Energy principles and the equations of motion in Galilean thermomechanics

A simple thermodynamic condition of the type of the first law is formulated. When combined with the Galilean principle of relativity, it leads to the classical structure of balance equations of continuum thermomechanics. The concepts of mass, linear momentum and those of the total, internal and kinetic energies are consequences of the axiom structure.The author wishes to thank Professor J. Kvasnica for valuable suggestions concerning the presentation of the paper.     

Transient soliton dynamics in perturbation fields

Transient soliton dynamics for perturbatively driven and damped sG and ⁴ solitons was found fort ^–1. The perturbed solitons remain stable with relativistic reduced time-dependent width. Internal oscillation modes of the solitons are asymptotically damped fort ^–1. There appears a relaxation regime with the field dependent superexponential relaxation of the soliton width which becomes exponential in the asymptotic regime.     

Fixed-exit channel-cut crystal x-ray monochromators for synchrotron radiation

Two types of fixed-exit channel-cut crystal x-ray monochromators are proposed. In both monochromators the groove walls are not parallel. The fixed position of exit beam is achieved by coupling the rotation of crystal with its radial or axial translation.The author is indebted to Dr. S. Mobilio from INFN Frascati and Dr. V. Holý from University J. E. Purkyn Brno for valuable discussion.     

Ultrafast excited state dynamics of the Na3F cluster: quantum wave packet and classical trajectory calculations compared to experimental results

Short-time, excited-state dynamics of the lowest isomer of the Na(3)F cluster is studied theoretically in order to interpret the features of recent time-resolved pump-probe ionization experiments [J. M. L'Hermite, V. Blanchet, A. Le Padellec, B. Lamory, and P. Labastie, Eur. Phys. J. D 28, 361 (2004)]. In the present paper, we propose an identification of the vibrational motion responsible for the oscillations in the ion signal, on the basis of quantum mechanical wave packet propagations and classical trajectory calculations. The good agreement between experiment and theory allows for a clear interpretation of the detected dynamics.     

Voltammetric determination of thiodiglycolic acid in urine

In urine the level of thiodiglycolic acid (TDGA) is a sensitive indicator of exposure of the human organism to some physiologically active or toxic substances, gases and vapors. The determination of TDGA by use of a voltammetric method based on electroreduction of TDGA in acidic solution at the hanging mercury drop electrode has been developed and practically tested. In order to eliminate the matrix effect of urine, prior to voltammetric measurement the samples are eluted from a small column of PVC powder. The method is simple, low cost, rapid and sensitive, appropriate for the needs of occupational medicine.     

Three-dimensional thermoacoustic theory for stratified media in a cylindrical photoacoustic cell

We present a method for the computation of temperature distribution in samples with a stratified structure provided the layers are perpendicular to the axis of a cylindrical photoacoustic cell and the interfaces of layers are motionless. We have modified the so-called matrix method which is frequently used in geophysics for computations of wave fields in stratified media. This method enables us to express explicitly the temperature distribution in the form of multiplication and addition of matrices which are made of constants characterizing physical properties of the medium. We have demonstrated numerically the utilization of this matrix method on two simple examples: the absorption saturation of one layer with a variable coefficient of absorption and the interference of two heat waves from different layers.