Objective: To assess the effect of alkaline versus acid surface treatment on bond strength of adhesives used for amalgam repair. Materials and Method: Sixty cylindrical samples were prepared by condensing amalgam into plastic tubes of 4mm diameter and 10mm length. Tubes were filled up to 5.0mm with admixed amalgam. They were allowed to set hard for three months. The samples were divided into A1...

Bridge grafting (15 mm) into the sciatic nerve of SD rats was carried out using tendon chitosan tubes having either a circular or triangular cross-section, as well as triangular tubes combined with laminin, CDPGYIGSR, or CSRARKQAASIKVAVSAD (n = 15 in each group). As a control, isografting (15 mm) was carried out in the SD rats (n = 7). Specimens were taken after 1, 2, 4, 6, and 8 weeks for hist...

The structures in magnetohydrodynamic (MHD) ow, ux tubes in particular, are investigated with respect to coherence in the direction of the magnetic eld. A length scale, which is interpreted as the diameter of the tubes, is derived from the MHD equations. This scale implies that the tendency towards alignment of ux lines in tubes is a diiusion driven phenomenon. The dynamics of the tubes is also...

The vulnerability of framed structures has been analyzed until recently from two different perspectives: Structural and socio-economical. For the sake of assessing the former, indexes and objective measurements have been proposed in the literature. These indexes include relatively accurate assessments of the strength, ductility, energy absorption, fire, blast response and resilience of the elem...

We show that strong Luttinger correlations of the electron liquid in armchair carbon nanotubes significantly enhance the onset temperature of the putative twist Peierls instability and lead to its 1/R3 dependence on the tube radius. Depending on the values of the coupling constants the umklapp processes can either assist or compete with the twist instability. In the case of a competition the um...

In this paper, cyclic flaring and sinking (CFS) as a new severe plastic deformation (SPD) method was employed to produce the ultrafine grain (UFG) copper tubes. The extra friction has eliminated in the CFS method that provided the possibility for production of longer UFG tubes compared to the other SPD methods. This process was done periodically to apply more strain and consequently finer grain...

A quench boiler is the key equipment in ethylene production for rapid cooling of high-temperature cracking gas. In boiler, heat transfer occurs between hot gas passing through inner exchange tubes with an average temperature 385 °C and cold water (or water) 350 °C. Required double-pipe transfer, special tubesheets formed by welding flat-round side are difficult to design, as no suitable design ...

We present the first 3D MHD study in spherical geometry of the non-linear dynamical evolution of magnetic flux tubes in a turbulent rotating convection zone. These numerical simulations use the anelastic spherical harmonic (ASH) code. We seek to understand the mechanism of emergence of strong toroidal fields through a turbulent layer from the base of the solar convection zone to the surface as ...

Fibers and yarns based on carbon nanotubes (CNT) are emerging as a possible improvement over more traditional high strength carbon fibers used as reinforcement elements in composite materials. This is driven by a desire to translate the exceptional mechanical properties of individual CNT shells to achieve high performance macroscopic fibers and yarns. One of the central limitations in this appr...