Planet formation via core accretion requires the production of km-sized planetesimals from cosmic dust. This process must overcome barriers to simple collisional growth, for which Streaming Instability (SI) is often invoked. Dust evolution still required create particles large enough undergo vigorous instability. The SI has been studied primarily with single size dust, and role full evolved dus...

In this paper, we investigate the determinants of political instability in Latin America. In a panel of 18 Latin American countries from 1971 to 2000, we find that democratic countries experience less average instability in the region, indicating that the move to increased democracy in the last couple decades may alleviate the persistent problem of instability in the area. We also find that inc...

BACKGROUND Little is known about the risk factors for glenohumeral joint instability. We hypothesized that a prior history of instability would be a significant risk factor for subsequent injury. METHODS We conducted a prospective cohort study over a four-year period within a high-risk group of young athletes to address the research hypothesis. Subjects were freshmen entering the U.S. Militar...

among the agents collection that should observe in instability of rural residences is attention urban dropped sewages ،because of more excecuted works in industvies and home consumption of cities are dealing with water . there fore ،more using of water results in more production of sewage and these sewages have safe place in human consumption cycle. these processes hurt direct evacuation of sew...

The static pull-in instability of beam-type micro-electromechanical systems is theoretically investigated. Two engineering cases including cantilever and double cantilever micro-beam are considered. Considering the mid-plane stretching as the source of the nonlinearity in the beam behavior, a nonlinear size-dependent Euler-Bernoulli beam model is used based on a modified couple stress theory, c...

CONTEXT Patellar instability is a common clinical problem, affecting between 7 and 49 people per 100,000. However, not all patellar instabilities are equal, the etiology of the disorder is multifactorial, and a clear understanding of the cause of instability is crucial for appropriate surgical treatment. The goal of this article is to identify how to best treat patellar instability to provide g...

In this article the instability of single phase flow in a circular pipe from laminar to turbulence regime has been investigated. To this end, after finding boundary conditions and equation related to instability of flow in cylindrical coordination system, which is called eigenvalue Orr Sommerfeld equation, the solution method for these equation has been investigated. In this article Chebyshev p...