25,353 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
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
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
Comparison of electric dipole moments and the Large Hadron Collider for probing CP violation in triple boson vertices
CP violation from physics beyond the Standard Model may reside in triple
boson vertices of the electroweak theory. We review the effective theory
description and discuss how CP violating contributions to these vertices might
be discerned by electric dipole moments (EDM) or diboson production at the
Large Hadron Collider (LHC). Despite triple boson CP violating interactions
entering EDMs only at the two-loop level, we find that EDM experiments are
generally more powerful than the diboson processes. To give example to these
general considerations we perform the comparison between EDMs and collider
observables within supersymmetric theories that have heavy sfermions, such that
substantive EDMs at the one-loop level are disallowed. EDMs generally remain
more powerful probes, and next-generation EDM experiments may surpass even the
most optimistic assumptions for LHC sensitivities.Comment: 26 pages, 14 figures, published version with more argument
Survey of vector-like fermion extensions of the Standard Model and their phenomenological implications
With the renewed interest in vector-like fermion extensions of the Standard
Model, we present here a study of multiple vector-like theories and their
phenomenological implications. Our focus is mostly on minimal flavor conserving
theories that couple the vector-like fermions to the SM gauge fields and mix
only weakly with SM fermions so as to avoid flavor problems. We present
calculations for precision electroweak and vector-like state decays, which are
needed to investigate compatibility with currently known data. We investigate
the impact of vector-like fermions on Higgs boson production and decay,
including loop contributions, in a wide variety of vector-like extensions and
their parameter spaces.Comment: 43 pages, 17 figures; v2: text modified to improve readability,
references added, journal versio
Scanamorphos: a map-making software for Herschel and similar scanning bolometer arrays
Scanamorphos is one of the public softwares available to post-process scan
observations performed with the Herschel photometer arrays. This
post-processing mainly consists in subtracting the total low-frequency noise
(both its thermal and non-thermal components), masking high-frequency artefacts
such as cosmic ray hits, and projecting the data onto a map. Although it was
developed for Herschel, it is also applicable with minimal adjustment to scan
observations made with some other imaging arrays subjected to low-frequency
noise, provided they entail sufficient redundancy; it was successfully applied
to P-Artemis, an instrument operating on the APEX telescope. Contrary to
matrix-inversion softwares and high-pass filters, Scanamorphos does not assume
any particular noise model, and does not apply any Fourier-space filtering to
the data, but is an empirical tool using purely the redundancy built in the
observations -- taking advantage of the fact that each portion of the sky is
sampled at multiple times by multiple bolometers. It is an interactive software
in the sense that the user is allowed to optionally visualize and control
results at each intermediate step, but the processing is fully automated. This
paper describes the principles and algorithm of Scanamorphos and presents
several examples of application.Comment: This is the final version as accepted by PASP (on July 27, 2013). A
copy with much better-quality figures is available on
http://www2.iap.fr/users/roussel/herschel
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