Investigation of the Viscoelastic Effect on Optical- Fiber Sensing and Its Solution for 3D-Printed Sensor Packages

Viscoelasticity is an effect seen in a wide range of materials and it affects the reliability of static measurements made using Fiber Bragg Grating-based sensors, because either the target structure, the adhesive used, or the fiber itself could be viscoelastic. The effect of viscoelasticity on FBG-based sensing has been comprehensively researched through theoretical analysis and simulation using a finite-element approach and a further data processing method to reconstruct the graphical data has been developed. An integrated sensor package comprising of an FBG-based sensor in a polymer host and manufactured by using three-dimensional printing was investigated and examined through tensile testing to validate the approach. The application of the 3D-printed FBG-based sensor package, coupled to the data process method has been explored to monitor the height of a railway pantograph, a critical measurement requirement to monitor elongation, employing a method that can be used in the presence of electromagnetic interference. The results show that the effect of viscoelasticity can be effectively eliminated, and the graphical system response allows results that are sufficiently precise for field use to be generated

Liquid-like thermal conduction in a crystalline solid

A solid conducts heat through both transverse and longitudinal acoustic phonons, but a liquid employs only longitudinal vibrations. Here, we report that the crystalline solid AgCrSe2 has liquid-like thermal conduction. In this compound, Ag atoms exhibit a dynamic duality that they are exclusively involved in intense low-lying transverse acoustic phonons while they also undergo local fluctuations inherent in an order-to-disorder transition occurring at 450 K. As a consequence of this extreme disorder-phonon coupling, transverse acoustic phonons become damped as approaching the transition temperature, above which they are not defined anymore because their lifetime is shorter than the relaxation time of local fluctuations. Nevertheless, the damped longitudinal acoustic phonon survives for thermal transport. This microscopic insight might reshape the fundamental idea on thermal transport properties of matter and facilitates the optimization of thermoelectrics.Comment: four figures, supplemental informatio

Prospects for Higgs Searches via VBF at the LHC with the ATLAS Detector

We report on the potential for the discovery of a Standard Model Higgs boson with the vector boson fusion mechanism in the mass range 115 with the ATLAS experiment at the LHC. Feasibility studies at hadron level followed by a fast detector simulation have been performed for H\to W^{(*)}W^{(*)}\to l^+l^-\sla{p_T}, $H\to\gamma\gamma$ and $H\to ZZ\to l^+l^-q\bar{q}$. The results obtained show a large discovery potential in the range 115. Results obtained with multivariate techniques are reported for a number of channels.Comment: 14 pages, 4 figures, contributed to 2003 Les Houches Workshop on Physics at TeV Colliders. Incorporated comments from ATLAS referee

Accurate DOA Estimation for Large-Scale Uniform Circular Array Using a Single Snapshot

© 1997-2012 IEEE. A large-scale antenna array is an enabling technique for millimeter-wave communications. Uniform circular arrays (UCAs) have the spatial invariance property, ensuring the same beamforming performance in the whole angular region. However, the direction-of-arrival (DOA) estimation in UCAs is challenging since the array response of a UCA does not conform to a Vandermonde structure as that of a uniform linear array. This letter proposes an accurate and low-complexity DOA estimation approach by exploiting the good correlation property of the array response of the UCA. The DOA estimates are first obtained from a circular convolution between a single snapshot and the designed coefficient vector. Then, by searching for the best initial phase of the coefficient vector, the DOA estimates can be refined to a configurable accuracy. The simulation results demonstrate that the proposed approach outperforms the state of the art by orders of magnitude in estimation accuracy

Episodic future thinking in generalized anxiety disorder

Research on future-oriented cognition in generalized anxiety disorder (GAD) has primarily focused on worry, while less is known about the role of episodic future thinking (EFT), an imagery-based cognitive process. To characterize EFT in this disorder, we used the experimental recombination procedure, in which 21 GAD and 19 healthy participants simulated positive, neutral and negative novel future events either once or repeatedly, and rated their phenomenological experience of EFT. Results showed that healthy controls spontaneously generated more detailed EFT over repeated simulations. Both groups found EFT easier to generate after repeated simulations, except when GAD participants simulated positive events. They also perceived higher plausibility of negative-not positive or neutral-future events than did controls. These results demonstrate a negativity bias in GAD individuals' episodic future cognition, and suggest their relative deficit in generating vivid EFT. We discuss implications for the theory and treatment of GAD.R01 MH060941 - NIMH NIH HHS; R01 MH078308 - NIMH NIH HHS; R01AG08441 - NIA NIH HHS; R01 AT007257 - NCCIH NIH HHS; R01MH60941 - NIMH NIH HHS; R01 AG008441 - NIA NIH HHS; R34 MH099311 - NIMH NIH HHS; R21MH102646 - NIMH NIH HHS; R01AT007257 - NCCIH NIH HHS; R21 MH102646 - NIMH NIH HHS; R34MH078308 - NIMH NIH HH