We address the problem of nding a minimal separator in a di rected acyclic graph DAG namely nding a set Z of nodes that d separates a given pair of nodes such that no proper subset of Z d separates that pair We analyze several versions of this problem and o er polynomial algorithms for each These include nding a minimal separator from a restricted set of nodes nding a minimum cost separator and...

The bird feather vane can be separated into two parts by pulling the barbs apart. The original state can be re-established easily by lightly stroking through the feather. Hooklets responsible for holding vane barbs together are not damaged by multiple zipping and unzipping cycles. Because numerous microhooks keep the integrity of the feather, their properties are of great interest for understan...

Indoor air distribution has great impact on people’s thermal sensation. Therefore, how to remove the indoor excess heat becomes an important issue to create a thermally comfortable indoor environment. To expel the extra indoor heat effectively, this paper used a dynamic CFD approach to study the effect of an air-supply guide vane swinging periodically on the indoor air distribution within a mod...

This article presents application of an adjoint method to the aerodynamic shape optimization of deflector vanes installed in the fan nozzle of a turbofan engine. The purpose of the vanes is to reduce jet noise radiated towards the community, and the specific application of this study is for a supersonic turbofan engines with bypass ratio 2.7. The cost function used in the optimization includes ...

SYNOPSIS Results of unconsolidated-undrained triaxial tests, field vane shear tests and cone penetration tests have been used to develop correlations between undrained shear strength and cone resistance for a soft to medium alluvial clay in the Lopez Canyon area of San Diego. When comparing uu triaxial results with cone resistance, the average cone factor was 11 with a standard deviation of 1.5...

"Pre-separator plus1D2D cyclone" and "pre-separator plus 1D3D cyclone" systems were tested with ground gin trash, which contains 10.35% lint fiber and 5.49% fine dust (less than 100 μm). Test results indicate that the pre-separator collected gin trash at over 97% collection efficiency. There were no significant differences in emission concentrations and overall collection efficiencies from thes...

The high replacement costs of aircraft gas turbine blades and vanes have created a fast-growing, highly-specialized segment of the aircraft repair industry. The economic rationale for repair in lieu of replacement is prima facie. The metallurgical rationale is less certain, but satisfactory flight performance over the past twenty-five years at least attests to the technical adequacy of blade an...

This study is concerned with a film cooling technique applicable to the protection of the endwalls of a gas turbine vane. In the experiments, cross-injection coolant flow from two-row, paired, inclined holes with nonintersecting centerlines was utilized. The test model is a scaled two-half vane. The levels of turbulence intensity used in the experiments are T.I. = 1.8%, 7%, and 12%. Other param...

Separators are used to protect cathodes from biofouling and to avoid electrode short-circuiting, but they can adversely affect microbial fuel cell (MFC) performance. A spray method was used to apply a polyvinyl alcohol (PVA) separator to the cathode. Power densities were unaffected by the PVA separator (339±29mW/m(2)), compared to a control lacking a separator in a low conductivity solution (1m...