Well-preserved holdfasts and early growth stages of the tubular cnidarian Sphenothallus are described from Silurian (Llandovery Series) Washington Land, North Greenland. The diameter holdfast is determined by formation a basal disc attached to substrate, upon which initially conical, but subsequently shell formed. characteristic opposing longitudinal thickenings developed at each angular margin...

We review on a recent construction of the on-shell supersymmetric brane action for the codimension-two branes with nonzero tension in the flux compactification of a 6D chiral gauged supergravity. On dimesionally reducing on 4D gauged supergravity for a new supersymmetric unwarped background with conical branes, we consider the modulus stabilization for determining the soft masses of the scalars...

A method for numerically solving the equation of radiative transfer in a spherical shell atmosphere is presented. The method uses a conical boundary and a Gauss-Seidel iteration scheme to solve for all orders of scattering along a single radial line in the atmosphere. Tests of the model indicate an accuracy better than 1% for most Earth-atmosphere situations. Results from this model are compare...

Consider a spherically symmetric spacelike slice through a spherically symmetric spacetime. One can derive a universal bound for the optical scalars on any such slice. The only requirement is that the matter sources satisfy the dominant energy condition and that the slice be asymptotically flat and regular at the origin. This bound can be used to derive new conditions for the formation of appar...

The confinement of double stranded (ds) viral DNA molecules has long attracted the interest of physicists. The bacteriophage viruses are the classical example of viruses where large pressures are produced by viral DNA confinement (in the range of tens of atmospheres)[1]. The protein shell the capsid has to be very strong so as to withstand these enormous pressures. In this article we propose th...

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...

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 ...

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...

Limpets are commonly found on wave-swept rocky shores, where they may be subjected to water velocities in excess of 20 m s(-1). These extreme flows can impose large forces (lift and drag), challenging the animal's ability to adhere to the substratum. It is commonly thought that the conical shape of limpet shells has evolved in part to reduce these hydrodynamic forces while providing a large ape...