The Tagish Lake chondrite and the interstellar parent body hypothesis

Investigation of the solvent extractable organic compounds in Tagish Lake. The results are used to test the interstellar parent body hypthesis for the origin of extraterrestrial organic matter

AKARI near-infrared spectroscopy of the aromatic and aliphatic hydrocarbon emission features in the galactic superwind of M 82

Aims. We investigate the properties of hydrocarbon grains in the galactic superwind of M 82. Methods. With AKARI, we performed near-infrared (2.5 - 4.5 um) spectroscopic observations of 34 regions in M 82 including its northern and southern halos. Results. Many of the spectra show strong emission at 3.3 um due to polycyclic aromatic hydrocarbons (PAHs) and relatively weak features at 3.4 - 3.6 um due to aliphatic hydrocarbons. In particular, we clearly detect the PAH 3.3 um emission and the 3.4 - 3.6 um features in halo regions, which are located at a distance of 2 kpc away from the galactic center. We find that the ratios of the 3.4 - 3.6 um features to the 3.3 um feature intensity significantly increase with distance from the galactic center, while the ratios of the 3.3 um feature to the AKARI 7 um band intensity do not. Conclusions. Our results clearly confirm the presence of small PAHs even in a harsh environment of the halo of M 82. The results also reveal that the aliphatic hydrocarbons emitting the 3.4 - 3.6 um features are unusually abundant in the halo, suggesting that small carbonaceous grains are produced by shattering of larger grains in the galactic superwind.Comment: 5 pages, 3 figures, 1 table, accepted for publication in A&

Changes in aliphatic hydrocarbon tracer composition during the digestive process of the marine worm Nereis virens. Preliminary results

In the laboratory, marine worms were fed with a mixture of algae and several aliphatic hydrocarbons for 15 days. By comparing hydrocarbons in food and in faeces, it appeared that the worm's digestive process led to changes in the distribution of the n-alkanes mixture. These changes were different from those only due to physical processes in the experimental conditions, indicating that marine worm feeding could substantially affect the fate of hydrocarbons in the sedimentary marine ecosystem

Trends in Materials' Outgassing Technology

Test sample acquisition and chemical analysis techniques for outgassing products from spacecraft, experiment modules, and support equipment is described. The reduction of test data to a computer compatible format to implement materials selection policies is described. A list of the most troublesome outgassing species is given and several materials correlations are discussed. Outgassing from solar panels, thermal blankets, and wire insulation are examined individually

Cleaning of a thermal vacuum chamber with shrouds in place

In February, 1991, a failure of a rotary booster pump caused the diffusion pumps to backstream into a 10 ft x 15 ft thermal vacuum chamber. Concerns existed about the difficulty of removing and reinstalling the shrouds without causing leaks. The time required for the shroud removal was also of concern. These concerns prompted us to attempt to clean the chamber without removing the shrouds

Method for estimating solubility parameter

Semiempirical correlations have been developed between solubility parameters and refractive indices for series of model hydrocarbon compounds and organic polymers. Measurement of intermolecular forces is useful for assessment of material compatibility, glass-transition temperature, and transport properties