test at 10 and 15 GPa. Spall strength measurements suggest that there is a decrease in the spall strength of 4340 with an increase in the shock wave amplitude as the transition pressure of 13.1 GPa is approached. At this transition pressure, a substantial increase in the spall strength, as well as a change in a mode of fracture from brittle to ductile are observed, both attributed to the allotropic phase transformation at this amplitude. DOE N91-10165# Los Alamos National Lab., NM. Physical Metallurgy Group. 1990 15 P SHOCK EXPERIMENTS IN METALS AND CERAMICS George T. Gray, III Presented at the Explomet 1990 Conference, San Diego, CA, 13-17 Aug. 1990 (Contract W-7405-eng-36) (DE90-016613; LA-UR-90-2677; CONF-9008125-6) Avail: NTIS HC/MF A03 Shock recovery and spallation experiments, in which material structure/property effects are systematically varied and characterized quantitatively, offer two important experimental techniques to probe the physical mechanisms controlling shock processes and dynamic fracture. This paper highlights the current state of knowledge and principal challenges of the structure/property effects of shock-wave deformation on metals and ceramics. Recent shock-recovery and spallation experimental results on post-mortem material properties and fracture behavior in metals and ceramics are reviewed. Finally, the influence of shock-wave deformation on several intermetallics and a recent experiment examining the Bauschinger effect in Al-4 percent Cu during shock loading are presented. DOE N91-10166# Pacific Northwest Lab., Richland, WA. (Contract DE-AC06-76RL-01830) (DE90-017192; PNL-SA-17825; CONF-900466-82) Avail: NTIS HC/MF A02 The strength and toughness of several high temperature beryllium- niobium (Be12Nb and Be17Nb2) and iridium-niobium (Ir3Nb) intermetallic compounds were evaluated. Materials were prepared by high rate sputter deposition and characterized by x ray diffraction and analytical electron microscopy before and after heat treatment. As-sputtered microstructures were varied from amorphous to microcrystalline by control of substrate temperature. Grain size, degree of order, and second-phase distribution were modified by subsequent heat treatment. Strength as a function of temperature was assessed by hot hardness tests and toughness estimated from indentation-induced crack lengths. Intermetallics exhibited very high strength and low toughness up to temperatures of approx 1000 C. Mechanical behavior was a direct function of the microstructural parameters including matrix phase composition, second phase distribution, and degree of order. DOE N91-10167# Oak Ridge National Lab., TN. Metals and Ceramics Div. E. P. George and C. T. Liu 1990 (DE90-017319; CONF-900632-1) Avail: NTIS HC/MF A03 Nickel and iron aluminides are two potentially useful ordered intermetallic alloy systems that share a problem common to many ordered intermetallics, namely brittle fracture and poor ductility at room temperature. However, recent developments have shown that it is possible to overcome this problem and get significantly improved room-temperature ductilities in both these alloy systems by employing a combination of micro-and macro-alloying techniques. Concurrently, our understanding of the underlying causes of brittle fracture in ordered intermetallics has improved dramatically. We review here recent results related to the ductility and fracture behavior of two nickel aluminides (Ni3Al and NIAI), and two iron aluminides (FeAl, and Fe3AI). We will show that the major difference between Ni3Al and the two iron aluminides is the following: in the former, brittle fracture is a result of intrinsically weak grain boundaries, whereas in the latter, brittle fracture is a result of an extrinsic factor, namely moisture-induced environmental embrittlement. The brittleness of Ni3AL can be overcome by microalloying with boron and carefully controlling the alloy stoichiometry, whereas the ductilization of iron aluminides requires modification of their surface composition (or environment) to minimize the chemical reaction with moisture in air. NiAl also has weak grain boundaries (like Ni3AI), which can be strengthened by the addition of small amounts of boron. However, because of its other problems, like poor cleavage strength and insufficient number of deformation modes, the ductility of NiAl is not significantly improved even after intergranular fracture is totally suppressed. N91-10168# Rolls-Royce Ltd., Bristol (England). CASTING ALLOYS FOR THE JET AGE DOE M. H. Griffiths Derby, England 22 Jun. 1989 10 p Presented at POS Jnl (IBF) Meeting, Stratford-upon-Avon, England, 