4,456 research outputs found

    Federal Judges and Presidential Power: Truman to Reagan

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    While there is a considerable literature consisting of commentaries on the substance of federal court decisions about presidential power, there has been little quantitative investigation of political factors influencing judicial decision-making in those cases. Analyzing the votes cast by judges at all levels of the federal judiciary during the post-World War II era, this study examines several conventional expectations about the impact of such political factors as political party affiliation and presidential appointment, the difference between the foreign and military affairs and domestic policy areas, length of judicial tenure, and judges\u27 possession of prior legislative or executive experience

    Phenyl Chlorocarbonate and Substitution Products as Acylating Agents

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    Hinsberg and Udranszky (1) converted 2-aminophenol into the 0- ·benzoyl-N-benzoyl derivative by means of the Schotten-Baumann (2) reaction. Raiford and Inman (3) prepared a number of N-carboaryloxy derivatives of 2-aminophenol by following the method of Groenvik (4) who used ethyl chlorocarbonate as the only reagent. When these compounds were mixed with caustic alkali solution for the purpose of acylating them (2) they were converted into the corresponding benzoxazolones while the required phenols were eliminated. It was further shown that warming 2-N-carboaryloxyaminophenol with pyridine and with acetic anhydride, respectively, caused ring closure, and that in the latter instance there was formed Nacetylbenzoxazolone, previously prepared in a different way by Kalckhoff (5). This tendency toward ring formation is so great that when 2-benzoylaminophenol, in caustic alkali or pyridine solution, is treated with phenyl chlorocarbonate phenol is liberated and N-benzoylbenzoxazolone is obtained in yields as high as 85%. No diacyl derivatives of 2-aminophenol were obtained by this method

    Atlantic menhaden, Brevoortia tyrannus, Purse Seine Fishery, 1972-84, with a brief discussion of age and size composition of the Landings

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    This report summarizes (I) annual purse seine landings of Atlantic menhaden, Brevoortia tyrannus, for 1972-84, (2) estimated numbers of fish caught by fishing area. (3) estimates of nominal fishing effort and catch-per-unit-effort, (4) mean fish length and weight, and (5) major changes in the fishery. During the 1970s stock size and recruitment increased and the age composition broadened. reversing trends witnessed during the fishery's decline in the 1960s. Landings steadily improved and by 1980 the total coast wide landings exceeded 400,000 metric tons. Nevertheless, the character of the fishery changed considerably. Eleven reduction plants processed fish at seven ports in 1972, but in 1984 only eight plants operated at live ports. Beginning in the mid-1960s the center of fishing aclivity shifted from the Middle Atlantic area to the Chesapeake Bay area, which has continued to dominate the fishery in landings and effort through the 1970s and 1980s. During this period the average size and age of fish in the catches declined. (PDF file contains 30 pages.

    Potential flow theory and operation guide for the panel code PMARC

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    The theoretical basis for PMARC, a low-order potential-flow panel code for modeling complex three-dimensional geometries, is outlined. Several of the advanced features currently included in the code, such as internal flow modeling, a simple jet model, and a time-stepping wake model, are discussed in some detail. The code is written using adjustable size arrays so that it can be easily redimensioned for the size problem being solved and the computer hardware being used. An overview of the program input is presented, with a detailed description of the input available in the appendices. Finally, PMARC results for a generic wing/body configuration are compared with experimental data to demonstrate the accuracy of the code. The input file for this test case is given in the appendices

    Fundamental noise limitations to supercontinuum generation in microstructure fiber

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    Broadband noise on supercontinuum spectra generated in microstructure fiber is shown to lead to amplitude fluctuations as large as 50 % for certain input laser pulse parameters. We study this noise using both experimental measurements and numerical simulations with a generalized stochastic nonlinear Schroedinger equation, finding good quantitative agreement over a range of input pulse energies and chirp values. This noise is shown to arise from nonlinear amplification of two quantum noise inputs: the input pulse shot noise and the spontaneous Raman scattering down the fiber.Comment: 16 pages with 6 figure

    Re-Engineering the ISS Payload Operations Control Center During Increased Utilization and Critical Onboard Events

