40 research outputs found
Effect of atmospheric-pressure plasma jet on normal and tumor cells in vitro
The purpose of this work is to investigate the effect of low-temperature plasma on tumor and normal cells. As a result of in vitro experiments, plasma-exposed tumor and normal cells demonstrate several effects such as cell detachment, apoptosis or necrosis according to cell type and exposure parameters (power, time of exposure, frequency). In experiments, the inhibition of tumor cell growth was observed up to 70% on the 5th day after exposure. The effect of gas discharge plasma on normal cells was the opposite, and by 5 days there was a stimulation of cell proliferation. The obtained data demonstrate the prospects of using this atmospheric-pressure plasma jet in biomedical research aimed at the treatment of cancer
Manganese catalysts to obtain olefins from C1-C4 alkanes
Oxidative transformations of C1-C4 alkanes into olefins on oxide manganese catalysts were under study. We also studied oxidative coupling of methane (OCM) into ethylene on deposited and applied on the silicon dioxide catalysts. We studied the influence of chemical composition of catalyst and promotors on the OCM. Adding a little amount of ethane and propane hydrocarbons to methane allows increasing the concentration of ethylene in gases and significantly increasing productivity in ethylene. The study also shows the impact of the amount of manganese and promotors applied on SiO2 on the yield of olefins during the conversion of C3-C4 alkanes
Phase-Space Volume of Regions of Trapped Motion: Multiple Ring Components and Arcs
The phase--space volume of regions of regular or trapped motion, for bounded
or scattering systems with two degrees of freedom respectively, displays
universal properties. In particular, sudden reductions in the phase-space
volume or gaps are observed at specific values of the parameter which tunes the
dynamics; these locations are approximated by the stability resonances. The
latter are defined by a resonant condition on the stability exponents of a
central linearly stable periodic orbit. We show that, for more than two degrees
of freedom, these resonances can be excited opening up gaps, which effectively
separate and reduce the regions of trapped motion in phase space. Using the
scattering approach to narrow rings and a billiard system as example, we
demonstrate that this mechanism yields rings with two or more components. Arcs
are also obtained, specifically when an additional (mean-motion) resonance
condition is met. We obtain a complete representation of the phase-space volume
occupied by the regions of trapped motion.Comment: 19 pages, 17 figure
On the superintegrable Richelot systems
We introduce the Richelot class of superintegrable systems in N-dimensions
whose n<=N equations of motion coincide with the Abel equations on n-1 genus
hyperellipic curve. The corresponding additional integrals of motion are the
second order polynomials of momenta and multiseparability of the Richelot
superintegrable systems is related with classical theory of covers of the
hyperelliptic curves.Comment: 13 pages, a talk given at the Conference "Symmetry Methods in
Physics" devoted to the memory of Professor Y.F.Smirnov, July 6-9, 200
Geodesic flows on Riemannian g.o. spaces
We prove the integrability of geodesic flows on the Riemannian g.o. spaces of
compact Lie groups, as well as on a related class of Riemannian homogeneous
spaces having an additional principal bundle structure.Comment: 12 pages, minor corrections, final versio
On the Hamiltonian formulation of the trigonometric spin Ruijsenaars-Schneider system
We suggest a Hamiltonian formulation for the spin Ruijsenaars–Schneider system in the trigonometric case. Within this interpretation, the phase space is obtained by a quasi-Hamiltonian reduction performed on (the cotangent bundle to) a representation space of a framed Jordan quiver. For arbitrary quivers, analogous varieties were introduced by Crawley-Boevey and Shaw, and their interpretation as quasi-Hamiltonian quotients was given by Van den Bergh. Using Van den Bergh’s formalism, we construct commuting Hamiltonian functions on the phase space and identify one of the flows with the spin Ruijsenaars–Schneider system. We then calculate all the Poisson brackets between local coordinates, thus answering an old question of Arutyunov and Frolov. We also construct a complete set of commuting Hamiltonians and integrate all the flows explicitly