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Author Emparanza, A.R.; Kampmann, R.; Caso, F.D.; Morales, C.; Nanni, A. url  openurl
  Title Durability assessment of GFRP rebars in marine environments Type Journal Article
  Year 2022 Publication Construction and Building Materials Abbreviated Journal  
  Volume 329 Issue Pages 127028  
  Keywords Composite FRP rebar, Durability, Service life, Marine structures, Reinforced concrete  
  Abstract Technologies developed over the last two decades have facilitated the use of glass fiber reinforced polymer (GFRP) bars as internal reinforcement for concrete structures, specially in coastal environments, mainly due to their corrosion resistance. To-date, most durability studies have focused on a single mechanical parameter (tensile strength) and a single aging environment (exposure to high alkalinity). However, knowledge gaps exists in understanding how other mechanical parameters and relevant conditioning environments may affect the durability of GFRP bars. To this end, this study assesses the durability for different physio-mechanical properties of GFRP rebars, post exposure to accelerated conditioning in seawater. Six different GFRP rebar types were submerged in seawater tanks, at various temperatures (23°C, 40°C and 60°C) for different time periods (60, 120, 210 and 365 days). In total six different physio-mechanical properties were assessed, including: tensile strength, E-modulus, transverse and horizontal shear strength, micro-structural composition and lastly, bond strength. It was inferred that rebars with high moisture absorption resulted in poor durability, in that it affected mainly the tensile strength. Based on the Arrhenius model, at 23°C all the rebars that met the acceptance criteria by ASTM D7957 are expected to retain 85% of the tensile strength capacity.  
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  Series Volume Series Issue Edition  
  ISSN 0950-0618 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (down) THL @ christoph.kuells @ Ruizemparanza2022127028 Serial 83  
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Author Rooyen, J.D. van; Watson, A.W.; Miller, J.A. url  openurl
  Title Using tritium and radiocarbon activities to constrain regional modern and fossil groundwater mixing in Southern Africa Type Journal Article
  Year 2022 Publication Journal of Hydrology Abbreviated Journal  
  Volume 614 Issue Pages 128570  
  Keywords Radiocarbon, Residence time, SADC, Tritium  
  Abstract This study combines historical records of 14C and 3H in the atmosphere and soil with renewal rate and groundwater lumped parameter models to predict the abundance of 14C and 3H in groundwater over time. 624 groundwater samples from numerous studies, over four decades (1978–2019), in South Africa, Namibia, Botswana and Mozambique were collated to compare with predicted groundwater activities of 14C and 3H within the South African Development Community (SADC) region. Spatial datasets of carbonate bearing lithology, C3/C4 vegetation, summer/winter rainfall and coastal proximity were used to apply corrections to 14C and 3H data. Corrected values of 14C and 3H were compared with the theoretical abundance of these tracers, derived from the lumped parameter models, to estimate the general mean residence times and presence of groundwater mixing between modern recharge and older groundwaters. This study found that corrected values produced varying mean residence times derived from 14C ages (∼500–28500 years) and a wide range of potentially mixed waters within each aquifer system (0–100 % of tested wells) across the study area. The largest proportions of mixed groundwater, as well as the youngest mean residence times, were found in alluvial and primary fractured rock aquifers (e.g., western coast of South Africa and southern Mozambique). The smallest proportions of mixed groundwater were predicted in deep confined clay-rich aquifers as well as layered coal bearing carbonate sequences (e.g., Orapa, Malwewe and Serowe, Botswana). Insights into the proportions of mixed groundwater and mean residence times can help assess hydrological resilience on a regional scale. Such information is pertinent in promoting socio-economic development and increased water/food security in the SADC region. By understanding the resilience of groundwater resources, robust and informed strategies for water equality and GDP growth in the SADC region can be envisioned and implemented.  
