In order to explain disk galaxy formation within the hierarchical structure formation, it seems that gas rich mergers must play an important role. We review here our previous studies which have shown the importance of mergers at high redshift being gas rich, in the formation of both the stellar halo and thick disk components of disk galaxies. Regulation of star formation in the building blocks ...

a four - year field experiment (1999-2002) was conducted on a silty clay loam soil at laklak research field of hamedan to determine the effects of crop residue management and plowing depth on soil fertility and wheat yield in a maize-wheat rotation. in this investigation, four corn residue managements were used consisting of 1) stalk shredding by maize stalk shredder 2) stalk shredding by disk ...

In this paper, we study N-policy for a finite population Bernoulli feedback queueing model for machine repair problem with degraded failure. The running times of the machines between breakdowns have an exponential distribution. The repair times of the machines are independent and identically distributed random variables. If at any time a machine fails, it is sent to the repairman for repairing,...

Parallel disk I/O subsystems are becoming more important in today’s large-scale parallel machines. Parallel disk systems provide a significant boost in I/O performance reducing the gap between processor and disk speeds. We describe a Unix-like file I/O user interface, implemented in a parallel file I/O subsystem on an MIMD machine, the nCUBE 2. Based on message passing, we develop parallel disk...

the aim of this research was to investigate performance of two combined plows compared to conventional plow. the experiments were conducted in a loamy soil texture with moisture content of 16-18% in karaj region of iran. combination of moldboard+chisel plow and disk plow+chisel plow were compared with conventional moldboard plow as three treatments. data was statistically analyzed using rcbd in...

background and importance: disk sequestration can be defined as a herniated disk with perforation of the fibrous ring (or outermost annulus fibrosus) and posterior longitudinal ligament with migration of the disk fragment to the epidural space. even after the introduction of high-resolution magnetic resonance imaging (mri), it is still frequently misinterpreted as neoplastic masses. unfortunate...

In the past few years, computer worms are seen as one of significant challenges of cloud computing. Worms are rapidly changing and getting more sophisticated to evade detection. One major issue to defend against computer worms is collecting worms’ payloads to generate their signature and study their behavior. To collect worms’ payloads, we identified challenges for detecting and collecting worm...

Studies of elemental abundances in stars belonging to the thin and the thick disk of our Galaxy are reviewed. Edvardsson et al. (1993) found strong evidence of [α/Fe] variations among F and G main sequence stars with the same [Fe/H] and interpreted these differences as due to radial gradients in the star formation rate in the Galactic disk. Several recent studies suggest, however, that the diff...