A Model for Bond Strength in Presence of Corrosion in Concrete

Corrosion of steel in concrete is the most detrimental source for reinforced concrete structures. Among the other effects, corrosion deteriorates the interface between steel and concrete. An axisyimmetric numerical model able to simulate the structural behaviour of bond between steel and concrete is here presented. The model is based on the thick-walled cylinder theory so that bond performance is a direct consequence of radial pressure acting on the rebar and coming from the surrounding elements and corrosion. Both elastic and inelastic contribution of concrete is also taken into account. The model is used to simulate pull-out tests present in literature. The results show the effectiveness of the model and is also compared with an empirical model already proposed in literature.

Photons emission and charge-exchange contributions to the energy loss of swift heavy ions in dense matter

In this paper we determine the inelastic contribution to the energy losses by swift heavy ions in dense matter. At equilibrium, the charge transfer stopping is determined by a simple energy balance and the excitation stopping is determined by the photons emission. Using an average atom model, we determine the density influence on these inelastic stoppings.

INFRARED EVOLUTION EQUATION FOR BACKWARD QUARK-GLUON SCATTERING

The infrared evolution equation is used to compute in the double logarithmic approximation the inelastic contribution to inclusive gluon production from backward quark-gluon scattering.

Applications of virtual objective aperture in TEM

In a special imaging mode (B mode) available on a customized JEM-4000EX microscope, the objective mini lens (OM) is strongly excited so that the back focal plane of the objective lens (OL) is imaged onto the plane of the selected-area aperture (SA), Fig. 1, with a magnification of 3.2x. Thus the S A functions as a virtual objective aperture, the applications of which are summarized below.1. Improving contrast in imaging thick sections of biological specimens.The increased inelastic scattering in thick specimens results in image blur due to chromatic aberration present in the magnetic lenses. Such blur degrades image resolution and contrast. The energy loss spectrum in Fig. 2 (curve 1), from a 1 μm section of frog spinal ganglion, suggests that the inelastic contribution to images of this type of specimen is substantial. The use of an objective aperture (OA) can reduce some of the unwanted contributions (curve 2), but the SA in B mode is much more effective, as suggested by Fig. 1 and demonstrated by curved 3.