SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 43, ISSUE 25 - DECEMBER 16, 2005

25 INORGANIC, ORGANIC AND PHYSICAL CHEMISTRY
Includes the analysis, synthesis, and use of inorganic and organic compounds; combustion theory; electrochemistry; andphotochemistry.

For related information see category 34 Fluid Dynamics and Thermodynamics.

For astrochemistry see category 90 Astrophysics.

20050240883 Lawrence Livermore National Lab., Livermore, CA USA

Kinetics of HMX and CP Decomposition and Their Extrapolation for Lifetime Assessment

Burnham, A. K.; Weese, R. K.; Andrzejewski, W. J.; Dec. 06, 2004; 28 pp.; In EnglishReport No.(s): DE2005-15011799; UCRL-TR-208411; No Copyright; Avail.: Department of Energy Information Bridge

Decomposition kinetics are determined for HMX (nitramine octahydro-1,3,5,7-tetranitro- 1,3,5,7-tetrazocine) and CP(2-(5-cyanotetrazalato) pentaammine cobalt (III) perchlorate) separately and together. For high levels of thermal stress, the twomaterials decompose faster as a mixture than individually. This effect is observed both in high-temperature thermal analysisexperiments and in long-term thermal aging experiments. An Arrhenius plot of the 10% level of HMX decomposition by itselffrom a diverse set of experiments is linear from120 to 260 degrees C, with an apparent activation energy of 165 kJ/mol.Similar but less extensive thermal analysis data for the mixture suggests a slightly lower activation energy for the mixture,and an analogous extrapolation is consistent with the amount of gas observed in the long-term detonator aging experiments,which is about 30 times greater than expected from HMX by itself for 50 months at 100 degrees C.NTIS

Chemical Reactions; Cobalt; Decomposition; Extrapolation; HMX; Kinetics; Reaction Kinetics

20050240963 Florida Univ., Gainesville, FL, USA, Los Alamos National Lab., NM USA

Influence of Radiation of Pit Solution Chemistry as it Pertains to the Transition from Metastable to Stable Pitting inSteels. (Report for September 15, 2001 to February 28, 2005)

January 2005; 20 pp.; In EnglishReport No.(s): DE2005-840166; No Copyright; Avail.: National Technical Information Service (NTIS)

An investigation was undertaken of the effect of gamma radiation on metastable pitting of mild carbon steels immersedin a solution similar to those existing at high level waste (HLW) deposits in the US. The object was to observe the extent towhich a dosage rate of 1 Mrad/hour (10 Kgrey/hour) affected measurable electrochemical parameters such as pitting potential,open circuit potential, rate of metastable pitting and repassivation potential. Methods for reliably measuring electrochemicalpotentials in a high radiation field were developed. Exploratory analyses were made of the ion product release and electrolytecomposition change in a confined volume simulating the conditions of a corrosion initiated pit during gamma irradiation. Asexpected the results indicated that the metastable pitting rate (as well as the general rate of corrosion) was significantlyenhanced by a radiation field.NTIS

Carbon Steels; Corrosion; Gamma Rays; Irradiation; Metastable State; Pitting; Radiation Chemistry; Solutions; Steels

20050242966 Savannah River National Lab., Aiken, SC, USA

Order-of-Magnitude Estimation of Benzene Concentration in Saltstone Vault

Choi, A. S.; Feb. 2005; 42 pp.; In English Report No.(s): DE2005-839498; WSRC-TR-2005-00071; No Copyright; Avail.: Department of Energy Information Bridge

The contents of Tank 48 that include the tetraphenylborate (TPB) precipitates of potassium and cesium will be grouted and stored in the Saltstone vault. The grouting process is exothermic, which should accelerate the decomposition of TPB precipitates eventually to benzene. Because the vault is not currently outfitted with an active ventilation system, there is a concern that a mixture of flammable gases may form in the vapor space of each cell filled with the curing grout. The purpose of this study was to determine if passive breathing induced by the diurnal oscillations of atmospheric pressure would provide any mitigating measure against potential flammability. Specifically, it was requested that a set of algorithms be developed that would predict the equilibrium concentration of benzene as a function of benzene generation rate, fill height, and the amplitude of the barometric pressure oscillations. These algorithms were to be derived based on several simplifying assumptions so that order of magnitude estimates could be made quickly for scoping purposes. This memo documents the resulting algorithms along with those key assumptions made. These algorithms were then applied to simulate several test cases, including the baseline case where the cell was filled to the maximum height of 25 ft at the bulk benzene generation rate of 3.4 g/hr. NTIS

