12,798 research outputs found
Maeda-Dadhich Solutions as Real Black Holes
A four-dimensional static Schwarzschild-like solution obtained in [3]-[6] in
the frames of the Einstein-Gauss-Bonnet gravity at the Kaluza-Klein split is
analyzed. The matter in these solutions is created by auxiliary dimensions. The
main goal of our work is to study physically sensible characteristics, which
could be observable. Study of the perturbed equations demonstrates their
stability under linear perturbations. The specific combinations of the
parameters, permitting to construct black hole-like objects with one or two
horizons or naked singularities are determined. Stable orbits of test particles
around these black holes are presented. We show the exotic thermodynamical
properties of the solution, when the Hawking evaporation law has the behavior
opposite to usual one in General Relativity
Nonlinearity of vacuum reggeons and exclusive diffractive production of vector mesons at HERA
The processes of exclusive photo- and electroproduction of vector mesons
(770), (1020) and (3096) at collision energies and transferred momenta squared are considered in
the framework of a phenomenological Regge-eikonal scheme with nonlinear Regge
trajectories in which their QCD asymptotic behavior is taken into account
explicitly. By comparison of available experimental data from ZEUS and H1
Collaborations with the model predictions it is demonstrated that corresponding
angular distributions and integrated cross-sections in the above-mentioned
kinematical range can be quantitatively described with use of two -even
vacuum Regge trajectories. These are the "soft" pomeron dominating the high
energy reactions without a hard scale and the "hard" pomeron giving an
essential contribution to photo- and electroproduction of heavy vector mesons
and deeply virtual electroproduction of light vector mesons.Comment: 25 pages, 12 figure
Controlling integrability in a quasi-1D atom-dimer mixture
We analytically study the atom-dimer scattering problem in the
near-integrable limit when the oscillator length l_0 of the transverse
confinement is smaller than the dimer size, ~l_0^2/|a|, where a<0 is the
interatomic scattering length. The leading contributions to the atom-diatom
reflection and break-up probabilities are proportional to a^6 in the bosonic
case and to a^8 for the up-(up-down) scattering in a two-component fermionic
mixture. We show that by tuning a and l_0 one can control the "degree of
integrability" in a quasi-1D atom-dimer mixture in an extremely wide range
leaving thermodynamic quantities unchanged. We find that the relaxation to
deeply bound states in the fermionic (bosonic) case is slower (faster) than
transitions between different Bethe ansatz states. We propose a realistic
experiment for detailed studies of the crossover from integrable to
nonintegrable dynamics.Comment: 12 pages, 1 figur
Active shielding of magnetic field with circular space-time characteristic
