53 research outputs found
A Parametrization of Cosmic Ray Shower Profiles Based on Shower Width
Cosmic ray (CR) air showers, detected via the air fluorescence technique, are
reconstructed in part using functions that parameterize the longitudinal
profile of each shower. The profile parameterization yields the position of
shower maximum, X_max, which is sensitive to the incident CR particle type:
e.g. p, C/N/O, Fe or photons. The integral of the profile is directly related
to the shower energy. The Pierre Auger fluorescence reconstruction uses the
Gaisser-Hillas 4-parameter form. The HiRes group has used both the
Gaisser-Hillas form and a 3-parameter Gaussian in Age form. Historically
analytic shower theory suggested yet other forms; the best known is a
3-parameter form popularized by Greisen. Our work now uses the shower full
width half-maximum, "fwhm", and shower asymmetry parameter, "f", to unify the
parameterization of all three profile functions. Furthermore shower profiles
expressed in terms of the new parameters: (fwhm, f) have correlations greatly
reduced over Gaisser-Hillas parameters (X_0, lambda). This allows shower
profile reconstructions to add constraints (if needed) on the mostly
uncorrelated parameters (fwhm, f).Comment: 12 pages, 6 figures, to be published in J. Phys G: Nucl. & Part. Phy
Pollination Biology of Darlingtonia californica (Sarraceniaceae), the California Pitcher Plant
Volume: 58Start Page: 22End Page: 3
NUCLEATE BOILING IN FLOWING AND HORIZONTAL LIQUID FILMS.
Nucleate boiling was studied occurring in water films on both horizontal and vertical surfaces so that performance could be compared. Lowering the depth of water below 5 mm on the horizontal surface improved heat transfer by both lowering surface temperature and increasing heat flux. At lower depths on horizontal surfaces the performance approached that of the vertical surface where an even thinner film was possible. The factors improving performance in the horizontal case must be considered in accounting for the performance of the vertical case since convection alone was shown to be insufficient. Additional nucleation, termed secondary nucleation, may account for the better boiling heat transfer in films as compared to nucleate boiling from well submerged surfaces
Limits for qualitative detection and quantitative determination. Application to radiochemistry
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