مجله علوم و فنون هسته ای
سال بیست و ششم شماره 3 (پیاپی 38، پاییز 1385)

[55Co] bleomycin has been widely used in oncological studies. Due to relative short half life of cobalt-55, optimization and feasibility studies for determination of the best labeling conditions is preferably performed using cobalt-57. In this study, the optimization of complexation conditions for time, temperature and ligand concentration were performed. The best labeling yield was obtained at room temperature in pH of 4-7, using 0.4 mCi of 57CoCl2 with 0.3mg of BLM in 30 minutes. The final radiopharmaceutical solution underwent common quality control tests, validating our future studies for animal scanning studies using [55Co]bleomycin complex.

The shadow cone technique is one of the methods which is used for determining the contribution of scattered particles on the response of neutron detectors. This technique is used for neutron field calibration in Agriculture, Medicine and Industry Research School (AMIRS). In this investigation, we have designed and constructed an optimized shadow cone. According to the calculated neutron dose equivalent attenuation factors, a cone with 20 cm of iron and 30 cm of polyethylene has been found as optimum. For this cone, the neutron dose equivalent attenuation factor for 241Am/Be neutron source, is 0.00035 for which the contribution of scattered neutrons in AMIRS neutron calibration laboratory according to the calculation and measurement results, can be evaluated with less than 0.5% of error. 

I-123 is a well known radioisotope used for thyroid and its metastases studies. Nowadays this radioisotope produces from Proton bombardment of enriched Xenon 124 by Cyclotron. In this article formulation and quality of the Na 123I has been mentioned. After bombardment, the target was rinsed by distillated water and a clear and colorless acidic solution containing Iodin-123 was obtained. In order to adjust the pH value on 7 and for preparation of Na 123I, a buffer was added to the solution. The results of the quality control were according to the U.S pharmacopoeia, as well as, the high radionuclide purity of 99.99% and radiochemical purity 98%. The solution was added to the capsules that had already filled by the inert powder. Each capsule contained 200 µCi of Na123I, and was sent to be used in hospital.

In this research, the reaction of LiOH + HF   LiF+H2O has been selected and some precipitation parameters such as pH, temperature, time, super saturation, and agitation type have been studied, and controlled. The morphology, phase analysis and particle size of the resulting powders were analyzed by SEM, XRD and LPSA. Finally, at temperature 25°C, pH of about 2-3, reaction time less than 1 sec, and agitation by ultrasonic bath, the pure nano lithium fluoride powders of about 100 nm were produced.

Electromagnetic field has various effects on living organisms such as blood composition or enzymatic changes. The effects depend on the electromagnetic intensity and the time of exposure. This study has been carried out to measure the variations of liver enzymes SGOT and SGPT Levels in 36 adult male, Guinea Pigs, that have been divided into 6 groups. Group A, as the control, exposed to nil electromagnetic field for two hours per day for 5 days. Group B, exposed to 0.013 micro T in 5 Hz for the same period. Group C, exposed to 0.207 micro T in 50 Hz in the similar condition. Group D, exposed for four hours per day for 5 days in 0.013 micro T in 5Hz. Group E, tested in 0.207 micro T in 50 Hz as the group D. Group F, used as the controlled group exposed for four hours per day in nil electromagnetic field. Blood of the Guinea pigs were analysed after 5 days. The results have shown significant differences among different groups, regarding the SGOT and SGPT when compared with those of the controlled group. Statistically, they are meaningful when measured by Dunnett test indicating a significant difference between the controlled group and the tested group, soas the SGOT and SGPT have decreased in both cases.

One of the most important application of rhenium is its use in nuclear medicine.The recovery of rhenium via biosorption by micro-organisms, in contrast to other methods, has not been investigated yet. In the present study the biosorption of rhenium on Bacillus sp. MGG-83 in a batch of stirred system is reported, and its optimum condition has been determined. The optimum pH-value of the medium was found to be 2 for rhenium. The maximum biosorption of rhenium was obtained at a temperature between 35–40 0C. The rhenium take up increases by increasing the rhenium concentration, and for 250 mg/l the take up was 146.3 mg/g dry wt. The uptake of rhenium within 5 min of incubation is relatively rapid and the continuation of absorption behaves slowly thereafter. The reduction in the V/X0value causes an increase of the adsorbed rhenium and that is due to the increase of the adsorption surface area. The desorption of rhenium which has been carried out with 0.1 M sodium hydroxide at 25 0C was 55%.

Fast neutron flux (14.8 MeV) of a neutron generator has been measured by activation technique. The measurements performed using Cu and Ni threshold detectors. 62Cu and 57Ni were produced through 63Cu (n, 2n) 62Cu and 58Ni (n, 2n)57Ni reactions. They decay by emitting 511 keV and 1377 keV gamma rays, respectively. The half life of 62Cu is 9.74min and that of 57 Ni is 36 hours. The flux of neutron has been calculated by measuring the activity after the irradiation time. Gamma spectroscopy of the activated foils was performed using a HPGe detector. By employing this technique the neutron flux of 2.64×107±3%n/s was obtained for 60 μΑ deuteron of 110 keV energy, bombarding a solid target of 3H.

Density has an important role in determining the variation limit of the physical properties of graphite. The density of the graphite is inversely proportional to its porosity. The porosity is produced in the structure of graphite due to the escape of volatile from the raw materials through thermal treatment during the fabrication process. There are direct and indirect methods for the measurement of porosity in the structure of graphite. Mercury and gas porosimetry are considered as direct methods, whereas the indirect method is based on bulk and picnometry density measurements. In this research work, by the use of  different types of density, the pore production in the fabricated graphite has been determined.