نتایج جستجو برای: radium isotopes.
تعداد نتایج: 27399 فیلتر نتایج به سال:
background: the present research has focused on the effect of radioactivity on drinking water from five sites in the region of zahedan city. materials and methods: the measurement of water activity in wells, river and spring has been used as a screening method. the determination of gamma emitters was performed by use the application of gamma spectrometry. results: the values of radium concentra...
Four isotopes of radium with different half-lives exist in nature. In aquatic systems, radium isotopes present distinct characteristics in salt water and fresh water environments. In fresh waters, radium appears adsorbed to particulate material while in sea water radium presents a conservative behavior, being the concentration of different isotopes of radium governed by the processes of dilutio...
Exploration of oil and natural gas from shale deposits can bring to the surface radioactivity. Naturally occurring Uranium-238 and Thorium-232 as part of their decay chains can produce radium isotopes, which are themselves precursors of radon gas. Due to the solubility of radium and its contaminated impact on the environments and health concerns, regulations on the levels of Ra226 and Ra228 in ...
We used two short-lived radium isotopes (223Ra, 224Ra) and a mass balance approach applied to the radium activities to determine the nutrient contribution of saline submarine groundwater discharge to the coastal waters of the northern Gulf of Aqaba (Israel). Radium isotope activities were measured along transects during two seasons at a site that lacked any obvious surficial water input. An ons...
Short lived Ra isotopes have been produced at the TRIμP facility in inverse kinematics via the fusion-evaporation reaction Pb+C at 8 MeV/u. Isotopes are separated from other reaction products online using the TRIμP magnetic separator. The energetic radium (Ra) isotopes at the exit of the separator were converted into low energy ions with a thermal ionizer. Ra isotopes have been identified by ob...
For removal of radium from saline waters in Upper Silesian mines, several methods of purification have been developed. The most efficient one is based on application of barium chloride, which was implemented in full technical scale in two Polish coal mines several years ago. Very good results of purification have been achieved-the removal efficiency exceeding 95% of the initial activity. Anothe...
We report a simple new technique for measuring low-level radium isotopes (224Ra and 226Ra) in natural waters. The radium present in natural waters is first preconcentrated onto MnO2-coated acrylic fiber (Mn fiber) in a column mode. The radon produced from the adsorbed radium is then circulated through a closed air-loop connected to a commercial radon-in-air monitor. The monitor counts alpha dec...
High levels of naturally occurring and carcinogenic radium isotopes have been measured in low-saline and oxic groundwater from the Rum Group of the Disi sandstone aquifer in Jordan. The combined 228Ra and 226Ra activities are up to 2000% higher than international drinking water standards. Analyses of the host sandstone aquifer rocks show 228Ra and 226Ra activities and ratios that are consistent...
Naturally occurring radioactive materials (NORM) found in liquid wastes from hydraulic fracturing are an emerging environmental health concern. The heavily drilled Marcellus Shale, for example, contains isotopes of radium, polonium, and lead. However, the few studies that have focused on NORM in fracking wastewater (produced fluids) have reported on a single element—radium. In this issue of EHP...
Radium activity in pore water of wetland sediments often differs from the amount expected from local production, decay, and exchange with solid phases. This disequilibrium results from vertical transport of radium with groundwater that flows between the underlying aquifer and surface water. In situations where groundwater recharge or discharge is significant, the rate of vertical water flow thr...
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