37,371 research outputs found

    From urban to national heat island: The effect of anthropogenic heat output on climate change in high population industrial countries

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    The project presented here sought to determine whether changes in anthropogenic thermal emission can have a measurable effect on temperature at the national level, taking Japan and Great Britain as type examples. Using energy consumption as a proxy for thermal emission, strong correlations (mean r2 = 0.90 and 0.89, respectively) are found between national equivalent heat output (HO) and temperature above background levels Δt averaged over 5‐ to 8‐yr periods between 1965 and 2013, as opposed to weaker correlations for CMIP5 model temperatures above background levels Δmt (mean r2 = 0.52 and 0.10). It is clear that the fluctuations in Δt are better explained by energy consumption than by present climate models, and that energy consumption can contribute to climate change at the national level on these timescales

    Uncovering anorexia nervosa in a biofeedback clinic for bowel dysfunction

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    Biofeedback is a conservative treatment based on behavioural techniques, which can be used in the management of bowel dysfunction. This article reports the results of a retrospective review of the clinical notes of 87 female patients attending a biofeedback service at St Mark's Hospital, Harrow. The initial review was conducted to examine the incidence of polycystic ovary syndrome (PCOS) in patients attending this service. Seven percent were found to have PCOS, which is within the normal range. However, a significant proportion of patients (11.5%) had a current history of anorexia nervosa, a higher rate than in the general population, which prompted further investigation. In this article, Sonya Chelvanayagam, Julie Duncan, Brigitte Collins and Lorraine O'Brien report on the results of this review and discuss the significance of its findings. © Copyright Terms & conditions

    A concept for a fuel efficient flight planning aid for general aviation

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    A core equation for estimation of fuel burn from path profile data was developed. This equation was used as a necessary ingredient in a dynamic program to define a fuel efficient flight path. The resultant algorithm is oriented toward use by general aviation. The pilot provides a description of the desired ground track, standard aircraft parameters, and weather at selected waypoints. The algorithm then derives the fuel efficient altitudes and velocities at the waypoints

    Surface pressure data for a supersonic-cruise airplane configuration at Mach numbers of 2.30, 2.96, 3.30

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    The tabulated results of surface pressure tests conducted on the wing and fuselage of an airplane model in the Langley Unitary Plan wind tunnel are presented without analysis. The model tested was that of a supersonic-cruise airplane with a highly swept arrow-wing planform, two engine nacelles mounted beneath the wing, and outboard vertical tails. Data were obtained at Mach numbers of 2.30, 2.96, and 3.30 for angles of attack from -4 deg to 12 deg. The Reynolds number for these tests was 6,560,000 per meter

    Estimations for the Single Diffractive production of the Higgs boson at the Tevatron and the LHC

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    The single diffractive production of the standard model Higgs boson is computed using the diffractive factorization formalism, taking into account a parametrization for the Pomeron structure function provided by the H1 Collaboration. We compute the cross sections at next-to-leading order accuracy for the gluon fusion process, which includes QCD and electroweak corrections. The gap survival probability () is also introduced to account for the rescattering corrections due to spectator particles present in the interaction, and to this end we compare two different models for the survival factor. The diffractive ratios are predicted for proton-proton collisions at the Tevatron and the LHC for the Higgs boson mass of MHM_H = 120 GeV. Therefore, our results provide updated estimations for the diffractive ratios of the single diffractive production of the Higgs boson in the Tevatron and LHC kinematical regimes.Comment: 20 pages, 6 figures, 3 table

    Nonlinearity of vacuum reggeons and exclusive diffractive production of vector mesons at HERA

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    The processes of exclusive photo- and electroproduction of vector mesons ρ0\rho^0(770), ϕ\phi(1020) and J/ψJ/\psi(3096) at collision energies 30GeV<W<300GeV30 GeV<W<300 GeV and transferred momenta squared 0<t<2GeV20<-t<2 GeV^2 are considered in the framework of a phenomenological Regge-eikonal scheme with nonlinear Regge trajectories in which their QCD asymptotic behavior is taken into account explicitly. By comparison of available experimental data from ZEUS and H1 Collaborations with the model predictions it is demonstrated that corresponding angular distributions and integrated cross-sections in the above-mentioned kinematical range can be quantitatively described with use of two CC-even vacuum Regge trajectories. These are the "soft" pomeron dominating the high energy reactions without a hard scale and the "hard" pomeron giving an essential contribution to photo- and electroproduction of heavy vector mesons and deeply virtual electroproduction of light vector mesons.Comment: 25 pages, 12 figure

    General moments of the inverse real Wishart distribution and orthogonal Weingarten functions

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    Let WW be a random positive definite symmetric matrix distributed according to a real Wishart distribution and let W1=(Wij)i,jW^{-1}=(W^{ij})_{i,j} be its inverse matrix. We compute general moments E[Wk1k2Wk3k4...Wk2n1k2n]\mathbb{E} [W^{k_1 k_2} W^{k_3 k_4} ... W^{k_{2n-1}k_{2n}}] explicitly. To do so, we employ the orthogonal Weingarten function, which was recently introduced in the study for Haar-distributed orthogonal matrices. As applications, we give formulas for moments of traces of a Wishart matrix and its inverse.Comment: 29 pages. The last version differs from the published version, but it includes Appendi

    Non-Markovian Stochastic Resonance

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    The phenomenological linear response theory of non-Markovian Stochastic Resonance (SR) is put forward for stationary two-state renewal processes. In terms of a derivation of a non-Markov regression theorem we evaluate the characteristic SR-quantifiers; i.e. the spectral power amplification (SPA) and the signal-to-noise ratio (SNR), respectively. In clear contrast to Markovian SR, a characteristic benchmark of genuine non-Markovian SR is its distinctive dependence of the SPA and SNR on small (adiabatic) driving frequencies; particularly, the adiabatic SNR becomes strongly suppressed over its Markovian counterpart. This non-Markovian SR theory is elucidated for a fractal gating dynamics of a potassium ion channel possessing an infinite variance of closed sojourn times.Comment: 4 pages, 1 figur

    Attosecond two-photon interferometry for doubly excited states of helium

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    We show that the correlation dynamics in coherently excited doubly excited resonances of helium can be followed in real time by two-photon interferometry. This approach promises to map the evolution of the two-electron wave packet onto experimentally easily accessible non-coincident single electron spectra. We analyze the interferometric signal in terms of a semi-analytical model which is validated by a numerical solution of the time-dependent two-electron Schr\"odinger equation in its full dimensionality.Comment: 5 pages, 4 figure
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