The role of the pectoral fin bud for outgrowth by fin axons was assessed by ablation of pectoral fin buds and by transplantation of fin buds to ectopic sites in the embryos of the Japanese medaka fish (Oryzias latipes). Normally nerves from segments 1-4 (S1-4) and less frequently the S5 nerve converged at the base of the fin bud by extending toward the fin bud on the ventral surface of the axia...

Animal propulsion systems are believed to show high energy and mechanical efficiency in assisting movement compared to artificial designs. As an example, batoid fishes have very light cartilaginous skeletons that facilitate their elegant swimming via enlarged wing-like pectoral fins. The aim of this work is to illustrate the hierarchical structure of the pectoral fin of a representative batoid,...

Plastic mulching with drip irrigation is a new water-saving rice cultivation technology, but little is known on its productivity and water-saving capacity. This study aimed to assess the production potential, performance, and water use efficiency (WUE) of rice under plastic mulching with drip irrigation. Field experiments were conducted over 2 years with two rice cultivars under different culti...

The evolution of the tetrapod limb involved an expansion and elaboration of the endoskeletal elements, while the fish fin rays were lost. Loss of fin-specific genes, and regulatory changes in key appendicular patterning genes have been identified as mechanisms of limb evolution, however their contributions to cellular organization and tissue differences between fins and limbs remains poorly und...

Engine life and effectiveness can be improved with effective cooling. The cooling mechanism of the air cooled engine is mostly dependent on the fin design of the cylinder head and block. The heat is conducted through the engine parts and convected to air through the surfaces of the fins. Insufficient removal of heat from engine will lead to high thermal stresses and lower engine efficiency. As ...

This paper provides a review on the fouling mechanism and its effect onto the performance of finned tube heat exchangers in HVAC systems. Fouling tends to degrade the performance of heat exchangers by decreasing the heat transfer coefficient and increasing the air-side pressure drop across the heat exchangers. Air side fouling depends on a number of factors on the air side, including type and c...

Q : dimensionless heat loss from the fin, q/(klw f φ ) Abstract Rt: dimensionless thermal resistance A reversed trapezoidal fin with fluid in the inside wall is analyzed using a two-dimensional analytical method. Thermal resistance for the reversed trapezoidal fin is presented as a function of the fin length and fin base height. The relationship between the inside fluid convection characteristi...

A new species of dart fish, Parioglossus galzini sp. nov., is described based on specimens collected in Haurei Bay, Rapa Island (French Polynesia). It is distinguished from all other described species of Parioglossus as follows: dark lateral body stripe absent, 100 or more scales in longitudinal series from above pectoral-fin base to base of caudal fin, pectoral-fin rays 19–21, membrane of firs...

The new propulsor, whose inspiration is from pectoral fins of fishes, has arisen increasing attention. To improve the performance of the existing labriform bionic pectoral fin, based on the structure and control mechanism of real fish pectoral fin, the under-actuated technology was utilized to design a new flexible bionic pectoral fin. Then, the kinematic model of pectoral fin during fish forwa...

In this paper, we analyze the values of entropic efficiency longitudinal fins by investigating coupling between function describing fin profile and corresponding steady-state temperature distribution along fin. By starting from different boundary conditions, look at maximizing From requesting that must comply with natural physical constraints, such as maximum thickness, obtain an optimal for a ...