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No full textThe method based on the multiphoton Ionization Mass Spectroscopy/Supersonic Jet (MPI-MS/SSJ) technique for determination of trace concentration of toxic organic substances in the air is studied and applied in many laboratories in the world. A short pulse laser system with Fourier transform – limited bandwidth is suitable to the alternatively ionization process of the cold molecules. The Distributed Feedback Dye Laser (DFDL) pumped by a Nd:YAG picosecond laser is setup and employed to this purpose. The short laser pulse of 12 ps, which is exactly adjusted to wavelength of 316.14 nm and 315.83 nm with bandwidth of 0.05 nm, is corresponding to detect polychlorodibenzofuran and polychlorodibezodioxine.Pozna
No full textPoznańIn this paper, using a general propagation equation of ultrashort pulses in an arbitrary dispersive nonlinear medium derived in [8] we study in the specific case of Kerr media. An obtained ultrashort pulse propagation equation which is called Generalized Nonlinear Schrödinger Equation usually has a very complicated form and looking for its solutions is usually a “mission impossible”. Theoretical methods to solve this equation are effective only for some special cases. As an example we describe the method of a developed elliptic Jacobi function expansion. Several numerical methods of finding approximate solutions are simultaneously used. We focus mainly on the following methods: Split-Step, Runge-Kutta and Imaginary-time algorithms. Some numerical experiments are implemented for soliton propagation and interacting high order solitons. We consider also an interesting phenomenon: the collapse of solitons
No full textPoznańWe apply the dynamic decomposition of Poincaré plots, which is a computationally intensive, visual method of analysing physiological time series, to the analysis of the interbeat interval variability, systolic blood pressure, stroke volume and total peripheral resistance which were simultaneously recorded from a patient with pheochromocytoma and rapid, repetitive haemodynamic changes over 6 hours. The resulting animation is analysed and interpreted. It is found that changes in total peripheral resistance usually precede those of other variables, and the magnitude of changes is greatest for this variable. It is demonstrated that the decomposition of Poincaré plots of multivariate signals can visualise both the order and the extent of ongoing instant changes
No full textPoznańIn the paper the material model for metals and its numerical applications are presented. The material model is stated in terms of continuum mechanics, in the framework of the thermodynamical theory of viscoplasticity. The fundamental achievement is that the constitutive relation includes a description of anisotropy of metal microstructure. Such approach gives qualitatively and quantitatively new results compared with the existing models because it is possible to trace the directions of softening and predict a damage path in process time. Numerical examples comprise full spatial modelling for HSLA-65 steel in adiabatic conditions (the analysis of anisotropic bodies can be led only on 3D models) including: tension of sheet steel and twisting of thin walled tube. During analyses strain rates of order 10 4-10 7 s–1 are observed and the process time up to full damage (loss of continuity in the localisation zone) is around 100-300 us
No full textPoznańThis paper investigates reliability properties of a flexible extended (seven parameters) Burr XII family of distributions. Moreover, closed forms for n-th moments are derived
No full textPoznańIn 1908 Gustav Mie published paper about scattering of light on spherical objects. This paper based on classical electrodynamics (Maxwell equations) is one of the most cited physical papers. In this paper on the occasion of 100 anniversary of Mie scattering several contemporary applications of Mie theory are shown, starting from light scattering on small metal droplets, until investigation of speed of evaporation of water micro droplets with and without nano inclusions