Aim. The synthesis of two degree of freedom robust two circuit system of active shielding of magnetic field with circular spacetime characteristic, generated by overhead power lines with "triangle" type of phase conductors arrangements for reducing the magnetic flux density to the sanitary standards level and to reducing the sensitivity of the system to plant parameters uncertainty. Methodology. The synthesis is based on the multi-criteria game decision, in which the payoff vector is calculated on the basis of the Maxwell equations quasi-stationary approximation solutions. The game decision is based on the stochastic particles multiswarm optimization algorithms. The initial parameters for the synthesis by system of active shielding are the location of the overhead power lines with respect to the shielding space, geometry and number of shielding coils, operating currents, as well as the size of the shielding space and magnetic flux density normative value, which should be achieved as a result of shielding. The objective of the synthesis is to determine their number, configuration, spatial arrangementand and shielding coils currents, setting algorithm of the control systems as well as the resulting of the magnetic flux density value at the shielding space. Results. Computer simulation and field experimental research results of two degree of freedom robust two circuit system of active shielding of magnetic field, generated by overhead power lines with Β«triangleΒ» type of phase conductors arrangements are given. The possibility of initial magnetic flux density level reducing and system sensitivity reducing to the plant parameters uncertainty is shown. Originality. For the first time the synthesis, theoretical and experimental research of two degree of freedom robust two -circuit t system of active shielding of magnetic field generated by single-circuit overhead power line with phase conductors triangular arrangements carried out. Practical value. Practical recommendations from the point of view of the practical implementation on reasonable choice of the spatial arrangement of two shielding coils of robust two -circuit system of active shielding of the magnetic field with circular space-time characteristic generated by single-circuit overhead power line with phase conductors triangular arrangements are given.Π¦Π΅Π»Ρ. Π‘ΠΈΠ½ΡΠ΅Π· ΠΊΠΎΠΌΠ±ΠΈΠ½ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ ΡΠΎΠ±Π°ΡΡΠ½ΠΎΠΉ Π΄Π²ΡΡ
ΠΊΠΎΠ½ΡΡΡΠ½ΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΠΊΡΠ°Π½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ»Ρ Ρ ΠΊΡΡΠ³ΠΎΠ²ΠΎΠΉ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π΅Π½Π½ΠΎ-Π²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΉ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΎΠΉ, Π³Π΅Π½Π΅ΡΠΈΡΡΠ΅ΠΌΠΎΠ³ΠΎ ΠΎΠ΄Π½ΠΎΠΊΠΎΠ½ΡΡΡΠ½ΠΎΠΉ Π²ΠΎΠ·Π΄ΡΡΠ½ΠΎΠΉ Π»ΠΈΠ½ΠΈΠ΅ΠΉ ΡΠ»Π΅ΠΊΡΡΠΎΠΏΠ΅ΡΠ΅Π΄Π°ΡΠΈ Ρ ΡΡΠ΅ΡΠ³ΠΎΠ»ΡΠ½ΡΠΌ ΠΏΠΎΠ΄Π²Π΅ΡΠΎΠΌ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΎΠ² Π΄Π»Ρ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΡ ΠΈΠ½Π΄ΡΠΊΡΠΈΠΈ ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ»Ρ Π΄ΠΎ ΡΡΠΎΠ²Π½Ρ ΡΠ°Π½ΠΈΡΠ°ΡΠ½ΡΡ
