133 research outputs found
Weak uniqueness and partial regularity for the composite membrane problem
We establish a generic weak uniqueness result and partial regularity of the
free boundary and of minimizers for the composite membrane problem
The Flow Constraint Influence on the Properties of Nuclear Matter Critical Endpoint
We propose a novel family of equations of state for symmetric nuclear matter
based on the induced surface tension concept for the hard-core repulsion. It is
shown that having only four adjustable parameters the suggested equations of
state can, simultaneously, reproduce not only the main properties of the
nuclear matter ground state, but the proton flow constraint up its maximal
particle number densities. Varying the model parameters we carefully examine
the range of values of incompressibility constant of normal nuclear matter and
its critical temperature which are consistent with the proton flow constraint.
This analysis allows us to show that the physically most justified value of
nuclear matter critical temperature is 15.5-18 MeV, the incompressibility
constant is 270-315 MeV and the hard-core radius of nucleons is less than 0.4
fm.Comment: 8 pages, 3 figure
Regularity of the minimizers in the composite membrane problem in R^2
We study the regularity of minimizers to the composite membrane problem in
the plane (ie given a domain omega and a positive number A, smaller than the
measure of omega, minimize the first Dirichlet eigenvalue for the Schrodinger
operator with potential equal to a fixed multiple of the characteristic
function of a subset D of omega, with measure A). We show that for minimizers,
the boundary of D is analytic
Antibacterial activities of Allium vineale, Chaerophyllum macropodum and Prangos ferulacea
Allium vineale L., Chaerophyllum macropodum Boiss. and Prangos ferulacea (L.) Lindl. have been used for cheese production in Turkiye for many centuries. In addition, it is traditionally believed by localpeople that these plants have antibacterial activity. The purpose of this study was to evaluate the antibacterial activity of these plants. Four solvent extracts (in methanol, ethanol, n-hexane and water) ofthe plants were investigated against Bacillus cereus, Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Salmonella enteritidis and Salmonella typhimurium by using disc diffusion method. The methanol, ethanol and nhexane extracts of all the plants showed antibacterial activity against B. cereus, B. subtilis, M. luteus and S. aureus, while the methanol extract of Allium vineale was also active against P. mirabilis.However, the water extracts of these plants had no antibacterial activity against any of the bacteria tested. The methanol extracts had the higher activity followed by the extracts of ethanol and n-hexane.A. vineale showed the higher antibacterial activity as compared with C. macropodum and P. ferulacea. As a result, organic solvent extracts (especially methanol and ethanol extracts) of these plants can beused as natural antibacterial additives for incorporation in cheese and various food products
How does dark matter affect compact star properties and high density constraints of strongly interacting matter
We study the impact of asymmetric bosonic dark matter on neutron starproperties, including possible changes of tidal deformability, maximum mass,radius, and matter distribution inside the star. The conditions at which darkmatter particles tend to condensate in the star's core or create an extendedhalo are presented. We show that dark matter condensed in a core leads to adecrease of the total gravitational mass and tidal deformability compared to apure baryonic star, which we will perceive as an effective softening of theequation of state. On the other hand, the presence of a dark matter haloincreases those observable quantities. Thus, observational data on compactstars could be affected by accumulated dark matter and, consequently,constraints we put on strongly interacting matter at high densities. To confirmthe presence of dark matter in the compact star's interior, and to break thedegeneracy between the effect of accumulated dark matter and stronglyinteracting matter properties at high densities, several astrophysical and GWtests are proposed.<br
Chemical Freeze-out of Strange Particles and Possible Root of Strangeness Suppression
Two approaches to treat the chemical freeze-out of strange particles in
hadron resonance gas model are analyzed. The first one employs their
non-equillibration via the usual \gamma_s factor and such a model describes the
hadron multiplicities measured in nucleus-nucleus collisions at AGS, SPS and
RHIC energies with \chi^2/dof = 1.15. Surprisingly, at low energies we find not
the strangeness suppression, but its enhancement. Also we suggest an
alternative approach to treat the strange particle freeze-out separately, but
with the full chemical equilibration. This approach is based on the
conservation laws which allow us to connect the freeze-outs of strange and
non-strange hadrons. Within the suggested approach the same set of hadron
multiplicities can be described better than within the conventional approach
with \chi^2/dof = 1.06. Remarkably, the fully equilibrated approach describes
the strange hyperons and antihyperons much better than the conventional one.Comment: 6 pages, 5 figure
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