Zero gravity liquid mixer

An apparatus for mixing liquids under conditions of zero gravity is disclosed. The apparatus is comprised of a closed reservoir for the liquids, with a means for maintaining a positive pressure on the liquids in the reservoir. A valved liquid supply line is connected to the reservoir for supplying the reservoir with the liquids to be mixed in the reservoir. The portion of the reservoir containing the liquids to be mixed is in communication with a pump which alternately causes a portion of the liquids to flow out of the pump and into the reservoir to mix the liquids. The fluids in the reservoir are in communication through a conduit with the pump which alternately causes a portion of the fluids to flow out of the pump and into the sphere. The conduit connecting the pump and sphere may contain a nozzle or other jet-forming structure such as a venturi for further mixing the fluids

Air removal device

The disclosure concerns a device suitable for removing air from water under both zero and one 'g' gravity conditions. The device is comprised of a pair of spaced membranes on being hydrophobic and the other being hydrophilic. The air-water mixture is introduced into the space therebetween, and the selective action of the membranes yields removal of the air from the water

The M\"obius function of generalized subword order

Let P be a poset and let P* be the set of all finite length words over P. Generalized subword order is the partial order on P* obtained by letting u \leq w if and only if there is a subword u' of w having the same length as u such that each element of u is less than or equal to the corresponding element of u' in the partial order on P. Classical subword order arises when P is an antichain, while letting P be a chain gives an order on compositions. For any finite poset P, we give a simple formula for the Mobius function of P* in terms of the Mobius function of P. This permits us to rederive in a easy and uniform manner previous results of Bjorner, Sagan and Vatter, and Tomie. We are also able to determine the homotopy type of all intervals in P* for any finite P of rank at most 1.Comment: 29 pages, 4 figures. Incorporates referees' suggestions; to appear in Advances in Mathematic

Techniques for aerothermal tests of large, flightweight thermal protection panels in a Mach 7 wind tunnel

Thermal performance and structural integrity are experimentally evaluated in the Langley 8-ft high temperature structures tunnel, which uses a combustion products test medium to provide realistic combinations of aerodynamic heating and loading. Recently developed techniques provide independent control of rate and magnitude of surface heating and differential pressure, protection against adverse acoustics buffeting during facility starting and stopping, programed radiant heating before exposing test panels to the high energy stream, and infrared radiometry for detailed surface temperatures. These techniques were verified repeatedly by return of useful data on metallic and nonmetallic panel concepts of reusable surface insulation

OPTION VALUES FOR PROVISIONS IN EXPORT CREDIT GUARANTEES

All major exporting countries of agricultural commodities have some form of credit guarantee program. As the importance of credit programs escalates, it is incumbent on policy makers to examine the value of their program relative to those of competitors. In this study, a model based on option pricing theory was developed to estimate the value of credit guarantees extended to importers and applied to U.S. and competing countries' programs. The Canadian guarantee has the lowest implicit value, followed by the U.S., Australian, and French guarantees. French guarantees had the highest implicit value due to higher coverage for interest and freight and insurance.International Relations/Trade,

Malt Barley Risk Management Strategies

Crop Production/Industries, Risk and Uncertainty,

PRODUCTION RISK AND CROP INSURANCE IN MALTING BARLEY: A STOCHASTIC DOMINANCE ANALYSIS

Malt barley is an important specialty crop in the Northern Plains and growers mitigate risk with federally subsidized crop insurance and production contracts. However, growers face considerable risk due to "coverage gaps" in crop insurance that result in uncertain indemnity payments due to uncertainty of their crop meeting contract specifications. A stochastic dominance model is developed to evaluate alternative risk efficient strategies for growers with differing risk attitudes and production practices (irrigation vs. dryland). Results show that efficient choices are highly dependent on risk attitudes for dryland growers, but not irrigated growers. Sensitivities with respect to acceptance risk and level of crop insurance subsidization are presented. Increased specialization of agricultural crops with greater emphasis on quality characteristics will limit dryland producer interest in federal crop insurance.Crop insurance, malting barley, stochastic dominance, stochastic efficiency, Risk and Uncertainty,

The observed day-to-day variability of Mars water vapor

The diurnal variability of atmospheric water vapor as derived from the Viking MAWD data is discussed. The detection of day to day variability of atmospheric water would be a significant finding since it would place constraints on the nature of surface reservoirs. Unfortunately, the diurnal variability seen by the MAWD experiment is well correlated with the occurrence of dust and/or ice hazes, making it difficult to separate real variations from observational effects. Analysis of the day to day variability of water vapor in the Martian atmosphere suggests that the observations are, at certain locations and seasons, significantly affected by the presence of water-ice hazes. Because such effects are generally limited to specific locations, such as Tharsis, Lunae Planum, and the polar cap edge during the spring, the seasonal and latitudinal trends in water vapor that have been previously reported are not significantly affected

BIOPHYSICAL SIMULATION IN SUPPORT OF CROP PRODUCTION DECISIONS: A CASE STUDY IN THE BLACKLANDS REGION OF TEXAS

Economic feasibility of Texas Blacklands corn production in relation to sorghum, wheat, and cotton is studied. Biophysical simulation generated yield data are integrated with an economic decision model using quadratic programming. Given the various scenarios analyzed, corn is economically feasible for the Blacklands. A crop mix of half corn and half cotton production is selected under risk neutrality with wheat entering if risk aversion is present. Corn and grain sorghum production are highly substitutable. Profit effects attributed to changing corn planting dates are more pronounced than profit changes resulting from altering corn population or maturity class.Crop Production/Industries,