We study the evolution of nitrogen in Galactic halo, thick disc, thin disc and bulge by comparing detailed chemical models with recent observations. The used this work have already been constrained to explain abundance patterns $\alpha$-elements metallicity distribution functions stars; here, we adopt them investigate origin N different components. First, consider sets yields importance various...

Abstract Rossby waves are a pervasive feature of the large-scale motions Earth’s atmosphere and oceans. These (also known as planetary r-modes) also play an important role in dynamics different astrophysical objects such solar interior, discs, rapidly rotating stars, exoplanetary atmospheres. This paper provides review theoretical observational aspects on spatial temporal scales various setting...

Spiral structure (both flocculent and Grand Design types) is very rarely observed in dwarf galaxies because the formation of spiral arms requires special conditions. In this work we analyze sample about 40 dS-galaxies found by scanning eye images late-type with $${{m}_{B}} < {{15}^{m}}$$ $${{M}_{B}} > - {{18}^{m}}$$ photometric diameter $${{D}_{{25}}} 12$$ kpc. We that apart from lower average ...

Some recent philosophical debate about persistence has focussed on an argument against perdurantism that discusses rotating perfectly homogeneous discs (the ‘rotating discs argument’; RDA). The argument has been mostly discussed by metaphysicians, though it appeals to ideas from classical mechanics, especially about rotation. In contrast, I assess the RDA from the perspective of the philosophy ...

Antibiotic resistance of Intensive Care Unit (ICU) born aerobic gram-negative bacteria was evaluated during a six months period at a teaching hospital in Tehran, and determination of the validity of the results obtained from disc diffusion tests, using discs manufactured in Iran. Disc susceptibility tests using Iranian and standard discs (diffusion discs available in international markets) were...

ABSTRACT Non-ideal magnetohydrodynamic (MHD) processes – namely Ohmic resistivity, ambipolar diffusion, and the Hall effect modify early stages of star formation process surrounding environment. Collectively, they have been shown to promote disc or hinder outflows. But which non-ideal has greatest impact? Using three-dimensional smoothed particle radiation MHD simulations, we model gravitationa...

ABSTRACT Rotationally supported, cold, gaseous discs are ubiquitous in astrophysics and appear a diverse set of systems, such as protoplanetary discs, accretion around black holes, or large spiral galaxies. Capturing the gas dynamics accurately these systems is challenging numerical simulations due to low sound speed compared bulk velocity gas, resolution limitations full disc models, fact that...