Journal articles on the topic 'Uranium counts'
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1
Løvborg, Leif, and Erik Mose. "Counting statistics in radioelement assaying with a portable spectrometer." GEOPHYSICS 52, no. 4 (April 1987): 555–63. http://dx.doi.org/10.1190/1.1442324.
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Counting performed with a portable gamma‐ray spectrometer to assay the concentrations of potassium, uranium, and thorium in the ground normally lasts between 1 and 10 minutes. The statistical uncertainties of the count rates measured in the energy windows are taken into consideration by ascribing standard deviations to the calculated assay values. Such a standard deviation is primarily governed by the counts recorded in two neighboring energy windows. A potassium standard deviation, for example, depends not only on the counts in the potassium window, but is also affected by the mixed uranium‐thorium counts recorded in the uranium window. Counting times of 1, 2, 4, and 10 minutes are normally appropriate in assaying uranium concentrations of 10 to 13, 5 to 7, ∼3, and ∼1.5 ppm eU. By counting for 10 minutes, it may be possible to detect unusually small radioelement concentrations of 0.5 ppm eTh, 0.3 ppm eU, and 0.04 percent K. However, the smallest concentrations that can be measured with a precision of 10 percent amount to about 2 ppm eTh, 1 ppm eU, and 0.15 percent K. Low‐grade uranium ore with whole‐rock concentrations of 100 to 800 ppm eU must contain at least 20 to 100 ppm eTh before reliable thorium assay values can be provided by counting for 1 minute. The corresponding uranium determination limits on thorium mineralizations carrying from 400 to 1 600 ppm eTh are from about 100 to almost 200 ppm eU. Usable potassium assay values are generally not obtained from a ground that contains more than 200 ppm eU or 400 ppm eTh.
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Raghuwanshi, S. S., B. K. Bhaumik, and S. G. Tewari. "A direct method for determining the altitude variation of the uranium stripping ratio in airborne gamma‐ray surveys." GEOPHYSICS 54, no. 10 (October 1989): 1350–53. http://dx.doi.org/10.1190/1.1442597.
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In airborne gamma‐ray spectrometric surveys, it is essential to calculate the net counts in the thorium, uranium, and potassium channels for quantitative analysis. The net uranium, thorium, and potassium counts are given by [Formula: see text], (1a) [Formula: see text] (1b) and [Formula: see text], (1c) where [Formula: see text], [Formula: see text], and [Formula: see text] are the background corrected counts per second for uranium, thorium, and potassium channels, respectively; α and β are the Compton contributions of thorium gamma rays in the uranium and potassium windows, respectively; and γ is the contribution of uranium gamma rays in the potassium window. In some countries, such as the U.S., Canada, and India, it is common practice to compute the stripping ratios by taking measurements over a set of calibration pads with known and varying amounts of uranium, thorium, and potassium (Grasty and Darnley, 1971; Grasty, 1975; Lovborg, 1984). These factors are determined by keeping the detector system inside the survey aircraft over the calibration pads. The stripping coefficients do not have fixed values but vary with source‐detector distance. Because most airborne surveys are conducted at about 120 m above ground level, the stripping ratios measured over the pads should be corrected for variations with ground clearance. In practice, the ground clearance in airborne gamma‐ray surveys may vary from about 40 m to 200 m depending upon the topography of the area flown. It is, therefore, necessary to know the values of the stripping coefficients as a function of ground clearance at least within the range of investigations. If this is known, it is possible to apply proper corrections while converting all data to a uniform datum of 122 m.
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Xie, Wenxiong, Jiansheng Li, and Jianyu Zhu. "Uranium mass and neutron multiplication factor estimates from time-correlation coincidence counts." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 797 (October 2015): 182–87. http://dx.doi.org/10.1016/j.nima.2015.05.066.
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Mittal, Saurabh, S. P. Sharma, Arkoprovo Biswas, and D. Sengupta. "Correlation of VLF-EM Data with Radiometric Measurements: Implications for Uranium Exploration around Beldih, South Purulia Shear Zone, India." International Journal of Geophysics 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/969462.
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This study is an attempt to correlate VLF-EM data with the radiometric measurements to decipher the subsurface structure and to locate uranium mineralization in the shear zone. The study area is around Beldih mine which is an open cast apatite mine located on the South Purulia Shear Zone. VLF method has been applied to map the structure and the presence of radioactive minerals has been delineated by the detection of highαandγcounts with respect to the background radiations. High radiation counts and high surfaceγactivity are found just above the higher apparent current-density zones in all the profiles studied, at various locations, indicating uranium and/or thorium mineralization as well as good correlation between these techniques.
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Petrie, Lainie, Nadia N. North, Sherry L. Dollhopf, David L. Balkwill, and Joel E. Kostka. "Enumeration and Characterization of Iron(III)-Reducing Microbial Communities from Acidic Subsurface Sediments Contaminated with Uranium(VI)." Applied and Environmental Microbiology 69, no. 12 (December 2003): 7467–79. http://dx.doi.org/10.1128/aem.69.12.7467-7479.2003.
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ABSTRACT Iron(III)-reducing bacteria have been demonstrated to rapidly catalyze the reduction and immobilization of uranium(VI) from contaminated subsurface sediments. Thus, these organisms may aid in the development of bioremediation strategies for uranium contamination, which is prevalent in acidic subsurface sediments at U.S. government facilities. Iron(III)-reducing enrichment cultures were initiated from pristine and contaminated (high in uranium, nitrate; low pH) subsurface sediments at pH 7 and pH 4 to 5. Enumeration of Fe(III)-reducing bacteria yielded cell counts of up to 240 cells ml−1 for the contaminated and background sediments at both pHs with a range of different carbon sources (glycerol, acetate, lactate, and glucose). In enrichments where nitrate contamination was removed from the sediment by washing, MPN counts of Fe(III)-reducing bacteria increased substantially. Sediments of lower pH typically yielded lower counts of Fe(III)-reducing bacteria in lactate- and acetate-amended enrichments, but higher counts were observed when glucose was used as an electron donor in acidic enrichments. Phylogenetic analysis of 16S rRNA gene sequences extracted from the highest positive MPN dilutions revealed that the predominant members of Fe(III)-reducing consortia from background sediments were closely related to members of the Geobacteraceae family, whereas a recently characterized Fe(III) reducer (Anaeromyxobacter sp.) and organisms not previously shown to reduce Fe(III) (Paenibacillus and Brevibacillus spp.) predominated in the Fe(III)-reducing consortia of contaminated sediments. Analysis of enrichment cultures by terminal restriction fragment length polymorphism (T-RFLP) strongly supported the cloning and sequencing results. Dominant members of the Fe(III)-reducing consortia were observed to be stable over several enrichment culture transfers by T-RFLP in conjunction with measurements of Fe(III) reduction activity and carbon substrate utilization. Enrichment cultures from contaminated sites were also shown to rapidly reduce millimolar amounts of U(VI) in comparison to killed controls. With DNA extracted directly from subsurface sediments, quantitative analysis of 16S rRNA gene sequences with MPN-PCR indicated that Geobacteraceae sequences were more abundant in pristine compared to contaminated environments,whereas Anaeromyxobacter sequences were more abundant in contaminated sediments. Thus, results from a combination of cultivation-based and cultivation-independent approaches indicate that the abundance/community composition of Fe(III)-reducing consortia in subsurface sediments is dependent upon geochemical parameters (pH, nitrate concentration) and that microorganisms capable of producing spores (gram positive) or spore-like bodies (Anaeromyxobacter) were representative of acidic subsurface environments.
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Polach, Henry, and Lauri Kaihola. "Determination of Radon by Liquid Scintillation α/β Particle Spectrometry: Towards the Resolution of a 14C Dating Problem." Radiocarbon 30, no. 1 (1988): 19–24. http://dx.doi.org/10.1017/s0033822200043927.
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Traces of uranium and radium within the 14C sample generate radon (Rn) which gets occluded during the benzene synthesis, thus generating false (extra) counts within the 14C counting window. This, if undetected, gives rise to erroneous 14C age determinations. The application of simultaneous α and β liquid scintillation spectrometry will enable a mathematical evaluation of the 14C signal unaffected by α and β particle emissions from radon decay daughters.
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Minty, B. R. S. "Airborne gamma‐ray spectrometric background estimation using full spectrum analysis." GEOPHYSICS 57, no. 2 (February 1992): 279–87. http://dx.doi.org/10.1190/1.1443241.
