We present a sample of 42 high-mass low-metallicity outliers from the mass–metallicity relation of star-forming galaxies. These galaxies have stellar masses that span log(M⋆/M⊙) ∼ 9.4 to 11.1 and are offset from the mass–metallicity relation by −0.3 to −0.85dex in 12+ log(O/H). In general, they are extremely blue, have high star formation rates for their masses, and are morphologically disturbe...

The presence of a substantial number of hot stars in the extremely metal-rich open cluster NGC 6791 has been a mystery. If these hot stars are in their core helium burning phase, they are significantly bluer (hotter) than predicted by canonical stellar evolution theory. No obvious explanation is available yet. We consider the effects of mass loss during the evolution of horizontal branch (HB) s...

Recent STIS and FUSE observations have detected O VI absorption lines at low redshift that are not clearly associated with any galactic system. In this paper, we argue that these lines are due to metal enriched hot gas in the intergalactic medium. Using numerical simulations of a cosmological-constant dominated cosmology, combined with reasonable assumptions about the metallicity distribution, ...

Here we investigate an exemplary chemodynamical evolutionary simulation of a dwarf irregular galaxy. By means of this model we demonstrate the existence of three gas mixing cycles: 1) An inner local cycle mixing the metals produced in stars locally, and 2) an outer galactic cycle on which hot gas is driven out of the galaxy by multiple supernovae type II and mixes on a short timescale with the ...

This paper discusses design, simulation and fabrication of new Micromechanical Thermal Converters (MTCs) based on GaAs developed for Gas sensors. GaAs MTCs seem to be very attractive for design of thermally based MEMS sensor devices. High thermal isolation of these devices can be done by implementing of free micromechanical hot plates which is designed as thin as possible. Metal oxide gas senso...

The emission-line spectrum of an H II region essentially reflects the shape of the EUV spectral energy distribution of the OB stars that ionize the gas. In principle one can use this spectrum to extract information about the age of the underlying association. In practice, a number of effects can lead to systematic errors in derived ages. The star-gas geometry is an important consideration, as i...

A parallel implementation of the preconditioned conjugate residual (PCR) method is described. The method is used to solve the discretized generalised Stokes problem derived from the simulation of complex 2D axisymetrical hot metal forming process. We numerically show that the use of a simple diagonal block (BDS) preconditioner results in a high level of parallelism. Nevertheless in 2D, the iter...

Type Ia supernovae (Ia SNe) provide a rich source of iron for hot gas in galactic stellar spheroids. However, the expected super-solar iron abundance of the hot gas is not observed. Instead, X-ray observations often show decreasing iron abundance toward galactic central regions, where the Ia SN enrichment is expected to be the highest. We examine the cause of this missing iron problem by studyi...

A therir~oir~echanically sound, deco~ipled inodel, nunierically unified for cold and hot bulk metal forming is cast into a finite eleme7it fonttulalioii. Tlie irlechanical niodale is based on elasto(visco)plastic niaterial costztutive laws and general interface frictional contact conditions with the assumption of rigid tools. ~ntroductiolz of a logarithn~ic strain based finite strain iriodel in...

In this research, a radial basis function artificial neural network (RBF-ANN) model was developed to predict the hot deformation flow curves of API X65 pipeline steel. The results of the developed model were compared with the results of a new phenomenological model that has recently been developed based on a power function of Zener-Hollomon parameter and a third order polynomial function of str...