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    With an increase in utilization and hours of payload operations being executed onboard the International Space Station (ISS), upgrading the NASA Marshall Space Flight Center (MSFC) Huntsville Operations Support Center (HOSC) ISS Payload Control Area (PCA) was essential to gaining efficiencies and assurance of current and future payload health and science return. PCA houses the Payload Operations Integration Center (POIC) responsible for the execution of all NASA payloads onboard the ISS. POIC Flight Controllers are responsible for the operation of voice, stowage, command, telemetry, video, power, thermal, and environmental control in support of ISS science experiments. The methodologies and execution of the PCA refurbishment were planned and performed within a four-month period in order to assure uninterrupted operation of ISS payloads and minimal impacts to payload operations teams. To vacate the PCA, three additional HOSC control rooms were reconfigured to handle ISS real-time operations, Backup Control Center (BCC) to Mission Control in Houston, simulations, and testing functions. This involved coordination and cooperation from teams of ISS operations controllers, multiple engineering and design disciplines, management, and construction companies performing an array of activities simultaneously and in sync delivering a final product with no issues that impacted the schedule. For each console operator discipline, studies of Information Technology (IT) tools and equipment layouts, ergonomics, and lines of sight were performed. Infusing some of the latest IT into the project was an essential goal in ensuring future growth and success of the ISS payload science returns. Engineering evaluations led to a state of the art Video Wall implementation and more efficient ethernet cabling distribution providing the latest products and the best solution for the POIC. These engineering innovations led to cost savings for the project. Constraints involved in the management of the project included executing over 450 crew-hours of ISS real-time payload operations including a major onboard communications upgrade, SpaceX un-berth, a Soyuz launch, roll-out of ISS live video and interviews from the POIC, annual BCC certification and hurricane season, and ISS simulations and testing. Continuous ISS payload operations were possible during the PCA facility modifications with the reconfiguration of four control rooms and standup of two temporary control areas. Another major restriction to the project was an ongoing facility upgrade that included a NASA Headquarters mandated replacement of all electrical and mechanical systems and replacement of an external generator. These upgrades required a facility power outage during the PCA upgrades. The project also encompassed console layout designs and ordering, amenities selections and ordering, excessing of old equipment, moves, disposal of old IT equipment, camera installations, facility tour re-schedules, and contract justifications. These were just some of the tasks needed for a successful project. This paper describes the logistics and lessons learned in upgrading a control center capability in the middle of complex real-time operations. Combining the efficiencies of controller interaction and new technology infusion were prime drivers for this upgrade to handle the increased utilization of science research on ISS. The success of this project could not jeopardize the current operations while these facility upgrades occurred

    A Multi-Sims Investigation of Water Content and D/H Ratios in Roberts Massif 04262 with Insight to Sources of Hydrogen in Maskelynite

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    We want to define the H2O content ([H2O]) and hydrogen (H) isotope composition of meteoritic material from Mars [1-3] with motivation to understand Mars volatile history, constrain geochemical signatures of interior water reservoirs (i.e. the Martian mantle) and explore effects of planetary (e.g. planet formation, magma ocean degassing) and local (e.g. volcanic degassing, impact melting and degassing) processes on H incorporated in minerals. Secondary ion mass spectrometry (SIMS) allows multiple avenues to address these questions. However, application to (1) precious astromaterials and (2) low level H measurements, pose specific challenges that are further complicated when combined. We present preliminary data of a multi-approach (SIMS vs. NanoSIMS) study of H in Roberts Massif 04262 (RBT 04262), an enriched lherzolitic shergottite with nonpoikilitic (NP) and poikilitic (P) lithologies [4]. We analyze olivine, pyrox-ene, and melt inclusions to compare indigenous mantle water, with impact-generated maskelynite to investigate H signatures due to shock

    Chalcogenide-glass polarization-maintaining photonic crystal fiber for mid-infrared supercontinuum generation

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    In this paper, we report the design and fabrication of a highly birefringent polarization-maintaining photonic crystal fiber (PM-PCF) made from chalcogenide glass, and its application to linearly-polarized supercontinuum (SC) generation in the mid-infrared region. The PM fiber was drawn using the casting method from As38Se62 glass which features a transmission window from 2 to 10 μm\mu m and a high nonlinear index of 1.13.10−17^{-17}m2^{2}W−1^{-1}. It has a zero-dispersion wavelength around 4.5 μm\mu m and, at this wavelength, a large birefringence of 6.10−4^{-4} and consequently strong polarization maintaining properties are expected. Using this fiber, we experimentally demonstrate supercontinuum generation spanning from 3.1-6.02 μm\mu m and 3.33-5.78 μm\mu m using femtosecond pumping at 4 μm\mu m and 4.53 μm\mu m, respectively. We further investigate the supercontinuum bandwidth versus the input pump polarization angle and we show very good agreement with numerical simulations of the two-polarization model based on two coupled generalized nonlinear Schr\"odinger equations.Comment: 13 pages, 8 figure

    Hydrogen Isotope Fractionation During Impact Degassing of Pyroxene and Maskelynite in Shergottite Larkman Nunatak 06319

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    Hydrogen in nominally anhydrous minerals (NAMs) in meteorites provides insight to mantle sources of indigenous water on differentiated bodies: e.g. Peslier et al. 2017 [1], including Mars [2-4]. However, all meteorite samples, including Martian shergottites, record impact events as fractures, deformation, silicate darkening, shock melt veins and pockets, etc. The effect of shock on hydrogen in NAMs is poorly constrained, and must be understood prior to using these data to infer planetary indigenous water. Here we present water contents and D/H ratios (calculated as dD, i.e. the variation of the D/H ratio relative to a standard, in this case sea water "SMOW") in pyroxene, olivine and maskelynite in the olivine-phyric shergottite Larkman Nunatak 06319 (LAR 06319) as a function of proximity to impact melt. While the results suggest impact may have a role in fractionating H isotopes, the magmatic signature of H2O in Mars can be preserved in some pyroxene
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