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Author Vogel, J.C.; Talma, A.S.; Heaton, T.H.E.; Kronfeld, J.
Title (up) Evaluating the rate of migration of an uranium deposition front within the Uitenhage Aquifer Type Journal Article
Year 1999 Publication Journal of Geochemical Exploration Abbreviated Journal
Volume 66 Issue 1 Pages 269-276
Keywords redox changes in aquifer, sandstone-type uranium deposit, South Africa, uranium series
Abstract The solubility of uranium in groundwater is very sensitive to changes in redox conditions. Many secondary (sandstone-type) uranium deposits have been formed when soluble U has precipitated after encountering reducing conditions in the subsurface. In the groundwater of the Uitenhage Aquifer (Cape Province, South Africa), 238U-series isotopes were used to assist in studying the history of the reducing barrier. Uranium isotopes were used to determine the present position of the barrier. Radium and radon were used to evaluate the path of migration that the front of the oxygen depletion zone has taken over the past 105 years. During this time the reducing barrier has moved, leaving in its wake a trail of U in various stages of secular equilibrium with its daughter 230Th. The 226Ra daughter of 230Th is not very mobile. Its growth upon the aquifer wall is reflected in the Rn content of the water. This in turn, due to the relatively great age of the water, indicates the extent of the 230Th ingrowth (from precipitated U) that took place before the barrier migrated.
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0375-6742 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ vogel_evaluating_1999 Serial 126
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Author Klaus, J.; Külls, C.; Dahan, O.
Title (up) Evaluating the recharge mechanism of the Lower Kuiseb Dune area using mixing cell modeling and residence time data Type Journal Article
Year 2008 Publication Journal of Hydrology Abbreviated Journal
Volume 358 Issue 3-4 Pages 304-316
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Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
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Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ Klaus2008evaluating Serial 28
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Author Arya, S.; Kumar, A.
Title (up) Evaluation of stormwater management approaches and challenges in urban flood control Type Journal Article
Year 2023 Publication Urban Climate Abbreviated Journal
Volume 51 Issue Pages 101643
Keywords Flood risk, Green infrastructure (GI), Stormwater management, Stormwater modelling, Vulnerability assessment, Urban floods
Abstract Across the globe, the damage caused by urban floods has increased manifold. The unchecked development has encroached the natural drainage, and the conventional drainage systems are inadequate in handling the augmented hydrological response. To counter this, a variety of approaches with the ability to adjust within the constraints of complex environments by managing surface runoff are being widely investigated and applied worldwide. These can put the flood water to better use, and the ecological balance may get restored. This review discusses recent progress made in the area of Green Infrastructure (GI), modelling tools that help in stormwater management, vulnerability analysis and flood risk assessment. Different ways of handling the problem are summarized through an extensive literature survey. The gaps and barriers that impede the implementation of stormwater management solutions and strategies for further improvement have also been presented. A case study of Gurugram city, India depicting the challenges being faced by urban flooding and the possible solutions through an expert survey is also presented.
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ISSN 2212-0955 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ Arya2023101643 Serial 224
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Author Jroundi, F.; Povedano-Priego, C.; Pinel-Cabello, M.; Descostes, M.; Grizard, P.; Purevsan, B.; Merroun, M.L.
Title (up) Evidence of microbial activity in a uranium roll-front deposit: Unlocking their potential role as bioenhancers of the ore genesis Type Journal Article
Year 2023 Publication Science of The Total Environment Abbreviated Journal
Volume 861 Issue Pages 160636
Keywords ISR, Metatranscriptomes, Microbial metabolisms, Ore genesis, Roll-front deposit, Uranium
Abstract Uranium (U) roll-front deposits constitute a valuable source for an economical extraction by in situ recovery (ISR) mining. Such technology may induce changes in the subsurface microbiota, raising questions about the way their activities could build a functional ecosystem in such extreme environments (i.e.: oligotrophy and high SO4 concentration and salinity). Additionally, more information is needed to dissipate the doubts about the microbial role in the genesis of such U orebodies. A U roll-front deposit hosted in an aquifer driven system (in Zoovch Ovoo, Mongolia), intended for mining by acid ISR, was previously explored and showed to be governed by a complex bacterial diversity, linked to the redox zonation and the geochemical conditions. Here for the first time, transcriptional activities of microorganisms living in such U ore deposits are determined and their metabolic capabilities allocated in the three redox-inherited compartments, naturally defined by the roll-front system. Several genes encoding for crucial metabolic pathways demonstrated a strong biological role controlling the subsurface cycling of many elements including nitrate, sulfate, metals and radionuclides (e.g.: uranium), through oxidation-reduction reactions. Interestingly, the discovered transcriptional behaviour gives important insights into the good microbial adaptation to the geochemical conditions and their active contribution to the stabilization of the U ore deposits. Overall, evidences on the importance of these microbial metabolic activities in the aquifer system are discussed that may clarify the doubts on the microbial role in the genesis of low-temperature U roll-front deposits, along the Zoovch Ovoo mine.
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Series Editor Series Title Abbreviated Series Title
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ISSN 0048-9697 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ jroundi_evidence_2023 Serial 138
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Author Min, M.; Xu, H.; Chen, J.; Fayek, M.
Title (up) Evidence of uranium biomineralization in sandstone-hosted roll-front uranium deposits, northwestern China Type Journal Article
Year 2005 Publication Ore Geology Reviews Abbreviated Journal
Volume 26 Issue 3 Pages 198-206
Keywords Biomineralization, China, Roll-front uranium deposit, Sandstone
Abstract We show evidence that the primary uranium minerals, uraninite and coffinite, from high-grade ore samples (U3O8\textgreater0.3%) in the Wuyiyi, Wuyier, and Wuyisan sandstone-hosted roll-front uranium deposits, Xinjiang, northwestern China were biogenically precipitated and psuedomorphically replace fungi and bacteria. Uranium (VI), which was the sole electron acceptor, was likely to have been enzymically reduced. Post-mortem accumulation of uranium may have also occurred through physio-chemical interaction between uranium and negatively-charged cellular sites, and inorganic adsorption or precipitation reactions. These results suggest that microorganisms may have played a key role in formation of the sandstone- or roll-type uranium deposits, which are among the most economically significant uranium deposits in the world.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-1368 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ min_evidence_2005 Serial 186
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