Atom Indonesia (E-Journal)
Not a member yet
530 research outputs found
Sort by
The Preliminary Prototype of Medium Dose Rate Brachytherapy Equipment
Get PDFA preliminary prototype of a brachytherapy equipment has been constructed. The work started by developing conceptual design, followed by basic design and detailed design. In the conceptual design, design requirements are stated. In the basic design, technical specifications for main components are determined. In detailed design, general drawings are discussed. The prototype consists of three main systems: a mechanical system, an instrumentation system, and a safety system. The mechanical system assures the movement mechanism of the isotope source position beginning from the standby position until the applicators. It consists of three main modules: a position handling module, a container module, and a channel distribution module. The position handling module serves to move the isotope source position. As shielding, the second module is to store the source when the equipment is in standby position. The prototype provides 12 output channels. The channel selection is performed by the third module. The instrumentation system controls the movement of source position by handling motor operations. It consists of several modules. A microcontroller module serves as a control center whose task includes both controlling motors and communicating with computer. A motor module serves to handle motors. 10 sensors, including their signal conditionings, are introduced to read the environment conditions of the equipment. LEDs are used to display these conditions. In order to facilitate the operators’ duty, communication via RS232 is provided. The brachytherapy equipment can therefore be operated by using computer. Interface software is developed using C# language. To complete both mechanical and instrumentation systems performance, a safety system is developed to make sure that the safety for operator and patients from receiving excessive radiation. An interlock system is introduced to guard against abnormal conditions. In the worst case, a manual intervention by the operator is provided when all other means are failing to store the isotope source into the safe container. The tests showed good results. The prototype can send the isotope source to applicators. The isotope source can be positioned with an accuracy of ± 0.5 mm and with a speed of 550 mm/second. These characteristics meet the design criteria.Received: 16 January 2013; Revised: 26 August 2013; Accepted: 29 August 201
Synthesis of 125I Labeled Estradiol-17β-Hemisuccinate and Its Binding Study to Estrogen Receptors Using Scintillation Proximity Assay Method
Get PDFResearch was carried out to obtain a selective ligand which strongly bind to estrogen receptors through determination of binding affinity of estradiol-17β-hemisuccinate. Selectivity of these compounds for estrogen receptor was studied using Scintillation Proximity Assay (SPA) method. Primary reagents required in the SPA method including radioligand and receptor, the former was obtained by labeling of estradiol-17β-hemisuccinate with 125I, while MCF7 was used as the receptor. The labeling process was performed by indirect method via two-stage reaction. In this procedure, first step was activation of estradiol-17β-hemisuccinate using isobutylchloroformate and tributylamine as a catalist, while labeling of histamine with 125I was carried out using chloramin-T method to produce 125I-histamine. The second stage was conjugation of activated estradiol-17β-hemisuccinate with 125I-histamine. The product of estradiol-17β-hemisuccinate labeled 125I was extracted using toluene. Furtherly, the organic layer was purified by TLC system. Characterization of estradiol-17β-hemisuccinate labeled 125I from this solvent extraction was carried out by determining its radiochemical purity and the result was obtained using paper electrophoresis and TLC were 79.8% and 84.4% respectively. Radiochemical purity could be increased when purification step was repeated using TLC system, the result showed up to 97.8%. Determination of binding affinity by the SPA method was carried out using MCF7 cell lines which express estrogen receptors showed the value of Kd at 7.192 x 10-3 nM and maximum binding at 336.1 nM. This low value of Kd indicated that binding affinity of estradiol-17β-hemisuccinate was high or strongly binds to estrogen receptor.Received: 04 December 2012; Revised: 19 December 2012; Accepted: 21 December 201
Derivation of Inter-Atomic Force Constants of Cu2O from Diffuse Neutron Scattering Measurement
Get PDFNeutron scattering intensity from Cu2O compound has been measured at 10 K and 295 K with High Resolution Powder Diffractometer at JRR-3 JAEA. The oscillatory diffuse scattering related to correlations among thermal displacements of atoms was observed at 295 K. The correlation parameters were determined from the observed diffuse scattering intensity at 10 and 295 K. The force constants between the neighboring atoms in Cu2O were estimated from the correlation parameters and compared to those of Ag2O.Received: 16 January 2013; Revised: 10 April 2013; Accepted: 15 April 201
Characteristics of Screen Mesh Wick Heat Pipe with Nano-fluid as Passive Cooling System