22 Jun. 1989 (PNR-90723; ETN-90-97948) Copyright Avail: NTIS HC/MF A02 The historical development of casting alloys applied to jet aero engines is summarized. Special attention is given to nickel based superalloys. Relevant developments are discussed highlighting important milestones achieved in terms of the effects of alloying elements and their constituent phases. The investment casting route is described. References to the various processing techniques now employed are made. These include directional solidification, single crystals, heat treatment and ceramic core technology. Current limitations and future developments designed to improve foundry practices are underlined. ESA 27 NONMETALLIC MATERIALS Includes physical, chemical, and mechanical properties of plastics, elastomers, lubricants, polymers, textiles, adhesives, and ceramic materials. For composite materials see 24 Composite Materials. N91-10169 United Kingdom Atomic Energy Authority, Harwell (England). Materials Development Div. ENVIRONMENTAL DEGRADATION OF MACRO DEFECT FREE (AERE-R-13354-1; HL88-1003-1) Copyright Avail: Issuing Macro defect free (MDF) cements derive their name from the absence of the large scale (greater than 200 microns) porosity normally found in cement. This is achieved by a processing route which has a low water to cement ratio, a polymeric processing aid, and high shear mixing. The resulting material shows a considerable increase in flexural strength compared to the same cement produced by conventional techniques. In high alumina cement (HAC) MDF's the flexural strength is approx. 200 MPa compared to 20 to 30 MPa for a normal HAC. The exact cause of the enhanced strength is subject to debate, but it is clear that the MFD's represent a considerable advance in the search for high strength cements. Theoretically any hydraulic cement can be used to make an MDF. In practice it is found that some cements are very sensitive to the polymeric agent and before the MDF can be produced a suitable polymer needs to be found. For example, HAC produces MDF with polyvinyl alcohol/acetate (PVA), and an ordinary portland cement (OPC) MDF with PVA or hydroxy propyl methyl cellulose (HPMC) or polyacrylamide as the polymeric aid. The materials studied include: NIM 127 (HAC PVA based), NIM 125 (HAC PVA based), NIM 223 (with a heat treatment to remove the polymeric phase), an OPC based MDF (based on HPMC), and an OPC based MDF (with PVAL). The effects of heat, gamma radiation and immersion in water on these MDF's are explored. In particular, the role that the polymer and cement used to make the MDF play in determining the response of the material to its environment is explored. Author N91-10170*# Southwest Texas State Coll., San Marcos. Dept. of Chemistry. TRIFLUOROMETHYL-SUBSTITUTED POLYMERS Semiannual Status Report, 1 Jan. - 30 Jun. 1990 Patrick E. Cassidy 11 Sep. 1990 13 p (Grant NAG1-631) (NASA-CR-186955; NAS 1.26:186955) Avail: NTIS HC/MF A03 CSCL 11C The synthesis of polymers is discussed. It includes: (1) the synthesis of fluorine-containing crosslinked poly(ether ketones); (2) the synthesis and characterization of poly(imide amides) and their N-methylated analogues; (3) the synthesis of fluorine-containing aromatic polyethers; (4) the synthesis of novel fluorine-containing aromatic polysiloxanes; and (5) the conversion of 6F-containing polythioethers to polysulfones. It is hoped that these polymers will find use as low dielectric materials in electronic applications, function as thermal control coatings, or be suitable elastomeric sealants for extreme service conditions. Author N91-10171# Argonne National Lab., IL. Tribology Section. A. Erdemir, G. R. Fenske, F. A. Nichols, R. A. Erck, and D. E. (DE90-007805; CONF-901009-1) Avail: NTIS HC/MF A02 Because of its layered crystal structure, boric acid, has been found to be lubricious. Its self-lubricating mechanism is related to the easy shear of atomic layers over one another. Moreover, laser-Raman spectroscopy and electron microscopy analyses have confirmed that thin boric acid films can form on surfaces containing boron and boric oxides. To study the lubricity and self lubricating mechanism of boric acid, pin-on-disk tests were performed on pairs of boric acid compacts and steel disks, boric oxide films and steel pins, boron films and steel pins, and boron-implanted steel disks and steel pins. The mean steady-state friction coefficients of these tribosystems ranged from 0.04 to 0.12. (Contract DE-AC06-76RL-01830) The design of an Advanced Ceramic Fabric (ACF) thermal management device for use in both interplanetary