Directly comparing coronal and solar wind elemental fractionation

As the solar wind propagates through the heliosphere, dynamical processes irreversibly erase the signatures of the near-Sun heating and acceleration processes. The elemental fractionation of the solar wind should not change during transit however, making it an ideal tracer of these processes. We aimed to verify directly if the solar wind elemental fractionation is reflective of the coronal source region fractionation, both within and across different solar wind source regions. A backmapping scheme was used to predict where solar wind measured by the Advanced Composition Explorer (ACE) originated in the corona. The coronal composition measured by the Hinode Extreme ultraviolet Imaging Spectrometer (EIS) at the source regions was then compared with the in-situ solar wind composition. On hourly timescales there was no apparent correlation between coronal and solar wind composition. In contrast, the distribution of fractionation values within individual source regions was similar in both the corona and solar wind, but distributions between different sources have significant overlap. The matching distributions directly verifies that elemental composition is conserved as the plasma travels from the corona to the solar wind, further validating it as a tracer of heating and acceleration processes. The overlap of fractionation values between sources means it is not possible to identify solar wind source regions solely by comparing solar wind and coronal composition measurements, but a comparison can be used to verify consistency with predicted spacecraft-corona connections.Comment: Accepted version; 8 pages, 7 figure

Vortex breakdown and control experiments in the Ames-Dryden water tunnel

Flow-field measurements have been made to determine the effects of core blowing on vortex breakdown and control. The results of these proof-of-concept experiments clearly demonstrate the usefulness of water tunnels as test platforms for advanced flow-field simulation and measurement

Control of forebody three-dimensional flow separations

Some experiments involving the development of the turbulent symmetric vortex flow about the lee side of a 5 deg semiangle conical forebody at high relative incidence are discussed. The cone was immersed in a Mach 0.6 airstream at a Reynolds number of 13.5 million based on the 1.4 - m axial length of the cone. Novel means of controlling the degree of asymmetry using blowing very close to the nose were investigated. Small amounts of air injected normally or tangentially to the cone surface, but on one side of the leeward meridian and beneath the vortex farthest from the wall, were effective in biasing the asymmetry. With this reorientation of the forebody vortices, the amplitude of the side force could be reduced to the point where its direction was reversed. This phenomenon could be obtained either by changing the blowing rate at constant incidence or by changing incidence at constant blowing rate. Normal injection was more effective than tangential injection. An organized and stable flow structure emerged with the jet vortices positioned above the forebody vortices

City and Countryside Revisited. Comparative rent movements in London and the South-East, 1580-1914

Economic historians have traditionally argued that urban growth in England was driven primarily by prior improvements in agricultural supply in the two centuries before the industrial revolution. Recent revisionist scholarship by writers such as Jan Luiten van Zanden and Robert Allen has suggested that 'the city drove the countryside, not the reverse'. This paper assembles new serial data on urban and agricultural rent movements in Kent, Essex and London, from 1580-1914, which enables us to provide a tentative estimate of the strength of the urban variable and the productivity of land across the rural-urban continuum. Our initial findings support the revisionist view, and throw new light on London's position within the wider metropolitan region. Comparative rent movements suggests a greater continuity between town and countryside than has often been assumed, with sharp increases in rental values occurring on the rural-urban fringes of London and the lower Medway valley

The Historical Origins of U.S. Exchange Market Intervention Policy

The present set of arrangements for U.S. exchange market intervention policy was largely developed after 1961 during the Bretton Woods era. However, that set had important historical precedents. In this paper we examine precedents to current arrangements, focusing on three historical eras: pre-1934 operations; the Exchange Stabilization Fund operations beginning in 1934; and the Bretton Woods era. We describe operations by the Second Bank of the United States in the pre-Civil War period and then operations by the U.S. Treasury in the post-Civil War period. After establishment of the Federal Reserve in 1914, the New York Fed engaged in isolated exchange market policies in the 1920s and 1930s, first under the direction of the Governor Benjamin Strong until his death in 1928, thereafter, under the direction of his successor, George Harrison. We then examine operations of the Exchange Stabilization Fund that the Gold Reserve Act of 1934 created as a Treasury Department agency. We exploit unique unpublished sources to analyze its dealings with the Banque de France and the Bank of England before and after the Tripartite Agreement. Finally, based on a unique data set of all U.S. Treasury and Federal Reserve foreign-exchange transactions, we discuss U.S. efforts from 1961 through 1972 to defend the dollar's parity under the Bretton Woods system.

New Velocity Distribution in the Context of the Eddington Theory

Exotic dark matter together with the vacuum energy (associated with the cosmological constant) seem to dominate the Universe. Thus its direct detection is central to particle physics and cosmology. Supersymmetry provides a natural dark matter candidate, the lightest supersymmetric particle (LSP). One essential ingredient in obtaining the direct detection rates is the density and velocity distribution of the LSP. The detection rate is proportional to this density in our vicinity. Furthermore, since this rate is expected to be very low, one should explore the two characteristic signatures of the process, namely the modulation effect, i.e. the dependence of the event rate on the Earth's motion and the correlation of the directional rate with the motion of the sun. Both of these crucially depend on the LSP velocity distribution. In the present paper we study simultaneously density profiles and velocity distributions based on the Eddington theory.Comment: 40 LaTex pages, 19 figures and one table. The previous version was expanded to include new numerical solutions to Poisson's equation. Sheduled to appear in vol. 588, ApJ, May 1, 300