2,978 research outputs found
Controlled intermittent interfacial bond concept for composite materials
Concept will enhance fracture resistance of high-strength filamentary composite without degrading its tensile strength or elastic modulus. Concept provides more economical composite systems, tailored for specific applications, and composite materials with mechanical properties, such as tensile strength, fracture strain, and fracture toughness, that can be optimized
Role of the methylene amidogen (H2CN) radical in the atmospheres of Titan and Jupiter
The methylene amidogen (H2CN) radical can be shown to be an important intermediate in models for the formation of HCN (via N + CH3) and the recombination of H to H2 (via H + HCN) on Titan as well as in models for the formation of HCN (via NH2 + C2H3) in the atmosphere of Jupiter. Experiments in our laboratory in a discharge flow system with mass spectrometric detection of both reactants and products have established that the major product channel (90 percent for the reaction N + CH3 is that leading to H2CN + H. The same result was obtained for N + CD3 yields D2CN + D. The rate constant for the reaction D + D2CN yields DCN + D2 was measured for the first time and k(298 K) greater than 7 x 10(exp -11) cu cm/s was found. The same result was obtained for the H atom reaction. This is the final step in the reaction sequence leading to HCN on both Titan and Jupiter and to formation of H2 from H on Titan. The first measurement of the ionization potentials for H2CN and D2CN was also made. From electron impact studies I.P. = (9.6 + or - 1.0) eV was obtained for both radicals. An upperlimit of I.P. less than 11.6 eV came from observations of the H2CN radical by photoionization mass spectrometry using an Ar resonance lamp (106.7 nm). Further photoionization experiments are planned using synchrotron radiation plus monochromator as a tunable vacuum UV light source
O\u27er the Distant Mountains Breaking
https://digitalcommons.library.umaine.edu/mmb-me/1190/thumbnail.jp
My God and Father While I Stray
https://digitalcommons.library.umaine.edu/mmb-me/1163/thumbnail.jp
I\u27m a Pilgrim, I\u27m a Stranger
https://digitalcommons.library.umaine.edu/mmb-me/1370/thumbnail.jp
My God and Father, While I Stray
https://digitalcommons.library.umaine.edu/mmb-me/1413/thumbnail.jp
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