Capillarity-Driven Flows at the Continuum Limit

We experimentally investigate the dynamics of capillary-driven flows at the nanoscale, using an original platform that combines nanoscale pores and microfluidic features. Our results show a coherent picture across multiple experiments including imbibition, poroelastic transient flows, and a drying-based method that we introduce. In particular, we exploit extreme drying stresses - up to 100 MPa of tension - to drive nanoflows and provide quantitative tests of continuum theories of fluid mechanics and thermodynamics (e.g. Kelvin-Laplace equation) across an unprecedented range. We isolate the breakdown of continuum as a negative slip length of molecular dimension.Comment: 5 pages; 4 figure

Anisotropy Studies of the Unresolved Far-infrared Background

Dusty, starforming galaxies and active galactic nuclei that contribute to the integrated background intensity at far-infrared wavelengths trace the large-scale structure. Below the point source detection limit, correlations in the large-scale structure lead to clustered anisotropies in the unresolved component of the far-infrared background (FIRB). The angular power spectrum of the FIRB anisotropies could be measured in large-area surveys with the Spectral and Photometric Imaging Receiver (SPIRE) on the upcoming Herschel observatory. To study statistical properties of these anisotropies, the confusion from foreground Galactic dust emission needs to be reduced even in the ``cleanest'' regions of the sky.The multi-frequency coverage of SPIRE allows the foreground dust to be partly separated from the extragalactic background composed of dusty starforming galaxies as well as faint normal galaxies. The separation improves for fields with sizes greater than a few hundred square degrees and when combined with Planck data. We show that an area of about $\sim$ 400 degrees$^2$ observed for about 1000 hours with Herschel-SPIRE and complemented by Planck provides maximal information on the anisotropy power spectrum. We discuss the scientific studies that can be done with measurements of the unresolved FIRB anisotropies including a determination of the large scale bias and the small-scale halo occupation distribution of FIRB sources with fluxes below the point-source detection level.Comment: 10 pages, 8 figures, replaced to match the extended version, accepted by Ap