Apparatus for making curved reflectors Patent

Forming mold for polishing and machining curved solar magnesium reflector with reinforcing rib

Process sequence produces strong, lightweight reflectors of excellent quality

Large compound curved surfaces for collecting and concentrating radiation are fabricated by the use of several common machining and forming processes. Lightweight sectors are assembled into large reflectors. With this concept of fabrication, integrally stiffened reflective sectors up to 25 square feet in area have been produced

Method and apparatus for making curved reflectors Patent

Fabrication of curved reflector segments for solar mirro

Baryon Magnetic Moments in Alternate 1/N_c Expansions

Recent work shows not only the necessity of a 1/N_c expansion to explain the observed mass spectrum of the lightest baryons, but also that at least two distinct large N_c expansions, in which quarks transform under either the color fundamental or the two-index antisymmetric representation of SU(N_c), work comparably well. Here we show that the baryon magnetic moments do not support this ambivalence; they strongly prefer the color-fundamental 1/N_c expansion, providing experimental evidence that nature decisively distinguishes among 1/N_c expansions for this observable.Comment: 18 pages, ReVTe

Do Fixed Exchange Rates Fetter Monetary Policy? A Credit View

The Bernanke-Blinder credit-view model is expanded to encompass a small, open economy with fixed exchange rates. In contrast to conventional wisdom and traditional models, monetary policy is resurrected as a stabilization tool. We show that various financial sector shocks have real aggregate demand effects. Further, we demonstrate that independent monetary policy actions can have substantive impacts on aggregate demand despite perfect capital mobility in bond markets and adherence to a fixed exchange rate regime as long as bank loans are imperfectly mobile.

Institutions and government growth: a comparison of the 1890s and the 1930s

Statistics on the size and growth of the U.S. federal government, in addition to public statements by President Franklin Roosevelt, seem to indicate that the Great Depression was the primary event that caused the dramatic growth in government spending and intervention in the private sector that continues to the present day. Through a comparison of the economic conditions of the 1890s and the 1930s, the authors argue that post-1930 government growth in the United States is not the direct result of the Great Depression, but rather is a result of institutional, legal, and societal changes that began in the late 1800s. Thus, the Great Depression did likely trigger increases in government spending and regulatory involvement, but historical factors produced the conditions that tended to lend permanence to the growth of government that occurred during the Great Depression.Federal government ; Depressions

Doppler lidar observations of sensible heat flux and intercomparisons with a ground-based energy balance station and WRF model output

This is an open access article - Copyright @ 2009 E. Schweizerbart'sche VerlagsbuchhandlungDuring the Convective and Orographically induced Precipitation Study (COPS), a scanning Doppler lidar was deployed at Achern, Baden-Wüttemberg, Germany from 13th June to 16th August 2007. Vertical velocity profiles ('rays') through the boundary layer were measured every 3 seconds with vertical profiles of horizontal wind velocity being derived from performing azimuth scans every 30 minutes. During Intense Observation Periods radiosondes were launched from the site. In this paper, a case study of convective boundary layer development on 15th July 2007 is investigated. Estimates of eddy dissipation rate are made from the vertically pointing lidar data and used as one input to the velocity-temperature co-variance equation to estimate sensible heat flux. The sensible heat flux values calculated from Doppler lidar data are compared with a surface based energy balance station and output from the Weather Research and Forecasting (WRF) model.Funding is obtained from NER

Events leading up to the June 2015 outburst of V404 Cyg

On 2015 June 15 the burst alert telescope (BAT) on board {\em Swift} detected an X-ray outburst from the black hole transient V404 Cyg. We monitored V404 Cyg for the last 10 years with the 2-m Faulkes Telescope North in three optical bands (V, R, and i$^{'}$). We found that, one week prior to this outburst, the optical flux was 0.1--0.3 mag brighter than the quiescent orbital modulation, implying an optical precursor to the X-ray outburst. There is also a hint of a gradual optical decay (years) followed by a rise lasting two months prior to the outburst. We fortuitously obtained an optical spectrum of V404 Cyg 13 hours before the BAT trigger. This too was brighter ($\sim1\rm\,mag$) than quiescence, and showed spectral lines typical of an accretion disk, with characteristic absorption features of the donor being much weaker. No He II emission was detected, which would have been expected had the X-ray flux been substantially brightening. This, combined with the presence of intense H$\alpha$ emission, about 7 times the quiescent level, suggests that the disk entered the hot, outburst state before the X-ray outburst began. We propose that the outburst is produced by a viscous-thermal instability triggered close to the inner edge of a truncated disk. An X-ray delay of a week is consistent with the time needed to refill the inner region and hence move the inner edge of the disk inwards, allowing matter to reach the central BH, finally turning on the X-ray emission.Comment: Accepted by ApJ Letter, 7 pages, 5 figure

Alternator and voltage regulator-exciter for a Brayton cycle space power system. Volume 1 - Design and development

Alternator and voltage regulator for Brayton cycle space power syste