Near-infrared spectroscopy of PKS 1549-79: a protoquasar revealed?

We present a near-infrared (near-IR) spectrum of the nearby radio galaxy PKS 1549-79 (z = 0.153). These data were taken with the aim of testing the idea that this object contains a quasar nucleus that is moderately extinguished, despite evidence that its radio jet points close to our line of sight. We detect broad Paalpha emission (FWHM 1745 +/- 40 km s(-1)), relatively bright continuum emission, and a continuum slope consistent with a reddened quasar spectrum (3.1 <A(V) <7.3), all emitted by an unresolved point source. Therefore we conclude that we have, indeed, detected a hidden quasar nucleus in PKS 1549-79. Combined with previous results, these observations are consistent with the idea that PKS 1549-79 is a young radio source in which the cocoon of debris left over from the triggering events has not yet been swept aside by circumnuclear outflows.

The prediction of intake potential and organic matter digestibility of grass silages by near infrared spectroscopy analysis of undried samples

A study was undertaken to examine a range of sample preparation and near infrared reflectance spectroscopy (NIPS) methodologies, using undried samples, for predicting organic matter digestibility (OMD g kg(-1)) and ad libitum intake (g kg(-1) W-0.75) of grass silages. A total of eight sample preparation/NIRS scanning methods were examined involving three extents of silage comminution, two liquid extracts and scanning via either external probe (1100-2200 nm) or internal cell (1100-2500 nm). The spectral data (log 1/R) for each of the eight methods were examined by three regression techniques each with a range of data transformations. The 136 silages used in the study were obtained from farms across Northern Ireland, over a two year period, and had in vivo OMD (sheep) and ad libitum intake (cattle) determined under uniform conditions. In the comparisons of the eight sample preparation/scanning methods, and the differing mathematical treatments of the spectral data, the sample population was divided into calibration (n = 91) and validation (n = 45) sets. The standard error of performance (SEP) on the validation set was used in comparisons of prediction accuracy. Across all 8 sample preparation/scanning methods, the modified partial least squares (MPLS) technique, generally minimized SEP's for both OMD and intake. The accuracy of prediction also increased with degree of comminution of the forage and with scanning by internal cell rather than external probe. The system providing the lowest SEP used the MPLS regression technique on spectra from the finely milled material scanned through the internal cell. This resulted in SEP and R-2 (variance accounted for in validation set) values of 24 (g/kg OM) and 0.88 (OMD) and 5.37 (g/kg W-0.75) and 0.77 (intake) respectively. These data indicate that with appropriate techniques NIRS scanning of undried samples of grass silage can produce predictions of intake and digestibility with accuracies similar to those achieved previously using NIRS with dried samples. (C) 1998 Elsevier Science B.V.

Screening wall effects of a thin fluidized bed by near-infrared imaging

Near-infrared (NIR) imaging was used to observe water vapour flow in a gas-solid fluidized bed reactor. The technique consisted of a broadband light, an optical filter with a bandwidth centred on strong water vapour absorptions, a Vidicon NIR camera, a nozzle from which an optically active mixture of gas and water vapour was trans-illuminated by an NIR beam and collected data of transmittance were normalized to actual optical path. The procedure was applied to a thin fluidized bed reactor with a low aspect ratio of tube to particle diameters (D-1/d(p)) in order to validate the wall effect on flow dynamics and mass transfer during the reduction of ceria-silica by hydrogen. High concentrations of water vapour emerged in the vicinity of the wall when the bed was operated at pseudo-static conditions but disappeared when the bed was run at minimum bubbling conditions. This result shows the capability of optical methods with affordable costs to 2D imaging opaque packed bed by using a spatially resolved probe located at the exit, which is of great benefit for in situ visualization of anisotropic concentrations in packed beds under industrially relevant conditions and thus for elucidation of the underlying reaction mechanism and diffusion interactions. Crown Copyright (c) 2011 Published by Elsevier B.V. All rights reserved.

Intense near-infrared luminescence of anhydrous lanthanide(III) iodides in an imidazolium ionic liquid

Anhydrous neodymium(III) iodide and erbium(Ill) iodide were dissolved in carefully dried batches of the ionic liquid 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C(12)mim][Tf2N]. Provided that the ionic liquid had a low water content, intense near-infrared emission could be observed for both the neodymium(III) ion and for the erbium(III) ion. Luminescence lifetimes have been measured, and the quantum yield of the neodymium(III) sample has been measured. Exposure of the hygroscopic samples to atmospheric moisture conditions caused a rapid decrease of the luminescence intensities. (C) 2004 Elsevier B.V. All rights reserved.

Strong erbium luminescence in the near-infrared telecommunication window

A new type of near-infrared emitting rare-earth complex has been synthesised, consisting of three bis(perfluoroalkylsulfonyl)imide ligands and one 1,10-phenanthroline molecule. The chelate rings formed by the rare-earth ion and the bidentate ligands do not contain any carbon atoms and can hence be considered as 'inorganic' chelate rings. The absence of C-H stretching vibration modes in the first coordination sphere of the rare-earth ion and the presence of a light-harvesting moiety (1,10-phenanthroline) bound to the rare-earth ion result in a complex that can be efficiently excited and exhibits intense near-infrared luminescence. (C) 2004 Elsevier B.V. All rights reserved.

