Atom Indonesia (E-Journal)
Not a member yet
530 research outputs found
Sort by
Surface Roughness and Grain Size Characterization of Annealing Temperature Effect For Growth Gallium and Tantalum Doped Ba0.5 Sr0.5TiO3Thin Film
Get PDFThin films 10 % gallium oxide doped barium strontium titanate (BGST) and 10 % tantalum oxide doped barium strontium titanate (BTST) were prepared on p-type Si (100) substrates using chemical solution deposition (CSD) method with 1.00 M precursor. The films were deposited by spin coating method with spinning speed at 3000 rpm for 30 seconds. The post deposition annealing of the films were carried out in a furnace at 200oC, 240oC, 280oC (low temperature) for 1 hour in oxygen gas atmosphere. The surface roughness and grain size analysis of the grown thin films are described by atomic force microscope (AFM) method at 5000 nm x 5000 nm area. The rms surface roughness BGST thin films at 5000 nm x 5000 nm area are 0.632 nm, 0.564 nm, 0.487 nm for temperature 200oC, 240oC, 280oC, respectively, whereas the grain size (mean diameter) are 238.4 nm, 219.0 nm, 185.1 nm for temperature 200oC, 240oC, 280oC, respectively. In fact, to increase annealing temperature from 200oC to 280oC would result in decreasing the rms roughness and grain size. Therefore, rms roughness and grain size would have the strong correlation annealing temperature. Received: 9 November 2008; Revised: 24 August 2009; Accepted: 25 August 200
The Mechanism of Mg2Al3 Formation by Mechanical Alloying
Get PDFSynthetic and characterization of the Mg2Al3 formation by mechanical alloying have been carried out using a high energy ball milling process. Mechanical alloying is a technique of solid state reactions among two or more metals to form a new alloy through the deformation properties of the metals. The Mg2Al3 alloy was formed by milling the individual constituents using a high energy ball milling under the varied milling time of 10, 20 and 30 h. The refinement results on the x-ray diffraction analysis show that the observation and calculation are fit to each other. After milling for 10, 20 and 30 h the mixed Mg and Al metals are converted into Mg2Al3 at the composition of 71.82, 90.73 and 96.19 wt%. It is concluded that the Mg2Al3 alloy can be performed by high energy mechanical alloying after 30 h of milling. The mechanism of the Mg2Al3 formation is discussed. Received: 14 August 2008; Revised:12 November 2008; Accepted: 11 December 200
Distribution of 137Cs In the Surface Soil of Serpong Nuclear Site
Get PDFThe distribution of 137Cs in the surface soil layer of Serpong Nuclear Site (SNS) was investigated by field sampling. The Objectives of the investigation is finding the profile of 137Cs distribution in the surface soil and the Tf value that can be used for estimation of radiation dose from livestock product-man pathways. The results indicates that the 137Cs activity in surface soil of SNS is 0.80 ± 0,29 Bq/kg, much lower than in the Antarctic. The contribution value of 137Cs from the operation of G.A.Siwabessy Reactor until now is undetectable. The Tf of 137Cs from surface soil to Panisetum Purpureum, Setaria Spha Celata and Imperata Cylindrica grasses were 0.71 ± 0.14, 0.84 ± 0.27 and 0.81 ± 0.11 respectively. The results show that value of the transfer factor of 137Cs varies between cultivated and uncultivated soil and also with the soils with thick humus. Received: 18 May 2010; Revised: 13 July 2011; Accepted: 20 July 201
Radio Protective Effects of Ginseng Extract in Gamma-Rays Induced Chromosomal Damages of Human Lymphocyte
Get PDFGinsan, a polysaccharide extracted from Panax ginseng and subsequently referred as ginseng, posses various biological properties as an anticancer and antioxidant agent. Ginseng also approved effective against radiation effects through its immunomodulating actions in whole body irradiated mouse. But its protective effects on radiation induced DNA damage are not thoroughly investigated, mainly in human. This experiment aimed to assess the effects of ginseng at 2 working doses in suppressing radiation effects of human peripheral blood lymphocyte (PBL) i.e. chromosome aberration and micronuclei yields. The treatment times were 24 hours before, subsequently (0 hour) or 3 hours after and irradiation with gamma rays at doses of 0.5 - 2.0 Gy (dose rate of 3.16 Gy/min). Treated and untreated blood cultivation and metaphase spreading technique was done according to standard procedures. Results showed that without ginseng treatments, radiation significantly increased dicentrics and micronuclei frequencies. Different with the results in mouse study, however, our results indicated that none of the experimental concentrations of ginseng crude water extract tested had an effect on baseline chromosomal aberration and micronuclei (MN) yields in PBL. A protective effect was only seen in chromosome aberration yields of sample irradiated with 2.0 Gy and treated with ginseng 3 h post irradiation rather than 24 h pre-irradiation in one volunteer. Opposite results that ginseng suspected to be a weak radiosensitizer was found in some cases. This may be due to discrepancies exist in route of treatment and its fundamental mechanisms of protective action between both studies. Even though in general it was not effective, the possible mechanism involved in radioprotective influence of ginseng is discussed
