Testing Prospects for Reliable Diatom Nanotechnology in Microgravity

The worldwide effort to grow nanotechnology, rather than use lithography, focuses on diatoms, single cell eukaryotic algae with ornate silica shells, which can be replaced by oxides and ceramics, or reduced to elemental silicon, to create complex nanostructures with compositions of industrial and electronics importance. Diatoms produce an enormous variety of structures, some of which are microtubule dependent and perhaps sensitive to microgravity. The NASA Single Loop for Cell Culture (SLCC) for culturing and observing microorganisms permits inexpensive, low labor in-space experiments. We propose to send up to the International Space Station diatom cultures of the three diatom species whose genomes are being sequenced, plus the giant diatoms of Antarctica (up to 2 mm diameter for a single cell) and the unique colonial diatom, Bacillaria paradoxa. Bacillaria cells move against each other in partial synchrony, like a sliding deck of cards, by a microfluidics mechanism. Will normal diatoms have aberrant pattern and shape or motility compared to ground controls? The generation time is typically one day, so that many generations may be examined from one flight. Rapid, directed evolution may be possible running the SLCC as a compustat. The shell shapes and patterns are preserved in hard silica, so that the progress of normal and aberrant morphogenesis may be followed by drying samples on a moving filter paper "diatom tape recorder". With a biodiversity of 100,000 distinct species, diatom nanotechnology may offer a compact and portable nanotechnology toolkit for exploration anywhere

Internal rotation and the chlorine nuclear quadrupole coupling tensor of 1-chloropropane

The rotational spectra of the trans and gauche forms of 1-chloropropane have been analyzed in the frequency range 8-40 GHz using Stark, waveguide FTMW, and pulsed molecular beam FTMW spectrometers. The spectra of Cl-35, Cl-37, and the three C-13 isotopomers have been observed for both conformers. The complete quadrupole Cl-coupling tensors have been determined and discussed within the structural considerations. For the gauche form the barrier to internal rotation of the methyl group has been determined to be 2908(4) cal/mol from A-E splittings observed in the first excited torsional state. Two A-E splittings have been observed only in the ground state of the trans form. From these splittings a barrier of 2760 cal/mol has been estimated. (C) 1997 Academic Press.</p