Journal of Nuclear Research and Applications
Volume:2 Issue: 1, Winter 2022

The Acidithiobacillus ferroxidans bacterium plays an important role in the bioleaching process of uranium. The rusticyanin protein is the second most crucial component in the electron transport chain in the membrane of the Acidithiobacillus ferroxidnas bacterium. This protein belongs to the large family of copper blue proteins. The protein sequence rusticyanin 23270 was derived from UniProtKB database. A suitable template for modeling was prepared from the Swiss model server, and the best protein model was made with Modeller software. The His143Leu mutation was developed using the Pymol software in the protein. The effect of the mutation on the stability of the protein structure was investigated by analysing the results of molecular dynamics simulation on the wild-type and mutant protein. The values RMSD and RMSF are the same for both wild-type and mutant. The amount of Rg in mutant protein is reduced. His143Leu mutation in the rusticyanin 23270 protein does not affect the secondary structure protein and slightly increases the folding and stability of the tertiary structure.

Selective laser melting (SLM) is an additive manufacturing technique in which a laser beam with a high energy density is used to melt a metal powder substrate. Although this technique has several advantages, including the possibility of fabricating complex metal components quickly, there are concerns about the mechanical properties of the parts produced by the SLM method. This is study aims to ensure the achievement of acceptable mechanical properties including yield stress, tensile strength, and elongation percentage compared to conventional manufacturing methods. For this purpose, samples of 316L stainless steel were printed using the SLM machine. These samples and samples of annealed 316L bar were tested under same conditions and by the same equipment. Despite the large differences in microscopic structure, no significant differences were observed in mechanical properties. Also, the obtained results were compared with the results related to the sample made by the DLD additive manufacturing method, which is similar to SLM in terms of energy source and raw materials. The result represents that the mechanical strength and microhardness of the sample produced by the SLM technique are higher than the other samples, and the elongation percentage is within the desirable range. The yield stress, tensile strength, and elongation are respectively 595Mpa, 696Mpa, and 34.5%, all of which are within the acceptable range required by the standards for such samples. The investigation of the microstructure shows a complete austenitic cellular structure without considerable solidification defects. Overall, the SLM additive manufacturing is a reliable process to produce 316L stainless steel parts in terms of mechanical properties.

One of the important factors of a nuclear reactor core is the fast fission factor.  This paper calculates this parameter based on space and energy-dependent method using the PTRAC card of MCNPX code. Tehran research reactor (TRR) is taken as a case study, and the parameter analyses are performed on the reactor core. Fast fission factor in TRR is evaluated regarding temperature effect, control rod positions, and fuel assembly positions. Using the PTRAC card, helpful information on fast fission factors is achieved throughout the reactor core. One MCNPX runs to return a data file about neutron interaction that can be analyzed many times in different manners to reveal this useful information. The method is simple and can be applied to any nuclear reactor core. The results obtained by this method can help nuclear reactor designers and nuclear reactor fuel managers to have a precise evaluation of the parameter. The method proposed in this paper for fast fission factor calculation is compared with the results previously published in the literature.

In this paper, we studied the effect of electron beam irradiation on the fabric to increase longevity of antibacterial coating and perfume release and measure it using the optical properties of the fabric. In other words, instead of using chemical compounds in the antibacterial coating and perfume structure, the change in the structural properties of the fabric as a substrate of antibacterial coating and perfume was examined. Three different types of fabrics, including fabric with polyester and cotton, fabric with felt and flannelette, and fabric with flannelette and cotton floss were irradiated at different doses without alcohol and in the presence of alcohol (96% ethanol) at an energy of 10 MeV with an electron beam of the Rhodotron accelerator TT200. Then, these three types of fabrics were impregnated with antibacterial coating and perfume after washing with cold water. Finally, the longevity of antibacterial coating and perfume on them was measured by using the Particle Density Reflection Parameters and He-Ne laser with a wavelength of 632 nm and a power of 5 mW. Experimental results showed that electron beam irradiation of the fabric in the presence of alcohol enhanced this property.

This study aimed to investigate the distribution of natural and anthropogenic pollutants and the enrichment of elements in air dust of Khuzestan province following the dust events. Dust samples were collected from nine regions including, Abadan, Ahvaz, Hoveyzeh, Susangerd, Shush, Omidieh, Ramhormoz, and Mahshahr. The INAA technique measured the concentration of elements. Using the results of PMF modeling and investigation of obtained factors for samples, a suitable reference element with the most negligible influence from pollutant sources was selected and used for EF calculations.  The results showed very large enrichments with EF> 20 for elements such as Zn, Se, Br in Susangerd, Ahvaz, and Abadan. The concentrations of Fe, Al, and Mg in some areas of the province were much higher than LC50. The enrichment factors and the correlations between the elements in the samples of various regions showed their dependence on local pollutant sources.

In a radiation individual monitoring program, the type testing of measuring devices is a great important part of the quality management system. The IEC-62387 standard applies to dosimetry systems that measure external photon and/or beta radiation within limited ranges of the associated physical parameters. In this work, a type-testing program was conducted for a manual thermoluminescence dosimetry (TLD) reader employing the IEC-62387  radiation and environmental performance criteria. The uncertainty of non-linearity of the response of the dosimetry system in a range of 0.7-850 mSv was obtained between -15% and + 17%, which fulfilled the IEC standard range of -16% to +18%. Furthermore, the total uncertainty of all reader tests was measured to be 12%, which was less than the criteria of 20% in the IEC standard. Thus, it can be concluded that the TLD reader met all requirements of the IEC standard for the reader-tests by an appropriate margin.