Atom Indonesia (E-Journal)
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Radiolysis of Reactive Azo Dyes in Aqueous Solution
Get PDFThe effects of radiation on aerated reactive dye solutions i.e Cibacron Violet, Cibacron Orange and Cibacron Yellow solutions have been studied. Parameters analysis were the change of pH after radiation, the change of absorption, degradation products and effects of pH on the radiolysis. The uv-vis absorption of solutions were observed before and after irradiation. pH variation was done from pHs 3, 5, 7, 9 and 12. Irradiation was done at doses of 0, 2, 4, 6, 8 and 10 kGy with dose rate of 5 kGy/h and was determined by a Fricke dosimeter. HPLC with UV detector was used to analyze the degradation products. Oxalic acid was the main degradation product and small amount of succinic acid was also detected
Hybrid Weakness Found in the Backcross Progeny of an Inter-Specific Cross of Oryza Sativa / O. Glumaepatula
Get PDFHybrid breakdown expressed as sterility or weakness or both in F2 or later generations is considered to be a reproductive barrier between two distantly related taxa. Hybrid breakdown that showed poor growth habit with fertile seeds was found in the backcross progenies (BC4F2) which were derived from a cross between a cultivated rice Oryza sativa L. cv. Taichung 65 and a wild rice Oryza glumaepatula Steud (Acc. IRGC 105668) where Taichung 65 was used as a recurrent parent. Through segregation analysis of BC4F2 population, a novel gene for weakness was identified, and this gene was designated as hwf1 (hybrid weakness f-1). RFLP (Restriction Fragment Length Polymorphism) analysis was employed to determine the chromosomal location of hwf1 gene. The result revealed that hwf1 was located between G3006 and C933 RFLP markers, with map distances of 0.5 cM and 1.9 cM, respectively, and co-segregated with C708, C820, and R288 on the short arm of chromosome 4. Since both O. glumaepatula (Acc. IRGC 105668) and Taichung 65 that was used as parents showed normal growth habit, the weakness in this study was assumed to be controlled by a set of complementary recessive genes. One of the complementary genes is hwf1 from O. glumaepatula, and another gene should be from Taichung 65, because the genetic background of the BC4F2 populations that were used for analysis is Taichung 65. The gene from Taichung 65 has not been identified yet, therefore, it is necessary to conduct the experiment for finding out the complement of hwf1 gene in near future. Received: 20 November 2008; Revised: 15 May 2009; Accepted: 16 May 200
Measuring the Corrosion Rate of Aluminum by Using Ultra Thin Layer Activation Technique
Get PDFCorrosion rate of aluminum (99.9% purity) in 0.001 M hydrochloride acid solution has been measured by using Ultra Thin Layer Activation (UTLA) technique. Iron foil of 25 μm thickness was used as the primary target and activated by 10.2 MeV proton beam coming from BATAN’s cyclotron with irradiation dose of 0.73 μAh (9.534 x 1015 protons/cm2). Radioisotope 56Co formed on the foil would have sufficient kinetic energy to run out of the foil’s surface and be implanted on the aluminum used as the secondary target. After 2 days of cooling down, about 0.397 MBq of 56Co stayed on the foil was counted by NaI(Tl) detector coupled with Multi Channel Analyzer (MCA).It was found that about 9.45% of the total 56Co formed on the iron foil was successfully implanted into aluminum target. Corrosion test of aluminum was conducted in a 2 inches diameter pipe filled with 0.001 M hydrochloride acid flowing with a rate of 80 liters/minute. The corrosion rate of the aluminum was determined from the change of 56Co activity during the process. The result of experiment indicated that the sample was corroded with a very slow rate of 0.064 nm/minute and 0.0054 nm/minute for measuring time of 0-180 and 180-300 minutes respectively
Analysis of Neutron Flux Distribution in Rsg-Gas Reactor With U-Mo Fuels
Get PDFThe use of U-Mo fuels in research reactors seems to be promising and, recently, world researchers have carried out these such activities actively. The National Nuclear Energy Agency (BATAN) which owns RSG-GAS reactor available in Serpong Research Center for Atomic Energy should anticipate this trend. It is, therefore, this research work on the use of U-Mo fuels in RSG-GAS reactor should be carried out. The work was focused on the analysis of neutron flux distribution in the RSG-GAS reactor using different content of molybdenum in U-Mo fuels. To begin with, RSG-GAS reactor core model was developed and simulated into X, Y and Z dimensions. Cross section of materials based on the developed cells of standard and control fuels was then generated using WIMS-D5-B. The criticality calculations were finally carried out applying BATAN-2DIFF code. The results showed that the neutron flux distribution obtained in U-Mo-fuel-based RSG-GAS core is very similar to those achieved in the 300-gram sillicide-fuel-based RSG-GAS reactor core. Indeed, the utilization of the U-Mo RSG-GAS core can be very similar to that of the high-density sillicide reactor core and even could be better in the future
Linacs for Medical Isotope Production
