2,809 research outputs found

    Conceptual design studies of candidate V/STOL lift fan commercial short haul transport for 1980 - 1985 V/STOL lift fan study

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    Conceptual designs of V/STOL lift fan commercial short haul transport aircraft for the 1980-85 time period were studied to determine their technical and economic feasibility. The engine concepts included both integral and remote fans. The scope of the study included definition of the hover control concept for each propulsion system, aircraft design, aircraft mass properties, cruise performance, noise and ride qualities evaluation. Economic evaluating was also studied on a basis of direct operating costs and route structure

    Variation of the Fine-Structure Constant and Laser Cooling of Atomic Dysprosium

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    Radio-frequency electric-dipole transitions between nearly degenerate, opposite parity levels of atomic dysprosium (Dy) were monitored over an eight-month period to search for a variation in the fine-structure constant, α\alpha. The data provide a rate of fractional temporal variation of α\alpha of (−2.4±2.3)×10−15(-2.4\pm2.3)\times10^{-15} yr−1^{-1} or a value of (−7.8±5.9)×10−6(-7.8 \pm 5.9) \times 10^{-6} for kαk_\alpha, the variation coefficient for α\alpha in a changing gravitational potential. All results indicate the absence of significant variation at the present level of sensitivity. We also present initial results on laser cooling of an atomic beam of dysprosium.Comment: 10 pages, 6 figures, fixed typos in section 5, updated result

    Critical Ultrasonics Near the Superfluid Transition : Finite Size Effects

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    The suppression of order parameter fluctuations at the boundaries causes the ultrasonic attenuation near the superfluid transition to be lowered below the bulk value. We calculate explicitly the first deviation from the bulk value for temperatures above the lambda point. This deviation is significantly larger than for static quantities like the thermodynamic specific heat or other transport properties like the thermal conductivity. This makes ultrasonics a very effective probe for finite size effects.Comment: 10 pages (LaTeX), 1 figure (PostScript

    Investigation of the Gravitational Potential Dependence of the Fine-Structure Constant Using Atomic Dysprosium

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    Radio-frequency E1 transitions between nearly degenerate, opposite parity levels of atomic dysprosium were monitored over an eight month period to search for a variation in the fine-structure constant. During this time period, data were taken at different points in the gravitational potential of the Sun. The data are fitted to the variation in the gravitational potential yielding a value of (−8.7±6.6)×10−6(-8.7 \pm 6.6) \times 10^{-6} for the fit parameter kαk_\alpha. This value gives the current best laboratory limit. In addition, our value of kαk_{\alpha} combined with other experimental constraints is used to extract the first limits on k_e and k_q. These coefficients characterize the variation of m_e/m_p and m_q/m_p in a changing gravitational potential, where m_e, m_p, and m_q are electron, proton, and quark masses. The results are ke=(4.9±3.9)×10−5k_e = (4.9 \pm 3.9) \times 10^{-5} and kq=(6.6±5.2)×10−5k_q = (6.6 \pm 5.2) \times 10^{-5}.Comment: 6 pages, 3 figure

    Choreography, controversy and child sex abuse: Theoretical reflections on a cultural criminological analysis of dance in a pop music video

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    This article was inspired by the controversy over claims of ‘pedophilia!!!!’ undertones and the ‘triggering’ of memories of childhood sexual abuse in some viewers by the dance performance featured in the music video for Sia’s ‘Elastic Heart’ (2015). The case is presented for acknowledging the hidden and/or overlooked presence of dance in social scientific theory and cultural studies and how these can enhance and advance cultural criminological research. Examples of how these insights have been used within other disciplinary frameworks to analyse and address child sex crime and sexual trauma are provided, and the argument is made that popular cultural texts such as dance in pop music videos should be regarded as significant in analysing and tracing public perceptions and epistemologies of crimes such as child sex abuse

    Quantum Scattering in Two Black Hole Moduli Space

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    We discuss the quantum scattering process in the moduli space consisting of two maximally charged dilaton black holes. The black hole moduli space geometry has different structures for arbitrary dimensions and various values of dilaton coupling. We study the quantum effects of the different moduli space geometries with scattering process. Then, it is found that there is a resonance state on certain moduli spaces.Comment: 15 pages, 19 figures, RevTeX 3.

    Documentary criminology: Girl Model as a case study

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    Visual and cultural criminology are integrated with documentary filmmaking to develop a theoretically grounded, practice-based approach called ‘documentary criminology’. The first section establishes the need for documentary filmmaking in criminology and outlines methodological opportunities. The second section examines theoretically the aesthetics and substance of documentary criminology. The third section takes the film Girl Model (Redmon and Sabin, 2011) as a case study to demonstrate how documentary criminology embedded in lived experience (in this case, the experience of scouts that recruit young Russian girls, purportedly for the modelling industry) can depict sensuous immediacy. The final section contrasts the aesthetic and ethical consequences of documentary criminology within Carrabine’s (2012, 2014) concept of ‘just’ images to a documentary filmmaking approach that remains interpretively open-ended. Readers can access Girl Model at https://vimeo.com/29694894 with the password industry

    Frequency Dependent Viscosity Near the Critical Point: The Scale to Two Loop Order

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    The recent accurate measurements of Berg, Moldover and Zimmerli of the viscoelastic effect near the critical point of xenon has shown that the scale factor involved in the frequency scaling is about twice the scale factor obtained theoretically. We show that this discrepancy is a consequence of using first order perturbation theory. Including two loop contribution goes a long way towards removing the discrepancy.Comment: No of pages:7,Submitted to PR-E(Rapid Communication),No of EPS files:

    Quantization of maximally-charged slowly-moving black holes

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    We discuss the quantization of a system of slowly-moving extreme Reissner-Nordstrom black holes. In the near-horizon limit, this system has been shown to possess an SL(2,R) conformal symmetry. However, the Hamiltonian appears to have no well-defined ground state. This problem can be circumvented by a redefinition of the Hamiltonian due to de Alfaro, Fubini and Furlan (DFF). We apply the Faddeev-Popov quantization procedure to show that the Hamiltonian with no ground state corresponds to a gauge in which there is an obstruction at the singularities of moduli space requiring a modification of the quantization rules. The redefinition of the Hamiltonian a la DFF corresponds to a different choice of gauge. The latter is a good gauge leading to standard quantization rules. Thus, the DFF trick is a consequence of a standard gauge-fixing procedure in the case of black hole scattering.Comment: Corrected errors in the gauge-fixing procedur
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