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Author Sahoo, S.K.; Jha, V.N.; Patra, A.C.; Jha, S.K.; Kulkarni, M.S. url  openurl
  Title (down) Scientific background and methodology adopted on derivation of regulatory limit for uranium in drinking water – A global perspective Type Journal Article
  Year 2020 Publication Environmental Advances Abbreviated Journal  
  Volume 2 Issue Pages 100020  
  Keywords Drinking water, Global policy, Regulatory limits, Toxicity, Uranium  
  Abstract Guideline values are prescribed for drinking water to ensure long term protection of the public against anticipated potential adverse effects. There is a great public and regulatory agencies interest in the guideline values of uranium due to its complex behavior in natural aquatic system and divergent guideline values across the countries. Wide variability in guideline values of uranium in drinking water may be attributed to toxicity reference point, variation in threshold values, uncertainty within intraspecies and interspecies, resource availability, socio-economic condition, variation in ingestion rate, etc. Although guideline values vary to a great extent, reasonable scientific basis and technical judgments are essential before it could be implemented. Globally guideline values are derived considering its radiological or chemical toxicity. Minimal or no adverse effect criterions are normally chosen as the basis for deriving the guideline values of uranium. In India, the drinking water limit of 60 µg/L has been estimated on the premise of its radiological concern. A guideline concentration of 2 µg/L is recommended in Japan while 1700 µg/L in Russia. The relative merit of different experimental assumption, scientific approach and its methodology adopted for derivation of guideline value of uranium in drinking water in India and other countries is discussed in the paper.  
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  ISSN 2666-7657 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ sahoo_scientific_2020 Serial 127  
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Author Pham, H.C.; Alila, Y. url  openurl
  Title (down) Science of forests and floods: The quantum leap forward needed, literally and metaphorically Type Journal Article
  Year 2024 Publication Science of The Total Environment Abbreviated Journal  
  Volume 912 Issue Pages 169646  
  Keywords Hydrological causality, Extreme value analyses, Land use impact, Peakflows, Extreme events epistemology, Experimental design  
  Abstract A century of research has generated considerable disagreement on the effect of forests on floods. Here we call for a causal inference framework to advance the science and management of the effect of any forest or its removal on flood severity and frequency. The causes of floods are multiple and chancy and, hence, can only be investigated via a probabilistic approach. We use the stochastic hydrology literature to infer a blueprint framework which could guide future research on the understanding and prediction of the effects of forests on floods in environments where rain is the dominant form of precipitation. Drawing parallels from other disciplines, we show that the introduction of probability in forest hydrology could stimulate a gestalt switch in the science of forests and floods. In light of increasing flood risk caused by climate change, this probabilistic framework can help policymakers develop robust forest and water management plans based on a defensible and clear understanding of floods.  
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  Series Volume Series Issue Edition  
  ISSN 0048-9697 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ Pham2024169646 Serial 244  
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Author Hall, S.M.; Gosen, B.S.V.; Zielinski, R.A. url  openurl
  Title (down) Sandstone-hosted uranium deposits of the Colorado Plateau, USA Type Journal Article
  Year 2023 Publication Ore Geology Reviews Abbreviated Journal  
  Volume 155 Issue Pages 105353  
  Keywords Colorado, Plateau, Uranium, Vanadium  
  Abstract More than 4,000 sandstone-hosted uranium occurrences host over 1.2 billion pounds of mined and in situ U3O8 throughout the Colorado Plateau. Most of the resources are in two distinct mineral systems with deposits hosted in the Triassic Chinle and Jurassic Morrison Formations. In the Chinle mineral system, base metal sulfides typically accompany mineralization. The Morrison mineral system is characterized by V/U ratios up to 20. The uranium source was likely volcanic ash preserved as bentonitic mudstones in the Brushy Basin Member of the Morrison Formation, and lithic volcanic clasts, ash shards, and bentonitic clay in the lower part of the Chinle Formation. Vanadium originated from two possible sources: iron–titanium oxides that are extensively altered in bleached rock near deposits or from similar minerals in variably bleached red beds interbedded with and beneath the Morrison. In Chinle-hosted deposits, in addition to volcanic ash, a contributing source of both vanadium and uranium is proposed here for the first time to be underlying red beds in the Moenkopi and Cutler Formations that have undergone a cycle of reddening-bleaching-reoxidation. Transport in both systems was likely in groundwater through the more permeable sandstones and conglomerate units. The association of uranium minerals with carbonate and more rarely apatite, suggests that transport of uranium was as a carbonate or phosphate complex. The first comprehensive examination of paleoclimate, paleotopography, and subsurface structure of aquifers coupled with analysis of the geochronology of deposits suggests that that there were distinct pulses of uranium mineralization/redistribution during the period from about 259 Ma to 12 Ma when oxidized mineralizing fluids were intermittently rejuvenated in the Plateau in response to changes in tectonic regime and climate. Multiple lines of evidence indicate that deposits formed at ambient temperatures of about 25 °C to no greater than about 140 °C. In both systems, deposits formed where groundwater flow slowed and was subject to evaporative concentration. Stagnant conditions allowed for prolonged interaction of U- and V-enriched groundwater with ferrous iron-bearing reductants, such as illite and iron–titanium oxides, and more rarely organic material such as plant debris. Paragenetically late in the sequence, reducing fluids introduced additional organic matter to some deposits. Reducing fluids and introduced organic matter (now amorphous and altered by radiolysis) may originate from regional petroleum systems where peak oil and gas generation was from ∼ 82 to ∼ 5 Ma. Our novel analysis indicates that these reducing fluids bleached rock and protected affected deposits from remobilization during exposure and weathering that followed uplift of the Plateau (∼80 to 40 Ma).  
