Determination of Sulfonated Water-Soluble Azo Dyes in Foods by SPE Coupled with HPTLC-DAD

JPC – Journal of Planar Chromatography – Modern TLC - The purpose of the present work is to demonstrate an application of high-performance thin-layer chromatography-diode array scanning...     

General difference calculus and its application to functional equations of the second order

One investigates a generalization of difference calculus and applies it to solve the functional equations of second order. Presented at the 11th Colloquium “Quantum Groups and Integrable Systems”, Prague, 20–22 June 2002. This work is supported in part by KBN grant 2 PO3 A 012 19.     

Auditory perception of sound source velocity

In this study we investigate the perception of the velocity of linearly moving sound sources passing in front of a listener. The binaural simulation of motion used in two psychoacoustical experiments includes changes in the overall sound pressure level, the Doppler effect, and changes in interaural time differences. These changes are considered as cues for the perception of velocity. The present experiments are an extension of the experiments performed by Lutfi and Wang [J. Acoust. Soc. Am. 106, 919-928 (1999)]. The results of Experiment I show that the differential velocity threshold is independent of the reference velocity (10, 20, 30, and 40 m/s), varying across listeners from 1.5 to 4.6 m/s. In Experiment II, a method based on the successive elimination of cues in compared pairs of signals was employed to estimate the weights of potential cues for velocity discrimination. The magnitudes of all underlying cues at thresholds are reported. The experimental results show the subject's preference for the Doppler cue and a weakest sensitivity to the cue related with interaural time differences. Finally, it was found that spatial differences in the source location at the endpoints of the motion trajectory are not a significant factor in the velocity discrimination task.     

On Mobility and Einstein Relation for Tracers in Time-Mixing Random Environments

In this paper we rigorously establish the existence of the mobility coefficient for a tagged particle in a simple symmetric exclusion process with adsorption/desorption of particles, in a presence of an external force field interacting with the particle. The proof is obtained using a perturbative argument. In addition, we show that, for a constant external field, the mobility of a particle equals to the self-diffusivity coefficient, the so-called Einstein relation. The method can be applied to any system where the environment has a Markovian evolution with a fast convergence to equilibrium (spectral gap property). In this context we find a necessary relation between forward and backward velocity for the validity of the Einstein relation. This relation is always satisfied by reversible systems. We provide an example of a non-reversible system, where the Einstein relation is valid.This revised version was published online in March 2005 with corrections to the page numbers.     

Tight multipartite Bell's inequalities involving many measurement settings

We derive tight Bell's inequalities for N>2 observers involving more than two alternative measurement settings. We give a necessary and sufficient condition for a general quantum state to violate the new inequalities. The inequalities are violated by some classes of states, for which all standard Bell's inequalities with two measurement settings per observer are satisfied.