Metal release from contaminated estuarine sediment under pH changes in the marine environment

The contaminant release from estuarine sediment due to pH changes was investigated using a modified CEN/TS 14429 pH-dependence leaching test. The test is performed in the range of pH values of 0-14 using deionised water and seawater as leaching solutions. The experimental conditions mimic different circumstances of the marine environment due to the global acidification, carbon dioxide (CO2) leakages from carbon capture and sequestration technologies, and accidental chemical spills in seawater. Leaching test results using seawater as leaching solution show a better neutralisation capacity giving slightly lower metal leaching concentrations than when using deionised water. The contaminated sediment shows a low base-neutralisation capacity (BNCpH 12 = -0.44 eq/kg for deionised water and BNCpH 12 = -1.38 eq/kg for seawater) but a high acid-neutralisation capacity when using deionised water (ANCpH 4 = 3.58 eq/ kg) and seawater (ANCpH 4 = 3.97 eq/kg). Experimental results are modelled with the Visual MINTEQ geochemical software to predict metal release from sediment using both leaching liquids. Surface adsorption to iron- and aluminium- (hydr)oxides was applied for all studied elements. The consideration of the metal-organic matter binding through the NICA-Donnan model and Stockholm Humic Model for lead and copper, respectively, improves the former metal release prediction. Modelled curves can be useful for the environmental impact assessment of seawater acidification due to its match with the experimental values.This work was supported by the Spanish Ministry of Economy and Competitiveness, Project No. CTM 2011-28437-C02-01, ERDF included. M. C. Martı´n-Torre was funded by the Spanish Ministry of Economy and Competitiveness by means of FPI. Fellowship No. BES-2012-053816

Relationship between Knowledge Management and Educational Performance of Faculty Members

Aims: According to special conditions of universities, realization of knowledge management in Iranian universities has the premier importance compared to other organizations and institutions. This study aimed to investigate the relationship between knowledge management dimensions and educational performance of faculty members.  Instrument & Methods: This descriptive-analytic study was conducted in 2014 and 127 faculty members of Payam-e-Noor University of the Southern Khorasan Province were selected through simple randomization. The Standard Knowledge Management Questionnaire and a researcher-made educational performance survey were used to collect data. The data were analyzed using Pearson correlation test and independent T test. Findings: Knowledge management and educational performance mean scores were 324.33±31.31 and 65.22±13.85, respectively. There was a positive relationship between knowledge management and its dimensions and educational performance. The relationship between knowledge management and its dimensions’ mean scores was significant in terms of gender. However, the relationship between educational performance mean scores was not significant in terms of gender. In terms of faculty’s academic degrees, the relationship between knowledge management and its dimension’s mean scores and their educational performance was significant, while it was insignificant in terms of tenure.    Conclusion: Knowledge management dimensions can both enhance and predict faculty’s educational performance

New approach to adapting electrochemical properties of cation-exchange membrane by incorporating tris(8-hydroxyquinolinato)aluminum nanoparticles

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Electrodialysis-mixed matrix tris(8-hydroxyquinolinato)aluminum (AlQ 3 ) nanoparticles entrapped heterogeneous cation-exchange membrane was prepared by the solution casting technique. The effect of the concentration of AlQ 3 in the casting solution on the physico-chemical properties of the homemade membranes was studied. AlQ 3 nanoparticles were synthesized via a simple precipitation method and characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction. The use of AlQ 3 nanoparticles in the membrane matrix led to an increase of the membrane electrical conductivity and surface hydrophilicity. The membrane ion-exchange capacity was enhanced by using AlQ 3 loading ratios up to 1.5 wt%; the IEC decreased for concentrations above 1.5 wt%. The increase of AlQ 3 content ratios up to 0.5 wt% in fabricated membrane initially caused to increase of water content. The membrane water content was decreased for the concentrations between 0.5 to 1.5 wt% and then showed an increasing trend again at higher additive loading ratios. The membrane potential, charge density, permselectivity, and transport number were improved obviously by the use of AlQ 3 nanoparticles in membrane body. The ion flux/permeability enhanced sharply by using of AlQ 3 up to 0.5 wt% in the membrane matrix and then began to decrease while the additive concentration was more than 0.5 wt%.status: publishe

Heliconical-layered nanocylinders (HLNCs)-hierarchical self-assembly in a unique B4 phase liquid crystal morphology

A unique morphology for bent-core liquid crystals forming the B4 phase has been found for a class of tris-biphenyl bent-core liquid crystal molecules with a single chiral side chain in the longer para-side of the molecule. Unlike the parent molecules with two chiral side chains or a chiral side chain in the shorter meta-side, which form helical nano- or microfilament B4 phases, the two derivatives described here form heliconical-layered nanocylinders composed of up to 10 coaxial heliconical layers, which can split or merge, braid, and self-assemble into a variety of modes including feather- or herringbone-type structures, concentric rings, or hollow nest-like superstructures. These multi-level hierarchical self-assembled structures, rivaling muscle fibers, display blue structural color and show immense structural and morphological complexity