The uncombed penumbral model proposed by Solanki & Montavon (1993) is used to understand some recent observational results found in penumbrae. This model uses a penumbral magnetic field structured into horizontal flux tubes embedded in a more vertical background field. A modified version of this model, with a weaker field strength in the horizontal tubes, is used to explain the gradient with he...

A modelling effort was made to try to predict the life of downhole tubes or casings, synthetically considering the effect of service influencing factors on corrosion rate. Based on the discussed corrosion mechanism and corrosion processes of downhole tubes, a mathematic model was established. For downhole tubes, the influencing factors are environmental parameters and stress, which vary with se...

Please cite this article in press as: Xiong J et al. M doi:10.1016/j.matdes.2010.08.016 A new type of lightweight sandwich panels consisting of vertically aligned hollow Al–Si alloy tubes as core construction and carbon fiber composite face sheets was designed. The hollow Al–Si alloy tubes were fabricated using precision casting and were bonded to the face sheets using an epoxy adhesive. The ou...

Polymeric tubes, including epoxy and reinforcing fibers, are widely used in the petroleum aerospace industries due to their high strength corrosion resistance. In this study, creep properties of resin-based tubes reinforced by Glass fibers (GFR), Carbon (CFR), Kevlar (KFR) were investigated using made a 45-degree unilateral winding method. The highest strain was obtained for CFR equal 0.7445 lo...

Aluminum cellular structures have been fabricated by combining a two-dimensional [0◦/90◦]2 arrangement of square Al 6061-T6 alloy tubes with orthogonal tubes inserted in the out-of-plane direction. By varying the tube wall thickness, the resulting three-dimensional cellular structures had relative densities between 11 and 43%. The dynamic compressive response of the three-dimensional cellular s...

Gradient variations of through-thickness residual stress, microstructure and texture greatly affect the performance cold radial forged tubes. In this work, distribution stress was measured based on Debye ring. The characterized with electron backscattering diffraction technique. by X-ray diffractometer. influence strength anisotropy tubes different thickness reductions analyzed. results show th...