Several physico-mechanical designs evolved in fish are currently inspiring robotic devices for propulsion and maneuvering purposes in underwater vehicles. Considering the potential benefits involved, this paper presents an overview of the swimming mechanisms employed by fish. The motivation is to provide a relevant and useful introduction to the existing literature for engineers with an interes...

We investigate cross-cut cylindrical heat sink to improve cooling of a light-emitting diode (LED) bulb compared with conventional plate-fin cylindrical heat sinks using various installation angles. In contrast to plate-fin heat sinks, whereby the fins in the upper heat sink do not provide effective cooling at large installation angles, flow formed between the cross-cut fins and the air reached ...

We present a new formulation of the motion of a flexible body with a vortex-sheet wake and use it to study propulsive forces generated by a flexible body pitched periodically at the leading edge in the small-amplitude regime. We find that the thrust power generated by the body has a series of resonant peaks with respect to rigidity, the highest of which corresponds to a body flexed upwards at t...

Cetaceans evolved flippers that are unique in both size and shape probably due to selection pressures associated with foraging and body size. Flippers function as control surfaces for maneuverability and stability. Flippers of cetaceans and engineered hydrofoils are similar with streamlined cross-sections and wing-like planforms, which affect lift, drag and hydrodynamic efficiency. Scale models...

This paper presents a design of an underwater vehicle mimicking undulating fins of fish. To mimic the actual flexible fin of real fish, a fin-like mechanism is modeled with a series of connecting linkages. By virtue of a specially designed strip, each link is able to turn and slide with respect to the adjacent link. The driving linkages are used to form a mechanical fin consisting of several fi...

The Dlx5 and Dlx6 genes encode homeodomain transcription factors essential for the proper development of limbs in mammalian species. However, the role of their teleost counterparts in fin development has received little attention. Here, we show that dlx5a is an early marker of apical ectodermal cells of the pectoral fin buds and of the median fin fold, but also of cleithrum precursor cells duri...

l We review here the results obtained during the past several years in a series of computational and experimental investigations aimed at understanding the origin of high-force production in the flapping wings of insects and the flapping and deforming fins of fish and the incorporation of that information into bioinspired vehicle designs. We summarize the results obtained on pectoral fin force ...

During a survey of the Mali Hka River drainage in Hponkanrazi Wildlife Sanctuary in December 2015, a new species was collected and is described herein as Oreoglanis hponkanensis. It is a member of the Oreoglanis siamensis species group and can be distinguished from its congeners in having a unique combination of the following characters: lower lip with median notch and posterior margin entire, ...

Recently interest in adsorption cooling systems has increased due to their capability to utilise low grade heat sources and environmentally friendly refrigerants. Currently, most of the commercially available adsorption cooling systems utilise granular packed adsorbent beds. Enhancing the heat transfer process inside the adsorbent bed will improve the overall efficiency of the adsorption system...

Fin ray structure in ray-finned fishes (Actinopterygii) largely defines fin function. Fin rays convert the muscle activity at the base of the fin to shape changes throughout the external fin web. Despite their critical functional significance, very little is known about the relationship between form and function in this key vertebrate structure. In this study we demonstrate that morphological s...