This paper preliminarily investigates the general transport properties (i.e., water sorptivity, water permeability, and gas permeability) of carbon-nanotube/cement composites. Carboxyl multi-walled carbon nanotubes (MWNTs) are dispersed into cement mortar to fabricate the carbon nanotubes (CNTs) reinforced cement-based composites by applying ultrasonic energy in combination with the use of surf...

We consider mixed nite element methods for second order elliptic equations on non-matching multiblock grids. A mortar nite element space is introduced on the non-matching interfaces. We approximate in this mortar space the trace of the solution, and we impose weakly a continuity of ux condition. A standard mixed nite element method is used within the blocks. Optimal order convergence is shown f...

The date of receipt and acceptance will be inserted by the editor Summary A residual based error estimator for the approximation of linear elliptic boundary value problems by nonconforming nite element methods is introduced and analyzed. In particular, we consider mortar nite element techniques. restricting ourselves to geometrically conforming domain decomposition methods using P1 approximatio...

Bricks-and-mortar companies wishing to create value-added Internet services do so in a business environment that is characterized by great uncertainty and, hence, formulating a coherent business strategy is exceedingly challenging. This paper presents a case study based analysis of the evolving eBusiness strategy of a bricks-andmortar grocer contrasted with the strategies of other competitors. ...

We consider the coupling of compressible and nearly incompressible materials within the framework of mortar methods. Taking into account the locking effect, we use a suitable discretization for the nearly incompressible material and work with a standard conforming discretization elsewhere. The coupling of different discretization schemes in different subdomains are handled by flexible mortar te...

Recently, nanomaterials (such as nanosilica) are receiving special attention because of their ability to improve the performance of concrete compared with traditional mineral admixtures. In this work, a number of specimens were prepared to study the behavior of cement mortar containing nanosilica. The cement replacement by nanosilica of 3% and 5% by weight of cement was used. The mechanical and...

In this paper we introduce a variant of the three-field formulation where we use only two sets of variables. Considering, to fix the ideas, the homogeneous Dirichlet problem for −∆u = g in Ω, our variables are i) the approximations uh of u in each sub-domain Ωs (each on its own grid), and ii) an approximation ψh of u on the skeleton (the union of the interfaces of the sub-domains) on an indepen...