Université de Fribourg

Growth of ice nanoparticles via uptake of individual molecules: pickup cross sections

Fedor, Juraj ; Lengyel, Jozef ; Kočišek, J. ; Poterya, V. ; Pysanenko, A. ; Svrčková, P. ; Fárník, M.

In: Journal of Physics: Conference Series, 2014, vol. 488, no. 10, p. 102016

We present cross sections for pickup of several atmospherically relevant molecules on ice nanoparticles with the 0.5-3 nm diameter range. The experimental values are supported by molecular dynamics simulations and analytical calculations based on long-range cluster-molecule potentials. The cross sections are all considerably larger than the geometrical cross section of nanoparticle and vary...

Université de Fribourg

Oxidation of sterols: energetics of C–H and O–H bond cleavage

Lengyel, Jozef ; Rimarčík, Ján ; Vagánek, Adam ; Fedor, Juraj ; Lukeš, Vladimír ; Klein, Erik

In: Food Chemistry, 2012, vol. 133, no. 4, p. 1435–1440

Phytosterols, as components of human diet, received much attention because of their cholesterol-lowering and antioxidant properties. We have theoretically studied sterols oxidation in terms of O–H and C–H bond dissociation enthalpies (BDE). In 17 Δ⁵- and Δ⁷-sterols, BDEs were obtained for reported sites of oxidation attack. Obtained results indicate that Δ⁷-sterols are more...