18,757 research outputs found
Inorganic thermal control pigment Patent
White paint production by heating impure aluminum silicate clay having low solar absorptanc
Measurement of airfoil heat transfer coefficients on a turbine stage
The primary basis for heat transfer analysis of turbine airfoils is experimental data obtained in linear cascades. A detailed set of heat transfer coefficients was obtained along the midspan of a stator and a rotor in a rotating turbine stage. The data are to be compared to standard analyses of blade boundary layer heat transfer. A detailed set of heat transfer coefficients was obtained along the midspan of a stator located in the wake of a full upstream turbine stage. Two levels of inlet turbulence (1 and 10 percent) were used. The analytical capability will be examined to improve prediction of the experimental data
Digital multishaker modal testing
A review of several modal testing techniques is made, along with brief discussions of their advantages and limitations. A new technique is presented which overcomes many of the previous limitations. Several simulated experiments are included to verify the validity and accuracy of the new method. Conclusions are drawn from the simulation studies and recommendations for further work are presented. The complete computer code configured for the simulation study is presented
Using temporal distributions of transient events to characterize cosmological source populations
The brightest events in a time series of cosmological transients obey an
observation time dependence which is often overlooked. This dependence can be
exploited to probe the global properties of electromagnetic and gravitational
wave transients (Howell et al. 2007a, Coward & Burman 2005). We describe a new
relation based on a peak flux--observation time distribution and show that it
is invariant to the luminosity distribution of the sources (Howell et al.
2007b). Applying this relation, in combination with a new data analysis filter,
to \emph{Swift} gamma-ray burst data, we demonstrate that it can constrain
their rate density.Comment: published in proceedings of FRONTIERS OF FUNDAMENTAL AND
COMPUTATIONAL PHYSICS: 10th International Symposium, AIP,1246,203, (2010
An improved method for estimating source densities using the temporal distribution of Cosmological Transients
It has been shown that the observed temporal distribution of transient events
in the cosmos can be used to constrain their rate density. Here we show that
the peak flux--observation time relation takes the form of a power law that is
invariant to the luminosity distribution of the sources, and that the method
can be greatly improved by invoking time reversal invariance and the temporal
cosmological principle. We demonstrate how the method can be used to constrain
distributions of transient events, by applying it to Swift gamma-ray burst data
and show that the peak flux--observation time relation is in good agreement
with recent estimates of source parameters. We additionally show that the
intrinsic time dependence allows the method to be used as a predictive tool.
Within the next year of Swift observation, we find a 50% chance of obtaining a
peak flux greater than that of GRB 060017 -- the highest Swift peak flux to
date -- and the same probability of detecting a burst with peak flux > 100
photons s^{-1} cm^{-2} within 6 years.Comment: Submitted to ApJ Letter
LEVEL OF STRUCTURAL AGGREGATION AND PREDICTIVE ACCURACY OF MILK SUPPLY RESPONSE ESTIMATES
Milk supply response was estimated for Pennsylvania using three different levels of structural aggregation. The base level involved the estimation of milk production in a single equation. Under the second method, production was the product of two equations: milk per cow and number of milk cows. The third method factored production into three equations: milk per cow, number of dairy farms, and number of cows per farm. As expected, the greater the degree of disaggregation the more was learned about the structural aspects of milk production. At the same time, predictive accuracy generally decreased, but the differences among models was slight.Livestock Production/Industries,
Comparison of theoretical and flight-measured local flow aerodynamics for a low-aspect-ratio fin
Flight test and theoretical aerodynamic data were obtained for a flight test fixture mounted on the underside of an F-104G aircraft. The theoretical data were generated using two codes: a two-dimensional transonic code called code H, and a three-dimensional subsonic and supersonic code called wing-body. Pressure distributions generated by the codes for the flight test fixture, as well as compared with the flight-measured data. The two-dimensional code pressure distributions compared well except at the minimum pressure point and the trailing edge. Shock locations compared well except at high transonic speeds. However, the two-dimensional code did not adequately predict the displacement thickness of the flight test fixture. The three-dimensional code pressure distributions compared well except at the trailing edge of the flight test fixture
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