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Superhydrophobicity And Contact-Line Issues, Lc Gao, Ay Fadeev, Tj Mccarthy
Superhydrophobicity And Contact-Line Issues, Lc Gao, Ay Fadeev, Tj Mccarthy
Lixin Gao
The wettability of several superhydrophobic surfaces that were prepared recently by simple, mostly single-step methods is described and compared with the wettability of surfaces that are less hydrophobic. We explain why two length scales of topography can be important for controlling the hydrophobicity of some surfaces (the lotus effect). Contact-angle hysteresis (difference between the advancing, θA, and receding, θR, contact angles) is discussed and explained, particularly with regard to its contribution to water repellency. Perfect hydrophobicity (θA/θR = 180°/180°) and a method for distinguishing perfectly hydrophobic surfaces from those that are almost perfectly hydrophobic are described and discussed. The Wenzel …
Power-Efficient Topology Control For Static Wireless Networks With Switched Beam Directional Antennas, V Namboodiri, Lx Gao, R Janaswamy
Power-Efficient Topology Control For Static Wireless Networks With Switched Beam Directional Antennas, V Namboodiri, Lx Gao, R Janaswamy
Lixin Gao
Topology control problems are associated with assignment of power levels to nodes of a wireless network so that the resulting graph topology satisfies certain properties. In this paper we consider the problem of power-efficient topology control with switched beam directional antennas taking into account their non-uniform radiation pattern within the beamwidth. Previous work in the area have all assumed a uniform gain model with these antennas which renders antenna orientation insignificant as a parameter in topology control algorithms. We present algorithms that take into account a model of non-uniform gain with the objectives of minimizing the total power and maximum …