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In the present work, gold (Au), silver (Ag), and copper (Cu) based mono- and bimetallic NPs are prepared using a cost-effective facile wet chemical route. The pH for the synthesis is optimized in accordance with the optical spectra and supported by the finite difference time domain simulation studies. FESEM and TEM micrographs are used to analyze the morphology of the prepared nanoparticles. TEM images of bimetallic nanoparticles (BMPs) verified their bimetallic nature. XRD studies confirmed the formation of fcc-structured mono- and bimetallic NPs. Photoluminescence studies of the as-synthesized NPs are in good agreement with the previous publications. These synthesized NPs showed enhanced catalytic activity for the reduction/degradation of 4-nitrophenol, rhodamine B, and indigo carmine dyes in the presence of sodium borohydride (NaBH 4 ) compared to NaBH 4 alone. For the reduction of 4-nitrophenol, Au, Cu, and CuAg nanoparticles exhibited good catalytic efficiency compared to others, whereas for the degradation of rhodamine B and indigo carmine dyes the catalytic efficiency is comparatively high for CuAg BMPs. Furthermore, the antibacterial assay is carried out, and Ag NPs display effective antibacterial activity against Klebsiella pneumoniae , Salmonella ser. Typhimurium, Acinetobacter baumannii , Shigella flexneri , and Pseudomonas aeruginosa .

Abstract:Saturation thickness for multiple scattering gamma rays from multiple sources has been measured experimentally and simulated using the Monte Carlo N-Particle (MCNP) Code. Experimental measurements were performed using a collimated beam of gamma-rays from 57 Co, 203 Hg, 133 Ba, 22 Na, 137 Cs, 65 Zn and 60 Co sources. The gamma rays were directed at rectangular aluminium targets of varying thickness. A NaI (Tl) scintillation detector placed at a backscattering angle of 180 • was used to detect the scattered photons. The measured and calculated saturation thickness increases with increasing energy of incident gamma-rays. Experimental and simulated values are compared and are in good agreement.