5,825 research outputs found

    Aggregation of metallochlorophylls - Examination by spectroscopy

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    Nuclear magnetic resonance measurements determine which metallochlorophylls, besides magnesium-containing chlorophylls, possess coordination aggregation properties. Infrared spectroscopy reveals that only zinc pheophytin and zinc methyl pheophorbide showed significant coordination aggregation, whereas divalent nickel and copper did not

    LAND MARKET LIBERALIZATION AND WEALTH DIFFERENTIATED LAND ACCESS: PANEL EVIDENCE FROM HONDURAS AND PERU

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    We evaluate the impact of agricultural land market liberalization policies in Latin America by empirically examining the degree to which the reforms have broken down the dependence of operational area on owned area. We use panel data sets from Honduras and Peru to estimate the relationship between operational and owned land holdings for pre and post reform periods.Land Economics/Use,

    Alien Registration- Boucher, Mary L. (Lewiston, Androscoggin County)

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    https://digitalmaine.com/alien_docs/30568/thumbnail.jp

    Absence of classical and quantum mixing

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    It is shown, under mild assumptions, that classical degrees of freedom dynamically coupled to quantum ones do not inherit their quantum fluctuations. It is further shown that, if the assumptions are strengthen by imposing the existence of a canonical structure, only purely classical or purely quantum dynamics are allowed.Comment: REVTeX, 4 page

    Mechanically Induced g-Jitter from Space Station Rotary Joints

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    The mission of the International Space Station is to provide a working laboratory in orbit for research in engineering, life sciences, and microgravity. Among the microgravity disciplines that are preparing to utilize this international resource are materials processing, combustion, fluid dynamics, biotechnology, and fundamental physics. The Station promises to enable significant advances in each of these areas by making available a research facility in which gravitational and other accelerations, and their corresponding buoyancy and diffusion effects on various physical processes, are orders of magnitude lower than they are on Earth. In order to fulfill this promise, it is not enough for the Space Station to simply replicate a typical terrestrial scientific laboratory in orbit. Although an orbiting laboratory is free of most of the effects of gravitational acceleration by virtue of its free fall condition, it also produces structural vibration or jitter that can interfere with the processes under study. To ensure the quality of the acceleration environment and enable a successful mission, the Space Station Program has limited potential disturbances in two ways: first, by isolating the most sensitive payloads from the vehicle structure, and second, by quieting major disturbances at their sources. The first area, payload isolation, is implemented inside the pressurized modules at the rack level. Sub-rack level isolators have also been developed. This paper addresses the second area, disturbance source limits, for one of the major sources of mechanical noise on the Space Station: the Solar Alpha Rotary Joints. Due to the potential for large disturbances to the microgravity environment, an initial analytical prediction of rotary joint vibration output was made. Key components were identified and tested to validate the analytical predictions. Based on the component test results, the final vibration output of the joints was verified by a test on each fully assembled flight unit. This paper describes the Space Station microgravity requirements, the rotary joint hardware, and the disturbance producing aspects of joint operation. The test setup, instrumentation, test conditions, and results for the component level and system level measurements are described. An overall forcing function that describes the maximum torque imparted to the Station is created based on the test results, and these disturbances are shown to meet the applicable Space Station microgravity requirements

    A high-speed linear algebra library with automatic parallelism

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    Parallel or distributed processing is key to getting highest performance workstations. However, designing and implementing efficient parallel algorithms is difficult and error-prone. It is even more difficult to write code that is both portable to and efficient on many different computers. Finally, it is harder still to satisfy the above requirements and include the reliability and ease of use required of commercial software intended for use in a production environment. As a result, the application of parallel processing technology to commercial software has been extremely small even though there are numerous computationally demanding programs that would significantly benefit from application of parallel processing. This paper describes DSSLIB, which is a library of subroutines that perform many of the time-consuming computations in engineering and scientific software. DSSLIB combines the high efficiency and speed of parallel computation with a serial programming model that eliminates many undesirable side-effects of typical parallel code. The result is a simple way to incorporate the power of parallel processing into commercial software without compromising maintainability, reliability, or ease of use. This gives significant advantages over less powerful non-parallel entries in the market

    An Overview of Animal Facilitated Therapy

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    An 81 year old woman sat in her wheelchair in front of a window at a nursing home surrounded by her family whom she no longer recognized. She had been in the home for two years, her mental and physical health steadily deteriorating. She spoke a language all her own, no longer could anyone decipher any English or Norwegian from it. The old woman plucked invisible entities from the air and placed them in her lap. The only glimmer of recognition or reality for her was aroused when she was asked about her cat, Munse. Grandma, how\u27s Munse? Where\u27s Munse, Grandma? The only understandable words she speaks: Munse? Here kitty. Meeow. She calls for her companion of eight years. A gray stuffed-toy cat is placed in her lap instead, she strokes it once or twice and then falls still and silent. What might it have meant to this elderly woman to have kept her companion with her? Could it have helped her hold on to reality longer, maintained her health and improved the general quality of her life

    Elementary Excitations in Quantum Antiferromagnetic Chains: Dyons, Spinons and Breathers

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    Considering experimental results obtained on three prototype compounds, TMMC, CsCoCl3 (or CsCoBr3) and Cu Benzoate, we discuss the importance of non-linear excitations in the physics of quantum (and classical) antiferromagnetic spin chains.Comment: Invited at the International Symposium on Cooperative Phenomena of Assembled Metal Complexes, November 15-17, 2001, Osaka, Japa
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