Π½ΠΎΡΠΌ ΠΈ Π΄Π»Ρ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΡ ΡΡΠ²ΡΡΠ²ΠΈΡΠ΅Π»ΡΠ½ΠΎΡΡΠΈ ΡΠΈΡΡΠ΅ΠΌΡ ΠΊ Π½Π΅ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Π½ΠΎΡΡΠΈ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² ΠΎΠ±ΡΠ΅ΠΊΡΠ° ΡΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡ. ΠΠ΅ΡΠΎΠ΄ΠΎΠ»ΠΎΠ³ΠΈΡ. Π‘ΠΈΠ½ΡΠ΅Π· ΠΎΡΠ½ΠΎΠ²Π°Π½ Π½Π° ΡΠ΅ΡΠ΅Π½ΠΈΠΈ ΠΌΠ½ΠΎΠ³ΠΎΠΊΡΠΈΡΠ΅ΡΠΈΠ°Π»ΡΠ½ΠΎΠΉ ΡΡΠΎΡ
Π°ΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΈΠ³ΡΡ, Π² ΠΊΠΎΡΠΎΡΠΎΠΉ Π²Π΅ΠΊΡΠΎΡΠ½ΡΠΉ Π²ΡΠΈΠ³ΡΡΡ Π²ΡΡΠΈΡΠ»ΡΠ΅ΡΡΡ Π½Π° ΠΎΡΠ½ΠΎΠ²Π°Π½ΠΈΠΈ ΡΠ΅ΡΠ΅Π½ΠΈΠΉ ΡΡΠ°Π²Π½Π΅Π½ΠΈΠΉ ΠΠ°ΠΊΡΠ²Π΅Π»Π»Π° Π² ΠΊΠ²Π°Π·ΠΈΡΡΠ°ΡΠΈΠΎΠ½Π°ΡΠ½ΠΎΠΌ ΠΏΡΠΈΠ±Π»ΠΈΠΆΠ΅Π½ΠΈΠΈ. Π Π΅ΡΠ΅Π½ΠΈΠ΅ ΠΈΠ³ΡΡ Π½Π°Ρ
ΠΎΠ΄ΠΈΡΡΡ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ Π°Π»Π³ΠΎΡΠΈΡΠΌΠΎΠ² ΡΡΠΎΡ
Π°ΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΌΡΠ»ΡΡΠΈΠ°Π³Π΅Π½ΡΠ½ΠΎΠΉ ΠΎΠΏΡΠΈΠΌΠΈΠ·Π°ΡΠΈΠΈ ΠΌΡΠ»ΡΡΠΈΡΠΎΠ΅ΠΌ ΡΠ°ΡΡΠΈΡ. ΠΡΡ
ΠΎΠ΄Π½ΡΠΌΠΈ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠ°ΠΌΠΈ Π΄Π»Ρ ΡΠΈΠ½ΡΠ΅Π·Π° ΡΠΈΡΡΠ΅ΠΌΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΠΊΡΠ°Π½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΠ²Π»ΡΡΡΡΡ ΡΠ°ΡΠΏΠΎΠ»ΠΎΠΆΠ΅Π½ΠΈΠ΅ Π²ΡΡΠΎΠΊΠΎΠ²ΠΎΠ»ΡΡΠ½ΠΎΠΉ
Π»ΠΈΠ½ΠΈΠΉ ΡΠ»Π΅ΠΊΡΡΠΎΠΏΠ΅ΡΠ΅Π΄Π°ΡΠΈ ΠΏΠΎ ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΡ ΠΊ ΡΠΊΡΠ°Π½ΠΈΡΡΠ΅ΠΌΠΎΠΌΡ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Ρ, Π³Π΅ΠΎΠΌΠ΅ΡΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ°Π·ΠΌΠ΅ΡΡ, ΠΊΠΎΠ»ΠΈΡΠ΅ΡΡΠ²ΠΎ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΎΠ² ΠΈ ΡΠ°Π±ΠΎΡΠΈΠ΅ ΡΠΎΠΊΠΈ Π»ΠΈΠ½ΠΈΠΈ ΡΠ»Π΅ΠΊΡΡΠΎΠΏΠ΅ΡΠ΅Π΄Π°ΡΠΈ, Π° ΡΠ°ΠΊΠΆΠ΅ ΡΠ°Π·ΠΌΠ΅ΡΡ ΡΠΊΡΠ°Π½ΠΈΡΡΠ΅ΠΌΠΎΠ³ΠΎ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π° ΠΈ Π½ΠΎΡΠΌΠ°ΡΠΈΠ²Π½ΠΎΠ΅ Π·Π½Π°ΡΠ΅Π½ΠΈΠ΅ ΠΈΠ½Π΄ΡΠΊΡΠΈΠΈ ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ»Ρ, ΠΊΠΎΡΠΎΡΠΎΠ΅ Π΄ΠΎΠ»ΠΆΠ½ΠΎ Π±ΡΡΡ Π΄ΠΎΡΡΠΈΠ³Π½ΡΡΠΎ Π² ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ ΡΠΊΡΠ°Π½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ. ΠΠ°Π΄Π°ΡΠ΅ΠΉ ΡΠΈΠ½ΡΠ΅Π·Π° ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ ΠΊΠΎΠ»ΠΈΡΠ΅ΡΡΠ²Π°, ΠΊΠΎΠ½ΡΠΈΠ³ΡΡΠ°ΡΠΈΠΈ, ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π΅Π½Π½ΠΎΠ³ΠΎ ΡΠ°ΡΠΏΠΎΠ»ΠΎΠΆΠ΅Π½ΠΈΡ ΠΈ ΡΠΎΠΊΠΎΠ² ΡΠΊΡΠ°Π½ΠΈΡΡΡΡΠΈΡ
ΠΎΠ±ΠΌΠΎΡΠΎΠΊ, Π°Π»Π³ΠΎΡΠΈΡΠΌΠ° ΡΠ°Π±ΠΎΡΡ ΡΠΈΡΡΠ΅ΠΌΡ ΡΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡ, Π° ΡΠ°ΠΊΠΆΠ΅ ΡΠ΅Π·ΡΠ»ΡΡΠΈΡΡΡΡΠ΅Π³ΠΎ Π·Π½Π°ΡΠ΅Π½ΠΈΡ ΠΈΠ½Π΄ΡΠΊΡΠΈΠΈ ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ»Ρ Π² ΡΠΊΡΠ°Π½ΠΈΡΡΠ΅ΠΌΠΎΠΌ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π΅. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ. ΠΡΠΈΠ²ΠΎΠ΄ΡΡΡΡ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ ΡΠ΅ΠΎΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈ ΠΏΠΎΠ»Π΅Π²ΡΡ
ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΡΡ
ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΉ ΠΊΠΎΠΌΠ±ΠΈΠ½ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ ΡΠΎΠ±Π°ΡΡΠ½ΠΎΠΉ Π΄Π²ΡΡ