Benzene; Concentration (Composition); Estimates

20050243069 Army Research Lab., Aberdeen Proving Ground, MD USA

Self-Assembled, Ultra-Hydrophobic Micro/Nano-Textured Surfaces

Rawlett, Adam M.; Orlicki, Joshua A.; Karikari, Afia; Long, Tim; Aug. 1, 2005; 18 pp.; In English Report No.(s): AD-A439525; ARL-TR-3547; No Copyright; Avail.: CASI: A03, Hardcopy

Hierarchical self assembly of nano-scale components (i.e., abalone shells, etc.) has been perfected by nature, yet the ability for scientists to utilize similar techniques is still in its infancy. The assembly of complex nano- and micro-components via self organizing means, rather than serial or parallel processing methods (e.g., electron beam lithography or nanoimprinting, respectively), could exploit the inherent benefit of these entities in a more elegant, economic means. The self assembly of regular arrays of nano- and microscale pores in polymer matrices, generated by so-called breath figures, will be discussed. Experimental parameters to vary the size, spacing, organization, long-range order, etc., of these selforganizing surfaces will also be discussed. Utilizing these regular arrays of pores as templates, we have patterned analogous arrays of pillars (inverse pores) from a polymer film cast onto the patterned surface. These micro-/nano-textured surfaces have greatly enhanced the hydrophobicity of the textured polymer when measured by contact angle. This method of producing ultrahydrophobic textured surfaces should be amenable to high-throughput, low-cost manufacturing of myriad polymeric surfaces. DTIC

Hydrophobicity; Nanotechnology; Polymers

20050243134 Eagle-Picher Technologies, LLC, Joplin, MO USA

Propulsion and Power Rapid Response To Research and Development Support. Delivery Order 0028: Lithium Carbon Monoflouride Cell Development

Counts, Timothy; Mar. 1, 2005; 49 pp.; In English; Original contains color illustrations Contract(s)/Grant(s): F33615-02-D-2299-0028; Proj-3145 Report No.(s): AD-A439631; AFRL-PR-WP-TR-2005-2141; No Copyright; Avail.: CASI: A03, Hardcopy

This document reports the work performed and the results obtained in developing materials and processes that could lead to a relatively high rate primary Li/CFx D cell. DTIC

Carbon; Electrochemical Cells; Lithium Batteries; Propulsion

20050243175 Joint Inst. for Lab. Astrophysics, Boulder, CO USA

Thermochemistry and Dynamics of Reactive Species: Nitrogen-rich Compounds, Metals and SiC Clusters in Free and Solvated Environment

Lineberger, William C.; Bierbaum, Veronica M.; Oct. 31, 2005; 17 pp.; In English Contract(s)/Grant(s): F49620-02-1-0371 Report No.(s): AD-A439698; AFRL-SR-AR-TR-05-0478; No Copyright; Avail.: CASI: A03, Hardcopy

We have completed a three-year program of research into the properties of nitrogen-rich heterocyclic compounds, all nitrogen compounds and silicon carbide clusters with adatoms. The research projects all include a very strong blend of experiment and state-of-the-art theory, obtaining structural and thermochemical properties of unusual and unstable species. The experimental approaches include anion photoelectron spectroscopy and detailed investigations of ion-molecule reactions using flowing afterglow and drift tube reactors. These techniques together provide complementary information that yields quantitative thermochemical information on very unstable species. The ability of the flow reactor to study minute quantities of ions also allows the investigation of speculative, possibly low-yield pathways to these energetic molecules. Specifically, we are studying the ion chemistry and thermochemical properties of a number of nitrogen-rich heterocyclic compounds and their radicals. Time-resolved photoelectron imaging measurements yield new insight into the ultrafast dynamics. DTIC

Metals; Nitrogen Compounds; Reactivity; Silicon Carbides; Thermochemistry