Design considerations for the airframe-integrated scramjet

Research programs at the NASA Langley Research Center on the development of airframe-integrated scramjet concepts (supersonic combustion ramjet) are reviewed briefly. The design and performance of a specific scramjet configuration are examined analytically by use of recently developed and substantiated techniques on boundary-layer development, heat transfer, fuel-air mixing, heat-release rates, and engine-cycle analysis. These studies indicate that the fixed-geometry scramjet module will provide practical levels of thrust performance with low cooling requirements. Areas which need particular emphasis in further development work are the combustor design for low speeds and the integrated nozzle design

Aggregate Milk Supply Response to the Milk Income Loss Contract Program

This research tests for changes in aggregate milk production due to the operation of the Milk Income Loss Contract (MILC) program since 2002. Aggregate production is decomposed into the size of the dairy herd and milk production per cow. We find no statistically significant response in either variable. This finding implies that the simultaneous operation of income and price support programs in the United States has not, thus far, proven self-defeating.dairy, income support, policy, price support, Agribusiness, Livestock Production/Industries,

On the Dichotomy between the Nodal and Antinodal Excitations in High-temperature Superconductors

Angle-resolved photoemission data on optimally- and under-doped high temperature superconductors reveal a dichotomy between the nodal and antinodal electronic excitations. In this paper we propose an explanation of this unusual phenomenon by employing the coupling between the quasiparticle and the commensurate/incommensurate magnetic excitations.Comment: 11 pages, 9 figure

Considerations in the Dairy Relocation Decision

Historically, U.S. dairymen have been thought to move to a new location to seek better economic opportunities or to leave an area that has become disadvantaged due to regulation or economics. Recently, there again have been major shifts in dairy production across the United States.Livestock Production/Industries,

High pressure mechanical seal

A relatively impervious mechanical seal is formed between the outer surface of a tube and the inside surface of a mechanical fitting of a high pressure fluid or hydraulic system by applying a very thin soft metal layer onto the outer surface of the hard metal tube and/or inner surface of the hard metal fitting. The thickness of such thin metal layer is independent of the size of the tube and/or fittings. Many metals and alloys of those metals exhibit the requisite softness, including silver, gold, tin, platinum, indium, rhodium and cadmium. Suitably, the coating is about 0.0025 millimeters (0.10 mils) in thickness. After compression, the tube and fitting combination exhibits very low leak rates on the order or 10.sup.-8 cubic centimeters per second or less as measured using the Helium leak test

Rice World Market Prices

The marketing loan program associated with rice features benefits calculated using a USDA-announced World Market Price (WMP) rather than the posted county prices that are used for most other commodities. This results in reduced risk protection for producers relative to other crops, and greater difficulty in making optimal use of program benefits. This research investigates the rice WMP, identifying the relative importance of various foreign prices and other potential influencing factors. The results of this research have important implications for financial planning and optimal risk management strategies for rice producers.Agricultural and Food Policy,

The Net Effect of Exchange Rates on Agricultural Inputs and Outputs

For more than thirty years, studies about the effect of the exchange rate on exports have been conducted. However, few have considered the combined effect of the exchange rate on imported inputs into the agricultural system and the exports of final agricultural products those inputs produce. A current concern is for the net effect as the total value and quantity of inputs imported has increased. This research examines the effect of exchange rate changes on imported inputs into the corn, wheat, and beef cattle production systems. Effects on cost of production budgets are calculated, examining affects on profitability. Vector Autoregression (VAR) and Bayesian Averaging of Classical Estimates (BACE) models were estimated to evaluate those effects. Daily and weekly price data were used for corn, wheat, feeder steers, ethanol, diesel, ammonia, urea, di-ammonium phosphate, and the exchange rate. A VAR model was estimated to model the relationship between the variables. After having incongruous test results in determining the lag length structure it was decided that a BACE model would be approximated. After estimating the BACE model the price responses of the commodities to the exchange rates was estimated. The price responses were used in demonstrating the effect of the exchange rate on a producer’s profitability. It was determined that, generally, a strengthening exchange rate has a negative impact on prices. It was also found that the exchange rate has a greater impact on prices now than it did 14 years ago, implying that the exchange rate now has a greater affect on profitability. A one percent increase in the value of the dollar led to a decline in profitability ranging from $0.02/bu in wheat to$0.56/cwt in feeder steers. However, agricultural producers should not be overly concerned about a lower valued dollar from the perspective of their agricultural business.Agricultural and Food Policy, Crop Production/Industries, International Relations/Trade, Livestock Production/Industries,

Life Support Systems for a New Lunar Lander

A life support system concept has been developed for a new NASA lunar lander concept. The ground rules and assumptions driving the design of this vehicle are different from the Constellation Altair vehicle, and have led to a different design solution. For example, this concept assumes that the lander vehicle arrives in lunar orbit independently of the crew. It loiters in lunar orbit for months before rendezvousing with the Orion Multi-Purpose Crew Vehicle (MPCV), resulting in the use of solar power for this new lander, rather than fuel cells that provided product water to the life support system in the Altair vehicle. Without the need to perform a single Lunar Orbit Insertion burn for both the lander and the MPCV, the modules do not have to be centered in the same way, so the new lander has a smaller ascent module than Altair and a large habitat rather than a small airlock. This new lander utilizes suitport technology to perform EVAs from the habitat, which leads to significantly different requirements for the pressure control system. This paper describes the major trades and resulting concept design for the life support system of a new lunar lander concept

The NASA-UC Eta-Earth Program: III. A Super-Earth orbiting HD 97658 and a Neptune-mass planet orbiting Gl 785

We report the discovery of planets orbiting two bright, nearby early K dwarf stars, HD 97658 and Gl 785. These planets were detected by Keplerian modelling of radial velocities measured with Keck-HIRES for the NASA-UC Eta-Earth Survey. HD 97658 b is a close-in super-Earth with minimum mass Msini = 8.2 +/- 1.2 M_Earth, orbital period P = 9.494 +/- 0.005 d, and an orbit that is consistent with circular. Gl 785 b is a Neptune-mass planet with Msini = 21.6 +/- 2.0 M_Earth, P = 74.39 +/- 0.12 d, and orbital eccentricity 0.30 +/- 0.09. Photometric observations with the T12 0.8 m automatic photometric telescope at Fairborn Observatory show that HD 97658 is photometrically constant at the radial velocity period to 0.09 mmag, supporting the existence of the planet.Comment: Submitted to ApJ, 7 pages, 6 figures, 5 table

Soil treatments and seasonal changes in the sour cherry

Publication authorized September 21, 1927.Digitized 2007 AES.Includes bibliographical references