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Deep reflection seismic experiments in western Poland

Młynarski S., Pokorski J., Dziewińska L., Jóżwiak W., Zientara P.

Geological Quarterly

2000

Vol. 44, Nr 2

175-181

The paper presents the interpretation of a composite seismic profile recorded to 18 s TWT which crosses western Poland from the south to north. The interpretation is based on data along the profiles GB-2, GB-2B-96 and 25-III-82 collected between 1987 and 1996. Two reflection horizons bordering the crystalline crust have been recognized: in the top - SK, and in the base (Moho - M). The Caledonian complex is distinguished in the northern part of the profile GB-2 north of the Dolsk Zone. The results obtained allow determination of crustal structure down to the Moho. Several deep fault zones have been delimited (in the regions of Dolsk, Szamotuły and Trans-European Fault) which cut the entire crust. Crustal thickness ranges from approximately 30 km in the Palaeozoic platform up to about 40 km along the Trans-European Suture Zone.

Infrared spectroscopic study of magnesium oxide catalysts doped with sodium ions

Ignaczak W., Jóżwiak W., Szubiakiewicz E., Paryjczak T.

Polish Journal of Chemistry

1999

vol. 73 nr 4

645-654

Infrared results concerning the surface species in MgO catalysts doped with Na+ ions are presented. Different surface carbonate structures and hydroxyls groups have been found. It was assumed that created carbonate compounds could be involved in decreasing of MgO specific surface area. Sodium carbonate and unidentate carbonate structures may cause elimination and blockage of low coordination sites of MgO surface, being responsible both for hydrogen detachment from CH4 molecules and for oxidation of methyl radicals to carbon oxides - the undesired reactions of oxidative coupling of methane (OCM). It was observed that increasing temperature led to decomposition of surface bicarbonate and unidentate carbonate structures. Some of them are being reconverted to more stable bicarbonate structures. Carbon dioxide and water desorptions result in gradual restoration of low coordinated sites of MgO, corresponding to high selectivity to C2 hydrocarbon formation. Sodium ions may also cause structural changes in MgO lattice. The catalysts were active and selective above 950 K for C2 hydrocarbon formation, although sodium carbonate is sufficiently stable under the conditions of the OCM process.