purpose: to compare the safety, efficacy, and visual results of laser in situ keratomileusis (lasik) in eyes with and without previous scleral buckling surgery in the same individuals. methods: in a prospective clinical trial, 14 eyes of 7 patients with myopic refractive error and history of scleral buckling in one eye, underwent lasik surgery in both eyes according to a standard surgical proto...

Using doubly-clamped silicon (Si) microbeam resonators, we demonstrate sub-attogram per Hertz (ag/Hz) mass sensitivity, which is extremely high sensitivity achieved by micro-scale MEMS mass sensors. We also characterize unusual buckling phenomena of the resonators. The thin-film based resonator is composed of a Si microbeam surrounded by silicon nitride (SiN) anchors, which significantly improv...

Metal thin-walled members have been widely used in building industry. Usually they are utilized as purlins, girts or ceiling beams. Due to slenderness of thin-walled cross-sections these structural members are prone to stability problems (e.g. flexural buckling, lateral torsional buckling). If buckling is not constructionally prevented their resistance is limited by buckling strength. In practi...

This paper presents the buckling analysis of the piezoelectric functionally graded material (FGM) rectangular plates subjected to non-uniformly distributed loads, heat and voltage based on the mesh-free method. A two-step solution procedure is implemented. The first step is to determine the pre-buckling stresses of the plates subjected to non-uniformly distributed loads. The second step is to s...

A study is presented of the post-buckling behavior and imperfection-sensitivity of complete spherical shells subject to uniform external pressure. The study builds on and extends the major contribution to spherical shell buckling by W.T. Koiter in the 1960’s. Numerical results are presented for the axisymmetric large deflection behavior of perfect spheres followed by an extensive analysis of th...

Seismic safety of liquid storage tanks is of considerable importance due to its application in different industries. In Iran, most of these storage tanks are designed based on API650 code provisions. Despite designing tanks according to API standard, the lesson learned from previous earthquakes, shows different kind of damage occurring on them. This study is an investigation on evaluating diffe...

Instability and structural transitions arise in many important problems involving dynamics at molecular length scales. Buckling of an elastic rod under a compressive load offers a useful general picture of such a transition. However, the existing theoretical description of buckling is applicable in the load response of macroscopic structures, only when fluctuations can be neglected, whereas mem...

It is of great significance to understand the underlying mechanism of buckling-driven wrinkles in graphene monolayer due to its applications in nanoelectromechanical systems (NEMS). In previous macroscopic studies based on continuum theory, the chirality-dependent buckling in graphene monolayer is considered as neglectable. However, we found that the growth of buckling-driven wrinkles in graphe...