NASA Scientific and Technical Aerospace Reports

esults show that the membranes exposured at 900 C for 1Hr has the most higher permeation capacity, indicated that our zeolite
membranes has the capacity to permeate hydrogen.
Author
Zeolites; Membrane Structures; Hydrogen; Cleaning; Purification
28
PROPELLANTS AND FUELS
Includes rocket propellants, igniters, and oxidizers; their storage and handling procedures; and aircraft fuels. For nuclear fuels see 73
Nuclear Physics. For related information see also 07 Aircraft Propulsion and Power; 20 Spacecraft Propulsion and Power; and 44
Energy Production and Conversion.
20040111282 Toledo Univ., OH, USA
Chemistry of Aviation Fuels
Knepper, Bryan; Hwang, Soon Muk; DeWitt, Kenneth J.; September 2004; 32 pp.; In English
Contract(s)/Grant(s): NAG3-2338; No Copyright; Avail: CASI; A03, Hardcopy
Minimum ignition energies of various methanol/air mixtures were measured in a temperature controlled constant volume
combustion vessel using a spark ignition method with a spark gap distance of 2 mm. The minimum ignition energies decrease
rapidly as the mixture composition (equivalence ratio, Phi) changes from lean to stoichiometric, reach a minimum value, and
then increase rather slowly with Phi. The minimum of the minimum ignition energy (MIE) and the corresponding mixture
composition were determined to be 0.137 mJ and Phi = 1.16, a slightly rich mixture. The variation of minimum ignition energy
with respect to the mixture composition is explained in terms of changes in reaction chemistry.
Author
Aircraft Fuels; Propellant Combustion; Combustion Chemistry; Combustion Effıciency; Ignition
20040111375 NASA Glenn Research Center, Cleveland, OH, USA
Damage Assessment of Stress-Thermal Cycled High Temperature
Ju, Jach-Yung; Prochazka, Michael; Ronke, Ben; Morgan, Roger; Shin, Eugene; [2003]; 8 pp.; In English; 14th International
Conference on Composite Materials, 14-18 Jul. 2003, San Diego, CA, USA
Contract(s)/Grant(s): 708-31-16
Report No.(s): Paper 1273; Copyright; Avail: CASI; A02, Hardcopy
We report on the characterization of bismaleimide and polyimide carbon fiber composite, microcrack development under
stress thermal cycling loading. Such cycle range from cryogenic temperatures associated with cryogenic fuel (LN, LOX)
containment to high temperatures of 300 degrees associated with future hypervelocity aeropropulsion systems. Microcrack
development thresholds as a function of temperature range of the thermal cycle, the number of cycles, and the applied stress
level imposed on the composite are reported. We have conducted stress-thermal cycles on thin bismaleimide-woven carbon
fiber foils for three temperature range cycles. The principle findings are that the full cycles from -196 degree celsius up to 250
degree celsius cause the most significant microcrack development. These observations indicate that the high temperature
portion of the cycle under load causes fiber-matrix interface failure and subsequent exposure to higher stresses at the
cryogenic, low temperature region results in composite matrix microcracking as a result of the additional stresses associated
with the fiber-matrix thermal expansion mismatch. Our initial studies for 12 ply PMR-II-50 polyimide/M6OJB carbon fabric
[0f, 90f, 90f, 0f, 0f, 90f] composites will be presented. The stress-thermal cycle test procedure for these will be described.
Moisture absorption characteristics between cycles will be used to monitor interconnected microcrack development. The
applied stress level will be 75 percent of the composite cryogenic -196 degree celsius ultimate strength.
Derived from text
Fiber-Matrix Interfaces; Cryogenic Temperature; Thermal Cycling Tests; Carbon Fibers; Damage Assessment; Microcracks
20040111437 Prins Maurits Lab. TNO, Rijswijk, Netherlands
Transportable Desensitizing of Munitions: A Feasibility Study
Stuivinga, M. E. C.; vanHam, N. H. A.; May 2004; 88 pp.; In Dutch
Contract(s)/Grant(s): A02/D/476; TNO Proj. 014.14369
Report No.(s): TD-2004-0028; PML-2004-A28; Copyright; Avail: Other Sources
This report describes a feasibility study for a facility for the destruction of unexploded ordnance (UXO) of the Second
World War. Munitions larger than 35 mm can be decommissioned by removing the initiation mechanism by water jet cutting
87