A systematic study of neutral mixed clusters, Li6-x Nax, Li6-x Kx and K6-x Nax (x=0-6), was performed within the framework of density functional theory. The aim of this work is to explore the geometry variation and the energy change of homonuclear hexamers (Li6 and K6) induced by impurities. It is found that the geometry of bimetallic hexamers varies with their compositions. The geometries of resulting clusters show evolution from D4h symmetry for Li6 to D3h symmetry for Na6 and K6. The stability of bimetallic hexamers has been also explained in terms of binding energy, excess energy, the second difference in energy, and the highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO-LUMO) gaps. It is found that replacing each Li–Li bond with Li–Na or Li–K bonds decreases the cluster stability, while replacing each K–K bond by K–Na leads to stability enhancement. Examining the cluster stability, excess energy and second difference in energy reveal that among studied bimetallic hexamers, Li2Na4 is the most stable mixed hexamer.

The geometries and binding energies of the Na+.(CO)1-3 and Na+.(N2)1-3 have been determined at the level of the CCSD/6-311++G(d, p) method. Our results show that the mono- and di-ligated complexes have linear configurations with the sodium ion carbonyl complexes exhibit larger binding energies due to possess an ion-dipole interaction. A trigonal planar geometry was obtained for the Na+.(N2)3 and Na+.(CO)3 complexes, with the latter having the greatest binding energy of ~ 4 kcal mol-1. The variation in the binding energy between these two types of complexes is due to the fact that the Na+.(CO)1-3 complexes have extra energy that comes from ion...dipole interaction energy. The sequential bond dissociation energies have been determined, and both types of complexes show a similar trend. The observed trend was found to follow the same variation in the ion...quadrupole interaction energies. The contribution of ion-dipole interaction to electrostatic interaction energy is negligible for Na+.(CO)1-3 complexes, accounting for less than 6.5% of the total electrostatic energy. Bond analysis of these complexes shows that sigma-donation of electrons, Clp⟶Na+3s, occurs in the sodium carbonyl ion complexes.

Salinity of soil and water is a serious problem affecting the growth and performance of plants in Iran. A pot experiment was conducted to asses the physiological effects of NaCl salinity on the olive trees growth. Four rates of NaCl concentrations (0, 50, 100, 150 mM) factorially combined with three olive trees cultivars. The experiment was based on completely randomized design with four replications. The plants were cut and vegetative characteristics such as leaf area, fresh and dry weight of leaves and the concentration of Na and K were measured at the end of the experiment. The rates of both photosynthesis (Pn) and transpiration were recorded during the growth of the plants using a photosynthesis meter (IRGA). The results showed that the growth of the plants in terms of leaf area, height and leaf fresh weight reduced as the salinity increased. However, the growth reduction of Manzanilla and Zard cultivars was more pronounced as the salinity increased. The rate of Pn tended to be lower in the high salinity treatments in all cultivars. The highest (1.8 mmol.m-2s-1) and lowest (1.0 mmol.m-2s-1) photosynthesis rate at high salinity were observed in Mission and Zard, respectively. Symptoms of toxicity as marginal necrosis on the leaves caused by salinity were initiated two months after applying salinity in Manzanilla and Zard cultivars. The concentration of Na in the leaves at high salinity (150mM) was 78% (Mission) and 83% (Zard and Manzanilla) compared with their controls. A positive relationship was found between K/Na and Pn rate, suggesting that the reduction in K concentration either by low uptake or the reduction of K/Na ratiohas a remarkable effect on Pn rate. Reduction in growth of olive trees in saline conditions was a result of the reduction in leaf area, K/Na and Pn rate. It can be concluded that Mission can tolerate up to EC value of 15 dS.m-1 and 150mM NaCl in seedling stage.

The effects of synthesis time and the number of synthesis layers were investigated on the synthesis of Na-X zeolite sublayer for fabricating a PEBA/Na-X hybrid membrane. The CO2/N2 separation was considered as the objective function to obtain an effective Na-X sublayer. SEM and AFM studies of the synthesized sublayers reveal that 6 hour synthesis time and one synthesis layer give an Na-X sublayer (ZSL6-1) with sub-micron thickness (< 1µm), and roughness of 13 nm. The N2 permeation (11900 GPU) shows the low mass transfer resistance through the ZSL6-1 sublayer. The ZSL6-1 sublayer in the hybrid structure of the membrane leads to the high stability of the multilayer structure via the anchoring effect of the polymer. Hydroxyl groups, along with positive and negative charges on the surface of the Na-X sublayer, cause to strong bonding of the polymer layer and prevent its delamination. The surface coverage of the sublayer by polymer has increased the mass transfer resistance just for N2 and increase the perm-selectivity. These properties, along with the high affinity of the Na-X to the adsorption of CO2, results in a 56% increase in the perm-selectivity of CO2/N2 (~70) compared to net PEBA (~40-50) and the recently reported hybrid membranes.

Kidneys play an important role in regulating the balance of water and ions in freshwater and seawater fish. However, complex kidney structures impair a comprehensive understanding of kidney function. In this study, in addition to the investigation of renal histology, Na+-K+-ATPase, Na+-K+-2Cl-cotransporter (NKCC), and Na+-H+ exchanger (NHE) were localized in the renal system of Walton's mudskipper (Priophthalmus waltoni). The kidney samples were fixed and they passed the preparing section and staining stages. The renal tubules were composed of proximal tubules and distal tubules, followed by collecting tubes and finally collecting ducts. The distribution of the Na+-K+-ATPase immune response varied in different sections of the nephron. The NKCC positioning was reported only in collecting tubes and collecting ducts, and proximal tubes and distal tubes did not respond to the antibody. Immunohistochemical response for NHE3 localization was detected only at the apex of epithelial cells of proximal tubules and collecting tubes. The distal tubes showed a negative reaction and the collecting ducts showed a weak response to NHE3 immunolocalization. In conclusion, Na+-K+-ATPase, NKCC, and NHE were differentially located in the renal system, suggesting that various physiological system operates in the renal system for ionic retention. This study provided valuable information to understand the ion regulation abilities of epithelial cells in various parts of P. waltoni nephrons.