Human exposure levels to ionizing radiation in Agbara Industrial Estate: an impact of Industrial activities in Nigeria.

A total of fifty-five soil samples were collected from four locations, namely, residential, industrial, dumpsite, and sewage in Agbara industrial estate, Ogun state, Nigeria. The samples were analyzed using a high purity germanium detector (HPGe) to measure the activity concentration of radionuclides. Background radiation measurements were also taken at each point where soil samples were collected using Geiger Muller (GM) counter. The mean activity concentrations measured in the soil samples were 171.33 for 40K, 9.11 for 232Th, and 5.05 for 226Ra in Bq/kg. The mean absorbed dose rate in the air due to radionuclides (40K, 232Th, and 226Ra) in the soil is calculated to be 14.77 nGy/h, and the mean annual effective dose equivalent (AEDE) is 0.02 mSv/year. The mean equivalent dose rate (EDR) from GM counter for background radiation is 0.22 µSv/h, and the mean annual effective dose rate (AEDR) is 0.39 mSv/year. These values are below the world average values, except EDR and AEDR with mean values higher than the world standard. The comparison of radiation dose rates revealed that radionuclides contributed 6.7% to background radiation. The equivalent dose (EDorgans) for various organs of the body was calculated, and results showed that values do not pose any immediate health hazard. The excess lifetime cancer risk (ELCR) due to exposure to background radiation indicated that the dwellers and industrial workers in the study area may develop cancer over a lifetime due to accumulated dose.

Graphene oxide:Fe2O3 nanocomposites for photodetector applications: experimental and ab initio density functional theory study.

In this report, a GO:Fe2O3 nanocomposite was synthesized using a one-step covalent attachment approach using a sol-gel technique. The optical absorbance, photoconductive, photo-capacitive, and electrical properties were obtained using spectroscopy, and current-voltage (I-V) measurements. An enhanced optical absorbance with corresponding band gap reduction is observed when Fe2O3 nanoparticles are incorporated in GO. A corresponding enhanced photoconductance in the order of ×101 was observed due to the impact of band gap narrowing. The enhanced photoconductivity and photo-capacitance can be attributed to energy and charge transfer between GO and Fe atoms, leading to the generation of photo-induced excitons. Density function theory calculations indicate increased charge transfer when GO is doped with Fe-O atoms, which is consistent with experimental data. The observed results could potentially enable the use of GO:Fe2O3 nanocomposites for photodetectors and other optoelectronic applications.