Search results

Sort By:

Limit search:

Proton Transfer in Strong Hydrogen Bonds Revealed by Infrared Spectra - Correlations between Structure and Spectra for the BrH : NH_3 Complex

100%

Szczepaniak K., Person W.

Acta Physica Polonica A

2007

vol. 112

issue S

S-19-S-38

Our scope is to achieve an understanding of the relation between the infrared spectrum and structure of a strong hydrogen-bonded complex, BrH : NH$_3$, and how and why this relationship is affected by the environment surrounding the complex. A series of DFT/B3LYP/6-31G(d,p) calculations was carried out for this system to obtain its structure and spectrum in different dielectric fields characterized by their relative permittivities. Changes in structure and spectrum (both frequencies and intensities) as the relative permittivity changes are explored. Calculations of spectra are made first under the harmonic approximation. In the next step the effect of anharmonicity was estimated for several different dielectric fields. The calculated anharmonic spectrum (for ε_r = 1.6) is compared with the experimentally observed infrared spectrum of the complex isolated in an Ar matrix at 10 K, obtained in our laboratory. The calculated frequencies and relative intensities for all normal modes agree with the corresponding experimental data surprisingly well. The potential usefulness of structure-spectra correlations is explored.

Assessment of the impact of a phosphatic fertilizer plant on the adjacent environment using fuzzy logic

52%

Szczepaniak K., Sârbu C., Astel A., Raińska1 E., Biziuk M., Culicov O., Frontasyeva M. V., Bode P.

Open Chemistry

2006

vol. 4

issue 1

29-55

The impact of a phosphatic fertilizer plant on the adjacent environment was examined. Selected rare earth elements, heavy metals and metalloids were determined in substrates and products, waste by-product, and grass and soil samples. Concentration gradients of elements in grass and soil samples along the southerly and easterly directions were examined and compared with the content of interior soil and grass samples, substrates, and products. Results were compared with available data on soil permissible element concentration levels. Two fuzzy principal component analysis (FPCA) methods for robust estimation of principal components were applied and compared with classical PCA. The efficiency of the new algorithms is illustrated. The investigation explored the impact of the plant on the adjacent environment. The most reliable results, in good agreement with types of samples, were produced using the FPCA-O algorithm

Refine search results

1 Acta Physica Polonica A

1 Open Chemistry

1 2007

1 2006

2 Szczepaniak K.

1 Astel A.

1 Biziuk M.

1 Bode P.

1 Culicov O.

1 Frontasyeva M. V.

1 Person W.

1 Raińska1 E.

1 Sârbu C.

Search results

Proton Transfer in Strong Hydrogen Bonds Revealed by Infrared Spectra - Correlations between Structure and Spectra for the BrH : NH_3 Complex

Assessment of the impact of a phosphatic fertilizer plant on the adjacent environment using fuzzy logic