We present a physically intuitive model of ice-lens formation and growth during the freezing of soils and other dense, particulate suspensions. Motivated by experimental evidence, we consider the growth of an ice-filled crack in a freezing soil. At low temperatures, ice in the crack exerts large pressures on the crack walls that will eventually cause the crack to split open. We show that the cr...

The maneuverability demonstrated by the weakly electric ghost knifefish (Apteronotus albifrons) is a result of its highly flexible ribbon-like anal fin, which extends nearly three-quarters the length of its body and is composed of approximately 150 individual fin rays. To understand how movement of the anal fin controls locomotion we examined kinematics of the whole fin, as well as selected ind...

This embedded module measures significant wave height and zero crossing periods through spectral energy from a record of time series heave motion. An ARM7TDMI core microcontroller serves as the main control unit which performs the appropriate control and signal conditioning. Monitored wave characteristic is transmitted with satellite modem. Mathematical equations on signal conditioning and expe...

[1] I examine the morphology of ice growth in porous media. Intermolecular forces cause premelted fluid to migrate and supply segregated ice growth (e.g., lenses) and frost heave. I account for the net effect of these microscopic interactions in a homogenized model formulated in terms of fundamental physical properties and characteristics of the porous medium that can be measured; no ad hoc par...

[1] Frost boils in the Arctic are a manifestation of patterned ground in the form of nonsorted circles. Active frost boils involve convection of water through the soil that can bring basic salts from depth to the surface. As such, active frost boils can mitigate acidification and thereby strongly influence the type of vegetation supported by Arctic soils. The presence or absence of active frost...

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In this paper a comparative study of two different control strategies is done: Gain scheduling with classic controllers (PD and second order filter) versus QFT. Both of them are used to decrease motion sickness in a high speed ferry produced by the vertical acceleration associated with heave and pitch motion. Copyright  2002 IFAC

We present dye visualizations of the wake behind a flexible plate flow when its leading edge is forced into harmonic heave motion. We show that, when the forcing amplitude is sufficiently large, a reverse Bénard-von Kármán vortex street is formed in the wake, indicative of the production of positive thrust.