Atom Indonesia (E-Journal)
Not a member yet
530 research outputs found
Sort by
Molybdenum-99 (99Mo) Adsorption Profile of Zirconia-Based Materials for 99Mo/99mTc Generator Application
Get PDFTechnetium-99m (99mTc) plays a major role in diagnostic nuclear medicine and has not yet been replaced with any other radionuclides. It is available through the 99Mo/99mTc generator. The use of low-specific-activity 99Mo for 99Mo/99mTc generator application requires high adsorptive capacity sorbents. This study focused on the determination of 99Mo adsorption capacity of several zirconia materials, namely monoclinic nanozirconia, orthorhombic nanozirconia, sulfated zirconia, and phosphated zirconia. These materials were synthesized by using the sol-gel method and characterized using FT-IR spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDS). The determination of 99Mo adsorption capacity of these materials was carried out by soaking the materials in a Na299MoO4 solution with pH of 3 and 7, at temperatures ranging from room temperature to 90 °C, for 1 and 3 hours. The results indicated that monoclinic nanozirconia has a 99Mo adsorption capacity of 76.9 mg Mo/g, whereas orthorhombic nanozirconia, sulfated zirconia, and phosphated zirconia have 99Mo adsorption capacities of 150.1 mg Mo/g, 15.58 mg Mo/g, and 12.74 mg Mo/g, respectively. It appears that orthorhombic nanozirconia has the highest 99Mo adsorption capacity among the synthesized materials and can be applied as a candidate material for the 99Mo/99mTc generator
Radiomitigative Effects of Approved Hematopoietic Drugs on Mice Exposed to Lethal Total-body Irradiation
Get PDFIn cases of radiological accidents, especially for victims exposed to high-dose total-body irradiation (TBI), the administration of appropriate approved hematopoietic drugs is the most rapid medical treatment for preventing severe acute radiation syndrome, which is associated with a high mortality rate. However, at present, there are few suitable pharmaceutical drugs available in Japan, aside from granulocyte colony-stimulating factor (G-CSF). Depending on the situation surrounding the accident, various drug treatment options and the development of effective drug therapies may be required. In the present study, we assessed various combinations of seven commercially available drugs-G-CSF, erythropoietin (EPO), romiplostim (RP), ancer (AN), cepharanthine (CE), leucon (LC) and leukoprol (LP)-in mice exposed to a lethal dose of 7 or 8 Gy of X-ray irradiation. Each drug was administered as a single or mixed intraperitoneal injection once or twice daily for three consecutive days. The single administration of the approved hematopoietic drugs CE, LC, or LP twice a day for 3 days significantly improved the 30-day survival rate of lethal TBI mice (p 0.05; 75%, 100%, or 100%, respectively) compared with the untreated TBI mice, accompanied by a gradual increase in the body weight. Furthermore, the combined administration of RP, EPO and G-CSF or single administration of RP alone gradually increased the body weight of mice exposed to lethal TBI, with 30-day survival rates of 75% or 100%, respectively (p 0.05). This study suggested that some new domestically approved hematopoietic drugs may have radiomitigative potential for mice exposed to lethal TBI, and the 12-h interval administration of LC or LP for 3 days to 7-Gy-TBI mice and 12-h interval administration of RP alone for 3 days to 8-Gy-TBI mice were the most suitable medications with respect to the 30-day survival rate. As long as the threat of nuclear disaster exists, diverse efforts in thefield of radiation emergency medicine, including the development of effective drug therapies, will be necessary
Reactivity Initiated Transient Response of TRIGA with the Progress of Core Burnt
Get PDFThis paper illustrates the effects on safety of TRIGA Mark-II research reactor of Bangladesh at its different steps of core burnt during reactivity induced transient. The modeling and simulation were carried by coupled point kinetics, neutronics, and thermal hydraulics code EUREKA-2/RR based on neutronics data calculated previously by Monte Carlo code for different burnt states of TRIGA core. Three burn steps until 150 MWD have been considered for present analysis which are regarded here as beginning of cycle (BOC); middle of cycle, MOC (75 MWD); and end of cycle, EOC (150 MWD). Initially, the results of steady state analysis obtained from EUREKA code for these three burn steps have been verified with that of COOLOD code. Based on consistency of the results from the two codes, transient simulation has been conducted considering reactor with non-function