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Unimolecular decay dynamics of internal energy selected molecules. Technical progress report. [Tetramethyldioxetane]

Description: Direct excitation of overtone vibrations in combination with time-resolved spectroscopic detection probes unimolecular processes in new detail. Observing product luminescence produced by the decay of tetramethyldioxetane excited to v = 3, 4, or 5 of the CH stretching vibration yields the unimolecular decay rate directly, provides overtone vibration spectra on a low pressure gas phase molecule, and reveals a new feature to the chemiluminescence kinetics. Laser induced fluorescence experiments to… more
Date: January 1, 1980
Partner: UNT Libraries Government Documents Department
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Contributions to the Water Problem

Description: Technical report describing the investigation of the short-lived activities produced in oxygen compounds by irradiation with pile neutrons. The most prominent of these activities in cooling water is a beta and gamma emitting activity of about 8 second half-life. Because of its production by epicadmium neutrons it was believed to be the 8 second N16 produced in the pile by n,p on O16. The identification has been accomplished and it is established that the 8 second activity is N16. Part 2 of the… more
Date: July 3, 1944
Creator: Novey, Theodore B.
Partner: UNT Libraries Government Documents Department
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Effect of water-bearing fiber in Kevlar 49-epoxy composites

Description: Water has been observed to be adsorbed, and possibly absorbed, by desiccated Kevlar 49 fiber to 6 percent of the fiber weight in 100 percent relative humidity. The effect of the water on the transverse flexural strength and elastic modulus of an aliphatic amine-cured epoxy, unidirectionally reinforced with saturated Kevlar 49, has been determined. Such composites are weaker than those made with fiber equilibrated to 0 percent relative humidity, and the effect persists after a 75/sup 0/C, 16-h p… more
Date: January 1, 1978
Creator: Moss, M.
Partner: UNT Libraries Government Documents Department
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Solvent extraction of phenols from water

Description: Methyl isobutyl ketone (MIBK) and diisopropyl ether (DIPE) have been evaluated as solvents for extraction of phenols, at high dilution, from water. Equilibrium distribution coefficients (K/sub D/) have been measured for phenol, dihydroxybenzenes and trihydroxybenzenes in both solvents as a function of pH. Particularly for the multihydric phenols, MIBK gives substantially higher values of K/sub D/ than does DIPE. The effect of pH can be described quantitatively through a simple ionization model,… more
Date: February 1, 1980
Creator: Greminger, D. C.; Burns, G. P.; Lynn, S.; Hanson, D. H. & King, C. J.
Partner: UNT Libraries Government Documents Department
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Stress relief of ceramic components in high voltage assemblies. Final report

Description: Two types of ceramic packages were evaluated to determine the effectiveness of encapsulating the ceramic components in beta eucryptite filled epoxy. The requirements (no high voltage breakdown, no ceramic cracking, and no encapsulant cracking) were met by the spark gap assembly, but the sprytron assembly had cracking in the encapsulant after thermal cycling. The encapsulation of the ceramic component in beta eucryptite filled epoxy with a stress decoupling material selectively applied in the st… more
Date: February 1, 1979
Creator: Heinen, R.J.
Partner: UNT Libraries Government Documents Department
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Multiheteromacrocycles that complex metal ions. Fifth progress report, 1 May 1978-30 April 1979

Description: The overall objective of this research is to design, synthesize and evaluate cyclic and polycyclic host organic compounds for their abilities to complex and lipophilize guest metal ions, their complexes and clusters. Host organic compounds consist of strategically placed solvating, coordinating and ion-pairing sites tied together by covalent bonds through hydrocarbon units around cavities shaped to be occupied by guest metal ions, or metal ions plus their ligands. Specificity in complexation is… more
Date: January 15, 1979
Creator: Cram, D. J.
Partner: UNT Libraries Government Documents Department
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RESEARCH AND DEVELOPMENT IN THE FIELD OF THORIUM CHEMISTRY AND METALLURGY. Monthly Progress Report for March 15 thru April 15, 1955

Description: A transition program, eliminating most of the wet chemical techniques for the preparation of cell feed and replacing these with a high temperature chlorination process, was begun. Crushing tests on a Fitz mill were initiated and tentative conclusions are that this type of equipment as superior to a combination of jaw and roll crushing. Small scale chlorination experiments indicate the feasibility of pelletizing ThOCO/sub 3/ for feed to a eontinuous hightemperature chlorinator. (D.E.B.)
Date: April 26, 1955
Creator: Wyatt, J.L.
Partner: UNT Libraries Government Documents Department
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STUDY OF SOLVENT AND CATALYST INTERACTIONS IN DIRECT COAL LIQUEFACTION

