2,584 research outputs found

    Finite element structural model of a large, thin, completely free, flat plate

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    A finite element structural model of a 30.48 m x 30.48 m x 2.54 mm completely free aluminum plate is described and modal frequencies and mode shape data for the first 44 modes are presented. An explanation of the procedure for using the data is also presented. The model should prove useful for the investigation of controller design approaches for large flexible space structures

    Using psychoeducation and role induction to improve completion rates in cognitive behavioural therapy

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    Background: Pre-treatment role induction interventions have been suggested to potentially enhance attendance and clinical outcomes in psychotherapy. Aims: This study aimed to evaluate the effects of a programme of 3 transdiagnostic seminars (TDS) for patients with common mental disorders accessing CBT in primary care. TDS included CBT psychoeducation and role induction. Methods: A random sample of patients (N = 49) participated in TDS followed by CBT (TDS+CBT) and they were compared to matched controls (N = 49) accessing usual CBT. TDS participants rated the relevance and quality of this intervention using an acceptability questionnaire (AQ). Treatment completion (vs. dropout) rates were compared across groups using chi-square tests. Post-treatment changes in depression (PHQ-9) and anxiety (GAD-7) symptoms were compared between groups using analysis of covariance controlling for potential confounders. Analyses were based on intention-to-treat principles. Results: Mean AQ ratings of the TDS intervention were comparable across diagnostic groups (p = .05). Treatment completion rates were significantly higher (p = .02) in the TDS+CBT group (87.8%) by comparison to usual CBT (68.8%). However, no significant differences in post-treatment symptom changes were found for depression (p = .34) or anxiety measures (p = .71). Conclusions: Incorporating a psychoeducational role induction prior to CBT significantly improved treatment retention, but not overall symptom reductions

    Electromagnetic mirror drive system

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    Oscillatory electromagnetic mirror drive system for horizon scanner

    Analysis and simulation of a magnetic bearing suspension system for a laboratory model annular momentum control device

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    A linear analysis and the results of a nonlinear simulation of a magnetic bearing suspension system which uses permanent magnet flux biasing are presented. The magnetic bearing suspension is part of a 4068 N-m-s (3000 lb-ft-sec) laboratory model annular momentum control device (AMCD). The simulation includes rigid body rim dynamics, linear and nonlinear axial actuators, linear radial actuators, axial and radial rim warp, and power supply and power driver current limits

    Transforming a Corner of a Light-Frame Wood Structure to a Set of Nonlinear Springs

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    The computational efficiency of a full-structure model for a light-frame building is enhanced by replacing the continuum of the detailed connections with rotational and translational nonlinear springs that are energetically equivalent between two bounds. This study examines the transformation from the physical exterior-wall-to-exterior-wall connection (a corner) of a light-frame wood structure, first, to a two-dimensional finite-element model and, then, to a set of nonlinear springs. Typical light-frame details are used as the starting point, and the product is the characteristic moment-rotation and load-displacement relationships for a 24-inch segment of the corner

    GaAs-based Self-Aligned Stripe Superluminescent Diodes Processed Normal to the Cleaved Facet

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    We demonstrate GaAs-based superluminescent diodes (SLDs) incorporating a window-like back facet in a self-aligned stripe. SLDs are realised with low spectral modulation depth (SMD) at high power spectral density, without application of anti-reflection coatings. Such application of a window-like facet reduces effective facet reflectivity in a broadband manner. We demonstrate 30mW output power in a narrow bandwidth with only 5% SMD, outline the design criteria for high power and low SMD, and describe the deviation from a linear dependence of SMD on output power as a result of Joule heating in SLDs under continuous wave current injection. Furthermore, SLDs processed normal to the facet demonstrate output powers as high as 20mW, offering improvements in beam quality, ease of packaging and use of real estate. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

    Trace anomalies and the ΔI=1/2\Delta I = 1/2 rule

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    Trace Anomaly Dominance in weak KK-decays successfully reproduces the ΔI=12\Delta I = {1\over 2} selection rule results, as observed in KS→ππ,KL→πππ,KS→γγK_S \to \pi\pi, K_L \to \pi\pi\pi, K_S \to \gamma\gamma and KL→π0γγK_L \to \pi^0 \gamma\gamma.Comment: 10 pages, no figur

    Astrophysical Neutrino Event Rates and Sensitivity for Neutrino Telescopes

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    Spectacular processes in astrophysical sites produce high-energy cosmic rays which are further accelerated by Fermi-shocks into a power-law spectrum. These, in passing through radiation fields and matter, produce neutrinos. Neutrino telescopes are designed with large detection volumes to observe such astrophysical sources. A large volume is necessary because the fluxes and cross-sections are small. We estimate various telescopes' sensitivities and expected event rates from astrophysical sources of high-energy neutrinos. We find that an ideal detector of km^2 incident area can be sensitive to a flux of neutrinos integrated over energy from 10^5 and 10^{7} GeV as low as 1.3 * 10^(-8) * E^(-2) (GeV/cm^2 s sr) which is three times smaller than the Waxman-Bachall conservative upper limit on potential neutrino flux. A real detector will have degraded performance. Detection from known point sources is possible but unlikely unless there is prior knowledge of the source location and neutrino arrival time.Comment: Section added +modification

    ν−K0\nu - K^0 Analogy, Dirac-Majorana Neutrino Duality and the Neutrino Oscillations

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    The intent of this paper is to convey a new primary physical idea of a Dirac-Majorana neutrino duality in relation to the topical problem of neutrino oscillations. In view of the new atmospheric, solar and the LSND neutrino oscillation data, the Pontecorvo ν−K0\nu - K^0 oscillation analogy is generalized to the notion of neutrino duality with substantially different physical meaning ascribed to the long-baseline and the short-baseline neutrino oscillations. At the level of CP-invariance, the suggestion of dual neutrino properties defines the symmetric two-mixing-angle form of the widely discussed four-neutrino (2+2)(2+2)-mixing scheme, as a result of the lepton charge conservation selection rule and a minimum of two Dirac neutrino fields. With neutrino duality, the two-doublet structure of the Majorana neutrino mass spectrum is a vestige of the two-Dirac-neutrino origin. The fine neutrino mass doublet structure is natural because it is produced by a lepton charge symmetry violating perturbation on a zero-approximation system of two twofold mass-degenerate Dirac neutrino-antineutrino pairs. A set of inferences related to the neutrino oscillation phenomenology in vacuum is considered.Comment: 13 pages, LaTeX. Minor modifications, new references adde
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