Now showing items 1-20 of 125

    • Physical interaction of nitrogen with Pyrex, stainless-steel, and nickel at very low-pressure 

      Outlaw, R. A.; Brock, F. J.; Wightman, J. P. (American Institute of Physics, 1974)
      The physical adsorption of nitrogen on the surfaces of Pyrex, 347 stainless steel, and polycrystallinenickel was investigated over the pressure range 1×10−12–3×10−7 Torr and for the temperatures 77.4 and 87.4 °K. The metal ...
    • improved laser-schlieren system for measurement of shock-wave velocity 

      Bander, J. A.; Sanzone, G. (AIP Publishing, 1974-07)
      An improved laser_schlieren system for the measurement of shock_wave velocities has been developed which employs a single detector.Calibration of multiple detectors has been obviated. The system has been shown to yield, ...
    • high-resolution time-of-flight mass-spectrometry impulse-field focusing pulse generators 

      Miller, R. L.; Browder, J. A.; Sanzone, G. (AIP Publishing, 1986-08)
      Experiments have shown that the unit mass resolution of conventional Wiley-McLaren time_of_flight (TOF)mass spectrometers can be significantly improved using the technique of impulse_field focusing (IFF). Details of the ...
    • Surface-analysis of gold containing polyimide films 

      Madeleine, D. G.; Spillane, S. A.; Taylor, L. T. (American Institute of Physics, 1987-05)
      Polyimide films with metallic surfaces were produced by thermal treatment of solutions containing HAuCl4⋅3H2O, hydrogen tetrachloroaurate trihydrate, and either Ciba–Geigy XU 218, poly[5(6)‐amino‐1‐(4’ phenyl)‐1,3,3 ...
    • Raman-scattering and optical studies of argon-etched GaAs surfaces 

      Feng, G. F.; Zallen, R.; Epp, J. M.; Dillard, J. G. (American Physical Society, 1991-04)
      We have studied the structual damage in low-energy argon-ion-bombarded (ion-etched) GaAs using Raman scattering and ultraviolet reflectivity. When combined with post-bombardment sequential chemical etching, the Raman results ...
    • Method for the conversion of cephalomannine to taxol and for the preparation of n-acyl analogs of taxol 

      Virginia Polytechnic Institute and State University; Kingston, David G.; Molinero, Anthony A.; Gunatilaka, A. Leslie (United States Patent and Trademark Office, 1995-11-28)
      The natural product cephalomannine can be converted to the important anticancer natural product taxol by a simple process involving the steps of dihydroxylation to give cephalomannine-diols, diol cleavage, benzoylation at ...
    • Synthesis of sphingosines 

      Virginia Tech Intellectual Properties, Inc.; Hudlicky, Tomas (United States Patent and Trademark Office, 1996-01-30)
      Provided by the present invention is a process for the biocatalytic synthesis of optically pure sphingosines from achiral starting material. The stereoisomers of sphingosine are prepared from chiral arene diols using ...
    • Synthesis of sphingosines 

      Virginia Tech Intellectual Properties, Inc.; Hudlicky, Tomas (United States Patent and Trademark Office, 1996-01-30)
      Provided by the present invention is a process for the biocatalytic synthesis of optically pure sphingosines from achiral starting material. The stereoisomers of sphingosine are prepared from chiral arene diols using ...
    • Aryl ethynyl phthalic anhydrides and polymers with terminal or pendant amines prepared with aryl ethynyl phthalic anhydrides 

      Virginia Polytechnic Institute and State University; Virginia Tech Intellectual Properties, Inc.; McGrath, James E.; Meyer, Gerald W. (United States Patent and Trademark Office, 1996-02-20)
      Arylethynyl phthalic anhydrides have been synthesized and shown to have particular application as endcappers or pendant groups in high performance/high temperature thermosets which include amine terminal or amine pendant groups.
    • Metallic material with low melting temperature 

      Center for Innovative Technology; Virginia Polytechnic Institute and State University; Virginia Tech Intellectual Properties, Inc.; Rancourt, James D.; Taylor, Larry T. (United States Patent and Trademark Office, 1996-04-16)
      A gallium-indium-zinc-copper metallic material has been found to exhibit many of the advantageous properties of mercury, such as electrical conductivity, fluidity, and high vaporization temperature. The metallic material ...
    • Enhanced nonlinear optical response of an endohedral metallofullerene through metal-to-cage charge transfer 

