Broadband laser polarization control with aligned carbon nanotubes

We introduce a simple approach to fabricate aligned carbon nanotube (ACNT) device for broadband polarization control in fiber laser systems. The ACNT device was fabricated by pulling from as-fabricated vertically-aligned carbon nanotube arrays. Their anisotropic property is confirmed with optical and scanning electron microscopy, and with polarized Raman and absorption spectroscopy. The device was then integrated into fiber laser systems (at two technologically important wavelengths of 1 and 1.5 um) for polarization control. We obtained a linearly-polarized light output with the maximum extinction ratio of ~12 dB. The output polarization direction could be fully controlled by the ACNT alignment direction in both lasers. To the best of our knowledge, this is the first time that ACNT device is applied to polarization control in laser systems. Our results exhibit that the ACNT device is a simple, low-cost, and broadband polarizer to control laser polarization dynamics, for various photonic applications (such as material processing, polarization diversity detection in communications), where the linear polarization control is necessary.Comment: 5 pages, 6 figure

Often Taking Peppers Change Body Constitution to Allergic Constitution

Pepper (chili or hot pepper) is one important plant for homology of food and medicine. At present, 1/4 people world worldwide are often taking peppers, also1/4 people world worldwide have allergic constitution. We observed many people who have allergic constitution are often taking peppers in the clinical. However, relation between often taking peppers and allergic constitution are unclear. In the present study, we examined the effects of peppers on immune system in rabbit that was administrated by peppers by means of intragastric administration q.d. for 3 months. Administration of peppers significantly increased contents of interleukin2(IL-2), IL-5, IL-16 , leukotriene D4(LTD4) , malonaldehyde (MDA) , bile acid (BA) and immune cells, especially eosinophile granulocyte (EO) and lymphocyte (LY) , significantly decreased activities of superoxide dismutase(SOD), in the serum of rabbits (respectively, P &lt;0.05 or P &lt;0.01 ). Our results indicate that often taking peppers could change body constitution to allergi constitution through induce individual immune dysfunction such as enhancement of IL-2, IL-5 , IL-16 , LTD4 ,BA ,EO and LY in the serum, increased free radicals; and suggest that regular consumption of peppers can become an independent cause of allergic constitution and has harmful actions to health.</p

Building a Virtual Weakly-Compressible Wind Tunnel Testing Facility

International audienceVirtual wind tunnel testing is a key ingredient in the engineering design process for the automotive and aeronautical industries as well as for urban planning: through visualization and analysis of the simulation data, it helps optimize lift and drag coefficients, increase peak speed, detect high pressure zones, and reduce wind noise at low cost prior to manufacturing. In this paper, we develop an efficient and accurate virtual wind tunnel system based on recent contributions from both computer graphics and computational fluid dynamics in high-performance kinetic solvers. Running on one or multiple GPUs, our massively-parallel lattice Boltzmann model meets industry standards for accuracy and consistency while exceeding current mainstream industrial solutions in terms of efficiency --- especially for unsteady turbulent flow simulation at very high Reynolds number (on the order of 10^7 ) --- due to key contributions in improved collision modeling and boundary treatment, automatic construction of multiresolution grids for complex models, as well as performance optimization. We demonstrate the efficacy and reliability of our virtual wind tunnel testing facility through comparisons of our results to multiple benchmark tests, showing an increase in both accuracy and efficiency compared to state-of-the-art industrial solutions. We also illustrate the fine turbulence structures that our system can capture, indicating the relevance of our solver for both VFX and industrial product design