Raman spectroscopy is a very popular, non-destructive tool for the structural characterisation of carbons. Raman scattering from carbons is always a resonant process, in which those configurations whose band gaps match the excitation energy are preferentially excited. Any mixture of sp , sp and sp carbon atoms always has a gap between 0 and 5.5 eV, and this energy 3 2 1 range matches that of IR...

The effect of UV (ultraviolet) irradiation on the adsorption of Au(III) ions on manganese dioxide and their reduction to Au(0) (gold with 0 valence state) was investigated using XPS (X-ray photoelectron spectroscopy) and 197Au Mössbauer spectroscopy. The UV irradiation accelerated the adsorption and the reduction. From the fact that the proportion of Au(0) estimated from Au 4f XPS spectra for s...

The catalytic activity of large zeolite H-ZSM-5 crystals in methanol (MTO) and ethanol-to-olefins (ETO) conversions was investigated and, using operando UV/Vis measurements, the catalytic activity and deactivation was correlated with the formation of coke. These findings were related to in situ single crystal UV/Vis and confocal fluorescence micro-spectroscopy, allowing the observation of the s...

A photocrosslinkable trehalose derivative carrying mesogenic groups was synthesized by esterification reactions. The derivative (TC-HBPHA) was synthesized by the reaction of partially cinnamoyl-modified trehalose (TC4) with 4-(4-hexyloxybenzoyloxy)phenoxy-6-oxohexanoic acid (HBPHA) as a mesogenic unit. TC-HBPHA showed a nematic liquid crystalline mesophase at a temperature range from 150 °C to ...

The compound (n-Bu4N)2Tc2Br8 was prepared by the metathesis of (n-Bu4N)2Tc2Cl8 with HBr (g) in dichloromethane and characterized by X-ray absorption fine structure spectroscopy and UV-vis spectroscopy. Analysis of the data gives a Tc-Tc distance of 2.16(1) A and a Tc-Br distance of 2.48(1) A. The Tc(III) oxidation state was inferred by the position of the edge absorption, which reveals a shift ...

The antioxidant effect of 5-Aminosalicylic acid (5-ASA) on copper-mediated LDL oxidation was followed either by the emitted chemiluminiscence (CL) or by UV-vis spectroscopy. 5-ASA addition extends the lag phase in a concentration-dependent manner without changes in the rate of the process in the autoaccelerated phase. The antioxidant behavior of 5-ASA was very similar to that of Trolox, a very ...

ABSTRACT The complicated chemical processes that occur during peroxide bleaching of pulp may be monitored by analysis of the dissolved substances in peroxide bleaching pressates with UV-visible spectroscopy. Sample preparation using filtration, pH adjustment and data manipulation assist in the extraction of information using UV absorbance spectroscopy. This information may be used to model pero...

Secondary organic aerosol (SOA) particles are generated by reacting d-limonene vapor and ozone in a Teflon reaction chamber. The reaction is carried out in either dry or humid air in darkness. The resulting SOA particles are collected on glass fiber filters, and their photochemical properties are probed using a combination of UV photodissociation action spectroscopy and absorption spectroscopy ...

Various techniques have been used (UV absorbance and fluorescence spectroscopy, polarised UV fluorescence microscopy, viscosimetry, electrophoresis and isoelectric focusing, superprecipitation, etc.) As suggested by several parameters, denervation interferes with the structure of actin by producing local conformation changes in the region of aromatic residues near the sites responsible for acti...

Cataractous and noncataractous human lenses were irradiated with ultraviolet (UV) light, and the resulting triplet and radical species were studied by electron paramagnetic resonance spectroscopy. Evidence is presented that free radicals are produced by a biphotonic process involving tryptophan as an intermediate triplet. This makes free radical production energetically feasible. A possible lin...