from the surface of Mars. The big unanswered question is, What belched? Subsurface Martian cows are highly unlikely. But scientists are seriously considering the possibility of bacteria. " As The Independent picks up the story: " One possibility is that the methane is produced by Martian microbes living deep enough for underground water to be in liquid form. At this depth they could be living o...

We formulate a new theoretical model for the swimming of a flexible body in a vortex street. We consider the class of periodic travelling-wave body motions, in the limit of small amplitude. We calculate the output power provided to the body by thrust forces, and the input power done against pressure forces, as functions of the aspect ratio and strength of the vortex street. We then formulate tw...

In this paper, a fuzzy logic controller for dynamic positioning of floating structures in deep water is presented. The core of the fuzzy controller is a set of fuzzy associative memory (FAM) rules that correlate each group of fuzzy control input sets to a fuzzy control output set. A FAM rule is a logical if-then type statement based on one’s sense of realism and experience or can be provided by...

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...

This paper discusses a fuzzy logic controller for dynamic positioning of drilling vessels in deep water. The core of the fuzzy controller is a set of fuzzy associative memory (FAM) rules that correlate each group of fuzzy control input sets to a fuzzy control output set. A FAM rule is a logical if-then type statement based on one’s sense of realism and experience or can be provided by an expert...

[1] We argue that key features of thrust earthquake triggering, inhibition, and clustering can be explained by Coulomb stress changes, which we illustrate by a suite of representative models and by detailed examples. Whereas slip on surface-cutting thrust faults drops the stress in most of the adjacent crust, slip on blind thrust faults increases the stress on some nearby zones, particularly ab...

Close circumnavigation is an important function indispensable for servicing satellites. We discuss the bielliptic yaround maneuver by impulsive thrust control for a small and low cost servicing satellite ying around a target satellite. An optimal feedback control scheme for the thrust is proposed to maintain this trajectory in the presence of disturbances. The extended Kalman lter is employed t...

Both numerical and experimental studies were conducted to evaluate the performance of an omni-flow wind turbine designed to provide renewable electricity on the top of urban buildings like skyscrapers. The numerical approach was based on Finite Volume Method (FVM) and the turbulence flow was studied with several commonly used Reynoldsaveraged Navier-Stokes turbulence models. The results of the ...

Objectives To analyze the kinematics of cervical rotation-traction manipulation (CRTM). Methods An experimental study measuring the kinematics of CRTM was conducted. A total of 18 healthy volunteers participated in the study. A single manipulator operated the CRTM for all subjects. Motion capture technology was adopted to track the trajectory during the CRTM operation. Results The manipulat...

The Main Central Thrust shear zone is the dominant crustal thickening feature in the Himalayas, largely responsible for the extreme relief and mass wasting of the range. Along the Bhagirathi River in NW India, the Main Central Thrust is several kilometers thick and separates high-grade gneisses of the Greater Himalayan Crystallines from Lesser Himalayan metasedimentary rocks. Th-Pb ion micropro...