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Full-Text Articles in Physics
Electron Impact Dissociation Of N2o And Co2 With Single Particle Detection Of O(1d2), Wladyslaw Kedzierski, E Blejdea, Aldo Dicarlo, J. W. Mcconkey
Electron Impact Dissociation Of N2o And Co2 With Single Particle Detection Of O(1d2), Wladyslaw Kedzierski, E Blejdea, Aldo Dicarlo, J. W. Mcconkey
Physics Publications
Production of metastable O(1D2) atoms following controlled electron impact on N2O and CO2 targets has been studied using a neon rare gas matrix detector operating at a temperature of <20 K. A 100 eV pulsed electron beam was used in conjunction with time-of-flight (TOF) techniques to establish O-atom fragment kinetic energies. Probable dissociation channels are discussed.
Metastable Oxygen Atom Detection Using Rare Gas Matrices, Wladyslaw Kedzierski, E Blejdea, Aldo Dicarlo, J. W. Mcconkey
Metastable Oxygen Atom Detection Using Rare Gas Matrices, Wladyslaw Kedzierski, E Blejdea, Aldo Dicarlo, J. W. Mcconkey
Physics Publications
The use of solid rare gas matrices as detectors of metastable oxygen atoms is investigated. A 100 eV electron beam colliding with N2O target gas is used as the source of O(1S). The parameters considered are surface temperature, time delay of excimer emission and spectral response to O(1S). In all cases, detector sensitivity maximized at temperatures ≤20 K. Krypton was found to provide the most sensitive surface and neon the least.
Theoretical Proposal For A Biosensing Approach Based On A Linear Array Of Immobilized Gold Nanoparticles, S.M.H. Rafsanjani, T. Cheng, S. Mittler, Chitra Rangan
Theoretical Proposal For A Biosensing Approach Based On A Linear Array Of Immobilized Gold Nanoparticles, S.M.H. Rafsanjani, T. Cheng, S. Mittler, Chitra Rangan
Physics Publications
We propose a sensing mechanism for detection of analytes that can specifically recognized. The sensor is based on closely-spaced chains of functionalized gold nanoparticles (NPs) immobilized on a waveguide surface, with the signal detected by evanescent waveguide absorption spectroscopy. The localized surface plasmon spectrum of a linear array of closely-spaced, hemispherical gold NPs is calculated using the discrete dipole approximation. The plasmon band is found to broaden to a nanowirelike spectrum when a dielectric coating is put on the particles, and the light polarization is along the NP chain. The origin of this broadening is shown to be the polarization-dependent …
Regulation Of Polar Peptidoglycan Biosynthesis By Wag31 Phosphorylation In Mycobacteria, C. Jani, H. Eoh, J.J. Lee, K. Hamasha
Regulation Of Polar Peptidoglycan Biosynthesis By Wag31 Phosphorylation In Mycobacteria, C. Jani, H. Eoh, J.J. Lee, K. Hamasha
Physics Publications
Background. Sensing and responding to environmental changes is a central aspect of cell division regulation. Mycobacterium tuberculosis contains eleven Ser/Thr kinases, two of which, PknA and PknB, are key signaling molecules that regulate cell division/morphology. One substrate of these kinases is Wag31, and we previously showed that partial depletion of Wag31 caused morphological changes indicative of cell wall defects, and that the phosphorylation state of Wag31 affected cell growth in mycobacteria. In the present study, we further characterized the role of the Wag31 phosphorylation in polar peptidoglycan biosynthesis. Results. We demonstrate that the differential growth among cells expressing different wag31 …
Towards The Clinical Application Of Laser-Induced Breakdown Spectroscopy For Rapid Pathogen Diagnosis: The Effect Of Mixed Cultures And Sample Dilution On Bacterial Identification, Steven J. Rehse, Q.I. Mohaidat, S. Palchaudhuri
Towards The Clinical Application Of Laser-Induced Breakdown Spectroscopy For Rapid Pathogen Diagnosis: The Effect Of Mixed Cultures And Sample Dilution On Bacterial Identification, Steven J. Rehse, Q.I. Mohaidat, S. Palchaudhuri
Physics Publications
Laser-induced breakdown spectroscopy has been utilized to classify and identify bacterial specimens on the basis of their atomic composition. We have characterized the effect that the presence of a second bacterial species in the ablated specimen had on the identification of the majority species. Specimens with a reduced number of bacterial cells (approximately 2500) were identified with 100% accuracy when compared to undiluted specimens. In addition, a linear dependence of the total spectral power as a function of cell number was determined. Lastly, a high selectivity was obtained for a LIBS-based analysis of nine separate bacterial strains from four genera.
Isotope Shift Measurements In The 2s1/2 → 2p3/2 Transition Of Be+ And Extraction Of The Nuclear Charge Radii For 7,10,11be, M. Zkova, Z. Andjelkovic, M. L. Bissell, Gordon W. F. Drake
Isotope Shift Measurements In The 2s1/2 → 2p3/2 Transition Of Be+ And Extraction Of The Nuclear Charge Radii For 7,10,11be, M. Zkova, Z. Andjelkovic, M. L. Bissell, Gordon W. F. Drake
Physics Publications
We have performed isotope shift measurements in the 2s1/2 → 2p3/2 transition of Be+ ions using advanced collinear laser spectroscopy with two counter-propagating laser beams. Measurements involving a frequency comb for laser stabilization and absolute frequency determination allowed us to determine the isotope shifts with an accuracy of 2 MHz. From the isotope shifts between 9Be and 7, 10, 11Be, high-accuracy mass shift calculations and the charge radius of the reference isotope 9Be we determined nuclear charge radii for the isotopes 7, 10Be and the one-neutron halo nucleus 11Be. The results are compared to nuclear-structure calculations using the fermionic molecular …
Editorial: 40th Anniversary Of Physical Review A (July 1, 2010), Gordon W. F. Drake
Editorial: 40th Anniversary Of Physical Review A (July 1, 2010), Gordon W. F. Drake
Physics Publications
No abstract provided.