Assessment of Water Quality in the Molnár János Cave – Budapest, Hungary

Molnár János Cave (MJC) is the only underwater cave and the only active one in the Buda Thermal Karst system (BTK). At MJC, there is a large amount of water that can be considered as a possible source of drinking water. We evaluated the physical and chemical parameters of the cave water to understand natural and possible anthropogenic interference in water quality. Therefore, measurements of temperature and chemical compositions were performed for dripwaters and water from the cave conduits over a four-year period and compared to historical data. Statistical analysis of the produced data revealed yearly changes as well seasonal periodicity in the component ion concentrations. In the case of dripwaters, we observed a periodicity that revealed information about the origin of the dripwater. For the first time, we had identified seasonal variations in conduit waters. Previous studies only analyzed water at the entrance of the cave. Then, this research focuses on the water from the newly discovered inner passages

Cave Air Analysis with Gas Chromatography Mass Spectrometry

Gas chromatography (GC) is a frequently used analytical method for the determination of permanent and organic air components. The analysis usually needs two different columns in practice. The molecular sieve stationary phase can separate oxygen, nitrogen and carbon monoxide, but irreversibly adsorbs carbon dioxide and water. Porapak type columns are applicable for the measurement of carbon dioxide, however oxygen, argon, nitrogen and carbon monoxide are co-eluted. Usually these two types of columns are used in parallel for the determination. Carboxen stationary phase can separate carbon monoxide and carbon dioxide, but argon, oxygen and nitrogen are co-eluted. Thermal conductivity detector (TCD) and flame ionization detector (FID) are used commonly together for the determination of the separated components. TCD is applied for permanent gas analysis whereas FID – combined with a methanizer – is used for the detection of carbon monoxide, carbon dioxide and light hydrocarbons. Mass spectrometer (MS) is also a potential detector, because the properly chosen fragment ions can increase the selectivity.We developed a method for the determination of air components, using only one column and one detector. This method is suitable for the measurements by combining the advantages of the carboxen column with mass spectrometry. The validation parameters of the method were in the acceptable interval, so this method is able to determine the air components. The application of this technique to the analysis of cave air provided valuable information to the exploration of the Molnár János cave system

Számításos kémiai módszerekkel támogatott foszfor- és szilíciumkémia = Computationally assisted of organophosphorus and organosilicon chemistry

A kutatás során a 14-es (C, Si, Ge, Sn) illetve a 15-ös (N,P) főcsoport elemeit tartalmazó molekulák vizsgálatával foglalkoztunk. Eredményeinket részben különleges kötésszerkezetek (karbének, foszfinidének) illetve hipervalens vegyületek előállíthatósága és stabilizációjuk lehetséges módjainak vizsgálatában értük el. Külön kiemelendő a konjugált foszfortartalmú rendszerek vizsgálata, melyeket szintetikus kutatócsoportokkal együttműködve végeztünk. Optoelektronikai alkalmazásokra felhasználható különböző konjugált/kondenzált foszfolszármazékok vizsgálatával Regis Reau és Thomas Baumgartner csoportjaival együttműködve születtek eredmények, míg a kationos, semleges és anionos diazafoszfol alapvázat Dietrich Gudat csoportjával együttműködve vizsgáltuk. Proazafoszfatrán szuperbázis és származékainak (John Verkade-val együttműködve) vizsgálata stabilizációjában megállapítottuk a transzannulláció szerepét és mértékét. Vizsgáltuk sziloxánláncok kialakulásának mechanizmusát és e láncok stabilitását. | The target molecules of our research contain group 14 (C, Si, Ge, Sn) and group 15 (N,P) elements. The most important results are related to unusual bonded molecules including carbenes, phosphinidenes, and hypervalent molecules, including their stabilization and synthesizability. Especially noteworthy results were obtained in cooperation with synthetic research groups in the field of conjugated organophosphorus compounds. Different cunjugated/annellated phosphole-based ring systems were targeted in cooperations with Regis Reau and Thomas Baumgartner. Cationic, neutral and anionic diazaphosphole systems were investigated with the Group of Dietrich Gudat. Investigating the proazaphosphatrane superbase and its derivatives (in a joint work with John Verkade) we have established the effect and extent of transannullation. The formation and the stability of siloxane chains was also investigated

Theoretical study of the Pu and Am dicarbide molecules

The electronic structure and ground-state molecular properties of Pu and Am dicarbides were investigated by relativistic multireference calculations using CASSCF/CASPT2 theory. The electronic ground state in both molecules corresponds to a symmetric triangular structure, in which the actinide atom is connected to a C2 moiety. The other experimentally relevant structure, the symmetric linear arrangement, is over 100 kJ/mol higher in energy. The bonding characteristics in the two structures were analysed on the basis of the valence molecular orbitals. Besides the usual 2-electron bonds some 1-electron bonding orbitals were also identified. We evaluated the electronic spectra with complete active space state interaction (CASSI) calculations taking into account spin-orbit coupling. The IR and Raman spectral characteristics were obtained using DFT calculations. Assessment of the present results with previously reported data on Th and U dicarbides provides information on the change of various molecular parameters in the actinide row.JRC.E.3-Materials researc

Pyridyl-Functionalised 3H-1,2,3,4-Triazaphospholes: Synthesis, Coordination Chemistry and Photophysical Properties of Low-Coordinate Phosphorus Compounds

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