Get PDFThis paper reviews efforts on using high energy (25-30 MeV) and high power (10-20 kW) electron linacs and lower energy (7 MeV) proton linacs for medical radioisotope production. Using high energy x-rays from the electron linacs, PET (Positron Emission Tomography) radioisotopes are produced through photonuclear reactions such as 19F(γ,n)18F, which also allow production of other PET radionuclides 11C, 13N, and 15O. Other mostly used medical radionuclides 99mTc can also be obtained by using the electron linacs, through photofission or photonuclear reactions. Proton linacs for PET have also been recently developed and the product has been available in the market since 2005. The linacs have been tested for 18F production. As a proton accelerator, the target systems and nuclear reactions are similar to the ones used in PET cyclotrons. Received: 01 February 2010; Revised: 05 April 2011; Accepted: 20 April 201
Micronutrient Daily Intake of Elementary School Children in Bandung as Determined by Using NAA and AAS Methods
Get PDFMicronutrients in human diet are known to be among the most essential sources of nutrition, that required by the human body in small amount to maintain normal physiological function. Micronutrient malnutrition (MNM) is widespread all over the world, mostly in the developing country, where young children tend to be the most at risk of developing micronutrient deficiencies. In Indonesia, data of micronutrient status of children is limited. Therefore, the assessment of micronutrient intake of young children is needed to carry out. Food samples were taken by duplicate diet method of 19 elementary school children in Bandung and were analyzed using neutron activation analysis and atomic absorption spectrophotometry. Quality control of data analysis was assessed using SRM NIST 1548a Typical Diet. The result was giving the average daily intake of Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Se and Zn were 228, 0.15, 0.57, 9.3, 929, 106, 2,1, 2314, 0.022 and 4.6 mg/day respectively and gives 22, 527, 86, 111, 17, 54, 116, 49 and 63% of Recommended Dietary Allowance (RDA) values. Its generally concluded that these children are still lack of micronutrient intake, and many of them were below their recommended dietary allowances. These result were expected could be used as baseline data and reference to encourage government and related institution in making policies for public health improvement and micronutrient malnutrition solution as well. Received: 20 November 2010; Revised: 03 April 2011; Accepted: 04 April 201
Geothermal Reservoir Characterization for Steam Field Management in Kamojang Geothermal Field-West Java
Get PDFKamojang is the first geothermal field in Indonesia with a vapor dominated system reservoir. Kamojang has been exploited for over 20 years producing about 1100 tons/hour of steam which is equivalent to 140 Mwe electricity energy. This research is aimed to study the reservoir character after 20 years of exploitation and to investigate the effect of reinjection as a artificial recharge for steam input in the future and also the nature of secondary processes in the reservoir using isotope geochemistry tools. The research is conducted by natural isotopes (18O, 2H and 3H) analysis of many sources of water (meteoric, cold spring, fumaroles and shallow groundwater) in the surrounding of Kamojang field and also fluid reservoir to establish fluid reservoir origins and isotopic composition. Gas analysis and isotopes monitoring on the 25 production wells have been conducted every 2-3 years intervals for more than 10 years to investigate the effect of exploitation to the reservoir performance. Tritium radiotracer test with 370 GBq (10 Ci) activity was conducted at the KMJ 15 reinjection well to determine qualitatively and quantitatively the flow of reinjection water to its surrounding producing well (KMJ 11, 14, 17, 18, 26, 17 and 30). Data interpretation and evaluation to determine reinjection water mass recovery and cooling prediction modeling were conducted using ICEBOX program package (TRINV and TRCOOL). Interpretation and evaluation of data concluded that reservoir fluid of Kamojang geothermal field was originated from meteoric water which infiltrated through fault structures at elevation of 1350 m –1650 m above sea level. There is no evidence that the fluid was originated from magmatic water. Reservoir fluid moved both laterally and vertically (deep fluid) with lateral fluid movement from west to the east. The isotope data analysis indicated there is water entry in west-northwest reservoir boundary. Water entry gradually moved from northwest to the southeast (through wells of KMJ 42, 40, 27, 26 and 28). Exploitation effect to ten of the observation wells shows a decrease in w/r ratio and liquid saturation from 35 % in the beginning to about 20,5 % on the average after 20 years of operation. Evaluation with TRINV and TRCOOL program shows that 13,5 % of water reinjected into KMJ 15 reinjection well was recovered in the surrounding production wells. The program model of the reservoir temperature cooling shows that water reinjection with flow rate of 10 kg/sec is very save. After 20 years of reinjection activity, the model predicts a production wells will be cooling of about 6.8oC.Received: 15 January 2009; Revised: 1 May 2009; Accepted: 5 May 200
