206 research outputs found
Gravitational waveforms for spinning compact binaries
The rotation of the bodies and the eccentricity of the orbit have significant
effects on the emitted gravitational radiation of binary systems. This work
focuses on the evaluation of the gravitational wave polarization states for
spinning compact binaries. We consider binaries on eccentric orbits and the
spin-orbit interaction up to the 1.5 post-Newtonian order in a way which is
independent of the parameterization of the orbit. The equations of motion for
angular variables are included. The formal expressions of the polarization
states are given with the inclusion of higher order corrections to the
waveform
Lissajous curves with a finite sum of prime number frequencies
The Ulam spiral inspired us to calculate and present Lissajous curves where
the orthogonally added functions are a finite sum of sinus and cosines
functions with consecutive prime number frequencies.Comment: 5 pages and 4 figure
Gravitational waves from binaries on unbound orbits
A generalized true anomaly-type parametrization, convenient to describe both
bound and open orbits of a two-body system in general relativity is introduced.
A complete description of the time evolution of both the radial and of the
angular equations of a binary system taking into account the first order
post-newtonian (1PN) is given. The gravitational radiation field emitted by the
system is computed in the 1PN approximation including higher multipole moments
beyond the standard quadrupole term. The gravitational waveforms in the time
domain are explicitly given up to the 1PN order for unbound orbits, but the
results are also illustrated on binaries on elliptic orbits with special
attention given to the effects of eccentricity.Comment: 27 pages, 10 figures, to appear in Phys. Rev.
A multibaker map for shear flow and viscous heating
A consistent description of shear flow and the accompanied viscous heating as
well the associated entropy balance is given in the framework of a
deterministic dynamical system. A laminar shear flow is modeled by a
Hamiltonian multibaker map which drives velocity and temperature fields. In an
appropriate macroscopic limit one recovers the Navier-Stokes and heat
conduction equations along with the associated entropy balance. This indicates
that results of nonequilibrium thermodynamics can be described by means of an
abstract, sufficiently chaotic and mixing dynamics. A thermostating algorithm
can also be incorporated into this framework.Comment: 11 pages; RevTex with multicol+graphicx packages; eps-figure
An analytic approach to the late ISW effect in a Lambda dominated universe
The integrated Sachs-Wolfe (ISW) effect in a Lambda dominated universe can be
an important factor in the evolution of cosmic microwave background
fluctuations. With the inclusion of cosmological constant we present the
complete analytic solution of the covariant linear perturbations of the
Einstein equations in the Newtonian gauge, in the case of a spatially flat
(K=0), Friedman-Robertson-Walker (FRW) universe, filled with pressureless ideal
fluid. We use the analytic time dependence of the perturbation potentials to
derive the anisotropy power spectrum of the late ISW effect. We choose the
scale invariant Harrison-Zeldovich spectrum for obtaining the C_l momenta and
show the agreement of our results with earlier, numeric calculations.Comment: 10 pages, 1 figur
Etán-etilén kolonna vizsgálata és optimalizálása
Az etán-etilén szétválasztás a vegyipari benzin feldolgozása során az egyik jelentős feladat. A
szeparációhoz nagy mennyiségű hideg és meleg energia szükséges, ezért az energiafelhasználás
csökkentésének lehetősége manapság is aktívan kutatott terület. Jelen cikk témája egy adott
tányérszámú etán-etilén kolonna vizsgálata folyamat szimulációs szoftverrel. A vizsgálatnak két fő
célja van, adott mennyiségű betáp mellett a maximális fejtermék biztosítása és a folyamat lefutásához
szükséges energiamennyiség minimalizálása. A rendszer energiaszükséglete meghatározható a
kiforraló, a kondenzátor és a betáp hőáramának összegével
Scots pine (Pinus sylvestris)
Technical guidelines are targeted to practical forest managers and provide summarized information on the biology and ecology of tree species, distribution ranges, importance and use, genetic knowledge, threats to genetic diversity and recommendations for long-term genetic conservation. For the full list of Technical guidelines produced, please visit http://www.euforgen.org/publications/technical_guidelines.htm
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