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  ISSN 0169-1368 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ hall_sandstone-hosted_2023 Serial 111  
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Author Baptista, V.S.G.; Coelho, V.H.R.; Bertrand, G.F.; Silva, G.B.L. da; Caicedo, N.O.L.; Montenegro, S.M.G.L.; Stefan, C.; Glass, J.; Heim, R.; Conrad, A.; Almeida, C. das N. url  openurl
  Title (down) Rooftop water harvesting for managed aquifer recharge and flood mitigation in tropical cities: Towards a strategy of co-benefit evaluations in João Pessoa, northeast Brazil Type Journal Article
  Year 2023 Publication Journal of Environmental Management Abbreviated Journal  
  Volume 342 Issue Pages 118034  
  Keywords Flood control, Groundwater, Injection well, Stormwater management, Urban drainage, Aquifer storage and recovery  
  Abstract Intense urbanisation in many coastal areas has led to intensification of groundwater consumption, while reducing permeable areas and increasing the frequency and magnitude of flooding. Among the potential strategies to compensate for these adverse effects, which are expected to become worse as a result of climate change, rooftop rainwater harvesting (RWH) in combination with managed aquifer recharge (MAR), may be indicated. This work investigated the performance of different configurations of such a system, tested as a twofold sustainable stormwater and domestic water management tool in a tropical metropole (João Pessoa, Brazil). This area located over a sedimentary aquifer system illustrates the water security challenges of densely urbanised areas in southern cities. To that end, several configurations of rooftop catchments and storage volumes were evaluated, by simulating a MAR-RWH system connected to the regional unconfined aquifer (Barreiras Formation) through a 6″ diameter injection well. Rainfall-runoff-recharge processes and water balances were simulated using monitored high-temporal resolution rainfall data. The results showed that catchments ranging from 180 to 810 m2, connected to tanks from 0.5 to 30.0 m³, are the optimal solutions in terms of efficient rainwater retention and peak flow reduction. These solutions provided mean annual estimates of aquifer recharge between 57 and 255 m³/yr from 2004 to 2019. The results of this study highlight the opportunity for MAR schemes to reconcile stormwater management and water supply goals.  
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  ISSN 0301-4797 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ Baptista2023118034 Serial 237  
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Author Li, X.; Shen, K.; Li, Q.; Deng, Y.; Zhu, P.; Wang, D. url  openurl
  Title (down) Roll-over behavior in current-voltage curve introduced by an energy barrier at the front contact in thin film CdTe solar cell Type Journal Article
  Year 2018 Publication Solar Energy Abbreviated Journal  
  Volume 165 Issue Pages 27-34  
  Keywords AlO HRT layer, Band alignment, CdTe solar cell, Roll-over behavior  
  Abstract Roll-over phenomenon in the current–voltage (J–V) curve is often observed in a CdTe thin film solar cell. The roll-over phenomenon, which is occurred near the open-circuit voltage in a light J–V curve, is due to Schottky energy barrier formed at the CdTe/metal interface in a CdTe solar cell back contact. In this study we report a J–V roll-over phenomenon which is induced by an energy barrier at the front contact of a CdTe solar cell. Two kinds of oxides, namely, Al2O3 and SnO2, were deposited as high-resistance transparent (HRT) layer between the window layer CdS and the fluorine doped tin oxide (FTO) front electrode in CdTe solar cells. These two oxides present much different electronic band alignment with FTO and CdS. SnO2 formed almost no energy barrier with CdS, this allowed smooth transport for photo-generated electrons from CdTe to CdS and FTO. However, Al2O3 formed a high energy barrier with CdS. The rather high energy barrier with a value of 3.43 eV at the CdS/Al2O3 interface induced a J–V roll-over phenomenon in a CdTe thin film solar cell, which dramatically led to a quick decrease for the cell device efficiency. The electron transport at the FTO/Al2O3/CdS interface is governed by tunneling effect. The results presented in this study demonstrate that the band structure at the front electrode plays an important role for the performance of a CdTe thin film solar cell.  
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  ISSN 0038-092x ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ li_roll-over_2018 Serial 187  
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