Objective(s): The purpose of this research is to study the effect of beta spectrum on absorbed fraction () and to find suitable analytical functions for beta spectrum absorbed fractions in spherical and ellipsoidal volumes with a uniform distribution for several radionuclides that are commonly used in nuclear medicine.Methods: In order to obtain the beta particle absorbed fraction, Monte Carlo simulations were performed by using the MCNPX code. The validation of the simulations was performed by calculating the absorbed fractions in spheres and comparing the results with the data published by other investigators. The absorbed fractions were calculated and compared by using an actual beta energy spectrum with those obtained through the mean beta energy of 14C, 199Au, 177Lu, 131I, 90Sr, 153Sm, 186Re, 32P, 90Y, 38Cl and 88Rb radionuclides.Results: The maximum difference between the absorbed fractions for beta particles accounting for the whole beta spectrum of all the considered nuclides was 29.62% with respect to the mean beta energy case. Suitable analytical relationships were found between the absorbed fraction and the generalized radius, and the dependence of the fitting parameters from beta spectrum energy was discussed and fitted by appropriate parametric functions.Conclusion: The results allowed the calculation of the absorbed fractions from the above stated beta sources uniformly distributed in spherical and ellipsoidal volumes of any ellipticity and volume, in a wide range of practical volumes that are not only used for internal dosimetry in nuclear medicine applications, but also in radiological protection estimates of doses from internal contamination.

Purpose: The measurement of natural radioactive decay in environmental samples such as soil has received increasing importance in recent years. Proportional counters in the form of large-area planar detectors are widely used for the initial screening of  radioactivity in environmental samples. In this study, the affecting factors in the alpha and beta particles emitted from natural radioactive soil sample was simulated using the Monte Carlo FLUKA code. Materials and Methods: These factors include the thickness of the sample, source-detector air gap, Mylar thickness, and gas detector density. Simulations were performed for alpha particles in 4. 8 MeV and in the conventional range for the investigation of radioactive elements inside the soil sample. Results: The final analyzed results show that the maximum number of primary particles can be measured up to 5 and 100 µm of soil sample thickness for alpha and beta particles, respectively. The maximum counting efficiencies for alpha and beta particles are 23% and 42%, respectively for our simulated sample. Conclusion: For alpha particles, gas detector density variations have no effect on the efficiency. For beta particles, this efficiency is constant up to 0. 0005 g/  density of gas. Furthermore, by increasing the air gap and Mylar thickness the efficiency will be decreased for both alpha and beta particles, while the variation of this value is remarkable for alpha particles.

In this experimental work, Polycarbonate/Bismuth Oxide (PC-Bi2O3) nanocomposites were prepared in various concentrations of 0, 10, 30, and 50 wt% with thicknesses of 1 mm and irradiated by a pure beta-emitter source of Sr-90. To fabricate the electrodes, copper sheets with thickness of 100 μ, m were attached to the top and bottom surfaces of the samples using the silver paste. Then, electric current as the dosimetry response, was measured at various dose rates ranging from 30 to 102 mSv. h−, 1 at a fixed voltage of 400 V using an electrometer. Results showed that increasing the Bi2O3 wt% led to improvement in the dosimetry response linearly at various dose rates. Also, the amounts of sensitivities for the samples of 0, 10, 30, and 50 wt% were measured as 20. 3, 19. 8, 28. 6, and 36. 7 nC. mSv−, 1. cm−, 3, respectively. Regarding the mechanism of beta interaction with a polymer-heavy metal oxide nanocomposite, the Bremsstrahlung radiation can be considered as a dominant effect.

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Background & Aims: 252Cf is a source of emission of neutron, gamma rays, and beta and alpha particles. In the common models of this source used in brachytherapy, only neutrons and gamma rays contribute in the dosimetry around the source. In this study, while investigating the escape of beta rays and bremsstrahlung X-rays from the source capsule of brachytherapy 252Cf of Isotron model, the dosimetry of the total effective radiation in the water environment around the source was performed and the total equivalent dose increase was calculated using 10B particles. Materials & Methods: Dosimetry for the neutron rays, the primary gammas, the secondary gammas, the beta particles, and the bremsstrahlung X-rays in the spherical water phantom performed with the radius of 20 cm at the distances of 0. 5 to 6 cm from the source using the Monte Carlo MCNPX. 2. 6. 0 code. Dose increment factor was calculated using B10 particles with a concentration of 50 ppm. Results: The highest relative difference in dose values, taking into account the X-ray and the beta particles their absence at the distance of 0. 5 cm from the source, was %19. As the distance from the source increases, the effect of these rays on the total equivalent dose rate decrease, as in the distance of 2. 5 cm distance, its values reach less than % 0. 5. The boron effect on the total equivalent dose increases by distance from the source, as at the 0. 5 to 6 cm distances from the source will increase from %0. 01 to more than % 22. Conclusion: According to the findings of this study, the dose of the X-rays and the beta particles passing through the source capsule are effective in the dosimetry around the source, and increasing the dose by 10B depends on increasing the tumor source distance, which should be considered in clinical applications.

