16,415 research outputs found

    Evaluation of aerothermal modeling computer programs

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    Various computer programs based upon the SIMPLE or SIMPLER algorithm were studied and compared for numerical accuracy, efficiency, and grid dependency. Four two-dimensional and one three-dimensional code originally developed by a number of research groups were considered. In general, the accuracy and computational efficieny of these TEACH type programs were improved by modifying the differencing schemes and their solvers. A brief description of each program is given. Error reduction, spline flux and second upwind differencing programs are covered

    The Taiwan ECDFS Near-Infrared Survey: Ultra-deep J and Ks Imaging in the Extended Chandra Deep Field-South

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    We present ultra-deep J and Ks imaging observations covering a 30' * 30' area of the Extended Chandra Deep Field-South (ECDFS) carried out by our Taiwan ECDFS Near-Infrared Survey (TENIS). The median 5-sigma limiting magnitudes for all detected objects in the ECDFS reach 24.5 and 23.9 mag (AB) for J and Ks, respectively. In the inner 400 arcmin^2 region where the sensitivity is more uniform, objects as faint as 25.6 and 25.0 mag are detected at 5-sigma. So this is by far the deepest J and Ks datasets available for the ECDFS. To combine the TENIS with the Spitzer IRAC data for obtaining better spectral energy distributions of high-redshift objects, we developed a novel deconvolution technique (IRACLEAN) to accurately estimate the IRAC fluxes. IRACLEAN can minimize the effect of blending in the IRAC images caused by the large point-spread functions and reduce the confusion noise. We applied IRACLEAN to the images from the Spitzer IRAC/MUSYC Public Legacy in the ECDFS survey (SIMPLE) and generated a J+Ks selected multi-wavelength catalog including the photometry of both the TENIS near-infrared and the SIMPLE IRAC data. We publicly release the data products derived from this work, including the J and Ks images and the J+Ks selected multiwavelength catalog.Comment: 25 pages, 25 figures, ApJS in pres

    System Design for a Nuclear Electric Spacecraft Utilizing Out-of-core Thermionic Conversion

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    Basic guidelines are presented for a nuclear space power system which utilizes heat pipes to transport thermal power from a fast nuclear reactor to an out of core thermionic converter array. Design parameters are discussed for the nuclear reactor, heat pipes, thermionic converters, shields (neutron and gamma), waste heat rejection systems, and the electrical bus bar-cable system required to transport the high current/low voltage power to the processing equipment. Dimensions are compatible with shuttle payload bay constraints

    Approximating a Federal Patent District Court after \u3ci\u3eTC Heartland\u3c/i\u3e

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    This article presents a patent litigation framework for other federal district courts to follow, using the example of the U.S. District Court for the Eastern District of Texas after TC Heartland. This article also provides an overview of the TC Heartland U.S. Supreme Court case and the In Re Cray Federal Circuit opinion, as well as how those two cases have impacted patent litigation in various district courts across the country, most notably in the District of Delaware. All district courts should learn various lessons from the District Court for the Eastern District of Texas and should model their practices after its approach to handling patent cases going forward

    A Bridge Between Copyright and Patent Law: Towards a Modern-Day Reapplication of the Semiconductor Chip Protection Act

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    This Paper analyzes the history of the Semiconductor Chip Protection Act (SCPA), 17 U.S.C. §§ 901–914, and asks why the statute is so seldom used in intellectual property litigation. Afterwards, this Paper makes the argument that the SCPA should be used more in intellectual property litigation, perhaps in tandem with patent litigation, and can be a viable form of protection for semiconductor micro-fabrication companies or integrated circuit design companies engaged in pioneering innovations within the cutting-edge field of semiconductor technology

    Investigation of nonlinear absorption processes with femtosecond light pulses in lithium niobate crystals

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    The propagation of high-power femtosecond light pulses in lithium niobate crystals (LiNbO3) is investigated experimentally and theoretically in collinear pump-probe transmission experiments. It is found within a wide intensity range that a strong decrease of the pump transmission coefficient at wavelength 388 nm fully complies with the model of two-photon absorption; the corresponding nonlinear absorption coefficient is betap~=3.5 cm/GW. Furthermore, strong pump pulses induce a considerable absorption for the probe at 776 nm. The dependence of the probe transmission coefficient on the time delay Deltat between probe and pump pulses is characterized by a narrow dip (at Deltat~=0) and a long (on the picosecond time scale) lasting plateau. The dip is due to direct two-photon transitions involving pump and probe photons; the corresponding nonlinear absorption coefficient is betar~=0.9 cm/GW. The plateau absorption is caused by the presence of pump-excited charge carriers; the effective absorption cross section at 776 nm is sigmar~=8×10^–18 cm^2. The above nonlinear absorption parameters are not strongly polarization sensitive. No specific manifestations of the relaxation of hot carriers are found for a pulse duration of ~=0.24 ps

    Femtosecond time-resolved absorption processes in lithium niobate crystals

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    emtosecond pump pulses are strongly attenuated in lithium niobate owing to two-photon absorption; the relevant nonlinear coefficient beta_p ranges from ~3.5 cm/GW for lambda_p = 388 nm to ~0.1 cm/GW for 514 nm. In collinear pump-probe experiments the probe transmission at the double pump wavelength 2lambda_p=776 nm is controlled by two different processes: A direct absorption process involving pump and probe photons (beta_r ~ or = 0.9 cm/GW) leads to a pronounced short-duration transmission dip, whereas the probe absorption by pump-excited charge carriers results in a long-duration plateau. Coherent pump-probe interactions are of no importance. Hot-carrier relaxation occurs on the time scale of < or ~0.1 ps
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