      Heflin, J. R.; Marciu, D.; Figura, C.; Wang, S.; Burbank, P.; Stevenson, S.; Dom, H. C. (AIP Publishing, 1998-06)
      A new mechanism for increasing the third-order nonlinear optical susceptibility, X-(3), is described for endohedral metallofullerenes. A two to three orders of magnitude increase in the nonlinear response is reported for ...
    • Dependence of fluorescence lifetimes of Y2O3 : Eu3+ nanoparticles on the surrounding medium 

      Meltzer, R. S.; Feofilov, S. P.; Tissue, B.; Yuan, H. B. (American Physical Society, 1999-11)
      The radiative lifetime, tau(R), of the D-5(0) metastable excited state of Eu3+ ions in nanocrystalline monoclinic Y2O3 samples is about four times longer than that in the micron size powder of the same material. The Eu3+ ...
    • Evidence for long-range interactions between rare-earth impurity ions in nanocrystals embedded in amorphous matrices with the two-level systems of the matrix 

      Meltzer, R. S.; Yen, W. M.; Zheng, H. R.; Feofilov, S. P.; Dejneka, M. J.; Tissue, B. M.; Yuan, H. B. (American Physical Society, 2001-09)
      The low-temperature homogeneous broadening of the electronic transitions of Eu3+ and Pr3+ rare-earth impurity ions in Y2O3 and LaF3 nanocrystals embedded into amorphous materials (polymer and oxyfluoride glass ceramics) ...
    • Low-resistance films of polyimides with impregnated copper sulfide 

      Rowe, R. V. A.; Kunita, M. H.; Porto, M. F.; Muniz, E. C.; Rubira, A. F.; Nery, R. C.; Radovanovic, E.; Taylor, L. T.; Nazem, N. (Cambridge University Press, 2001-11)
      Surface modification of polyimides has been used to obtain better interaction with an inorganic material. Copper sulfide incorporation onto the surface of commercial Kapton (R) polyimide showed that treatment with base was ...
    • Measurement of 3-alkyl-2-methoxypyrazine by headspace solid-phase microextraction in spiked model wines 

      Hartmann, P. J.; McNair, H. M.; Zoecklein, B. W. (American Society for Enology and Viticulture, 2002)
      The effect of wine matrix ingredients and conditions on the headspace sampling of 3-alkyl-2-methoxypyrazines was investigated with solid-phase microextraction (SPME) and capillary gas chromatography, using a nitrogen ...
    • Transience of plasma surface modification as an adhesion promoter for polychlorotrifluorethylene 

      Subrahmanyan, Sumitra; Dillard, John G.; Love, B. J.; Romand, M.; Charbonnier, M. (American Institute of Physics, 2002-05-01)
      Poly (chlorotrifluoroethylene) (PCTFE) and other fluoropolymers are increasingly used as inner layer dielectrics. However, these polymers have low surface energies and correspondingly poor adhesive proper-ties. Results are ...
    • Between the Scylla of hidebound conservatism and the Charybdis of mindless speculation 

      Bauer, Henry H. (Inter-Research, 2004)
      The ‘quality’ of a scientific publication is not an absolute but must be assessed in relation to a journal’s mission. It should be judged primarily by its disciplined intellectual rigor, bearing in mind what course the ...
    • Influence of buried hydrogen-bonding groups within monolayer films on gas-surface energy exchange and accommodation 

      Ferguson, M. K.; Lohr, J. R.; Day, B. S.; Morris, J. R. (American Physical Society, 2004-02-20)
      Self-assembled monolayers (SAMs) of carbonyl-containing alkanethiols on gold are employed to explore the influence of hydrogen-bonding interactions on gas-surface energy exchange and accommodation. H-bonding, COOH-terminated ...
    • Scanning near-field optical microscopy utilizing silicon nitride probe photoluminescence 

      Lulevich, V.; Ducker, W. A. (AIP Publishing, 2005-11)
      We describe a simple method for performing high-resolution scanning near-field optical microscopy (SNOM). A commercial Si3N4 tip is illuminated by an intense light source, which causes the tip to emit redshifted (inelastically ...
    • An atomic force microscope tip as a light source 

      Lulevich, V.; Honig, Christopher D. F.; Ducker, William A. (AIP Publishing, 2005-12-01)
      We present a simple method for causing the end of a silicon nitride atomic force microscope (AFM) tip to emit light, and we use this emitted light to perform scanning near-field optical microscopy. Illumination of a silicon ...