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  ISSN 0022-1694 ISBN Medium  
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  Notes Approved no  
  Call Number (down) THL @ christoph.kuells @ rooyen_using_2022 Serial 94  
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Author Romeo, N.; Mabry, J.; Hillegonds, D.; Kainz, G.; Jaklitsch, M.; Matsumoto, T. url  openurl
  Title Developments of a field gas extraction device and krypton purification system for groundwater radio-krypton dating at the IAEA Type Journal Article
  Year 2022 Publication Applied Radiation and Isotopes Abbreviated Journal  
  Volume 189 Issue Pages 110450  
  Keywords  
  Abstract The long-lived radio-krypton isotope 81Kr (t1/2 = 2.29 × 105 yr) is an ideal tracer for old groundwater age dating in the range of 105–106 years which goes beyond the reach of radio-carbon (14C) age dating. Analytical breakthrough made over the last two decades in Atom Trap Trace Analysis (ATTA) has enabled the use of this isotope with extremely low abundance (81Kr/Kr = 6 × 10−13) to be used as a practical dating tool for very old groundwater. The International Atomic Energy Agency aims to provide this new isotope tool for better groundwater resource management of Member States and developed a field sampling device to collect dissolved gas samples from groundwater and a system to separate and purify trace amounts of krypton from the gas samples for the ATTA analysis. The design, setup and performances of our sampling and purification systems are described here. Our system can produce a high purity aliquot of about 5 μL of krypton from 5 L of air sample (recovery yield of >90%). The samples made by our system were confirmed to be acceptable for the ATTA analysis.  
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  ISSN 0969-8043 ISBN Medium  
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  Notes Approved no  
  Call Number (down) THL @ christoph.kuells @ Romeo2022110450 Serial 214  
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Author Ren, Y.; Yang, X.; Hu, X.; Wei, J.; Tang, C. url  openurl
  Title Mineralogical and geochemical evidence for biogenic uranium mineralization in northern Songliao Basin, NE China Type Journal Article
  Year 2022 Publication Ore Geology Reviews Abbreviated Journal  
  Volume 141 Issue Pages 104556  
  Keywords Bacterial sulfate reduction, In-situ S isotope of pyrite, Northern Songliao basin, Sandstone-type uranium deposit, Sifangtai Formation  
  Abstract The sandstone-hosted uranium mineralization areas in the Sanzhao Sag of the northern Songliao Basin have been newly identified. The target stratum is the Upper Cretaceous Sifangtai Formation and the uranium mineralization mainly occurs in the bottom of Sifangtai Formation, corresponding to channel sand bodies in meandering river system, characterized by medium to fine-grained sandstone. This study proposes the uranium metallogenic model through petrographic observation, whole rock geochemistry, mineralogical study of uranium occurrence form (SEM), organic matter rock–eval pyrolysis analysis (REP) and in-situ sulfur isotope determination of different generations of pyrite by LA-MC-ICP-MS. Compared with the sandstones collected in barren reduction and oxidization zones, the mineralized sandstones show obvious increase in the contents of TOC, total sulfur, Y and U. Petrographic observations indicate that organic matters are mainly inherited from land plants. REP data display that the organic matter (OM) disseminated in the sandstone has very low hydrogen index (HI) from around 0 to 21 mg HC/g TOC and varied oxygen index (OI) from 44 to 115 mg CO2/g TOC, corresponding to Type Ⅳ kerogen (degraded kerogen). There are two types of coffinite with different grain size, micro-particles (μm-sized) and large aggregates (generally up to 100 μm) respectively. The coffinite micro spherules exhibit short rod-like or worm-like morphology occurring in clay matrix and cell cavities in degradofusinite or around subidiomorphic-idiomorphic pyrite. The coarse-grained coffinite contains other mineral facies (e.g. pyrite, quartz) and some of large coffinite aggregates display thrombolite-type microbial structures. The irregular pyrite relict particles in coarse-grained colloidal coffinite have light sulfur isotope compositions characterized by δ34S values from –39.96‰ to –49.89‰. The δ34S values of colloidal pyrite in replacement of OM or of the sub-idiomorphic FeS2 cement filling in the cavities of OM range from –52.77‰ to –13.88‰. Some of sub-idiomorphic pyrite cement and idiomorphic crystal have the heavier signature from – 27.06‰ to + 14.23‰. The light sulfur isotope signature suggests that the sulfur originates from bacterial sulfate reduction (BSR). The OM replacement by pyrite and the highest OI values recorded by REP in uranium mineralized samples are lines of evidence of biodegradation. Bacteria use the organic matter as food source and produce isotopically light reduced sulfur species. Oxygenated uranium-bearing waters infiltrated through the denudated windows at Daqing placanticline into the porous reduced sandstones deposited in the Sanzhao Sag. Uranium was indirectly reduced by BSR-derived iron disulfides or directly reduced by sulfate-reducing bacteria.  
