Qualitative and quantitative analysis of voice onset by means of a multidimensional voice analysis system (MVAS) using high-speed imaging

High-speed filming is one of the most informative methods for assessing voice physiology data. Tracing high-speed images of the glottis provides quantitative parameters such as the glottal area and the glottal width function. By way of example, a number of studies are discussed which extract quantitative data from high-speed images showing voice onsets. Furthermore, a new computer system (MVAS; multi-dimensional voice analysis system) is presented that synchronously displays a laryngoscopic high-speed film, the electroglottographical signal, and several acoustic analyses of the recorded voice sample. The automatic measurement of glottal width and glottal area from the laryngoscopic images is also provided. Looking at former studies and our analyses of voice onsets reveals a tremendous intersubject and even intrasubject variability (different prephonatory closure, different time span until full amplitude is reached, different open quotient).     

Bose-Einstein condensate coupled to a nanomechanical resonator on an atom chip

We theoretically study the coupling of Bose-Einstein condensed atoms to the mechanical oscillations of a nanoscale cantilever with a magnetic tip. This is an experimentally viable hybrid quantum system which allows one to explore the interface of quantum optics and condensed matter physics. We propose an experiment where easily detectable atomic spin flips are induced by the cantilever motion. This can be used to probe thermal oscillations of the cantilever with the atoms. At low cantilever temperatures, as realized in recent experiments, the backaction of the atoms onto the cantilever is significant and the system represents a mechanical analog of cavity quantum electrodynamics. With high but realistic cantilever quality factors, the strong coupling regime can be reached, either with single atoms or collectively with Bose-Einstein condensates. We discuss an implementation on an atom chip.     

Nickel hydrides supported by a non-innocent diphosphine arene pincer: mechanistic studies of nickel-arene H-migration and partial arene hydrogenation

Nickel hydrides supported by a terphenyl diphosphine were synthesized and found to undergo nickel-to-arene H-transfers. Some of the resulting complexes also undergo the reverse (C-to-Ni) H-migration, indicating the potential for storing H-equivalents in this type of pincer ligand. NMR spectroscopy, single crystal X-ray diffraction, and isotopic labeling studies investigating the mechanism of these processes are discussed.     

Series representations for densities functions of a family of distributions—Application to sums of independent random variables

Series representations for several density functions are obtained as mixtures of generalized gamma distributions with discrete mass probability weights, by using the exponential expansion and the binomial theorem. Based on these results, approximations based on mixtures of generalized gamma distributions are proposed to approximate the distribution of the sum of independent random variables, which may not be identically distributed. The applicability of the proposed approximations are illustrated for the sum of independent Rayleigh random variables, the sum of independent gamma random variables, and the sum of independent Weibull random variables. Numerical studies are presented to assess the precision of these approximations.     

Spectres RPE et structure électronique de quelques radicaux bicycliques

Les spectres RPE de deux nouveaux radicaux hydrocarbonés bicycliques: [2,2,2]bicyclo-octène-2-yle-6 et [2,2,1]bicycloheptyle-2, ont été étudiés.

Les résultats principaux sont:

des couplages γ encore plus élevés que dans le [2,2,2]bicyclo-octyle-2;

des couplages distincts avec les deux protons du CH₂ en position β;

un couplage a _α ^H très voisin de ceux qu'on observe dans les radicaux hydrocarbonés classiques.

Ces résultats ont été interprétés dans l'hypothèse d'un carbone radicalaire plan (électron célibataire dans une orbitale p pure du carbone) et d'une faible torsion de la molécule autour de son axe C₁C₄.

Les faibles valeurs des densités de spin calculées et les valeurs élevées des couplages à longue distance indiquent une délocalisation de l'électron célibataire qui pourrait être due à une structure partiellement insaturée de ces molécules.