Dollarization and Euroization in Transition Countries: Currency Substitution, Asset Substitution, Network Externalities and Irreversibility

We examine the extent, causes and consequences of transition countries’ use of foreign currency as a co-circulating medium of exchange and store of value. Using new estimates of foreign cash in circulation, we obtain unique measures of currency substitution, asset substitution, and dollarization, and examine the consequences of network externalities for hysteresis and irreversibility. Finally, we examine factors leading some transition countries to euroize officially and bilaterally, and others to euroize unilaterally - that is, without prior sanction by the EMU.dollarization, euroization, transition economies, currency substitution, asset substitution, foreign currency, network externalities, irreversibility, underground economy

Design of a Versatile, Teleoperable, Towable Lifting Machine with Robotic Capabilities for Use in Nasa's Lunar Base Operations

The lifting machine will assist in lifting cargo off of landers sent to the Moon and in the construction of a lunar base. Three possible designs were considered for the overall configuration of the lifting machine: the variable angle crane, the tower crane, and the gantry crane. Alternate designs were developed for the major components of the lifting machine. A teleoperable, variable angle crane was chosen as its final design. The design consists of a telescoping boom mounted to a chassis that is supported by two conical wheels for towing and four outriggers for stability. Attached to the end of the boom is a seven degree of freedom robot arm for light, dexterous, lifting operations. A cable and hook suspends from the end of the boom for heavy, gross, lifting operations. Approximate structural sizes were determined for the lifter and its components. However, further analysis is needed to determine the optimum design dimensions. The design team also constructed a model of the design which demonstrates its features and operating principals

Preliminary Investigation of Cyclic De-Icing of an Airfoil Using an External Electric Heater

An investigation was conducted in the NACA Lewis icing research tunnel to determine the characteristics and requirements of cyclic deicing of a 65,2-216 airfoil by use of an external electric heater. The present investigation was limited to an airspeed of 175 miles per hour. Data are presented to show the effects of variations in heat-on and heat-off periods, ambient air temperature, liquid-water content, angle of attack, and. heating distribution on the requirements for cyclic deicing. The external heat flow at various icing and heating conditions is also presented. A continuously heated parting strip at the airfoil leading edge was found necessary for quick, complete, and consistent ice removal. The cyclic power requirements were found to be primarily a function of the datum temperature and heat-on time, with the other operating and meteorological variables having a second-order effect. Short heat-on periods and high power densities resulted in the most efficient ice removal, the minimum energy input, and the minimum runback ice formations. The optimum chordwise heating distribution pattern was found to consist of a uniform distribution of cycled power density in the impingement region. Downstream of the impingement region the power density decreased to the limits of heating which, for the conditions investigated, extended from 5.7 percent chord on the upper surface of the airfoil to 8.9 percent chord on the lower surface. Ice removal did not take place at a heater surface temperature of 32 F; surface temperatures of approximately 50 to 100 F were required to effect removal. Better de-icing performance and greater energy savings would be possible with a heater having a higher thermal efficiency

Predation by \u3ci\u3eAchaearanea Tepidariorum\u3c/i\u3e (Araneae: Theridiidae) on \u3ci\u3eAnoplophora Glabripennis\u3c/i\u3e (Coleoptera: Cerambycidae)

Anoplophora glabripennis is a large wood-boring cerambycid beetle that has recently invaded North America and Europe from Asia. We discovered the common house spider, Achaearanea tepidariorum, in large cages housing A. glabripennis on trees and confirmed the ability of A. tepidariorum to prey upon adult A. glabripennis by placing the two species together within smaller containers where they could be more easily observed. Adult A. glabripennis, up to 600% of the spiders’ body length, exceed the maximum relative size of prey previously reported for A. tepidariorum or for solitary webbuilding spiders in general