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A comparative study was conducted to investigate the gamma and neutron radiation shielding properties of composites made from iron metal (micro and nano) dispersed within natural rubber (NR). The aim was to attenuate neutron and γ‐rays. The study utilized the gamma spectroscopy technique and the Monte Carlo FLUKA code. To assess the gamma ray shielding, a 3×3 Nal (Tl) detector and radioactive point sources were employed. Two comparative studies were carried out, one using Fe loaded NR (Fe/NR) composites in microsize and the other using Fe/NR composites in nanosize. The objective was to determine the impact of iron nanoparticles on the shielding ability of the composites. The findings revealed that the Fe/NR composites in nanosize exhibited superior gamma radiation shielding ability compared with the Fe/NR composites in microsize. These results were supported by the FLUKA Monte Carlo code, which demonstrated good agreement with both the experimental and theoretical XCOM data. [ABSTRACT FROM AUTHOR]

A combined experimental and theoretical study investigated the corrosion inhibition potential of 2-dimethylaminopropionamidoanti-pyrine (DMAPAAP) on mild steel in 1 M hydrochloric acid (HCl) solution. The weight loss method was used to determine the corrosion rate of mild steel in HCl solution both in the absence and presence of different concentrations of DMAPAAP. The effect of exposure time and temperature on the corrosion inhibition efficiency of DMAPAAP was also investigated. The results showed that DMAPAAP exhibited good inhibitory properties against the corrosion of mild steel in an HCl solution. The corrosion rate of mild steel increased with increasing inhibitor concentration, exposure time, and temperature. The highest inhibition efficiency of 91.9 % was achieved at 5 mM concentration of DMAPAAP after 5 hours of exposure time at 333 K. Density functional theory (DFT) calculations were carried out to support the experimental results and understand the inhibition process's mechanism. The adsorption of DMAPAAP on the mild steel surface was found to be both chemisorption and physisorption and followed the Langmuir adsorption isotherm. The inhibition efficiency increased with increasing electrondonating groups in the molecule, which was attributed to forming a protective film on the metal surface. Overall, the combined experimental and theoretical study provides a deeper understanding of the corrosion inhibition mechanism of DMAPAAP on mild steel in HCl solution and demonstrates its potential as an effective corrosion inhibitor for mild steel in industrial applications. [ABSTRACT FROM AUTHOR]

Background and Objectives: Clostridium difficile is a gram-positive obligate anaerobic bacillus. Accurate and rapid diagnosis of this bacterium as well as assessment of its drug resistance pattern are one of the important issues in controlling infections caused by C. difficile. The purpose of the present study was to detect toxicogenic C. difficile and to evaluate drug resistance pattern of these strains to routine therapeutic drugs. Methods: A total of 68 samples were collected from patients hospitalized in hospitals of Qom province. All samples were rapidly cultured in the specialized CCFA Agar medium.After these procedures, the bacteria were used for DNA extraction and then PCR was performed on the cdd3 gene for definitive detection of the bacteria. Finally, the presence of A and B toxins’ genes was determined by PCR and resistance to metronidazole, vancomycin, and clindamycin, was determined by agar dilution method. Chi-square test was used to analyze the results. Results: In this study, 6 isolates had A and B toxins, the highest antibiotic resistance was against clindamycin (45.45%) and metronidazole (36.36%), and all the isolates, were sensitive to vancomycin. Conclusion: Drug resistance pattern in the obtained strains still introduces vancomycin as the treatment of choice.