Analysis of Compositional Effects on Global Flow Regimes in CO2 Near-Miscible Displacements in Heterogeneous Systems

Transport in Porous Media - The objective of this paper is developing new methodology for constructing the inflow performance relationships (IPRs) of unconventional reservoirs experiencing...     

HPLC–MS Profiling and Structural Identification of [14C]-Diclofenac Metabolites in Mouse Bile

Biliary metabolites present at 6 h post-dose following a single oral dose of [¹⁴C]-diclofenac (10 mg kg^?1) to male bile duct-cannulated C57BL/6 J mice were profiled and identified. Over the 6 h duration of the study ~19.5 % of the administered radioactivity was excreted into the bile as either [¹⁴C]-diclofenac or metabolites. When profiled using HPLC with online radiodetection, the presence of at least 13 radiolabelled components was indicated. These compounds were shown, by consecutive reaction mass spectrometry, to comprise a range of hydroxylated metabolites conjugated to either taurine, glucose and/or glucuronic acid. Both phenolic and acylglucuronide-containing metabolites were observed. The confirmation of the presence of these glucuronide conjugates in mouse bile may have important consequences in the light of emerging theories concerning the role of bacterial glucuronidases for the GI-tract toxicity of NSAIDs such as diclofenac.     

Infrared optical constants, dielectric constants, molar polarizabilities, transition moments, dipole moment derivatives and Raman spectrum of liquid cyclohexane

Previous studies have been done in this laboratory focusing on the optical properties of several liquid aromatic and aliphatic hydrocarbons in the infrared. The current study reports the infrared and absorption Raman spectra of liquid cyclohexane. Infrared spectra were recorded at 25 °C over a wavenumber range of 7400–490 cm⁻¹. Infrared measurements were taken using transmission cells with pathlengths ranging from 3 to 5000 μm. Raman spectra were recorded between 3700 and 100 cm⁻¹ at 25 °C using a 180° reflection geometry. Ab initio calculations of the vibrational wavenumbers at the B3LYP/6311G level of theory were performed and used to help assign the observed IR and Raman spectra. Extensive assignments of the fundamentals and binary combinations observed in the infrared imaginary molar polarizability spectrum are reported. The imaginary molar polarizability spectrum was curve fitted to separate the intensity from the various transitions and used to determine the transition moments and magnitudes of the derivatives of the dipole moment with respect to the normal coordinates for the fundamentals.     

Online analysis of products from a direct ethanol fuel cell

Methodology for the online analysis of the main products from a direct ethanol fuel cell (DEFC) has been developed. The liquid exhaust from the fuel cell is first passed through a conductivity cell to determine the concentration of acetic acid and then CO₂ is extracted into a nitrogen stream for determination with a flow-through infrared-based CO₂ sensor. The other major product, acetaldehyde can be obtained by difference from the current. The continuous measurement of these products allows monitoring of changes in product distributions with time and operating conditions, resulting in a simple online system for rapid evaluation of anode catalysts in DEFCs.     

Molecular distribution sensing in a fluorescence resonance energy transfer based affinity assay for glucose

A newly developed method for determining molecular distribution functions is applied to a widely researched glucose affinity sensor. The reduction in fluorescence resonance energy transfer (FRET) to a malachite green (MG)-dextran complex from allophycocyanin (APC) bound to concanavalin A (ConA) due to displacement of the complex by glucose from ConA provides the basis of the assay. The higher sensitivity and specificity of a new approach to fluorescence decay analysis, over the methods based on conventional Forster-type models, is demonstrated and critical parameters in competitive binding FRET sensing derived.     

Incorporation of ferrocene into polypyrrole films via an ionic adduct with boron trifluoride

1-(Ferrocenyl)ethanol has been immobilized within polypyrrole films during their electrochemical deposition, or following their deposition, via its adduct with boron trifluoride. Dissociation of H⁺ from this adduct, formed in a solution of boron trifluoride diethyl ether (BFEE) in acetonitrile, produces an anion that can act as a counterion for oxidized polypyrrole. Its subsequent hydrolysis produces a polypyrrole film containing neutral 1-(ferrocenyl)ethanol which was found to be strongly retained. In addition to producing a novel type of polypyrrole–ferrocene composite, this work provides clear evidence to support the efficacy of this methodology for the incorporation of neutral species within conducting polymer films.     

A pseudo-hamiltonian model for small alkali metal clusters

The dissociation energies and equilibrium geometries of the molecules Na₃, Na₃ ⁺, K₃ and K₃ ⁺ are calculated using a simple model hamiltonian. The model was previously developed by Roach and Baybutt to explain an anomalous feature in the bonding of alkali metal diatomics. For polyatomics it is convenient to introduce a small gaussian expansion of Slater orbitals, and this also allows the use of an improved method of evaluating integrals over the core volumes. Although Na₃ and K₃ are only predicted to be metastable (like H₃), their calculated ionization potentials are in quite good agreement with experiment. The failure of the model for the other alkali metals is discussed.     

Deactivation resistant PdSb/C catalysts for direct formic acid fuel cells

Formic acid oxidation at novel carbon supported PdSb alloy catalysts has been studied in a multi-anode direct formic acid fuel cell with supporting mechanistic studies in a conventional electrochemical cell. The optimized PdSb/C catalysts show better high voltage and long term performances than a comparable commercial Pd/C catalyst and much better resistance to poisoning (deactivation). Electrochemical stripping voltammograms show that the presence of Sb lowers the potential required for CO oxidation, and greatly decreases the accumulation of CO on the catalyst surface during formic acid oxidation.     

Ru oxide/carbon fabric composites for supercapacitors

Ru oxide/carbon fabric composites (Ru oxide/CF) were prepared by impregnating carbon fabric (CF) with a hydrous RuO₂ suspension. Their properties were characterized by scanning electron microscopy, impedance spectroscopy, cyclic voltammetry, and constant current discharging. Specific capacitance increased with increasing loading of Ru oxide. The apparent average specific capacitance of the Ru oxide component reached 1,085 F g⁻¹ for a 9.15% loading, with a peak of 1,984 F g⁻¹ at approximately 0.3 V vs Ag/AgCl. The presence of Ru oxide decreases the ionic resistance of the CF and appears to increase its specific capacitance by generating additional electroactive surface functionality.