ΠΊΠΎΠ½ΡΡΡΠ½ΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΠΊΡΠ°Π½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ»Ρ, Π³Π΅Π½Π΅ΡΠΈΡΡΠ΅ΠΌΠΎΠ³ΠΎ Π²ΠΎΠ·Π΄ΡΡΠ½ΠΎΠΉ Π»ΠΈΠ½ΠΈΠ΅ΠΉ ΡΠ»Π΅ΠΊΡΡΠΎΠΏΠ΅ΡΠ΅Π΄Π°ΡΠΈ Ρ ΡΡΠ΅ΡΠ³ΠΎΠ»ΡΠ½ΡΠΌ ΠΏΠΎΠ΄Π²Π΅ΡΠΎΠΌ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΎΠ². ΠΠΎΠΊΠ°Π·Π°Π½Π° Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΡ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΡ ΡΡΠΎΠ²Π½Ρ ΠΈΠ½Π΄ΡΠΊΡΠΈΠΈ ΠΈΡΡ
ΠΎΠ΄Π½ΠΎΠ³ΠΎ ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ»Ρ Π²Π½ΡΡΡΠΈ ΡΠΊΡΠ°Π½ΠΈΡΡΠ΅ΠΌΠΎΠ³ΠΎ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π° ΠΈ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΡ ΡΡΠ²ΡΡΠ²ΠΈΡΠ΅Π»ΡΠ½ΠΎΡΡΠΈ ΡΠΈΡΡΠ΅ΠΌΡ ΠΊ Π½Π΅ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Π½ΠΎΡΡΡΠΌ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² ΠΎΠ±ΡΠ΅ΠΊΡΠ° ΡΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡ. ΠΡΠΈΠ³ΠΈΠ½Π°Π»ΡΠ½ΠΎΡΡΡ. ΠΠΏΠ΅ΡΠ²ΡΠ΅ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½Ρ ΡΠΈΠ½ΡΠ΅Π·, ΡΠ΅ΠΎΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΊΠΎΠΌΠ±ΠΈΠ½ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ ΡΠΎΠ±Π°ΡΡΠ½ΠΎΠΉ Π΄Π²ΡΡ
ΠΊΠΎΠ½ΡΡΡΠ½ΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΠΊΡΠ°Π½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ»Ρ, Π³Π΅Π½Π΅ΡΠΈΡΡΠ΅ΠΌΠΎΠ³ΠΎ ΠΎΠ΄Π½ΠΎΠΊΠΎΠ½ΡΡΡΠ½ΠΎΠΉ Π²ΠΎΠ·Π΄ΡΡΠ½ΠΎΠΉ Π»ΠΈΠ½ΠΈΠ΅ΠΉ ΡΠ»Π΅ΠΊΡΡΠΎΠΏΠ΅ΡΠ΅Π΄Π°ΡΠΈ Ρ ΡΡΠ΅ΡΠ³ΠΎΠ»ΡΠ½ΡΠΌ ΠΏΠΎΠ΄Π²Π΅ΡΠΎΠΌ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΎΠ². ΠΡΠ°ΠΊΡΠΈΡΠ΅ΡΠΊΠ°Ρ ΡΠ΅Π½Π½ΠΎΡΡΡ. ΠΡΠΈΠ²ΠΎΠ΄ΡΡΡΡ ΠΏΡΠ°ΠΊΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ΅ΠΊΠΎΠΌΠ΅Π½Π΄Π°ΡΠΈΠΈ ΠΏΠΎ ΠΎΠ±ΠΎΡΠ½ΠΎΠ²Π°Π½Π½ΠΎΠΌΡ Π²ΡΠ±ΠΎΡΡ Ρ ΡΠΎΡΠΊΠΈ Π·ΡΠ΅Π½ΠΈΡ ΠΏΡΠ°ΠΊΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π΅Π½Π½ΠΎΠ³ΠΎ ΡΠ°ΡΠΏΠΎΠ»ΠΎΠΆΠ΅Π½ΠΈΡ Π΄Π²ΡΡ
ΡΠΊΡΠ°Π½ΠΈΡΡΡΡΠΈΡ
ΠΎΠ±ΠΌΠΎΡΠΎΠΊ Π΄Π²ΡΡ
ΠΊΠΎΠ½ΡΡΡΠ½ΠΎΠΉ ΡΠΎΠ±Π°ΡΡΠ½ΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΠΊΡΠ°Π½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ»Ρ Ρ ΠΊΡΡΠ³ΠΎΠ²ΠΎΠΉ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π΅Π½Π½ΠΎ-Π²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΉ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΎΠΉ, ΡΠΎΠ·Π΄Π°Π²Π°Π΅ΠΌΠΎΠ³ΠΎ ΠΎΠ΄Π½ΠΎΠΊΠΎΠ½ΡΡΡΠ½ΠΎΠΉ Π²ΠΎΠ·Π΄ΡΡΠ½ΠΎΠΉ Π»ΠΈΠ½ΠΈΠ΅ΠΉ ΡΠ»Π΅ΠΊΡΡΠΎΠΏΠ΅ΡΠ΅Π΄Π°ΡΠΈ Ρ ΡΡΠ΅ΡΠ³ΠΎΠ»ΡΠ½ΡΠΌ ΠΏΠΎΠ΄Π²Π΅ΡΠΎΠΌ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΎΠ²
A note on the Deser-Tekin charges
Perturbed equations for an arbitrary metric theory of gravity in
dimensions are constructed in the vacuum of this theory. The nonlinear part
together with matter fields are a source for the linear part and are treated as
a total energy-momentum tensor. A generalized family of conserved currents
expressed through divergences of anti-symmetrical tensor densities
(superpotentials) linear in perturbations is constructed. The new family
generalizes the Deser and Tekin currents and superpotentials in quadratic
curvature gravity theories generating Killing charges in dS and AdS vacua. As
an example, the mass of the -dimensional Schwarzschild black hole in an
effective AdS spacetime (a solution in the Einstein-Gauss-Bonnet theory) is
examined.Comment: LATEX, 7 pages, no figure
Genotoxic effects of copper sulfate in rabbits
