247,343 research outputs found
Solar driven liquid metal MHD power generator
A solar energy collector focuses solar energy onto a solar oven which is attached to a mixer which in turn is attached to the channel of a MHD generator. Gas enters the oven and a liquid metal enters the mixer. The gas/liquid metal mixture is heated by the collected solar energy and moves through the MHD generator thereby generating electrical power. The mixture is then separated and recycled
Measuring and interpreting current permanent and transitory earnings and dividends : methods and applications / BEBR No. 815
Bibliography: p. 21-22
New analytic results for electroweak baryon number violation
Real-time anomalous fermion number violation has been investigated for
massless chiral fermions in spherically symmetric SU(2) Yang-Mills gauge field
backgrounds which can be weakly dissipative or even nondissipative. Restricting
consideration to spherically symmetric fermion fields, a relation has been
found between the spectral flow of the Dirac Hamiltonian and two
characteristics of the background gauge field. This new result may be relevant
to electroweak baryon number violation in the early universe.Comment: 7 pages with jhep3.cls, based on a talk at the International
Europhysics Conference on High Energy Physics, Budapest, 200
Vicarious learning through capturing task‐directed discussions
The vicarious learner group has been developing a multimedia database system to promote and enhance the role of dialogue in learning. A specific interest, and the origin of the projects' collective name, is in the question of whether and how dialogue can be helpfully ‘reused’. What benefits can students gain from dialogue as observers, not just as participants? We describe our initial attempts to generate and capture educationally effective discourse exchanges amongst and between students and tutors. Problems encountered with available CMC discourse formats led to our development of a set of Task Directed Discussions (TDDs). A medium‐sized corpus of discourse exchanges was collected using the TDDs. A selection of nearly two hundred of these TDD exchanges formed the multimedia discourse database to the implemented prototype system, Dissemination. Initial results from a controlled experiment and evaluation of Dissemination are outline
Image data compression application to imaging spectrometers
The potential of image data compression techniques to satisfy the anticipated requirements of imaging spectrometer missions is discussed. Noiseless coding, rate controlled compression, cluster compression, and error protection are addressed
Some practical universal noiseless coding techniques, part 2
This report is an extension of earlier work (Part 1) which provided practical adaptive techniques for the efficient noiseless coding of a broad class of data sources characterized by only partially known and varying statistics (JPL Publication 79-22). The results here, while still claiming such general applicability, focus primarily on the noiseless coding of image data. A fairly complete and self-contained treatment is provided. Particular emphasis is given to the requirements of the forthcoming Voyager II encounters of Uranus and Neptune. Performance evaluations are supported both graphically and pictorially. Expanded definitions of the algorithms in Part 1 yield a computationally improved set of options for applications requiring efficient performance at entropies above 4 bits/sample. These expanded definitions include as an important subset, a somewhat less efficient but extremely simple "FAST' compressor which will be used at the Voyager Uranus encounter. Additionally, options are provided which enhance performance when atypical data spikes may be present
Solar-driven liquid metal magnetohydrodynamic generator
A solar oven heated by concentrated solar radiation as the heat source of a liquid metal magnetohydrodynamic (LMMHD) power generation system is proposed. The design allows the production of electric power in space, as well as on Earth, at high rates of efficiency. Two types of the solar oven suitable for the system are discussed
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