Solid State Phenomena Vol. 231

Abstract: In environmental monitoring and water protection one has to deal with various hydrated specimens, and therefore, there is a need for scanning electron microscopes which are suited for hydrated specimens. Wet specimens can be observed in a hydrated state using a commercial Peltier cooling holder for conventional microscopes. However, the optimization of the time of observation for the sample needs to be determined by carrying out experiments in advance for specifically determining the optimal observation time. The temperature-pressure conditions also require optimization to obtain good quality images of amoeba and fungi. Further studies are required to establish whether the same imaging conditions would be possible to replicate closely the observation on other biological specimens.

Abstract: The calorimetric measurements together with microscopic observations and analyses relating to the interaction of cement paste with sulfate and nitrate solutions of various concentration were carried out. These salts modify the rate of cement hydration at early age. In the presence of sulfates the formation of some well crystallized calcium sulfates or calcium sulfoaluminates can be found. In case of nitrates there is no additional products. However, one can observe that the calcium silicate phase becomes less fibrous but more compact, with very small individual particles, as the nucleation from the liquid phase is disturbed. There are the accompanying cations incorporated in this product.