We compare the methods of continuous solvent (Soxhlet) and supercritical solvent extractions for the removal of the organic template from nanostructured silica monoliths. Our monoliths are formed by templating the L3 liquid crystal phase of cetylpyridinium chloride in aqueous solutions with tetramethoxy silane. The monoliths that result from both Soxhlet and supercritical extraction methods are...

We propose a phase-space formulation for the nonlinear Schrödinger equation with a white-noise potential in order to shed light on two problems: the rate of dispersion and the singularity formation. Our main tools are the energy laws and the variance identity. The method is completely elementary. For the problem of dispersion, we show that in the absence of dissipation the ensemble-average disp...

The reaction pathway of vinyl acetate synthesis is scrutinized by reacting gas-phase ethylene (at an effective pressure of 1 x 10-4 Torr) with eta2-acetate species (with a coverage of 0.31 +/- 0.02 monolayer) on a Pd(111)-O(2x2) model catalyst surface in ultrahigh vacuum. It is found that the 1414 cm-1 infrared feature due to the symmetric OCO stretching mode of the acetate species decreases in...

In this study the first supercritical fluid based protocol for the extraction, analysis, and isolation of six polar compounds, i.e., o-vanillin (1), styracin (2), vanillin (3), trans-cinnamic acid (4), vanillic acid (5), and shikimic acid (6), was developed. First, eight styrax resin products (R1-R8) obtained from various Liquidambar tree species, which are known to contain compounds 2-6, were ...

Percolation describes the sudden emergence of large-scale connectivity as edges are added to a lattice or random network. In the Bohman-Frieze-Wormald model (BFW) of percolation, edges sampled from a random graph are considered individually and either added to the graph or rejected provided that the fraction of accepted edges is never smaller than a decreasing function with asymptotic value of ...

The effect of alkyl group substituents on the degradation kinetics of poly(alkyl methacrylates) namely poly (n-butyl methacrylate) (PBMA), poly (iso-propyl methacrylate) (PPMA), poly (ethyl methacrylate) (PEMA), and poly (methyl methacrylate) (PMMA) in supercritical and subcritical conditions was studied at various temperatures (250 – 375 o C). The molecular weight distributions were measured b...

In the standard scenario of isolated low-mass star formation, strongly magnetized molecular clouds are envisioned to condense gradually into cores, driven by ambipolar diffusion. Once the cores become magnetically supercritical, they collapse to form stars. Most previous studies based on this scenario are limited to axisymmetric calculations leading to single supercritical core formation. The a...

Abstract. By the mean of a multi-scale analysis we describe the typical geometrical structure of the clusters under the FK measure in random media. Our result holds in any dimension d > 2 provided that slab percolation occurs under the annealed measure, which should be the case in the whole supercritical phase. This work extends the one of Pisztora [29] and provides an essential tool for the an...

In this study, moisture content, free fatty acids, peroxide, iodine value, unsaponifiable matter, saponification value, fatty acid composition and tocopherol contents of wheat germ oil obtained by SC-CO2 extraction and cold press technology were investigated. Moisture, free fatty acid (FFA), peroxide value, iodine value, unsaponifiable matter and saponification value of cold pres...