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  ISSN 0169-1368 ISBN Medium  
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  Notes Approved no  
  Call Number (down) THL @ christoph.kuells @ ren_mineralogical_2022 Serial 144  
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Author Prusty, S.; Somu, P.; Sahoo, J.K.; Panda, D.; Sahoo, S.K.; Sahoo, S.K.; Lee, Y.R.; Jarin, T.; Sundar, L.S.; Rao, K.S. url  openurl
  Title Adsorptive sequestration of noxious uranium (VI) from water resources: A comprehensive review Type Journal Article
  Year 2022 Publication Chemosphere Abbreviated Journal  
  Volume 308 Issue Pages 136278  
  Keywords Adsorbents, Adsorption, Techniques, Uranium, Wastewater  
  Abstract Groundwater is usually utilized as a drinking water asset everywhere. Therefore, groundwater defilement by poisonous radioactive metals such as uranium (VI) is a major concern due to the increase in nuclear power plants as well as their by-products which are released into the watercourses. Waste Uranium (VI) can be regarded as a by-product of the enrichment method used to produce atomic energy, and the hazard associated with this is due to the uranium radioactivity causing toxicity. To manage these confronts, there are so many techniques that have been introduced but among those adsorptions is recognized as a straightforward, successful, and monetary innovation, which has gotten major interest nowadays, despite specific drawbacks regarding operational as well as functional applications. This review summarizes the various adsorbents such as Bio-adsorbent/green materials, metal oxide-based adsorbent, polymer based adsorbent, graphene oxide based adsorbent, and magnetic nanomaterials and discuss their synthesis methods. Furthermore, this paper emphasis on adsorption process by various adsorbents or modified forms under different physicochemical conditions. In addition to this adsorption mechanism of uranium (VI) onto different adsorbent is studied in this article. Finally, from the literature reviewed conclusion have been drawn and also proposed few future research suggestions.  
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  ISSN 0045-6535 ISBN Medium  
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  Notes Approved no  
  Call Number (down) THL @ christoph.kuells @ prusty_adsorptive_2022 Serial 131  
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Author Paradis, C.J.; Hoss, K.N.; Meurer, C.E.; Hatami, J.L.; Dangelmayr, M.A.; Tigar, A.D.; Johnson, R.H. url  openurl
  Title Elucidating mobilization mechanisms of uranium during recharge of river water to contaminated groundwater Type Journal Article
  Year 2022 Publication Journal of Contaminant Hydrology Abbreviated Journal  
  Volume 251 Issue Pages 104076  
  Keywords Desorption, Dissolution, Groundwater, Surface water, Tracer, Uranium  
  Abstract The recharge of stream water below the baseflow water table can mobilize groundwater contaminants, particularly redox-sensitive and sorptive metals such as uranium. However, in-situ tracer experiments that simulate the recharge of stream water to uranium-contaminated groundwater are lacking, thus limiting the understanding of the potential mechanisms that control the mobility of uranium at the field scale. In this study, a field tracer test was conducted by injecting 100 gal (379 l) of oxic river water into a nearby suboxic and uranium-contaminated aquifer. The traced river water was monitored for 18 days in the single injection well and in the twelve surrounding observation wells. Mobilization of uranium from the solid to the aqueous phase was not observed during the tracer test despite its pre-test presence being confirmed on the aquifer sediments from lab-based acid leaching. However, strong evidence of oxidative immobilization of iron and manganese was observed during the tracer test and suggested that immobile uranium was likely in its oxidized state as U(VI) on the aquifer sediments; these observations ruled out oxidation of U(IV) to U(VI) as a potential mobilization mechanism. Therefore, desorption of U(VI) appeared to be the predominant potential mobilization mechanism, yet it was clearly not solely dependent on concentration as evident when considering that uranium-poor river water (\textless0.015 mg/L) was recharged to uranium-rich groundwater (≈1 mg/L). It was possible that uranium desorption was limited by the relatively higher pH and lower alkalinity of the river water as compared to the groundwater; both factors favor immobilization. However, it was likely that the immobile uranium was associated with a mineral phase, as opposed to a sorbed phase, thus desorption may not have been possible. The results of this field tracer study successfully ruled out two common mobilization mechanisms of uranium: (1) oxidative dissolution and (2) concentration-dependent desorption and ruled in the importance of advection, dispersion, and the mineral phase of uranium.  
