44,436 research outputs found
Draft genome sequence of "Candidatus Cronobacter colletis" NCTC 14934T, a new species in the genus Cronobacter
Members of the Cronobacter genus are associated with serious infections in neonates. This is the first report of the draft genome sequence for the newly proposed species Cronobacter colletis
Theory of Interfacial Plasmon-Phonon Scattering in Supported Graphene
One of the factors limiting electron mobility in supported graphene is remote
phonon scattering. We formulate the theory of the coupling between graphene
plasmon and substrate surface polar phonon (SPP) modes, and find that it leads
to the formation of interfacial plasmon-phonon (IPP) modes, from which the
phenomena of dynamic anti-screening and screening of remote phonons emerge. The
remote phonon-limited mobilities for SiO, HfO, h-BN and
AlO substrates are computed using our theory. We find that h-BN
yields the highest peak mobility, but in the practically useful high-density
range the mobility in HfO-supported graphene is high, despite the fact
that HfO is a high- dielectric with low-frequency modes. Our
theory predicts that the strong temperature dependence of the total mobility
effectively vanishes at very high carrier concentrations. The effects of
polycrystallinity on IPP scattering are also discussed.Comment: 33 pages, 7 figure
Measurement by wake momentum surveys at Mach 1.61 and 2.01 of turbulent boundary-layer skin friction on five swept wings
Measurement by wake momentum surveys at Mach 1.61 and 2.01 of turbulent boundary layer skin friction on five swept wing
Coulomb Excitation of Multi-Phonon Levels of the Giant Dipole Resonance
A closed expression is obtained for the cross-section for Coulomb excitation
of levels of the giant dipole resonance of given angular momentum and phonon
number. Applications are made to the Goldhaber-Teller and Steinwedel-Jensen
descriptions of the resonance, at non-relativistic and relativistic bombarding
energies.Comment: 16 pages, 5 figure
Dry and wet interfaces: Influence of solvent particles on molecular recognition
We present a coarse-grained lattice model to study the influence of water on
the recognition process of two rigid proteins. The basic model is formulated in
terms of the hydrophobic effect. We then investigate several modifications of
our basic model showing that the selectivity of the recognition process can be
enhanced by considering the explicit influence of single solvent particles.
When the number of cavities at the interface of a protein-protein complex is
fixed as an intrinsic geometric constraint, there typically exists a
characteristic fraction that should be filled with water molecules such that
the selectivity exhibits a maximum. In addition the optimum fraction depends on
the hydrophobicity of the interface so that one has to distinguish between dry
and wet interfaces.Comment: 11 pages, 7 figure
Investigation of passive atmospheric sounding using millimeter and submillimeter wavelength channels
Activities within the period from July 1, 1992 through December 31, 1992 by Georgia Tech researchers in millimeter and submillimeter wavelength tropospheric remote sensing have been centered around the calibration of the Millimeter-wave Imaging Radiometer (MIR), preliminary flight data analysis, and preparation for TOGA/COARE. The MIR instrument is a joint project between NASA/GSFC and Georgia Tech. In the current configuration, the MIR has channels at 90, 150, 183(+/-1,3,7), and 220 GHz. Provisions for three additional channels at 325(+/-1,3) and 8 GHz have been made, and a 325-GHz receiver is currently being built by the ZAX Millimeter Wave Corporation for use in the MIR. Past Georgia Tech contributions to the MIR and its related scientific uses have included basic system design studies, performance analyses, and circuit and radiometric load design, in-flight software, and post-flight data display software. The combination of the above millimeter wave and submillimeter wave channels aboard a single well-calibrated instrument will provide unique radiometric data for radiative transfer and cloud and water vapor retrieval studies. A paper by the PI discussing the potential benefits of passive millimeter and submillimeter wave observations for cloud, water vapor and precipitation measurements has recently been published, and is included as an appendix
Investigation of passive atmospheric sounding using millimeter and submillimeter wavelength channels
Activities within the period from January 1, 1992 through June 30, 1992 by Georgia Tech researchers in millimeter and submillimeter wavelength tropospheric remote sensing have been centered around the integration and initial data flights of the MIR on board the NASA ER-2. Georgia Tech contributions during this period include completion of the MIR flight software and implementation of a 'quick-view' graphics program for ground based calibration and analysis of the MIR imagery. In the current configuration, the MIR has channels at 90, 150, 183 +/- 1,3,7, and 220 GHz. Provisions for three additional channels at 325 +/-1,3 and 9 GHZ have been made, and a 325-GHz receiver is currently being built by the ZAX Millimeter Wave Corporation for use in the MIR. The combination of the millimeter wave and submillimeter wave channels aboard a single well-calibrated instrument will provide the necessary aircraft radiometric data for radiative transfer and cloud and water vapor retrieval studies. A paper by the PI discussing the potential benefits of passive millimeter and submillimeter wave observations for cloud, water vapor and precipitation measurements has recently been accepted for publication (Gasiewski, 1992), and is included as Appendix A. The MIR instrument is a joint project between NASA/GSFC and Georgia Tech. Other Georgia Tech contributions to the MIR and its related scientific uses have included basic system design studies, performance analyses, and circuit and radiometric load design
Optical nonlinearity enhancement of graded metallic films
The effective linear and third-order nonlinear susceptibility of graded
metallic films with weak nonlinearity have been investigated. Due to the simple
geometry, we were able to derive exactly the local field inside the graded
structures having a Drude dielectric gradation profile. We calculated the
effective linear dielectric constant and third-order nonlinear susceptibility.
We investigated the surface plasmon resonant effect on the optical absorption,
optical nonlinearity enhancement, and figure of merit of graded metallic films.
It is found that the presence of gradation in metallic films yields a broad
resonant plasmon band in the optical region, resulting in a large enhancement
of the optical nonlinearity and hence a large figure of merit. We suggest
experiments be done to check our theoretical predictions, because graded
metallic films can be fabricated more easily than graded particles.Comment: 11 pages, 2 eps figures, submitted to Applied Physics Letter
Quantum derivation of the use of classical electromagnetic potentials in relativistic Coulomb excitation
We prove that a relativistic Coulomb excitation calculation in which the
classical electromagnetic field of the projectile is used to induce transitions
between target states gives the same target transition amplitudes, to all
orders of perturbation theory, as would a calculation in which the interaction
between projectile and target is mediated by a quantized electromagnetic field.Comment: 1 .zip file containing LaTex source plus three figures as .eps file
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