Atom Indonesia (E-Journal)
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Optimization of Electrodeposition Parameters to Increase 99mTc Radioactive Concentration
Get PDFThe use of low activity concentration 99mTc would result in low-quality labeled compound for diagnostic purpose. The low activity concentration of labeled compound will alter biodistribution and lead to false imaging in diagnostic applications. Electrodeposition could be an alternative method for increasing the activity concentration of 99mTc solution. The influence of electrodeposition parameters such as electrolytes, concentration of electrolyte, and voltage and time of deposition were examined to find the optimum condition for electrodeposition. Electrolytes to be evaluated were NaNO2, Na-oxalate, NaOH, and NaCl. Concentration factor is defined by ratio of final against initial concentration of 99mTc. The quality assessment of 99mTc after electrodeposition was conducted by labeling test of methylene diphosphonate (MDP) and 1,4,8,11-tetraaza cyclotetradecyl-1,4,8,11-tetramethylene phosphonic acid (CTMP). The results showed that the addition of NaNO2 electrolyte gave the highest electrodeposition yield in comparison with Na-oxalate, NaOH, and NaCl, while the optimum concentration of electrolytes was 0.67 M. The optimum depostion voltage and duration were 7 V and 90 minutes, respectively. The electrodeposition yield was 96 % under optimized condition with a concentration factor of up to 7.96. In the quality assessment, MDP and CTMP were successfully labeled by concentrated 99mTc to give 99mTc-MDP and 99mTc-CTMP labeled compounds with radiochemical purities of more than 95 %.Received: 2 November 2015; Revised: 14 July 2016; Accepted: 3 October 201
Effects of Gamma Irradiation on Ruminal Degradation of Samurai 1 Sweet Sorghum Bagasse
Get PDFThe purpose of this study was to investigate the influence of gamma irradiation on dry matter, organic matter, and neutral detergent fiber degradability of Samurai 1 sweet sorghum bagasse, to facilitate its utilization in ruminant diets. Sorghum bagasse was obtained from Samurai 1 sorghum stem by-product after juice extraction. Gamma irradiation was carried out in a cobalt-60 irradiator in the Center for the Application of Isotopes and Radiation. Two polyethylene packages of samples were irradiated in gamma cell (Co-60) at doses of 50 and 100 kGy in the presence of air. Treatments were untreated/unirradiated and 50- and 100-kGy gamma irradiation. Sample were incubated in the rumen for periods of 0, 8, 24, 48, and 72 h with in sacco method. The observed parameters were the degradations of dry matter (DM), organic matter (OM), and neutral detergent fiber (NDF). DM, OM and NDF degradation characteristics were also observed. DM degradation of 50 kGy irradiation dose started higher than untreated samples after 24 hours incubation while OM degradation started higher than untreated samples after 48 hours incubation. DM and OM degradation of 100 kGy irradiation started higher than untreated after 8 hours incubation. Gamma irradiation treatment of 50 kGy and 100 kGy could increase NDF degradation on 8 to 72 hours incubation. Irradiation was also capable to increase NDF degradation rate (c fraction) and ruminal effective degradation (ED) value on Samurai 1 sweet sorghum bagasse. Gamma Irradiation could break down the lignocellulose materials, break β 1,4 branch chain of cellulose and make it easily digested for rumen bacteria. The best dose of gamma irradiation for processing Samurai 1 sweet sorghum bagasse as a fiber source for ruminants was 100 kGy.Received: 10 December 2015; Revised: 10 October 2016; Accepted: 10 October 201
Simulation of Spray Injection in the Pressurizer Using RELAP5
Get PDFA modeling research using Relap5 to assess the pressurizer of a pressurized water reactor(PWR) power plant has been performed. The heater and water injection systems in the pressurizer system of the PWRare of greatimportance for system pressure control.The heater is designed to increase the pressure while the water sprayer injection is to perform depressurization. Most of studies conducted in the past mainly focused on determining the effects of nozzle spray design and droplet size using testing loops. The purpose of this simulation is to analyze the spray injection flow rate against the pressure characteristics of the pressurizer using RELAP5. Through this approach, the optimum injection flow rate of full scale plant pressurizer can be analyzed. The parameters investigated are pressure and temperature.In RELAP5, the pressurizer tank wasmodeled with six volume nodes and the heater was modeled by using heat structure. In the model, the sprayer takes water from the cold leg to inject it into the top of tank region.The resultsshowedthat the mass flow of about 4 kg/s is the mosteffectivevalueto limit pressure in the pressurizer to below 15.7 MPa. However, the flow rates of 8 kg/s and more cause overpressure. This simulation is usefulto complement the data related to the water flow rate injection systems of the pressurizer
