NASA Scientific and Technical Aerospace Reports

to provide suitable gradient estimates for highly stretched curved meshes. Good overall flow solution accuracy can be retained
in spite of poor gradient estimates, due to the presence of flow alignment in exactly the same regions where the poor gradient
accuracy is observed. However, the use of entropy fixes has the potential for generating large but subtle discretization errors.
Author
Unstructured Grids (Mathematics); Least Squares Method; Gradients; Discretization (Mathematics)
20040070733 Case Western Reserve Univ., Cleveland, OH, USA
I-BEM Calculations of the Frequency Dispersion and AC Current Distribution at a Disk/Ring-Disk Electrode
Cahan, B. D.; Space Electrochemical Research and Technology: Abstracts; [1991], pp. 23; In English; See also 20040070726;
No Copyright; Available from CASI only as part of the entire parent document
The Iterative Boundary Equation Method (I-BEM) has been applied to the problem of frequency dispersion at a disk
electrode in a finite geometry. The I-BEM permits the direct evaluation of the AC potential (a complex variable) using complex
boundary conditions. The point spacing was made highly nonuniform, to give extremely high resolution in those regions where
the variables chamber most rapidly (i.e., in the vicinity of the edge of the disk). Results are analyzed with respect to "IR
correction, ‘I equipotential surfaces, and reference electrode placement. The current distribution is also examined for a
ring-disk configuration, with the ring and the disk at the same AC potential. It is shown that the apparent impedance of the
disk is inductive at higher frequencies. the literature, and usually agree to better than 0.001%.
Author
Alternating Current; Electrodes
20040070784 NASA Langley Research Center, Hampton, VA, USA
Error Analysis of p-Version Discontinuous Galerkin Method for Heat Transfer in Built-up Structures
Kaneko, Hideaki; Bey, Kim S.; [2004]; 22 pp.; In English
Contract(s)/Grant(s): NAG1-01092; No Copyright; Avail: CASI; A03, Hardcopy
The purpose of this paper is to provide an error analysis for the p-version of the discontinuous Galerkin finite element
method for heat transfer in built-up structures. As a special case of the results in this paper, a theoretical error estimate for the
numerical experiments recently conducted by James Tomey is obtained.
Author
Error Analysis; Galerkin Method; Heat Transfer; Parabolic Differential Equations; Finite Element Method; Discontinuity
20040070816
Chiral Analyses of Organic Compounds in Carbonaceous Meteorites
Pizzarello, Sandra; April 22, 2004; 5 pp.; In English
Contract(s)/Grant(s): NAG5-9451; Copyright; Avail: CASI; A01, Hardcopy
Contents include the following: 1. Characterization of Tagish Lake organic content. The first two grant years were largely
devoted to the molecular and isotopic analyses of Tagish Lake organic composition. This carbonaceous meteorite fell in
Canada in the winter of the year 2000, and its exceptional atmospheric entry and subsequent recovery (e. g., the sample was
recovered and stored by avoiding hand contact and above freezing temperatures) contributed in providing a rare and pristine
extraterrestrial material. 2. Chiral analyses of Murchison and Murray soluble organics. One of the most intriguing finding in
regard to soluble meteorite organics is the presence within the amino acid suite of some compounds displaying L-enantiomeric
excesses. This configuration is exclusive in the amino acids of terrestrial proteins and the finding has raised speculations of
a possible role of amino acids from meteorites in the origin of homochirality on the early Earth. The main objective for this
NASA funding was the characterization of enantiomeric excesses in meteorites and we have conducted several studies toward
establishing their distribution and indignity.
Derived from text
Chirality; Organic Compounds; Carbonaceous Meteorites; Extraterrestrial Matter
20040070820 Stanford Univ., Stanford, CA, USA
Validation and Improvement of SRTM Performance over Rugged Terrain
Zebker, Howard A.; [2004]; 7 pp.; In English
Contract(s)/Grant(s): NAG5-9040; No Copyright; Avail: CASI; A02, Hardcopy
We have previously reported work related to basic technique development in phase unwrapping and generation of digital
elevation models (DEM). In the final year of this work we have applied our technique work to the improvement of DEM’s
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