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Physical Processes Relevant to Deep Soil-Water Movement
Published in Daniel B. Stephens, Andrea J. Kron, Andrea Kron, Vadose Zone Hydrology, 2018
Daniel B. Stephens, Andrea J. Kron, Andrea Kron
Drainage in the soil profile occurs where the soil water content is decreasing over time (Figure 21A). Where the profile was initially completely satiated throughout, the drainage process is referred to as internal drainage, as illustrated in this figure. Most frequently, infiltration from precipitation only partially wets the vadose zone, as shown in Figure 21B at time t1. In this case, after infiltration ceases, the water behind the wetting front can move upward in response to evaporation or it can move downward due to gravity and matric potential gradients. Note in Figure 21B that at some time, t2, after infiltration stopped, the upper part of the profile has drained while the lower part of the profile has wetted. This process is called redistribution. It is highly probable that most groundwater recharge occurs during redistribution, especially where the water table is deep and precipitation events are brief.
Synthesis, characterizations, crystal structures, and theoretical studies of copper(II) and nickel(II) coordination complexes
Published in Journal of Coordination Chemistry, 2020
Bharti Mohan, Mukesh Choudhary, Shabbir Muhammad, Neeladri Das, Khushwant Singh, Achintya Jana, Sulakshna Bharti, H. Algarni, Abdullah G. Al-Sehemi, Santosh Kumar
The FMOs play a crucial role in understanding the nature of intramolecular charge transfer processes in chemical compounds. The FMOs are also crucial for predicting the reactivity of chemical compounds. The FMOs including HOMO, HOMO-1, LUMO and LUMO + 1 for 1, 2 and 3 are drawn in Figure 6. An overview of Figure 6 shows that in 1, its HOMO and HOMO-1 are made up entirely from the 2,4-dichloro-6-formylphenoxy moieties and charge redistribution is seen over the same ligand. For 2, its HOMO and LUMO orbitals are nearly degenerate as shown by a small energy gap and a similar distribution pattern between these two orbitals. Its intramolecular charge redistribution mainly occurs from HOMO-1 to LUMO. Similarly, the HOMO of 3 is mainly composed of (E)-4-bromo-2-(((2, 3-dihydro-[1,1′-biphenyl]-3-yl) imino) methyl) phenolate where lone pairs of electron of the bromine atoms play an important role. On the other hand, the LUMO and LUMO + 1 consist of the Ni(II) ion and 2,2′-bipyridine ligands in 3. The intramolecular charge transfer (ICT) transition shows significant redistribution of electron density from HOMO to LUMO + 1 orbital in 3. The transition nature might be described as ligand to metal Ni(II) and ligand to ligand charge transfer character for 3.
Sediment aluminum:phosphorus binding ratios and internal phosphorus loading characteristics 12 years after aluminum sulfate application to Lake McCarrons, Minnesota
Published in Lake and Reservoir Management, 2020
William F. James, Joseph M. Bischoff
At low added Al concentrations to sediments of Lake McCarrons (<27 g/m2, Table 2), the Al:P molar ratio approached 10:1 to 15:1 (P:Al molar ratio ∼0.1), similar to findings of de Vicente et al. (2008a) and Jensen et al. (2015). They suggested that this stoichiometric relationship represented a final P binding saturation ratio and that Al dosage should follow a 10:1 molar ratio. Based on sediment redox-P, the Al dosage of 77 g/m2 for Lake McCarrons should have represented a much higher treatment ratio of ∼100:1 molar if the Al floc had settled evenly over the application area. Thus, uneven Al floc redistribution resulted in areas where the Al dosage was optimal for apparent P binding saturation and other areas that were overdosed at least with respect to sediment redox-P concentrations.
Anisotropic derivatives of (-)-L-lactic acid and their nanocomposites
Published in Liquid Crystals, 2018
V. S. Bezborodov, S. G. Mikhalyonok, N. M. Kuz’menok, A. S. Arol, G. A. Shandryuk, A. S. Merekalov, O. A. Otmakhova, G. N. Bondarenko, R. V. Talroze
The comparison of spectra of surface-modified NPs with the spectra of corresponding acids (Figure 2(а2 и б2)) proves the fact that the ligands of polycyclic acids substitute the oleic acid ligands. At the same time the substitution of ligands does not lead to any essential changes in the absorption (Figure 3) and PL spectra (Figure 4). As it is seen from the excitonic band of absorption and luminescence of NPs modified by (R)-2-[4ʹ’-(trans-4-butylcyclohexyl)-2ʹ-chloroterphenyloxy-4-]propanoic acid (10c) there is a slight blue shift. The possible explanation for that shift may be the redistribution of energy between the polyaromatic ligand NP’s surface.