Molecular Identification of Mycobacterium tuberculosis and Analysis of Its Resistance to Rifampin in Sputa From Tuberculosis Suspected Patients
Get PDFAn accurate identification of different species of Mycobacterium provides to allow appropriate treatment for Mycobacterium tuberculosis infection. Beside that, drug resistance of M. tuberculosis strains to rifampin is not clearly understood in contributing to the spread of tuberculosis in Indonesia. To assess the molecular mechanism of rifampin resistance, a number of clinical specimens of M. tuberculosis were analyzed their molecular nature of a part of the rpoB gene using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) methods. DNA’s extracted from sputum samples were amplified and 32P-labeled by PCR with the specific primers and the product was analyzed their mutation conferring resistance by MDE gel electrophoresis. Of the 70 specimens tested, 57 specimens were positive for M. tuberculosis organism only, three specimens contained a mixture of M. tuberculosis and non tuberculosis mycobacteria (NTM), and 10 specimens were negative approved by Duplex PCR. Of these sixty DNA positive samples (thus the sensitivity of PCR was 85.71%), 5 (8.3%) of them suspected to contain mutations in rpoB which were associated with rifampin resistance. Even though the frequency of mutation was low, the results from our study clearly indicate that the molecular mechanism of rifampin resistance in M. tuberculosis isolates from Indonesia involves alterations in the rpoB gene. Molecular diagnosis by PCR which is fast and easy to perform is useful for early and rapid detection of TB in sputum specimen. Received: 27 February 2009; Revised: 28 August 2010; Accepted: 30 August 201
Analytical Methods INAA and PIXE Applied to Characterization of Airborne Particulate Matter in Bandung, Indonesia
Get PDFUrbanization and industrial growth have deteriorated air quality and are major cause to air pollution. Air pollution through fine and ultra-fine particles is a serious threat to human health. The source of air pollution must be known quantitatively by elemental characterization, in order to design the appropriate air quality management. The suitable methods for analysis the airborne particulate matter such as nuclear analytical techniques are hardly needed to solve the air pollution problem. The objectives of this study are to apply the nuclear analytical techniques to airborne particulate samples collected in Bandung, to assess the accuracy and to ensure the reliable of analytical results through the comparison of instrumental neutron activation analysis (INAA) and particles induced X-ray emission (PIXE). Particle samples in the PM2.5 and PM2.5-10 ranges have been collected in Bandung twice a week for 24 hours using a Gent stacked filter unit. The result showed that generally there was a systematic difference between INAA and PIXE results, which the values obtained by PIXE were lower than values determined by INAA. INAA is generally more sensitive and reliable than PIXE for Na, Al, Cl, V, Mn, Fe, Br and I, therefore INAA data are preffered, while PIXE usually gives better precision than INAA for Mg, K, Ca, Ti and Zn. Nevertheless, both techniques provide reliable results and complement to each other. INAA is still a prospective method, while PIXE with the special capabilities is a promising tool that could contribute and complement the lack of NAA in determination of lead, sulphur and silicon. The combination of INAA and PIXE can advantageously be used in air pollution studies to extend the number of important elements measured as key elements in source apportionment. Received: 20 November 2010; Revised: 09 August 2011; Accepted: 15 August 201
Tunneling Magnetoresistance (TMR) on Fe-Al2O3 Nano Granular Film Growth by Helicon Plasma Sputtering
Get PDFFe-Al2O3 nanogranular thin film by helicon plasma sputtering with the variation of Fe content from 0.1 to 0.7 volume fraction have been prepared. The magnetic and magnetoresistance properties were investigated by a Vibrating Sample Magnetometer (VSM) and a Four Point Probe (FPP). The Rutherford BackScattering (RBS) was performed with the SIMNRA software. Conversion Electron Mossbauer Spectroscopy (CEMS) study was also performed to estimate the fraction of Fe and α-Fe2O3 in the granular film. The results suggested that the percolation concentration occured at 0.55 Fe volume fractions, with the maximum Magnetoresistance (MR) ratio of 3%. The present MR ratio that was lower than the previous results may be related to the existence of α-Fe2O3 phase
