محمدصادق اسلامی

In this paper, by using Monte Carlo simulation of MCNPX software, the design and optimization of the dimensions and distances between the plastic scintillation detectors used in the gamma ray portal monitor in order to build based on these optimized dimensions It can be. The test and performance evaluation steps of the gamma ray portal monitor based on the radiation acceptance test section of the International Electrotechnical Commission standard No. IEC 62244:2024 including the false alarm test, the background effects test (on the performance of the detectors), the gamma radiation detection test and the out-of-range response test is accepted. The results of the conducted evaluation tests confirm the compliance of this portal monitor with the IEC 62244 standard. Based on this, it can be concluded that the design, simulation and placement of the detectors have been done with sufficient accuracy and are approved. Also, the minimum detectable activity of the device for the 60Co source was equal to 0.7 microcurie activity and for the 137Cs source equal to 1.5 microcurie activity at 1 meter with a discrimination level of ±2.7σ, which is comparable to the available commercial monitors.

The phenomenon of dust in the western border of the country has increased in terms of continuity and concentration, disrupting the ecological potential of this region. In addition to affecting infrastructure and causing social problems, it also adversely affects people's health. To identify the factors affecting this phenomenon, the SODA approach was used as a simple technique with a cognitive mapping approach. Cognitive mapping can show the importance of a particular factor based on the values of all factors affecting a phenomenon. In this study, seven experts in the field of water resources were interviewed, andafter reaching a consensus, nine factors were identified as the most effective in the occurrence of this phenomenon. The results of the analysis, using concepts related to graph theory, determined the relative activity (centrality) of nodes and the formation of a proximity matrix. This showed that the mismanagement of water resources, the lack of attention to watershed management in the region, and the unilateral development of Turkey in the area—including the construction of numerous dams upstream of the Tigris River—were identified as the most active nodes and factors. These two factors had the highest impact, with a relative weight of 0.015 in terms of prioritization. On the other hand, the analysis showed that the Iran-Iraq war and the security strategies of the Ba'athist regime in Iraq were identified as the factors with the least activity with a relative weight of 0.007 in the dust issue. Finally, this approach can lead to the extraction of practical and applied strategies to solve environmental problems such as dust.