Degradation of Cibacron Red Dye using ZnO as a Catalyst Coated on the Surface of the Glass in the Photocatalytic Process
Get PDFIndustrial discharges are the main causes of surface and groundwater contamination. Photocatalytic process is one of the methods that could be used to degrade organic compounds that released from industrial wastewater. Photocatalytic process of 10 ppm cibacron red dye with irradiation of UV lamp and ZnO as a catalyst that coated on the surface of the glass the size of 8 cm x 8 cm x 0.4 cm have been studied. Experiments consisting of (i) variation of ZnO catalyst at temperature 200oC, 300oC, 400oC, and 500oC, and (ii) the efficiency achieved by the resulting ZnO obtained from the best variation in (i) as the UV-photocatalytic agent in degradation of cibacron red dye. The UV irradiation was done at interval time 0; 0.5; 1; 2; ; 4; and 6 hours. Degradation could be achieved using ZnO catalyst at temperature 500oC, the percentage degradation at 289 nm, 515 nm, and 545 nm were 84.5±1.0%, 100% and 100%, respectively.Received: 20 November 2010; Revised: 27 October 2011; Accepted: 04 November 201
The Measurements of Calcification Rates in Reef Corals Using Radioisotope 45Ca at Pongok Sea, South Bangka
Get PDFCoral reef ecosystem is one of the most important ecological systems in the Indonesian coastal zone. The aim of this study which was undertaken between August - October 2006, is to measure the calcification of corals in a reef coral in the Pongok Sea, South Bangka using 45Ca. The steps in conducting this study were surveying of the site, preparation, transplanting, incubation in the 45Ca - solution, and analysis of the coral fragments. The results showed that at the depth of 5 m different counts per minute (cpm) trend occurred. For the samples taken from the transplantation of the Artificial Colony (Ac) the cpm showed that with the progress of time the cpm declined, reaching its lowest cpm at 5 hours after retransplanting of the coral fragments. On the other hand the samples obtained from the natural (Nc) colony showed that the cpm increased with time progress. At the 10 m depth where only the coral fragment of the natural colony (Nc) was observed a different pattern showed up. Here with the progress of time up to 3 hours the cpm increased and after that it declined to reach a low cpm at 5 hours of observation. The cpm values were then transformed to disintegrations per minute (dpm), μCi and at the end to 45Ca content. The same trend is shown for dpm, μCi/0.5 g sample and μg Ca/0.5 g sample. The 45Ca content (μg/0.5g sample) were used to show the calcification rates of coral fragments. It showed clearly that 45Ca could be used to calculate the magnitude of calcification. Received: 08 December 2009; Revised: 05 April 2011; Accepted: 05 April 201
Simpler and More Accurate: Weighing the Mercury in Electrolytic Cells by Radiotracer Dilution Method
Get PDFWeight of mercury in electrolytic cell of soda industry is usually measured gravimetrically, which is typical labor work in character. Error sources of the gravimetric method might have come from the fact that some mercury’s are usually trapped in the cell due to complicated structure of electrolytic cell. This cause unknown errors. In addition, formation of amalgam at the cathode may cause a further uncertainty in the measurement. Total error from gravimetric method is 4% on average. Radiotracer dilution method provides advantages either for simplification of procedure and reduction of measurement error. In this experiment radioisotope mercury 203Hg, which was prepared in nuclear reactor was used to examine 13 of 14 electrolytic cells of soda plant. Each electrolytic cell was designed containing approximately 700 kg inactive mercury. Before injection, the radioisotope mercury was mixed with non radioisotope mercury in a bath to obtain a suitable injection aliquots and standard references. Calibration curve, which was derived from two stage dilution processes taken from standard references, was used to examine degree of mixing between radioisotope and non radioisotope mercury and it was also used in weight calculation of non radioisotope mercury in electrolytic cell. Injection was carried out simply by pouring the injection aliquots into the flowing mercury at the inlet side of the cell. Mercury samples from the cells were extracted at regular time intervals and filled into vials for counting. This was done for the primary conformation of the completeness of mixing of the tracer with the non radioisotope mercury in each cell. When complete mixing is achieved, the unknown quantity of mercury in each cell was calculated based on mass balance principle. From the calculation the weight of mercury in each electrolytic cell was not the same and maximum error of measurement obtained from this method is 2.48 %. Compared to gravimetrically error mentioned above, it was clear that radiotracer dilution method gives better result in terms of higher accuracy and simpler procedure in measurement of the weight of mercury in electrolytic cells. Above all, this method is very suitable to be implemented in soda industry.Received: 20 November 2009; Revised: 31 August 2010; Accepted: 31 August 201