60 research outputs found

    Battery-operated Independent Radiation Detector Data Report from Exploration Flight Test 1

    Get PDF
    Citation: Bahadori AA, Semones EJ, Gaza R, Kroupa M, Rios RR, Stoffle NN, Campbell-Ricketts T, Pinsky LS, and Turecek D 2015 Battery-operated Independent Radiation Detector Data Report from Exploration Flight Test 1 NASA/TP-2015-218575 NASA Johnson Space Center: Houston, TX http://ston.jsc.nasa.gov/collections/TRS/397.refer.htmlThis report summarizes the data acquired by the Battery-operated Independent Radiation Detector (BIRD) during Exploration Flight Test 1 (EFT-1). The BIRD, consisting of two redundant subsystems isolated electronically from the Orion Multi-Purpose Crew Vehicle (MPCV), was developed to fly on the Orion EFT-1 to acquire radiation data throughout the mission. The BIRD subsystems successfully triggered using on-board accelerometers in response to launch accelerations, acquired and archived data through landing, and completed the shut down routine when battery voltage decreased to a specified value. The data acquired are important for understanding the radiation environment within the Orion MPCV during transit through the trapped radiation belts

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

    Get PDF
    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Data Processing Engine (DPE): Data Analysis Tool for Particle Tracking and Mixed Radiation Field Characterization with Pixel Detectors Timepix

    Full text link
    Hybrid semiconductor pixelated detectors from the Timepix family are advanced detectors for online particle tracking, offering energy measurement and precise time stamping capabilities for particles of various types and energies. This inherent capability makes them highly suitable for various applications, including imaging, medical fields such as radiotherapy and particle therapy, space-based applications aboard satellites and the International Space Station, and industrial applications. The data generated by these detectors is complex, necessitating the development and deployment of various analytical techniques to extract essential information. For this purpose, and to aid the Timepix user community, it was designed and developed the "Data Processing Engine" (DPE) as an advanced tool for data processing designed explicitly for Timepix detectors. The functionality of the DPE is structured into three distinct processing levels: i) Pre-processing: This phase involves clusterization and the application of necessary calibrations and corrections. ii) Processing: This stage includes particle classification, employing machine learning algorithms, and the recognition of radiation fields. iii) Post-processing: Involves various analyses, such as directional analysis, coincidence analysis, frame analysis, Compton directional analysis, and the generation of physics products, are performed. The core of the DPE is supported by an extensive experimental database containing calibrations and referential radiation fields of typical environments, including protons, ions, electrons, gamma rays and X-rays, as well as thermal and fast neutrons. To enhance accessibility, the DPE is implemented into various user interface platforms such as a command-line tool, an application programming interface, and as a graphical user interface in the form of a web portal.Comment: 9 pages, proceedings IWORI

    Modulating patterns of two-phase flow with electric fields

    Get PDF
    This paper describes the use of electro-hydrodynamic actuation to control the transition between three major flow patterns of an aqueous-oil Newtonian flowin a microchannel: droplets, beads-on-a-string (BOAS), and multi-stream laminar flow. We observed interesting transitional flow patterns between droplets and BOAS as the electric field was modulated. The ability to control flow patterns of a two-phase fluid in a microchannel adds to the microfluidic tool box and improves our understanding of this interesting fluid behavior

    The interleukin-33 receptor (ST2) is a novel therapeutic target to attenuate the progression of hemophilic arthropathy

    Get PDF
    Hemophilia A is an X-linked bleeding disorder caused by a blood clotting protein factor VIII deficiency. Patients with hemophilia develop recurrent bleeding episodes. When bleeding occurs in the joints, hemophilic arthropathy (HA) may develop, resulting in hemarthroses and joint deformation. A novel congenic mouse model of severe hemophilia A was generated using CRISPR/CRISPR-associated protein 9 targeting of exon 1 of the F8 gene (F8em1-/-) to explore changes in the bleeding and inflammation during HA. F8em1-/- mice have a high penetrance of spontaneous bleeding, with joint bleeds progressing to arthropathy. F8em1-/- mice were subjected to needle-induced damage to the knee to assess synchronized joint bleeding, and the development of HA and synovial inflammation was assessed. The synovium of injured joints of F8em1-/- mice had differential and temporal expression of inflammatory genes after injury. Pathway analysis identified upregulation of the interleukin-1 (IL-1) family cytokines, IL-1β and IL-33; and respective receptors IL-1 receptor accessory protein and T1/ST2 (ST2) in the synovium of mice after needle-induced HA. Soluble ST2 and IL-33 levels were elevated in the plasma of F8em1-/- mice in acute stages after needle injury to the joints. Dual ST2-deficient F8em1-/- mice were generated, with ST2-deficient hemophilic mice developing significantly reduced joint damage after needle injury relative to F8em1-/- mice. Using a therapeutic intervention, blocking ST2 after joint injury significantly ameliorated joint damage during HA in hemophilic mice. These studies in a new mouse model of HA identify a crucial role of ST2 in HA pathogenesis and highlight its potential as a novel therapeutic target.</p

    Neuron–astrocyte interactions in the medial nucleus of the trapezoid body

    Get PDF
    The calyx of Held (CoH) synapse serves as a model system to analyze basic mechanisms of synaptic transmission. Astrocyte processes are part of the synaptic structure and contact both pre- and postsynaptic membranes. In the medial nucleus of the trapezoid body (MNTB), midline stimulation evoked a current response that was not mediated by glutamate receptors or glutamate uptake, despite the fact that astrocytes express functional receptors and transporters. However, astrocytes showed spontaneous Ca2+ responses and neuronal slow inward currents (nSICs) were recorded in the postsynaptic principal neurons (PPNs) of the MNTB. These currents were correlated with astrocytic Ca2+ activity because dialysis of astrocytes with BAPTA abolished nSICs. Moreover, the frequency of these currents was increased when Ca2+ responses in astrocytes were elicited. NMDA antagonists selectively blocked nSICs while D-serine degradation significantly reduced NMDA-mediated currents. In contrast to previous studies in the hippocampus, these NMDA-mediated currents were rarely synchronized

    Space radiation measurements during the Artemis I lunar mission

    Get PDF
    Space radiation is a notable hazard for long-duration human spaceflight. Associated risks include cancer, cataracts, degenerative diseases and tissue reactions from large, acute exposures. Space radiation originates from diverse sources, including galactic cosmic rays, trapped-particle (Van Allen) belts and solar-particle events. Previous radiation data are from the International Space Station and the Space Shuttle in low-Earth orbit protected by heavy shielding and Earth’s magnetic field and lightly shielded interplanetary robotic probes such as Mars Science Laboratory and Lunar Reconnaissance Orbiter. Limited data from the Apollo missions and ground measurements with substantial caveats are also available. Here we report radiation measurements from the heavily shielded Orion spacecraft on the uncrewed Artemis I lunar mission. At differing shielding locations inside the vehicle, a fourfold difference in dose rates was observed during proton-belt passes that are similar to large, reference solar-particle events. Interplanetary cosmic-ray dose equivalent rates in Orion were as much as 60% lower than previous observations. Furthermore, a change in orientation of the spacecraft during the proton-belt transit resulted in a reduction of radiation dose rates of around 50%. These measurements validate the Orion for future crewed exploration and inform future human spaceflight mission design

    Measurement of the bbb\overline{b} dijet cross section in pp collisions at s=7\sqrt{s} = 7 TeV with the ATLAS detector

    Get PDF

    Search for single production of vector-like quarks decaying into Wb in pp collisions at s=8\sqrt{s} = 8 TeV with the ATLAS detector

    Get PDF
    corecore