Boron and nitrogen-rich carbons from ionic liquid precursors with tailorable surface properties

A novel strategy for tailoring the adsorption and structural properties of ionic liquid derived carbons has been developed. By changing the carbonization temperature and ratios of ionic liquids (ILs) containing a cross-linkable anion, such as 1-butyl-3-methylimidazolium tricyanomethanide [BMIm][C(CN)(3)] and 1-ethyl-3-methylimidazolium tetracyanoborate [EMIm][B(CN)(4)], boron and nitrogen-rich carbons with slit-like pores and specific surface areas exceeding 500 m(2) g(-1) have been prepared. Furthermore, the nitrogen-rich carbons exhibit high adsorption capacity for CO(2) adsorption and selectivity for CO(2)/N(2) separation.     

A benchmark spike‐in data set for biomarker identification in metabolomics

The development and the validation of innovative approaches for biomarker selection are of paramount importance in many ‐omics technologies. Unfortunately, the actual testing of new methods on real data is difficult, because in real data sets, one can never be sure about the “true” biomarkers. In this paper, we present a publicly available metabolomic ultra performance liquid chromatography–mass spectrometry spike‐in data set for apples. The data set consists of 10 control samples and three spiked sets of the same size, where naturally occurring compounds are added in different concentrations. In this sense, the data set can serve as a test bed to assess the performance of new algorithms and compare them with previously published results. We illustrate some of the possibilities provided by this spike‐in data set by comparing the performance of two popular biomarker‐selection methods, the univariate t‐test and the multivariate variable importance in projection. To promote a widespread use of the data, raw data files as well as preprocessed peak lists are made available. Copyright © 2012 John Wiley & Sons, Ltd.     

Development of reliable analytical tools for evaluating the influence of reductive winemaking on the quality of Lugana wines

This paper presents methods for the definition of important analytical tools, such as the development of sensitive and rapid methods for analysing reduced and oxidised glutathione (GSH and GSSG), hydroxycinnamic acids (HCA), bound thiols (GSH-3MH and Cys-3MH) and free thiols (3MH and 3MHA), and their first application to evaluate the effect of reductive winemaking on the composition of Lugana juices and wines.     

Valuation of sinking-fund bonds in the Vasicek and CIR frameworks∗Financial support from Murst Fondo 40% on ‘Modelli di struttura a termine dei tassi d'interesse’ is gratefully acknowledged.

In a sinking-fund bond, the issuer is required to retire portions of the bond prior to maturity, with the option of doing so either by calling the bonds by lottery, or by buying them back at their market value. This paper discusses the valuation of a default-free sinking-fund bond issue in the Vasicek (1977) and, alternatively, the Cox, Ingersoll and Ross (CIR) (1985) frameworks. We show in particular that, calling the bond issue without the delivery option ‘corresponding serial’, and the one without the prepayment feature ‘corresponding coupon’, under no-arbitrage a sinking-fund bond can be priced either in terms of the corresponding coupon bond and a bond call option, or in terms of the corresponding serial and a bond put option. We also present a detailed comparative-statics analysis of our valuation model, where we show that a sinking-fund bond has a stochastic duration intermediate between the ones of the corresponding serial and coupon bonds. We argue that such a feature gives a further rational for the presence of the delivery option. Moreover, we compare our results with the ones of Ho (1985), who has previously discussed the valuation problem under scrutiny.     

Multi-frame pyramid correlation for time-resolved PIV

A novel technique is introduced to increase the precision and robustness of time-resolved particle image velocimetry (TR-PIV) measurements. The innovative element of the technique is the linear combination of the correlation signal computed at different separation time intervals. The domain of the correlation signal resulting from different temporal separations is matched via homothetic transformation prior to the averaging of the correlation maps. The resulting ensemble-averaged correlation function features a significantly higher signal-to-noise ratio and a more precise velocity estimation due to the evaluation of a larger particle image displacement. The method relies on a local optimization of the observation time between snapshots taking into account the local out-of-plane motion, continuum deformation due to in-plane velocity gradient and acceleration errors. The performance of the pyramid correlation algorithm is assessed on a synthetically generated image sequence reproducing a three-dimensional Batchelor vortex; experiments conducted in air and water flows are used to assess the performance on time-resolved PIV image sequences. The numerical assessment demonstrates the effectiveness of the pyramid correlation technique in reducing both random and bias errors by a factor 3 and one order of magnitude, respectively. The experimental assessment yields a significant increase of signal strength indicating enhanced measurement robustness. Moreover, the amplitude of noisy fluctuations is considerably attenuated and higher precision is obtained for the evaluation of time-resolved velocity and acceleration.     

Cosmological tests with strong gravitational lenses using Gaussian processes

Strong gravitational lenses provide source/lens distance ratios \({\mathcal {D}}_{\mathrm{obs}}\) useful in cosmological tests. Previously, a catalog of 69 such systems was used in a one-on-one comparison between the standard model, \(\varLambda \)CDM, and the \(R_{\mathrm{h}}=ct\) universe, which has thus far been favored by the application of model selection tools to many other kinds of data. But in that work, the use of model parametric fits to the observations could not easily distinguish between these two cosmologies, in part due to the limited measurement precision. Here, we instead use recently developed methods based on Gaussian Processes (GP), in which \({\mathcal {D}}_{\mathrm{obs}}\) may be reconstructed directly from the data without assuming any parametric form. This approach not only smooths out the reconstructed function representing the data, but also reduces the size of the \(1\sigma \) confidence regions, thereby providing greater power to discern between different models. With the current sample size, we show that analyzing strong lenses with a GP approach can definitely improve the model comparisons, producing probability differences in the range \(\sim \) 10–30%. These results are still marginal, however, given the relatively small sample. Nonetheless, we conclude that the probability of \(R_{\mathrm{h}}=ct\) being the correct cosmology is somewhat higher than that of \(\varLambda \)CDM, with a degree of significance that grows with the number of sources in the subsamples we consider. Future surveys will significantly grow the catalog of strong lenses and will therefore benefit considerably from the GP method we describe here. In addition, we point out that if the \(R_{\mathrm{h}}=ct\) universe is eventually shown to be the correct cosmology, the lack of free parameters in the study of strong lenses should provide a remarkably powerful tool for uncovering the mass structure in lensing galaxies.