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Title Hybrid model with viscous relativistic hydrodynamics: a role of constraints on the shear-stress tensor Author info A. S. Khvorostukhin ... [et al.] Author Khvorostukhin A. S. (34%)
Co-authors Kolomeitsev Evgeni E. 1970- (33%) UMBFP06 - Katedra fyziky
Toneev V. D. (33%)
Source document The European Physical Journal A : Hadrons and Nuclei. Vol. 57, no. 10 (2021), pp. 294-1-294-25. - New York : Springer Nature, 2021 Keywords relativistic hydrodynamics heavy ion collisions viscosity Form. Descr. články - journal articles Language English Country Germany Annotation We present the hybrid model connecting the parton–hadron–string dynamic model (PHSD) and a hydrodynamic model taking into account shear viscosity within the Israel–Stewart approach. The numerical scheme, initialization, and particlization procedure are discussed in detail. The performance of the code is tested on the pion and proton rapidity and transverse mass distributions calculated for Au + Au and Pb+Pb collisions at AGS–SPS energies. The influence of the switch time from transport to hydro models, the viscous parameter, and freeze-out time are discussed. Since the applicability of the Israel–Stewart hydrodynamics assumes the perturbative character of the viscous stress tensor, πμν, which should not exceed the ideal energy–momentum tensor, T μν id , hydrodynamical codes usually rescale the shear stress tensor if the inequality πμν T μν id is not fulfilled in some sense. There are several conditions used in the literature and we analyze in detail the influence of different conditions and values of the cut-off parameter on observables.We show that the form of the corresponding condition plays an important role in the sensitivity of hydrodynamic calculations to the viscous parameter – a ratio of the shear viscosity to the entropy density, η/s. It is shown that the constraints used in the vHLLE and MUSIC models give the same results for the observables.With these constraints, the rapidity distributions and transverse momentum spectra are most sensitive to a change of the η/s ratio. We demonstrate that these constraints do not guarantee that each element of the πμν tensor is smaller than the corresponding element T μν id . As an alternative, a strict condition is used. When applied it reduces the sensitivity of the proton and pion momentum distributions to the viscosity parameter. We performed global fits of the rapidity and transverse mass distributions of pion and protons. It was also found that η/s as a function of the collision energy monotonically increases from Elab = 6 AGeV up to Elab = 40 AGeV and saturates for higher SPS energies. We observe that it is difficult to reproduce simultaneously pion and proton rapidity distribution within our model with the present choice of the equation of state without a phase transition. URL Link na plný text Public work category ADC No. of Archival Copy 50708 Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika 
article
Title Mechanism of r-mode stability in young rapidly rotating pulsars Author info E. E. Kolomeitsev, D. N. Voskresensky Author Kolomeitsev Evgeni E. 1970- (50%) UMBFP06 - Katedra fyziky
Co-authors Voskresensky Dmitri (50%)
Source document The European Physical Journal A : Hadrons and Nuclei. Vol. 50, no. 12 (2014), pp. [1-5]. - Berlin : Springer, 2014 Keywords r-modes viscosity neutron stars young pulsars Language English Country Germany systematics 53 Annotation We demonstrate that stability of r-modes in young rapidly rotating pulsars might be explained if one takes into account strong medium modifications of the nucleon-nucleon interaction because of the softening of pionic degrees of freedom in dense nucleon matter. Presence of the efficient direct Urca processes is not required. Within our model the most rapidly rotating observed young pulsar PSR J0537-6910 should have the mass > 1.8M_sol Public work category ADC No. of Archival Copy 31379 Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika 
unrecognised
Title The hydrodynamic oscillator and its use in the investigation of chemical oscillators Par.title Hydrodynamický oscilátor a jeho využitie v štúdiu chemických oscilátorov Author info Ľubica Adamčíková, Zuzana Melichová Author Adamčíková Ľubica (50%)
Co-authors Melichová Zuzana 1966- (50%) UMBFP08 - Katedra chémie
Source document Collection of Czechoslovak Chemical Communications. Vol. 57, no. 8 (1992), pp. 1621-1628. - Prague : The Czech Academy of Sciences, 1992 Keywords hydrodynamické oscilátory hydrodynamic oscillators oscilácie kmitanie - oscillation viskozita viscosity Language English Country -CS systematics 54 Public work category ADF No. of Archival Copy 22425 Repercussion category ORLIK, Marek. Reakcje oscylacyjne : porządek i chaos. Warszawa : Wydawnictwa naukowo-techniczne, 1996. [343] s. ISBN 83-204-1970-0.
KLEČKOVÁ, Marta - BLAŽKOVÁ, Radmila. Hydrodynamický oscilátor ve školním experimentu. In 50. sjezd chemických společností, Zlín, 8. - 11. záři 1997. Olomouc : Univerzita Palackého, 1997. ISBN 80-7067-745-7, s. 155.
Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika unrecognised