Search Results

You are looking at 1 - 4 of 4 items for :

  • Author or Editor: B. Jensen x
  • Chemistry and Chemical Engineering x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

The distribution of Hf, Zr and Nb between aqueous solutions of mineral acids and solutions of 1-phenyl-3-methyl-4-acylpyrazolones-5 (acyl=acetyl, ethoxycarbonyl, butyryl, capronyl, capryl and benzoyl) in various organic solvents has been studied. The dependence of the distribution ratio of metal on the acidity of the aqueous phase, the analytical concentrations of reagents and metals, and on the organic solvent was investigated. The composition of the complex extracted is MeP4 for Hf and Zr. The conditions for the separation of Zr, Hf and Nb are defined, and a comparison is made with extractions by means of thenoyltrifluoroacetone.

Restricted access

Abstract  

The solubility of magnesium-ammonium-phosphate (struvite) has been studied employing radioisotope32P as tracer. The amount of sample in solution is determined by measuring the Cherenkov radiation due to the fast -particles emitted from this radionuclide. The themodynamic solubility product is determined at various temperatures and compared with former results.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors:
G. Skarnemark
,
A. Ödegaard-Jensen
,
J. Nilsson
,
B. Bartos
,
E. Kowalska
,
A. Bilewicz
, and
P. Bernhardt
Restricted access
Journal of Flow Chemistry
Authors:
Ketan Pimparkar
,
Bernard Yen
,
John R. Goodell
,
Veronique I. Martin
,
Wen-Hsuan Lee
,
John A. Porco Jr.
,
Aaron B. Beeler
, and
Klavs F. Jensen

Abstract

In an effort to utilize microfluidics to enable photochemistry, we have devised a method for fabrication of devices with UV-transmissive glass. The photochemical device is successfully incorporated into a system utilizing high-pressure capillary mercury lamps and cooling system. We have demonstrated the ability to carry out photochemical transformations with substantial rate acceleration. Furthermore, we highlight the ability to carry out analytical-scale reactions on a pulse flow automated system while modulating wavelength and residence time to identify optimal photochemical reaction conditions. The analytical conditions were also successfully converted to continuous-flow preparative scale.

Restricted access