and near-earth space must consider several important aspects of the environment. First, the radiation field at various locations is dominated by a proton component which deposits its energy on the surface of the device. Second, the ACF materials, as well as pressure liner materials, must also be compatible with the working fluids selected for the system. Third, the fluid dynamics and heat transfer characteristics of this device should be adequately characterized. With the proper consideration of materials and operating conditions, the Bubble Membrane Radiator (BMR) may be utilized for several advanced space missions. DOE N91-10174# Ames Lab., IA. MONOMOLECULAR AND THIN POLYMER FILMS: FABRICATION, CHARACTERIZATION, APPLICATIONS, AND MODELS OF WETTING Ph.D. Thesis Lai Kwan Chau 24 Aug. 1990 166 p (Contract W-7405-eng-82) (DE90-016415; IS-T-1487) Avail: NTIS HC/MF A08 A variety of chemically modified surfaces were synthesized and their molecular structures and reactivities were characterized. These interfaces include: (1) Monomolecular films of n-alkanoic acids (CH3(CH2)nCOOH) and n-perfluorocarboxylic acids (CF3(CF2)nCOOH) on silver; and (2) calcichrome immobilized at an anion exchange polymer film. The monomolecular films were fabricated by the self-assembly method and characterized by optical ellipsometry, infrared reflection spectroscopy, and contact angle measurements. A comparison is given of the properties of these films with regard to composition, defectiveness, intermolecular environment, molecular orientation, wettability, and formation thermodynamics. As it is relevant to monolayer formation thermodynamics, the isoelectric point of the surface of evaporated silver films was determined by contact angle titration. Potential applications of these films are discussed. Monomolecular films as models of wetting are also examined in terms of van der Waals interactions at the macroscopic interfaces. Theoretical considerations of the effects of intermolecular forces on depth sensitivity of wetting and limiting contact angles of various systems are assessed. One of the synthesized interfaces has been applied as a Ca(II) optical sensor. The sensor was fabricated by electrostatic immobilization of calcichrome at an anion exchange polymer film. The structure and reactivity of this interface was characterized by ultraviolet-visible diffuse reflectance spectroscopy and infrared photoacoustic spectroscopy. Equations to determine the metal complex formation constant and acid dissociation constants of the immobilized reagent form diffuse reflectance spectra are developed. Possible causes affecting the reactivity of an immobilized indicator are discussed. DOE Several aluminum oxide ceramic disks were received from Coors Ceramics for analysis of black spots occurring on some of the disks. The disks were analyzed by x ray fluorescence, using the x ray microprobe in the scanning mode, and by x ray diffraction. The elements (greater than Z=14) observed, listed in order of approximate concentration, were Zr (several percent), Fe, Ca, Ni, and Sr, (minor to trace amounts). X ray diffraction analysis revealed a major amount of A12, 03 (corundum), a minor amount of ZrO2, and minor unidentified lines. Some of the unidentified lines could be accounted for by CaA12, Si2, 08 and BaA12, Si2, 08. There were no significant differences between the analyses of the rejected disks and those of the accepted ones. DOE N91-10176# Los Alamos National Lab., NM. Materials Science and Technology Div. HIGH-STRAIN-RATE COMPRESSION AND FRACTURE OF B4C-ALUMINUM CERMETS William R. Blumenthal 1990 11 p Presented at the Explomet Conference, La Jolla, CA, 12-17 Aug. 1990 (Contract W-7405-eng-36) (DE90-016568; LA-UR-90-2699; CONF-9008125-5) Avail: NTIS HC/MF A03 The compressive behavior of liquid-metal infiltrated boron carbide-aluminum cermets were studied as a function of strain rate, composition, and microstructure. Hopkinson split pressure bar (HSPB) and quasi-static compression tests were conducted using dumb-bell-shaped specimens. Results showed cermet compressive strength to be independent of loading rate. Strength was also found to be independent of the aluminum alloy used to infiltrate pre-sintered 65 vol percent B4C preforms. compositions with the smallest phase size displayed the best strength and ductility. DOE (Contracts DE-AC03-76SF-00098; LBL-4559910) The research described is intended to assist in developing the technology for the production of molybdenum, molybdenum carbide and titanium nitride coatings. These coatings have the potential to serve as an alternative to present