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We have developed a new technique for estimating airborne gamma‐ray spectrometric backgrounds. The background comes from three sources, namely aircraft, cosmic and atmospheric (radon) radiation. The aircraft and cosmic components are independently estimated by suitable calibration and the monitoring of a 3–6 MeV “cosmic” channel. Multichannel observations of the spectra are used to estimate the atmospheric background directly based on the observation that for gamma‐ray counts above the Compton continuum, the low energy [Formula: see text] photopeak at 0.609 MeV for atmospheric radiation suffers far less attenuation relative to the [Formula: see text] peak at 1.76 MeV than is the case for radiation from uranium in the ground. Since thorium and potassium sources do not contribute appreciably to these peak countrates, they can be used to calculate the contributions of radon and uranium to the observed spectrum. The technique appears to be less susceptible to errors due to the effects of variations in the vertical distribution of airborne radon and its daughters than upward‐looking detector techniques.
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Wolfaardt, G. M., M. J. Hendry, and D. R. Korber. "Microbial distribution and diversity in saturated, high pH, uranium mine tailings, Saskatchewan, Canada." Canadian Journal of Microbiology 54, no. 11 (November 2008): 932–40. http://dx.doi.org/10.1139/w08-084.
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Microbiological analyses were conducted on core samples collected along a vertical profile (0–66 m below surface) from the tailings management facility (TMF) at the Rabbit Lake uranium mine in northern Saskatchewan, Canada. Bacterial numbers in the core materials were similar to surrounding soils and surface waters, regardless of the seemingly unfavorable pH (mean = 9.9) and temperature (∼0 °C) in the TMF. The greatest number of viable cells (105CFU/g) was detected at the interface between the tailings and overlying standing water, below which cell counts decreased rapidly with depth. Whole-community metabolic profiles for samples from the different depths grouped into 3 clusters; however, these groups could not be positively correlated with sampling depth, temperature, redox potential, pH, or ore-mill feed. Flow-cell studies demonstrated microbial communities in the tailings surface water could develop biofilms and maintain cell activity at both pH 10 and 7, and altering the pH between these 2 values had little effect on biofilm viability. These results demonstrate the resilience and adaptive nature of naturally occurring microbial communities and signify a potential role of microbial activity in the long-term geochemical evolution of the TMF.
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Garsi, Jerome-Philippe, Eric Samson, Laetitia Chablais, Sergey Zhivin, Christine Niogret, and Dominique Laurier. "Half-century archives of occupational medical data on French nuclear workers: a dusty warehouse or gold mine for epidemiological research?" Archives of Industrial Hygiene and Toxicology 65, no. 4 (December 1, 2014): 407–16. http://dx.doi.org/10.2478/10004-1254-65-2014-2465.
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Abstract This article discusses the availability and completeness of medical data on workers from the AREVA NC Pierrelatte nuclear plant and their possible use in epidemiological research on cardiovascular and metabolic disorders related to internal exposure to uranium. We created a computer database from files on 394 eligible workers included in an ongoing nested case-control study from a larger cohort of 2897 French nuclear workers. For each worker, we collected records of previous employment, job positions, job descriptions, medical visits, and blood test results from medical history. The dataset counts 9,471 medical examinations and 12,735 blood test results. For almost all of the parameters relevant for research on cardiovascular risk, data completeness and availability is over 90 %, but it varies with time and improves in the latest time period. In the absence of biobanks, collecting and computerising available good-quality occupational medicine archive data constitutes a valuable alternative for epidemiological and aetiological research in occupational health. Biobanks rarely contain biological samples over an entire worker’s carrier and medical data from nuclear industry archives might make up for unavailable biomarkers that could provide information on cardiovascular and metabolic diseases
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Rochín-Bañaga, Heriberto, Donald W. Davis, and Tobias Schwennicke. "First U-Pb dating of fossilized soft tissue using a new approach to paleontological chronometry." Geology 49, no. 9 (May 19, 2021): 1027–31. http://dx.doi.org/10.1130/g48386.1.
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Abstract Previous U-Pb dating of fossils has had only limited success because of low uranium content and abundance of common Pb as well as element mobility during late diagenesis. We report the first accurate U-Pb dating of fossilized soft tissue from a Pliocene phosphatized bivalve mold using laser ablation–inductively coupled mass spectrometry (LA-ICPMS). The fossilized soft tissue yields a diagenetic U-Pb age of 3.16 ± 0.08 Ma, which is consistent with its late Pliocene stratigraphy and similar to the oldest U-Pb age measured on accompanying shark teeth. Phosphate extraclasts give a distinctly older age of 5.1 ± 1.7 Ma, indicating that they are likely detrital and may have furnished P, promoting phosphatization of the mold. The U-Pb ages reported here along with stratigraphic constraints suggest that diagenesis occurred shortly after the death of the bivalve and that the U-Pb system in the bivalve mold remained closed until the present. Shark teeth collected from the same horizon show variable resetting due to late diagenesis. Data were acquired as line scans in order to exploit the maximum Pb/U variation and were regressed as counts, rather than ratios, in three-dimensional space using a Bayesian statistical method.
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De Stefano, R., B. Pérot, C. Carasco, and E. Simon. "Simulation of delayed gamma rays from neutron-induced fissions using MCNP 6.1." EPJ Web of Conferences 225 (2020): 06007. http://dx.doi.org/10.1051/epjconf/202022506007.
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As part of its R&xD activities in the fields of radioactivewaste drum storage and homeland security, the NuclearMeasurement Laboratory of CEA Cadarache has started studiesrelated to the detection of induced delayed fission gamma rays asa signature of U/Pu presence either in radioactive wastes or incargo containers and luggage. The study described in the presentpaper explores the feasibility of detecting fission delayed gammarays of nuclear materials interrogated by a pulsed neutrongenerator. For this purpose, Monte Carlo simulations have beenperformed with ACT, the MNCP6 Activation Control Card.Simulated results have been compared with experimental data tovalidate the numerical model. Samples of uranium andplutonium have been irradiated for 2 hours with a pulsed D-Tneutron generator delivering 14 MeV neutrons with an averageemission of 8.107 n/s, which are thermalised in a graphite cellcalled REGAIN. At the end of irradiation, activated nuclearmaterials were placed in a low-background, high-resolutiongamma spectroscopy station in order to detect delayed gammarays emitted by fission products. Anomalies have been observedin the calculated time decay curve of fission delayed gamma rayswith MCNP6 ACT card, but the time behavior is correct for non-fission activated materials like aluminum or copper. On the otherhand, the number of counts recorded in the main simulatedgamma ray lines from activated nuclear material fission productsis consistent with the experimental results, thus validating thesimulation scheme in view of further studies on thecharacterization of radioactive waste drums or special nuclearmaterial detection in cargo containers.
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Kolmašová, Ivana, Ondřej Santolík, Jakub Šlegl, Jana Popová, Zbyněk Sokol, Petr Zacharov, Ondřej Ploc, et al. "Continental thunderstorm ground enhancement observed at an exceptionally low altitude." Atmospheric Chemistry and Physics 22, no. 12 (June 20, 2022): 7959–73. http://dx.doi.org/10.5194/acp-22-7959-2022.
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Abstract. Two long-lasting thunderstorm ground enhancement (TGE) events were registered at the Milešovka meteorological observatory in Czechia (50.55∘ N, 13.93∘ E; 837 m altitude) on 23 April 2018, during linearly organized thunderstorms. Two intervals of increased photon counts were detected by a plastic scintillator, respectively lasting 70 and 25 min and reaching 31 % and 48 % above the background radiation levels. Using numerical simulations, we verified that the observed increases in count rates are consistent with the energy spectrum of previously observed TGEs. We investigated the relevant data from a suite of meteorological instruments, a Ka-band cloud radar, an electric field mill, and a broadband electromagnetic receiver, all placed at the Milešovka observatory, in order to analyse the context in which these unique continental TGEs occurred at an exceptionally low altitude. The onset of the TGEs preceded the onset of precipitation by 10 and 3 min, respectively, for the two events. Both this delayed rain arrival and an energy threshold of 6.5 MeV for registered particles clearly exclude the detection the decay products of the radon progeny washout during the TGE intervals. At the same time, the European lightning detection network EUCLID detected numerous predominantly negative intracloud lightning discharges at distances closer than 5 km from the particle detector, while the occurrence of cloud-to-ground discharges was suppressed. The cloud radar recorded presence of graupel below the melting level, and the composition of hydrometeors suggested good conditions for cloud electrification. The observed variations in the near-surface electric field were unusual, with very brief negative-electric-field excursions reaching −20 kV in a quick succession. At the same time, sub-microsecond unipolar pulses emitted by close corona discharges saturated the broadband magnetic loop antenna. All these measurements indicate that a strong lower positive-charge region was present inside the thundercloud. The bottom thundercloud dipole was probably responsible for acceleration of the seed electrons in the air. These seed electrons might originate in the secondary cosmic ray particles but could also come from a high concentration of radon in the air collected during the propagation of the convective system above the uranium-rich soils before the thunderstorms overpassed the Milešovka observatory.
