Low temperature dilatation measurements in the silicate research

The main application fields of thermal expansion measurements in the silicate research are summarized. Special emphases is given to frost dilatometry, the expansion effect due to water freezing on the low temperature thermal expansion curves of water saturated porous solids.

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Zusammenfassung Es werden die Hauptanwendungsgebiete von thermischen Expansionsmessungen in der Silikatforschung zusammengefa\t. Besonderes Augenmerk wurde der Frostdilatometrie geschenkt, dem Expansionseffekt durch das Gefrieren von Wasser bei thermischen Expansionskurven wassergesÄttigter poröser Feststoffe im unteren Temperaturbereich.

     

Technology and Organisation of Inka Pottery Production in the Leche Valley. Part I: Study of Clays

We report on an interdisciplinary approach to the study of finds of unfired clay lumps and unfired broken vessels from two workshops in the Leche Valley, north coast of Peru. The material is used as a reference in the study of pottery making at both workshops.     

On the Bertrand paradox

In this papel we discuss the classical Bertrand paradox recalling the five known planar probabilistic models and introducing a new continuous family of planar probabilistic models, depending on a parameterx∈]1, +∞[. We also show that two of the classical models can be obtained as the limit, in law, from the new ones, whenx tends to 1 and +∞, respectively.     

Depth profile analysis of thin film solar cells using SNMS and SIMS

SNMS (sputtered neutrals mass spectrometry) and SIMS (secondary ion mass spectrometry) are used for the depth profile analysis of thin film solar cells based on amorphous silicon. In order to enhance depth resolution, model systems are analyzed only representing parts of the layered system. Results concerning the TCO (transparent conducting oxide)/p interface and the n/i interface are presented. To minimize matrix effects, SNMS is used when the sample consists of layers with different matrices. Examples are the TCO/p interface (where the transition lengths of the depth profiles are found to be sharper when ZnO is used as TCO compared to SnO₂) and SnO₂/ZnO interfaces in coated TCO layers (where a Sn contamination inside the ZnO layer is found depending on the plasma pressure during the ZnO deposition). SIMS is used when the limits of detection reached by SNMS are not sufficient. Examples are H depth profiles in ZnO layers or P depth profiles near the n/i-interface.