From algal suspensions to magma upwellings, one finds jets which exhibit complex symmetry-breaking instabilities as they are decelerated by their surroundings. We consider here a model system—a saline jet descending ...
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From algal suspensions to magma upwellings, one finds jets which exhibit complex symmetry-breaking instabilities as they are decelerated by their surroundings. We consider here a model system—a saline jet descending through a salinity gradient—which produces dynamics unlike those of standard momentum jets or plumes. The jet coils like a corkscrew within a conduit of viscously entrained fluid, whose upward recirculation braids the jet, and nearly confines transverse mixing to the narrow conduit. We show that the underlying jet structure and certain scaling relations follow from similarity solutions to the fluid equations and the physics of Kelvin-Helmholtz instabilities.
We present design features and applications of a novel UV-visible-NIR FLIM system with optical sectioning, high resolution (50ps), and large temporal dynamic range (750ps-1μs) to probe cellular metabolism and detect ...
We developed a controlled-environment FLIM system towards intracellular oxygen sensing, with a resolution of approximately 8 μM, covering the entire physiologic range (0-300 μM). We measured oxygen levels in normal ...
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Numerical simulations of time-resolved light transport in inhomogeneous tissues reveal quantitative, 3D-distributions of excitation and fluorescent light. Visualizations generated can assist the optimization of endosc...
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This paper presents an algorithm to improve sub-sea acoustic multibeam bottom mapping based on the simultaneous mapping and localization (SLAM) methodology. Multibeam bathymetry from underwater water vehicles can yiel...
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This paper presents an algorithm to improve sub-sea acoustic multibeam bottom mapping based on the simultaneous mapping and localization (SLAM) methodology. Multibeam bathymetry from underwater water vehicles can yield valuable large scale terrain maps of the sea door, but the overall accuracy of these maps is typically limited by the accuracy of the vehicle position estimates. The solution presented here uses small bathymetric patches created over short time scales in a sub-mapping context. These patches are registered with respect to one another and assembled in a single coordinate frame to produce a more accurate terrain estimate and provide improved renavigation of the vehicle trajectory. The mapping is implemented using a delayed state extended Kalman filter (EKF) and results are shown for a real world multibeam data set collected at the mid-Atlantic ridge using the JASON ROV.
Intracellular oxygen levels were measured in vivo under physiological-temperature controlled conditions by monitoring the fluorescence lifetime of the oxygen sensitive dye ruthenium tris(2,2′-dipyridyl) dichloride he...
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Buoy based seafloor observatories require lightweight synthetic strength member electro-optical anchor cables to be feasible. Typically these cables have maximum elongations of around 0.6% before damage occurs to the ...
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ISBN:
(纸本)0933957343
Buoy based seafloor observatories require lightweight synthetic strength member electro-optical anchor cables to be feasible. Typically these cables have maximum elongations of around 0.6% before damage occurs to the copper and optical elements and therefore provide minimal compliance to absorb wave and current forces acting on the surface buoy and cable. A stretchy mechanical system known as a snubber has been developed at WHOI for absorbing wave energy and protecting the buoy electro-optical cable from excessive strain. Results are presented from field trials of three different ocean mooring designs that all use snubber hoses as a key design element.
We devise an inverse statistical-mechanical methodology to find optimized interaction potentials that lead spontaneously to a target many-particle configuration. Target structures can possess varying degrees of disord...
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We devise an inverse statistical-mechanical methodology to find optimized interaction potentials that lead spontaneously to a target many-particle configuration. Target structures can possess varying degrees of disorder, thus extending the traditional idea of self-assembly to incorporate both amorphous and crystalline structures as well as quasicrystals. For illustration purposes, our computational technique is applied to yield an optimized isotropic (nondirectional) pair potential that spontaneously yields the three-coordinated honeycomb lattice as the ground state structure in two dimensions. This target choice is motivated by its three-dimensional analog, the diamond lattice, which is known to possess desirable photonic band gap properties.
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