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Carasco, C., B. Pérot, J. L. Ma, H. Toubon, and A. Dubille-Auchère. "Improving gross count gamma-ray logging in uranium mining with the NGRS probe." EPJ Web of Conferences 170 (2018): 05001. http://dx.doi.org/10.1051/epjconf/201817005001.
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AREVA Mines and the Nuclear Measurement Laboratory of CEA Cadarache are collaborating to improve the sensitivity and precision of uranium concentration measurement by means of gamma ray logging. The determination of uranium concentration in boreholes is performed with the Natural Gamma Ray Sonde (NGRS) based on a NaI(Tl) scintillation detector. The total gamma count rate is converted into uranium concentration using a calibration coefficient measured in concrete blocks with known uranium concentration in the AREVA Mines calibration facility located in Bessines, France. Until now, to take into account gamma attenuation in a variety of boreholes diameters, tubing materials, diameters and thicknesses, filling fluid densities and compositions, a semi-empirical formula was used to correct the calibration coefficient measured in Bessines facility. In this work, we propose to use Monte Carlo simulations to improve gamma attenuation corrections. To this purpose, the NGRS probe and the calibration measurements in the standard concrete blocks have been modeled with MCNP computer code. The calibration coefficient determined by simulation, 5.3 s-1.ppmU-1 ± 10%, is in good agreement with the one measured in Bessines, 5.2 s-1.ppmU-1. Based on the validated MCNP model, several parametric studies have been performed. For instance, the rock density and chemical composition proved to have a limited impact on the calibration coefficient. However, gamma self-absorption in uranium leads to a nonlinear relationship between count rate and uranium concentration beyond approximately 1% of uranium weight fraction, the underestimation of the uranium content reaching more than a factor 2.5 for a 50 % uranium weight fraction. Next steps will concern parametric studies with different tubing materials, diameters and thicknesses, as well as different borehole filling fluids representative of real measurement conditions.
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Akob, Denise M., Heath J. Mills, Thomas M. Gihring, Lee Kerkhof, Joseph W. Stucki, Alexandre S. Anastácio, Kuk-Jeong Chin, et al. "Functional Diversity and Electron Donor Dependence of Microbial Populations Capable of U(VI) Reduction in Radionuclide-Contaminated Subsurface Sediments." Applied and Environmental Microbiology 74, no. 10 (March 31, 2008): 3159–70. http://dx.doi.org/10.1128/aem.02881-07.
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ABSTRACT In order to elucidate the potential mechanisms of U(VI) reduction for the optimization of bioremediation strategies, the structure-function relationships of microbial communities were investigated in microcosms of subsurface materials cocontaminated with radionuclides and nitrate. A polyphasic approach was used to assess the functional diversity of microbial populations likely to catalyze electron flow under conditions proposed for in situ uranium bioremediation. The addition of ethanol and glucose as supplemental electron donors stimulated microbial nitrate and Fe(III) reduction as the predominant terminal electron-accepting processes (TEAPs). U(VI), Fe(III), and sulfate reduction overlapped in the glucose treatment, whereas U(VI) reduction was concurrent with sulfate reduction but preceded Fe(III) reduction in the ethanol treatments. Phyllosilicate clays were shown to be the major source of Fe(III) for microbial respiration by using variable-temperature Mössbauer spectroscopy. Nitrate- and Fe(III)-reducing bacteria (FeRB) were abundant throughout the shifts in TEAPs observed in biostimulated microcosms and were affiliated with the genera Geobacter, Tolumonas, Clostridium, Arthrobacter, Dechloromonas, and Pseudomonas. Up to two orders of magnitude higher counts of FeRB and enhanced U(VI) removal were observed in ethanol-amended treatments compared to the results in glucose-amended treatments. Quantification of citrate synthase (gltA) levels demonstrated a stimulation of Geobacteraceae activity during metal reduction in carbon-amended microcosms, with the highest expression observed in the glucose treatment. Phylogenetic analysis indicated that the active FeRB share high sequence identity with Geobacteraceae members cultivated from contaminated subsurface environments. Our results show that the functional diversity of populations capable of U(VI) reduction is dependent upon the choice of electron donor.
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Chen, Rui, Cheng-Yuan Luo, Hai-Tao Wang, Zhi-Feng Liu, Xiong-Jie Zhang, Ren-Bo Wang, Shu-Min Zhou, and Bin Tang. "A union neutron-gamma logging method for determination of uranium-radium disequilibrium coefficient." Nuclear Technology and Radiation Protection 35, no. 2 (2020): 103–8. http://dx.doi.org/10.2298/ntrp2002103c.
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Owing to the influence of continuous running of ground water, the uranium atoms can be separated physically from their daughters for the reason of different solubilities and the uranium deposit often shows the disequilibrium feature between uranium and its daughter products (radium principally). It is important, when spectral gamma ray logging, to quantify the uranium content which can cause inaccuracy of the result. This paper, based on spectral ? ray logging method, proposes a neutron-gamma logging method to determine the coefficient of uranium-radium disequilibrium. In this method, characteristic peak count rate of uranium is taken from prompt fission neutron logging, whereas characteristic peak count rate of radium, thorium and potassium are taken from spectral gamma ray logging. Based on this method, the union logging tool including epithermal neutron, thermal neutron, and gamma detector along with D-T generator, have been developed. The experimental results, in standard model wells, show that this method is in good agreement within 7% in core assay results. It shows that the union neutron-? logging method can be used for field uranium logging jobs.
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Nurtazin, Sabir, Steven Pueppke, Temirkhan Ospan, Azamat Mukhitdinov, and Timur Elebessov. "Quality of Drinking Water in the Balkhash District of Kazakhstan’s Almaty Region." Water 12, no. 2 (February 1, 2020): 392. http://dx.doi.org/10.3390/w12020392.
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The thinly populated Balkhash District of Kazakhstan’s Almaty Region lies in the lower reaches of the Ili-Balkhash basin, which is shared by China and Kazakhstan. The district is arid and heavily dependent on inflows of surface water, which are threatened by the effects of upstream population growth, economic development, and climate change. The quality of drinking water from centralized water systems and tube wells in nine villages of the district was analyzed, and the organoleptic properties of water from these sources was also assessed by an expert and via surveys of local residents. Although most samples met governmental standards for the absence of chemical impurities, high concentrations of mineralization, chlorides, boron, iron, and/or uranium were present in some well water samples. Levels of these pollutants were as much as 4-fold higher than governmental maxima and as much as 16-fold higher than concentrations reported previously in surface water. All centralized water samples met standards for absence of microbial contamination, but total microbial counts in some well water samples exceeded standards. Organoleptic standards were met by all the water from five villages, but centralized water from one village and well water from four villages failed to meet standards based on expert judgment. Residents were, for the most part, more satisfied with centralized rather than well water, but there was no obvious relationship between the failure of water to meet standards and the locations or populations of the settlements. This is the first comprehensive assessment of groundwater used for drinking in the lower Ili-Balkhash basin, and although it relies on a limited number of samples, it nevertheless provides evidence of potentially serious groundwater contamination in the Balkhash District. It is thus imperative that additional and more detailed studies be undertaken.
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Bezhunov, G., N. Rykov, and B. Ryazanov. "DEVELOPMENT OF A COMPACT PULSED NEUTRON SYSTEM FOR MEASURING THE MASS OF FISSILE NUCLIDES IN SOLID RADIOACTIVE WASTE." PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. SERIES: NUCLEAR AND REACTOR CONSTANTS 2021, no. 3 (September 26, 2021): 49–67. http://dx.doi.org/10.55176/2414-1038-2021-3-49-67.
