Study and Characterization of Natural Radioactivity Levels and Radiological Hazards of Soil in Wasit Governorate

In this paper studied and measured the natural radioactive for agricultural soil samples surrounding Kut as well as gardens, home, casinos and others. Eighteen samples of agricultural land were taken on three deep depths the first depth 10 cm and the second 20 cm and the third 30 cm. Twenty-five samples were taken from public parks, parks, casinos and other parks. They are all measured using a system NaI (Tl) 3″ × 3″. The results that the radioactive effectiveness of uranium for all samples are ranged 17.19 to 38.68 Bq/Kg and at a rate of 30.55 Bq/Kg for all samples. Thorium series values were between 56.45 to 13.26 Bq/Kg with average 38.60 Bq/Kg. With regard to potassium, values were ranged 537.20 to 118.30 Bq/Kg at a rate of 250.25 Bq/Kg. The values of radioactive effectiveness for potassium are within the globally allowed compared with the radioactive effectiveness of the Thorium. The radium equivalent and the rate absorbed dose in air and the external and internal hazard index and the annual effective dose has been calculated and that all values are within the globally allowed limits.

PURIFICATION OF RARE EARTH ELEMENTS FROM THORIUM, URANIUM, AND RADIOACTIVE ISOTOPES

This article presents the results of industrial tests of the technology of sorption, precipitation and extraction purification of the concentrate of rare earth elements (REE) from radioactive decay products of the uranium and thorium series. It has been shown that the combination of sorption, selective precipitation, and extraction processes makes it possible to effectively purify REE from U, Th, Po, Ra, RaD, and Ac and to obtain radiation-safe nitrogencontaining solutions for the production of fertilizers and individual REE.

Development of highly radiopure NaI(Tl) scintillator for PICOLON dark matter search project

The highly radiopure NaI(Tl) was developed to search for particle candidates of dark matter. The optimized methods were combined to reduce various radioactive impurities. The 40K was effectively reduced by the re-crystallization method. The progenies of the decay chains of uranium and thorium were reduced by appropriate resins. The concentration of natural potassium in NaI(Tl) crystal was reduced down to 20 ppb. Concentrations of alpha-ray emitters were successfully reduced by appropriate selection of resin. The present concentration of thorium series and 226Ra were 1:2 ± 1:4 μBq/kg and 13 ± 4 μBq/kg, respectively. No significant excess in the concentration of 210Pb was obtained, and the upper limit was 5.7 μBq/kg at 90% C. L. The achieved level of radiopurity of NaI(Tl) crystals makes construction of a dark matter detector possible.

Natural and artificial nuclides in Salesópolis reservoir

Natural radioactivity is ubiquitous in the environment mainly due to the presence of the nuclides from the uranium and thorium series and 40K. Although in the South Hemisphere nuclear tests have been fewer in number than that in the North, artificial radionuclides can also be found spread at ground level. In this study, the activity concentrations of natural nuclides from the uranium and thorium series, 40K and the artificial 137Cs were determined in a sediment core with 42 cm depth collected in the middle of the Salesópolis reservoir, located in the Metropolitan Region of São Paulo city (SPMR). The Usina Parque Rio Tietê reservoir belongs to the Alto do Tietê system for the capture, storage and treatment of water for SPMR. Therefore, the quality of the water and sediments of this dam is of great importance. The activity concentrations were measured by gamma spectrometry. Samples were measured and saved at regular intervals at a maximum of 160 000 seconds. The gross area were determined for each peak and plotted against time and the counting rate was obtained by the slope of the curve. Background and reference materials were also counted and treated in the same way. Results showed that 226Ra varied from 45 to 116 Bq kg-1; 228Ra, from 80 to 165 Bq kg-1; 40K, from 155 to 1 187 Bq kg-1 and 137Cs varied from 0.3 to 7 Bq kg-1. The methodology applied for determining low levels of 137Cs in sediment proved to be efficient and reproducible.

Analysis of a Single-Λ Hypernuclear Event in KEK-PS E373 Nuclear Emulsion Experiment

The purpose of this research is to identify a single-Λ hypernucleus and its decay products which support to get more information about hyperon-nucleon interaction. Before performing the analysis of a single-Λ hypernucleus, first, we have deduced the density of emulsion by calibrating the range-energy relation using alpha decay events data from thorium series. It is very important for the mass reconstruction of hypernucleus events in nuclear emulsion. And we have reconstructed a single-Λ hypernucleus event by using the kinematical reconstruction for mesonic and non-mesonic decay modes. From the result of our analysis, we can uniquely identify that single-Λ hypernucleus is $ {}_\Lambda ^9 B $ and decay products are 4He,3He, proton and neutron.

Earliest direct evidence of monument building at the archaeological site of Nan Madol (Pohnpei, Micronesia) identified using 230Th/U coral dating and geochemical sourcing of megalithic architectural stone

Archaeologists commonly use the onset of the construction of large burial monuments as a material indicator of a fundamental shift in authority in prehistoric human societies during the Holocene. High-quality direct evidence of this transition is rare. We report new interdisciplinary research at the archaeological site of Nan Madol that allows us to specify where and when people began to construct monumental architecture in the remote islands of the Pacific. Nan Madol is an ancient administrative and mortuary center and the former capital of the island of Pohnpei. It was constructed over 83 ha of lagoon with artificial islets and other architecture built using columnar basalt and coral. We employed geochemical sourcing of basalt used as architectural stone and high-precision uranium-thorium series dates (230Th/U) on coral from the tomb of the first chief of the entire island to identify the beginning of monument building at Nan Madol in AD 1180-1200. Over the next several centuries (AD 1300-1600) monument building began on other islands across Oceania. Future research should be aimed at resolving the causes of these social transformations through higher quality data on monument building.