Atom Indonesia (E-Journal)
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Synthesis and Characterization of Graft Copolymer Rice Straw Cellulose-Acrylamide Hydrogels Using Gamma Irradiation
Get PDFRice straw cellulose available as waste biomass was graft copolymerized with acrylamide monomer by simultaneous gamma irradiation as initiator. The effects of bleaching of cellulose and irradiation dose were evaluated. Evidence of grafting is obtained from comparison of Fourier Transfer Infrared (FTIR) of the cellulose and grafted cellulose. X-ray diffraction analysis shows that crystallinity was reduced through graft copolymerization. Kinetic investigations of the graft copolymerization were also carried out, and the rate constant parameter (kp/kt0.5) has been found to be 4.9922 l0.5. mol-0.5.s-0.5. The results show that for the same dose, grafting efficiency is higher with the bleached cellulose form than with the unbleached form. The grafting efficiency and the gel fraction increases with increasing total irradiation doses. At higher radiation doses crosslink density starts to increase considerably while swelling degree decreases with the increasing crosslink density.Received: 16 January 2013 Revised: 3 June 2013; Accepted: 21 June 201
Non-destructive Residual Stress Analysis Around The Weld-Joint of Fuel Cladding Materials of ZrNbMoGe Alloys
Get PDFThe residual stress measurements around weld-joint of ZrNbMoGe alloy have been carried out by using X-ray diffraction technique in PTBIN-BATAN. The research was performed to investigate the structure of a cladding material with high temperature corrosion resistance and good weldability. The equivalent composition of the specimens (in %wt.) was 97.5%Zr1%Nb1%Mo½%Ge. Welding was carried out by using TIG (tungsten inert gas) technique that completed butt-joint with a current 20 amperes. Three region tests were taken in specimen while diffraction scanning, While diffraction scanning, tests were performed on three regions, i.e., the weldcore, the heat-affected zone (HAZ) and the base metal. The reference region was determined at the base metal to be compared with other regions of the specimen, in obtaining refinement structure parameters. Base metal, HAZ and weldcore were diffracted by X-ray, and lattice strain changes were calculated by using Rietveld analysis program. The results show that while the quantity of minor phases tend to increase in the direction from the base metal to the HAZ and to the weldcore, the quantity of the ZrGe phase in the HAZ is less than the quantity of the ZrMo2 phase due to tGe element evaporation. The residual stress behavior in the material shows that minor phases, i.e., Zr3Ge and ZrMo2, are more dominant than the Zr matrix. The Zr3Ge and ZrMo2 experienced sharp straining, while the Zr phase was weak-lined from HAZ to weldcore. The hydrostatic residual stress (σ) in around weld-joint of ZrNbMoGe alloy is compressive stress which has minimum value at about -2.73 GPa in weldcore region. Received: 16 January 2013; Revised: 25 April 2013; Accepted: 10 June 201
The use of 32P Method to Evaluate the Growth of Lowland Rice Cultivated in a System of Rice Intensification (SRI)
Get PDFA pot experiment has been conducted to evaluate the growth of the Dyah Suci, a lowland rice variety, in an SRI (System of Rice Intensification) planting system. The phosphorus-32 (32P) isotope technique was used to evaluate the growth of plants in relation with their phosphorus uptake. The uptake was assumed to vary in the same direction as the growth of the plant. The 32P uptake is assumed to vary in the opposite direction to the plant’s total phosphorus uptake. Here the 32P uptake is expressed in count per minutes (cpm) which is then transformed to disintegration per minute (dpm). The results show that, in terms of promoting the plant’s uptake of phosphorus, the SRI planting system is superior to the conventional planting system, and it is manifested in the higher dry weight of straw and grain. From this experiment it is concluded that the 32P method can be used satisfactorily as a tool for explaining therelation between P-uptake and plant growth.Received: 04 Juny 2013; Revised: 22 August 2013; Accepted: 30 August 201
Development of Data Acquisition and Control Software for Neutron Radiography Facility at Serpong, Indonesia
