74,237 research outputs found
Current state of development of Eurocomprehension research
"Eurocomprehension" is the term used to describe European intercomprehension in Europe’s three major language families, the Romance, the Slavic and the Germanic. The aim of eurocomprehension is to achieve multilingualism conforming to EU lanÂguage policy goals through the entry-point of receptive competence in a modular structure. Linguistic intercomprehension research forms the transfer bases for the cognitive use of relations between the language groups which didactics of multiÂlingualism implement. ..
Active cooling requirements for propellant storage
Recent NASA and DOD mission models have indicated future needs for orbital cryogenic storage and supply systems. Two thermal control systems which show the greatest promise for improving propellant storage life were evaluated. One system was an open cycle thermodynamic vent type with a refrigeration system for partial hydrogen reliquefaction located at the LH2 tank and a vapor cooled shield for integrated and non-integrated tank designs to reduce boiloff. The other was a closed system with direct refrigeration at the LH2 tank. A reversed Brayton cycle unit was baselined for the propellant processor. It is concluded that: (1) reliquefaction systems are not attractive for minimizing propellant boiloff; (2) open cycle systems may not be economically attractive for long term storage; (3) a number of refrigeration systems are available to assist in the long term storage of cryogenic propellants; and (4) shields can significantly improve the performance of mechanical coolers
Hydrogen-oxygen electrolytic regenerative fuel cells, 1 August - 1 September 1966
Single cells with potassium titanate matrices for improved cycle life performance of hydrogen- oxygen regenerative fuel cell
Applications of model structure determination to flight test data
Several statistical and information criteria need to be considered when selecting an adequate model. Incorrect stability and control derivates result from inadequate aerodynamic model structure. Stepwise regression is used to determine the structure for an adequate model. Flight data which covers a nonlinear aerodynamic model range may be analyzed as a single data set or partitioned into several distinct sets. Stepwise regression for model structure detemination and parameter estimation was successfully applied to three aircraft types (single engine general aviation, unaugmented modern jet fighter, jet transport)
Hydrogen-oxygen electrolytic regenerative fuel cells, August 1 - September 1, 1965
Hydrogen-oxygen electrolytic regenerative fuel cell tests with various electrode structures and prototype multicell testin
Were the Acquisitive Conglomerates Inefficient?
This paper challenges the conventional wisdom that the 1960s conglomerates were inefficient. I offer valuation results consistent with recent event-study evidence that markets typically rewarded diversifying acquisitions. Using new data, I compute industry-adjusted valuation, profitability, leverage, and investment ratios for thirty-six large, acquisitive conglomerates from 1966 to 1974. During the early 1970s, the conglomerates were less valuable and less profitable than standalone firms, favoring an agency explanation for unrelated diversification. In the 1960s, however, conglomerates were not valued at a discount. Evidence from acquisition histories suggests that conglomerate diversification may have added value by creating internal capital markets.diversification, mergers and acquisitions, conglomerates, restructuring
Validity of the Taylor Hypothesis for Linear Kinetic Waves in the Weakly Collisional Solar Wind
The interpretation of single-point spacecraft measurements of solar wind
turbulence is complicated by the fact that the measurements are made in a frame
of reference in relative motion with respect to the turbulent plasma. The
Taylor hypothesis---that temporal fluctuations measured by a stationary probe
in a rapidly flowing fluid are dominated by the advection of spatial structures
in the fluid rest frame---is often assumed to simplify the analysis. But
measurements of turbulence in upcoming missions, such as Solar Probe Plus,
threaten to violate the Taylor hypothesis, either due to slow flow of the
plasma with respect to the spacecraft or to the dispersive nature of the plasma
fluctuations at small scales. Assuming that the frequency of the turbulent
fluctuations is characterized by the frequency of the linear waves supported by
the plasma, we evaluate the validity of the Taylor hypothesis for the linear
kinetic wave modes in the weakly collisional solar wind. The analysis predicts
that a dissipation range of solar wind turbulence supported by whistler waves
is likely to violate the Taylor hypothesis, while one supported by kinetic
Alfven waves is not.Comment: 10 pages, 3 figures, Accepted for publication in The Astrophysical
Journa
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