Pore structure and connectivity determine how microstructured materials perform in applications such as catalysis, fluid storage and transport, filtering or as reactors. We report a model study on silica aerogel using a time-of-flight magnetic resonance imaging technique to characterize the flow field and explain the effects of heterogeneities in the pore structure on gas flow and dispersion wi...

Motivated by the recent prediction that uniaxially compressed aerogel can stabilize the anisotropic A phase over the isotropic B phase, we measure the pressure dependent superfluid fraction of (3)He entrained in 10% axially compressed, 98% porous aerogel. We observe that a broad region of the temperature-pressure phase diagram is occupied by the metastable A phase. The reappearance of the A pha...

0168-583X/$ see front matter 2010 Elsevier B.V. doi:10.1016/j.nimb.2010.12.035 ⇑ Corresponding author. E-mail address: [email protected] (H. Yan). We report measurements of the energy dependence of the total neutron scattering cross-section of CH4 both in bulk and confined in aerogel glass for neutron energies between 0:3 and 200 meV. Solid CH4 in phase II is an effective slow neutron moderat...

Charged particle identification at the PANDA experiment will be performed over a wide range of momenta by Čerenkov detectors. One option to identify higher momentum charged particles under small polar angles could be the use of silica aerogels as radiator. Simultaneously, an aerogel Čerenkov counter is being designed for the Kaos spectrometer at the Mainz Microtron MAMI for the discrimination b...

Phase transitions inside the pores of an aerogel are investigated by modelizing the aerogel structure by diffusion-limited cluster-cluster aggregation on a cubic lattice in a finite box and considering q-states Potts variables on the empty sites interacting via nearest-neighbours. Using a finite size scaling analysing of Monte-Carlo numerical results, it is concluded that for q = 4 the transiti...

Introduction: Returned extraterrestrial samples, planetary, asteroidal or cometary, are so valuable that initial assessment of the most appropriate analytical protocols for each grain is essential. It is particularly important to know the distribution and interrelationships of specific mineral components. Numerous sophisticated microanalysis techniques are now available [1], yet many may damage...

K. Matsumoto,* J. V. Porto, L. Pollack, E. N. Smith, T. L. Ho, and J. M. Parpia Laboratory of Atomic & Solid State Physics and Materials Science Center, Cornell University, Ithaca, New York 14853 (Received 14 January 1997) We present evidence for a nonzero pressure, T ­ 0 superfluid phase transition of 3He in 98.2% open aerogel. Unlike bulk 3He which is a superfluid at T ­ 0 at all pressures (d...

We infer the magnitude of the superfluid gap for He in aerogel from measurements of the normal fluid density as a function of temperature. We compute the effective Yosida function for two different aerogel samples over a range of pressures. We find that the suppression factor of the zero-temperature superfluid gap, scaled by kBTc , ranges from 0.5 to 0.8 as compared to the pressure-dependent we...

The development of high efficient and low energy consumption approaches for the transformation of cellulose is of high significance for a sustainable production of high value-added feedstocks. Herein, electrocatalytic oxidation technique was employed for the selective conversion of cellulose to gluconate in alkaline medium by using concentrated HNO3 pretreated carbon aerogel (CA) supported Au n...