methods of protecting the metal parts, at positive potential, of high temperature sulfur or sulfide batteries (e.g., chromizing). This research project was prompted by the observation that only very few materials are corrosion resistant in a high-temperature high sulfur activity environment containing polysulfide or FeS2. Among these materials only molybdenum has really satisfactory corrosion resistance. In LICI-KCI eutectic containing FeS2, titanium nitride has also shown adequate corrosion resistance. In polysulfide melts chromium shows good corrosion resistance, and chromizing is presently used to protect the internal surface of the containers in the sodium-sulfur battery, as manufactured at Chloride Silent Power Ltd. It should be noted that the issue of an optimal coating for the sodium-sulfur battery container is somewhat clouded and may be resolved satisfactorily only when there is more information about the effect of very small amounts of dissolved metal, such as chromium or molybdenum, on the life of the sodium-beta-alumina electrolyte. Nevertheless, there is a clear incentive for exploring molybdenum, or molybdenum derivatives, and titanium nitride as alternative protecting materials. DOE N91-10178# Oak Ridge National Lab., TN. Engineering Technology Div. DESIGN METHODOLOGY NEEDS FOR FIBER-REINFORCED CERAMIC HEAT EXCHANGERS J. J. Blass and M. B. Ruggles Aug. 1990 47 p (Contract DE-AC05-84OR-21400) (DE90-016659; ORNL/TM-11012) Avail: NTIS HC/MF A03 The purpose is to identify significant development and validation needs that must be satisfied to establish a viable design methodology for use of ceramic fiber reinforced, ceramic matrix composite materials in advanced heat exchangers for high temperature and high pressure applications. This is part of an initiative undertaken to foster the development and commercializaiton of high pressure heat exchange systems (HIPHES). Previous studies identified several industrial applications of HIPHES technology in which the use of fiber reinforced ceramic composites can provide very significant benefits. The studies resulted in a recommended development program that includes an early assessment of design methodology needs for these materials and applications. To provide this assessment, Oak Ridge National Laboratory (ORNL) assembled a panel of experts with government, university, and industrial affiliations. The present panel met in April 1988 for presentations and discussions related to structural design methodology for fiber reinforced ceramic heat exchanger components. DOE N91-10179# Pacific Northwest Lab., Richland, WA. Materials and Chemical Sciences Center. OPTICAL PROPERTIES OF INORGANIC POLYMERS Kim F. Ferris and Steven M. Risser Nov. 1989 7 p Presented at the Materials Research Society Fall Meeting, Aberdeen, MD, 27 Nov. 2 Dec. 1989 (Contract DE-AC06-76RL-01830) (DE90-017143; PNL-SA-18059; CONF-891119-139) Avail: NTIS HC/MF A02 The electronic structure of organic and inorganic polymeric systems are well described by their molecular symmetry, even with the large bond polarity shown by such systems as polyphosphazenes. Calculations were performed using semiempirical Hamiltonians to determine the electronic structure and optical nonlinearities for a series of model phosphonitrilic and organic compounds. The optical transition energies for phosphonitrilic compounds are greater than their organic counterparts as a result of in-plane pi' bonding interactions, and are modulated by the electronegativity of the substituent groups on the phosphorus atoms. Values are reported for the vertical ionization energy and electronic absorption wavelengths, and use molecular orbital contour analysis to show the effects of ligand electronegativity on the pi' network. Hyperpolarizabilities were calculated from third order perturbation theory for a series of phosphonitrilic compounds, (X sub 2 P-N) sub n, as a function of bond length alternation and ligand substitution. In contrast to organic polyenes, the difference in pi orbital energy between phosphorus and nitrogen is critical to determining the onset of saturation and the magnitude of the hyperpolarizability. DOE N91-10180# Pacific Northwest Lab., Richland, WA. Materials and Chemical Sciences Center. EFFECTS OF IN-PLANE pi PRIME BONDING ON ELECTRONIC TRANSITION ENERGIES FOR INORGANIC POLYMERS Kim F. Ferris, Steven M. Risser, and Angela K. Hanson Mar. 1990 8 P Presented at the Materials Research Society Fall Meeting, Boston, MA, 27 Nov. 2 Dec. 1989 (Contract DE-AC06-76RL-01830) (DE90-017144; PNL-SA-17230; CONF-891119-138) Avail: NTIS HC/MF A02 The electronic