6,282 research outputs found

    Topography driven spreading

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    Roughening a hydrophobic surface enhances its nonwetting properties into superhydrophobicity. For liquids other than water, roughness can induce a complete rollup of a droplet. However, topographic effects can also enhance partial wetting by a given liquid into complete wetting to create superwetting. In this work, a model system of spreading droplets of a nonvolatile liquid on surfaces having lithographically produced pillars is used to show that superwetting also modifies the dynamics of spreading. The edge speed-dynamic contact angle relation is shown to obey a simple power law, and such power laws are shown to apply to naturally occurring surfaces

    The origin of very wide binary systems

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    The majority of stars in the Galactic field and halo are part of binary or multiple systems. A significant fraction of these systems have orbital separations in excess of thousands of astronomical units, and systems wider than a parsec have been identified in the Galactic halo. These binary systems cannot have formed through the 'normal' star-formation process, nor by capture processes in the Galactic field. We propose that these wide systems were formed during the dissolution phase of young star clusters. We test this hypothesis using N-body simulations of evolving star clusters and find wide binary fractions of 1-30%, depending on initial conditions. Moreover, given that most stars form as part of a binary system, our theory predicts that a large fraction of the known wide 'binaries' are, in fact, multiple systems.Comment: 4 pages, 1 figure, to appear in the proceedings of IAU Symposium 266, eds. R. de Grijs & J.R.D. Lepin

    Energy-effcient master-slave edge-router upgrade paths in active remote nodes of next-generation optical access

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    Our design rules offers maximally energy-efficient Gb/s -> Tb/s edge-router upgrade paths. One path assumes 10% average traffic intensity with 68% energy-efficiency gains over 5 upgrades, while 30% traffic load enables 45% energy-efficiency gains over 9 generations

    Avoidance of the left lateral decubitus position during sleep in patients with heart failure: relationship to cardiac size and function

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    AbstractObjectivesWe sought to determine whether patients with congestive heart failure (CHF) avoid the left lateral decubitus (LLD) position during sleep and, if so, whether this avoidance would be more pronounced in those with greater degrees of cardiomegaly.BackgroundAnecdotal reports suggest that, in patients with CHF, the LLD position is associated with discomfort due to the enlarged apical heart beat and greater degree of dyspnea (trepopnea) than other positions. It has also been suggested that the LLD position is associated with increased sympathetic nervous activity.MethodsA total of 75 patients with CHF and 75 control subjects underwent nocturnal polysomnography with monitoring of body position. Echocardiography was performed in all patients with CHF to determine left ventricular end-diastolic diameter (LVEDD). A total of 40 patients underwent cardiac catheterization from which pulmonary capillary wedge pressure (PCWP) and cardiac output (CO) were obtained.ResultsPatients with CHF spent significantly less time in the LLD position than in the right lateral decubitus position. No such difference was observed among control subjects. Among patients with CHF, those with larger LVEDD, higher PCWP, and lower CO spent less time in the LLD position.ConclusionsPatients with CHF avoid the LLD position spontaneously during sleep. This may be a protective strategy to avoid discomfort from the enlarged apical heart beat or further hemodynamic or autonomic compromise

    Final Report: Buffalo National River Ecosystems

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    The objective of this study was to sample the Buffalo River on a seasonal basis for a year, in order to determine whether any potential water quality problems existed

    Measurement of abnormal bone composition in vivo using noninvasive Raman spectroscopy

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    X-ray-based diagnostic techniques, which are by far the most widely used for diagnosing bone disorders and diseases, are largely blind to the protein component of bone. Bone proteins are important because they determine certain mechanical properties of bone and changes in the proteins have been associated with a number of bone diseases. Spatially Offset Raman Spectroscopy (SORS) is a chemically specific analytical technique that can be used to retrieve information noninvasively from both the mineral and protein phases of the bone material in vivo. Here we demonstrate that SORS can be used to detect a known compositional abnormality in the bones of a patient suffering from the genetic bone disorder, osteogenesis imperfecta, a condition which affects collagen. The confirmation of the principle that bone diseases in living patients can be detected noninvasively using SORS points the way to larger studies that focus on osteoporosis and other chronic debilitating bone diseases with large socioeconomic burdens
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