Enhancement of the pozzolanic activity of natural clays by mechanochemical activation

Replacement of cement with supplementary cementitious materials (SCMs) is a proven method to reduce clinker in cement and contribute to decreased CO2 emissions. Natural clays are commonly occurring materials that do not possess pozzolanic activity in their original state. Mechanochemical activation (MCA) can be an alternative and sustainable method to enhance their reactivity. In this study, the pozzolanic reactivity of three natural clays, originating from Sweden, was analyzed after the application of MCA in a planetary ball mill. Strength activity index (SAI), Frattini test, and conductivity test were used to evaluate the pozzolanic reactivity. All processed clays by MCA have achieved a SAI greater than 100%, while the Frattini test indicated an improved pozzolanic activity of samples containing a higher amount of clay minerals. The obtained results show that MCA could improve the pozzolanic reactivity, but the effect depends on the mineralogical composition and particle size of the clays

Spontaneous skin canine tumors: toluidine blue stain detection of mast cells in tissue section.

Dog mast cell tumor (MCT) is common in dog. The etiology of canine MCTs is unknown, but it is probably multi-factorial. Its incidence is higher than it has found in human. There are demonstrated several common biological and clinical characteristics in both species. Cutaneous mast cells are located in the dermis and hypodermis. The objective of this study is to detect of MC on Toluidine Blue stained slides. There were examined 74 dogs of difference breeds and aged, from Tirana city. Six of them demonstrated the skin canine tumors. Skin samples were obtained from these animals. Macroscopic examination of the tumor revealed nodular ulcerated lesion with areas of necrosis and hemorrhage, accompanied with normal superjacent epidermis and annexes. Serial sections obtained from biopsy specimens were processed with toluidine blue staining pH 4.5, specific for MC identification. This study suggests that Toluidine blue, pH 4.5 stain may give a good information about skin tumors in dog, histologically with benign behavior