structure of organic and inorganic polymeric systems are well described in terms of their molecular symmetry, even with the large bond polarity shown by such systems as polyphosphazenes. Calculations were performed using the semi-empirical (Complete Neglect of Differential Overlap) CNDO/1 method to determine the valence electronic structure for a series of model phosphonitrilic and organic compounds. The optical transition energies for phosphonitrilic compounds are greater than their organic counterparts as a result of in-plane pi' bonding interactions. The extent of these interactions is modulated by the electronegativity of the substituent groups on the phosphorus atoms. Values are reported for the vertical ionization energy and electronic absorption wavelengths, and use molecular orbital contour analysis to show the effects of ligand electronegativity on the pi' network. DOE N91-10181# Oak Ridge National Lab., TN. Carl J. McHargue and Linda L. Horton 1990 7 p (Contract DE-AC05-84OR-21400) (DE90-017313; ORNL/FTR-3720) Avail: NTIS HC/MF A02 The visit to the University Claude Bernard was for the purpose of analyzing data obtained there and at the Oak Ridge National Laboratory in a collaborative research program, to exchange samples, to plan further work, and to revise drafts of two manuscripts for publication. One of the travelers served on the jury for the doctoral examination of E. Abonneau. The travelers also attended the NATO-ASI entitled, Diamond and Diamond-Like Films and Coatings, and served on the Organizing Committee. DOE N91-10182*# National Aeronautics and Space Administration. Donald J. Progar and Terry L. StClair Nov. 1990 27 P (NASA-TM-102742; NAS 1.15:102742) Avail: NTIS HC/MF A03 CSCL 11C The processability of aromatic polyimides can be improved by the addition of bis (amide) acids or bisimides to LARC-TPI. These low molecular weight additives apparently lower the melt viscosity of aromatic polyimides without affecting the glass transition temperature. Well-consolidated, fiber reinforced composites were fabricated using this technology. LARC-TPI can be processed as a thermoplastic polyimide to form high strength bonds, however, this is generally accomplished by processing at relatively high bonding pressures. An adhesive investigation is presented on the effects of two bisimide additives to LARC-TPI in an attempt to improve the bonding process by lowering the viscosity of the material to achieve improved bond strength properties. Apparently, the high flow which is exhibited by the additives when they melt, tended to be masked by the more viscous LARC-TPI. 28 PROPELLANTS AND FUELS Author Includes rocket propellants, igniters, and oxidizers; their storage and handling procedures; and aircraft fuels. For related information see also 07 Aircraft Propulsion and Power, 20 Spacecraft Propulsion and Power, and 44 Energy Production and Conversion. N91-10183# Sandia National Labs., Albuquerque, NM. Structural THERMOCHEMISTRY OF SHOCK-INDUCED EXOTHERMIC M. B. Boslough 1990 10 P Presented at the Explomet Conference, San Diego, CA, 12-17 Aug. 1990 (Contract DE-AC04-76DP-00789) (DE90-016104; SAND-90-0647C; CONF-9008125-4) Avail: NTIS HC/MF A02 Steady detonation theory was used to describe shock induced chemical reactions in a variety of powder mixtures. By introducing a number of simplifications, pressure and temperature increases caused by a reaction can be estimated by considering only the initial powder density, porosity, heat of reaction and thermophysical properties of the product phases. For a given mixture, the pressure increase is greater for higher initial powder packing density. Materials with large volume increases associated with the reaction will demonstrate the largest pressure increases, as expected. Shock temperatures can be approximated by a linearly increasing function of pressure, where the zero-pressure intercept is the adiabatic reaction temperature and the slope depends on initial porosity, volume change and product specific heat. The approximation provides a means of characterizing shock induced chemical reactions in terms of zero-pressure material properties. DOE in sealed containers after long storage times can damage internal components. Any tritium leak is an immediate health hazard. Hydrogen scavengers or getters can avert all of these potential problems by irreversibly removing hydrogen from such environments. Early hydrogen getters were metals that, though effective, were sensitive to oxygen. More recent work with crystalline organic materials has yielded formulations that will scavenge hydrogen in the presence or absence