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A system for measuring the mass of fissile nuclides (FN) in solid radioactive waste (SRW) in containers up to 200 liters has been developed, manufactured and tested. The measuring system includes a pulsed neutron generator (PNG) with a neutron output of 2·108 neutrons/s, a neutron moderating unit with counters of supra-cadmium neutrons and a chamber for containers up to 200 liters, a time pulse analyzer, a personal computer with a software for accumulation and processing of time spectra of pulses from neutron registration. Experimental and computational studies have been carried out for models of containers with solid radioactive waste of 120 and 211 liters with matrices of quartz sand, graphite and paper of various densities with FN content in an amount from 0.01 to 100 g using reference or well-characterized samples with different enrichment in U-235 (from 5 to 90 %) and PuO2 reference sample, with different chemical composition (dioxide, uranyl nitrate solution, oxide-nitrous oxide), different geometrical sizes, placed homogeneously or heterogeneously over the volume of the container. The parameters of the measuring system were determined, including the response values in units of counts per second per gram of FN in the container and per the PNG neutron. The measurement time at an PNG frequency of 20 Hz with a neutron yield of ~107 neutrons/pulse is from 100 to 300 s. The lower limit for U-235 mass measuring for typical TPO matrices is 0.01 g per container. The influence of various factors on the measurement results was estimated: the moisture content of the matrix, the chemical composition and density of the matrices, the mass fraction of U-238 in uranium, the heterogeneity of the FN arrangement in the container, the presence of internal neutron sources. Measurements of the mass of fissile nuclides in containers using the developed system are possible for the case of the presence of internal neutron sources in the container with an intensity of up to 5·107 neutrons/s per container.
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Marchais, T., B. Pérot, C. Carasco, J.-L. Ma, P.-G. Allinei, H. Toubon, R. Goupillou, and J. Collot. "The use of self-induced X-ray fluorescence in gamma-ray spectroscopy of uranium ore samples." EPJ Web of Conferences 225 (2020): 05003. http://dx.doi.org/10.1051/epjconf/202022505003.
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Gamma logging for uranium exploration are currently based on total counting with Geiger Müller gas detectors or NaI (TI) scintillators. However, the total count rate interpretation in terms of uranium concentration may be impaired in case of roll fronts, when the radioactive equilibrium of the natural 238U radioactive chain is modified by differential leaching of uranium and its daughter radioisotopes of thorium, radium, radon, etc. Indeed, in case of secular equilibrium, more than 95 % of gamma rays emitted by uranium ores come from 214Pb and 214Bi isotopes, which are in the back-end of 238U chain. Consequently, these last might produce an intense gamma signal even when uranium is not present, or with a much smaller activity, in the ore. Therefore, gamma spectroscopy measurements of core samples are performed in surface with high-resolution hyper-pure germanium HPGe detectors to directly characterize uranium activity from the 1001 keV gamma ray of 234mPa, which is in the beginning of 238U chain. However, due to the low intensity of this gamma ray, i.e. 0.84 %, acquisitions of several hours are needed. In view to characterize uranium concentration within a few minutes, we propose here a method using both the 92 keV gamma ray of 234Th and the 98.4 keV uranium X-ray. This last is due to uranium self-induced fluorescence caused by gamma radiations of 214Pb and 214Bi, which create a significant Compton scattering continuum acting as a fluorescence source and resulting in the emission of uranium fluorescence X-rays. The comparison of the uranium activity obtained with the 92 keV and 98.4 keV lines allows detecting a uranium heterogeneity in the ore. Indeed, in case of uranium nugget, the 92 keV line leads to underestimated uranium concentration due to gamma self-absorption, but on the contrary the 98.4 keV line leads to an overestimation because of increased fluorescence. In order to test this new approach, several tens of uranium ore samples have been measured with a handheld HPGe FALCON 5000 detector.
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Morichi, Massimo, Erica Fanchini, and Giacomo Mangiagalli. "A Novel Portable Device For Gamma And Neutron Spectroscopy With Special Nuclear Material Identification." EPJ Web of Conferences 225 (2020): 07006. http://dx.doi.org/10.1051/epjconf/202022507006.
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The development of new types of detectors and the increased performance of the electronics have paved the way for developing advanced systems for the measurement and identification of radioactive material that can be involved, for example, in illicit trafficking. Radioactive isotope identifiers are today commercially available. Nowadays those systems make use of inorganic scintillators as Sodium Iodide (NaI(Tl)) or, for enhanced resolution, Lanthanum Bromide (LaBr3) to identify the gamma emitters through their characteristic gamma lines. The most complete systems usually include an additional 3He proportional counter for neutron detection and counting. The performances of such devices are compliant with standards as the IEC 62327 Hand Held Instruments for the Detection and Identification of Radionuclides. This paper presents a new type of portable radioactive isotope identifier. This device, based on an organic liquid scintillator with excellent Pulse Shape Discrimination (PSD) proprieties for the simultaneous detection of gamma rays and neutrons, detects radioactive source as Special Nuclear Material (SNM), medical, industrial and Naturally Occurring Radioactive Material. The exclusive feature of this instrument is the identification of neutron sources with discrimination between fission sources (like Californium 252Cf) and alpha-n type sources (like Americium Beryllium Am-Be) from Plutonium and Uranium through an innovative dedicated algorithm. Individual thresholds for neutron and gamma counts are calculated to allow detection with 95% detection probability for a dose rate on the front face of the scintillator of at least 50 nSv/h. Alarms are triggered separately when the respective rate exceed these thresholds. The neutron source detection has also been proved in a gamma ray field up to 100 μSv/h. The electronics is equipped with two analog inputs and two high voltage power supplies in a small form factor thus becoming an enabling technology for higher performance yet portable radioactive isotope identifier devices, which can include more detectors and perform data fusion analysis. The addition of a second detector allows to detect a masked neutron source through the PSD algorithm performed by the liquid scintillator detector while the added inorganic scintillator identifies the masking gamma emitters. The inorganic scintillator allows also the calculation of Pu and U enrichment grade through characteristic gamma emission line.
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Zirakparvar, N., Cole Hexel, Andrew Miskowiec, Julie Smith, Michael Ambrogio, Douglas Duckworth, Roger Kapsimalis, and Brian Ticknor. "A NanoSIMS 50 L Investigation into Improving the Precision and Accuracy of the 235U/238U Ratio Determination by Using the Molecular 235U16O and 238U16O Secondary Ions." Minerals 9, no. 5 (May 18, 2019): 307. http://dx.doi.org/10.3390/min9050307.
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A NanoSIMS 50 L was used to study the relationship between the 235U/238U atomic and 235U16O/238U16O molecular uranium isotope ratios determined from a variety of uranium compounds (UO2, UO2F2, UO3, UO2(NO3)2·6(H2O), and UF4) and silicates (NIST-610 glass and the Plesovice zircon reference materials, both containing µg/g uranium). Because there is typically a greater abundance of 235U16O+ and 238U16O+ molecular secondary ions than 235U+ and 238U+ atomic ions when uranium-bearing materials are sputtered with an oxygen primary ion beam, the goal was to understand whether use of 235U16O/238U16O has the potential for improved accuracy and precision when compared to the 235U/238U ratio. The UO2 and silicate reference materials showed the greatest potential for improved accuracy and precision through use of the 235U16O/238U16O ratio as compared to the 235U/238U ratio. For the UO2, which was investigated at a variety of primary beam currents, and the silicate reference materials, which were only investigated using a single primary beam current, this improvement was especially pronounced at low 235U+ count rates. In contrast, comparison of the 235U16O/238U16O ratio versus the 235U/238U ratio from the other uranium compounds clearly indicates that the 235U16O/238U16O ratio results in worse precision and accuracy. This behavior is based on the observation that the atomic (235U+ and 238U+) to molecular (235U16O+ and 238U16O+) secondary ion production rates remain internally consistent within the UO2 and silicate reference materials, whereas it is highly variable in the other uranium compounds. Efforts to understand the origin of this behavior suggest that irregular sample surface topography, and/or molecular interferences arising from the manner in which the UO2F2, UO3, UO2(NO3)2·6(H2O), and UF4 were prepared, may be a major contributing factor to the inconsistent relationship between the observed atomic and molecular secondary ion yields. Overall, the results suggest that for certain bulk compositions, use of the 235U16O/238U16O may be a viable approach to improving the precision and accuracy in situations where a relatively low 235U+ count rate is expected.
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Carlson, Shawn M., George W. Robinson, Mark J. Elder, John A. Jaszczak, and Theodore J. Bornhorst. "Greenockite and Associated Uranium-Vanadium, Minerals from the Huron River Uranium Prospect Baraga County, Michigan." Rocks & Minerals 82, no. 4 (January 2007): 298–309. http://dx.doi.org/10.3200/rmin.82.4.298-309.
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Kipp, Gregory G., James J. Stone, and Larry D. Stetler. "Arsenic and uranium transport in sediments near abandoned uranium mines in Harding County, South Dakota." Applied Geochemistry 24, no. 12 (December 2009): 2246–55. http://dx.doi.org/10.1016/j.apgeochem.2009.09.017.
