Brown Coal Bulletin, 2019 (vol. 59), issue 2
Comparative measurement of the mobile units for the measurement of pollutants in the atmosphere
Ing. Jan Brejcha
Zpravodaj Hnědé uhlí 2019, 59(2)
The article is focused on the participation of mobile measuring unit operated by the Brown Coal Research Institute a.s. (VúHU a.s.) on comparative measurements of mobile measurement units, which is under the designation PT#O/8/(year) organised by National reference laboratory for outdoor air from the Státní zdravotní ústav Praha (State Health Institute Prague) as a part of the program of eligibility testing of laboratories.
Development of the teeth of excavators with improved characteristics
Ing. Vlastimil Moni, Ph.D., Ing. David Hradil, Ing. Tomáš Miletič
Zpravodaj Hnědé uhlí 2019, 59(2)
The goal of the article is to find the optimal procedure of thermal or thermo-chemical treatment of the teeth of excavators with the highest resistance to wear, implemented within the framework of the project. The project addresses the optimization research of shapes and especially materials used in the manufacture of cutting elements of mining and ground machinery depending on mining conditions, utilising the most advanced knowledge in the field of material engineering and metallurgy, cryogenics and nanotechnology to improve the efficiency of cutting process and the life of this key node of earth moving and mining machinery.
Indications of two unknown maar-diatreme volcanoes of Quaternary age near Libá in western Bohemia by gravity survey
RNDr. Jan Mrlina, Ph.D., Dr. Horst Kämpf, Ing. Václav Polák, Ing. Michal Seidl, Ph.D.
Zpravodaj Hnědé uhlí 2019, 59(2)
In the year 2014, we have identified two crater formations in the morphology of the terrain resembling volcanic structure of maar/diatreme at the Ztracený rybník nature reserve. They are located northwest of Cheb in the western Bohemia on the territory formed by the Smrčiny/Fichtelgebirge granite massif. In the same year we have carried out gravity survey on the profiles as well as at random points according to the accessibility of the terrain. Measurements were difficult especially at the bottom of the larger crater of Ztracený rybník due to the swampy surface, which is very unstable for gravimetric measurement. After the data processing we produced...
Fossil resin duxit, its chemical composition and properties
Mgr. Martina Havelcová, Ph.D., Ing. Vladimír Machovič, CSc., Mgr. Alexandra Špaldoňová, Ph.D., Ing. Ivana Sýkorová, DrSc., Ing. Karel Mach, Ph.D., Zdeněk Dvořák
Zpravodaj Hnědé uhlí 2019, 59(2)
The paper provides information on chemical composition of a fossil resin called duxite. Methods of elemental analysis, microscopy, chromatography, and infrared spectroscopy were used to analyse samples mostly found in mineralized tree trunks and deposited in the Miocene sediments of the Most and Sokolov basins. All studied samples have shown similar chemical compositions, rich in sesquiterpenes (α-cedran, cuparene) and diterpenes of abietane, pimarane, and dehydroabietane structures. The infrared spectra have confirmed an aromatic character of duxite and higher maturity of the samples. The identified compounds indicate that the source of duxite...