31,117 research outputs found
Wind and solar powered turbine
A power generating station having a generator driven by solar heat assisted ambient wind is described. A first plurality of radially extendng air passages direct ambient wind to a radial flow wind turbine disposed in a centrally located opening in a substantially disc-shaped structure. A solar radiation collecting surface having black bodies is disposed above the fist plurality of air passages and in communication with a second plurality of radial air passages. A cover plate enclosing the second plurality of radial air passages is transparent so as to permit solar radiation to effectively reach the black bodies. The second plurality of air passages direct ambient wind and thermal updrafts generated by the black bodies to an axial flow turbine. The rotating shaft of the turbines drive the generator. The solar and wind drien power generating system operates in electrical cogeneration mode with a fuel powered prime mover
Causal Classical Theory of Radiation Damping
It is shown how initial conditions can be appropriately defined for the
integration of Lorentz-Dirac equations of motion. The integration is performed
\QTR{it}{forward} in time. The theory is applied to the case of the motion of
an electron in an intense laser pulse, relevant to nonlinear Compton
scattering.Comment: 8 pages, 2 figure
The Invisible Higgs Decay Width in the Add Model at the LHC
Assuming flat universal extra dimensions, we demonstrate that for a light
Higgs boson the process will be observable at the level at the LHC for the
portion of the Higgs-graviscalar mixing () and effective Planck mass
() parameter space where channels relying on visible Higgs decays fail to
achieve a signal. Further, we show that even for very modest values
of the invisible decay signal probes to higher than does the
(-independent) jets/\gam + missing energy signal from graviton
radiation. We also discuss various effects, such as Higgs decay to two
graviscalars, that could become important when is of order 1.Comment: 6 pages, 2 figures, To appear in the Proceedings of the Les Houches
Workshop 2003: ``Physics at TeV Colliders'', ed. F. Boudjem
Application of a Bayesian Method to Absorption Spectral-Line Finding in Simulated ASKAP Data
The large spectral bandwidth and wide field of view of the Australian SKA
Pathfinder radio telescope will open up a completely new parameter space for
large extragalactic HI surveys. Here we focus on identifying and parametrising
HI absorption lines which occur in the line of sight towards strong radio
continuum sources. We have developed a method for simultaneously finding and
fitting HI absorption lines in radio data by using multi-nested sampling, a
Bayesian Monte Carlo algorithm. The method is tested on a simulated ASKAP data
cube, and is shown to be reliable at detecting absorption lines in low
signal-to-noise data without the need to smooth or alter the data. Estimation
of the local Bayesian evidence statistic provides a quantitative criterion for
assigning significance to a detection and selecting between competing
analytical line-profile models.Comment: 8 pages, 5 figures and 1 table; accepted for publication in PAS
A Small Family of Elements with Long Inverted Repeats is Located Near Sites of Developmentally Regulated DNA Rearrangement in \u3cem\u3eTetrahymena thermophila\u3c/em\u3e
Extensive DNA rearrangement occurs during the development of the somatic macronucleus from the germ line micronucleus in ciliated protozoans. The micronuclear junctions and the macronuclear product of a developmentally regulated DNA rearrangement in Tetrahymena thermophila, Tlr1, have been cloned. The intrachromosomal rearrangement joins sequences that are separated by more than 13 kb in the micronucleus with the elimination of moderately repeated micronucleus-specific DNA sequences. There is a long, 825-bp, inverted repeat near the micronuclear junctions. The inverted repeat contains two different 19-bp tandem repeats. The 19-bp repeats are associated with each other and with DNA rearrangements at seven locations in the micronuclear genome. Southern blot analysis is consistent with the occurrence of the 19-bp repeats within pairs of larger repeated sequences. Another family member was isolated. The 19-mers in that clone are also in close proximity to a rearrangement junction. We propose that the 19-mers define a small family of developmentally regulated DNA rearrangements having elements with long inverted repeats near the junction sites. We discuss the possibility that transposable elements evolve by capture of molecular machinery required for essential cellular functions
Consumption of submerged aquatic macrophytes by rudd (scardinius erythrophthalmus L.) in New Zealand
In experiments in New Zealand, rudd (Scardinius erythrophthalmus L.) of 108–277mm fork length (FL) ate a wide range of native and introduced submerged aquatic macrophytes in captivity and in the field. Rudd consumed the native charophytes Chara globularis Thuill., Chara fibrosa Ag. ex Bruz., and Nitella spp., the native macrophytes Potamogeton ochreatus Raoul. and Myriophyllum propinquum A. Cunn., and the introduced macrophytes Elodea canadensis Michx., Egeria densa Planch., Lagarosiphon major L., and Ceratophyllum demersum L. Rudd consistently consumed the Nitella spp. and Potamogeton ochreatus before Ceratophyllum demersum. From the results of experiments in tanks and in the field, we found the order of highest to lowest palatability was: Nitella spp. > Potamogeton ochreatus > Elodea canadensis> Chara globularis = Chara fibrosa> Egeria densa = Lagarosiphon major > Myriophyllum propinquum > Ceratophyllum demersum. The order of consumption was subject to some variation with season, especially for Egeria densa, Lagarosiphon major, and Myriophyllum propinquum. Rudd
consumed up to 20% of their body weight per day of Egeria densa in spring, and 22% of their body weight per day of Nitella spp. in summer. Consumption rates were considerably lower in winter than in summer. The results of our field trial suggested that the order of consumption also applies in the field and that rudd are having a profound impact on vulnerable native aquatic plant communities in New Zealand. Nitella spp. and Potamogeton ochreatus are likely to be selectively eaten, and herbivory by rudd might prevent the re-establishment of these species in
restoration efforts
Inclusion of unsteady aerodynamics in longitudinal parameter estimation from flight data
A simple vortex system, used to model unsteady aerodynamic effects into the rigid body longitudinal equations of motion of an aircraft, is described. The equations are used in the development of a parameter extraction algorithm. Use of the two parameter-estimation modes, one including and the other omitting unsteady aerodynamic modeling, is discussed as a means of estimating some acceleration derivatives. Computer generated data and flight data, used to demonstrate the use of the parameter-extraction algorithm are studied
- …