Velocity effects on the shape of pure H2O isolated lines: complementary tests of the partially correlated speed-dependent Keilson-Storer model.

Complementary tests of the partially correlated speed-dependent Keilson-Storer (pCSDKS) model for the shape of isolated transition of pure water vapor [N. H. Ngo et al., J. Chem. Phys. 136, 154310 (2012)] are made using new measurements. The latter have been recorded using a high sensitivity cavity ring down spectrometer, for seven self-broadened H(2)O lines in the 1.6 µm region at room temperature and for pressures from 0.5 to 15 Torr. Furthermore, the H(2) (18)O spectra of [M. D. De Vizia et al., Phys. Rev. A 83, 052506 (2011)] in the 1.38 µm region, measured at 273.15 K and for pressures from 0.3 to 3.75 Torr have also been used for comparison with the model. Recall that the pCSDKS model takes into account the collision-induced velocity changes, the speed dependences of the broadening and shifting coefficients as well as the partial correlation between velocity and rotational-state changes. All parameters of the model have been fixed at values previously determined, except for a scaling factor applied to the input speed-dependent line broadening. Comparisons between predictions and experiments have been made by looking at the results obtained when fitting the calculated and measured spectra by Voigt profiles. The good agreement obtained for all considered lines, at different temperature and pressure conditions, confirms the consistency and the robustness of the model. Limiting cases of the model have been then derived, showing the influence of different contributions to the line shape.

Phenotypic prediction based on metabolomic data for growing pigs from three main European breeds.

Predicting phenotypes is a statistical and biotechnical challenge, both in medicine (predicting an illness) and animal breeding (predicting the carcass economical value on a young living animal). High-throughput fine phenotyping is possible using metabolomics, which describes the global metabolic status of an individual, and is the closest to the terminal phenotype. The purpose of this work was to quantify the prediction power of metabolomic profiles for commonly used production phenotypes from a single blood sample from growing pigs. Several statistical approaches were investigated and compared on the basis of cross validation: raw data vs. signal preprocessing (wavelet transformation), with a single-feature selection method. The best results in terms of prediction accuracy were obtained when data were preprocessed using wavelet transformations on the Daubechies basis. The phenotypes related to meat quality were not well predicted because the blood sample was taken some time before slaughter, and slaughter is known to have a strong influence on these traits. By contrast, phenotypes of potential economic interest (e.g., lean meat percentage and ADFI) were well predicted (R(2) = 0.7; P < 0.0001) using metabolomic data.

Photoacoustic Detection of New Bands of HCN between 11 390 and 13 020 cm(-1).

A laser photoacoustic technique has been used to measure the absorption spectrum of HCN in the region from 11 390 to 13 020 cm(-1) with a resolution that is limited by the Doppler- and pressure-broadened linewidth. This is a very sensitive technique that has allowed us to measure very weak bands with a small volume of gas. These measurements provide the rovibrational constants for a number of newly observed vibrational energy levels. Copyright 2000 Academic Press.

Relaxation and Lineshape of the 500.4-GHz Line of Ozone Perturbed by N(2) and O(2).

N(2)- and O(2)-broadened linewidths of the J = 34(2,32) <-- 34(1,33) transition of ozone located at 500.4 GHz have been measured at three temperatures in the 247-295 K range by using a video-type spectrometer. Besides the Voigt profile commonly used as theoretical model for millimeter-wave investigations, different other theoretical lineshapes, the speed-dependent Voigt profile, the Galatry profile, and the speed-dependent Galatry profile, have been considered to analyze the experimental spectra, to retrieve the pressure-broadening parameters, and to give an account of the pointed out line-narrowing effect. The results for O(3) perturbed by N(2) and O(2) are finally compared to calculations based on the complex semiclassical theory of Robert and Bonamy, and with previous reported values involving the same kind of transitions. Finally, it is shown that observed line narrowings result nearly exclusively from the dependence of relaxation on molecular speeds. Copyright 2000 Academic Press.

Pressure-Induced Frequency Lineshifts in the nu2 Band of Ammonia: An Experimental Test of the Rydberg-Ritz Principle.

Self-induced frequency lineshifts of NH3 in the nu2 band have been measured for low J and K values. By combination with lineshift parameters previously published for other frequency ranges, it is possible to consider several level manifolds connected by superabundant numbers of transitions. Using statistical tests, these results lead to a quite meaningful experimental confirmation of the nonadditivity of pressure lineshifts, that is, the Rydberg-Ritz combination principle cannot be extended to collisionally perturbed systems. Copyright 1999 Academic Press.

Self and Polar Foreign Gas Line Broadening and Frequency Shifting of CH3F: Effect of the Speed Dependence Observed by Millimeter-Wave Coherent Transients

The shape of the (J, K: 2, 1 <-- 1, 1) millimeter line of CH3F in collision with polar buffer molecules has been investigated in the temperature range 140-300 K. The experiments exploit a Stark switching coherent transient technique, namely the optical free precession phenomenon, the Fourier transform of which is the usual steady state absorption lineshape. Using various buffer gases (CH3Br, CH3F, and NH3), the observed time domain signals provide the first experimental evidence in the millimeter range that line broadenings as well as frequency shiftings depend on the relative speed of collision partners; that is, lineshapes can become narrowed and asymmetric according to the molecular mass ratio and the type of collisional interaction involved. The experimental signals are analyzed with a time domain speed-dependent Voigt profile: for the polar buffer molecules considered, it is shown that a simultaneous interpretation of the broadening and narrowing parameters as well as of their temperature dependence can be satisfactorily obtained only with a realistic collision theory; in contrast with atomic buffer gases, velocity changing collisions play a negligible role. Copyright 1997 Academic Press. Copyright 1997Academic Press