INVESTIGATION OF THE EFFECTS OF MARBLE MATERIAL PROPERTIES ON THE SURFACE QUALITY

This study aims to investigate the effects of material properties of marble on surface roughness and glossiness.For this purpose, four types of limestones were investigated.Physicomechanical properties of samples were determined through laboratory measurements.Mineralogical and petrographical characterizations were made using thin-section analysis.

The Bulgarian Geomagnetic Reference Field (BulGRF) for 2015.0 epoch and its secular variation model prediction up to 2020.0 is produced and presented in this paper.The main field model is based on the well-known polynomial approximation in latitude and longitude of the geomagnetic field elements.The challenge in our modelling strategy was to update