of air. They commonly utilize a catalyst to add hydrogen across of carbon-carbon double or triple bond. Because of the instability of organic materials to ionizing radiation, a getter that will be stable after reaction with tritium is a further challenge. We will describe hydrogen getter materials and systems developed at Sandia National Laboratories and at Allied-Signal, Kansas City Division. These materials have the proven ability to scavenge and contain hydrogen and tritium. The technologies are based on the irreversible removal of hydrogen by catalytic hydrogenation of unsaturated organic compounds. DOE N91-10185# Sandia National Labs., Albuquerque, NM. H. Mike Smith, Tim J. Shepodd, and Laura R. Gilliom (Allied-Signal (DE90-016284; KCP-613-4204; CONF-8909204-6) Avail: NTIS HC/MF A03 Hydrogen getter technologies are described which were developed at SNL and KCD over the past decade. The technologies are based on the irreversible removal of hydrogen by catalytic hydrogenation of unsaturated organic compounds. Different types have been developed: crystalline getters, dialkynes combined with heterogeneous catalysts; and a polymeric getter, a thermoplastic elastomer capable of reacting with hydrogen in the presence of oxygen without producing water. These materials can remove up to 300 cc (STP) of hydrogen per gram of material, and can maintain atmospheres of less than 10 ppM hydrogen. Crystalline getters for tritium and the combination hydrogen (tritium), water, and oxygen are described. The accumulation of hydrogen is usually an undesired event. Large leaks from hydrogen storage and handling facilities pose explosion hazards. Small amounts of hydrogen that may build up in sealed containers after long storage times can damage integral components. Any tritium leak is an immediate health hazard. Hydrogen scavengers or getters can avert all of these potential problems by irreversibly removing hydrogen from such environments. The development is described of two types of organic getters: the first is a new crystalline getter, based on 1,4-bis (phenylethynyl) benzene (5) (DEB); the second is a polymeric hydrogen getter, based on styrene-butadiene copolymer. DOE N91-10186# Teledyne/McCormick Selph, Hollister, CA. (DE90-016865; UCRL-CR-104639) Avail: NTIS HC/MF A05 Teledyne McCormick Selph has successfully completed the objectives of the program; the formulation, synthesis, and characterization of several cast solid propellants possessing very high burn rates (of the order of several meters per second) and suitable for incorporation as the propelling charge for a variety of modern gun systems of various calibers, and for potential rocket applications. More specifically, the tasks successfully accomplished include: (1) The selection of candidate propellant compositions based upon the practical factors of chemical stability and compatibility, density, heat of formation, availability and cost; (2) Theoretical thermochemical and ballistic evaluation and subsequent downselection; (3) Batch preparation of selected candidates and manufacturing process parameters studies; (4) Experimental determination of safety characteristics and ballistic evaluation (i.e., burn rate determination); and (5) Preliminary studies of grain (DE90-016558; LA-11903-MS) Avail: NTIS HC/MF A03 The presence of a nearly constant process time that characterizes the fast reaction portion found in the detonation of condensed high explosives can be explained by the transition state theory. Through hydrodynamic modeling, time is identified as the excitation time for the production of an energetic state that can go either forward to achieve decomposition or backward to the original unexcited state. The energetic state is a representation of a nonequilibrium condition that favors the chemical reaction, whereas the unexcited or equilibrium state does not. This process time is determined by matching the experimental interface velocimetry record, and its value is nearly constant over a wide range of conditions. DOE N91-10188# Pennsylvania State Univ., University Park. THERMAL STABILITY OF JET FUEL Final Report, Sep. 1988 Dec. 1989 Semih Eser, Chunshan Song, Ronald M. Copenhaver, Janice Perison, and Harold H. Schobert 1990 125 p (Contract DE-AC22-88PC-88827) (DE90-016801; DOE/PC-88827/T5) Avail: NTIS HC/MF A06 The principal objectives of this study were to investigate the thermal stability of a suite of alkylated phenols as typical trace contaminants in jet fuels and to determine the thermal stability of various fractions of a coal-derived and a petroleum-derived JP-8 jet fuel as well as the thermal