W. R. McKinney

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The role of humic acid (HA) in the biodegradation of toxic polycyclic aromatic hydrocarbons (PAHs) has been the subject of controversy, particularly in unsaturated environments. By utilizing an infrared spectromicroscope and a very bright, nondestructive synchrotron photon source, we monitored in situ and, over time, the influence of HA on the progression(More)
Synchrotron radiation based Fourier transform IR (SR-FTIR) spectromicroscopy allows the study of individual living cells with a high signal to noise ratio. Here we report the use of the SR-FTIR technique to investigate changes in IR spectral features from individual human lung fibroblast (IMR-90) cells in vitro at different points in their cell cycle. Clear(More)
We consider the initial-value problem for the radially symmetric nonlinear Schrödinger equation with cubic nonlinearity (NLS) in d = 2 and 3 space dimensions. To approximate smooth solutions of this problem, we construct and analyze a numerical method based on a standard Galerkin finite element spatial discretization with piecewise linear, continuous(More)
At the Advanced Light Source, three protein crystallography beamlines have been built that use as a source one of the three 6 T single-pole superconducting bending magnets (superbends) that were recently installed in the ring. The use of such single-pole superconducting bend magnets enables the development of a hard X-ray program on a relatively low-energy(More)
Synchrotron radiation-based Fourier transform infrared spectromicroscopy is a newly emerging analytical tool capable of monitoring the biochemistry within an individual living mammalian cell in real time. This unique technique provides infrared (IR) spectra, hence chemical information, with high signal to noise at spatial resolutions as fine as 3-10 microm.(More)
Two recently commissioned infrared beamlines on the 1.4 bending magnet port at the Advanced Light Source, LBNL, are described. Using a synchrotron as an IR source provides three primary advantages: increased brightness, very fast light pulses, and enhanced far-IR flux. The considerable brightness advantage manifests itself most beneficially when performing(More)
chromate [Cr(VI)] species on surfaces of geologic materials. Time-resolved SR-FTIR spectra indicate that, in the presence of endoliths (mineral-inhabiting microorganisms), microbial reduction of Cr(VI) to Cr(III) compounds on basaltic mineral surfaces is the key mechanism of Cr(VI) transformation. It proceeds in at least a two-step reaction with Cr(V)(More)
Bursts of coherent synchrotron radiation at far-infrared and millimeter wavelengths have been observed at several storage rings. A microbunching instability has been proposed as the source for the bursts. However, the microbunching mechanism has yet to be elucidated. We provide the first evidence that the bursts are due to a microbunching instability driven(More)
INTRODUCTION The bright continuous spectrum of radiation from all storage rings extends into the infrared (IR) region of the spectrum. In fact, within about two orders of magnitude, all synchrotron radiation sources provide an essentially similar source of IR light. While synchrotrons do not provide as much flux as a typical laboratory source, the highly(More)
Vibrational spectroscopy, when combined with synchrotron radiation-based (SR) microscopy, is a powerful new analytical tool with high spatial resolution for detecting biochemical changes in individual living cells. In contrast to other microscopy methods that require fixing, drying, staining or labeling, SR-FTIR microscopy probes intact living cells(More)