Get PDFA system for data acquisition and control software for the neutron radiography facility at Serpong has been developed. The software was developed to replace the previously existing control software which was no longer used due to problems on its computer hardware. Visual Basic running under Microsoft Windows operating system was used in developing the new software. In the hardware side, the film grabber and the motor driver were replaced. In the new system, the film grabber which was used to capture the image in the old system is replaced with a programmable CCD camera. The motor driver which was used to control the camera in two directions has been replaced with a four-direction motor driver. The software is capable of displaying the images in a real time mode and record the images in the hard disk of a personal computer. To obtain optimal image quality, the software processes the captured images by performing temperature adjustment, camera exposure time adjustment, and integration of the captured image in a certain frame numbers. The software is capable of taking a number of snapshots at a certain time interval. For neutron tomography purposes, the software takes the snapshots automatically at a sample position in line with the stepping movement of the rotating sample table. The snapshots were saved in a picture format and a numeric format for further processing. The software has been successfully tested for real time method and tomography reconstruction. The data captured by using this software has been verified using both commercial and in-house computed tomography software. Received: 16 January 2013; Revised: 20 August 2013; Accepted: 23 August 201
Labeling of the Recombinant Streptokinase Using Iodine-131 as a New Thrombolytic Agent
Get PDFStroke and acute myocardial infarction is a disease with the highest mortality in the world. WHO has estimated in 2008, 30% of deaths from heart disease and more than 80% of this cases have been occurred in developing countries. Streptokinase (SK) as an effective thrombolytic agent has been used as a drug of choice for about forty years ago. SK is plasminogen (PG) activator that converts plasminogen to active protease, called plasmin (PN) which degrades fibrin to soluble products. Recombinant streptokinase (SKA) from genetic engineering has been developed at School of Pharmacy ITB to reduce or eliminate immunogenicity of SK. However, scientific disclosures relating to dynamic and its kinetic studies in the body have still to be proven. One method that can explain this phenomenon is the pharmacological studies using radionuclide labeled compounds. Radioiodine labeled compound is used extensively and most suitable for biological studies. This paper describes the preparation of 131I-SKA and its characterization. The labeling conditions of SKA, such as chloramine-T as an oxidizing agent, amount of SKA, incubation time, and size of resin to purify the labeling yield have been observed. The result showed that the optimum condition of labeling (35.11%) was obtained using 10 µg of chloramine-T and 60 seconds of incubation time. The highest radiochemical purity (97.46 ± 1.14%) has also been obtained by passing through the resin chromatography column using 100 mg Dowex 1x8, size 50-100 mesh. The characterization of 131I-SKA with SDS PAGE method and autoradiography showed the similar performance with unlabeled-SKA.Received: 04 December 2012; Revised: 20 December 2012; Accepted: 21 December 201
Accelerator-Driven System Analysis by Using Different Nuclear Data Libraries
Get PDFAn accelerator-driven system (ADS) has been investigated to transmute minor actinide (MA) included in high-level waste. In the neutronic design of the ADS, the accuracy of nuclear data for MA and lead bismuth (LBE) which is the candidate material for coolant and spallation target, is important. To know the current accuracy of nuclear data libraries, this study aims to compare representative nuclear data libraries, JENDL-4.0, 3.3, ENDF/B-VII.1 and VII.0 through the neutronic calculation of the ADS geometry proposed as the IAEA benchmark problem. The calculation results showed that about 1.1%dk, 0.7%dk and 2.7%dk differences were observed between JENDL-4.0 and ENDF/B-VII.1, ENDF/B-VII.0 and JENDL-3.3 at the beginning of cycle, respectively. These results mean that the current nuclear data libraries are still insufficient for the neutronic design of the ADS. The enhancement of nuclear data libraries by cross section measurement is required and, moreover, integral experiments with MA and LBE isotopes are essential. Received: 29 June 2012; Revised: 22 August 2012; Accepted: 30 August 201
On-line Diagnosing on Trayed Column of Etylene Plant Using Gamma Ray Scanning
Get PDFNuclear based technology called gamma scanning technique found its application for troubleshooting and diagnosing industrial process performance. The success of application of the gamma scanning technique is attributed to its unique ability in providing information which is cannot be obtained by any other techniques. One of the most prominent advantages of the gamma scanning technique was demonstrated by implementing this technology for scanning caustic/water wash tower DA 202 which was running in normal condition of operation. The DA 202 tower is trayed column having diameter of 4.2 m and height of 40 m. The scanning work has been performed using 70 mCi 60Co isotope as gamma emitter and scintillation detector as radiation counter to investigate condition of ten trays, starting from tray # 13 at elevation of 35050 mm to tray # 4 at elevation of 26950 mm above ground level. Scan data show that all trays were in their position. Tray # 4 to tray #10 were functioned properly and carried approximately the same amount of liquid. Light flooding on tray # 11 and heavy flooding on tray # 12 were identified. Partial flooding was identified on tray # 13. Further examination at the time of shutdown it was found that the liquid flooding on tray # 12 was caused by presence of a bucket covered with solidified mud. Received: 05 December 2011; Revised: 17 December 2012; Accepted: 18 December 201
