Valdis Seglins

Application of chemical trated illite clay for development of ceramics products

The chemically treatment by alkali solutions of illite clay, so-called geopolymer method, were studied to show the impact on changes of structure and crystalline phases composition of treated not dehydroxylated illite Quarternary clay, as well as ceramic properties and compressive strength of sintered respective ceramic samples. The degree of activating process were followed by FTIR-spectra, X-ray diffraction and differencial thermal analysis. The low temperature ceramic product was achieved by sintering of alkali solution (KOH or NaOH 1M, 3M, 4M and 6M) activated clay samples in temperature range from 100°C to 700°C . Sintered ceramic samples were characterized by compressive strength, total porosity, bulk density and shrinkage. It is shown that treatment of the illite Quarternary clay by KOH changes illite structure, but not destroyed. Main changes could be connected with changes of O-Al-OH grouping where O is associated with neighbour Si- layer That results into lowering of sintering temperature and development of amorphous (glassy) phase of sintered at 600–700 °C ceramic samples together with growing of total porosity. Consolidated at 600°C ceramic samples have the compressive strength ranged from 16–23 N.mm2. These values increases with growing of concentration of used alkali solution as well as with temperature for NaOH treated samples and is comparable with compressive strength for the respective ceramic products sintered at 900 °C.

Non-destructive methods for evaluation of the state of preservation in historical stone monuments: the case study of the Step Pyramid in Saqqara

Abstract This study aims to facilitate visual interpretation of the photo documentation data by evaluation of the 3D model of the Step Pyramid of Djoser using MicroStation V8i software. The integration of the data into the 3D model allowed to make number of conclusions regarding the structure of the Step Pyramid, potential threats to its stability, stone material used for the construction of the pyramid and differences in quality of the mortar applied. The results of this study denote high potential of this methodology for its application in preliminary studies of stone monuments on Memphite necropolis area to contribute the elaboration of future preservation and conservation strategy.

Development and evaluation of surface cleaning/disinfection preparations

Acknowledgements Surface cleaning preparations (SCPs) are applied in different areas, e.g., healthcare, housekeeping, car washing, etc. A great attention is focused on developing an effective cleaning and disinfection preparations for controlled environments in pharmaceutical and biotechnology operations. In this study, commercially available and newly developed surface cleaning formulations were compared for their efficacy. Experiments were aimed at evaluating the effect of quaternaryammonium-based formulations (QABF) added to different cleaning compositions,on microbial susceptibility, in particular, Pseudomonas fluorescens AM11. Disinfection properties of preparations were tested on Pseudomonas fluorescens AM11 in suspension, according to standard procedures, as well as on dry surface, by agar diffusion method and batch cultivation. Three preparations (A, B and C) with different initial disinfection activity were amended with N,N-dimethyldodecylamine Noxide (DDAO) (Fig.1). DDAO represents quaternary-ammonium-based formulations (QABF) with surfactant and antimicrobial activity.