Abstract We construct an approximate solution which describes the gravitational emission from a naked singularity formed by the gravitational collapse of a cylindrical thick shell composed of dust. The assumed situation is that the collapsing speed of the dust is very large. In this situation, the metric variables are obtained approximately by a kind of linear perturbation analysis in the backg...

In this paper the effect of composite hoop-wrapped on stress intensity factor for semi-elliptical external crack which located in spherical pressure vessel, were investigated through the Finite Element Analysis. In order to find the effect of some parameters such as composite thickness and width, internal pressure and crack geometry, comparisons between different cases were done and discussed i...

The influence of the flaw shape on the variation of stress-intensity factors along the crack front is examined for longitudinal inner surface flaws in pressure vessels, and for corner cracks present at the intersection of a pressure vessel and a nozzle. For the inner surface flaw problem, the geometry of the pressure vessel considered is that of a commercial pressure vessel. The analyzed flaw s...

The review of non-destructive testing pressure vessel for compressed air is given, as well the assessment and analysis defects on integrity itself. focus here welded joints, most critical areas in vessels, especially if thickness large, like case considered (50 mm), cylindrical storage vessels made HSLA steel. Toward this end conventional NDT methods, such UT Radiography are used first phase re...

Cylindrical adsorbers are usually used for pressure swing adsorption (PSA) processes. In this study, the flat-box adsorbers which stack together replaced the traditional cylindrical adsorbers. Simulation was performed for separation of air (21% oxygen; 79% nitrogen) in Skarstrom cycle. Instantaneous equilibrium between solid and gas phase with non-isothermal operation were assumed and the bed p...

We present a short and self-contained proof of Jin’s theorem about the piecewise syndeticity of difference sets which is entirely elementary, in the sense that no use is made of nonstandard analysis, ergodic theory, measure theory, ultrafilters, or other advanced tools. An explicit bound to the number of shifts that are needed to cover a thick set is provided. Precisely, we prove the following:...

Advances in the apptication of supercritical (SC), gaseous (G), and ]iquid (LQ) C02 hayc been made regarding the interaction with biological materials or organisms. There are sevcral reports dealing with the influences of SC, G, and LQ C02 on proteins,i'2) amino acids,i) enzymes,3'S) and microbial eells.b'7) Kamihara et aL have described that wet cells (water content of 70-90g,h) of baker's yea...

Abstract The wet winding process is an established manufacturing technology for the production of rotationally symmetrical components made fiber‐reinforced plastic (FRP), such as type‐IV hydrogen pressure vessels. In this process, FRP laminate produced by continuously depositing impregnated fiber band on core in a pattern adapted to component stress. Despite long history there are shortcomings ...