The detection of ultrasound using fiber-optic sensors

Ultrasound is a valuable tool for the detection of damage in structures and the characterization of material properties. Its detection is conventionally done by piezoelectric transducers, however fiber-optic sensors can operate over a greater range of frequencies and also yield information on the direction of wave propagation. The interaction between fiber sensors and ultrasound both demonstrates the integrating features of intrinsic fiber-optic sensors and presents new opportunities in ultrasonic detection, offering enormous diversity in polar and frequency response. This paper summarizes the interaction mechanisms between ultrasound and fiber sensors and confirms their functional flexibility. We use these results to demonstrate the practical use of these sensors to detect and locate damage in a sample

Renal function, revascularization and risk

Peer reviewedAuthor versio

Modeling Collaboration in Academia: A Game Theoretic Approach

In this work, we aim to understand the mechanisms driving academic collaboration. We begin by building a model for how researchers split their effort between multiple papers, and how collaboration affects the number of citations a paper receives, supported by observations from a large real-world publication and citation dataset, which we call the h-Reinvestment model. Using tools from the field of Game Theory, we study researchers' collaborative behavior over time under this model, with the premise that each researcher wants to maximize his or her academic success. We find analytically that there is a strong incentive to collaborate rather than work in isolation, and that studying collaborative behavior through a game-theoretic lens is a promising approach to help us better understand the nature and dynamics of academic collaboration.Comment: Presented at the 1st WWW Workshop on Big Scholarly Data (2014). 6 pages, 5 figure

Hubble Space Telescope Constraints on the Winds and Astrospheres of Red Giant Stars

We report on an ultraviolet spectroscopic survey of red giants observed by the Hubble Space Telescope, focusing on spectra of the Mg II h & k lines near 2800 A in order to study stellar chromospheric emission, winds, and astrospheric absorption. We focus on spectral types between K2 III and M5 III, a spectral type range with stars that are noncoronal, but possessing strong, chromospheric winds. We find a very tight relation between Mg II surface flux and photospheric temperature, supporting the notion that all K2-M5 III stars are emitting at a basal flux level. Wind velocities (V_w) are generally found to decrease with spectral type, with V_w decreasing from ~40 km/s at K2 III to ~20 km/s at M5 III. We find two new detections of astrospheric absorption, for Sigma Pup (K5 III) and Gamma Eri (M1 III). This absorption signature had previously only been detected for Alpha Tau (K5 III). For the three astrospheric detections the temperature of the wind after the termination shock correlates with V_w, but is lower than predicted by the Rankine-Hugoniot shock jump conditions, consistent with the idea that red giant termination shocks are radiative shocks rather than simple hydrodynamic shocks. A full hydrodynamic simulation of the Gamma Eri astrosphere is provided to explore this further.Comment: 16 pages, 8 figures, to appear in The Astrophysical Journa

A Stroll Down the Dark Side: Ultraviolent Japanese Animation’s Roots in Postwar Japan, Globalization, and Western Consumption

Study of the root causes of the creation of dark and violent Japanese animation and the phenomena of American consumption of it