As a major structural dynamic criterion in designing thin shells, the fundamental frequency is maximized for a specified total structural mass. The general optimization problem of metallic conical shell structures with clamped / free ends has been treated formally among all other types of boundary conditions. Both stiffened and unstiffened constructions are examined with the effective design va...

Rice dwarf virus (RDV), a member of the Reoviridae family, is a double-stranded RNA virus. Infection of rice plants with RDV reduces crop production significantly and can pose a major economic threat to Southeast Asia. A 25-A three-dimensional structure of the 700-A-diameter RDV capsid has been determined by 400-kV electron cryomicroscopy and computer reconstruction. The structure revealed two ...

The objective of this investigation was to determine the quasi-static indentation response and failure mode in three-dimensional (3D) printed trapezoidal core structures, and to characterize the energy absorbed by the structures. In this work, the trapezoidal sandwich structure was designed in the following two ways. Firstly, the trapezoidal core along with its facesheet was 3D printed as a sin...

We study the morphological evolution of strained heteroepitaxial films using a kinetic Monte Carlo method in three dimensions. The elastic part of the problem uses a Green's function method. Isolated islands are observed under deposition conditions for deposition rates slow compared with intrinsic surface roughening rates. They are hemispherical and truncated conical for high and low temperatur...

The buckling of aboveground circular steel tanks with conical roof is considered in this paper. The specific source of loads investigated is wind action during hurricane storms in the Caribbean islands. The structure is modeled using a finite element discretization with the computer package ALGOR. Bifurcation buckling of the shell is computed for a given static wind pressure distribution. Then ...

In this paper we derive the linear elastic Cosserat shell model incorporating in variational problem effects up to order $O(h^{5})$ thickness $h$ as a particular case of recently introduced geometrically nonlinear model. The existence and uniqueness solution is proven suitable admissible sets. To end, inequalities Korn-type for shells are established which allow show coercivity Lax-Milgram theo...

We report the discovery of two new large H i shells in the direction of the Coalsack nebula. Both shells were observed with the Parkes Radio Telescope as part of the Southern Galactic Plane Survey. The largest shell, GSH 304-00-12, is at a distance of ∼ 1.2 kpc and has derived physical dimensions of 280×200 pc. The second shell, GSH 305+01-24, is at a distance of ∼ 2.2 kpc and has derived dimen...

Certain ferroelectric materials possess dual electrostrictive and piezoelectric characteristics, depending on their specific Curie temperatures. The nonlinear electro-mechanical effect of electrostrictive materials provides stronger actuation performance as compared with that of piezoelectric materials. Due to the complexity of the generic ferroelectric actuators, micro-electromechanics, struct...

X iv :1 70 4. 01 92 2v 1 [ m at h. C O ] 6 A pr 2 01 7 Sandwiches Missing Two Ingredients of Order Four José D. Alvarado Simone Dantas Dieter Rautenbach 1 Instituto de Matemática e Estat́ıstica, Universidade Federal Fluminense, Niterói, Brazil [email protected], [email protected] 2 Institute of Optimization and Operations Research, Ulm University, Ulm, Germany dieter.rautenbach@uni-ul...

In a recent paper, we introduced the simultaneous representation problem (defined for any graph class C) and studied the problem for chordal, comparability and permutation graphs. For interval graphs, the problem is defined as follows. Two interval graphs G1 and G2, sharing some vertices I (and the corresponding induced edges), are said to be “simultaneous interval graphs” if there exist interv...