No abstract

No abstract

We report the first science results from the Space Environment Viability of Organics (SEVO) payload aboard the Organism/Organic Exposure to Orbital Stresses (O/OREOS) free-flying nanosatellite, which completed its nominal spaceflight mission in May 2011 but continues to acquire data biweekly. The SEVO payload integrates a compact UV-visible-NIR spectrometer, utilizing the Sun as its light source, with a 24-cell sample carousel that houses four classes of vacuum-deposited organic thin films: polycyclic aromatic hydrocarbon (PAH), amino acid, metalloporphyrin, and quinone. The organic films are enclosed in hermetically sealed sample cells that contain one of four astrobiologically relevant microenvironments. Results are reported in this paper for the first 309 days of the mission, during which the samples were exposed for ∼2210 h to direct solar illumination (∼1080 kJ/cm(2) of solar energy over the 124-2600 nm range). Transmission spectra (200-1000 nm) were recorded for each film, at first daily and subsequently every 15 days, along with a solar spectrum and the dark response of the detector array. Results presented here include eight preflight and 16 in-flight spectra of eight SEVO sample cells. Spectra from the PAH thin film in a water-vapor-containing microenvironment indicate measurable change due to solar irradiation in orbit, while three other nominally water-free microenvironments show no appreciable change. The quinone anthrarufin showed high photostability and no significant spectroscopically measurable change in any of the four microenvironments during the same period. The SEVO experiment provides the first in situ real-time analysis of the photostability of organic compounds and biomarkers in orbit.

Specific details are given for double-tuning the Varian V-4333 probe for use in the following heteronuclear magnetic double resonance experiments: observe 'H at 100 MHz; irradiate 2H, 19F, or 31P; observe 19F at 94 MHz; irradiate 'H, 'H, or 31P. An inexpensive source of audiofrequency-noise is described which, in conjunction with the double-tuned probe and several commercially available components, constitutes the basis of a versatile heteronuclear-decoupler. Examples are given which illustrate the effectiveness of this decoupler. Double-tuning of the Varian V-4333 probe by introducing a second transmitter coil is also described.Canadian Journal of Chemistry, 48, 59 (1970) Introduction Proton-proton nuclear magnetic double resonance (n.m.d.r.) experiments are now used (1) routinely in the course of many structural studies. With a few notable exceptions, routine applications (2, 3) of heteronuclear n.m.d.r. experiments have been less widespread even though some suitable equipment is commercially a~a i l a b l e .~ Prompted initially by an interest in the n.m.r. spectra of organo-fluorine a n d organophosphorus derivatives, we have developed a versatile heteronuclear-decoupler for use with a Varian HA-100 spectrometer. The key features of this decoupler are as follows. (a) It does not interfere with the routine operation of the instrument, and can itself be used "routinely". (b) Rapid changeover between the nuclei to be irradiated can be effected merely by changing a "double-tuned" probe adaptor. (c) It can be used (in principle) to irradiate any chosen nuclear species. (d) The modification of the Varian V-4333 probe4 can be performed by "semi-skilled" personnel and is readily "reversible".

No abstract