stability of the unfractionated fuels. The thermal treatment experiments were carried out in nitrogen and air atmospheres (100 psig cold) using 15 ml microautoclave reactors. The reactors were heated in a fluidized sand bath at temperatures ranging from 150 C to 450 C. The samples of the coal-derived and petroleum-derived jet fuels were separated into five distillate fractions and these fractions were characterized by high-resolution gas chromatography-mass spectrometry (GC-MS). The thermal treatment products from the alkylated phenols were analyzed by 1-H and 13-C Nuclear Magnetic Resonance spectroscopy and gas chromatography/mass spectroscopy. DOE N91-10189# Institut Franco-Allemand de Recherches, Saint-Louis (France). COMBUSTION DIAGNOSTICS OF PROPELLANTS WITH H. H. Licht 1 Jun. 1989 The combustion of gun propellants in flake geometry composed from several layers of different formulations was investigated. Although visual control and ballistic behavior exhibited a typical discontinuity due to the structure, the burning characteristics of these sandwich powders could be interpreted like that of a uniform propellant. The burning rate exponent of such sandwich flake, based upon nitramines, may be degressive or progressive dependent on the sequence of the layers. ESA N91-10190# National Aerospace Lab., Tokyo (Japan). (NAL-TR-1062T; ISSN-0389-4010) Avail: NTIS HC/MF A03 Combustion tests were conducted using liquid oxygen (LOX)/gaseous hydrogen, LOX/gaseous methane, and LOX/RJ-1J as propellants. Two water-cooled calorimetric combustors and two types of injectors, i.e., a coaxial and impinging injector, were used. The maximum chamber pressure was 10 MPa and the heat flux reached 100 MW per sq m in the maximum. Heat flux values measured at the throat section were lower than those predicted by the simplified Bartz's equation. A modified Bartz's equation, which uses 0.023 as a coefficient (instead of 0.026 as in the original) and which takes into account the injector end effect as well as the film cooling effect, more accurately predicted the measured heat flux distribution of the coaxial type injector. With regard to LOX/RJ-1J propellants, an empirical correlation for the thermal resistance of the carbon layer deposited on the chamber wall was obtained. It was observed that the values of thermal resistance measured were a small percentage of the values found previously. Author Marshall Space Flight Center, Huntsville, AL. ANALYSIS TECHNIQUES FOR RESIDUAL ACCELERATION Melissa J. B. Rogers, J. Iwan D. Alexander (Alabama Univ., Various aspects of residual acceleration data are of interest to low-gravity experimenters. Maximum and mean values and various other statistics can be obtained from data as collected in the time domain. Additional information may be obtained through manipulation of the data. Fourier analysis is discussed as a means of obtaining information about dominant frequency components of a given data window. Transformation of data into different coordinate axes is useful in the analysis of experiments with different orientations and can be achieved by the use of a transformation matrix. Application of such analysis techniques to residual acceleration data provides additional information than what is provided in a time history and increases the effectiveness of post-flight analysis of low-gravity experiments. Author 31 ENGINEERING (GENERAL) Includes vacuum technology; control engineering; display engineering; cryogenics; and fire prevention. N91-10192 Texas A&M Univ., College Station. Avail: Univ. Microfilms Order No. DA9015434 An internship with the Martin Marietta Astronautics Group that was performed in partial fulfillment of the requirements for the Doctor of Engineering degree is documented. The internship included assignments with two Martin Marietta companies, on three different programs and in four areas of engineering. A first-hand look is taken at system engineering, SDI and advanced program management, and the way Martin Marietta conducts business. The five internship objectives were related to assignments in system modeling, system integration, engineering analysis and technical management: (1) The effects of thermally and mechanically induced mirror surface distortions upon the wavefront intensity field of a high energy laser beam passing through the optical train of a space-based laser system were modeled. (2) The restrictive as opposed to the broad interpretation of the 1972 ABM Treaty, and the capability of the Strategic Defense Initiative Zenith Star Program to comply with the Treaty were evaluated. (3) The capability of |