An overview is presented of classic and more recent applications of liquid chromatography for the analysis of metal species. The different approaches involving ion-exchange, ion-pair, and chelation separation mechanisms are discussed as well as the new philosophy of simply removing interferents before specific detections of metal ions (alkali and alakaline earths, rare earths, heavy and transit...

We develop a semi-analytic model for planet formation during the pre-main sequence contraction phase of a low mass star. During this evolution, the stellar magnetosphere maintains a fixed ratio between the inner disk radius and the stellar radius. As the star contracts at constant effective temperature, the ‘snow line’, which separates regions of rocky planet formation from regions of icy plane...

satellite orbit determination is a method of determining the state vector, i.e., position and velocity, of a low earth orbiting (leo) satellite or interplanetary spacecraft. during the past two decades, many satellites with various applications including geodetic applications have been launched at low altitudes. for instance, topex / poseidon, champ, grace and goce are the examples of the geode...

Aluminum is a significant impurity in the ion-adsorption rare earth ore. The changes occurrences of aluminum have great influence on leaching In this paper, column method was employed using magnesium sulfate as agent to investigate effects pH and concentration earths. results show that at low concentrations, earths greatly enhanced, while not significantly affected by decrease agent. At high sl...

The study was carried out by determining the effect of calcium ethylenediaminetetraacetate on the excretion and distribution in rats of a number of rare earths and yttrium, and correlating the magnitude of these effects with the stability constants of the chelates formed with some of the rare earths. These rare earths were selected because they form a long series of closely related elements wit...