The accuracy of each simulating beta-voltaic battery parameter is very important, especially in microbatteries. The aim of this study is to improve the calculation of beta-battery parameters’ accuracy. For this purpose, at first, using the Monte Carlo N-Particle code (MCNPX), the energy accumulation distribution of the 63Ni beta particle spectrum inside a silicon semiconductor has been simulated. Then, the ATLAS C-Interpreter function in C ++ was defined, using one of the SILVACO code abilities (the parameter F. RADIATE BEAM statement). Finally, the device electric parameters have been obtained using ATLAS-SILVACO based on the location-dependent of MCNPX results. For validation, the calculations were performed for a battery sample made of 16 mm2 cross-section and 1 mCi activity of radioisotope 63Ni as a source, and finally, the results were compared with one experimental result and two analytical methods. The calculations repeated for the other sample with 100 mCi activity and 1 cm2 of geometry, and compared its results with an analytical method results. The results showed that the simulation of micro-battery characteristics by the MCNPX-SILVACO hybrid code using threedimensional electron-hole pairs’ distribution in semiconductor and the full spectrum of beta particles creates a significant increase in the accuracy of the computation, and provides a good capability to optimize the design of the battery.

Micronutrients have an important role in growth and yield of plants. This investigatin was carried out to evaluate effect of foliar applications of three micronutrients (Fe, Mn and Zn) at different times (4-6 and 8-10 leaf stage) with three replication on sugar beet. Based on results obtained all of the micronutrients used increased sugar beet sugar yield. Highest root yield was obtained by using 9 % of micronutrients at 4-6 leaf stage, but other concentrations did not have any effect on sugar beet yield. All of the three micronutrient concentrations increased root yield significantly. Application of 6% concentration increased root yield by 15.6 %. Mn application did not have any effect on sugar yield.9 % concentration of Zn foliar application increased sugar yield by 16.4 %, and application of 6 and 9% of Fe increased sugar yield by 18.6 and 36 % respectively. Sugar percent did not changed by Mn application, but high concentrations of Fe and Zn at 8-10 leaf stage increased it. Highest increase in sugar percent obtained by using Fe 9 % foliar appliction. Because of economical importance of sugar and root yield, foliar application of 9 % of Fe and Zn at 8-10 leaf stage will be suitable.

Experiments were carried out in a completely randomized design with 3 replication factorial arrangement. Experimental treatments were including genotype factor (including 15 sea beet samples from Khuzestan, Elam, Kermanshah, Kurdistan and Azerbaiyjan provinces and two sensitive and susceptible cultivar of sugar beet) and salinity factors (concentration of 0, 50, 100 and 400 mM) and drought factors (5 levels of 0, 3, 6, 9 and 12 bar). Results showed that the effect of salinity and drought treatments on germination percentage, radicle, plumule length, radicle, and plumule weight traits were significant and in both experiments with increasing stress intensity germination percentage, radicle and plumule length, radicle and plumule weight traits decreased. In both experiments, the germination percentage trait was less and hypocotyl weight trait more affected by stresses than other traits. Alsoو in both experiments, radicle growth was less affected by stress than the plumule. Statistical estimations showed that there was a significant difference between investigated genotypes for germination percentage, radicle length, plumule length, radicle weight and plumule weight in both experiments. In salinity and drought stress conditions, at least 5 and 7 sea beet genotypes were identified from Elam, Kermanshah, Khuzestan and Azerbaiyjan provinces, which were better in terms of germination and early growth characteristics than sugar beet cultivars. Based on this, it can be concluded that sea beet has high diversity and resistance potential against salinity and drought stresses during germination and early growth stages, and can be used to produce more resistance sugar beet against salinity and drought stresses.

Nanoparticles with a wide range of unique features have been allocated many applications in the field of nanotechnology. Their special properties and their interaction with biological molecules have grabbed the attention of many researchers. These particles, because of their small size and unique characteristics, can be used in various fields, especially the life sciences. Because the lack of any logical model of nanoparticle and biomolecule interaction, their properties and influences on the environment have been evaluated using various separate and non-comparable studies. Nanoparticles interact with plants, animals, and humans and have various and essential impacts on them and these should be considered. The aim of this article is to conduct a morphological and proteomic study of the interaction of biomolecular, bacterial and plant models with silver nanoparticles. The findings are associated with trypsin and human blood serum albumin (as a molecular model), Staphylococcus aureus and Bacillus Thurigiensis (as bacterial models) and Oryza sativa L. (rice) as a plant model.