In the present work the pull-in voltage of a micro cracked cantilever beam subjected to nonlinear electrostatic pressure was studied. Two mathematical models were employed for modeling the problem: a lumped mass model and a classical beam model. The effect of crack in the lumped mass model is the reduction of the effective stiffness of the beam and in the beam model; the crack is modeled as a m...

The static pull-in instability of beam-type micro-electromechanical systems is theoretically investigated. Two engineering cases including cantilever and double cantilever micro-beam are considered. Considering the mid-plane stretching as the source of the nonlinearity in the beam behavior, a nonlinear size-dependent Euler-Bernoulli beam model is used based on a modified couple stress theory, c...

This article analyses the push and pull factors that bring visitors to the Iranian national parks. The study used a structured questionnaire to collect data on these factors and the socio-demographic profile of the visitors. Survey conducted in Boujagh National Park, an area of 3177 hectares located in the north of the Iran, produced 400 questionnaires. The factor analysis identified four push ...

This paper reports results from an investigation into the suction caissons failure mechanisms under vertical pull-out loads. An insight to the failure mechanisms of suction caissons paves the path for developing analytical solutions to their pull-out capacity. The numerical models of suction caissons have first been calibrated by and verified against several experimental data from other researc...

The effect of zinc phosphate (ZP) and zinc calcium phosphate (ZCP) coatings on the reinforcing mechanisms of smooth steel fiber in cementitious matrix have been studied. The results of pull out tests illustrated that by coating smooth steel fiber the pull-out load may be increased up to 100%. The effect of zinc phosphate coating on interface bonding was more than zinc-calcium phosphate coating....

In this paper, the pull-in instability of piezoelectric polymeric nanocomposite plates reinforced by functionally graded single-walled carbon nanotubes (FG-SWCNTs) based on modified strain gradient theory (MSGT) is investigated. Various types of SWCNTs are distributed in piezoelectric polymeric plate and also surface stress effect is considered in this research. The piezoelectric polymeric nano...

We present a novel visual attention tracking technique based on Shared Attention modeling. Our proposed method models the viewer as a participant in the activity occurring in the scene. We go beyond image salience and instead of only computing the power of an image region to pull attention to it, we also consider the strength with which other regions of the image push attention to the region in...

In this paper, the effect of the crack on dynamic behavior of cracked micro-beam in the presence of DC and AC loads are investigated. By applying the residual axial stress and fringing field stress, a nonlinear analytical model of cracked micro-beam is presented and crack is modeled by a massless rotational spring. The governing equation of the system is solved using Galerkin procedure and shoo...

the present research attempts to explain dynamic pull-in instability of functionally graded micro-cantilevers actuated by step dc voltage while the fringing-field effect is taken into account in the vibrational equation of motion. by employing modern asymptotic approach namely homotopy perturbation method with an auxiliary term, high-order frequency-amplitude relation is obtained, then the infl...

The question of land in Zimbabwe has always been political and gendered. Whereas land reform was necessary in the context of highly unequal land ownership patterns and poverty, this paper shows that the Fast Track Land Reform Programme diminished opportunities or spaces for women to be empowered and shrunk the democratic spaces for genuine participation of women in the development process by de...