Chemical exchange phenomena in NMR spectra can be quantitatively interpreted to measure the rates of ligand binding, as well as conformational and chemical rearrangements. In macromolecules, processes that occur slowly on the chemical shift time scale are frequently studied using 2D heteronuclear ZZ or N(z)-exchange spectroscopy. However, to successfully apply this method, peaks arising from ea...

Water is the first and foremost limiting factor for agricultural production, and undoubtedly, water crisis is considered as one of the international challenges for governments and human societies. Given that virtual water was first used as a way to tackle water scarcity in countries with limited water resources, so that countries with low water should import food from abundant countries...

In present research work, homogeneous anion exchange membranes based on polysulfone (QAPSFs) were prepared via chloromethylation, amination and alkalization. In amination step, trimethylamine and N,N,N',N'-tetramethyl-1,6-hexanediamine were used as amination and crosslinking agents, respectively. The chloromethylated polysulfone was characterized by 1HNMR spectroscopy and chloromethylation degr...

soil productivity is generally associated with poor nutrient status and the physical condition of the soil, but the effect of soil mineralogy on soil productivity has received little attention. in this qualitative study, interactions between mineralogy and physico-chemistry and their role on the productivity of two luvisols, an arenosol and a vertisol are investigated. minerals identified in th...

When immersed in water cells of hepatomas produced by p-dimethyl-aminoazobenzene (butter yellow) take in less water than liver cells from which they are derived and more rapidly undergo disintegration; cholangiomas produced by butter yellow undergo similar changes. As a result of the injury of the tumor cells by water the osmotic exchange, characteristic of the normal liver cells under the same...

Carrier-mediated exchange coupling, known as Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, plays a fundamental role in itinerant ferromagnetism and has great application potentials in spintronics. A recent theorem based on the imaginary-time method shows that the oscillatory RKKY interaction becomes commensurate on bipartite lattice and predicts that the effective exchange coupling is alway...