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  ISSN 0169-7722 ISBN Medium  
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  Notes Approved no  
  Call Number (down) THL @ christoph.kuells @ paradis_elucidating_2022 Serial 135  
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Author Eliades, M.; Bruggeman, A.; Djuma, H.; Christofi, C.; Kuells, C. url  doi
openurl 
  Title Quantifying Evapotranspiration and Drainage Losses in a Semi-Arid Nectarine (Prunus persica var. nucipersica) Field with a Dynamic Crop Coefficient (Kc) Derived from Leaf Area Index Measurements Type Journal Article
  Year 2022 Publication Water Abbreviated Journal  
  Volume 14 Issue 5 Pages  
  Keywords  
  Abstract Quantifying evapotranspiration and drainage losses is essential for improving irrigation efficiency. The FAO-56 is the most popular method for computing crop evapotranspiration. There is, however, a need for locally derived crop coefficients (Kc) with a high temporal resolution to reduce errors in the water balance. The aim of this paper is to introduce a dynamic Kc approach, based on Leaf Area Index (LAI) observations, for improving water balance computations. Soil moisture and meteorological data were collected in a terraced nectarine (Prunus persica var. nucipersica) orchard in Cyprus, from 22 March 2019 to 18 November 2021. The Kc was derived as a function of the canopy cover fraction (c), from biweekly in situ LAI measurements. The use of a dynamic Kc resulted in Kc estimates with a bias of 17 mm and a mean absolute error of 0.8 mm. Evapotranspiration (ET) ranged from 41% of the rainfall (P) and irrigation (I) in the wet year (2019) to 57% of P + I in the dry year (2021). Drainage losses from irrigation (DR_I) were 44% of the total irrigation. The irrigation efficiency in the nectarine field could be improved by reducing irrigation amounts and increasing the irrigation frequency. Future studies should focus on improving the dynamic Kc approach by linking LAI field observations with remote sensing observations and by adding ground cover observations.  
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  ISSN 2073-4441 ISBN Medium  
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  Notes Approved no  
  Call Number (down) THL @ christoph.kuells @ Marinos2022 Serial 82  
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Author Aldawsari, S.; Kampmann, R.; Harnisch, J.; Rohde, C. url  doi
openurl 
  Title Setting Time, Microstructure, and Durability Properties of Low Calcium Fly Ash/Slag Geopolymer: A Review Type Journal Article
  Year 2022 Publication Materials Abbreviated Journal  
  Volume 15 Issue 3 Pages  
  Keywords  
  Abstract Ordinary Portland cement (OPC) is known for its significant contribution to carbon dioxide emissions. Geopolymer has a lower footprint in terms of CO2 emissions and has been considered as an alternative for OPC. A well-developed understanding of the use of fly-ash-based and slag-based geopolymers as separate systems has been reached in the literature, specifically regarding their mechanical properties. However, the microstructural and durability of the combined system after slag addition introduces more interactive gels and complex microstructural formations. The microstructural changes of complex blended systems contribute to significant advances in the durability of fly ash/slag geopolymers. In the present review, the setting time, microstructural properties (gel phase development, permeability properties, shrinkage behavior), and durability (chloride resistance, sulfate attack, and carbonatation), as discussed literature, are studied and summarized to simplify and draw conclusions.  
