112 research outputs found
Abstract composition rule for relativistic kinetic energy in the thermodynamical limit
We demonstrate by simple mathematical considerations that a power-law tailed
distribution in the kinetic energy of relativistic particles can be a limiting
distribution seen in relativistic heavy ion experiments. We prove that the
infinite repetition of an arbitrary composition rule on an infinitesimal amount
leads to a rule with a formal logarithm. As a consequence the stationary
distribution of energy in the thermodynamical limit follows the composed
function of the Boltzmann-Gibbs exponential with this formal logarithm. In
particular, interactions described as solely functions of the relative
four-momentum squared lead to kinetic energy distributions of the
Tsallis-Pareto (cut power-law) form in the high energy limit.Comment: Submitted to Europhysics Letters. LaTeX, 3 eps figure
The cultural and geopolitical dimensions of nation-building in the Ukraine
Ukraine belongs among those young countries where the beginnings of democratisation and nation-building approximately coincided. While the development of nation states in Central Europe was usually preceded by the development of nations, the biggest dilemma in the Ukraine is whether a nation-state programme — parallel to the aim of state-building — is able to bring unfinished nation-building to completion. Ukraine sways between the EU and Russia with enormous amplitude. The alternating orientation between the West and the East can be ascribed to superpower ambitions reaching beyond Ukraine. Eventually, internal and external determinants are intertwined and mutually interact with one another. The aim of the paper is to explain the dilemmas arising from identity problems behind the Ukraine’s internal and external orientation
Multiphysical computations of the electrical machines using FEM
In this paper three problems representing the multiphysical aspect of electrical
machine computation are addressed. The interaction between magnetic and structural
mechanical systems is demonstrated by the finite element method (FEM) structural
investigation of the turbo-generator end-winding deformations. Multiphysical simulation of
the acoustical problem is presented by weakly coupled electromagnetic, structural dynamic
and acoustic simulations. And finally, a procedure based on computational fluid dynamics
(CFD) simulation for acquiring the convective heat transfer coefficients is proposed in order
to improve the accuracy of the coupled electro-thermal FEM simulations
Quantitative dSTORM superresolution microscopy
Localization based superresolution technique provides the highest spatial resolution in optical microscopy. The final image is formed by the precise localization of individual fluorescent dyes, therefore the quantification of the collected data requires special protocols, algorithms and validation processes. The effects of labelling density and structured background on the final image quality were studied theoretically using the TestSTORM simulator. It was shown that system parameters affect the morphology of the final reconstructed image in different ways and the accuracy of the imaging can be determined. Although theoretical studies help in the optimization procedure, the quantification of experimental data raises additional issues, since the ground truth data is unknown. Localization precision, linker length, sample drift and labelling density are the major factors that make quantitative data analysis difficult. Two examples (geometrical evaluation of sarcomere structures and counting the γH2AX molecules in DNA damage induced repair foci) have been presented to demonstrate the efficiency of quantitative evaluation experimentally
The First Comprehensive Photometric Study of the Algol-type System CL Aurigae
We present the first extensive photometric results of CL Aur from our BVRI
CCD photometry made on 22 nights from 2003 November through 2005 February.
