قائمة الطعام
A comprehensive study was conducted to determine thorium, uranium and potassium elemental concentrations in surface soils throughout the accessible area of Cyprus using high-resolution gamma-ray spectrometry. A total of 115 soil samples was collected from all over the bedrock surface of the island b …
PDF | On Oct 1, 2021, F. M. Khaleal and others published Separation of Uranium and Thorium from Mica-Rich Schist Bands Concentrate of Wadi Abu Rusheid Area, South Eastern Desert, Egypt | Find ...
19 days for thorium. Uranium was determined by measuring y-rays from 228 keV of 2"Np and tho-rium from 312 keV of "'Pa. 2.3 CD/MS The instrument used was a commercial GD/MS system (VG 9000, VG Isotopes). A pin-shaped 398. Volume 93, Number 3, May-June 1988 Journal of Research of the National Bureau of Standards ...
Owing to their natural radioactivity, uranium (U) and thorium (Th) play significant roles in environmental sciences for monitoring radiation dose and in geological sciences for understanding sedimentary processes. The Odisha coastal area, in eastern India, is a well-known high background radiation area that is rich in monazites and rutile.
The aim of this study is to determine uranium (238U), potassium (40K) and thorium (232Th) in the radioactive elements by measuring the natural rocks in the vicinity of Antalya province by using ...
A rapid, simple and non-destructive method was developed for the determination of thorium, uranium by gamma ray spectrometry (high purity Ge detector) in thorium–uranium mixture. Using the calibration curves, thorium and uranium were analyzed in synthetic samples with RSD ~2 %. Inter element effect suggested that 583 and 185.7 keV gamma lines are more suitable for the …
The X-ray fluorescence was used to determine traces of uranium and thorium in zircon, forming a tablet with 100 mg of zircon (Voldet, 1972), the author has determined the values in the range of 100 to 2000 ppm of uranium and 100 to 300 ppm of thorium in rocks zircon of Greenland. XRF is also used for the
3-6: Uranium Thorium dating While radiocarbon dating is limited to about <50 000 y and the 40K- Ar dating method is limited to volcanic material and also used to be limited to samples of more than 100 000 y of age, the Uranium Thorium method is an alternative approach to extend the radiocarbon dating range to 1 000 000 y in time. uranium thorium
Uranium and thorium in a relatively clean matrix can easily be Thorium (20 ppm) determined by direct injection. Table 1 lists a similar gradient separation that can be used to separate of uranium and thorium, as shown in Figure 2. Figure 3 shows the determination of uranium in phosphate rock sample (SRM 12OC) using direct injection.
Uranium and thorium contents were determined by the delayed-neutron technique. Details of the procedure are given by Millard (1976). The samples were pulverized to minus 140 mesh (0.105 mm) in a vertical grinder with ceramic plates. An average sample weight of 8 g was used for each analysis,
Determined uranium and thorium biosorption isotherms were independent of the initial U or Th solution concentration. Solution pH affected the exhibited uptake. In general, lower biosorptive uptake was exhibited at pH 2 than at pH 4. No discernible difference in uptake was observed between pH 4 and pH 5 where the optimum pH for biosorption lies.
The uranium-thorium system has been determined by 0. N. Carlson (6), and his diap-ram is given in Fig. 3. A eutectic occurs at 2.5-3.0 weight per cent thorium and at a temperature of 1086°C. A liquid immiscibility gap exists over the range from 10 up to 72 weight per …
Uranium and Thorium Determination in Water Samples Taken along River Kura. Journal of Materials Science and Engineering B, 2016. Famil Humbatov. Download PDF. Download Full PDF Package. This paper. A short summary of this paper. 37 Full PDFs related to this paper. Read Paper. Download PDF.
The determination of activities of thorium, uranium, plutonium, americium, and curium at very low levels has been performed by a new α liquid scintillation system (PERALS, name registered to Ordela, Inc.). The limit of detection has been determined for these nuclides with calculated values often lower than those obtained by other methods, like ICPMS/HP/Mistral, time-resolved laser-induced ...
and 228Ac in the samples, and 238U was determined from the average of the 214Pb and 214Bi concentrations. Radiological concentrations of 232Th, 238U, and 40K were then converted to total elemental concentrations of thorium, uranium, and potassium in surface soils, as described below. Total thorium and uranium concentrations are reported in ...
The calculated number of stages required for 0.1% uranium loss and 1.0% thorium loss using constant feed (BF) composition and a range of flow ratios is shown in Table 1. The number of stages is determined by the requirements for thorium in the strip section and for …
Uranium and thorium isotopes were determined separately to prevent interference of 228 Th from 232 U tracer with 228 Th from natural series of 232Th. This procedure was applied to faeces from people living in the Poos de Caldas plateau, a high natural radioactivity region of Brazil, and vegetables from the Laboratory of Environmental Monitoring ...
