Dissolved solutes exchange

The third mechanism of capillary exchange is bulk flow. In this case, water and dissolved solutes move across capillaries due to hydrostatic pressure and osmotic pressure. When the balance of these two forces causes fluid to move out of the capillary, it is referred to as filtration. When these forces cause fluid to move into the capillary, it is referred to as reabsorption. 

Extraction of Pu - For the extraction of Pu the acidity of the dissolver solution should be adjusted to 1.5M HN03, with the addition of NaN02 to ensure complete conversion of Pu to Pu(IV). Detailed processing parameters are shown in Fig. 1 The Pu was further purified by anion exchange. 

A 0.1 ml aliquot of the dissolved spent fuel solution was diluted by adding 50 mL of pure water. The sample solution was heated and dried, and was dissolved again in 3 mL of 0.5 moEdm hydrochloric acid. The resulted hydrochloric dissolver solution was loaded onto resin (8 mL column volume). Tertiary pyridine resin of a non-support type was used as pre-filter anion exchange resin. After sample loading, the column was fed with 4 column volumes of 0.5 mol/dm hydrochloric acid solution. The resin was rinsed by pure water of 4 column volumes. Then. 1 mL of resin was taken from the column and rinsed again by pure water. After the rinse, the rinsing water and resin were encapsulated in a plastic vial. Furthermore, 3 column volumes of 1 mol/dm sodium hydroxide solution were fed to the resin. After the alkali rinse, the resin and eluted sodium hydroxide solution were analyzed by y-ray spectrometry to confirm the adsorbed nuclides. 

A membrane can be either a liquid or a solid. Its electrical properties arise when it allows transport of an ion of one charge but not that of another. Membranes are usually sufficiently thick that one can distinguish an inside region and two outer boundary regions which are in contact with electrolyte solutions. Two types of membranes are considered here (1) membranes of solid and glassy materials (2) liquid membranes with dissolved ion-exchanging ions or neutral ion carriers (ionophores). In fact all of these membranes are involved in ion exchange. It is important to understand how this process affects the potentials which develop in the system at both sides of the membrane. 

EXCHANGE OF DISSOLVED SOLUTES BETWEEN SOIL/SEDIMENT AND THE WATER COLUMN... 

The exchange of dissolved solutes across the soil-floodwater interface is calculated using Pick s first law (see Section 14.3.1) (Berner, 1980) and Equation [14.12]... 

The IE process is based on the competition between the solute and the counterion in the mobile phase, which is essentially aqueous or aqueous-organic solution of a salt or buffer. Salt (ionic strength) gradients in IE chromatography are frequently used in the separation of complex peptides, proteins, and other biopolymer samples as a complementary technique to RP solvent gradient separations, often in a 2-D setup. The gradients usually start at a low salt (chloride, sulfate, etc.) concentration and typically mn from 0.005 to 0.5 M. A buffer is used to control the pH acetonitrile and methanol may be added to improve the resolution and urea to improve the solubility of proteins that are difficult to dissolve. Ion exchangers with weak hydrophobic matrices usually prevent protein denaturation in aqueous mobile phases. 

The electrolytic dissolver vessel is a long slab (162 mm side to side) which tapers to a V-shape trough at the bottom. The height is 660 mm to the top of the overflow channel. The dissolver solution is circulated also through a surge tank and heat exchanger. In processing EBR-II fuel assemblies the safety limit requirement is... 

Accurately weigh about 6 g NaCl and dissolve in distilled water. Pass the solution through a well-rinsed cation exchange column (Dowex 50W) in the hydrogen form. The equivalent amount of HCl is washed from the column (in 10 column volumes) into a volumetric flask and made up to volume. Equivalent weight is the formula weight. 

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