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Jensen, Martin, and Jason Herrmann. "Uranium Mineralization at the Apex Mine Lander County Nevada." Rocks & Minerals 87, no. 3 (May 10, 2012): 270–78. http://dx.doi.org/10.1080/00357529.2012.676847.
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Saunders, Donald F., K. Ray Burson, Jim F. Branch, and C. Keith Thompson. "Relation of thorium‐normalized surface and aerial radiometric data to subsurface petroleum accumulations." GEOPHYSICS 58, no. 10 (October 1993): 1417–27. http://dx.doi.org/10.1190/1.1443357.
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A new exploration method has been developed using surface and aerial gamma‐ray spectral measurements in prospecting for petroleum in stratigraphic and structural traps. Formerly troublesome lithologic and environmental variables are suppressed by correcting potassium and uranium readings using a new process of thorium normalization. Normalized potassium shows characteristic low concentrations above petroleum deposits. Normalized uranium shows higher values than normalized potassium over petroleum and generally lower values elsewhere. We attribute these anomalies to effects of microbial consumption of microseeping light hydrocarbons. Studies of National Uranium Resource Evaluation (NURE) Program aerial, gamma‐ray, spectral data covering portions of six states have shown characteristic normalized potassium and uranium anomalies above 72.7 percent of 706 oil and gas fields. Additionally, an average of 27 similar untested anomalies were found for each 1000 square mi (2600 square km) covered. Similar aerial gamma‐ray spectral data are available over large portions of potential petroleum areas of the U.S. including Alaska and Australia. Preliminary tests in two basins in Australia showed positive correlation between radiometrically favorable areas and known oil and gas regions. Ground‐based, gamma‐ray, spectral measurements found the same types of potassium and uranium anomalies over all twelve fields evaluated. Since 1988, our research of surface radiometric data coupled with soil gas hydrocarbon and soil magnetic susceptibility surveys has resulted in discovery of four oil and gas fields in Concho County, Texas.
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Muhammad, Adi Gunawan, and Frederikus Dian Indrastomo. "Validitas dan Reliabilitas Data Estimasi Kadar Uranium Sektor Lembah Hitam, Kalan, Kalimantan Barat." EKSPLORIUM 40, no. 2 (November 30, 2019): 75. http://dx.doi.org/10.17146/eksplorium.2019.40.2.5672.
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ABSTRAKMineralisasi uranium (U) di Sektor Lembah Hitam pada batuan metalanau dan metapelit sekistosan berasosiasi dengan mineral pirit, pirhotit, magnetit, molibdenit, turmalin, dan kuarsa. Kehadiran mineral U ditandai dengan nilai radiometri batuan yang mencapai 15.000 c/s. Estimasi cepat kadar U adalah menggunakan perhitungan gamma ray hasil logging gross-count gamma lubang bor LH-01. Penelitian ini bertujuan untuk mendapatkan validitas dan reliabilitas data estimasi kadar U. Hasil estimasi kadar U logging disebandingkan dengan analisis geokimia untuk mendapatkan faktor koreksi (Fk). Analisis geokimia menggunakan metode X-Ray Fluorescence (XRF) pada sampel batuan terpilih di interval kedalaman yang mewakili batuan dan mineralisasi di lubang tersebut. Estimasi kadar U di kedalaman 8,80–9,81 m berdasarkan gross-count gamma ray menunjukkan nilai kadar 456 ppm eU, sementara analisis XRF menunjukkan rerata kadar 177 ppm U. Nilai faktor koreksi (Fk) yang didapatkan dari estimasi kadar di kedalaman 8,80–9,81 m adalah 0,388. Nilai tersebut menunjukkan validitas dan reliabilitas data estimasi yang digunakan rendah. Kesebandingan estimasi kadar U dipengaruhi oleh beberapa faktor, antara lain: sistem logging gross-count gamma ray, ketidaksetimbangan uranium, ukuran sampel, dan unsur radioaktif lainnya. Untuk meningkatkan validitas dan reliabilitas data estimasi, maka diperlukan penambahan sampel analisis XRF dengan mempertimbangkan lingkar dan interval kedalaman lubang bor. ABSTRACTUranium (U) mineralisation in Lembah Hitam Sector in metasilt and schistossic metapellite rocks was assosiated with pyrite, pyrhotite, magnetite, molibdenite, tourmaline, and quartz minerals. The existence of U mineral was marked from its radiometric value reaching 15,000 c/s. The faster way to estimate U grade is using gamma-ray values calculation from gross-count gamma logging at borehole LH-01. The research is aimed to obtain the validity and reliablility of U grade estimating data. The logging estimation result then compared with geochemical analysis to obtain the correction factor (Fk). Geochemical analysis is using X-Ray Fluorescence (XRF) method on selected rock samples represent rock and mineralisastion depth interval inside the borehole. The result of uranium grade estimation using gross-count gamma ray calculation in depth 8.80–9.81 m is 456 eU while based on XRF analysis, the result is 177 ppm U. The correction factor (Fk), obtained from grade estimation at 8.80–9.81 m depth is 0.388. The value indicates that the validity and reliability estimation data is low. Ratio of U grade estimation depends on some factors, like gross-count gamma ray logging system; uranium disequilibrium, sampels size; and other radioactive elements. In order to increase the validity and reliability estimation data, XRF analysis samples should be added by considering the borhole diameter and depth interval.
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Missimer, Thomas M., Christopher Teaf, Robert G. Maliva, Ashley Danley-Thomson, Douglas Covert, and Michael Hegy. "Natural Radiation in the Rocks, Soils, and Groundwater of Southern Florida with a Discussion on Potential Health Impacts." International Journal of Environmental Research and Public Health 16, no. 10 (May 21, 2019): 1793. http://dx.doi.org/10.3390/ijerph16101793.
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Southern Florida is underlain by rocks and sediments that naturally contain radioactive isotopes. The primary origin of the radioactive isotopes is Miocene-aged phosphate deposits that can be enriched in uranium-238 and its daughter isotopes. Nodular phosphate containing radionuclides from the Miocene has been reworked into younger formations and is ubiquitous in southern Florida. When the nodular phosphate is exposed to groundwater with geochemical conditions favorable for its dissolution, uranium, radium, and radon may be released into the groundwater system. Uranium concentrations have been measured above the 30 µg/L drinking water standard at only one location in Lee County. Radium226/228 exceedances of the drinking water standard have been documented in numerous wells in Sarasota County. Indoor radon activities have exceeded the 4 piC/L guideline in five southern Florida counties. The exceedance of radioactivity standards in drinking water does not occur in municipal drinking water supplies, but rather only in some domestic self-supply wells. Health risks for exposure to radiation from domestic self-supply wells could be mitigated by testing of well water and, if necessary, switching to the use of a different aquifer or treatment process. While the risk of exposure to radon in indoor air in southern Florida is generally low, some areas are enriched in soil radon that migrates into structures, which could be addressed by improved ventilation.
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Ohioma, Ohi Jerry. "Detection of Sulphide Deposit Using Uranium/Potassium Ratio Map." Ghana Journal of Geography 12, no. 1 (July 25, 2020): 145–58. http://dx.doi.org/10.4314/gjg.v12i1.8.
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Potassium (K) response is associated with minerals that can be easily weathered, whereas uranium (U) is usually related to residual clay, oxides and accessory minerals. With a view to interpret for the detection of sulphide deposit based on similar responses exhibited by the various rock units, radiometric data set was interpreted. The study area is located within Latitude +8000’00’’to +8030’00’’ and Longitude +5030’00’’E to +6000’00’’E. The data was collected in most parts of the Nigeria by Fugro Airborne Services Ltd. Johannesburg in collaboration with the Nigerian Geological Survey agency using a light aircraft that was flown in NW-SE direction with a nominal terrain clearance of 80 m and at a speed of 70-80 m/s, with a flight line spacing of 500 m apart. The acquired data was subjected to elemental concentration enhancement using Geosoft Oasis Montaj Software. From the interpreted data, the red coloured portions indicate high uranium and low potassium formations (H-U/K), while the blue coloured portions indicate low uranium and high potassium formations (L-U/K). The regions L-U/K have recorded low U/K ratios, meaning that L-U/K have very low uranium count rates as compared to the count rates of potassium in these regions; this signifies potassium abundance. This also suggests igneous activities that usually culminate to the emplacement of the meta-volcanic lithologies. H-U/K and M-U/K (Moderate U/K formations) are seen to have patches of high U/K ratios within the central portions. This high U/K ratio was therefore, as a result of sulphide deposition.
