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Full-Text Articles in Engineering
Effective Medium Equations For Chemotaxis In Porous Media, Francisco J. Valdes-Parada, Mark L. Porter, K. Narayanaswamy, Roseanne Ford, Brian D. Wood
Effective Medium Equations For Chemotaxis In Porous Media, Francisco J. Valdes-Parada, Mark L. Porter, K. Narayanaswamy, Roseanne Ford, Brian D. Wood
Francisco J. Valdes-Parada
Biodegradation is an important mechanism for contaminant reduction in groundwater environments; in fact, in-situ bioremediation and bioaugmentation methods represent alternatives to traditional methods such as pump-and-treat. Chemotaxis has shown to enhance bacterial transport toward or away from concentration gradients of chemical species in laboratory experiments and can signifficantly increase contaminant flux undergoing degradation at the interfaces of lowand high-permeability regions. In this work, the method of volume averaging is used to upscale the microscale description of chemotactic microbial transport in order to obtain the corresponding macroscale equations for bacteria and the attractant. As a first apprach, cellular growth/death and consumption …
Separation Of Time Scales For Transient Dispersion, Mark L. Porter, Francisco J. Valdes-Parada, Brian D. Wood
Separation Of Time Scales For Transient Dispersion, Mark L. Porter, Francisco J. Valdes-Parada, Brian D. Wood
Francisco J. Valdes-Parada
No abstract provided.
Modelado Matemático En Ingeniería, Francisco J. Valdes-Parada
Modelado Matemático En Ingeniería, Francisco J. Valdes-Parada
Francisco J. Valdes-Parada
En esta plática se discute de una manera sencilla la importancia que tiene el modelado matemático en Ingeniería. Para ello, se presenta una visión personal sobre el papel que juegan asignaturas como fenómenos de transporte y termodinámica en la formación de licenciatura y posgrado en Ingeniería. Más aún, con el objetivo de ilustrar la importancia de los cambios de escala que frecuentemente aparecen en Ingeniería, se analiza el caso del flujo de un soluto a través de tubos capilares. De esta manera, se tiene un sistema donde a escala microscópica son relevantes la difusión (radial y axial) y convección (axial) …
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 …
Asymptotic Analysis Of The Selective Dip Coating Of Power-Law Fluids, N Tiwari, Jm Davis
Asymptotic Analysis Of The Selective Dip Coating Of Power-Law Fluids, N Tiwari, Jm Davis
Jeffrey M. Davis
The dip coating of a chemically micropatterned surface bearing alternating wetting and nonwetting vertical strips is analyzed for a non-Newtonian power-law fluid. Asymptotic matching is used to determine the thickness of liquid films deposited on the O(10 μm) strips at small capillary and Bond numbers. The chemical patterning that confines the fluid laterally induces a significant transverse curvature of the free-surface. The streamwise variation in this transverse curvature along the strip provides an additional contribution to the capillary pressure gradient that is not present for uniform surfaces. Consequently, the difference in the thickness of the deposited liquid film relative to …
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 …