The octopus arm requires special motor control schemes because it consists almost entirely of muscles and lacks a rigid skeletal support. Here we present a 2D dynamic model of the octopus arm to explore possible strategies of movement control in this muscular hydrostat. The arm is modeled as a multisegment structure, each segment containing longitudinal and transverse muscles and maintaining a ...

This study aimed to analyse the effect of growth during a summer break on biomechanical profile of talented swimmers. Twenty-five young swimmers (12 boys and 13 girls) undertook several anthropometric and biomechanical tests at the end of the 2011-2012 season (pre-test) and 10 weeks later at the beginning of the 2012-2013 season (post-test). Height, arm span, hand surface area, and foot surface...

The aim of our study is to analyze the impact of insertion holes in the middle of obstacles on the flow around a surface-mounted cube, In order to do this; we studied four configurations of obstacles in a channel with a Reynods number based on obstacle height ReH = 40000. The hexahedral structured meshes were used to solve the fluid dynamics equations .The finite volume method are employed to s...

To understand the basic characteristics of the observed S-shaped wind profile and the exponential flux profile within forest canopies, three hypotheses are postulated. The relationship between these fundamental profiles is well established by combining the postulated hypotheses with momentum equations. Robust agreements between theoretical predictions and observations indicate that the nature o...

The middle-latitude standing wave problem is investigated by means of a quasi-geostrophic, linear, steadJ;-state model in which the zonal current is perturbed by the lower boundary topography and by a distribution of heat sources and sinks. All the perturbations are assumed to have a single meridional wavelength and the dissipation is considered to take place in the surface boundary layer using...

A heavy truck wind tunnel test program is currently underway at the Langley Full Scale Tunnel (LFST). Seven passive drag reducing device configurations have been evaluated on a heavy truck model with the objective of understanding the practical limits to drag reduction achievable on a modern tractor trailer through add-on devices. The configurations tested include side skirts of varying length,...

Flow resistance due to vegetation may greatly affect the conveyance of a channel, and thus evaluating the resistance is a critical task in river engineering and restoration. Therefore, flow resistance of natural willows and sedges was studied in a laboratory flume. The aim was to investigate, how type, density and combination of vegetation, flow depth and velocity influence vegetal drag or fric...

The Breguet range equation indicates that to the first order of approximation range will be maximized by maximizing ML/D, where M is the Mach number and L/D is the lift/drag ratio. Since the drag coefficient increases very rapidly as the Mach number approaches one, this leads to the design of a long range aircraft which fly at high subsonic speeds, typically in the range Mach 0.8 to 0.85, just ...

During forward flight, a bird's body generates drag that tends to decelerate its speed. By flapping its wings, or by converting potential energy into work if gliding, the bird produces both lift and thrust to balance the pull of gravity and drag. In flight mechanics, a dimensionless number, the body drag coefficient (C(D,par)), describes the magnitude of the drag caused by the body. The drag co...

The aim of this article was to compare swimming power output between boys and girls and to model the relationship between swimming power output and sprinting performance in young swimmers. One hundred young swimmers (49 boys and 51 girls, aged between 11 and 13 years) underwent a test battery including anthropometrics (body mass, height, arm span [AS], and trunk transverse surface area), kinema...