Ionic liquids as solvents for near-infrared emitting lanthanide complexes

It is shown that ionic liquids are promising solvents for near-infrared emitting lanthanide complexes, because ionic liquids are polar non-coordinating solvents that can solubilize lanthanide complexes. Neodymium(III) tosylate, bromide, triflate and sulfonylimide complexes were dissolved in 1-alkyl-3-methylimidazolium ionic liquids that contain the same anion as the neodymium(III) complexes. Near-infrared luminescence spectra of these neodymium(III) salts were measured by direct excitation of the neodymium(III) ion. The absorption spectra show detailed crystal-field fine structure and Judd-Ofelt parameters have been determined. Intense near-infrared luminescence was observed upon ligand excitation for neodymium(III) complexes with 1,10-phenanthroline or beta-diketonate ligands. (C) 2004 Elsevier B.V. All rights reserved.

TIME-RESOLVED RESONANCE RAMAN-SPECTROSCOPY AND RAMAN SPECTROELECTROCHEMISTRY OF (CO)(5)W[4,4'-BPY]W(CO)(5), PROBED IN THE VISIBLE AND NEAR-INFRARED

Time-resolved resonance Raman spectroscopy of the lowest energy excited state of the 4,4'-bipyridyl ligand-bridged complex, [(CO)(5)W(L)W(CO5] (1), and Raman spectroscopy of electrochemically reduced 1, both give bands characteristic of the the L(.-) species. This confirms that the ligand L is negatively charged in the lowest energy exicited state which is therefore metal-ligand charge transfer (MLCT) in character. Raman spectra of the radical anion of 1 excited in the far red (800 nm) exhibited a band near 2050 cm(-1) due to a vco symmetric CO stretching mode, compared to the corresponding band at 2070 cm(-1) in the spectrum of the parent, uncharged complex. The lower vco in the reduced complex supports the recent finding by time-resolved IR spectroscopy of a similar frequency decrease for nu(CO) in the longest lived (MLCT) excited state of 1 which was attributed to electron/hole localisation in this state on the IR time scale.

The application of Near-Infrared Reflectance Spectroscopy (NIRS) to detect melamine adulteration of soya bean meal

Soya bean products are used widely in the animal feed industry as a protein based feed ingredient and
have been found to be adulterated with melamine. This was highlighted in the Chinese scandal of
2008. Dehulled soya (GM and non-GM), soya hulls and toasted soya were contaminated with melamine
and spectra were generated using Near Infrared Reflectance Spectroscopy (NIRS). By applying chemometrics
to the spectral data, excellent calibration models and prediction statistics were obtained. The coefficients
of determination (R2) were found to be 0.89–0.99 depending on the mathematical algorithm used,
the data pre-processing applied and the sample type used. The corresponding values for the root mean
square error of calibration and prediction were found to be 0.081–0.276% and 0.134–0.368%, respectively,
again depending on the chemometric treatment applied to the data and sample type. In addition, adopting
a qualitative approach with the spectral data and applying PCA, it was possible to discriminate
between the four samples types and also, by generation of Cooman’s plots, possible to distinguish
between adulterated and non-adulterated samples.

The use of handheld near-infrared reflectance spectroscopy (NIRS) for the proximate analysis of poultry feed and to detect melamine adulteration of soya bean meal

The use of handheld near infrared (NIR) instrumentation, as a tool for rapid analysis, has the potential to be used widely in the animal feed sector. A comparison was made between handheld NIR and benchtop instruments in terms of proximate analysis of poultry feed using off-the-shelf calibration models and including statistical analysis. Additionally, melamine adulterated soya bean products were used to develop qualitative and quantitative calibration models from the NIRS spectral data with excellent calibration models and prediction statistics obtained. With regards to the quantitative approach, the coefficients of determination (R2) were found to be 0.94-0.99 with the corresponding values for the root mean square error of calibration and prediction were found to be 0.081-0.215 % and 0.095-0.288 % respectively. In addition, cross validation was used to further validate the models with the root mean square error of cross validation found to be 0.101-0.212 %. Furthermore, by adopting a qualitative approach with the spectral data and applying Principal Component Analysis, it was possible to discriminate between adulterated and pure samples.

Classification the geographical origin of corn distillers dried grains with solubles by near infrared reflectance spectroscopy combined with chemometrics: A feasibility study

In this study, 137 corn distillers dried grains with solubles (DDGS) samples from a range of different geographical origins (Jilin Province of China, Heilongjiang Province of China, USA and Europe) were collected and analysed. Different near infrared spectrometers combined with different chemometric packages were used in two independent laboratories to investigate the feasibility of classifying geographical origin of DDGS. Base on the same dataset, one laboratory developed a partial least square discriminant analysis model and another laboratory developed an orthogonal partial least square discriminant analysis model. Results showed that both models could perfectly classify DDGS samples from different geographical origins. These promising results encourage the development of larger scale efforts to produce datasets which can be used to differentiate the geographical origin of DDGS and such efforts are required to provide higher level food security measures on a global scale.