Toroidal quark matter: Do discrete energy level corrections destroy the dinotor's metastability?

We show that the dinotor is sensitive to discrete energy level corrections to the continuum approximation for the density of states. These corrections do not destroy the metastability of the dinotor, but may produce a ‘magic number’ effect. New metastable configurations of the dinotor may also exist, possibly creating further difficulty identifying the dinotor as the cause of the anomalon effect.     

Die kationische Polymerisation von Ketenacetalen und die Darstellung und Charakterisierung von Poly(1,3-diketonen)

Ohne Zusammenfassung     

Measurement of field effects on dielectronic recombination of Si11+ ions

Cross sections for dielectronic recombination can be influenced by the presence of external electric fields in the electron--ion collision region. In most of the previous experiments with multiply charged ions such fields were present but unknown. Therefore, comparisons of experimental results with theoretical calculations were ambiguous: for obtaining best possible agreement, theory could use the field strength as a free parameter to adjust the calculated cross sections to the experiment. In recent measurements with 10 MeV/u Si¹¹⁺ ions stored in CRYRING, controlled external motional electric fields up to 183 V/cm were introduced in the electron cooler. Significant cross section enhancements were found for Rydberg states n > 20. This revised version was published online in August 2006 with corrections to the Cover Date.     

Analysis of the low temperature fluorescence and phosphorescence spectra of p-difluorobenzene

The low temperature fluorescence spectra (4.2 K) of solid solutions of p-difluorobenzene-h₄ (pDFB-h₄) and -d₄ have been recorded and analyzed. The absence of fluorescence from vibrationally excited states at 4.2 K eliminates the sequence and “hot band” structure which complicate the analysis of the vapor fluorescence spectrum. On the basis of a comparison of our vibrational analysis with those published for the vapor phase fluorescence, several incorrect assignments in the latter have been identified. The high resolution and lack of spectral congestion obtained in the low temperature matrix isolated fluorescence spectra also allowed additional vibrational assignments to be made. These results are of added importance because of the extensive use which has been made of pDFB for radiationless relaxation studies in the vapor phase. The phosphorescence spectrum of crystalline pDFB-h₄ was observed with sufficient intensity to locate the electronic origin to make several vibrational assignments. Additionally, the zero-field splitting of the first triplet excited state was measured by optically detected magnetic resonance techniques.     

Stimulated stokes emission with a dye laser: Intense tuneable radiation in the infrared

Tuneable stimulated Stokes emission is generated at ≈2.9 μm in barium vapor with an oscillator-amplifier dye laser. The conversion efficiency is as high as 40% and the energy output as high as 30 mJ. The emission is tuneable over ≈100 cm^-1. At high vapor pressures the tuning profile is markedly asymmetric.     

On-line mass spectrometry in fermentation

The on-line application of mass spectrometry (m.s.) includes analysis of the fermentor gas phase by using a capillary inlet and analysis of the liquid phase by using membrane probes. Gas-phase measurements with a capillary inlet are fast and accurate for all gases of interest (O₂, N₂, CO₂, H₂, etc.). Liquid-phase measurements are done with steam-sterilizable membrane inlet probes, permitting direct analysis of dissolved gases and various volatiles. With these two inlets, automatic measurement of both the liquid and gas phases is possible when a microcomputer is used. This was applied to the batch fermentation of Bacillus subtilis. A further application of the membrane probe is evaluation of fermentation process state; this involves measuring the spectra of all detectable volatiles and correlating this information with the process state (e.g., product formation). Sufficient characteristic volatiles were found in various industrial fermentation samples. When mass spectra are treated by factor analysis, useful correlations are found with the product concentrations measured off-line. Calibration depending on the process conditions is necessary for this method, but it is widely applicable and allows automatic monitoring.     

Investigations of stabilizing additives. I. A model system for studying radical scavenging activity in solution

In the current study an electron spin resonance model system was developed to compare the thermal stability and radical scavenging activity of stabilizers in solution. High-resolution spectra and the influence of molecular structure on radical stability provided a basis for the interpretation of spin concentration data in the model system. A correlation was established between the radical scavenging activity measured in the model system and actual behavior in irradiated polypropylene formulations measured by radiation-induced degradation of mechanical properties.