Sardjono P.,Indonesian Institute of Sciences |
Adi W.A.,National Nuclear Energy Agency
Advanced Materials Research | Year: 2014
It has been carried out synthesis and characterization of thermal and magnetic properties of the lanthanum barium manganite perovskite. The perovskite material was prepared from oxides, namely La2O3, BaCO3, and MnCO3. The mixture was milled for 10h and then sintered at temperature of 1000 °C for 10h. Thermal analysis and magnetic properties were measured by differential thermal analysis (TG-DTA) and vibrating sample magnetometer (VSM), respectively. Decomposition phase of MnCO3 become MnO occurred at temperatures around 390°C with releasing in CO2. Since lanthanum manganite has a stable ion configuration, magnetic properties of thrfese systems are built from MnO phase transformation become a-Mn2O3 is arrayed antiferromagnetic due to the presence of lanthanum in the system. And this anti-ferromagnetic behavior occurred due to magnetic interactions between Mn3+ adjacent ions through super-exchange mechanism. While lanthanum barium manganite had a less stable ion configuration, therefore magnetic properties of these systems are built from phase transformation MnO become α-Mn3O4 is arrayed ferromagnetic due to the presence of lanthanum and barium in this system. The presence of lanthanum and barium trigger in the emergence of mixed-valence Mn ions, so that occur to magnetic interaction between Mn3+ and Mn4+ through the double-exchange mechanism. © (2014) Trans Tech Publications, Switzerland.
Setiawan B.,National Nuclear Energy Agency |
AIP Conference Proceedings | Year: 2014
Interaction of radiostrontium (Sr-90) with site candidate soil for demonstration disposal facility to be constructed in the near future at Serpong has been done. This activity is to anticipate the interim storage facility at Serpong nuclear area becomes full off condition, and show to the public how radioactive waste can be well managed with the existing technology. To ensure that the location is save, a reliability study of site candidate soil becomes very importance to be conducted through some experiments consisted some affected parameters such as contact time, effect of ionic strength, and effect of Sr+ ion in solution. Radiostrontium was used as a tracer on the experiments and has role as radionuclide reference in low-level radioactive waste due to its long half-live and it's easy to associate with organism in nature. So, interaction of radiostrontium and soil samples from site becomes important to be studied. Experiment was performed in batch method, and soil sample-solution containing radionuclide was mixed in a 20 ml of PE vial. Ratio of solid: liquid was 10-2 g/ml. Objective of the experiment is to collect the specific characteristics data of radionuclide sorption onto soil from site candidate. Distribution coefficient value was used as indicator where the amount of initial and final activities of radiostrontium in solution was compared. Result showed that equilibrium condition was reached after contact time 10 days with Kd values ranged from 1600-2350 ml/g. Increased in ionic strength in solution made decreased of Kd value into soil sample due to competition of background salt and radiostrontium into soil samples, and increased in Sr ion in solution caused decreased of Kd value in soil sample due to limitation of sorption capacity in soil samples. Fast condition in saturated of metal ion into soil samples was reached due to a simple reaction was occurred. © 2014 AIP Publishing LLC.
