NASA Scientific and Technical Aerospace Reports

nonparametric theory, he was able to reproduce all observables - photocurrent, ion yield, laser-induced fluorescence as a
function of intensity and time - to develop one of the most complete descriptions of strong-field ionization and dielectric
breakdown in the condensed phase. An important follow-up to this work was to demonstrate the contrast between He and Xe
by carrying out strong-field ionization experiments in liquid Xe. With the method for sudden generation of Rydberg states
developed, he carried out time-dependent measurements of the liquid response to Rydberg excitations.
DTIC
Electrical Faults; Helium; Hydrodynamics; Ionization; Molecular Dynamics; Superfluidity
20040112002 NASA Glenn Research Center, Cleveland, OH, USA
Synthesis and Luminescent Chemosensory Behavior of N,N’-bis(p-aminophenyl)-1,5-bis(p-
(tetraethyleneglycoloxy)phenyl)anthracene-2,3,6,7-tetracarboxyl bisimide
Ilhan, Faysal; Tyson, Daniel S.; Meador, Michael A.; [2004]; 2 pp.; In English; Copyright; Avail: CASI; A01, Hardcopy
We have utilized the photoenolization reaction of a dibenzoyl-p-xylene derivative to synthesize two new, highly
substituted anthracene-based molecules. ABI-NO2 and ABI-NH2 maintained photostability with longer wavelength
absorption and emission spectra as compared to unsubstituted anthracene. Conversion of the periphery nitro groups to amines
created an internal photoinduced electron transfer scenario that quenched the luminescence of ABI-NH2. Reversible or
irreversible reaction of the attached amines resulted in fluorescence recovery. Sensitivity, of ABI-NH2 and other potential
derivatives, to toxic chemicals may prove useful for early detection systems.
Derived from text
Synthesis (Chemistry); Anthracene; Luminescence; Chemical Reactions; Polymers; Imides
20040112018 NASA Glenn Research Center, Cleveland, OH, USA
Single Droplet Combustion of Decane in Microgravity: Experiments and Numerical Modeling
Dietrich, D. L.; Struk, P. M.; Ikegam, M.; Xu, G.; March 16, 2004; 19 pp.; In English
Contract(s)/Grant(s): RTOP 101-32-0B; No Copyright; Avail: CASI; A03, Hardcopy
This paper presents experimental data on single droplet combustion of decane in microgravity and compares the results
to a numerical model. The primary independent experiment variables are the ambient pressure and oxygen mole fraction,
pressure, droplet size (over a relatively small range) and ignition energy. The droplet history (D(sup 2) history) is non-linear
with the burning rate constant increasing throughout the test. The average burning rate constant, consistent with classical
theory, increased with increasing ambient oxygen mole fraction and was nearly independent of pressure, initial droplet size
and ignition energy. The flame typically increased in size initially, and then decreased in size, in response to the shrinking
droplet. The flame standoff increased linearly for the majority of the droplet lifetime. The flame surrounding the droplet
extinguished at a finite droplet size at lower ambient pressures and an oxygen mole fraction of 0.15. The extinction droplet
size increased with decreasing pressure. The model is transient and assumes spherical symmetry, constant thermo-physical
properties (specific heat, thermal conductivity and species Lewis number) and single step chemistry. The model includes
gas-phase radiative loss and a spherically symmetric, transient liquid phase. The model accurately predicts the droplet and
flame histories of the experiments. Good agreement requires that the ignition in the experiment be reasonably approximated
in the model and that the model accurately predict the pre-ignition vaporization of the droplet. The model does not accurately
predict the dependence of extinction droplet diameter on pressure, a result of the simplified chemistry in the model. The
transient flame behavior suggests the potential importance of fuel vapor accumulation. The model results, however, show that
the fractional mass consumption rate of fuel in the flame relative to fuel vaporized is close to 1.0 for all but the lowest ambient
oxygen mole fractions.
Author
Hydrocarbons; Drops (Liquids); Combustion Chemistry; Microgravity
20040112039 NASA Glenn Research Center, Cleveland, OH, USA
Structure of Flame Balls at Low Lewis-Number (SOFBALL): New Results from STS-107
Abid, Mohamed; Liu, Jianbang; Ronney, Paul D.; Kwon, Oh-Chae; Struk, Peter; Weiland, Karen J.; [2004]; 8 pp.; In English;
41st Aerospace Sciences Meeting, 1-6 Jan. 2004, Reno, NV, USA
Contract(s)/Grant(s): NAG3-2887; NAG3-1523; NAG3-2124; WBS 101-42-02
Report No.(s): AIAA Paper 2004-0289; Copyright; Avail: CASI; A02, Hardcopy
Experiments on steady, spherically-symmetric premixed-gas flames ("flame balls") performed on STS-107 are
described. These experiments were motivated by results obtained on earlier Space Shuttle missions. The motivation and
69