41,947 research outputs found
Channel-wall limitations in the magnetohydrodynamic induction generator
Discussion of magnetohydrodynamic induction generator examines the machine in detail and materials problems influencing its design. The higher upper-temperature limit of the MHD system promises to be more efficient than present turbine systems for generating electricity
Job Creation, Destruction and Transition in Poland, 1988-1998: Panel Evidence
Longitudinal data from interviews with Poles of working age conducted in 1988, 1993 and 1998 present a detailed view of the transition from a state dominated to a market economy. Job loss in state firms and job creation in new private firms are the dominant employment change, other than retirements from the labor force. In the Polish case, a significant proportion of this movement over the 1988 to 1998 period involves a period of unemployment or exit from the labor force before obtaining a private sector job. A second feature of the Polish transition is considerable job competition between workers leaving the state sector and those who were out of the labor force at the beginning of the transition. The likelihood of moving to the private sector was higher for the better educated and for residents of regions with a robust de novo economy, suggesting that the supply of jobs in the private sector combined with higher levels of human capital lead to faster and smoother transitions. Lastly, wage differences between the state sector and the de novo sector appear to have little association with mobility, suggesting that movement is not strongly related to the opportunity to find a higher paying job.http://deepblue.lib.umich.edu/bitstream/2027.42/39887/3/wp502.pd
Some developments in improved methods for the measurements of the spectral irradiances of solar simulators
Measurement of spectral emission from solar simulators - photoelectric photometr
Imaging X-ray spectrometer
An X-ray spectrometer for providing imaging and energy resolution of an X-ray source is described. This spectrometer is comprised of a thick silicon wafer having an embedded matrix or grid of aluminum completely through the wafer fabricated, for example, by thermal migration. The aluminum matrix defines the walls of a rectangular array of silicon X-ray detector cells or pixels. A thermally diffused aluminum electrode is also formed centrally through each of the silicon cells with biasing means being connected to the aluminum cell walls and causes lateral charge carrier depletion between the cell walls so that incident X-ray energy causes a photoelectric reaction within the silicon producing collectible charge carriers in the form of electrons which are collected and used for imaging
Development of improved method for measurement of spectral irradiance from solar simulators Progress and status report
Instruments for measurement of spectral irradiances from solar simulator
Hidden Dirac Monopoles
Dirac showed that the existence of one magnetic pole in the universe could
offer an explanation of the discrete nature of the electric charge. Magnetic
poles appear naturally in most grand unified theories. Their discovery would be
of greatest importance for particle physics and cosmology. The intense
experimental search carried thus far has not met with success. I proposed a
universe with magnetic poles which are not observed free because they hide in
deeply bound monopole--anti-monopole states named monopolium. I discuss the
realization of this proposal and its consistency with known cosmological
features. I furthermore analyze its implications and the experimental
signatures that confirm the scenario.Comment: Comments: 15 pages, 3 figure
Optical alignment system Patent
Electro-optical/computer system for aligning large structural members and maintaining correct positio
Real-time simulation model of the HL-20 lifting body
A proposed manned spacecraft design, designated the HL-20, has been under investigation at Langley Research Center. Included in that investigation are flight control design and flying qualities studies utilizing a man-in-the-loop real-time simulator. This report documents the current real-time simulation model of the HL-20 lifting body vehicle, known as version 2.0, presently in use at NASA Langley Research Center. Included are data on vehicle aerodynamics, inertias, geometries, guidance and control laws, and cockpit displays and controllers. In addition, trim case and dynamic check case data is provided. The intent of this document is to provide the reader with sufficient information to develop and validate an equivalent simulation of the HL-20 for use in real-time or analytical studies
On a q-analogue of the multiple gamma functions
A -analogue of the multiple gamma functions is introduced, and is shown to
satisfy the generalized Bohr-Morellup theorem. Furthermore we give some
expressions of these function.Comment: 8 pages, AMS-Late
Comment on "Novel Convective Instabilities in a Magnetic Fluid"
Comment on the paper "Novel Convective Instabilities in a Magnetic Fluid" by
W. Luo, T. Du, and J. Huang, Phys. Rev. Lett., v.82, p.4134 (1999).Comment: 1 page, 1 figure, To appear in Phys. Rev. Lett. (2001
- …