a simple method has been developed for the preconcentration of copper(ii) based on the adsorption of its modified nano polyacrylonitrile fiber. modified nano polyacrylonitrile fiber (panf) was prepared by adding of acrylic fibers to msethanolamine (mma) with different concentration solutions. the stability of a chemically modified nano polyacrylonitrile fiber especially in concentrated hydrochl...

Introduction In the 1970s, exterior bonded steel reinforcement was used sporadically to reinforce bridges to attain higher service load capacities. This steel post-strengthening system consisted of steel straps bonded with epoxies to the exterior of concrete beams. An alternative to the steel retrofit is woven carbon fiber reinforced polymer fabric applied in the same manner as steel. Carbon fi...

The first form of damage in composite laminates is often matrix microcracks that are defined as intralaminar or ply cracks across the thickness of the ply and parallel to the fibers in that ply (see reviews in [1,2]). Tensile loading, fatigue loading, environment, and thermal cycling can all lead to microcrack formation. Microcracks can form in any ply that has a significant component of the ap...

The effect of adding different percentages nano-graphene oxide (NGO) into the epoxy resin on mechanical properties NGO/epoxy and maximum peeling force fiber-metal laminates (FMLs) with composite cores are investigated in this paper. Three NGO including 0.1, 0.35 0.50 weight (wt. %) used to fabricate tensile test samples NGO/epoxy. Hand lay-up method is FML specimens glass fiber reinforced plast...

This paper summarizes a series of studies on the interface of fiber reinforced polymer laminates externally bonded to concrete substrates, carried out in the Laboratory of Engineering for Maintenance Systems, Hokkaido University. Appropriate test methods and bond models for shear bond, tensile bond and cleavage bond (bond under dowel force) are shown. Finally, experimental results on shear bond...

In the present paper, the damage of fiber-reinforced composite laminates is considered with the aim to examine the change of their mechanical properties. The crucial issue for theoretical analysis is to construct constitutive relations, which take into account the development of damage, along with stress and strain. The paper is mainly focused on this problem. In order to derive an adequate des...

Carbon fiber composites are of significant interest for use in deployable space structures. Elastically folded thin laminates can be utilized as hinge mechanisms in structural systems such as solar arrays, reflectors, and instrument booms, allowing for compact packaging during launch to orbit. While the initiative to utilize composite laminates in deployable structures has increased it also has...