Action variables for Toda Lattices

This Letter contains constructions of complex action variables for both the full Kostant-Toda Lattice in sl(n, ) and the generalized nonperiodic tridiagonal Toda lattice associated to an arbitrary complex semisimple Lie algebra g. The main tool is the explicit factorization solution for certain Hamiltonian flows. The Letter also contains a generalization of the standard factorization solution theorem necessary for the analysis of the full Kostant-Toda lattice.     

Computer controlled spreading resistance system for measurement of carrier concentration profiles of silicon structures

A new computer controlled equipment for carrier concentration profile determination of silicon structures by a spreading resistance technique is presented. The required data and plots can easily be obtained by means of a new software package, which has been specially developed for this purpose. Measurements have been performed on different structures in order to verify the suitability of both the measuring system and the software package. The reproducibility has been found to be within 5% for the investigated structures.     

The coupling of supercritical fluid chromatography and field ionization time-of-flight high-resolution mass spectrometry for rapid and quantitative analysis of petroleum middle distillates

We report the first coupling of supercritical fluid chromatography (SFC) with field ionization time-of-flight high-resolution mass spectrometry (FI-ToF HRMS), in parallel with ultraviolet (UV) detection and flame ionization detection (FID), for rapid and quantitative analysis of petroleum middle distillates. SFC separates petroleum middle distillates into saturates and 1- to 3-ring aromatics. FI generates molecular ions for hydrocarbon species eluted from the SFC. The high resolution and exact mass measurements by ToF mass spectrometry provide elemental compositions of the molecules in the petroleum product. The amounts of saturates and aromatic ring types were quantified using the parallel SFC-FID assisted by SFC-UV. With a proper carbon-number calibration, the detailed composition of the petroleum middle distillate was rapidly determined.     

Prediction of aqueous solubility of drugs and pesticides with COSMO-RS

The COSMO-RS method, originally developed for the prediction of liquid-liquid and liquid-vapor equilibrium constants based on quantum chemical calculations, has been extended to solid compounds by addition of a heuristic expression for the Gibbs free energy of fusion. By this addition, COSMO-RS is now capable of a priori prediction of aqueous solubilities of a wide range of typical neutral drug and pesticide compounds. Only three parameters in the heuristic expression have been fitted on a data set of 150 drug-like compounds. On these data an rms deviation of 0.66 log-units was achieved. Later, the model was tested on a set of 107 pesticides, which have been critically selected based on two experimental data sources and by a crosscheck with an independent HQSAR model. On this data set an rms of 0.61 log-units was achieved, without any adjustments to the structurally extremely diverse pesticides. This result verifies the ability of this extended COSMO-RS to predict aqueous solubilities of drugs and pesticides of almost arbitrary structural classes. The new method is COSMO-RSol.