Comparative Analysis of Direct and Indirect 131I Measurement Methods from the Stack to Outdoor
Get PDFThe radioisotope production facility at PUSPIPTEK Serpong produces and processes 131I that can disperse to the settlements (community) and the environment around the Serpong Nuclear Area (SNA). 131I is produced routinely for medical uses in hospitals and pharmacies, for both domestic uses and export. 131I is a beta and gamma emitting radioactive material and can cause thyroid cancer. The problem was that there was so far no research and in-depth assessment of the aerial dispersion of 131I radioactivity emitted from the radioisotope production stack to the environment at actual conditions. The research was conducted through simultaneous measurement of 131I radioactivity in the stack of the 131I radioisotope production facility, Serpong, and outdoor in house courtyards around SNA in normal condition (no accident) based on the variations of the distance and wind direction. Direct measurements were carried out with a portable in-situ NaI(Tl) detector at outdoor, and with a LaBr3 detector in the stack. Indirect measurements were carried out by using charcoal filter and vacuum pump in the stack and outdoor. The direct measurement method has many advantages over the indirect measurement. The direct measurement method was found to be more accurate, less expensive, easier to operate, needing just one operator in its implementation, portable, and can be operated continuously and for long durations. The overall activity concentrations of 131I on average obtained by either direct or indirect method were still below the upper limit of 131I activity concentration in the air (530 Bq/m3) stipulated by the Regulation of the Chairman of BAPETEN (Perka BAPETEN) No. 7/2013.
In Vitro Infectivity Study of Cryopreserved Irradiated Intraerythrocytic Form of Plasmodium falciparum
Get PDFIn control human malaria infection studies using irradiated Plasmodium falciparum, the cell bank of irradiated P. falciparum infected erythrocytes is needed. The cell banking methods represent an obvious way to obtain suitable material for blood stage Plasmodium. In a cell bank development of irradiated Plasmodium infected erythrocytes, the ability to cryopreserve procedure of Plasmodium is important to recover the infectivity of irradiated Plasmodium. This study aims at evaluating the in vitro infectivity of cryopreserved irradiated intra-erythrocytic form P. falciparum. A protein profile investigation using Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) of cryopreserved P. falciparum also conducted in this study to know the cryopreserved effect on the protein of irradiated P. falciparum. Plasmodium falciparum of 3D7 strain in human erythrocytes was maintained in invitro continuous culture. When the percentage of parasites was 10-20%, the culture was harvested and irradiated with gamma rays at a dose of 175 Gy. Irradiated P. falciparum then was mixed with cryopreserved solution and stored in -80 °C for one hour before transferred into liquid nitrogen for 20, 40 and 60 days. After being stored the irradiated P. falciparum was thawed and cultured for 20 days. The percentage of parasitaemia was enumerated by examining Giemsa stained thin blood films prepared for 20 days after initiation of culture. Results showed that storage time significantly (p0.05) influence the percentage of parasitaemia. The cooling procedure and cryopreservation media may affect this study results. It also showed that there was insignificant difference of P. falciparum protein profile in all storage times. Overall it can be assumed that the irradiated P. falciparum still kept their infectivity after stored in liquid nitrogen for 60 days. Further study using different cooling procedure and different formula of cryopreservation media with a longer storage time should be conduct to validate this study results