Fifteen new timings of minimum light were obtained. During the past 104 years,
the orbital period has varied due to a periodic oscillation superposed on a
continuous period increase. The period and semi-amplitude of the oscillation
are about 21.6 yrs and 0.0133 d, respectively. This detail is interpreted as a
light-travel-time effect due to a low-luminosity K-type star gravitationally
bound to the CL Aur close system. Our photometric study indicates that CL Aur
is a relatively short-period Algol-type binary with values of q=0.602 and
i=88.2. Mass transfer from the secondary to the primary eclipsing
component is at least partly responsible for the observed secular period change
with a rate of dP/dt = +1.4 d yr. A cool spot model has
been calculated but we think that an alternative hot-spot model resulting from
a gas stream impact on the hot star is more reasonable despite two difficulties
with the explanation. Absolute dimensions of the eclipsing system are deduced
and its present state is compared with tracks for single star and conservative
close binary evolution. Finally, we examine the possible reconciliation of two
different calculations of the luminosity of the hot spot and a
re-interpretation of the secular term of the period variability.Comment: 26 pages, including 5 figures and 9 tables, accepted for publication
in A
A thermodynamic approach to the relaxation of viscosity and thermal conductivity
A novel higher order theory of relaxation of heat and viscosity is proposed
based on corrections to the traditional treatment of the relativistic energy
density. In the framework of generalized Bjorken scaling solution to
accelerating longitudinal flow we point out that the energy flux can be
consequently set to zero in the stationary case, independently of the choice of
a specific local rest frame, like the Landau-Lifshitz or Eckart one. We
investigate and compare several cooling and re-heating scenarios for the Quark
Gluon Plasma (QGP) within this approach.Comment: 13 pages, 4 figure
Testing SNe Ia distance measurement methods with SN 2011fe
The nearby, bright, almost completely unreddened Type Ia supernova 2011fe in
M101 provides a unique opportunity to test both the precision and the accuracy
of the extragalactic distances derived from SNe Ia light curve fitters. We
apply the current, public versions of the independent light curve fitting codes
MLCS2k2 and SALT2 to compute the distance modulus of SN 2011fe from
high-precision, multi-color (BVRI) light curves. The results from the two
fitting codes confirm that 2011fe is a "normal" (not peculiar) and only
slightly reddened SN Ia. New unreddened distance moduli are derived as 29.21
+/- 0.07 mag (D ~ 6.95 +/- 0.23$ Mpc, MLCS2k2), and 29.05 +/- 0.07 mag (6.46
+/- 0.21 Mpc, SALT2). Despite the very good fitting quality achieved with both
light curve fitters, the resulting distance moduli are inconsistent by 2 sigma.
Both are marginally consistent (at ~1 sigma) with the HST Key Project distance
modulus for M101. The SALT2 distance is in good agreement with the recently
revised Cepheid- and TRGB-distance to M101. Averaging all SN- and Cepheid-based
estimates, the absolute distance to M101 is ~6.6 +/- 0.5 Mpc.Comment: 8 pages, 7 figures, accepted for publication in A&
Effect of beta-carotene and nucleotide base supplementation on blood composition and immune response in weaned pigs
The effect of synthetic beta-carotene and synthetic nucleotide base on daily weight gain, feed consumption and certain haematological, biochemical and immunological parameters of piglets were studied in a 3-week experiment. Beginning one week prior to weaning, the diet fed to one experimental group of piglets was supplemented with 10% Rovimix Beta-carotene at 875 mg/kg of diet. Synthetic uracil and adenine (98%, Sigma-Aldrich) were mixed into the diet of the other experimental group at doses of 500 mg/kg of diet for each substance. The control group received the basic diet without any supplementation. The changes observed over time in the haematological parameters and in certain biochemical variables could be regarded as physiological. By day 21 of the experiment, beta-carotene supplementation had significantly lowered the neutrophilic granulocyte percentage and elevated the lymphocyte percentage, while in the other two groups a change of opposite tendency occurred. At the end of the experimental period there was a decrease in plasma vitamin E concentration due to carotene supplementation (control: 6.1 ± 1.5, nucleotide: 6.3 ± 2.5, carotene: 2.3 ± 1.5 mg/L). Lymphocyte blastogenesis induced by phytohaemagglutinin and concanavalin A increased by 50 and 130%, respectively, in the nucleotide group and by 60 and 30%, respectively, in the carotene group, while it did not change in the control group. The supplements exerted no positive effect on the in vivo cellular immune response
Interferometric Observations of the Hierarchical Triple System Algol
Algol is a triple stellar system consisting of a close semidetached binary
orbited by a third object. Due to the disputed spatial orientation of the close
pair, the third body perturbation of this pair is a subject of much research.
In this study, we determine the spatial orientation of the close pair orbital
plane using the CHARA Array, a six-element optical/IR interferometer located on
Mount Wilson, and state-of-the-art e-EVN interferometric techniques. We find
that the longitude of the line of nodes for the close pair is
\Omega_1=48\degr\pm2\degr and the mutual inclination of the orbital planes of
the close and the wide pairs is 95\degr\pm3\degr. This latter value differs
by 5\degr from the formerly known 100\degr which would imply a very fast
inclination variation of the system, not borne out by the photometric
observations. We also investigated the dynamics of the system with numerical
integration of the equations of motions using our result as an initial
condition. We found large variations in the inclination of the close pair (its
amplitude \sim 170\degr) with a period of about 20 millennia. This result is
in good agreement with the photometrically observed change of amplitude in
Algol's primary minimum.Comment: ApJ, in press. This is the accepted version; will be changed with the
final version later (minor language corrections
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