3,832 research outputs found

    Monitoring solar-type stars

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    Old UBV and recent uvby photometry of solar-type dwarfs and other standard stars yield an upper limit of variability (determined by observational errors) of about 0.004 mag rms. A factor two improvement in this upper limit is achievable

    Monitoring solar-type stars for luminosity variations

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    Since 1984, researchers have made more than 1500 differential photometric b (471 nm) and y (551 nm) measurements of three dozen solar-like lower main sequence stars whose chromospheric activity was previosly studied by O. C. Wilson. Here, researchers describe their methodology and the statistical tests used to distinguish intrinsic stellar variability from observational and instrument errors. The incidence of detected variability among the program and comparison stars is summarized. Among the 100 plus pairs of stars measured differentially, only a dozen were found that were unusually constant, with peak-to-peak amplitudes of seasonal mean brightness smaller than 0.3 percent (0.003 mag) over a two-to-three-year interval

    The cosmic ray interplanetary radial gradient from 1972 - 1985

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    It is now established that the solar modulation of cosmic rays is produced by turbulent magnetic fields propagated outward by the solar wind. Changes in cosmic ray intensity are not simultaneous throughout the modulation region, thus requiring time dependent theories for the cosmic ray modulation. Fundamental to an overall understanding of this observed time dependent cosmic ray modulation is the behavior of the radial intensity gradient with time and heliocentric distance over the course of a solar modulation cycle. The period from 1977 to 1985 when data are available from the cosmic ray telescopes on Pioneer (P) 10, Voyager (V) 1 and 2, and IMP 8 spacecraft is studied. Additional data from P10 and other IMP satellites for 1972 to 1977 can be used to determine the gradient at the minimum in the solar modulation cycle and as a function of heliocentric distance. All of these telescopes have thresholds for protons and helium nuclei of E 60 MeV/nucleon

    Patient safety and quality improvement: Iatrogenic venous air embolism in diagnostic imaging

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    The Medicines and Healthcare products Regulatory Agency (MHRA), the executive agency for the Department of Health (DoH) in England, ensures medicines and medical devices work and are safe. An incidence of fatal arterial embolism (AE) was reported, in which air was inadvertently injected into a patient rather than contrast media during a Computer Tomography (CT) examination with a contrast power injector pump. Instigating the issuing of safety notification MDA_SN_96261 however this was withdrawn with the implication being that the equipment is safe and the incidence was human error

    Sometime : I\u27ll Hear Your Sweet Voice Calling

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    https://digitalcommons.library.umaine.edu/mmb-vp/5425/thumbnail.jp

    Ground effects related to landing of airplanes with low-aspect-ratio wings

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    Influence of ground induced aerodynamic effects on landing maneuver of aircraft with low aspect ratio wing

    Field Programmable Port Extender (FPX) User Guide (Version 2.2)

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    This manual summarizes how to insert the Field Programmable Port Extender (FPX) into the Washington University Gigabit Switch (WUGS), how to install the NCHARGE control software, how to initialize the system, and how to reprogram a user-defined module into the FPX over the network using the included web-based tools

    The intensity recovery of Forbush-type decreases as a function of heliocentric distance and its relationship to the 11-year variation

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    Recent data indicating that the solar modulation effects are propagated outward in the heliospheric cavity suggest that the 11-year cosmic ray modulation can best be described by a dynamic time dependent model. In this context an understanding of the recovery characteristics of large transient Forbush type decreases is important. This includes the typical recovery time at a fixed energy at 1 AU as well as at large heliocentric radial distances, the energy dependence of the recovery time at 1 Au, and the dependence of the time for the intensity to decrease to the minimum in the transient decreases as a function of distance. These transient decreases are characterized by their asymmetrical decrease and recovery times, generally 1 to 2 days and 3 to 10 days respectively at approx. 1 AU. Near earth these are referred to as Forbush decreases, associated witha shock or blast wave passage. At R equal to or greater than + or - 10 AU, these transient decreases may represent the combined effects of several shock waves that have merged together

    The FPX KCPSM Module: An Embedded, Reconfigurable Active Processing Module for the Field Programmable Port Extender (FPX)

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    While hardware plugins are well suited for processing data with high throughput, software plugins are well suited for implementing complex control functions. A plugin module has been implemented for the FPX that executes software on an embedded soft-core processor. By including this module in an FPX design, it is possible to implement active networking functions on the FPX using both hardware and software. The KCPSM, an 8-bit microcontroller developed by Xilinx Corp., has been embedded into an FPX module. The module includes circuits to be reprogrammed over the network and to execute new programs between the processing of data packerts. A sample application, called the FPX KXPSM Module has been developed that illustrates how easily an application can make use of the hybrid system. This module loads the program memory of the KCPSM from an incoming UDP packet, and executes the new program upon receiving a new incoming UDP packet. The resulting circuit runs at 70MHz and occupies 35% on a Xilinx XCV1000E-7-FG680
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