Entity

Time filter

Source Type


Santoso M.,Nuclear Technology Center for Materials and Radiometry | Lestiani D.D.,Nuclear Technology Center for Materials and Radiometry | Markwitz A.,Institute of Geological & Nuclear Sciences
Journal of Radioanalytical and Nuclear Chemistry | Year: 2013

A total of 44 pairs of airborne particulate matter samples were collected in the intersection of Simprug, Pondok Indah, South Jakarta. Sampling of airborne particulate matter was conducted in July 2008-July 2009 using a Gent stacked filter unit sampler in two size fractions of <2.5 μm (fine) and 2.5-10 μm (coarse). Mass concentrations, black carbon as well as elemental concentrations were investigated as a pre-study in step to the evaluation of air quality in these roadside areas. Black carbon was determined by reflectance and elemental analysis was performed using proton induced X-ray emission, PIXE. The data set of fine particulate matters obtained from the characterization was then analyzed using receptor modeling EPA PMF3 for source apportionment. Source apportionment identified 5 factors, i.e. soil (9.2 %), construction mixed with road dust (20.9 %), motor vehicles (31.5 %), biomass burning mixed with seasalt (30.9 %), and industry (7.5 %). Motor vehicles is the dominant sources that contributes to the fine particulate matter in Jakarta. © 2012 Akadémiai Kiadó, Budapest, Hungary. Source


Syarif D.G.,Nuclear Technology Center for Materials and Radiometry
Advanced Materials Research | Year: 2014

Replacement of water as the conventional nuclear reactor coolant with nanofluid in order to increase the efficiency of heat transfer in the nuclear reactors becomes a strong need. In this work, a study of synthesis and characterization of ZrO2 nanoparticle and water-ZrO2 nanofluid was done. The ZrO2 nanopowder was synthesized using a precipitation method from ZrOCl2.8H2O (ZOC) that was prepared from local zircon (ZrSiO4) using caustic fusion method with calcination temperature of 800°C. The ZrO2 nanoparticle contained two phases namely cubic and monoclinic with crystallite size of 12 nm measured using Debye-Scherrer method. Stability of nanofluids that was prepared by mixing the ZrO2 nanoparticle with water depended on pH. The nanofluids with pHs less than 5 and larger than 8 were stable. Sedimentation test showed that the water-ZrO2 nanofluid produced in this study was very stable until at least 9 days. A typical basic nanofluid has zeta potential of about -41 mV and a typical acidic one has zeta potential of +45 mV. Thermal conductivity of the nanofluids was 4-9% larger than that of water. © (2014) Trans Tech Publications, Switzerland. Source


Nordin J.A.,University of Technology Malaysia | Prajitno D.H.,Nuclear Technology Center for Materials and Radiometry | Saidin S.,University of Technology Malaysia | Nur H.,University of Technology Malaysia | And 2 more authors.
Materials Science and Engineering C | Year: 2015

Hydroxyapatite (HAp) is an attractive bioceramics due to its similar composition to bone mineral and its ability to promote bone-implant interaction. However, its low strength has limited its application as load bearing implants. This paper presented a work focusing on the improvement of HAp mechanical property by synthesizing iron (Fe)-reinforced bovine HAp nanocomposite powders via mechanosynthesis method. The synthesis process was performed using high energy milling at varied milling time (3, 6, 9, and 12 h). The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and scanning electron microscopy (SEM). Its mechanical properties were investigated by micro-Vicker's hardness and compression tests. Results showed that milling time directly influenced the characteristics of the nanocomposite powders. Amorphous BHAp was formed after 9 and 12 h milling in the presence of HPO4 2 - ions. Continuous milling has improved the crystallinity of Fe without changing the HAp lattice structure. The nanocomposite powders were found in spherical shape, agglomerated and dense after longer milling time. The hardness and Young's modulus of the nanocomposites were also increased at 69% and 66%, respectively, as the milling time was prolonged from 3 to 12 h. Therefore, the improvement of the mechanical properties of nanocomposite was attributed to high Fe crystallinity and homogenous, dense structure produced by mechanosynthesis © 2015 Elsevier B.V. All rights reserved. Source


Lestiani D.D.,Nuclear Technology Center for Materials and Radiometry | Santoso M.,Nuclear Technology Center for Materials and Radiometry | Trompetter W.J.,Institute of Geological & Nuclear Sciences | Barry B.,Institute of Geological & Nuclear Sciences | And 2 more authors.
Journal of Radioanalytical and Nuclear Chemistry | Year: 2013

Monitoring the air quality in ambient air is an important step for assessing the air pollution level in one region and its impact to the human health. In this study, the determination of chemical elements concentrations in airborne particulate matter collected in suburban area of Lembang, Indonesia was carried out. Samples were collected using a Gent stacked filter unit sampler in two size fractions of <2.5 μm (fine) and 2.5-10 μm (coarse). Sampling was conducted twice a week for 24 h from January 2008 to June 2009 and 123 pairs of samples were collected. Black carbon was determined by reflectance and chemical elements analysis were performed using particle induced X-ray emission (PIXE). PIXE as one of ion beam analysis techniques is suitable for analyzing particulate matter for its multielemental analysis with good limits of detection. Results showed that none of daily concentrations of PM2.5 and PM10 exceeded the 24 h Indonesian NAAQS for PM2.5 and PM10. Chemical elements such as Mg, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Hg and Pb were determined and the correlation between these elements was reported in order to understand the anthropogenic sources of particulate matter. © 2012 Akadémiai Kiadó, Budapest, Hungary. Source

Discover hidden collaborations