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Office, Fuji Technology Press Editorial. "Development of Disaster Management Robots for Use in Investigating Nuclear Accidents." Journal of Disaster Research 3, no. 4 (August 1, 2008): 305–6. http://dx.doi.org/10.20965/jdr.2004.p0305.
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Nuclear accidents have occurred at Japan’s fast-breeder reactor Monju and in Tokai Village etc., and incidents involving nuclear reactors damaged due to natural disasters such as earthquakes are anticipated. In this case, conditions such as leakage of radioactivity must be grasped as soon as possible without exposing anyone to radiation. The Monju accident occurred near Tsuruga City in Fukui Prefecture in December 1995. Liquid sodium used as coolant leaked and a fire broke out. The Tokai Village incident occurred at a uranium processing plant in Tokai Village, Naka County, Ibaraki Prefecture, in September 1999. In this case, a uranium solution went critical and two subcontracted employees workers died of radiation exposure.
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Office, Fuji Technology Press Editorial. "Development of Disaster Management Robots for Use in Investigating Nuclear Accidents." Journal of Disaster Research 3, no. 4 (August 1, 2008): 305–6. http://dx.doi.org/10.20965/jdr.2008.p0305.
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Nuclear accidents have occurred at Japan’s fast-breeder reactor Monju and in Tokai Village etc., and incidents involving nuclear reactors damaged due to natural disasters such as earthquakes are anticipated. In this case, conditions such as leakage of radioactivity must be grasped as soon as possible without exposing anyone to radiation. The Monju accident occurred near Tsuruga City in Fukui Prefecture in December 1995. Liquid sodium used as coolant leaked and a fire broke out. The Tokai Village incident occurred at a uranium processing plant in Tokai Village, Naka County, Ibaraki Prefecture, in September 1999. In this case, a uranium solution went critical and two subcontracted employees workers died of radiation exposure.
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NIGM, Ahmed A., Baher M. GHEITH, and Mohamed A. SHAHEEN. "A comprehensive study for the airborne gamma-rays spectrometry results of Gabal El-Hassnawia, Central Eastern Desert, Egypt." Contributions to Geophysics and Geodesy 52, no. 3 (September 30, 2022): 395–422. http://dx.doi.org/10.31577/congeo.2022.52.3.3.
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The present study utilizes the airborne gamma-ray spectrometric data of Gabal El-Hassnawia and its vicinity in an attempt to refine the surface geological mapping and recognize the radioelements occurrences. The statistically analysed surface lineaments derived from the Landsat image proved that they are oriented to the NW, NNW, N–S, and ENE trends. Qualitatively, the highest radiometric levels are related to the younger granites, the intermediate levels are observed over the Hammamat sediments and the acidic metavolcanics while the low levels are coinciding with the metasediments, ultramafites and basic to intermediate metavolcanics. The composite images show a good close correlation with the geologically mapped rock units. The factor analysis proved that the radiometric variables uranium (eU), potassium (K) and thorium (eTh) as well as total count (TC) are highly correlated positively with each other. Three principal factors F1, F2 and F3 are extracted from the data and their scores were used in differentiating the rock types according to their radiometric levels; consequently, nine interpreted litho-radiometric units were identified. Three types of younger granites and two types of Hammamat sediments could be distinguished among the nine units. These units are subjected to statistical treatment with the goal of identifying the uranium occurrences that exceeds X + 2S and X + 3S as targets of exploration. Accordingly, it is found that the uranium province zones are related to the three types of granite (G1, G2 and G3), the second type of Hammamat sediment (H2) and more or less the acidic metavolcanics. The uranium migration indicated that the second type of Hammamat sediment (H-2) is the only unit that the uranium is migrated in whereas; the uranium is migrated out in all other units.
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Bomber, Brenda J., Ernest B. Ledger, and Thomas T. Tieh. "Ore petrography of a sedimentary uranium deposit, Live Oak County, Texas." Economic Geology 81, no. 1 (February 1, 1986): 131–42. http://dx.doi.org/10.2113/gsecongeo.81.1.131.
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Olds, Travis A. "Mercury Minerals of the Huron River Uranium Prospect, Baraga County, Michigan." Rocks & Minerals 87, no. 2 (March 30, 2012): 134–41. http://dx.doi.org/10.1080/00357529.2011.618775.
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Saunders, Donald F., J. F. Branch, and C. K. Thompson. "Tests of Australian aerial radiometric data for use in petroleum reconnaissance." GEOPHYSICS 59, no. 3 (March 1994): 411–19. http://dx.doi.org/10.1190/1.1443603.
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Recon Exploration Pty. Ltd. has successfully completed initial testing of a new method for processing and interpretation of AGSO’s (Australian Geological Survey Organization, formerly Bureau of Mineral Resources) aerial gamma‐ray spectrometer data for petroleum exploration in the Canning Basin, Western Australia and the Otway Basin, Victoria. Count‐rate data for potassium and uranium were normalized to the thorium count rate for each sample to suppress unwanted effects of variations in surface lithology or soil type, soil moisture, vegetation cover, and counting geometry. The Canning Basin test area included five producing oil fields. All except one clearly exhibit significant and characteristic radiometric anomalies which include negative normalized potassium and more positive normalized uranium values. The Otway Basin test areas included PPL-1 commercial gas production which is associated with a group of significant radiometric anomalies similar to those in the Canning Basin. These results are similar to extensive ongoing tests in the U.S. and are explained in terms of well‐understood geological, geochemical, and geophysical models. Based on 69 wells in the three test areas, it is estimated that the chance of encountering hydrocarbons (economic production or shows) in wells within the radiometrically favorable zones is about 2.6 times greater than outside the favorable areas.
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Metz, Matthew, and Janelle London. "State Vehicle Electrification Mandates and Federal Preemption." Michigan Journal of Environmental & Administrative Law, no. 9.2 (2020): 433. http://dx.doi.org/10.36640/mjeal.9.2.state.
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By requiring that new vehicles sold after a certain date be electric, states can lower drivers’ vehicle operating costs, boost local employment, and lower electric rates. But there’s a widespread perception that states can’t take advantage of these opportunities because a state vehicle electrification mandate would be preempted by federal law. Not so. While the Federal Clean Air Act (CAA) prohibits state regulations “relating to” the control of emissions in motor vehicles, and the Federal Energy Policy and Conservation Act (EPCA) prohibits state regulations “related to” fuel economy standards, there is a strong rationale for federal courts to reject preemption of state vehicle electrification mandates. The Supreme Court has indicated repeatedly that state laws regulating a product or process “upstream” that have an effect “downstream” are not preempted by the federal law. A state law conditioning construction of nuclear power plants on adequate means for storage and disposal of nuclear waste is not preempted by a federal law regulating nuclear plant safety, although its effect is to advance nuclear plant safety. A state ban on uranium mining is not preempted by a federal law on uranium milling and tailing safety, although its effect is to advance uranium milling and tailing safety. Similarly, a state law requiring that cars run on electricity should not be preempted by federal law on emissions and fuel economy standards, although its effect is to reduce emissions and improve fuel economy. Moreover, there is no conflict between a state vehicle electrification law and the purposes of the CAA and EPCA. The purpose of the Clean Air Act is to clean the air. The relevant purpose of the Energy Policy and Conservation Act is to reduce energy demand. Neither statute has a purpose of ensuring that new vehicles have at least some emissions, nor that they continue to use gasoline. This Article concludes that state vehicle electrification legislation should not be preempted. Neither the CAA nor the EPCA directly regulates how vehicles are powered. Neither statute explicitly prohibits states from mandating electrification of vehicles. And legal precedent limiting regulation of vehicles based on emissions or fuel economy standards has never addressed vehicle electrification mandates. Further, states have compelling reasons for vehicle electrification mandates that have nothing to do with regulating emissions or improving fuel economy standards. Such reasons may be sufficient to avoid preemption. The Supreme Court’s increasingly preemption-skeptical jurisprudence, as articulated in Virginia Uranium v. Warren, limits courts’ ability to scrutinize state motives in passing vehicle electrification statutes. Thus, although preemption cannot be dismissed as a concern, the stage has been set for state-based vehicle electrification mandates.
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Muhammad, Adi Gunawan, and Bambang Soetopo. "Pemodelan dan Estimasi Sumberdaya Uranium di Sektor Lembah Hitam, Kalan, Kalimantan Barat." EKSPLORIUM 37, no. 1 (May 31, 2016): 1. http://dx.doi.org/10.17146/eksplorium.2016.37.1.2668.