Suseno H.,National Nuclear Energy Agency |
Prihatiningsih W.R.,National Nuclear Energy Agency
Marine Pollution Bulletin | Year: 2014
Environmental samples (seawater, sediments and biota) were collected along the eastern and western Indonesian coasts between 2011 and 2013 to anticipate the possible impacts of the Fukushima radioactive releases in Indonesia. On the eastern coasts (south and north Sulawesi), the 137Cs concentrations in the seawater and sediments were 0.12-0.32 Bq m-3 and 0.10-1.03 Bq kg-1, respectively. On the western coasts (West Sumatra, Bangka Island, North Java, South Java and Madura island), the 137Cs concentrations in the seawater and sediments were 0.12-0.66 Bq m-3 and 0.19-1.64 Bq kg-1, respectively. In general, the 137Cs concentrations in the fish from several Indonesian coasts were
Darsono,National Nuclear Energy Agency
Macromolecular Symposia | Year: 2015
Summary An experiment on surface coating of sengon wood (Paraserianthes falcataria L. Nielsen) using ultra violet (UV) irradiation has been conducted. Epoxy acrylate and urethane acrylate resins were used as coating materials after addition of tripropylene glycol diacrylate and a photoinisiator, Darocure 1173. Irradiation was conducted using UV light at the conveyor speed of 2, 3, 4, and 5 m/min. Parameters observed were glossyness, adhesion, hardness, abrasion resistance and chemical, solvent and stain resistance. The superior results of the epoxy acrylate films were obtained to show excellent adhesion on the surface of wood meeting with the standard because of greater remaining values than 50% (ASTM 2571-71), together with the high degrees of abrasion, hardness, glossyness and torelance against chemicals, solvent, and stain except against 10% NaOH solution. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Rosilawati M.L.,National Nuclear Energy Agency
Acta medica Indonesiana | Year: 2011
to develop an assay system of a radioisotope (32P)-based PCR dot-blot hybridization technique and evaluation of the assay directly for TB sputum samples to detect mutation at codon 306 of embB gene of Mycobacterium tuberculosis related with ethambutol (EMB) resistance. one hundred and sixteen of sputum samples were used in this study. Bacterial genome in sputum samples was extracted and tested for mutation at codon 306 of embB gene by the developed PCR dot blot assay using a radioisotope (32P)-labeled oligonucleotide. The positive results were confirmed by DNA sequencing. all 116 sputum samples were PCR positive for M. tuberculosis. Of 116 samples, three (2.59%) were EMB resistant-M. tuberculosis (MTB) and showed a substitution mutation (ATG/Met'-->GTG/Val) at codon 306 of embB gene. None of mutation was detected at codon 299 of embB gene. we successfully developed a radioisotope (32P)-based PCR dot blot hybridization technique for detection of mutation at codon 306 of embB gene related with EMB resistant M. tuberculosis. The assay can detect a large number of samples that is suitable for monitoring, surveillance, and epidemiology studies.
Sudjadi U.,National Nuclear Energy Agency
Advanced Materials Research | Year: 2013
Surface hardening on local disc brakes with DC-plasma nitrocarburizing apparatus has been carried out. Local disc brake was nitrocarburized at temperatures of 700 °C, 800°C, and 900°C for 3 hours, respectively. The results show that the hardness of sample of local disc brake before nitrocarburization was 167.86 Kgf/mm2, after the sample was nitrocarburized at temperature 900 °C for 3 hours, the hardness increased up to 649.38 Kgf/mm2. Matrixes on the base material were austenite, ferrite, and perlite. © (2013) Trans Tech Publications, Switzerland.
Suwarno H.,National Nuclear Energy Agency
Advanced Materials Research | Year: 2013
The RERTR Program (Reduced Enrichment in Research and Test Reactors) is an attempt to utilize uranium fuel enriched below 20% for nuclear research reactors. Since the program was launched by the United States in 1978, the International Atomic Energy Agency (IAEA) has recommended that UxSiy alloys, particularly U3Si2 and U3Si compounds, be used to fuel nuclear research reactors with uranium loading rate up to 4.8 gU/cm3. Unfortunately, there are difficulties in reprocessing U3Si2 and U3Si compounds due to the Si content. To overcome this problem, the IAEA initiated international cooperation to find the best solution in the development of new nuclear fuels to substitute the UxSiy alloys. In order to synthesize nuclear fuel containing high loading of uranium, research in developing uranium nitride (UN) from uranium metal has been conducted by reacting the massive uranium metal with hydrogen gas at a temperature of 573 K followed by dehydriding at a temperature of 773 K under vacuum pressure and nitriding at a temperature of 1073 K by introducing nitrogen gas in the reaction chamber. The X-ray diffraction analysis results showed that the hydriding process caused the uranium metal to turn into a stable compound, UH3, which was identified by the changes of the massive shapes into fine metal powders. Dehydriding process at a temperature of 773 K caused the UH3 compound to decompose into U metal powders, and when the metal powders were reacted with N2 gas at 1073 K a stable phase identified as UN was formed. The results showed that it is possible to produce UN powders by hydriding, dehydriding, and nitriding process, although special handling of UH3 and UN powders is required due to their pyrophoric nature. © (2013) Trans Tech Publications, Switzerland.