This study was carried out to determine the genotoxic effects of oral application of CuSO4 in rabbits by the chromosome aberration (CA) and sister chromatid exchange (SCE) tests. Ten male New Zealand rabbits (5 months old, weighing 3.5-4.0 kg) were allocated into two groups. The first group received CuSO4 (5H2O) in drinking water for 6 consecutive days. The second group was used as a control. On the 7th day, blood samples were taken from the ear marginal vein and the SCE and CA tests in peripheral lymphocytes were used as genotoxicity and mutagenicity endpoints, respectively. Results showed a significant increase in the frequencies of the aberrant cells (7.4Β±0.24, P<0.001) and CA (chromatid fragments 3.2Β±0.37, chromosome fragments 4.2Β±0.37, P<0.001), and total aberrations (7.4Β±0.24, P<0.001) after the treatment with CuSO4 when compared with the control group. The level of SCE per cell in the CuSO4-treated rabbits (9.66Β±0.062) was significantly higher than in rabbits from the control group. These findings show that copper exhibits a genotoxic and mutagenic potential in rabbits
Mass Dependence of Ultracold Three-Body Collision Rates
We show that many aspects of ultracold three-body collisions can be
controlled by choosing the mass ratio between the collision partners. In the
ultracold regime, the scattering length dependence of the three-body rates can
be substantially modified from the equal mass results. We demonstrate that the
only non-trivial mass dependence is due solely to Efimov physics. We have
determined the mass dependence of the three-body collision rates for all
heteronuclear systems relevant for two-component atomic gases with resonant
s-wave interspecies interactions, which includes only three-body systems with
two identical bosons or two identical fermions
First result with AMBER+FINITO on the VLTI: The high-precision angular diameter of V3879 Sgr
Our goal is to demonstrate the potential of the interferometric AMBER
instrument linked with the Very Large Telescope Interferometer (VLTI)
fringe-tracking facility FINITO to derive high-precision stellar diameters. We
use commissioning data obtained on the bright single star V3879 Sgr. Locking
the interferometric fringes with FINITO allows us to record very low contrast
fringes on the AMBER camera. By fitting the amplitude of these fringes, we
measure the diameter of the target in three directions simultaneously with an
accuracy of 25 micro-arcseconds. We showed that V3879 Sgr has a round
photosphere down to a sub-percent level. We quickly reached this level of
accuracy because the technique used is independent from absolute calibration
(at least for baselines that fully span the visibility null). We briefly
discuss the potential biases found at this level of precision. The proposed
AMBER+FINITO instrumental setup opens several perspectives for the VLTI in the
field of stellar astrophysics, like measuring with high accuracy the oblateness
of fast rotating stars or detecting atmospheric starspots
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