A recently devised new method for numerical Abel inversion is compared with four other commonly used methods. One of them, the convolution method, is employed in computer tomography for reconstructing asymmetrical objects. It is investigated whether this method can be adapted for the case of radial symmetry.As a first approach the comparison is performed by computer simulation. Special attention is given to the propagation of errors according to their origin. The result is a recipe for minimizing errors and for choosing the optimal method for reconstruction.The second step is a comparison of experimentally obtained radial profiles with functions resulting from Abel inversion of measured side-on data. Thus it is shown that the concept developed by computer simulation can be applied in practice.

Wire-shaped iron samples are resistively volume heated as part of a fast capacitor discharge apparatus. Measurements of current through the specimen, voltage across the specimen, radiance temperature, and thermal expansion of the specimen as functions of time allow the determination of specific heat and various dependencies among enthalpy, electrical resistivity, temperature, and density for liquid iron up to 5000 K. High pressures, up to 3800 bar. are used to obtain the liquid state far above the normal boiling point. An estimate of critical-point data for iron is given by using experimental data of the vapor pressure of liquid iron.

We have classified about 400 new spectral lines of neutral tantalum via laser excitation or observation of laser-induced fluorescence. 37 energy levels with even parity and seven levels with odd parity were found by means of systematic hyperfine structure investigations. For the new levels angular momentum, parity, magnetic hyperfine interaction constant A and electric quadrupole interaction constant B were deduced. In addition, we have classified 230 new lines observed in high resolution Fourier transform spectra by analysing their observed hyperfine structure patterns.

The knowledge of absorption coefficients of the gases CO, CO2 and H2O at high temperatures is important for the in situ determination of the concentration of these gases in combustion system. These coefficients can be calculated using molecular data form the HITRAN database. The 1996 edition of this database contains a special high temperature database for CO, CO2 and H2O. Based on these data absorption coefficients and spectra of CO, CO2 and H2O have been calculated for different concentrations and temperatures. Additionally, measurements were carried out using a high temperature calibration gas cell and in situ Fourier transform infrared spectroscopy absorption spectroscopy. A comparison between the spectra calculated and measured showed a good agreement. At temperatures of 1100°C large deviations between these results of theory and experiment could be found for certain spectral regions of CO2. Based on these results the measuring system was used for the quantitative analysis of the combustion gases in a pilot-scale horizontally moving grate furnace as well as in a laboratory scale furnace using wood chips, waste wood and fibreboard as fuels.

In this study, travel had a positive effect on the perceived health status of the traveller. The positive effects of travel seemed to outweigh the impact of health problems. Travel did not lead to increased health-related costs, neither in individual health expenses nor indirectly through increased medical consultation rates.

No abstract

Enthalpy, resistivity and density as a function of temperature of binary Fe‐Ni alloys have been measured by a fast resistive pulse heating technique. Six different concentrations, including Invar‐type alloy, have been investigated to cover the entire range of the phase diagram. The temperature range was from room temperature to 2400 K.

No abstract