Search Results (70)
Organic geochemistry of stratified eutrophic alpine lakes (Lake Bled)
The identification and quantification of organic compounds present in the environment is a major area of application in modern analytical chemistry. However, it is still scarcely recognized that, in addition to the chemical identity and concentration of organic compounds, there is more information to be found about their source and …
Radon as a tool in geophysical research
Radon (222Rn, half-life 3.82 days) is a natural radioactive noble gas which originates from the radioactive decay of radium (226Ra) in the Earth's crust. It is a known hazard to humans, due to its radioactivity. Moreover, radon can also be used as a versatile tool in geophysical research. In order …
Investigation of heterogeneous reactions of trifluoromethane with some metal oxides, hydroxides and carbonates
Heterogeneous reactions of trifluoromethane CHF3 with solid xerogel oxides, alkali hydroxides and carbonates were investigated under static and dynamic conditions and at moderate temperatures. In all cases, main reaction is fluorination characterised by a complete decomposition (mineralisation) of the fluorinating agent, CHF3, and the formation of the solid metal fluorides. …
Determination of steroid estrogens in environmental samples using chemical analysis (GC-MSD) and an in vitro estrogenicity assay (ER-Calux®)
The presence of steroid estrogens in the environment has been studied intensively for two decades because of their possible deleterious effects on living organisms at very low (ng/L) concentrations. To determine concentrations of steroid estrogens and the estrogenic potential of environmental samples, sophisticated and sensitive analytical techniques as well as …
Development of silicon carbide based implants with improved biocompatibility and mechanical properties
With emerging need for orthopaedic implants and prolonged exposure of organism to implants also problems connected to elution of metal ions that in some cases cause adverse reactions in the human body, emerge. The main aim of our work was therefore to investigate the potential of silicon carbide (SiC) to …
Liquid-crystal microdroplets as optical microresonators and lasers
This thesis investigates the use of single liquid-crystal droplets as optical microresonators and lasers. We have shown that liquid-crystal droplets can support a number of different optical modes that can be excited by introducing a fluorescent dye in the liquid crystal material and using an external excitation source of light. …
Extension of the range of primary vacuum calibration methods with the use of nonevaporable getters
Measurement of ultrahigh vacuum (UHV) and extremely high vacuum (XHV) is important in many advanced research and technology fields such as: equipment for surface analysis, particle accelerators, simulation of interstellar space, processing of advanced semiconductors, electron tubes, FE displays, etc. For traceable calibrations of UHV and XHV gauges we need …
Superhydrophility of plasma treated materials
In this doctoral thesis, we present the superhydrophilic effect on surfaces of three different materials, i.e. highly oriented pyrolytic graphite, graphite foil and graphite grain in polymer composite. In order to induce this complicated effect on the surface we used reactive oxygen plasma treatment. The plasma was created in glass …
Nitrate migration in plant-soil-groundwater system
Nitrogen (N) is an essential nutrient for plant growth and one which has the greatest effect on the yield. Since effective indigenous sources are insufficient by far to support current levels of global agricultural outputs, N is intensively applied by farmers in the form of N-based fertilisers. However, excessive rates …
Development of analytical methods for speciation of organotin compounds in environmental samples using gas chromatography and mass spectrometry
Organotin compounds (OTCs) are the organometallic compounds with the most numerous applications. Today, it is more than 50 years of their intensive development and use. While they are highly useful chemicals they are also extremely toxic to a wide array of aquatic and terrestrial living organisms at very low concentrations. …