Uranium, thorium and lead concentrations and isotopic compositions were determined on total rocks and a feldspar sample from widely separated parts of the Granite Mountains in central Wyoming. Linear relations defined by 206Pb/204Pb - 207Pb/204Pb and 208Pb/204Pb - 232Th/204Pb for the total rock samples define 2.8 billion-year isochrons. In contrast, 238U/206Pb ages are anomalously old by a ...
determine that the fossils are roughly 600,000 years old. This is approximately 200,000 years older than originally thought. The dates are based on uranium/thorium dates on rocks above and below the fossils. The new dates indicate that migration of Homo Erectus …
The uranium, thorium, and rare earth elements (REEs) concentrations were determined from the same soil samples using inductively coupled plasma mass spectrometry (ICP-MS).
Uranium and thorium are two common natural radioactive elements with high concentrations in Earth's crust. The main aim of this study is to estimate the inhaled effective dose of uranium and thorium caused by a typical radioactive rare earth ore to the occupational population and the surrounding public. The particulate matter (PM) concentrations in the atmosphere of four typical workplaces ...
A comprehensive study was conducted to determine thorium, uranium and potassium elemental concentrations in surface soils throughout the accessible area of Cyprus using high-resolution gamma-ray spectrometry. A total of 115 soil samples was collected from all …
Thorium Thorium-232 is the parent of the thorium (4n) series. Its daughter, 228Th is formed through two intermediate nuclides, one of which is 228Ra. Radium is a far more mobile element than thorium, and the half- life of 228Ra (6.7yrs) in sufficiently long to allow significant separation of …
The impurities of uranium and thorium at ultra-low levels in electrolytic copper using RNAA via their induced nuclides U-239/Np-239 and Pa-233, were determined. Obtained results showed that electrolytic copper samples contained impurities of uranium and thorium in ultra-trace levels: up to 45 pg/g (550 nBq/g) for uranium and up to 80 pg/g (330 ...
From alcoholic solutions of nitric acid thorium can be strongly bound on the anion exchanger while uranium is much more weakly bound which enables its separation from thorium. After the separation, uranium and thorium are determined by spectrophotometric method with arsenazo III at 652 nm and 662 nm respectively.
The Spectral gamma ray data includes uranium, thorium and potassium that logged from 5447 ft. to 5653 ft. depth of the well. The analysis includes values of uranium (U) and thorium (Th) in ppm, where potassium (K) is recorded in percentage. The values of potassium and thorium are plotted on (clay type diagram of Schlumberger).
Uranium-Thorium dating is a way of determining the age of a rock by the amount of radioactive Thorium it contains. This method can be used to determine the age of calcium carbonate materials, such ...
Uranium and thorium are not stable. They break down in a process called radioactive decay. More than 99% of natural uranium exists in a form (isotope) called uranium-238 while more than 99% of natural thorium exists as thorium-232. These metals decay very slowly eventually to form lead.
The tailings or wastes produced by the extraction or concentration of uranium or thorium from any ore processed primarily for its source material content. as determined by the U.S. Nuclear Regulatory Commission, including mills, in-situ recovery in-situ recoveryA process to recover uranium in which fluids are injected into ground water to ...
@misc{etde_22300537, title = {Uranium and thorium nuclides series determined in medicinal plants commonly used in Brazil} author = {Silva, P., Francisconi, L., and Damatto, S.} abstractNote = {In recent years the study of medicinal plants has become the focus of ever more extensive research all over the world due to their diversity and potential as source of medicinal products.
The age dependence of the natural concentration of uranium and thorium in the skeleton was investigated using human vertebrae bone collected from two Canadian locations (Winnipeg, Manitoba, and Regina, Saskatchewan). The concentration of both radioelements in digested ashed bone samples was determined using sector-field inductively coupled ...
Uranium and thorium content in long-tailed ducks (Clangula hyemalis L.). Szefer P, Falandysz J. Concentrations of uranium and thorium have been determined in liver, breast muscle, leg muscle, stomach and heart of long-tailed ducks wintering in Gdańsk Bay during 1980-81.
12%A routine procedure has been developed for the simultaneous determination of uranium and thorium in high concentration thorium ores. INAA is used to determine the uranium and thorium concentration. However, for very low concentrations of uranium a radiochemical procedure based on the use of NPy/benzene as an extractant has to be employed. The precision and accuracy …
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