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  ISSN 1996-1944 ISBN Medium  
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  Notes Approved no  
  Call Number (down) THL @ christoph.kuells @ ma15030876 Serial 84  
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Author Kumar, V.; Setia, R.; Pandita, S.; Singh, S.; Mitran, T. url  openurl
  Title Assessment of U and As in groundwater of India: A meta-analysis Type Journal Article
  Year 2022 Publication Chemosphere Abbreviated Journal  
  Volume 303 Issue Pages 135199  
  Keywords Arsenic, Geology, Groundwater, Health risk, Soil texture, Uranium  
  Abstract More than 2.5 billion people depend upon groundwater worldwide for drinking, and giving quality water has become one of the great apprehensions of human culture. The contamination of Uranium (U) and Arsenic (As) in the groundwater of India is gaining global attention. The current review provides state-of-the-art groundwater contamination with U and As in different zones of India based on geology and soil texture. The average concentration of U in different zones of India was in the order: West Zone (41.07 μg/L) \textgreater North Zone (37.7 μg/L) \textgreater South Zone (13.5 μg/L)\textgreater Central Zone (7.4 μg/L) \textgreater East Zone (5.7 μg/L) \textgreaterSoutheast Zone (2.4 μg/L). The average concentration of As in groundwater of India is in the order: South Zone (369.7 μg/L)\textgreaterCentral Zone (260.4 μg/L)\textgreaterNorth Zone (67.7 μg/L)\textgreaterEast Zone (60.3 μg/L)\textgreaterNorth-east zone (9.78 μg/L)\textgreaterWest zone (4.14 μg/L). The highest concentration of U and As were found in quaternary sediments, but U in clay skeletal and As in loamy skeletal. Results of health risk assessment showed that the average health quotient of U in groundwater for children and adults was less than unity. In contrast, it was greater than unity for As posing a harmful impact on human health. This review provides the baseline data regarding the U and As contamination status in groundwater of India, and appropriate, effective control measures need to be taken to control this problem.  
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  ISSN 0045-6535 ISBN Medium  
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  Call Number (down) THL @ christoph.kuells @ kumar_assessment_2022 Serial 161  
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Author Khaneiki, M.L.; Al-Ghafri, A.S.; Klöve, B.; Haghighi, A.T. url  openurl
  Title Sustainability and virtual water: The lessons of history Type Journal Article
  Year 2022 Publication Geography and Sustainability Abbreviated Journal  
  Volume 3 Issue 4 Pages 358-365  
  Keywords Proto-industrialization, Water scarcity, Non-hydraulic polity, Virtual water, Political economy  
  Abstract This article aims to show that virtual water has historically been an adaptation strategy that enabled some arid regions to develop a prosperous economy without putting pressure on their scarce water resources. Virtual water is referred to as the total amount of water that is consumed to produce goods and services. As an example, in arid central Iran, the deficiency in agricultural revenues was offset by more investment in local industries that enjoyed a perennial capacity to employ more workers. The revenues of local industries weaned the population from irrigated agriculture, since most of their raw materials and also food stuff were imported from other regions, bringing a remarkable amount of virtual water. This virtual water not only sustained the region’s inhabitants, but also set the stage for a powerful polity in the face of a rapid population growth between the 13th and 15th centuries AD. The resultant surplus products entailed a vast and safe network of roads, provided by both entrepreneurs and government. Therefore, it became possible to import more feedstock such as cocoons from water-abundant regions and then export silk textiles with considerable value-added. This article concludes that a similar model of virtual water can remedy the ongoing water crisis in central Iran, where groundwater reserves are overexploited, and many rural and urban centers are teetering on the edge of socio-ecological collapse. History holds an urgent lesson on sustainability for our today’s policy that stubbornly peruses agriculture and other high-water-demand sectors in an arid region whose development has always been dependent on virtual water.  
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  ISSN 2666-6839 ISBN Medium  
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  Notes Approved no  
  Call Number (down) THL @ christoph.kuells @ Khaneiki2022358 Serial 272  
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