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Sektor Lembah Hitam merupakan bagian dari Pegunungan Schwaner dan stratigrafi bagian atas Cekungan Kalan. Lapisan pembawa uranium (U) berasosiasi dengan metabatulanau dan metapelit sekistosan berarah N 265° E/60° S. Pemboran evaluasi telah dilakukan dengan jarak 50 m dari titik yang sudah ada (FKL 14 dan FKL 13) untuk mengetahui model dan jumlah sumber daya U berkategori terukur. Untuk mencapai tujuan tersebut beberapa kegiatan perlu dilakukan, yaitu mengkaji hasil penelitian terdahulu, pendataan geologi dan pemineralan U, estimasi kadar secara kuantitatif menggunakan log gross-count gamma ray, pembuatan basis data, pemodelan dan estimasi sumber daya U. Berdasarkan pemodelan sepuluh titik pemboran dan didukung dengan data pengamatan inti pemboran, rata-rata kadar mineralisasi U di sektor Lembah Hitam dapat diketahui. Kadar rata-rata berkisar antara 0,0076 – 0,95 % eU3O8, dengan tebal mineralisasi berkisar antara 0,1 – 4,5 m. Mineralisasi U hadir sebagai isian fraktur (urat) atau kelompok urat dan sebagai isian matrik breksi tektonik, berasosiasi dengan mineral pirit, pirhotit, magnetit, molibdenit, turmalin, dan kuarsa dalam metabatulanau dan metapelit sekistosan. Penghitungan sumber daya U terhadap 26 tubuh bijih dengan radius pencarian 25 m didapatkan tonase bijih sebesar 655,65 ton. Menggunakan cut-off grade 0,01 % eU3O8 dihasilkan bijih sebanyak 546,72 ton dengan rata-rata kadar 0,101 % eU3O8. Sumber daya U dikategorikan sebagai sumber daya terukur berkadar rendah.Lembah Hitam Sector is part of Schwaner Mountains and Kalan Basin upper part stratigraphy. Uranium (U) mineralization layer is associated with metasiltstone and metapelites schistose heading to N 265° E/60° S. Evaluation drilling carried out with a distance of 50 m from an existing point (FKL 14 and FKL 13) to determine the model and the amount of U resources in measured category. To achieve these objectives some activities including reviewing the previous studies, geological and U mineralization data collecting, grades quantitative estimation using log gross-count gamma ray, database and modeling creation and resource estimation of U carried out. Based on modeling on ten drilling data and completed with drilled core observation, the average grade of U mineralization in Lembah Hitam Sector obtained. The average grade is ranging from 0.0076 - 0.95 % eU3O8, with a thickness of mineralization ranging from 0.1 - 4.5 m. Uranium mineralization present as fracture filling (veins) or groups of veins and as matrix filling in tectonic breccia, associated with pyrite, pyrrhotite, magnetite, molybdenite, tourmaline and quartz in metasiltstone and metapelites schistose. Calculation of U resources to 26 ores body using 25 m searching radius resulted in 655.65 tons ores. By using 0.01 % cut-off grade resulted in 546.72 tons ores with an average grade 0.101 % eU3O8. Uranium resource categorized as low-grade measured resources.
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Carasco, C., B. Perot, J. L. Ma, H. Toubon, and A. Dubille-Auchere. "Improving Gross Count Gamma-Ray Logging in Uranium Mining With the NGRS Probe." IEEE Transactions on Nuclear Science 65, no. 3 (March 2018): 919–23. http://dx.doi.org/10.1109/tns.2018.2800909.
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McAlister, John J., Grainne Cooney, and Michael J. Higgins. "Accumulation of Uranium in Granitic Soils Overlying the Mourne Mountains, County Down, Northern Ireland." Microchemical Journal 56, no. 3 (July 1997): 315–26. http://dx.doi.org/10.1006/mchj.1996.1399.
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Cruz, Nathan, Robert Buscaglia, Matthew Salanga, and Robert Kellar. "Environmentally Relevant Levels of Depleted Uranium Impacts Dermal Fibroblast Proliferation, Viability, Metabolic Activity, and Scratch Closure." Toxics 9, no. 9 (September 3, 2021): 211. http://dx.doi.org/10.3390/toxics9090211.
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Uranium (U) is a heavy metal used in military and industrial settings, with a large portion being mined from the Southwest region of the United States. Uranium has uses in energy and military weaponry, but the mining process has released U into soil and surface waters that may pose threats to human and environmental health. The majority of literature regarding U’s human health concern focuses on outcomes based on unintentional ingestion or inhalation, and limited data are available about its influence via cutaneous contact. Utilizing skin dermis cells, we evaluated U’s topical chemotoxicity. Employing soluble depleted uranium (DU) in the form of uranyl nitrate (UN), we hypothesized that in vitro exposure of UN will have cytotoxic effects on primary dermal fibroblasts by affecting cell viability and metabolic activity and, further, may delay wound healing aspects via altering cell proliferation and migration. Using environmentally relevant levels of U found in water (0.1 μM to 100 μM [UN]; 23.8–23,800 ppb [U]), we quantified cellular mitosis and migration through growth curves and in vitro scratch assays. Cells were exposed from 24 h to 144 h for a time-course evaluation of UN chemical toxicity. The effects of UN were observed at concentrations above and below the Environmental Protection Agency threshold for safe exposure limits. UN exposure resulted in a dose-dependent decrease in the viable cell count; however, it produced an increase in metabolism when corrected for the viable cells present. Furthermore, cellular proliferation, population doubling, and percent closure was hindered at levels ≥10 μM UN. Therefore, inadvertent exposure may exacerbate pre-existing skin diseases in at-risk demographics, and additionally, it may substantially interfere in cutaneous tissue repair processes.
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Hood, Madison M., Cortland F. Eble, James C. Hower, and Shifeng Dai. "Geochemistry, petrology, and palynology of the Princess No. 3 coal, Greenup County, Kentucky." International Journal of Coal Science & Technology 7, no. 4 (February 7, 2020): 633–51. http://dx.doi.org/10.1007/s40789-020-00298-0.
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AbstractThe high volatile C bituminous-rank, Bolsovian-age Princess No. 3 coal, a correlative of the heavily-mined Hazard No. 7 coal and the Peach Orchard and Coalburg Lower Split coals, was investigated three sites at a mine in Greenup County, Kentucky. The coal exhibits a “dulling upwards” trend, with decreasing vitrinite and a greater tendency towards dull clarain and bone lithotypes towards the top of the coal. The relatively vitrinite-rich basal lithotype is marked by a dominance of lycopod tree spores. The palynology transitions upwards to a middle parting co-dominated by tree fern and small lycopod spores and an upper bench dominated by tree ferns with contributions from small ferns, cordaites, and calamites. The lithotypes generally have a moderate- to high-S content with a variable ash yield. Sulfur, Fe2O3, and certain siderophile elements are highest near the top of the coal. As observed in other coals, uranium and Ge are enriched at the top and bottom margins of the coal. The rare earth chemistry at the top of the coal has a significantly lighter distribution (higher LREE/HREE) than at the base of the coal.
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Hinck, Jo E., Greg Linder, Abigail J. Darrah, Charles A. Drost, Michael C. Duniway, Matthew J. Johnson, Francisca M. Méndez-Harclerode, et al. "Exposure Pathways and Biological Receptors: Baseline Data for the Canyon Uranium Mine, Coconino County, Arizona." Journal of Fish and Wildlife Management 5, no. 2 (December 2014): 422–40. http://dx.doi.org/10.3996/052014-jfwm-039.
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肖, 旭华. "Metallogenic Geological Conditions and Prospecting Criteria of Dongcheng Uranium Deposit in Guiyang County, Hunan Province." Advances in Geosciences 12, no. 06 (2022): 925–32. http://dx.doi.org/10.12677/ag.2022.126088.
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Hand, Bryce M., and Jeffrey E. Banikowski. "Radon in Onondaga County, New York: Paleohydrogeology and redistribution of uranium in Paleozoic sedimentary rocks." Geology 16, no. 9 (1988): 775. http://dx.doi.org/10.1130/0091-7613(1988)016<0775:riocny>2.3.co;2.
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Boice, John D., Michael Mumma, Sarah Schweitzer, and William J. Blot. "Cancer mortality in a Texas county with prior uranium mining and milling activities, 1950–2001." Journal of Radiological Protection 23, no. 3 (September 1, 2003): 247–62. http://dx.doi.org/10.1088/0952-4746/23/3/302.
