A retargeting procedure is developed for use as a nonlinear low thrust guidance scheme. The selection of a control program composed of a sequence of inertially fixed thrust-acceleration vectors permits all trajectory computations to be made with closed form expressions, and allows the controls to be represented by constant parameters, thrust-acceleration vectors and thrusting times. By requirin...

Speed and position control systems for marine vehicles have been subject to an increased focus with respect to performance and safety. An example is represented by drilling operations performed with semi submersible rigs where the control of position and heading requires high accuracy. Drifting from the well position could cause severe damage to equipment and environment. Also, the use of under...

Sandbox experiments with different boundary conditions demonstrate that antiformal stacks result from a forward-breaking thrust sequence. An obstacle blocks forward thrust propagation and transfers the deformation back to the hinterland in a previously formed true duplex. In the hinterland, continued shortening causes faults to merge toward the tectonic transport direction until the older thrus...

The aim of the present study was to investigate the light and electron microscopic structure of the tongue in White-eared bulbul (Pycnonotus leucotis). Six adult White-eared bulbul (3 males and 3 females) in Shahrekord district were used in the investigation. Samples of the apex, body and root of the tongue were prepared routinely for light and electron microscopic study. Results showed that th...

The aims of this study were to explore the hydrodynamic mechanism of Xenopus laevis swimming and to describe how hind limb kinematics shift to control swimming performance. Kinematics of the joints, feet and body were obtained from high speed video of X. laevis frogs (N=4) during swimming over a range of speeds. A blade element approach was used to estimate thrust produced by both translational...

Thrust generation and scaling parameters for flapping flexible wings are investigated using an integrated framework of computational fluid dynamics and structural dynamics solvers. To explore the influences of the density ratio and the effective stiffness on the thrust generation, surrogate models have been generated for a flapping thin isotropic flat Zimmerman wing in still air at = 1.5×10. Ti...

in a prospective clinical trial, the incidence of scrotal tongue in psoriatic patients was studied. one hundred psoriatics and the same number of non-psoriatic individuals were evaluated for the incidence of fissured tongue, age, duration of illness, and clinical types of psoriasis. in this study 49 psoriatic patients (49%) and 28 non-psoriatic persons (28%) had fissured tongue. the most common...

This paper focused on evaluation of machining parameters influencing thrust force during drilling of Al–SiC–Gr metal matrix composites using multifaceted carbide drills. There are three machining parameters i.e. Spindle speed, Feed rate, Drill diameter. Experiments are conducted on a vertical machining centre using Taguchi design of experiments. Taguchi orthogonal array is designed with three l...

It is shown analytically that the thrust from a simple plasma thruster (in the absence of a magnetic field) is given by the maximum upstream electron pressure, even if the plasma diverges downstream. Direct thrust measurements of a thruster are then performed using a pendulum thrust balance and a laser displacement sensor. A maximum thrust of about 2 mN is obtained at 700 W for a thruster lengt...

Angular maneuvering scheme along with standard flight operations such as taking-off, landing and hovering is proposed for a quadcopter with indoor or outdoor flying capabilities. This is achieved by simultaneously controlling the speed of the four rotors in order for the quadcopter to attain the correct orientation. The total thrust is determined using the inputs of altitude, pitch and roll ang...