Helical propulsion is at the heart of locomotion strategies utilized by various natural and artificial swimmers. We used experimental observations and a numerical model to study the various fluctuation mechanisms that determine the performance of an externally driven helical propeller as the size of the helix is reduced. From causality analysis, an overwhelming effect of orientational noise at ...

Ski8p is a WD-repeat protein with an essential role for the Ski complex assembly in an exosome-dependent 3'-to-5' mRNA decay. In addition, Ski8p is involved in meiotic recombination by interacting with Spo11p protein. We have determined the crystal structure of Ski8p from Saccharomyces cerevisiae at 2.2 A resolution. The structure reveals that Ski8p folds into a seven-bladed beta propeller. Map...

This presentation and technical paper describes the scanning and processing of data for the recovered propeller of the United States Navy Warship U.S.S. Monitor. The propeller, designed by inventor John Ericsson, was recovered by NOAA in 1998, conserved over the next six years, and is now on display at The Mariners’ Museum in Newport News, Virginia, where it was scanned in place. Two different ...

This paper numerically discusses how the performance of a NACA marine propeller is affected by the number of blades, which is one of the most crucial geometrical parameters determining the performance of a propeller. Results are presented in terms of the hydrodynamic and structural parameters. The results show that changing the number of blades changes the hydrodynamic efficiency, torque, thrus...

The aim of this paper is to present a hybrid electrical air-cushion tracked vehicle (HETAV) for the operation on swamp peat. Mathematical models are incorporated with accounting kinematics and dynamics behaviors of the vehicle. Sinkage of the HETAV is sensed by an ultrasonic displacement (UD) sensor, in order to operate the air-cushion system. The air-cushion of HETAV is protected with a novel-...

Quantitative abdominal T(2) measurements may be useful for lesion differentiation and functional tissue characterization. However, T(2) mapping of the abdomen with conventional spin-echo (SE) and turbo-spin-echo (TSE) approaches can be challenging due to physiologic motion artifacts. Multishot TSE-based PROPELLER (Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction) can...