Potassium distribution

Delmau, L.H., Bostick, D.A., Haverlock, T.J., Moyer, B.A. 2002. Caustic-side solvent extraction Extended equilibrium modeling of cesium and potassium distribution behavior. Oak Ridge National Laboratory Report. ORNL/TM-2002/116. 

Delmau, L. H., Bostick, D. A., Haverlock, T. J., and Moyer, B. A. Caustic-Side Solvent Extraction, Extended Equilibrium Modeling of Cesium and Potassium Distribution Behavior, Report ORNL/TM-2002/116, Oak Ridge National laboratory, Oak Ridge, TN, May 2002. 

Conway (1942) and Smulikowski (1954) have interpreted the potassium-distribution data to indicate that there is a potassium deficiency in Tertiary and Recent seas. However, Spiro and Gramberg (1964) made analyses of the composition of cations adsorbed on argillaceous rocks of northern Siberia and concluded that ... the highest content of potassium is inherent in marine water of the Permian Period. In Triassic seas the content of the potassium dropped significantly, and reached a minimum in seas of the Jurassic Period. Beginning with Cretaceous, the amount of potassium in sea water increased again, and during the Quaternary Period its level approached that of the Permian seas. These ideas are extremely speculative. 

Potassium distribution on surface after desorption was analysed by using EPMA. A previous report concerned the result of the K mapping after production of CACF. According to the mapping result with magnitude x 3500, the white parts showed distribution of K. K did not show any difference from the result of the test conducted after the manufacture of CACF against the sample where NO was adsorbed and desorbed. 

Finally, hyperosmolality results in enhanced movement of potassium from the cell into the extracellular fluid. This occurs most likely because of the associated cell shrinkage and water loss, which increases the intracellular-to-extracellular potassium gradient." This is seen most commonly in conditions such as diabetic ketoacidosis. Conversely, hypo-osmolality does not seem to affect potassium distribution. 

Intrinsic defects in the skeletal muscle ion channels have been found to disturb potassium distribution (Hoffmann et al. 1986, Ptacek et al. 1994). These are the periodic familial hypo- and hyperkalemic paralyses and abnormality of the voltage-sensitive calcium channel (Peterson 1997). 

The human body has a limited capacity to increase body stores of potassium. The major causes of hyperkalemia are excess potassium intake and mixed doses of potassium and sodium electrolyte solutions (Mahfoud et al. 2003), reduced renal losses (acute renal failure, end-stage renal disease, mineralocorticoid deficiency, potassiumsparing diuretics) and redistributions of potassium (hemolyses, necrosis, muscle injury, catecholamine antagonists, insulin deficiency, abnormal skeletal muscle sodium channels) (Peterson 1997). Increased intake by itself is rarely the sole cause of significant hyperkalemia. However, sustained hyperkalemia usually indicates an underlying defect in renal potassium excretion or impaired potassium distribution (KCl supplements or salt substitutes). The... 

Lithium causes a shift in potassium distribution from intracellular to extracellular potassium. 

Lithium causes disturbances in electrical conduction (i.e., flattening of T-wave). The shift in potassium distribution caused by the drug also causes supersensitivity to potassium, and may lead to cardiac arrest. 

The hydrogen-ion distribution curves are nearly horizontal. This means Aat at a given freezing rate the diflFerence between solute anions and solute cations in the ice remains approximately constant. For the same reason, the hydrogen ion concentration does not appreciably aflFect the distribution coeflBcients computed from the slopes or semilogariAmic plots (68), except for some very dilute solutions, such as 5 X 10 M KF (Figure 12), in which k could not be computed from the potassium distribution curve. 

Thus a coefficient of 0.2 equalizes the products of tissue and medium K" " and Cl concentrations. It is the chloride ratio Cl /Cl. or distribution and not the potassium distribution which is responsible for this departure from the Donnan electrochemical equilibrium distribution. 

Figure 2.21. Macroheterogeneity of catalyst 1 in the precursor state. The two left-hand figures show how two magnetite grains are separated by a crystal of calcium iron oxide (boundaries marked by arrows). The right-hand figures demonstrate the uneven potassium distribution. The area A contains spherical particles of iron oxide.

Figure 2. Fit of potassium distribution ratios for nitrate media...

Figure 4. Fit of cesium and potassium distribution ratios for chloride media...

Cobalt compounds have been in use for centuries, notably as pigments ( cobalt blue ) in glass and porcelain (a double silicate of cobalt and potassium) the metal itself has been produced on an industrial scale only during the twentieth century. Cobalt is relatively uncommon but widely distributed it occurs biologically in vitamin B12 (a complex of cobalt(III) in which the cobalt is bonded octahedrally to nitrogen atoms and the carbon atom of a CN group). In its ores, it is usually in combination with sulphur or arsenic, and other metals, notably copper and silver, are often present. Extraction is carried out by a process essentially similar to that used for iron, but is complicate because of the need to remove arsenic and other metals. 

The metal-ion complexmg properties of crown ethers are clearly evident m their effects on the solubility and reactivity of ionic compounds m nonpolar media Potassium fluoride (KF) is ionic and practically insoluble m benzene alone but dissolves m it when 18 crown 6 is present This happens because of the electron distribution of 18 crown 6 as shown m Figure 16 2a The electrostatic potential surface consists of essentially two regions an electron rich interior associated with the oxygens and a hydrocarbon like exterior associated with the CH2 groups When KF is added to a solution of 18 crown 6 m benzene potassium ion (K ) interacts with the oxygens of the crown ether to form a Lewis acid Lewis base complex As can be seen m the space filling model of this... 

The partitioning of the potassium ion between the resin and solution phases is described by the concentration distribution ratio, D ... 

The potassium or calcium salt form of oxaUc acid is distributed widely ia the plant kingdom. Its name is derived from the Greek o>ys, meaning sharp or acidic, referring to the acidity common ia the foflage of certain plants (notably Oxalis and Mmex) from which it was first isolated. Other plants ia which oxahc acid is found are spinach, rhubarb, etc. Oxahc acid is a product of metabohsm of fungi or bacteria and also occurs ia human and animal urine the calcium salt is a principal constituent of kidney stones. 

The unsaturation present at the end of the polyether chain acts as a chain terminator ia the polyurethane reaction and reduces some of the desired physical properties. Much work has been done ia iadustry to reduce unsaturation while continuing to use the same reactors and hoi ding down the cost. In a study (102) usiag 18-crown-6 ether with potassium hydroxide to polymerise PO, a rate enhancement of approximately 10 was found at 110°C and slightly higher at lower temperature. The activation energy for this process was found to be 65 kj/mol (mol ratio, r = 1.5 crown ether/KOH) compared to 78 kj/mol for the KOH-catalysed polymerisation of PO. It was also feasible to prepare a PPO with 10, 000 having narrow distribution at 40°C with added crown ether (r = 1.5) (103). The polymerisation rate under these conditions is about the same as that without crown ether at 80°C. 

Among the properties sought in the solvent are low cost, avadabihty, stabiUty, low volatiUty at ambient temperature, limited miscibility in aqueous systems present in the process, no solvent capacity for the salts, good solvent capacity for the acids, and sufficient difference in distribution coefficient of the two acids to permit their separation in the solvent-extraction operation. Practical solvents are C, C, and alcohols. For industrial process, alcohols are the best choice (see Amyl alcohols). Small quantities of potassium nitrate continue to be produced from natural sources, eg, the caUche deposits in Chile. 

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