Salt solution flows in walls of monumental buildings

The main cause of the degradation of monumental buildings' walls is capillary transport of moisture with dissolved salts. These processes are cyclic and lead to salt crystallization in the external parts of walls. In the present work the moisture measurements, which were made on the walls of a 13^th Century church in Opole/Poland, are presented. It is also the superficial model for salt solution flows proposed.     

Analysis of accuracy of measurement of quadratic electro-optic coefficients in uniaxial crystals: a case study of KDP

Taking KDP as an example of a uniaxial crystal, we analyze contributions to its quadratic electro-optic response with a view to explaining differences in published values of certain quadratic coefficients. In an eigenvalue theory of light propagation we show that the linear electro-optic coefficient contributes to the quadratic response, even under ideal laboratory conditions. In addition, the effect of imperfect crystal cutting and alignment is investigated by means of computer calculations based on the Jones calculus. It is found that, for relatively small inaccuracies, the calculated values of the quadratic coefficient g(xyxy) are approximately two orders of magnitude greater when measured with a static field than with a dynamic one. This finding could explain the observed spread in some results for KDP-type crystals.