143 research outputs found
CONCENTRATION INDEPENDENT ABSOLUTE INTENSITY DETERMINATIONS:A NEW METHOD
No full text J. R. Oppenhelimer, Proc. Cambridge Phil. Soc. 23, 327 (1926). Address of Chackerian: NASA Ames Research Center, MS:245-6, Moffett Field, CA 94035.Author Institution:We discuss some general considerations for obtaining, independently of any information on molecular concentration, absolute intensity determinations from relative molecule. This new method exploits the effect, first elucidated sixty years , which vibration-rotation interaction has on relative rovibrational line intensities in a vibrational band. This approach is important for vibrational fundamental bands of diatomic molecules since they cannot be studies by the lifetime method which requires the radiative relaxation lifetime to be much shorter than competing collisional relaxation processes. Our new method should be particularly significant for diatomic radical species whose concentrations can be inferred only indirectly
``COMPLETE'' GROUND STATE ROTATIONAL CONSTANTS OF FROM PERTURBATION ALLOWED TRANSITIONS IN THE BAND
No full text Supported by the Monticello Foundation administered by the California Institute of Technology. C. Chackerian, JR., and G. Guelachvili, J. Mol. Spectrosc. 84, 447-456 (1980).Author Institution:The highly accurate ground state constants previously from an analysis of allowed transitions in the band are augmented with values for and . The latter were determined via ground state combination differences between allowed and perturbation allowed transitions in the parallel and perpendicular components of the band. These ground state differences were obtained for levels with and
HCL FUNDAMENTAL ROVIBRATIONAL SELF-BROADENING COEFFICIENTS BETWEEN 200K AND 300K
No full text C. Chackerian, Jr. and G. Guelachvili, J. Mol. Spectrosc. 97, 316 (1983).Author Institution: Astrophysical Experiments Branch, NASA Ames Research CenterThe temperature dependence of the HCL vibrational fundamental self-broadening is obtained from high resolution Fourier spectra using the direct retrieval . The temperature dependence of the broadening is explained in terms of a simple ``two component'' phenomenological model
``ANOMALOUS'' RO-VIBRATIONAL INTENSITIES IN THE BANDS OF
No full text J.B. Burkholder, P.D. Hammer, C.J. Howard, A.G. Maki, G. Thompson, and C. Chackerian, Jr., J. Mol. Spectrosc. 124, 137 (1987). C. Chackerian, Jr., G. Guelachvili, A. Lopez-Pineiro. and R.H. Tipping, J. Chem. Phys. 90. 641 (1989). D.D. Nelson, Jr., A. Schiffman, D.J. Nesbitt and J.D. Yaron, J. Chem. Phys. (to be published).Author Institution: Laboratoire d'Infrarouge, Universite de Paris-Sud.; Laboratoire d'Infrarouge, NASA-Ames Research CenterRelative line Intensities of p- and r- branch transitions of diatomic radical molecules (ClO, NH, OH) have recently1-3 been used along with the theory of the Herman-Wallis effect to obtain estimates of electric dipole vibrational transition moments. Of the first and second row diatomic hydrides, ab initio calculations predict SH to exhibit the largest H.W. effect. Indeed, our spectra confirm a very large effect, and we present here an attempt at a quantitative analysis of the Herman-Wallis intensity perturbation in SH
ABSOLUTE RO-VIBRATIONAL INTENSITIES FOR THE VIBRATIONAL BANDS OF
No full text C. Chackerian. Jr. J Chem Phys 85, 1200 (1986) C. Chackerian. Jr. C. W Bauschlicher, S. R. Langhoff. A. Lopes-Pineiro and R. H. Tipping (to be published)Author Institution: NASA-Ames Research Center, Moffett Field; Leboratotre d'lnfrarouge associ\'e au CNRS, Universit\'e de Paris-sud; Departmento de Outmica Fisica, Facultad de Ciencias, Universided de Extremedura; Department of Physics and Astronomy, University of AlabamaWe determine absolute ro-vibrational line intensities for vibrational bands of the astrophysically important species. NH, indepently of any information on its molecular concentration. To this end we measure relative line intensities across bends. The effect of vibration rotation interaction on the line intensities then allows a direct determination of the derivative of the electric-dipole fundamental band transition . The results of these experiments are then compared to theoretical obtained via high quality ab initu calculations of the electric dipole moment function
Development of a Potential Vaccine for Asthma Using IgE and Virus Like Particles
Get PDFHighly dense, repetitive antigens such as virus particles induce strong immune responses. Correspondingly, Virus Like Particles (VLPs), which consist of the viral structural proteins, can be used as molecular scaffolds to increase the antigenicity of normally poorly immunogenic antigens. This ability to elicit strong antibody responses is not limited to foreign antigens, but also to self-antigens, which are normally subject to B-cell tolerance. The intention of this proposal is to develop a system for rapid identification of asthma vaccine candidates based on potent immunogenicity of antigens (IgE) displayed in dense repetitive arrays on virus-like particles. The technology is based on virus-like particles (VLPs) of the RNA bacteriophage MS2. MS2 VLPs can be viewed as a modular self-assembly system in which a highly immunogenic protein scaffold can be decorated with diverse target sequences using recombinant techniques. MS2 VLPs can be modified to present diverse target sequences on their surfaces. These recombinant VLPs induce strong antibody responses against the target sequence. I propose to generate MS2-based immunogens targeting domains involved in IgE receptor binding. A vaccine that induces antibody responses against IgE may be beneficial in treating asthma and allergies
Why HIV virions have low numbers of envelope spikes: implications for vaccine development.
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