Prediction of Separation Length of Turbulent Multiphase Flow Using Radiotracer and Computational Fluid Dynamics Simulation
Get PDFMultiphase flow modeling presents great challenges due to its extreme importance in various industrial and environmental applications. In the present study, prediction of separation length of multiphase flow is examined experimentally by injection of two kinds of iodine-based radiotracer solutions into a hydrocarbon transport pipeline (HCT) having an inner diameter of 24 in (60,96 m). The main components of fluids in the pipeline are water 95%, crude oil 3% and gas 2%. A radiotracing experiment was carried out at the segment of pipe which is located far from branch points with assumptions that stratified flows in such segment were achieved. Two radiation detectors located at 80 and 100 m from injection point were used to generate residence time distribution (RTD) curve resulting from injection of radiotracer solutions. Multiphase computational fluid dynamics (CFD) simulations using Eulerian-Eulerian control volume and commercial CFD package Fluent 6.2 were employed to simulate separation length of multiphase flow. The results of study shows that the flow velocity of water is higher than the flow rate of crude oil in water-dominated system despite the higher density of water than the density of the crude oil. The separation length in multiphase flow predicted by Fluent mixture model is approximately 20 m, measured from injection point. This result confirms that the placement of the first radiation detector at the distance 80 m from the injection point was correct. Received: 04 December 2012; Revised: 29 January 2013; Accepted: 09 March 201
Evaluating Genetic Variability of Sorghum Mutant Lines Tolerant to Acid Soil
Get PDFHigh rainfall in some parts in Indonesia causes soil become acidic. The main constraint of acid soil is phosphor (P) deficiency and aluminum (Al) toxicity which decrease plant productivity. To overcome this problem, it is important to develop a crop variety tolerant to such conditions. Sorghum is probably one of the potential crops to meet that objective. Sorghum has been reported to have wide adaptability to various agro-ecology and can be used as food and animal feed. Unfortunately, sorghum is not Indonesian origin so its genetic variability is still low. From previous breeding works with induced mutation, some promising mutant lines have been developed. These mutant lines were included in the experiment carried out in Tenjo with soil condition was classified as acid soil with pH 4.8 and exchangeable-Al content 2.43 me/100 g. The objectives of this experiment were to study the magnitude of genetic variability of agronomy and grain quality characters in sorghum in order to facilitate the breeding improvement of the species. Plant materials used in this study were ten genotypes, including 6 mutant lines and 4 control varieties. The randomized block design with three replications was used in the experiment. The genetic variabilities of agronomic and grain quality characters existed among genotypes, such as plant height, number of leaves, stalk diameter, biomass weight, panicle length, grain yield per plant, 100 seed weight and tannin content in the grain. The broad sense heritabilities of agronomic characters were estimated ranging from medium to high. Grain yield showed significantly positive correlation with agronomic characters observed, but it was negatively correlated with protein content. Received: 05 December 2011; Revised: 21 June 2012; Accepted: 02 July 201
Determination of Total Arsenic in Seaweed Products by Neutron Activation Analysis
Get PDFSeaweed products are widely consumed as food nowadays. Seaweeds are known to contain arsenic due to their capability to accumulate arsenic from the environment. Arsenic is a known toxic element which naturally occurs in the environment. Ingestion of high levels of arsenic will cause several adverse health effects. Arsenic in food occurs at trace concentrations which require sensitive and selective analysis methods to perform elemental analysis on. Validated neutron activation analysis was used to determine the arsenic contents in seaweed products namely catoni from domestic product and nori from foreign products. The total arsenic concentration in the samples analyzed ranges from 0.79 mg/kg to 30.14 mg/kg with mean concentration 14.39 mg/kg. The estimated exposure to arsenic contributed by the analyzed products is from 0.07% up to 8.54% of the established provisional tolerable daily intake (PTDI) which is still far below the maximum tolerable level. Received: 16 January 2013; Revised: 11 April 2013; Accepted: 13 April 201