Get PDFThe heat pipe is one of the cooling media which is potential to be developed for the passive cooling system for nuclear reactors. To enhance the performance of the heat pipe, nanofluids have been used as the working fluid for the heat pipe. This paper studies the characteristics of nanofluids as the working fluid of heat pipe with screen mesh wick, which was the mixture of nano-sized particles (Al2O3 and TiO2) with water as the base fluid. The nanoparticles have average diameter of 20 nm, made with 1% to 5% volume fraction. The heat pipe thermal performance was tested using heater with different heat load. The experimental result shows the use of 5% Al2O3-water improve the thermal performance by reducing the temperature at evaporator side as much as 23.7% and the use of TiO2-water reduce the temperature at evaporator side as much as 20.2% compared to the use of water. The use of nanofluid also decreases the thermal resistance of heat pipe. As the use of nanofluid improves thermal performance of heat pipe, it has a potential for applications along with heat pipes at nuclear reactors.Received: 04 December 2012, Revised: 13 February 2013, Accepted: 25 February 201
Design Study of Full Scale Accelerator Driven System (ADS), for Transmuting High Level Waste of MA/Pu
Get PDFThe ADS system used in this study consisting of a high intensity proton linear accelerator, a spallation target, and a sub-critical reactor core. The Pb-Bi spallation target is bombarded by high intensity protons coming from the accelerator. The fast neutrons generated from the spallation reaction were used to drive the sub-critical reactor core. In this ADS system, the neutron source is in the center of reactor core region, so that the neutron distribution was concentrated in the center of core region. In this case, the B/T of MA/Pu could be performed effectively in the center of core region. The neutron energy in the outer region of reactor core was decreased due to the moderation of fuel and coolant materials. Such condition gives a chance to perform Burning and/or Transmutation of LLFPs.The basic parameters of this system are shown in the form of neutronic design, neutron spectrum and B/T rate, including other aspects related to the safety operation system. Furthermore, the analysis of the ADS system was accomplished using ATRAS computer code of the Japan Atomic Energy Research Institute, JAERI[1]. Due to the complexity of the reactor calculation codes, the author has carried out only those calculations needed for analyzing the neutronics system and some parameters related to the safety system. Design study of the transmutation system was a full-scale power level system of 657.53 MWt sub-critical reactor for an accelerator-driven transmutation system. The liquid Pb-Bi was used together as the spallation target materials and coolant of the system, because of some advantages of Pb-Bi in the system concerning the comparison with the sodium coolant. Moreover, they have a possibility to achieve a hard neutron energy spectrum, avoid a positive void reactivity coefficient, allow much lower system operating temperatures, and are favorable for safety in the event of coolant leakage. The multiplication factor of sub-critical core design was adjusted exclusively through the high intensity protons beam accelerator at the spallation target. The fuel was assumed to have homogeneous compositions in the form of (MA-Pu) ZrN mixture with 15N enriched. The compositions of Pu and MA were the same with the compositions of UO2 fuel from 33-GWd/t burn-up in PWRs spent fuel after 5 year cooling. The results have been compared with the spent fuel composition from 45 and 60 GWd/t burn-up in PWRs at the same cooling time. The calculation of the burn-up step was 730 days per one batch reloading by using 4-regions core calculation model. The specific parameters of ADS system used in the calculation are described in Table1
Comparison Between Classic and Fuzzy Logic Method on Corrosion Rate of Zinc Metal in Diluted Sulphuric Acid After Nitridation Process
Get PDFNitridation of zinc metal in DC nitridation machine by varying temperature from 150oC to 300oC and time of nitridation from 15 to 75 minutes were carried out. Nitrided zinc metal were corroded in diluted sulfuric acid solution in room temperature. The relationship between corrosion rate of zinc metal with temperature and time of nitridation were described in classic method. The results found were not satisfied because it contained ambiguous, uncertainty and imprecision data. The relationship of two inputs and one output were also described by using Fuzzy Logic. The performance of Fuzzy Logic has been carried out through triangular, S and Z shape membership function for two inputs temperature and time respectively, and one output corrosion rate or ICorr. Meanwhile two trapezoidals and one triangular were used for output corrosion rate. Nine rules were used to perform defuzzyfication, and it was also described three dimensions relationship between temperature, time of nitridation and corrosion rate. The results found that maximum corrosion rates were found in the three parts, but the lowest corrosion rate was found at the middle temperature and the lowest time of nitridation as shown in the surface viewe
Preparation of Sulfonated Poly (ethylene-co-tetrafluoroethylene-graft-styrene) Based Polymer Electrolyte Membranes for Fuel Cell by using Gamma Irradiation Technique
