A method has been developed for quantitative analysis of all major sulfur forms in coal, both organic and inorganic, from sulfur K-edge X-ray absorption fine structure (XAFS) spectroscopy. The method is based on least-squares analysis of the X-ray absorption near-edge structure, or XANES, into a series of peaks that represent Isnp photoelectron transitions. Because the major sulfur forms occurring in coal (pyrite, organic sulfide, thiophene, sulfoxide, sulfone, and sulfate) have characteristic s -*• p transition energies, the relative peak area contributed to the XANES by each sulfur form can be determined. These peak areas are converted to weight percentages of sulfur by using calibration constants derived from XANES data from standard compound mixtures. This method has been

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Significant enhancement in supercapacitor performance was achieved via the synthesis of nanocrystalline RuO 2 on vertically aligned Few Layered Graphene (FLG) nanoflakes, synthesized on bare n-type heavily doped silicon substrates by microwave plasma chemical vapour deposition. The RuO 2 nanoparticles (diameter <2 nm) were deposited using a combination of low base pressure radio frequency magnetron sputtering and subsequent electrochemical cycling in acidic media. The welldispersed RuO 2 nanoparticles on FLGs achieve a specific capacitance of the order of 650 F g À1. The specific capacitance of RuO 2-FLGs is significantly higher than pristine sputtered RuO 2 ($320 F g À1) and FLGs ($6 F g À1) indicative of the synergistic effect between the FLGs and RuO 2. In addition, the fabricated RuO 2-FLG supercapacitors show excellent cycling capability with approximately 70% retention of initial specific capacitance over 4000 cycles at high charging-discharging rates of 500 mV s À1. The superior electrochemical performance is attributed to the good electronic conductivity of the FLGs as well as high utilization of well-dispersed RuO 2 nanoparticles on FLGs.

In this paper we analyze the inviscid regime (for which viscosity is unimportant and the flow occurs due to the balance between the capillary and the inertial effects) that invariably precedes the classical century-old Washburn regime during capillary filling. We demonstrate that a new nondimensional number, namely, the product of the Ohnesorge number and the ratio between the filling length (ℓ) and the radius of the capillary (R), dictates the occurrence of this regime and the other well-known regimes in a capillary filling problem. We also identify that this inviscid regime occurs for the time that is of the order of the capillary time scale and, as has been quantified before [Quere, Eur. Phys. Lett. 39, 533 (1997); Joly, J. Chem. Phys. 135, 214705 (2011)], is characterized by the filling length being linearly proportional to the filling time. We establish the universality of this regime by pinpointing the existence of this regime (showing appropriate dependencies of the capillary radii and density) from existing experimental and Molecular Dynamics Simulation results that signify disparate ranges of length and time scales.

In this paper, we identify that the different regimes encountered in a vertical capillary filling or a capillary-rise problem are determined entirely by two dimensionless parameters: Ohnesorge number (Oh) and Bond number (Bo). The initial universal inertial regime, which has been analyzed in our recent paper [Das et al., Phys. Rev. E 86, 067301 (2012)], is followed by any one of three possible regimes, dictated by the ratio Oh/Bo. For Oh/Bo>>1, the viscous effects dominate the gravitational effects, and one encounters the classical Washburn regime. For the other limit, i.e., Oh/Bo<<1, the viscous effects are insignificant and there is no Washburn regime. On the contrary, the inertial regime transits to the oscillatory regime with the filling length ℓ oscillating about the Jurin height (~1/Bo), which is the maximum height attained by a liquid column in vertical capillary filling, with the viscous effects (~Oh) dictating the nature of the oscillations. For Oh/Bo~1, we get a behavior intermediate of these two extreme regimes. Finally, we identify the correct force picture that drives the oscillatory regime and in the process achieve quantitative match with the experimental results, that was precluded in the previous studies.