of scram. Reactivity inserted amount ranges within 0.001 to 0.02 dk/k with three durations of insertions of 0.1s, 1s, and 5s. Major parameters such as reactor core maximum power and fuel clad maximum temperature have been reported. The analysis presents transient pattern of these parameters due to change in amount and duration of inserted reactivity. The maximum imposed reactivity that causes the fuel clad to exceed its design temperature at each burn step has been evaluated in this study. It is also observed here for each amount and durations of inserted reactivity, maximum value of both power and clad temperature found to decrease with the progress of core burnt. These results obtained from this analysis will be useful for reactor operators and management team during core upgrading and modification program
Eye Lens Doses Received by Radiation Workers in Interventional Medical Procedures
Get PDFThe International Commission on Radiological Protection (ICRP) has recently recommended that the occupational dose limit for the eye lens be reduced to 20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv. ICRP clearly states that the recommendations are chiefly based on epidemiological evidence that suggested the eye lens dose threshold for cataract induction revised downwards from 2-5 Gy to about 0.5 Gy. Interventional medical workers are at greater health risk from radiation exposure to eyes as a result of the procedures they undertake than most other medical specialists. An extensive study has been carried out to measure the eye lens doses received by 373 interventional medical radiation workers in twelve large hospitals in Indonesia. Measurements were made using Thermo Scientific Harshaw thermoluminescence dosimeter (TLD) chip (size 3.2 mm × 3.2 mm × 0.15 mm) put inside an EYE-D holder placed in the worker’s temple. The procedures performed are grouped based on classification made by the UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation). The results showed that in general the measured data are in an agreement with some published data, even though a large range of doses was observed. The highest mean eye lens dose of 0.2378 mSv per procedure was received by interventionists who worked in the abdominal interventions procedure. Overall, from the results of measurement, it can be concluded that most interventionists might receive eye lens dose exceeding the dose limit if the procedures are carried out on daily basis, and the abdominal interventions procedures were found to be the ones that give the highest risk to the eye lens of workers as it delivered the highest dose to this particular organ
Finite-Difference Time-Domain Simulations of Radon Transport in Porous Media
Get PDFIn this work, an efficient algorithm, using a finite-difference time-domain (FDTD) technique, is proposed for modeling the variation of radon concentration as a function of soil structure parameters and vice versa. The development of the FDTD model is based on the simultaneous resolution of the radon transport equation in a porous, homogeneous medium, namely the soil. This equation describes the concentration of radon per pore volume unit. The numerical results are compared with those of the literature or with the theoretical ones
Characterization of Fe-Chitosan-Succinate- NN’-Methylene Bis-Acrylamide as Ion Imprinted Polymer
Get PDFHigh level of phosphate in the aquatic environment can reduce the amount of dissolved oxygen in the water which is harmful to the preservation of aquatic ecosystems. However, ion-imprinted polymer (IIP) is available to adsorp tripolyphosphate (TPP). In this study, Fe (III)-chitosan-succinate-tripolyphosphate complex was synthesized with NN’-Methylene Bis-Acrylamide (MBA) as a crosslinking agent and gamma-ray as reaction initiator. The aim of the study is to observe the physical and chemical characteristics of radiation-induced crosslinking of IIP in the present of MBA. The results show that tripolyphosphate ion adsorption capacity on the Fe-chitosan-succinate-MBA ion-imprinted polymer improved by 75.62 % than that of the non-imprinted polymer.The Differential Scanning Calorimetry (DSC) analysis shows a significant difference in the endothermic, exothermic and glass transitions of chitosan, chitosan-succinate when compared to their complex salts. The Fourier Transform Infra-Red (FTIR) analysis shows the presence of tripolyphosphate groups bonded by Fe-Chitosan-succinate-MBA ion imprinted polymer. Scanning Electron Microscope (SEM) analysis of IIP exhibits a significantly difference surface shapes between IIP with template still within the polymer matrix and after removal