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Idiz, Erdem F., Donald Carlisle, and I. R. Kaplan. "Interaction between organic matter and trace metals in a uranium rich bog, Kern County, California, U.S.A." Applied Geochemistry 1, no. 5 (September 1986): 573–90. http://dx.doi.org/10.1016/0883-2927(86)90065-x.
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Minty, Brian R. S., Phil McFadden, and Brian L. N. Kennett. "Multichannel processing for airborne gamma‐ray spectrometry." GEOPHYSICS 63, no. 6 (November 1998): 1971–85. http://dx.doi.org/10.1190/1.1444491.
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The conventional approach to the processing of airborne gamma‐ray spectrometric data is to first sum the observed spectra over three relatively broad energy windows. These three window count rates are then processed to obtain estimates of the potassium (K), uranium (U), and thorium (Th) elemental abundances. However, multichannel spectra contain additional information on the concentrations of K, U, and Th in the source, on the distance between the source and the detector, and on the relative contribution of atmospheric radon to the observed spectrum. This information can be extracted using multichannel processing procedures. The observed spectrum is considered as the sum of three terrestrial and three background component spectra, which are determined through suitable airborne and ground calibrations. The background components can be calculated independently and removed from the observed spectra. A parametric model based on a principal component analysis of the terrestrial components as functions of simulated detector height is then used to find the effective heights at which the K, U, and Th terrestrial components best fit the background‐corrected airborne data. The component spectra for these heights are then fitted to the background‐corrected observed spectra to obtain elemental count rates. The multichannel processing results in significant reductions in the fractional errors associated with the estimated elemental count rates. For three surveys processed using the new methodology, the average deviations of the K, U, and Th elemental count rates from the estimated mean elemental count rates at each observation point are reduced by 12.4%, 26.5 %, and 20.3 %, respectively, when compared with the conventional three‐channel method. This results in a better structural resolution of small anomalies in enhanced images of the processed data.
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Hafeez, Tharwat H. Abdel, Mohamed A. S. Youssef, and Waheed H. Mohamed. "Utilization of airborne gamma ray spectrometric data for geological mapping and radioactive mineral exploration of Gabel Umm Tineidba area, south eastern desert, Egypt." World Journal of Engineering 12, no. 2 (April 1, 2015): 149–60. http://dx.doi.org/10.1260/1708-5284.12.2.149.
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The present work utilizes airborne gamma ray spectrometric data in a trial to refine surface geology of igneous, metamorphic and sedimentary rocks, detect any radioactive mineralization at Gabel Umm Tineidba area South Eastern Desert, Egypt. The study area is covered by rock exposures ranging in age from the Precambrian to Quaternary. Airborne gamma ray spectrometry can be very helpful in mapping surface geology. This provides estimates of the apparent surface concentrations of the most common naturally occurring radioactive elements, such as potassium (K), equivalent uranium (eU) and equivalent thorium (eTh). This is based on the assumption that, the absolute and relative concentrations of these radioelements vary measurably and significantly with lithology. The composite image technique is used to display simultaneously three parameters of the three radioelement concentrations and their three binary ratios on one image. The technique offers much in terms of lithological discrimination, based on color differences and showed efficiency in defining areas, where different lithofacies occur within areas mapped as one continuous lithology. The integration between surface geological information and geophysical data led to detailing the surface geology and the contacts between different rock units. Significant locations or favourable areas for uranium exploration are defined, where the measurements exceed (X+2S), taking X as the arithmetic mean of eU, eU/eTh and eU/K measurements and S as the standard deviation corresponding to each variables. The study area shows the presence of fifteen relatively high uraniferous zone. In addition, the trend analysis based on the total count map and the published geological map shows that, most of the well-developed structural lineaments have NS, ENE, NNE and NNW trends.
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Dicu, T., B. D. Burghele, A. Cucoș, R. Mishra, and B. K. Sapra. "ASSESSMENT OF ANNUAL EFFECTIVE DOSE FROM EXPOSURE TO NATURAL RADIOACTIVITY SOURCES IN A CASE–CONTROL STUDY IN BIHOR COUNTY, ROMANIA." Radiation Protection Dosimetry 185, no. 1 (December 1, 2018): 7–16. http://dx.doi.org/10.1093/rpd/ncy211.
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Abstract The purpose of the article is to evaluate the annual effective dose for 80 women divided into two samples; one sample located in the former uranium Băiţa-Ştei area, hereinafter referred to as case sample, respectively for a control sample, located in the same county, but exposed in most cases to indoor radon activity concentrations <300 Bq m−3. In this regard, the homemade ‘RaThoGamma’ kit was used, which contained two thermoluminescent dosimeters, a CR-39 track detector (RSKS) for indoor radon activity concentration, two CR-39 track detectors (Radtrak2®/ Radtrak2T®) for radon and thoron activity concentrations as well as Direct Radon Progeny Sensors/Direct Thoron Progeny Sensors for measuring time-averaged radon and thoron progenies concentrations. In addition, a total of 80 water samples were collected in order to evaluate the ingestion dose due to radon and radium activity concentrations in drinking water. The maximum total annual effective dose in the control sample was 14.1 mSv, while in the case sample the maximum annual effective dose was 60.5 mSv. This difference is mainly due to radon progenies inhalation. Other pathways did not show a statistically significant difference between the two samples, showing a minor contribution to the annual effective dose.
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Tigmeanu, Codruta Victoria, Ramona Amina Popovici, Anca Porumb, Angela Codruta Podariu, Lavinia Ardelean, Iustin Olariu, Ion Virgil Corlan, Mihaela Florica Adomnicai, and Alexandra Roi. "Radioactivity - Risk Factor in Oral Health and of Structural Dental Anomalies." Revista de Chimie 69, no. 7 (August 15, 2018): 1901–4. http://dx.doi.org/10.37358/rc.18.7.6441.
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The dentition goes through a complex process of development, a process that can be influenced by internal and external factors. Our study was perfomed on a group of 1673 children from different areas in Bihor county. The uranium mining exploitation in this specific area is very popular, but with an unfortunate consequence: pollution. This factor has had a great impact upon the workers, but also the surrounding areas. The aim of the present epidemiological study is to evaluate the incidence of dental anomalies upon the targeted group and to identify the correlation between the impact of the pollution upon the development of the dentition. All the data was obtained during a clinical examination, documented and afterwards statistically analyzed. Our study concluded that the examined subjects presented with a high percentage of structural dental anomalies, with an average incidence in the polluted areas that can be explained by the interactions that occur and the influence of the radioactive substances upon the development.
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Sass, Andrea M., Henrik Sass, Marco J. L. Coolen, Heribert Cypionka, and Jörg Overmann. "Microbial Communities in the Chemocline of a Hypersaline Deep-Sea Basin (Urania Basin, Mediterranean Sea)." Applied and Environmental Microbiology 67, no. 12 (December 1, 2001): 5392–402. http://dx.doi.org/10.1128/aem.67.12.5392-5402.2001.
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ABSTRACT The Urania basin is a hypersaline sulfidic brine lake at the bottom of the eastern Mediterranean Sea. Since this basin is located at a depth of ∼3,500 m below the sea surface, it receives only a small amount of phytoplankton organic carbon. In the present study, the bacterial assemblages at the interface between the hypersaline brine and the overlaying seawater were investigated. The sulfide concentration increased from 0 to 10 mM within a vertical interval of 5 m across the interface. Within this chemocline, the total bacterial cell counts and the exoenzyme activities were elevated. Employing 11 cultivation methods, we isolated a total of 70 bacterial strains. The 16S ribosomal DNA sequences of 32 of the strains were identical to environmental sequences detected in the chemocline by culture-independent molecular methods. These strains were identified as flavobacteria, Alteromonas macleodii, and Halomonas aquamarina. All 70 strains could grow chemoorganoheterotrophically under oxic conditions. Sixty-six strains grew on peptone, casein hydrolysate, and yeast extract, whereas only 15 strains did not utilize polymeric carbohydrates. Twenty-one of the isolates could grow both chemoorganotrophically and chemolithotrophically. While the most probable numbers in most cases ranged between 0.006 and 4.3% of the total cell counts, an unsually high value of 54% was determined above the chemocline with media containing amino acids as the carbon and energy source. Our results indicate that culturable bacteria thriving at the oxic-anoxic interface of the Urania basin differ considerably from the chemolithoautotrophic bacteria typical of other chemocline habitats.
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Dickson, Bruce, and Geoff Beckitt. "The application of Monte Carlo modelling to downhole total-count logging of uranium: part I – low grade mineralisation." Exploration Geophysics 44, no. 1 (March 2013): 56–62. http://dx.doi.org/10.1071/eg12018.
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