4,402 research outputs found

    Observational results of microwave temperature profile measurements from the airborne Antarctic ozone experiment

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    The Microwave Temperature Profiler, MTP, is installed on NASA's ER-2 aircraft. MTP measures profiles of air temperature versus altitude. Temperatures are obtained every 13.7 seconds for 15 altitudes in an altitude region that is approximately 5 km thick (at high flight levels). MTP is a passive microwave radiometer, operating at the frequencies 57.3 and 58.8 GHz. Thermal emission from oxygen molecules provides the signal that is converted to air temperature. MTP is unique in that it is the only airborne instrument of its kind. The MTP instrument was used during the Airborne Antarctic Ozone Experiment, AAOE, to enable potential vorticity to be measured along the flight track. Other uses for the MTP data have become apparent. The most intriguing unexpected use is the detection and characterization of mountain waves that were encountered during flights over the Palmer Peninsula. Mountain waves that propagate into the polar vortex may have implications for the formation of the ozone hole. Upward excursions of air parcels lead to a brief cooling. This can begin the process of cloud formation. It is important to determine how much additional formation of polar stratospheric cloud (PSC) material is possible by the passage of air parcels through a mountain wave pattern that endures for long periods. Other mountain wave effects have been suggested, such as a speeding up of the vortex, and a consequent cooling of large air volumes (which in turn might add to PSC production)

    Regression Equations and Table for Estimating Numbers of Eggs in Jack Pine Budworm (Lepidoptera: Tortricidae) Egg Masses in Michigan

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    Three simple linear regression equations were developed to estimate the numbers of eggs in spruce budworm, Choristoneura fumiferana, egg masses in Michigan. One equation was developed for each of 2-row, 2- row + , and 3-row egg masses. A table of estimated numbers of eggs per egg mass is given for each of the three row types for egg mass lengths from 1 to 13 mm

    An annotated checklist of the Tephritidae (Diptera) of Florida

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    A total of 73 species of tephritid flies has been recorded from Florida since the early 1800s. Of these, 7 species are considered to represent occasional waifs or accidental introductions from surrounding regions that are not known to have established populations in Florida; 6 are exotic pests which failed to colonize or were extirpated; and 7 species are represented only by early literature records and are considered dubious for the state. Thus, the tephritid fauna of Florida currently comprises a total of 53 species of which 1 species is precinctive to the state and considered to be endangered

    Evaluation of seals, lubricants, and adhesives used on LDEF

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    A wide variety of seals, lubricants, and adhesives were used on the Long Duration Exposure Facility (LDEF). The results, to date, of the Systems Special Investigation Group (SIG) and the Materials SIG investigation into the effect of the long term low Earth orbit (LEO) exposure on these materials is discussed. Results of this investigation show that if the material was shielded from exposure to LDEF's external environment, the 69 month exposure to LEO had minimal effect on the material. However, if the material was on LDEF's exterior surface, a variety of events occurred ranging from no material change, to changes in mechanical or physical properties, to complete disappearance of the material. The results are from the following sources: (1) visual examinations and/or testing of materials performed by various LDEF experimenters, (2) testing done at Boeing in support of the Materials or Systems SIG investigations, (3) testing done at Boeing on Boeing hardware flown on LDEF

    INCOME AND CAPITALIZATION RATE RISK IN AGRICULTURAL REAL ESTATE MARKETS

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    Farmland Prices, Farmland Returns, Capitalization Rates, Risk, Asset Bubbles, Land Economics/Use, Q14,

    New records of Tephritidae (Diptera) from Great Smoky Mountains National Park - 2

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    Thirty additional species of tephritid flies (Diptera: Tephritidae) from Great Smoky Mountains National Park (GSMNP), including historical records, are presented together with information on host(s), if known, distributions, and life histories. This brings the total number of tephritid flies recorded from GSMNP to 46

    Actuarial Impacts of Loss Cost Ratio Ratemaking in U.S. Crop Insurance Programs

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    This study examines the actuarial implications of the loss cost ratio (LCR) ratemaking methodology employed by the Risk Management Agency as a component of base rates for U.S. crop insurance programs, and identifies specific conditions required for the LCR methodology to result in unbiased rates when liabilities trend. Specifically, constant relative yield risk resulting in growing absolute variance through time and other restrictive requirements are required for the LCR to result in unbiased rates. These requirements are tested against a large farm-level data set for Illinois corn. Our findings indicate that the conditions required for appropriate use of the LCR methodology are violated for this high premium volume market, resulting in large implied rate biases. The process does not correct itself through time with the addition of longer rating periods as sometimes claimed. A simple correction function is suggested and demonstrated.actuarially fair, crop insurance, insurance rating, loss cost ratio, risk growth, Risk Management Agency, yield trends, Crop Production/Industries, Risk and Uncertainty,

    Navier-Stokes analysis and experimental data comparison of compressible flow in a diffusing S-duct

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    Full three-dimensional Navier-Stokes computational results are compared with new experimental measurements for the flowfield within a round diffusing S-duct. The present study extends previous computational and experimental results for a similar smaller scale S-duct. Predicted results are compared with the experimental static and total pressure fields, and velocity vectors. Additionally, wall pressures, velocity profiles in wall coordinates, and skin friction values are presented. The CFD results employ algebraic and k-epsilon turbulence models. The CFD computed and experimentally determined separated flowfield is carefully examined
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