Nesting Success and Feeding Habits of Great Blue Herons on the Mississippi River near Cassville, Wisconsin and East Dubuque, Illinois.

Nesting Great Blue Herons (Ardea herodias L.) were studied on Brinkman\u27s Island near Cassville, Wisconsin and on Catfish Island near East Dubuque, Illinois during the breeding seasons of 1978, and 1980-1985. Eggshells and unhatched eggs dropped from nests indicated 94% (n = 1501) of the eggs hatched. Nests near Cassville and East Dubuque contained an average of 2.2 to 2.6 young sufficiently large to be visible from the ground and an average of 1.7 to 2.4 hatchlings survived to fledging, respectively. The larger heronry on Brinkman\u27s Island fledged an average of 1.7 young per nest annually and continued to increase in size. The smaller heronry on Catfish Island fledged an average on 2.4 young per nest. Eighty-six fish of 24 species common to the Mississippi River were found beneath nests. Stomach contents of dead young found beneath nests contained crayfish, rodent hair, and fish

Debeaking Laying Stock to Control Cannibalism.

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Improved energy resolution for VHE gamma-ray astronomy with systems of Cherenkov telescopes

We present analysis techniques to improve the energy resolution of stereoscopic systems of imaging atmospheric Cherenkov telescopes, using the HEGRA telescope system as an example. The techniques include (i) the determination of the height of the shower maximum, which is then taken into account in the energy determination, and (ii) the determination of the location of the shower core with the additional constraint that the direction of the gamma rays is known a priori. This constraint can be applied for gamma-ray point sources, and results in a significant improvement in the localization of the shower core, which translates into better energy resolution. Combining both techniques, the HEGRA telescopes reach an energy resolution between 9% and 12%, over the entire energy range from 1 TeV to almost 100 TeV. Options for further improvements of the energy resolution are discussed.Comment: 13 Pages, 7 figures, Latex. Astroparticle Physics, in pres

Oxygen diffusion in alpha-Al2O3

Oxygen self diffusion coefficients were determined in single crystal alpha-Al2O3 using the gas exchange technique. The samples were semi-infinite slabs cut from five different boules with varying background impurities. The diffusion direction was parallel to the c-axis. The tracer profiles were determined by two techniques, single spectrum proton activation and secondary ion mass spectrometry. The SIMS proved to be a more useful tool. The determined diffusion coefficients, which were insensitive to impurity levels and oxygen partial pressure, could be described by D = .00151 exp (-572kJ/RT) sq m/s. The insensitivities are discussed in terms of point defect clustering. Two independent models are consistent with the findings, the first considers the clusters as immobile point defect traps which buffer changes in the defect chemistry. The second considers clusters to be mobile and oxygen diffusion to be intrinsic behavior, the mechanism for oxygen transport involving neutral clusters of Schottky quintuplets

Keys to Profitable Commercial Turkey Production.

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Keys to Profitable Commercial Turkey Production.

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Status of the Whipple Observatory Cerenkov air shower imaging telescope array

Recently the power of the Cerenkov imaging technique in Very High Energy gamma-ray astronomy was demonstrated by the detection of the Crab nebula at high statistical significance. In order to further develop this technique to allow the detection of weaker or more distant sources a second 10 m class reflector was constructed about 120 m from the original instrument. The addition of the second reflector will allow both a reduction in the energy threshold and an improvement in the rejection of the hadronic background. The design and construction of the second reflector, Gamma Ray Astrophysics New Imaging TElescope (GRANITE) is described

How to Produce Broilers for Show.

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Search for gamma-rays from M31 and other extragalactic objects

Although the existence of fluxes of gamma-rays of energies 10 to the 12th power eV is now established for galactic sources, the detection of such gamma-rays from extragalactic sources has yet to be independently confirmed in any case. The detection and confirmation of such energetic photons is of great astrophysical importance in the study of production mechanisms for cosmic rays, and other high energy processes in extragalactic objects. Observations of m31 are discussed. It is reported as a 10 to the 12th power eV gamma-ray source. Flux limits on a number of other extragalactic objects chosen for study are given

Oxidation of Carbon/Carbon through Coating Cracks

Reinforced carbon/carbon (RCC) is used to protect the wing leading edge and nose cap of the Space Shuttle Orbiter on re-entry. It is composed of a lay-up of carbon/carbon fabric protected by a SiC conversion coating. Due to the thermal expansion mismatch of the carbon/carbon and the SiC, the SiC cracks on cool-down from the processing temperature. The cracks act as pathways for oxidation of the carbon/carbon. A model for the diffusion controlled oxidation of carbon/carbon through machined slots and cracks is developed and compared to laboratory experiments. A symmetric cylindrical oxidation cavity develops under the slots, confirming diffusion control. Comparison of cross sectional dimensions as a function of oxidation time shows good agreement with the model. A second set of oxidation experiments was done with samples with only the natural craze cracks, using weight loss as an index of oxidation. The agreement of these rates with the model is quite reasona