Suwarno H.,National Nuclear Energy Agency
Advanced Materials Research | Year: 2011
The synthesis and characterizations of Fe-Ti and Mg-Ti-Fe alloys with the atomic ratio of Fe:Ti = 2:1 and Mg:Ti:Fe = 2:5:6 prepared by mechanical alloying technique in toluene solution and measurement the hydrogen absorption properties of the yields have been performed. The Fe-Ti and Mg-Ti-Fe elemental powders are milled with the milling time of 30 h, in a Mixer Mill, type PW 700i high energy ball mill. The milled specimens are analyzed with an X-ray diffractometer, Philip, type PW 1710, using Cu as the anode tube and λ = 1.5406 Å. Qualitative and quantitative analyses are determined using Rietveld method developed by Fuji Izumi. The microstructure of the specimens after milling and hydriding are identified with a scanning electron microscope, Philip type 550. The refinement analysis of the x-ray diffractions results for Fe-Ti alloy shows that before milling the specimen consists of Ti and Fe phases, and after 30 h of milling new phases identified as FeTi and Fe2Ti are formed. In case of Mg-Ti-Fe alloy after 30 h of milling new phases identified as Fe2Ti and FeTi compounds are formed with the absence of Mg-Ti and Mg-Fe. Quantitative analysis of the milled powders shows that the mass fractions of FeTi and Fe2Ti phases are correspondingly 22.5 wt% and is 21.1 wt%, and the rest is Fe. The disappearance of Mg peaks after milling is suggested from the transformation of the crystallite into amorphous state. On hydriding at room temperature, the milled Fe-Ti and Mg-Fe-Ti powders are transformed into β-Ti4FeH8.5, Fe and TiH2. Considering the high hydrogen capacity and the low hydriding temperature of the Mg-Ti-Fe alloy compared to those of Fe-Ti alloy, the Mg-Ti-Fe alloy could be promoted as a new hydrogen storage material. © (2011) Trans Tech Publications, Switzerland.
Hadi Y.S.,Bogor Agricultural University |
Rahayu I.S.,Bogor Agricultural University |
Danu S.,National Nuclear Energy Agency
Journal of Tropical Forest Science | Year: 2015
Termite resistance of jabon wood impregnated with methyl methacrylate. Jabon ( Anthocephalus cadamba) wood specimens were impregnated for 10, 20 and 30 min with monomer methyl methacrylate (MMA) and then polymerised by 60Co gamma radiation (10 and 30 kGy). After the polymerisation process, polymer loadings were calculated. For comparison, control specimen was prepared using untreated wood. All wood specimens were tested for resistance to subterranean termite (Coptotermes curvignathus) in the laboratory for 4 weeks according to the Indonesian standard. At the end of the test period, wood specimen weight loss, resistance class, termite mortality and feeding rate were determined. Results showed that the average polymer loading reached 69% and the MMA wood had better resistance to subterranean termite than untreated wood. The untreated wood belonged to resistance class V (very poor resistance) but MMA wood was rated as class II (resistant). Compared with untreated wood, MMA wood also had less weight loss (77.7%), a lower termite feeding rate (73%) and increased termite mortality (20.9%). Impregnation period, radiation dose and interaction of both of these factors affected wood weight loss and termite feeding rate. The best combination treatment was 30 min of MMA impregnation and 30 kGy of radiation. © Forest Research Institute Malaysia
Suseno H.,National Nuclear Energy Agency |
Wahono I.B.,Agency for Assessment and Application of Technology
Marine Pollution Bulletin | Year: 2015
As data on anthropogenic radionuclide concentrations (i.e., 134Cs and 137Cs) in Indonesian marine environments including the Indian Ocean are scarce, offshore monitoring has been performed in the West Sumatra and South Java Seas. The activity concentration of 137Cs ranges from below minimum detectable activity (MDA) to 0.13Bqm-3 in the surface seawater of the South Java Sea and from lower than MDA to 0.28Bqm-3 in the surface seawater of the West Sumatra Sea. The concentrations of 137Cs in the surface seawater of the West Sumatra and South Java Seas are lower than the estimation of 137Cs concentration in the subsurface waters owing to the input of the North Pacific Ocean via the Indonesian Throughflow (ITF). The concentrations of 134Cs in the sampling locations were lower than MDA. These results have indicated that these Indonesian marine waters have not yet been influenced by the Fukushima radioactive release. © 2015 Elsevier Ltd.