The Reevaluation of MIBI as the Ligand of 99mTc-MIBI Radiopharmaceutical for Myocardial Imaging
Get PDFMethoxy isobutyl isonitrile labelled with technetium-99m (99mTc) radionuclide can be used for the evaluation of acute myocardial infarction. The 99mTc-MIBI radiopharmaceutical is available in the lyophilized-kit, which is separately packed with its radionuclide. Recently, in CNTMR-BATAN Bandung, 99mTc-MIBI radiopharmaceutical was prepared using MIBI ligand synthesized in 1996 as lyophilized-kits having the radiochemical purity less than 90 % and not accumulated in the myocardium. It could be caused by several factors, among others were technical preparation of lyophilized dry-kit and the quality of MIBI; therefore the reevaluation of the ligand for the quality improvement was needed. Firstly, MIBI ligand was recristallized. It was found that MIBI as [Cu(MIBI)4]BF4 salt was a glassy solid with the melting point of 98 -99 oC. The infra red analysis showed the presence of spectra vibration at 1085, 1180 cm-1 and 2180, 2220 cm-1 for –OCH3 and N≡C groups, respectively. The preparation of 99mTc-MIBI was performed by adding 99mTc radionuclide into new MIBI liquid-kit, then boiled in water bath for minimum period of 10 minutes. The radiochemical purity of 99mTc-MIBI was analysed by thin layer chromatographic method using absolute ethanol as a mobile phase. The pre-clinical evaluation was observed in Wistar rat and clinical studies were performed in volunter using gamma camera. It is revealed that the radiochemical purity of more than 90 % i.e. 96.83 ± 1.43 % was still stable until 24 hours storage at room temperature. The stability studies of 99mTc-MIBI in human blood plasma showed that in 6 hours, the radiochemical purity was decreased to 90.89 ± 2.90 %. Clinical application of 99mTc-MIBI with tomography techniques using gamma camera showed the distinct accumulation of radioactivity in the heart
Modelling of Ion Transport in Solids with a General Bond Valence Based Force-Field
Get PDFEmpirical bond length - bond valence relations provide insight into the link between structure of and ion transport in solid electrolytes. Building on our earlier systematic adjustment of bond valence (BV) parameters to the bond softness, here we discuss how the squared BV mismatch can be linked to the absolute energy scale and used as a general Morse-type interaction potential for analyzing low-energy pathways in ion conducting solid or mixed conductors either by an energy landscape approach or by molecular dynamics (MD) simulations. For a wide range of Lithium oxides we could thus model ion transport revealing significant differences to an earlier geometric approach. Our novel BV-based force-field has also been applied to investigate a range of mixed conductors, focusing on cathode materials for lithium ion battery (LIB) applications to promote a systematic design of LIB cathodes that combine high energy density with high power density. To demonstrate the versatility of the new BV-based force-field it is applied in exploring various strategies to enhance the power performance of safe low cost LIB materials (LiFePO4, LiVPO4F, LiFeSO4F, etc.).Received: 11 October 2010; Revised: 26 October 2010; Accepted: 28 October 201
Modified Starch of Sorghum Mutant Line Zh-30 for High Fiber Muffin Products
Get PDFSorghum mutant line Zh-30 is a breeding line developed at the Center for the Application of Isotope and Radiation Technology, BATAN by using mutation techniques. Gamma irradiation with the dose of 300 Gy was used to induce sorghum genetic variation. Through selection processes in several generations, the mutant line Zh-30 was identified to have better agronomic characteristics, better grain quality and higher grain yield than the original variety. Research on modified starch quality of this mutant line was done to identify its potential use in food industry. Functionality of pregelatinized, hydroxypropyl and crosslinked starch of this mutant line (Mutant TexInstant 30) has been studied for its use in high fiber muffin products. Characteristics of high fiber muffins containing 1.50; 3.50 and 5.50% of Mutant Tex-Instant 30 replacement levels to wheat flour were evaluated using both sensory panel and physical test methods. With regard to the sensory parameters, the high fiber muffins containing 1.50 - 5.50 % Mutant Tex-Instant 30 in general were not significantly different compared to the standard reference muffin. Results of physical evaluations showed that all Mutant Tex-Instant 30 containing products retained more moisture during baking than the standard reference. Tenderness of all products decreased at similar rate following 24 and 48 hr of room temperature storage and seven days at freezer temperature. These results suggested that sorghum mutant line Zh-30 starch could be modified and potentially used in food industry as a subtitute of wheat flour. Received: 26 June 2008; Revised:27 August: 2008; Accepted: 22 December 200