We use fully-coupled three-dimensional computer simulations to examine aerodynamics of elastic wings oscillating at resonance. Wings are modeled as planar elastic plates plunging sinusoidally at a low Reynolds number. The wings are tilted from horizontal, thereby generating asymmetric flow patterns and non-zero net aerodynamic forces. Our simulations reveal that resonance oscillations of elasti...

Bionic micro-air vehicles (MAV) having the maneuverability of dragonflies would be capable of fast forward flight, hovering and even backward flight. In order to achieve desirable designs for high performing MAVs, it is essential to understand the aerodynamics and structures of the insect wings and more importantly, the interactions between the operating flows and flexible structural wings. Her...

A linear, aeroelastic analysis of a low aspect ratio swept back trapezoidal wing modeled as a cantilever plate is presented. An analytical and numerical formulation for both the aerodynamic forcing and structural response of the wing was developed. The analytical model uses a three dimensional time domain vortex lattice aerodynamic method. A Rayleigh-Ritz approach has been used to transfer equa...

The wings of butterflies and moths (Lepidoptera) are typically covered with thousands flat, overlapping scales that endow the colorful patterns. Yet, numerous species Lepidoptera have evolved highly transparent wings, which often possess altered morphology reduced size, presence membrane surface nanostructures dramatically reduce reflection. Optical properties anti-reflective been characterized...

Densely stacked Ag nanoparticles with an average diameter of 199 nm were effectively deposited on TiO2-coated cicada wings (Ag/TiO2-coated wings) from a water-ethanol solution of AgNO3 using ultraviolet light irradiation at room temperature. It was seen that the surfaces of bare cicada wings contained nanopillar array structures. In the optical absorption spectra of the Ag/TiO2-coated wings, th...

Erythrodiplax ana sp. nov. (male holotype, six male and three female paratypes), collected in Vereda wetlands (a unique Neotropical savanna environment) in Uberlândia (Minas Gerais) and Chapada dos Guimarães (Mato Grosso), Brazil, is described and illustrated. The new species fits in Borror's Basalis Group, and can be distinguished from other species by the combination of the following traits: ...

Its longitudinal mass stretches along the curve of plot, and moving forward from surrounding construction, it closes set free-standing buildings with two marked wings. Like a retaining wall or fortification: resists clutter hillside. It was as if gravity had attracted him to bay plot — loose-textured block. —The composition wing bastion-like element bisects volume building. With proportions lat...

The life-like fidelity of organisms captured in amber is unique among all kinds of fossilization and represents an invaluable source for different fields of palaeontological and biological research. One of the most challenging aspects in amber research is the study of traits related to behaviour. Here, indirect evidence for pheromone-mediated mating behaviour is recorded from a biting midge (Ce...