pengujian dapat disimpulkan bahwa laju oksidasi dan korosi bahan memenuhi persyaratan desain bahan komponen pembangkit energi dalam PLTN maju.
Transmission Electron Microscopy Characterization of High-Temperatur Oxidation of Fe-20Cr-5Al Alloy Prepared by Focused Ion Beam Technique Dani, Mohammad; Untoro, Pudji; Panca Putra, Teguh Yulius Surya; Parikin, Parikin; Mayer, Joachim; Dimyati, Arbi
Makara Journal of Technology Vol 19, No 2 (2015)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (397.594 KB) | DOI: 10.7454/mst.v19i2.3141

Abstract

The Focused Ion Beam (FIB) technique was applied for cross section preparation of the oxidized alloy for Transmission Electron Microscopy (TEM) study. Prior to preparation, the specimens of Fe-20Cr-5Al alloy sheet were oxidized in air at 1200 oC for 2 minutes, 10 minutes, 2 hours, and 100 hours. The microstructure and elemental composition of the samples were characterized using TEM equipped with an Energy Dispersive X-Ray Spectroscopy (EDX). The Electron Energy Loss Spectroscopy (EELS) was used to determine of the light elements. The TEM investigation reveals remarkable microstructure evolution of the specimens during oxidation which generally exhibit a typical multi-layer structure. The TEM images, however, can provide detailed description about the phases occur after oxidation such as the Tungsten (W) and the Gallium (Ga) layers on top of the samples obviously formed during FIB preparation, the formation of Al2O3 and Cr2O3 layer, MgAl2O4 spinel, porosity, Zr/Hf/Mg phases or clusters inside the oxide scale. Hence, the FIB technique has been proven to be reliable preparation technique for microstructural and elemental studies of Fe-20Cr-5Al alloy using TEM.
Esterification of Waste Cooking Oil Using Ultrasonic: Kinetic Study Agustian, Egi; Jessica, Jessica; Untoro, Pudji; Sulaswatty, Anny
Jurnal Kimia Terapan Indonesia (Indonesian Journal of Applied Chemistry) Vol 20, No 2 (2018)
Publisher : Research Center for Chemistry - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (521.053 KB) | DOI: 10.14203/jkti.v20i2.397

Abstract

Waste cooking oil (WCO) have a great potential as an alternative raw material for producing biodiesel. The literatures kinetic of the esterification of WCO in the presence of phosphoric acid catalyst with ultrasonic assisted are rare and most literatures used conventional method. This study aims to determine the optimum condition and the parameters of first and second order kinetics of the WCO esterification which was assisted by ultrasonic bath. Variables that used in this study are methanol/oil mole ratio, acid catalyst concentration and reaction temperature. The highest conversion was 42.08% with methanol/oil mole ratio of 15:1, a catalyst (phosphoric acid) concentration of 9% wt and temperature of 50oC within 90 minutes. The reaction time was reduced to 3 times (minute) compare to conventional method and fatty acid reduced 42%. Kinetic parameters were calculated with assumption that the esterification was the irreversible reaction. The reaction rate constant increasing with temperature. The value of activation energy for esterification of WCO is 42.94 kJ/mol for first order reaction and 35.30 kJ/mol for second order reaction.
PENGARUH JENIS PADUAN MIKRO Fe-Cr HASIL METODE ULTRASONIK PADA PEMBENTUKAN BONGKAH PADUAN Fe-Cr MELALUI SINTERING DUA TAHAP Silalahi, Marzuki; Untoro, Pudji; Suharno, Bambang; Harjanto, Sri
Jurnal Sains Materi Indonesia Vol 15, No 3: APRIL 2014
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1108.741 KB) | DOI: 10.17146/jsmi.2014.15.3.4353

Abstract

PENGARUH JENIS PADUAN MIKRO Fe-Cr HASIL METODE ULTRASONIK PADA PEMBENTUKAN BONGKAH PADUAN Fe-Cr MELALUI SINTERING DUA TAHAP. Fe-Cr adalah paduan yang memiliki ketahanan pada suhu tinggi dan potensial digunakan sebagai interkonek pada sel bakar Solid Oxide Fuel Cell (SOFC). Pada penelitian ini telah dilakukan sintesis bongkah paduan Fe-Cr dengan menggunakan serbuk paduan mikro Fe-Cr hasil sintesis dengan metode ultrasonik. Metode ultrasonik dimanfaatkan untuk sintesis paduan mikro Fe-Cr melalui penggunaan gelombang suara ultrasonik. Langkah yang dilakukan adalah konsolidasi partikel paduan mikro Fe-Cr melalui kompaksi tanpa lubrikan, kemudian dalam kapsul kaca kuarsa dilakukan proses sintering sampai 1000 oC selama 1 jam, lalu dilanjutkan sintering hingga 1300 oC selama 2 jam, lalu didinginkan dalam tungku. Karakterisasi struktur mikro dilakukan dengan Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (SEM-EDS), X-Ray Diffraction (XRD) disertai analisis dengan metode Rietveld dan pengukuran densitas sesungguhnya. Partikel paduan mikro Fe-Cr seutuhnya lebih stabil dan konsisten dalam pembentukan fasa bongkah paduan Fe-Cr melalui sintering bertahap. Diperoleh bongkah paduan Fe-Cr homogen tanpa oksida.
ULTRASONIC TREATMENT EFFECT ON THE CONSOLIDATION OF Fe-Cr PARTICLE MIXTURES AFTER COMPACTION AND SINTERING PROCESS Silalahi, Marzuki; Untoro, Pudji; Suharno, Bambang; Harjanto, Sri
Metalurgi Vol 29, No 2 (2014): Metalurgi Vol.29 No.2 Agustus 2014
Publisher : Pusat Penelitian Metalurgi dan Material - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (449.765 KB) | DOI: 10.14203/metalurgi.v29i2.289

Abstract

ULTRASONIC TREATMENT EFFECT ON THE CONSOLIDATION OF Fe-Cr PARTICLEMIXTURES AFTER COMPACTION AND SINTERING PROCESS. Fe-Cr microalloys which obtained byultrasonic method are the initial cores for the consolidation process. Therefore its facilitate the formation of thehomogeneous bulk of Fe-Cr alloy with a stable phase. In this research, the synthesis of bulk of Fe-Cr alloy fromthe particles mixture of (Fe+Cr) as the ultrasonic treatment results has been carried out. The particlesconsolidation has been carried out through a process of compaction without adding any lubricants and followedby sintering process in the quartz glass capsules by using induction furnace at 1300 °C. Consolidation of mixtureof Fe-Cr particles that have not undergone previous ultrasonic treatment is also made for a comparison. Theinvestigation by using the SEM (scanning electron microscope)- and density measurements method werepreformed on the Fe-Cr green powders compaction. The bulk of Fe-Cr alloys that are produced trough sinteringprocess was observed using SEM-EDS (energy dispersive spectroscopy), XRD (x-ray diffraction), and densitymeasurements method. The bulk of Fe-Cr alloy prepared with ultrasonically treated Fe-Cr microalloy powders,is more homogeneous in composition and has a better phase stability in comparison to Fe-Cr powders preparedwithout the ultrasonic treatment. Production of bulk Fe-Cr alloy in quartz glass capsule during the sinteringprocess has produced Fe-Cr alloy without oxides.