Description: Using a reactor in which the coal is physically separated from the solid catalyst by a porous wall permeable to the hydrogen donor solvent, it was shown that direct contact between the catalyst and the coal is not required for catalyzed coal liquefaction. This occurs however only when there is a hydrogen atmosphere, as liquefaction with catalyst participation does not occur in a nitrogen atmosphere. Liquefaction by hydrogen transfer from the donor solvent itself does occur. This suggests that t… more
Date: January 1, 2000
Creator: Klein, Michael T.
Partner: UNT Libraries Government Documents Department
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Excitations and possible bound states in the S = {1/2} alternating chain compound (VO){sub 2}P{sub 2}O{sub 7}

Description: Magnetic excitations in an array of (VO){sub 2}P{sub 2}O{sub 7} single crystals have been measured using inelastic neutron scattering. Until now, (VO){sub 2}P{sub 2}O{sub 7} has been thought of as a two-leg antiferromagnetic Heisenberg spin ladder with chains running in the a-direction. The present results show unequivocally that (VO){sub 2}P{sub 2}O{sub 7} is best described as an alternating spin-chain directed along the crystallographic b-direction. In addition to the expected magnon with mag… more
Date: July 30, 1997
Creator: Tennant, D. A.; Nagler, S. E. & Sales, B. C.
Partner: UNT Libraries Government Documents Department
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THE REACTION OF ALUMINUM HYDRIDE WITH 3d TRANSITION METAL HALIDES. Progress Report for March 17, 1955 to November 1, 1955

Description: The reactions of AlH/sub 3/ in ether and in tetrahydrofuran solution with anhydrous halides of Fe, Co, and Ni are described. Reactions were carried out anaerobically at room temperature and below. In all instances, finely divided black products were obtained, some of which may contain metal to hydrogen bonds. Analytical results are presented for more than forty reactions, and possible mechanisms are discussed in a preliminary way. Observations are reported on the magnetic behavior of the produc… more
Date: November 1, 1955
Creator: Rice, M.J. Jr.; Gibb, T.R.P. Jr. & Meloni, E.G.
Partner: UNT Libraries Government Documents Department
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Damage to fused silica windows while under simultaneous exposure to flowing solvents and laser radiation and 308nm

Description: This paper reports the results of a study to determine the degrading effects of flowing dye solvents on the laser damage threshold of fused-silica windows at 308nm. Thresholds were measured at the SiO/sub 2/solvent interface in a test cell. Bare SiO/sub 2/ tested in air at 308nm (20ns) typically exhibits a threshold ranging from 4 to 10 Jcm/sup 2/; with the solvent cyclohexane in contact, a threshold as low as 0.3 Jcm/sup 2/ was measured. The damage data indicate that window lifetime (number of… more
Date: January 1, 1987
Creator: Mauro, B. R.; Foltyn, S. R. & Sanders, V. E.
Partner: UNT Libraries Government Documents Department
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Investigation into the high strain-rate behavior of compacted sand using the split-Hopkinson pressure bar technique

Description: The results of compressive high strain-rate experiments on compacted sand are presented. Experiments were conducted on a 60.3 mm split Hopkinson pressure bar (SHPB). The experiments showed that the assumptions necessary for a valid SHPB experiment are satisfied when using compacted sand samples constrained to a nearly uniaxial strain state. Results show that the sample stress-strain response is governed principally by the initial sample gas porosity, and that no strain-rate dependence is exhibi… more
Date: January 1, 1985
Creator: Felice, C. W.; Brown, J. A.; Gaffney, E. S. & Olsen, J. M.
Partner: UNT Libraries Government Documents Department
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Characterization of oxynitride dielectric films grown in NO/O{sub 2} mixtures by rapid thermal oxynitridation

Description: Ultra-thin oxynitride films were grown on Si by direct rapid thermal processing (RTP) oxynitridation in NO/O{sub 2} ambients with NO concentrations from 5% to 50%. During oxynitridation, nitrogen accumulated at the Si/dielectric interface and the average concentration of in N through the resulting films ranged from 0.3 to 3.0 atomic percent. The average concentration of N in the films increased with increasing NO in the ambient gas, but decreased with longer RTP times. The maximum N concentrati… more
Date: February 29, 2000
Creator: Everist, Sarah C.; Meisenheimer, Timothy L.; Nelson, Gerald C. & Smith, Paul Martin
Partner: UNT Libraries Government Documents Department
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Irradiation effects on the mechanical properties of composite organic insulators

Description: Four kinds of cloth-filled organic composites (filler: glass or carbon fiber; matrix: epoxy or polymide resin) were irradiated with 2-MeV electrons at room temperature, and were examined with regard to the mechanical properties. Following irradiation, the Young's (tensile) modulus of these composites remains practically unchanged even after irradiation up to 15,000 Mrad. The shear modulus and the ultimate strength, on the other hand, begin to decrease after the absorbed dose reaches about 2000 … more
Date: 1983~
Creator: Egusa, S.; Kirk, M. A.; Birtcher, R. C.; Hagiwara, M. & Kawanishi, S.
Partner: UNT Libraries Government Documents Department
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