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    Category Physics

    Scientists have now measured a Crucial Fusion Reaction, involving H and a rare Isotope of Oxygen, 17O, that occurs inside stars

    January 11, 2016, Categories  Physics, Astronomy/Space

    Coincidence spectrometer employed in the present work. The HPGe crystal (yellow) is located in close geometry to the target. Both the target and the HPGe detector are surrounded by a 16-segment NaI(Tl) annulus (green). The five-sided plastic scintillators used to reject cosmic-ray muons are not shown.

    Coincidence spectrometer employed in the present work. The HPGe crystal (yellow) is located in close geometry to the target. Both the target and the HPGe detector are surrounded by a 16-segment NaI(Tl) annulus (green). The five-sided plastic scintillators used to reject cosmic-ray muons are not shown.

    Stars shine because nuclear reactions in their interiors convert mass to energy at a rate of many million tons/ s. At the same time, these nuclear reactions change the composition of the matter in the stellar interior. Thermonuclear fusion takes place quiescently in stars that are much older than the Sun, and also explosively in novae and supernovae. To explain how stars work, we need to measure the rates of the important nuclear reactions...

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    Researchers have built a Polarimeter on a Microchip, revolutionizing design of widely used scientific tool.

    January 10, 2016, Categories  Physics, Technology/Electronics

    Light from an optical fiber illuminates the metasurface, is scattered in four different directions, and the intensities are measured by the four detectors. From this measurement the state of polarization of light is detected. Credit: Capasso Lab/Harvard SEAS

    Light from an optical fiber illuminates the metasurface, is scattered in four different directions, and the intensities are measured by the four detectors. From this measurement the state of polarization of light is detected. Credit: Capasso Lab/Harvard SEAS

    What do astrophysics, telecommunications and pharmacology have in common? Each of these fields relies on polarimeters – instruments that detect the direction of the oscillation of electromagnetic waves, ie polarization of light.

    When light is reflected or scattered off an object, its polarization changes and measuring that change reveals a lot of information. Astrophysicists, for example, use polarization measurements to analyze the surface of distant, or to map the giant magnetic fields spanning our galaxy...

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    Damaged Material, Heal Thyself

    January 9, 2016, Categories  Physics, Technology/Electronics, Chemistry/Nanotechnology

    Secretion in droplet-embedded gel permits self-repairing behavior. Three-dimensional confocal fluorescence images show damaged gel (top) after 0.5 hours and the self-repaired gel after 72 hours (bottom). Credit: Image courtesy of Joanna Aizenberg

    Secretion in droplet-embedded gel permits self-repairing behavior. Three-dimensional confocal fluorescence images show damaged gel (top) after 0.5 hours and the self-repaired gel after 72 hours (bottom). Credit: Image courtesy of Joanna Aizenberg

    Inspired by healing wounds in skin, a new approach protects and heals surfaces using a fluid secretion process. In response to damage, dispersed liquid-storage droplets are controllably secreted. The stored liquid replenishes the surface and completes the repair of the polymer in seconds to hours.

    The fluid secretion approach to repair the material has also been demonstrated in fibers and microbeads...

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    Electronically Connected Graphene Nanoribbons foresee High-Speed Electronics

    January 9, 2016, Categories  Physics, Technology/Electronics

    Figure 1 shows interconnected graphene nanoribbons (GNRs). The interconnection points are observed as elbow structures. The inset of (a) shows the chemical structure of an elbow interconnection point of two chiral-edge GNRs. The top panel of (b) shows the scanning tunneling microscopy topograph, highlighting a single GNR and a pair of connected GNRs (elbow). The bottom panel of (b) shows the local density of states (LDOS) of these two structures share the same electronic architecture, including the elbow interconnection point. This indicates that electronic properties, such as electron and thermal conductivities, should be comparable between termini 1-2 and termini 3-4. Credit: Patrick Han

    Figure 1 shows interconnected graphene nanoribbons (GNRs). The interconnection points are observed as elbow structures. The inset of (a) shows the chemical structure of an elbow interconnection point of two chiral-edge GNRs. The top panel of (b) shows the scanning tunneling microscopy topograph, highlighting a single GNR and a pair of connected GNRs (elbow). The bottom panel of (b) shows the local density of states (LDOS) of these two structures share the same electronic architecture, including the elbow interconnection point. This indicates that electronic properties, such as electron and thermal conductivities, should be comparable between termini 1-2 and termini 3-4. Credit: Patrick Han

    Chemical interconnection bridges electronic properties of graphene-nanoribbons with zigzag-edge featu...

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