Get PDFPoly (ethylene-co-tetrafluoroethylene-graft-styrene-sulfonate) was successfully prepared by irradiation grafting of a styrene monomer into ethylenetetrafluoro-ethylene (ETFE) films and followed by sulfonation of the graft chains. Five film sheets of ETFE which having a size of 3 cm x 8 cm, thickness of 25 µm were packed in vacuum using a Y type tube filled with argon gas. The samples were irradiated using γ-rays with a dose of 15 kGy at 15 kGy/h. The iradiated samples were grafted by using styrene monomer at 60o C for 1, 3, 5, 7 and 9 h, respectively. The grafted samples (ETFE-g-St) were washed with xylene to remove homopolymer of polystyrene, and then its degree of grafting (DG) was determined. Sulfonation was carried out by using 0.2 M chlorosulfonic acid in dichloroethane solution at a water bath of 60oC for 6 h. Sulfonated samples (ETFE-g-St-SO3H) were washed with water to neutralize its acidity, and dried in a vacuum drier at 40oC for 15 h. The dried sample was weighed as sulfonated sample in order to determine the degree of sulfonation (%DS). Membrane properties of EFTE-g-St-SO3H sample such as ion exchange capacity (IEC), proton conductivity in cross direction (σ1), and in-plane direction (σ11) were determined by using a HIOKI-3522 LCR HI tester. Durability test of samples were conducted in hot water and 3% H2O2 respectively.. The proton conductivity measurement and durability of the membrane were compared to Nafion 112® as standard. The experimental results showed that the degree of grafting was increased with time of reaction for copolymerization, while %DS gave excellent results with an average of 92.7%. The IEC value was more affected by the %DG as compared to that of %DS effect. The average of σl value of the sample was 0.055 S/cm, compared to σ1 of Nafion112® that was 0.066 S/cm. The average of σ11 of the sample was 0.18 S/cm, while the σ11 of Nafion 112® was = 0.36 S/cm. The sample of SA004 with 53.49% DG was more stable than both the SA001 (21.48%DG) and SA003 (41.52% DG) in durability’s test of the samples against hot water (334 h resistance). On the peroxides test, all of samples were degraded at 114 h. Received: 20 November 2011; Revised: 28 March 2012; Accepted: 30 April 201
Study of 99mTc Pertechnetate Radiopharmaceuticals in Relation to Thyroid Hormone for Toxic and non-Toxic Diffuse Goiter
Get PDFAbnormalities of the thyroid gland in the form of enlargement of the thyroid gland are called a goiter. Goiter is divided into two types, namely toxic and non-toxic diffuse goiter. Diagnosis could be done with thyroid scan (in vivo) and test for thyroid hormone value (in vitro). Thyroid scan is applied by giving injection of 99mTc Pertechnetate as much as 2 - 5 mCi intravenally in the arm and then thyroid gland and salivary glands imaging were conducted in the fifth minute, tenth minute and fifteenth minute using gamma camera. Thyroid hormones test in blood is done with radioimmunoassay method. The same pattern showed the accumulation polad of the radioactive number from quotation of salivary glands. The accumulation percentage activity of 99mTc Pertechnetate in thyroid gland for the case of toxic diffuse goiter is larger than the case of non-toxic diffuse goiter. The results of this study indicate that the predictors for the case of toxic diffuse goiter could be characterized by high thyroid uptake which the the value of T3 hormone ≥ 3.3 ng/dl, the value of T4 hormone ≥ 165 nmol/l, and the value of TSH hormone ≤ 0.2 μIU/ml. While the case of non-toxic diffuse goiter could be characterized by low thyroid uptake which the value of T3 hormone ≥ 1.2 ng/dl, the value of T4 hormone ≥ 90 nmol/l, and the value of TSH hormone ≤ 1.8 μIU/ml. Received: 14 November 2011; Revised: 18 April 2012; Accepted: 21 April 201
Neutron-Gamma Pulse Shape Discrimination with a NE-213 Liquid Scintillator by Using Digital Signal Processing Combined with Similarity Method
Get PDFNeutron-Gamma Pulse Shape Discrimination with a NE-213 Liquid Scintillator by Using Digital Signal Processing Combined with Similarity Method. Measurement of mixed neutron-gamma radiation is difficult because a neuclear detector is usually sensitive to both radiations. A new attempt of neutron-gamma pulse shape discrimination for a NE-213 liquid scintillator is presented by using digital signal processing combined with an off-line similarity method. The output pulse shapes are digitized with a high speed digital oscilloscope. The n-γ discrimination is done by calculating the index of each pulse shape, which is determined by the similarity method, and then fusing it with its corresponding pulse height. Preliminary results demonstrate good separation of neutron and gamma-ray signals from a NE-213 scintillator with a simple digital system. The results were better than those with a conventional rise time method. Figure of Merit is used to determine the quality of discrimination. The figure of merit of the discrimination using digital signal processing combined with of line similarity method are 1.9; 1.7; 1.1; 1.1; and 0.8 ; on the other hand by using conventional method the rise time are 0.9; 0.9; 0.9; 0.7; and 0.4 for the equivalent electron energy of 800 ; 278 ; 139 ; 69 ; and 30 keV
Production of Natural Rubber Grafted Styrene Copolymer Latex as Water Base Coatings
Get PDFTwelve kinds formulation of natural rubber grafted copolymer styrene (NR-g-S) prepared by gamma radiation co-polymerization technique has been carried out. The characteristic of NR-g-S and its water base coating such as molecular structure, particle size, and the properties of latex and its film were evaluated. The results showed that the NR-g-S latex as a water base coating has low viscosity, height strength, good grease resistance, good flexibility, good aging and corrosion resistance on concrete cement and metal. The average particle size is between 270-300 nm, and the bonding between poly-isoprene of NRL and styrene molecules were grafted copolyme