30,508 research outputs found

    Wind and solar powered turbine

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    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

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    Assuming flat universal extra dimensions, we demonstrate that for a light Higgs boson the process ppWW+XHiggs,graviscalars+Xinvisible+Xpp\to W^*W^* +X \to Higgs,graviscalars +X \to invisible+X will be observable at the 5σ5 \sigma level at the LHC for the portion of the Higgs-graviscalar mixing (ξ\xi) and effective Planck mass (MDM_D) parameter space where channels relying on visible Higgs decays fail to achieve a 5σ5 \sigma signal. Further, we show that even for very modest values of ξ\xi the invisible decay signal probes to higher MDM_D than does the (ξ\xi-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 mh/MDm_h/M_D 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

    Causal Classical Theory of Radiation Damping

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    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

    A Corpus-Based, Pilot Study of Lexical Stress Variation in American English

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    Phonological free variation describes the phenomenon of there being more than one pronunciation for a word without any change in meaning (e.g. because, schedule, vehicle). The term also applies to words that exhibit different stress patterns (e.g. academic, resources, comparable) with no change in meaning or grammatical category. A corpus-based analysis of free variation is a useful tool for testing the validity of surveys of speakers' pronunciation preferences for certain variants. The current paper presents the results of a corpus-based pilot study of American English, in an attempt to replicate Mompéan's 2009 study of British English

    Consumption of submerged aquatic macrophytes by rudd (scardinius erythrophthalmus L.) in New Zealand

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    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

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    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
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